Advances in Research on the Impact of Diet on Human Gut Microbiota Composition and Metabolites

As research into gut microbiota deepens, the impact of diet on the composition of human gut microbiota and their metabolites has gradually become a focal point. This paper reviews recent advancements in understanding how diet influences gut microbiota composition and their metabolic products. Firstly, it introduces the basic concepts of gut microbiota and their role in maintaining health. Next, it explores the effects of different types of diets (such as high-fiber, high-fat, high-protein, and refined sugar diets) on the composition of gut microbiota and analyzes their impact on microbiota diversity. Then, it discusses the influence of diet on gut microbiota metabolites, including short-chain fatty acids, amino acid metabolites, and gases. Further, it examines the practical applications of dietary interventions on health, especially their potential impact on chronic diseases. Finally, the paper summarizes the limitations of current research and suggests future research directions and challenges. Overall, the influence of diet on gut microbiota and their metabolites holds profound health significance and provides important evidence for formulating scientific dietary recommendations

Kinetic and thermodynamic analysis of ultra-high pressure and heat-induced denaturation of bovine serum albumin by surface plasmon resonance

Purpose: To undertake comparative kinetic and thermodynamic analyses of the interaction of bovine serum albumin (BSA) with IgG pre-treated with ultra-high pressure (UHP) and moderate heat.Methods: BSA solutions were processed at 100 – 600 MPa and 25 – 40 °C. We applied an optical biosensor based on surface plasmon resonance (SPR). The dissociation and association kinetics of antigen-antibody complexes were measured at different temperatures. By analyzing the resultant sensograms, the association rate constant (ka), dissociation rate constant (kd), equilibrium dissociation constant (KD), and thermodynamic parameters were calculated.Results: The equilibrium disassociation constant, KD, ranged from a low value of 3.15 × 10−7 M (0.1 MPa, 25 °C) to a high value of 66.42 × 10−7 M (600 MPa, 55 °C). Increase in pressure and temperature led to decrease in the affinity of BSA for IgG. Pressure levels above 300 MPa promoted interactions between breakage of disulfide bonds, and the unfolding and aggregation of BSA.Conclusions: These results show that the combination of UHP and moderate heat treatment cdecrease the allergenicity of BSA by changing their protein conformation.Keywords: Ultra - high pressure, Bovine serum albumin, Surface plasmon resonance, Kinetics, Thermodynamics, Allergen

Construction of PAN-based activated carbon nanofibers for hydrogen storage under ambient pressure

Adsorption agents are an important class of solid hydrogen storage materials. Attributed to their high specific surface area and adjustable nanopore structure, activated carbon nanofibers have attracted extensive attention in the application of solid hydrogen storage. The research in this field mostly focuses on applications with a hydrogen pressure condition of 30 to 300 bar, while there have been few systematic studies on the hydrogen storage performance of these materials under ambient pressure. In this study, polyacrylonitrile-based activated carbon nanofibers were constructed by electrospinning technology and ultrasonic-assisted activation technology for the application of atmospheric hydrogen storage. Their nanopore structure was revealed to be mainly composed of micropores, and the relative contents of micropore volume and ultramicropore volume were 77.92% to 88.3% and 22.34% to 24.68%, respectively. Attributed to the synergy of rich microporous structure and surface chemical structure, the atmospheric hydrogen storage density of activated carbon nanofibers could reach 2.64 wt% at 77 K and 1 bar. After the optimization analysis of adsorption isotherm models, the Multisite-Langmuir model was found as more suitable for accurately describing the atmospheric hydrogen adsorption process of activated carbon nanofibers.Cited as: Yu, J., Lin, T., Li, J., Zhang, W., Bao, W., Zhu, B. Construction of PAN-based activated carbon nanofibers for hydrogen storage under ambient pressure. Capillarity, 2023, 6(3): 49-56. https://doi.org/10.46690/capi.2023.03.0

Pairwise Proximal Policy Optimization: Harnessing Relative Feedback for LLM Alignment

Large Language Models (LLMs) can acquire extensive world knowledge through pre-training on large corpora. However, due to exposure to low-quality data, LLMs may exhibit harmful behavior without aligning with human values. The dominant approach for steering LLMs towards beneficial behavior involves Reinforcement Learning with Human Feedback (RLHF), with Proximal Policy Optimization (PPO) serving as the default RL optimizer. Despite its effectiveness, PPO has limitations when optimizing rewards trained from comparison-based loss. Primarily, PPO is not invariant to equivalent reward functions containing identical preference information due to the need to calibrate the reward scale. Additionally, PPO's necessity for token-wise updates introduces complexity in both function approximation and algorithm design compared to trajectory-wise optimization. This paper proposes a new framework, reinforcement learning with relative feedback, and a novel trajectory-wise policy gradient algorithm, Pairwise Proximal Policy Optimization (P3O) that operates directly on comparative rewards. We show theoretically that P3O is invariant to equivalent rewards and avoids the complexity of PPO. Empirical evaluations demonstrate that P3O outperforms PPO in the KL-Reward trade-off and can align with human preferences as well as or better than prior methods. In summary, this work introduces a simpler yet effective approach for aligning LLMs to human preferences through relative feedback.Comment: 19 pages, 5 figure

Current understanding of disease control and its application in patients with chronic rhinosinusitis

BackgroundDisease control is a primary treatment goal for patients with chronic rhinosinusitis (CRS). This study aims to summarize the evaluation parameters of disease control and then identify predictors of poorly controlled CRS.MethodsA systematic review of the literature was performed on PubMed, Google Scholar, Scopus, and Cochrane databases to identify studies relating to disease control in CRS.ResultsThe concept of disease control in patients with CRS involved the longitudinal assessment of the disease state and was also an important goal of treatment. As a metric of the disease state, the disease control reflected the ability to keep disease manifestations within certain limits, the efficacy after treatment, and the impact on quality of life. Validated measurements, such as EPOS2012 criteria, EPOS2020 criteria, Sinus Control Test, and patient/physician-reported global level of CRS control, have been utilized in clinical practice. These existing disease control instruments incorporated various disease manifestations and categorized patients into two (well-controlled and poor-controlled), three (uncontrolled, partly controlled, and controlled), or five (not at all, a little, somewhat, very, and completely) control categories. Eosinophilia, high computerized tomography score, bilateral sinonasal disease, asthma, allergic rhinitis, female gender, aspirin intolerance, revision surgery, low serum amyloid A, and specific T cell subtype would predict poorly controlled CRS.ConclusionThe concept of disease control and its application were gradually developed in patients with CRS. The existing disease control instruments demonstrated a lack of uniformity regarding the controlled criteria and included parameters

The effects of supervised exercise training on weight control and other metabolic outcomes in patients with type 2 diabetes: a meta-analysis

Few studies have investigated the dose–response relationship between exercise and weight control. This study aimed to assess the effects of different types of supervised exercise training on weight control and other metabolic outcomes in patients with type 2 diabetes mellitus and explore the dose–response relationship between exercise volume/duration and these outcomes. PubMed/MEDLINE, Embase, and Cochrane databases were searched for studies between January 1980 and June 2019. Randomized control trials in type 2 diabetes mellitus patients with supervised exercise training versus control treatment were included. The primary outcome was changes in body weight (kg). The secondary outcomes included changes in waist circumference (cm) and total body fat percentage (%). Forty-two randomized control trials, including 3,625 patients with type 2 diabetes mellitus were included. Overall, exercise treatment was associated with significant reduction in body weight (weighted mean differences, −1.10 kg; 95% CI [−1.58, −0.62], p

Fuzzy logic based energy management strategy for a fuel cell/battery/ultra-capacitor hybrid ship

In this paper, energy management strategy based on fuzzy logic is proposed for a fuel cell hybrid ship, combining proton exchange membrane fuel cell (PEMFC), battery and ultra-capacitor (UC). This hybrid system aims to optimize power distribution among each energy unit. The simulation model of the fuel cell hybrid power system is established in the MATLAB/SIMULINK simulation environment. The fuzzy logic energy strategy is verified by simulation according to the typical drive cycle of ship. The simulation results show that the proposed energy management strategy is able to satisfy power required by the ship, reduce the dynamic load of fuel cell, maintain the state of charge (SOC) of battery and SOC of the UC, and optimize the performance, fuel economy and efficiency of the hybrid systemThe research is supported by the program of the National Natural Science Foundation (No.61304186 and No.51007056)

Risk factors for deep vein thrombosis in patients with pelvic or lower-extremity fractures in the emergency intensive care unit

IntroductionThis study aimed to investigate the incidence of deep vein thrombosis (DVT) in patients with pelvic or lower-extremity fractures in the emergency intensive care unit (EICU), explore the independent risk factors for DVT, and investigate the predictive value of the Autar scale for DVT in these patients.MethodsThe clinical data of patients with single fractures of the pelvis, femur, or tibia in the EICU from August 2016 to August 2019 were retrospectively examined. The incidence of DVT was statistically analyzed. Logistic regression was used to analyze the independent risk factors for DVT in these patients. The receiver-operating characteristic (ROC) curve was used to evaluate the predictive value of the Autar scale for the risk of DVT.ResultsA total of 817 patients were enrolled in this study; of these, 142 (17.38%) had DVT. Significant differences were found in the incidence of DVT among the pelvic fractures, femoral fractures, and tibial fractures (P < 0.001). The multivariate logistic regression analysis showed multiple injuries (OR = 2.210, 95% CI: 1.166–4.187, P = 0.015), fracture site (compared with tibia fracture group, femur fracture group OR = 4.839, 95% CI: 2.688–8.711, P < 0.001; pelvic fracture group OR = 2.210, 95% CI: 1.225–3.988, P = 0.008), and Autar score (OR = 1.198, 95% CI: 1.016–1.353, P = 0.004) were independent risk factors for DVT in patients with pelvic or lower-extremity fractures in the EICU. The area under the ROC curve (AUROC) of the Autar score for predicting DVT was 0.606. When the Autar score was set as the cutoff value of 15.5, the sensitivity and specificity for predicting DVT in patients with pelvic or lower-extremity fractures were 45.1% and 70.7%, respectively.DiscussionFracture is a high-risk factor for DVT. Patients with a femoral fracture or multiple injuries have a higher risk of DVT. In the case of no contraindications, DVT prevention measures should be taken for patients with pelvic or lower-extremity fractures. Autar scale has a certain predictive value for the occurrence of DVT in patients with pelvic or lower-extremity fractures, but it is not ideal