3CL protease (3CLpro) of SARS-CoV-2 is a pivotal enzyme required in coronavirus replication and transcription. Its highly conserved structure and the absence of homologous proteins in the host make it an ideal target for broad-spectrum anti-coronavirus drug development. In this work, we systematically investigated and compared the binding modes and dynamic properties of the four stereoisomers of a pyridyl-urea diyne ester (PyDU) molecule with two chiral centers within the 3CLpro active site. Through molecular docking, MD simulations, MM/GBSA binding free-energy calculations, and DCCM analysis, all four stereoisomers were stabilized primarily by hydrophobic packing. Among them, the (R,S) isomer exhibited the best overall performance, including docking score, binding free-energy components, and key residue interactions. The (R,S) and (S,R) isomers also enhanced the cooperative motions around the binding pocket, while the (R,S) isomer further modulated the flexibility of domain III, which may influence 3CLpro dimerization. Conversely, the (S,S) isomer exhibited the weakest affinity due to insufficient hydrophobic contact. By innovatively integrating chirality, binding energy and protein dynamical features, we revealed the dual role of chirality in modulating affinity and dynamic responses, which provides a theoretical basis for the chiral-guided design of coronavirus inhibitors.

Diabetic tendinopathy is a common and disabling musculoskeletal complication of diabetes, clinically characterized by tendon thickening, pain, impaired healing capacity and compromised biomechanical performance, collectively undermining joint function and quality of life. Its pathogenesis is multifactorial. On the one hand, chronic hyperglycaemia promotes the abnormal accumulation of advanced glycation end products (AGEs) within tendon collagen, leading to non-enzymatic crosslinking and engagement of the receptor for AGEs (RAGE), which in turn triggers inflammasome activation and sustains inflammatory responses. On the other hand, the diabetic milieu disrupts collagen metabolic homeostasis, impairs microvascular function and induces peripheral neuropathy; together, these alterations drive extracellular matrix degeneration and weaken the mechanical properties of tendon. Exercise, as a non-pharmacological intervention, can ameliorate these pathological changes through multiple integrated mechanisms. First, exercise attenuates tendon inflammation and restores microenvironmental homeostasis. Regular physical activity reduces AGE-RAGE signalling, thereby suppressing downstream expression of tumour necrosis factor (TNF) and interleukin-1β (IL-1β), while upregulating the anti-inflammatory cytokine interleukin-10 (IL-10). This shift from a pro-inflammatory to a pro-resolving milieu not only restrains chronic inflammation but may also limit excessive inflammasome activation in tenocytes and tissue-resident immune cells. Second, exercise enhances local expression of insulin-like growth factor 1 (IGF-1), thereby activating the phosphoinositide 3-kinase (PI3K)-protein kinase B (Akt) signalling pathway. This axis stimulates tenocyte proliferation, augments synthesis of type I collagen —— the principal load-bearing component of tendon —— and thereby promotes tissue repair, preserves tensile strength and supports matrix synthesis and structural integrity. In addition, exercise improves blood supply and nutrient delivery to tendon by increasing the expression of vascular endothelial growth factor (VEGF), connective tissue growth factor (CTGF) and the small leucine-rich proteoglycan decorin (DCN), thereby enhancing capillary growth, coordinating collagen fibrillogenesis and actively suppressing pathological vascular calcification. Exercise also increases the expression of angiopoietin-like 4 (ANGPTL4), fibroblast growth factor 2 (FGF-2) and CD34. Through the concerted actions of these factors, exercise promotes angiogenesis, restores the microvascular network and ensures adequate oxygen and nutrient supply to relatively ischaemic tendon tissue. Finally, exercise elevates levels of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), supporting neuronal survival, axonal growth and the function of sensory and sympathetic nerve endings within tendon, thereby exerting neurotrophic and neuromodulatory effects and improving tendon innervation and neuromuscular control. Moreover, exercise upregulates collapsin response mediator protein 2 (CRMP-2), a molecule involved in axonal guidance and regeneration, and moderately increases the activity of substance P (SP), thereby helping to regulate neurogenic inflammation, pain perception and trophic support for tenocytes. Drawing together current evidence, this review systematically summarizes the mechanisms underlying diabetic tendinopathy and examines the mechanistic basis of exercise intervention, with the aim of providing a theoretical framework for the development of precise exercise strategies for affected individuals. However, several key issues remain unresolved: the therapeutic efficacy and mechanistic specificity of different exercise modalities in diabetic tendinopathy have yet to be defined, and early diagnostic biomarkers remain insufficiently characterized. Future studies should apply multi-omics approaches to profile AGE subtypes, miRNA signatures and collagen metabolic products, and should also clarify the adverse effects and underlying mechanisms of excessive exercise or mechanical overloading in diabetic tendinopathy. Such efforts will further elucidate the therapeutic effects and mechanisms of exercise in diabetic tendinopathy and provide a stronger basis for precision exercise prescription and fitness guidance in patients with diabetes.

Aim To study the mechanism of salidro-side combined with rosavin in rats with ischemic stroke.Methods The MCAO rats was established by using thread-embolic method.The rats were divided into the sham group,MCAO group,salidroside com-bined with rosavin group,and positive control group;the drug was given continuously for seven days.Western blot was used to detect apoptosis indicators.Proteomics was used to analyse differential proteins(DEPs).STEP receptor inhibitor was injected into the lateral ventricles,the rats were administered for seven days,then the apoptosis indicators were detected.Re-sults Salidroside combined with rosavin could reduce neurological function scores in MCAO rats and inhibit cell apoptosis.Quantitative proteomics identified 496 DEPs in brain tissue and discovered core proteins STEP,p38,and CRTC1.Salidroside combined with rosavin could promote the STEP and CRTC1 while in-hibiting p38 protein.After treatment with STEP inhibi-tor,those effects were reversed.Conclusion Salidro-side combined with rosavin can inhibit cell apoptosis in MCAO rats,which is closely related to the regulation of the STEP/p38/CRTC1 signaling pathway.

OBJECTIVE: Several epidemiological observational studies have related particulate matter (PM) exposure to Inflammatory bowel disease (IBD), but many confounding factors make it difficult to draw causal links from observational studies. The objective of this study was to explore the causal association between PM _2.5 exposure, its absorbance, and IBD. METHODS: We assessed the association of PM _2.5 and PM _2.5 absorbance with the two primary forms of IBD (Crohn's disease [CD] and ulcerative colitis [UC]) using Mendelian randomization (MR) to explore the causal relationship. We conducted two-sample MR analyses with aggregated data from the UK Biobank genome-wide association study. Single-nucleotide polymorphisms linked with PM _2.5 concentrations or their absorbance were used as instrumental variables (IVs). We used inverse variance weighting (IVW) as the primary analytical approach and four other standard methods as supplementary analyses for quality control. RESULTS: The results of MR demonstrated that PM _2.5 had an adverse influence on UC risk (odds ratio [ OR] = 1.010; 95% confidence interval [ CI] = 1.001-1.019, P = 0.020). Meanwhile, the results of IVW showed that PM _2.5 absorbance was also causally associated with UC ( OR = 1.012; 95% CI = 1.004-1.019, P = 0.002). We observed no causal relationship between PM _2.5, PM _2.5 absorbance, and CD. The results of sensitivity analysis indicated the absence of heterogeneity or pleiotropy, ensuring the reliability of MR results. CONCLUSION Based on two-sample MR analyses, there are potential positive causal relationships between PM _2.5, PM _2.5 absorbance, and UC.
Humans ; Mendelian Randomization Analysis ; Particulate Matter/analysis* ; Polymorphism, Single Nucleotide ; Inflammatory Bowel Diseases/genetics* ; Air Pollutants/analysis* ; Crohn Disease/genetics* ; Colitis, Ulcerative/genetics* ; Genome-Wide Association Study ; Risk Factors ; Environmental Exposure

Aim To study the mechanism of salidro-side combined with rosavin in rats with ischemic stroke.Methods The MCAO rats was established by using thread-embolic method.The rats were divided into the sham group,MCAO group,salidroside com-bined with rosavin group,and positive control group;the drug was given continuously for seven days.Western blot was used to detect apoptosis indicators.Proteomics was used to analyse differential proteins(DEPs).STEP receptor inhibitor was injected into the lateral ventricles,the rats were administered for seven days,then the apoptosis indicators were detected.Re-sults Salidroside combined with rosavin could reduce neurological function scores in MCAO rats and inhibit cell apoptosis.Quantitative proteomics identified 496 DEPs in brain tissue and discovered core proteins STEP,p38,and CRTC1.Salidroside combined with rosavin could promote the STEP and CRTC1 while in-hibiting p38 protein.After treatment with STEP inhibi-tor,those effects were reversed.Conclusion Salidro-side combined with rosavin can inhibit cell apoptosis in MCAO rats,which is closely related to the regulation of the STEP/p38/CRTC1 signaling pathway.

A mounting body of research suggests that circRNAs significantly contribute to the develop-ment of myocardial fibrosis.The microarray results of human circular RNA expression profile indicated that circHERC4_041 expression increased in the myocardium of patients with heart failure,RT-qPCR a-nalysis confirmed that the myocardial expression level of circHERC4_041 in individuals with heart failure were considerably elevated compared to that in healthy organ donors.Fluorescence in situ hybridization(FISH)confirmed that circHERC4_041 was abundant in the cytoplasm of human cardiomyocyte AC16.Overexpression of circHERC4_041 in mouse myocardial fibroblasts(mCFs)mediated by adenovirus in-hibited the expression of fibrosis-related proteins in mCFs.Experiments involving cell proliferation,wound healing,and Transwell assays demonstrated that overexpression of circHERC4_041 suppressed the growth and mobility of mCFs(P＜0.001).Sequence analysis results suggested that circHERC4_041 con-tains potential ribosome entry sequence(IRES)and open reading frame(ORF).Western blot confirmed that circHERC4_041 could translate the 516 amino acid HERC4-516aa protein,which was mainly located in the cytoplasm of the cell.Cell functional experiments confirmed that circHERC4_041 inhibited the fi-brotic phenotype of mCFs by specifically translating HERC4-516aa(P＜0.05).The specific interaction between HERC4-516aa and transglutaminase 2(TGM2)was confirmed by IP-MS screening and Co-IP i-dentification.Further results found that the degradation of TGM2 was promoted through proteasome path-way.The overexpression of TGM2 in mCFs facilitated by adenoviral vectors could counteract the suppres-sive effects of HERC4-516aa on the fibrotic phenotype of mCFs.Therefore,this study confirmed that the HERC4-516aa protein translated by circHERC4_041 can specifically bind to TGM2 to inhibit the fibrotic phenotype of myocardial fibroblasts.

Objective:To investigate clinical application effect of 5E rehabilitation management combined with health education knowledge in elderly patients with acute myocardial infarction(AMI).Methods:This randomized con-trolled study enrolled 98 elderly AMI patients admitted in Department of Cardiology,Hefei Eighth People's Hospital between July 2020 and February 2023.They were divided into control group(n=49,routine health education knowl-edge mode nursing)and intervention group(n=49,additional 5E rehabilitation management).Both groups were intervened for 2 months.Cardiac function indexes,mental state,scores of disease cognition,Pittsburgh Sleep Qual-ity Index(PSQI),Medical Outcomes Study 36-Item Short-Form Health Survey(SF-36)and incidence of com-plications were compared between two groups.Results:After 2-month intervention,compared with patients in control group,those in intervention group had significant higher left ventricular ejection fraction(LVEF)[(51.66±2.01)％vs.(45.88±1.51)％],scores of disease cognition[(89.43±2.38)points vs.(81.13±1.16)points]and SF-36[(645.58±26.00)points vs.(432.72±18.50)points],and significant lower left ventricular end-dias-tolic diameter(LVEDd)[(47.74±0.86)mm vs.(51.20±1.36)mm],creatine kinase(CK)[(140.89±5.15)U/L vs.(154.32±2.61)U/L],scores of Self-Rating Depression Scale(SDS)[(31.88±1.16)points vs.(41.06±1.22)points],Self-Rating Anxiety Scale(SAS)[(31.09±1.12)points vs.(40.47±0.87)points]and PSQI[(5.54±0.64)points vs.(7.70±0.85)points](P＜0.001 all).Incidence of complications in intervention group was significantly lower than that of control group(4.08％vs.18.36％,P=0.025).Conclusion:5E rehabilitation management combined with health education knowledge mode could significantly improve cardiac function,negative emotions and sleep quality,improve disease cognition and quality of life,and reduce incidence of complications in elderly AMI patients.

Objective To understand the current situation of healthcare-associated infection(HAI)in China,pro-vide data support and decision-making basis for formulating scientific and effective strategies for HAI prevention and control.Methods A nationwide cross-sectional survey on HAI was conducted among various types and levels of medical institutions in China according to a unified protocol of bedside surveys and case investigations.Results In 2024,a total of 5 736 medical institutions and 2 751 765 patients were surveyed.Among them,34 889 HAI cases were identified,with a prevalence rate of 1.27％.The number of HAI episodes was 38 032,and case prevalence rate was 1.38％.The prevalence rate of HAI in medical institutions in different regions of China ranged from 0.66％to 2.35％.Among medical institutions of different scales,those with a bed capacity of ≥900 had the high-est incidence of HAI,reaching 1.65％.The most common infection site was the lower respiratory tract(44.66％),followed by the urinary tract(12.94％),surgical site(9.32％),upper respiratory tract(7.02％),and bloodstream infection(5.78％).The top 3 departments with the highest HAI rates were the general intensive care unit(10.02％),department of neurosurgery(5.51％),and department(group)of hematology(5.34％).A total of 23 238 strains of HAI pathogens were detected,with 10 714 strains(46.10％)from lower respiratory tract speci-mens.The top 5 detected strains were Klebsiella pneumoniae(14.76％),Pseudomonas aeruginosa(13.33％),Escherichia coli(12.79％),Acinetobacter baumannii(9.23％),and Staphylococcus aureus(7.88％).231 944 pa-tients underwent class Ⅰ incision surgery were monitored,with 1 647 cases experienced surgical site infection,and the prevalence rate of surgical site infection was 0.71％.The number of patients who should undergo pathogen de-tection(patients receiving therapeutic and therapeutic combined prophylactic antimicrobial agents)was 715 179,while the actual number was 480 492,with a pathogen detection rate of 67.18％.425 225 patients received patho-genic detection before treatment,with a detection rate of 59.46％.Conclusion The overall HAI prevalence in Chi-na is lower,showing disparities among medical institutions of different regions and scales.Therefore,precise imple-mentation of measures is necessary for HAI prevention and control,with a focus on high-risk institutions and high-risk departments,key areas,and critical procedures.All levels of medical institutions should continuously reduce the incidence of HAI by strengthening monitoring,standardizing the use of antimicrobial agents,and reinforcing basic HAI prevention and control measures.

ObjectiveTo study the regulatory effect of the partial sequence within the 3’ untranslated region （3’UTR） of slit guidance ligand 1 （Slit1） （Slit1-3’UTR） on the fibrotic phenotypes of cardiac fibroblasts （CFs） and its potential mechanism. MethodsThe adenovirus vector was used to overexpress the 1526nt sequence of Slit1-3’UTR in ICR neonatal mouse CFs （mCFs）. The expression of fibrosis-related genes in mCFs， such as collagen type 1 alpha1（COL1A1）， collagen type 3 alpha3 （COL3A1） and alpha smooth muscle actin （α-SMA） were detected by Western blot assay. The effect of Slit1-3’UTR 1526nt on the proliferation and migration of mCFs was assessed by EdU staining and Trans-well assays. Angiotensin Ⅱ （Ang Ⅱ） was used to treat mCFs， and the impact of Slit1-3’UTR 1526nt on the fibrotic phenotypes of Ang Ⅱ-induced mCFs was evaluated. After overexpression of Slit1-3’UTR 1526nt， miR-34a-5p mimic was transfected into mCFs， followed by actinomycin D treatment to detect the mRNA stability of Slit1-3’UTR 1526nt， and the levels of miR-34a-5p and its target gene SIRT1（si-SIRT1） in mCFs were determined. The effects of miR-34a-5p and small interfering RNA targeting SIRT1 on the Slit1-3’UTR 1526nt-mediated regulation of fibrotic phenotypes were also determined. ResultsAdenovirus-mediated overexpression of Slit 1-3’UTR 1526nt was achieved in mCFs. Overexpression of Slit 1-3’UTR 1526nt markedly inhibited the expression of the fibrosis-related genes， proliferation and migration of mCFs and fibrotic phenotypes of Ang Ⅱ. The results of actinomycin D assay showed that miR-34a-5p inhibited the stability of Slit1-3’UTR 1526nt in mCFs， while the level of miR-34a-5p was reduced in mCFs with overexpression of Slit1-3’UTR 1526nt. Transfection of miR-34a-5p promoted the fibrotic phenotypes， and reversed the inhibitory effect of Slit1-3’UTR 1526nt on the fibrotic phenotypes of mCFs. Overexpression of Slit1-3’UTR 1526nt significantly increased the level of miR-34a-5p target gene SIRT1 in mCFs. Transfection of miR-34a-5p and si-SIRT1 consistently reversed the inhibitory effects of Slit1-3’UTR 1526nt on the fibrotic phenotypes of mCFs. ConclusionSlit1-3’UTR1526nt inhibits the fibrotic phenotypes of mCFs by binding to miR-34a-5p and increasing the expression of its target gene of SIRT1.

Langerhans cell histiocytosis of bone is a rare tumor disease characterized by the large accumulation of CD1a⁺ and CD207⁺ dendritic cells in tissues of unknown cause.It mainly occurs in children aged 1-4 years old,with incidences of 4-6 per million in children and 1-2 per million in adults.Due to its low incidence,diverse clinical manifestations,and no obvious specificity of imaging manifestations,the definitive diagnosis and early treatment of this type of tumor are challenging.In this paper,we report 8 cases of Langerhans cell histiocytosis of bone and review the relevant literature published in the past five years to summarize the clinical characteristics,pathological features,diagnosis,treatment,and prognosis of this disease.
Humans ; Bone Diseases/therapy* ; Histiocytosis, Langerhans-Cell/therapy*