漏声表面波生物传感器检测系统构建时靶序列浓度的影响

目的 探讨新型的漏声表面波(LSAW)传感器检测系统构建时,人乳头状瘤病毒(HPV)靶序列浓度对其杂交效应和反应时间的影响.方法 LSAW传感器表面先固定上1.0 μmol/L的肽核酸(PNA)探针,观察终浓度为1 pg/L～1 mg/L的HPV靶序列DNA与探针进行杂交所引起的相位变化及反应所需时间,并对相位下降值与靶序列浓度做线性回归,确定其线性范围.结果 随着靶序列浓度从1 pg/L增加到1 mg/L,杂交反应引起的相位下降值呈先增加后趋于缓和的趋势,以100μg/L为分界线,而杂交平衡时间并没有显现出一定的变化趋势;在1 pg/L～100μg/L的HPV靶序列浓度范围内,相位变化与靶序列浓度的线性回归方程为△P=2.3392 1gC+14.584,相关系数r2=0.9622.结论 随着靶序列浓度的升高,杂交反应引起的相位下降值呈典型饱和曲线趋势,靶序列浓度的线性检测范围为:1 pg/L～100μg/L.     

离子强度对乙型脑炎病毒基因传感器检测系统的影响

目的 探讨磷酸盐缓冲液(PBS)中Na+浓度值对乙型脑炎病毒(JEV)基因传感器检测系统的影响.方法 漏声表面波(LSAW)基因传感器表面固定终浓度为1.0μmol/L的乙型脑炎病毒探针,然后分别在pH 7.6的10 mmol/L PBS缓冲液(含Na+浓度值0.1～0.6 mol/L)中和终浓度为1.0 μmol/L的JEV靶序列杂交,分别记录相位变化及反应所需时间.结果 杂交反应引起的相位变化是先上升后趋于缓和的趋势,以0.3 mol/L Na+浓度为分界线;杂交平衡时间同相位变化一致,当PBS中Na+浓度为0.3 mol/L,杂交反应的平衡时间为33 min.结论 随着Na+浓度的升高,杂交反应引起的相位变化呈典型的饱和曲线趋势,PBS中Na+浓度0.3 mol/L,杂交反应平衡时间33 min,是LSAW-JEV基因传感器杂交的最适反应条件.     

PNA与DNA探针对漏声表面波传感器特异性的影响

目的探讨以PNA作为杂交探针与普通的DNA探针相比,在漏声表面波生物传感器生物杂交反应中的优越性。方法用巯基固定法将PNA、DNA两种探针分别固定在漏声表面波生物传感器的金膜表面,分别与完全匹配、1个及2个碱基错配的靶序列进行杂交反应,观察两种不同的探针与靶序列反应所引起的相位变化及反应平衡时间。结果与DNA探针相比,PNA探针识别碱基错配的能力显著提高,且杂交平衡时间更短。结论 PNA探针可提高漏声表面波生物传感器的检测特异性。     

乙型肝炎病毒靶序列浓度对新型肽核酸压电基因传感器阵列的影响

目的探索乙型肝炎病毒(HBV)靶序列浓度值对肽核酸压电基因传感器阵列杂交效应的影响.方法压电基因传感器阵列表面先固定上1.5μmol/L的bis-PNA探针,观察终浓度为1pg/L至100μg/L的HBV DNA与探针,进行杂交所引起的频率变化及反应所需时间.并对频率下降值与靶序列浓度做线性回归,确定其线性范围.结果靶序列浓度为1pg/L时,传感器未能检测出任何频率的改变.随着浓度从10 pg/L增加到100μg/L,杂交反应引起的频率下降值呈先增加后趋于缓和的趋势,以10μg/L为分界线,而杂交平衡时间并没有显现出一定的变化趋势.在10pg/L到10μg/L的浓度范围内,浓度与频率下降值的线性回归方程为lgC=-2.7455 0.0691×△F,相关系数r=0.9923.结论随着靶序列浓度的升高,杂交反应引起的频率下降值呈典型饱和曲线趋势,靶序列浓度的线性检测范围为10pg/L～10μg/L.     

漏声表面波传感器检测HPV及传感器再生性研究

目的 应用漏声表面波(LSAW)生物传感器实时检测HPV,并对传感器进行再生性研究.方法 每次实验前分别用Piranha液、1 mol/L HCI和1 mol/L NaOH等溶液清洗传感器反应区域,在相同实验条件下,再生使用20次;探讨传感器的信号响应及再生性能.结果 再生使用5次时核酸杂交引起的相当于第1次的89.60%,变异系数为4.24%,再生检测10次时响应信号相当于第1次的71.56%,变异系数为10.14%;再生10次后传感器检测能力开始迅速降低.结论 LSAW生物传感器可以特异性地进行人乳头状瘤病毒(HPV)的快速检测,并具有较好的再生性.     

长、短链探针以链延伸反应提高基因传感器检测MRSA灵敏度的实验研究

目的：利用链延伸反应的原理延长引物链以提高石英谐振式基因传感器表面的质量负载，从而提高传感器检测MRSA的灵敏度。方法：以不对称PCR的反应产物做为长链探针，人工合成的寡核苷酸片段为短链探针，在基因传感器阵列表面分别固定上金黄色葡萄球菌mecA和femA的长链及短链探针共4种探针片段，与相应的靶序列杂交后，加入Klenow酶，37℃进行链延伸反应1h。结果：长、短链探针均有效地固定了传感器表面。mecA,femA短链探针在链延伸反应前的检测灵敏度为0.5nmol/L，但经链延伸反应后检测灵敏提高到了0.05nmol/L；而长链探针却无法与相应的基因组靶序列发生杂交。结论：短链探针链延伸反应有效地提高了石英谐振式基因传感器的灵敏度，但该法不适用于链探针。     

基于非对称发夹探针的杂交链反应技术应用于病原菌检测的实验研究

目的 应用基于非对称发夹探针的杂交链反应技术,检测肺炎克雷伯菌不对称PCR产物,建立一种新的病原菌快速检测方法.方法 采用Array Designer 4.0软件,针对肺炎克雷伯菌的16S rDNA可变区域设计非对称发夹式DNA探针,优化探针浓度,以不对称PCR扩增肺炎克雷伯菌16rDNA可变区所制备的单链DNA为靶序列,采用HCR进行检测和分析.结果 HCR体系中发夹探针最佳浓度为1μmol/L;当靶序列初始浓度≥0.05μmol/L时,通过琼脂糖凝胶电泳可观察到明显的HCR聚合物;不对称PCR法制备的单链DNA可以启动杂交反应.结论 应用基于非对称发夹探针的杂交链反应技术检测病原菌具有反应体系简单,无需酶促反应等优点,可对血流感染病原菌基因组进行简便、快速、特异的检测.     

漏声表面波生物传感器液相检测系统的构建及检测HPV的实验研究

目的 建立漏声表面波生物传感器液相检测技术平台，并用该检测系统实时检测人乳头瘤病毒（HPV）。方法 构建检测和参比双路延迟线，并观察在液相中两路延迟线的相位变化规律；以人乳头瘤病毒为检测对象，用传感器检测系统对其进行实时检测。结果 两路延迟线的相位值在液相中发生不同的变化；检测HPV时，检测延迟线的相位值发生较大的变化，而参比通道的相位曲线变化不是很大。结论 成功构建了漏声表面波生物传感器液相检测技术平台，并实现对双链DNA病毒HPV实时检测反应。     

多聚T尾型探针在压电石英晶体微天平DNA传感器检测铜绿假单胞菌中的实验研究

目的 构建一种压电石英晶体微天平(QCM)DNA传感器多聚T尾型探针敏感膜制备新方法,同时对其重要影响因素进行优化探讨.方法 设计一种多聚T尾型探针,固定在压电QCM DNA传感器晶振表面,对探针固定浓度.杂交温度和杂交时间等因素进行实验研究,进一步将构建的多聚T尾型探针DNA传感器和普通探针DNA传感器用于铜绿假单胞菌检测,比较两种传感器的频率响应性能,同时对该压电QCM DNA传感器的再生性能进行研究.结果 探针最佳固定浓度为2.0 μmol/L,最适杂交温度为40℃,最适杂交时间为90 min;多聚T尾型探针DNA传感器的响应性能显著大于普通探针DNA传感器(P<0.05),可以重复使用7次.结论 基于多聚T尾型探针的压电QCM DNA传感器,具有杂交效率高、技术难度低、频率响应性能高等优点,在压电QCM DNA传感器基因检测领域有较好的应用前景.     

漏声表面波生物传感器不同检测方法的实验研究

目的构建双通道漏声表面波生物传感器液相检测技术平台。方法以人乳头状瘤病毒为检测对象,传感器检测系统运用相位、频率及延迟线3种检测方法对其进行实时检测;利用扫描隧道显微镜观察传感器裸金表面、固定巯基化探针以及核酸杂交后的金膜表面结构的微观变化。结果相位和频率两种检测方法较好;扫描隧道显微镜下可以看到裸金膜表面金原子排列有序;探针分子分布密度增加;杂交后寡核酸分子密度更为密集。结论成功构建了漏声表面波生物传感器液相检测技术平台并运用多种检测方法;扫描隧道显微镜可以形象直观地对传感器金膜表面、核酸杂交进行直接观察,结果进一步证实了实验结论的正确性。     

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.     

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.