全文获取类型
收费全文 | 1540篇 |
免费 | 0篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 4篇 |
轻工业 | 2篇 |
无线电 | 1篇 |
一般工业技术 | 4篇 |
冶金工业 | 1526篇 |
自动化技术 | 2篇 |
出版年
2021年 | 1篇 |
2013年 | 1篇 |
2011年 | 2篇 |
2003年 | 1篇 |
1999年 | 37篇 |
1998年 | 464篇 |
1997年 | 275篇 |
1996年 | 174篇 |
1995年 | 101篇 |
1994年 | 71篇 |
1993年 | 109篇 |
1992年 | 12篇 |
1991年 | 13篇 |
1990年 | 12篇 |
1989年 | 20篇 |
1988年 | 24篇 |
1987年 | 20篇 |
1986年 | 28篇 |
1985年 | 18篇 |
1983年 | 1篇 |
1982年 | 8篇 |
1981年 | 8篇 |
1980年 | 12篇 |
1978年 | 2篇 |
1977年 | 39篇 |
1976年 | 84篇 |
1975年 | 2篇 |
1955年 | 1篇 |
排序方式: 共有1540条查询结果,搜索用时 15 毫秒
21.
V Mooser A Maillard C Bonny M Steinmann P Shaw DP Yarnall DK Burns DF Schorderet P Nicod G Waeber 《Canadian Metallurgical Quarterly》1999,55(2):202-208
Islet-brain 1 (IB1), a regulator of the pancreatic beta-cell function in the rat, is homologous to JIP-1, a murine inhibitor of c-Jun amino-terminal kinase (JNK). Whether IB1 and JIP-1 are present in humans was not known. We report the sequence of the 2133-bp human IB1 cDNA, the expression, structure, and fine-mapping of the human IB1 gene, and the characterization of an IB1 pseudogene. Human IB1 is 94% identical to rat IB1. The tissue-specific expression of IB1 in human is similar to that observed in rodent. The IB1 gene contains 12 exons and maps to chromosome 11 (11p11.2-p12), a region that is deleted in DEFECT-11 syndrome. Apart from an IB1 pseudogene on chromosome 17 (17q21), no additional IB1-related gene was found in the human genome. Our data indicate that the sequence and expression pattern of IB1 are highly conserved between rodent and human and provide the necessary tools to investigate whether IB1 is involved in human diseases. 相似文献
22.
23.
Most patients in acute myocardial infarction (AMI) undergo emergent coronary angiography (CAG). However, when to analyze lipoprotein profiles in AMI is not clear. To determine whether lipoprotein profiles change during catheterization, we measured serum lipid and apolipoprotein concentrations in 65 patients (51 men and 14 women) before and after catheterization. Heparin was injected at 50 units/kg for CAG and 200 units/kg for percutaneous transluminal coronary angioplasty (PTCA). We found that cholesterol and triglyceride decreased by 9.4% (P < 0.001) and 53.1% (P < 0.001), respectively, after catheterization. Apolipoproteins also decreased significantly. Variables decreased two to five times more after PTCA than after CAG. Lipoprotein lipase mass was higher after PTCA (267.8 +/- 135.3 micrograms/L) than after CAG (93.3 +/- 48.4 micrograms/L; P < 0.05). In conclusion, lipoprotein profiles change during catheterization. We recommend avoiding analysis of lipoprotein profiles after emergent CAG in AMI. 相似文献
24.
25.
Because knowledge has advanced in several fields related to the treatment of early breast cancer, revising the landmark 1992 standards for breast-conservation treatment by these four organizations is appropriate. The current report reviews and summarizes the literature and describes the selection and evaluation of patients, the technical aspects of surgical treatment and irradiation, follow-up care, and areas for further research. 相似文献
26.
27.
DP Kernick 《Canadian Metallurgical Quarterly》1997,349(9051):570; author reply 572-570; author reply 573
28.
29.
DP Gaver 《Canadian Metallurgical Quarterly》1995,20(5):326-8; author reply 330-3
30.
FS Celi G Canettieri DP Yarnall DK Burns M Andreoli AR Shuldiner M Centanni 《Canadian Metallurgical Quarterly》1998,141(1-2):49-52
The conserved residue Asp477 in yeast transketolase is located in the substrate channel of the enzyme and forms a hydrogen bond with the C2-hydroxyl group of the acceptor substrate. The significance of this interaction for the recognition of the preferred acceptor substrates, D-alpha-hydroxyaldehydes was investigated by site-directed mutagenesis. In the wild-type enzyme the kcat/KM values are by three to four orders of magnitude lower for 2-deoxyaldoses or substrates with L-configuration at the C2-atom. In the Asp477 Ala mutant, the kcat/KM values for D-alpha-hydroxyaldehydes are decreased by a thousandfold, while the kcat/KM values for substrates with L-configuration or 2-deoxyaldoses are similar to wild-type enzyme. These results indicate that Asp477 is involved in determining the enantioselectivity of transketolase. 相似文献