Damage of hippocampal neurons in rats with chronic alcoholism

Chronic alcoholism can damage the cytoskeleton and aggravate neurological deficits. However, the effect of chronic alcoholism on hippocampal neurons remains unclear. In this study, a model of chronic alcoholism was established in rats that were fed with 6% alcohol for 42 days. Endogenous hydrogen sulfide content and cystathionine-beta-synthase activity in the hippocampus of rats with chronic alcoholism were significantly increased, while F-actin expression was decreased. Hippocampal neurons in rats with chronic alcoholism appeared to have a fuzzy nuclear mem- brane, mitochondrial edema, and ruptured mitochondrial crista. These findings suggest that chronic alcoholism can cause learning and memory decline in rats, which may be associated with the hydrogen sulfide/cystathionine-beta-synthase system, mitochondrial damage and reduced expression of F-actin.

宝天曼国家级自然保护区蚯蚓物种多样性及其影响因素

宝天曼国家级自然保护区独特的地理位置和气候条件使其成为生物多样性研究热点地区之一,但关于该地区蚯蚓物种多样性的研究却十分匮乏。本研究在系统调查宝天曼国家级自然保护区蚯蚓物种的基础上,联合5个线粒体基因(COI、COII、ND1、12S、16S)构建蚯蚓系统发育树,并结合海拔、土壤、凋落物质量等环境因素建立结构方程模型,初步探讨了宝天曼蚯蚓多样性形成的主要影响因素。研究结果表明:(1)宝天曼国家级自然保护区共记录到蚯蚓3科5属14种,多为广布种,其中巨蚓科为优势科;(2)蚯蚓物种数随海拔升高而增加,但500–1,000 m海拔段的蚯蚓α多样性更高,分布也更均匀,符合中间高度膨胀格局;(3)在局域尺度上,海拔高度对蚯蚓物种多样性和系统发育多样性的影响较大,其次为土壤性质和凋落物质量。宝天曼国家级自然保护区蚯蚓物种组成及多样性成因的研究丰富了我国蚯蚓物种库和基因库。

Influence evaluation of loading conditions during pressurized thermal shock transients based on thermal-hydraulics and structural analyses

The thermal hydraulic （TH） behavior of coo- lant water is a key factor in the structural integrity assessments on reactor pressure vessels （RPVs） of pressurized water reactors （PWRs） under pressurized thermal shock （PTS） events, because the TH behavior may affect the loading conditions in the assessment. From the viewpoint of TH behavior, configuration of plant equipment and their dimensions, and operator action time considerably influence various parameters, such as the temperature and flow rate of coolant water and inner pressure. In this study, to investigate the influence of the operator action time on TH behavior during a PTS event, we developed an analysis model for a typical Japanese PWR plant, including the RPV and the main components of both primary and secondary systems, and performed TH analyses by using a system analysis code called RELAP5. We applied two different operator action times based on the Japanese and the United States （US） rules： Operators may act after 10 min （Japanese rules） and 30 min （the US rules） after the occurrence of PTS events. Based on the results of TH analysis with different operator action times, we also performed structural analyses for evaluating thermal-stress distributions in the RPV during PTS events as loading conditions in the structural integrity assessment. From the analysis results, it was clarified that differences in operator action times significantly affect TH behavior and loading conditions, as the Japanese rule may lead to lower stresses than that under the US rule because an earlier operator action caused lower pressure in the RPV.

Effect of arsenite on the proteome of earthworms Eisenia fetida

Arsenic(As)is broadly distributed due to natural and anthropogenic sources,and it is toxic to organisms.This study aimed to investigate the proteomic response in earthworm exposed to As^(3+).Earthworms were exposed to As^(3+)in soil at 5-80 mg kg1,and samples were collected after 60 days exposure.Two-dimensional electrophoresis(2-DE)was used to separate the proteins in earthworm homogenate,then differentially expressed proteins(DEPs)were identified using MALDI-TOF/TOF-MS analysis.After 2-DE,36 DEPs were found and 24 of them were successfully identified.79.2%of DEPs were upregulated compared to the control group.The maximum fold change reached 53.8 in spot 3108 in the 80 mg kg^(-1)As group.Two proteins were not found in the control group but found in the As treated groups.Proteins were grouped into metabolism,signal transduction,stress-related,transport,regulation,and predicted/hypothetical protein categories based on their function.The protein-protein interaction between the DEPs indicated that serum albumin(ALB)is very important,related to 6 other proteins.Proteins were then verified by western blot,the results were in agreement with the proteomic analyses.The identification of induced or repressed proteins because of As^(3+)in earthworms is helpful to explore the underlying mechanisms of soil arsenic ecotoxicity.

Earthworms in soil ecology and organic waste management

Earthworms are important members of the soil macrofauna.Since C.Darwin(1881)described the important function of earthworms in pedogenesis and in maintenance of soil fertility,there has been continual interest in studying earthworm biology and ecology.Most of the attention in such studies is on earthworm functions in soil nutrient recycling.However,with increasing concerns about the environment,studies using earthworms to mediate organic waste treatment and as an indicator of soil pollution and remediation strategies have grown rapidly in recent years.

Behavior and respiration responses of the earthworm Eisenia fetida to soil arsenite pollution

Soil arsenic(As)pollution from mining and industrial sources is a serious issue in China.Earthworms are considered ecosystem engineers and contribute to soil fertility development and maintenance of soil physico-chemical properties.In this study,earthworms were exposed to soils with different sodium arsenite concentrations(0,5,20,and 80 mg As kg^(-1))for 60 d to investigate the changes in soil properties and the responses of the earthworms(e.g.,burrowing activity and respiration).Earthworm burrowing activity decreased with increasing arsenite concentrations,and earthworm respiration was significantly lower in soils with 20 and 80 mg As kg^(-1) compared to 0 mg As kg^(-1).Changes in soil properties were also observed after incubation of As-amended soil with earthworms.Specifically,soil pH decreased,while soil electrical conductivity and contents of soil NH3--N,Olsen-P,and available K increased.Our results suggest that arsenite negatively impacts the metabolic activity of earthworms,leading to reduced burrowing activity,which in turn modifies the effects of earthworms on soil fertility and remediation.