微量分光光度法快速测定饮用水中硫酸盐

目的建立一种快速测定饮用水中硫酸盐的微量分光光度法。方法基于硫酸钡比浊法原理,采用自主研发的可自动进样、比色、计算、清洗的微量自动分析仪及其配套试剂盒,对饮用水中硫酸盐进行测定。结果方法的线性范围为5 mg/L~80 mg/L,相关系数(r)为0.997 8,检出限为2.66 mg/L,RSD1%,自来水加标回收率为89.5%~109.0%,对硫酸盐质控样品的测定结果均在标准定值范围内,相对误差为0.36%~0.91%。采用本法测定实际样品中的硫酸盐,其结果与国家标准方法基本一致。结论微量分光光度法测定饮用水中硫酸盐,操作简单快速、准确、精密度高,与国家标准比浊法相比,量程翻倍,试剂种类、样本用量及废液的生成大幅减少,更加环保,适合在村镇集中式供水单位推广使用。     

微量纳氏试剂分光光度快速检测方法测定生活饮用水中的氨氮

目的研究适用于农村地区生活饮用水中氨氮检测的简便方法。方法采用课题组建立的微量纳氏试剂分光光度快速检测方法进行测定,在方法检测浓度范围内绘制标准曲线,分析方法的线性范围及可用性,通过测定空白样品20次,估算方法的检出限,并进行精密度和加标回收试验,对快速检测方法和国家标准检验方法的水样检测结果进行配对t检验。结果快速检测方法在浓度为0.02 mg/L~2.00 mg/L时,线性关系良好,相关系数(r)=0.999 3,检出限为0.01 mg/L。方法的相对标准偏差(RSD)为0.74%~2.47%,加标回收率为96.7%~100.0%。快速检测方法和722分光光度计纳氏试剂分光光度法的测定结果比较,差异无统计学意义。结论快速检测方法的操作简便、测定快速、结果准确、节省试剂,适用于农村地区饮用水中氨氮的检测。     

离子色谱法和铬酸钡分光光度法测定水中硫酸盐的比较

目的比较离子色谱法和铬酸钡分光光度法测定水中硫酸盐的异同。方法分别从方法适用范围、取样量、分析时间、线性范围、加标回收率、精密度、检出限和测定结果进行分析和比较离子色谱法和铬酸钡分光光度法。结果离子色谱法和铬酸钡分光光度法测定硫酸盐的标准合成水样(<10.0 mg/L)的回收率分别为86.5%~93.1%和99.7%~101.0%;用两种方法分别测定20份水样(>10.0 mg/L),并对结果进行配对t检验,t=1.395,P>0.05,无显著性差异。离子色谱法测定水中硫酸盐的检出限、检测限、线性范围、加标回收率和RSD分别为0.0028 mg/L、0.1 mg/L、0.1~300 mg/L、90.0%~100.2%和0.3%~0.8%;铬酸钡分光光度法的检出限、线性范围、加标回收率和RSD分别为1.68 mg/L、5.0 mg/L、5~200 mg/L、97.2%~100.4%和0.4%~2.2%。实验结果表明铬酸钡分光光度法在测定低浓度(<10.0 mg/L)硫酸盐的准确度较离子色谱法低,而大于10.0 mg/L时,两种方法均可以取得较好的准确度。离子色谱法测定水中的硫酸盐取样量少、分析时间短、线性范围、检出限和精密度都优于铬酸钡分光光度法。结论铬酸钡分光光度法在测定低浓度(<10.0 mg/L)硫酸盐的准确度较离子色谱法低,而大于10.0 mg/L时,两种方法均可以取得较好的准确度。离子色谱法比铬酸钡分光光度法简便、快速、可同时检测多种阴离子,更适合大批量样品的检测,宜推广。     

离子选择电极法、离子色谱法和氟试剂分光光度法测定水中氟化物的比较

目的比较离子选择电极法、离子色谱法和氟试剂分光光度法测定水中氟化物的异同。方法分别从方法的适用范围、检测效率、取样量、线性范围、检出限、检测限、准确度、精密度、加标回收率来比较分析离子选择电极法、离子色谱法和氟试剂分光光度法。结果离子选择电极法线性范围、检出限、检测限、RSD、加标回收率分别为(0.06~3)mg/L、0.02 mg/L、0.1 mg/L、0.20%~0.50%、96.4%~103%;离子色谱法分别为(0.002~5)mg/L、0.0005 mg/L、0.002 mg/L、0.84%~1.40%、94.2%~99.6%;氟试剂分光光度法分别为(0.1~2)mg/L、0.03 mg/L、0.1 mg/L、1.72%~1.76%、84.7%~99.2%。结论离子选择电极法在线性范围内准确度和精密度较好,是一种既经济又经典的氟化物检测方法;氟试剂分光光度法适于在基层实验室普及,测定低浓度样品能得到较满意的结果,较高浓度样品的准确度和回收率不理想;离子色谱法适用范围广,特别是高浓度氟化物的检测优势明显,已成为实验室主要检测手段。     

新型自动比色法测定饮用水中的铝

目的建立一种新型快速测定饮用水中铝的自动比色法,并评价其效果。方法在国家标准方法基础上,优化试剂剂型,简化操作步骤,对方法测量范围、精密度、准确度以及实际样品测定进行实验研究。结果方法线性范围为0.008~0.20 mg/L,相关系数(r)为0.9995,检出限为0.006 mg/L,RSD为0.42%~2.60%,自来水加标回收率为87.5%~102%,对铝质控样品的测定结果均在标准定值范围内,相对误差为0.46%~4.15%。采用本法测定饮用水中铝结果与国家标准方法结果基本一致。结论新型自动比色法测定饮用水中铝,快速、准确、精密度高,操作人员无需自行配制试剂,测试所需试剂和样品用量少,节约环保,适合在村镇集中式供水单位普及应用。     

酚试剂分光光度法测定饮用水中甲醛

目的 建立测定饮用水中甲醛方法.方法 利用水溶液中甲醛与酚试剂反应生成嗪,嗪在酸性溶液中被高铁离子氧化成蓝绿色化合物,产生颜色与甲醛含量成正比的原理,采用酚试剂分光光度法对饮用水中的甲醛含量进行测定,并与AHMT分光光度法比较.结果 本方法的线性范围0.005～0.100 mg/L,检出限为5×10-4mg/L,RSD为1.02%～1.17%,样品加标回收率为96.4%～107.2%.结论 该法用于实际水样检测,结果满意.     

酚试剂分光光度法测定水中微量戊二醛

[目的]建立一种快速有效地检测水中微量戊二醛的酚试剂分光光度法。[方法]采用戊二醛与酚试剂(3-甲基-苯并噻唑腙,MBTH)反应生成嗪,嗪在酸性溶液中能够被高铁离子氧化生成蓝绿色化合物,利用产生的颜色与戊二醛含量成正比的原理,采用酚试剂分光光度法对水中微量戊二醛含量进行测定,分析入射波长、酚试剂浓度、显色剂酸溶解条件、显色温度和显色时间等因素对实验结果的影响并确定最佳条件。[结果]确定了604 nm处为最佳吸收波长;MBTH和硫酸高铁铵的最佳用量分别为200 mg/L和1 800 mg/L;在30℃下放置15 min后MBTH与戊二醛能够充分反应生成嗪;其次研究了显色剂酸溶解条件,其最佳盐酸溶解用量为0.2 mol/L;最后研究得出最佳显色温度和显色时间为40℃下静置40 min。在最佳测试条件下,吸光度与戊二醛浓度在0.005~1.00 mg/L范围内呈现良好线性关系,检测限为0.005 mg/L,相对标准偏差为0.34%,平均加标回收率为98.13%。[结论]该方法检测限低、灵敏度高、线性范围宽,能够快速有效地检测水中微量戊二醛。     

荧光分光光度法与直接分光光度法测定饮用水中挥发酚

目的:用4-氨基安替吡啉直接分光光度法、荧光分光光度法两种方法测定水中挥发酚,并做了方法比较。方法:使用此两种方法分别测定样品及标准中的挥发酚的含量,比较其相关系数、线性范围、回收率与检出限。结果:以上两种方法的相关系数都为0.9997,线性范围都为0 mg/L～2.00 mg/L,平均回收率分别为101%、100%,检出限分别为0.013 mg/L、0.004 mg/L。结论:荧光分光光度法有很好的精密度与准确度,方法简单且试剂毒性小,适合检验受到污染的饮用水样品。     

离子色谱法测定饮用水中的硝酸盐

目的研究应用861 Advanced Compact IC离子色谱仪测定饮用水中硝酸盐的分析方法。方法将水样经过0.45μm微孔滤膜过滤,选用Metrosep A Supp4阴离子分离柱对硝酸根离子进行分离,由电导检测器测定含量。结果该方法的相关性好(r>0.9995),线性范围为0.50~10.0 mg/L,方法的精密度(RSD,n=6)小于0.87%,回收率范围98.30%~99.70%。与分光光度法对比,结果差异无统计学意义(P>0.05)。结论方法快速、准确、灵敏度高、线性范围广,有较高的实用价值。     

饮用水中亚氯酸盐的快速检测方法研究

目的建立生活饮用水中亚氯酸盐的快速检测方法。方法利用N,N-二乙基对苯二胺(DPD)分光光度法原理,采用自主研制的余氯、二氧化氯五参数快速检测仪对饮用水中亚氯酸盐进行测定,将国家标准检验方法中的离子色谱法与快速检测方法的测定结果进行对比分析。结果在低(0.10 mg/L)、中(0.60 mg/L)、高(1.80 mg/L)3种不同浓度下,快速检测方法的相对标准偏差(RSD)为1.88%~8.94%,加标回收率为83.3%~108.0%,水样测定结果与国家标准检验方法检测结果差异无统计学意义(P0.05)。结论快速检测方法将所需试剂集成为试剂盒,大大节省了试剂用量,降低了实验分析成本,与国家标准检验方法相比,简化了分析过程,产生的废水废液少。快速检测仪操作简单快速,携带方便,适合用于生活饮用水中亚氯酸盐的测定。     

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 human drama of genetics: 'hard' and 'soft' media representations of inherited breast cancer

This paper examines media coverage of 'breast cancer genetics', and explores its implications for public understanding. We present a content analysis of coverage in British newspapers and look at a variety of popular forms, including women's magazines, television soap opera and radio drama. Genetic/inherited risk receives a great deal of coverage across a wide range of media formats and outlets. Much of this attention has focused on individuals from 'high risk families' and dilemmas around prophylactic mastectomies. Through examining media coverage, combined with interviews with media personnel and their sources, we show why this story proved so attractive to the media and highlight the different production values which influence coverage. Finally, we introduce preliminary findings from focus group discussions to demonstrate how such 'human interest' framing has engaged audience attention and influenced public understandings. The paper concludes by highlighting the implications for analysing, predicting, and engaging with, media representations of science.     

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.     

Worker education in the primary prevention of occupational dermatoses

This paper reports the evaluation of a skin care education programmeconducted on a fine chemicals manufacturing site where over1,000 employees are located. Approximately 60% are involvedin chemical manufacture. Over a 12 month period production staffreceived training in prevention of occupational dermatoses linkedto a site-wide poster initiative. The incidence of new casesof occupational dermatoses fell from 0.055 (70 cases in 1,277employees) to 0.021 (27 cases in 1,277 employees) before andafter the intervention respectively (p<0.0001). After otherfactors such as chemicals handled, observer bias and changesin reporting related to socioeconomic climate were taken intoaccount it is concluded that this study demonstrates the importanceof worker education as a tool for primary prevention of disease.Training materials such as video and poster presentations maybe effectively used in the chemical manufacturing industry asan adjunct to prevention and control of exposure to substanceshazardous to the skin. Such methods may also be used in otherindustries where there are significant risks of dermatoses.     

Regional Variation in Travel-related Illness acquired in Africa,March 1997–May 2011

To understand geographic variation in travel-related illness acquired in distinct African regions, we used the GeoSentinel Surveillance Network database to analyze records for 16,893 ill travelers returning from Africa over a 14-year period. Travelers to northern Africa most commonly reported gastrointestinal illnesses and dog bites. Febrile illnesses were more common in travelers returning from sub-Saharan countries. Eleven travelers died, 9 of malaria; these deaths occurred mainly among male business travelers to sub-Saharan Africa. The profile of illness varied substantially by region: malaria predominated in travelers returning from Central and Western Africa; schistosomiasis, strongyloidiasis, and dengue from Eastern and Western Africa; and loaisis from Central Africa. There were few reports of vaccine-preventable infections, HIV infection, and tuberculosis. Geographic profiling of illness acquired during travel to Africa guides targeted pretravel advice, expedites diagnosis in ill returning travelers, and may influence destination choices in tourism.     

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.     

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.