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61.
H Takeuchi  I Yokoi  A Mori 《Experientia》1976,32(5):606-608
We examined effects of several vasoactive peptides (substance P, physalaemin, neurotensin, bradykinin, angiotensin etc.) on the excitability of molluscan giant neurones identified in the subesophageal ganglia of Achatina fulica Férussac. Of these peptides, only physalaemin showed a remarkable excitatory effect on a giant tonically autoactive neurone.  相似文献   
62.
研究了以兰113B-P204-煤油-H2SO4液膜体系从稀NiSO4溶液中分离回收镍的方法。实验结果表明液膜法除Ni2+在技术上是可行的。讨论了膜相组成、酸度、乳水比、油内比、搅拌转速及试剂比等因素对传质过程的影响。并考察了膜相的重复使用。  相似文献   
63.
大豆蛋白质的泡沫分离研究 I.操作工艺条件   总被引:1,自引:0,他引:1  
在一连续操作的泡沫精馏塔中,考察了各种操作条件对大豆蛋白质溶液泡沫分离过程的影响,包括:进料浓度、进气流量、pH值、回流比等,确定了较佳的操作条件。用流动法测定了大豆蛋白质在气液界面上的表面过剩浓度并回归了线性吸附方程。结果表明:在溶液浓度较稀时,表面过剩浓度与溶液浓度呈线性关系。  相似文献   
64.
本书是施普林格出版社2005年出版的一本关于螺旋压缩机的新著。螺旋式压缩机是一种最常见的用于压缩气体的机器,由于其构造简单、工作效率高而受到人们的关注。本书系统阐述了螺旋压缩机的种类、几何参数转子的设计工作原理和螺旋压缩机的计算。  相似文献   
65.
浅析市场经济条件下水资源管理的三大转变   总被引:1,自引:0,他引:1  
在市场经济条件下,水资源管理要实现三大转变:一是由传统防范和利用意识向市场资源型转变,建立起水的资源观、可持续利用观和价值观;二是由行政管水的运行机制向水市场体系转变,逐步建立起市场调节与政府调控相结合的新的管理机制;三是由政出多门的管理体制向水务一体化管理体制转变,建立起“统一、高效、负责”的水务一体化管理体制。  相似文献   
66.
水功能区的划分是实现水资源综合开发、合理利用、积极保护、科学管理的基础工作。根据“全国水功能区划技术细则”,结合对山西省黄河流域的自然、社会情况,尤其是水资源状况的综合分析,系统介绍了水功能区划的方法,对山西省黄河流域河流地表水进行了水功能区划并提出管理建议。  相似文献   
67.
催化动力学测定痕量钴研究综述   总被引:1,自引:0,他引:1  
综述了近年来催化动力学光度法测定痕量钴的进展情况。对催化显色动力学光度法、催化褪色动力学光度法、催化荧光光度法、阻抑动力学光度法、催化化学发光光度法等几个类别,从反应介质、灵敏度、线性范围等方面介绍了对不同反应体系的研究情况,并对催化动力学光度法测定痕量钴的发展趋势做出预测。  相似文献   
68.
This paper, which presents an annotated checklist of the ‘lower Nymphalidae’ (Libytheinae, Danainae, Satyrinae, Charaxinae), is the fourth in a series on the butterfly fauna of Mount Kilimanjaro. Four genera of lower Nymphalidae (Danaus, Amauris, Bicyclus, Charaxes), with a total of 11 included species, are known or believed to occur within the main forest zone, from c. 1800 to 2800 m. Of these, only three species of Charaxes (Charaxes berkeleyi, Charaxes ansorgei, Charaxes xiphares) may be restricted locally to this primary forest. The lower slopes fauna, below 1800 m, is considerably richer, with a total of 11 genera and 41 species listed (8 species of which extend into the forest zone). Possible additional species, dubious earlier records, problems with African subspecies of Danaus chrysippus, a need for more work on certain Satyrinae, and classification of the genus Charaxes are discussed. An identification key to the subfamilies of Nymphalidae, and the 19 genera of Libytheinae, Danainae, Satyrinae, Charaxinae that occur in Tanzania, together with a key to the adults of all the species of these four subfamilies considered to occur or have occurred on Kilimanjaro, with 206 colour images, are included as online Supplementary Information.  相似文献   
69.
Myostatin, a member of the transforming growth factor-β superfamily, is a potent negative regulator of skeletal muscle growth and is conserved in many species, from rodents to humans. Myostatin inactivation can induce skeletal muscle hypertrophy, while its overexpression or systemic administration causes muscle atrophy. As it represents a potential target for stimulating muscle growth and/or preventing muscle wasting, myostatin regulation and functions in the control of muscle mass have been extensively studied. A wealth of data strongly suggests that alterations in skeletal muscle mass are associated with dysregulation in myostatin expression. Moreover, myostatin plays a central role in integrating/mediating anabolic and catabolic responses. Myostatin negatively regulates the activity of the Akt pathway, which promotes protein synthesis, and increases the activity of the ubiquitin–proteasome system to induce atrophy. Several new studies have brought new information on how myostatin may affect both ribosomal biogenesis and translation efficiency of specific mRNA subclasses. In addition, although myostatin has been identified as a modulator of the major catabolic pathways, including the ubiquitin–proteasome and the autophagy–lysosome systems, the underlying mechanisms are only partially understood. The goal of this review is to highlight outstanding questions about myostatin-mediated regulation of the anabolic and catabolic signaling pathways in skeletal muscle. Particular emphasis has been placed on (1) the cross-regulation between myostatin, the growth-promoting pathways and the proteolytic systems; (2) how myostatin inhibition leads to muscle hypertrophy; and (3) the regulation of translation by myostatin.  相似文献   
70.
Brain-derived neurotrophic factor (BDNF) is a secreted protein of the neurotrophin family that regulates brain development, synaptogenesis, memory and learning, as well as development of peripheral organs, such as angiogenesis in the heart and postnatal growth and repair of skeletal muscle. However, while precise regulation of BDNF levels is an important determinant in defining the biological outcome, the role of microRNAs (miRs) in modulating BDNF expression has not been extensively analyzed. Using in silico approaches, reporter systems, and analysis of endogenous BDNF, we show that miR-1, miR-10b, miR-155, and miR-191 directly repress BDNF through binding to their predicted sites in BDNF 3′UTR. We find that the overexpression of miR-1 and miR-10b suppresses endogenous BDNF protein levels and that silencing endogenous miR-10b increases BDNF mRNA and protein levels. Furthermore, we show that miR-1/206 binding sites within BDNF 3′UTR are used in differentiated myotubes but not in undifferentiated myoblasts. Finally, our data from two cell lines suggest that endogenous miR-1/206 and miR-10 family miRs act cooperatively in suppressing BDNF through their predicted sites in BDNF 3′UTR. In conclusion, our results highlight miR-1, miR-10b, miR-155, and miR-191 as novel regulators of BDNF long and short 3′UTR isoforms, supporting future research in different physiological and pathological contexts.  相似文献   
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