苏云金芽胞杆菌无晶体突变株对小鼠和雏鸡的安全性

以苏云金芽胞杆菌无晶体突变株BMB304为受试菌株,对小鼠和雏鸡进行安全性测试,考察BMB304在鸡肠道中的存留情况,以探索利用苏云金芽胞杆菌S-层表面展示系统研制热稳定性禽用口服活菌疫苗的安全性和可行性.小鼠腹腔一次性注射1010 CFUBMB304菌液1.0 mL,观察14 d,未发现有急性毒性反应.小鼠饮用含BMB304 108 CFU/mL、107 CFU/mL和106 CFU/mL的饮用水28 d,各组小鼠精神和饮食正常,剖检未见异常变化,各剂量组小鼠体重变化、脏器系数、血常规指标及血液生化指标与对照组无显著性差异.雏鸡24 h内灌服1010 CFU BMB304芽胞液1.0mL,14 d内未出现急性毒性反应.饲喂雏鸡含BMB304芽胞108 CFU/g、107 CFU/g和106 CFU/g饲料28 d,雏鸡精神和饮食正常,剖检未见异常变化,各剂量组的日增重与对照组差异不显著.饲喂雏鸡含BMB304芽胞106 CFU/g饲料3 d后,经测定,芽胞能在肠道中萌发并至少存留5 d但不超过7 d.研究表明,苏云金芽胞杆菌无晶体突变株BMB304对小鼠和雏鸡安全无毒,且能在鸡肠道内暂时定植,能被用于研制在细胞表面展示外源抗原并能常温长期保存的新型禽用口服疫苗.     

环氧树脂固化剂的毒性和防护

环氧树脂固化剂长期与人体接触会引发很多病症。环氧树脂固化剂的蒸汽、尘埃如侵蚀体表可造成过敏、疱疹;吸入呼吸道可引发咳喘;进入消化系统可致泻、呕吐等。 环氧树脂固化剂的毒性和刺激性 1.急性毒性 通常以半致死量LD50=毫克/公斤表示。LD50数值小表示毒性大,相反则认为毒性小。 乙二胺(LD50=756毫克/公斤),接触者除皮肤损伤外,尚可引起过敏性哮喘或持久性头痛;小白鼠每天吸入7小时乙二胺225ppm浓度之蒸汽,即可导致脱毛及内脏器官的病变而死亡。二乙烯三胺(LD50=2.33克/公斤)对皮肤和眼睛有很强的刺激,在其饱和蒸汽中8小时即可死亡;…     

一起急性丙烯醇中毒事故引起的思考

丙烯醇为无色刺激性液体.相对分子质量为58.08,比重0.8476,混溶于水、醇和醚.属中等毒类.对粘膜如鼻,特别是眼粘膜有强烈的刺激作用,并有较强的全身毒性.亦有微弱的麻醉作用.笔者现将1起急性丙烯醇中毒事故调查、处理过程及对有关问题的思考报告如下.     

注意制造壳芯的防护问题

使用粉状酚醛树脂粘结剂制造铸件用的壳芯,具有很多优点。但是,制造壳芯时,骨料石英砂有砂尘危害;粘结剂酚醛树脂有树脂粉尘危害;固化剂乌洛托品有刺激性;脱模剂能产生汽油蒸汽;同时在混砂、制壳、浇注、落砂时,还会产生如下表所列的有害气体和恶臭。 矽尘能引起矽肺。树脂粉尘能刺激眼、鼻、气管,而且具有爆炸性。有一次,保养工在厂房高空作业时,扰动了积聚在校上的树脂粉尘,尘云被制壳机上的火焰点燃,造成了爆炸。苯酚蒸汽能引起恶心、呕吐、呼吸困难、眩晕及各种神经症状,还能刺激皮肤,引起皮炎。乌托洛品是原发性物质,接触皮肤,能引起皮…     

了解化学性皮肤灼伤

正化学性皮肤灼伤是常温或高温的化学物接触到皮肤,对皮肤刺激、腐蚀作用及化学反应热引起的急性皮肤损害,不包括火焰伤、水烫伤和冻伤。化学性皮肤灼伤的原因化学烧伤可由各种刺激性和有毒的化学物质引起,包括强酸、强碱、苯酚、甲苯(有机溶剂)、芥子气、磷等。化学烧伤可引起组织坏死并在烧伤后几小时慢慢扩展。1.温度。引起皮肤烧伤的最低温度为44℃,温度一时间曲线在45~50℃之间呈线形,而在51℃以上呈渐进性,在70℃暴露1秒钟即可引起跨表皮坏死。     

苏云金芽胞杆菌基因工程菌WG-001和1125BG在盆栽土壤中的安全性评估

自从遗传改造微生物诞生以来,其安全性问题受到了持续关注和研究.本文报道了苏云金芽胞杆菌基因工程菌WG-001和1125BG在盆栽大白菜的土壤环境中的安全性评估结果.实验结果表明:当用工程菌WG-001和1125BG分别以1013 cfu/cm2和1010 cfu/cm2的高土壤密度喷洒盆栽大白菜后,工程菌菌数迅速上升而后逐渐下降,最后分别以相对较低的菌数水平(105 cfu/g干土样和106 cfu/g干土样)在实验土壤中稳定存在;对土壤中土著细菌群落在有限时间(15d)内产生了一定影响,而对土著真菌与放线菌无显著影响;未发现工程菌WG-001中特异基因发生丢失;未检测到工程菌WG-001和1125BG中特异基因(WG-001为cry1Aa和cry1Ac,1125BG为gfp)向土著细菌、真菌、放线菌和盆栽大白菜的水平转移.本文实验结果显示,高密度喷洒的两种工程菌未显著影响实验土壤环境,具有很高的安全性.同时发现以不同的喷药量喷洒两种工程菌后,在盆栽土壤中其存活水平、菌数降低的速率以及对土著细菌的影响能力都表现出不同的特点.     

劳动特效护肤霜的研制及效果观察

为防治职业性皮肤病,保护工人身体健康,采用水解明胶研制和生产出劳动特效护肤霜。对这种护肤霜的使用,作者用统一的方法,在冬季对５１９ 例皲裂患者进行效果观察。发现对各种程度的皲裂均有显著疗效。有效率达９８．２０％ ,治愈率达８９．２１％ ,皲裂程度愈轻效果愈明显。在使用过程中,未见任何刺激性和副作用,部分患者用这种护肤霜擦脸后,皮肤变得细嫩光滑。经过安全和毒性试验表明：无毒性、无致敏性、无刺激性。三种致突变试验均属阴性。长期使用是安全的。观察表明：对皮肤皲裂有显著的治疗功效,同时还能有效地保护皮肤     

预访刺激性气体中毒

(一)新工人小王在装氯气时,不小心吸了一口氯气。他顿时一阵猛咳,感到胸闷、气急、头晕,并出现呕吐。李师傅把他送到医院,经治疗后才慢慢平静下来。 (二)医生在小王的病历上写上了“轻度刺激性气体中毒”。小王问:“什么叫刺激性气体?”医生告诉他:“凡是对人体的呼吸道粘膜、眼及皮肤有直接刺激作用的气体都叫刺激性气体。刺激性气体有很多,如氯、氨、二氧化硫、三氧化硫,及氯化氢、硫酸、硝酸的酸雾,还有光气、臭氧、硫酸二甲酯等不下几十种。 (三)小王问道:“吸了这些气体都会象我刚才那样吗?”医生说:“吸入刺激性气体的浓度及时间不同,…     

拟除虫菊酯类农药中毒

拟除虫菊酯类农药,由于具有高效、安全、低残留的优点,70年代以来得到迅速发展,全世界它的产量已占化学农药总产量的20～30%,法、英、美、日等国陆续合成的有近千种,其中效能较好的有20余种,在我国推荐使用的有二氯苯醚菊酯,杀灭菊酯、多虫畏、溴氰菊酯、氯氰菊酯、甲氰菊酯、熏虫菊酯、苄菊酯、苯醚菊酯、杀螟菊酯等。 拟除虫菊酯类农药的毒性,大多数属中等毒性范围,如杀螟菊酯原药对皮肤和眼无刺激性,粉剂有中等刺激性。我国常用的拟除虫菊酯类农药主要是溴氰菊酯。象从法国进口的敌杀死,主要成分就是溴氰菊酯。敌杀死的毒性属高毒类,应引…     

二溴海因危险性试验研究

为评价二溴海因(简称DBDMH)在使用、储运过程中的危险性,采用75℃热稳定性试验对二溴海因在高热条件下的稳定性进行了研究,采用C600微量热法测试了二溴海因的放热起始温度、分解热,并依据《联合国关于危险货物运输的建议书-试验和标准手册》对其爆炸性进行了筛选,通过固体氧化性试验和家兔皮肤刺激性/腐蚀性试验分别对二溴海因的氧化性和皮肤刺激性进行了测试。结果表明:二溴海因在75℃热稳定性试验过程中没有出现着火或爆炸,未出现自加热迹象,不属于太不稳定不能运输的物质;其分解反应只有一步,起始反应温度大约为157℃,分解热为384.8J/g,不属于爆炸品;二溴海因具有氧化性,根据《联合国关于危险货物运输的建议书-规章范本》其包装级别为Ⅱ级;在家兔皮肤刺激性/腐蚀性试验中未见不可逆损伤,对皮肤具有强刺激性。     

油浸变压器排油注氮装置在500kV变电站的设计与应用

在分析500kV变电站主变压器消防系统的现状,比较3类消防系统优缺点的基础上,详细论述了主变排油注氮装置的结构组成、工作原理、参数计算、控制系统设计以及需要注意的事项等,为下一步排油注氮装置的推广应用打下基础.     

HAZOP结合What-if方法在某延迟焦化装置除焦中的应用

为克服传统危险与可操作性（HAZOP）定性分析方法在复杂操作、间歇作业等过程中使用的局限性,提出在传统HAZOP定性分析方法的基础上结合What-if（故障假设）方法,对人的不安全行为和操作规程不完备所导致的风险后果分析作出补充。详细说明其技术原理、工作流程等使用细节,系统阐述该方法与传统HAZOP定性分析方法的区别,并在某延迟焦化装置的除焦操作的风险分析中应用。经分析,识别出在“给水-泡焦”节点,有“操作规程错误”场景2项,“操作规程不具体”场景1项,不存在“操作人员未按操作规程执行”场景。研究结果表明:本文方法有效且具有较好效果,可以广泛应用于操作规程/作业指导书审查、作业过程隐患排查等方面,帮助企业开展操作层面的风险识别与管理,提升企业的生产安全水平。     

潞安矿区煤层渗透率的各向异性特征实验研究

为了研究原位煤体渗透性的各向异性特征,以山西潞安常村矿3号煤层圆柱试样为对象,利用TCQT-Ⅲ型低渗煤层气相驱替增产试验装置,对煤样进行加载,并以氮气注入压力2.0 MPa的条件下,分析垂直层理和平行层理2个方向的煤体变形和渗透率变化特征。实验结果表明:煤样在加载过程中,平行和垂直层理煤样渗透率均随着有效应力的增大而减小,平行层理方向的渗透率始终大于垂直层理方向,应力加载初期渗透率急剧下降,最后逐渐趋于平缓;径向应变的增加量与渗透率呈正相关性,且平行层理相关性大于垂直层理;沿平行层理方向的裂隙度大于沿垂直层理方向,沿垂直层理方向的应变量大于沿平行层理方向;应变增加量均随有效应力的增加而逐渐减小。研究结果可为煤层井网布置及优化提供参考。     

Nighttime pedestrian fatalities: A comprehensive examination of infrastructure,user, vehicle,and situational factors

Introduction: Pedestrian fatalities in the United States increased 45.5% between 2009 and 2017. More than 85% of those additional pedestrian fatalities occurred at night. Method: We examine Fatality Analysis Reporting System (FARS) data for fatal pedestrian crashes that occurred in the dark between 2002 and 2017. Within-variable and before/after examinations of crashes in terms of infrastructure, user, vehicle, and situational characteristics are performed with one-way analysis of variance (ANOVA) and two-sample t-tests. We model changes in crash characteristic proportions between 2002–2009 and 2010–2017 using linear regressions and test for autocorrelation with Breusch-Godfrey tests. Results: The increase in fatal nighttime pedestrian crashes is most strongly correlated with infrastructure factors: non-intersection unmarked locations (saw 80.8% of additional fatalities); 40–45 mph roads (54.6%); five-lane roads (40.7%); urban (99.7%); and arterials (81.1%). In addition, SUVs were involved in 39.7% of additional fatalities, overrepresenting their share of the fleet. Increased pedestrian alcohol and drug involvement warrant further investigation. The age of pedestrians killed increased more (18.1%) than the national average (3.2%). Conclusions: By identifying factors related to the increase in nighttime pedestrian fatalities, this work constitutes a vital first step in making our streets safer for pedestrians. Practical Applications: More research is needed to understand the efficacy of different solutions, but this paper provides guidance for such future research. Engineering solutions such as road diets or traffic calming may be used to improve identified infrastructure issues by reducing vehicle speeds and road widths. Rethinking vehicle design, especially high front profiles, may improve vehicle issues. However, the problems giving rise to these pedestrian fatalities are likely a result of not only engineering issues but also interrelated social and political factors. Solutions may be correspondingly comprehensive, employing non-linear, systems-based approaches such as Safe Systems.     

Footedness and Mounting—Short Review and Two Case Studies

Footedness is a personal quality like handedness. Footedness may be associated with moving ability during mounting, dismounting, and jumping movements. Occupational accidents have occurred during movement at different working levels, during the use of access and exit systems, and during the mounting of vehicles. Aging can also affect accident risk and body laterality. For example, falling accidents on stairs are common among the elderly. One reason for accidents may be that the structure of the access system or stair system is unsuitable for individual moving patterns depending partly on body laterality. Footedness and the way the feet are used may be contradictory to the demands of the moving situation, especially during uncommon or rapid situations. This contradiction may trigger disturbance during moving. The aims of this pilot study were (a) to review the literature briefly and (b) to describe the use of the dominant and nondominant foot by farmers and the elderly when mounting a tractor and stairs, respectively. The study also gives ideas for future studies based on both (a) and (b).     

AHP与GA-SVM耦合模型在滑坡预警中的应用*

为了减少滑坡造成的损失,提高滑坡预测的准确性,通过搭建灾害模拟平台获得滑坡的实验数据,在获得多组模拟实验数据后,分析各变量的特性。首先,通过层次分析(Analytic Hierarchy Process,AHP)算法,对滑坡进行危险度划分;然后,通过支持向量机(Support Vector Machine,SVM)建立模型,遗传算法(Genetic Algorithm,GA)再优化SVM参数,提出1种层次分析法与GA-SVM相耦合的模型。研究结果表明:AHP方法划分后的数据,通过GA与SVM结合建立的模型精度较好,实验预测结果与实际结果较为吻合,与单一SVM相比,精度更高,结果更好,更加适用于多变量的复杂非线性滑坡预警。     

Debunking the false dichotomy of leadership idealism and pragmatism: Critical evaluation and support of newer genre leadership theories

Leadership theories have shifted over the last few decades from a focus on managerial functions and economic leader–follower exchanges toward greater focus on the interpersonal dynamics occurring within the leadership process. Theories such as transformational, ethical, authentic, and other “newer genre” theories were created to address neglected topics such as leader vision and inspirational messages, transparency, emotional effects, morality, individualized attention, and intellectual stimulation. Critiques of these theories, however, have been raised. In this paper, we address five of those critiques and argue for the validity and practical effectiveness of the new genre theories. Further, we describe how newer genre leadership research should be viewed as a performative epistemology, entailing a process of co‐creation involving scholars and practitioners. Finally, from this view, we provide general ideas for leader development. Copyright © 2014 John Wiley & Sons, Ltd.     

Occupational Safety and Health in Finland

In Finland, occupational safety is the responsibility of the employer, while the occupational safety and health laws are enforced by the Labour Inspection Service, an organization of the state. The Labour Inspection is divided in 11 administrative districts, and it employs 360 professionals. They are mandated to carry out site visits without prearranged appointments to inspect safe work situations, working hours, construction safety, or any aspect of accident risks. The inspectors are also mandated to verify the existence of sufficient occupational health services as prescribed by the Occupational Health Services Act for all employees. The occupational health services are typically provided by enterprise-owned medical departments, by mutually owned health care centers, by private practitioners, or by municipal health care centers. The latter are required by law to provide all services as prescribed by the legislation to anyone who comes to the facility. This situation is prevalent in the countryside, where there are very few private caregiving centers. Declaring occupational accidents and disease cases is mandatory, and the Inspection districts examine all accidents to establish causes and consequences, and to initiate prosecution in case of criminal negligence. Labour Inspection Districts are also notified of the new occupational disease cases as they are declared to insurance companies. Insurance for occupational disease, accidents, and death is an obligation of the employer, although they can choose the insurance company. The medical confidentiality between the workers and their occupational health care providers is very strict. Official statistics are maintained by the state Statistics Finland organization, and they may be used, for example, for research purposes by scientific institutes like the Finnish Institute of Occupational Health. Construction industry accounts for 25% of all fatal accidents (120 cases per 1 million working hours), followed by mechanical, wood, metal, machinery, and pulp and paper industry (10% each of fatal accidents) with rates ranging from 100–160 cases per 1 million working hours. There are some 5,000 occupational disease cases per year (rate 22/10,000 employed). The major disease categories include repetitive strain injuries (1,300 cases), respiratory allergies (600 cases), occupational skin diseases (1,000 cases), and 900 cases of noise-caused hearing loss. In 1998, 589 cases of asbestos-related diseases were reported.     

森林地表火蔓延模拟方法及其计算机实现

进行了森林火蔓延的研究,对传统的经验公式和模型进行改进,明显发现改进的模型有更好的结果,用计算机巧妙准确地实现了模拟模型,在风力不是特别大,地形变化不是特别剧烈时,该模型有较高精度;并结合火蔓延的主要因素（气象因子、气候、地形等）,进行系统分析,写出算地,编制实现地表火蔓延的预测预报计算机系统软件。这对于有效的组织扑救、减少火灾损失、计算森林火灾的损失评估有重要意义。     

公路隧道火灾逃生疏散研究

以苍岭隧道为背景,首先采用经验计算理论和计算软件building EXODUS相结合的方式,从被困人员的安全疏散时间、高温烟气的影响、隧道横通道的利用率以及人员的疏散行为特性进行了研究。结果表明:中小规模火灾情况下的安全疏散时间控制在8 min之内,高温烟气影响不大,但横通道的利用率不平均,且人员疏散路线相对集中。然后对存在的逃生疏散问题提出针对性建议以及其他相关建议,旨在为更大程度降低事故的严重性和经济财产损失。