Capacity Consumption Research Articles

Mechanical Behaviors of Orthogonal Spiral Metal Skeleton–Polyurethane Elastomer Composites under Complex Loading Modes

Herein, a novel material design strategy is proposed: an interpenetrating composite composed of a woven orthogonal spiral metal skeleton and polyurethane (PU) elastomer. This interpenetrating composite combines rigidity and flexibility, exhibiting excellent elasticity and deformation recovery. The deformation behavior and mechanical properties of the composites under various loading conditions are investigated through experiments and numerical simulations. Different degrees of warping behaviors occur in composites with various structural parameters under uniaxial tension. Alternating rotations and double spiral arrangements can significantly limit the warping phenomenon, with a maximum reduction of 78%. The bending load capacity is regularly increased by increasing the wire diameter and decreasing the pitch. Increasing the number of loaded spiral wires enhances the bending load capacity of the composites. Uniaxial compression tests demonstrate that the composites have excellent load‐carrying capacity and strain recovery, with compressive strength 1.5 times that of pure PU. Cyclic compression tests further illustrate the excellent energy consumption capacity and stability of the composites. Overall, the introduction of orthogonal spiral skeletons into the composites demonstrates the potential to achieve enhanced load‐carrying capacity and large strain recovery simultaneously.

Research on the Development Trend of New Energy Electric Vehicles in China based on Mathematical Model

As the global economic development moves closer to the direction of green sustainability, the international automobile market pays more and more attention to the development of new energy vehicles. New energy electric vehicle (NEV), as a kind of new energy vehicles, has developed rapidly in recent years due to its characteristics of low pollution, low energy consumption, peak power consumption and adjustment capacity, and has been welcomed by global consumers and governments. The Chinese government conforms to the development of The Times and actively promotes the development of its industry. This paper aims to study the development trend of China's new energy electric vehicles in China, through the establishment of multiple linear regression equation model analysis of different factors of new energy electric vehicles, and using the stochastic comparison model compared the influence of new energy electric vehicles on the traditional energy vehicle industry, and establish the influence factor model, analyze the international policy influence on the development of new energy electric vehicles, in the whole research process to test and the advantages and disadvantages analysis.

Wind-Solar-Thermal Power Coupling System in The Power Market Environment Benefit Distribution Studies

With the continuous increase in the proportion of new energy, China’s power system will further increase the capacity and flexibility of new energy consumption capacity and flexibility in the future. The combined operation of renewable energy and thermal power can improve the utilization rate of renewable energy and the economy of thermal power operation to a certain extent, and is one of the effective ways to solve the problem of curtailment of wind and solar power. Based on the combing of the market mode of wind-solar-thermal coupling system, this paper discusses the game relationship between wind power, photovoltaic power and thermal power, and proposes the operation strategy of wind-solar-thermal power coupling system under the spot market; Then, with the goal of maximizing economic benefits, a two-stage stochastic optimization model was constructed in the coupled operation mode and the independent operation mode, respectively, and the contribution of the alliance members in the day-ahead market, flexibility contribution and environmental cost contribution was weighed, and the revenue distribution method between renewable energy and thermal power was proposed by introducing the market contribution index; Finally, based on the simulation and verification of a local power grid in Liaoning Province, the results show that the proposed joint operation strategy effectively improves the overall revenue level, and proposes a gain cooperative revenue distribution strategy with computational efficiency, which fully considers the contribution of each entity to the alliance for fair distribution, and is conducive to guiding the coordinated development of new energy and thermal power.

The synergy of renewable energy consumption, green technology, and environmental quality: Designing sustainable development goals policies

AbstractGreen technology (GT) and the utilization of renewable energy (RE) are widely acknowledged as a catalyst for energy efficiency, economic growth, and a tool for combating environmental degradation. Although various studies have examined the ecological repercussions of these two improvements, they have primarily used traditional pollution indicators (namely, carbon emissions and ecological footprint) and ignored nations with the highest cleaner energy adoption. To bridge this gap, the present research seeks to analyze the relationship between GT, RE consumption, economic growth, trade, and load capacity factor in the top‐10 renewable economies. In addition to environmental pollution indicators, the study utilizes the load capacity factor as a novel proxy for environmental quality and investigates the load capacity curve hypothesis using the Cross‐sectional‐autoregressive distributed lag model from 1990 to 2021. According to the empirical findings, all explanatory variables have a significant long‐term effect on the load capacity. More precisely, GT and RE consumption contribute to the sustainability of the ecosystem, while trade increases the ecological deficit. Furthermore, the findings do not support the validity of the load capacity curve hypothesis, implying that the environmental restorative benefits of economic well‐being may not manifest in the latter stages of economic growth. Given these findings, policymakers in the top‐10 renewable economies should seize the environmental prospects offered by GT and RE and update trade and growth policies in a way that promotes biocapacity while simultaneously reducing the ecological footprint to reach the long‐term sustainable development goals (SDGs), particularly SDGs 7 and 13.

FORCED INTERNAL DISPLACEMENT OF THE UKRAINIAN POPULATION: RISKS RAISED BY WAR

The large-scale war forced millions of Ukrainians to leave their homes in search of safety. The mass displacement of the population led to an increase in the level of uncertainty and raised risks for both individuals and the whole of society. This article aims to assess the scale of internal migration in Ukraine during the war and to investigate the impact of this phenomenon on the quantitative and qualitative characteristics of the labor potential and the possibilities of its use. Our assessment of the number of internally displaced persons (IDPs), and our examination of the state of their adaptation and integration in the new territories of residence are based on administrative data about the registration of citizens as IDPs provided by social services as well as the surveys and research findings by international organizations and domestic sociological institutions. We present an overview of individual challenges and risks raised by the forced displacement of the population, and highlight the specific features of their manifestation. In particular, we single out an increase in the demographic burden, a decrease in the number of people of reproductive age, a reduction in the number of jobs, an increase in the burden on the budget, a drop in labor productivity, a loss or reduction in the income of a large part of the population, a limit of access to quality social services, as well as unemployment, deterioration of the quality of employment, increased social vulnerability, and weakening of social cohesion. Risks increase the probability of negative changes that lead to uncertainty, deterioration of the demographic situation, weakening of the stability of the economy, decline in the level and quality of life of the population, deepening of social inequality, growth of social tension, decline in the consumption capacity of the population, complete or partial loss of social ties and jobs. We offer recommendations regarding priorities and specific measures of the national state policy aimed at avoiding risks and minimizing their possible consequences. The implementation of this policy should be focused on establishing legal, economic, and institutional frameworks for easing tensions in the areas of material security and employment, improving the demographic situation as well as the quality and availability of social services, and improving living conditions.

Determination of cyclic behavior of various cross-section composite column-beam connections reinforced with FRP composite using FEM analysis and ML models

ABSTRACT This study examined the cyclic behavior of glass-fiber-reinforced polymer composite column-beam connectors in various diameters. Mean learning (XGBoost and the random forest algorithm) and numerical methods were used to identify the data collected experimentally due to the rotation behavior. The initial sample had a column length of 1200 mm and a cross-section of 80 × 80 mm, with a beam section measuring 80 × 160 mm. The second sample had a 100 × 100 mm column and a beam section measuring 100 × 200 and 1200 mm, respectively. For the third sample, the column’s dimensions were 130 × 130 mm in cross-section and 1200 mm in length, and the beam was 130 × 260 mm. Spruce wood is used to make glulam components for columns and beams. Following the creation of the column-beam connections, glass-based fiber-reinforces polymer (FRP) fabric was used to wrap the column-beam connections that needed strengthening. The cyclic behavior of the reinforced reference samples and the samples with reinforced column-beam joint areas was examined. The column-beam connection with code C13B13-R has the most load-carrying capacity (13.9 kN), while the beam with code C08B08-UR has the lowest load-carrying capacity (03.4 kN). Examining the table reveals that the findings of the numerical analysis and the experiment provide comparable conclusions. When comparing experimental and numerical results, similar values are found for stiffness values (R 2 of 0.99), load-bearing capacity (R 2 of 0.99), and energy consumption capacity (R 2 of 0.99). With R 2 of 0.9978, RMSE of 0.01017, and MAE of 0.01043, the random forest approach identified the stiffness values in the model with the best accuracy. It has been shown that the seismic behavior of column-beam couplings built with these materials may be studied with mean learning models and numerical analysis, instead of demanding and time-consuming experimental studies.

Study on Physical Fitness Index BMI and VO<sub>2</sub> Max of Physical Education Students

Physical activity is human body movement of any type, while physical education programs use physical activity to teach children how to improve and sustain an active lifestyle. One of the most crucial factors to think about when evaluating a subject's cardiorespiratory efficiency is their Physical Fitness Index (PFI). The risks involved in implementing BMI for adults also affect kids and teenagers. The term "maximal oxygen consumption capacity" (VO<sub>2</sub>max) refers to the body's capacity to consume oxygen in the skeletal muscle mitochondria at a maximum rate during vigorous full-body exercise. To investigate correlation body mass index, physical fitness index and maximal oxygen capacity (VO<sub>2</sub>max) among physical education students. The investigator was selected 36 BPED students (Male: 20 & Female: 16) from University of Kalyani, Kalyani, Nadia. The age range of subject from 19 to 25 years. To conduct this study measured body mass index though Quetelet index, physical fitness index through Harvard step test and maximal oxygen capacity (VO<sub>2</sub>max) through Queens College Step test were considered. Conclusion of this present study were no significant relationship between physical fitness index and body mass index of male, female students and students as a whole. Significantly relationship between VO<sub>2</sub> max and body mass index for female students but in case of male and student as a whole found no relationship. Positive relationship between physical fitness index and VO<sub>2</sub> max for male students and student as a whole but in case of female found no relationship.

The mitochondrial function of peripheral blood mononuclear cells in frail older patients

BackgroundFrailty increases the incidence of geriatric syndromes and even the risk of death in old adults. However, the diagnostic criteria for frailty are inconsistent because of complex pathological processes and diverse clinical manifestations. To determine the effective biomarker and recognize frail status early, we investigated the correlation of mitochondrial morphology and function of human peripheral blood mononuclear cells (PBMCs) with frailty status in older adults. MethodsThis Cross-sectional study followed 393 participants (aged 25–100 years, female 31.04 %) from the First Affiliated Hospital of Nanjing Medical University. The frailty status of subjects was assessed by the physical frailty phenotype (PFP) scale. We analyzed mitochondria functions including mitochondria copy number (mtDNAcn), the mRNA expressions of mitochondrial dynamics-related genes mitofusin 1(MFN1), mitofusin 2(MFN2), optic atrophy protein-1(OPA1), fission protein-1(FIS1) and dynamin-related protein 1(DRP1), mitochondrial oxidative respiration and reactive oxygen species(ROS) levels in PBMCs. Mitochondria morphology, size, and number were observed by transmission electron microscopy (TEM). ResultsAfter adjustment for sex and BMI, mtDNAcn, the mRNA expression of FIS1, mitochondrial respiratory function (proton leak, maximum oxygen consumption, and respiratory reserve) and ROS level were significantly correlated with age (P = 0.031, 0.030, 0.042, 0.003, 0.002, 0.022, respectively). After correcting for age, sex, and BMI, mtDNAcn and the mRNA expression of OPA1 were correlated with 4 m gait speed respectively (P = 0.003, 0.028, respectively). Compared with non-frail people, mtDNAcn, the mRNA expression of MFN1, mitochondrial basal respiration, proton leak, maximum oxygen consumption, ATP production and space capacity were significantly decreased in frail older adults (P = 0.013, 0.036, 0.026, 0.024, 0.012, 0.032, 0.020, respectively). ROS levels were significantly increased in the frail group (P = 0.016). Compared with non-frail people, the number, length, and perimeter, area of mitochondria were reduced in frail group under TEM (all P < 0.001). ConclusionMitochondrial dysfunctions (decreased mtDNAcn, impaired mitochondrial morphology, imbalanced mitochondrial dynamic, impaired mitochondrial respiratory function, and increased ROS levels) were significantly correlated with frail status.

Investigation of the effect of the flow rate of coolant on the kinetics of carbon dioxide hydrate growth using sigmoidal growth model

Relaxation time plays a crucial role in studying reaction kinetics and other processes. This study addresses the importance of relaxation time and suggests methods to minimize it. In this article, we adjust the relaxation time by extracting heat from the hydrate formation process through variations in the flow rate of the cooling fluid. It has been demonstrated that heat transfer plays a dominant role in this process. The kinetics of carbon dioxide hydrate growth were evaluated by increasing the flow rate of cooling fluid using modified sigmoidal growth curve equations, including Logistics and Gompertz. It was conducted a nonlinear least-squares regression analysis to fit sigmoidal functions to the cumulative formation curves of hydrate generated from gas uptake in the static reactor over time. The percentage of error between Areal and Amodel shows that the Gompertz model with Q = 14.59 Lit/min at T = 276 K and Q = 20.25 Lit/min at T = 277 K is the best model for predicting the maximum consumption capacity of CO2. The results also showed that increasing the cooling fluid’s flow rate reduces relaxation time at any temperature. Moreover, increasing the flow rate of the cooling fluid decreased the average relaxation time by 2 % to 60 % at T = 276 K and by 7 % to 22 % at T = 277 K compared to the lowest investigated flow rate. Additionally, reducing the experimental temperature while keeping the flow rate of the cooling fluid constant led to a reduction in the relaxation time.

Ozone-Resistant Bacteria, an Inconvenient Hazard in Water Reclamation: Resistance Mechanism, Propagating Capacity, and Potential Risks.

Resistant bacteria have always been of research interest worldwide. In the urban water system, the increased disinfectant usage gives more chances for undesirable disinfection-resistant bacteria. As the strongest oxidative disinfectant in large-scale water treatment, ozone might select ozone-resistant bacteria (ORB), which, however, have rarely been reported and are inexplicit for their resistant mechanisms and physiological characteristics. In this study, six strains of ORB were screened from a water reclamation plant in Beijing. Three of them (O7, CR19, and O4) were more resistant to ozone than all previously reported ORB or even spores. The ozone consumption capacity of extracellular polymeric substances and cell walls was proved to be the main sources of bacterial ozone resistance, rather than intracellular antioxidant enzymes. The transcriptome results elucidated that strong ORB possessed a combined antioxidant mechanism consisting of the enhanced transcription of protein synthesis, protein export, and polysaccharide export genes (LptF, LptB, NodJ, LivK, LviG, MetQ, MetN, and GltU). This study confirmed the existence of ORB in urban water systems and brought doubts to the idea of a traditional control strategy against chlorine-resistant bacteria. A salient "trade-off" effect between the ozone resistance and propagation ability indicated the weakness and potential control approaches of ORB.

Seismic Performance of Recycled-Aggregate-Concrete-Based Shear Walls with Concealed Bracing

Relatively few studies have been conducted on the seismic performance of recycled aggregate concrete (RAC) shear walls with concealed bracing. To promote the development of high-performance green building structures and the application of RAC in structural components, the seismic performance of RAC shear walls under different influencing factors was tested, and low-cycle reversed loading tests were performed on ten RAC shear walls with different shear-to-span ratios. The test parameters included the recycled coarse aggregate (RCA) replacement ratio, the recycled fine aggregate (RFA) replacement ratio, the axial compression ratio, the shear span ratio and whether to set up the concealed bracing. The influence of the above variables on the seismic performance was then assessed. The results revealed that the bearing capacity, ductility, stiffness and energy dissipation capacity of the RAC shear walls decreased in line with an increase in the replacement ratio of the RFA. However, the bearing capacity, energy consumption and stiffness of the RAC shear walls decreased within 10% and the ductility decreased within 15%. The RAC shear walls were able to meet the seismic requirements of the building structure after reasonable design and use. As the axial compression ratio increased, the bearing capacity of the RAC shear walls improved, but their elastic–plastic deformation capacity was reduced. Setting the concealed bracing significantly improved the seismic performance of the RAC shear walls, such that they achieved a seismic performance close to that of the natural aggregate concrete (NAC) shear wall. After setting up the concealed bracing, the load carrying capacity of the RAC shear walls increased by up to 15%, the ductility increased by up to 20% and the energy consumption capacity increased by up to 50%. A mechanical calculation model of the RAC shear wall was then established by considering the effect of recycled aggregate, the calculated results of which were a good match with the test results.

Comparative Analysis of the Performance and Study of the Effective Anchorage Length of Semi-Grouted and Fully-Grouted Sleeve Connection

Based on the insufficient data on bonding performance and effective anchorage length of sleeve grouting in assembled structure. Combining the existing studies, the sleeve grouting joint test for the static unidirectional tensile test was designed, and the influencing factors are reinforcement diameter and reinforcement anchorage length. Then, the failure mode, load-displacement relationship, energy consumption capacity and bearing capacity of the grouting sleeve connection are analysed, and the stress mechanism of the specimen in the one-way tensile state is expounded. This paper considers the actual damage state of the joint, according to the failure of the reinforcement outside the joint and the sleeve; referring to the reinforcement-concrete bond strength research theory, the effective anchorage length formula is proposed. When the steel bar is pulled out, the bond strength and bearing capacity mainly depend on the effective anchorage length. However, when the specimen breaks the steel bar outside the joint, it depends on the material performance of the steel bar itself. The research results of this paper can lay a theoretical foundation for the application of sleeve grouting joints.

A multi-node thermodynamic model on temperature-vacuum swing adsorption (TVSA) for carbon capture: Process design and performance analysis

The adsorption technology plays a significant role in the carbon capture domain for mitigating the CO2 emissions, whereas the heterogeneous character is presented in practical adsorption process. In this study, a multi-node thermodynamic model is established for temperature-vacuum swing adsorption (TVSA) considering the end non-uniform adsorption. It shows superior performance for the assessment of practical TVSA cycle compared with lumped model. Through the influence analysis of different operation parameters based on multi-node model, specific exergy consumption increases from 41.6 to 62.4 kJ/mol caused by simultaneous drop of heat consumption and lift of work consumption as feed pressure raises from 1.0 to 3.0 bar. Exergy efficiency ranges between 13.8 % and 15.0 % as CO2 concentration increases from 10 % to 20 %. However, those under ppm-level are below 0.86 %, presenting the higher exergy consumption but lower desorption capacity represented for direct air capture. The heat consumption of front half part of adsorption bed is 39.7 % higher than the latter one, proving the potential cascaded desorption of subzone heating is superior for reducing the energy consumption. Furthermore, exergy consumption is lifted due to enhancement of work consumption of vacuum pump as vacuum pressure reduces from 1.0 to 0.02 bar, resulting exergy efficiency drops from 19.6 % to 13.4 %.

Assessment of the Renewable Energy Consumption Capacity of Power Systems Considering the Uncertainty of Renewables and Symmetry of Active Power

The rapid growth of renewable energy presents significant challenges for power grid operation, making the efficient integration of renewable energy crucial. This paper proposes a method to evaluate the power system’s capacity to accommodate renewable energy based on the Gaussian mixture model (GMM) from a symmetry perspective, underscoring the symmetrical interplay between load and renewable energy sources and highlighting the balance necessary for enhancing grid stability. First, a 10th-order GMM is identified as the optimal model for analyzing power system load and wind power data, balancing accuracy with computational efficiency. The Metropolis–Hastings (M-H) algorithm is used to generate sample spaces, which are integrated into power flow calculations to determine the maximum renewable energy integration capacity while ensuring system stability. Short-circuit ratio calculations and N-1 fault simulations validate system robustness under high renewable energy integration. The consistency between the results from the M-H algorithm, Gibbs sampling, and Monte Carlo simulation (MCS) confirms the approach’s accuracy.

Hysteretic performance of high-strength steel square hollow section T joints considering fracture behavior

The performance of high-strength steel (HSS) welding joints is crucial for tubular structure design. This paper investigates the hysteretic performance of HSS square hollow section (SHS) T joints considering fracture behaviors. The hysteresis and tensile tests of the HSS SHS T joints and a comparative analysis of failure modes and bearing capacity are conducted. Parameter analysis is conducted based on the validated FE model considering fracture and elastoplastic constitutive relationship with a wide range of parameters covered, including the cross-sectional width ratio and the wall thickness ratio between brace and chord, and the width-thickness ratio of the chord, and the seam weld size of the joint connection. The results show that fracture behavior can affect the failure mode and bearing capacity of the joints, and it cannot be ignored in the hysteresis analysis process. The energy consumption capacity and the ductility coefficients increase when β increases from 0.2 to 1.0, τ increases from 0.3 to 1.0 and 2 γ decreases from 40 to 20. Meanwhile, joints’ failure modes and residual strength vary with the above parameters. It is necessary to use the damage fracture constitutive model of steel in numerical simulation.

Battery health-considered energy management strategy for a dual-motor two-speed battery electric vehicle based on a hybrid soft actor-critic algorithm with memory function

Energy management strategies (EMSs) ease mileage anxiety and improve the health performance of battery electric vehicles (BEVs). This study proposes a soft actor-critic (SAC)-based EMS for dual-motor two-speed BEV to minimize electrical energy consumption and battery capacity losses. In addition, two optimization tricks are employed to optimize the original SAC. The linear mapping trick is integrated into the actor-network of SAC to enable agents to search for optimal EMS in a discrete (driving mode)-continuous (torque distribution) hybrid action space. The SAC-based EMS is modeled as a partially observable Markov decision process (POMDP) to obtain more information about the real state of the environment. Based on this, another optimization trick, the long short-term memory (LSTM) network, is integrated into the actor and critic of SAC to make full use of both historical and current environmental information. Simulation results show that the proposed method learns the optimal EMS, its converged episodes are shortened to the 97th, the health performance of the battery is the closest to the dynamic programming (DP)-based EMS, and maintains battery operating at a range of 30–40°C. In addition, the proposed EMS has the best adaptability in test cycles, reaching 99.42% and 99.29% of DP-based EMS, respectively.

Two-layer optimal scheduling method for regional integrated energy system considering flexibility characteristics of CHP system

A regional integrated energy system (RIES) guarantees the fulfillment of a diversified load demand of users by coordinating all types of energy equipment and is a two-layer optimal scheduling method that takes into consideration the flexibility of the characteristics of the combined heat and power (CHP) system is proposed in this paper. First, the thermoelectric output characteristics of hydrogen fuel cell (HFC) and CHP units are analyzed to establish an energy equipment model that takes into consideration the variability of the operating conditions. Subsequently, a two-layer optimal scheduling model of the RIES is established, where the upper layer takes into consideration the operating costs, carbon emission penalties, and renewable energy consumption capacity to determine the strategy for allocating the energy flow, and the lower layer considers the energy efficiency as the optimization objective to determine the output modes of the HFC and CHP units. Finally, an adaptive closed-loop control strategy is used to avoid the continuous startup and shutdown of the CHP unit. The simulation results show that the proposed method can effectively reduce operating costs and carbon emissions, improve energy efficiency and renewable energy consumption, and promote the efficient utilization of integrated energy resources.

Design and Characterization of a Wearable Inertial Measurement Unit.

The utilization of inertial measurement units as wearable sensors is proliferating across various domains, such as health care, sports, and rehabilitation. This expansion has produced a market of devices tailored to accommodate very specific ranges of operational demands. Simultaneously, this growth is creating opportunities for the development of a new class of devices more oriented towards general-purpose use and capable of capturing both high-frequency signals for short-term, event-driven motion analysis and low-frequency signals for extended monitoring. For such a design, which combines flexibility and low cost, a rigorous evaluation of the device in terms of deviation, noise levels, and precision is essential. This evaluation is crucial for identifying potential improvements and refining the design accordingly, yet it is rarely addressed in the literature. This paper presents the development process of such a device. The results of the design process demonstrate acceptable performance in optimizing energy consumption and storage capacity while highlighting the most critical optimizations needed to advance the device towards the goal of a smart, general-purpose unit for human motion monitoring.

Experimental Study on a Damage-Control and Repairable Fully Precast Beam-Column Joint

ABSTRACT A novel joint with a splice lap was proposed, which was damage-control and repairable fully precast beam-column joint (DRBJ) connected by energy-dissipating connecting steel plates to remarkably diminish the residual displacement of an RC frame under strong earthquakes and ensure the rapid rehabilitation of the structure. Four one-half scale beam-column-joint specimens were designed and fabricated in different connection forms and lap lengths, and one of the specimens was loaded again under the same conditions after repair. Low cyclic loading tests on DRBJ were conducted to investigate their hysteresis curves and energy-dissipation capacities. The test results revealed that the plastic deformation of DRBJ was concentrated on connecting steel plates, while the residual displacement was small. The deformation and bearing capacities of the short-lap joint were higher than those of the long-lap junction, and the bearing, energy consumption, and deformation capacities of the DRBJ connected by strip plates were still superior to those of the DRBJ connected by the rectangular plates. The DRBJ showed satisfactory repairability and energy-dissipation capacity with the help of the strip plates. A simplified force–displacement model was established based on the analysis of the functioning mechanism of DRBJ. The calculated results of the rotational stiffness and the test results agree well, which can provide a reference for the design of this type of splice joint.

Identification and molecular mechanism of novel hypoglycemic peptide in ripened pu-erh tea: Molecular docking, dynamic simulation, and cell experiments

Ripened pu-erh tea is known to have beneficial hypoglycemic properties. However, it remains unclear whether the bioactive peptides produced during fermentation are also related to hypoglycemic potential. This study aimed to identify hypoglycemic peptides in ripened pu-erh tea and to elucidate their bioactive mechanisms using physicochemical property prediction, molecular docking, molecular dynamics simulations, and cell experiments. Thirteen peptides were identified by liquid chromatography–mass spectrometry/mass spectrometry (LC-MS/MS). Among them, AADTDYRFS (AS-9) and AGDGTPYVR (AR-9) exhibited high α-glucosidase inhibitory activity, with half-maximal inhibitory concentration (IC50) values of 0.820 and 3.942 mg/mL, respectively. Molecular docking and dynamics simulations revealed that hydrogen bonding, hydrophobic interactions, and van der Waals forces assist peptides AS-9 and AR-9 in forming stable and tight complexes with α-glucosidase. An insulin-resistance (IR)-HepG2 cell model was established. AS-9 was non-toxic to IR-HepG2 cells and significantly increased the glucose consumption capacity, hexokinase, and pyruvate kinase activities of IR-HepG2 cells (p < 0.05). AS-9 alleviated glucose metabolism disorders and ameliorated IR by activating the IRS-1/PI3K/Akt signaling pathway and increasing the expression levels of MDM2, IRS-1, Akt, PI3K, GLUT4, and GSK3β genes. In addition, no hemolysis of mice red blood cells red blood cells occurred at concentrations below 1 mg/mL. This work first explored hypoglycemic peptides in ripened pu-erh tea, providing novel insights for enhancing its functional value.