全文获取类型
收费全文 | 755篇 |
免费 | 98篇 |
出版年
2021年 | 13篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 8篇 |
2015年 | 26篇 |
2014年 | 24篇 |
2013年 | 25篇 |
2012年 | 25篇 |
2011年 | 30篇 |
2010年 | 20篇 |
2009年 | 24篇 |
2008年 | 25篇 |
2007年 | 29篇 |
2006年 | 18篇 |
2005年 | 28篇 |
2004年 | 22篇 |
2003年 | 26篇 |
2002年 | 22篇 |
2001年 | 29篇 |
2000年 | 26篇 |
1999年 | 22篇 |
1998年 | 22篇 |
1997年 | 14篇 |
1996年 | 15篇 |
1995年 | 8篇 |
1994年 | 15篇 |
1993年 | 14篇 |
1992年 | 16篇 |
1991年 | 17篇 |
1990年 | 24篇 |
1989年 | 30篇 |
1988年 | 18篇 |
1987年 | 16篇 |
1986年 | 17篇 |
1985年 | 8篇 |
1984年 | 12篇 |
1983年 | 8篇 |
1982年 | 7篇 |
1981年 | 4篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1970年 | 9篇 |
1969年 | 6篇 |
1968年 | 4篇 |
1967年 | 4篇 |
1963年 | 5篇 |
1955年 | 4篇 |
1929年 | 3篇 |
1916年 | 3篇 |
1879年 | 3篇 |
排序方式: 共有853条查询结果,搜索用时 481 毫秒
101.
102.
N. Ramsay 《BMJ (Clinical research ed.)》1988,297(6644):357-358
103.
Mapping the human CAS2 gene, the homologue of the mouse brown (b) locus, to human chromosome 9p22-pter 总被引:4,自引:0,他引:4
C D Chintamaneni M Ramsay M A Colman M F Fox R T Pickard B S Kwon 《Biochemical and biophysical research communications》1991,178(1):227-235
Melanin biosynthesis is a multistep process with the first step being the conversion of L-tyrosine to L-Dopa catalyzed by the enzyme tyrosinase. The enzymes which catalyze the other steps of melanogenesis are not known. One murine pigmentation gene, the brown (b) locus, when mutated, leads to a brown or hypopigmented coat. The b-locus protein has been shown to display catalase activity. The human b-locus, therefore, is designated as CAS2. We used the mouse b-locus cDNA to isolate the human homologue, which in turn, was used to map the CAS2 locus to a human chromosome. The potential CAS2 protein codes for 527 amino acids containing a putative signal sequence and transmembrane domain. The CAS2 protein has primary and probably secondary structures similar to human tyrosinase. The CAS2 was mapped to human Chromosome 9 by somatic cell hybridization and, more specifically, to 9p22-pter by in situ hybridization. The assignment of CAS2 on the human Chromosome 9 extends this region of known homology on mouse Chromosome 4. 相似文献
104.
Sam Ramsay Smith 《BMJ (Clinical research ed.)》1983,287(6409):1985-1987
105.
106.
107.
108.
The technique of quasielastic light scattering (QELS) in the presence of a sinusoidal electric field (QELS-SEF) was used to examine the diffusion of poly(lysine) in the extraordinary phase, which is defined by the anomalously small value in the apparent diffusion coefficient (Dapp, obtained by QELS methods) as the added salt concentration is lowered below 10 mM. Spectra were obtained for high-molecular-weight poly(lysine) (800,000) in 0.5 mM KCl, using a driving frequency of 90 Hz. It was observed that the linewidth, hence apparent diffusion coefficient (DSF), increased with electric field strength (E) over the range 6 < E < 30 V/cm. As might be anticipated, the asymptotic limit, DSF(E = 0), was almost numerically equivalent to Dapp at this KCl concentration. As E approached the upper limit value of 31 V/cm, the value of DSF approached the high salt (500 mM KCl) value of Dapp. These observations are discussed in terms of small-ion dispersion effects. 相似文献
109.
The dog is the main reservoir of Leishmania infantum, the causative agent of visceral leishmaniasis (VL) in humans in Southern Europe. In order to identify the risk of dogs from
a Leishmania non-endemic area traveling to a Leishmania -endemic area becoming infected and the risk of transmitting infection to humans in non-endemic areas an investigation was
performed, in which the results of a questionnaire were combined with the results of a serologic survey. 相似文献
110.