低剂量CT在眼眶部外伤扫描中最优化应用研究

目的 探讨眼眶部外伤后低剂量CT扫描的最优化。方法 对336例眼眶部外伤患者行眼眶部低剂量CT扫描,并对每例患者行晶状体视神经层面常规剂量CT扫描,对比该层面二者的图像质量与患者的辐射剂量。结果 眼眶部低剂量CT扫描与常规剂量CT扫描,对显示眶内结构及眶壁骨质,2种扫描方法图像质量差异无显著性。低剂量单次扫描的CT剂量加权指数(CTDIw)为7.4 mGy,常规剂量的CTDIw为24.6 mGy。结论 眼眶部低剂量CT扫描可获得与常规剂量几乎相同的影像信息和图像质量,且单层扫描CT剂量加权指数(CTDIw)减少了17.2 mGy。     

低剂量CT扫描技术在脑出血检查中的应用价值

目的：探讨低剂量CT扫描技术在脑出血检查中的应用价值。方法对40例脑出血患者行头颅低剂量CT扫描,分析评价其图像质量,记录CT容积剂量指数（CTDIvol）,并与传统扫描的辐射剂量进行比较。结果图像清晰无伪影,对比度、分辨率均符合诊断要求;应用低剂量技术,40例患者的平均CTDIvol为37.25 mGy,较传统扫描方式的46.08 mGy,降低约19.1%。结论低剂量CT扫描技术可降低患者的辐射剂量,具有良好的应用前景。     

婴幼儿颞骨低剂量螺旋CT扫描的防护价值

目的:探讨婴幼儿(≤6周岁)颞骨多层螺旋CT低剂量扫描的防护价值。方法:采用CT高分辨率螺旋扫描方式,选择60例幼儿颞骨检查者用40mA和80mA随机分成2组进行螺旋扫描,扫描参数:管电压140kV,层厚、层间距都是1.25mm,机架旋转速度每圈1s,螺距:0.562。采用标准盲式评估方法,由2名资深技术专家对2组扫描剂量下的图像质量进行评估,并对DLP进行对比。结果:扫描mA从80降至40时,平均DLP由原来的171.6mGy·cm降至74.4mGy·cm,下降幅度可达56.6%;选择40mA进行扫描时图像噪声略有增大,但2组扫描的图像质量均能达到医学影像诊断要求,没有统计学意义(P>0.05)。结论:以40mA扫描的图像质量完全能满足临床与影像诊断的要求,同时,对婴幼儿的发育与健康成长起到很好防护价值,低剂量CT扫描应大力推广应用。     

640层CT低剂量容积扫描在腰椎间盘突出检查中的应用研究

目的 评价640层CT低剂量容积扫描技术与螺旋扫描图像质量,探讨低剂量容积扫描在腰椎间盘检查中的应用价值.方法 对80例怀疑腰椎间盘突出并需要CT检查的患者,采用640层CT(Aquilion One)进行容积扫描,并对图像结果进行对比评价,观察对比其对腰椎结构的显示差异以及对剂量的统计,与螺旋扫描方式的CT剂量指数(CTDIvol)进行对照.结果 80例应用640层CT低剂量容积扫描技术患者图像质量与螺旋扫描方式比较差异无统计学意义(P＞0.05),但在管电流70 mA下行640层低剂量容积扫描方式的CTDIvol明显低于螺旋扫描方式,差异有统计学意义(t=-5.344,P＜0.05).结论 应用Aquilion One CT容积扫描技术在腰椎间盘突出检查中图像质量高,剂量低于螺旋扫描方式成像的剂量,有利于患者的辐射防护,对临床和患者意义巨大.     

低剂量螺旋CT扫描在早期肺癌中的应用价值

目的探讨低剂量螺旋CT在早期肺癌诊断中的应用价值。方法选择2009年1月—2013年6月经临床观察和手术病理证实的早期肺癌患者48例54个结节进行分析,采用Philips公司的Brilliance 6排螺旋CT机进行常规剂量和低剂量扫描,计数资料采用χ2检验,P0.05为差异有统计学意义。结果低剂量扫描共检出结节45个,检出率83.33%。对磨玻璃结节的检出率最低,为71.43%;结节越大检出率越高,5 mm的检出率为92.31%;对结节毛刺的检出率最低,为64.71%。常规剂量扫描图像质量优秀率91.67%,优良率100.00%;低剂量优秀率71.92%,优良率93.75%。二者优秀率比较差异有统计学意义(P0.05),优良率比较差异无统计学意义(P0.05)。常规剂量扫描有效放射剂量(145.79±18.33)mGy·cm2,低剂量扫描有效放射剂量(89.36±11.72)mGy·cm2,二者比较差异有统计学意义(P0.05)。结论低剂量螺旋CT在检出早期肺癌方面具有较高检出率,并且具有低剂量的优势,但是对图像质量有一定影响,影响磨玻璃样小病灶及细微结构的显示,在临床工作中应予以重视。     

耳部低剂量CT扫描的辐射防护及诊断价值

目的 通过耳部低剂量CT扫描,合理选择剂量,探讨耳部低剂量扫描的辐射防护及诊断价值。方法 60例受检者分为三组,分别为10 mA,50 mA和100 mA组,每组20人,进行低剂量扫描。其他参数不变,改用200mA对三组受检者进行常规剂量扫描,作为标准对照组。比较单层CT剂量加权指数(CTDIVOI)和图像质量的不同。结果 三组不同毫安组单层CT剂量加权指数分别为2.15 mGy,10.77 mGy,21.54 mGy,常规剂量(200 mA)组为43.08 mGy。10mA组图像质量与其它组比较,差别明显,具有统计学意义。其他三组差别不显著。结论 耳部低剂量CT扫描能够降低病人辐射剂量,图像质量满足临床诊断的要求。     

双源CTDoubleflash螺旋扫描模式在评价冠状动脉成像中的应用

目的回顾性比较双源CT Double flash螺旋扫描模式与普通螺旋扫描在评价冠状动脉成像中的应用。方法对101例患者应用Double flash螺旋扫描模式行冠状动脉CT扫描,114例患者应用普通螺旋扫描,分析2种扫描模式容积CT剂量指数(CTDIvol)、有效辐射剂量(ED)和图像质量;图像质量评价采用4分法:1分为优秀,4分为不能诊断;由2位高年资医师以双盲法单独对所有的冠状动脉段图像进行评价。结果 Double flash螺旋扫描的ED和CTDIvol分别为(1.67±0.39)mSv和(4.92±1.32)mGy,普通螺旋扫描的ED和CTDIvol分别为(5.08±1.419)mSv和(31.68±15.45)mGy,2种扫描模式的ED和CTDIvol比较,差异有统计学意义(P0.01);Double flash螺旋扫描不可诊断节段比率为0.57%(7/1219)低于普通螺旋扫描冠脉不可诊断节段比率0.72%(10/1381),但2种图像质量评分比较,差异无统计学意义(P0.05),60%和30%两个时相图像伪影互补17.8%(18/101)。结论 Double flash扫描模式可明显降低辐射剂量,保证较高诊断的图像质量。     

低剂量CT扫描对青少年副鼻窦疾病的应用价值

目的：探讨低剂量CT扫描对青少年副鼻窦疾病的应用价值。方法：对35例青少年副鼻窦疾病患者分别行低剂量和常规剂量扫描,对比两种剂量扫描所得图像质量与患者的辐射剂量。结果：低剂量和常规剂量扫描两种扫描方法所显示的图像质量没有显著差异（p〉0.05）,低剂量CT扫描单次扫描的辐射剂量加权指数（CTDIvol）为7.6mGy,常规剂量的为28.1mGy,两种扫描方法辐射剂量有显著差异（p〈0.01）。结论：低剂量CT扫描在副鼻窦疾病中是可行的,能保证图像的质量,又有效的降低患者的辐射损伤。     

心血管螺旋CT常规组与低剂量组的对比研究

目的:探讨螺旋CT常规组与低剂量组在心血管中的对比研究.方法:随机对20例60岁以上患者进行常规参数组(220mA)心脏CT检查,两周内进行复查时使用低剂量组(140mA)采集图像,分析两组CT扫描参数对患者剂量的影响,对所得图像行图像质量等级评估.结果:图像评分都大于3分,CTDIvo1随管电流量(mA)的下降而减低,220mA的91.72mGy与140mA的56.05mGy比较,下降38.89％.两组间CT值方差比较F=3.662,P=0.000<0.05,具有统计学差异.结论:低剂量组(140mA)可以应用在老年心脏血管CT检查中,可以在达到诊断目地的前提下,降低患者所受的辐射剂量.     

Aquilion ONE VOLUM低剂量扫描技术在儿科的应用价值

目的评价Aquilion One VOLUM低剂量扫描技术在儿科中的应用价值。方法应用Aquilion One CT对儿科需要行CT检查的患者50例,进行宽探测器平台下容积（VOLUM）扫描,并对图像结果进行评价,以及对剂量的统计与相应年龄行4排螺旋CT螺旋扫描的患者的剂量指数（CTD Ivol）进行对照。结果 50例应用Aquilion One容积CT行VOLUM扫描患者图像与4排螺旋CT螺旋扫描无明显差异,但行Aquilion One VOLUM扫描的剂量指数（CTD Ivol）明显低于4排组。结论 Aquilion One CT VOLUM扫描技术在儿科成像伪影少,图像质量高,剂量远远低于4排螺旋CT儿科成像的剂量。     

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 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.     

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.     

The risk of heat exhaustion at a deep underground metalliferous mine in relation to surface temperatures

The risk of heat exhaustion at a deep underground metalliferous mine was assessed in relation to thermal conditions prevailing on the surface. For each day of a 1-year prospective case series of heat exhaustion, surface 24-h mean wet and dry bulb temperatures were recorded. From this data, 24-h mean wet bulb globe temperatures were derived using certain assumptions. The three surface temperature variables were significantly higher on those days on which heat exhaustion occurred, compared to those days on which it did not occur (P < 0.001). The relative risk of heat exhaustion on days when the 24-h mean wet bulb globe temperature was in the range 26.0-28.0 degrees C was 4.82 (95% confidence interval 2.12-10.96). Surface temperature data could be used at this mine to warn miners about the risk of heat exhaustion.