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   32988篇
  免费   2034篇
  国内免费   161篇
耳鼻咽喉   327篇
儿科学   477篇
妇产科学   320篇
基础医学   4992篇
口腔科学   961篇
临床医学   3212篇
内科学   7686篇
皮肤病学   503篇
神经病学   3724篇
特种医学   1975篇
外科学   4431篇
综合类   195篇
一般理论   12篇
预防医学   1415篇
眼科学   662篇
药学   1867篇
中国医学   54篇
肿瘤学   2370篇
  2023年   271篇
  2022年   459篇
  2021年   859篇
  2020年   523篇
  2019年   726篇
  2018年   835篇
  2017年   633篇
  2016年   918篇
  2015年   1029篇
  2014年   1284篇
  2013年   1584篇
  2012年   2610篇
  2011年   2621篇
  2010年   1556篇
  2009年   1408篇
  2008年   2313篇
  2007年   2297篇
  2006年   2231篇
  2005年   2089篇
  2004年   1807篇
  2003年   1723篇
  2002年   1608篇
  2001年   349篇
  2000年   267篇
  1999年   346篇
  1998年   344篇
  1997年   246篇
  1996年   185篇
  1995年   161篇
  1994年   134篇
  1993年   100篇
  1992年   112篇
  1991年   108篇
  1990年   75篇
  1989年   85篇
  1988年   61篇
  1987年   60篇
  1986年   62篇
  1985年   54篇
  1984年   52篇
  1983年   59篇
  1982年   48篇
  1981年   44篇
  1980年   37篇
  1979年   34篇
  1976年   36篇
  1975年   45篇
  1974年   42篇
  1972年   50篇
  1935年   36篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Benign coital headache   总被引:1,自引:0,他引:1  
We studied the natural history of patients with a diagnosis of benign coital headache who presented to a private neurological clinic between the years 1978 and 1991. Thirty-two patients (24M, 8F) were invited to participate and 26 patients (83%) responded. The period of follow-up ranged from six months to 14 years (median 6 years). Thirteen patients (50%) had recurrent attacks of coital headache epochs separated by intervals of up to 10 years. Eleven of these patients suffered a concomitant primary headache whereas this was present in only one of those patients without recurrent attacks of coital headache (p < 0.001). In all but one patient, who had a transient blurred vision, the headache was not accompanied by nausea, vomiting, visual disturbances, sensory/motor disturbances, or unconsciousness. We concluded that benign coital headache can be clearly distinguished from headaches due to cerebral aneurysm or arteriovenous malformation rupture. The presence of a concomitant primary headache syndrome is a risk-factor for recurrence of coital headache.  相似文献   
102.
A modified exeimer laser energy delivery system was used to irradiate 100 segments of normal and fibrous aorta in vitro. The laser beam was scanned into 8 fiber bundles consisting of 50 fibers each resulting in a reduction of the applied pulse energy. The total repetition rate was increased to 150 Hz in order to keep the repetition rate per fiber bundle close to 20 Hz and to minimize thermal injury. The results demonstrate that effective ablation (etch rate per 8 pulses > 2.0 μm) occurred at an energy fluency of 50 mJ/mm2 in both normal and fibrous aorta. Tissue damage (carbonization, tissue separation, fissures, cracks, and vacuolization) was in a range of 100 ± 28 to 152 ± 30 μm for normal aorta and in a range of 57 ± 35 to 110 ± 39 μm for fibrous aorta. We conclude that effective ablation of normal and fibrous human aorta can be achieved by the application of smooth excimer laser coronary angioplasty. This improvement of excimer laser technology may result in a reduction of shock wave- and cavitation-induced damage leading to a reduction of tissue injury. However, this awaits further in vitro and in vivo confirmation. © 1993 Wiley-Liss, Inc.  相似文献   
103.
Summary We examined 81 men exposed for a long time to carbon disulphide (CS2) and tested the possible electrocardiographic (ECG) changes of ischemic heart disease (I.H.D.). The subjects were examined twice in two years. In order to make the ECG evaluation more objective, the Minnesota Code was applied. Two obligatory ECG examinations and only one submaximal effort test were carried out. For comparative evaluation, the control group was examined once. We proved that, in spite of the accepted opinion concerning the atheromatous action of CS2, this compound does not cause ECG symptoms of I.H.D. in a higher percentage of exposed persons. It also does not cause any significant increase in I.H.D. symptoms in dynamic ECG observations.  相似文献   
104.
105.
106.
Phosphorus was imaged in vivo in human cortical and trabecular bone and the T(1) and T(2) (*) were measured. An ultrashort TE (UTE) pulse sequence (TE = 70 microm) was used with half pulse excitation and radial mapping of k-space from the center out. T(2) (*) was measured using multiple echo times and T(1) was measured both by saturation recovery and by a method using different RF pulse amplitudes. Seven normal subjects (32-85 years) were examined. Phosphorus was imaged, with a true in-plane resolution of 2.9 x 2.9 mm and a signal-to-noise ratio (SNR) of 19:1, in both cortical and trabecular bone. The mean T(2) (*) value was 207 +/- 12 micros, and the mean T(1) value was 8.6 +/- 3.0 sec. Images and measurements were obtained in realistic times on a clinical MR system. This may provide a new approach to characterizing disease of bone.  相似文献   
107.
108.
Wiener Medizinische Wochenschrift - Aggressives Tumorwachstum, frühe Metastasierung und hohe Assoziation mit intensivem Nikotinkonsum sind die Charakteristika des kleinzelligen...  相似文献   
109.
Although magnetic resonance imaging is the most accurate imaging method of evaluating the anterior cruciate ligament, several plain radiographic signs suggestive of anterior cruciate ligament injury have been described. Plain radiographs also play an important role in evaluating anterior cruciate ligament reconstruction.  相似文献   
110.
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