瓦里安Varian2100C医用电子直线加速器疑难故障检修实例

Varian2100C医用电子直线加速器是Varian医用电子直线加速器C系列机型,虽然Varian2100C在许多医院已报废不用,但Varian医用电子直线加速器C系列机型在国内外使用还较多,通过对Varian2100C医用电子直线加速器疑难故障检修、分析及总结,希望对各位同行检修Varian医用电子直线加速器C系列机型有一定的帮助。     

医用电子直线加速器放射安全管理的探讨

随着临床技术的发展,许多医院都使用医用直线电子加速器（以下称直线加速器）用于治疗肿瘤。鉴于直线加速器本身的特殊性,医院应加强对直线加速器的放射防护管理,使其各项指标符合放射防护基本原则及国家相关法规标准要求。     

浅析上海市医用电子直线加速器配置及应用情况

目的 通过对全市在用医用电子直线加速器的检查,了解医用电子直线加速器的配置和应用现状。方法 根据有关法律法规制作检查表,联合放射治疗质控中心对全市在用24家医疗机构34台医用电子直线加速器实施检查。结论 上海市医用电子直线加速器配置集中在中心城区三级医疗机构,在用电子直线加速器机房放射防护情况及医务人员依法执业情况良好。     

医用电子直线加速器常用电气故障诊断及维修方法研究

目的:探讨医用电子直线加速器的常见电气故障诊断及维修方法的实现。方法:针对医用电子直线加速器的常见电气故障,结合工作实例,提出了几种诊断及维修医用电子直线加速器的常用方法。结果:利用这些方法可快速解决医用电子直线加速器的常见电气故障。结论:实践证明利用这些方法维修医用电子直线加速器切实有效,简单可行。     

医用直线加速器的机房建设

目的探讨直线加速器机房建设要点。方法结合实际,对直线加速器安装过程中的选址、机房、防护与屏蔽、通风等进行分析。结果总结了直线加速器场地要求和机房建设要求。结论对直线加速器安装具有重要指导意义,防止因设计失误给机房运行带来不良后果。     

直线加速器的日常保养和质保检测

直线加速器作为医院临床治疗的一类大型医疗设备,结构复杂,使用濒率高,而且在电离辐射计量学中,对放疗计量的精确度要求最高,对直线加速器的日常保养和质保检测就越重要。本文介绍了直线加速器日常保养的内容及采取一些措施;直线加速器的各项质量保证指标检测。     

北京市医用电子直线加速器性能检测结果分析

目的了解北京市医用电子直线加速器设备性能的状况,推进医用电子直线加速器的质量控制检测,提高放射治疗质量。方法选取16台医用电子直线加速器为研究对象,根据2011年度卫生行业科研专项的实施方案确定性能指标,并按照国家标准和国际电工委员会的相关标准对医用电子直线加速器的性能进行检测与分析。结果 16台医用电子直线加速器初检的合格率为75%,经调试后复检合格率为100%;主要不合指标均为加速器X射线的性能指标,分别为X射线辐射野均整度和对称性,X射线辐射剂量示值的误差;调查结果反映了该地区医用电子直线加速器的质量控制状况。结论加强医用电子直线加速器的质量控制,配备相应的质量控制设备,定期查验设备性能状况以保证放射治疗的精确执行。     

针对 TrueBeam 医用直线加速器的质量控制方法

美国瓦里安公司全新设计的医用直线加速器TrueBeam的质量控制方法与传统直线加速器的质量控制方法存在一些不同。本文将介绍专门针对TrueBeam 直线加速器的常用的质量控制方法。     

浙江省医用直线加速器分布情况及配置策略

目的：分析医用电子直线加速器在浙江省的分布情况,为浙江省各级放疗机构配置医用直线加速器提供参考。方法：对浙江省医用直线加速器的分布与地区、经济收入和人口分布的关系进行比较分析。同时与国内外医用加速器配置情况进行比较。结果：浙江省的医用加速器人均拥有量略高于全国平均水平,但配置仍不足,而且分布不均衡。结论：医用直线加速器的分布与地区的经济发展状况、人口学特征相关,各级医院在配置医用直线加速器时应充分考虑当地的人均收入水平、人口密度,并综合考虑放疗物理师的配置、加速器生产厂家的服务质量等因素。     

医科达加速器高压部分的工作原理及应用

目的：通过掌握医用直线加速器高压部分的工作原理,使医技等相关工作人员在加速器高压部分出现故障时做出快速判断、修理和维护,有效保持加速器的正常性能,确保其正常使用。方法：了解医用直线加速器的主要组成部分,通过框图重点介绍加速器高压部分,着重讨论充电变压器的充电原理和PFN的充放电原理。结果：通过掌握医用直线加速器高压部分的工作原理对保证加速器的使用性能正常和判断高压部分的故障原因有着重要意义。结论：了解加速器的应用进展情况可更好为医院选择合适的医用直线加速器。     

Le processus du vieillissement : longévité et alimentation

Ageing and the nutrition knew two great evolutions recently. First of all, progress of the genetics of ageing which showed the genetic control of longevity. In addition, the important corpus of knowledge accumulated in the field of the food restriction, one of the rare interventions not-genetics known to increase the longevity of the mammals. This type of food mode being associated with a reduction in pathologies related to the age. The conjunction of these two targets of research made it possible to discover at animal models, mainly invertebrate, the subjacent genetic mechanisms binding the level of food and longevity. The comprehension of these genetic mechanisms will make it possible to open therapeutic new prospects connected to the processes of ageing. From yeast to mammals, a certain number of homologous genetic ways were shown. This rise of knowledge brings a beam, always growing, of data showing that the nervous system power station plays a part crucial in the perception of the requirements out of food also in the invertebrates.     

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.     

Ethical requirements for occupational health research--compliance arrangements for a single company in relation to a recent major nuclear industry study.

The media coverage given to occupational health studies in the field of ionizing radiation has, on occasion, been the cause of very real distress to radiation workers and their families. In response to this situation the Chief Medical Officers of the major UK nuclear companies developed an ethical policy for future involvement in research, based on the duty of care which researchers owe to a key customer of such studies: the worker. The policy consists of four principal elements: medical confidentiality; worker information; worker consent and the guarantee of the availability to the workers of pre-publication knowledge of the results. The policy issued in 1991/92 has achieved growing acceptance among researchers and medical journals, though the medical officers involved have been aware of some scepticism, particularly in relation to the practicalities of the dissemination of pre-publication information. The Record Linkage Study published in November 1997 marked a major piece of research work involving data from 120,000 radiation workers that had been carried out since the development of the policy. This paper reports on the successful compliance arrangements to meet the ethical requirements of that study within a single UK nuclear company, and is published to demonstrate that with commitment from researchers, the journal and occupational health staff such ethical requirements, and particularly the need for pre-publication information can be met in full.     

Les cellules endothéliales du tissu adipeux

The adipose tissue plays a major role in energy homeostasis through the storage and release of fatty acids as well as adipokine production. The endothelial cells of the adipose tissue vascular network constitute a barrier between the blood and the adipocyte compartments. They are key players in the metabolic status of the fat mass controlling the exchanges of nutrients, hormones, oxygen and immune-inflammatory cells. Recent data highlight the process of lipid handling at the endothelial cell surface and of the transendothelial transit of fatty acids. The extension of the vascular network and its functionality are necessary for the adipose tissue integrity. Insufficient oxygen supply generates hypoxic area within the tissue that favors metabolic abnormalities and the recruitment of immuno-inflammatory cells. The present review relates to the role of adipose tissue endothelial cells in the adipose tissue physiology. Their involvement and more particularly the role of accelerated ageing, in the link between obesity and associated metabolic and cardiovascular pathologies are described.     

The impact of needle-exchange programs on the spread of HIV among injection drug users: A simulation study

Objective. To determine the impact of the implementation of a needle-exchange program (NEP) on the spread of human immunodeficiency virus (HIV) in an injection drug user (IDU) community. We conducted a Monte Carlo simulation study of a theoretical population of 10,000 IDUs. The population was followed monthly from 1984 to 2000. HIV was assumed to be transmitted only by needle sharing. The NEP was introduced in 1989 and evaluated over a period of 11 years. The impacts of the proportion of the population attending the NEP, the risk level of IDUs attending the NEP, the reduction in needle-sharing frequency, and the number of new needle-sharing partners acquired at the NEP on prevalence and incidence of HIV were determined. Increasing the proportion of the population who always attend the NEP and eliminating needle-sharing incidents among IDUs who always attended the NEP were the most effective ways of reducing the spread of HIV. Attracting high-risk users instead of lower risk users to the NEP also reduced the spread of HIV, but to a lesser extent. NEPs are effective at reducing the spread of HIV; even under the worst case scenario of low risk users more likely to attend the NEP, one additional partner per month as a result of attending the NEP, and poor NEP attendance, the estimated prevalence was still less than that from the scenario without an NEP. Under our model, NEPs were shown to reduce the spread of HIV significantly. Efforts should be focused on getting as many IDUs as possible to become regular NEP attenders and stop sharing needles rather than partially reducing the frequency of sharing by a larger number of IDUs.     

肥胖对中小学生生理机能与常见疾病的影响

目的 使用2009年、2012年、2015年3个年份的样本量来分析重庆地区在2009—2015年间的肥胖检出情况、肥胖对学生的身体机能和常见疾病的影响情况,为改善学生生理机能、降低相关疾病寻找依据和方法。方法 通过分析2009年、2012年、2015年重庆市学生体质健康监测的累加数据,观察肥胖对学生血压、肺活量、肺活量指数、视力等身体机能的影响以及对近视、龋齿等常见疾病的影响。结果 2009年、2012年、2015年学生累计样本数为202 235人,体质量指数为肥胖的学生9 529人,肥胖率为4.71%,其中男生肥胖率为5.79%,女生肥胖率为3.73%,男生肥胖率高于女生,差异有统计学意义(χ2=473.66,P<0.01);城市学生肥胖率为5.88%,乡村学生肥胖率为3.66%,城市学生肥胖率高于乡村学生,差异有统计学意义(χ2=551.30,P<0.01)。在生理功能方面,非肥胖组学生右眼视力、左眼视力、收缩压、舒张压、肺活量、肺活量指数均优于肥胖组学生,差异有统计学意义(P<0.01)。肥胖组学生龋失补总牙数均值与非肥胖组学生比较,差值为-0.22颗/人,差异有统计学意义(t=-16.31,P<0.01);肥胖组与非肥胖组的龋齿检出率分别为13.43%和20.54%,差异有统计学意义(χ2=113.34,P<0.01);肥胖组近视检出率右眼左眼分别为57.45%、 57.00%,非肥胖组近视检出率右眼左眼分别为51.86%、51.47%,肥胖组近视检出率与非肥胖组近视检出率差异有统计学意义(χ2右眼=113.34,P<0.01;χ2左眼=109.11,P<0.01)。结论 2009年、2012年、2015年重庆市中小学生肥胖检出率均处于一个较低水平,肥胖表现出了显著的性别间、城乡间差异;肥胖易使学生视力降低、血压升高、肺功能储备降低。     

Obésité : que nous dit l’épidémiologie ?

In most developed and developing countries, a regular increase of the prevalence of obesity has been documented during the last decade(s) of the xxth century. The last figure from the USA is for the first time discordant with this general trend by showing a clear slowing down since year 2000. In children likewise, a rapid increase in the prevalence of obesity took place in the second half of the xxth century but recent publications from France, Switzerland, UK, USA also report a stabilization of childhood overweight and obesity prevalences. The experience of developing countries clearly shows the impact of socioeconomic status improvement and urbanization on the prevalence of obesity. In developed countries like France, a striking element was the diffuse nature of the adult obesity epidemic observed from the 1990s. The general improvement of living conditions after the Second World War probably explains the diffuse nature of the epidemics. Specifically, the changes in the nutritional status of children that happened at that time have long lasting consequences for adult obesity epidemics. Indeed, a new current in epidemiology, lifecourse epidemiology, has prompted over the past decade a new approach of the pathophysiology of chronic diseases, including obesity. Lifecourse epidemiology considers factors affecting the susceptibility to diseases over the whole life with critical periods during developmental phases. Critical periods for the susceptibility to obesity have been documented in prenatal life, during the first 6 months of postnatal life and from 3 years on starting at the time of the adiposity rebound. Parental obesity is involved at each of the critical periods. The transgenerational transmission of obesity is explained by genetic factors, shared lifestyle but also epigenetics especially during the early developmental periods. The slowing down of the childhood obesity epidemics observed in several developed countries may signal that factors affecting the early susceptibility to obesity have recently changed.     

The prevalence of work-related upper limb disorders in a printing factory

The association between problems of the upper limb and the workplaceis complex. A large printing manufacturer in the North Westof England sought the advice of both a surgeon, specializingin problems of the upper limb and an ergonomist in an attemptto control the frequency of these abnormalities amongst itsworkforce. The prevalence of these problems prior to and afterthe introduction of a number of recommendations was collatedand the results are discussed. Effectively the introductionof sensible and sympathetic modifications to the workplace appearedto reduce the number of upper limb disorders.     

Occupational Health Services in Manufacturing Industries in Nigeria

The provision of adequate health care facilities to cater forthe health of workers is an important consideration in the managementof manufacturing industries, since productivity is dependenton the health status of the workers. There are very few studiesevaluating the health care provision in Nigerian industries.This study elucidates such health care services in Edo and DeltaStates of Nigeria. One hundred and thirty-five (56%) of the241 registered manufacturing industries in Edo and Delta Statesof Nigeria were randomly selected and investigated. The responserate was 91.1% and the result showed that the medical staffcomprised 2.5% of the total workforce, with the large scaleindustries contributing the highest proportion of these. Fourpoint five per cent of the medical staff had formal trainingin occupational health and 15.6% of them visited the factoryshop floor. The doctor:staff ratio in the medium and large scaleindustries were 1:819 and 1:618 respectively. It was found thatall the industries used the health care facilities providedby the government, there were no clinics in all the small scaleindustries and group practice was not used by any of the industriesstudied. Pre-employment medical examinations were carried outin each of the groups of industries (100%, 39.4% and 5%) respectively,as were periodic medical examinations during employment, althoughto a lesser extent (100%, 13.2%, 0%) for the large, medium andsmall scale industries respectively. These finding suggest theavailability of a reasonable standard of health care provisionfor large scale industries and somewhat less availability formedium and small scale industries. Health education of boththe employers of labour, and the employees and the enforcementof existing laws are needed to improve the existing standardof occupational health services.     

Appraisal standards in occupational medicine

Following a series of serious misdemeanours by British doctors, the General Medical Council (GMC) has introduced a system of re-licensing called 'revalidation'. Annual medical appraisal forms an important cornerstone of the proposed system, but specific guidance is lacking on the content of appraisal for occupational physicians, and the kinds of evidence that they might bring to critical reviews of performance. Two educational bodies, the Revalidation Committee of the Faculty of Occupational Medicine, Royal College of Physicians and the Education Panel of the Society of Occupational Medicine, have jointly developed a set of recommendations on appraisal to further the process. In this paper we summarize the background and present the guidelines promulgated by the Faculty and the Society.