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   891篇
  免费   48篇
  国内免费   2篇
耳鼻咽喉   1篇
儿科学   34篇
妇产科学   5篇
基础医学   126篇
口腔科学   12篇
临床医学   36篇
内科学   204篇
皮肤病学   12篇
神经病学   111篇
特种医学   93篇
外科学   85篇
综合类   124篇
预防医学   23篇
眼科学   5篇
药学   21篇
肿瘤学   49篇
  2022年   3篇
  2021年   26篇
  2019年   5篇
  2018年   5篇
  2017年   5篇
  2016年   4篇
  2015年   16篇
  2014年   9篇
  2013年   16篇
  2012年   26篇
  2011年   19篇
  2010年   33篇
  2009年   28篇
  2008年   30篇
  2007年   30篇
  2006年   34篇
  2005年   24篇
  2004年   32篇
  2003年   33篇
  2002年   23篇
  2001年   18篇
  2000年   19篇
  1999年   33篇
  1998年   45篇
  1997年   34篇
  1996年   32篇
  1995年   23篇
  1994年   43篇
  1993年   18篇
  1992年   17篇
  1991年   18篇
  1990年   13篇
  1989年   27篇
  1988年   21篇
  1987年   32篇
  1986年   25篇
  1985年   25篇
  1984年   13篇
  1983年   13篇
  1982年   7篇
  1981年   8篇
  1980年   10篇
  1979年   4篇
  1978年   4篇
  1977年   7篇
  1976年   5篇
  1975年   5篇
  1974年   6篇
  1973年   3篇
  1972年   3篇
排序方式: 共有941条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
5.
6.
In order to evaluate the effects of pentoxifylline on sperm motility and longevity, a controlled in-vitro study was conducted on normozoospermic donor semen samples using the Cellsoft automated system for sperm motility analysis. After incubation and selection, pentoxifylline was found to improve the recovery of spermatozoa and to increase their velocity. In the subgroup of progressively motile spermatozoa, curvilinear velocity was also enhanced. It is concluded that pentoxifylline has an effect on the vigour, but not on the pattern, of sperm motion. Pentoxifylline did not improve the motility characteristics of senescent spermatozoa in normozoospermic sperm samples. Sperm survival, as shown by supra-vital staining, and motility longevity both decreased with time after pentoxifylline treatment.  相似文献   
7.
A 34-year-old woman with no family history of orthochromatic leukodystrophy (OLD) developed progressive intellectual deterioration, a frontal syndrome and spastic tetraparesis. She died four years after the onset of the clinical illness. Neuropathological studies included light and electron microscopy of cerebral and nerve biopsies, and a complete postmortem examination. Light microscopy demonstrated OLD with pigmented macrophages and glial cells. Electron microscopy showed electron-dense, membrane-bound intracytoplasmic lamellar inclusions with curved or straight parallel arrangement, or fingerprint pattern, in white matter macrophages, astrocytes and oligodendrocytes. Cortical cells contained lipofuscin which was normal in type and amount. This suggests that the material in white matter glial cells and macrophages is ceroid pigment, however, the distribution is not that seen in ceroid-lipofuscinosis. Similar inclusions have been found in oligodendrocytes in other forms of OLD. Biochemical study did not show evidence of demyelination. Galactolipids were normal. Polyunsaturated fatty acids were decreased. The most striking feature was an increase in plasmalogens.  相似文献   
8.
9.
A study of 17 patients with autoimmune axonal or demyelinating peripheral neuropathy in combination with M-component is described. The M-component was associated with MGUS (monoclonal gammopathy of undetermined significance) in 12 patients, CLL in one patient, WaldenstrÖm's disease in one patient, and myeloma in three patients. Immunohistological examination with direct and indirect fluorescence showed binding of antibodies to nerve structures of the same class and light chain as seen in the M-component. In five cases of IgM M-component, the demyelinating neuropathy was caused by binding of the IgM M-protein and complement C3b to myelin-associated glycoproteins (MAG). In 12 cases with axonal neuropathy, binding of IgG to the connective tissue of the peri- and endoneurium was found in 50% of cases, IgM in five cases, and IgD in one case. None of the patients had central nervous system (CNS) symptoms. The clinical and therapeutic difficulties are discussed; only two patients with an acute course responded to immunosuppression. A marked co-expression of other autoimmune phenomena is interpreted in the light of cross-reactions between the autoantibody and similar tissue autoantigens.  相似文献   
10.
The occurrence of hyperplastic pacinian corpuscles in the hand is rare, with only 13 cases reported in the literature. We describe such a case in a 70-year-old male who had worked as a locksmith for many years. A grape-like cluster of firm, rice-sized nodules was discovered in the subcutaneous tissue of the finger following a glass-induced injury. Histopathological findings revealed pacinian corpuscles to be increased in size and number. Individual corpuscles consisted of a central nerve fiber surrounded by 35 to 60 concentric lamellae (normal controls from other specimens: 13–15 lamellae). The external corpuscular diameter ranged from 1.8 to 3.2 mm (normal controls from other specimens: 1.6 mm). Immunohistochemistry showed positive staining with Leu 7 antibody and anti-glial fibrillary acidic protein in the small nerves situated in the vicinity of the pacinian corpuscles, but not in the corpuscles themselves. The lesion reported here clearly differed from both neurofibroma with occasional pacinian differentiation and the so-called pacinian neurofibroma. There was no evidence of neurofibromatosis.  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