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   3848篇
  免费   228篇
  国内免费   16篇
耳鼻咽喉   10篇
儿科学   110篇
妇产科学   115篇
基础医学   530篇
口腔科学   36篇
临床医学   361篇
内科学   1000篇
皮肤病学   69篇
神经病学   338篇
特种医学   90篇
外科学   397篇
综合类   6篇
预防医学   185篇
眼科学   28篇
药学   329篇
中国医学   12篇
肿瘤学   476篇
  2024年   5篇
  2023年   27篇
  2022年   75篇
  2021年   106篇
  2020年   83篇
  2019年   93篇
  2018年   128篇
  2017年   86篇
  2016年   102篇
  2015年   105篇
  2014年   142篇
  2013年   187篇
  2012年   281篇
  2011年   318篇
  2010年   154篇
  2009年   177篇
  2008年   300篇
  2007年   267篇
  2006年   244篇
  2005年   246篇
  2004年   224篇
  2003年   200篇
  2002年   200篇
  2001年   24篇
  2000年   23篇
  1999年   32篇
  1998年   33篇
  1997年   20篇
  1996年   27篇
  1995年   16篇
  1994年   17篇
  1993年   21篇
  1992年   21篇
  1991年   17篇
  1990年   10篇
  1989年   15篇
  1988年   7篇
  1987年   7篇
  1986年   5篇
  1985年   10篇
  1984年   7篇
  1983年   7篇
  1982年   6篇
  1981年   4篇
  1980年   2篇
  1979年   2篇
  1978年   2篇
  1977年   4篇
  1967年   1篇
  1935年   1篇
排序方式: 共有4092条查询结果,搜索用时 15 毫秒
61.
PURPOSE: We report the case of a male newborn with Ohtahara syndrome and right hemimegalencephaly who presented epileptic negative myoclonus in the first days of life. METHODS: Prolonged polygraphic studies were performed, as well as MRI and a full clinical examination. RESULTS: EEG showed a constant and nonreactive pattern of burst suppression. There were several kinds of electro-clinical seizures (generalized myoclonia, short atonias, typical spasm and tonic spasms) at the beginning of the EEG's burst. The periods of EMG silence, lasting less than 300 ms, were associated with stereotyped EEG transients. CONCLUSIONS: Epileptic negative myoclonus can be observed also in neonatal age. The short transient impairment of motor function observed in the newborn seems linked to the slow component of spike-wave discharge, but its mechanism is still not clear.  相似文献   
62.
We report two cases of histoplasmosis occurring in human immunodeficiency virus-positive patients who immigrated to Italy, and focus our attention on the clinical features and therapeutic aspects, with particular emphasis on secondary prophylaxis. The patients had comparable human immunodeficiency virus baseline parameters, but had a completely different compliance over therapeutic regimens. The two patients were followed in two different city hospitals of our region, Padua and Verona, and the diagnosis was made on the basis of instrumental, histologic, and microbiologic findings. One of them was treated with corticosteroids because of nephrotic syndrome.  相似文献   
63.
Glycoprotein Po (Po) and peripheral myelin protein 22 (PMP22) are two proteins playing a crucial physiological role in the maintenance of the multilamellar structure of peripheral myelin. We here demonstrate that the removal of circulating androgens by orchidectomy induces a significant decrease of the synthesis of Po and PMP22 in the rat sciatic nerve. In case of Po, this effect may be counteracted by the subsequent treatment with testosterone metabolites, dihydrotestosterone or 5alpha-androstan-3alpha,17beta-diol (3alpha-diol). Experiments have been consequently performed in order to evaluate the role of androgen receptor (AR) in the control of Po synthesis. In vivo treatment with flutamide (i.e., an antagonist of AR) induces a decrease of the synthesis of this myelin protein in the sciatic nerve of intact male rats confirming a role for this steroid receptor. On the contrary, PMP22 seems not to be under the control of AR, but a role for GABAA receptor may be proposed. This concept is based on the findings that: (a) only 3alpha-diol, which is able to interact with GABAA receptor, is effective in stimulating the synthesis of PMP22 in the sciatic nerve of castrated male rats, and (b) flutamide treatment is ineffective in decreasing the protein levels in intact male rats. The observations here reported clearly show similarities and dissimilarities with the effects exerted by other members of neuroactive steroid family, like for instance progesterone derivatives, which will be discussed in text.  相似文献   
64.
65.
66.
Fusariosis is a hyalohyphomycosis due to Fusarium species that mainly occurs in immunocompromised hosts. The clinical spectrum of Fusarium infection comprises localized and disseminated forms. A case of localized cutaneous fusariosis caused by Fusarium solani in a renal transplant patient is described, and the skin manifestations of the disease are discussed.  相似文献   
67.
68.
Activity-guided fractionation was used to determine the antibacterial component of an ethanolic extract of the leaves of an Australian native medicinal plant, Eremophila duttonii F. Muell. (Myoporaceae). The extract, previously shown to have activity against Gram positive bacteria, was shown to have activity against additional Gram positive bacteria, including Clostridium perfringens, C. sporogenes and Listeria monocytogenes. Thin layer chromatography (TLC) was used to separate the extract into seven coloured fractions in visible light, one of which was shown by bioautography to contain antibacterial activity. Recovery of the component from the TLC plate and testing for antibacterial activity using a plate-hole diffusion assay supported this result. The purity of the component was verified by high-performance liquid chromatography and a time-kill experiment indicated that the purified component showed identical bactericidal activity to the whole extract. TLC spray reagents indicated that the component was a sterol, terpene or sugar but not a flavonoid, while the pigmented nature suggested a carotenoid.  相似文献   
69.
BACKGROUND: Papular xanthoma (PX) is a rare normolipidemic non-Langerhans cell histiocytoxanthomatosis affecting both children and adults. OBJECTIVE: We describe an adult case of PX associated with angiokeratoma of Fordyce and review the literature in order to compare and discuss previous reports. METHODS: We studied the clinical, histopathological, immunocytochemical and ultrastructural findings. RESULTS: We report the findings of our case and compare our case with those described in the literature. CONCLUSIONS: Three clinical patterns of PX appeared to emerge in the review of the literature: a self-healing form, a persistent form and a progressive form. The progressive form of PX can be considered the same clinical entity that is also described as progressive nodular histiocytosis.  相似文献   
70.
Acute mediastinitis is an uncommon and potentially devastating infection. Generally, mediastinitis occurs as a postoperative infection following median sternotomy. We describe a case of acute mediastinitis in a patient with ischaemic heart disease, secondary to the spread of cutaneous infection of the chest wall in the application site of transdermal nitroglycerine patches.  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