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   1822篇
  免费   203篇
  国内免费   28篇
耳鼻咽喉   7篇
儿科学   165篇
妇产科学   31篇
基础医学   267篇
口腔科学   91篇
临床医学   224篇
内科学   347篇
皮肤病学   49篇
神经病学   37篇
特种医学   181篇
外科学   308篇
综合类   42篇
预防医学   106篇
眼科学   42篇
药学   55篇
中国医学   2篇
肿瘤学   99篇
  2023年   14篇
  2022年   10篇
  2021年   18篇
  2020年   14篇
  2019年   9篇
  2018年   50篇
  2017年   46篇
  2016年   43篇
  2015年   64篇
  2014年   79篇
  2013年   107篇
  2012年   53篇
  2011年   42篇
  2010年   84篇
  2009年   95篇
  2008年   36篇
  2007年   62篇
  2006年   59篇
  2005年   45篇
  2004年   48篇
  2003年   40篇
  2002年   55篇
  2001年   30篇
  2000年   39篇
  1999年   47篇
  1998年   114篇
  1997年   91篇
  1996年   108篇
  1995年   71篇
  1994年   80篇
  1993年   40篇
  1992年   23篇
  1991年   31篇
  1990年   18篇
  1989年   35篇
  1988年   35篇
  1987年   30篇
  1986年   27篇
  1985年   28篇
  1984年   15篇
  1983年   11篇
  1982年   22篇
  1981年   15篇
  1980年   16篇
  1979年   5篇
  1978年   8篇
  1977年   9篇
  1976年   13篇
  1975年   10篇
  1974年   2篇
排序方式: 共有2053条查询结果,搜索用时 15 毫秒
11.
12.
We assessed in 1662 consecutive diabetic patients systolic arm-ankle indexes by a Doppler ultrasonic method. In those patients with indexes greater than or equal to 1.3 directional Doppler sonometry and mercury strain gauge plethysmography were performed. In some instancies electronic oscillography, duplex sonography and vital microscopy were additionally done. In 4.45% of the patients functional findings of a mediasclerosis could be encountered. Location of arterial mediacalcinosis was documented by x-ray examinations. Sensitivity of none invasive methods was merely 100%, specificity ranged from 96% (Dopplersonometry) to 80% (Duplexsonometry). In 18.9% an occlusive arterial disease could additionally be found. Mediasclerosis preferentially was encountered in Type II diabetics of older age. In this group painful distal neuropathy in many instances existed mimicking claudication, retinopathy and nephropathy was as frequent as in other diabetics. Normal or elevated Doppler indexes did not exclude occlusive arterial disease whereas diabetics with mediasclerosis and ulcero-gangreneous lesions or amputations in most of the cases did not have occlusive arterial disease.  相似文献   
13.
14.
15.
Inversion recovery (IR), commonly considered a pulse sequence capable of producing T1-weighted images with excellent display of normal anatomy, is versatile: The null point and peak time provide a useful, succinct summary of the properties of IR and its capacity for producing both T1- and T2-weighted images. Shortening of the inversion time (TI) and creation of a short-TI inversion-recovery (STIR) pulse sequence increases sensitivity to malignancy and other abnormalities by making the effects of prolonged T1 and T2 on signal intensity additive and by nulling the signal from fat. The authors examined over 300 patients with various malignancies and compared STIR images with T1- and T2-weighted images obtained at 0.5 T. In 43 cases, signal-difference-to-noise ratios (SD/Ns) were calculated between tumor, fat, and muscle. In general, STIR images demonstrated tumor as a conspicuously high-intensity area in a background of muted, discernible anatomic detail. The good contrast achieved with STIR sequences between tumor and fat (SD/N = 18.1) and tumor and muscle (SD/N = 12.9) consolidated into a single image the information contained separately on T1- and T2-weighted images, which facilitates efficient detection and localization of malignancy.  相似文献   
16.
Computed tomography (CT) was performed in 42 patients with 49 clinically suspected tears of the posterior tibial tendon. Twenty-eight of the 49 suspected tears were subsequently surgically explored and repaired. Three patterns of tendon abnormalities were recognized on CT scans: type I-intact, hypertrophied, heterogeneous tendon; type II-attenuated tendon; and type III-absence of a portion of a tendon. Types I and II correlated with partial rupture seen during surgery, and type III correlated with complete rupture of the tendon. CT findings were accurate in 96% of the patients who underwent surgery. In four cases (14%), tendon rupture was seen on CT scans, but the extent of the injury was underestimated and the rupture was misclassified. Reactive periostitis of the distal tibia was seen in 71% of diseased tendons and may represent an important factor in the diagnosis of tendon rupture.  相似文献   
17.
18.
OBJECTIVE: Although cutaneous leishmaniasis (CL) occurs mostly in the facial area, periocular involvement accounts for 2-5% of the facial lesions. CL lesions localized in the periocular region can easily be confused with various other diseases. The aim of this study was to examine the frequency of periocular involvement in CL in the Cukurova region of Turkey, as well as the clinical characteristics, diagnosis and methods of treatment of this disease. METHODS: Between December 1998 and December 2004, patients who were diagnosed with CL were evaluated prospectively with respect to periocular involvement. RESULTS: From the 2066 patients evaluated with CL, 2622 lesions were identified. In 59 (2.9%) of these patients, a total of 66 (2.5%) lesions were located in the periocular area. Thirty-two (48.5%) of these lesions were of the papular type, 15 (22.7%) the nodulo-ulcerative type, 10 (15.2%) the plaque type, and nine (13.6%) the nodular type. Dacryocystitis was identified in four patients with periocular involvement. Over the follow-up period, no ocular or periocular deformities or complications developed in these patients. CONCLUSION: Patients suspected of CL should be evaluated and treated early in the course of their disease to prevent any permanent ocular or periocular deformities.  相似文献   
19.
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