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   11248篇
  免费   916篇
  国内免费   55篇
耳鼻咽喉   74篇
儿科学   362篇
妇产科学   297篇
基础医学   1566篇
口腔科学   136篇
临床医学   1605篇
内科学   2008篇
皮肤病学   164篇
神经病学   985篇
特种医学   240篇
外科学   1346篇
综合类   198篇
一般理论   22篇
预防医学   1251篇
眼科学   392篇
药学   772篇
中国医学   44篇
肿瘤学   757篇
  2024年   13篇
  2023年   123篇
  2022年   147篇
  2021年   281篇
  2020年   231篇
  2019年   363篇
  2018年   391篇
  2017年   293篇
  2016年   330篇
  2015年   349篇
  2014年   498篇
  2013年   639篇
  2012年   907篇
  2011年   929篇
  2010年   489篇
  2009年   408篇
  2008年   699篇
  2007年   733篇
  2006年   693篇
  2005年   720篇
  2004年   648篇
  2003年   598篇
  2002年   485篇
  2001年   166篇
  2000年   134篇
  1999年   125篇
  1998年   104篇
  1997年   82篇
  1996年   65篇
  1995年   58篇
  1994年   50篇
  1993年   53篇
  1992年   45篇
  1991年   43篇
  1990年   37篇
  1989年   36篇
  1988年   47篇
  1987年   29篇
  1986年   36篇
  1985年   21篇
  1984年   23篇
  1983年   15篇
  1982年   16篇
  1981年   12篇
  1980年   9篇
  1979年   5篇
  1978年   9篇
  1977年   5篇
  1974年   4篇
  1973年   5篇
排序方式: 共有10000条查询结果,搜索用时 320 毫秒
1.
A pulsion hernia of the tympanic membrane is an outwardly bulging, thin, atrophic area of the tympanic membrane. Those patients who develop pulsion hernias repeatedly autoinflate the middle ear and consequently maintain a positive middle ear pressure, which pushes the thin atrophic portion of the tympanic membrane laterally beyond the normal plane of the tympanic membrane. The thinness of the tympanic membrane over the pulsion hernia suggests that the herniation has developed through a pre-existing area of weakness where the fibrous middle layer has disappeared.  相似文献   
2.
3.
A pilot project was established from 1992 to 1994 to provide people with chronic schizophrenia living in Dundee, Scotland, with a National Health Service sheltered workshop that would be fully integrated into the local business community. Of the 43 clients who attended the sheltered workshop, 38 agreed to take part in the project. Typical attenders were single, middle-aged men with schizophrenia. Twenty-five per cent had spent more than two years in hospital; 75% had been unemployed for more than five years. The clients' use of National Health Service day facilities more than halved while attending the workshop. Their hospital readmission rates were low (16%) compared with the local readmission rates for people with schizophrenia in Dundee (86%). A training approach based on the general principles of social skills training contributed to positive vocational outcomes for one-third of the workshop clients. The findings suggest that the onus of responsibility for providing work for many individuals with schizophrenia remains with the National Health Service, and in particular, occupational therapy. Occupational therapy staff must assess their clients effectively and provide quality training leading to opportunities for paid employment. These results have implications for the training of occupational therapy staff and also for the staffing structure in sheltered workshops. Copyright © 1997 Whurr Publishers Ltd.  相似文献   
4.
5.
Cerebral blood flow and glucose utilization were measured in rat neocortex, hippocampus and striatum following methylenedioxymethamphetamine injection (5 mg/kg, i.v.), using the tracers [14C]iodoantipyrine and [14C]2-deoxyglucose, respectively. In control rats, blood flow was coupled to glucose metabolism, but in methylenedioxymethamphetamine-treated rats, marked hyperperfusion was measured in frontal and parietal cortex with no change in glucose use. This suggests that methylenedioxymethamphetamine has the potential to disrupt cerebrovascular control.  相似文献   
6.
In a homogeneous medium of soft tissue the radiation dose distribution due to a nonuniformly distributed beta source can be calculated by convolution of the beta dose point kernel of the nuclide with the source distribution. A possible extension of the technique to the calculation of the dose distribution in heterogeneous media involving relatively simple geometric interfaces requires the knowledge of the resulting perturbation to the beta point kernels in individual media. We simulated a soft-tissue-bone planar interface by a polystyrene (PST)-aluminum junction and measured the change in beta dose from the dose value in homogeneous PST due to a point source of 32P using 7LiF thermoluminescent dosimeters. With the point source at the interface, the dose rates at 0-31, 125-156, and 283-314 mg/cm2 separations from the interface were increased by (12 +/- 3)%, (8 +/- 2)%, and (3 +/- 2)%, respectively, compared with homogeneous PST. With the point source at a PST-air planar interface to simulate a soft-tissue-air junction, the dose rates at 0-31, 139-170, and 283-314 mg/cm2 from the interface were decreased by (25 +/- 4)%, (11 +/- 7)%, and (5 +/- 2)%, respectively. The changes in dose rates for these two interfaces have also been measured with degraded spectra of 32P. Comparison of the experimental data with Monte Carlo calculation for a point source and the two-group method of calculation for a plane source is also presented.  相似文献   
7.
In a group of patients with breast lumps, diagnosis made by pre-operative aspiration cytology was compared with that obtained by histological section of excised specimens. Results showed that aspiration cytology correctly diagnosed 89% of malignant lesions and 92.6% of benign lesions based upon histological diagnosis. Cytological diagnosis of benign disease had a false negative rate of 6% while cytological diagnosis of malignant disease had a 2.7% false positive rate. Only 3.5% of cytologies returned an inadequate diagnosis. This study shows that aspiration cytology should be useful in allowing a better psychological preparation of patients before surgery as well as better utilization of operation theatre facilities.  相似文献   
8.
9.
10.
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