BALB／C鼠睾丸组织中冷诱导RNA结合蛋白的cDNA克隆与序列分析

冷诱导RNA结合蛋白(Cold inducible RNA-binding protein,CIRP)在多种冷应激细胞(包括重组中国仓鼠卵巢细胞)中被发现.迄今为止,冷应激对活体生物基凶表达的影响还未见报道.和细胞相比,生物体具有更加复杂的冷应激调节机制.本研究以冷处理的BALB/C鼠为实验动物,从其睾丸组织巾克隆出了CIRP的cDNA.结果表明,CIRP在生物体中能够被低温诱导,可能防止生物体遭受冷损伤.根据克隆的cDNA所推测的氨基酸序列与GenBank上公布的小鼠、大鼠、人类、牛蛙、美西螈、非洲爪蟾胚胎细胞和卵母细胞的CIRP氨基酸序列同源性分别为100%、99.40%、95.5%、67.4%、58.4%、76.9%和79.1%.这表明CIRP在生物进化过程中是高度保守的,可能具有多种生理功能.因此,这一研究将为探索人类和动物冷应激分子机制创立系统试验模型和奠定新的实践基础.图5参14     

检验用起重机供电电源断错相自动切换装置的设计

起重机供电电源断错相保护功能的常规检验方法较为烦琐,有时还可能影响检验结果的正确判断.设计一种供电电源断错相自动切换装置用于断错相保护功能的检验,以降低劳动强度、提高检验效率,并有效保证检验结论的正确性.     

不同冬夏寄主棉蚜种群重复序列引物DNA多态性分析

应用重复序列引物ＰＣＲ技术研究了中国不同冬夏寄主上棉蚜种群的ＤＮＡ多态性,通过筛选出的３种适用于棉蚜的重复序列引物,用它们的扩增结果进行相似性指数Ｉｓ和Ｎｅｉ’ｓ遗传距离Ｄ的计算,并根据遗传距离对所研究的棉蚜种群做聚类分析,结果表明,用遗传距离指标可以将冬夏寄主上的棉蚜分开,并且在不同的冬寄主之间,较适宜越冬的不同寄主上的棉蚜呈现出更大的相似性。在实验数据的分析过程中,还发现遗传距离指标比相似性指     

应用Tail-PCR扩增蓝猪耳T-DNA侧翼序列

蓝猪耳是一种重要的具有观赏和科研价值的花卉植物.采用TAIL-PCR成功扩增了转基因蓝猪耳T-DNA插入位点的侧翼序列,扩增片断长度为200～2 000 bp,大多数片段在400 bp和800 bp左右,其中36%的序列含有植物的同源序列.通过与GenBank数据库比对,确定了部分T-DNA插入位点周边序列编码的可能蛋白,并提交序列7条;另外还对T-DNA转化植物时整合的位点进行了分析,发现断裂位点集中在距右边界15～18 bD和右边界外234 bp处,分别占总扩增片段的47.62%和38.10%.这为利用T-DNA标签进行蓝猪耳基因克隆和功能分析提供了实验技术上的保证.图2表2参24     

A novel Dempster-Shafer theory-based approach with weighted average for failure mode and effects analysis under uncertainty

Risk priority number (RPN) is a commonly-used prioritization method in failure mode and effects analysis (FMEA) for systemic reliability and safety study. However, conventional RPN confronts wide criticisms, due to the neglect of the uncertainties of experts' opinions. It is important to handle the conflicts among experts' multi-opinions which could be described in imprecise, incomplete or crisp forms in lack of knowledge. In this paper, a novel method is proposed to alleviate and/or eliminate counter-intuitive behaviors against conflicts among multi-opinions under Dempster-Shafer theory. Firstly, the abnormity test for experts’ opinions is undertaken to identify and discard those distinct judgments. Then, an approach to determining the subjective weights of experts is proposed, which is used in weighted average for multi-opinions before calculating RPNs. Finally, the risk priority evaluation on main engine crankcase explosion failure on-board ship is implemented to verify the feasibility of the proposed approach.     

Dynamic accident modeling for high-sulfur natural gas gathering station

Dynamic accident modeling for a gas gathering station is implemented to prevent high-sulfur natural gas leakage and develop equipment inspection strategy. The progress of abnormal event occurring in the gas gathering station is modeled by the combination of fault tree and event sequence diagram, based on accident causal chain theory, i.e. the progress is depicted as sequential failure of safety barriers, then, the occurrence probability of the consequence of abnormal event is predicted. Consequences of abnormal events are divided into accidents and accident precursors which include incidents, near misses and so on. The Bayesian theory updates failure probability of safety barrier when a new observation (i.e. accident precursors or accidents data) arrives. Bayesian network then correspondingly updates failure probabilities of basic events of the safety barriers with the ability of abductive reasoning. Consequence occurrence probability is also updated. The results show that occurrence probability trend of different consequences and failure probability trend of safety barriers and basic events of the safety barriers can be obtained using this method. In addition, the critical basic events which play an important role in accidents occurrence are also identified. All of these provide useful information for the maintenance and inspection of the gas gathering station.     

北京市地下水中高危害污染物筛选

地下水污染物对用水安全和人民健康造成了巨大的威胁.为开展地下水中高危害污染物筛选,改进了传统的危害评价方法,构建了涵盖毒理学优先指数法（Tox Pi）,吸收、分布、代谢、排泄（ADME）性质评估法和二模网络分析法的污染物危害评估-筛选-表征综合体系,针对北京市地下水中非靶检测到的234种疏水性有机污染物（HOCs）开展危害评估和毒害污染物筛选.利用Tox Pi方法筛选出危害潜力排名前20的污染物,在此基础上耦合其ADME性质进一步识别出17种高优先级HOCs,并通过二模网络分析,系统表征了这17种高优先级HOCs作用的基因分子靶点,通过关联性和加权平均度分析最终得到10种高危害的HOCs,并揭示其毒作用类型多集中于内分泌干扰效应、致癌效应以及遗传毒性.研究结果可为我国区域地下水污染物的防治提供技术支撑.     

高压输电线路并列架设空间工频电场研究

利用等效电荷法计算多线路并列架设空间工频电场。结果表明,并列架设输电线路之间的工频电场会出现不同程度的叠加或削减,进而影响线路下方工频电场的强度和变化趋势。提出了多线路并列架设的线路空间布置建议,为输电线路环境影响评价模拟类比线路选取提供参考。     

Differences in soil nitrification and denitrification capacities following reclamation years of native desert soils to irrigated croplands in Hexi Corridor Region of Northwest China北大核心CSCD

Nitrogen (N) loss in irrigated croplands from coupled nitrification and denitrification shows considerable differences due to differences in soil properties and agricultural management practices. Previous research has demonstrated that soil physicochemical properties strongly affect nitrification and denitrification capacities of cropland soils. However, existing research on soil nitrification and denitrification following the conversion of native desert soils to irrigated croplands lacks long-term tracking and monitoring capabilities. Therefore, six types of reclamation years of irrigated croplands and uncultivated sandy land in the Hexi Corridor marginal oasis in northwestern China were selected for study, and the differences in soil nitrification and denitrification rates and physicochemical properties were studied over 42 sites in the desert-oasis ecotone derived from seven reclamation sequences, including the years of 0, 15, 30, 50, 80, 100, and 150. The results showed that the nitrification and denitrification rates of soil first increased and then decreased with the increase in reclamation years. The highest soil nitrification rate and denitrification rate were observed at 80 years of cultivation (101.4 μg g-1 d-1) and 100 years of cultivation (0.93 μg g-1 d-1), respectively. In addition, the soil nitrification and denitrification rates in the natural sandy land were significantly lower than those in the cultivated croplands (P < 0.05). There were significant correlations among soil nutrients, soil moisture, and soil particle size composition between the nitrification and denitrification rates (P < 0.05). Regression analysis showed that environmental variables accounted for 69.7% and 75.7% of the variation in nitrification and denitrification rates, respectively. Among them, organic matter content, pH, soil moisture, and NH4+-N content were the key factors affecting the change in soil denitrification rate, while organic matter content, NO3--N, pH, and clay content were the key factors affecting the change in soil denitrification rate. © 2022 Science Press. All rights reserved.     

Priorities for global felid conservation

Conservation resources are limited, necessitating prioritization of species and locations for action. Most prioritization approaches are based solely on biologically relevant characteristics of taxa or areas and ignore geopolitical realities. Doing so risks a poor return on conservation investment due to nonbiological factors, such as economic or political instability. We considered felids, a taxon which attracts intense conservation attention, to demonstrate a new approach that incorporates both intrinsic species traits and geopolitical characteristics of countries. We developed conservation priority scores for wild felids based on their International Union for Conservation of Nature status, body mass, habitat, range within protected area, evolutionary distinctiveness, and conservation umbrella potential. We used published data on governance, economics and welfare, human population pressures, and conservation policy to assign conservation‐likelihood scores to 142 felid‐hosting countries. We identified 71 countries as high priorities (above median) for felid conservation. These countries collectively encompassed all 36 felid species and supported an average of 96% of each species’ range. Of these countries, 60.6% had below‐average conservation‐likelihood scores, which indicated these countries are relatively risky conservation investments. Governance was the most common factor limiting conservation likelihood. It was the major contributor to below‐median likelihood scores for 62.5% of the 32 felid species occurring in lower‐likelihood countries. Governance was followed by economics for which scores were below median for 25% of these species. An average of 58% of species’ ranges occurred in 43 higher‐priority lower‐likelihood countries. Human population pressure was second to governance as a limiting factor when accounting for percentage of species’ ranges in each country. As conservation likelihood decreases, it will be increasingly important to identify relevant geopolitical limitations and tailor conservation strategies accordingly. Our analysis provides an objective framework for biodiversity conservation action planning. Our results highlight not only which species most urgently require conservation action and which countries should be prioritized for such action, but also the diverse constraints which must be overcome to maximize long‐term success.