Medical geology in tropical countries with special reference to Sri Lanka

Sri Lanka provides an ideal opportunity for the study of the effect of geology on human health. The vast majority of the people of Sri Lanka still live in rural areas within areas termed geochemical provinces. Very broadly, one could say that a geochemical province has characteristic chemical composition in soil, water stream sediments and rocks, enabling their delineation from others. The chemical composition is presumed to be have an impact on the health of the inhabitants of the particular geochemical province, particularly because of the fact that their food and water are obtained mostly from the terrain itself. This leads to the concept of “diseases of geochemical origin”. Among these are dental fluorosis, iodine deficiency disorders (IDDs) and selenium-based diseases. The Dry Zone of Sri Lanka has several areas rich in groundwater fluoride, the ingestion of which leads to dental fluorosis. Iodine deficiency diseases are more common in the Wet Zone, though their aetiologies are more complicated. Interestingly, it has also been observed that significant proportions of the female population of Sri Lanka are selenium-deficient, which could well be related to the geological environment. Chronic renal failure (CRF) has been observed in some areas of the Dry Zone of Sri Lanka, where there is a relationship of CRF with the mineral content of drinking water. This subject matter falls under the auspices of Medical Geology, a scientific discipline still in its infancy, and much more concerted studies are needed to attract the attention of medical research.     

污水处理厂污泥中几种典型酚类内分泌干扰物的调查

采用超声萃取-C18柱富集净化和柱前衍生气相色谱/质谱方法,检测了我国北方某市四个典型污水处理厂不同工艺段污泥中烷基酚和聚氧乙烯醚的几种典型中间降解产物以及双酚A等内分泌干扰物质.2003年,2004年和2006年三年的分析结果表明,所有的污泥样品中都检测到了壬基酚类物质的存在,总浓度范围为1.00-128.45 mg·kg-1之间,在活性污泥中以壬基酚单氧乙烯醚和壬基酚二氧乙烯醚为主,消化污泥和浓缩污泥中则以壬基酚为主.随着时间的推移,这类物质在城市污泥中有逐渐降低的趋势.辛基酚和双酚A都低于检出限.     

AzaC预处理增加TCDD对特殊细胞P450基因的诱导

利用RT-PCR检测不同物质诱导细胞的CYP基因 mRNA的表达水平.在HepG2细胞,TCDD能诱导CYP1A1、CYP1B1及CYP1A2基因表达,CYP1A1、CYP1B1基因比CYP1A2基因更容易被诱导,用AzaC处理后CYP1B1基因表达无改变;在A549细胞和SPC-A1细胞,Azac预处理后增加了TCDD对CYP1家族的诱导.也就是AzaC增加了CYP1A1、CYP1A2和CYP1B1基因表达水平.图1表1参10     

Removal of tetrachlorobisphenol A and the effects on bacterial communities in a hybrid sequencing biofilm batch reactor-constructed wetland system

SBBR-CW system was proposed to effectively treat wastewater containing TCBPA. CW unit contributed more than SBBR to the removal of TCBPA. TCBPA changed the composition and structure of bacterial community in the system. GAOs massively grew in SBBR, but did not deteriorate TP removal efficiency. Tetrachlorobisphenol A (TCBPA) released into the sewage may cause environmental pollution and health risk to human beings. The objective of this study was to investigate the removal of TCBPA and bacterial community structures in a laboratory-scale hybrid sequencing biofilm batch reactor (SBBR)-constructed wetland (CW) system. The results showed that the removal efficiency of chemical oxidation demand (COD), ammonia, total nitrogen and total phosphorus in the SBBR-CW system was 96.7%, 97.3%, 94.4%, and 88.6%, respectively. At the stable operation stage, the system obtained a 71.7%±1.8% of TCBPA removal efficiency with the influent concentration at 200 mg/L. Illumina MiSeq sequencing of 16S rRNA gene revealed that the presence of TCBPA not only reduced the bacterial diversity in the SBBR-CW system, but also altered the composition and structure of bacterial community. After the addition of TCBPA, Proteobacteria increased from 31.3% to 38.7%, while Acidobacteria and Parcubacteria decreased greatly in the SBBR. In contrast, Acidobacteria replaced Proteobacteria as the dominant phylum in the upper soils of CW. The results indicated that TCBPA stimulated the growth of GAOs in the SBBR without deteriorating the phosphorus removal due to the presence of sufficient carbon sources. The ammonia oxidizing bacteria, Nitrosomonas, and denitrification bacteria, Hyphomicrobium and Pseudomonas, were inhibited by TCBPA, resulting in a decreasing the removal efficiency of TN and ammonia.     

4A沸石去除水中Pb~(2+)的研究

在静态条件下,研究了4A沸石对废水中Pb2+的吸附性能,并探讨了影响吸附的因素。实验表明:当温度为30℃,废水pH为5~6,0.01 g4A沸石对100 mg/LPb2+溶液10 mL吸附20 min,Pb2+的去除率可达到99%以上。在实验研究条件下,4A沸石对Pb2+的吸附符合Langmuir和Freundlich等温吸附方程,相关系数为0.9819和0.9998。经计算,4A沸石对Pb2+的饱和吸附量为125 mg/g。4A沸石吸附水中Pb2+,达到吸附平衡的时间较短;溶液pH值的变化对吸附效果影响不显著;温度从室温略微升高,Pb2+的去除率略有增大。吸附在4 A沸石上的Pb2+可回收利用,处理后的4A沸石可以再生,且重复使用性能较好。     

环境与灾害监测预报小卫星数据应用评价

以环境与灾害监测预报小卫星(HJ-1A/B)和TM的CCD数据,从波段配准、空间分辨力、非监督分类、数理统计分析和地统计分析等方面与TM数据比对,对HJ-1A/B星数据质量进行评价。结果认为,HJ-1A/B CCD数据整体数据质量较好,在今后的宏观区域环境监测、灾害监测预报中将会发挥重要作用。     

A/O法合并处理煤转气废水和生活污水

探讨了A/O法合并处理煤转气废水和生活污水的工艺原理及试运行效果。实践证明,该方法是处理高浓度煤转气废水的简单新方法,经处理后的污水可达到国家规定的排放标准。     

乙酰辅酶A羧化酶:脂肪酸代谢的关键酶及其基因克隆研究进展

乙酰辅酶A羧化酶(Acetyl-CoA carboxylase,ACC)在脂肪酸合成和分解代谢中发挥着重要作用.系统介绍了该酶的结构与分类、生物学作用与应用、抑制剂的类型与作用机理以及基因克隆4个方面的进展.ACC在大多数原核生物中为多亚基型酶,而在大多数真核生物中为多功能型单亚基酶,在天蓝色链霉菌和古菌勤奋金属球菌中为另外两种特殊类型;但都具备3个关键的功能域,即生物素羧化酶(BC)、生物素羧基载体蛋白(BCCP)和羧基转移酶(CT).CT功能域作为潜在的靶标广泛应用于植物除草剂的筛选和哺乳动物肥胖、糖尿病等代谢疾病的药物设计中.ACC基因也成为转基因油料作物和生物柴油研究中重要的靶标基因.研究表明,植物质体中的β-CT亚基是多亚基型ACC的限制因子,而BCCP是脂肪酸合成的负调控因子.油脂的合成代谢十分复杂,且存在反馈抑制机制,因此克隆和表达ACC基因可以提高宿主中ACC的活性,但不一定能显著促进脂肪酸的积累.图2参52     

A/O-MBR处理某经济区市政污水的效能

采用A/O-MBR法处理某经济区市政污水,对其进、出水的水质进行连续监测,考察系统稳定性和处理效果。结果表明,在水力停留时间12小时,污泥龄30天,回流比75%,好氧段DO浓度1.3～8.5 mg/L的条件下,系统对COD、氨氮、总氮、总磷的平均去除率分别为92.04%、93.66%、78.04%、91.06%。反硝化...     

关于《安全生产法》的几点思考

《安全生产法》是我国安全生产领域的第一部基本法,其颁布实施意义深远。本文就《安全生产法》不尽完善的地方,提出了自己的看法,并提出立法建议,旨在今后进一步完善《安全生产法》,以及做好实施《安全生产法》的相关配套和细化的立法工作。