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   3420篇
  免费   350篇
  国内免费   17篇
耳鼻咽喉   31篇
儿科学   102篇
妇产科学   45篇
基础医学   449篇
口腔科学   187篇
临床医学   240篇
内科学   721篇
皮肤病学   72篇
神经病学   181篇
特种医学   98篇
外科学   496篇
综合类   197篇
一般理论   1篇
预防医学   208篇
眼科学   144篇
药学   273篇
  1篇
中国医学   22篇
肿瘤学   319篇
  2023年   39篇
  2022年   52篇
  2021年   132篇
  2020年   96篇
  2019年   103篇
  2018年   117篇
  2017年   104篇
  2016年   120篇
  2015年   138篇
  2014年   155篇
  2013年   157篇
  2012年   251篇
  2011年   214篇
  2010年   120篇
  2009年   124篇
  2008年   162篇
  2007年   156篇
  2006年   143篇
  2005年   139篇
  2004年   168篇
  2003年   103篇
  2002年   112篇
  2001年   81篇
  2000年   83篇
  1999年   76篇
  1998年   33篇
  1997年   27篇
  1996年   25篇
  1995年   15篇
  1994年   28篇
  1993年   16篇
  1992年   35篇
  1991年   42篇
  1990年   55篇
  1989年   36篇
  1988年   33篇
  1987年   35篇
  1986年   34篇
  1985年   31篇
  1984年   27篇
  1983年   18篇
  1982年   12篇
  1981年   9篇
  1980年   10篇
  1979年   34篇
  1977年   14篇
  1975年   7篇
  1974年   7篇
  1972年   11篇
  1971年   9篇
排序方式: 共有3787条查询结果,搜索用时 15 毫秒
51.
A continuous production of significant pancreatic enzymes, which are thought to be responsible for the maintenance of the digesting process, is frequently found in fulminant necrotizing pancreatitis. Since the medical therapies known to be effective are based upon the rationale of slowing pancreatic secretion, a simple measure which permits the "burning out" of residual pancreatic tissue might therefore have a therapeutic value. In this study, 2 hr after the induction of acute hemorrhagic pancreatitis, 5 dogs (Group I) were treated with 1.5 ml Ethibloc injected into the pancreatic duct; 5 other animals (Group II) were given 1.5 ml saline; Group III (5 dogs) had no treatment. All animals in Group II and 4 of the 5 animals in Group III expired within 8 days postoperatively. In contrast, 4 of 5 animals from Group I survived. Although some of the biochemical parameters showed significant changes after the induction of acute pancreatitis, no differences were seen between the three groups. In the expired animals, the picture of histological examination was that of a fulminant acute hemorrhagic pancreatitis of the left lobe. In the survival dogs although normal pancreatic tissue was present in the right lobe at necropsy at intervals, there was always a pancreatic atrophy of the left lobe and striking adhesions with the surrounding tissues suggesting the severity of the disease in the acute phase. These findings suggest that pancreatic duct occlusion causing the exocrine secretion to stop may have beneficial effects in the treatment of acute fulminant pancreatitis in the acute phase and may improve the survival rate.  相似文献   
52.
53.
54.
Picky eating is a common cause of concern for parents of young children. Paediatricians and family physicians are in a key position to help parents learn ways to feed their children effectively. Despite the high prevalence of picky eating, the growth of the majority of picky eaters does not suffer adversely. In the absence of worrying signs and symptoms, reassurance of the child’s normal growth would help allay parental anxieties. Reinforcement of basic feeding principles and providing healthy dietary advice are important strategies to help parents manage children who are picky eaters.  相似文献   
55.
Lumbar discal cyst is a rare cause of radiculopathy. Their exact pathogenesis and the optimal treatment modality remain unidentified. Depending on their location, discal cysts cannot always be easily identified intraoperatively. We describe 2 patients with discal cysts and introduce an intraoperative discography technique for discal cyst location. Both patients were treated with surgical excision; with intraoperative discography, the cystic lesions could easily be detected and removed.  相似文献   
56.
Anterior repositioning splints (ARS) are used primarily for the management of temporomandibular joint (TMJ) anterior disc displacement with reduction (ADDwR). However, the exact physiological effects of ARS are still unclear. This study investigated the short and long‐term effects of ARS on disc and condyle angles/positions by metric analysis. Twenty‐two subjects diagnosed with ADDwR were recruited. Maxillary full‐coverage ARS were fabricated, and MRI of TMJs was obtained before splint treatment, immediate post‐insertion and 6 months after splint treatment. Disc–condyle relationship was determined by disc–condyle angle measurement. Disc and condyle positions were described as X‐Y coordinates with the summit of glenoid fossa as the origin of the coordinates. Thirty‐two TMJs were classified as ADDwR and 12 were normal. Upon ARS insertion, all TMJs with ADDwR got normal disc–condyle relationships. The condyles moved significantly forward and downward, while the discs moved significantly backward and upward. MRI at 6 months after treatment (without ARS insertion) indicated that only 40·6% (13/32) of the joints were maintained in the normal disc–condyle relationship. The majority of condyles returned to their pre‐treatment positions, while the discs generally moved anteriorly again. The use of ARS resulted in forward and downward condyle movement, and a concurrent backward movement of the disc resulting in ideal spatial disc–condyle relationship. The stability of this relationship, however, could not be maintained in the majority of TMJs upon ARS removal. Findings explain the good short‐term clinical outcomes with ARS and their relatively lower efficacy in the long term.  相似文献   
57.
58.
59.
Current Doppler echocardiography quantification of mitral regurgitation (MR) severity has shortcomings. Proximal isovelocity surface area (PISA)-based methods, for example, are unable to account for the fact that ultrasound Doppler can measure only one velocity component: toward or away from the transducer. In the present study, we used ultrasound-based computational fluid dynamics (Ub-CFD) to quantify mitral regurgitation and study its advantages and disadvantages compared with 2-D and 3-D PISA methods. For Ub-CFD, patient-specific mitral valve geometry and velocity data were obtained from clinical ultrasound followed by 3-D CFD simulations at an assumed flow rate. We then obtained the average ratio of the ultrasound Doppler velocities to CFD velocities in the flow convergence region, and scaled CFD flow rate with this ratio as the final measured flow rate. We evaluated Ub-CFD, 2-D PISA and 3-D PISA with an in vitro flow loop, which featured regurgitation flow through (i) a simplified flat plate with round orifice and (ii) a 3-D printed realistic mitral valve and regurgitation orifice. The Ub-CFD and 3-D PISA methods had higher precision than the 2-D PISA method. Ub-CFD had consistent accuracy under all conditions tested, whereas 2-D PISA had the lowest overall accuracy. In vitro investigations indicated that the accuracy of 2-D and 3-D PISA depended significantly on the choice of aliasing velocity. Evaluation of these techniques was also performed for two clinical cases, and the dependency of PISA on aliasing velocity was similarly observed. Ub-CFD was robustly accurate and precise and has promise for future translation to clinical practice.  相似文献   
60.
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