差分脉冲和方波伏安法研究亲和素-生物素固载ssDNA的生物传感器

目的:建立一种新型的DNA检测技术,能快速、灵敏的识别目的DNA。方法:生物素标记的ssDNA通过生物素-亲和素体系固载到Pt电极上,制作了DNA传感器,[Co(phen)3]3+作指示剂,用差分脉冲伏安法(DPV)和方波伏安法(SWV)对此传感器进行研究。结果:在pH 6.8~7.0,[Co(phen)3]3+浓度80μmol/L条件下,杂交前后指示剂峰电流的差值与溶液中互补DNA的浓度有良好的线性关系,DPV法测量起始子的线性范围是8.0×10-9~2.8×10-8mol/L,终止子的线性范围是7.2×10-9~7.2×10-8mol/L;SWV法测量起始子的线性范围是8.5×10-9~3.5×10-8mol/L,终止子的线性范围是7.2×10-9~9.0×10-8mol/L。两种检测方法均能很好的识别样品中的DNA片断。结论:该方法测量灵敏度高,能很好地识别转基因食品中的特异DNA序列。     

水中间苯二酚的表面活性剂增强铈(Ⅳ)-间苯二酚化学发光体系测定法

目的建立测定水中的间苯二酚的化学发光新方法。方法在酸性介质中,利用表面活性剂吐温40作为Ce(Ⅳ)-间苯二酚化学发光反应体系的增敏剂,建立了Ce(Ⅳ)-间苯二酚-吐温40化学发光新体系,结合流动注射技术建立测定痕量的间苯二酚化学发光分析法。结果该方法的线性范围为8.0×10-8～5.0×10-5mol/L,检出限为6.0×10-8mol/L,对5.0×10-6mol/L间苯二酚进行11次平行测定,相对标准偏差为3.5%。结论该法可用于实验室废水、复方间苯二酚溶液(Ⅰ)中的间苯二酚含量的测定。     

聚DL-α-氨基丙酸修饰电极的制备及应用

目的建立修饰电极测定多巴胺的新方法。方法在pH6.0的磷酸盐缓冲溶液中,用循环伏安法制备聚DLα氨基丙酸修饰玻碳电极,研究多巴胺在聚DLα氨基丙酸修饰电极上的电化学行为,建立测定多巴胺的电化学分析方法。结果在pH7.0的磷酸盐缓冲溶液中,测定多巴胺的线性范围:1.0×10-4mol/L～1.0×10-6mol/L,1.0×10-6mol/L～8.0×10-9mol/L,检测限:1.0×10-9mol/L。结论该方法简单、快速、灵敏,用于药剂中多巴胺的测定,结果满意。     

用聚L-缬氨酸修饰电极循环伏安法测定药剂中的多巴胺

目的:建立修饰电极测定多巴胺的新方法。方法:在pH9.0的磷酸盐缓冲溶液中,用循环伏安法制备聚L-缬氨酸修饰玻碳电极,研究多巴胺在聚L-缬氨酸修饰电极上的电化学行为,建立测定多巴胺的电化学分析新方法。结果:在pH6.0的磷酸盐缓冲溶液中,多巴胺在聚L-缬氨酸酸修饰玻碳电极上出现一对灵敏的氧化还原峰,峰电位分别为:Epa=0.296V,Epc=0.205V(对饱和甘汞电极)。用循环伏安法测定多巴胺的线性范围:1.0×10-9～5.0×10-7mol/L,5.0×10-7～5.0×10-4mol/L,检出限:8.0×10-10mol/L。结论:该方法简单、快速、灵敏,用于药剂中多巴胺的测定,结果满意。     

水中微量苯酚的碳纳米管化学修饰电极测定法

目的探讨应用多壁碳纳米管膜修饰电极测定环境水样中微量苯酚。方法制备了多壁碳纳米管膜修饰电极,采用循环伏安法和方波伏安法,测定环境水样中微量苯酚,同时还研究了苯酚在此修饰电极上的电化学行为。结果在pH7.0的磷酸盐缓冲溶液中,苯酚在多壁碳纳米管修饰玻碳电极上出现一灵敏的氧化峰,峰电位为0.69V。与裸玻碳电极相比,多壁碳纳米管膜修饰电极能显著提高苯酚的氧化峰电流。苯酚的线形范围为4.0×10-8～1.0×10-5mol/L,检测限可达1.0×10-8mol/L。5.0×10-7mol/L苯酚平行测定10次的相对标准偏差为5.2%。结论该电化学方法可用于环境水样中微量苯酚的测定。     

阳离子表面活性剂敏化的极谱催化波法测定螺内酯

目的:建立螺内酯含量测定的新方法。方法:应用阳离子表面活性剂CTMAB增敏的极谱催化波法。结果:在包含1 0 0mmol/LKIO3和8 0×1 0 - 8mol/LCTMAB的B -R缓冲液(pH =9 0 )条件下,螺内酯一阶导数峰高与其浓度在0 . 0 1～6 . 0 0 μmol/L范围内成线性,线性方程为Y =1 0 . 37(mm) +6 5 . 9X (r=0 .9997)。日内催化波峰高的精密度为2 . 6 %,平均回收率为1 0 1 3%。结论:该方法灵敏度高,操作简便,准确度好,可用于螺内酯片剂中螺内酯含量的测定。     

甘草酸二钾的极谱法测定及其应用

目的:建立非油脂性化妆品样品中甘草酸二钾的电化学分析方法。方法:用滴汞电极检测甘草酸二钾在B ritton-Rob inson(B-R)缓冲溶液中的电化学信号,对检测条件进行优化,并应用于实际化妆品样品的分析检测。结果:甘草酸二钾在滴汞电极上于-1.44 V(vs.SCE)处在上产生一个灵敏的二阶导数极谱还原峰。在最佳条件下,二阶导数峰电流值(ip″)同甘草酸二钾的浓度在1.11×10-6~3.34×10-5mol/L范围内呈良好的线性关系,线性回归方程为ip(″nA)=211.65C(μmol/L)+25.67,相关系数r为0.995,检出限为9.34×10-7mol/L,用于非油脂性模拟化妆品中的检测回收率为98.4%~103.6%。结论:本方法操作简便、信号灵敏、选择性好,可应用于化妆品样品的检测。     

香烟烟气中羰基化合物含量的测定—2.4一二硝基苯肼法

香烟烟气中含有相当数量的羰基化合物,它们能致癌或协同致癌。本文采用2.4一二硝基苯肼法,对香烟主流烟气中的羰基化合物含量进行测定获得成功。该方法的线性范围为4.28×10~(-7)～1.54×10~(-4)mol/L,(r=0.9978),最低检出限为4.28×10~(-7)mol/L;样本加标回收率和日间变异系数分别为91.5％～107.8％(n=12)和4.1％(n=7)。已测定市售有滤嘴与无滤嘴“大重九”牌香烟(昆明),过滤嘴仅滤除去羰基化合物的23％。     

高效液相色谱法测定MTX药物浓度

目的:建立以高效液相法(HPLC)测定MTX化疗后丢弃的棉签与针头中含有的MTX浓度的榆测方法。方法:将标本处理后,在AGILENT 1100高效液相色谱仪上进行测定。色谱柱:C18柱(大连依利特,250mm),流动相:0.1mol/L KH2PO4-K2HPO4,甲醇(87:13),流速:1.0ml/min,在UV 313nm处检测。结果:HPLC法检测MTX在10-7-10-4mol/L范围内呈线性,回归方程为:Y=2.73×107X+35.85(r=0.999)。MTX高、中、低浓度平均回收率分别为69.4％、66.7％、47.2％。送检的棉签所含MTX的量1.2×10-8-2.71×10-5mol/L,针头所含MTX的量2.13×10-8-2.50×10-5mol/L。结论:所建立的高效液相色谱法可以简便准确地测出大剂量MTX化疗抽血后丢弃的棉签与针头中所含MTX的浓度,以防止MTX对护理人员造成的皮肤局部刺激如接触性皮炎及长期直接接触引起的口腔粘膜溃疡、呕吐、白细胞下降等典型化疗药物毒副反应,从而对保护护理人员的健康以及避免环境污染有实际指导作用。     

聚L-丝氨酸修饰电极的制备及测定针剂中的多巴胺

目的:建立用氨基酸修饰电极测定多巴胺的新方法。方法:用循环伏安法制备聚L-丝氨酸修饰玻碳电极,研究神经递质多巴胺在聚L-丝氨酸修饰玻碳电极上的电化学行为,建立循环伏安法测定痕量多巴胺的新方法。结果:在pH 7.0的磷酸盐缓冲溶液中,多巴胺在聚L-丝氨酸修饰玻碳电极上产生一对氧化还原峰,峰电位分别为Epa=0.278 V,Epc=0.066 V(相对Ag/AgC l电极)。用循环伏安法测定多巴胺的线性范围:5.0×10-6~1.0×10-3mol/L,检测限:1.0×10-6mol/L。对1.0×10-4mol/L多巴胺溶液平行测定15次,其相对标准偏差为4.8%。结论:方法简单,电极稳定性好,用于针剂中多巴胺的测定,结果满意。     

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.