全文获取类型
收费全文 | 490篇 |
免费 | 29篇 |
国内免费 | 77篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 29篇 |
妇产科学 | 2篇 |
基础医学 | 80篇 |
口腔科学 | 7篇 |
临床医学 | 91篇 |
内科学 | 106篇 |
皮肤病学 | 16篇 |
神经病学 | 17篇 |
特种医学 | 94篇 |
外科学 | 42篇 |
综合类 | 26篇 |
预防医学 | 8篇 |
眼科学 | 6篇 |
药学 | 50篇 |
1篇 | |
中国医学 | 1篇 |
肿瘤学 | 19篇 |
出版年
2021年 | 3篇 |
2019年 | 4篇 |
2017年 | 6篇 |
2016年 | 4篇 |
2015年 | 10篇 |
2014年 | 10篇 |
2013年 | 12篇 |
2012年 | 8篇 |
2011年 | 8篇 |
2010年 | 8篇 |
2009年 | 14篇 |
2008年 | 4篇 |
2007年 | 61篇 |
2006年 | 14篇 |
2005年 | 21篇 |
2004年 | 9篇 |
2003年 | 12篇 |
2002年 | 3篇 |
2001年 | 11篇 |
2000年 | 14篇 |
1999年 | 12篇 |
1998年 | 26篇 |
1997年 | 34篇 |
1996年 | 28篇 |
1995年 | 25篇 |
1994年 | 21篇 |
1993年 | 16篇 |
1992年 | 5篇 |
1991年 | 8篇 |
1990年 | 13篇 |
1989年 | 15篇 |
1988年 | 18篇 |
1987年 | 8篇 |
1986年 | 11篇 |
1985年 | 12篇 |
1984年 | 5篇 |
1983年 | 7篇 |
1982年 | 14篇 |
1981年 | 12篇 |
1980年 | 10篇 |
1979年 | 4篇 |
1978年 | 6篇 |
1977年 | 5篇 |
1976年 | 9篇 |
1975年 | 12篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1961年 | 2篇 |
1941年 | 2篇 |
排序方式: 共有596条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Kundel HL; Gefter W; Aronchick J; Miller W Jr; Hatabu H; Whitfill CH; Miller W Sr 《Radiology》1997,205(3):859
5.
Molecular genetic characterization of XRCC4 function 总被引:2,自引:0,他引:2
XRCC4 is a generally expressed protein of 334 amino acids that is involved
in the repair of DNA double-strand breaks and in V(D)J recombination, but
its function is unknown. In this study, we have used a mutational approach
and the yeast two-hybrid method to perform an initial characterization of
this protein. We show that the XRCC4 protein is located in the nucleus. We
also demonstrate that several potential phosphorylation sites are not
required for XRCC4 function in a transient V(D)J recombination assay. In
addition, we show that XRCC4 forms a homodimer in vivo with the
homodimerization domain being located within amino acids 115-204. Finally,
we define a core domain of XRCC4 that functions in V(D)J recombination and
comprises amino acids 18-204. Potential functions of XRCC4 are discussed.
相似文献
6.
7.
P Wevers R Picken G Schmidt B Jann K Jann J R Golecki M Kist 《Infection and immunity》1980,29(2):685-691
A strain of Escherichia coli O18ac isolated from the stool sample of a patient with diarrhea was found to agglutinate human erythrocytes. From the results presented it is suggested that this hemagglutination is mediated by pili. Isolated pilus preparations agglutinated human erythrocytes, whereas pilus-negative mutants did not. The serological and chemical analyses indicate that the pili associated with E. coli O18ac are distinct from other types found with E. coli. 相似文献
8.
Nucleotide sequence of the gene for heat-stable enterotoxin II of Escherichia coli. 总被引:23,自引:11,他引:23 下载免费PDF全文
Previously, the gene for heat-stable enterotoxin II (STII) has been mapped by transposon Tn5 insertion mutagenesis in the chimeric R-Ent plasmid pCG86 (Mazaitis, A. J., R. Maas, and W. K. Maas, J. Bacteriol. 145:97-105, 1981). DNA segments containing this gene were cloned from the wild-type and STII-insertion-mutant plasmid. The position of the Tn5 insertion was determined, and a 530-base-pair-long segment of the wild-type plasmid corresponding to the Tn5 insertion site was sequenced. An open reading frame for the STII gene was identified and is characterized by typical promoter and ribosome binding site sequences. The deduced STII structural gene codes for a protein 71 amino acids long, including a typical signal peptide of 23 amino acids and a mature protein of 48 amino acids. The size and overall structure of STII are similar to those of STI, but the amino acid compositions of the two heat-stable enterotoxins are completely different. 相似文献
9.
10.
Chromosome abnormalities clustering and its implications for pathogenesis and prognosis in myeloma. 总被引:19,自引:0,他引:19
C S Debes-Marun G W Dewald S Bryant E Picken R Santana-Dávila N González-Paz J M Winkler R A Kyle M A Gertz T E Witzig A Dispenzieri M Q Lacy S V Rajkumar J A Lust P R Greipp R Fonseca 《Leukemia》2003,17(2):427-436
The nonrandom recurrent nature of chromosome abnormalities in myeloma suggests a role for them in disease pathogenesis. We performed a careful cytogenetic analysis of patients with abnormal karyotypes (n = 254), to discern patterns of association, search for novel abnormalities and elucidate clinical implications. Patients with karyotypic abnormalities suggestive of myelodysplasia/acute leukemia were excluded. In this study we compared survival by abnormality only between patients with abnormal karyotypes. Patients with abnormalities were more likely to have features of aggressive disease as compared to all other patients without abnormalities entered into the myeloma database (lower hemoglobin, higher beta(2)-microglobulin, labeling-index and plasmocytosis; all P < 0.0001). Several groups of patients could be readily identified; hypodiploid (22%), pseudodiploid (36%), hyperdiploid (31%) and near-tetraploid (11%). Clustering associations were seen among several trisomies and monosomy of chromosome 13 and 14. Several monosomies (-2, -3, -13, -14 and -19), 1p translocations/ deletions, and hypodiploidy were associated with a significantly shorter survival. Trisomy of chromosome 13 was rare ( <2%). Even among patients with abnormal karyotypes, specific chromosome abnormalities can impart biologic variability in myeloma, including several monosomies, hypodiploidy and abnormalities of 1p. 相似文献