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   12062篇
  免费   703篇
  国内免费   155篇
耳鼻咽喉   198篇
儿科学   101篇
妇产科学   145篇
基础医学   2154篇
口腔科学   338篇
临床医学   995篇
内科学   1944篇
皮肤病学   468篇
神经病学   1050篇
特种医学   797篇
外科学   1615篇
综合类   157篇
一般理论   2篇
预防医学   487篇
眼科学   278篇
药学   1292篇
  1篇
中国医学   151篇
肿瘤学   747篇
  2024年   7篇
  2023年   82篇
  2022年   292篇
  2021年   478篇
  2020年   203篇
  2019年   304篇
  2018年   365篇
  2017年   284篇
  2016年   395篇
  2015年   508篇
  2014年   660篇
  2013年   752篇
  2012年   1065篇
  2011年   994篇
  2010年   647篇
  2009年   559篇
  2008年   765篇
  2007年   764篇
  2006年   664篇
  2005年   570篇
  2004年   462篇
  2003年   394篇
  2002年   324篇
  2001年   229篇
  2000年   199篇
  1999年   141篇
  1998年   99篇
  1997年   82篇
  1996年   70篇
  1995年   51篇
  1994年   41篇
  1993年   38篇
  1992年   43篇
  1991年   38篇
  1990年   38篇
  1989年   45篇
  1988年   35篇
  1987年   31篇
  1986年   29篇
  1985年   26篇
  1984年   15篇
  1983年   8篇
  1982年   21篇
  1981年   13篇
  1980年   13篇
  1979年   9篇
  1978年   11篇
  1977年   14篇
  1976年   14篇
  1975年   7篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
The aim of this study was to design a new intravenous blood–gas exchange device and to estimate the design characteristics of the device with a dimensionless function by using a substance that can be used instead of bovine blood. In addition, the characteristics of oxygen transfer were estimated using empirical formulas and the reliability of the equations was ascertained by comparing their output with an experiment performed using bovine blood. The dimensionless function was derived using distilled water and bovine blood to estimate the oxygen transfer rate. Using the derived equations, the calculated oxygen transfer rates for bovine blood and distilled water were similar for Reynolds numbers ranging from 0.7 to 7.0. Therefore, it is possible to estimate the oxygen transfer rate in bovine blood, which is a non-Newtonian fluid, using distilled water, which is a Newtonian fluid. Moreover, it was possible to verify the related equations because the oxygen transfer rate could be estimated using the derived equations, according to the diameters of the various device modules.  相似文献   
5.
Previously, we prepared two different monoclonal antibodies (mAbs) against human 4-1BB (CD137): an agonistic mAb BBK-1 and an antagonistic mAb BBK-2. In this paper, we describe the molecular cloning of these two mAbs and present comparisons of their amino acid sequences. cDNAs encoding the heavy (H) and light (L) chains of the two mAbs were cloned by screening of cDNA libraries constructed from hybridomas secreting these mAbs. Comparisons of amino acid sequences of the two mAbs showed that, while the constant regions of the H and L chains were identical between the two mAbs, the variable region showed 45% identity in H chains and 48% identity in L chains. This suggests that these two mAbs recognize different epitopes of 4-1BB and may have different effects on the activity of 4-1BB.  相似文献   
6.
7.
The present study investigated the role of central metabotropic glutamate receptors (mGluRs) in interleukin-1beta (IL-1beta)-induced mechanical allodynia and mirror-image mechanical allodynia in the orofacial area. Experiments were carried out on male Sprague-Dawley rats weighing 230 to 280 g. After administration of 0.01, 0.1, 1, or 10 pg of IL-1beta into a subcutaneous area of the vibrissa pad, we examined the withdrawal behavioral responses produced by 10 successive trials of an air-puff ramp pressure applied ipsilaterally or contralaterally to the IL-1beta injection site. Subcutaneous injection of IL-1beta produced mechanical allodynia and mirror-image mechanical allodynia in the orofacial area. Intracisternal administration of CPCCOEt, a mGluR1 antagonist, or MPEP, a mGluR5 antagonist, reduced IL-1beta-induced mechanical allodynia and mirror-image mechanical allodynia. Intracisternal administration of APDC, a group II mGluR agonist, or L-AP4, a group III mGluR agonist, reduced both IL-1beta-induced mechanical allodynia and mirror-image mechanical allodynia. The antiallodynic effect, induced by APDC or L-AP4, was blocked by intracisternal pretreatment with LY341495, a group II mGluR antagonist, or CPPG, a group III mGluR antagonist. These results suggest that groups I, II, and III mGluRs differentially modulated IL-1beta-induced mechanical allodynia, as well as mirror-image mechanical allodynia, in the orofacial area. PERSPECTIVE: Central group I mGluR antagonists and groups II and III mGluR agonists modulate IL-1beta-induced mechanical allodynia and mirror-image mechanical allodynia in the orofacial area. Therefore, the central application of group I mGluR antagonists or groups II and III mGluR agonists might be of therapeutic value in treating pain disorder.  相似文献   
8.
This study examined the relations betweensociotropy, autonomy, and stress severity ratings forhypothetical life events that were objectivelycategorized as interpersonal or achievement-related infocus. The hypothesis that sociotropy and autonomyserve as vulnerability factors to dysphoria in thepresence of life stress that matches the theme of thevulnerability was also examined in 6-week and 12-week follow-up evaluations. Results provided onlypartial support for the predicted relations amongsociotropy, autonomy, and perceived stress severityratings of interpersonal and achievement-related events. Longitudinal results failed to support thehypothesis that sociotropy and autonomy serve asvulnerability factors for matching interpersonal andachievement-related stress. It was concluded thatobjectively categorizing life events as interpersonal orachievement-related is problematic given that themeaning of life events can vary across individuals, andthat these meanings are likely to vary partly as a function of sociotropy and autonomy.  相似文献   
9.
10.
BACKGROUND: We have seen several patients with itchy lichenified plaques located bilaterally on the elbows and/or knees and have named this condition 'psoriatic neurodermatitis' (PN). OBJECTIVE: The purpose of this study was to compare clinical and histopathological characteristics of these patients to those of patients with typical lichen simplex chronicus (LSC). METHODS: Nineteen patients with PN and 34 patients with typical LSC were included. Besides clinical dermatological evaluation, the prick test was carried out on 49 patients; the Phadiatop test on 40 patients; the patch test with European standard series on 47 patients; histopathological evaluation on 39 patients; and clinical psychiatric examination on 38 patients. RESULTS: Almost exclusively, PN was seen in females and was located on the extremities. It caused more plaques than typical LSC did. In PN, the plaques were smaller, sharper, more keratotic and less excoriated, and had fewer lichenoid papules around them. Itching was usually more severe in the evening, while resting and in a hot environment in typical LSC, but not in PN. In plaques of PN, microabscesses in the horny layer, hypogranulosis, regular acanthosis and thinning of the suprapapillary plates were more frequent, and hyperpigmentation in the basal layer was less. In patients with PN, depressive disorder was found more frequently; and generalized anxiety disorder or psychosomatic characteristics, less. There were no significant differences in the results of prick, Phadiatop and patch tests between patients with PN and those with typical LSC. CONCLUSION: In our opinion, it is most likely that the so-called PN is itchy psoriasis superimposed by LSC.  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