The functional realization of proteins and other biological macromolecules depends on conformational dynamics and allosteric regulation, and elucidating their molecular mechanisms is an important foundation for understanding life processes. Molecular dynamics simulations are a powerful tool for investigating conformational evolution at the atomic level. However, traditional methods are limited by simulation timescales and high free-energy barriers, making it difficult to effectively capture rare conformations and their transition pathways. As a result, the development of enhanced sampling techniques has become key to overcoming this bottleneck. As a classical enhanced sampling technique, metadynamics suffers from several shortcomings, including strong dependence on collective variables and significant errors caused by bias potential accumulation. This article reviews three major improvement strategies. The first combines stochastic resetting with metadynamics, using trajectory-resetting mechanisms to improve sampling efficiency while avoiding the difficulty of optimizing collective variables. The second, SinkMeta, employs a “sinking” bias effect to enable efficient exploration of specific regions and paths. The third, OPES-based hybrid methods, improve the stability of free-energy estimation by optimizing the target distribution or the way the bias is constructed. These methods provide new ideas for characterizing free-energy landscapes and studying conformational transitions in complex biological systems, while also promoting the continued development of enhanced sampling methodologies.

AIM:To investigate whether melatonin can ameliorate acute myocardial infarction(AMI)by in-hibiting ferroptosis.METHODS:H9C2 cells were cultured in AnaeroPack system with low sugar and serum-free medium for 10 h to construct a cell model of AMI.Then cells were treated with melatonin and ferroptosis inducer erastin.The cell activity,reactive oxygen species(ROS),lipid peroxidation,mitochondrial membrane potential(MMP),and ferroptosis related protein expression were detected.A rat model of AMI induced by isoprenaline(ISO)injection was established to evaluate the effects of melatonin,in which the myocardial infarction size,cardiac injury,pathological changes,oxidative stress,iron ion and ferroptosis related protein expression were examined.RESULTS:Melatonin decreased the oxidative stress,lipid peroxidation and expression of ferroptosis protein in cardiomyocytes induced by hypoxia,but these effects could be impeded by the ferroptosis inducer erastin.Furthermore,in vivo experiments,we also found that melatonin im-proved the myocardial infarction size,cardiac injury,pathological changes,oxidative stress,and alleviated iron ion accu-mulation and ferroptosis.CONCLUSION:The cardioprotective effects of melatonin in AMI are associated with the inhi-bition of ferroptosis.

Aim To investigate the effect of cordycepin(COR)on gentamicin(GEN)-induced nephrotoxicity and the molecular mechanism of inhibiting oxidative stress and ferroptosis induced by GEN.Methods The oral SD rats were divided into a control group,GEN group,and GEN+COR group.Following the success-ful setting up of the animal model,the serum creatinine(CR)and urea nitrogen(BUN)levels of rats were measured,and renal tissue injury was assessed using HE staining.In addition,the contents of malondialde-hyde and glutathione in kidney tissues of SD rats in each group were detected,and the expressions of fer-roptosis markers GPX4 and SLC7A11 were analyzed by Western blot.Results Compared with the control group,CR and BUN in GEN-stimulated group signifi-cantly increased(P＜0.01),and the level of CR and BUN was effectively reduced after 50 mg·kg-1 COR oral administration.HE results also showed that COR could alleviate the kidney tissue damage caused by GEN.COR could reverse the increase of malondialde-hyde level and the decrease of glutathione level caused by GEN in rat kidney tissue,and COR could restore the decrease of GPX4 and SLC7A11 protein levels induced by GEN.Conclusion COR can reduce GEN-induced kidney injury by inhibiting oxidative stress and ferrop-tosis.

Objective To propose an improved Y OLOv8-based visible small target detection method to solve the problems of the UAV visible light system in accuracy and timeliness when applied to measuring small targets.Methods A YOLOv8 network consisting of Backbone,Neck and Head was used as the base framework to construct an AGC-YOLO model.Firstly,a convolutional block attention module(CBAM)was incorporated into Backbone to improve the feature expression of the model;secondly,some traditional convolution modules were replaced with the changeable kernel convolution module AKconv to reduce the network parameters;finally,a Gold-YOLO module was involved in Neck to enhance the detection ability for targets with different sizes.VisDrone2019 dataset was used to carry out ablation and comparison experiments,and the efficacy of the AGC-YOLO model for detecting small targets was evaluated in terms of mean average precision(mAP),frames per second(FPS),giga floating-point operations per second(GFLOPs)and parameters.Results The AGC-YOLO model had the FPS,GFLOPs and parameters being 31.90,9.20 and 11.30 M respectively,meeting the real-time detection speed requirements of drones(FPS not lower than 30),in which the mAP50(the mAP with the intersection over union being 0.5)was increased by 15％,6％and 5％when compared with those of the lightweight YOLOv8n,Ghost-YOLO and YOLO-BiFPN models.Conclusion The method proposed behaves well in speed,decreased parameters and precision,and is worthy promoting for UAV visible small target detection.[Chinese Medical Equipment Journal,2025,46(1):1-6]

AIM:To investigate whether melatonin can ameliorate acute myocardial infarction(AMI)by in-hibiting ferroptosis.METHODS:H9C2 cells were cultured in AnaeroPack system with low sugar and serum-free medium for 10 h to construct a cell model of AMI.Then cells were treated with melatonin and ferroptosis inducer erastin.The cell activity,reactive oxygen species(ROS),lipid peroxidation,mitochondrial membrane potential(MMP),and ferroptosis related protein expression were detected.A rat model of AMI induced by isoprenaline(ISO)injection was established to evaluate the effects of melatonin,in which the myocardial infarction size,cardiac injury,pathological changes,oxidative stress,iron ion and ferroptosis related protein expression were examined.RESULTS:Melatonin decreased the oxidative stress,lipid peroxidation and expression of ferroptosis protein in cardiomyocytes induced by hypoxia,but these effects could be impeded by the ferroptosis inducer erastin.Furthermore,in vivo experiments,we also found that melatonin im-proved the myocardial infarction size,cardiac injury,pathological changes,oxidative stress,and alleviated iron ion accu-mulation and ferroptosis.CONCLUSION:The cardioprotective effects of melatonin in AMI are associated with the inhi-bition of ferroptosis.

Aim To investigate the effect of cordycepin(COR)on gentamicin(GEN)-induced nephrotoxicity and the molecular mechanism of inhibiting oxidative stress and ferroptosis induced by GEN.Methods The oral SD rats were divided into a control group,GEN group,and GEN+COR group.Following the success-ful setting up of the animal model,the serum creatinine(CR)and urea nitrogen(BUN)levels of rats were measured,and renal tissue injury was assessed using HE staining.In addition,the contents of malondialde-hyde and glutathione in kidney tissues of SD rats in each group were detected,and the expressions of fer-roptosis markers GPX4 and SLC7A11 were analyzed by Western blot.Results Compared with the control group,CR and BUN in GEN-stimulated group signifi-cantly increased(P＜0.01),and the level of CR and BUN was effectively reduced after 50 mg·kg-1 COR oral administration.HE results also showed that COR could alleviate the kidney tissue damage caused by GEN.COR could reverse the increase of malondialde-hyde level and the decrease of glutathione level caused by GEN in rat kidney tissue,and COR could restore the decrease of GPX4 and SLC7A11 protein levels induced by GEN.Conclusion COR can reduce GEN-induced kidney injury by inhibiting oxidative stress and ferrop-tosis.

Objective:To investigate the risk factors and prognosis of postoperative atrial fibrillation(POAF) and delayed-onset POAF(dPOAF).Methods:In a retrospective cohort study involving consecutive patients who underwent cardiac surgery across provincial cardiovascular consortium consisted of 57 hospitals in Jiangsu Province from January 2015 to December 2022, the incidence and implications of dPOAF were examined. dPOAF was defined as being diagnosed within 30 days of discharge.Results:Among 2 788 patients with postoperative new-onset POAF, 154(5.5%)cases had dPOAF, median onset time 21(15, 26)days following surgery. Compared to in-patient diagnosed POAF, dPOAF was associated with increased rates of hypertension(28.6% vs. 9.0%, P<0.001), diabetes(10.4% vs. 3.2%, P<0.001), heart failure(39.6% vs. 19.3%, P<0.001), peripheral vascular disease(13.6% vs. 2.2%, P<0.001), and higher CHA2DS2-VASc score(≥2)(59.8% vs. 43.2%, P<0.001). Female patients were less likely to develop dPOAF( OR=0.44, 95% CI: 0.30-0.63, P<0.001). During follow-up period, there was no significant difference in major adverse cardiovascular events(MACEs)( HR=1.33, 95% CI: 0.82-2.17), overall mortality( HR=0.58, 95% CI: 0.07-4.67), or thromboembolism events( HR=0.57, 95% CI: 0.26-1.25). Conclusion:This study underscores the risk factors and prognosis associated with dPOAF compared to in-hospital POAF. It highlights the imperative for vigilant monitoring and individualized management strategies tailored to patients at risk of dPOAF.

BACKGROUND AND OBJECTIVE: Patients with glioma experience a high symptom burden and have diverse palliative care needs. However, the assessment scales used in palliative care remain non-standardized and highly heterogeneous. To evaluate the application patterns of the current scales used in palliative care for glioma, we aim to identify gaps and assess the need for disease-specific scales in glioma palliative care. METHODS: We conducted a systematic search of five databases including PubMed, Web of Science, Medline, EMBASE, and CINAHL for quantitative studies that reported scale-based assessments in glioma palliative care. We extracted data on scale characteristics, domains, frequency, and psychometric properties. Quality assessments were performed using the Cochrane ROB 2.0 and ROBINS-I tools. RESULTS: Of the 3,405 records initially identified, 72 studies were included. These studies contained 75 distinct scales that were used 193 times. Mood (21.7%), quality of life (24.4%), and supportive care needs (5.2%) assessments were the most frequently assessed items, exceeding half of all scale applications. Among the various assessment dimensions, the Distress Thermometer (DT) was the most frequently used tool for assessing mood, while the Short Form-36 Health Survey Questionnaire (SF-36) was the most frequently used tool for assessing quality of life. The Mini Mental Status Examination (MMSE) was the most common tool for cognitive assessment. Performance status (5.2%) and social support (6.8%) were underrepresented. Only three brain tumor-specific scales were identified. Caregiver-focused scales were limited and predominantly burden-oriented. CONCLUSIONS: There are significant heterogeneity, domain imbalances, and validation gaps in the current use of assessment scales for patients with glioma receiving palliative care. The scale selected for use should be comprehensive and user-friendly.
Humans ; Glioma/psychology* ; Palliative Care/methods* ; Quality of Life ; Psychometrics ; Brain Neoplasms/psychology*

Extensive epigenetic reprogramming involves in memory CD8+ T-cell differentiation. The elaborate epigenetic rewiring underlying the heterogeneous functional states of CD8+ T cells remains hidden. Here, we profile single-cell chromatin accessibility and map enhancer-promoter interactomes to characterize the differentiation trajectory of memory CD8+ T cells. We reveal that under distinct epigenetic regulations, the early activated CD8+ T cells divergently originated for short-lived effector and memory precursor effector cells. We also uncover a defined epigenetic rewiring leading to the conversion from effector memory to central memory cells during memory formation. Additionally, we illustrate chromatin regulatory mechanisms underlying long-lasting versus transient transcription regulation during memory differentiation. Finally, we confirm the essential roles of Sox4 and Nrf2 in developing memory precursor effector and effector memory cells, respectively, and validate cell state-specific enhancers in regulating Il7r using CRISPR-Cas9. Our data pave the way for understanding the mechanism underlying epigenetic memory formation in CD8+ T-cell differentiation.
CD8-Positive T-Lymphocytes/metabolism* ; Cell Differentiation ; Chromatin/immunology* ; Animals ; Mice ; Immunologic Memory ; Epigenesis, Genetic ; SOXC Transcription Factors/immunology* ; NF-E2-Related Factor 2/immunology* ; Mice, Inbred C57BL ; Gene Regulatory Networks ; Enhancer Elements, Genetic

Objective To propose an improved Y OLOv8-based visible small target detection method to solve the problems of the UAV visible light system in accuracy and timeliness when applied to measuring small targets.Methods A YOLOv8 network consisting of Backbone,Neck and Head was used as the base framework to construct an AGC-YOLO model.Firstly,a convolutional block attention module(CBAM)was incorporated into Backbone to improve the feature expression of the model;secondly,some traditional convolution modules were replaced with the changeable kernel convolution module AKconv to reduce the network parameters;finally,a Gold-YOLO module was involved in Neck to enhance the detection ability for targets with different sizes.VisDrone2019 dataset was used to carry out ablation and comparison experiments,and the efficacy of the AGC-YOLO model for detecting small targets was evaluated in terms of mean average precision(mAP),frames per second(FPS),giga floating-point operations per second(GFLOPs)and parameters.Results The AGC-YOLO model had the FPS,GFLOPs and parameters being 31.90,9.20 and 11.30 M respectively,meeting the real-time detection speed requirements of drones(FPS not lower than 30),in which the mAP50(the mAP with the intersection over union being 0.5)was increased by 15％,6％and 5％when compared with those of the lightweight YOLOv8n,Ghost-YOLO and YOLO-BiFPN models.Conclusion The method proposed behaves well in speed,decreased parameters and precision,and is worthy promoting for UAV visible small target detection.[Chinese Medical Equipment Journal,2025,46(1):1-6]