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关键词： 博落回提取物   血根碱   生物学活性   动物生产应用  

摘要： 血根碱作为博落回提取物的主要活性成分,在抗炎、抑菌、抗肿瘤等方面具有多种药理作用,农业部也已经批准博落回提取物(血根碱为主要成分)作为二类新中兽药应用于动物生产。本文通过对血根碱在抗炎、抗氧化、肠道健康、抗肿瘤、抑菌等生物学活性及其机制和博落回提取物在动物生产中的应用情况进行综述,为博落回提取物在动物生产中应用提供一些理论参考。

关键词： 考试评价   生命观念   动物的主要类群  

摘要： 生命观念是学生在概念性知识学习的基础上对生命现象实证后的想法或观点，是生物学科核心素养中独具生物学特点的维度，是学科核心素养的标志和关键。初中学生在生物学学习过程中，形成的生命观念是学生到高中乃至终身的学习成果。生命观念的形成过程中需要众多基本事实和重要概念来支撑，因此，在考试评价中要尽量在真实的情境中作答，从理性思维和科学探究的层面进行总结和提炼，并从生命观念的高度加深对生命世界的理解和认识，从而真正促成学生从学会事实到学会学习的转变。这样的考试既能正确评价初中生物学的教与学情况，又能为发展学生的生物学核心素养这一生物学课程的根本目的服务，对当前的初中生物学教学起到很好的引领作用。

关键词： 哺乳动物雷帕霉素靶蛋白   摄食调控   脂质合成   蛋白质合成   作用机制  

摘要： 哺乳动物雷帕霉素靶蛋白(mTOR)是一种高度保守的蛋白激酶,在动物的摄食、脂质和蛋白质合成、细胞自噬和衰老等方面都发挥了重要的生理作用,已成为当前生物学研究的一大热点。本文就mTOR的结构、组织分布和生理功能及作用机制进行了综述,以期为研究mTOR信号通路的作用机制提供一定的参考。

关键词： Targeting   Genetics   Cells   Genomics   Electron correlation  

摘要： Next-generation DNA sequencing technologies have led to a massive accumulation of genomic and transcriptomic data from patients and healthy individuals. The major challenge ahead is to understand the functional significance of the elements of the human genome and transcriptome, and implications for diagnosis and treatment. Genetic screens in mammalian cells are a powerful approach to systematically elucidating gene function in health and disease states. In particular, recently developed CRISPR/Cas9-based screening approaches have enormous potential to uncover mechanisms and therapeutic strategies for human diseases. The focus of this review is the use of CRISPR interference (CRISPRi) and CRISPR activation (CRISPRa) for genetic screens in mammalian cells. We introduce the underlying technology and present different types of CRISPRi/a screens, including those based on cell survival/proliferation, sensitivity to drugs or toxins, fluorescent reporters, and single-cell transcriptomes. Combinatorial screens, in which large numbers of gene pairs are targeted to construct genetic interaction maps, reveal pathway relationships and protein complexes. We compare and contrast CRISPRi and CRISPRa with alternative technologies, including RNA interference (RNAi) and CRISPR nuclease-based screens. Finally, we highlight challenges and opportunities ahead.

关键词： Ediacara biota   Ediacaran-Cambrian transition   Biologic turnover   Disturbance   Ecosystem engineering   Shuram carbon isotope excursion  

摘要： The radiation of early animals involved dramatic turnover of both eukaryotic life and marine environments, but the factors that drove origination and extinction of taxa remain controversial. Herein, we review current interpretations and uncertainties regarding changes in biodiversity through the Ediacaran Period. Overall, ocean oxygenation and/or ecological restructuring of ecosystems may have driven biologic turnover over time. To explore these possibilities, we provide a conceptual model, rooted in ecological theory, which holistically describes biodiversity change in terms of environmental disturbance frequency/intensity and essential resource availability. In light of this framework, we evaluate two potential drivers of turnover: evolution of mobile animals and the Shuram negative carbon isotope excursion event. Early trace-making bilaterians-acting as a control on substrate stability and microbial release of dissolved organic carbon (DOC;an essential resource for osmotrophic organisms with nutrient-dependent growth) may have played key roles in both the diversification and disappearance of the Ediacara biota. We hypothesize that evolution of grazing bilaterians prior to 555 Ma caused perturbations in sediment stability and DOC concentrations, which limited competitive exclusion and allowed for diversification of Ediacara-type organisms, as exemplified by fossils in the taxonomically and ecologically rich localities of the White Sea assemblage. The 550 Ma advent of behaviors, which were capable of mixing sediments, may have subsequently pushed environmental disturbance and resource availability to critical levels that depleted biodiversity, manifested in the depauperate Nama assemblage, and ultimately drove the Ediacara biota to extinction. Concurrently, changes in global redox budgets, sea level, or oceanic DOC reservoir size during the Shuram event may have contributed to biologic turnover by causing environmental disturbances, promoting metapopulation fragmen

摘要： Ingestive behavior is controlled by multiple distinct peripheral and central physiological mechanisms that ultimately determine whether a particular food should be accepted or avoided. As rodents consume a fluid they display stereotyped rhythmic tongue movements, and by analyzing the temporal distribution of pauses of licking, it is possible through analyses of licking microstructure to uncover dissociable evaluative and motivational variables that contribute to ingestive behavior. The mean number of licks occurring within each burst of licking (burst and cluster size) reflects the palatability of the consumed solution, whereas the frequency of initiating novel bouts of licking behavior (burst and cluster number) is dependent upon the degree of gastrointestinal inhibition that accrues through continued fluid ingestion. This review describes the analysis of these measures within a context of the behavioral variables that come to influence the acceptance or avoidance of a fluid, and the neurobiological mechanisms that underlie alterations in the temporal distribution of pauses of licks. The application of these studies to models of obesity in animals is also described.

关键词： 动物福利   高中生物学   动物福利教育  

摘要： 近年来社会上一些虐待和残害动物的事件被陆续曝光,动物福利成为一个备受公众关注的话题,所以在201 6年最新修订的高中生物学课程标准中,选修模块新设动物福利模块,可见在高中生物学课程中开设动物福利教育具有一定的必要性。

关键词： 动物生物学实验   主体   实践  

摘要： 强调了动物生物学实验以学生为主体,对实验内容的讲授、实验的准备、实验的操作及评分系统等方面进行了初步探索和实践。整个教学过程以学生实践为中心,大力开发学生的创新思维,积极锻炼学生的胆识,努力提高学生的动手能力和团队协作能力,达到培养应用型人才的目的。

关键词： 动物医学   动物生物学   教学创新   实践教育  

摘要： 动物医学专业是一门综合性较强的课程,旨在将学生培养成为优秀的应用型人才。在动物医学专业教学过程中,要注重实践教育,将提高学生的综合能力水平当作教育的重点。本文对动物医学专业实践教育的相关策略进行分析与探讨,旨在提高该课程教学水平。

关键词： 丁酸钠   丁酸   肠道功能   肠道健康  

摘要： 丁酸钠是我国允许使用的饲料添加剂之一,目前已经广泛应用于畜牧养殖业中。丁酸钠可以在动物胃肠道内水解形成丁酸,丁酸不仅能为肠道上皮细胞提供能量,而且对刺激胃肠道细胞发育、修护受损肠道黏膜、改善肠道微生物菌群平衡以及增强肠道免疫能力等都有显著作用。研究就丁酸钠在动物肠道功能方面的作用进行综述。