有机干扰物影响纳米Ag液灭活噬菌体MS2效果的实验研究

[目的]通过有机干扰物牛血清白蛋白(BSA)的存在与否比较研究纳米Ag液对噬菌体MS2的不同灭活效果,为纳米Ag在生活及环境中的实际应用提供基础资料. [方法]采用悬液定量灭活试验测定纳米Ag液对噬菌体MS2的灭活对数值(LIV). [结果]在不加有机干扰物BSA时,100 mg/L纳米Ag液作用60 min,对噬菌体MS2的灭活对数值LIV为4.01log10,400 mg/L作用20 min,其LIV达4.12log10;而加入3%的BSA后,400 mg/L纳米Ag液作用1 440 min(24 h),对噬菌体MS2的LIV为3.61log10,800 mg/L作用90 min,其LIV为4.02log10. [结论]环境中有机干扰物的存在将会极大程度地降低纳米Ag液对噬菌体MS2的灭活效果.     

载银纳米二氧化钛水溶液对噬菌体和细菌杀灭效果的比较研究

[目的]观察载银纳米二氧化钛水溶液对MS2和T4噬菌体,大肠杆菌(8099)和金黄色葡萄球菌(ATCC6538)的杀灭效果。[方法]采用悬液定量灭活(杀灭)试验测定载银纳米二氧化钛水溶液对噬菌体和细菌的灭活(杀灭)对数值。[结果]对噬菌体MS2,800mg/L载银纳米二氧化钛水溶液作用60min,或1400mg/L作用15min,灭活对数值均﹥4.00,对噬菌体T4,1400mg/L或2800mg/L载银纳米二氧化钛水溶液作用144min(6h),灭活对数值均﹤1.00;而200mg/L以上的载银纳米二氧化钛水溶液作用30min即可使大肠杆菌和金黄色葡萄球菌的杀灭对数值﹥5.00。[结论]在本实验条件下,噬菌体对载银纳米二氧化钛水溶液的抵抗力远远强于细菌,且噬菌体T4的抵抗力大于MS2,金黄色葡萄球菌对载银纳米二氧化钛水溶液的抵抗力大于大肠杆菌。     

纳米二氧化钛对噬菌体MS2灭活效果的初步观察

[目的]在实验条件下观察纳米二氧化钛对噬菌体MS2的灭活效果,以初步判断噬菌体MS2对纳米二氧化钛的抵抗力.[方法]消毒剂对噬菌体的灭活效果采用悬液定量灭活实验,中和剂鉴定实验,噬菌体的检测采用双层琼脂法.[结果]①紫外光激发组,800 mg/L纳米二氧化钛对噬菌体MS2作用5 min或者200 mg/L,纳米二氧化钛对噬菌体MS2作用10 min就能达到消毒水平.②自然光激发组,1 000mg/L纳米二氧化钛对噬菌体MS2作用5 min或者200 mg/L纳米二氧化钛对噬菌体MS2作用20 min就能达到消毒水平.[结论]在紫外光激发和自然光激发下,纳米二氧化钛均能在短时间内灭活噬菌体MS2达到消毒水平,提高的纳米二氧化钛作用浓度可以增强对噬菌体MS2的灭活效果.噬菌体MS2对纳米二氧化钛的抵抗力不强.     

三种噬菌体对二氯异氰尿酸钠消毒剂抵抗力的比较

目的筛选出消毒实验中评价消毒因子对病毒灭活效果的指示噬菌体,研究噬菌T4、ψx174D和f2对二氯异氰尿酸钠（NaDCC）消毒剂的抵抗力。方法消毒剂对噬菌体的灭活效果采用悬液定量灭活实验、中和剂鉴定实验,噬菌体的检测采用双层琼脂法。结果（1）有效氯浓度为150mg／L的NaDCC溶液与噬菌体舛作用40min,或有效氯浓度为300mg／L作用5min,即可达到消毒水平[对噬菌体舛的灭活对数值或噬菌体舛的对数减少值（log10 N0-log10 Nt）≥4．00log10]。（2）有效氯浓度为300mg／L的NaDCC溶液与噬菌体ψx174D作用5min,或有效氯浓度为400mg／L作用3min达到消毒。（3）有效氯浓度为2000mg／L的NaDCC溶液与噬菌体口作用20min,或有效氯浓度为4000mg／L作用5min达到消毒。结论上述3种噬菌体对NaDCC的抵抗力为：噬菌体口〉噬菌体T4〉噬菌体ψx174D。     

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。     

过氧乙酸对MS_2噬菌体灭活效果观察

目的实验室观察MS_2噬菌体对过氧乙酸(PAA)溶液的抵抗力。方法参考《消毒技术规范(2002版)》,采用悬液定量灭活实验方法就室温条件下不同水平的PAA溶液对MS_2噬菌体的灭活能力进行初步实验室观察。结果质量浓度为1200、800、500mg/L的PAA溶液分别在15、30、60 min内对MS_2噬菌体的平均灭活对数值均达到lg4以上,200mg/L的PAA在60min对悬液内噬菌体的平均灭活对数值为lg2.49。结论实验条件下,低水平的PAA溶液即可对MS_2噬菌体产生较好的灭活效果。     

室内紫外线灯管数量配置不足原因分析及对策

按照卫生部1999-09<医院消毒技术规范>的规定[1],采用室内悬吊式紫外线对空气进行直接照射消毒时,室内安装紫外线消毒灯(30 W紫外线灯,在1 m处的强度＞70 μW/cm3)的数量为平均每立方米不少于1.5 W.我院感染管理科于2009-12对全院所有科室的治疗室、换药室等配置室内悬吊式紫外线灯管的房间进行了实际体积测量,并按实际房间体积乘以1.5 W除以30 W,计算出该房间实际应该配置的紫外线灯管数量.     

血液中细菌灭活方法的研究

目的筛选一种能有效灭活血液中细菌的消毒方法.方法采用定量杀菌试验观察杀菌效果.结果在筛选试验的最大作用剂量下,活性炭碘法、8-甲氧补骨脂素(8-MOP)光化学效应法、短波紫外线(UVC)法和亚甲蓝(MB)光敏效应法作用40min,可以使血液中的大肠杆菌分别下降0.800、1.920、2.772和2.552 log,同时血浆游离Hb分别增加679.16、16.06、107.70和1.68 mg/L;PT分别延长6.40、4.60、5.10和0.80s.结论按照既能有效灭活血液中的细菌,又能保持血液的成分和功能没有明显变化的原则,初步筛选的血液中细菌的灭活方法是MB光敏效应法.     

太阳光及紫外线照射诱发M13mp2噬菌体DNA产生8-OHdG的作用

[目的 ]分析太阳光及长波紫外线 (UVA)、中波紫外线 (UVB)诱发Ml3mp2噬菌体DNA产生 8 羟基脱氧鸟苷(8 OHdG)的作用。 [方法 ]用太阳光、UVA和UVB照射处理M13mp2噬菌体样品 ,以HPLC EC检测DNA样品中的 8 OHdG。 [结果 ] 1、3、5h太阳光照射和 2 8、10 8、2 5 0、5 0 0kJ/m2 剂量UVA照射后的样品均可检测到 8 OHdG含量增加 ,并存在与照射剂量的依存关系。较高剂量 (2 6kJ/m2 )UVB照射也可引起 8 OHdG的产生。 [结论 ]太阳光照射致M13mp2噬菌体突变作用中 ,存在DNA的氧化损伤 ,主要是UVA的作用。     

紫外线C对A549细胞HSPs表达的影响

[目的]研究紫外线C(UVC)对热休克蛋白(heat shock proteins,HSP)27、70及90的影响。[方法]用紫外线不同照射剂量(0、10、20、40、80J/m2)来照射A549细胞株,用Western-blot检测HSP27、HSP70、HSP90的表达水平。[结果]随着UVC剂量的升高,HSP70和HSP27的表达水平先升高,达到一个高峰后又降低。HSP27表达在20J/m2时达到高峰,HSP70表达在40J/m2时达到高峰,HSP90各剂量的UVC照射下,未见显著性变化。与对照组(0J/m2)相比,在10J/m2时,HSP27和HSP70表达增加(P<0.05);在20J/m2时,HSP27表达显著增加(P<0.01),HSP70表达也继续增加(P<0.05);在40J/m2时,HSP27表达开始下降,但与对照组相比差异没有显著性(P>0.05),HSP70表达仍显著增加,与对照组相比差异有显著性(P<0.01)。在80J/m2时,HSP27表达与对照组和40J/m2组相比,差异无显著性(P>0.05),HSP70表达下降,但仍高于对照组(P<0.05)。在10、20、40和80J/m2的UVC照射下,HSP90表达变化均未见显著性差异(P>0.05)。[结论]随着UVC剂量的升高,HSP70和HSP27的表达水平先升高,达到一个高峰后又降低。HSP27,HSP70能被一定剂量范围的UVC照射所诱导,高剂量UVC照射时HSP27、HSP70的表达被抑制,但HSP90表达未发现能被诱导。     

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.     

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.     

Assessing occupational and environmental exposure

Exposure assessment is a poorly understood component of the science of epidemiology. The relationship between exposure to chemicals and ill-health outcomes is often calculated using crude exposure measures such as ever/never exposed or duration. When investigating subtle effects, exposures need to be characterized much more fully in terms of intensity, frequency, duration and route. While occupational exposures tend to be much greater than those experienced from the wider environment there is a need to remember that, for many chemicals, exposure can occur occupationally, environmentally and through consumer use of products containing the material of interest. Inhalation exposure has generally been the traditional focus for most epidemiological investigations but there is now growing awareness of the importance of the dermal and ingested routes of contact and internalization. Quantification of the exposure also needs to be related to a biological mechanism of action and exposure metrics need to be selected accordingly. Occupational exposures can generally be measured using simple well-validated techniques. Environmental exposures require much more sensitive instruments and are more difficult to assess. Exposure modelling, particularly for the environmental fate of chemicals has undergone many recent developments and Monte Carlo techniques can be used to characterize model uncertainty and variability. This approach to exposure assessment can now be used in the setting of the wider environment and will enable a far better understanding of the relationship between exposure and disease.     

Mercury toxicity due to the smelting of placer gold recovered by mercury amalgam

A 19-year-old man developed tremor in both hands and fatigue after starting work at a placer gold mine where he was exposed to mercury-gold amalgam. Examination revealed an intention tremor, dysdiadochokinesis and mild rigidity. The 24-h urinary mercury concentration reached a peak of 715 nmol/l (143 ug/l) shortly before the clinical examination, after which he was removed from working in the gold room [Mercury No. Adverse Effect Level: 250 nmol/l (50 ug/l)]. On review 7 weeks later his tremor had almost resolved and the dysdiadochokinesis and rigidity had gone. The 24-h urinary mercury concentration had fallen to 160 nmol/l (32 ug/l). The principal exposure to mercury was considered to be the smelting of retorted gold with previously unrecognized residual mercury in it. The peak air concentration of mercury vapour during gold smelting was 0.533 mg/m3 (Mercury Vapour ACGIH TLV: 0.05 mg/m3 TWA). Several engineering and procedural controls were instituted. This episode occurred at another mine site, unrelated to Mount Isa Mines Limited.     

How Adults with Acquired Brain Damage Perceive Computer Training as a Rehabilitation Tool: A Focus-group Study

The aim of this study was to explore and describe how adult outpatients with acquired brain damage and referred to occupational therapy perceive computer training with the RehaCom programs, in order to evaluate the method of treatment as a tool in the rehabilitation of persons with cognitive disorders. By using focus-group discussions as a qualitative method of research when analysing the result, five themes with corresponding categories emerged, describing a development of understanding and learning about capacities. Themes describing how the participants could apply strategies to overcome shortcomings in daily occupations and the therapeutic role of the occupational therapist were identified as well. The result shows that a computer training program such as RehaCom can be used as an educational tool, for example, to guide a person who is trying to adopt compensatory strategies to avoid overload by taking pauses. It was found that anything the participants learned was also applicable to occupational performance in daily life.