AVL COMPACT2血气分析仪的原理和故障分析

AVL COMPACT2血气分析仪可分为管路测量系统和电路系统两部分。电路系统要求接UPS或稳压电源,集成化程度较高,一般不出问题。管路测量系统包括4个电极及各种管路,是故障易发区域。4个电极是pH电极、pH参比电极、CO2电极、O2电极。pH电极和pH参比电极相邻安放在测量     

微分极谱伏安法测定水中氯化物

水中氯化物的电化学分析中应用银电极电解氯根法［１］、汞电极法［２］、旋转银盘电极法［３］已做报导。我们用ＭＰ－１型溶出分析仪的银棒电极组成三电极系统，在选定的实验条件和支持电解质底液中，水中的Ｃｌ－产生一灵敏的极谱波。由此消除了因饱和甘汞参比电极组成三电极系统中其ＫＣｌ的Ｃｌ－对水中氯化物测定的干扰。该方法简便、灵敏、快速，实验结果令人满意。１实验部分１．１　仪器与试剂１．１．１　ＭＰ－１型溶出分析仪（山东电讯七厂）。三电极系统：滴汞电极为工作电极，银棒电极为参比电极，铂电极为辅助电极。 银棒电…     

浮地式二电极心电记录

N.V.thakor和J.G.Webster护详细地分析并比较了浮地式心电记录中各种记录模式的50周干扰。我们用自己设计的心电遥测发射机及监护仪对此作了实验验证。和他们结论不同之处是:浮地式差分二电极系统并非绝对劣于浮地式差分三电极系统;一般地,二者性能相仿;虽然在克服由于电极阻抗不平衡的不利影响方面二电极系统不如三电极系统,但省了一个电极在某些场合是重要的。     

在线水质电导率信号采集系统的电路设计

目的：为提高电导率的测量精度，设计一种利用单片机技术实现电导率信号在线采集功能的系统。方法：根据水质电导率测量原理，分析了影响电导率测量精度的两个主要因素：温度和电极极化效应。采用正负方波脉冲作为电导率测量的激励源，减小电极的极化误差；采用数字温度传感器DS18B20补偿温度的影响。结果：通过模块化的软件编程，实现了信号采集、显示及控制等功能，减小了温度及电极极化效应的影响，提高了测量精度。结论：该系统具有精度高、操作简单等优点，经进一步完善后可满足实际应用的要求。     

心房心外膜标测电极的研制

介绍一种心房心外膜多位点标测电极－电极板电极的制作方法。该电极简便易行。标测所得双极电图形尖锐、清晰、基线平稳，与计算机辅助的信号处理系统相连可用于房性心律失常的心外实时标测。     

医用传感器(六)

在生物系统中采用电极测量生化参数,如 pH,PO_2,PCO_2等,或测量生理电量,如ECG、EEG,EMG 等都涉及到电极一电介质界面问题。在这个界面上,一方面通过离子运动进行电荷传输;另一方面通过电子进行导电。这两种导电情况作为一个连续的电气通路可以看作是一个能量转换过程,因而可以把电极测量作为传感器工作来考虑。     

三电极系统内部参数的研究与仿真

目的：研究三电极系统内部参数的变化与工作电极流过的电流（包括法拉第电流与非法拉第电流）的定量关系。方法：基于驱动电压—电流系统,建立一个描述系统内的参数模型,通过对模型参数的数值改变给出了参数变化对工作电流的影响。结果：仿真的Randle模型和金属涂层电极模型等2种模型参数的研究结果与电化学实验的观察结果相一致。结论：仿真模型的研究为电化学噪声的估算与影响提供了参考,对电化学产品的数据精确性及抗干扰能力具有重要的意义。     

基于LabVIEW的心电信号检测实验系统设计

介绍了基于LabVIEW的心电信号检测实验系统的软硬件设计过程。该系统利用LabvIEW7.0图形化语言编程,将心电电极采集的信号进行显示、分析、存储、打印。本系统适合医学院校师生开展心电信号的采集、数据保存、数据处理算法等方面的实验和研究。     

RDS111型回旋加速器离子源分析与检修

离子源系统是回旋加速器的关键组成部分之一，也是保证加速器正常运转所必须的系统之一，其作用是提供加速粒子。西门子RDS111型回旋加速器的离子源系统是垂直安装于加速器内部的．该系统包括ARC电源、BIAS电源、潘宁离子源、氢气流量控制器以及相应的水冷却。     

Ag／AgCl粉末电极和镀层电极在脑部EIT测量中的比较研究

目的：针对一种新型的医用Ag／AgCl粉末电极和传统的医用Ag／AgCl镀层电极，比较两者在脑部电阻抗断层成像（Electrical Impedance Tomography，EIT）测量中的性能差异。方法：基于自行开发的EIT系统，分别利用Ag／AgCl粉末电极和镀层电极，分别对物理模型和人体对象进行脑部电阻抗断层成像测量，并且通过提出的两个指标（高频信噪比和低频信噪比）及接触阻抗来评价电极系统的特性。结果：相对于Ag／AgCl镀层电极，Ag／AgCl粉末电极具有更好的抗噪性和稳定性。结论：Ag／AgCl粉末电极能更有效地满足脑部EIT监护的要求。     

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.     

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.     

The design of hazard risk assessment matrices for ranking occupational health risks and their application in mining and minerals processing

Two hazard risk assessment matrices for the ranking of occupational health risks are described. The qualitative matrix uses qualitative measures of probability and consequence to determine risk assessment codes for hazard-disease combinations. A walk-through survey of an underground metalliferous mine and concentrator is used to demonstrate how the qualitative matrix can be applied to determine priorities for the control of occupational health hazards. The semi-quantitative matrix uses attributable risk as a quantitative measure of probability and uses qualitative measures of consequence. A practical application of this matrix is the determination of occupational health priorities using existing epidemiological studies. Calculated attributable risks from epidemiological studies of hazard-disease combinations in mining and minerals processing are used as examples. These historic response data do not reflect the risks associated with current exposures. A method using current exposure data, known exposure-response relationships and the semi-quantitative matrix is proposed for more accurate and current risk rankings.     

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.     

The rise and fall in incidence of malignant mesothelioma from a British Naval Dockyard, 1979-1999

BACKGROUND: The incidence of malignant mesothelioma in Britain is predicted to rise over the next 15-25 years because of past failure to protect the workforce against inhalation of asbestos. In British Naval dockyards, alternative insulation materials and respiratory protection were introduced from the mid-1960s. Aims This study was carried out to investigate the effects of these control measures on mesothelioma deaths in dockyard workers. METHODS: Cases of mesothelioma of the pleura and peritoneum between 1979 and 1999 in workers from the Devonport Naval Dockyard, south-west England, were sought from coroners' and medico-legal records. RESULTS: Three hundred and one cases were identified, 7% peritoneal. The peak incidence occurred in 1991 with 25 cases per annum (quadratic model fit R(2) = 74.2%, P < 0.001) and we predict that by 2003 the incidence will fall to fewer than five cases per annum. The mean time between first exposure and presentation was 48.5 years [95% confidence interval (CI) = 47.3-49.8], but this was significantly shorter in the more heavily exposed trades, when compared with the less heavily exposed (42 years, 95% CI = 39.0-45.0, versus 49.5 years, 95% CI = 48.2-50.9). Those with higher exposure were also at significantly greater risk of peritoneal disease (P < 0.023, Fisher's exact test). CONCLUSION: The reduction in incidence of mesothelioma is greater than can be accounted for by reduction in numbers of dockyard workers over the last 50 years. Changes in insulation materials and improved industrial hygiene measures introduced into the Devonport Dockyard from the mid-1960s have resulted in an earlier decline in the incidence of malignant mesothelioma than that predicted for the British workforce as a whole.