全文获取类型
收费全文 | 1077918篇 |
免费 | 71878篇 |
国内免费 | 1398篇 |
专业分类
耳鼻咽喉 | 15029篇 |
儿科学 | 34642篇 |
妇产科学 | 28652篇 |
基础医学 | 153735篇 |
口腔科学 | 29626篇 |
临床医学 | 95135篇 |
内科学 | 204464篇 |
皮肤病学 | 24413篇 |
神经病学 | 81776篇 |
特种医学 | 43035篇 |
外国民族医学 | 201篇 |
外科学 | 163711篇 |
综合类 | 21723篇 |
现状与发展 | 1篇 |
一般理论 | 267篇 |
预防医学 | 74767篇 |
眼科学 | 24575篇 |
药学 | 86300篇 |
7篇 | |
中国医学 | 2809篇 |
肿瘤学 | 66326篇 |
出版年
2019年 | 7807篇 |
2018年 | 11352篇 |
2017年 | 8946篇 |
2016年 | 10156篇 |
2015年 | 11327篇 |
2014年 | 15351篇 |
2013年 | 22307篇 |
2012年 | 30707篇 |
2011年 | 32454篇 |
2010年 | 19054篇 |
2009年 | 17902篇 |
2008年 | 30105篇 |
2007年 | 32233篇 |
2006年 | 32877篇 |
2005年 | 31176篇 |
2004年 | 29857篇 |
2003年 | 28700篇 |
2002年 | 27709篇 |
2001年 | 60122篇 |
2000年 | 61554篇 |
1999年 | 51014篇 |
1998年 | 12485篇 |
1997年 | 11028篇 |
1996年 | 11047篇 |
1995年 | 10341篇 |
1994年 | 9361篇 |
1993年 | 8883篇 |
1992年 | 37842篇 |
1991年 | 36331篇 |
1990年 | 35777篇 |
1989年 | 34339篇 |
1988年 | 30906篇 |
1987年 | 30027篇 |
1986年 | 28235篇 |
1985年 | 26472篇 |
1984年 | 19205篇 |
1983年 | 16131篇 |
1982年 | 8831篇 |
1979年 | 17041篇 |
1978年 | 11420篇 |
1977年 | 10243篇 |
1976年 | 8851篇 |
1975年 | 10080篇 |
1974年 | 11661篇 |
1973年 | 11295篇 |
1972年 | 10768篇 |
1971年 | 10102篇 |
1970年 | 9257篇 |
1969年 | 8947篇 |
1968年 | 7922篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Daniel K. Howe Michael H. Vodkin Robert J. Novak Govinda Visvesvara G. L. McLaughlin 《Parasitology research》1997,83(4):345-348
Species-level identification of Acanthamoeba isolates is difficult and gives little or no indication of the isolate's pathogenicity. We identified two amplification-based genetic markers that were highly correlated with pathogenicity in Acanthamoeba spp. One marker, designed to amplify a 485-bp fragment of the small-subunit ribosomal RNA gene (ssrDNA), was preferentially amplified from the nonpathogenic strains; amplifications from the pathogenic strains yielded anomalous fragments of 650 and 900?bp. A second marker was developed on the basis of the anomalous 650-bp fragment. Primers to this sequence preferentially amplified a noncoding locus (called Ac6) only from the pathogenic strains. These two genetic markers may be useful for identification of pathogenic Acanthamoeba spp. strains. 相似文献
992.
M. Emoto H. Iwasaki K. Oshima M. Kikuchi Y. Kaneko T. Kawarabayashi 《Virchows Archiv : an international journal of pathology》1997,431(4):249-256
Rhabdomyosarcoma (RMS) is occasionally found in the female genital tract, and mostly appears as one of the heterologous mesenchymal
components in uterine carcinosarcoma designated as malignant mixed müllerian tumour (MMMT). We examined the biological properties
of a pure rhabdomyosarcoma (RMS) cell line designated FU-MMT-3, which was newly established from a surgical specimen taken
from a patient with uterine MMMT. We also evaluated c-myc and MYCN gene amplification in three RMS cell lines (including FU-MMT-3) derived from three MMMTs by Southern blot analysis.
FU-MMT-3 cells were propagated continuously for 57 serial passages over a 2-year period in vitro. FU-MMT-3 was able to produce
tumours demonstrating pure RMS in athymic nude mice. Cytogenetically, FU-MMT-3 showed a triploidy pattern, with complex karyotypic
abnormalities including trisomy of chromosome 8. All three RMS cell lines, including FU-MMT-3, showed amplification of the
c-myc gene (approximately fourfold to eightfold), while no cell lines demonstrated MYCN gene amplification. FU-MMT-3 is considered
to provide a useful system for the study of the biological behaviour of RMS in MMMTs. Extra copies of chromosome 8 and c-myc gene amplification may be associated with the rhabdomyoblastic differentiation in MMMT.
Received: 7 January 1997 / Accepted: 2 May 1997 相似文献
993.
994.
995.
Y. Kajiya M. Nakajo N. Ichinari Y. Kajiya K. Yamazumi T. Otuji T. Tanaka 《Abdominal imaging》1997,22(1):111-113
A foregut cyst is formed as a result of abnormal budding and pinching of the tracheobronchial tree when bronchial buds develop
to form the primitive respiratory tree. Foregut cysts are clinically classified as bronchogenic, esophageal, enterogastric,
or ciliated hepatic. We present a foregut cyst that occurred in the retroperitoneum and was difficult to distinguish from
other retroperitoneal cystic mass lesions. Magnetic resonance imaging was useful in revealing the cyst's continuity to adjacent
organs.
Received: 19 June 1995/Accepted: 23 July 1995 相似文献
996.
997.
S Tanaka T Nishihara T Nagashima K Kawai S Nakai M Adachi 《Journal of clinical neuroscience》1997,4(1):57-62
The effects of 3,4-dihydro-6-[4-(3,4-dimethoxybenzoyl)-1-piperazinyl]-2(1H)-quinolinone (vesnarinone) on the growth of glioma cells were examined in vitro. Vesnarinone at a dose of 100 mug/ml suppressed the growth of four different glioma cell lines, U-251MG, U-373MG, U-87MG and A-172, by approximately 50%, with an elongation of the cytoplasmic process on day 5 of culture. The long-term culture of U-87MG with 10 mug/ml of vesnarinone was continued up to day 34. Although growth suppression was approximately 25% on day 5, it reached over 95% on day 34. An increase in the cyclic adenosine monophosphate content of glioma cells cultured with vesnarinone was observed by enzyme-linked immunosorbent assay (ELISA). The accumulation of glial fibrillary acidic protein was observed to occur with vesnarinone by ELISA. These findings suggest that vesnarinone suppressed the growth and induced differentiation of glioma cells in vitro. 相似文献
998.
K. Wilhelmsen D. Mirel K. Marder M. Bernstein A. Naini S. M. Leal L. J. Cote M.-X. Tang G. Freyer J. Graziano R. Mayeux 《Annals of neurology》1997,41(6):813-817
The cytochrome P450 mono-oxygenase gene, CYP2D6 on chromosome 22q13 (ch22q13), has been inconsistently associated with Parkinson's disease. Associations with CYP2D6 have either been absent altogether or have involved more than one polymorphism, many of which have the same metabolic effect on gene expression. We examined the association between CYP2D6 polymorphisms and Parkinson's disease in a case-control study and included 10 polymorphic dinucleotide repeat markers linked to CYP2D6 to determine whether the association was present or due to linkage disequilibrium. There was no association between any polymorphism of CYP2D6 and Parkinson's disease, but two of 10 dinucleotide repeat markers linked to CYP2D6 were associated with the disease. These results provide evidence to suggest that there may be an unidentified locus for susceptibility to Parkinson's disease that is in linkage disequilibrium with dinucleotide repeat markers mapping near CYP2D6 on ch22q13. 相似文献
999.
1000.
Gil I Wolfe Dennis K Burns Daniel Krampitz Richard J Barohn 《Neuromuscular disorders : NMD》1997,7(8):536-538
We describe the presence of cylindrical spirals on muscle biopsy from a 31-year-old man who developed rhabodomyolysis following a long run. He had a prior history of exertional cramps and myoglobinuria. His maternal grandfather had similar symptoms. Transmission electron micrographs demonstrated continuity between the lamellae of the cylindrical spirals and native myofilaments. Whether these unusual structures confer a derangement in myofilament function is uncertain. 相似文献