重组包涵体蛋白质的折叠复性

综述了减少包涵体形成、包涵体分离和溶解以及包涵体折叠复性的策略及其最新进展 .详细讨论了包涵体蛋白质折叠复性的基本原则、包涵体折叠复性促进剂和包涵体折叠复性方法     

富脯氨酸模体研究进展

综述了近年来富脯氨酸模体的研究进展状况,并将其分为PxxP核心序列模体、聚脯氨酸模体、PPxY核心序列模体以及其他类型的模体4类,论述了富脯氨酸膜体的生物学功能及其常出现的原因.     

微体的概念及其发展

微体是一种细胞器,其种类主要包括过氧化物酶体、糖酵解酶体和乙醛酸循环体。本文主要介绍了微体的概念及其发展,乙醛酸循环体和过氧化物酶体之间的关系,过氧化物酶体、糖酵解酶体和乙醛酸循环体的功能。     

中国秀体溞属常见种类记述

秀体溞是枝角类中重要的属,其分类一直存在较大分歧。目前我国秀体溞属有10个种,即短尾秀体溞Diaphanosoma brachyurum Liévin,1848、兴凯秀体溞D.chankensis Ueno,1939、奥氏秀体溞D.orghidani Negrea,1982、模糊秀体溞D.dubium Manujlova,1964、杜蒙特秀体溞D.dumonti Korovchinsky,1996、镰角秀体溞D.excisum Sars,1885、蒙古秀体溞D.mongolianum Ueno,1938、多刺秀体溞D.sarsi Richard,1894、大眼秀体溞D.macrophtalma Korovchinsky & Mirabdullaev,1995、热带秀体溞D.tropicum Korovchinsky,1998。在综合现有文献和研究模式标本的基础上,建立了上述10个种的分类检索表,并对我国最为常见的4个种:短尾秀体溞D.brachyurum Lievin,1848、奥氏秀体溞D.orghidani Negrea,1982、模糊秀体溞D.dubium Manujlova,1964、镰角秀体溞D.excisum Sars,1885的形态特征和地理分布进行了详细描述。分析了目前我国与国际在秀体溞分类上的一些异同,讨论了我国秀体溞分类中存在的同名异种或同种异名的问题。     

植物油体在生物技术中的应用研究进展

油体是植物种子尤其是油料植物种子的重要贮脂细胞器,具有较强的物化稳定性,而且易于通过离心法分离提取。研究表明,油体是由外层的磷脂和油体结合蛋白以及包裹在内部的液态基质（主要为三酰甘油）形成的弹性球体或椭球体。目前,在植物中共发现三类油体结合蛋白,它们主要存在于油体表面。鉴于油体和油体结合蛋白的结构特殊性,二者在生物技术领域得到了广泛应用。本文重点综述了油体在表达纯化外源蛋白方面的优势、策略以及在生产药用蛋白、制备固定化酶、捕捉抗体和药用酶、生产营养素和提高植物抗性等多个领域的研究进展,并介绍了人工油体和油体乳化剂方面的开发应用情况。     

经营强度对毛竹林土壤团聚体稳定性和碳氮磷分布的影响

土壤团聚体是土壤有机质分解、腐殖质形成的主要场所，不同粒径团聚体的组成特征可以衡量土壤肥力状况。为了探明经营强度(施肥、垦复频次)对毛竹林土壤团聚体的影响，以粗放经营毛竹林为对照，以中强度(每4年施肥、垦复一次)和高强度(每2年施肥、垦复一次)集约经营毛竹林为对象，利用干筛和湿筛结合的方法分离毛竹林0～10、10～20和20～30 cm土层土壤水稳性团聚体，分析不同土层中各粒径团聚体有机碳、全氮和有效磷的分布情况。结果表明：经营强度对毛竹林土壤团聚体组成、稳定性以及有机碳、全氮、有效磷含量有显著影响。与对照相比，中、高强度集约经营降低了0～10 cm土层土壤大团聚体比例和团聚体稳定性，增加了20～30 cm土层土壤大团聚体比例和团聚体稳定性，减少了大团聚体有机碳含量以及微团聚体有机碳、全氮和有效磷含量，说明中、高强度经营不利于0～10 cm土层土壤大团聚体的形成和大团聚体对碳的固存，减少人为干扰有利于土壤团聚体对有机碳的积累以及微团聚体对氮、磷的积累。大团聚体质量分数和大团聚体有机碳含量与团聚体稳定性均呈显著正相关，且二者对团聚体稳定性的影响解释最强，因此，大团聚体和大团聚体有机碳含量...     

淀粉体发育过程中淀粉核心、晶体结构与淀粉体DNA的关系

在马铃薯块茎、百合鳞茎淀粉体DNA的研究中,使用了3种DNA染色方法,都比较一致地反映了淀粉体DNA的分布和形态。又系统观察了在不同发育时期淀粉体及淀粉体DNA的变化,揭示了淀粉体DNA与淀粉核心、晶体结构的关系。实验证明,淀粉核心是淀粉体DNA最先出现的地方。DNA复制形成了晶体结构(晶体核)以及辐射状的晶体结构,这是淀粉体DNA随着发育时期的增长而不断复制的结果。     

普通小麦减数分裂中单价体的错分裂

本文综述了有关普通小麦减数分裂中单价体错分裂的研究工作,其中包括研究单价体错分裂的意义、单价体错分裂发生的时期、位置、方式以及错分裂发生的原因,单价体错分裂的研究方法及单价体错分裂研究的现状。     

大肠杆菌中重组蛋白包含体的形成机制及其影响因素

本文介绍了近年有关重组蛋白包含体形成机制的研究进展,探讨了蛋白性质、温度、分子伴随物等因素对包含体形成的影响,从蛋白折迭的角度对包含体这一现象进行了分析,从而为控制外源基因表达产物形成包含体提供理论指导。     

水稻花粉植株非整倍体的细胞遗传学

在290棵水稻花粉植株中获得水稻非整倍体植株,频率为10.7％。其中初级三体为6.7％,四体为1.7％,单体为1.3％,缺体为1.0％;双三体为0.7％。额外染色体粗线期分析表明,19个初级三体分别归属于三体3,三体4,三体8,三体10和三体12。粗线期分析还鉴定了四体、双三体、缺体和单体的染色体组成。花粉母细胞减数分裂的染色体行为表明,非整倍体花粉植株的主要染色体畸变为粗线期的疏松配对、单价体;终变期的单价体和四价环;中期Ⅰ的染色体拖曳及四价体;后期Ⅰ的染色体桥和落后染色体。     

一品红试管苗移栽驯化期叶片的解剖结构变化

对一品红试管苗移栽驯化,同时研究了驯化过程中叶片结构的变化,结果表明,一品红在珍珠岩基质中成活率达98%,随着移栽时间的延长,表皮细胞增大,排列紧密;叶肉细胞间隙减小,栅栏组织细胞长度增加,主脉增厚,导管数目增加,保水,输水和抗逆能力增强。     

The characterization and ultrastructure of two new strains of Butyrivibrio

Strains B-385-1 and 2-33 are numerically important components rumen bacterial populations , but they have remained (taxonomically) undefined. In spite of some resemblance to Selenomonas ruminantium in their cell size and in their formation of tufts of flagella, they more closely resemble Butyrivibrio fibrisolvens in the subpolar location of their flagella, in their guanine + cytosine content, and in most biochemical characteristics, including butyrate formation. Cells of these strains stain Gram negative, as do both Selenomonas and Butyrivibrio, but their cell walls closely resemble those of Butyrivibrio in their Gram-positive type of molecular architecture and in their cleavage pattern in freeze-etching. Cells of these strains and of B. fibrisolvens have a very thin (ca. 12 nm) peptidoglycan cell wall; thus, they fail to retain the crystal violet complex of the Gram stain and stain Gram negative. This important structural characteristic of their cell walls places strains B-385-1 and 2-33 within the genus Butyrivibrio and certain morphological and biochemical characteristics distinguish them from B. fibrisolvens.     

Function and structure of inherently disordered proteins

The application of bioinformatics methodologies to proteins inherently lacking 3D structure has brought increased attention to these macromolecules. Here topics concerning these proteins are discussed, including their prediction from amino acid sequence, their enrichment in eukaryotes compared to prokaryotes, their more rapid evolution compared to structured proteins, their organization into specific groups, their structural preferences, their half-lives in cells, their contributions to signaling diversity (via high contents of multiple-partner binding sites, post-translational modifications, and alternative splicing), their distinct functional repertoire compared to that of structured proteins, and their involvement in diseases.     

Glycosyltransferases: managers of small molecules

Studies of the glycosyltransferases (GTs) of small molecules have greatly increased in recent years as new approaches have been used to identify their genes and characterize their catalytic activities. These enzymes recognize diverse acceptors, including plant metabolites, phytotoxins and xenobiotics. Glycosylation alters the hydrophilicity of the acceptors, their stability and chemical properties, their subcellular localisation and often their bioactivity. Considerable progress has been made in understanding the role of GTs in the plant and the utility of GTs as biocatalysts, the latter arising from their regio- and enantioselectivity and their ability to recognize substrates that are not limited to plant metabolites.     

The Color of My Skin: A Measure to Assess Children's Perceptions of Their Skin Color

The Color of My Skin is an instrument developed to assess children's internalized idea (abstraction) of the color of their skin; their satisfaction with that color; the desire, if any, to change the color of their skin; and their affect regarding their skin color. The assessment is part of a questionnaire utilized in a 3-year longitudinal study that examines psychosocial development, physical health, and behavioral adjustment of Puerto Rican children (N = 257) reared in the Greater Boston area. The results demonstrate that children's internalized representation of their skin color is a construct that can be reliably and validly measured. The children's ratings of their skin color were not associated with their sex, school grade, ethnic identity, the child's or the parent's nativity, or the racial or ethnic compositions of 3 social contexts: their neighborhood, their classmates, and their closest friends. Puerto Rican children did not show a preference for light-colored skin. Moreover, there were no significant differences in self-esteem based on the child's self-reported skin color. The lack of association between self-esteem and skin color was interpreted in light of a developmental tendency prevalent in early to middle childhood to place a positive value on different aspects of one's self. Whereas almost all children (96%) reported being happy or very happy with their color, 16% of the children would like to change their skin color if they could (51% to a lighter and 46% to a darker color).     

Biotechnological potential of pectinolytic complexes of fungi

Plant cell wall-degrading enzymes, such as cellulases, hemicellulases and pectinases, have been extensively studied because of their well documented biotechnological potential, mainly in the food industry. In particular, lytic enzymes from filamentous fungi have been the subject of a vast number of studies due both to their advantages as models for enzyme production and their characteristics. The demand for such enzymes is rapidly increasing, as are the efforts to improve their production and to implement their use in several industrial processes, with the goal of making them more efficient and environment-friendly. The present review focuses mainly on pectinolytic enzymes of filamentous fungi, which are responsible for degradation of pectin, one of the major components of the plant cell wall. Also discussed are the past and current strategies for the production of cell wall-degrading enzymes and their present applications in a number of biotechnological areas.     

猕猴桃茎尖超低温保存过程中超微结构观察

应用透射电镜观察了猕猴桃组培苗茎尖细胞在玻璃化法超低温保存过程中的超微结构变化.研究发现:在预培养、PVS2脱水处理过程中,茎尖细胞内液泡逐渐变多、变小,质壁分离愈加显著,表明细胞的抗冻力增强;在随后的冷冻和解冻过程中,部分细胞的质壁分离更加严重,细胞壁与细胞膜之间出现液腔,细胞器变得模糊,有些细胞的细胞膜、甚至细胞壁撕裂,细胞腔内留下破碎的细胞膜和细胞残片,细胞结构破坏严重,这可能是导致材料在恢复培养中死亡的原因之一;部分细胞经过7d的恢复培养后,细胞器清晰,细胞膜完好并紧贴细胞壁,细胞中央出现较大的液胞,具有与对照相似的结构特征,最终存活下来并能够再生植株.     

Impacts of Encouraging Dog Walking on Returns of Newly Adopted Dogs to a Shelter

This study involved examining the ability of a postadoption intervention to reduce returns of newly adopted dogs to shelters by encouraging physical activity between adopters and their dogs. Guardians in the intervention group received emails with dog behavior and human activity advice as well as invitations to join weekly dog walks. Both the intervention and control groups completed surveys regarding outdoor activity with their dogs, their dog-walking habits, and perceptions of their dogs’ behaviors. Adopter–dog pairs in the intervention group were not significantly more active than those in the control group, nor did they show a reduced incidence of returning their dogs. Guardians in both groups who reported higher obligation and self-efficacy in their dog walking were more active regardless of experimental condition; however, obligation, dog-walking self-efficacy, and perceptions about their dogs’ on-leash behaviors did not predict rates of return to the shelter. These findings add to the understanding of shelter dog re-relinquishment and the effective utilization of resources postadoption, and they indicate further research is needed to address the complexities of this newly forming human–dog relationship.     

Plastic Repair Following the Removal of Large Desmoid Tumors of the Abdominal Wall

The case records of 100 patients over the age of 60 at the time of their admission to a state mental hospital in California were evaluated, using rigid criteria to determine whether the precipitating cause for their state hospitalization was due to a deterioration of their mental state or a change in their socio-environmental milieu. The results of the study indicated that 77 per cent of these patients were in hospital because of a deterioration in their own mental state while 23 per cent were there because of a deterioration in their socio-environmental milieu. The data also were indicative that the proportion of patients put in hospital because of a deterioration in their socio-environmental milieu might conceivably be higher than 23 per cent if subtle changes in family attitude towards the patient could be adequately evaluated.     

Principles of the therapeutic use of monoclonal antibodies in oncology

Monoclonal antibodies have reached the stage of therapeutic agents, mostly in oncology, as illustrated by their wide use in lymphoma, breast cancer or colorectal cancer. The unravelling of their mechanisms of action and their interactions with their cellular receptors allows us to engineer new classes of therapeutic antibodies with increased efficacy. The identification of some of the tumour escape mechanisms may also help to define new approaches for patient selection and immunomonitoring. The present review addresses these various aspects.