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   383154篇
  免费   24365篇
  国内免费   2825篇
耳鼻咽喉   5200篇
儿科学   8298篇
妇产科学   10121篇
基础医学   53662篇
口腔科学   11911篇
临床医学   30338篇
内科学   79191篇
皮肤病学   8592篇
神经病学   27637篇
特种医学   14120篇
外国民族医学   82篇
外科学   61441篇
综合类   9973篇
现状与发展   1篇
一般理论   64篇
预防医学   17550篇
眼科学   9506篇
药学   31177篇
  7篇
中国医学   2213篇
肿瘤学   29260篇
  2021年   2767篇
  2019年   2801篇
  2018年   4606篇
  2017年   3490篇
  2016年   3600篇
  2015年   4131篇
  2014年   5831篇
  2013年   7511篇
  2012年   10208篇
  2011年   10394篇
  2010年   6300篇
  2009年   5936篇
  2008年   9618篇
  2007年   10472篇
  2006年   10400篇
  2005年   9449篇
  2004年   8992篇
  2003年   8696篇
  2002年   8389篇
  2001年   28299篇
  2000年   28848篇
  1999年   23718篇
  1998年   5222篇
  1997年   4287篇
  1996年   3893篇
  1995年   3521篇
  1994年   3149篇
  1993年   2859篇
  1992年   16099篇
  1991年   14859篇
  1990年   14205篇
  1989年   14006篇
  1988年   12621篇
  1987年   12087篇
  1986年   11134篇
  1985年   10349篇
  1984年   6939篇
  1983年   5635篇
  1982年   2729篇
  1979年   5507篇
  1978年   3359篇
  1977年   2992篇
  1975年   2655篇
  1974年   3091篇
  1973年   2884篇
  1972年   2846篇
  1971年   2788篇
  1970年   2523篇
  1969年   2551篇
  1968年   2266篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
This study focuses on obtaining more information about the site of anastomosis, with three-dimensional examination using methylmethacrylate resin (Mercox) corrosion casts. Seventy microvascular anastomoses were performed in Wistar albino rats, divided into two groups before sacrifice. In Group 1 (35), Mercox was injected into the vessels, whereas in Group 2 (35), the tissues were prepared without injecting Mercox. Both groups were compared under the scanning electron microscope (SEM). The SEM preparation in Group 1 was simple, easy, and artifacts were significantly minimized. The anastomotic site could be well appreciated in three-dimensional views. Clear negative imprints of the endothelial surface were achieved without any breakage in the Mercox corrosion cast, and it can be reliably used in the evaluation of small vessel anastomosis.  相似文献   
82.
Experience in the treatment of 30 cases with gas gangrene from war wounds   总被引:1,自引:0,他引:1  
Z Y Li  X L Wang  X S Wang 《中华外科杂志》1986,24(10):580-1, 637
  相似文献   
83.
We experienced one necropsy case of brainstem encephalitis of Iizuka type (BSE) and one necropsy case of the brain-stem syndrome (BSS) of typical neuro-Beh?et's disease, and compared them clinically and neuropathologically. Clinically both of these cases showed chronic progressive mental disturbance, pseudobulbar paresis, spastic tetraparesis, cerebrospinal fluid pleocytosis, increased protein, and brainstem atrophy observed by X-CT. Neuropathologically, irregular, boundary-indistinct demyelinating lesions and obsolete softening lesions were sporadically found, associated with perivascular lymphocytic infiltration and gliosis centering on the brainstem. In this way, both cases were similar in many points except for the presence or absence of cutaneo-muco-ocular signs specific for Beh?et's disease. Also BSE and BSS reports in the literature showed that both diseases were similar not only in clinical findings consisting of mental disturbance and brainstem signs but also in neuropathological findings with similar topographical distribution of the same histopathological changes, including the variations and diversity of these characteristics. Especially of much interest is their similarity in characteristic mental disturbance. In discriminating BSE from multiple sclerosis and other diseases with exclusive involvement of the brainstem, it is important to understand their clinical characteristics. The characteristic mental disturbance includes damage to memory and sentiment, a change in personality, and lowering in spontaneity, but calculation ability and orientation are comparatively preserved. Of course the similarity in clinical and neuropathological findings does not necessarily mean the identical etiopathogenesis. However, it is possible to consider that neuro-Beh?et's disease (syndrome) may form a wide spectrum with BSE and typical neuro-Beh?et's disease at the both ends, regarding the time and spatial diversity of the appearance of cutaneo-muco-ocular signs.  相似文献   
84.
85.
For monitoring the changes in intracellular free Ca2+ concentration ([Ca2+]i), we developed a simple system combining a fluorescence microscope, an image intensifier, a video-camera, a cathode ray tube display and a photodiode, employing quin2 as a Ca2+ indicator. We recorded increases of the fluorescence intensity due to [Ca2+]i rises, when high K+ medium, neurotransmitter and Ca2+ ionophore were applied to the single cells of nervous system origin in culture. The present system is capable of simultaneous detection of the [Ca2+]i changes from multiple separate cells.  相似文献   
86.
Phenytoin-induced gingival overgrowth is a recognized side effect in many cerebral palsy patients using diphenyl hydantoin for the control of seizures. Severe gingival overgrowth in these patients can affect normal masticatory function, lead to poor occlusal development, and compromise esthetics. This report addresses the complex nature of treating phenytoin-induced gingival overgrowth in a mentally retarded 20-year-old female patient. For this patient, full-mouth gingivectomy procedure was performed under general anesthesia in a single session. Post operative follow-up was uneventful. This article discusses major indications, contraindications, and protocols to be followed for periodontal surgical procedures done under general anesthesia.  相似文献   
87.
88.
In this new radioimmunoassay system for determination of amatoxins in urine and plasma, a novel chemical approach is used for antigen and 125I-tracer production, based on a detoxified alpha-amanitin derivative (aldoamanitin). Total assay time, including data processing, is less than 100 min. The lowest detectable concentration is 1 microgram/L for urine, 0.1 microgram/L for plasma. In the clinically significant range, within-run CVs are less than 8%. This new 125I-based assay is a significant improvement over existing 3H technology in terms of speed, precision, and freedom from interference.  相似文献   
89.
90.
Bilateral cervical lymph node dissection was performed in 71 cases of papillary thyroid carcinoma, considered to be relatively early cases because of mobility, irrespective of the size of tumor or presence of node enlargement. Of these, 33 cases received additional node dissection of the anterosuperior mediastinum through longitudinal sternotomy. The number of lymph nodes examined per subject averaged 89.9, the number of metastatic nodes was 13.8, and metastasis was noted in 88.7% of all cases. Lymph node metastasis tended to be more frequent on the affected side, but was simultaneously scattered over the whole cervical area. As to sites, metastasis of paratracheal nodes on the affected side occurred at a frequency of 66.2%, inferior and superior jugular nodes at 62.0% and 59.0% respectively, pretracheal nodes at 50.7%, and tracheoesophageal nodes at 47.9%. The high incidence of para- and pretracheal nodes suggests that the lymph flow in this direction is of great importance in metastasis. In fact, lymph nodes in the mediastinum, which were directly continuous with these nodes, showed as high as 39.4% metastasis in cases of anterosuperior mediastinal extirpation. This extensive node dissection is considered to be very preferable as at least the agony of survival with carcinoma can be lessened.  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