Genetic effects of 1,3-butadiene and associated risk for heritable damage

A summary of the results of the studies conducted in the EU Project "Multi-endpoint analysis of genetic damage induced by 1,3-butadiene and its major metabolites in somatic and germ cells of mice, rats and man" is presented. Results of the project are summarized on the detection of DNA and hemoglobin adducts, on the cytotoxic and clastogenic effects in somatic and germinal cells of mice and rats, on the induction of somatic mutations at the hprt locus of experimental rodents and occupationally exposed workers, on the induction of dominant lethal mutations in mice and rats, and on heritable translocations induced in mice, after exposure to butadiene (BD) or its major metabolites, butadiene monoepoxide (BMO), diepoxybutane (DEB) and butadiene diolepoxide (BDE). The primary goal of this project was to collect experimental data on the genetic effects of BD in order to estimate the germ cell genetic risk to humans of exposure to BD. To achieve this, the butadiene exposure are based on data for heritable translocations and bone marrow micronuclei induced in mice and chromosome aberrations observed in lymphocytes of exposed workers. A doubling dose for heritable translocations in human germ cells of 4900 ppm/h is estimated, which, assuming cumulative BD exposure over the sensitive period of spermatogenesis, corresponds to 5-6 weeks of continuous exposure at the workplace to 20-25 ppm. Alternatively, the rate of heritable translocation induction per ppm/h of BD exposure is estimated to be approximately 0.8 per million live born, compared to a spontaneous incidence of balanced translocations in humans of approximately 800 per million live born. These estimates have large confidence intervals and are only intended to indicate orders of magnitude of human genetic risk. These risk estimates are based on data from germ cells of BD-exposed male mice. The demonstration that clastogenic damage was induced by DEB in preovulatory oocytes at doses which were not ovotoxic implies that additional studies on the response of mammalian female germ cells to BD and its metabolites are needed. The basic assumption of the above genetic risk estimates is that experimental mouse data obtained after BD exposure can be extrapolated to humans. Several points exist in the present report and in the literature which contradict this assumption: (1) the level of BMO-hemoglobin adducts was significantly elevated in BD-exposed workers; however, it was considerably lower than would have been predicted from comparable rat and mouse exposures; (2) the concentrations of the metabolites DEB and BMO were significantly higher in mouse than in rat blood after BD exposure. Thus, while metabolism of BD is qualitatively similar in the two species, it is quantitatively different; (3) no increase of HPRT mutations was shown in 19 workers exposed on average to 1.8 ppm of BD, while in a different population of workers from a US plant exposed on average to 3.5 ppm of BD, a significant increase of HPRT variants was detected; and (4) data from cancer bioassays and cancer epidemiology suggest that rat is a more appropriate model than mouse for human cancer risk from BD exposure. However, the dominant lethal study in rats gave a negative result. At present, we do not know which BD metabolite(s) may be responsible for the genetic effects even though the bifunctional alkylating agent DEB is the most likely candidate for the induction of clastogenic events. Unfortunately, methods to measure DEB adducts in hemoglobin or DNA are only presently being developed. Despite these several uncertainties the use of the mouse genetic data is regarded as a justifiable and conservative approach to human genetic risk estimation given the considerable heterogeneity observed in the biotransformation of BD in humans.     

The syndrome of depressive depersonalization

Nineteen patients (9 men, 10 women aged 22--38 years) with depressions were examined. The phenomena of anesthesia of ideatoric functions dominated in clinical picture of such depression. This depression is defined as the depression of estrangement. Psychopathologic differentiation of mental estrangement in the structure of depression and in similar disorders of self-consciousness which were formed in depressions under conditions of "transitional syndrome" (according to G.Gross) is outlined. This syndrome is characterised by irreversible negative disorders of "defective depersonalization". The following signs permit to distinguish depression of estrangement from "transitional syndrome": partiality of the estrangement's phenomenon; connection between psychopathologic formations and pathology of imagination (figurative expressiveness, demonstrativity, lability to psychogenic and medical actions); conformity of the syndrome's structure and characteristics of premanifested personality's structure (combination of hyperthymic features with histrionic and/or narcissic ones). "Apperceptive anesthesia" is suggested for designation of the variant of the depression described.     

iDCX 51在Webit上的设计与实现

Webit是一个独立的、低成本的网络服务器,由东大新业技术股份有限公司研制成功.iDCX 51是Intel公司开发的实时操作系统,在工业控制等领域已成功应用,为使其能在Webit中也能够运行,以增强Webit的性能,对此本文以Webit内部单片机AT90S8515为例介绍iDCX 51往Webit中移植的设计与实现,并对移植后的时间性能进行了测试与对比分析,得知其任务切换时间与最大中断禁止时间这两项关键的时间性能指标分别减少33.3%和31.9%,表明系统移植后实时性得到了提高.     

单级倒立摆建模及其控制方法设计

单级倒立摆控制是一个即复杂而又对准确性、快速性要求很高的非线性不稳定系统控制问题。单级倒立摆数学模型的建立对研究其稳定性具有指导作用。用拉格朗日功能平衡法建立了倒立摆的刚体动力学方程,采用了LQR法对其进行了控制设计,并且进行了MATLAB仿真,结果表明此方法均可以成功控制倒立摆,使其稳定并具有良好的鲁棒性。     

Neural basis for the genesis and control of digitalis arrhythmias

The author discussed the increase in the frequency of traumatic paralyses of the ocular muscles, and reported 6 cases of inferior oblique muscle paresis caused by local blunt or sharp traumas (haematoma, contusion, rupture, incarceration) and one case of traumatic Brownian pseudo-paralysis. The localisation of the injuries in 3 cases was on the inferior temporal part and in the other 3 cases on the superior part of the bulbar conjunctiva. Atypical horizontal deviation and characteristic vertical deviation, torsion and torticollis were observed in the majority of cases. One patient recovered spontaneously. 3 patients became asymptomatic after correction by prisms and one after recession of contralateral superior rectus muscle. The symptoms remained unchanged in the case of a "blow out" fracture (in spite of operation) and a Brown's syndrome (without treatment).     

Abdominoperineal resection following anterior resection

A series of 11 patients undergoing abdoninoperineal resection for "suture line recurrence" following anterior resection is presented. Five-year survival is 10%. Technically, the procedure is difficult and major problems are encountered, including large blood loss and ureteral complications. These patients had an inadequate distal margin of resection at the time of anterior resection. The survival of this group of patients underscores the importance of making the correct judgment about anterior or abdominoperineal resection at the time of the initial presentation of the patient. The phrase "suture line recurrence" is a misnomer; all of these patients had advanced pelvic malignancy. If the adequacy of the distal margin is questionable or a distal margin of 5 cm cannot be obtained safely at the time of anterior resection, abdominoperineal resection should be performed, as the opportunity for cure of a recurrence should this rule be compromised is limited.     

GHT型变阻力制动缓冲托罐装置在顾桥矿的应用

以顾桥矿为实例,分析了GHT型变阻力制动缓冲托罐装置应用于该矿井的情况,通过比较说明了变阻力制动的优越性,并建立了制动力学模型,通过理论计算和试验,论证该装置对立井提升安全保护的可靠性。     

基于无线传感器网络的LEACH算法的改进

无线传感器网络是监控远程环境的工具之一.由于能量和存储空间的限制，其路由协议必须维持较小的路由信息并尽可能的减少能量消耗。该论文对经典的LEACH路由算法，提出了改进，改进后的算法基于无线电传输范围和簇成员数目形成簇，同时在转发阶段引进了CSMA/CD（载波监听多路访问/冲突检测）技术以减少冲突。最后用Matlab对LEACH算法和改进后的算法进行仿真，证实改进后的算法在能量消耗上比LEACH算法有了很大提高。     

网络在实验教学中的应用研究

本文分析了高校实验教学的现状以及实验课的课堂指导局限性,提出以网络辅助课堂指导,使其成为实验教学的一种补充,并分析了网络作为实验教学补充形式的优势和可能存在的问题。根据通信电路实验室的实验内容和发展规划,提出建设电子技术制作、开发和应用网站的实施方案。确定网站的发展分两个阶段,规划了每个阶段的任务。网站的系统平台充分利用了新技术的优势采用了Linux＋Apache＋PHP＋MySQL。为了搞好网络教学这种现代化的教学模式,笔者从教师、学生及网站等几个方面提出一些建议。     

基于互联网的电厂实时监控图形显示技术的应用

基于B/S体系结构开发Internet应用程序是当前的流行趋势.介绍了基于Internet的电厂实时监控图形显示技术的实现方法.采用目前工业监控环境中的图形动态交互技术,针对图形刷新闪烁现象这一关键问题提出了不同的解决方法.最后介绍了基于ActiveX控件技术的动态图形显示技术的应用实例.