镍加抗坏血酸基体改进剂石墨炉原子吸收法测定罐头中的锡

目的本文探讨用石墨炉原子吸收法测定罐头中的锡的实验方法。方法样品采用微波消解,以镍加抗坏血酸作为基体改进剂,塞曼扣背景,石墨炉原子吸收法进行测定。结果锡浓度在0μg～60μg/L范围内线性良好,相关系数为0.9992;该方法检出限为0.62μg/L;回收率为95%～103%;。结论本方法具有快速、准确、灵敏度高等优点,适用于罐头中锡的测定。     

涉水产品中锡含量石墨炉原子吸收光谱法测定及ICP-MS法验证

目的:建立测定涉水产品中锡含量测定的石墨炉原子吸收法并通过电感耦合等离子体质谱法(ICP-MS)进行验证。方法:样品经模拟自来水浸泡24 h,以硝酸钙溶液作为基体改进剂,石墨炉原子吸收光谱法进行测定,ICP-MS法进行验证。结果:线性范围0~10μg/L,相关系数0.9993,检出限0.21μg/L,回收率96.3%~102.2%,RSD为1.6%~3.7%。石墨炉方法测量结果与ICP-MS法测量结果一致。结论:该方法操作简单、方便,稳定性好,测量结果准确可靠,可以用于涉水产品中锡的测定。     

石墨炉原子吸收法快速测定尿中锡实验条件的优化

目的 优化石墨炉原子吸收法快速测定尿中锡的实验条件。方法 运用数理统计方法,选择基体改进剂和实验条件,正交设计优化石墨炉升温程序,工作曲线外标法定量。结果 以1.0 g/L的钯为基体改进剂,尿样稀释20%后直接进样,选择灰化温度为1 000℃,优化后石墨炉升温程序测定。方法检出限为13.5μg/L,回收率为93.6%～96.6%,精密度(RSD)为2.2%～6.0%。结论 数理统计和正交设计方法,可快速、科学优化石墨炉原子吸收快速测定尿中锡的实验条件,建立的方法可用于尿中锡的快速测定。     

石墨炉原子吸收光谱法测定植物油中砷

目的:建立检测植物油中砷含量的石墨炉原子吸收光谱方法。方法:样品经微波消化后,采用硝酸镁作为基体改进剂,石墨炉原子吸收光谱法测定。结果:方法线性范围为0μg/L～20μg/L,相关系数为0.9997,方法检出限为0.006 mg/kg,RSD为2.7%～3.2%,加标回收率为84.7%～99.0%。结论:本法简便、灵敏度高、重现性好,适用于植物油中砷的测定。     

石墨炉原子吸收光谱法直接测定尿液中锡

目的建立石墨炉原子吸收法直接测定尿液中锡的方法。方法通过比较不同定量方法及化学改进剂系列对尿锡测定结果的影响,提出用0.1%钯-0.06%硝酸镁为化学改进剂,2%硝酸-2%硼酸体系对比稀释尿样,工作曲线法定量、峰面积积分,Zeeman石墨炉原子吸收光谱法直接测定尿液中锡。结果方法的线性范围为0.0μg/L~100.0μg/L,检出限为0.86μg/L,尿样的相对标准偏差(RSD)为2.90%~8.80%,平均回收率为99.4%~104.0%。结论利用此法分析样品及标准物质,结果满意。该方法分析速度快、操作简便、灵敏度高、准确度好,适用于尿液中锡的批量测定。     

基于石墨炉原子吸收法的全血中镉的方法学研究

目的:采用石墨炉原子吸收法(GFAAS)直接测定全血中的镉。方法:全血样品经2%硝酸、0.2%磷酸二氢铵混合溶液稀释后,用横向塞曼石墨炉原子吸收光谱法直接测定全血中镉。结果:对16份样本进行测定,相对标准偏差10%,加标回收率在97%～106%之间。标准曲线在0μg/L～4μg/L范围内线性良好,方法的检出限为0.02μg/L,质控样品检测结果满意。结论:本法简便、快速、灵敏,准确度高,精密度好,适用于全血中镉的测定。     

直接稀释-石墨炉原子吸收法测定全血中的铅

目的:建立直接稀释-石墨炉原子吸收光谱法测定全血中铅的方法.方法:用混合基体改进剂[0.2g/L PdCl2 0.1 g/L Tritonx-100 1.0 ml/L HNO3]直接稀释血样,Zeeman石墨炉原子吸收光谱仪,全自动进样方法进行测定.结果:方法线性范围为0～40μg/L,相关系数为0.9998,RSD为3.3%～10%,回收率为90%～103%,方法的检出限为1.2μg/L.结论:该法准确度、精密度良好,样品不需消化,污染小,是一种简便、快速、可行的测定全血中铅的方法.     

石墨炉原子吸收光谱法测定蔬菜中钼

目的:建立石墨炉原子吸收光谱法测定蔬菜中钼的方法。方法:采用灰化法对样品进行前处理,应用石墨炉原子吸收测定钼含量。结果:钼浓度在0μg/L~45μg/L范围内具有良好的线性关系,r=0.9999;方法的检出限为3.7μg/L,相对标准偏差为4.87%~5.65%,方法回收率在91%~104%。结论:方法精密准确,快捷灵敏,便于推广。     

石墨炉原子吸收法直接测定碳酸及茶饮料中的铅

目的去除繁琐的样品前处理,探讨一种更加快速环保的样品测定方法,使得石墨炉原子吸收法能够直接测定茶饮料及碳酸饮料中铅。方法以钼酸铵为基体改进剂,优化石墨炉测定程序,样品直接进样或经稀释后进样,用石墨炉原子吸收法测定。结果采用改进后的方法获得的工作曲线浓度-吸光度相关系数r为0. 999 5,线性范围为0μg/L～80μg/L,方法检出限为0. 18μg/L,低、中、高3个浓度重复性实验的相对标准偏差为2. 22%～3. 77%,回收率为93. 9%～102. 7%。工作曲线线性、精密度、准确度等效果良好。此法无需消解样品,采用的钼酸铵价格便宜,节约了大量的时间和成本。结论采用钼酸铵作为基体改进剂,用石墨炉原子吸收法直接测定茶饮料及碳酸饮料中铅的含量,是测定饮料中铅的一种简便、快速、准确的方法。     

石墨炉原子吸收分光光度法直接测定全血中锗

目的:建立石墨炉原子吸收分光光度法测定全血中锗的方法。方法:样品无需处理,以0.1%Tri-tonX-100/0.2%HNO3(v/v)为稀释液,以0.5 mg/ml硝酸钙为基体改进剂,对血液适当稀释后,直接用石墨炉原子吸收分光光度法测定锗的含量。结果:方法最低检出限(n=10)为0.75 mg/L,线性范围为0μg/L～190μg/L,相对标准偏差0.8%～3.2%,回收率为99.5%～103.6%。结论:方法具有简便、快速、回收率高、精密度高的优点,适用于全血中锗含量的测定。     

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.