The profound effects of microcystin on cardiac antioxidant enzymes, mitochondrial function and cardiac toxicity in rat

Deaths from microcystin toxication have widely been attributed to hypovolemic shock due to hepatic interstitial hemorrhage, while some recent studies suggest that cardiogenic complication is also involved. So far, information on cardiotoxic effects of MC has been rare and the underlying mechanism is still puzzling. The present study examined toxic effects of microcystins on heart muscle of rats intravenously injected with extracted MC at two doses, 0.16LD(50) (14 mu g MC-LReq kg(-1) body weight) and 1LD(50) (87 mu g MC-LReq kg(-1) body weight). In the dead rats, both TTC staining and maximum elevations of troponin I levels confirmed myocardial infarction after MC exposure, besides a serious interstitial hemorrhage in liver. In the 1LD(50) dose group, the coincident falls in heart rate and blood pressure were related to mitochondria dysfunction in heart, while increases in creatine kinase and troponin I levels indicated cardiac cell injury. The corresponding pathological alterations were mainly characterized as loss of adherence between cardiac myocytes and swollen or ruptured mitochondria at the ultrastructural level. MC administration at a dose of 1LD(50) not only enhanced activities and up-regulated mRNA transcription levels of antioxidant enzymes, but also increased GSH content. At both doses, level of lipid peroxides increased obviously, suggesting serious oxidative stress in mitochondria. Simultaneously. complex I and III were significantly inhibited, indicating blocks in electron flow along the mitochondrial respiratory chain in heart. In conclusion, the findings of this study implicate a role for MC-induced cardiotoxicity as a potential factor that should be considered when evaluating the mechanisms of death associated with microcystin intoxication in Brazil. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

新型渗透变形仪的研制

针对现有渗透变形仪存在的密封止水效果差、试样固定装置影响过流面积、仪器复杂等缺陷,通过对岩土渗透变形特性及测试原理进行分析,研制出一种适用于黏性土、水泥土类的新型渗透变形仪,该仪器设计方法独特,在试样外套橡皮膜并加围压的柔性密封止水,以及在试样顶部采用圆环型透水石固定试样等方法,既能测定岩土体的渗透系数又能测定渗透变形特性,同时,既保证试样的渗流面积不受影响又允许试样产生渗透变形,而且在渗透水压力作用下试样周围的密封性良好。实际工程应用结果表明,该仪器测定的岩土体的渗透系数及抗渗比降具有很高的可靠性和精度。

复杂断块油藏形成机制及剩余油预测

The central uplift in the Huimin depression is famous for its large amounts of faults and small-scale fault-block area, and it is the famed typical complicated fault-block group oil & gas field in the whole world. After many years of rolling exploration and exploitation, many complex oil &gas field have been discovered in the central uplift, and won the splendent fruit. With the gradual deepening and development of the rolling exploitation, the exploration faces more and more difficulties. Therefore, it is important to reveal the forming mechanism and distributing rule of the complex fault-block reservoir, and to realize the forecast of the complex fault-block reservoir, sequentially, expedite the exploration step. This article applies the new multi-subject theory, method and technique such as structure geometry, kinematics, dynamics, structural stress field, fluid potential field, well logging record and constrained inversion of seismic records, coherence analysis, the seal mold and seal history of oil-bounded fault etc, and try to reveal the forming mechanism and distributing law of the complex fault-block reservoir, in result, implements the forecast of the fault-block reservoir and the remaining oil distributing. In order to do so, this article synthetically carries out structural estimate, reservoir estimate, fault sealing history estimate, oil-bearing properties estimate and residual. This article also synthetically researches, describes and forecast the complex fault-block in Huimin depression by use of the techniques, e.g. seismetic data post-stack processing technique, multi-component demarcating technique, elaborate description technique for the fault-block structure, technique of layer forecasting, fault sealing analysis technique, comprehensive estimate technique of fault-block, comprehensive analysis and estimate technique of remaining oil etc. The activities of the faults varies dramatically in the Huimin depression, and most of the second-class and the third-class faults are contemporaneous faults, which control the macroscopical distribution of the reservoir in the Huimin depression. The fourth-class faults cause the complication between the oil & gas among the fault-blocks. The multi-period strong activities of the Linyi fracture resulted in the vertical migration of large amount of oil & gas along with the faults. This is the main reason for the long vertical distribution properties near the Linyi fracture in the Huimin depression. The sealing ability of the fault is controlled by the property,size and direction of the main stress, the contact relationship of the both sides of the fault, the shale polluting factor, and the configuration relationship between the fault move period and the migration period of oil & gas. The article suggest four fault-sealing modes in the research zone for the first time, which establishes the foundation for the further forecast of the complex fault-block reservoir. Numerical simulation of the structural stress field reveals the distribution law and the evolvement progress of the three-period stress field from the end of the Dongying period to the Guantao period to nowadays. This article puts forward that the Linyi and Shanghe regions are the low value of the maximum main stress data. This is combined with the fault sealing history estimate, then multi-forming-reservoir in the central uplift is put forward. In the Shanghe oilfield, the article establishes six reservoir geological modes and three remaining oil distributing modes(the plane, the inside layer and the interlayer), then puts forward six increase production measure to enhance the remaining oil recovery ratio. Inducting the exploitation of oilfield, it wins notable economic effects and social effects.

同事关系质量及其作用机制

Although the research into coworker relationship quality has been recognized one of key factors related to organization performance, and has been thought a new trend in organization behavior research with the flatting of organization structure and complication of task assignment, there is relatively little empirical research on the mechanism between coworkers’ interaction, contraring to the fruitful results on member exchange research based on social network theory, say nothing of the influence of cultural differences such as GUANXI. This research developed the scale for the assessment of Coworker Relationship Quality by literature review, deep interview, and questionnaires, compared the predictable ability of Coworker Relationship Quality (CRQ) scale and Coworker Exchange (CWX) scale on employees’ work attitudes and behaviors. Finally, the mediating effect of Coworker Relationship Quality between employees’ similarities on personality and their work attitudes and behaviors was investigated. Following are main results. Firstly, we found that the interpersonal communication, trust, and mutual support are the key factors of coworker relationship quality, which is similar to the result getting from western samples. But Chinese people are more GUANXI ORIENTATION, means they want to build longtime relationship with others, not only when they are coworkers, but also when one of them left the organization. Secondly, though the core meaning of CRQ and CWX are same, their predictable ability on organization outcomes is different. CRQ is more powerful than CWX, especially on turnover intention. The result showed that after controlling the effect of demographic variables and CRQ, CWX cannot predict turnover intention significantly, but CRQ can still predict turnover intention significantly after controlling demographic variables and CWX. Thirdly, the partial mediating effect of CRQ between positive affectivity similarity and organizational citizenship behavior, coworker satisfaction, organizational commitment and turnover intention are validated, but we did not find the mediating effect of CRQ between demographic variable similarity and workers’ attitudes and behaviors. The Similarity Attraction Paradigm, Social Identity Theory, and Self Category Theory were supported.