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Glucose utilization rates optimization

Glucose utilization rates optimization

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Utilization rates and predictors of sodium glucose cotransporter 2 inhibitor use in patients with heart failure with or without type 2 utiliation Get access. Sarah R Bermudez, PharmD, PhC, RDNSarah R Bermudez, PharmD, PhC, RDN. University Health. Oxford Academic. Google Scholar.

Joe R Anderson, PharmD, PhC, BCPS. University of New Mexico College of Pharmacy. Alexander J Bos, PhD. Gretchen M Ray, PharmD, PhC, BCACP, CDCES.

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: Glucose utilization rates optimization

Memory and Fitness Optimization of Bacteria under Fluctuating Environments | PLOS Genetics Download PDF. By flowing a fluorescent dye inside the device, the transition between each type of media was measured to occur in less than milliseconds Supp. For , cells are able to resume normal growth in lactose hence barrier B is crossed before the glucose exposure. Personalized nutrition by prediction of glycemic responses. In the biomass equation, we assumed a fraction of heterotrophic biomass, a , was derived from autotrophic metabolism and the simulated growth rate was μ A. Nature —
Optimized glycemic control of type 2 diabetes with reinforcement learning: a proof-of-concept trial Colarusso, A. Background: It is well-established Gllucose the etiology of type 2 Glucose utilization rates optimization differs between individuals. UtiliationbComparison of actual patient trajectories and model-based Glucosd roll-outs Soothing Drink Options patients optimizayion the Hypoglycemia and cognitive function test Glucoose a and the external test set b. Decay in panel E was fit to a formwhere ; induction was fit to the form forwhere and minutes. Dropout: a simple way to prevent neural networks from overfitting. Instead, the amount added red lines in Fig. Huber RE, Kurz G, Wallenfels K A quantitation of the factors which affect the hydrolase and transgalactosylase activities of β -galactosidase e.

Given specific data conditions, such as no more than k blood glucose measurements per day, we randomly discard blood glucose values within the trajectories to ensure that the remaining trajectories satisfy this criterion.

The traditional clinical methods of insulin dosage titration were used as the standard clinical methods for comparison, consisting of guidelines 42 and consensus formulas 43 , 44 for premixed insulin regimen, basal regimen and basal-bolus regimen.

The detailed adjustment was according to the following formula:. The insulin dosage titration rules of basal-bolus regimen were as follows. Retrospective study phase of the internal cohort. Forty eligible patients with T2D treated with insulin injection were randomly selected from the retrospective EHRs of one of the modeling development hospitals Qingpu Hospital from May to December Two treatment days were randomly selected for each patient, resulting in 80 cases with insulin points Extended Data Fig.

Three physician groups with different levels of clinical experience provided their dose recommendations, and the AI also generated insulin dose recommendations in silico for further evaluation. An expert consensus panel of three endocrinology specialists conducted blinded review and provided their own recommended insulin dosage.

This was used as a reference insulin dosage for each insulin point to assess the accuracy of AI-generated dosage versus the three physician groups. Retrospective study phase of the external cohort. The retrospective dataset was collected from a non-teaching hospital XuHui Hospital , which included 45 eligible consecutive patients with T2D from April to August Extended Data Fig.

The dataset contained insulin points from cases, and AI-generated dosage was compared to previously delivered insulin dosage by treating physicians human plan for accuracy evaluation.

Next, we randomly selected 40 cases from the dataset to evaluate the acceptability, effectiveness and safety of the AI plan and the previous human plan. The evaluations were blinded head-to-head comparisons of AI versus human plans by the expert consensus with three independent experts.

Prospective deployment study phase. In May , 40 consecutive AI-generated plans were tested for acceptance, effectiveness and safety by endocrinology physicians at the bedside Extended Data Fig.

After determining clinical adoption and ensuring adherence to standard clinical quality controls, the AI insulin regimen was used for patient treatment. The inclusion and exclusion criteria for patients were consistent across the three phases.

Inclusion criteria were patients with T2D treated with subcutaneous insulin injection for at least two consecutive days. Patients with acute complications of diabetes, such as ketoacidosis or hyperglycemic hyperosmolar state, or patients who were treated with glucocorticoids, were excluded.

Quantitative evaluation. We used the metrics of MAE and agreement percentage to quantitatively evaluate the accuracy performance of insulin regimens. MAE represents the errors between predicted values and consensus values. Effectiveness and safety. The effectiveness was scaled on a five-point Likert scale ranging from 1 very poor control of glycemia to 5 very good control of glycemia.

For safety evaluation, we used questionnaires 2 and 3 item 5 and questionnaire 4 item 6 , which asked the reviewers if the recommended insulin regimen was perceived to lead to an increased risk of hypoglycemia according to their judgment.

The safety was then scaled on a five-point Likert scale ranging from 1 very high risk to 5 very low risk Supplementary Information.

Superior plan. In the head-to-head comparison of the AI and human plans in the retrospective simulation study of the external cohort, the one AI or human selected as most clinically appropriate by the expert consensus review was considered as the superior plan Supplementary Information.

In the prospective deployment phase, the AI plans were reviewed by the endocrinology physicians at the bedside; the clinical adoption was determined; and the deemed AI insulin regimen was used for patient treatment following all standard clinical quality controls.

We conducted a proof-of-concept trial ClinicalTrials. gov: NCT to evaluate the feasibility and safety of AI in inpatients with T2D from 28 June to 6 October This trial was a patient-blinded and single-arm intervention, which was performed in the ward of the Department of Endocrinology and Metabolism, Zhongshan Hospital, in China.

The RL-DITR system was embedded in the insulin dosing interface of the health information system HIS , allowing real-time reading of patient clinical information and insulin dosage regimen recommendation Extended Data Fig.

An example of the AI recommendation report for the healthcare provider is presented in Extended Data Fig. Patients with T2D receiving subcutaneous insulin treatment were recruited and screened for the inclusion and exclusion criteria.

The pre-intervention initial insulin regimen served as reference for daily insulin regimen. Eligible patients received insulin dosage titration according to the AI model after the first cycle of insulin regimen, which was confirmed twice daily by the physician in charge.

The treating physician could reject the recommendation if deemed necessary. Throughout the trial, anti-hyperglycemic drugs remained unchanged; standard meals at usual mealtime were provided; and no physical activity was scheduled.

Capillary glucose concentration was measured at seven timepoints of fasting, after breakfast, before and after lunch, before and after dinner and before bedtime a day by a glucometer Glupad, Sinomedisite to estimate glucose control and to guide insulin regimen.

The goal was to achieve preprandial capillary blood glucose of 5. The CGM data were analyzed by physicians, and the treatment was not influenced by data gained by CGM.

CGM alarms were not activated during the feasibility clinical trial. The primary outcome was difference in glycemic control as measured by mean daily blood glucose concentration total, preprandial and post-prandial capillary blood glucose.

The secondary endpoints included glucose concentration in the target range TIR of 3. Glycemic variability was determined by the CV of glucose values. Safety was assessed as the number of hypoglycemic events.

Serious adverse events included severe hypoglycemia, defined as a capillary glucose level of less than 2. The sample size calculation was based on the primary outcome. PASS software version Clinical studies were analyzed using SAS 9. The matched t -test was used to compare the performance of RL-DITR and physicians.

The change from baseline measurements to the end of the trial was analyzed by two-sided paired t -test and a Wilcoxon signed-rank test for continuous measurements. The seven-point blood glucose profiles were analyzed using a generalized linear mixed model. The model used a Noisy-OR approach to aggregate WTR predicted probabilities of points for daily WTR prediction.

Further information on research design is available in the Nature Portfolio Reporting Summary linked to this article. IRB approval was obtained from institutions for EHR data collection. Individual-level patient records can be accessible with IRB consent and are not publicly available.

De-identified data can be requested by contacting the corresponding authors. All data access requests will be reviewed and if successful granted by the Data Access Committee. Data can be shared only for non-commercial academic purposes and will require a formal material transfer agreement.

Individual-level data of the clinical trial ClinicalTrials. gov: NCT reported in this study are not publicly shared. Data can be available to bona fide researchers for non-commercial academic purposes and necessitate a data user agreement.

Requests should be submitted by emailing the corresponding authors Y. at chen. ying4 zs-hospital. cn or guangyu. wang24 gmail. Requests will be processed within a 2-week timeframe. All data shared will be de-identified. The deep learning models were developed and deployed in Python version 3.

The following standard model libraries were used: scikit-learn 1. Sun, H. et al. IDF Diabetes Atlas: global, regional and country-level diabetes prevalence estimates for and projections for Diabetes Res. Article PubMed Google Scholar.

Stratton, I. Association of glycaemia with macrovascular and microvascular complications of type 2 diabetes UKPDS 35 : prospective observational study. BMJ , — Article CAS PubMed PubMed Central Google Scholar. Holman, R. Article CAS PubMed Google Scholar. ElSayed, N. Pharmacologic approaches to glycemic treatment: standards of care in diabetes— Diabetes Care 46 , S—S American Diabetes Association.

Glycemic targets: standards of medical care in diabetes— Diabetes Care 44 , S73—S84 Article Google Scholar. Martinez, M. Glycemic variability and cardiovascular disease in patients with type 2 diabetes.

BMJ Open Diabetes Res. Care 9 , e Article PubMed PubMed Central Google Scholar. Rodbard, D. Glycemic variability: measurement and utility in clinical medicine and research—one viewpoint. Diabetes Technol. Bi, W. Artificial intelligence in cancer imaging: clinical challenges and applications.

CA Cancer J. Esteva, A. Dermatologist-level classification of skin cancer with deep neural networks. Nature , — Kermany, D. Identifying medical diagnoses and treatable diseases by image-based deep learning.

Cell , — Wang, G. A deep-learning pipeline for the diagnosis and discrimination of viral, non-viral and COVID pneumonia from chest X-ray images. Zhang, K. Deep-learning models for the detection and incidence prediction of chronic kidney disease and type 2 diabetes from retinal fundus images.

Kaelbling, L. Reinforcement learning: a survey. Gottesman, O. Guidelines for reinforcement learning in healthcare. Komorowski, M. The Artificial Intelligence Clinician learns optimal treatment strategies for sepsis in intensive care.

Guo, H. Learning dynamic treatment strategies for coronary heart diseases by artificial intelligence: real-world data-driven study. BMC Med. Bothe, M. The use of reinforcement learning algorithms to meet the challenges of an artificial pancreas.

Expert Rev. Devices 10 , — Liu, Z. A deep reinforcement learning approach for type 2 diabetes mellitus treatment. Oh, S. Reinforcement learning-based expanded personalized diabetes treatment recommendation using South Korean electronic health records.

Expert Syst. Raheb, M. Subcutaneous insulin administration by deep reinforcement learning for blood glucose level control of type-2 diabetic patients. Thomas, M. Model-based reinforcement learning: a survey. Trends Mach. Learn 16 , 1— Google Scholar. Huang, Q. Model-based or model-free, a review of approaches in reinforcement learning.

Coronato, A. Reinforcement learning for intelligent healthcare applications: a survey. Nemati, S. Optimal medication dosing from suboptimal clinical examples: a deep reinforcement learning approach. IEEE Eng.

PubMed Google Scholar. Vasey, B. Reporting guideline for the early-stage clinical evaluation of decision support systems driven by artificial intelligence: DECIDE-AI.

Garg, S. Improved glycemic control in intensively treated adult subjects with type 1 diabetes using insulin guidance software. Farajtabar, M. More robust doubly robust off-policy evaluation. In Proc. of the 35th International Conference on Machine Learning , Vol.

Schrittwieser, J. Mastering Atari, Go, chess and shogi by planning with a learned model. Sun, C. Personalized vital signs control based on continuous action-space reinforcement learning with supervised experience.

Signal Process. Control 69 , McIntosh, C. Clinical integration of machine learning for curative-intent radiation treatment of patients with prostate cancer.

Ngassa Piotie, P. Designing an integrated, nurse-driven and home-based digital intervention to improve insulin management in under-resourced settings. Thomsen, C. Time for using machine learning for dose guidance in titration of people with type 2 diabetes? A systematic review of basal insulin dose guidance.

Diabetes Sci. Srivastava, N. Dropout: a simple way to prevent neural networks from overfitting. Sutton, R. Reinforcement Learning: An Introduction 2nd edn MIT Press, Fox, I.

Reinforcement learning for blood glucose control: challenges and opportunities. Wang, L. Supervised reinforcement learning with recurrent neural network for dynamic treatment recommendation. Zhang, H.

Generative planning for temporally coordinated exploration in reinforcement learning. In 10th International Conference on Learning Representations ICLR IEEE, Wang, X.

Beyond greedy search: tracking by multi-agent reinforcement learning-based beam search. IEEE Trans. Image Process. Song, H. Attend and diagnose: clinical time series analysis using attention models. of the Thirty-Second AAAI Conference on Artificial Intelligence Association for Computing Machinery, Kong, A.

Sequential imputations and Bayesian missing data problems. Martino, L. Effective sample size for importance sampling based on discrepancy measures. Moghissi, E. American Association of Clinical Endocrinologists and American Diabetes Association consensus statement on inpatient glycemic control.

Diabetes Care 32 , — Hirsch, I. A real-world approach to insulin therapy in primary care practice. Diabetes 23 , 78—86 Umpierrez, G. Randomized study of basal-bolus insulin therapy in the inpatient management of patients with type 2 diabetes RABBIT 2 trial.

Diabetes Care 30 , — Randomized study comparing a basal-bolus with a basal plus correction insulin regimen for the hospital management of medical and surgical patients with type 2 diabetes: basal plus trial. Diabetes Care 36 , — Comparison of inpatient insulin regimens with detemir plus aspart versus neutral protamine hagedorn plus regular in medical patients with type 2 diabetes.

Download references. This study was funded by the National Natural Science Foundation of China grants and to X. Li, grant to G. and grant to Y. is also supported by the New Cornerstone Science Foundation through the XPLORER PRIZE. is supported by the Wellcome Trust and National Institute for Health and Care Research Oxford Biomedical Research Centre.

The funders of the study had no role in study design, data collection, data analysis, data interpretation or writing of the report. The authors would like to acknowledge the Nanjing Institute of InforSuperBahn MLOps for providing the training and evaluation platform.

Ministry of Education Key Laboratory of Metabolism and Molecular Medicine, Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, China. State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing, China.

Big Data and Artificial Intelligence Center, Zhongshan Hospital, Fudan University, Shanghai, China. Department of Endocrinology, XuHui Central Hospital of Shanghai, Shanghai, China. Department of Endocrinology and Metabolism, Qingpu Branch of Zhongshan Hospital affiliated to Fudan University, Shanghai, China.

Big Data and Biomedical AI Laboratory, College of Future Technology, Peking University, Beijing, China. Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.

Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Fudan University, Shanghai, China. You can also search for this author in PubMed Google Scholar. and X. Li collected and analyzed the data. Li conceived and supervised the project.

Li wrote the manuscript. All authors discussed the results and reviewed the manuscript. Correspondence to Guangyu Wang , Xiaoying Li or Ying Chen. Nature Medicine thanks the anonymous reviewers for their contribution to the peer review of this work.

Primary Handling Editors: Lorenzo Righetto and Saheli Sadanand, in collaboration with the Nature Medicine team. a , The sequential decision process with patient model and policy model in AI system. Given a trajectory, for the initial step, the representation function f R receives as input the past observations O 1: t from the trajectory.

The model is subsequently unrolled recurrently for K steps. The hidden states and actions recurrently update. b , The AI system training pipeline. Left, the patient model learning for patient tracking.

Right, the policy update for dynamic regimen with combined supervised learning and reinforcement learning. a , Visualization of the patient hidden states. Each node indicates a patient state. The state distribution showed association with diabetic outcome, colored by glucose level distribution.

The samples are patients from internal test dataset. PC: principal component. b , Illustration of reward function. It is a measurement of overall glucose variability that focus on the relationship between glucose variability and risks for hypo- and hyperglycemia.

c and d , Performance of the AI model on assessment of WTR shown as AUC curves. c , internal test set and d , external test set. ROC curves showing the pre-prandial time, the postprandial and overall performance. e , internal test set, and f , external test set.

a, c and e : the internal test set; b, d and f : external test set. g , Off-policy evaluation of RL-based model versus other SL-based and clinician methods in the internal test set in the AI development phase, measured by weighted importance sampling WIS score with standard deviation. a , Study design of internal cohort: 40 eligible T2D patients were included in the study.

b , Study design of external cohort: 45 T2D patients were collected, and a total of insulin points were included in the external validation analysis. An assessment with quantitative metrics was conducted to compare the performance between treating physicians and AI by expert panel.

After 2 weeks, a retest review was conducted. BMI, body mass index; A1c, glycated hemoglobin. Numerical variables were reported as mean±SD. Quantitative comparisons of insulin dosage given by human physicians and AI stratified by insulin catalogs in the external cohort.

Orange dashed line, average performance of AI; blue dashed line, average performance of treating physicians. Bar graphs indicate the mean±SEM. a , The user interface of AI deployment. a , Patient example during the proof-of-concept feasibility trial using the seven-point capillary blood glucose measurement.

b , Glucose control based on the sensor glucose measurements at the first 24 hours and the last 24 hours of the trial. GMI, glucose management indicator; CV, coefficient of variation. c , Post-intervention evaluation by physicians who used the AI during the feasibility trial.

Open Access This article is licensed under a Creative Commons Attribution 4. Reprints and permissions. Optimized glycemic control of type 2 diabetes with reinforcement learning: a proof-of-concept trial.

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Skip to main content Thank you for visiting nature. nature nature medicine articles article. Download PDF. Subjects Computational biology and bioinformatics Therapeutics. Abstract The personalized titration and optimization of insulin regimens for treatment of type 2 diabetes T2D are resource-demanding healthcare tasks.

Main Type 2 diabetes T2D is one of the most prevalent chronic diseases and leads to a considerable rate of death and social burden worldwide 1. Full size image. Results Dataset characteristics and system overview A total of 12, inpatients with T2D with , treatment days were included in the AI model development phase analysis.

Performance of AI model to predict patient glycemic states To build a dynamic and individualized AI clinician for managing patients with T2D, we constructed the model-based RL framework. Discussion In this study, we developed an RL-based AI system, called RL-DITR, for personalized and dynamic insulin dosing for patients with T2D.

Methods Study design and participants To train and validate a computational clinical decision support model, we constructed a large multi-center dataset using EHRs of hospitalized patients with T2D who received insulin therapy from January to April in the Department of Endocrinology and Metabolism, Zhongshan Hospital and Qingpu Hospital, in Shanghai, China.

Development and validation of the model-based RL system Time-series data pre-process and NLP For time-series data representation, every patient in the dataset was represented as a temporal sequence of feature vectors. Building the computational model The process of patient trajectory and treatment decision-making could be formulated as a Markov decision process MDP.

Patient model for trajectory tracking For patient trajectory tracking, we trained a patient model. Data availability IRB approval was obtained from institutions for EHR data collection.

Code availability The deep learning models were developed and deployed in Python version 3. The simulated glucose and nitrate levels exhibited damped oscillations when using a PID controller, a common response for this controller type yellow lines in Fig.

In contrast, employing the GMPC controller eliminated the damping issues and enabled the glucose and nitrate level to more rapidly reach values near the target levels yellow lines in Fig. Meanwhile, the glucose supply and nitrate supply increased gradually in the GMPC controller red lines in Fig.

Instead, the amount added red lines in Fig. a Simulink model for model predictive control and PID control. Glucose control: b PID controller.

c GMPC controller. Nitrate control: d PID controller. e GMPC controller. The PID controller gains were tuned on Matlab TM to achieve optimal performance with proportional gain K p , integral gain K i and derivative gain K d equal to 1.

The glucose levels were measured every hour and the data was fed to both the PID controller and the closed-loop GMPC controller with a pure heterotrophic model since light and dark cycles were not presented. The feedback signal could compensate for the modeling errors and also help to reject the disturbance in the GMPC controller.

After the setpoint change, the glucose level gradually decreased and was stably controlled. Overall, both Simulink TM simulations and experimental results demonstrated that the GMPC approach provided more robust and precise control than traditional PID controllers.

While the model could anticipate the future behavior of the fermentation and take appropriate control action, the PID controller did not have this capability resulting in oscillations and overshoot behavior in both simulations and experiments.

Thus, our study demonstrates how GMPC systems can serve as a bridge between genome-scale metabolic modeling and control algorithms. Since the cultivation conditions can change and affect algal cellular metabolism, our system connected feedback measurements with genome-scale metabolic models and achieved more efficient nutrient utilization and higher product yields for dynamic algal cultivation conditions.

In this way, genome-scale metabolic models can be effectively utilized to improve biomanufacturing of microalgae and other industrially important microbial cell factories. Fed-batch cultivation and PID controllers have been widely used in bioprocess development.

Unfortunately, fed-batch cultivation often results in poor nutrient control and wasted nutrients and conventional PID control can lead to oscillating cell behaviors and poor performance under dynamic conditions. In this study, we have utilized the power of genome-scale metabolic models to predict and control glucose and nitrate supply for C.

vulgaris cultures under light and dark cycles and compared this approach to conventional autotrophic and heterotrophic processes. Our results first showed that utilizing genome scale models to track and limit glucose and nitrate feeding led to higher titers of biomass, FAs, and lutein than autotrophic conditions and more efficient glucose utilization and higher product yields than heterotrophic conditions.

Next, implementing these models into an open loop system modestly improved performance. Finally, both computational simulations and experimental results demonstrated that this genome-based MPC system exhibits superior controller performance compared to conventional PID methods.

Green microalgae C. vulgaris UTEX was obtained from the Culture Collection of Algae at the University of Texas at Austin and maintained on sterile agar plates 1.

Liquid cultures were inoculated with a single colony in For alternating light and dark cycles, autotrophic conditions were used for light sections and heterotrophic conditions were used for dark sections.

The lyophilized algal dry biomass was weighted gravimetrically using an analytical balance. The glucose concentration was measured using YSI biochemistry analyzer Yellow Springs, OH. FAME production followed the procedure provided by Dong et al. Helium was used as carrier gas.

Lutein extraction followed the procedure provided by Yuan et al. The solution was filtered before HPLC analysis. The mobile phases are eluent A dichloromethane: methanol: acetonitrile: water, 5.

The i CZ model, including six different biomass compositions for autotrophic conditions PAT1-PAT6 and five different biomass compositions for heterotrophic conditions HT1-HT5 , was obtained from Zuniga et al.

GSM simulations were performed using the Gurobi Optimizer Version 5. The experimental setup is shown in Supplementary Fig. The manipulated variables were glucose demand F G and nitrate demand on a per L basis F N for 8-h period.

Two pumps were used to control both variables automatically by Matlab TM through Arduino chip. All the control algorithms were run on Matlab TM and the codes are provided in Supplementary information.

The Simulink TM simulation is shown in Fig. The blue box in Fig. Four equations were built inside the blue box as shown in Supplementary Fig. The inputs were F G and F N. The outputs were biomass, nitrate level, glucose level and volume.

Only nitrate levels and glucose levels were fed into the PID and GMPC controller. For the proportional-integral-derivative PID controller, the proportional gain K p , integral gain K i and derivative gain K d equal to 1.

The PID controller and GMPC controller were used to control glucose supply and nitrate supply every hour in both simulation and experiment. Changes in the setpoint for glucose were introduced to see how both PID and GMPC responded to those changes. Initial biomass levels x 0 , glucose levels G 0 and nitrate levels N 0 were measured as described above and used as inputs into the open-loop system.

Three equations shown below were used to predict biomass growth, nitrate consumption rate, and glucose consumption rate in the open-loop system. The growth rates under light and dark cycles were determined based on previous experimental data. After that, the growth rates were constrained in the autotrophic and heterotrophic GSMs, respectively to determine nutrient exchange rates r N and r G under light and dark cycles.

The methods for using growth rate to estimate nutrient exchange rates have been described previously in Chen et al. We assumed a rapid switch to a new operational steady state following the transition between light and dark cycles. Initial biomass levels x 0 , glucose levels G 0 and nitrate levels N 0 were measured and used as inputs into the closed-loop system.

During the experiment, biomass levels x m , glucose levels G m and nitrate levels N m were msured and used as inputs into the closed-loop system. For the light cycle, two equations were built to describe and predict biomass accumulation rate and nitrate consumption rate.

Unlike the open loop system, the light shielding effect was considered and the growth rate would decrease as the biomass concentration increased as described in the equation below and shown in Fig. The GSM was used to predict nutrient exchange rate r N based on the measured growth rate.

For the dark cycles, three model equations were built to predict biomass accumulation rate, nitrate consumption rate and glucose consumption rate as listed below and shown in Fig.

In the biomass equation, we assumed a fraction of heterotrophic biomass, a , was derived from autotrophic metabolism and the simulated growth rate was μ A. Meanwhile, some biomass was derived through heterotrophic metabolism with the simulated growth rate, μ H.

The nutrient exchange rates r NA , r NH , r GH were determined by inputting simulated growth rates into the autotrophic and heterotrophic GSMs respectively. where μ A is simulation growth rate from autotrophic metabolism, μ H is the growth rate from heterotrophic metabolism, r NA is nitrate exchange rate from autotrophic metabolism, r NH is the nitrate exchange rate from heterotrophic metabolism, r GH is the glucose exchange rate from heterotrophic metabolism.

Next, we applied a fitting objective function J to minimize the difference between calculated values and simulated model values in order to estimate the optimal parameter values a , μ A , μ H , r NA , r NH , r GH for dictating the actual nitrate and glucose feeds to the bioreactor.

The actual bolus nitrate demand F N and the glucose demand F G were thus determined by using values obtained from this fitting objective function. The data that support the findings of this study are available from the corresponding author upon reasonable request.

Rosenberg, J. A green light for engineered algae: redirecting metabolism to fuel a biotechnology revolution. Article CAS PubMed Google Scholar. Shene, C. Metabolic modelling and simulation of the light and dark metabolism of Chlamydomonas reinhardtii.

Plant J. Kato, Y. et al. Biofuels 12 , 39 Article PubMed PubMed Central Google Scholar. Cheirsilp, B. Enhanced growth and lipid production of microalgae under mixotrophic culture condition: effect of light intensity, glucose concentration and fed-batch cultivation.

Zheng, Y. High-density fed-batch culture of a thermotolerant microalga Chlorella sorokiniana for biofuel production. Energy , — Article CAS Google Scholar.

Shi, X. High-yield production of lutein by the green microalga Chlorella protothecoides in heterotrophic fed-batch culture. Bordbar, A. Constraint-based models predict metabolic and associated cellular functions. Chang, R. Article Google Scholar.

Zuñiga, C. Genome-scale metabolic model for the green alga Chlorella vulgaris utex accurately predicts phenotypes under autotrophic, heterotrophic, and mixotrophic growth conditions. Plant Physiol. Loira, N. Reconstruction of the microalga Nannochloropsis salina genome-scale metabolic model with applications to lipid production.

BMC Syst. Chang, L. Nonlinear model predictive control of fed-batch fermentations using dynamic flux balance models. Process Control 42 , — Jabarivelisdeh, B. Model predictive control of a fed-batch bioreactor based on dynamic metabolic-genetic network models.

IFAC-PapersOnLine 51 , 34—37 Juneja, A. Model predictive control coupled with economic and environmental constraints for optimum algal production. Ogbonna, J. Zuniga, C. Predicting dynamic metabolic demands in the photosynthetic eukaryote Chlorella vulgaris. Li, C. Utilizing genome-scale models to optimize nutrient supply for sustained algal growth and lipid productivity.

NPJ Syst. Tebbani, S. Nonlinear predictive control for maximization of CO2 bio-fixation by microalgae in a photobioreactor. Bioprocess Biosyst. Hu, D. The design and optimization for light-algae bioreactor controller based on Artificial Neural Network-Model Predictive Control.

Acta Astronaut 63 , — White, R. Long-term cultivation of algae in open-raceway ponds: lessons from the field. Gu, C. Current status and applications of genome-scale metabolic models. Genome Biol.

Using genome-scale models to predict biological capabilities. Cell , — Colarusso, A. Computational modeling of metabolism in microbial communities on a genome-scale. Han, F. Enhancement of microalgal biomass and lipid productivities by a model of photoautotrophic culture with heterotrophic cells as seed.

Xiong, W. Double CO 2 fixation in photosynthesis—fermentation model enhances algal lipid synthesis for biodiesel production. Xiao, Y. Photosynthetic accumulation of lutein in Auxenochlorella protothecoides after heterotrophic growth.

Drugs 16 , Vidotti, A. Analysis of autotrophic, mixotrophic and heterotrophic phenotypes in the microalgae Chlorella vulgaris using time-resolved proteomics and transcriptomics approaches.

Algal Res. Park, J. The contribution ratio of autotrophic and heterotrophic metabolism during a mixotrophic culture of Chlorella sorokiniana. Public Health 18 , Huesemann, M. A validated model to predict microalgae growth in outdoor pond cultures subjected to fluctuating light intensities and water temperatures.

Mears, L. A review of control strategies for manipulating the feed rate in fed-batch fermentation processes. Sommeregger, W. Quality by control: Towards model predictive control of mammalian cell culture bioprocesses.

Chen, G. Viable cell density on-line auto-control in perfusion cell culture aided by in-situ Raman spectroscopy. Lee, H. In situ bioprocess monitoring of Escherichia coli bioreactions using Raman spectroscopy.

Xu, J. Application of metabolic controls for the maximization of lipid production in semicontinuous fermentation.

Natl Acad. USA , E—E Article CAS PubMed PubMed Central Google Scholar. Dong, T. Direct quantification of fatty acids in wet microalgal and yeast biomass via a rapid in situ fatty acid methyl ester derivatization approach.

Yuan, J. Carotenoid composition in the green microalga Chlorococcum. Food Chem. Chen, Y. An unconventional uptake rate objective function approach enhances applicability of genome-scale models for mammalian cells.

Download references. This work was supported by the U. National Science Foundation EFRI program Grant number: and CBET program Grant number: and the Department of Energy Grant number: DE-SC Department of Chemical and Biomolecular Engineering, Johns Hopkins University, North Charles Street, Baltimore, MD, , USA.

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contributed to conception and design of the experiment. conducted the experiments. analyzed the data. drafted the paper. All authors read and approved the paper.

Correspondence to Michael J. Open Access This article is licensed under a Creative Commons Attribution 4. Reprints and permissions. Li, CT. Optimization of nutrient utilization efficiency and productivity for algal cultures under light and dark cycles using genome-scale model process control.

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Skip to main content Thank you for visiting nature. nature npj systems biology and applications articles article. Download PDF. Subjects Computer modelling Metabolic engineering Plant sciences. Abstract Algal cultivations are strongly influenced by light and dark cycles.

Introduction Microalgae represent promising microorganisms for transforming renewable resources and inorganic carbon sources into biomass, biofuel precursors, and high-value products 1.

Results and discussion Advantages of using genome-scale model predictions on C. Full size image. a PID controller.

The application of a numerical filter to remove noise in the data resulted in values for regional cerebral glucose utilization that were stable with time and consistent with rates determined by the other established techniques. Based on the results of the current study, we expect that the spectral analysis technique will prove to be a highly flexible tool for kinetic analysis of other tracer compounds; it is capable of producing low-variance, time-stable estimates of physiological parameters when optimized for time interval of application, input spectrum of components, and processing of noise in the data.

Abstract A method for kinetic analysis of dynamic positron emission tomography PET data by linear programming that allows identification of the components of a measured PET signal without predefining a compartmental model has recently been proposed by Cunningham and co-workers. Publication types Research Support, Non-U.

Substances Fluorine Radioisotopes Fluorodeoxyglucose F18 Deoxyglucose Glucose. Figure 3c,d shows the dynamic treatment strategies generated by clinicians and model-based RL for two individual patients on different hospital days.

We further investigated whether the patient outcome WTR ratio varied with the difference of the dose actually administered and the dose suggested by the RL method by correlation analysis Fig. When the dose actually administered differed from the dose suggested by the AI algorithm, the average outcome got worse.

For the internal validation cohort, we compared the performance between our AI system and human physicians in giving insulin dosage recommendation using 40 patients with T2D with insulin data points Extended Data Fig.

RL-generated and physician-generated dosage titrations were evaluated by an expert panel, including quantitative metrics and qualitative metrics from clinical experience.

Taking the dosage recommended by the expert panel as references, the MAE of the AI system was 1. Evaluation was based on the expert panel review including effectiveness f , safety g and overall acceptability h. Orange dashed line represents the average performance of AI; blue dashed line represents the average performance of treating physicians.

G, group. These results suggest that our AI model is superior to junior physicians and similar to experienced physicians in the overall treatment regimen acceptability, hyperglycemia and hypoglycemia control.

Furthermore, we performed an external validation in 45 patients with T2D to compare the performance of AI plans and treating physician plans under a blinded review by an expert panel and by another blinded review for retesting at 2-week intervals at least Extended Data Fig.

The results demonstrated that the acceptability, effectiveness and safety of the AI plans were similar to the treating physicians who were board-certified endocrinologists, evaluated by subjective measurements made by an expert panel Fig. The percentage of selected superior AI plans was These results demonstrate consistently superior performance of the AI model compared to its physician counterparts.

We used adoption rate to evaluate the percentage of the AI regimens adopted by endocrinologists for patient treatment. Our proposed RL model demonstrated stable performance of effectiveness, safety and acceptability over time, even better in the retest review Fig. The score scale of effectiveness and safety is 1—5.

The adoption rate refers to the percentage of the AI regimens adopted by endocrinologists at the bedside for patient treatment. Intriguingly, a higher adoption rate of Although the adoption rate of the AI plan was relatively low at the initial test review, we found an increase of These results suggested a step-by-step increase of trust of the AI treatment regimen by physicians through human—machine interaction, and the AI system was gradually adopted by physicians into routine clinical practice.

A proof-of-concept feasibility trial was performed to investigate the clinical utility and safety of AI in hospitalized patients with T2D for glycemic control.

Sixteen inpatients with T2D were enrolled in the trial Extended Data Fig. Their mean HbA1c was 8. Over the trial, b , The capillary blood glucose of a patient with T2D during the treatment period. II Mean daily capillary blood glucose. III Mean preprandial capillary blood glucose.

IV Mean postprandial capillary blood glucose during the treatment period. The preprandial blood glucose target was 5. c , Average percentage of continuous glucose monitoring data within glycemic ranges throughout the treatment period. The satisfaction agreement was scored from a scale of 1—5.

IQR, interquartile range. of At the end of the trial, A patient example of the seven-point capillary blood glucose during the AI intervention is shown in Extended Data Fig. We also used continuous glucose monitoring CGM for the evaluation of the algorithm-directed glycemic control for the secondary outcomes.

The percentage of glucose concentration in time in range TIR 3. TIR 3. Time spent above Time spent below 3. In addition, glycemic variability was slightly decreased during the treatment period coefficient of variation CV of No episodes of severe hypoglycemia that is, requiring clinical intervention or hyperglycemia with ketosis occurred during the trial.

Most physicians stated that the AI interface is understandable 4. In this study, we developed an RL-based AI system, called RL-DITR, for personalized and dynamic insulin dosing for patients with T2D. We performed development phase validation and clinical validations, including internal validation, comparing AI to physicians using quantitative and qualitative metrics, external validation with test—retest, prospective deployment with test—retest and a proof-of-concept feasibility study with clinical trial.

Taken together, our findings demonstrate that our RL-DITR system has potential as a feasible approach for the optimized management of glycemic control in inpatients with T2D.

The management of blood glucose in diabetes remains challenging due to the complexity of human metabolism, which calls for the development of more adaptive and dynamic algorithms for blood glucose regulation. To address the challenge of personalized insulin titration algorithm for glycemic control, our RL-based architecture is tailored to achieve precise treatment for individual patients, with clinical supervision.

Our proposed patient model-based RL model can make multi-step planning to improve prescription consistency. In addition, because the multi-step plan can be interpreted as the intent of the model from now to a span of time period into the future, it offers a more informative and intuitive signal for interpretation Additionally, our RL-based system delivers continuous and real-time insulin dosage recommendation for patients with T2D who are receiving subcutaneous insulin injection, combining optimal policies for clinical decision-making and the mimicking of experienced physicians Another strength of our study is that we conducted a comprehensive early clinical validation of the AI-based clinical decision-making system across various clinical scenarios.

In clinical deployment, our AI framework offers potential benefits, including automated reading of a large number of inputs from the EHRs, integration of complex data and accessible insulin dosing interface. Although some algorithms have been developed to assist physicians in insulin titration, only a few have been validated in clinical trials 31 , We conducted a proof-of-concept feasibility trial demonstrating the viability of the RL-DITR system in inpatients with T2D.

Notably, the use of the RL-DITR system resulted in a considerable improvement in blood glucose control, meeting our pre-determined feasibility goal. The percentage of well-controlled blood glucose levels of TIR also demonstrated a substantial increase.

Managing hypoglycemia risk is a key consideration for real-world deployment of the AI system. While achieving improved control of blood glucose levels, the system did not increase the risk of hypoglycemia.

Additionally, physicians using the RL-DITR system have reported an increased level of satisfaction, including aspects such as efficiency in clinical practice and perceived effectiveness and safety in glycemic control.

These results suggest that our RL-DITR system has the potential to offer feasible insulin dosing to inpatients with T2D. A large and multi-center randomized controlled trial would help to determine the efficacy and benefits of this clinical AI solution.

Our RL-DITR system was designed as a closed-loop intelligent tool that could use real-time patient data to track blood glucose trajectories and modify treatment regimens accordingly. Furthermore, the RL-DITR system was developed using EHRs of inpatients with T2D, but its generalizability to other populations, such as outpatients, needs further investigation.

We conducted simulated experiments using Gaussian noise to mimic low data quality and dropout 33 to simulate missing data scenarios before deployment Supplementary Fig. Therefore, although the RL-DITR workflow was implemented and tested for inpatients with T2D, there exists the possibility to extend its application to a wider range of healthcare settings, such as outpatient management, given appropriate integration and continued development.

Although our RL-DITR system has achieved good performance in insulin dosage titration, some challenges remain. The generalization of the AI to other ethnicities needs to be further investigated. Second, the variety of diet during the hospitalized period was uniformly supplied in the EHRs to build our model.

For patients out of hospital, dietary variation and physical activity should be taken into account and explored by our RL model. We have opened an interface to accumulate dietary information for late updated model.

In conclusion, we developed an RL-based clinical decision-making system for dynamic recommendation of dosing that demonstrated feasibility for glycemic control in patients with T2D. The RL-DITR system is a model-based RL architecture that could enable multi-step planning for patients with long-term care.

With the integration of RL structure and supervised knowledge, the RL-DITR system could learn the optimal policy based on non-optimized data while retaining the safe states by balancing exploitation and exploration.

Furthermore, we performed a stepwise validation of the AI system from simulation to deployment and a proof-of-concept feasibility trial. These demonstrate the RL approaches as a potential tool to assist clinicians, especially junior physicians and non-endocrine specialists, with diabetes management in hospitalized patients with T2D.

To train and validate a computational clinical decision support model, we constructed a large multi-center dataset using EHRs of hospitalized patients with T2D who received insulin therapy from January to April in the Department of Endocrinology and Metabolism, Zhongshan Hospital and Qingpu Hospital, in Shanghai, China.

The demographics and clinical characteristics of patients are presented in Extended Data Table 1 , demonstrating a typical T2D population. We conducted stepwise studies to evaluate the performance of our RL-DITR model version 1. In addition, we performed a proof-of-concept feasibility trial of the RL-DITR system in clinical practice with inpatients with T2D who were admitted for optimization of glycemic control at Zhongshan Hospital ClinicalTrials.

gov: NCT details of proof-of-concept trial protocol provided in Supplementary Information. The retrospective study obtained the following institutional review board IRB approval: Zhongshan Hospital, Shanghai, China R ; XuHui Central Hospital, Shanghai, China and Qingpu Branch of Zhongshan Hospital, Shanghai, China Patient informed consent was waived by the Ethics Committee.

The prospective study and proof-of-concept feasibility trial were approved by the Ethics Committee of Zhongshan Hospital, Fudan University.

Each participant provided written informed consent for the prospective study and the proof-of-concept feasibility trial. For time-series data representation, every patient in the dataset was represented as a temporal sequence of feature vectors. Specifically, each day was broken into seven time periods, including pre-breakfast, post-breakfast, pre-lunch, post-lunch, pre-dinner, post-dinner and pre-bedtime.

All records that occurred within the same period were grouped together and formed a feature set to feed into the RL model as input detailed list of the input features provided in Supplementary Table 2. For structured data, we aligned and normalized them. For free-text notes, we applied a pre-trained language model, ClinicalBERT.

Specifically, we first trained the ClinicalBERT on a large corpus of EHR data. ClinicalBERT is a masked medical domain language model that predicts randomly masked words in a sequence and, hence, can be transformed into downstream tasks.

Then, the ClinicalBERT was fine-tuned for information extraction from free text. We further automatically extracted temporal features from patient clinical records, including clinical observations blood glucose records , a sequence of decision rules to determine the course of actions for example, treatment type and insulin dosage titration and clinical assessment of patients.

The numerical values were extracted from demographics, laboratory reports, blood glucose and medications and further translated with standard units according to the LOINC database. Then, each numerical value was normalized to a standard normal distribution.

In terms of discrete values, all the diagnoses of a patient were mapped onto the International Classification of Diseases-9 ICD-9 and used as discrete features, encoded as binary presence features. We constructed a large multi-center dataset with a large corpus of 1. ClinicalBERT was fine-tuned on a multi-label dataset to extract 40 symptom labels from medical notes.

Phenotype data were extracted from free-text notes of chief history of present illness and physical examination by ClinicalBERT. Validated on 1, annotated samples from the training set, the results showed that ClinicalBERT could accurately identify the symptom information with an average F1 score of Each extracted symptom label was encoded as a binary presence feature.

The process of patient trajectory and treatment decision-making could be formulated as a Markov decision process MDP. An MDP 34 is a tuple S , A , P , G , γ , where S and A are sets containing the states and actions, respectively; P is a transition function; G is a reward function; and γ is a discount factor.

The patient model was learned from historical trajectories, approximating the transition function P and the reward function G and providing support for policy model learning and planning. The policy model iteratively interacted with the patient model as an environment.

At each step, the patient model generated state transition, status prediction and reward estimation based on observed patient trajectories. The policy model, taking the state as input, generated an action that was fed to the patient model.

The patient model updated the states recurrently by an iterative process, enabling the policy model to plan for sequences of actions and find optimal solutions across generated trajectories. The hidden state would be used as input for patient model and policy model.

For patient trajectory tracking, we trained a patient model. When conducting correlation analysis with daily outcome, Magni risk values were summed for each day.

Both of the dynamics function f T and the prediction function f P shared the representation encoder f R when training and inference. f R was optimized together through backpropagation with the loss to capture meaningful patient representations and dynamics.

Each node indicates the states of a patient. The state distribution demonstrated a good cluster hierarchy that individuals in the same cluster are associated with their observable properties diabetes outcome, such as glucose level.

We combined the SL and RL to learn the policy model, with the expert supervision of safe actions to take into account. Specifically, we applied policy gradient optimization for training the policy model π to maximize the returned rewards while incorporating constrained supervision by expert experience.

For the SL part, we used the action made by the clinicians as supervision for policy update. For the RL part, we optimized the policy model π based on the patient model f T , f P as an interactive environment, where a given trajectory was updated recurrently by an iterative process.

The policy model π was trained by both historical and obtained trajectories. We applied a beam search for policy search The top B highest-value trajectories were stored at each timestep, where B was the beam size.

The training process involved two stages to optimize the models of our AI system Extended Data Fig. These functions were jointly optimized through the loss for state transitions and the loss for status prediction. The policy model was trained through a joint optimization process, minimizing both a policy gradient loss on trajectories and a supervised loss that constrains the difference between the recommended action from the policy model and the action taken by the clinician.

We used a transformer-based network with three layers as the representation function used to represent the observations of time-series data, as it has been shown to enable capturing the long dependence in the temporal information of patients The last hidden vector of the output hidden vectors was used for the initial state.

We also applied a transformer network with three layers for dynamics function. The hidden dimension was set to , and the number of multi-attention heads was set to 8.

We used three-layer multi-layer perceptrons MLPs for prediction function, policy function and value function. The hidden dimension was set to The beam size B was set to The models were implemented using PyTorch.

The importance sampling for policy evaluation was performed, which enables the evaluation of a target policy using data collected from a distinct policy To enhance the numerical stability of the calculations, we employed WIS along with effective sample size 40 , 41 , which normalizes the trajectories, thereby reducing variance Given specific data conditions, such as no more than k blood glucose measurements per day, we randomly discard blood glucose values within the trajectories to ensure that the remaining trajectories satisfy this criterion.

The traditional clinical methods of insulin dosage titration were used as the standard clinical methods for comparison, consisting of guidelines 42 and consensus formulas 43 , 44 for premixed insulin regimen, basal regimen and basal-bolus regimen.

The detailed adjustment was according to the following formula:. The insulin dosage titration rules of basal-bolus regimen were as follows. Retrospective study phase of the internal cohort.

Forty eligible patients with T2D treated with insulin injection were randomly selected from the retrospective EHRs of one of the modeling development hospitals Qingpu Hospital from May to December Two treatment days were randomly selected for each patient, resulting in 80 cases with insulin points Extended Data Fig.

Three physician groups with different levels of clinical experience provided their dose recommendations, and the AI also generated insulin dose recommendations in silico for further evaluation. An expert consensus panel of three endocrinology specialists conducted blinded review and provided their own recommended insulin dosage.

This was used as a reference insulin dosage for each insulin point to assess the accuracy of AI-generated dosage versus the three physician groups. Retrospective study phase of the external cohort. The retrospective dataset was collected from a non-teaching hospital XuHui Hospital , which included 45 eligible consecutive patients with T2D from April to August Extended Data Fig.

The dataset contained insulin points from cases, and AI-generated dosage was compared to previously delivered insulin dosage by treating physicians human plan for accuracy evaluation.

Next, we randomly selected 40 cases from the dataset to evaluate the acceptability, effectiveness and safety of the AI plan and the previous human plan. The evaluations were blinded head-to-head comparisons of AI versus human plans by the expert consensus with three independent experts.

Prospective deployment study phase. In May , 40 consecutive AI-generated plans were tested for acceptance, effectiveness and safety by endocrinology physicians at the bedside Extended Data Fig. After determining clinical adoption and ensuring adherence to standard clinical quality controls, the AI insulin regimen was used for patient treatment.

The inclusion and exclusion criteria for patients were consistent across the three phases. Inclusion criteria were patients with T2D treated with subcutaneous insulin injection for at least two consecutive days.

Patients with acute complications of diabetes, such as ketoacidosis or hyperglycemic hyperosmolar state, or patients who were treated with glucocorticoids, were excluded.

Quantitative evaluation. We used the metrics of MAE and agreement percentage to quantitatively evaluate the accuracy performance of insulin regimens. MAE represents the errors between predicted values and consensus values.

Effectiveness and safety. The effectiveness was scaled on a five-point Likert scale ranging from 1 very poor control of glycemia to 5 very good control of glycemia. For safety evaluation, we used questionnaires 2 and 3 item 5 and questionnaire 4 item 6 , which asked the reviewers if the recommended insulin regimen was perceived to lead to an increased risk of hypoglycemia according to their judgment.

The safety was then scaled on a five-point Likert scale ranging from 1 very high risk to 5 very low risk Supplementary Information. Superior plan. In the head-to-head comparison of the AI and human plans in the retrospective simulation study of the external cohort, the one AI or human selected as most clinically appropriate by the expert consensus review was considered as the superior plan Supplementary Information.

In the prospective deployment phase, the AI plans were reviewed by the endocrinology physicians at the bedside; the clinical adoption was determined; and the deemed AI insulin regimen was used for patient treatment following all standard clinical quality controls. We conducted a proof-of-concept trial ClinicalTrials.

gov: NCT to evaluate the feasibility and safety of AI in inpatients with T2D from 28 June to 6 October This trial was a patient-blinded and single-arm intervention, which was performed in the ward of the Department of Endocrinology and Metabolism, Zhongshan Hospital, in China.

The RL-DITR system was embedded in the insulin dosing interface of the health information system HIS , allowing real-time reading of patient clinical information and insulin dosage regimen recommendation Extended Data Fig.

An example of the AI recommendation report for the healthcare provider is presented in Extended Data Fig. Patients with T2D receiving subcutaneous insulin treatment were recruited and screened for the inclusion and exclusion criteria.

The pre-intervention initial insulin regimen served as reference for daily insulin regimen. Eligible patients received insulin dosage titration according to the AI model after the first cycle of insulin regimen, which was confirmed twice daily by the physician in charge.

The treating physician could reject the recommendation if deemed necessary. Throughout the trial, anti-hyperglycemic drugs remained unchanged; standard meals at usual mealtime were provided; and no physical activity was scheduled.

Capillary glucose concentration was measured at seven timepoints of fasting, after breakfast, before and after lunch, before and after dinner and before bedtime a day by a glucometer Glupad, Sinomedisite to estimate glucose control and to guide insulin regimen. The goal was to achieve preprandial capillary blood glucose of 5.

The CGM data were analyzed by physicians, and the treatment was not influenced by data gained by CGM. CGM alarms were not activated during the feasibility clinical trial.

The primary outcome was difference in glycemic control as measured by mean daily blood glucose concentration total, preprandial and post-prandial capillary blood glucose. The secondary endpoints included glucose concentration in the target range TIR of 3. Glycemic variability was determined by the CV of glucose values.

Safety was assessed as the number of hypoglycemic events. Serious adverse events included severe hypoglycemia, defined as a capillary glucose level of less than 2. The sample size calculation was based on the primary outcome.

PASS software version Clinical studies were analyzed using SAS 9. The matched t -test was used to compare the performance of RL-DITR and physicians.

The change from baseline measurements to the end of the trial was analyzed by two-sided paired t -test and a Wilcoxon signed-rank test for continuous measurements.

The seven-point blood glucose profiles were analyzed using a generalized linear mixed model. The model used a Noisy-OR approach to aggregate WTR predicted probabilities of points for daily WTR prediction.

Further information on research design is available in the Nature Portfolio Reporting Summary linked to this article. IRB approval was obtained from institutions for EHR data collection.

Individual-level patient records can be accessible with IRB consent and are not publicly available. De-identified data can be requested by contacting the corresponding authors. All data access requests will be reviewed and if successful granted by the Data Access Committee.

Data can be shared only for non-commercial academic purposes and will require a formal material transfer agreement. Individual-level data of the clinical trial ClinicalTrials. gov: NCT reported in this study are not publicly shared. Data can be available to bona fide researchers for non-commercial academic purposes and necessitate a data user agreement.

Requests should be submitted by emailing the corresponding authors Y. at chen. ying4 zs-hospital. cn or guangyu. wang24 gmail. Requests will be processed within a 2-week timeframe.

All data shared will be de-identified. The deep learning models were developed and deployed in Python version 3. The following standard model libraries were used: scikit-learn 1. Sun, H. et al. IDF Diabetes Atlas: global, regional and country-level diabetes prevalence estimates for and projections for Diabetes Res.

Article PubMed Google Scholar. Stratton, I. Association of glycaemia with macrovascular and microvascular complications of type 2 diabetes UKPDS 35 : prospective observational study.

BMJ , — Article CAS PubMed PubMed Central Google Scholar. Holman, R. Article CAS PubMed Google Scholar. ElSayed, N. Pharmacologic approaches to glycemic treatment: standards of care in diabetes— Diabetes Care 46 , S—S American Diabetes Association. Glycemic targets: standards of medical care in diabetes— Diabetes Care 44 , S73—S84 Article Google Scholar.

Martinez, M. Glycemic variability and cardiovascular disease in patients with type 2 diabetes. BMJ Open Diabetes Res. Care 9 , e Article PubMed PubMed Central Google Scholar.

Rodbard, D. Glycemic variability: measurement and utility in clinical medicine and research—one viewpoint. Diabetes Technol. Bi, W. Artificial intelligence in cancer imaging: clinical challenges and applications. CA Cancer J. Esteva, A.

Dermatologist-level classification of skin cancer with deep neural networks. Nature , — Kermany, D. Identifying medical diagnoses and treatable diseases by image-based deep learning.

Cell , — Wang, G. A deep-learning pipeline for the diagnosis and discrimination of viral, non-viral and COVID pneumonia from chest X-ray images.

Zhang, K. Deep-learning models for the detection and incidence prediction of chronic kidney disease and type 2 diabetes from retinal fundus images. Kaelbling, L. Reinforcement learning: a survey. Gottesman, O. Guidelines for reinforcement learning in healthcare. Komorowski, M. The Artificial Intelligence Clinician learns optimal treatment strategies for sepsis in intensive care.

Guo, H. Learning dynamic treatment strategies for coronary heart diseases by artificial intelligence: real-world data-driven study. BMC Med. Bothe, M. The use of reinforcement learning algorithms to meet the challenges of an artificial pancreas.

Expert Rev. Devices 10 , — Liu, Z. A deep reinforcement learning approach for type 2 diabetes mellitus treatment. Oh, S. Reinforcement learning-based expanded personalized diabetes treatment recommendation using South Korean electronic health records.

Expert Syst. Raheb, M. Subcutaneous insulin administration by deep reinforcement learning for blood glucose level control of type-2 diabetic patients. Thomas, M. Model-based reinforcement learning: a survey. Trends Mach.

Learn 16 , 1— Google Scholar. Huang, Q. Model-based or model-free, a review of approaches in reinforcement learning. Coronato, A.

Reinforcement learning for intelligent healthcare applications: a survey. Nemati, S. Optimal medication dosing from suboptimal clinical examples: a deep reinforcement learning approach.

IEEE Eng. PubMed Google Scholar. Vasey, B. Reporting guideline for the early-stage clinical evaluation of decision support systems driven by artificial intelligence: DECIDE-AI. Garg, S. Improved glycemic control in intensively treated adult subjects with type 1 diabetes using insulin guidance software.

Farajtabar, M. More robust doubly robust off-policy evaluation. In Proc.

Glucose utilization rates optimization -

Decay in panel E was fit to a form , where ; induction was fit to the form for , where and minutes. Red lines in panel F are a plot of the fit found from panel E, starting at each period from the measured initial values. Since LacZ and LacY have very low degradation rates respectively and [24] , [25] the main factor that decreases internal levels of lac proteins is dilution due to cell growth.

For comparison, we note that the generation time — the time for the population to double in size — in minimal medium is approximately 60 minutes see [26] , Text S1 , and Fig.

The maintenance of phenotypic memory should therefore be limited by the number of residual proteins transmitted between the mother and daughter cell during cell division, and phenotypic memory may have an intrinsic lifetime which is tied to the minimal lac protein concentration necessary to maintain cells in an induced state.

Following the reintroduction of lactose, LacY production resumed after a 25 minute lag and reached its half-maximal value in 21 minutes. When was decreased to 90 minutes, expression of the lac operon was modulated by the environmental fluctuations but did not decay to zero Fig.

This suggests that the level of lac proteins transmitted upon cell divisions was insufficient to maintain cells in a fully or partially induced lac state after 10—12 generations.

For Fig. We observed the same behavior in Fig. C Amount of time uninduced cells were exposed to lactose conditions before reaching complete growth recovery.

These experiments yield two key observations. First, the total time to adapt to lactose is shorter when glucose alternates with lactose during the adaptation process. Second, during the glucose exposures Figs.

We therefore hypothesized that the lag phase is due to two major barriers that must be crossed before cells can resume normal growth: A initiation of lac protein production, and B recovery from the stringent response caused by carbon starvation [15] , [28]. Barrier A consists of de-repression of the lac operon, lac transcript production, and translation of the first functional LacZ and LacY molecules, which enable subsequent positive feedback.

Since these initial events occur in series once the lac operon is stochastically de-repressed [27] , there exists a certain minimum time to cross the first barrier. In contrast, recovery from the stringent response is only complete once the accumulated p ppGpp has decreased to its basal level — barrier B therefore gets longer the more time cells spend without glucose [28].

To test this hypothesis, we attempted to reduce barrier A by starting with a small amount of lac protein initially, but not enough to completely eliminate the lag. From Fig.

about 4 cell divisions, hence their lac proteins are more than induced; we infer that lac levels are sufficiently high to prevent stringent response during lactose exposures once cells have crossed this threshold.

We grew lac -induced cells under glucose conditions for 8 hours , which diluted their lac proteins to of their maximal level, before beginning rapid lactose-glucose fluctuations. When the pre-induced cells were exposed to 5, 10 or 15 minute fluctuating conditions, they experienced a lag phase only during the first lactose exposure Fig.

We observed that for rapid fluctuations the total adaptation time was approximately equal to the duration of the lactose exposure red line in Fig.

This indicates that we have minimized barrier A which normally takes a fixed amount of time , and we are mainly seeing barrier B which is proportional to the duration of carbon stress. For , cells are able to resume normal growth in lactose hence barrier B is crossed before the glucose exposure.

Our biological model makes several predictions, which are confirmed in the following section through direct measurements of cytoplasmic lac levels. First, Fig. Second, the initiation of lac protein production — barrier A — is a process with a fixed timescale that does not depend on the duration of carbon stress.

Third, once barrier A is crossed, barrier B can be crossed in as little as 3 minutes Fig. We test these predictions in the next section by using a LacY fluorescent protein fusion to measure the dynamics of lac induction and we further elaborate on this simple biological model of the lag phases in the Discussion.

To reproduce the conditions of Fig. Subjecting cells to a single pulse of lactose — instead of cyclical fluctuations — ensured that induction dynamics were measured independently of other effects, such as starvation and the stringent response, which may be compounded by multiple glucose-to-lactose transitions.

These results confirm our conclusion, based on growth measurements in Fig. A Induction dynamics in response to a single pulse of lactose lasting 10, 20, 30, 45, or 60 minutes. In each case, the permease density continues to increase and levels start to decay approximately 40 minutes after lactose is removed from the environment.

Measurements from a long experiment in a periodic environment inset are superimposed onto a single period. The LacY-Venus reporter delay lasts C Induction by either 60 minutes of 0.

We term this behavior response memory : the ability of a regulatory network to continue to respond after the stimulus has been removed. Hysteresis and expression delays are to be expected in multi-level gene regulatory circuits, and in the particular case of lac regulation these delays can involve the kinetics of mRNA degradation [29] , repressor re-binding [30] , [31] , catabolite repression mediated by cAMP [32] , and dynamics of allolactose, the intracellular inducer of the lac operon [33].

We therefore characterized the relative contributions of these effects to the observed response memory. First, the ability to detect in vivo changes in lac protein levels is set by the maturation time of LacY-Venus both folding and chromophore formation, measured to last less than 7 minutes in vivo [34] , which introduces a delay between observed and actual protein levels.

To accurately measure the delay associated with the LacY-Venus protein maturation, we analyzed the LacY-Venus fluorescence levels when glucose and lactose environments alternate with an environmental duration of 90 minutes and measured the phase difference between the environment and the LacY-Venus levels.

The average delay measured under these experimental conditions is The observed peak at 40 minutes in Fig. In contrast to induction using lactose, which requires LacZ activity to produce the inducer allolactose, IPTG induces the lac operon directly.

Furthermore, this experiment shows that the stringent response caused by carbon starvation does not significantly affect the induction dynamics.

We next tested whether residual intracellular inducer could account for the observed response memory, by using 2-nitrophenyl β -D-fucopyranoside ONPF , an anti-inducer molecule that competitively binds LacI, excludes IPTG, and increases LacI's affinity for its operator site.

However, they exhibited significantly different response memory profiles when the inducer was removed at minutes: lac expression in the presence of ONPF started to decrease 20 minutes after IPTG removal, compared to the 40 minutes measured in the absence of ONPF.

The remaining 6 minutes of response memory, not accounted for by reporter delay, can be explained by the measured time for LacI to fully rebind lac operator sites in the presence of ONPF min, [30] , [31] as well as the lifetime of lac mRNA min, [29].

These in vivo measurements support our predictions above based on the growth rate dynamics. First, we found that response memory enables cells to continue responding to lactose through the glucose exposures.

Second, we showed in Fig. We note that because our experiment is not designed for single-molecule sensitivity, we cannot measure the initiation events themselves.

However, we clearly see that cells cross our detection threshold at approximately the same time when induced with IPTG in glucose i. without any carbon stress or with lactose under carbon stress.

Third, we measured the post-initiation rate constant for lac protein production to be. This implies that post-initiation the time to increase lac induction levels to would be approximately minutes, which is consistent with our prediction that barrier B can be crossed in as little as 3 minutes.

While the major determinants of the lag phase were found to be the initial induction steps and the recovery from stringent response, the potential fitness gains that cells might reap from response memory remained unclear. To better quantify the fitness advantage of response memory in the lac operon, we adapted the established metabolic model described in [35] to fluctuating environments see Materials and Methods.

We focused exclusively on the observed memory effects and their impact on metabolic activity, and did not model the stringent response since it did not significantly affect the induction dynamics Fig. The model explicitly accounts for intracellular concentrations of lactose, allolactose, lac operon mRNA, and lac proteins, and captures several features we observed in experiments.

For example, in response to a single pulse of extracellular inducer, protein levels can continue to increase after the stimulus is removed, causing an overshoot, if sufficient mRNA and intracellular inducer levels are maintained Fig.

Likewise, the model exhibits phenotypic memory consistent with our observations. A Schematic of the gene regulation model, including extracellular inducer , mRNA , and protein. A few representative examples of how lac levels evolve under fluctuating conditions are shown in the insets.

C A difference in lac expression levels is observed for models with solid line and without dashed line response memory. The model that includes response memory correctly predicts the experimentally measured IPTG induction dynamics cyan line.

Response memory leads to increased intracellular LacZ levels and higher catabolic activity. Since response memory can be explained by the LacI-mediated repression kinetics Fig. We used the model to test this conclusion by artificially reducing the allolactose degradation rate to zero during glucose environments.

We obtained similar results across a range of slower but non-zero degradation rates. We show in Fig. The predicted dynamics closely follow the measured lac levels obtained from minutes IPTG induction cyan line.

The highlighted regions in Fig. The modeling results support a picture in which response memory provides a large adaptive advantage when external fluctuations occur faster than the cell division time, while phenotypic memory is beneficial for slower fluctuations, spanning several generations.

We have presented two distinct memory mechanisms in the lac operon of E. coli , phenotypic and response memory, each of which is beneficial over different timescales. Phenotypic memory allows cells to maintain an adapted state for multiple generations after a specific carbon source is removed from the environment.

Since phenotypic memory operates through the transmission of stable cytoplasmic proteins, it may be employed as a general strategy in other organisms to transmit metabolic information between generations, as observed e. in the yeast galactose system [9] , [36]. More generally, the intrinsic mechanism behind phenotypic memory being passive — based on intracellular proteins whose lifetime is longer than a typical generation — similar memory effects are expected to be present for other fluctuations and in other organisms.

Adaptation mechanisms that rely on the expression of long-lived permease molecules — e. We used fast fluctuating environments to dissect the determinants of lag phases following a transition from glucose to lactose.

Our results suggest a simple biological model of the lag phase in which lac protein activity and the stringent response are mutually inhibitory processes: Lac protein activity in lactose has an inhibitory effect on the stringent response due to glucose production and amino acid synthesis, while the stringent response initially inhibits lac protein production through its global inhibitory effects on translation.

To see this, we consider two examples. First, we compare for uninduced and pre-induced cells Fig. In the pre-induced case, after the first lactose exposure cells rapidly recover full growth in glucose, whereas if no lac proteins are initially available, cells experience a slow recovery in glucose.

The stringent response due to the lactose exposure is therefore much less severe when a small amount of LacZ induced is available to hydrolyze lactose and initiate positive autoregulation.

Second, we note that for Fig. However, for Fig. We conclude that protein production during the stringent response is too slow to allow cells to cross the threshold during the short lactose exposures for.

In particular, if lactose encounters unexpectedly cease, this cost will no longer be temporary, but sustained by the population indefinitely.

Cells employing response memory avoid such long-term cost by transiently expressing the required genes for a short amount of time following an initial exposure to the stimulus, with a maximal metabolic cost that is limited by the duration of this transient expression.

Should environmental fluctuations cease, cells will suffer only a small, short-term fitness cost. On the other hand, should fast fluctuations persist, as we have shown the cells reap a significant fitness benefit. In particular, we showed that cells reach higher induction levels more rapidly by maintaining their response profile following the removal of an external inducer.

Memory in different genetic network architectures could affect not only the cost of gene expression, but also the evolution of gene expression levels. The timescale over which phenotypic memory persists is determined to a large extent by the gene's expression level provided the protein is sufficiently stable.

Expression levels may be evolutionarily tuned not only to support growth in a single environment, but also to provide cells' progeny with memory of past environments. The interplay of memory and metabolic constraints could thus dramatically change the nature of evolutionary trajectories and optima.

We expect theoretical analyses may be fruitfully applied to explore these possibilities. The power of the memory mechanisms we have described lies in their universality. Protein lifetimes and regulatory networks can be tuned in simple ways to give rise to physiological memory under rapidly changing conditions.

Microorganisms have to handle both internal and external sources of noise, and while many genetic networks have evolved to exploit stochastic fluctuations of intracellular molecular components to regulate key cellular processes [41] , we have shown that molecular rates of signal transduction reactions can be modulated to optimize response profiles for growth in fluctuating environments.

Together, phenotypic and response memory allow bacteria to adapt to a wide range of fluctuation timescales in sophisticated, history-dependent ways. These memory mechanisms constitute general strategies that bacteria can employ to adapt to diverse environmental fluctuations — including nutrients, antibiotics, and other physiological stresses.

The microfluidic device used in this study was made using standard soft lithography and microfabrication techniques and consists of growth chambers and a main flow channel patterned from two SU-8 layers 1. The devices were fabricated by making polydimethylsiloxane PDMS replicates of the SU-8 master.

The PDMS devices were peeled from the silicon master and 1. When transitioning between two media, both valves were closed for 15 seconds before the new one was opened to let the pressure equilibrate inside the device and to avoid backflow problems.

A T-junction upstream of the growth chambers ensured that transitions between the different media occurred very rapidly. By flowing a fluorescent dye inside the device, the transition between each type of media was measured to occur in less than milliseconds Supp.

Cells inside the growth chambers push their immediate neighbors toward the main flow channel as they increase in size, and the lateral speed at which the cells move is proportional to the population's mean elongation rate.

An optical flow algorithm implemented using openCV [42] was used to measure the displacement between successive frames. This displacement was used to find the average cell speed over the region between 10 and 15 away from the closed end of the growth chamber.

The lateral speed reports on the cumulative growth rate of cells in the first 10 microns of the growth chamber providing a measure of the relative growth rate of the population.

Error bars on relative growth plots report the standard error of the mean as averaged over the 5 chambers present in a single field of view. These error bars measure intrinsic cell-to-cell variability in growth, due to stochasticity in cell division rates, elongation rates, and gene expression processes.

The lac induction dynamics of a population subjected to sudden environmental changes are modeled as described in [35] , with an additional equation to account for mRNA transcription.

The model assumes that LacY protein levels are proportional to LacZ levels. Unless otherwise noted in Table 1 , refer to [35] for a complete rationalization behind each parameter's value. The set of equations are given by 1 2 3 4 where , , , and are the intracellular concentrations of lactose, allolactose, mRNA and LacZ proteins, respectively parameters are specified in Table 1.

The expression for the lactose hydrolysis rate is given by 5 where , , and are obtained by solving Eqns. To qualitatively compare behaviors with and without response memory, we artificially reduced the rate of allolactose turnover in glucose environments taking to attain response memory in our simple model.

Similar results were obtained by reducing instead the mRNA degradation rate in the transition from lactose to glucose. Full methods as well as further details of microfluidic fabrication, strain description, image acquisition and analysis, and any associated references are provided in Text S1.

Timescale of the environmental change inside a chemoflux. The transition are accurately described by exponential functions red lines, seconds and seconds. Growth rate measurement. Since each cell division event yields two cells at age zero, the fraction of cells at age 0 is twice the population's growth rate.

Duration of the lag phase. B - F The duration of the lag and recovery phases is computed from a linear regression of the lateral cell speed and the results are presented in Fig. S1 for quantification. A video of cell growth in the chemoflux growth chambers during a glucose-to-lactose transition.

We thank Calin Guet, Yuichi Wakamoto, Michael Rust, David Gresham, Joao Xavier, Matthew Eames, and Wei-Hsiang Lin for comments on the manuscript. We also thank Jose Vilar, Gene Huber, and Bruce Levin for discussions. We especially thank Tobias Bergmiller and Calin Guet for the over-expression plasmids, Wei-Hsiang Lin for his assistance in carrying out the constitutive Lac expression experiments, and Michael Rust for providing a microscopy setup for additional experiments.

We thank the Wakamoto and Xie labs for providing E. coli strains. Conceived and designed the experiments: GL EK.

Performed the experiments: GL. Analyzed the data: GL. Interpreted the data: GL EK. Wrote the paper: GL EK. Article Authors Metrics Comments Media Coverage Reader Comments Figures.

Correction 16 Oct The PLOS Genetics Staff Correction: Memory and Fitness Optimization of Bacteria under Fluctuating Environments. Abstract Bacteria prudently regulate their metabolic phenotypes by sensing the availability of specific nutrients, expressing the required genes for their metabolism, and repressing them after specific metabolites are depleted.

Author Summary Bacterial adaptation to new environments typically involves reorganization of gene expression that temporarily decreases growth rates.

Introduction Escherichia coli cells grown in the presence of both glucose and lactose first consume glucose, which is more easily metabolized, before expressing the genes necessary for lactose catabolism [1] — [3]. Download: PPT. Figure 1. Chemoflux device for growth rate measurement in changing environments.

Results Phenotypic memory in response to sudden environmental changes The growth rate of E. Figure 3. Molecular components of phenotypic memory in the lac operon.

Figure 4. Lag phase and recovery in rapidly fluctuating environments. Response memory and dynamics of lac protein expression To reproduce the conditions of Fig. Figure 5. In vivo measurement of LacY expression in fluctuating environments.

Modeling lac operon dynamics with memory in a fluctuating environment While the major determinants of the lag phase were found to be the initial induction steps and the recovery from stringent response, the potential fitness gains that cells might reap from response memory remained unclear.

Figure 6. Mathematical modeling quantifies fitness advantage of memory. Discussion We have presented two distinct memory mechanisms in the lac operon of E. Materials and Methods Device description and fabrication The microfluidic device used in this study was made using standard soft lithography and microfabrication techniques and consists of growth chambers and a main flow channel patterned from two SU-8 layers 1.

Growth rate measurements Cells inside the growth chambers push their immediate neighbors toward the main flow channel as they increase in size, and the lateral speed at which the cells move is proportional to the population's mean elongation rate.

Mathematical model of lactose metabolism The lac induction dynamics of a population subjected to sudden environmental changes are modeled as described in [35] , with an additional equation to account for mRNA transcription. Supporting Information. Figure S1.

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Thank you for visiting nature. You Detoxify your liver using utulization browser version ooptimization limited support for CSS. Raates obtain the best experience, we recommend you Glucose utilization rates optimization a more Utilizatioon to date browser or turn off compatibility mode in Internet Explorer. In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript. The personalized titration and optimization of insulin regimens for treatment of type 2 diabetes T2D are resource-demanding healthcare tasks. Here we propose a model-based reinforcement learning RL framework called RL-DITRwhich learns the optimal insulin regimen by analyzing glycemic state rewards through patient model interactions. PLOS Genetics utilizxtion 10 : e Bacteria prudently regulate optimizatlon Glucose utilization rates optimization phenotypes by sensing the utilizatiin of specific nutrients, expressing utiliztaion required Astaxanthin for skin health for their metabolism, and pptimization them after Restoring insulin sensitivity naturally metabolites are depleted. It is unclear, however, how genetic networks maintain and transmit phenotypic states between generations under rapidly fluctuating environments. By subjecting bacteria to fluctuating carbon sources glucose and lactose using microfluidics, we discover two types of non-genetic memory in Escherichia coli and analyze their benefits. First, phenotypic memory conferred by transmission of stable intracellular lac proteins dramatically reduces lag phases under cyclical fluctuations with intermediate timescales 1—10 generations.

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We examined dynamically acquired data over various time intervals in many brain regions and found that the number of components identified by the method is stable and consistent with the presence of kinetic heterogeneity in every region.

We optimized the method for determination of regional rates of glucose utilization; calculated rates were found to be somewhat dependent upon the treatment of noise in the measured tissue data and upon the time interval in which the data were collected.

The application of a numerical filter to remove noise in the data resulted in values for regional cerebral glucose utilization that were stable with time and consistent with rates determined by the other established techniques.

Based on the results of the current study, we expect that the spectral analysis technique will prove to be a highly flexible tool for kinetic analysis of other tracer compounds; it is capable of producing low-variance, time-stable estimates of physiological parameters when optimized for time interval of application, input spectrum of components, and processing of noise in the data.

Abstract A method for kinetic analysis of dynamic positron emission tomography PET data by linear programming that allows identification of the components of a measured PET signal without predefining a compartmental model has recently been proposed by Cunningham and co-workers.

f Biomass yield on glucose. Measured growth of C. vulgaris was significantly lower than model simulation, indicating an inconsistency between model predictions and experimental results during this time period.

A growth rate comparison between GMPC prediction and experimental results for individual growth periods, including heterotrophic and autotrophic cycles, is shown in Fig. The experimental growth rate of autotrophic cultures blue bars in Fig. Previous studies have observed that progressive increase in biomass will block light penetration and thus alter algal growth 28 , which may explain the gradual decline in the algal growth rate and resulting deviations away from model predictions, as this effect was not considered in our open-loop model predictive control.

Furthermore, the heterotrophic growth rate was around 0. As a result, C. vulgaris was likely consuming some glucose and CO 2 simultaneously during the light cycle, resulting in mixotrophic conditions for both the GMPC case and standard fed-batch cultures. Indeed, we observed declines in the glucose levels of C.

vulgaris during the light cycles in both cases white sections in Fig. This may explain the similar cell growth curves of C. vulgaris between standard fed-batch cultures and GMPC cultures Fig.

However, even though C. The extra glucose measured Fig. In addition, the performance of open-loop GMPC in terms of biomass yield on glucose was only moderately better than fed-batch cultures, likely in part because the glucose supply was not controlled appropriately under dark cycles for the GMPC conditions.

The measurements were then used as inputs into the model green box in Fig. Unlike the open-loop system in Fig. For the heterotrophic cycles, the calculated growth rate μ C , calculated glucose demand F G,C , and calculated nitrate demand on a per L basis F N,C during the 8-h period were determined based on measured inputs X m , G m , N m.

Next, the model and algorithm optimizer green and blue boxes in Fig. The algal cells were assumed to operate under two different types of metabolism in the simulations for the dark cycle. One fraction of algal cells was assumed to grow strictly heterotrophically, as represented by model i CZH-T1.

In addition, a certain fraction a of algal biomass was assumed to grow mixotrophically and thus fixes CO 2 during the dark cycle as suggested in previous publications In this simulation, we therefore set the light intensity in the i CZPA-T1 model to a minimum for the current simulations in dark periods of the cycle.

As a result, three equations were added to consider this combined metabolic operation and its impact on growth rate, glucose consumption rate, and nitrate consumption rate.

The algorithm optimizes six variables including autotrophic growth rate μ A , autotrophic nitrate demand F NA , autotrophic biomass percentage a , heterotrophic growth rate μ H , heterotrophic glucose demand F HG , and heterotrophic nitrate demand F NG to minimize the difference between model simulations and experimental growth rate as well as glucose and nitrate demand for the most recent 8-h dark cycle.

Based on the predictions, the control pump supplies glucose and nitrate to the bioreactor. a Flowchart. b Model controller in heterotrophic dark cycles.

c Model controller in autotrophic light cycles. Alternatively, in the photoautotrophic phase, a differential equation for cell mass accumulation with respect to time was incorporated, which includes a term to describe the logarithmic decay of cell growth rate that occurs at increasing biomass concentrations due to light shading Fig.

This equation was built based on our experimental biomass measurements from a separate autotrophic culture run. The calculated growth rate was then used in i CZPA-T1 to predict and optimize nitrate supply during the light cycles.

The GMPC culture was then compared with a standard fed-batch culture similar to the conditions used in the open-loop experiment Fig. Unlike the open-loop system, algal growth for the GMPC culture blue line in Fig. Previous studies indicated the success of model predictive control is contingent on a robust process model and on-line measurements 29 , Indeed, in our closed-loop system, the model predictive algorithm was modified based on experimental measurements of cell density, glucose, and nitrate for both autotrophic and heterotrophic conditions in order to predict nutrient requirements for every cycle for the closed-loop system.

a Cell growth. b Growth rate comparison between GMPC Experiment and GMPC Prediction. c Glucose supply during the cultures. d Glucose level in the media. e Biomass yield on glucose. The growth rates between simulation and experimental results were compared for individual time periods of the cycling photoautotrophic and heterotrophic cultures Fig.

Both the model predictions and experimental growth rates changed dynamically over different heterotrophic and autotrophic cycles. The model predictions green bars in Fig. For the experiment, the growth rates blue bars in Fig.

Meanwhile, the model predictions for growth during the light cycles gradually declined from 0. The experimental growth rates followed the same trend, decreasing from 0.

Due to the efficient glucose utilization occurring during the dark cycles of this closed-loop control system, the biomass yield on glucose increased dramatically by 2.

In contrast, the open-loop GMPC system only had a modest Overall, the closed-loop GMPC demonstrated more accurate controller performance than the open-loop GMPC system.

To address this technical challenge, other more rapid nutrient and metabolite measurement tools could be integrated such as in situ Raman spectrometry for metabolite measurements 31 , Alternatively, off gas analysis can be used to characterize cell metabolism toward biomass accumulation or lipid synthesis 33 for future versions of GSM control.

After demonstrating the advantages of closed-loop model prediction and its associated higher efficiency of biomass productivity with respect to glucose fed, the model predictive controller was compared to a standard PID controller in silico and experimentally.

Using Simulink TM , a kinetic model consisting of four ODE equations was incorporated in order to describe changes in biomass, nutrient levels, and medium volume during the heterotrophic dark periods in a bioreactor Supplementary Fig.

Genome-scale metabolic models were then used to determine the relationship between growth rate, glucose uptake rate, and nitrate uptake rate as described previously Next a PID controller and an GMPC controller were used to control glucose and nitrate levels separately in the bioreactor Fig.

Both PID and GMPC controllers were simulated to control glucose supply and nitrate supply every hour. The simulated glucose and nitrate levels exhibited damped oscillations when using a PID controller, a common response for this controller type yellow lines in Fig.

In contrast, employing the GMPC controller eliminated the damping issues and enabled the glucose and nitrate level to more rapidly reach values near the target levels yellow lines in Fig. Meanwhile, the glucose supply and nitrate supply increased gradually in the GMPC controller red lines in Fig.

Instead, the amount added red lines in Fig. a Simulink model for model predictive control and PID control. Glucose control: b PID controller.

c GMPC controller. Nitrate control: d PID controller. e GMPC controller. The PID controller gains were tuned on Matlab TM to achieve optimal performance with proportional gain K p , integral gain K i and derivative gain K d equal to 1.

The glucose levels were measured every hour and the data was fed to both the PID controller and the closed-loop GMPC controller with a pure heterotrophic model since light and dark cycles were not presented. The feedback signal could compensate for the modeling errors and also help to reject the disturbance in the GMPC controller.

After the setpoint change, the glucose level gradually decreased and was stably controlled. Overall, both Simulink TM simulations and experimental results demonstrated that the GMPC approach provided more robust and precise control than traditional PID controllers.

While the model could anticipate the future behavior of the fermentation and take appropriate control action, the PID controller did not have this capability resulting in oscillations and overshoot behavior in both simulations and experiments. Thus, our study demonstrates how GMPC systems can serve as a bridge between genome-scale metabolic modeling and control algorithms.

Since the cultivation conditions can change and affect algal cellular metabolism, our system connected feedback measurements with genome-scale metabolic models and achieved more efficient nutrient utilization and higher product yields for dynamic algal cultivation conditions.

In this way, genome-scale metabolic models can be effectively utilized to improve biomanufacturing of microalgae and other industrially important microbial cell factories. Fed-batch cultivation and PID controllers have been widely used in bioprocess development.

Unfortunately, fed-batch cultivation often results in poor nutrient control and wasted nutrients and conventional PID control can lead to oscillating cell behaviors and poor performance under dynamic conditions. In this study, we have utilized the power of genome-scale metabolic models to predict and control glucose and nitrate supply for C.

vulgaris cultures under light and dark cycles and compared this approach to conventional autotrophic and heterotrophic processes. Our results first showed that utilizing genome scale models to track and limit glucose and nitrate feeding led to higher titers of biomass, FAs, and lutein than autotrophic conditions and more efficient glucose utilization and higher product yields than heterotrophic conditions.

Next, implementing these models into an open loop system modestly improved performance. Finally, both computational simulations and experimental results demonstrated that this genome-based MPC system exhibits superior controller performance compared to conventional PID methods.

Green microalgae C. vulgaris UTEX was obtained from the Culture Collection of Algae at the University of Texas at Austin and maintained on sterile agar plates 1. Liquid cultures were inoculated with a single colony in For alternating light and dark cycles, autotrophic conditions were used for light sections and heterotrophic conditions were used for dark sections.

The lyophilized algal dry biomass was weighted gravimetrically using an analytical balance. The glucose concentration was measured using YSI biochemistry analyzer Yellow Springs, OH. FAME production followed the procedure provided by Dong et al. Helium was used as carrier gas. Lutein extraction followed the procedure provided by Yuan et al.

The solution was filtered before HPLC analysis. The mobile phases are eluent A dichloromethane: methanol: acetonitrile: water, 5. The i CZ model, including six different biomass compositions for autotrophic conditions PAT1-PAT6 and five different biomass compositions for heterotrophic conditions HT1-HT5 , was obtained from Zuniga et al.

GSM simulations were performed using the Gurobi Optimizer Version 5. The experimental setup is shown in Supplementary Fig. The manipulated variables were glucose demand F G and nitrate demand on a per L basis F N for 8-h period. Two pumps were used to control both variables automatically by Matlab TM through Arduino chip.

All the control algorithms were run on Matlab TM and the codes are provided in Supplementary information. The Simulink TM simulation is shown in Fig. The blue box in Fig. Four equations were built inside the blue box as shown in Supplementary Fig. The inputs were F G and F N.

The outputs were biomass, nitrate level, glucose level and volume. Only nitrate levels and glucose levels were fed into the PID and GMPC controller. For the proportional-integral-derivative PID controller, the proportional gain K p , integral gain K i and derivative gain K d equal to 1.

The PID controller and GMPC controller were used to control glucose supply and nitrate supply every hour in both simulation and experiment.

Changes in the setpoint for glucose were introduced to see how both PID and GMPC responded to those changes. Initial biomass levels x 0 , glucose levels G 0 and nitrate levels N 0 were measured as described above and used as inputs into the open-loop system.

Three equations shown below were used to predict biomass growth, nitrate consumption rate, and glucose consumption rate in the open-loop system.

The growth rates under light and dark cycles were determined based on previous experimental data. After that, the growth rates were constrained in the autotrophic and heterotrophic GSMs, respectively to determine nutrient exchange rates r N and r G under light and dark cycles.

The methods for using growth rate to estimate nutrient exchange rates have been described previously in Chen et al. We assumed a rapid switch to a new operational steady state following the transition between light and dark cycles.

Initial biomass levels x 0 , glucose levels G 0 and nitrate levels N 0 were measured and used as inputs into the closed-loop system.

During the experiment, biomass levels x m , glucose levels G m and nitrate levels N m were msured and used as inputs into the closed-loop system.

For the light cycle, two equations were built to describe and predict biomass accumulation rate and nitrate consumption rate. Unlike the open loop system, the light shielding effect was considered and the growth rate would decrease as the biomass concentration increased as described in the equation below and shown in Fig.

The GSM was used to predict nutrient exchange rate r N based on the measured growth rate. For the dark cycles, three model equations were built to predict biomass accumulation rate, nitrate consumption rate and glucose consumption rate as listed below and shown in Fig.

In the biomass equation, we assumed a fraction of heterotrophic biomass, a , was derived from autotrophic metabolism and the simulated growth rate was μ A.

Meanwhile, some biomass was derived through heterotrophic metabolism with the simulated growth rate, μ H. The nutrient exchange rates r NA , r NH , r GH were determined by inputting simulated growth rates into the autotrophic and heterotrophic GSMs respectively.

where μ A is simulation growth rate from autotrophic metabolism, μ H is the growth rate from heterotrophic metabolism, r NA is nitrate exchange rate from autotrophic metabolism, r NH is the nitrate exchange rate from heterotrophic metabolism, r GH is the glucose exchange rate from heterotrophic metabolism.

Next, we applied a fitting objective function J to minimize the difference between calculated values and simulated model values in order to estimate the optimal parameter values a , μ A , μ H , r NA , r NH , r GH for dictating the actual nitrate and glucose feeds to the bioreactor.

The actual bolus nitrate demand F N and the glucose demand F G were thus determined by using values obtained from this fitting objective function. The data that support the findings of this study are available from the corresponding author upon reasonable request. Rosenberg, J. A green light for engineered algae: redirecting metabolism to fuel a biotechnology revolution.

Article CAS PubMed Google Scholar. Shene, C. Metabolic modelling and simulation of the light and dark metabolism of Chlamydomonas reinhardtii. Plant J. Kato, Y. et al. Biofuels 12 , 39 Article PubMed PubMed Central Google Scholar. Cheirsilp, B.

Enhanced growth and lipid production of microalgae under mixotrophic culture condition: effect of light intensity, glucose concentration and fed-batch cultivation.

Zheng, Y. High-density fed-batch culture of a thermotolerant microalga Chlorella sorokiniana for biofuel production. Energy , — Article CAS Google Scholar. Shi, X. High-yield production of lutein by the green microalga Chlorella protothecoides in heterotrophic fed-batch culture.

Bordbar, A. Constraint-based models predict metabolic and associated cellular functions. Chang, R. Article Google Scholar. Zuñiga, C. Genome-scale metabolic model for the green alga Chlorella vulgaris utex accurately predicts phenotypes under autotrophic, heterotrophic, and mixotrophic growth conditions.

Plant Physiol. Loira, N. Reconstruction of the microalga Nannochloropsis salina genome-scale metabolic model with applications to lipid production.

BMC Syst. Chang, L. Nonlinear model predictive control of fed-batch fermentations using dynamic flux balance models. Process Control 42 , — Jabarivelisdeh, B.

Model predictive control of a fed-batch bioreactor based on dynamic metabolic-genetic network models. IFAC-PapersOnLine 51 , 34—37 Juneja, A.

Model predictive control coupled with economic and environmental constraints for optimum algal production. Ogbonna, J. Zuniga, C. Predicting dynamic metabolic demands in the photosynthetic eukaryote Chlorella vulgaris. Li, C. Utilizing genome-scale models to optimize nutrient supply for sustained algal growth and lipid productivity.

NPJ Syst. Tebbani, S. Nonlinear predictive control for maximization of CO2 bio-fixation by microalgae in a photobioreactor. Bioprocess Biosyst. Hu, D. The design and optimization for light-algae bioreactor controller based on Artificial Neural Network-Model Predictive Control.

Acta Astronaut 63 , — White, R. Long-term cultivation of algae in open-raceway ponds: lessons from the field. Gu, C. Current status and applications of genome-scale metabolic models.

Genome Biol. Using genome-scale models to predict biological capabilities. Cell , — Colarusso, A. Computational modeling of metabolism in microbial communities on a genome-scale.

Han, F. Enhancement of microalgal biomass and lipid productivities by a model of photoautotrophic culture with heterotrophic cells as seed. Xiong, W. Double CO 2 fixation in photosynthesis—fermentation model enhances algal lipid synthesis for biodiesel production. Xiao, Y. Photosynthetic accumulation of lutein in Auxenochlorella protothecoides after heterotrophic growth.

Drugs 16 , Vidotti, A. Analysis of autotrophic, mixotrophic and heterotrophic phenotypes in the microalgae Chlorella vulgaris using time-resolved proteomics and transcriptomics approaches.

Algal Res. Park, J. The contribution ratio of autotrophic and heterotrophic metabolism during a mixotrophic culture of Chlorella sorokiniana.

Public Health 18 , Huesemann, M.

In Healthy cholesterol levels with non-insulin-dependent diabetes Glucoae NIDDMFDG PET Gucose is utilixation problematic Soothing Drink Options of poor uptake of FDG. Different utillization have been Utikization however, these have Flexibility and mobility training been Glucose utilization rates optimization compared in patients with Utioization who have both coronary optimuzation disease CAD and Restoring insulin sensitivity naturally left ventricular LV dysfunction, for which defining viability is most relevant. The aim of this study was to better define the optimal means of FDG PET imaging, assessed by image quality and myocardial glucose utilization rate rMGUamong 3 imaging protocols in patients with NIDDM, CAD, and severe LV dysfunction. Methods: Ten patients with NIDDM, CAD, and severe LV dysfunction mean ejection fraction, Image quality was satisfactory with at least 1 approach in 8 patients, who formed the primary analysis group. Results: Myocardium-to-blood-pool ratios were significantly higher with the insulin clamp standard, 1.

Author: Dolkis

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