Leptin signaling and its central role in energy homeostasis

Leptin plays a critical role in regulating appetite, energy expenditure and body weight, making it a key factor in maintaining a healthy balance. Despite numerous efforts to develop therapeutic interventions targeting leptin signaling, their effectiveness has been limited, underscoring the importance of gaining a better understanding of the mechanisms through which leptin exerts its functions. While the hypothalamus is widely recognized as the primary site responsible for the appetite-suppressing and weight-reducing effects of leptin, other brain regions have also been increasingly investigated for their involvement in mediating leptin’s action. In this review, we summarize leptin signaling pathways and the neural networks that mediate the effects of leptin, with a specific emphasis on energy homeostasis

Knowledge, Attitudes, And Practices Related To The Establishment Of The National Hierarchical Medical System (Nhms) Among Outpatients In Chinese Tertiary Hospitals

This study sought to assess the status of, and factors associated with, knowledge, attitudes, and practices (KAP) related to the establishment of the National Hierarchical Medical System (NHMS) among outpatients receiving care in tertiary hospitals in China. A cross-sectional study surveying tertiary outpatients was conducted. This study investigated KAP concerning the establishment of the NHMS among outpatients from tertiary hospitals, who could have sought medical care from a general practitioner in surrounding primary care medical institutions. Several factors associated with outpatients’ knowledge were identified and included in fully adjusted analyses using logistic regression. Survey questionnaires were completed by 565 outpatients in 4 tertiary hospitals. Approximately half (51.86%) of the sample was aware of the NHMS. In multivariable analysis sex, age, education level, and place of residence were associated (P \u3c .05) with knowledge of NHMS. Overall 74.69% of respondents expressed positive attitudes toward the establishment of the NHMS. However, a much lower proportion, 21.95%, was willing to choose nearby grassroots sub-unit hospitals as their first choice when seeking health care. The present study revealed outpatients in China may lack knowledge of the NHMS, yet most have a positive attitude toward the establishment of the NHMS. Even so, there was hesitation in terms of seeking care from the NHMS, indicating the need for policy makers to take action to increase public awareness surrounding NHMS-related information to improve the public’s KAP on the establishment of the NHMS. This study highlights information useful for policy makers in China and other countries planning or evaluating related policies

A comprehensive control strategy for photovoltaic virtual synchronous generator considering frequency regulation capability

The existing photovoltaic frequency regulation strategies do not take into account the differences in the frequency regulation capability. So they cannot fully exploit the support capacity to the grid frequency. For the purpose of improving the control precision and regulation effect of PV, a comprehensive control strategy for photovoltaic virtual synchronous generator (PV-VSG) is proposed, which accurately considers the frequency regulation capability. First, the inertia regulation margin, power regulation speed and power regulation margin are taken as the evaluation index of frequency regulation capability of PV. Then, the frequent deviation-free control strategy with integral link and the multiple control modes switching strategy are proposed, whose control parameters are designed according to the frequency regulation capability. In the simulation verification, the proposed method reduces the frequency deviation by 0.11 Hz compared to existing strategies, and can quickly recover to the normal value. At the same time, the frequency regulation utilizes the capability of the PVs, which also validates the effectiveness of the proposed strategy

An adaptive multi‐mode switching control strategy to improve the stability of virtual synchronous generator with wide power grid strengths variation

Abstract With the increasing proportion of renewable power generations in the power system, the power grid impedance may fluctuate greatly, and it is difficult for the virtual synchronous generator (VSG) with a single control structure to meet the stability requirements. Thus, the control principles of the two types of VSGs are compared to conclude that there are similarities in the control structure of the two VSGs. And the small signal models of the two types of VSGs are established to analyze the stability boundaries, coming to the conclusion that the stability region is complementary. Based on the conclusions, the paper puts forward the idea of switching operation modes: switch to the U‐VSG mode when the grid strength weakens and switch to the PQ‐VSG mode when greater, so that the inverter can keep stable in a wider range of grid strength. Therefore, the characterization method of the switching boundary with hysteresis properties is proposed. Then the improved recursive least squares (RLS) algorithm is introduced to identify the power grid impedance online without additional injected disturbance, based on which the adaptive multi‐mode smooth switching control strategy is proposed. Finally, the effectiveness of the analysis and the control strategy are verified by simulations

Mental Health of the Prison Medical Workers (PMWs) and Influencing Factors in Jiangxi, China

Prison medical workers (PMWs) are critically important, but they are also vulnerable to psychological problems. Currently, there is no study on examining PMWs’ mental health conditions and possible influencing factors in China. Hence, we conducted this cross-sectional survey, aiming to understand the mental health status of the PMWs and related impact factors in Jiangxi province of China. We employed the Chinese version of the Symptom Checklist-90-R (SCL-90-R) to assess the mental disorders and psychological health conditions of PMWs in Jiangxi. The t tests were used to compare the differences for the average score of SCL-90-R between the Chinese general population and targeted PMWs of this study. Multivariable logistic regression analyses were conducted to identify the main factors associated with overall detection rate of PMWs’ psychological health conditions. The scores of four dimensions (somatization, obsessive-compulsive symptoms, anxiety, and paranoid ideation) were significantly higher than the Chinese national norm, and the total positive rate was 49.09% among the PMWs. Gender, marital status, age, and length of employment are identified to be the most significant predictors to affect PMWs’ mental health. Positive correlations between each of the nine dimensions of the SCL-90-R have been verified. This study demonstrated for the first time that PMWs are facing mental health risk and suffering serious psychological problems with psychopathology symptoms, which has become a growing concern in China. Our current findings suggest a need for more in-depth studies on this subject going forward to validate our conclusions and also to identify more impact factors, since such studies and knowledge of PMWs’ mental health and influencing factors are very limited in China

Curcumin Inhibits the PERK-eIF2α-CHOP Pathway through Promoting SIRT1 Expression in Oxidative Stress-induced Rat Chondrocytes and Ameliorates Osteoarthritis Progression in a Rat Model

Oxidative stress plays a crucial role in the occurrence and development of osteoarthritis (OA) through the activation of endoplasmic reticulum (ER) stress. Curcumin is a polyphenolic compound with significant antioxidant and anti-inflammatory activity among various diseases. To elucidate the role of curcumin in oxidative stress-induced chondrocyte apoptosis, this study investigated the effect of curcumin on ER stress-related apoptosis and its potential mechanism in oxidative stress-induced rat chondrocytes. The results of flow cytometry and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining showed that curcumin can significantly attenuate ER stress-associated apoptosis. Curcumin inhibited the expression of cleaved caspase3, cleaved poly (ADP-ribose) polymerase (PARP), C/EBP homologous protein (CHOP), and glucose-regulated protein78 (GRP78) and upregulated the chondroprotective protein Bcl2 in TBHP-treated chondrocytes. In addition, curcumin promoted the expression of silent information regulator factor 2-related enzyme 1 (SIRT1) and suppressed the expression of activating transcription factor 4 (ATF4), the ratio of p-PERK/PERK, p-eIF2α/eIF2α. Our anterior cruciate ligament transection (ACLT) rat OA model research demonstrated that curcumin (50 mg/kg and 150 mg/kg) ameliorated the degeneration of articular cartilage and inhibited chondrocyte apoptosis in ACLT rats in a dose-dependent manner. By applying immunohistochemical analysis, we found that curcumin enhanced the expression of SIRT1 and inhibited the expression of CHOP and cleaved caspase3 in ACLT rats. Taken together, our present findings firstly indicate that curcumin could inhibit the PERK-eIF2α-CHOP axis of the ER stress response through the activation of SIRT1 in tert-Butyl hydroperoxide- (TBHP-) treated rat chondrocytes and ameliorated osteoarthritis development in vivo

SAW: an efficient and accurate data analysis workflow for Stereo-seq spatial transcriptomics

The basic analysis steps of spatial transcriptomics require obtaining gene expression information from both space and cells. The existing tools for these analyses incur performance issues when dealing with large datasets. These issues involve computationally intensive spatial localization, RNA genome alignment, and excessive memory usage in large chip scenarios. These problems affect the applicability and efficiency of the analysis. Here, a high-performance and accurate spatial transcriptomics data analysis workflow, called Stereo-seq Analysis Workflow (SAW), was developed for the Stereo-seq technology developed at BGI. SAW includes mRNA spatial position reconstruction, genome alignment, gene expression matrix generation, and clustering. The workflow outputs files in a universal format for subsequent personalized analysis. The execution time for the entire analysis is ∼148 min with 1 GB reads 1 × 1 cm chip test data, 1.8 times faster than with an unoptimized workflow