BackgroundPrevious research indicated that isomers and alternatives of per- and polyfluoroalkyl substances (PFAS) probably disturb glucose metabolism; however, current epidemiological evidence on the associations of PFAS with fasting blood glucose is inconsistent. Besides, studies on the joint association of multiple components of PFAS and fasting blood glucose as well as the key component are scarce. ObjectiveTo evaluate the associations of PFAS isomers and alternatives with fasting blood glucose and their joint effects, as well as identify the key component among population without glucose metabolism problems. MethodsWe selected 923 adults without glucose metabolism problems or missing data from the Isomers of C8 Health Project in China (2015—2016). Serum PFAS isomers and alternatives and fasting blood glucose were measured using ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) and automatic biochemical analyzer. We applied multiple linear regression to explore the associations of 16 pollutants which were detected among over 80% participants with fasting blood glucose. Meanwhile, we utilized qgcomp and Bayesian kernel machine regression (BKMR) models to explore the joint effects of PFAS isomers and alternatives mixture on target outcome indicators and identify the key component. ResultsThe average age among the 923 participants in this study was (62.4±13.8) years old, including 472 men (51.1%) and 451 women (48.9%). Among selected PFAS isomers and alternatives, the highest serum concentration was ∑3+4+5m-PFOS (perfluoro-3/4/5-methylheptanesulfonate) with a median concentration of 10.20 ng·mL−1. The concentrations of linear perfluorooctane sulfonate (n-PFOS, 9.61 ng·mL−1), perfluorooctanoic acid (PFOA, 4.55 ng·mL−1), linear perfluorohexane sulfonic acid (n-PFHxS, 2.48 ng·mL−1), 6:2 chlorinated polyfluorinated ethersulfonic acid (6:2 Cl-PFESA, 1.90 ng·mL−1), perfluoro-6-methylheptanesulfonate (iso-PFOS, 1.85 ng·mL−1), perfluorobutanoic acid (PFBA, 1.81 ng·mL−1), perfluorinated n-nonanoic acid (PFNA, 1.39 ng·mL−1), and perfluoro-1-methylheptanesulfonate (1m-PFOS, 1.27 ng·mL−1) were higher than 1.00 ng·mL−1. After being adjusted for selected confounders, PFAS isomers and alternatives were positively associated with fasting blood glucose. With 1 ln unit concentration increment of 6:2 Cl-PFESA and PFNA, the estimated changes of fasting blood glucose were 0.18 (95%CI: 0.13, 0.23) mmol·L−1 and 0.24 (95%CI: 0.18, 0.30) mmol·L−1, respectively. The multi-pollutant models indicated a joint association of PFAS isomers and alternatives mixture with fasting blood glucose. The BKMR models reveals that as the quantiles of mixture elevated from the 50th to the 75th percentile, the values of fasting blood glucose increased 0.25 (95%CI: 0.21, 0.30) mmol·L−1, and the posterior inclusion probability of PFNA was 0.92, implying that PFNA was the key component. ConclusionPFAS isomers and alternatives are positively associated with fasting blood glucose. PFNA is the key component of the joint association.

目的 了解本地区学龄前儿童25羟基维生素D[25-hydroxyvitamin,D 25(OH)D]的人群分布特征,制定适合本地区学龄前儿童25(OH)D的生物学参考区间,为学龄前儿童健康检查提供参考依据.方法 收集2021年5月至12月深圳市宝安区石岩街道幼儿园健康检查标本,采用胶乳免疫比浊法使用贝克曼AU5800全自动生化仪检测25(OH)D.结果 3785名学龄前儿童的25(OH)D检测结果呈偏态分布;男、女性别间差异有统计学意义(P<0.05),男孩血浆中25(OH)D水平高于女孩;不同年龄组间差异有统计学意义(P<0.05),随着年龄增长,幼儿25(OH)D水平呈下降趋势(P<0.05);制定的学龄前25(OH)D生物学参考区间为9.1～34.9ng/mL;参考国际、国内多数机构和专家共识(医学决定水平),本研究中52.4％的学龄前儿童VD正常,VD不足的占40.0％,VD缺乏的占7.6％.结论 基于本地区人群分布特征数据的研究建立的25(OH)D生物学参考区间具有重要的临床应用价值.

BACKGROUND:The global prevalence of autism spectrum disorder (ASD) is on the rise, and high levels of exposure to toxic heavy metals may be associated with this increase. Urine analysis is a noninvasive method for investigating the accumulation and excretion of heavy metals. The aim of this study was to identify ASD-associated urinary metal markers.METHODS:Overall, 70 children with ASD and 71 children with typical development (TD) were enrolled in this retrospective case-control study. In this metallomics investigation, inductively coupled plasma mass spectrometry was performed to obtain the urine profile of 27 metals.RESULTS:Children with ASD could be distinguished from children with TD based on the urine metal profile, with ASD children showing an increased urine metal Shannon diversity. A metallome-wide association analysis was used to identify seven ASD-related metals in urine, with cobalt, aluminum, selenium, and lithium significantly higher, and manganese, mercury, and titanium significantly lower in the urine of children with ASD than in children with TD. The least absolute shrinkage and selection operator (LASSO) machine learning method was used to rank the seven urine metals in terms of their effect on ASD. On the basis of these seven urine metals, we constructed a LASSO regression model for ASD classification and found an area under the receiver operating characteristic curve of 0.913. We also constructed a clinical prediction model for ASD based on the seven metals that were different in the urine of children with ASD and found that the model would be useful for the clinical prediction of ASD risk.CONCLUSIONS:The study findings suggest that altered urine metal concentrations may be an important risk factor for ASD, and we recommend further exploration of the mechanisms and clinical treatment measures for such alterations.

目的 比较不同萃取溶剂对蔬果中21种有机氯农药的提取效果,以探索蔬果中有机氯农药的最佳提取体系.方法 选取菠菜、苹果、土豆这3种常见蔬果为代表采集样品,匀浆后分别以乙腈、乙酸乙酯、丙酮、正己烷和1:1(V/V)的乙腈-丙酮、乙腈-乙酸乙酯、乙腈-正己烷、乙酸乙酯-丙酮、丙酮-正己烷和乙酸乙酯-正己烷混合溶剂为萃取剂,经QuEChERS净化后,用气相色谱-质谱法检测样品中的有机氯农药残留.结果 上述4种单一溶剂以及6 种混合溶剂的平均萃取效率分别为 82.5％、80.6％、78.6％、76.5％、92.9％、83.6％、90.3％、82.5％、85.4％、84.1％.结论 混合溶剂较单一溶剂萃取效率更高;其中乙腈-丙酮和乙腈-正己烷这2种混合溶剂对蔬果中21种常见有机氯农药的萃取效率最高且稳定性好,可作为常见农药残留的萃取溶剂,以作参考.

目的 对深圳市某高尔夫球杆生产企业在正常生产期间出现的53例职业性手臂振动病(occupational hand-arm vibration disease,OHAVD)进行职业卫生学分析,为高尔夫生产企业的职业卫生防护提供科学依据.方法 通过现场职业卫生调查及检测检验,结合职业健康检查、职业病鉴定结果等,对某高尔夫球杆生产企业2013-2016年期间发生的职业性手传振动病患者进行调查分析.结果 该厂共有生产员工1 772人,手传振动工人职业接触率占23.87％,主要以木杆头、铁杆头制作为主;对47个手传振动岗位的ahw(4)进行检测,26个岗位超标,不合格率为55.32％,但超标岗位均未超过9 m/s2;53例OHAVD患者,轻度51例(96.22％),中度2例(3.77％),患者症状普遍较轻;经劳动能力鉴定,2例患者劳动能力为六级(3.77％),其他均为八级(96.22％).结论 该企业工作场所手传振动岗位存在超标超时严重,企业存在设备布局不合理,无有效的减振措施及个体防护等问题.

Objective:To analyze the uncertainty of spectrophotometry method determination of urea in swimming pool water.Method:Urea content in swimming pool water was detected by spectrophotometry method,uncertainty of test results was analyzed based on uncertainty evaluation criteria. Result:When sampling for 10 mL,k=2,the content of the detection result of the urea was 0.746 mg/L,the uncertainty was 0.101 mg/L. Conclusion:Uncertainty of test results of urea content in the pool water are composed of a number of components,spectrophotometric determination reflects the scientific nature,is with important guiding significance for the swimming pool water quality monitoring.

目的 建立空气中二丙二醇甲醚的采样和气相色谱测定方法.方法 用活性炭管采集,二氯甲烷-甲醇(85∶15,V/V)解吸,经HP FFAP毛细管柱分离后,用火焰离子化检测器(FID)测定,以外标法定量.结果 标准曲线在20 μg/ml ～ 500 μg/ml线性关系良好,回归方程为y=56.70x-0.166,相关系数r=0.9992.最低检出限为0.75μg/ml,定量下限为2.5 μg/ml,以采集1.5L标准状态下的空气计算,最低检出浓度为0.5 mg/m3,定量下限为1.7 mg/m3.一缩二乙二醇、一缩二丙二醇、二乙二醇甲醚、二乙二醇二甲醚、二乙二醇二乙醚等共存时,不干扰测定.日内精密度为0.4％ ～2.5％,日间精密度为2.5％～4.5％.100 mg活性炭的穿透容量＞14.0 mg,采样效率为100％.解吸效率为86.4％ ～ 95.5％,RSD为2.3％ ～3.0％.结论 本法满足GBZ/T 210-2008的要求,可用于空气中二丙二醇甲醚的测定.

目的 建立工作场所空气中二丙二醇甲醚的采样和气相色谱测定方法.方法 用活性炭管采集,85+15二氯甲烷-甲醇(v/v)解吸,经HP FFAP毛细管柱分离,火焰离子化检测器(FID)测定,外标法定量.结果 在20～500μg/ml范围内线性好,回归方程A=56.70C-0.166,相关系数r=0.999 2.一缩二乙二醇,一缩二丙二醇,二乙二醇甲醚,二乙二醇二甲醚,二乙二醇二乙醚等共存时不干扰测定.结论 本法满足《工作场所空气中毒物检测方法的研制规范》的要求,可用于工作场所空气中二丙二醇甲醚的测定.

目的:探讨实验室质量控制管理的重点及意义.方法:联系本所微生物实验室的实际情况,讲述实验室质量控制管理的要点.结论:通过从加强微生物检验室质量管理体系、检验人员以及检验质量控制前、中、后阶段的控制,以此来全面做好对微生物检验质量控制工作.

Objective To investigate the content of trans fatty acid in food by using gas chromatography.Methods The contents of trans fatty acid in several kinds of fat products were determinated and analysed by using gas chromatography.Results The trans-and cis-fatty acids were separated with each other,and the result showed that the contents of trans fatty acid were 9.9%～14.3% in butter and 12.8% in cream.Conclusion Gas chromatography has the advantages of simplicity,repeatability and sensitivity,and it can be used for detecting trans fatty acids in food in many laboratories.

Objective: To investigate sanitary status of drinking water(pure water,mineral spring water) from barreled,bottled,straight drinking,tap and well at some towns of Shenzhen city,and provide the evidence for sanitary supervision and management.Methods:Test and analysis sample of drinking water(pure water,mineral water),including barreled water,bottled water,straight drinking water,tap and well water between 2005~2007 by random and submittal inspection.Results: Among 599 samples,542 samples were qualified,the tatal passing rate of 87.5%.Among them,the passing rate of barreled or bottled water is 93.6%,straight drinking water 91.2%,tap water 89.9% and well water 61.1%.Conclusion:The sanitary status of drinking water at some towns of Shenzhen city is good.

[Objective]To analyze and evaluate the uncertainty components in measuring nitrates content in water.[Methods]Based on evaluation and denotation of measuring uncertainty(JJF1059-1999),mathematic model of uncertainty was established,and the synthesis uncertainty and expansion uncertainty of nitrate in water by ultraviolet spectrophotometry was obtained.[Results]In determination of nitrates content in water by ultraviolet spectrophotometry,when contents of nitrate were between 0.20~ 8.0 mg/L,synthesis uncertainty was 0.044 mg/L and expansion uncertainty was 0.09 mg/L.[Conclusion]Analysis of measurement uncertainty can control the confidence and accurateness of results,and ensure the quality of measurement.

Objective To establish a method for determination of n-hexane in the air of working place by solvent desorption gas phase chromatography. Methods The expriments were conducted in laboratory and on the site according to <Standardard technique for determination of toxic substances in the air of workshop>. Results The recovery rates of solvents desorption gas phase chromatographiy in determining n-hexane in the air of workplace were 93.4%～96.1% and the minimum detection limit was 0.5mg/m3. 0.5mg/m3; the relative standard deviation (RSD) of different solubility was 0.4%～1.3%; Linear scope was 0.0～892.8μg/ml; The coexistence of normal heptane and n-pentane with n-hexane in the air did not interfere with the results of determination. Conclusion This method meets the requirement of <Standardard technique for determination of toxic substances in the air of workshop> and it is suitable for determination of n-hexane in the air of workplace.