Molecular mechanisms of nickel carcinogenesis: gene silencing by nickel delivery to the nucleus and gene activation/inactivation by nickel-induced cell signaling

We have summarized the molecular and cellular events involved in nickel (Ni) compound induced carcinogenesis. The major hypothesis for nickel carcinogenic action has involved the ability of the Ni compound to deliver high concentrations of Ni intracellularly, enter the nucleus and interact with chromatin. Ni has been found to selectively damage heterochromatin, and a major action of Ni is its ability to silence the expression of genes located near heterochromatin by inducing a loss of histone H4 and H3 acetylation and DNA hypermethylation. When Ni silences critical genes, such as tumor suppressor genes, the cell is altered to a greater state of neoplastic transformation. The carcinogenic hazard of Ni compounds has been directly related to the ability of that Ni compound to raise the intracellular Ni ions. The mechanisms of Ni-induced gene silencing will be discussed. However, recently it has been found that soluble Ni ions can interact with the cell surface receptors and activate cell signaling resulting in the induction of a variety of cellular genes. In particular, the Ca and hypoxia inducible factor pathway is activated in all cells exposed to soluble Ni ions. In the case of HIF-1 induction, a cell is now equipped with the expression of a variety of genes that will allow the cell to survive the lack of oxygen and thus should enable a previously initiated cancer cell to progress into a full malignant state and metastasize. These new findings support the view that soluble Ni ions exhibit carcinogenic potential by activating cell promotion and lend strength to the epidemiological data showing soluble Ni to be associated with cancer risk in Ni refinery workers.     

青藏铁路列车运行控制系统的安全性分析

分析了青藏铁路中多种不利因素对轨道电路参数的影响 ;提出了在青藏铁路不宜采用现行基于轨道电路的列车运行控制系统 ,而应选择基于通信的列车运行控制系统的理由 ;给出了系统的基本结构及提高系统可靠性的措施 ;与此同时 ,就人们关心的无线传输列车控制数据的可靠性和安全性难题 ,通过建立马尔可夫模型的方法进行了分析     

合肥"10·28"特大爆炸事故分析

本文对合肥"10·28"特大爆炸事故进行了分析,确定了本次爆炸事故的爆炸位置和类型,分析了爆炸混合气体来源及本次爆炸的特点.提出了今后为防止类似爆炸事故的发生,在设计规范标准、设计布置、施工和日常管理中应注意的问题.     

水电站工程项目区生态环境现状评价方法初探——以开都河柳树沟水电站工程为例

在野外实地调查和遥感影像解译的基础上,采用传统生态学样方调查法和景观生态学生态完整性评价法相结合的方法,对开都河柳树沟水电站工程项目区生态环境现状进行评价.评价结果显示,这种评价方法能更全面有效的对项目区的生态环境现状进行评价.     

矿区工业旅游资源开发的SWOT分析——以四川省嘉阳煤矿为例

随着矿区矿产资源的枯竭,大多数矿区正在积极寻求可持续的发展道路。矿区工业旅游资源的开发利用,将从一个全新的角度促进矿区的可持续发展。在理解矿区工业旅游内涵及意义的基础上,借助SWOT分析法,对四川省嘉阳煤矿工业旅游资源的优势、劣势、机遇及威胁进行了全面分析,以期为嘉阳矿区工业旅游资源的开发利用和对嘉阳矿区社会经济的可持续发展提供参考依据。     

Exposure Programme on Atmospheric Corrosion Effects of Acidifying Pollutants in Tropical and Subtropical Climates

Many national exposure programmes have been performed in tropical and subtropical climates during the last 50 years. However, ambitious programmes involving more than a few countries are scarce. In this paper a recently formed network of test sites is described involving 12 test sites in Asia (India, Vietnam, Thailand, Malaysia and China including Hong Kong) and four test sites in Africa (South Africa, Zambia and Zimbabwe). This effort is part of the 2001–2004 Swedish International Development Agency (SIDA) funded Programme on Regional Air Pollution in Developing Countries (RAPIDC). Corrosion attack after one (2002–2003) year of exposure (carbon steel, zinc, copper, limestone and paint coated steel) are presented together with environmental data (SO₂, NO₂, HNO₃, O₃, particles, amount and pH of precipitation, temperature and relative humidity) for all the test sites. The obtained corrosion values are substantially higher than expected for limestone, higher than expected for carbon steel and lower than expected for zinc compared to values calculated using the best available dose–response functions.     

催化湿式氧化法处理吡虫啉农药废水

自制了Cu／Mn，Cu／Ce，Cu／Ni，Ce／Mn，Ce／Ag等催化剂，经过性能比较，选择催化活性较高且金属溶出量较小的Cu／Ni作催化剂。用催化湿式氧化法处理吡虫啉农药废水，考察了各种因素对处理效果的影响。实验结果表明：在进水pH为6．93、Cu／Ni加入量为4．0g、反应温度为190oC、氧分压为1．6MPa、反应时间为120min的条件下，COD去除率为95％；处理后废水的BOD5／COD从0．093增至0．590，可生化性明显改善。     

雾灵山自然保护区的生态效应与保护对策

通过对雾灵山国家级自然保护区的调查，研究保护区的生态沿革，分析保护区的生态功能、生态作用等生态效应，针对当前所存在的草甸严重退化、动物种群密度降低、水量减少等生态问题，提出对保护区的生态环境应尽快制定环境保护规范化，建立生物多样性保护权威机构，实行社区共管，开展科学生态旅游等措施。     

多因素耦合条件下硫化矿自燃神经网络动态预测模型研究

硫化矿石自燃是多种因素、多场耦合综合作用的结果,是一典型的非线性问题。笔者应用人工神经网络技术,以Matlab软件为平台,通过现场调查和理论分析,建立了矿石含硫量、通风强度、环境温度3因素与硫化矿石自燃之间的预测模型;通过数据样本学习与部分现场监测数据相结合进行模拟,研究表明预测数据与实测结果基本吻合,误差控制在10%以内,取得了较好的效果。该研究为预防硫化矿石自燃提供一个新的思路和方法,具有一定的理论意义和应用价值。     

水质自动监测中的质量保证与质量控制

质量保证与质量拉制是水质自动监测中十分重要的技术工作和管理工作，包括人员素质、运行与管理机制、试剂与标准溶液的配制及文件记录等。在实际工作中，监测人员可根据仪器的运行状况，定期对仪器进行校准、标准溶液的棱查、比对实验验证及试剂有效性检查，用以检查仪器的基线飘移情况。如果分析中出现一个异常值，它的前后均为正常值，这种数值大多是由仪器的进样、仪器内部试剂传输等原因所致，如果发生原因不明的数据异常，就要及时检查系统的各个环节并采集实际水样进行人工分析，直至查清原因，剔除异常值，并在周报中加以说明，以确保上报数据的准确性、精密性和可比性。