一种新型气体流量测定仪的设计

基于新型量热式传感器和DSP小波变换信号处理的工作原理,设计了一种新型的气体流量测定系统。该系统通过流量传感器、电压放大器、A/D转换器、数字信号处理器、热源控制电路等硬件电路和配套软件及算法来实现。设计具有精度高、性能稳定和较高的噪声抑制等优点,特别适用于小潮气量低流速条件下的测量。     

基于平板探测器的小动物微型CT成像系统

介绍了一套适用于小动物成像的高分辨微型CT成像系统。该系统采用用焦点为100μm的微焦点射线源和成像面积为13cm×13cm的平板探测器测量数据,以旋转扫描的锥束算法进行图像重建。经测试,平板探测器的MTF在调制度10％时,可达到31lp／cm．CT系统放大倍率为1．94时,分辨率可达185μm。用兔股骨为样品,可清晰观察到骨小梁结构．表明该系统可高分辨地实现小动物样本的三维结构成像。     

EIS硬件故障诊断系统的设计与应用

为了能够迅速准确地对电阻抗扫描成像系统的硬件电路中所发生的故障进行定位，研究设计了一套故障诊断系统。基于数据采集（DAQ）板和数字输入输出（DIO）板，设计了故障诊断系统的硬件模块；利用Visual Studio．NET开发了故障诊断系统的软件模块。使用该故障诊断系统可以对EIS成像系统中主要的数字、模拟信号进行实时采集，同时实现对数据的分析处理与结果显示。借助于该故障诊断系统可以有效地检测出EIS系统中的硬件故障。     

一种基于传统超声成像系统平台的组织弹性成像功能的实现

通过分析超声弹性成像算法的技术特点和临床成像需求,设计和实现了一种展开于汕头超声SIUICTS-8800影像系统平台之上的超声组织成像功能算法,具有实时性,弹性图像对比度较高,适用手持探头方式等特点。     

医用红外实时成像系统的设计

目的：针对目前医用红外成像系统的诸多缺陷,设计一种基于非制冷焦平面阵列红外探测器的医用红外实时成像系统。方法：设计的系统硬件部分由光学系统、红外探测器、热图采集与预处理电路,以及用于图像显示与处理的便携式计算机等组成;系统软件主要包括原始图像数据的获取与校正模块、图像实时处理与显示模块、伪彩处理模块以及图像保存与离线分析模块等4个功能部分;并针对像元的非均匀性提出了两点校验算法,提高了成像质量。结果：医用红外实时成像系统无需制冷,使用方便,整机温度分辨率为0.1℃,测温范围为-20℃～100℃,使用环境温度范围为0℃～40℃,实时成像速度为25帧/s,满足临床需要。结论：实验证明,本红外成像系统可快速实时成像,能满足临床检查需要。     

肺部电阻抗成像系统

肺功能的连续监测对临床肺疾病患者的及时治疗十分重要.文中讨论了肺部电阻抗成像（EIT）的硬件系统,针对人体肺部仿真模型,利用Landweber预迭代算法进行图像重建研究.和线性反投影相比,结果表明,Landweber预迭代算法可削弱拖尾现象,提高图像质量,且重建过程分为离线预迭代和在线一步成像,提高了实时成像速度.     

用于康普顿相机的成像探测系统研制

目的 针对核设施热点成像应用设计康普顿相机的探测器和读出电子学系统。方法 采用两块像素型碲锌镉探测器分别作为康普顿相机的散射层和吸收层,利用SRE4002模块、信号处理电路、模数转换电路和主控板等构成读出电子学系统,并针对康普顿相机应用设计了数据采集逻辑和控制程序,可对探测器每个像素的能量响应进行实际校准测试。结果 测试发现该探测系统的位置分辨与像素设计一致;校准后662 keV处总能量分辨和平均能量分辨约为3%。结论 该系统的位置分辨和能量分辨符合康普顿相机研究需求,单像素能量校准有效改善了能量分辨,可为康普顿散射成像研究提供硬件支持,并对其他γ成像系统设计具有借鉴意义。     

基于DSP的生物医学信号处理实验平台设计

目的：设计一个实验平台,使生物医学工程专业的学生可以学习在数字信号处理器（DSP）上处理生物医学信号的方法。方法：采用数字化心电信号作为实验平台的数据源,在现有的DSP实验平台上设计完成各种生物医学信号处理算法。结果：在实验平台上开发了心电发生器、滤波、压缩、频谱分析、心率检测等实验．同时将此实验平台作为学习生物医学信号处理仪器设计的原型,取得了良好的教学效果。结论：学生使用基于DSP的生物医学信号处理实验平台既能够学习和深刻理解生物医学信号处理的算法,还能够学习如何使用DSP来实现这些算法,教学效果显著,但仍有待于进一步完善。     

基于ActiveMIL的数字化X射线图像采集系统的设计

本文介绍了X射线数字成像技术,阐述在使用影像增强器的诊断设备中,数字化X射线图像采集系统的硬件组成。设计了基于Active MIL组件的X射线图像采集系统软件,其编程语言为VC++/CLR,实现了图像的实时显示、单帧采集、序列采集、畸变校正处理、分析、存档等功能。结果表明:所设计的图像采集系统工作稳定,采集图像清晰,实现了设计的要求。     

超声多普勒自相关彩色血流成像原理和数字实现技术研究

分析了自相关方法构成的多普勒彩色血流成像的基本原理,采用数字技术对算法的具体实现进行了研究,提出了一种完整的超声成像系统的彩色血流成像自相关估计器的设计和具体实现方法,该方法理论充分,计算精度较高,系统实现简单灵活,为彩色超声多普勒血流成像临床应用提供了基础。     

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.     

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.     

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.