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   119844篇
  免费   6071篇
  国内免费   146篇
耳鼻咽喉   1808篇
儿科学   5295篇
妇产科学   3993篇
基础医学   16458篇
口腔科学   2872篇
临床医学   8571篇
内科学   23062篇
皮肤病学   3422篇
神经病学   9342篇
特种医学   5168篇
外国民族医学   32篇
外科学   19542篇
综合类   1600篇
一般理论   29篇
预防医学   6126篇
眼科学   3444篇
药学   8291篇
中国医学   326篇
肿瘤学   6680篇
  2018年   927篇
  2017年   796篇
  2016年   1112篇
  2015年   1246篇
  2014年   1622篇
  2013年   2400篇
  2012年   3451篇
  2011年   3510篇
  2010年   2058篇
  2009年   1997篇
  2008年   3565篇
  2007年   3828篇
  2006年   3958篇
  2005年   4081篇
  2004年   4005篇
  2003年   3836篇
  2002年   3783篇
  2001年   7203篇
  2000年   7216篇
  1999年   5988篇
  1998年   1641篇
  1997年   1561篇
  1996年   1339篇
  1995年   1209篇
  1994年   1094篇
  1993年   1122篇
  1992年   3770篇
  1991年   3579篇
  1990年   3564篇
  1989年   3350篇
  1988年   2989篇
  1987年   2903篇
  1986年   2805篇
  1985年   2618篇
  1984年   1943篇
  1983年   1595篇
  1982年   927篇
  1981年   915篇
  1980年   765篇
  1979年   1823篇
  1978年   1346篇
  1977年   1111篇
  1976年   936篇
  1975年   1178篇
  1974年   1213篇
  1973年   1199篇
  1972年   1040篇
  1971年   975篇
  1970年   881篇
  1969年   787篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
The detection of antineuronal antibodies against cytoplasm and nuclei of Purkinje cells is considered to be an essential factor in the diagnosis of neurologic paraneoplastic syndromes. Published data rely on different immunological methods and relatively small numbers of patients. The clinical relevance of this phenomenon is not clear from the literature. A positive correlation between antibody detection and the appearance of neurologic paraneoplastic syndromes has been reported, but this finding has been questioned in critical reviews.  相似文献   
42.
Summary A necrotizing, nonprogressive myopathy with unusual paracrystalline inclusion bodies is described in a patient who underwent long-term treatment with megadoses of vitamin E. The clinical course and morphological findings suggest a close relationship to the administration of the vitamin. The theoretical pathogenesis of muscle damage and the possible origin of paracrystalline inclusion bodies are discussed.Presented at the Jahrestagung der österreichischen Gesellschaft für Neuropathologie in Bad Ischl, on April 17, 1986This study was supported by a grant from the Deutsche Forschungsgemeinschaft (Ba 916)  相似文献   
43.
BACKGROUND: Alternaria alternata is one of the most important allergenic fungi worldwide. Mannitol dehydrogenase (MtDH) has previously been shown to be a major allergen of Cladosporium herbarum and cross-reactivity has been demonstrated for several fungal allergens. OBJECTIVE: The present study's objective was to clone the MtDH from an A. alternata cDNA library, express and purify the recombinant non-fusion protein and test its IgE-binding properties. Methods A cDNA library prepared from A. alternata hyphae and spores was screened for mannitol dehydrogenase by DNA hybridization with the radioactively labelled C. herbarum homologue as a probe. The resulting clone was sequenced and heterologously expressed in Escherichia coli as a recombinant non-fusion protein, which was purified to homogeneity and analysed for its IgE-binding capacity. RESULTS: The coding sequence of the full-length cDNA clone comprises 798 bp encoding a protein with a molecular mass of 28.6 kDa and a predicted pI of 5.88. Protein sequence analysis revealed an identity of 75% and a homology of 86% between the MtDHs of A. alternata and C. herbarum. The functional mannitol dehydrogenase was expressed in the E. coli strain BL21(DE3) transformed with the vector pMW172 and purified to homogeneity. The enzyme catalyses the NADPH-dependent conversion of d-fructose to d-mannitol. In IgE-ELISA and immunoblots, MtDH is recognized by 41% of A. alternata-allergic patients. In vivo immunoreactivity of the recombinant MtDH was verified by skin prick testing. Finally, inhibition-ELISA experiments confirmed cross-reactivity between the MtDHs of A. alternata and C. herbarum. CONCLUSION: Mannitol dehydrogenase (Alt a 8) represents an important new allergen of the ascomycete A. alternata that might be suitable for improving diagnostic and therapeutic procedures.  相似文献   
44.
45.
Fire fighter helmet ventilation analysis   总被引:1,自引:0,他引:1  
A series of wind tunnel tests was conducted on selected fire fighter helmets to identify design factors which affect helmet ventilation at various air velocities and head orientation angles. Biomedical heat flux transducers were mounted on the surface of an electrically heated mannequin head to monitor convective heat loss. Under the experimental conditions, specific helmet design features were identified which can contribute to improved helmet ventilation and thus improve body metabolic heat loss. Attention to helmet design and helmet suspension systems is recommended to reduce fire fighter heat stress.  相似文献   
46.
47.
48.
49.
Presented in this work is a rare injury of a blunt abdominal trauma in a child. Besides a partial rupture of the kidney and a retro-/intraperitoneal haematoma, a further injury occurred from the accident: an initially clinically indetectable tear of the A. iliaca communis which was found intraoperatively and with systematic CT analysis. Traumatic blood vessel lesions of the abdominal aorta and in particular the iliac blood vessels are very rare in children. By such violent impact injuries, it is therefore vital to perform a clinical examination of the foot pulse, systematic analysis of radiology diagnostics, and intraoperative exploration. The growth phase should be considered for therapy of the blood vessels depending on the child's age group. As the long-term results of graft implants are practically unknown, if possible a primary suture or vein patch should be performed.  相似文献   
50.
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