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   5247篇
  免费   281篇
  国内免费   22篇
耳鼻咽喉   53篇
儿科学   398篇
妇产科学   87篇
基础医学   431篇
口腔科学   133篇
临床医学   365篇
内科学   1031篇
皮肤病学   57篇
神经病学   390篇
特种医学   134篇
外科学   1128篇
综合类   128篇
现状与发展   1篇
一般理论   3篇
预防医学   226篇
眼科学   163篇
药学   392篇
中国医学   15篇
肿瘤学   415篇
  2023年   47篇
  2022年   113篇
  2021年   243篇
  2020年   110篇
  2019年   154篇
  2018年   210篇
  2017年   140篇
  2016年   174篇
  2015年   180篇
  2014年   238篇
  2013年   292篇
  2012年   438篇
  2011年   468篇
  2010年   256篇
  2009年   224篇
  2008年   306篇
  2007年   315篇
  2006年   259篇
  2005年   230篇
  2004年   201篇
  2003年   162篇
  2002年   119篇
  2001年   59篇
  2000年   54篇
  1999年   50篇
  1998年   29篇
  1997年   23篇
  1996年   15篇
  1995年   14篇
  1992年   31篇
  1991年   32篇
  1990年   24篇
  1989年   18篇
  1988年   28篇
  1987年   16篇
  1986年   13篇
  1985年   17篇
  1984年   12篇
  1983年   16篇
  1982年   14篇
  1981年   10篇
  1979年   10篇
  1978年   19篇
  1977年   21篇
  1976年   12篇
  1975年   11篇
  1974年   20篇
  1973年   14篇
  1972年   15篇
  1970年   12篇
排序方式: 共有5550条查询结果,搜索用时 15 毫秒
71.
72.
Gall bladder Carcinoma (GBC) is the fifth most common cancer of the digestive tract and frequently diagnosed in late stage of disease. Estimation of circulating free DNA (cfDNA) in serum has been applied as a “liquid biopsy” in several deep seated malignancies. Its value in diagnosis of gall bladder carcinoma has not been studied. The present study was designed to assess the role of cfDNA in the diagnosis of GBC and correlate levels with the TNM stage. Serum was collected from 34 patients with GBC and 39 age and sex matched controls including 22 cholecystitis and 17 healthy individuals. Serum cfDNA levels were measured through quantitative polymerase chain reaction (qPCR) by amplification of β-globin gene. Performance of the assay was calculated through the receiver operating characteristic (ROC) curve. The cfDNA level was significantly lower in healthy controls and cholecystitis (89.32 ± 59.76 ng/ml, 174.21 ± 99.93 ng/ml) compared to GBC (1245.91 ± 892.46 ng/ml, p = <0.001). The cfDNA level was significantly associated with TNM stage, lymph node involvement and jaundice (0.002, 0.027, and 0.041, respectively). Area under curve of ROC analysis for cancer group versus healthy and cholecystitis group was 1.00 and 0.983 with sensitivity of 100 %, 88.24 % and specificity of 100 % respectively. Quantitative analysis of cfDNA may distinguish cholecystitis and gall bladder carcinoma and may serve as new diagnostic, noninvasive marker adjunct to imaging for the diagnosis of GBC.  相似文献   
73.
IntroductionPercutaneous anterior-posterior (AP) screw is an option for posterior malleolus fracture fixation when the fracture fragment can be reduced indirectly by the mean of ligamentotaxis. However, anterior anatomic structures could be injured during screw placement.Materials and methodsEleven below-knee cadavers were employed for the placement of AP screws in an attempt of fixing assumed Haraguchi Type-I posterior malleolar fractures. Three entry points were selected as medial to the anterior tibial tendon (ATT), lateral to the ATT, and lateral to the extensor digitorum longus (EDL). Three AP screws were placed under guidance of fluoroscopy. After dissection, measurements were made (mm) from each screw to nearby structures. Distances were calculated and damage to structures was documented.ResultsMean, minimum, and maximum distances from the medial screw to the greater saphenous vein, TA, EHL, anterior tibial artery (ATA), and deep peroneal nerve (DPN), were 18.1 (12–25) mm, 2.0 (0–5) mm, 13.6 (9–20) mm, 16.6 (9–25) mm, and 20.1 (12–27) mm. From the middle screw to the ATA, DPN, TA, EHL, and EDL, were 1.2 (0–3) mm, 4.9 (3–9) mm, 3.8 (1–7) mm, 0.4 (0–2) mm, and 13.6 (10–18) mm. From the lateral screw to the superficial peroneal nerve (SPN), EDL, DPN, and ATA, were 10.8 (0–16) mm, 1.2 (0–4) mm, 15.9 (11–25) mm, 19 (15–27) mm. The SPN was found partially cut by the lateral screw on 1 specimen.ConclusionsLateral and middle percutaneous AP screw placement put certain anatomic structures at-risk of injury. Medial screw placement did not result in appreciable damage to adjacent structures. Entry point of AP screws should be selected with respect to posterior malleolar fracture and anatomic structures.Level of evidenceIV.  相似文献   
74.
75.
Acute aortic syndrome is a group of life-threatening diseases of the thoracic aorta that usually present to the emergency department. It includes aortic dissection, aortic intramural hematoma, and penetrating aortic ulcer. Rare aortic pathologies of aorto-esophageal fistula and mycotic aneurysm may also be included in this list. All these conditions require urgent treatment with complex clinical care and management. Most patients who present with chest pain are evaluated with a chest radiograph in the emergency department. It is important that maximum diagnostic information is extracted from the chest radiograph as certain signs on the chest radiograph are extremely useful in pointing towards the diagnosis of acute aortic syndrome.  相似文献   
76.
77.
Competency-based assessments (CBAs) have gained traction in graduate medical education and inform important learner outcomes through the continuum of medical training. Active participation in new CBAs presents challenges to faculty working in a busy clinical environment. As such, the implementation of new CBAs can be approached with intention to foster acceptance and engagement with new evaluations. This paper describes strategies utilized to implement CBAs among clinician educators during a national assessment pilot. Our methods are grounded in educational, psychological, business, ecological, communication, and information technology theory. Our primary interventions included creating a multilevel vision, engaging a dedicated work group, incorporating quality improvement methodology, and integrating technology to successfully implement the assessments. These practical and effective interventions may also be applied to the implementation of other educational innovations.  相似文献   
78.
The nutcracker syndrome is a rare clinical manifestation of symptoms caused by the compression of the left renal vein by an overriding superior mesenteric artery, an anatomical variant otherwise known as the nutcracker phenomenon. Usually present in women and children, when symptomatic, it commonly presents with hematuria, proteinuria, and chronic pelvic pain. Effective modalities of treatment apart from conservative management, include both invasive surgical procedures such as renal vein transposition and autotransplantation of the kidney and more popular recently, the less invasive endovascular stenting. Both options, however, are not without complications, such as, retroperitoneal hematomas or stent migration, thrombosis and restenosis. We now present a case of spontaneous renosplenic shunting in a 68-year-old lady of Chinese descent with the nutcracker syndrome—the first of such cases to be ever reported in a patient with no preexisting predilection for chronic liver disease and portosystemic shunting. Despite having significant pelvic venous congestion as evident on computed tomography scans, she remained asymptomatic. This may present a novel paradigm shift for the treatment of the nutcracker syndrome —surgical creation of a renosplenic bypass instead of current modalities, an alternative solution which can be performed laparoscopically and is without problems related to stent use. The creation of laparoscopic splenorenal bypass has been reported once thus far in Cleveland Ohio by Chung and Gill with good symptomatic improvement but no further studies since to validate its long-term effectiveness.  相似文献   
79.
80.
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