黄海表层沉积物中重金属的分布特征与生态风险评价

[目的]研究黄海表层沉积物中重金属的分布特征,评价其生态风险.[方法]对黄海海域表层沉积物中重金属(Cu、Mn、Pb、Zn、Cr、Fe、Hg和Cd)的含量分布和富集状况进行了调查,分析了重金属之间以及重金属与有机碳(TOC)含量之间的相关性,并采用Hakan-son的潜在生态危害指数法评价了该海域重金属污染的程度及其潜在的生态危害.[结果]在南黄海中部和威海以北的北黄海西部海域表层沉积物中Cu、Pb、Zn、Cr、Fe和Hg的含量偏高,海州湾和北黄海北部含量偏低,Mn、Cd的分布较不均匀,离散程度较大;黄海表层沉积物中各项重金属含量均存在正相关性,Ph与Zn、Zn与Cr、Pb与Cr的相关系数分别达到0.97、0.96和0.94.Cd和Cu呈显著相关,但Cd与其他重金属无显著相关关系,重金属与TOC之间也存在正相关.潜在生态危害评价结果表明,黄海表层沉积物只有部分站点处于生态危害的中等级别,大多站点生态危害轻微,各个重金属元素的潜在生态风险程度由强到弱依次为Cd>Hg>Cu>Pb>Cr>Zn,对黄海表层沉积物具有潜在影响的重金属主要是Cd;底质环境质量评价显示,南黄海中部的泥质沉积区域环境质量较差,应予以重视.[结论]该研究为黄海环境保护和生态系统的可持续发展提供了理论依据.     

五指山茶园表层土壤重金属污染危害评价

[目的]评价五指山茶园表层土壤重金属污染的危害程度.[方法]采样分析五指山茶园表层土壤重金属(Cr、Ni、Cu、Zn、As、Cd、Pb)的平均含量及富集状况,分别以现代工业化以前沉积物中重金属的全球最高背景值和我国<土壤环境质量标准>的一级自然背景值为参比值,采用潜在生态危害指数法对五指山茶园表层土壤重金属的富集系数和生态危害系数以及生态危害指数进行了评价.[结果]以2种背景值为参比得出的重金属污染水平相近,Cd和Pb是对五指山茶园表层土壤生态环境具有潜在影响的主要重金属元素.[结论]五指山茶园表层土壤重金属的潜在危害程度为轻微-中等污染水平.     

典型冶炼企业集中区土壤重金属污染分析及风险评价

以南方典型有色金属冶炼企业集中区为研究对象,对冶炼企业厂界内表层土壤中Cd、Pb、As、Zn、Hg、Cu、Cr（Ⅵ）、Ni八种元素含量进行测定分析,利用单因子污染指数法、内梅罗污染指数法、潜在生态风险和健康风险模型对冶炼厂的生产区、储存区、废水治理区、固废贮存区或处置区进行重金属污染评价及风险评价。结果表明,冶炼厂内土壤受到Cd、Pb、As、Zn四种元素不同程度的污染;风险评价结果显示,冶炼厂内土壤总体存在强潜在生态风险,Cd、As、Zn是主要生态危害元素;同时As存在非致癌风险和致癌风险,Pb存在非致癌风险;厂内污染主要集中在生产区和废水治理区。     

闽江口塔礁洲湿地重金属的分布特征

对闽江口塔礁洲湿地40个采样点的表层沉积物中的重金属含量进行测定.结果表明:Cu、Pb、Zn、Cd的含量分别为4.13-42.62、40.31-104.63、50.36-516.39、0.14-1.39mg·kg-1;各元素平均含量从大到小排序为Zn、Pb、Cu、Cd;对比国内外典型河口,塔礁洲湿地的Cu、Cd含量处于较低水平,但Pb、Zn的污染则较为严重;地累积指数法评价结果显示,塔礁洲主要受Cd和Zn的污染,不同重金属污染程度从大到小排序为Cd、Zn、Pb、Cu;潜在生态危害指数法评价结果显示,塔礁洲湿地的潜在生态危害指数(RI)均值为315.7±156.4,属于强的生态危害;塔礁洲湿地主要潜在生态危害重金属为Cd、Pb、Cu、Zn,均属于轻微的生态危害.     

某矿区农田土壤重金属分布特征与生态风险评价

为探明贵州六盘水某矿区周边农田土壤重金属的分布特征及污染程度,以矿区周边农田为研究对象,采集表层土壤测定Cr、Ni、Cu、Pb、Zn和As含量,分析重金属空间分布特征,评价土壤重金属污染程度及潜在生态风险,并探究其来源。结果显示,6种重金属元素含量均高于贵州省土壤重金属背景值,超标倍数依次为Cu(5.82)>Ni(2.52)>Zn(2.46)>Pb(1.81)Cr(1.51)>As(1.18),重金属分布显示矿区煤矸石山和洗选厂周边的农田土壤重金属富集较为严重。单项污染指数均值显示Cu处于重度污染水平,Ni、Zn为轻度污染水平,Pb、Cr、As为轻微污染水平;综合污染处于重度污染级别。地质累积指数法评价结果显示:Cu、Ni、Zn、Pb处于轻度污染,Cr、As表现为尚未污染水平。研究区重金属的综合潜在生态风险指数为68.02,已经达到轻度危害程度,其中Cu、Ni对综合潜在生态风险(RI)的贡献最大。多元统计分析结果显示,Zn与Pb、Zn与As以及Cu与Pb的相关性较强,表明Zn、Pb、AS、Cu的来源较相似,为第一类来源,主要源于采矿活动产生的三废;Ni、Cr分别为第二、三类来源,第二类重金属来源与汽车尾气的排放、机械损耗有关;第三类重金属主要受土壤母质影响。4种评价结果基本一致,矿区周边农田土壤重金属处于重度污染,轻度危害程度,Cu、Ni是研究区土壤影响最显著的生态风险因子,重金属主要源于采矿活动产生的三废。     

贵州丹寨县铅锌矿区小流域土壤重金属污染特征及生态风险评价

为探究贵州丹寨县铅锌矿区矿业活动对土壤系统运转对环境影响,以丹寨县兴仁镇铅锌矿区土壤为研究对象,采集小流域内河流周边不同土地利用类型土壤表层(0~20cm)的样品,分析测定土壤中Cu、Cd、Pb、Zn、Mn、Hg、As 7种重金属含量。应用单因子污染指数法、内梅罗综合污染指数法、地质累积指数法、潜在生态指数法对矿区不同土壤层重金属进行污染程度和潜在生态风险进行评价。结果表明,0~10cm土壤中Cu、Cd、Pb、Zn、Mn、Hg、As含量分别是贵州省土壤背景值的0.65、5.13、1.74、2.45、0.59、5.08、0.27倍。10~20cm土壤中Cu、Cd、Pb、Zn、Mn、Hg、As含量分别是贵州省土壤背景值的0.71、3.11、1.18、2.21、0.65、4.88、0.21倍。不同小流域与不同深度土层危害程度有所差异,通过评价结果得出研究区主要污染重金属元素为Cd、Hg,土壤重金属处于中等及以上潜在生态危害程度。     

某铅锌尾矿库周边土壤重金属污染特征及其来源分析

以某铅锌尾矿库周边土壤为研究对象,测定土壤中Cd、Hg、As、Pb、Cr、Cu、Zn、Ni重金属含量,采用地质统计分析掌握重金属含量空间分布,再利用单因子污染指数、内梅罗综合污染指数和地质累积指数评价重金属污染状况,并结合相关性分析和主成分分析探重金属来源。结果表明,土壤中Cd、Hg、As、Pb、Cr、Cu、Zn、Ni平均含量分别为10.4、1.54、132、653、62.8、73.8、1 392、31.6 mg/kg,越靠近尾矿库,Cd、As、Pb、Cu、Zn、Hg含量越高。内梅罗综合污染指数表明,研究区综合污染指数为11.2,为重污染,单因子污染指数和地质累积指数表明,研究区土壤Cd污染最严重,其次是As、Zn、Pb、Cu、Hg污染,Cr和Ni无污染。相关性分析和主成分分析表明,Cd、Hg、As、Pb、Zn之间存在显著正相关关系,主要受铅锌尾矿库长期堆存、转运及加工等人为活动影响,Cr、Ni主要来自土壤母质,Cu主要受矿业活动和农业活动共同影响。     

巩义煤矿区周边土壤重金属积累特征研究

测定了巩义某煤矿区周边区域土壤中的重金属含量,并运用单因子污染指数、内梅罗综合指数及地质累计指数评价了该区域重金属污染特征。结果表明,该地土壤已出现多种重金属元素不同程度的累积,Cr,Ni,Cu,Zn,Cd,Pb和As的平均依次分别为59.9,32.23,31.46,99.29,0.32,113.14和8.23 mg/kg。单因子污染指数表明,7种元素单因子污染指数分别为0.95,1.18,1.57,1.59,1.60,5.07和0.84,Pb属重度污染,Ni,Cu,Zn和Cd属轻污染,As,Cr属安全水平。内梅罗综合指数指出,该区域土壤均存在不同程度的重金属污染,84%的采样点处于重污染水平。地质累计指数表明,该区域Pb平均级别属偏中污染,Zn,Cu平均级别均属轻污染,Cd,Ni,Cr和As元素平均级别均属无污染。     

福州仓山工业密集区周边菜地土壤重金属的含量与评价

为研究工业密集区菜地土壤重金属的污染特征,选取福建省福州市仓山工业密集区周边8片菜地为研究对象,分析土壤Zn、Pb、Cr、Ni、Cu的含量特征,以福建省土壤环境背景值和食用农产品产地环境质量标准为评价标准进行菜地土壤重金属污染现状评价和潜在生态风险评价.结果表明:供试菜地土壤中,Ni含量超标最严重,平均含量达297.53 mg·kg-1,其次是Pb和Cr,Cu含量最小,老工业区土壤的Zn、Cr、Ni、Cu污染比新工业区严重.单项污染指数法和多项综合污染指数法与Hakanson潜在生态风险指数法评价的结果基本一致:Ni的污染指数最高、其次是Pb和Cr,Cu污染最轻;壁头村菜地土壤重金属综合污染最严重,其次是梁厝村;潜在生态危害系数大小为:Ni>Pb>Cr>Zn>Cu;潜在生态风险程度大小为:壁头村>梁厝村>浦口村>螺洲>黄山村>云风洲>竹榄洲>盘屿;老工业区周边的菜地土壤重金属综合污染指数和潜在生态危害指数明显高于新工业区.     

地质高背景区铅锌矿废弃地土壤重金属污染评价

调查研究了某废弃铅锌矿区周边农田土壤中重金属Hg、As、Cd、Cr、Pb、Cu、Zn的污染状况,并结合单因素指数法、地累积指数法、污染指数负荷法、灰色聚类法及聚类热图分析对重金属污染程度和空间分布状况进行评价,采用相关性分析和主成分分析识别污染途径。结果表明,研究区Cd、Zn、Hg、Pb、Cu和As含量均超过贵州省土壤背景值。Cd的外源污染最严重,Zn、Pb、Hg次之。重金属污染程度与河流以及距矿区距离呈正相关。主要污染因子为Cd,次要污染因子为Hg和Zn,各采样点均处于严重污染。研究区重金属来源可分为4类,Cu、Cd、Zn属工业源污染,主要为矿山开采;As、Hg污染与工业源和农业源有关;Cr、Pb含量受交通源与工业源以及自然源多方面影响。     

Role of clozapine in the occurrence of chromosomal abnormalities in human bone-marrow cells in vivo and in cultured lymphocytes in vitro

Bone-marrow chromosomes were examined from 38 mentally and physically retarded and two psychiatric patients who were being treated with a variety of neuropharmacologic drugs. Twenty of these patients used clozapine (Leponex). The clastogenic effects of clozapine in vitro were studied in the lymphocyte cultures of three patients--one free of hematologic disease and two who 6 months earlier had had agranulocytosis attributed to the use of clozapine. The mean frequency of cytogenetic abnormalities in the bone-marrow cells of patients who used clozapine was significantly increased (P less than 0.05). The two patients who had had agranulocytosis had a greater frequency of cytogenetic abnormalities in their cultured lymphocytes in vivo and in vitro than the patient free of hematologic disease. A clone with a 13/14 chromosome translocation was detected in one of the patients. As all patients received a number of drugs during the in vivo and in vitro studies no definite conclusions could be drawn regarding the role played by clozapine in the occurrence of chromosomal abnormalities.     

Regional differences in suicide in Hungary in the light of registered cases of depression

Author made a revision on the theory published by Rihmer and alii in the year 1989. According to this theory the marked regional differences of suicide in Hungary are caused by the different discovery of the "endogen depression" (rate of diagnosed depression). So the lower is the diagnosis of depression the higher is the suicide rate in a given territory. They have seen a negative correlation between the number of working physicians and the suicide rates. Author made a reexamination on a correct database between 1985-1994. He has also made a study using the DSM-III-R diagnostic criteria in four counties of Hungary. His results deny the theory above mentioned. The rank-correlation of the number of GP and the suicide rates in Hungary in years 1985-1994 did not show correlation. So the underdiagnosis of the depressive disorders and the different number of GP are not the cause of the regional differences of suicide in Hungary.     

Inhibitory effect of suramin in rat models of angiogenesis in vitro and in vivo

The aim of the present study was to test the ability of the chemotherapeutic agent suramin to inhibit angiogenesis in experimental models in vitro and in vivo. In the culture of rat aortic rings on fibronectin, suramin dose-dependently inhibited vascular cell growth, achieving the maximal effect (mean - 88% versus controls, P < 0.05) at 400 microg/ml. Image analysis showed that suramin could inhibit microvessel sprouting in fibrin from rat aortic rings as evaluated by the ratio between the cellular area and the mean gray value of the sample (sprouting index); suramin at 50 microg/ml significantly reduced the sprouting index from the control value of 0.35+/-0.04 to 0.14+/-0.02 mm2/gray level (P < 0.05). Likewise, the area occupied by cells was 19.2+/-1.8 mm2 as compared with 41.8+/-4.2 mm2 in controls (P < 0.05). In the rat model of neovascularization induced in the cornea by chemical injury, suramin at 1.6 mg/eye per day reduced the length of blood vessels (0.7+/-0.1 mm as compared with 1.5+/-0.1 mm in controls, P < 0.05). In the same model the ratio between the area of blood vessels and the total area of the cornea (area fraction score) was decreased by suramin from 0.19+/-0.02 in controls to 0.03+/-0.003 (P < 0.05). Suramin given i.p. at 30 mg/ kg per day markedly inhibited the neovascularization induced in the rat mesentery by compound 48/80 or conditioned medium from cells secreting the angiogenic protein fibroblast growth factor-3 (FGF-3). The area fraction score in control rats treated with compound 48/80 was 0.31+/-0.03, and this was reduced to 0.07+/-0.01 by suramin (P < 0.05). After i.p. administration of FGF-3 the area fraction score was reduced by suramin from 0.29+/-0.03 to 0.05+/-0.01 (P < 0.05). These results provide evidence that suramin exerts inhibitory effects on angiogenesis in both in vitro and in vivo models.     

Efficacy of lomefloxacin in treatment of nonspecific inflammatory diseases and in prophylaxis of postoperative complications in urology

Clinical and bacteriological efficacies of lomefloxacin and ofloxacin were comparatively estimated in the treatment of 104 urologic patients with nonspecific inflammatory diseases and in 36 urologic patients for prophylaxis of inflammatory complications after surgical interventions. The majority of the urinary tract pathogens i.e. Enterobacteriaceae spp. and gramnegative nonfermenting bacteria were highly susceptible to both the fluoroquinolones. The clinical and bacteriological efficacies of lomefloxacin amounted to 94.4 and 80.7 per cent and those of ofloxacin to 92 and 79.2 per cent respectively. The prophylactic use of lomefloxacin and ofloxacin was efficient in 94.7 and 94.1 per cent of the cases respectively. The antibacterial prophylaxis in urologic patients should be applied not only at the period of surgical interventions but also during the early postoperative period.     

Difference in changes of plasma volume in two types of Goldblatt hypertension in rabbits

High plasma renin concentration (PRC) and hematocrit (Ht) were observed in hypertensive rabbits with one renal artery clipped and an intact opposite kidney (Group A), while rather low PRC and Ht in hypertensive ones with one renal artery clipped and the opposite kidney removed (Group B). Plasma volume (PV), blood volume (BV), and packed cell volume (PCV) were estimated in these two types of hypertensive rabbits, and also in sham-operated rabbits (Group C). In Group A, 4 weeks after clipping of a renal artery, PV was decreased and significant inverse correlations were observed between PV and the elevation of blood pressure and between PV and PRC. A significant correlation between PRC and the elevation of blood pressure was also found 4 and 12 weeks after the clipping. PCV was increased until 12 weeks after clipping. In Group B, PV was increased 1 and 4 weeks after clipping, then returned to the initial level. Ht was decreased 1 and 12 weeks, and PCV was decreased 12 weeks after clipping. These results would indicate that a high Ht seen in Group A was partly due to the decreased PV and partly due to the increased PCV, while, in Group B, a low Ht in early stage might be mainly due to the increased PV, but in the late stage, a decreased PCV appeared to play a role to lower Ht. PRC seems to be affected differently by PV in these two types of hypertension.     

PLC在高炉汽动式鼓风机监控系统的应用

鞍钢高炉15号鼓风机是VASi-9018型轴流式汽轮压缩机，通过技术改造，采用先进的电子控制技术，建成了全新的具有现代化水平的汽轮压缩机控制系统。     

Role of signal peptides in targeting of proteins in cyanobacteria

Proteins of cyanobacteria may be transported across one of two membrane systems: the typical eubacterial cell envelope (consisting of an inner membrane, periplasmic space, and an outer membrane) and the photosynthetic thylakoids. To investigate the role of signal peptides in targeting in cyanobacteria, Synechococcus sp. strain PCC 7942 was transformed with vectors carrying the chloramphenicol acetyltransferase reporter gene fused to coding sequences for one of four different signal peptides. These included signal peptides of two proteins of periplasmic space origin (one from Escherichia coli and the other from Synechococcus sp. strain PCC 7942) and two other signal peptides of proteins located in the thylakoid lumen (one from a cyanobacterium and the other from a higher plant). The location of the gene fusion products expressed in Synechococcus sp. strain PCC 7942 was determined by a chloramphenicol acetyltransferase enzyme-linked immunosorbent assay of subcellular fractions. The distribution pattern for gene fusions with periplasmic signal peptides was different from that of gene fusions with thylakoid lumen signal peptides. Primary sequence analysis revealed conserved features in the thylakoid lumen signal peptides that were absent from the periplasmic signal peptides. These results suggest the importance of the signal peptide in protein targeting in cyanobacteria and point to the presence of signal peptide features conserved between chloroplasts and cyanobacteria for targeting of proteins to the thylakoid lumen.