反相液相色谱法同时测定食物中维生素K_1和K_2

方法：食物中ＶＫ１、ＶＫ２用己烷提取，以石油醚乙醚（８５１５）为展开剂，于ＧＦ２５４ｎｍ硅胶薄板上纯化，正己烷萃取，离心，８０℃水浴蒸干。用甲醇溶解残留物，经ＯＤＳ－Ｃ１８反相柱，以甲醇为流动相。结果：在１．５ｍｌ／ｍｉｎ的流速下，选择２５４ｎｍ检测，ＶＫ１、ＶＫ２能很好地分离，ＶＫ１和ＶＫ２两者的回收率分别为８８．３％～９０．８％和８９．８％～９１．５％，变异系数为４．８２％～５．４９％。结论：反相液相色谱法简单、准确、适合于食物中ＶＫ１、ＶＫ２的分析。     

离子对反相高效液相色谱同时测定饮品中Vpp,VB6及咖啡因含量

建立了离子对反相高效液相谱色（ＨＰＣ）同时测定饮吕中ＶＰＰ、ＶＢ６和咖啡因的方法。以庚烷磺酸钠为离子对试剂,甲醇：水２：８（１％冰乙酸）为流动相。ＶＰＰ、ＶＢ６及咖啡因的线性范围分别是４０－２００μｇ／ｍｌ、８－４０μｇ／ｍｌ及５０－２５０μｇ／ｍｌ。回收率分别为９８．５０－１０１．８％、９９．６０－１０４．０％、及９９．３０－１０２．５％。该法可用于饮品中ＶＰＰ、ＶＢ６及咖啡因的含量测定,对３批     

串珠镰刀菌素的薄层及高效液相色谱测定法

建立了玉米、稻谷中串珠镰刀菌素的薄层和高效液相色谱测定方法。样品用水－乙腈（５：９５Ｖ／Ｖ）提取，正己烷脱脂后用ＰＴ－Ｃ１８色谱预处理柱净化，经０．４５μｍ滤膜过滤后供高效液相色谱分析；薄层色谱分析可省略掉ＰＴ－Ｃ１８柱净化步骤。两种方法的最低检出量依次为５ｎｇ和１００ｎｇ。在玉米、稻谷样品中各加入０．２～２０μｇ／２０ｇ串珠镰刀菌素时，其不同水平的平均回收率为：７６％～８１％（薄层色谱法）和７５．２％～１０３．６％（高效液相色谱法）。     

猪肉及罐头中己烯雌酚的市郊和液相色谱分析

ＨＰＬＣ法测猪肉及罐头中己烯雌酚，色谱柱为Ｃ１８径向加压柱，流动相为乙醇和水，紫外检测波长２８０ｎｍ。该法的回收率在９７．０％－１０１．５％之间，变异系数为２．１％－５．１％，最小检出量为０．０２μｇ。     

蔬菜中维生素K_1的测定——HPLC法

目的：　为了检测蔬菜中维生素Ｋ１（ＶＫ１）的含量,需建立一个特异性强分离效果好的检测方法。方法：　蔬菜样品经丙酮、石油醚提取后,再用失活磷酸盐处理过的氧化铝进行柱色谱净化处理,分别用极性不同的洗脱液将样品中ＶＫ１ 从干扰物中分离出来,收集石油醚∶乙醚（９７∶３）洗脱组分,浓缩定容。然后用Ｃ１８色谱柱对ＶＫ１ 进行定性定量分析,流动相为甲醇：正己烷（９８∶２）,紫外检测波长为２４８ｎｍ 。结果：　在流速为１．５ｍ ｌ／ｍ ｉｎ 的条件下,ＶＫ１ 的保留时间为１５．６ｍ ｉｎ,方法批内、批间ＲＳＤ％ 分别为１．４％ ～６．１％ 和１．３％ ～７．１％ ,回收率范围为９０．９％ ～１０９．３％ 。结论：　采用失活的磷酸盐处理过的氧化铝色谱柱对样品进行净化处理,可以提高分离效果。     

高效液相色谱检测低氧时大鼠脑组织中腺苷酸含量

本文介绍高效液相色谱检测低氧时大鼠脑组织中腺苷酸，并将ＡＭＰ、ＡＤＰ、ＡＴＰ分别定量。取大鼠脑组织０．５ｇ，以０．５ｍｏｌ／Ｌ高氯酸溶液处理后，用美国Ｗａｔｅｒｓ－２４４型高效液相色谱，４４０型紫外检测器，波长２５４ｎｍ进行检测，用国产ＹＷＧＣ１８不锈钢柱，流动相为甲醇：乙腈：ＩＰＲＡ：水＝８０：６０：１４：３４６（ｍｌ，Ｖ／Ｖ）。方法的回收率ＡＭＰ、ＡＤＰ、ＡＴＰ分别为９８．５６％￣１００．４８     

化妆品品溴硝丙二醇和尼泊金酯的高效液相色谱法测定

采用反相高效液相色谱法，同时测定化妆品中溴硝丙二醇和尼泊金甲酯、乙酯、丙酯、异丙酯、丁酯、异戊酯等7种防腐剂。色谱柱：10μmYWG-C18柱；流动相：甲醇－四氢呋喃－水（60：50：100V／V），紫外检测波长为254nm。样品用流动相超声萃,取各组分回收率为90．4％－109．3％，相对标准偏差为0．7％－7．5％。     

乳腺癌病人乳腺脂肪中有机氯残留量的测定

本研究用正己烷直接提取脂肪中有机氯，经１．５％ＯＶ－１７＋１９．５％ＱＦ－１气相色谱柱分离后，用电子捕获检测器测定，结果表明９种有机氯都很好的分离，回收率在８３．５％～９５．２％之间。     

反相高效液相色谱法测定奶粉中的烟酸和烟酰胺

本文采用反相高效液相色谱法，经过对样品进行热水草取、酸性沉淀蛋白质等简单的前处理，用１５ｃｍ×４．６ｍｍＣ１８色谱柱分窝，流动相为７．１％甲醇、３．０％异丙醇、９．１％的０．００５ｍｉｌ辛烷磺酸钠水溶液（高氯酸调ｐＨ＝２．１０），紫外２６１ｎｍ检测，采用标准加入法进行定量分析。本方法变异系数ＣＶ％＝１．５９，回收率范围９３．４３％～１０１．５１％。烟酸的最低检出限为４．０×００－１０ｇ；烟酰胺的最低捡出限为５．２×１０－１０ｇ。     

苯暴露者尿中反，反－粘康酸高效液相色谱检测法的建立及应用

本研究应用特异、敏感的高效液相色谱法，在紫外吸收波长２６５ｎｍ时，检测苯的代谢物，尿中的反，反－粘康酸（ｔｔＭＡ）。１ｍｌ尿液与２ｍｌ含香草酸作内标的Ｔｒｉｓ缓冲液混合，通过经预处理的阴离子交换柱。经磷酸、醋酸钠及去离子水洗涤，ｔｔＭＡ最后用１．５ｍｏｌ／Ｌ氯化钠－甲溶液洗脱。流动相为５ｍｏｌ／Ｌ醋酸钠含１％（Ｖ／Ｖ）醋酸和１２％甲醇（Ｖ／Ｖ）。流速为ｌｍｌ／ｍｉｎ，至第６ｍｉｎ时流速为１．５ｍｌ／ｍｉｎ。ｔｔＭＡ和内标ＶＡ分别在６．８和１２．８ｍｉｎ检出。本实验ｔｔＭＡ最低检出量为０．０５ｍｇ，回收率在９０％以上。现场应用结果提示，尿液ｔｔＭＡ可作为苯暴露者的生物监测指标。     

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.     

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.     

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.     

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.     

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.     

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.