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   3265篇
  免费   291篇
  国内免费   9篇
耳鼻咽喉   23篇
儿科学   109篇
妇产科学   79篇
基础医学   372篇
口腔科学   201篇
临床医学   290篇
内科学   561篇
皮肤病学   60篇
神经病学   345篇
特种医学   154篇
外科学   413篇
综合类   125篇
预防医学   357篇
眼科学   110篇
药学   240篇
中国医学   1篇
肿瘤学   125篇
  2021年   48篇
  2020年   31篇
  2019年   44篇
  2018年   59篇
  2017年   48篇
  2016年   36篇
  2015年   56篇
  2014年   57篇
  2013年   81篇
  2012年   121篇
  2011年   165篇
  2010年   82篇
  2009年   80篇
  2008年   100篇
  2007年   129篇
  2006年   127篇
  2005年   139篇
  2004年   113篇
  2003年   101篇
  2002年   115篇
  2001年   78篇
  2000年   87篇
  1999年   91篇
  1998年   63篇
  1997年   47篇
  1996年   41篇
  1995年   47篇
  1994年   37篇
  1992年   75篇
  1991年   46篇
  1990年   56篇
  1989年   75篇
  1988年   61篇
  1987年   77篇
  1986年   76篇
  1985年   69篇
  1984年   56篇
  1983年   58篇
  1982年   34篇
  1981年   35篇
  1979年   52篇
  1978年   46篇
  1977年   36篇
  1976年   41篇
  1975年   31篇
  1974年   35篇
  1973年   38篇
  1971年   28篇
  1970年   31篇
  1969年   40篇
排序方式: 共有3565条查询结果,搜索用时 46 毫秒
1.
2.
3.
4.
The purpose of this study is to show the spectrum of adjacent organ invasion and to make a brief review of hepatic alveolar hydatid disease (AHD), using CT and MR imaging. We retrospectively reviewed CT and MR images of three patients with various adjacent organ invasions surgically and histologically proven to be AHD. Local invasion to right kidney and adrenal, right hemidiaphragm and lung were detected in one patient, right adrenal in another patient and gall bladder, duodenum, gastric wall and pancreas invasion in the other. AHD may rarely extend to the gall bladder, stomach, duodenum, pancreas, right adrenal and kidney, diaphragm, pleura and lung. The extension of the disease outside the liver is usually encountered in patients with large, peripherally located masses in the advanced stage of the disease.  相似文献   
5.
6.
Tears of the retinal pigment epithelium (RPE) are a recognized complication of pigment epithelium detachments associated with age-related macular degeneration (ARMD). The RPE tears are often associated with a poor visual prognosis and typically do not occur with subretinal hemorrhage. We report the case of a 76-year-old man with ARMD who developed an RPE tear associated with subretinal hemorrhage, without a demonstrable subretinal neovascular membrane. Temporally, there was a marked decrease in his vision that returned to his earlier baseline visual acuity over the course of six months of observation.  相似文献   
7.
The present study examined the hypothesis that oxytocin (OT) may influence female sexual behavior in prairie voles (Microtus ochrogaster). The effectiveness of OT to induce sexual behavior was tested in ovariectomized females that were injected daily with estradiol benzoate (EB, 0.02 micrograms, twice), a dose insufficient for estrus induction. On the third day females received intracerebroventricular (ICV) injections of OT (1, 300, or 1000 ng) or saline vehicle. In the presence of minimal estrogen stimulation, OT did not induce sexual receptivity, or influence autogrooming or other social interactions. The behavioral effects of OT were examined in another group of ovariectomized females that received daily oil or EB injections (10 micrograms, twice) followed on the third day by either ICV (1, 300, or 1000 ng) or intraperitoneal (IP) (1, 3, or 10 micrograms) injections of OT. Among EB-treated females, only those in confirmed estrus, prior to ICV or IP injection, were included in these studies. There was a dose-related decrease in the percentage of females that remained in behavioral estrus after ICV OT. In those females that continued to show sexual behavior, lordosis frequencies and durations were unaffected by ICV OT. Nonsexual behavior did not differ between mated females and those exhibiting OT-inhibited sexual behavior. In females that were EB-treated, autogrooming and side-by-side behavior increased after ICV OT, while there was a decline in aggression. Female sexual and nonsexual behaviors were not significantly affected by IP OT.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
8.
A 15-year-old girl presented de novo in diabetic ketoacidosis having been comatose for 24 h (day 1). A CT scan and lumbar puncture performed on admission were normal and her conscious level slowly improved over several days. On day 7 she had central neurological signs of bilateral knee clonus and an extensor plantar response. In addition, she had developed lower motor neurological signs of an ulnar nerve palsy of the left forearm, and ulnar, median, and radial nerve palsies of the right forearm. Magnetic resonance imaging (MRI), performed on day 12, showed multiple small cerebral haematomata with appearances at least several days of age. The scattered lesions were localized particularly to the parieto-occipital region, with sparing of the basal ganglia and without cerebral oedema, a novel feature not previously described in juvenile ketoacidosis. Four months later there was minimal residual disability of her right arm. The clinical findings together with the MRI images suggested that the peripheral nerve and central lesions were temporally related, suggesting a common aetiology. However, it is likely that MRI showed cerebral lesions which may have been missed by the conventional CT scanning performed initially.  相似文献   
9.
Crohn's disease of the vulva   总被引:1,自引:0,他引:1  
We have reported a case of Crohn's disease of the vulva, an unusual manifestation of inflammatory bowel disease. The initial management of this condition should be medical, using antibiotics and established regimens to control gastrointestinal symptoms. Surgical therapy is appropriate when medical management fails, as it did in our patient.  相似文献   
10.
Canal Master instruments have a short, fluted cutting area and a small flexible shaft; they may be predisposed to rapid wear and breakage. This study examined new and used files as to tip, flute, and shaft design when new and with increasing time of canal preparation. One hundred files prepared 140 curved canals. Sizes #20, #40, and #60 files were examined unused and after 1, 3, 5, and 7 min of use. Evaluation was for uniformity when new and for deterioration and breakage with usage. The smaller sizes (#20 and #40) had some inconsistencies when new and were most predisposed to wear and breakage with time. Findings suggest that smaller files could have had improved quality control by the manufacturer. Also, they should be used with caution and discarded after short times of use in small, curved canals. This should minimize instrument separation and maximize cutting efficiency.  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