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   1382篇
  免费   93篇
  国内免费   6篇
耳鼻咽喉   12篇
儿科学   88篇
妇产科学   12篇
基础医学   160篇
口腔科学   120篇
临床医学   105篇
内科学   193篇
皮肤病学   54篇
神经病学   46篇
特种医学   121篇
外科学   277篇
综合类   63篇
预防医学   59篇
眼科学   12篇
药学   70篇
肿瘤学   89篇
  2022年   11篇
  2021年   11篇
  2020年   18篇
  2019年   18篇
  2018年   25篇
  2017年   18篇
  2016年   26篇
  2015年   30篇
  2014年   25篇
  2013年   45篇
  2012年   53篇
  2011年   58篇
  2010年   50篇
  2009年   42篇
  2008年   49篇
  2007年   46篇
  2006年   60篇
  2005年   49篇
  2004年   35篇
  2003年   43篇
  2002年   58篇
  2001年   45篇
  2000年   44篇
  1999年   53篇
  1998年   37篇
  1997年   32篇
  1996年   27篇
  1995年   30篇
  1994年   25篇
  1993年   20篇
  1992年   24篇
  1991年   18篇
  1990年   32篇
  1989年   37篇
  1988年   40篇
  1987年   34篇
  1986年   31篇
  1985年   28篇
  1984年   17篇
  1983年   15篇
  1982年   10篇
  1981年   14篇
  1980年   9篇
  1979年   8篇
  1977年   12篇
  1976年   6篇
  1975年   12篇
  1972年   8篇
  1970年   8篇
  1969年   7篇
排序方式: 共有1481条查询结果,搜索用时 31 毫秒
1.
Collagens are the most abundant proteins in the extracellular matrix. They provide a framework to build organs and tissues and give structural support to make them resistant to mechanical load and forces. Several intra‐ and extracellular modifications are needed to make functional collagen molecules, intracellular post‐translational modifications of proline and lysine residues having key roles in this. In this article, we provide a review on the enzymes responsible for the proline and lysine modifications, that is collagen prolyl 4‐hydroxylases, 3‐hydroxylases and lysyl hydroxylases, and discuss their biological functions and involvement in diseases.  相似文献   
2.
Congenital esophageal cysts in adults   总被引:1,自引:0,他引:1  
Sixteen adult patients with congenital esophageal cysts were operated on between 1957 and 1979. Preoperatively, 7 patients (44%) were asymptomatic and the cyst was found incidentally on a routine chest roentgenogram. Esophageal symptoms were present in only 3 patients (19%), whereas most symptomatic patients had precordial sensations or arrhythmias. A correct preoperative diagnosis was made in only 1 patient. After enucleation of the cyst, preoperative symptoms were alleviated in all patients and short-term results were excellent. However, long-term follow-up 13.2 +/- 5.6 (+/- standard deviation) years later revealed moderate reflux in 9 (64%) of the surviving 14 patients. During esophagoscopy, macroscopic esophagitis was found in 12 (92%) of 13 patients. On histological examination of specimens obtained by forceps biopsy, esophagitis was present in 10 (77%) of 13 patients and included Barrett esophagus in 2. We conclude that, despite excellent early results, long-term follow-up of patients who undergo operation for congenital esophageal cysts is indicated because of the increased incidence of reflux esophagitis.  相似文献   
3.
4.
The purpose of this study was to correlate histologic findings in temporomandibular joint (TMJ) condyles and discs with their macroscopic appearance at surgery. The 24 patients with internal derangement of the joint included 20 women and 4 men (mean age, 37 years; range, 18 to 61 years). The tissue lesions varied in degree from mild soft-tissue fraying and bone remodeling to extensive resorption and new cartilage and bone formation with high phosphatase enzyme activities, and even to loss of articular soft tissue and breakdown of cortical bone. Reactions may arise in the hard tissues before they occur in the articular surface layers.  相似文献   
5.
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   
6.
7.
Doppler ultrasonography and strain gauge plethysmography were used prospectively to study the hemodynamic changes in 20 patients' (5 men and 15 women) legs operated on by means of subfascial closure for insufficiency of perforating veins. In 10 patients (50%) the valves of the deep veins were incompetent as verified by Doppler ultrasonography, and deep vein thrombosis had previously been diagnosed in seven patients. After subfascial ligature, strain gauge plethysmography showed no changes in arterial flow, venous capacity, or in venous emptying rate. However, both venous reflux flow and reflux volume were significantly lowered (p less than 0.01) after surgery as compared to values before operation. The clinical objective results were good in all cases. In two of four patients with fair subjective results the arterial flow was pathologically high, which probably implies the presence of microscopic arteriovenous fistulas. It is concluded that strain gauge plethysmography can quantitate the change in deep venous reflux after ligation of perforating veins.  相似文献   
8.
9.
A 15-year-old boy with a terminal deletion of the short arm of chromosome 4 is described. The patient has a mild clinical phenotype that is incompatible with Wolf-Hirschhorn syndrome. Careful neurological examination including CT scan did not show any signs of Huntington disease. The chromosomal breakpoint was analyzed by means of polymorphic DNA probes localized close to the tentative Huntington (HD) locus. The breakage has occurred between D4S43 and D4S90 loci and thus deletes part of the chromosomal candidate regions for the HD locus. © 1992 Wiley-Liss, Inc.  相似文献   
10.
Samples from 96 children with acute respiratory infection were obtained simultaneously with nasal, nasopharyngeal, and oropharyngeal swabs and by nasopharyngeal aspiration and were cultured on chocolate and blood agar plates. The rates of isolation of Streptococcus pneumoniae and Haemophilus influenzae detected by the four sampling methods were compared. Nasopharyngeal aspirates were optimal for the detection of both S. pneumoniae (isolation rate, 33%) and H. influenzae (isolation rate, 31%). When a nasopharyngeal aspirate is not available, such as for healthy children or children with no obtainable secretions, the nasopharyngeal swab seems optimal for the detection of both S. pneumoniae and H. influenzae among children younger than 13 months of age. Among older children, similarly, the nasopharyngeal swab seems optimal for the detection of S. pneumoniae; however, for H. influenzae, the oropharyngeal swab seems optimal.  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