Effects of cadmium on intracellular cation homoeostasis in the yeast Saccharomyces cerevisiae

Previous studies have demonstrated that cadmium can induce biochemical and physiological changes in yeast Saccharomyces cerevisiae. However, studies on the influence of cadmium on the ion balance in the cell and the interaction between cadmium and other ions are still relatively few in number. By using inductively coupled plasma-atomic emission spectrometry, the contents of some cations, including Zn²⁺, Ca²⁺, Fe³⁺, Cu²⁺, Mg²⁺, K⁺, and Na⁺ were measured. The data showed that the levels of Zn²⁺ and Fe³⁺ were increased, while those of Cu²⁺, K⁺, and Na⁺ were decreased after cadmium treatment. Afterwards, using the drop test assay, the interactions between cadmium and the selected ions were investigated. The results suggested that the cytotoxicity of cadmium could be attributable to the interference of cadmium with the intracellular cation homoeostasis. Calcium channel transporter Cch1 participates in the intracellular uptake of cadmium. Additionally, Zn²⁺, Ca²⁺, Fe³⁺, Mg²⁺, and K⁺ can rescue the toxic effect of cadmium in yeast.     

Epidemiological investigation on mercury contamination in gold mining and its effect on health

Ｉｎｒｅｃｅｎｔｙｅａｒｓ,ｍｅｒｃｕｒｙｃｏｎｔａｍｉｎａｔｉｏｎｈａｓｂｅｅｎ ｐａｉｄ ｇｒｅａｔａｔｔｅｎｔｉｏｎｔｏｏｖｅｒｔｈｅｗｏｒｌｄ(Ｚｉｌｌｏｕｘ ,1993;Ｍｏｎａｍｙ ,1993;Ｇｕａｎ ,1994;Ｙａｎｇ ,1992 ;Ｌｉ,1993;1994;ＳＣＯＰＥ ,1994) .ＴｈｅｐｒｉｎｃｉｐａｌｆｏｃｕｓｉｓｔｏｄｅｃｒｅａｓｅＨｇｃｏｎｔａｍｉｎａｔｉｏｎｉｎｏｒｄｅｒｔｏｐｒｏｔｅｃｔｔｈｅｅｃｏｓｙｓｔｅｍｅｎｖｉｒｏｎｍｅｎｔａｎｄｔｈｅｈｕｍａｎ’ｓｈｅａｌｔｈ .Ｉｔｉｓｄｉｆｆｅｒｅｎｔｆｒｏｍ“ｍｉ…     

废旧三元锂离子电池回收利用碳足迹

公路运输是我国交通运输领域主要温室气体排放源,新能源汽车行业作为实现交通运输领域“双碳”目标的重要抓手,未来面临大批动力电池报废情况,为量化评估废旧锂电池回收利用行业产生的碳减排效益,从生命周期角度构建废旧三元锂电池回收利用碳足迹核算模型,通过优化电力结构和运输结构,对废旧锂电池回收利用的碳减排潜力作预测评估,此外,使用误差传播方程进行不确定性分析保证碳足迹结果的可靠有效.结果表明,当前中国企业使用湿法技术回收1 kg废旧三元锂电池的碳足迹为-2760.90 g（定向循环工艺）和-3752.78 g（循环再造工艺）,碳足迹的不确定性分别为16 %（定向循环工艺）和15 %（循环再造工艺）.从碳排放贡献率分析,再生产品阶段是废旧三元锂电池湿法回收利用减碳首要贡献来源,电池获取、拆解和末端处置阶段是增碳主要来源.相比于优化运输结构,通过优化电力结构,可有效实现更大的碳减排潜力,协同优化情景下,相比于优化前可实现14 %~19 %的碳减排,与原生产品相比定向循环工艺和循环再造工艺分别可实现9 %和11 %的减排潜力.     

Allelopathic inhibition on red tide microalgae Skeletonema costatum by five macroalgal extracts

This study aims to identify effective antialgal allelochemicals from marine macroalgae that inhibit the growth of red tide microalgae. Practically, new algicidal agents were developed to control red tide. The growth inhibitory effects of 5 marine macroalgae Porphyra tenera, Laminaria japonica, Ulva pertusa, Enteromorpha clathrata, and Undaria pinnatifida on Skeletonema costatum were evaluated by adding crude seawater extracts of macroalgal dry tissue into the culture medium containing S. costatum. The half-effective concentrations at 120 h (EC_{50, 120 h}) of the seawater extracts were 0.6, 0.9, 1.0, 1.0, and 4.7 g/L for the five macroalgae above, respectively. E. clathrata, L. japonica and U. pertusa showed strong allelopathic effect on the growth of S. costatum. There have been no previous reports with regard to the allelopathic effects of the former two macroalgae so far. The possible allelochemicals of 21 compounds of the E. clathrata were detected using Gas chromatography-mass spectrometry (GC-MS) analysis. Unsaturated fatty acids, acrylic acid (C₃H₄O₂), and linolenic acid (C₁₈H₃₀O₂) were the most likely allelochemicals in E. clathrata.     

Screening of δ-aminolevulinic acid dehydratase from Pseudomonas strains as biosensor for lead and some other metals contamination

δ-Aminolevulinic acid dehydratase (ALAD; E.C. 4.2.1.24) is a metalloprotein and plays a crucial role in heme synthesis. Its sensitivity to toxic metals depends on the metallic co-factors. In this study the effects of some heavy metals on ALADs activity of five Pseudomonas isolates from Akar?ay stream (Afyonkarahisar) have been studied in order to determine whether their ALADs could be used as biosensor for lead and other heavy metals contamination. The data obtained from the study were analysed statistically by using SPSS 10.0 software for Windows. According to the results, Ni(II) increased the ALAD activity of Pseudomonas putida, Pseudomonas pseudoalcaligenes and Pseudomonas aureginosa ATTC 27853. Mn(II) also increased the enzymic activity in all strains examined except P. pseudoalcaligenes. These were found not to be statistically meaningful. P. aeruginosa 2’s enzymic activity was inhibited by Mg(II) and Zn(II), significantly (p’lt;’.05). There was a statistically meaningful relation between enzymic activity of both P. pseudoalcaligenes, P. putida and increasing Pb(II) concentration (p’lt;’.05). In addition, a formula was also deviced in order to determine the doses of metals in the environment of the organisms. As a result of the study, we can suggest that Pseudomonas ALADs can be used as a biosensor for lead and some other heavy metal exposure in aquatic environments.     

基于GF-1 WFV影像和随机森林算法的总氮反演研究

基于高分一号卫星影像遥感数据和水库水质实测数据,利用随机森林回归算法建立遥感反射率与总氮浓度的定量反演模型,以获取东风水库总氮浓度的时空分布情况,进而对水库总氮污染情况进行分析.结果 表明,总氮反演模型精度较高,决定系数R2为0.879,均方根误差为0.169 mg/L,但仍有提升空间.将模型运用于2016-2018年GF-1 WFV影像遥感数据,反演得到东风水库总氮浓度时空分布情况.结果 表明,2016年水库总氮浓度呈波动性变化,2017-2018年除个别月份外,水库总氮浓度整体呈下降趋势.从水质标准来看,水库总氮浓度介于Ⅲ～Ⅴ类水质标准,且存在富营养化风险.从不同季节变化情况来看,春冬季总氮浓度较高,夏秋季浓度较低.从空间差异性来看,区域变化规律性不太明显.     

热水器生命周期环境影响评价模型及其应用研究

在现有热水器环境影响评价方法比较的基础上,用生命周期环境影响评价方法建立热水器的环境影响评价模型,计算分析热水器产品资源消耗、臭氧耗竭、能源强度和全球变暖四个指标,分析评价结果表明,四个指标在生命周期贡献值大小依次是臭氧耗竭、全球变暖、能源强度和资源消耗.热水器环境影响较大的零部件有压缩机、制冷剂、电机和铜管等.并对比分析了四种环境影响评价方法,得出生命周期环境影响评价模型是较为全面的评价模型.     

Exploratory multinomial logit model–based driver injury severity analyses for teenage and adult drivers in intersection-related crashes

Objective: Teenage drivers are more likely to be involved in severely incapacitating and fatal crashes compared to adult drivers. Moreover, because two thirds of urban vehicle miles traveled are on signal-controlled roadways, significant research efforts are needed to investigate intersection-related teenage driver injury severities and their contributing factors in terms of driver behavior, vehicle–infrastructure interactions, environmental characteristics, roadway geometric features, and traffic compositions. Therefore, this study aims to explore the characteristic differences between teenage and adult drivers in intersection-related crashes, identify the significant contributing attributes, and analyze their impacts on driver injury severities.

Methods: Using crash data collected in New Mexico from 2010 to 2011, 2 multinomial logit regression models were developed to analyze injury severities for teenage and adult drivers, respectively. Elasticity analyses and transferability tests were conducted to better understand the quantitative impacts of these factors and the teenage driver injury severity model's generality.

Results: The results showed that although many of the same contributing factors were found to be significant in the both teenage and adult driver models, certain different attributes must be distinguished to specifically develop effective safety solutions for the 2 driver groups.

Conclusions: The research findings are helpful to better understand teenage crash uniqueness and develop cost-effective solutions to reduce intersection-related teenage injury severities and facilitate driver injury mitigation research.     

现代荒漠化过程中人为影响的系统分析——以内蒙古自治区乌审旗现代荒漠化过程为例

人类生产系统同资源环境之间存在复杂的多重反馈作用机制,现代荒漠化过程是人类活动不当造成的。本文对现代荒漠化过程中人为影响的系统分析表明：现代荒漠化过程中,各指标的变化速率不是一成不变的,而具有明显的阶段性；将控制人口增长速度与增加农牧业生产的物质技术投入、提高农牧业生产的集约化水平结合在一起,实行综合治理,是防治荒漠化的重要措施。     

西藏中部巴木错湖泊面积变化及其原因分析

受气候变化影响,西藏中部内陆湖泊在最近10 a来出现了水位上涨、湖面扩大等情况。采用遥感技术及统计学方法分析了西藏中部巴木错湖泊面积年内、年际变化及其原因。结果表明:①湖泊周边班戈站的年降水量、年平均气温、年平均地温以及年平均相对湿度等呈现增加趋势,年平均风速显现下降趋势;②2009年的面积在2月、5月和8月出现了三个"峰值",主要与湖面封冻、气温升高及降水增加等有关,年际变化呈逐步增加趋势;③经线性相关、多元回归等分析发现,年内变化受各月面降水量AP、蒸发量E和气温T的影响,合计贡献率为90.0%,排序为AP>E>T;年际变化受年平均风速SWS、7月降水量P7、平均地温ST和气温T的影响,合计贡献率为65.2%,排序为SWS>P7>ST>T。