酱油中硼酸的测定方法研究及本底值调查

目的:建立酱油中硼酸(硼砂)的测定方法;调查酱油中硼酸(硼砂)的本底值含量。方法:用EHD萃取-姜黄素分光光度法对出口酱油企业进行酱油中硼酸含量的本底值抽样调查。结果:该法在0～6 0 μg范围内有良好的线性关系,相关系数r>0 . 9990 ;变异系数CV (%)在1 . 7%～3 .7%之间;回收率在92 . 9%～98 .0 %之间;最低检测浓度为1 5mg/kg;与姜黄素分光光度法比较,结果差异无显著性(t =0 . 4 78,P >0 .0 5 )。酱油中硼酸本底值在7 8mg/kg～1 4 3. 8mg/kg之间,均值为4 2 . 5mg/kg ,标准差为2 8 .4mg/kg。结论:该法简便快速,灵敏可靠,适用于酱油中硼酸(硼砂)的测定。     

3-甲氧基-甲亚胺H分光光度法测定饮用天然矿泉水中硼酸

研究了在pH6.5乙酸铵介质中,硼酸与3-甲氧基-甲亚胺H(C     

食品中硝酸盐的麝香草酚分光光度测定法

目的　探讨快速、准确的测定食品中硝酸盐含量的方法。方法　建立了麝香草酚分光光度法 ,利用紫外分光光度计测定食品中硝酸盐含量。结果　该方法最低检出浓度为 1.2mg/kg ,其样品的RSD为 1.80 %～ 2 .0 3 % ,回收率为 92 .7%～10 2 .3 % ,平均回收率为 96.2 % ,RSD为 4.41%。测定结果与国标法 (GB/T 5 0 0 9.3 3 -2 0 0 3 )比较 :t =0 .164 ,P >0 0 5 ,两者差异无显著性。结论　该法具有方法稳定 ,样品前处理简便 ,操作流程短 ,干扰少等特点。适于食品中硝酸盐的测定。     

酱油中硼酸含量的萃取-比色法快速测定

食品卫生法禁止在食品中添加使用硼酸及其盐类。目前。定量检测食品中硼酸及其硼酸盐的化学方法有：(1)以姜黄素为显色剂的分光光度法；(2)以甲亚胺-H为显色剂的分光光度法；(3)容量滴定法；(4)电感藕合等离子体发射光谱(ZCP)法。这几种方法用于检测酱油时，都需要将样品调至碱性，于水浴上蒸干，然后炭化、灰化，前处理过程非常费时。一般需要8h。本文用乙基己二醇-氯仿溶液直接萃取样品中的硼酸。可除去共存盐的影响。     

3,5-diBr-DMPAP光度法测定全血铁

目的 :建立一种快速、简便、灵敏分光光度法测定全血中微量铁。方法 :在表面活性剂 Tri-ton X-1 0 0存在下 ,用 2 -(3 ,5 -二溴 -2 -吡啶偶氮 ) -5 -二甲氨基酚 (简称 3 ,5 -di Br-DMPAP)作显色剂直接光度法测定全血中微量铁。结果 :该方法在 p H4.0的乙酸 -乙酸钠缓冲液中 ,以 746nm为测定波长 ,可选择性测定全血中微量铁 ,本法线性范围为 0～ 1 0μg/ 3 .4ml,表观摩尔吸光数为 2 .75× 1 0 4 L/ (mol· cm) ,回收率为 98.4%～ 1 0 1 .3 %。结论 :该法具有操作快速、简便、结果灵敏可靠等优点 ,适合临床应用     

分光光度法测定食品中硼砂

目的 :建立姜黄素分光光度法测定食品中硼砂含量的方法。方法 :食品在碱性条件下灰化 ,在酸性条件下姜黄素分光光度法测定硼砂含量。结果 :方法的线性好 (r=0 .9999) ,样品测定的相对标准差 rsd<5 % ,加标回收率为 90 .0 %～ 10 4 .5 % ,检出限为 0 .0 6 mg/kg。结论 :该方法灵敏、准确、精密、易于操作 ,适用于食品中硼砂测定     

聚乙二醇辛基苯基醚-酚试剂分光光度法测定公共场所空气中甲醛研究

目的:建立稳定、灵敏、可靠的聚乙二醇辛基苯醚(OP)-酚试剂分光光度法测定公共场所空气中甲醛的方法。方法:采用OP为稳定剂,酚试剂分光光度法测定甲醛。结果:甲醛浓度在0.002 mg/m3～0.25 mg/m3范围内呈良好的线性关系(R2)=0.9997,回收率在93.0%～100.0%,相对标准偏差≤5%(n=6),最低检出限为0.02μg。结论:采用OP-酚试剂分光光度法测定公共场所空气中甲醛,具有快速、灵敏、准确的优点,可用于公共场所空气中甲醛的测定。     

5-Br-DMPAP选择性光度法测定发样中微量铁

目的 :建立一种快速、简便、灵敏分光光度法测定发样中微量铁。方法 :在表面活性剂 Triton X- 10 0存在下 ,用 2 - (5 -溴 - 2 -吡啶偶氮 ) - 5 -二甲氨基酚 (简称 5 - Br- DMPAP)作显色剂直接光度法测定发样中微量铁。结果 :该方法在 p H4.0的乙酸 -乙酸钠缓冲液中 ,以 746 nm为测定波长 ,可选择性测定发样中微量铁 ,本法线性范围为 0～ 10 μg/ 10 m l,表现摩尔吸光数为 2 .75× 10 4L/ (mol.cm) ,回收率为 98.4%～ 10 1.3%。结论 :该法具有操作快速、简便、结果灵敏可靠等优点 ,适应临床应用     

硫酸—硝酸处理灰化法测定高盐食品中的铅

用混酸 (硫酸 -硝酸 )处理灰化的高盐食品 ,并用硫酸钠稀释标准系列以消除干扰。用原子吸收法测定高盐食品中的铅含量。方法的最低检出浓度为 0 .10 m g/ kg。结果表明 ,本法对含铅量为 8.70、2 .40和1.40μg的 3种样品测得相对标准差分别为 1.72 %、5 .0 0 %和 7.14% ,回收率为 90 %～ 10 9%。本法和萃取火焰原子吸收分光光度法测定铅的结果无明显差异 (P>0 .0 5 )。标准曲线相关系数前者为 0 .9995 ,后者为0 .9991(P<0 .0 5 )。用硝酸溶液 (0 .5 mol/ L)溶解灰化物 ,消除了氯化物的干扰 ,直接火焰原子吸收分光光度法测定铅的结果明显高于前二者的测定结果 ,而且精密度、准确度高 ,线性关系好 ,完全符合卫生检验要求     

新试剂4，4′-2（2-氯-4-硝基重氮氨基）联苯分光光度法测定水中阳离子表面活性剂

目的：建立了分光光度法测定氯化十四烷基二甲基苄铵的新方法。方法：在pH11．5—12．5碱性介质中，利用4，4′-二（2-氯-4-硝基重氮氨基）联苯（CNDADP）与氯化十四烷基二甲基苄铵（Zeph）的显色反应，在最大吸收波长580nm处，用光度法测定水样中微量的Zeph。结果：Zeph的浓度在0～3．0&#215;10%^-5mol／L范围内符合比耳定律。表观摩尔吸光系数为2．39&#215;10^4/mol&#183;cm。结论：方法简单，灵敏度高，选择性较好，可用于水中微量氯化十四烷基二甲基苄铵的测定。     

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.