首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   97篇
  免费   2篇
电工技术   2篇
化学工业   36篇
金属工艺   2篇
机械仪表   3篇
能源动力   2篇
轻工业   13篇
无线电   4篇
一般工业技术   14篇
冶金工业   21篇
自动化技术   2篇
  2023年   2篇
  2022年   2篇
  2021年   3篇
  2020年   1篇
  2019年   4篇
  2018年   1篇
  2015年   1篇
  2014年   6篇
  2013年   5篇
  2012年   8篇
  2011年   5篇
  2010年   5篇
  2009年   6篇
  2008年   8篇
  2007年   2篇
  2005年   1篇
  2004年   2篇
  2003年   1篇
  2002年   2篇
  2001年   4篇
  2000年   1篇
  1999年   3篇
  1998年   11篇
  1997年   6篇
  1996年   2篇
  1995年   3篇
  1994年   1篇
  1993年   2篇
  1988年   1篇
排序方式: 共有99条查询结果,搜索用时 0 毫秒
1.
Heat shock protein 47 (HSP47), a collagen-specific molecular chaperone, is causally related to fibrotic diseases, including idiopathic pulmonary fibrosis. The identification of Compounds that interfere with the HSP47-collagen interaction is essential for the development of relevant therapeutics. Herein, we prepared human HSP47 as a soluble fusion protein expressed in E. coli and established an assay system for HSP47 inhibitor screening. We screened a natural and synthetic Compound library established at Nagasaki University. Among 1023 Compounds, 13 exhibited inhibitory activity against human HSP47, of which three inhibited its function in a dose-dependent manner. Epigallocatechin-3-O-gallate, one of these three Compounds, is a typical polyphenol Compound derived from tea leaves. Structurally related Compounds were synthesized and examined for their activity, revealing a hydroxyl group at A-ring position 5 as important for its activity. The present findings provide valuable insight for the development of natural product-derived therapeutics for fibrotic diseases, including idiopathic pulmonary fibrosis.  相似文献   
2.
The tungsten-inert-gas (TIG) arc welding experiments of cemented carbide YG30 and steel 45 were carried out using the Ni-Fe-C filling alloys. The eta phases and mechanical properties of welded joints were analyzed by means of scanning electronic microscope (SEM) , transmission electronic microscope (TEM) coupled with selected diffraction, electronic probe microanalysis and bending strength method. The experimental results show that the chemical composition of the filling alloys affects eta phase formation. When the carbon and nickel contents in filling alloys are O. 61 wt% and 55. 29 wt% ,respectively, no eta phases form. And the joint bending strength is the highest to 1. 352 GPa. But if they are O. 01wt% and 55.38wt%, the eta phases are formed at the boundaries of the cemented carbide and the weld, and the thickness of eta phase layer is about 110 micrometers. And the joint bending strength is low. Usually, these eta phases are anomalously granular,and easy to accumulate at the boundaries between cemented carbides and the weld. They are multiple M6C rich in tungsten and iron.  相似文献   
3.
4.
We evaluated the effects of seven mushroom extracts (Grifola frondosa, Pholiota nameko, Panellus serotinus, Hypsizygus marmoreus, Pleurotus cornucopiae, Armillaria mellea, and Flammulina velutipes) on cytotoxic activity and cytokine production of lamina propria leukocytes (LPLs) isolated from rat small (S) and large (L) intestinal mucosa. Boiling water extracts from seven species of mushrooms showed no direct cytotoxicity against the YAC-1 target cells. However, prominent increases of cytotoxicity were observed in S- and L-LPLs co-cultured with P. serotinus extract. Cytokine production (TNFα, IFNγ, IL-12 p70, and IL-4) of S- and L-LPLs was stimulated in response to P. cornucopiae extract. Mushroom extracts contributed to target cell adhesion and/or cytokine production in the effector cells. The promotion of cytotoxic activity in S- and L-LPLs was not necessarily related to β-glucan content of the mushroom.  相似文献   
5.
6.
The cDNAs and genes for two isozymes of cytochrome P450nor of the fungus Cylindrocarpon tonkinense, P450nor1 and P450nor2, were cloned and sequenced. Their deduced amino acid sequences respectively showed 83 and 70% identity to that of P450nor of Fusarium oxysporum, and 69% identity to each other. The genes for P450nor1 and P450nor2 were termed, respectively, CYP 55A2 and CYP 55A3. The cDNA for P450nor1 contained a targeting-like presequence upstream the N-terminus of mature protein whereas that for P450nor2 did not, suggesting their different intracellular localisations. We also succeeded in expressing these P450nor isoforms in the host-vector system of the yeast Saccharomyces cerevisiae. We purified one of the recombinant proteins, P450nor of F oxysporum. Little difference could be observed between the native and recombinant proteins in catalytic and spectroscopic properties. We constructed chimeric proteins of P450nor of F oxysporum and P450nor2 which are different in their specificity against the electron donors: reduced pyridine nucleotides. The specificity of chimeric proteins against NADH/NADPH showed that the specificity is determined by the N-terminal half of protein. We found a consensus amino acid sequence between three isoforms of P450nor, A-X-G-X-X-A, similar to the NAD-binding motif G-X-G-X-X-G/A in the region that corresponds to the B'-helix in P450cam.  相似文献   
7.
8.
HPLC elution behaviors of La-fullerenes were investigated by use of the radiochemical methods. Elution curves of La-fullerenes could be observed in detail for the first time, and the persistent presence of La in the whole elution curve was demonstrated. Production of La-fullerenes containing a radioactive 140La could be achieved for the first time.  相似文献   
9.
A fluorous micellar system in water has been created to produce a large interfacial area between these media that retains substrates, effectively facilitating intermolecular Diels–Alder reactions due to repulsion effects from both media. Because LiFOS functioned not only as a surfactant but also as a supporting electrolyte, an electrochemical approach could be introduced to evaluate the rate acceleration effects. The measurement of the particle size distribution of the fluorous micelles clearly supported these evaluations.  相似文献   
10.
In this paper, two novel structures of porous silicon (PS) light-emitting diodes (LEDs) are proposed aiming at the reduction of series resistance, Rs. The basic idea of the novel structures is to suppress the excessive growth of nanoporous silicon (nano-PS) layer that is electroluminescence- (EL-) active but highly resistive. The initial wafer of the first structure consists of a lightly-doped layer stacked on a highly-doped substrate. As a consequence of anodization, nano-PS layer is formed only in the lightly-doped layer, while meso-PS layer with moderate resistivity is formed in the highly-doped substrate. The second structure consists of alternately stacked nano- and meso-PS layers, since it is expected that multiple thin nano-PS layers connected in series are less resistive than a single thick nano-PS layer. Preliminary experimental results proved the effectiveness of these novel structures on the reduction of Rs.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号