ObjectiveTo analyze the risk factors for long-term cardiovascular events in patients undergoing long-term peritoneal dialysis （PD）， and to construct and validate a visual nomogram prediction model based on multiple parameters. MethodsA prospective cohort study was conducted， consecutively enrolling 248 maintenance PD patients （dialysis duration ≥ 3 months）. Demographic characteristics， clinical indicators， laboratory parameters， and echocardiographic indices （including left ventricular ejection fraction ［LVEF］， ratio of early diastolic mitral inflow velocity to early diastolic mitral annular velocity （E/e’）， etc.） were collected. The composite endpoint was defined as the occurrence of cardiovascular events or cardiovascular death， with non-cardiovascular death as the competing risk and loss to follow-up or the end of follow-up as censoring events. Fine-Gray competing risks model was used to screen independent predictors， based on which a nomogram model was constructed. Internal validation was performed using the Bootstrap method （1 000 resamplings）， and the concordance index （C-index） and time-dependent receiver operating characteristic （time-dependent ROC） curve were calculated to evaluate the model performance. ResultsWith a median follow-up of 29 months （interquartile range： 24–35 months）， 88 patients （35.48%） reached the composite endpoint， including 80 cases of cardiovascular events and 8 cases of cardiovascular death， and 4 patients died of non-cardiovascular causes. Multivariate Fine-Gray analysis revealed that age， diabetes mellitus， hemoglobin （HGB） level and E/e' ratio were independent influencing factors of the composite endpoint. Specifically， each 1-year increase in age was associated with a 3.0% increase in the risk of the composite endpoint （HR=1.030， P=0.006）； patients with diabetes mellitus had a 167.9% higher risk compared with non-diabetic patients （HR=2.679， P=0.007）； each 1g/L increase in HGB level contributed to a 1.5% reduction in the risk （HR=0.985， P=0.003）； and each 0.1 increase in E/e' ratio led to a 7.2% increase in the risk （HR=1.072， P=0.045）. The nomogram model had a C-index of 0.76 （95% CI： 0.698–0.820）， and the AUC of the time-dependent ROC curve reached 0.849 at 23 months of follow-up. ConclusionIncreased age， complicated with diabetes mellitus， decreased HGB， and elevated E/e' ratio are independent risk factors of long-term occurrence of cardiovascular events and cardiovascular death in patients undergoing long-term PD. The nomogram model constructed based on the above variables has good predictive value and clinical applicability， which can provide a reference for cardiovascular risk stratification and individualized intervention in long-term PD patients.

Objective: To analyze the dynamic changes and influencing factors of latent tuberculosis infection (LTBI) among junior and senior high school students, so as to provide evidence based references for precise tuberculosis prevention and control on campus. Methods: A retrospective cohort study was conducted among 11 206 junior and senior high school students in Yuhang District, Hangzhou, who underwent tuberculin skin test (TST) at baseline in 2023 (T0). Participants were followed up for two consecutive years (T1 in 2024, T2 in 2025), and TST results were analyzed. Cox proportional hazards regression model was used to identify influencing factors of LTBI, and generalized estimating equations (GEE) were applied to examine the sex-baseline grade-time interaction effects. Results: The cumulative incidence of LTBI among enrolled students was 10.01%, showed a distinct grade related gradient: the grade 7 cohort had the highest cumulative incidence of 12.62%, which decreased significantly with increasing grade level ( χ 2=109.12, P <0.01). Multivariate Cox regression analysis indicated that, compared with the grade 7 cohort, the grade 8 cohort ( aHR =0.60) and the grade 9 cohort ( aHR =0.43) had lower risks of LTBI (both P <0.01). Boarding school students had a 62% lower risk of LTBI than non boarding school students ( aHR =0.38, P <0.01). GEE analysis showed that, with grade 7 girls at T1 as the reference group, LTBI risk significantly increased among grade 7 girls at T2 ( β =0.23), whereas the most prominent risk reduction was observed among grade 9 boys ( β =-1.69) (both P <0.05). Conclusions LTBI risk among junior and senior high school students exhibits significant population heterogeneity and temporal dynamics. The grade 7 academic year represents a critical window for tuberculosis prevention. Girls advancing to the grade 8 should be prioritized as the key population for targeted interventions. The boarding school campus management model exerts a protective effect against LTBI among junior and senior high school students.

Infectious diseases continue to pose a threat to global public health. Successive global shocks caused by emerging and re-emerging pathogens have continuously challenged existing surveillance systems, highlighting the urgent need to build efficient and precise pathogen surveillance networks. Pathogen genomic databases have been developed rapidly in recent two decades, significantly improving the molecular identification, evolutionary analysis, and transmission tracking of pathogens, and changing disease surveillance strategies and patterns. This paper summarizes the developmental history and current state of pathogen genomic databases, and discusses their applications in public health, including pathogen variation surveillance, emerging or suspected pathogen identification, and epidemiological tracing. Furthermore, this paper systematically analyzes the limitations and key challenges faced by current global health prevention and control system, and suggests the focus of the development of online pathogen databases to address existing shortcomings, ultimately improve global infectious disease surveillance and early warning

Objective To analyze the epidemiological characteristics and disease burden of drug-resistant tuberculosis cases among elderly patients in Wuhan.Methods Clinical data of elderly pa-tients with pulmonary tuberculosis in Wuhan from January 2019 to December 2022 were retrospectively analyzed.Sputum samples were collected for Mycobacterium tuberculosis isolation,and drug suscepti-bility testing was performed using the proportion method.The epidemiological characteristics of drug-resistant tuberculosis and the direct economic burden of the patients were analyzed.Results A total of 972 elderly patients with positive Mycobacterium tuberculosis tests were included.The overall tuberculosis drug resistance rate was 21.19％(206/972).Male,rural residence,lower education level(primary school or below)and retreatment history significantly increased the risk of developing drug-resistant tu-berculosis(P＜0.05).The direct economic burden for elderly patients with drug-resistant tuberculosis was 24,101.52(8,283.98,39,598.89)RMB,and the indirect economic burden was 1,858.64(528.66,3,085.26)RMB.Conclusion The incidence of drug resistance in elderly tuberculosis is high,and male,rural residence,low education level and tuberculosis retreatment are the risk factors for drug resistance in elderly tuberculosis,and their economic burden is heavy after drug resistance.

Objective To study the hemodynamic characteristics of autologous arteriovenous fistula(AVF)and provide a theoretical basis for reducing its stenosis rate.Methods Bidirectional fluid-structure interaction(FSI)simulations were conducted on a modified AVF model.Flow field and wall shear stress(WSS)distributions in the internal fistula at different periods and angles in a cardiac cycle were analyzed for retrograde flow(confluence)and anterograde flow(shunt)modes in models with varying anastomosis angles.Results Under confluence modes,the WSS＜1 Pa area in the 60° anastomosis angle model was the smallest(7.027 mm2),while the 45°,60°,and 90° models showed no significant differences in eddy current size and intensity.Under shunt modes,the 45° anastomosis angle model had the smallest WSS＜1 Pa area(9.079 mm2),but the 60° model exhibited the lowest eddy current intensity and distribution area.In addition,the difference in the WSS＜1 Pa area between the 60° and 45° models was only 2.661 mm2.Conclusions Under both confluence and shunt flow modes,establishing an AVF with 60° anastomosis angle is conducive to reducing the risk of vascular stenosis in arteriovenous fistula.

Objective:To assess the consistency between displayed doses and actual doses of the computed tomography(CT)equipment of different manufactories and types through compares the actual measured dose and the displayed dose in CT examination on head of children,so as to provide references for rapid estimation and scientific assessment for the dose in CT examination on head of children.Methods:The CT equipment of two kinds of commonly used brands were selected,which included Brand A(imported equipment,16-slice and 64-slice)and Brand B(domestic equipment,16-slice and 32-slice).A pediatric head phantom was used to conduct scan according to pre-set scan protocol for children at different ages.A ionization chamber that like a pen was adopted to measure CT dose index(CTDI)values of scanning the head of children under various scan parameters,which were compared with the displayed values in equipment.Results:For 16-slices CT of Brand A,the ratio range of actually measured dose to displayed dose was between 1.08 and 1.10.For the 64-slices CT of Brand A,that was between 1.11 and 1.17.For the 16-slices CT of Brand B,that was between 1.00 to 1.04.For the 32-slices CT of Brand B,that was between 1.12 to 1.21.All ratios were slightly higher than 1,but were within a relatively concentrated range.Under the products of different tube voltages(kV)and tube current-time(mAs),the volatility of ratio range of actually measured dose to displayed dose of different ages was less than 5%,which indicated the deviations were stable,and the influence of parameters was less.Conclusion:In CT examinations on head of children,the consistency of the ratio value between actually measured value and displayed value is higher under the acquiescent scan conditions of the scan protocol for head of children at different ages,which can conduct rapidly dose estimation as a certain conversion coefficient.

Objective:To assess the consistency between displayed doses and actual doses of the computed tomography(CT)equipment of different manufactories and types through compares the actual measured dose and the displayed dose in CT examination on head of children,so as to provide references for rapid estimation and scientific assessment for the dose in CT examination on head of children.Methods:The CT equipment of two kinds of commonly used brands were selected,which included Brand A(imported equipment,16-slice and 64-slice)and Brand B(domestic equipment,16-slice and 32-slice).A pediatric head phantom was used to conduct scan according to pre-set scan protocol for children at different ages.A ionization chamber that like a pen was adopted to measure CT dose index(CTDI)values of scanning the head of children under various scan parameters,which were compared with the displayed values in equipment.Results:For 16-slices CT of Brand A,the ratio range of actually measured dose to displayed dose was between 1.08 and 1.10.For the 64-slices CT of Brand A,that was between 1.11 and 1.17.For the 16-slices CT of Brand B,that was between 1.00 to 1.04.For the 32-slices CT of Brand B,that was between 1.12 to 1.21.All ratios were slightly higher than 1,but were within a relatively concentrated range.Under the products of different tube voltages(kV)and tube current-time(mAs),the volatility of ratio range of actually measured dose to displayed dose of different ages was less than 5%,which indicated the deviations were stable,and the influence of parameters was less.Conclusion:In CT examinations on head of children,the consistency of the ratio value between actually measured value and displayed value is higher under the acquiescent scan conditions of the scan protocol for head of children at different ages,which can conduct rapidly dose estimation as a certain conversion coefficient.

Infectious diseases continue to pose a threat to global public health. Successive global shocks caused by emerging and re-emerging pathogens have continuously challenged existing surveillance systems, highlighting the urgent need to build efficient and precise pathogen surveillance networks. Pathogen genomic databases have been developed rapidly in recent two decades, significantly improving the molecular identification, evolutionary analysis, and transmission tracking of pathogens, and changing disease surveillance strategies and patterns. This paper summarizes the developmental history and current state of pathogen genomic databases, and discusses their applications in public health, including pathogen variation surveillance, emerging or suspected pathogen identification, and epidemiological tracing. Furthermore, this paper systematically analyzes the limitations and key challenges faced by current global health prevention and control system, and suggests the focus of the development of online pathogen databases to address existing shortcomings, ultimately improve global infectious disease surveillance and early warning

Objective To study the hemodynamic characteristics of autologous arteriovenous fistula(AVF)and provide a theoretical basis for reducing its stenosis rate.Methods Bidirectional fluid-structure interaction(FSI)simulations were conducted on a modified AVF model.Flow field and wall shear stress(WSS)distributions in the internal fistula at different periods and angles in a cardiac cycle were analyzed for retrograde flow(confluence)and anterograde flow(shunt)modes in models with varying anastomosis angles.Results Under confluence modes,the WSS＜1 Pa area in the 60° anastomosis angle model was the smallest(7.027 mm2),while the 45°,60°,and 90° models showed no significant differences in eddy current size and intensity.Under shunt modes,the 45° anastomosis angle model had the smallest WSS＜1 Pa area(9.079 mm2),but the 60° model exhibited the lowest eddy current intensity and distribution area.In addition,the difference in the WSS＜1 Pa area between the 60° and 45° models was only 2.661 mm2.Conclusions Under both confluence and shunt flow modes,establishing an AVF with 60° anastomosis angle is conducive to reducing the risk of vascular stenosis in arteriovenous fistula.

Objective To establish testing and evaluation methods for radiation shielding performance of a self-shielded radiotherapy system by measuring the radiation levels around the self-shielded head and neck radiotherapy system. Methods A total of 14 monitoring points were selected outside the restricted zone of the system. Under radiation conditions from five different fixed directions, an ion chamber survey meter was used to measure and identify the maximum ambient dose equivalent rate at the 14 points. The time-averaged dose rate was then calculated based on the workload. In accordance with relevant radiation protection standards, an instantaneous dose rate of 10 μSv/h and a time-averaged dose rate of 2.0 μSv/h were proposed as the criteria for shielding protection evaluation. Results Based on the ambient dose equivalent rates at the 14 monitoring points outside the restricted zone, the maximum instantaneous dose rate outside the restricted zone was 7.4 μSv/h. With a workload of 15 patients per day, the maximum time-averaged dose rate was 1.0 μSv/h, which can be used as the criteria for shielding protection evaluation. Conclusion By considering both instantaneous dose rate and time-averaged dose rate, a comprehensive safety assessment of the radiation shielding performance of a self-shielded radiotherapy system can be conducted.