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   8671篇
  免费   1589篇
  国内免费   162篇
耳鼻咽喉   127篇
儿科学   150篇
妇产科学   64篇
基础医学   1798篇
口腔科学   352篇
临床医学   1006篇
内科学   822篇
皮肤病学   43篇
神经病学   874篇
特种医学   311篇
外国民族医学   1篇
外科学   517篇
综合类   814篇
预防医学   2027篇
眼科学   113篇
药学   555篇
  5篇
中国医学   476篇
肿瘤学   367篇
  2023年   376篇
  2022年   283篇
  2021年   238篇
  2020年   169篇
  2019年   178篇
  2018年   305篇
  2017年   63篇
  2016年   416篇
  2015年   745篇
  2014年   613篇
  2013年   586篇
  2012年   417篇
  2011年   269篇
  2010年   388篇
  2009年   362篇
  2008年   236篇
  2007年   76篇
  2006年   92篇
  2005年   146篇
  2004年   562篇
  2003年   128篇
  2002年   124篇
  2001年   117篇
  2000年   39篇
  1999年   63篇
  1998年   170篇
  1997年   255篇
  1996年   263篇
  1995年   219篇
  1994年   341篇
  1993年   221篇
  1992年   261篇
  1991年   264篇
  1990年   248篇
  1989年   181篇
  1988年   193篇
  1987年   79篇
  1986年   122篇
  1985年   110篇
  1984年   94篇
  1983年   60篇
  1982年   108篇
  1981年   74篇
  1980年   45篇
  1979年   32篇
  1978年   27篇
  1977年   23篇
  1976年   14篇
  1975年   13篇
  1973年   9篇
排序方式: 共有10000条查询结果,搜索用时 515 毫秒
51.
The development of aberrant pigmentation represents an unwelcome complication to an otherwise successful split skin graft resulting in a loss of colour match and, so it follows, of cosmesis. We present two cases where lasers have been successful in the treatment of this problem.  相似文献   
52.
53.
In this report, we give details of two families in which fixed subaortic stenosis was found in more than one member. It is rare for this entity to show familial incidence.  相似文献   
54.
S. WAKI 《Parasite immunology》1994,16(11):587-591
The effects of administrating recombinant human granulocyte colony-stimulating factor (rhG-CSF) and passively transferring immune serum on infection with an attenuated variant of Plasmodium berghei XAT (Pb XAT), in severe combined immunodeficiency (SCID) mice were examined. In immune competent (C.B-17) mice, the attenuated parasite infection was inevitably self-resolving and degenerating forms inside erythrocytes appeared, coinciding with the drop in parasitaemia, whereas SCID mice were unable to control parasite growth and all the mice died. Continuous administration with rhG-CSF caused neutrophilic granulocytosis in both SCID and C.B-17 mice. The effect of rhG-CSF on the infection in C.B-17 mice was to suppress the course of the parasitaemia at an early phase whereas it had no effect in SCID mice. When immune serum was transferred on the day of infection, the prepatent period was prolonged two days in both SCID and C.B-17 mice. When administration with rhG-CSF was combined with transfer of immune serum, SCID mice showed four days delay in patency and degenerating parasites were seen during the course of parasitaemia, although the infection was ultimately fatal. C.B-17 mice similarly treated showed a seven day delay in the onset of the patent parasitaemia which was of a lesser magnitude and shorter in duration compared with control mice. On the other hand, when C.B-17 mice were splenectomized three weeks before infection and then treated with rhG-CSF and immune serum, no degenerating parasites were seen during the infection and all mice died with high parasitaemias. These results show that antibody-dependent neutrophil-mediated parasite killing may occur in the spleen of mice infected with P. berghei XAT.  相似文献   
55.
甲状腺功能亢进性心脏病的围术期处理   总被引:1,自引:0,他引:1  
目的探讨甲状腺功能亢进(甲亢)性心脏病的围术期处理的方法与效果。方法对98例甲亢性心脏病围手术期的处理措施和效果结合文献进行分析总结。结果98例经充分术前准备和精确的心功能评估达手术要求,再配合术中恰当的麻醉、轻柔快捷的手术、合理的术后处理,本组除1例中止手术外,其余均顺利完成手术,围术期无心血管并发症出现。结论甲亢性心脏病并非甲亢手术的禁忌证,A-B级心功能下进行手术是安全的。  相似文献   
56.
Intermediate filaments derived from different cell types are antigenically distinct. Monoclonal antibodies to human intermediate filament proteins can, therefore, be used as tissue-specific reagents capable of distinguishing cell type in poorly differentiated neoplasms. We report a case demonstrating the specificity of antiintermediate filament protein antibodies in establishing a difficult orbital diagnosis of esthesioneuroblastoma.  相似文献   
57.
Transformation of a Drosophila virilis white mutant host strain was attempted using a hobo vector containing the D. melanogaster mini-white+ cassette (H[w+, hawN]) and an unmodified or heat shock regulated hobo transposase helper. Two transformant lines were recovered with the unmodified helper (HFL1), one containing only the white+ marked vector, and a sibling line containing the vector as well as an HFL1 helper integration. An approximate total transformation frequency of 1% is deduced. A high frequency of wing and eye morphology mutants were also observed, suggesting that hobo may have mobilized a related element in D. virilis. The data reaffirms a relatively low transformation vector activity for the hobo transposon in D. virilis; however, nearly full interspecific expression of the white+ marker supports its possible function in other species as well.  相似文献   
58.
Melanoses of the gastrointestinal tract   总被引:4,自引:0,他引:4  
Electronmicroscopy and electron probe energy dispersive X-ray analysis studies have substantially contributed to our understanding of the various gastrointestinal tract melanoses. The nature of the pigment granules which occur in the various melanoses is discussed; their pattern of distribution in melanosis coli, melanosis ilei, melanosis duodeni and melanosis oesophagi is summarized and current knowledge of the aetiology and pathogenesis of these conditions is reviewed. Brief mention is also made of other examples of lipofuscin pigmentation, and a case of haemosiderosis ilei is described.  相似文献   
59.
Nodular hyperplasia surrounding fibrolamellar carcinoma   总被引:2,自引:0,他引:2  
We report a case of acetaminophen-induced liver necrosis in a 14-year-old girl. At autopsy, a 9 cm subcapsular nodule was present in the right lobe of the liver which showed distinct zonation: a central greyish white area of fibrolamellar carcinoma with a peripheral fleshy, tan-coloured rim ranging from 1 to 2 cm in thickness. This peripheral zone consisted of nodular, hyperplastic parenchyma resembling the changes seen in focal nodular hyperplasia, and stood out from the adjacent necrotic parenchyma. The sparing of this zone from the deleterious effects of acetaminophen provides indirect evidence of a predominantly arterial rather than portal blood supply to this region. The arterial supply was most probably derived from the tumour vasculature and may explain the parenchymal hyperplasia sometimes reported adjacent to a fibrolamellar carcinoma. Awareness of this phenomenon is essential when evaluating a needle biopsy, as sampling of this region may lead to a false negative diagnosis.  相似文献   
60.
In human cortex and hippocampus area, [3H]5-HT (5 nM) labels 5-HT1A, 5-HT1D and 5-HT1E sites. After masking 5-HT1A receptors by 0.1 μM 8-OH-DPAT, the binding displaced by 0.1 μM 5-CT presumably represented 5-HT1D sites and the remaining binding 5-HT1E sites. In frontal cortex, 5-HT1A receptors represented the main binding in layers II and VI and a lower fraction on other layers. 5-HT1D and 5-HT1E sites, were more homogeneously distributed in layers II to VI (21–34% of specific [3H]5-HT binding). 5-HT1E sites were of similar affinities (KD close to 6–8 nM) in the cortical layers II to VI. In CA1 field of hippocampus, (pyramidal layer, stratum radiatum, molecular layer), CA2 and dentate gyrus, 5-HT1A receptors represented the major fraction, 5-HT1D sites a significant fraction and 5-HT1E a minor fraction of the specific [3H]5-HT binding. In CA3–CA4 fields, 5-HT1A receptors were less densely present, 5-HT1D sites were predominant and 5-HT1E sites represented a significant fraction (27%). The highest densities of 5-HT1E sites have been measured in subiculum, where 5-HT1A, 5-HT1D, and 5-HT1E binding sites were equally represented and in entorhinal cortex where 5-HT1E sites represented the major binding in layer III. They were also present in layers II and IV (29 and 24%) and, to a lesser extent, in layers V and VI. 5-HT1A sites were predominant in layer VI, II and V and were less abundant in other layers. 5-HT1D were homogeneously present in layers II, III, IV and were present in low amounts in other layers. No 5-HT1E were detected in choroid plexus, where [3H]5-HT was dramatically reduced by mesulergine (5-HT2C receptors). No significant displacement of [3H]5-HT by mesulergine was measured in other structures.  相似文献   
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