Lead levels in Chromolaena odorata (Compositae) along rural and urban roads in Akwa Ibom State, Nigeria

Concentrations of lead(Pb) were determined in leaf samples of \%Chromolaena adorata\% from a rural road and an urban road in Akwa Ibom State of Nigeria in relation to vehicular traffic density. Mixed results were obtained wich no trend to indict automobile exhaust fumes. Lead was not detected in rain water from these areas and leaf lead levels seemed to relate more to soil lead concentrations. There was no significant difference in mean leaf lead levels between rural and urban leaf samples and between washed and unwashed leaf samples. It was suggested that the lack of concordance between vehicular traffic density and lead levels in leaves along the highways indicates either a low level use of tetraethyl leaded petrol or, a relatively low vehicular traffic density with lead from exhaust fumes not reaching a threshold to affect levels in plants or be detected in the atmosphere. Implications of concentrations obtained in leaves to consumers when compared with international standards were discussed.

Lead Concentration in Hong Kong Roadside Dust after Reduction of Lead Level in Petrol

Samples of roadside dust were collected from 30 sites in Hong Kong.The total concentrations of 10 metals in the samples were analyzed,and the correlation coefficients among the metal contents and the annual average daily traffic(AADT)in 1986 were determined.Pb was found to have a significant correlation(P<0.01)with AADT.No correlation was found between Al, Ba,Cd,Cr,Cu,Fe,Mn,Ni,and Zn with respect to AADT.A general decrease in the level of Pb in roadside dust in the past few years has been observed since the reduction in the level of lead in petrol.1989 Academic Press,Inc.

Umbilical Cord Blood Lead Levels in Shanghai, China

This study was designed to determine the cord blood lead (BPb) levels of babies born in one urban area of Shanghai, and to preliminarily identify the demographic, social environment and prenatal factors which have an effect on the cord BPb concentrations. From August to November 1993, umbilical cord blood samples were obtained from 605 live newborns in the Yangpu Maternal and Child Hospital. 257 samples were excluded from measurement because of clotting. In 348 cord samples, the geometric mean of cord BPb levels was 9. 2μg/dl, with a 95 % confidence interval of the mean 8. 86-9. 54 (μg/dl). 142 babies (40. 8 % ) had cord BPb levels of 10μg/dl or greater. As a result of this high percentage of newborns with BPb levels equal to or greater than 10 μg/dl, we estimate that each year in the Shanghal City about 60,000 newborns are at risk for developing neuropsychological deficiencies caused by maternal lead exposure during pregnancy. To investigate the factors affecting cord blood levels, the subjects with levels greater than the 70th percentile (10. 7μg/dl) (n = 104) and less than the 3oth percentile (7. 4μg/dl) (n = 104) were selected to compare the demographic, environ ment and prenatal medical history. Increased BPb levels at birth were associated with maternal passive smoking, a family member being occupationally exposed to lead, proximity to major traffic way, household coal combustion, neighborhood coal combustion, low level of meternal occupations, and the increasing occurrence of having the high lead foodstuff pidan (preserved duck egg) during pregnancy. We conclude that prenatal lead exposure has become an impor tant health issue for young children in Shanghai

Association between Polymorphisms of MALAT1 and Blood Lead Levels in Lead-exposed Workers

Lead,a heavy metal,which is nonessential but may be harmful to the human body,has been widely used to manufacture many products for use in the modern world.Lead-acid batteries have the advantages of low price,high safety,and advanced technology.

A Systematic Assessment of Blood Lead Level in Children and Associated Risk Factors in China

In this study, we searched multiple databases for all relevant original articles (1996-2013). To investigate blood lead levels (BLL) and possible risk factors for lead exposure among children in China A total of 388 articles met our inclusion criteria. The overall geometric mean (GM) BLL was 71 μg/L, and the prevalence of elevated BLL (EBLL, defined as BLL &ge;100 μg/L) was 18.48% among children. The prevalence of EBLL remained significantly higher among boys. In children less than 6 years of age, there were significantly increasing trends in both BLL and prevalence of EBLL in an age-dependent manner. The ban on leaded gasoline significantly reduced the BLL as well as EBLL prevalence; however, children whose parents had lower educational levels or were exposed to lead in the workplace had a higher EBLL prevalence. Despite its decline over time, the average BLL among children in China remains higher than the average level most recently reported in the United States. Childhood lead poisoning remains a public health problem in China.

Blood Lead Levels During Pregnancy and Its Influencing Factors in Nanjing,China

Objective To investigate the blood lead levels (BLLs) in the duration of pregnancy and 6-12 weeks after delivery,and analyze the influencing factors of BLLs in healthy pregnant women.Methods Pregnant women were recruited from September 2009 to February 2010 at the prenatal clinic in Nanjing Maternity and Child Health Care Hospital.Altogether 174 healthy pregnant women without pregnant or obstetric complications or abnormal pregnancy outcomes were enrolled as the gravida group,and 120 healthy non-pregnant women as the control group.BLLs during pregnancy were determined by flame atomic absorption spectroscopy.Results BLLs in all the three pregnancy trimesters and postpartum were 59.8±24.3,55.4±20.1,55.9±19.7,and 67.6±17.4 μg/L,respectively,and the mean BLL in control group was 67.5±21.3 μg/L.BLLs during all the three trimesters were lower in the gravida group than in the control group (P=0.043,0.021,and 0.028).Furthermore,occupations,nutrients supplementation,and time of house/apartment painted were associated with BLLs in pregnant women.Lead-related occupations,cosmetics use,and living in a house painted less than 1 year before are risk factors of high BLLs among pregnant women,while calcium,iron,zinc,and milk supplements are protective factors.Conclusion Supplementing calcium,iron,zinc,and milk,or avoiding contact with risk factors may help people,especially pregnant women,to reduce lead exposure.

Two-echelon inventory model with service level constraint and controllable lead time sensitive to order quantity

The decision-making and optimization of two-echelon inventory coordination were analyzed with service level constraint and controllable lead time sensitive to order quantity.First,the basic model of this problem was established and based on relevant analysis,the original model could be transformed by minimax method.Then,the optimal order quantity and production quantity influenced by service level constraint were analyzed and the boundary of optimal order quantity and production quantity was given.According to this boundary,the effective method and tactics were put forward to solve the transformed model.In case analysis,the optimal expected total cost of two-echelon inventory can be obtained and it was analyzed how service level constraint and safety factor influence the optimal expected total cost of two-echelon inventory.The results show that the optimal expected total cost of two-echelon inventory is constrained by the higher constraint between service level constraint and safety factor.

Economic Responsibility Audit of Leading Cadres of the Party and Government at the Grassroots Level-Existing Problems and Countermeasures

Economic responsibility audit is an important part of the socialist audit supervision system with Chinese characteristics.It is an important responsibility of audit institutions at all levels to carry out economic responsibility audit.This article conducts a comprehensive and profound analysis of the problems existing in the current grassroots economic responsibility audit work.In addition,countermeasures and suggestions are proposed in this article,which are of positive significance to promote the economic responsibility audit work of leading cadres.

中国县级领导班子群体特征研究——基于东西部比较分析

面对东西部发展存在的巨大差距,西部地区必须全面提升发展质量,而这离不开作为地区发展“领头羊”的领导班子的引领和推动。现有文献对于领导干部群体特征以及配置结构进行了深入的归纳和探讨,但也有必要比较区域间领导干部整体水平的差异并分析其潜在原因,据此对症下药。比较东西部领导班子的群体特征,对于西部地区领导干部的培养、选拔有一定参考价值。论文运用高层梯队理论,采用分层抽样的方法,在广东省、天津市、陕西省、重庆市获得562名县级党政领导班子的履历信息,从人口统计学特征、教育背景、职业发展经历三个维度进行分析,对比研究东西部地区县级党政领导班子群体特征的共性和差异。本研究利用EXCEL对县级领导班子特征各个指标的变量进行统计分析,通过均值、标准差等数据展示变量的分布结构和特征;利用SPSS21.0对东西部县级领导班子的差异性特征进行分组,通过t检验、卡方检验等呈现数据间的差异性。研究表明,东西部党政领导班子在性别、民族、政治面貌、教育背景等方面呈现出相似的特征,但在籍贯来源、年龄、任职经历、晋升路径等方面呈现出显著差异,西部地区县级领导班子年龄分布呈现“两头多,中间少”、籍贯结构“本地多,外地少”、教育背景“偏人文,轻理工”、“任职经历单一,工作经验同质性高”、自下而上晋升比例更低等明显特征。针对分析结果,建议西部县级党政领导班子要着重加强领导班子协同效能建设、优化领导班子干部队伍结构、完善现代干部任用选拔机制,以及进一步强化领导干部的交流制度。

分子水平上的虚拟仿真实验之思政元素的挖掘与提炼——以“高分子的构象、形态及尺寸的模拟与计算”项目为例

高分子的构象、形态及尺寸的模拟与计算,是分子水平上的虚拟仿真实验项目,结合诺贝尔奖获得者de Gennes和P.J.Flory的理论工作、由项目组自身教研成果转化、师生合作研发而成。与小分子化合物相比,高分子的研究方法有很大的不同,特别是需要采用统计方法来描述高分子链的构象、形态,计算高分子链的平均尺寸,这是经典的物理化学方法所不能完成的。本项目从研发到教学实践、再经改进,教学内容的更新优化中,自然融入了诺贝尔奖成果、哲学思想、科学思维、学科发展史、教研成果等多个维度的思政元素。

中国龙头科技企业技术创新能力驱动路径研究——基于fsQCA研究方法

为推动中国科技企业高质量发展,提升科技企业创新能力,对中国龙头科技企业技术创新能力进行深入探究。基于企业内部研发资金投入、研发人员投入和税收优惠、地方补贴及行业技术5个前因条件,阐述其对中国龙头科技企业技术创新能力的影响。采用模糊集定性比较分析法对26家中国不同行业上市龙头科技企业进行分析,构建前因条件对创新能力的影响框架,结果发现:从整体看,企业研发投入、地方政府补贴以及行业技术通过不同条件组态影响龙头科技企业创新能力;从企业资源看,相较于研发资金,研发人员对龙头科技企业创新能力的影响更加显著;从外部环境看,市场和政府采用优势互补方式驱动龙头科技企业创新,且市场行业技术对企业创新的影响更显著,地方政府补贴对企业创新发挥显著激励作用。

基于体育强国建设的安徽省和江苏省体育产业集聚水平对比

体育产业是我国部分地区经济迅速增长的支柱性产业,在体育强国建设背景下,该文选取安徽、江苏这两个省份,对两个地区的产业集聚水平展开分析。研究结果表明,安徽省产业集聚水平虽然比江苏省低,但一直处在上升的状态,两者产业集中度存在显著差别。针对上述情况,提出行之有效的建议,以期为类似研究提供一定的参考和依据。

高含硫天然气净化装置过滤器液位计引管失效分析

介绍了某大型净化厂脱硫单元原料气过滤器失效的问题,对过滤器液位计引管直管段及焊接法兰进行化学成分、金相组织、断口形貌等分析,探讨失效的主要原因。结果表明,原料气过滤器失效的原因是过滤器的材质不符合要求,长期处于偏低温度和酸性介质环境中导致原料气过滤器氯化物应力腐蚀失效。准确掌握设备失效成因,有针对性地采取防护措施,对于确保装置长周期安全运行具有重要的意义。

单细胞视角下铅的体内代谢与检测

在全球工业需求和储能需求持续增加的背景下,铅污染仍然是当前主要的环境问题之一。持续的铅暴露导致了复杂的体内毒理效应,其临床治疗效果受限于铅检测技术的缺乏与铅动力学研究的不足。单细胞水平上铅的检测技术,可以揭示动力学相关的细胞机制,从微观角度考量细胞异质性对人体内铅运输和铅分布的影响。分析了铅污染现状并归纳了铅暴露源特征,总结了单细胞水平上铅代谢与检测方面的研究进展。细胞机制与细胞异质性对完善铅的动力学模型和理解有关机制的作用不容忽视。单细胞检测技术作为有效的研究工具,包括流式细胞技术、质谱流式细胞技术以及基于电感耦合等离子体质谱的单细胞电感耦合等离子体质谱技术、电感耦合等离子体飞行时间质谱技术和激光烧蚀-电感耦合等离子体质谱技术等,需要更加标准化与体系化的检测方案。基于生物数学模型与单细胞检测技术的发展,单细胞视角下铅的动力学研究有望进一步细化与完善。

如何让壮志不难酬?领导动机对领导力涌现的作用机制研究

基于内隐领导理论与解释水平理论,探究领导动机通过工作绩效影响领导力涌现的内在逻辑与边界条件。研究发现:领导动机强的员工是否选择提升工作绩效(角色内绩效、创新绩效、组织公民行为)来实现领导之志,取决于其解释水平,高解释水平员工在领导动机驱动下会提升角色内绩效、创新绩效,从事组织公民行为,而低解释水平员工则不然;仅提升角色内绩效难以实现领导力涌现,而提升创新绩效和从事组织公民行为则有助于此。

高校基层党组织引领青年思想的价值意涵、历史经验与创新路径

高校基层党组织是引领青年思想的核心力量,是高校培根铸魂、立德树人的生力军。立足新的时代方位,高校基层党组织引领青年思想呈现出多重价值意涵。因此,深刻认识高校基层党组织引领青年思想的价值意涵,总结百年来高校基层党组织的历史经验,重点剖析新时代青年思想的新特征,进而从引领主客体、引领机制、引领模式与引领效果等方面,构建“立足政治认同,凝聚思想引领共识;完善工作格局,健全思想引领机制;多种方式并举,革新思想引领”模式;坚持问题导向,提升思想引领效果等新路径,为党培育担负民族复兴使命的接班人贡献力量。

产学研融合对制造业领军企业关键核心技术突破绩效的影响——政府与市场双元制度情境的调节作用

在我国制造业关键核心技术被“卡脖子”的形势下,产学研融合成为制造业领军企业实现关键核心技术突破的普遍选择。立足国家战略需求,聚焦制造业领军企业这一技术创新关键主体,基于中国独特的政府与市场双元驱动制度情境,利用制造企业500强名单中A股上市企业数据,实证检验产学研融合程度对制造业领军企业关键核心技术突破绩效的影响,以及政府与市场双元驱动制度情境的调节作用。结果表明:第一,产学研融合广度与深度均对制造业领军企业关键核心技术突破绩效具有显著正向影响;第二,政府支持与市场化程度可强化产学研融合广度对制造业领军企业关键核心技术突破绩效的正向影响;第三,政府支持与市场化程度可强化产学研融合深度对制造业领军企业关键核心技术突破绩效的正向影响。结论可丰富产学研融合与关键核心技术突破相关研究,对中国制造业领军企业借助产学研深度融合突破关键核心技术具有一定的实践指导价值。

党建引领城市社区治理有效性的内在逻辑——基于“政党功能—社会参与”的分析框架

厘清党建引领城市社区治理有效性的内在逻辑是提升社区治理效能的前提。以构建党组织领导的社区治理共同体为目标导向,以政党与社会关系为内在依据,通过建构“政党功能—社会参与”的分析框架可以发现,党建引领城市社区治理的有效性取决于政党功能发挥度和社会力量参与度的高低配置状况。两者交叉形成了“放任型”“管控型”“自治型”和“引领型”四种治理模式,分别折射出了政党与社会无涉、政党整合社会、政党赋权社会、政党引领社会的潜藏逻辑。其中,“引领型”是最有效的模式,因为其能发挥政党功能激活社会参与,形成政党主导下的多元共治。为实现这种模式需要从赋权增能强化政党功能、广泛动员促进社会参与、寓党建于治理提升耦合度三个方面发力。深层次看,党建引领城市社区治理的有效性最终指向的是秩序与活力的平衡,党建引领的核心作用就在于解决这个二元性难题。

基层党建引领农村精神文明建设的时代诉求、现实困境与优化路径

发挥基层党建引领,加强农村精神文明建设,是全面推进乡村振兴的重要内容。基层党建引领农村精神文明建设是丰润农民精神生活的内在要求、激发农民内生动力的迫切需要、发展乡村文化产业的驱动力量。当前,基层党建引领农村精神文明建设主要存在着理论教育不够深入导致内涵意蕴挖掘不足、社会号召力不够显著导致主体活力激发不足、工作作风不够务实导致实践效果提升不足、运行机制不够健全导致保障体系完善不足等现实困境。为此基层党建应强化思想引领、增强主体协同、突出政治领导、健全运行机制,进而深化精神文明建设内涵意蕴、汇聚精神文明建设主体合力、增强精神文明建设实践效果、织密精神文明建设制度网格,为乡村振兴蓄势赋能。

基层法治建设视域下基层领导干部法治思维培养问题研究

规范基层法治建设运行机制,不仅需要加强领导、明确责任,完善推进监督机制,还需要强化基层领导干部法治思维,为基层法治建设提供坚实有力的队伍保障。因此明晰基层领导干部法治思维的概念、准确认识基层领导干部培养法治思维的重要性十分必要。通过分析基层领导干部法治思维培养中存在的问题,探讨培养法治思维的具体方法,提出树立正确法治理念、强化依法行政实践、完善干部任用机制、加强法治宣传教育四大改进措施,提升基层领导干部法治思维能力。