阳离子表面活性剂与溴酚蓝的共振瑞利散射及分析应用

目的：建立一种简便快速的环境水样中阳离子表面活性剂(CS)测定新方法。方法：溴酚蓝(BPB)共振光散射水相直接测定法。结果：研究了酸性三苯甲烷类染料BPB与溴化十六烷基三甲基胺(CTMAB)作用的共振光散射光谱，在pH=1．8-2．2的范围内，加入CTMAB导致BPB共振光散射剧烈增强，在λex=λem=533nm处，存在一共振散射峰，其强度与CTMAB的浓度成线性关系，据此建立了一种测定水中CS的共振光散射法。方法的线性范围为0-1.85μg／ml，检出限为0．43ng／nd。结论：方法简便、快速，灵敏度高。对合成样本进行了含量测定，获得了满意的结果。     

罗丹明B共振光散射法测定水中痕量亚硝酸根

〔目的〕研究一种灵敏而简便的环境水样中痕量NO-2 测定新方法。〔方法〕在盐酸介质中 ,NO-2 、碘化钾和罗丹明B(RhB)同时存在时可形成离子缔合物 ,离子缔合物的形成使共振光散射强度急剧增强 ,据此建立了测定水样中痕量NO-2 的共振光散射法。〔结果〕该缔合物的最大共振光散射峰位于 6 2 6 .6nm处 ,NO-2 的浓度在 10 .0～ 180 μg/L范围内与共振光散射强度呈良好的线形关系 ,方法的检出限为 3.88μg/L ,测定雨水、塘水实际水样时的相对标准偏差为 1.16 %～ 2 .0 6 % ,加标回收率为 94 .6 %～ 95 .8%。〔结论〕该方法在室温下即可进行 ,操作简便 ,具有较高的灵敏度和选择性 ,用于环境水样中NO-2 的测定 ,结果满意。     

阴离子表面活性剂的龙胆紫褪色光度测定法

在弱酸性的邻苯二甲酸氢钾-HCl缓冲介质中,阴离子表面活性剂(AS)与龙胆紫(CV)染料反应,形成离子缔合物,溶液颜色发生明显改变。最大褪色波长为578 nm[十二烷基硫酸钠(SDS)体系]、574 nm[十二烷基苯磺酸钠(SDBS)体系],在此波长处,阴离子表面活性剂的浓度与体系吸光度呈良好线性关系,从而建立测定阴离子表面活性剂的光度法。在最大褪色波长处,AS的浓度在0~2.79×10-5mol/L(SDS体系)、0~2.90×10-5mol/L(SDBS体系)范围内遵守比耳定律,表现摩尔吸光系数为1.72×104L/(mol.cm)(SDS体系)、1.86×104L/(mol.cm)(SDBS体系),检出限为8.90×10-7mol/L(SDS体系)、7.81×10-7mol/L(SDBS体系)。该方法具有较高的灵敏度和良好的选择性,用于水样中AS的测定,结果满意。     

人血清白蛋白荧光猝灭法测定水环境中Cu(Ⅱ)

〔目的〕建立环境水样Cu(Ⅱ )的分析新方法。〔方法〕人血清白蛋白荧光猝灭法。〔结果〕根据Cu(Ⅱ )在pH=7.43的KH2 PO4 -Na2 HPO4 缓冲溶液中对HSA荧光的猝灭效应 ,建立了HSA荧光猝灭法测定Cu(Ⅱ )的分析新方法。在实验最适条件下Cu(Ⅱ )浓度在 0 .13 -6.0 0 μg/ml范围内有良好的线性关系 (r =0 .997)。方法检出限 3 8ng/ml;相对标准偏差 6.4%-1.5 %;样品加标回收率 94.5 %-10 1.0 %。〔结论〕方法简便 ,特异 ,灵敏度高。可直接用于环境水样中Cu(Ⅱ )的测定。     

Cd(Ⅱ)-碘化钾-结晶紫-OP10反应的分光光度研究及应用

〔目的〕为研究灵敏而简便的环境水样中痕量镉测定技术。〔方法〕在表面活性剂OP -10存在下 ,镉与结晶紫、碘化钾形成混配缔合物 ,建立了测定水体中痕量镉的光度法。〔结果〕该缔合物的最大吸收波长在 63 5 .9nm ,表观摩尔吸光系数ε为 1.0 4× 10 6 L mol·cm ,回收试验的相对标准偏差为 1.15 % -2 .68% ,回收率为 99.0 % -10 0 .8% ,在 0 -1.0 μgCd/10ml范围内服从比尔定律。〔结论〕该体系是测定镉的超高灵敏度光度法之一。本方法用于环境水样及中镉的测定 ,获得了满意结果。     

苋菜红两相滴定法测定水中阴离子表面活性剂

本文首次提出以苋菜红为指示剂,用两相滴定法测定水中阴离子表面活性剂的方法。用此法测定了环境水样中的阴离子表面活性剂,相对标准差为0.65％～6.5％,回收率为94％～105％,检测下限为50μg/L。方法简便,快速,具有良好的选择性,适用于河水和生活废水中阴离子表面活性剂的测定。     

8-羟基脱氧鸟苷与吡啰红Y作用的共振光散射光谱及分析应用

目的：建立一种灵敏简便的样品中8-OH-dG分析新方法。方法：在pH9．0的R．B缓冲液中，吡啰红Y阳离子染料与8-OH-dG阴离子形成离子缔合物，导致体系的共振光散射增强。结果：在优化的实验条件下，体系的共振光散射强度随着8-OH-dG的加入在339nm处急剧增强。共振光散射的增强（△IRLS）与8-OH-dG加入量成线性关系．据此建立8-OH-dG的共振光散射检测新方法，方法的线性范围为50．0—226．4ng/ml、检出限15．2ng／ml。结论：该方法快速、简便，已成功用于加标样品的分析。     

核固红共振光散射法测痕量亚硝酸根

目的:建立测定痕量亚硝酸根的新方法。方法:在盐酸介质中痕量亚硝酸根与核固红发生重氮化反应,使得核固红溶液的共振散射光强度明显下降,从而建立了共振光散射法测定痕量亚硝酸根的新方法。结果:方法的线性范围为2.0×10-8~2.8×10-7g/ml,检出限为9.34×10-9g/ml,回收率为95.5%~98.6%。结论:该方法简便快速,用于环境水样中痕量亚硝酸根的测定,结果满意。     

健那绿光度法测定水中阴离子表面活性剂

本文建立了健那绿分分光光度法水相测定环境水样中阴离子表面活性剂的新方法.在pH3.0的H3PO4-H2PO4-缓冲溶液中,λmax=605nm,十二烷基苯磺酸钠在0-75μg/10mL范围内遵守比耳定律,表观摩尔吸光系数为1.1×104L·mol-1·cm-1.用建立的方法测定了环境水样中的阴离子表面活性剂,结果满意.     

共振散射光谱法测定水中铬(Ⅵ)

目的：建立共振散射光谱法测定水中铬（Ⅵ）的新方法。方法：在磷酸介质中，微量的铬（Ⅵ）氧化I^-产生I3^-配阴离子，而I3^-又进一步与藏红T形成离子缔合物，离子缔合物可产生共振散射光谱。结果：铬（Ⅵ）浓度在0.01-0．32μg／ml范围内与共振光散射强度有良好的线性，方法的检出限为0．004μg／ml。用于环境水样中铬（Ⅵ）的测定，加标回收率在96．5％，102．4％之间。结论：该方法灵敏度高，简便、快速，反应条件易控制，可用于水样中微量铬（Ⅵ）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.