Clinical trial registration， as a cornerstone for transparency in medical scientific research， aims to systematically and comprehensively disclose key information such as trial design and implementation protocols before trial initiation. This reduces selective reporting and outcome bias， avoids unnecessary duplicate research， thereby protects research participants’ legitimate rights and interests and ethical compliance， and ultimately upholds research integrity and public trust. However， despite the widespread international recognition of its importance and necessity， registration practices worldwide still exhibit significant disparities. From an ethical perspective， this paper deeply analyzed the current status of clinical trial registration and the challenges it confronted， including issues such as insufficient awareness of prospective registration， inconsistent registration standards， persistent difficulties in data openness， sharing， and result disclosure， as well as imbalanced global governance of registration. It further explored multi-dimensional paths involving institutional coordination， technological empowerment， global collaboration， and ethical guidance， to promote clinical trial registration to realize full-cycle closed-loop management from registration and implementation to result reporting. These will provide solid theoretical support and practical references for establishing a more ethically resilient， highly transparent， and sustainably operational clinical trial registration system.

OBJECTIVE To explore the effect of tracking methodology on investigation of contamination incidents of bronchoalveolar lavage fluid(BALF)specimens from the children.METHODS The onsite tracking was carried out for the contamination incidents of BALF specimens of the children through the tracking methodology,the quality control processes of cleaning and disinfection of bronchofiberscopes and the tracking routes were determined.The quality control process of cleaning and disinfection of bronchofiberscopes were evaluated,the existing risks were found out,and the specific improvement measures were formulated.RESULTS The onsite tracking was carried out for the incident of carbapenem-resistant Klebsiella pneumoniae(CRKP)that was caused by the contamination of 12 BALF specimens from pediatrics department wards before and after Nov.1,2021.No.2180014C bronchofiber-scope without biological surveillance was determined as the high-risk point of contamination of BALF specimens,the monitoring procedure of cleaning and disinfection of the bronchofiberscopes was revised.The BALF specimens that were submitted from Dec.1,2021 to Dec.31,2021 were tracked,and no CRKP was detected among the 23 submitted specimens.Totally 12 bronchofiberscope specimens were collected for biological surveillance,and the qualified rate was 100.00％.The treatment rooms of pediatrics department,hand disinfection effect of health care workers of cleaning and disinfection rooms and disinfection effect of object surfaces were monitored,and the quali-fied rate was increased from 98.39％to 100.00％.CONCLUSIONS The tracking methodology is an effective tool for quality management and can be used for evaluation of quality process of cleaning and disinfection of bronchofi-berscopes,which may find out the causes for adverse events in a timely manner and raise the medical safety.

OBJECTIVE To explore the effect of tracking methodology on investigation of contamination incidents of bronchoalveolar lavage fluid(BALF)specimens from the children.METHODS The onsite tracking was carried out for the contamination incidents of BALF specimens of the children through the tracking methodology,the quality control processes of cleaning and disinfection of bronchofiberscopes and the tracking routes were determined.The quality control process of cleaning and disinfection of bronchofiberscopes were evaluated,the existing risks were found out,and the specific improvement measures were formulated.RESULTS The onsite tracking was carried out for the incident of carbapenem-resistant Klebsiella pneumoniae(CRKP)that was caused by the contamination of 12 BALF specimens from pediatrics department wards before and after Nov.1,2021.No.2180014C bronchofiber-scope without biological surveillance was determined as the high-risk point of contamination of BALF specimens,the monitoring procedure of cleaning and disinfection of the bronchofiberscopes was revised.The BALF specimens that were submitted from Dec.1,2021 to Dec.31,2021 were tracked,and no CRKP was detected among the 23 submitted specimens.Totally 12 bronchofiberscope specimens were collected for biological surveillance,and the qualified rate was 100.00％.The treatment rooms of pediatrics department,hand disinfection effect of health care workers of cleaning and disinfection rooms and disinfection effect of object surfaces were monitored,and the quali-fied rate was increased from 98.39％to 100.00％.CONCLUSIONS The tracking methodology is an effective tool for quality management and can be used for evaluation of quality process of cleaning and disinfection of bronchofi-berscopes,which may find out the causes for adverse events in a timely manner and raise the medical safety.

African swine fever(ASF)is a highly contagious and pathogenic disease affecting both domestic and wild pigs,which is caused by African swine fever virus(ASFV).In European epidem-ics,low-virulence strains of ASFV,which do not have hemadsorbing properties,have been identi-fied.Following the identification of highly virulent genotype Ⅱ ASFV strains in China in 2018,subsequently,low-virulence strains of genotype Ⅱ and genotype Ⅰ emerged.Recombination be-tween genotypes Ⅰ and Ⅱ has also led to the occurrence of high-virulence strains.This indicates a complex and diverse genetic evolution of ASFV during the epidemiological transmission,which po-ses significant challenges for vaccine development and disease surveillance.Here,we provide an o-verview of the novel epidemiological characteristics of ASFV,with a focus on genetic variations and pathogenic differences during the outbreaks of ASF.We also explore how ASFV genetic varia-tions impact immune escape and pathogenicity of the virus,and the challenges they pose for vac-cine development,disease diagnosis,and surveillance.The aim of this review is to enhance our un-derstanding of the genetic evolution and mutation mechanisms of ASFV,providing a theoretical basis for the development of vaccines and research on diagnostic technologies.

Colorectal cancer is a common malignancy of the digestive tract, and the gut microbiota is closely related to the occurrence and development of colorectal cancer. The intestinal florae mainly change the host intestinal immune environment and affect the function of the intes-tinal barrier by releasing toxins and producing metabolites to participate the occurrence and deve-lopment of colon cancer. The intestinal florae can be used as biomarkers for early screening and prognosis prediction for colorectal cancer. In addition, the intestinal florae can affect the efficacy of chemotherapy, radiotherapy and immunotherapy for colorectal cancer. The authors review the research progress of gut microbiota in occurrence and development, screening, prognosis prediction and treatment of colorectal cancer, and discuss the application prospects of gut microbiota in the prevention and treatment of colorectal cancer.

Objective To understand the characteristics of population distribution,risk factors and risk links of occupational exposure among health care workers(HCWs)in a hospital.Methods Occupational exposure among HCWs between January 2011 and June 2014 were monitored,data about occupational categories of HCWs,expo-sure locations,exposure links and exposure modes were analyzed statistically.Results Among 286 occupational ex-posure cases,the female and male HCWs accounted for 22.03% (n=63)and 77.97% (n=223)respectively;the incidence of occupational exposure in 2011 ,2012,2013 and January-June of 2014 was 38.81 %(n=111),26.22% (n=75),23.43% (n=67)and 11 .54% (n=33)respectively;occupational exposure of junior nurses,doctors,nurs-ing attendants,technicians,senior nurses and cleaners was 31 .97%,19.90%,15.79%,7.64%,4.17%,and 2.84% respectively;exposure mainly occurred at the time of sorting waste,withdrawing or changing needles,dis-carding sharps into sharps containers,surgical suturing or instruments passing,and puncturing (including drawing blood),the constituent ratio was 22.38%,19.58%,14.34%,12.94% and 11 .19%,respectively;the main loca-tions where exposure occurred were wards,operating rooms and injection (treatment)rooms,the constituent ratio was 51 .40%,19.58% and 11 .54% respectively.Conclusion Hospital should establish comprehensive occupational exposure monitoring and risk management system,strengthen standard prevention,enhance the training about occu-pational exposure among high-risk population,and monitor and intervene on risk factors and links,so as to reduce the incidence of HCWs’occupational exposure.