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.

Objective:To investigate the role of SiHa cell-derived exosomal hsa-miR-29c-3p in the angiogenesis of cervical cancer(CC).Methods:Cancer tissue specimens from 45 patients with cervical squamous cell carcinoma(CSCC)and normal cervical tissue specimens from 15 controls were collected from Department of Gynecology,Hengyang Central Hospital from January 2019 to December 2021.CSCC SiHa cells and human umbilical vein endothelial cells(HUVECs)were routinely cultured.miRNA-NC,hsa-miR-29c-3p,si-miRNA-NC,and si-hsa-miR-29c-3p were transfected into SiHa cells with Lipofectamine 2000,grouped as miRNA-NC group,hsa-miR-29c-3p group,si-miRNA-NC group and si-hsa-miR-29c-3p group,respectively.HUVECs were transfected with mimic-NC,miR-29c-3p-mimic,pCMV-NC,and pCMV-ATAD2B(ATPase family protein 2B with AAA domain)using Lipofectamine 2000,grouped as the mimic-NC group,miR-29c-3p-mimic group,pCMV-NC group,pCMV-ATAD2B group,and pCMV-ATAD2B+miR-29c-3p-mimic group.The expression of hsa-miR-29c-3p in CSCC tissues was detected by in situ hybridization(ISH),and CD31-positive blood vessels in CSCC tissues and xenograft tissues were detected by immunohistochemistry(IHC).Exosomes from SiHa and C33a cells were isolated and characterized using transmission electron microscopy(TEM)and western blotting(WB).The uptake of exosomes by HUVECs was examined.The expression of hsa-miR-29c-3p and ATAD2B mRNA in SiHa and C33a cells,as well as in their derived exosomes,was detected using qPCR.Tube-forming assay,Transwell assay,and scratch healing assay were performed to detect the effect of exosomes on the ability of HUVEC migration and tube formation.Dual luciferase reporter gene assay verified the interaction between hsa-miR-29c-3p and ATAD2B.Xenograft experiments examined the effects of SiHa cell-derived exosomes on transplanted tumor growth and angiogenesis in each group.Results:hsa-miR-29c-3p was highly expressed in CSCC tissues and was positively correlated with microvessel density(MVD)(all P<0.05).Exosomes derived from SiHa and C33a cells exhibited typical exosomal morphology and protein expression patterns.Exosomal hsa-miR-29c-3p from SiHa and C33a cells were efficiently taken up by HUVECs in vitro.The SiHa cell-derived exosomal hsa-miR-29c-3p promoted not only the tube-forming and migration of HUVECs in vitro but also the xenograft growth and angiogenesis in vivo(all P<0.05).hsa-miR-29c-3p directly targeted ATAD2B and regulated its expression(P<0.05).Overexpression of ATAD2B reversed the promotive effect of hsa-miR-29c-3p on tube-formation,migration,and scratch-healing in HUVECs(all P<0.05).Conclusion:SiHa cell-derived exosomal hsa-miR-29c-3p regulates angiogenesis in CSCC tissues by targeting ATAD2B.Exosomal hsa-miR-29c-3p may be a potential diagnostic marker and therapeutic target for CC diagnosis and treatment.

Objective:To evaluate the strengths and weaknesses of the total payment policy in China′s county medical community (CMC), and to provide decision-making basis for the high-quality development of CMC and its medical security system.Methods:Official websites of China′s provincial and prefectural governments, the Health Commission and the Medical Security Bureau were searched for policies related to total payment in CMC (issued from May 2019 to December 2023), and 10 representative sample policies were selected based on the balance of the temporal and spatial distribution and the completeness of the content. The policy modeling consistency (PMC) index model was used to quantitatively evaluate the sample policies by identifying primary and secondary variables.Results:The PMC index model variables for the total payment policies in CMC included 10 primary variables such as policy nature, policy timeliness, and policy receptors, and 54 secondary variables such as prediction, recommendation, and regulation. The average PMC index score for the 10 sample policies is 6.86, which was generally at a good level, with five policies each of excellent and good grades. In terms of the primary indicators, the policy nature (0.77), policy receptor (0.82) and policy content (0.73) scored highly, while the policy timeliness (0.35), policy synergy (0.54) and guarantee mechanism (0.53) scored lowly. A comparison of the two policies with the highest and lowest scores revealed that the main reasons for the low scores were the single setting of policy objectives, the lack of dynamic monitoring of key indicators and the inadequacy of guarantee mechanisms such as multisectoral collaboration.Conclusions:China′s total payment policy in CMC was generally better, but it still needed to be strengthened in terms of policy timeliness, policy synergy and guarantee mechanism. It was recommended that local governments can optimize policies by comprehensively considering the timeliness of long-medium-and short-term policies, giving full play to the synergistic effects of medical security policies, and improving the multi-dimensional co-management and guarantee mechanism.

After the wooden shipwreck was recovered from the marine underwater environment,the wooden components undergo varying degrees of degradation,therefore,accurately determining the extent of degradation is a fundamental scientific issue for implementing effective preservation strategies.In this work,the wooden remains of Pinus massoniana excavated from the"Nanhai No.1"shipwreck(Southern Song Dynasty)were investigated and compared with the modern wood to discriminate the degradation levels of archaeological wood using attenuated total reflection Fourier transform infrared(ATR-FTIR)spectroscopy.The residual sugar content within wood cell walls was determined using a non-invasive automated microscale ATR-FTIR method to extract chemical information from the wood tangential section.Microstructural characterization of wood samples was conducted by super depth of field microscopy and scanning electron microscopy.FTIR spectral analysis was performed to evaluate the degradation state and elucidate changes in cellulose crystallinity.Finally,the combination of FTIR spectroscopy with the sparse partial least squares discriminant analysis(sPLS-DA)model facilitated the rapid discrimination of degradation levels in shipwreck archaeological wood,and the performance of the model was evaluated using receiver operating characteristic(ROC)curves and area under the curve(AUC).The results showed that the higher the degree of wood degradation,the lower the residual sugar content in the wood cell wall,and the residual glucose content of highly degraded wood was only 4.7％.Significant differences were observed in both the tangential section microstructure and FTIR characteristic absorption patterns across degradation levels,and as the degradation advanced,progressive cell wall loosening occurred alongside selective removal of polysaccharide components,and the relative lignin content was increased,resulting in an elevated A1509/A1370 ratio in FTIR spectra.The sPLS-DA model achieved excellent discrimination performance with AUC values exceeding 0.9,confirming that the combination of FTIR spectroscopy with sPLS-DA enabled accurate assessment of degradation levels in shipwreck archaeological wood.This study developed a rapid and accurate methodology for assessing degradation levels in shipwreck archaeological wood based on microscale ATR-FTIR spectroscopy,which would help to promote the accurate assessment of the preservation state of waterlogged wooden artifacts.

Under the background of forensic medicine becoming a first-level discipline,the opportuni-ties and challenges of discipline development coexist.Starting from the actual situation and characteris-tics of local medical colleges and universities,this paper discusses the problems and solutions for the development of forensic medicine discipline from the perspective of building a regional high-level medical university.Combined with the experiences of carrying out forensic medicine education in our college,this paper supplies our thoughts and practices on improving the discipline system,enhancing the ability to serve society,perfecting the talent cultivation model and promoting forensic culture,to provide reference and inspiration for the development of forensic medicine in other universities,jointly promote the advancement of forensic medicine in China to a new stage,and contribute the wisdom and strength of forensic medical experts to the construction of a law-based China,a safe China and a healthy China.

Objective To verify the efficacy of a domestic human DNA quantification kit based on real-time fluorescence quantitative PCR in detecting the total human DNA concentration,male DNA concen-tration in mixed male/female DNA samples,the degree of DNA degradation and inhibitor tolerance.Methods Samples with different concentrations,different male/female ratios,different concentrations of inhibitors,and different degradation degrees were tested using the domestic human DNA quantification kit based on real-time fluorescence quantitative PCR.This kit was compared with a similar product on the market and was applied to the detection of DNA from real cases.Results This human DNA quan-tification kit can effectively detect human DNA as low as 0.001 65 ng/μL,and 6.25 pg/μL of male DNA in mixed samples with a male-to-female ratio of 1∶15 000.Even when the sample contains as high as 400 ng/μL of humic acid or 1 000 μmol/L of hemin alone,the DNA concentration can still be accurately detected.The degradation index can effectively characterize the degradation degree of the sample.This kit has been successfully applied in forensic practice.Conclusion This human DNA quan-tification kit is accurate and reliable in detection.It can accurately reflect the degradation of DNA and inhibitor tolerance.It has good performance in quantitative accuracy,determination of the male/female ratio in mixed samples,and inhibitor tolerance.It has application potential in forensic case examination.

Objective : To investigate the effect of chromosome instability(CIN) associated gene polypeptide N-acetylgalactosaminyltransferase 7(GALNT7) on proliferation and apoptosis of HCT116 colon cancer cells. Methods : The HCT116 cell line withGALNT7knockdown was constructed by lentiviral infection. The correlation betweenGALNT7and CIN was verified by chromosome spread assay. The effect ofGALNT7on cell proliferation was detected by live cell counting, and the effect ofGALNT7on cell cycle distribution was detected by flow cytometry and Western blot. Caspase-3 activity and Western blot assays were used to detect the effect ofGALNT7on apoptosis. Results : HCT116 cells showed a slower proliferation rate upon knocking down ofGALNT7, and exhibited a more scattered karyotype distribution and a phenotype of increased degree of CIN. Inhibition ofGALNT7in HCT116 cells resulted in cell cycle arrest, upregulation of P21 and downregulation of CDK6 protein levels, as well as increased levels of Caspase-3 activity, cleaved PARP1 and PUMA protein expression, and decreased levels of BCL-2 protein expression. Conclusion TheGALNT7gene may promote proliferation and inhibit apoptosis of HCT116 colon cancer cells through the suppression of CIN generation.