测定鲜食用菌中总汞含量的直接测汞仪法

目的 建立鲜食用菌中总汞快速准确的测量方法。方法 使用HydraⅡ型测汞仪,样品直接进样,对50份样品进行测定。结果 结果表明,在1.0～200 ng范围内线性良好,相对标准偏差为1.40%～5.56%,回收率在93.3%～106.5%之间,最低检出限为0.218μg/kg,满足实验要求。结论 使用测汞仪直接测定鲜食用菌中总汞含量,具有灵敏度高、方便快捷,无须前处理等优点,便于推广,适用于鲜食用菌中总汞的快速测定。     

直接测汞仪快速测定食品中的总汞

利用DMA-80直接测汞仪,建立食品中总汞的快速测定方法。食品置于样品舟中,无需前处理直接测定其总汞含量。结果表明,本法在0~100 ng范围内呈良好线性关系,加标回收率为96.3%~108.6%,精密度为3.32%,检出限为0.4μg/kg。分析菠菜和圆白菜标准物质,检测结果准确可靠。本法检出限低,回收率高,精密度好,操作简便,适用于食品中总汞含量的准确快速测定。     

全自动测汞仪直接测定食品中总汞

目的运用MA-3000全自动测汞仪,结合运用还原催化和金汞齐富集技术,建立直接测定固体、液体食品中汞含量的方法。方法将固体食品样品用粉碎机粉碎之后精确称取适量,液体样品准确量取一定体积,应用全自动测汞仪建立汞标准曲线,直接测定食品样品的汞含量。结果经试验确定食品样样品直接测定汞,测定优化条件为分解温度850℃,分解时间为2 min。在最佳实验条件下,标准汞溶液在0.0 ng~200.0 ng时,呈现较好的线性关系,标准曲线相关系数≥0.999 8,加标回收实验汞回收率为96.6%~104.9%,测定结果的相对标准偏差为2.87%~3.47%,方法检出限为0.005 5 ng。结论该方法与原子荧光法比较,2种方法差异无统计学意义。本方法操作简便、快捷、准确、灵敏、重复性好,适合快速批量直接进样测定蔬菜、海产品、谷物、人体尿液、头发中总汞,结果令人满意。     

DMA-80直接测汞仪测定尿中总汞

目的:采用DMA-80直接测汞仪建立尿中总汞含量的直接测定方法。结果:方法在0~500 ng范围内线性良好,检出限为0.3μg/L,RSD为0.83%~2.46%,加标回收率为99.6%~107.0%,对质控样进行检测,结果满意。结论:该方法简便、快速、灵敏度高、结果准确,适用于对尿中总汞的测定。     

直接测汞仪测定尿中总汞

【目的】建立以直接测汞仪测定尿汞的方法。【方法】利用DMA80型直接测汞仪对尿样进行分析测定。【结果】该方法在尿汞为1.0～200.0 ng水平时具有良好的线性关系,该方法检出限为0.4μg/L,样品测定精密度为0.38%～1.68%,回收率为92.6%～96.9%。【结论】该方法可以作为尿中总汞的日常检测方法。     

微波消解-原子荧光光谱法测定生物样品中微量汞

目的建立生物样品中微量汞的原子荧光光谱测定方法。方法采取微波消解,氢化物发生-原子荧光光谱对生物样品中汞进行测定。结果线性范围为0～2.00μg/L,相关系数为0.9998,方法检出限为0.023μg/L,平均回收率在96.40%～99.82%,相对标准偏差为1.23%～1.59%。结论本测定方法具有检出限低、灵敏度高、简便、快速、准确、线性范围宽等优点,能满足职业中毒调查中准确测定生物样品中微量汞的要求。     

直接测汞仪法快速测定婴幼儿配方乳粉中汞

目的建立直接测汞仪快速检测婴幼儿配方乳粉中汞的方法。方法通过正交试验优化仪器条件,设定干燥温度250℃,干燥时间60 s,分解温度700℃和分解时间120 s,直接称样测定汞。结果方法线性范围0~600μg/L,r≥0.9990,方法检出限为0.1μg/kg,高、中、低浓度加标回收率为88.0%~109.4%,精密度≤3.4%。结论该方法快速准确,样品无需前处理,环境污染小,适用于婴幼儿配方乳粉中汞的快速测定。     

原子荧光法测透析用水中砷硒锑汞

目的:建立透析用水中砷、硒、锑、汞四种微量元素的原子荧光分析法。方法:水中砷和锑加还原剂后同时测定;硒经硝酸高氯酸氧化后,再经盐酸还原后测定;汞直接加硝酸使酸度为5%后测定。结果:汞的检出限为0.024μg/L;硒的检出限为0.044μg/L;砷的检出限为0.011μg/L;锑的检出限为0.015μg/L。结论:本法用来测定透析用水中极其微量的砷、硒、锑、汞简便快速,且在双道原子荧光法仪中可同时进行砷和锑的检测。     

肌酐校正—碱性硼氢化钾还原法测定尿液中的汞

目的:研究肌酐较正—碱性硼氢化钾还原—冷原子吸收光谱法测定汞的方法。方法:尿样以硼氢化钾还原,在253.7 nm波长下,读取最大峰值。根据标准系列峰值与浓度的线性关系,经肌酐较正计算样品中汞的浓度。结果:尿汞在2.0～180μg/L的范围内,检测浓度与峰值呈直线相关关系,回归方程Y=2.86×103x+16.9,最低检出浓度为2.0μg/L,精密度0.377%～1.82%,回收率91.1%～104.0%,尿汞浓度须经肌酐较正。结论:方法快速简便,精密准确,适用于大批量样品的现场分析。     

化妆品中汞含量的热解析快速测定法

目的建立利用热解析法对化妆品中汞含量快速测定的方法。方法确定进行汞含量测定所需要的仪器工作参数。研究样品检测所需的不同实验条件,做出标准曲线。结果相对标准偏差小于3%,样品加标回收率在95%～105%之间,方法的检出限为0.02 ng。结论方法的精密度、准确度良好,且简单、快速,准确,适用于化妆品中汞含量的测定。     

Calcium intake in the elderly: validation of a dietary questionnaire

Epidemiological studies of calcium and osteoporosis have been hampered by the lack of a suitable tool for assessing calcium intake. This report describes a new frequency and amount questionnaire for measuring present and past calcium intake in the elderly. The validity of the questionnaire was tested against two commonly used standards of dietary assessment, five-day duplicate diets and seven-day weighed dietary inventories. The resulting correlation coefficients were, respectively, r = 0.76 and r = 0.69, while that for repeatability was r = 0.84. Furthermore, the questionnaire categorized subjects into thirds of the distribution of intake with almost no gross misclassification. It is suggested that the present findings may be extended to the majority of normal, healthy elderly subjects, implying wide application for the questionnaire in the assessment of calcium intake in the elderly.     

The occurrence of antimicrobial substances in toilet,sink and shower drainpipes of clinical units: A neglected source of antibiotic residues

Antibiotics represent one of the most important drug groups used in the management of bacterial infections in humans and animals. Due to the increasing problem of antibiotic resistance, assurance of the antibacterial effectiveness of these substances has moved into the focus of public health. The reduction in antibiotic residues in wastewater and the environment may play a decisive role in the development of increasing rates of antibiotic resistance. The present study examines the wastewater of 31 patient rooms of various German clinics for possible residues of antibiotics, as well as the wastewater of five private households as a reference.To the best of our knowledge, this study shows for the first time that in hospitals with high antibiotic consumption rates, residues of these drugs can be regularly detected in toilets, sink siphons and shower drains at concentrations ranging from 0.02?μg·L^?1 to a maximum of 79?mg·L^?1. After complete flushing of the wastewater siphons, antibiotics are no longer detectable, but after temporal stagnation, the concentration of the active substances in the water phases of respective siphons increases again, suggesting that antibiotics persist through the washing process in biofilms. This study demonstrates that clinical wastewater systems offer further possibilities for the optimization of antibiotic resistance surveillance.     

Self-reported health problems among Swedish miners one year after unemployment

Unemployment is considered to be a public health concern sincedeterioration in the health of the unemployed is often anticipated.However, for some groups, such as miners, unemployment mightimprove health due to a cessation of potentially harmful occupationalexposures. This study evaluates the health of 79 miners in oneSwedish iron-ore mine, and 226 age-matched controls from thegeneral population, during one year after the closure of themine. The participants received a questionnaire regarding medicalhistory and subjective symptoms at the beginning of the studyperiod, and after one year. Statistically significant negativeeffects on self-reported health attributable to unemploymentwere not found, although neuropsychiatric symptoms were morecommon among the unemployed miners. The miners reported a statisticallysignificant improvement in grip force (p=0.031). They had asignificantly higher prevalence of symptoms associated withmining related exposures when compared with the population controls;pain in the upper extremities [relative risk (RR)=2.27, 95%confidence interval (Cl)=1.44–3.59), back pain (RR=1.84;Cl=1.237–2.75), vasospastic disease of the fingers (RR=2.05;Cl=1.18–3.57) and obstructive respiratory symptoms (attacksof dyspnea and wheezing: RR=3.67; Cl=1.167–11.6).     

Excès de cas humains et animaux de tularémie en France au cours de l’hiver 2007–2008 : émergence ou phénomène isolé ?

Context

Tularemia is a zoonosis affecting humans and hares in France. We describe the results of surveillance in both species, in 2007 and 2008.

Methods

Human tularemia cases are mandatorily notifiable in France since 2003. In hares, surveillance relies on volunteer hunter associations in all districts of the country. Data from mandatory reports and volunteer surveillance in 2007/2008 were analyzed and compared with previous results.

Results

In 2007/2008, 144 cases were reported in humans and 117 cases in hares. This was a 100% increase compared to previous years. Human cases differed from those of previous years only by the frequency of contact with breeding animals. Human cases without any documented risk exposure were also more frequent.

Conclusion

An increase of tularemia cases occurred in 2007/2008 in both species. Complementary studies are needed to identify the species reservoir in France to understand the causes of this peak of cases.     

Occupational health hazards in mining: an overview

This review article outlines the physical, chemical, biological, ergonomic and psychosocial occupational health hazards of mining and associated metallurgical processes. Mining remains an important industrial sector in many parts of the world and although substantial progress has been made in the control of occupational health hazards, there remains room for further risk reduction. This applies particularly to traumatic injury hazards, ergonomic hazards and noise. Vigilance is also required to ensure exposures to coal dust and crystalline silica remain effectively controlled.     

Manufacture and use of nanomaterials: current status in the UK and global trends

This paper provides an overview of the production and use of nanomaterials (NMs), particularly in the UK. Currently, relatively few companies in the UK are identifiable as NM manufacturers, the main emphasis being the bulk markets in metals and metal oxides, and some niche markets such as carbon nanotubes and quantum dots. NM manufacturing in the UK does not reflect the global emphasis on fullerenes, nanotubes and fibres. Some assumptions have been made about the types of NM that are likely to be imported into the UK, which currently include fullerenes, modified fullerenes and other carbon-based NMs including nanotubes. Many university departments, spin-offs and private companies have developed processes for the manufacture of NMs but may only be producing small quantities for research and development (R&D) purposes. However, some have the potential to scale up to produce large quantities. The nanotechnology industry in the UK has strong R&D backup from universities and related institutions. This review has covered R&D trends at such institutions, and appropriate information has been added to a searchable database. While several companies are including NMs in their products, only a few (e.g. manufacturers of paints, coatings, cosmetics, catalysts, polymer composites) are using nanoparticles (NPs) in any significant quantities. However, this situation is likely to change rapidly. There is a need to collect more information about exposure to NPs in both manufacturing and user scenarios. As the market grows, and as manufacturers switch from the micro- to the nanoscale, the potential for exposure will increase. More research is required to quantify any risks to workers and consumers.     

深圳公立医院管理体制改革制度设计

深圳公立医院管理体制改革实行政事分开、管办分开,在理事会架构下按法定机构模式组建市医管中心,落实公立医院运营管理自主权.作者从当前公立医院管理体制的弊端入手,介绍了深圳市进行公立医院管理体制改革的基本思路及改革方案设计的主要举措,深入剖析了的改革方案的特点,并对改革效果进行了预测.     

Effects of nitrogen dioxide on red blood cells of rats: Changes in components of red cell membranes during in vivo exposure to NO2

Red cell membranes, prepared from red blood cells of rats exposed to 4, 10, or 20 ppm nitrogen dioxide (NO₂) for 1 to 10 days, were examined for evidence of changes in membrane components. Appreciable changes were not found in contents of phospholipid and cholesterol during exposure to 10 ppm NO₂. By contrast, protein content altered with the time of exposure. Moreover, changes in protein composition were observed by employing sodium dodecyl sulfate — polyacrylamide gel electrophoresis. Twenty-four-hour exposure to NO₂ at the concentration above 10 ppm resulted in a marked increase in the percentage of lysophosphatidylethanolamine (LysoPE) to the total phospholipids. The prolonged exposure to 10 ppm NO₂ gave rise to a further increase in LysoPE, whereas the percentage of phosphatidylethanolamine (PE) showed a gradual decrease. A 1-day exposure to 4.0 ppm NO₂ also caused an increase in sialic acid content and decreases in those of PE and hexose. In addition to contents of these components the percentage of LysoPE increased 5 days after exposure and the elevated values were maintained up to the end of exposure period. These results demonstrate that red blood cells in circulation exhibit different membrane properties in terms of lipid and carbohydrate composition during 10 days of exposure to 4.0 ppm NO₂.     

Investigating clusters in the workplace and beyond

Clusters of disease are common and occur in the workplace and in the general community. They often arouse considerable concern among the population. Investigations have sometimes lead to exciting new knowledge, but in general the investigation of clusters is difficult and often unrewarding, especially for community clusters. In the workplace, investigations are more likely to find associations and even new causes, but still many clusters remain enigmatic. Despite this, there are many reasons for investigating clusters, including allaying community concern and identifying uncontrolled exposures. A structure for investigating clusters in the workplace is suggested.