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   2655717篇
  免费   212868篇
  国内免费   8404篇
耳鼻咽喉   36133篇
儿科学   87112篇
妇产科学   73453篇
基础医学   365088篇
口腔科学   73923篇
临床医学   255800篇
内科学   533104篇
皮肤病学   65203篇
神经病学   222695篇
特种医学   102576篇
外国民族医学   736篇
外科学   400132篇
综合类   50464篇
现状与发展   44篇
一般理论   968篇
预防医学   206306篇
眼科学   58385篇
药学   188601篇
  8篇
中国医学   5336篇
肿瘤学   150922篇
  2021年   21907篇
  2019年   21983篇
  2018年   34623篇
  2017年   28385篇
  2016年   32432篇
  2015年   35711篇
  2014年   48674篇
  2013年   70098篇
  2012年   82998篇
  2011年   87080篇
  2010年   56354篇
  2009年   56365篇
  2008年   81585篇
  2007年   85564篇
  2006年   88258篇
  2005年   83240篇
  2004年   79786篇
  2003年   76839篇
  2002年   74068篇
  2001年   129889篇
  2000年   132246篇
  1999年   111870篇
  1998年   32912篇
  1997年   29423篇
  1996年   29764篇
  1995年   28702篇
  1994年   25915篇
  1993年   24141篇
  1992年   85742篇
  1991年   82065篇
  1990年   79186篇
  1989年   76458篇
  1988年   69868篇
  1987年   68282篇
  1986年   63810篇
  1985年   60716篇
  1984年   45131篇
  1983年   38172篇
  1982年   22626篇
  1981年   20130篇
  1979年   39004篇
  1978年   27539篇
  1977年   23341篇
  1976年   21562篇
  1975年   22860篇
  1974年   26838篇
  1973年   25414篇
  1972年   23802篇
  1971年   21992篇
  1970年   20239篇
排序方式: 共有10000条查询结果,搜索用时 70 毫秒
991.
992.
993.
Abstract Migraine without aura is typically considered a female condition. The purpose of this study was to determine if there have been any changes in the female-to-male ratio of the disease over time. We included in the study all patients with migraine without aura (n=3457) referred to the Parma University Headache Centre between 1976 and 1995. They were divided into subgroups with respect to gender and year-range of onset of migraine (before 1960, in the 1960s, in the 1970s, in the 1980s, and between 1990 and 1995). Gender ratio ranged from 3.6:1 (in patients with onset before 1960) to 2.8:1 (in patients with onset in the 1980s), with no statistically significant changes during the observation period.  相似文献   
994.
Social phobia, fear of negative evaluation and harm avoidance.   总被引:1,自引:0,他引:1  
This naturalistic, prospective investigation examined the role of fear of negative evaluation and the personality trait of harm avoidance in the anxiety levels of treated social phobia patients. One hundred and fifty-seven patients with DSM-IV social phobia were assessed before starting treatment and were then followed for up to two years. As expected, greater fear of negative evaluation and higher scores of harm avoidance were associated with greater anxiety at the 6 month follow-up, and harm avoidance remained a significant predictor at 24 months. However, no evidence was found for an interaction between the personality and cognitive variables examined. The findings are discussed in terms of the relative independence of these factors, as well as their potential implications for the treatment of this disorder.  相似文献   
995.
996.
997.
998.
Campath-1H (alemtuzumab) induction was used for renal transplantation in combination with sirolimus as immunosuppression. We previously reported a high (28%) rate of early rejection with this regimen, and now report 3-year outcomes. Twenty-nine patients were recipients of either deceased donor or non-HLA (Human Leukocyte Antigen) identical living donor primary renal allografts. Clinical parameters including infection, malignancy, kidney function, and kidney histology were followed prospectively for 3 years. Three-year cumulative graft and patient survival were 96% and 100%, respectively. Twenty patients were maintained on steroid-free immunosuppressive regimens, and 15 patients were maintained on monotherapy for immunosuppression (12 on sirolimus). No serious infectious complications were observed and two patients developed basal cell skin cancer. The 3-year results of our initial pilot study demonstrate good graft (96%) and patient (100%) outcomes. Campath-1H induction has yielded a high proportion of patients maintained on immunosuppressive monotherapy (57%) without serious infectious- and no malignancy-related complications. The reported regimen yielded novel insights into both Campath-1H and sirolimus therapy in renal transplantation. Because of the higher incidence of early rejection, we recommend a modified strategy of immunosuppression including a brief course of a calcineurin inhibitor.  相似文献   
999.
Hypocretins (HCRTs) modulate a variety of behavioral and physiological processes, in part via interactions with multiple ascending modulatory systems. Further, HCRT efferents from the lateral hypothalamus innervate midbrain dopamine (DA) nuclei, and DA cell bodies express HCRT receptors. Combined, these observations suggest that HCRT may influence behavioral state and/or state-dependent processes via modulation of DA neurotransmission. The current studies used in vivo microdialysis in the unanesthetized rat to first characterize the effect of intracerebroventricular infusion of HCRT-1 (0.07, 0.7 nmol) on extracellular levels of DA within the prefrontal cortex (PFC) and nucleus accumbens (Acc). Electroencephalographic/electromyographic measures of sleep-wake state were collected along with select behavioral measures (eg locomotor activity, grooming). HCRT-1 dose-dependently increased PFC dialysate DA levels, and these increases were closely correlated with increases in time spent awake. In contrast, Acc DA levels were unaffected. Additional studies examined whether HCRT-1 acts directly within the ventral tegmental area (VTA) to selectively increase PFC DA efflux and modulate behavioral state. Unilateral infusion of HCRT-1 (0.1, 1.0 nmol) within the VTA increased PFC, but not Acc, DA levels. Importantly, intra-VTA infusion of HCRT-1 increased the time spent awake and grooming. Moreover, HCRT-induced increases in both time spent awake and time spent grooming were significantly correlated with post-infusion PFC DA levels. The current observations predict a prominent modulatory influence of HCRT on PFC-dependent cognitive and affective processes that results, in part, from actions within the VTA. Additionally, these observations suggest that the activation of VTA DA neurons contributes to the behavioral state-modulatory actions of HCRT.  相似文献   
1000.
OBJECTIVES: To evaluate changes in the mobility of the whole urethra, in the proximal urethra (funneling) and in the thickness of the urinary bladder wall, after a successful tension-free vaginal tape (TVT) procedure. METHODS: This prospective longitudinal study included 52 women with urodynamically confirmed stress urinary incontinence who had undergone a successful TVT procedure. Ultrasound examination was performed before the TVT procedure and at a median of 3 (range, 3-6) months after surgery. For all women, the changes to the urethra and urinary bladder induced by surgery were examined. For three mobility groups (low, intermediate and high urethral mobility before surgery) we compared the changes induced by the operation and the typical position and mobility of the tape. RESULTS: The position of the urethra at rest was not influenced by surgery. The operation significantly decreased the mobility of all parts of the urethra during Valsalva. The absolute changes of the vector of the urethral movement differed according to the mobility group (average decrease, 6 mm; decrease for women with low, intermediate and high mobility, respectively, 2-3 mm, 4-6 mm and 9 mm). The change in relative mobility was the same in all groups. The operation decreased funneling (width and depth) during maximal Valsalva. After surgery there was an increase in the thickness of the bladder wall (by 0.64 and 0.73 mm, respectively, at the anterior part and trigone). CONCLUSIONS: A successful TVT procedure did not influence the position of the urethra at rest but significantly decreased the mobility of the urethra during Valsalva and also decreased funneling at maximal Valsalva.  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