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.

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.

Migratory birds are found worldwide.These birds are natural carriers of pathogens,because of their long-distance mi-grations across different climatic and geographic regions.The pathogens carried by migratory birds can enter ecosystems along migra-tory routes through direct and indirect contact between animal hosts,thereby potentially threatening the health of local poultry and even humans.Herein,we systematically analyzed evidence of pathogen spillover between migratory birds and poultry,and summa-rized the three modes of long-distance pathogen transmission by migratory birds(internal carriage,surface carriage,and environmen-tal contamination),as well as the two pathways of pathogen spillover between migratory birds and poultry(direct contact and indirect contact).Furthermore,this study proposes a multi-tiered mitigation strategy,grounded in the One Health framework,for targeting animal-environment-human interfaces to decrease the pathogen transmission risks associated with migratory birds.Key interventions include establishing an early-warning surveillance system for migratory flyways,enhancing biosecurity protocols in poultry production systems,and developing cross-regional risk assessment models for pathogen spread.Our findings provide critical theoretical founda-tions and empirical evidence for preventing zoonotic disease emergence and safeguarding sustainable poultry production.This inte-grated approach advances the coordinated development of biosafety measures and global health security.

This study analyzed the genetic evolutionary characteristics of sandflies and their effects on the spread of kala-azar in various environments in endemic provinces in China,to provide a scientific basis for kala-azar disease prevention and control.Sand-flies were collected in kala-azar endemic areas such as southern Xinjiang,the large hilly areas of southern Gansu,the northern Sich-uan and Taihang Mountains,and surrounding small hills.The cytochrome c oxidase subunit I and cytochrome b gene fragments of mito-chondrial DNA were amplified to identify sandfly species.The COI and Cytb gene sequences of sandflies from southern Xinjiang and Si-chuan recorded in NCBI were also collected.The intraspecific and interspecific genetic differences of sandflies were calculated in MEGA11.0,and a phylogenetic tree was constructed through the neighbor-joining method,for analysis of the genetic and evolutionary characteristics of sandfly populations and their effects on disease transmission.A total of 155 sandflies were collected from nine sam-pling sites in seven provinces of China;the species included Phlebotomus chinensis,Phlebotomus wui,and Sergentomyia squamirostris.Five sandfly species belonging to two genera were collected:P.chinensis,P.wui,and Phlebotomus alexandri in the genus Phleboto-mus,and S.squamirostris in the genus Sergentomyia.Genetic evolution analysis based on COI and Cytb gene sequences indicated intra-specific genetic distances of 0-0.062 and 0-0.056,respectively,and interspecific genetic distances of 0.126-0.176 and 0.110-0.171,respectively.The phylogenetic tree indicated that P.wui,P.alexandri,Phlebotomus longiductus,and S.squamirostris clus-tered into one branch.The sequences of P.chinensis in the large and small hilly areas clustered into two geographical clades.In the small hilly areas,the sequences of P.chinensis aggregates showed small genetic differences,the pathogen infection was consistent,and the cases showed an epidemic spread trend.Large genetic differences at the molecular level were observed among sandflies in dif-ferent ecological regions,thus indicating key effects on leishmaniasis transmission.On the basis of these findings,prevention and con-trol strategies should be adapted to local conditions,and precise and effective prevention and control measures should be formulated according to the genetic evolution characteristics of sandflies in different regions,to better control the transmission of Kala-azar.

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 explore the correlation between fasting blood glucose(FBG)level and fractional flow reserve(FFR)in patients with borderline coronary artery disease,and to clarify its potential influence on FFR measurement.Methods From August 2020 to August 2023,the data of 135 patients with coronary atherosclerotic heart disease who received coronary angiography and FFR evaluation in the Fourth Affiliated Hospital of Harbin Medical University were retrospectively collected.According to the exclusion and inclusion criteria,85 cases of borderline diseased vessels of single coronary artery with stenosis degree of 50％-80％were screened out,and they were divided into FBG≥6.1 mmol/L group(47 cases)and FBG＜6.1 mmol/L group(38 cases).The baseline data,angiographic and functional indexes of the two groups were compared,and the correlation between FBG and FFR was analyzed.Results Compared with the FBG＜6.1 mmol/L group,the FBG≥6.1 mmol/L group had a higher proportion of FFR negative results(72.3％vs.23.7％,P＜0.001),and the FFR measurement values were generally increased[0.84(0.80,0.90)vs.0.75(0.68,0.80),P＜0.001],with statistically significant differences.Pearson correlation analysis was performed on all lesions,and FFR＞0.80(negative result)was positively correlated with FBG≥6.1 mmol/L(r=0.484,P＜0.001).Conclusions Among the patients with borderline coronary artery disease(50％-80％stenosis)included in this study,FBG≥6.1 mmol/L is significantly correlated with FFR＞0.80.For patients with borderline coronary lesions with elevated FBG,the influence of blood glucose factors should be carefully considered in clinical interpretation of FFR results.

Migratory birds are found worldwide.These birds are natural carriers of pathogens,because of their long-distance mi-grations across different climatic and geographic regions.The pathogens carried by migratory birds can enter ecosystems along migra-tory routes through direct and indirect contact between animal hosts,thereby potentially threatening the health of local poultry and even humans.Herein,we systematically analyzed evidence of pathogen spillover between migratory birds and poultry,and summa-rized the three modes of long-distance pathogen transmission by migratory birds(internal carriage,surface carriage,and environmen-tal contamination),as well as the two pathways of pathogen spillover between migratory birds and poultry(direct contact and indirect contact).Furthermore,this study proposes a multi-tiered mitigation strategy,grounded in the One Health framework,for targeting animal-environment-human interfaces to decrease the pathogen transmission risks associated with migratory birds.Key interventions include establishing an early-warning surveillance system for migratory flyways,enhancing biosecurity protocols in poultry production systems,and developing cross-regional risk assessment models for pathogen spread.Our findings provide critical theoretical founda-tions and empirical evidence for preventing zoonotic disease emergence and safeguarding sustainable poultry production.This inte-grated approach advances the coordinated development of biosafety measures and global health security.

This study analyzed the genetic evolutionary characteristics of sandflies and their effects on the spread of kala-azar in various environments in endemic provinces in China,to provide a scientific basis for kala-azar disease prevention and control.Sand-flies were collected in kala-azar endemic areas such as southern Xinjiang,the large hilly areas of southern Gansu,the northern Sich-uan and Taihang Mountains,and surrounding small hills.The cytochrome c oxidase subunit I and cytochrome b gene fragments of mito-chondrial DNA were amplified to identify sandfly species.The COI and Cytb gene sequences of sandflies from southern Xinjiang and Si-chuan recorded in NCBI were also collected.The intraspecific and interspecific genetic differences of sandflies were calculated in MEGA11.0,and a phylogenetic tree was constructed through the neighbor-joining method,for analysis of the genetic and evolutionary characteristics of sandfly populations and their effects on disease transmission.A total of 155 sandflies were collected from nine sam-pling sites in seven provinces of China;the species included Phlebotomus chinensis,Phlebotomus wui,and Sergentomyia squamirostris.Five sandfly species belonging to two genera were collected:P.chinensis,P.wui,and Phlebotomus alexandri in the genus Phleboto-mus,and S.squamirostris in the genus Sergentomyia.Genetic evolution analysis based on COI and Cytb gene sequences indicated intra-specific genetic distances of 0-0.062 and 0-0.056,respectively,and interspecific genetic distances of 0.126-0.176 and 0.110-0.171,respectively.The phylogenetic tree indicated that P.wui,P.alexandri,Phlebotomus longiductus,and S.squamirostris clus-tered into one branch.The sequences of P.chinensis in the large and small hilly areas clustered into two geographical clades.In the small hilly areas,the sequences of P.chinensis aggregates showed small genetic differences,the pathogen infection was consistent,and the cases showed an epidemic spread trend.Large genetic differences at the molecular level were observed among sandflies in dif-ferent ecological regions,thus indicating key effects on leishmaniasis transmission.On the basis of these findings,prevention and con-trol strategies should be adapted to local conditions,and precise and effective prevention and control measures should be formulated according to the genetic evolution characteristics of sandflies in different regions,to better control the transmission of Kala-azar.

Objective To explore the correlation between fasting blood glucose(FBG)level and fractional flow reserve(FFR)in patients with borderline coronary artery disease,and to clarify its potential influence on FFR measurement.Methods From August 2020 to August 2023,the data of 135 patients with coronary atherosclerotic heart disease who received coronary angiography and FFR evaluation in the Fourth Affiliated Hospital of Harbin Medical University were retrospectively collected.According to the exclusion and inclusion criteria,85 cases of borderline diseased vessels of single coronary artery with stenosis degree of 50％-80％were screened out,and they were divided into FBG≥6.1 mmol/L group(47 cases)and FBG＜6.1 mmol/L group(38 cases).The baseline data,angiographic and functional indexes of the two groups were compared,and the correlation between FBG and FFR was analyzed.Results Compared with the FBG＜6.1 mmol/L group,the FBG≥6.1 mmol/L group had a higher proportion of FFR negative results(72.3％vs.23.7％,P＜0.001),and the FFR measurement values were generally increased[0.84(0.80,0.90)vs.0.75(0.68,0.80),P＜0.001],with statistically significant differences.Pearson correlation analysis was performed on all lesions,and FFR＞0.80(negative result)was positively correlated with FBG≥6.1 mmol/L(r=0.484,P＜0.001).Conclusions Among the patients with borderline coronary artery disease(50％-80％stenosis)included in this study,FBG≥6.1 mmol/L is significantly correlated with FFR＞0.80.For patients with borderline coronary lesions with elevated FBG,the influence of blood glucose factors should be carefully considered in clinical interpretation of FFR results.