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   10439篇
  免费   501篇
  国内免费   47篇
耳鼻咽喉   63篇
儿科学   221篇
妇产科学   69篇
基础医学   1322篇
口腔科学   216篇
临床医学   620篇
内科学   2348篇
皮肤病学   248篇
神经病学   551篇
特种医学   392篇
外科学   2335篇
综合类   53篇
预防医学   239篇
眼科学   243篇
药学   897篇
中国医学   8篇
肿瘤学   1162篇
  2023年   66篇
  2022年   46篇
  2021年   186篇
  2020年   104篇
  2019年   162篇
  2018年   184篇
  2017年   140篇
  2016年   171篇
  2015年   178篇
  2014年   266篇
  2013年   366篇
  2012年   507篇
  2011年   566篇
  2010年   335篇
  2009年   263篇
  2008年   491篇
  2007年   479篇
  2006年   476篇
  2005年   518篇
  2004年   512篇
  2003年   457篇
  2002年   523篇
  2001年   311篇
  2000年   355篇
  1999年   331篇
  1998年   148篇
  1997年   117篇
  1996年   112篇
  1995年   115篇
  1994年   99篇
  1993年   69篇
  1992年   255篇
  1991年   207篇
  1990年   221篇
  1989年   183篇
  1988年   172篇
  1987年   183篇
  1986年   149篇
  1985年   163篇
  1984年   94篇
  1983年   72篇
  1982年   48篇
  1979年   86篇
  1978年   49篇
  1977年   41篇
  1974年   40篇
  1973年   32篇
  1972年   36篇
  1970年   32篇
  1969年   42篇
排序方式: 共有10000条查询结果,搜索用时 512 毫秒
11.
12.
Pins and wires offer the simplest and most effective tools for managing bone fractures and dislocations. Migration of these devices within the chest is rare, but can cause serious problems. The spontaneous migration of Kirschner wires from the right clavicle to the mediastinum resulted in penetrating injury of the esophagus and pseudo-aneurysm of the brachiocephalic artery in an 84-year-old patient. Two Kirschner wires were removed via a vertical incision on the right shoulder without thoracotomy and the brachiocephalic artery was replaced with a Dacron graft.  相似文献   
13.
Fluctuating PEEP (F-PEEP) is a newly developed PEEP in which end-expiratory pressure (EEP) is periodically changed within a certain range. In a dog model with unilateral lung injury induced by the introduction of hydrochloric acid, F-PEEP in which the EEP was periodically changed from 0.5 to 1.5 kPa at periods of 6 min, and conventional PEEP (C-PEEP) with an optimized EEP of 1.0 kPa, were each applied for 30 min. F-PEEP produced a significantly greater improvement of PaO2 and intrapulmonary shunt (QS/QT) than C-PEEP, and at the low EEP phase, the greatest improvement accompanied by an increased dynamic compliance and a large cardiac output was obtained. These results suggest that F-PEEP provides a useful mode of artificial ventilation for the treatment of unilateral lung injury.  相似文献   
14.
Ceruletide, a potent analogue of cholecystokinin, was administered by injection to eight schizophrenics treated with neuroleptics. We examined the dose–response effect on microvibration (MV) recorded from the chin of these patients. After 15 min of bed rest, MV was recorded for 5 min as a control recording. Subsequently, saline or ceruletide, at a dose of either 0.4 m?g/kg or at 0.8 m?g/kg, was injected according to a Latin square design with an interval of 4 weeks for washing out the drug effect and MV was recorded for 30 min. MV data obtained were subjected to the fast Fourier transform and an average power spectrum was computed. A three-way analysis of variance for these data was performed upon dose-effect, time-effect after treatment, and band-effect of the average power spectrum. The present results were similar to previous findings which had revealed effects of ceruletide on tardive dyskinesia symptoms, namely, the effects of ceruletide on MV were different according to the subjects (three cases: facilitation followed by inhibition, three cases: inhibition, two cases: no effects). The dose-response curve of ceruletide appears to be linear in some cases and an inverted U-shape in other cases. Present findings showed small doses of systemically administered ceruletide would modify muscle tonus of schizophrenics under chronic treatment of neuroleptics, and provided further reason for the therapeutic drug of tardive dyskinesia.  相似文献   
15.
For the diagnosis and evaluation of the therapy for male infertility and for predicting the outcome of AIH and IVF-ET, technically simple, replicable tests that can be performed virtually anywhere and that have definite reliability are required. The results of the HOS test correlate well with the functions of the sperm cell membrane, indicating such aspects as motility, and it is thought to be a particularly effective test of human sperm fertility. Because the HOS test reflects the functions and integrity of the sperm cell membrane, it should be possible to use it to predict the potential for fertilization of frozen sperm.  相似文献   
16.
O-beta-D-Galactopyranosyl-(1----4)-O-beta-D-galactopyranosyl-(1----4)-D- glucopyranose (designated as 4'GL) is produced from lactose by Cryptococcus laurentii. The influence of chronic ingestion of 4'GL on body weight gain, organ weight, serum lipids, and liver lipids was investigated in rats. The body weight gains of the 5% and 10% 4'GL-diet groups were higher than that of the control group. Food intake and fecal dry weight were significantly increased (p less than 0.05) by 4'GL feeding. The 4'GL diet produced a significant increase (p less than 0.01) in the wet weight and contents of both the cecum and the colon. However, no significant increase was observed in the weight of the stomach, small intestine, liver, or other organs. The effects of 4'GL on serum and liver lipid levels were not observed in this experiment. The digestion of 4'GL was measured in vitro using the artificial gastric juice, alpha-amylase of human saliva, alpha-amylase of hog pancreas, and mucosa of rat intestine. 4'GL was not hydrolyzed by these enzymes. Long-term ingestion of 4'GL did not cause any induction of 4'GL hydrolyzing enzyme activity in the rat small intestine.  相似文献   
17.
Ruptured aneurysm of the sinus of Valsalva is a rare cardiac lesion. A ruptured aneurysm of the sinus of Valsalva in the right ventricle of a 64-year-old man was successfully repaired. The patient was admitted to the hospital with high fever and chest oppression. Diagnosis was made by two dimensional echocardiography, cardiac catheterization, and cardiac angiography. An aortotomy, main pulmonary arteriotomy, and right ventriculotomy were performed. There was no VSD, and the aneurysm originated from the right coronary sinus, rupturing into the right ventricle inlet portion. The ruptured aneurysm of the sinus of Valsalva was closed with a Dacron patch from inside the aorta. He is doing well after surgery. There was no heart murmur. CTR decreased and pulmonary blood flow fell to a normal value. As far as we know, this patient is the second oldest patient in Japan with surgical repair.  相似文献   
18.
19.
The spectral response curve (amplitude versus wavelength) of the R2 of the early receptor potential (ERP) was studied in normal, protan, and deutan subjects. The R2 amplitude peaked at 520nm in most normal subjects. The R2 at long wavelengths was smaller than normal in protans and larger than normal in deutans when the maximum amplitudes were normalized to 100% at the peak. The ratio of the R2 amplitude at 460 nm to that at 600 nm clearly differed between protans and deutans. The ERP and the rapid off-response, which is mainly due to the cessation of the late receptor potential, were recorded in the same subjects. The ratio of the sensitivity of the rapid off-response at 500 nm to that at 600 nm was correlated with the ratio of the R2 amplitude at 460 nm to that at 600nm (correlation coefficient, 0.823, p < 0.001). This study, in conjunction with our previous study, indicates that the abnormality is in the outer segments of the cones in protans and deutans.  相似文献   
20.
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