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11.
应用红外热象技术测试舌面温度的研究   总被引:3,自引:0,他引:3  
应用红外热象技术研究健康人及几种典型病患者的舌面温度随年龄、性别、舌色的变化,介绍了健康人典型的舌热象图,并初步探索了舌面温度与人体脏腑的关系。详述了所研制的低温位热管黑体及舌热象摄制方法。  相似文献   
12.
sHsps and their role in the chaperone network   总被引:17,自引:0,他引:17  
Small Hsps (sHsps) encompass a widespread but diverse class of proteins. These low molecular mass proteins (15—42 kDa) form dynamic oligomeric structures ranging from 9 to 50 subunits. sHsps display chaperone function in vitro, and in addition they have been suggested to be involved in the inhibition of apoptosis, organisation of the cytoskeleton and establishing the refractive properties of the eye lens in the case of α-crystallin. How these different functions can be explained by a common mechanism is unclear at present. However, as most of the observed phenomena involve nonnative protein, the repeatedly reported chaperone properties of sHsps seem to be of key importance for understanding their function. In contrast to other chaperone families, sHsps bind several nonnative proteins per oligomeric complex, thus representing the most efficient chaperone family in terms of the quantity of substrate binding. In some cases, the release of substrate proteins from the sHsp complex is achieved in cooperation with Hsp70 in an ATP-dependent reaction, suggesting that the role of sHsps in the network of chaperones is to create a reservoir of nonnative refoldable protein.  相似文献   
13.
结合白族学生母语改进英语语音教学的探索   总被引:2,自引:1,他引:2  
分析了引起白族学生语音障碍的重要因素:源于母语迁移之干扰,教材编排不够合理,英语教学法缺乏"本土化".提出解决白族学生语音障碍问题的对策与措施.  相似文献   
14.
3-dimension HPNX offiattice model is developed from the 2-dimension HP offiattice model. In the HP model, 20 types of amino acid monomers are divided into two classes, H (non-polar monomer) and P (polar monomer). In the HPNX model, polar monomers are split into positively charged (P), negatively charged (N) and neutral (X) monomers. A new evolutionary algorithm is applied to study long chains of the HPNX offiattice protein model. This method successfully predict the structures of several proteins in the 3-dimension space that are similar to the structures gotten by X-Ray Crystallography and NMR and published in the PDB(Protein Data Bank).  相似文献   
15.
本从中国式英语的实例来分析以下英语语言差异:(1)简洁与复杂;(2)抽象和具体;(3)形合与意合,母语的负迁移是中国式英语产生的原因之一,母语的负迁移所导致的错误就是语际错误,错误分析是研究第二语言习得的重要方法,从母语负迁移的心理理论基础及其表现形式方面看,母语负迁移是第二语言习得过程中致错的重要原因。  相似文献   
16.
人类舌运动类型   总被引:11,自引:3,他引:11  
介绍了舌运动类型的研究历史和研究成果及5种舌运动类型(卷舌、叠舌、翻舌、三叶舌、尖舌)在不同人群中的出现率,着重论述了近年来我国学者这方面的工作。  相似文献   
17.
Misfolded or incompletely assembled multisubunit glycoproteins undergo endoplasmic reticulum-associated degradation (ERAD) regulated in large measure by their N-linked polymannose oligosaccharides. In this quality control system lectin interaction with Glc3Man9GlcNAc2 glycans after trimming with endoplasmic reticulum (ER) -glucosidases and -mannosidases sorts out persistently unfolded glycoproteins for N-deglycosylation and proteolytic degradation. Monoglucosylated (Glc1Man9GlcNAc2) glycoproteins take part in the calnexin/calreticulin glucosylation-deglucosylation cycle, while the Man8GlcNAc2 isomer B product of ER mannosidase I interacts with EDEM. Proteasomal degradation requires retrotranslocation into the cytosol through a Sec61 channel and deglycosylation by peptide: N-glycosidase (PNGase); in alternate models both PNGase and proteasomes may be either free in the cytosol or ER membrane-imbedded/attached. Numerous proteins appear to undergo nonproteasomal degradation in which deglycosylation and proteolysis take place in the ER lumen. The released free oligosaccharides (OS) are transported to the cytosol as OS-GlcNAc2 along with similar components produced by the hydrolytic action of the oligosaccharyltransferase, where they together with OS from the proteasomal pathway are trimmed to Man5GlcNAc1 by the action of cytosolic endo--N-acetylglucosaminidase and -mannosidase before entering the lysosomes. Some misfolded glycoproteins can recycle between the ER, intermediate and Golgi compartments, where they are further processed before ERAD. Moreover, properly folded glycoproteins with mannose-trimmed glycans can be deglucosylated in the Golgi by endomannosidase, thereby releasing calreticulin and permitting formation of complex OS. A number of regulatory controls have been described, including the glucosidase-glucosyltransferase shuttle, which controls the level of Glc3Man9GlcNAc2-P-P-Dol, and the unfolded protein response, which enhances synthesis of components of the quality control system.Received 26 January 2004; accepted 25 February 2004  相似文献   
18.
Apoptosis is essential to eliminate secretory epithelial cells during the involution of the mammary gland. The environmental regulation of this process is however, poorly understood. This study tested the effect of HAMLET (human -lactalbumin made lethal to tumor cells) on mammary cells. Plastic pellets containing HAMLET were implanted into the fourth inguinal mammary gland of lactating mice for 3 days. Exposure of mammary tissue to HAMLET resulted in morphological changes typical for apoptosis and in a stimulation of caspase-3 activity in alveolar epithelial cells near the HAMLET pellets but not more distant to the pellet or in contralateral glands. The effect was specific for HAMLET and no effects were observed when mammary glands were exposed to native a-lactalbumin or fatty acid alone. HAMLET also induced cell death in vitro in a mouse mammary epithelial cell line. The results suggest that HAMLET can mediate apoptotic cell death in mammary gland tissue.Received 30 January 2004; received after revision 5 March 2004; accepted 16 March 2004  相似文献   
19.
The structure-function paradigm claims that a specific function of a protein is determined by its unique and rigid three-dimensional (3D) structure. Thus, following its biosynthesis on the ribosome, a protein must fold to be functional. This idea represents one of the cornerstones of modern biology. Numerous cases when, due to the effect of environmental factors or because of genetic defects (mutations), a polypeptide chain has lost its capability to gain a proper functional 3D structure (i.e. became misfolded), seem to confirm this concept. Consequences of such misfolding are well known and represent lost of function, aggregation, development of conformational disorders and cell death. However, the recent revelation of countless examples of intrinsically disordered proteins has cast doubt on the general validity of the structure-function paradigm and revealed an intriguing route of functional disorder. Thus, in a living cell, a polypeptide chain chooses between three potential fates – functional folding, potentially deadly misfolding and mysterious nonfolding. This choice is dictated by the peculiarities of amino acid sequence and/or by the pressure of environmental factors. The aim of the present review is to outline some interesting features of these three routes.Received 5 March 2003; received after revision 28 March 2003; accepted 31 March 2003  相似文献   
20.
梁嵘 《自然科学史研究》2003,22(2):157-167,T001,T002
舌诊是以观察疾病时舌色的变化为主要目的而诞生的诊断技术。但是在舌诊书籍的流传过程中,中国医家逐渐用文字说明替代了舌诊图的色彩,而日本的医家却给舌诊图涂上了艳丽的颜色。中日医家对舌诊图的不同态度,体现了在图像的背后,两国医家所持有的不同医学观念。中国医家强调“理”在医学中的重要性,认为把握“理”,进一步达到“医者意也”的境界是医家的最高追求,拘泥于具体的图像会束缚人们把握医学的道理。日本医家主张通过“眼可见,手可及”的实验方法掌握识别疾病的技术,反对中国医家所强调的“理”与“意”。由此可知,如何以史为鉴,继承中日传统医学之优势、克服其弊端,使中医学为现代医疗卫生事业做出贡献,是医学研究者与史学研究者的重要使命。  相似文献   
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