医院污水中SARS冠状病毒核酸的检验

目的　了解收治SARS病人的定点医院污水中是否含有病毒和病毒核酸。方法　采用载阳电荷滤材吸附浓集污水中的SARS冠状病毒 ,消毒前浓集污水 2 5L ,消毒后 2 5～ 5 0L ;采用VERO细胞培养及RT -PCR技术检测SARS冠状病毒。结果　建立的阳电荷浓集方法对污水中加标f2 噬菌体回收率平均 12 7% ,而SARS冠状病毒回收率只有 1 0 2 %。消毒前在 30 9医院和小汤山医院污水的6d监测中均检测出SARS冠状病毒核酸 ;消毒后 ,在 30 9医院只有 3d监测出病毒核酸 ,其余样品均未检出病毒核酸 ;两医院所有的污水回收液中均未检出活病毒或具有感染性的病毒。结论收治SARS病人医院污水中含有SARS冠状病毒核酸 ,但没有检出活病毒或具有感染性的病毒 ,因此 ,在当时条件下 ,医院污水 ,尤其是消毒后污水传播SARS冠状病毒可能性较小。     

病毒氯消毒的实验研究(Ⅱ)——对一级处理出水中病毒的大剂量氯消毒

本文报告对人工污染脊髓灰质炎2型病毒及f2大肠菌噬菌体的一级处理出水做加氯消毒实验的结果。实验表明,单独以投氯剂量、总余氯或游离余氯、以及“浓(度)时(间)积”都不能表示消毒效果,但投氯剂量(D)、总余氯量(R)及游离余氯(F)之间的比例却与病毒灭活水平存在一定关系。连续出现R/D<0.50和F/R>0.10可能标志有4个数量级的病毒灭活率。根据消毒过程中余氯动力学变化和病毒残留率的变化来推断,病毒是做为污水中耗氯的总体物质成员参与对氯反应的,只有超大剂量(40—140mg/L)加氯把污水中全部耗氯物质消灭殆尽时才能达到满意的消毒效果。耗氯物质消灭殆尽的标志是连续出现R/D<0.50并伴有或一度伴有F/R>0.10,这也可以用做消毒效果良好的指标。     

饮水试验中二氧化氯对大肠杆菌F2噬菌体消毒效果的实验研究

[目的]研究二氧化氯对大肠杆菌F2噬菌体消毒效果及将大肠杆菌F2噬菌体作为评价消毒效果的指示微生物的可行性进行评价,同时观察残留二氧化氯浓度衰减速度。[方法]采用悬液定量杀菌试验,观察大肠杆菌F2噬菌体对常用化学消毒剂二氧化氯的抵抗力。[结果]二氧化氯投加量为1 mg/L时,作用10 min,对大肠杆菌F2噬菌体的杀灭对数值4.0;作用30 min,染菌水样中残留二氧化氯浓度分别降解为0.35 mg/L;二氧化氯投加量为2 mg/L时,作用3 min,对大肠杆菌F2噬菌体的杀灭对数值4.0;作用30 min,染菌水样中残留二氧化氯浓度分别降解为0.68 mg/L。[结论]大肠杆菌F2噬菌体对二氧化氯消毒剂,在常规剂量作用下,可有效灭活大肠杆菌F2噬菌体。因此选择大肠杆菌F2噬菌体作为病毒消毒试验的指示微生物,可明显缩短病毒灭活效果评价周期。二氧化氯衰减速度随浓度和时间的变化而加快。     

微电流协同氯对水中大肠杆菌噬菌体f2的灭活效应

目的 观察微电流（DC）与游离氯（FC）对水中大肠杆菌噬菌体f2的协同灭活效果。方法 用电流密度0.4-1.2mA/m2协同游离氯0.2～0.3mg/L对水中大肠杆菌噬菌体f2进行了灭活试验,用Berenbaum方法判断微电流与氯灭活病毒有无协同效应,并比较单独氯处理与协同处理的灭活效果。结果 电流密度达到0.4 mA/cm2对水中大肠杆菌噬菌体f2有弱灭活作用,电流密度0.6 mA/cm2与游离氯0.2mg/L或电流密度0.4 mA/cm2与游离氯0.3 mg/L有协同灭活效应,且灭活率K值与单独用氯比较,差异有显著性（P<0.05）。水的pH值低、硬度高及有机物含量低时,电氯协同有较好的灭活效果。结论 电流密度达到一定强度时协同游离氯可提高低浓度氯对水中大肠杆菌噬菌体f2灭活的效果。     

消毒剂对污水中人轮状病毒、猴轮状病毒和其它肠道病毒的灭活作用

作者用氯、二氧化氯、过乙酸和臭氧作消毒剂,对污水中的人轮状病毒、猴轮状病毒(SA-11),脊灰1型,柯萨奇B_5型和埃可1型病毒以及f_2噬菌体进行了灭活实验。向500 ml Pyrex烧杯中加入100 ml污水,置水浴中搅拌下,再加入每毫升含有10~5～10~6的病毒感染单位,最后加入消毒剂。氯和二氧化氯的最初投加剂量分别为5.0、10.0、15.0 mg/l     

二氧化氯对地表水消毒效果的实验研究

目的了解二氧化氯对地表水消毒效果,为实际应用尤其是部队野外作业时的饮水消毒提供依据.方法通过研究二氧化氯对地表水消毒前后水样的浊度和嗅阈值的变化,比较了二氧化氯与二氯异氰尿酸钠对含酚污水除臭的差异.测定了二氧化氯于水中细菌总数、大肠菌群、大肠杆菌噬菌体f2的杀灭效果.结果二氧化氯对地表水的降浊效果明显,除臭率为50%～80%.当水中含酚时,与二氯异氰尿酸钠处理水相比,二氧化氯除臭效果更佳.10mg/L的二氧化氯对湖水和较清洁河水作用30min,能完全杀灭其中的细菌,对污染较重的河水中的细菌,杀灭率为99.9%.消毒处理后大肠菌群指标均能达到生活饮用水标准(＜3/L).1mg/L二氧化氯对含1.414×104pfu/ml大肠杆菌噬菌体f2的湖水作用1h,灭活率为99.9%.结论二氧化氯对地表水降浊除臭作用明显,消毒后细菌学指标能达到生活饮用水标准.     

病毒氯消毒的实验研究(Ⅰ)——病毒在不耗氯介质中对氯的抵抗力

本文报告在不耗氯介质中几种肠病毒(脊髓灰质炎1、2型,克萨奇B5,埃可12)和f2大肠菌噬菌体的氯消毒实验结果。病毒经过超速离心纯化;投氯剂量范围在2～12毫克萨升之间,接触0.5～60分钟间测定残留病毒量及各种余氯量。结果表明,肠病毒中以克萨奇B5抵抗力最强,以下依次为脊髓灰质炎2、1型、埃可12。这一结果与Liu等报告中的实验结果不同而与其以一级反应的计算结果相似。与文献相比,灭活99％病毒所需加氯剂量以本实验为最低,表明本实验条件下揭示出的是或接近是病毒本身对氯的抵抗力,没有受其它耗氯物质的干扰。     

SARS病毒存活研究结果

WHO网络合作工作组的科学家们报告了首次针对SARS病毒在不同环境下的存活时间的研究结果。医院内常用的各种消毒剂效果的研究结果进一步证实了当前所推荐的感染控制措施的合理性。香港、日本以及德国进行的最新研究结果表明 ,正如所预料的那样 ,SARS病毒在物体表面干燥后可以存活 4 8小时。在其他表面存活稳定性的研究仍在继续。科学家们还验证了病毒在排泄物中的存活时间。在香港一家实验室的研究证明病毒在粪便中至少可以存活2天 ,在尿液中至少存活 2 4小时。香港另一家实验室研究表明腹泻病人的粪便酸度低于正常粪便 ,病毒在其中可…     

加氯消毒对医院污水中肠道病毒、致病菌、指示菌灭活情况的实验研究

在实验室条件下研究了不同余氯量及不同接触时间对医院污水中病毒、致病菌和指示菌的灭活情况,重点在于比较不同余氟量对肠道病毒灭活的影响,实验结果表明:消毒接触时间为90分钟,余氯量为6.20mg/L,肠道病毒灭活率可达到100％;接触时间为60分钟,余氯为4.80mg/L,每升污水中总大肠菌群数已少于500个,其灭活率达到99.99％;接触时间90分钟,余氯为4.10mg/L,未检出沙门氏菌。     

饮用水中甲型肝炎病毒灭活研究

用ＰＬＣ／ＰＲＦ／５肝癌细胞培养甲型肝炎病毒（ＨＡＶ），用ＥＬＩＳＡ方法检测经细胞培养增殖病毒的方法，进行评价氯灭活水中ＨＡＶ的效果。实验结果表明，甲型肝炎病毒对氯的抗力比大肠杆菌强，在脱氯自来水中加入ＨＡＶ，氯投加量３．０ｍｇ／Ｌ，接触５～３０ｍｉｎ，余氯１．１ｍｇ／Ｌ，才能灭活水中的ＨＡＶ。而用氯胺消毒，必须达１５ｍｇ／Ｌ，接触时间５～３０ｍｉｎ，才能灭活水中的ＨＡＶ。     

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.