Objective: To understand the epidemiological characteristics and disease burden of influenza like illness (ILI) among student populations, so as to provide data support for policy formulation and optimal allocation of health resources. Methods: From January 2024 to February 2025, a questionnaire survey was conducted among parents of kindergarten, primary school, junior and senior high school students in 9 districts of Shenzhen, including Longhua, Futian, Bao an, Longgang, Luohu, Nanshan, Guangming, Pingshan and Yantian. Parents were asked to complete the questionnaire based on whether their children had fever, cough, vomiting, diarrhea, rash and other common symptoms in 2024. A total of 3 537 parents were investigated, and 444 ILI cases were included as study subjects. The epidemiological burden, including incidence rate of influenza, visitation rate, years lived with disability (YLDs) and economic burden (including direct economic burden, indirect economic burden and intangible burden) were analyzed. Results: The incidence rate of influenza among students in Shenzhen in 2024 was 12.55%. The ILI incidence rates in kindergarten, primary school, junior and senior high school were 14.01%, 11.69% and 5.23%, respectively, with a statistically significant difference ( χ 2= 45.20, P <0.01). The ILI consultation rate among students was 85.36%, and the consultation rates in kindergarten (87.36%) and primary school students (84.62%) were higher than those in junior and senior high school students ( 56.52 %) ( χ 2=16.47, P <0.01). A total of 78.88% of cases did not receive etiological detection.The median total economic burden per ILI case was 2 354.62 yuan, including direct medical costs of 300.00 yuan, direct non medical costs of 212.50 yuan, indirect costs of 1 000.00 yuan, and intangible burden of 500.00 yuan. Conclusions Schools are high risk environment for influenza, and younger students are a high risk group for ILI. The disease burden caused by student ILI remains substantial.

ObjectiveTo assess changes in the incidence， prevalence， and disability-adjusted life-year （DALY） burden of ulcerative colitis （UC） in China and worldwide from 1990 to 2023 using data from the Global Burden of Disease Study 2023 （GBD 2023）， and to examine demographic drivers and future trends. MethodsUC data for China， the world， and 204 countries and territories were extracted from the GBD 2023 Results Tool. Age-standardized incidence rate （ASIR）， age-standardized prevalence rate （ASPR）， and age-standardized DALY rate （ASDR）， with 95% uncertainty interval （UI）， were obtained. Joinpoint regression was used to estimate average annual percent change （AAPC） and 95% confidence interval （CI）. Spearman rank correlation， inequality and frontier analyses， Das Gupta decomposition， and autoregressive integrated moving average （ARIMA） models were used to assess associations with the sociodemographic index （SDI）， cross-country burden disparities， demographic drivers， and trends from 2024 to 2035， respectively. ResultsIn 2023， the ASIR， ASPR， and ASDR in China were 0.94， 5.95， and 5.94 per 100 000 population， respectively， lower than the corresponding global estimates of 2.87， 28.48， and 13.82 per 100 000 population. From 1990 to 2023， China’s ASIR and ASPR increased， with AAPCs of 2.720% （95% CI： 2.133%-3.309%） and 2.261% （95% CI： 1.617%-2.908%）， whereas the ASDR decreased （AAPC=-3.056%， 95% CI： -3.449% to -2.662%）. Globally， ASIR increased slightly， whereas ASPR and ASDR decreased. In China， the crude incidence， prevalence， and DALY rates peaked at ages 50-54 years， 60-64 years， and ≥95 years， respectively. ASIR and ASPR were positively correlated with SDI （r_s=0.5794 and 0.6177， both P<0.001）， whereas the correlation between ASDR and SDI was not statistically significant （r_s=0.0666， P=0.343）. In China， epidemiological change contributed most to increases in incident and prevalent cases， and changes in age-specific rates contributed most to the decline in DALYs； globally， population growth and population aging contributed most to the increase in DALYs. By 2035， China’s ASIR， ASPR， and ASDR were projected to be 1.23， 6.37， and 2.55 per 100 000 population， respectively. ConclusionsFrom 1990 to 2023， the age-standardized incidence and prevalence rates of UC increased in China， whereas the age-standardized DALY rate decreased， and peaks in absolute burden generally shifted toward middle-aged and older age groups. The projected directions may persist. These findings may provide reference for long-term UC management and health-resource planning.

ObjectiveTo assess changes in the incidence， prevalence， and disability-adjusted life-year （DALY） burden of ulcerative colitis （UC） in China and worldwide from 1990 to 2023 using data from the Global Burden of Disease Study 2023 （GBD 2023）， and to examine demographic drivers and future trends. MethodsUC data for China， the world， and 204 countries and territories were extracted from the GBD 2023 Results Tool. Age-standardized incidence rate （ASIR）， age-standardized prevalence rate （ASPR）， and age-standardized DALY rate （ASDR）， with 95% uncertainty interval （UI）， were obtained. Joinpoint regression was used to estimate average annual percent change （AAPC） and 95% confidence interval （CI）. Spearman rank correlation， inequality and frontier analyses， Das Gupta decomposition， and autoregressive integrated moving average （ARIMA） models were used to assess associations with the sociodemographic index （SDI）， cross-country burden disparities， demographic drivers， and trends from 2024 to 2035， respectively. ResultsIn 2023， the ASIR， ASPR， and ASDR in China were 0.94， 5.95， and 5.94 per 100 000 population， respectively， lower than the corresponding global estimates of 2.87， 28.48， and 13.82 per 100 000 population. From 1990 to 2023， China’s ASIR and ASPR increased， with AAPCs of 2.720% （95% CI： 2.133%-3.309%） and 2.261% （95% CI： 1.617%-2.908%）， whereas the ASDR decreased （AAPC=-3.056%， 95% CI： -3.449% to -2.662%）. Globally， ASIR increased slightly， whereas ASPR and ASDR decreased. In China， the crude incidence， prevalence， and DALY rates peaked at ages 50-54 years， 60-64 years， and ≥95 years， respectively. ASIR and ASPR were positively correlated with SDI （r_s=0.5794 and 0.6177， both P<0.001）， whereas the correlation between ASDR and SDI was not statistically significant （r_s=0.0666， P=0.343）. In China， epidemiological change contributed most to increases in incident and prevalent cases， and changes in age-specific rates contributed most to the decline in DALYs； globally， population growth and population aging contributed most to the increase in DALYs. By 2035， China’s ASIR， ASPR， and ASDR were projected to be 1.23， 6.37， and 2.55 per 100 000 population， respectively. ConclusionsFrom 1990 to 2023， the age-standardized incidence and prevalence rates of UC increased in China， whereas the age-standardized DALY rate decreased， and peaks in absolute burden generally shifted toward middle-aged and older age groups. The projected directions may persist. These findings may provide reference for long-term UC management and health-resource planning.

Objective: To investigation and analyze the causes and characteristics of a food poisoning incident caused by Clostridium perfringens in schools, so as to provide a reference for prevention and control of food poisoning incidents. Methods: From March 11 to 12,2024,on site epidemiological and hygienic investigations were conducted by using food poisoning case questionnaires and on site hygienic investigation forms in Shenzhen. Information related to the poisoning incident was collected through field investigations and telephone interviews. A case control study was used to analyze the suspected food responsible for the incident. Risk analysis in χ 2 analysis was used to obtain OR values. Results: The Clostridium perfringens food poisoning incident involved two schools, with a cumulative total of 52 cases. School A had an attack rate of 2.21%(45/2 040), school B had an attack rate of 1.29% (7/544). The main clinical symptoms were diarrhea (100.00%) and abdominal pain (84.62%), with a minority experiencing fever ( 3.85 %). Analysis via the case control study indicated that consuming mushroom and meat sauce during lunch on March 11, 2024, was a risk factor for the poisoning incident ( OR =124.50, 95% CI =14.53-937.51, P <0.05). On site investigation revealed that the mushroom and meat sauce provided by the schools on March 11 was prepared by the catering company the previous day, stored without refrigeration, and not reheated before serving the next day. A total of 31 patient anal swabs, 16 food samples, and 14 kitchen staff anal swabs were sent for laboratory testing. Clostridium perfringens was isolated from 22 case samples. Among these, type A Clostridium perfringens (alpha toxin) was detected in 8 case samples, 4 kitchen staff anal swabs, and 2 retained samples of the mushroom and meat sauce. Conclusions The incident is a food poisoning outbreak caused by Clostridium perfringens contamination in schools. Avoiding cross contamination and ensuring proper storage are key to preventing Clostridium perfringens food poisoning.

Autoimmune hepatitis （AIH） is an inflammatory disease caused by immune dysfunction， and its pathogenic mechanism remains unclear. In recent years， a large number of studies have shown that iron homeostasis imbalance and ferroptosis are closely associated with the pathogenesis and progression of AIH. This article reviews the pathological mechanism and impact of iron overload and ferroptosis in AIH， in order to provide new insights and theoretical bases for research on the mechanism and clinical treatment of AIH.

【Objective】 To investigate the electronic screen exposure of preschool children in Longhua District of Shenzhen, and to analyze the influencing factors. 【Methods】 A total of 25 266 children in kindergarten in Longhua District of Shenzhen were selected as study subjects. A self-designed questionnaire (completed by their guardians) was used to investigate the use of electronic products in the families of preschoolers in April 2019. 【Results】 A total of 23 407 valid questionnaires were collected in this survey, of which 12 593 (53.80%) were boys and 10 814 (46.20%) were girls; and 17 188(73.43%) children were 5 years old. Among the surveyed children, the rate of excessive exposure to electronic screens (>1h/d) was 37.72%, and 6.40% of preschool children used electronic products for more than 2 hours per day. There were statistically significant differences between the excessive exposure group and the non-excessive exposure group in gender, household registration, parents′ educational level, average monthly household income, whether exclusive electronic products,whether restriction of children′s use of electronic products, whether living with elders, only children or not, and the type of main caregiver (P<0.05). Multivariate binary Logistic regression analysis showed that girls, mothers with college education or above,not living with elders,primary caregivers being parents or nannies/others,and no exclusive electronic products were protective factors for children′s excessive exposure to electronic products(P<0.05).Non-household resident population,not-only child,and non-restriction of children′s use of electronic products were risk factors for children′s excessive exposure to electronic products(P<0.05). 【Conclusions】 The excessive use of electronic products in preschoolers is a common phenomenon in Longhua district, Shenzhen. Therefore, it is necessary to strengthen the intervention on the use time of electronic products in preschoolers, and pay more attention to the influence of family environmental factors.

Objective: To develop asolvent extraction-direct mercury analyzer method for determination of methylmercury in urine. Methods: After the urinehydrolyzesd by hydrobromic acid, methylmercury was extracted by tolueneand reverse-extracted from L-cysteine solution, it was then detectedbydirect mercuryanalyzer. Results: The linear range was 0.2-50.0 μg/L, and the related coefficient was 0.9999. The relative standard deviations (RSD) within the group were 5.04%-6.64%, and the RSD between the group were 5.65%-8.11 %. The average recovery efficiencies were 85.4%-95.5%. The detection limitation was 0.0482 μg/L and the quantification concentrations was 0.1607 μg/L. Conclusion: The method, which has low detection limit, high sensitivity, easy to operate, is stability for the determination of methylmercury in urine.
Mercury ; Methylmercury Compounds

[摘 要] 目的：基于小鼠渐进衰老模型探讨衰老所致“正虚”的免疫功能衰退表征的特点。方法：使用不同月龄（2、6、15月龄）C57BL/6小鼠，通过流式细胞术检测并比较小鼠外周血和脾组织中T细胞、髓源性抑制细胞（MDSC）及其亚群的丰度变化。结果：外周血中T细胞亚群表型为CD3+CD4+CD44-CD62L+的幼稚CD4+ T细胞（2 vs 6月龄，P=0.137；2 vs 15月龄，P=0.004；6 vs 15月龄，P=0.105）和表型为CD3+CD8+CD44-CD62L+的幼稚CD8+ T细胞（2 vs 6月龄，P=0.179；2 vs 15月龄，P=0.001；6 vs 15月龄，P=0.015）出现与衰老有关的细胞比例降低，差异具有统计学意义。表型为CD3+CD4+CD44+CD62L+的中央记忆CD8+ T细胞出现与衰老有关的比例升高，差异具有统计学意义（2 vs 6月龄，P=0.01；2 vs 15月龄，P=0.007；6 vs 15月龄，P=0.164）。对脾组织的检测结果具有与外周血相同特点。同时，CD8+ T细胞比例随衰老逐渐升高（2 vs 6月龄，P=0.027；2 vs 15月龄，P<0.001；6 vs 15月龄，P<0.001）；表型为CD8+CD28+的活化CD8+ T细胞亚群比例也出现随月龄增长的上升（2 vs 6月龄，P=0.863； 2 vs 15月龄，P=0.016；6 vs 15月龄，P=0.024），差异均具有统计学意义。结论：衰老所致“正虚”过程中，不同免疫细胞亚群变化并不都反映免疫抑制特点，虽然总体免疫功能下降，但单一表型难以反应整体免疫功能变化。

Objective To explore the effect of immune senescence on lung cancer metastasis and reveal the mechanism of Fuzheng traditional Chinese medicine Jinfukang in the prevention and treatment of the metastasis. Methods A lung metastasis model of Lewis lung cancer cells was established in C57BL/6 mice with different ages (15 months, 6 months, and 2 months). Mice in the 6-month-old group were given Jinfukang intragastrically for 42 days. Pulmonary metastasis was analyzed by in vivo imaging, anatomical microscopic observation, and HE staining. The proportion of memory T cells and NK cells in peripheral blood was detected by flow cytometry. Results The lung metastatic tumor formation rate of 15-month-old and 6-month-old mice was significantly higher than that of 2-month-old mice (all P < 0.05). Abundance of CD4+T cells in peripheral blood was positively correlated with age (2-month-old vs. 6-month-old, P=0.041; 2-month-old vs.15-month-old, P=0.041; 6-month-old vs.15-month-old, P=0.953). The abundance of NK cells was negatively correlated with age (2-month-old vs. 6-month-old, P=0.009; 2-month-old vs.15-month-old, P=0.009; 6-month-old vs. 15-month-old, P=0.574). However, the survival time of mice in the Jinfukang group was longer (P > 0.05) and the level of NK cells in peripheral blood was significantly higher (P=0.029) than those in the normal saline group. Conclusion Immune senescence can promote the metastasis of lung cancer. The prolongation of the survival time of mice administered with Jinfukang may be related to delaying immune senescence and increasing the number of NK cells.

Objective　We established a model by using microfluidic chip that is a horizontal side by side diffusion system through microporous separating three adjacent channels in a triple-culture using neurons,astrocytes,and bEnd.3.Methods　(1)In the in vitro microphysiological system of neurovascular unit,we identified the seed density,seed time,seed sequence and seed method.(2)We adopt the repeated measures data of ANOVA to see whether there is significant difference in the viability when the three cell types are tri-cultured and separately mono-cultured.Results　(1) In the novel in vitro NVU model,the seed density of the neurons,astrocytes and bEnd.3 is 5×10^6~10×10^6 /ml,3×10^5~8×10^5个/ml and 1×10^5~5×10^5/ml.The seed sequence is from neurons to astrocytes to bEnd.3.The seed time is that after the previous seeded cells enter the exponential phase,the next cells will be seeded.(2)We adopt the repeated measures data of ANOVA to see whether there is significant difference in the viability when the three cell types are tri-cultured and separately mono-cultured.Conclusion　In this study,neurons,astrocytes and bEnd.3 were tri-cultured by using microfluidic chip.In this tri-culture model,these three kinds of cells have high cell viability.