茶叶中茶多糖的提取和测定方法

〔目的〕建立一种简便、快速、灵敏的测定茶叶中茶多糖含量的方法。〔方法〕按醇析水提法 ,通过正交试验获得茶多糖提取最佳条件 ,苯酚—硫酸法比色测定茶多糖含量。〔结果〕茶多糖吸收波长为 490nm ;线性范围为 8～ 72 μg/ml ;重现性好 ,CV =0 .95 6% (n =6) ;平均回收率为 99.9% ,CV =2 .0 3 7% (n =6) ;不同茶叶样品茶多糖含量在 1.2 92 %～4 5 2 9%之间。〔结论〕该法简便、快速、稳定、灵敏 ,重现性好。茶叶越粗老茶多糖含量越高     

流动注射测定饮用水中挥发性酚类化合物方法的研究

〔目的〕为获得一种方便、准确和灵敏测定水中挥发性酚类化合物的检测方法。〔方法〕应用流动注射技术在线测定饮用水中挥发性酚类化合物 ,水样在线蒸馏后不经氯仿萃取直接进行定量分析。〔结果〕方法的最低检测浓度为 1.5 μg/L :线性范围 1.5 μg L～ 5 0 μg/L呈直线 ,其相关系数r≥ 0 .999;相对标准偏差为 2 .3 %～ 7.4% ;加标回收率为 88.9%～ 10 9%。〔结论〕本方法操作简便、灵敏度高、线性范围、精密度和准确度符合检测要求。     

气相色谱法测定食品中甜蜜素

甜蜜素又名环己基氨基磺酸钠 (C6H12 NNaO3 S) ,是一种复合食品添加剂 ,用作甜味剂的一种。国家卫生标准GB2 76 0- 1996规定其使用限量为 0 6 5～ 8 0g/kg〔1〕。目前 ,已报道的测定方法有气相色谱法〔2〕、液相色谱法〔3〕、比色法〔4〕、薄层色谱法〔4〕。但所用的样品处理方法对大批量食品样品的测定效果不佳。本文根据实际情况 ,改进样品处理方法及提取剂 ,采用NaOH -CuSO4沉淀体系预处理样品 ,CCl4提取 ,气相色谱法测定。方法简便快速、灵敏准确、可靠 ,适用于多种食品样品的测定。1　实验部分1 1　实验原理　在硫酸介质中环己…     

人血清中甲胺磷的气相色谱测定法

目的探讨人血清中甲胺磷的测定方法。方法血清经丙酮萃取后,用火焰光度气相色谱法直接测定甲胺磷含量。结果人血清中甲胺磷的气相色谱测定法的检出限为0．05ng,最低检出浓度为0．40μg／ml,平均加标回收率为90．5％-105．6％,相对标准偏差为4．52％-6．63％。结论该方法灵敏、准确、可靠,适合人血清中甲胺磷的检测。     

电导滴定法测定水中溶解氧的研究

〔目的〕建立一种测定水中溶解氧的新方法。〔方法〕用盐酸标准溶液滴定金属铊与水中溶解氧反应的产物 ,以电导法指示滴定终点。〔结果〕相对标准偏差为 0 .3 8% -0 .97% ,相对误差为 -1.96% -1.85 %。〔结论〕本法准确度好 ,快捷灵敏 ,抗干扰能力强 ,是一种测定水中溶解氧的简便可靠的方法。     

气相色谱法测定动物性食品中二氯二甲吡啶酚的研究

〔目的〕建立一种快速测定动物性食品中二氯二甲吡啶酚的方法。〔方法〕在超声振荡下用甲醇提取动物性食品试样中残留的二氯二甲吡啶酚 ,提取液通过氧化铝柱和阴离子交换柱进行净化 ,然后经乙酰化后 ,用气相色谱法测定。〔结果〕方法在 0 -2 .5 μg ml范围呈良好的线性关系 ,其相关系数为 0 .9992 ;方法最小检测量为 8.0× 10 - 3mg Kg ;方法的平均回收率大于 90 .0 % ,相对标准偏差为 4.2 %。〔结论〕该方法是一种快速、简便、灵敏度较高的检测动物性食品中二氯二甲吡啶酚的方法。     

新的双试剂自动分析法测定血清铜:5-Br-PADCAP直接光度法

〔目的〕建立简便、灵敏的双试剂自动化分析法测定血清铜。〔方法〕在表面活性剂存在下 ,用 2 (5 溴 2 吡啶偶氮 ) 5 [(N ,N 二羧基甲基 )氨基 ]苯酚 (5 -Br -PADCAP)为显色剂测定血清铜。〔结果〕该法线性范围 0～ 65 μmol/L ,平均回收率为 10 0 .7% ,批内变异系数 (CV)和批间变异系数分别为 0 .0 2 4、0 .0 3 6,与原子吸收分光光度法比较具有良好的相关性 ,线性回归方程和相关系数分别为Y =1.10 47X -0 .15 3 8,r =0 .9897。 5 4例健康人血清铜含量为 8.2 9～ 2 2 .45 μmol/L(x± 2s)。〔结论〕用 5 Br PADCAP双试剂自动化分析法测定血清铜方法简便、灵敏可靠 ,适合临床应用     

顶空气相色谱法测定饮料中甜蜜素

甜蜜素的甜度是蔗糖 30～ 4 0倍 ,被广泛的应用于饮料〔3〕 。目前 ,测定饮料中甜蜜素通常采用的预处理方法繁琐 ,温度影响大。本文用顶空气相色谱法测定 ,该方法无预处理 ,无特定温度 ,具有灵敏、准确、省时、快速等优点 ,线性范围 5～ 6 0 0 0 μg ,平均回收率为 94 6 9%～ 10 0 83% ,相对标准偏差 0 81%～ 2 14 % ,P >0 0 5 ,最低检出限 1 3μg〔1〕 。1　原理和方法1 1　原理在硫酸介质中环己基氨基磺酸钠与亚硝酸钠反应 ,生成环己醇亚硝酸酯 ,根据平衡原理 ,进行顶空样品分析。1 2　操作步骤1 2 1仪器 :美国惠普HP - 5 890气相…     

快速同时检测大豆异黄酮保健食品中三种雌激素的HPLC法

〔目的〕研究检测大豆异黄酮类保健食品中三种雌激素 (雌二醇、雌酮、己烯雌酚 )含量的分析法。〔方法〕采用HypersilODS2C18色谱柱 (2 5 0mm× 4.6mmID ,5 μm) ,流动相甲醇 -水 (体积比 5 3 :47) ,流速 1.0mL/min ,检测波长 2 80nm等作为色谱条件 ,同时检测三种雌激素。〔结果〕该方法的线性范围在 0 .5～ 2 5 0mg/L ,相关系数r在 0 .998以上 ,相对标准偏差 (RSD)为 0 .9%～ 1.8% ,回收率在 91.3 %～ 98.3 %以上。〔结论〕该法具有快速、准确、灵敏等优点 ,适合大豆异黄酮中雌激素的检测     

水平观测ICP-OES法直接测定尿中十种微量元素

〔目的〕建立直接测定尿中 10种微量元素的方法。〔方法〕采用水平观测ICP -OES法进行测定。〔结果〕尿样经稀释一倍后 ,通过选用最佳仪器条件 ,rf功率 1.3 5KW、气溶胶载气压力为 2 .0 7× 10 5Pa时 ,可有效克服尿中Na基体引起的干扰。方法精密度和准确度均符合痕量分析的要求。〔结论〕该法简便快速、灵敏准确 ,适合尿中微量元素的分析     

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.     

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.