测定海参中硒含量的微波消解-氢化物原子荧光光谱法

目的 建立微波消解—氢化物原子荧光光谱法测定海参中硒的方法.方法 以微波消解处理样品,氢化物原子荧光光谱法进行测定.结果 测定硒的线性范围为0 ～ 100 μg/L,相关系数为0.9994,方法回收率为92.9％～ 104.5％,精密度为4.4％～7.3％.结论 该方法灵敏度和准确度高,操作简便,具有较低的检出限,可以用于海参中硒含量的测定.     

微波消解—原子荧光光谱法测定富硒精米中硒

目的建立微波消解—氢化物发生原子荧光光谱法测定富硒精米中硒的方法。方法富硒精米样品经微波消解后,用氢化物原子荧光光谱法测定富硒精米中硒的浓度。结果本法在硒浓度为0～10μg/L范围有良好的线性关系,相关系数r=0.9997,检出限为0.002 mg/kg;相对偏差为0.57%～2.7%;回收率为99.8%～101.0%。结论该方法具有简便、快速、灵敏度高等优点,适合日常批量检测。     

膨化食品中铅的氢化物-原子荧光测定法

目的 建立氢化物-原子荧光法测定膨化食品中铅的方法.方法 用硝酸-高氯酸微机消解仪消化样品,氢化物-原子荧光法进行测定.结果 该法的线性检测范围为0～100 μg/L,检出限为0.31 μg/L,回收率为 93.4%～105.6%.结论 该法适用批量样品消解、检测,具有操作简便、快速、灵敏度和精密度高、结果可靠的优点,适合膨化食品中铅的检测分析.     

空气中碲的微波消解-氢化物发生原子荧光测定法

目的 研究氢化物发生原子荧光法测定工作场所空气中碲的前处理方法.方法 将微孔滤膜经微波消解后,应用氢化物发生原子荧光法测定碲的含量.结果 线性范围为0.11-40.0μg/L,检出限为0.11μg/L,最低检出浓度为9x10-5mg/m3(以采集30L空气样品计),样品加标回收率为95.5%～98.2%,RSD＜3%.结论 微波消解-氢化物发生原子荧光法快速准确,灵敏度高,精密度好,可用于工作场所空气中碲的测定.     

北虫草中硒的微波消解，氢化物-原子荧光光谱测定法

目的　建立微波消解样品 ,氢化物发生 -原子荧光光谱测定北虫草中微量硒Se的方法。方法　用微波消解样品 ,原子荧光测定含量。结果　在优化条件下 ,方法检出限为 0 15ng/ml,相对标准偏差 5 87% ,线性范围 0～ 10 0ng/ml,相关系数r=0 9997,不同浓度回收率 99 8%～ 10 5 8%。结论　用微波消解 ,氢化物 -原子荧光光谱法对北虫草中硒测定 ,此方法简便且灵敏度高。     

茶叶中硒的微波消解-原子荧光测定法

目的 建立微波消解-原子荧光法测定茶叶中硒的方法.方法 样品经硝酸-双氧水微波消解后,用原子荧光光度计对其中的硒含量进行检测.结果 在最佳实验条件下,硒的检出限为0.188 μg/L,相对标准偏差＜3.41％,用国家标准物质绿茶测定结果,回收率为92.0％～103.2％.结论 该方法操作简单,精密度高,结果准确可靠,适用于茶叶中硒的测定.     

头发中硒的微波消解氢化物原子荧光光谱测定法

目的建立微波消解氢化物原子荧光光谱法测定头发中硒的分析方法。方法样品经微波消解后采用氢化物原子荧光光谱法测定头发中的硒,通过控制硼氢化钾浓度和溶液酸度来提高方法的灵敏度。结果实验表明,方法的线性范围0~20μg/L,相关系数r0.999 0,检出限为0.42μg/L,测定值在标准物质标准值不确定度范围内,相对标准偏差小于8%。结论该方法操作简单、快速,结果准确、可靠,适用于头发中硒的测定。     

微波消解-氢化物发生原子荧光光谱法测定人发中总硒

目的:建立微波消解-氢化物发生原子荧光光谱测定人发中硒的方法。方法:发样经微波消解后,以抗坏血酸、硫脲为还原剂,用氢化物发生原子荧光光谱测定硒的浓度。结果:本法在硒浓度为0μg/L～10μg/L的范围具有良好的相关系数(r=0.9997),其最低检出浓度为0.088μg/L。应用此法对发样进行加标回收实验,加入量为2.5μg/L时,回收率范围为86.1%～101.9%,平均回收率92.8%;加入量为5.0μg/L时,回收率范围为85.4%～95.4%,平均回收率90.2%。结论:该法简便快速、灵敏度高、重现性好,适用于人发中微量硒的快速测定。     

人血和尿中锡的高压微波络合消解氢化物发生-原子荧光测定法

目的 建立人血、尿中锡的高压微波络合消解氢化物发生-原子荧光测定法.方法 利用高压微波络合消解已加入1％ EDTA溶液的人血和尿液,在样品测定液中加入150 g/L硫脲-抗坏血酸5ml来掩蔽镍、铁、砷、硒等干扰离子;以2％硫酸作为介质,以2％的硼氢化钠溶液作为还原剂,采用氢化物发生-原子荧光法测定锡浓度.结果 在10～100 μg/ml的线性范围内,血中锡所得回归方程为y=9.391 1x-16.312,r=0.999 7;尿中锡所得回归方程为y=8.244 7x-27.849 6,r=0.998 2.血、尿中锡的检出限分别为0.090、0.020 μg/L.该方法的RSD为1.4％～6.1％,回收率在98.1％～101.8％之间.结论 该方法样品消解完全,测定时间短,待测元素损失少,基体干扰少,准确度和灵敏度较高,精密度好,且所用原子荧光仪器相对便宜,适用于基层单位对人血、尿中锡浓度的测定.     

微波消解-氢化物发生原子荧光光谱法测定食品中铅

目的建立食品中铅的氢化物发生-原子荧光光谱法。方法样品加硝酸经微波消解,氢化物发生-原子荧光光谱法测定铅含量。结果该法的线性范围为0~50μg/L,相关系数为0.999 5,方法检出限为0.010μg/L,相对标准偏差2.1%~4.4%,回收率为91.2%~108.4%。结论原子荧光光谱法测定食品中铅灵敏度高,准确、快捷。     

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.