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91.
S Oikawa  M Imai  A Ueno  S Tanaka  T Noguchi  H Nakazato  K Kangawa  A Fukuda  H Matsuo 《Nature》1984,309(5970):724-726
Recent identification of natriuretic-diuretic activity in peptides isolated from human and rat atrial tissue implicates them in the control of extracellular fluid volume and electrolytic homeostasis. The presence of multiple forms of the peptides ranging from 3,000 to 13,000 molecular weight (MW) suggests they may all derive from the same precursor. The established amino acid sequence of alpha-human atrial natriuretic polypeptide (alpha- hANP ), a 28-residue peptide with potent natriuretic activity, provided the means to elucidate the structure of the precursor for alpha- hANP and the gene encoding it. Here we report the cloning and sequence analysis of the cDNA of human atrial mRNA encoding a precursor of alpha- hANP . The cDNA encodes gamma-human atrial natriuretic polypeptide (gamma- hANP ) of 13,000 MW, whose C-terminal 28 amino acid residues may be processed as alpha- hANP .  相似文献   
92.
Summary A novel and sensitive noncompetitive enzyme immunoassay for kassinin is described. Kassinin was biotinylated using sulfosuccinimidyl-6-(biotinamido)hexanoate. The biotinylated kassinin was trapped on antikassinin IgG-coated polystyrene balls and, after washing to eliminate other biotinylated substances, was eluted with HCl. The biotinylated kassinin eluted was reacted with anti-kassinin Fab'-peroxidase conjugate and trapped onto streptavidin-coated polystyrene balls. Peroxidase activity bound to the polystyrene balls was assayed by fluorimetry. The detection limit of kassinin was 0.13 pg (0.1 fmol)/tube or 0.065 g/l of rat plasma, which was 750-fold or 15-fold lower than that for competitive radioimmunoassay.  相似文献   
93.
企业通常会通过网站介绍和发布信息,但是拥有一个独立主机的网站维护费用比较昂贵。租赁一个虚拟主机,可以大幅度降低成本。开源的LAMP在软件方面的投资成本较低,从网站的流量上看,全世界70%以上的访问流量是LAMP来提供的,LAMP是最强大的网站解决方案之一。在建设律师事务所网站时,使用LAMP架构,降低了开发成本,实现了网站内容的动态更新,后期的维护成本很低。嵌入了CKEditor,CKFinder,jQuery等开源软件,增强了网站的整体功能。  相似文献   
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95.
Ma KF  Tanaka H  Song SR  Wang CY  Hung JH  Tsai YB  Mori J  Song YF  Yeh EC  Soh W  Sone H  Kuo LW  Wu HY 《Nature》2006,444(7118):473-476
Determining the seismic fracture energy during an earthquake and understanding the associated creation and development of a fault zone requires a combination of both seismological and geological field data. The actual thickness of the zone that slips during the rupture of a large earthquake is not known and is a key seismological parameter in understanding energy dissipation, rupture processes and seismic efficiency. The 1999 magnitude-7.7 earthquake in Chi-Chi, Taiwan, produced large slip (8 to 10 metres) at or near the surface, which is accessible to borehole drilling and provides a rare opportunity to sample a fault that had large slip in a recent earthquake. Here we present the retrieved cores from the Taiwan Chelungpu-fault Drilling Project and identify the main slip zone associated with the Chi-Chi earthquake. The surface fracture energy estimated from grain sizes in the gouge zone of the fault sample was directly compared to the seismic fracture energy determined from near-field seismic data. From the comparison, the contribution of gouge surface energy to the earthquake breakdown work is quantified to be 6 per cent.  相似文献   
96.
1 IntroductionYAGlaserweldingprocesscanbeconductedbyarobotusinganopticalfibertotransferthelaserenergyontoaworkpieceduetoitssmallwavelength (1.0 6mm ) .ThustheweldingautomationlevelcanbehighlyincreasedcomparedwithCO2 laserwelding .Therefore ,recentlyyears ,YAGlaserweldingprocesshasbeenquicklydevelopedandappliedformanufac turingofautomobileandchemicalvesselsetc .Gener ally ,thepowerofaCWYAGlaserisnotsohigh (sofarupto 10kW )duetoitslowefficiencyofenergyconversion .Whenweldingwithamiddleorl…  相似文献   
97.
Protein translocation across the bacterial membrane, mediated by the secretory translocon SecYEG and the SecA ATPase, is enhanced by proton motive force and membrane-integrated SecDF, which associates with SecYEG. The role of SecDF has remained unclear, although it is proposed to function in later stages of translocation as well as in membrane protein biogenesis. Here, we determined the crystal structure of Thermus thermophilus SecDF at 3.3?? resolution, revealing a pseudo-symmetrical, 12-helix transmembrane domain belonging to the RND superfamily and two major periplasmic domains, P1 and P4. Higher-resolution analysis of the periplasmic domains suggested that P1, which binds an unfolded protein, undergoes functionally important conformational changes. In vitro analyses identified an ATP-independent step of protein translocation that requires both SecDF and proton motive force. Electrophysiological analyses revealed that SecDF conducts protons in a manner dependent on pH and the presence of an unfolded protein, with conserved Asp and Arg residues at the transmembrane interface between SecD and SecF playing essential roles in the movements of protons and preproteins. Therefore, we propose that SecDF functions as a membrane-integrated chaperone, powered by proton motive force, to achieve ATP-independent protein translocation.  相似文献   
98.
Protein quality-control, especially the removal of proteins with aberrant structures, has an important role in maintaining the homeostasis of non-dividing neural cells. In addition to the ubiquitin-proteasome system, emerging evidence points to the importance of autophagy--the bulk protein degradation pathway involved in starvation-induced and constitutive protein turnover--in the protein quality-control process. However, little is known about the precise roles of autophagy in neurons. Here we report that loss of Atg7 (autophagy-related 7), a gene essential for autophagy, leads to neurodegeneration. We found that mice lacking Atg7 specifically in the central nervous system showed behavioural defects, including abnormal limb-clasping reflexes and a reduction in coordinated movement, and died within 28 weeks of birth. Atg7 deficiency caused massive neuronal loss in the cerebral and cerebellar cortices. Notably, polyubiquitinated proteins accumulated in autophagy-deficient neurons as inclusion bodies, which increased in size and number with ageing. There was, however, no obvious alteration in proteasome function. Our results indicate that autophagy is essential for the survival of neural cells, and that impairment of autophagy is implicated in the pathogenesis of neurodegenerative disorders involving ubiquitin-containing inclusion bodies.  相似文献   
99.
Summary The subcellular distribution of cholinesterase (ChE) was studied in the gastrocnemius muscle of rats after strong or weak nerve crushing. The ChE activities of muscle were decreased to a greater extent by strong crushing than by weak crushing. In particular, the ChE activity of the fraction containing sarcoplasmic reticulum was most greatly decreased. These results suggest that the change in the ChE activity of the microsomal fraction most finely reflects the strength of nerve crushing.Acknowledgments. This study was accomplished in Central Research Laboratories, Sankyo Co. Ltd. The authors wish to thank Prof. Tsuneyuki Nakazawa, Department of Neuropsychiatry, School of Medicine, Fujita-Gakuen University, and Dr Yutaka Sakai for their valuable advice and support, Sr Jean M. Michalec for her critical comments, and Miss Hamako Katano, Mr Naoji Mikuni and Miss Yoshie Ishii for their skillful technical assistance.  相似文献   
100.
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