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   2311篇
  免费   95篇
  国内免费   12篇
耳鼻咽喉   107篇
儿科学   115篇
妇产科学   71篇
基础医学   143篇
口腔科学   137篇
临床医学   228篇
内科学   429篇
皮肤病学   13篇
神经病学   87篇
特种医学   162篇
外科学   516篇
综合类   47篇
预防医学   82篇
眼科学   44篇
药学   82篇
中国医学   6篇
肿瘤学   149篇
  2023年   21篇
  2022年   28篇
  2021年   70篇
  2020年   43篇
  2019年   41篇
  2018年   86篇
  2017年   53篇
  2016年   79篇
  2015年   81篇
  2014年   125篇
  2013年   117篇
  2012年   158篇
  2011年   136篇
  2010年   72篇
  2009年   68篇
  2008年   136篇
  2007年   174篇
  2006年   149篇
  2005年   137篇
  2004年   140篇
  2003年   105篇
  2002年   97篇
  2001年   67篇
  2000年   51篇
  1999年   52篇
  1998年   18篇
  1997年   9篇
  1996年   8篇
  1995年   6篇
  1994年   3篇
  1992年   10篇
  1991年   7篇
  1990年   3篇
  1989年   3篇
  1988年   7篇
  1987年   5篇
  1985年   4篇
  1984年   2篇
  1983年   2篇
  1982年   2篇
  1981年   3篇
  1979年   4篇
  1978年   2篇
  1972年   4篇
  1970年   2篇
  1969年   4篇
  1968年   2篇
  1967年   2篇
  1966年   4篇
  1955年   2篇
排序方式: 共有2418条查询结果,搜索用时 16 毫秒
51.
New files (ProTaper Next/HyFlex/OneShape) are made from novel nickel‐titanium (NiTi) alloys/treatments. The purpose of this study was to compare the cyclic fatigue resistance of these new instruments with that of Revo‐S instruments. Four groups of 20 NiTi endodontic instruments were tested in steel canals with a 3 mm radius and a 60° angle of curvature. The cyclic fatigue of the following NiTi instruments with a tip size 25 and 0.06 taper that were manufactured with different alloys was tested: ProTaper Next X2 (M‐Wire), OneShape (conventional NiTi), Revo‐S Shaping Universal (conventional NiTi) and HyFlex 25/0.6 (controlled memory NiTi wire). A one‐way anova and post‐hoc Tukey's test (α = 0.05) revealed that the HyFlex files had the highest fatigue resistance and the Revo‐S had the least fatigue resistance among the groups (P < 0.001).  相似文献   
52.
53.
54.
Our aim was to compare the outcomes and satisfaction rates of men undergoing penile prostheses implantation (PPI) secondary to radical prostatectomy (RP) and other causes of vasculogenic erectile dysfunction (ED). A total of 142 patients, of whom 60 underwent PPI due to ED following RP (Group 1) and 82 underwent PPI due to ED with other vasculogenic causes (Group 2) were included in this study. The preoperative erectile status was evaluated with the International Index of Erectile Function (IIEF). The satisfaction of patients and partners were evaluated by a telephone interview using Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) questionnaire and Erectile Dysfunction Inventory of Treatment Satisfaction Partner Survey. Preoperative mean IIEF scores were significantly lower in Group 1 (17.5 ± 6.4 vs. 24.2 ± 5.1, p = 0.01). For Groups 1 and 2, the mean EDITS scores of the patients were 58 ± 10 and 71 ± 8, respectively, and that for the partners were 46 ± 8 and 65 ± 7, respectively. Group 1 had significantly lower scores both for the EDITS and the EDITS Partner Survey (p = 0.03, p = 0.01, respectively). Patients who had undergone RP and their partners were found to have lower satisfaction rates compared to patients with other causes of vasculogenic ED who had penile implant surgery. From this point of view, it is important to know the patient's expectations about the treatment outcomes and a preoperative psychological and sexual counseling should be managed for possible treatment alternatives after RP.  相似文献   
55.
Spontaneous coronary artery dissection (SCAD) is a rare disease that is usually seen in young women in left descending coronary artery and result in events like sudden cardiac death and acute myocardial infarction. A 70-year-old man was admitted to the emergency department with chest pain which started 1 h ago during a relative’s funeral. The initial electrocardiography demonstrated 2 mm ST-segment depression in leads V1-V3 and the patient underwent emergent coronary angiography. SCAD simultaneously in two different coronary arteries [left anterior descending (LAD) artery and left circumflex (LCx)] artery was detected and SCAD in LCx artery was causing total occlusion which resulted in acute myocardial infarction. Successful stenting was performed thereafter for both lesions. In addition to the existence of SCAD simultaneously in two different coronary arteries, the presence of muscular bridge and SCAD together at the same site of the LAD artery was another interesting point which made us report this case.  相似文献   
56.
Isolated atrial septal defect (ASD) is the most common form of congenital heart abnormalities in adults and approximately 80% are located in the region of the fossa ovalis (ostium secundum ASD).1 Indications for closure are in cases where the ratio of pulmonary-to-systemic flow (Qp/Qs) is higher than 1.5, without significant elevation of pulmonary vascular resistance.Surgical closure of ASDs has been performed for over 60 years and techniques have steadily improved, using smaller incisions and minimally invasive techniques. On the other hand, in the last 20 years, various transcatheter ASD closure techniques and devices have been developed, among which, percutaneous treatment with a septal occluder device is the most popular.2,3Despite increasing use of occluder devices and the fact that studies have been published internationally pointing out some of the advantages and disadvantages compared with surgery in adults, no formal comparison of efficacy, morbidity and complications has been published.2-4 We present a retrospective comparison of short-term (three months) results for transcatheter and surgical closure of 163 ostium secundum ASD patients in a university hospital.  相似文献   
57.
58.
59.
60.
Objectives: The aim of this study was to compare in vitro root fracture resistance following root canal filling with AH 26 using lateral condensation, BeeFill, and Thermafil techniques. Study Design: Eighty extracted human mandibular premolars with similar dimensions were selected. In order to standardize the roots, measurements were taken in two separate regions of the teeth—at the cemento-enamel junction and 8 mm apically from the junction—buccolingual as well as mesiodistal for every tooth. Teeth were then randomly divided into five groups (n=16). With the exception of the non-prepared group (Group 1), instrumentation was done in all groups. In group 2, instrumentation but no filling was performed; in group 3, the obturation was done with AH 26 + gutta-percha; in group 4, with AH 26 + BeeFill and in group 5, AH 26 + a Thermafil obturator was used. All the roots were mounted vertically in copper rings and filled with acrylic resin, exposing 8 mm of the coronal part. A universal testing machine was used for the strength test. Results: The results were analyzed using the one-way ANOVA test. The significance between the groups was tested with Temhane’s T2 test. The results indicate that instrumentation of root canals had a significant effect on fracture resistance (p<0.05). In addition, there were no differences between the root canal obturation techniques; furthermore, these techniques did not create a statistically important resistance to vertical fracture (p>0.05). Conclusions: The results suggest that instrumentation of root canals significantly weakens the tooth structure to fracture and the root canal obturation techniques that are used are not able to form reinforcement. Key words:AH 26, obturation technique, vertical fracture.  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