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   2837篇
  免费   290篇
  国内免费   64篇
耳鼻咽喉   17篇
儿科学   93篇
妇产科学   14篇
基础医学   445篇
口腔科学   92篇
临床医学   247篇
内科学   384篇
皮肤病学   117篇
神经病学   510篇
特种医学   151篇
外科学   317篇
综合类   74篇
预防医学   180篇
眼科学   72篇
药学   172篇
中国医学   1篇
肿瘤学   305篇
  2021年   49篇
  2020年   37篇
  2019年   50篇
  2018年   46篇
  2017年   33篇
  2016年   47篇
  2015年   53篇
  2014年   53篇
  2013年   79篇
  2012年   115篇
  2011年   97篇
  2010年   88篇
  2009年   86篇
  2008年   105篇
  2007年   126篇
  2006年   114篇
  2005年   117篇
  2004年   96篇
  2003年   90篇
  2002年   97篇
  2001年   89篇
  2000年   85篇
  1999年   97篇
  1998年   80篇
  1997年   62篇
  1996年   55篇
  1995年   53篇
  1994年   33篇
  1993年   52篇
  1992年   90篇
  1991年   79篇
  1990年   66篇
  1989年   77篇
  1988年   68篇
  1987年   60篇
  1986年   42篇
  1985年   53篇
  1984年   39篇
  1983年   36篇
  1982年   21篇
  1981年   23篇
  1980年   32篇
  1979年   24篇
  1977年   20篇
  1976年   20篇
  1975年   22篇
  1974年   18篇
  1972年   25篇
  1971年   20篇
  1970年   18篇
排序方式: 共有3191条查询结果,搜索用时 31 毫秒
1.
The initial management of bladder outflow obstruction typically related to benign prostatic hyperplasia (BPH) falls to a large extent within the remit of general practice. Referral onwards to secondary care typically arises following the failure to respond to conservative measures or when complications have supervened; the most significant of which is urinary retention. In the hospital setting, anaesthesia, constipation and immobility are the common precipitants. What follows is a practical guide to the management of these situations and provides an overview of the conservative, medical, minimally invasive and surgical treatments available.  相似文献   
2.
3.
Mouse polyclonal antisera were raised to the Mr 130,000 and Mr 115,000 cell surface glycoproteins, desmocollins, of desmosomes from bovine nasal epithelium. Immunoblotting confirmed that the antisera were specific for the desmocollins. An immunofluorescence study showed that the antisera distinguished between the basal and suprabasal layers of bovine and human epidermis. The antibodies reacted with cultured keratinocytes only after calcium-induced stratification. In epidermis, therefore, there appears to be a difference between the desmocollins of basal and suprabasal cells that may be important in relation to epidermal differentiation. Previous work has shown that polyclonal antisera raised in other animals (guinea pigs and rabbits) against desmocollins, as well as against other desmosomal components, react with all desmosome-containing epithelia. In contrast, an immunofluorescence survey of bovine, rat, and human tissues showed that the present mouse antisera stained only suprabasal skin cells and the arachnoid layer of the meninges, demonstrating that these have common determinants that distinguished their desmocollins from those of all other tissues. The antibodies also stained 11 of 12 meningiomas and, therefore, may be useful as a marker not only for the diagnosis of these tumors but also for investigation of their histogenesis.  相似文献   
4.
5.
Children with pure depression or depression plus an anxiety-related disorder (n = 14) had a higher drug response rate (57%) and a lower placebo response rate (20%) when compared to children with depression plus a concomitant conduct or oppositional disorder (n = 17) (33% drug response rate and 67% placebo response rate). These findings could explain why studies of prepubertal-onset depression found no differences between drug and placebo treatment assuming that a large percentage of the studies' subjects had concomitant conduct or oppositional disorders. The children with pure depression or depression plus an anxiety-related disorder had different symptom clusters from those with depression plus a concomitant conduct or oppositional disorder. The former had more severe CDRS ratings on sleep, appetite disturbance, depressed feelings, and psychomotor retardation. In contrast, those with a concomitant conduct or oppositional disorder had shorter attention spans and were more likely to disturb other children (based on Conners scale scores).  相似文献   
6.
7.
8.
9.
Summary Single-chain toxin was investigated in vitro and in vivo for limited proteolysis into the fully active two-chain toxin. Plasmin from serum, elastase and gelatinase from leucocytes, as well as clostripain from C. histolyticum cleaved single-chain toxin and increased by that way its ability to inhibit [3H]noradrenaline release in vitro. Cultured mouse brain generated fragments from 125I-single-chain toxin which were cell-associated. Some of them comigrated in electrophoresis with light and heavy chain after mercaptolysis. When injected i. v. into rats, 125I-single-chain-toxin disappeared from the blood with a half-life of about 11 h without signs of nicking. However, after its injection into the triceps surae muscle both single- and two-chain toxin were found in the ipsilateral ventral horn of the spinal cord. Thus single-chain toxin is subjected to limited proteolysis by enzymes involved in tissue damage, by cultured brain tissue, and during or after its retrograde axonal transport to the spinal cord. Limited proteolysis is necessary for the release of the light chain known to mediate the action of toxin on several systems.  相似文献   
10.
The exact regional correlation of findings of facial bone scans, planar or SPECT, to dental orthopan X-ray films (OPT) is difficult because of the very different projection techniques. To improve correlative imaging in this regard a projection algorithm was developed that uses SPECT data of the skull for reconstructing an orthopan tomoscintigraphic projection. Fourteen conventional SPECT slices of the upper and lower jaws were obtained during bone scanning. All mandibular slices were superimposed resulting in a horseshoe shaped structure, which was marked by an ROI which was divided into segments. All 14 SPECT slices were then masked by this segmental ROI, thereby marking the teeth-carrying bone in all slices. The information from this horseshoe like ROI is then transformed into lines. Line by line arrangement results in an orthopan projection, the orthopan tomoscintigram. This new display allows 1:1 true scale superimposition with the X-ray OPT and markedly facilitates correlative imaging.  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