卫生研究最新文献

{"title":"[Association of Chinese visceral adiposity index with bone mineral content and bone metabolic markers of middle school students in Yinchuan from 2017 to 2023].","authors":"Jianxi Liu, Longkai Shi, Linlin Chen, Yingli Xu, Xiaoyan Ma, Mei Tian, Wenqing Ding","doi":"10.19813/j.cnki.weishengyanjiu.2026.04.016","DOIUrl":"https://doi.org/10.19813/j.cnki.weishengyanjiu.2026.04.016","url":null,"abstract":"<p><strong>Objective: </strong>To investigate the relationship between the Chinese visceral adiposity index (CVAI), bone mineral content (BMC), and serum osteocalcin (OC) and type I collagen cross-linked C-terminal peptide (CTX) levels in Yinchuan middle school students.</p><p><strong>Methods: </strong>A total of 1603 students aged 12-18 years in Yinchuan City were selected as study subjects with a mean age of (14.99±1.51) years old in 2017-2023 by stratified clustering sampling, including 915(57.1%) boys, 1149(71.7%)Han, 201(12.5%)Hui and 191(11.9%) from other ethnic groups. Height and weight were measured, and total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were measured. The serum osteocalcin and type I collagen cross-linked C-terminal peptide were measured by enzyme linked immunosorbent assay (ELISA). Regression models combined with restricted cubic spline were used to analyze the relationship between CVAI and low bone mass and low bone metabolism markers among middle school students in Yinchuan City, and receiver operating characteristic(ROC) curves were used to analyze the effect of their assessment on low bone mass.</p><p><strong>Results: </strong>After adjusting for confounding factors of gender, age, smoking, alcohol consumption, physical activity and outdoor activity hours, the risk of low bone mass was lower in the Q4 of CVAI than in the Q1(OR=0.03, 95%CI 0.01-0.07), and the result were similar after stratification by gender (P<0.05); the risk of low OC in the Q4 of CVAI was higher than that in the Q1(OR=1.98, 95%CI 1.36-2.88), while the risk of low CTX was lower than that of Q1(OR=0.52, 95%CI 0.36-0.75, P<0.05). A linear dose-response relationship was observed between CVAI and low bone mass and low CTX (Poverall trend<0.05, Pnonlinearity>0.05), while a nonlinear dose-response relationship was found between CVAI and low OC(Poverall trend<0.05, Pnonlinearity<0.05). The ROC curve analysis revealed that CVAI had the best diagnostic performance for low bone mass (AUC=0.87, 95%CI 0.85-0.90, P<0.05).</p><p><strong>Conclusion: </strong>Increased CVAI can reduce the risk of low bone mass and low CTX, and increase the risk of low OC in Yinchuan middle school students.</p>","PeriodicalId":57744,"journal":{"name":"卫生研究","volume":"55 4","pages":"631-646"},"PeriodicalIF":0.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148665092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Research on the market and industry development of foods containing microbial food cultures in China in 2025].","authors":"Yingying Wu, Miao Guo, Yue Zheng, Huiting Fang, Wei Wang, Yuan Meng, Jingxia Ma, Shuang Zhang, Xuefeng Cai, Jing Xiao","doi":"10.19813/j.cnki.weishengyanjiu.2026.04.003","DOIUrl":"10.19813/j.cnki.weishengyanjiu.2026.04.003","url":null,"abstract":"<p><strong>Objective: </strong>To systematically investigate the Chinese food market for food-grade microbial strains in 2025, clarify the fundamental attributes such as the concept, classification, and efficacy types of these strains, analyze differences in domestic and international policies, standards, and management models, assess the current market development status and core issues.</p><p><strong>Methods: </strong>A combination of literature review and field survey was adopted. First, the evolution, definition, classification system, and efficacy types of food-grade microbial strains were systematically reviewed. Second, differences in the policy frameworks and management models for food-grade microbial strains between domestic and international contexts were compared. Finally, based on survey data collected from 470 ordinary food products containing food-grade microbial strains from July to October 2025, quantitative and qualitative analyses of market size, product characteristics, and existing issues were conducted.</p><p><strong>Results: </strong>The food-grade microbial strains have a long history of application, with their concepts and classifications continuously refined as biotechnology advances. In 2022, both domestic and international lists of microbial strains were updated, and the reclassification of lactobacilli had a significant impact on the food industry. The Chinese market for food-grade microbial strains showed sustained growth, reaching a terminal market size of 134.89 billion yuan in 2024. Products were diversifying and becoming more refined, with composite microbial agent-containing products dominating the market. However, issues such as non-standard labeling, unauthorized functional claims for ordinary foods, and insufficient support for food-grade microbial strain testing technology persisted. Additionally, while both domestic and international regulations prioritized safety and emphasized strain-specific characteristics, notable differences existed in regulatory classification, approval process design, and health claim requirements.</p><p><strong>Conclusion: </strong>The Chinese food market for food-grade microbial strains has significant growth potential. However, addressing existing issues requires multifaceted measures, including strengthening full-chain supervision of labeling standards, improving the inspection and testing technology system for food-grade microbial strains, strictly regulating the functional claims of ordinary foods, and enhancing the core competitiveness of domestic enterprises. These efforts will help resolve current market challenges and promote the industry's sustainable development toward standardization and high quality.</p>","PeriodicalId":57744,"journal":{"name":"卫生研究","volume":"55 4","pages":"544-553"},"PeriodicalIF":0.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148665132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Effects of Pediococcus acidilactici fermentation on the quality and functional properties of mulberry juice].","authors":"Lingna Qiu, Kuerban Kadierya, Xuening Ma, Dan Weng","doi":"10.19813/j.cnki.weishengyanjiu.2026.04.008","DOIUrl":"https://doi.org/10.19813/j.cnki.weishengyanjiu.2026.04.008","url":null,"abstract":"<p><strong>Objective: </strong>To investigate the effects of Pediococcus acidilactici fermentation on mulberry juice quality.</p><p><strong>Methods: </strong>Fresh mulberry juice was used as the raw material and inoculated with P. acidilactici strain 003W to establish a fermentation system. After fermentation at 37 ℃ for 48 h, the active components (total phenolics and anthocyanins), physicochemical indexes (pH, total acid content, reducing sugar content), antioxidant activity (DPPH and ABTS+ radical scavenging rates), and electronic tongue flavor characteristics (sourness, astringency, richness, etc. ) were evaluated before and after fermentation.</p><p><strong>Results: </strong>The result showed that after fermentation, the total phenolic content increased from 11.01 mg GAE/mL to 13.41 mg GAE/mL, and the anthocyanin content increased from 0.60 mg RE/mL to 0.79 mg RE/mL. The pH value decreased from 5.70 to 4.34; the total acid content (expressed as lactic acid) increased from 4.10 g/L to 12.24 g/L; and the reducing sugar content (expressed as glucose) decreased from 85.00 mg/mL to 75.00 mg/mL. The DPPH free radical scavenging rate and ABTS+ free radical scavenging rate reached 40.08% and 49.87% from 18.00% and 28.00%(P<0.05). Electronic tongue analysis indicated that the sourness and richness of fermented mulberry juice were enhanced, while the astringency was significantly reduced, resulting in a more harmonious flavor profile.</p><p><strong>Conclusion: </strong>This study demonstrates that fermentation by P. acidilactici 003W effectively enhances the content of active components, antioxidant capacity, and flavor characteristics of mulberry juice, offering a scientific foundation for developing high-value probiotic mulberry beverages.</p>","PeriodicalId":57744,"journal":{"name":"卫生研究","volume":"55 4","pages":"580-584"},"PeriodicalIF":0.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148665054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Factors associated with sarcopenia prevalence in the elderly in a community of Dongtai City in 2024].","authors":"Chi Zhai, Jiongnan Wang, Ting Zhong, Shiyu Yin, Bing Xu, Hongbin Zhu, Weiwei Cui, Shaokang Wang, Hui Xia, Wang Liao, Guiju Sun, Shenghong Yao","doi":"10.19813/j.cnki.weishengyanjiu.2026.04.020","DOIUrl":"https://doi.org/10.19813/j.cnki.weishengyanjiu.2026.04.020","url":null,"abstract":"<p><strong>Objective: </strong>To explore the related factors of sarcopenia in the elderly in a community of Dongtai City.</p><p><strong>Methods: </strong>Based on the National Basic Public Health Service Project, a cross-sectional survey was conducted among 806 community-dwelling elderly aged 65 and over in Dongtai City from April to June 2024. The general data and physical examination data of the elderly in the sarcopenia group and the non-sarcopenia group were compared, and Logistic regression was used for multivariate analysis.</p><p><strong>Results: </strong>The average age of 806 community elderly was (72.05±5.48) years old, including 327 males (40.57%) and 479 females (59.43%). There were 156 patients with sarcopenia, with a detection rate of 19.35%. In terms of general data, compared with the non-sarcopenia group, the elderly in the sarcopenia group showed the characteristics of advanced age, low married proportion, high non-drinking rate and low exercise frequency(P＜0.05). In terms of general data, compared with the non-sarcopenia group, the elderly in the sarcopenia group showed the characteristics of advanced age, low married proportion, high non-drinking rate and low exercise frequency(P＜0.05). In terms of physical examination data, in addition to body fat percentage, the proportion of low weight (BMI＜18.5) and obesity (BMI≥28.0) in the elderly in the sarcopenia group was higher. Waist circumference ((85.30±7.86)cm vs. (88.53±9.10)cm), hip circumference ((91.73±6.36)cm vs. (95.33±6.51)cm), average thigh circumference ((43.84±3.97)cm vs. (46.34±4.26)cm), muscle mass ((36.80±6.09)kg vs. (42.50±7.55)kg) and body fat mass ((18.93±6.49)kg vs. (20.92±6.70)kg) were significantly lower than those in the non-sarcopenia group(P＜0.05). The result of multivariate regression analysis showed that the result of multivariate regression analysis showed that advanced age (71-75 years old: OR=2.123, 95%CI 1.241-3.630; 76-80 years old: OR=5.056, 95%CI 2.918-8.760; ≥81 years old: OR=7.134, 95%CI 3.841-13.250), exercise ≥3 times/week (OR=0.635, 95%CI 0.411-0.982) and waist circumference (OR=0.958, 95%CI 0.936-0.981) were significantly associated with sarcopenia in the elderly in the community(P＜0.05).</p><p><strong>Conclusion: </strong>Advanced age is associated with an increased risk of sarcopenia in the elderly in this community, while regular exercise is associated with a decreased risk of sarcopenia.</p>","PeriodicalId":57744,"journal":{"name":"卫生研究","volume":"55 4","pages":"661-668"},"PeriodicalIF":0.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148665138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[The mediating role of malnutrition risk in associations between selected factors and disability among older adults].","authors":"Zhaowen Cheng, Yue Qiu, Zhicheng Wang","doi":"10.19813/j.cnki.weishengyanjiu.2026.04.019","DOIUrl":"https://doi.org/10.19813/j.cnki.weishengyanjiu.2026.04.019","url":null,"abstract":"<p><strong>Objective: </strong>To investigate whether malnutrition risk mediated the associations between selected factors and disability among older adults.</p><p><strong>Methods: </strong>Data were derived from the China Elderly Nutrition and Health Survey conducted in 2015. A multistage stratified cluster sampling method was used, and 3011 adults aged 60 years and older from six provincial-level sampling frames were included in the final analysis. The risk of malnutrition was assessed using the nutrition screening initiative (NSI) scale, widely implemented for community-dwelling older adults. Mediation effect analyses were performed using the testing procedures within Mplus 8 software. Parameter estimation utilized the Maximum Likelihood method, and bias-corrected 95%CI were estimated with 5000 bootstrap resamples.</p><p><strong>Results: </strong>Malnutrition risk significantly mediated several associations between selected factors and disability. Key findings included: Compared to those living and eating alone, older adults co-residing with children/grandchildren exhibited lower malnutrition risk, subsequently reducing disability risk (b=-0.103, bootstrap 95%CI -0.197--0.025, P<0.05). Higher annual household income per capita was associated with lower malnutrition risk, thereby reducing disability risk (b=-0.124, bootstrap 95%CI -0.170--0.086, P<0.001). Older adults with a chronic disease burden had higher malnutrition risk, which in turn elevated disability risk (b=0.099, bootstrap 95%CI 0.047-0.161, P<0.01). Higher nutrition knowledge levels inversely affected malnutrition risk, thereby lowering disability risk (b=-0.019, bootstrap 95%CI -0.033--0.006, P<0.01).</p><p><strong>Conclusion: </strong>The elevated disability risk observed among older adults who live and eat alone, experience poor economic security, possess low nutrition knowledge, or suffer from chronic diseases may be related to their higher malnutrition risk.</p>","PeriodicalId":57744,"journal":{"name":"卫生研究","volume":"55 4","pages":"653-660"},"PeriodicalIF":0.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148665173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Enumeration and precise identification techniques of Lactococcus in food].","authors":"Xin Li, Li Bai, Xianhui Chen, Jiayi Liu, Xiaohui Lin, Yinping Dong","doi":"10.19813/j.cnki.weishengyanjiu.2026.04.006","DOIUrl":"https://doi.org/10.19813/j.cnki.weishengyanjiu.2026.04.006","url":null,"abstract":"<p><strong>Objective: </strong>To explore qualitative and quantitative detection method for Lactococcus in food samples.</p><p><strong>Methods: </strong>Lactococcus were enumerated and isolated from commercially available food samples, systematic identification of isolates was achieved by combining techniques of colony morphology on plates, microscopic examination, biochemical reactions, metabolic substances, 16S rRNA gene sequencing, and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) analysis.</p><p><strong>Results: </strong>A total of 47 food samples including yogurt and cheese, that containing Lactococcus were collected in this study. The result indicated that the highest isolation rate of Lactococcus was observed in yogurt samples at 87.5%(7/8), followed by cheese at 58.3%(14/24). The Lactococcus content in both yoghurt and lactic acid beverage was higher than 1×107 CFU/mL. In cheese, 64.3％(9/14)contained Lactococcus between 1×106 and 1×107 CFU/g, while the remaining 35.7％(5/14)were within the range of 1×103 to 1×105 CFU/g. In biscuit, it was exceeded 1×106 CFU/g, while butter and sour cream contained approximately 1×104 CFU/g.184 strains were isolated from the aforementioned samples.59 isolates were identified as L. lactis subsp. lactis, 13 were L. lactis subsp lactis biovar diacetylactis and 3 were L. cremoris.</p><p><strong>Conclusion: </strong>The Lactococcus detection method established in this study enables the enumeration and identification of Lactococcus in food. The combination of traditional microbiological identification method with molecular biology and mass spectrometry techniques enables precise differentiation of Lactococcus species, subspecies, and even biological types in samples.</p>","PeriodicalId":57744,"journal":{"name":"卫生研究","volume":"55 4","pages":"567-588"},"PeriodicalIF":0.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148665091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Changes in energy and macronutrient composition among students aged 6-13 in Beijing in 2015 and 2019].","authors":"Yingjie Yu, Dandan Guo, Bo Yu, Xiaohui Yu, Liyu Huang, Yao Zhao, Xiaofeng Liu","doi":"10.19813/j.cnki.weishengyanjiu.2026.04.013","DOIUrl":"https://doi.org/10.19813/j.cnki.weishengyanjiu.2026.04.013","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Objective: &lt;/strong&gt;To analyze the changes in energy intake and macronutrient energy contribution among students aged 6-13 years in Beijing, between 2015 and 2019.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;A cross-sectional study was conducted in Beijing in 2015 and 2019. Participants were selected using a multi-stage stratified cluster sampling method. Briefly, three urban districts and four suburban districts were chosen. From each district, four primary schools and four middle schools were selected. Within each school, two classes were randomly chosen from grades 1, 3, and 5 of primary schools and grade 1 of middle schools. From one of the two classes in each grade, 12 students were randomly selected for the dietary survey. Valid samples included 1056 students in 2015 and 1125 students in 2019 (aged 6-13 years). Dietary data were collected using the 3-day 24-hour dietary recall method combined with household condiment weighing. Energy intake and energy contribution ratios of carbohydrate, fat, and protein were calculated using the Chinese Food Composition Table. Linear mixed-effects models (LMM) were used to examine changes in continuous outcomes (energy intake and macronutrient energy contribution), while generalized linear mixed-effects models (GLMM) were applied to analyze changes in the risk of abnormal macronutrient contribution (low carbohydrate, high fat). A year-by-district interaction term was included to explore regional heterogeneity, with year 2015 and suburban areas as the reference groups.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;No statistically significant differences were observed in the distributions of age and gender between the two survey years. However, the proportion of students from urban areas was significantly higher in 2019 compared to 2015 (χ2= 6.21, P&lt;0.05). In 2015, the energy intake (M(P25, P75)) was 1609.2 (1327.8, 2049.4) kcal/d, with carbohydrate, fat, and protein contributing 49.7%, 35.8%, and 14.5% of total energy, respectively. In 2019, the energy intake decreased to 1492.9 (1225.9, 1803.6) kcal/d, with corresponding percentages of 45.6%, 39.5%, and 14.9%. Significant main effects of year were observed: energy intake and carbohydrate contribution decreased significantly (β= -71.29 and -3.21, P&lt;0.05), while fat and protein contributions increased significantly (β= 2.87 and 0.34, P&lt;0.05). Significant year-by-district interactions indicated that the declines in energy intake and carbohydrate contribution, as well as the rise in fat contribution, were more pronounced in urban than in suburban areas (β=-199.04, -1.75, and 1.62, P&lt;0.05). The proportions of students with low carbohydrate contribution and high fat contribution increased by 20.6 and 11.6 percentage points from 2015 to 2019, respectively, with significantly elevated risks (OR=2.50 and 2.24, P&lt;0.01). The increase in risk of low carbohydrate contribution was significantly greater in urban areas (interaction OR=1.56, P&lt;0.05).&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;T","PeriodicalId":57744,"journal":{"name":"卫生研究","volume":"55 4","pages":"607-612"},"PeriodicalIF":0.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148665102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Determination of 32 pesticide residues in human urine by amino multi-walled carbon nanotubes-based dispersive solid-phase extraction coupled with ultra-performance liquid chromatography-tandem mass spectrometry].","authors":"Lingzhen Xu, Ye Wang, You Xia","doi":"10.19813/j.cnki.weishengyanjiu.2026.04.022","DOIUrl":"https://doi.org/10.19813/j.cnki.weishengyanjiu.2026.04.022","url":null,"abstract":"<p><strong>Objective: </strong>An analytical method for the determination of 32 pesticide residues in human urine was established using amino multi-walled carbon nanotubes (NH2-MWCNTs)-based dispersive solid-phase extraction combined with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).</p><p><strong>Methods: </strong>25% saturated sodium chloride solution was added to precipitate protein in the urine. The pH was adjusted to 5 using 20 mmol/L ammonium acetate solution. The target analytes were adsorbed onto amino multi-walled carbon nanotubes, followed by desorption with acetonitrile. Finally, the extract was analyzed by UPLC-MS/MS.</p><p><strong>Results: </strong>Good linearity for the 32 pesticides was observed within the concentration range of 1-100 μg/L, with correlation coefficients (r) all above 0.999. Fortified at three concentration levels (4, 40, and 200 μg/L, n=6), average recoveries were obtained in the range of 91.2%-110.0%, with relative standard deviations ranging from 1.1%-4.6%. The limits of detection and quantification were determined to be 0.003-0.03 μg/L and 0.01-0.1 μg/L, respectively. The adsorption process of the 32 pesticides onto the NH2-MWCNTs was found to be well described by the pseudo-second-order kinetic model and the Langmuir isotherm model.</p><p><strong>Conclusion: </strong>This method is simple and rapid to operate, accurate, and highly sensitive, enabling the rapid detection of 32 pesticide residues in human urine.</p>","PeriodicalId":57744,"journal":{"name":"卫生研究","volume":"55 4","pages":"676-684"},"PeriodicalIF":0.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148665044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Epidemiological characteristics and changes of screen time among students aged 6-14 years in Beijing in 2015 and 2019].","authors":"Xinyue Guo, Yao Zhao, Dandan Guo, Bo Yu, Xiaohui Yu, Xiaofeng Liu, Yingjie Yu","doi":"10.19813/j.cnki.weishengyanjiu.2026.04.012","DOIUrl":"https://doi.org/10.19813/j.cnki.weishengyanjiu.2026.04.012","url":null,"abstract":"<p><strong>Objective: </strong>To analyze the characteristics and changes in screen time among students aged 6-14 years in Beijing in 2015 and 2019.</p><p><strong>Methods: </strong>A multistage cluster sampling approach was adopted. A survey on after-school screen time was conducted among students in grades 1, 3, 5, and 7 (first year of junior high school) in 7 districts of Beijing in 2015 and 2019, using the Nutrition and Health Status Questionnaire developed by the Beijing Center for Disease Prevention and Control. A total of 4152 primary and secondary school students were surveyed in 2015, and 4202 in 2019. The Mann-Whitney U test and chi-square test were employed to analyze differences in daily average screen time and the prevalence of exceeding the daily screen time limit among respondents with different demographic characteristics. Using a generalized linear mixed model (GLMMs) to analyze the association between different years, gender, age, residential areas, and whether screen time exceeds the limit.</p><p><strong>Results: </strong>Survey result showed that the median screen time of respondents was 54 (31, 84) min/d in 2015 and 41 (26, 69) min/d in 2019, representing a decrease of 13 min/d (P<0.01). The prevalence of exceeding the daily screen time limit (≥2 h/d) was 10.06% (403/4005) in 2015 and 5.01% (203/4052) in 2019, a reduction of 5.05 percentage points (P<0.01). Compared with 2015, the daily average screen time (school days, weekends, and the entire week) of respondents across different genders, age groups, and regions all decreased in 2019 (male：Z=-6.95, Z=-9.37, Z=-9.55；female：Z=-4.63, Z=-10.77, Z=-8.94；6-9 years：Z=-4.12, Z=-8.38, Z=-7.06；10-14 years：Z=-7.63, Z=-11.89, Z=-11.63；urban：Z=-5.37, Z=-10.48, Z=-9.11；suburban：Z=-6.13, Z=-10.02, Z=-9.62；P <0.01). GLMMs analysis revealed that the daily average screen time exceeding rate among survey subjects in 2019 was lower than in 2015 (β = -0.74, OR=0.48，95% CI 0.40-0.57). Compared with their counterparts with the same characteristics, respondents who were male (β = 0.26, OR=1.29, 95%CI 1.09-1.53), aged 10-14 years(β=0.67，OR=1.95，95%CI 1.64-2.32), and residing in suburban areas (β=0.57, OR=1.77, 95%CI 1.47-2.12) had a significantly higher rates of excessive screen time (P<0.01).</p><p><strong>Conclusion: </strong>The daily average screen time and prevalence of excessive screen time among primary and secondary school students in Beijing decreased significantly overall in 2019 compared with 2015. However, male students, age 10-14 years, and those residing in suburban areas consistently had higher screen time and a higher prevalence of excessive screen time than their counterparts within the same categories.</p>","PeriodicalId":57744,"journal":{"name":"卫生研究","volume":"55 4","pages":"601-606"},"PeriodicalIF":0.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148665055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Development of a qPCR assay for quantitative detection of Streptococcus mutans utilizing lyophilized reference materials and its application in quantifying S. mutans from probiotics co-cultures].","authors":"Rui Guo, Yuefeng Wang, Qian Liao, Jie Lyu, Huijing Liang, Haiping Zhang, Shenghui Cui","doi":"10.19813/j.cnki.weishengyanjiu.2026.04.007","DOIUrl":"https://doi.org/10.19813/j.cnki.weishengyanjiu.2026.04.007","url":null,"abstract":"<p><strong>Objective: </strong>To establish a quantitative real-time polymerase chain reaction (qPCR) method for detection of Streptococcus mutans based on ready-to-use lyophilized reference materials (RMs) and apply it in screening of probiotics against cariogenic S. mutans.</p><p><strong>Methods: </strong>Primers and probes were designed targeting the gtfB gene, a specific single-copy gene associated with the core cariogenicity of S. mutans. A qPCR detection method was established and systematically validated. Ready-to-use lyophilized RMs derived from S. mutans ATCC 25175 with high uniformity and stability were prepared to construct a quantitative regression model between cycle threshold (Ct) and colony forming units (CFU). This was then utilized to accurately quantify S. mutans in multi-species cultures mixed with four strains of probiotic, respectively and thereby evaluating their inhibitory activities.</p><p><strong>Results: </strong>The established qPCR method exhibited excellent analytical specificity, yielding positive amplification only for 10 strains of S. mutans (Ct=14.84-16.79) with no cross-reactivity against 18 strains of microbials other than S. mutans. The limit of quantification was 2.10×103 CFU/mL, showing a high concordance rate (91.59%-108.76%) with traditional plate counting method. The prepared lyophilized RMs met the China national standard requirements for uniformity, with a mean Ct value of 17.45 (SD=0.13) across 20 individual samples, allowing for direct quantitative detection without pre-activation. Evaluation of intervention revealed that all four strains of probiotics (three for Ligilactobacillus salivarius and one for Lacticaseibacillus paracasei) exerted inhibitory effects on S. mutans with a characteristic of strain-specific. The inhibitory potency followed the order of L. salivarius BH0006> BH0004> BH0005> L. paracasei BH0013.</p><p><strong>Conclusion: </strong>The qPCR quantification assay based on standardized lyophilized RMs developed in this study is of high sensitivity, specificity, and accuracy. It effectively overcomes the technical bottleneck of quantifying S. mutans in multispecies cultures.</p>","PeriodicalId":57744,"journal":{"name":"卫生研究","volume":"55 4","pages":"573-579"},"PeriodicalIF":0.0,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148665110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}