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   3444篇
  免费   173篇
  国内免费   30篇
耳鼻咽喉   110篇
儿科学   128篇
妇产科学   132篇
基础医学   258篇
口腔科学   134篇
临床医学   297篇
内科学   802篇
皮肤病学   79篇
神经病学   201篇
特种医学   151篇
外科学   770篇
综合类   52篇
预防医学   85篇
眼科学   131篇
药学   169篇
中国医学   13篇
肿瘤学   135篇
  2024年   2篇
  2023年   19篇
  2022年   39篇
  2021年   50篇
  2020年   47篇
  2019年   67篇
  2018年   79篇
  2017年   69篇
  2016年   120篇
  2015年   133篇
  2014年   171篇
  2013年   187篇
  2012年   246篇
  2011年   217篇
  2010年   137篇
  2009年   149篇
  2008年   323篇
  2007年   315篇
  2006年   294篇
  2005年   273篇
  2004年   218篇
  2003年   157篇
  2002年   104篇
  2001年   51篇
  2000年   49篇
  1999年   25篇
  1998年   5篇
  1997年   8篇
  1996年   3篇
  1995年   5篇
  1992年   11篇
  1991年   8篇
  1990年   9篇
  1989年   17篇
  1988年   8篇
  1987年   3篇
  1986年   3篇
  1985年   4篇
  1984年   3篇
  1983年   2篇
  1981年   3篇
  1978年   2篇
  1977年   1篇
  1975年   1篇
  1974年   1篇
  1973年   1篇
  1971年   1篇
  1970年   1篇
  1968年   1篇
  1967年   1篇
排序方式: 共有3647条查询结果,搜索用时 15 毫秒
91.
92.
93.
94.
Transcatheter aortic valve replacement can be an effective, reliable treatment for severe aortic stenosis in surgically high-risk or ineligible patients. However, various sequelae like coronary artery obstruction can occur, not only in the long term, but also immediately after the procedure. We present the case of a 78-year-old woman whose left main coronary artery became obstructed with calculus 2 hours after the transfemoral implantation of an Edwards Sapien XT aortic valve. Despite percutaneous coronary intervention in that artery, the patient died. This case reminds us that early recognition of acute coronary obstruction and prompt intervention are crucial in patients with aortic stenosis who have undergone transcatheter aortic valve replacement.  相似文献   
95.
96.

Background

We aimed to investigate the correlation between ECG QRS voltage changes, N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels and clinical improvement in decompensated heart failure (DHF).

Methods and results

DHF patients (n = 56) with a mean age of 67.5 ± 12.6 years showed limb QRS amplitude increase and NT-proBNP level decrease with clinical improvement (p < 0.001). Significant correlation was found between percent changes (Δ%) in body weight and Δ% in QRS voltages of aVR, aVF, DII, ΣQRSI + II and ΣQRS (all limb-leads) (r = − 0.40; r = − 0.35; r = − 0.32; r = − 0.30; r = − 0.30 respectively, p < 0.05). No correlation was found between Δ% in NT-proBNP and body weight (r = − 0.23, p = 0.09). Δ% NT-proBNP was correlated with Δ% QRS voltage only in aVR (r = − 0.312, p = 0.019). In ROC analysis, ≥ 0.5 mm increase in aVR QRS voltage was found to predict ≥ 5 kg weight loss with a sensitivity of 74% and specificity of 62% (p = 0.013, AUC: 0.699).

Conclusions

Increase in QRS voltages especially in aVR was found to be more sensitive than NT-proBNP to predict clinical improvement in DHF.  相似文献   
97.
98.
Purpose: Urinary stones are common and can be diagnosed with computed tomography (CT) easily. In this study, we aimed to specify the opacity characteristics of various types of calcified foci that develop through the urinary system by using an image analysis program. With this method, we try to differentiate the calculi from the non-calculous opacities and also we aimed to present how to identify the characteristic features of renal and ureteral calcules. Materials and methods: We obtained the CT studies of the subjects (n?=?48, mean age?=?41 years) by using a dual source CT imaging system. We grouped the calculi detected in the dual-energy CT sections as renal (n?=?40) or ureteric (n?=?45) based on their locations. Other radio-opaque structures that were identified outside but within close proximity of the urinary tract were recorded as calculi “mimickers”. We used ImageJ program for morphological analysis. All the acquired data were analyzed statistically. Results: According to thorough morphological parameters, there were statistically significant differences in the angle and Feret angle values between calculi and mimickers (p?p?=?0.003) and kidney (p?=?0.001) stones. Conclusions: Computer-based morphologic parameters can be used simply to differentiate between calcular and noncalcular densities on CT and also between renal and ureteric stones.  相似文献   
99.
The aim of this study was to evaluate utility of gadoxetic acid disodium (Gd‐EOB‐DTPA)‐enhanced magnetic resonance cholangiography (MRC) for the detection of biliary complications after living donor liver transplantation (LDLT). A total of 18 patients with suspected biliary complications underwent MRC. T2‐weighted MRC and contrast‐enhanced MRC (CE‐MRC) were used to identify the biliary complications. MRC included routine breath‐hold T2‐weighted MRC using half‐Fourier acquisition single‐shot turbo spin‐echo (HASTE) sequences and Gd‐EOB‐DTPA‐enhanced MRC T1‐weighted volumetric interpolated breath‐hold examination (VIBE) sequences. Before confirming the biliary complications, one observer reviewed the MRC images and the CE‐MRC images separately. The verification procedures and MRC findings were compared, and the sensitivity, specificity, and accuracy of both techniques were calculated for the identification of biliary complications. The observer found six of seven biliary complications using CE‐MRC. The sensitivity was 85.7% and the accuracy was 94.4%. Using MRC alone, sensitivity was 57.1% and accuracy was 55.5%. The accuracy of Gd‐EOB‐DTPA‐enhanced MRC was superior to MRC in locating biliary leaks (p < 0.05). The usage of Gd‐EOB‐DTPA‐enhanced MRC yields information that complements the MRC findings that improve the identification of biliary complications. We recommend the use of MRC in addition to Gd‐EOB‐DTPA‐enhanced MRC to increase the preoperative accuracy when assessing the biliary complications after LDLT.  相似文献   
100.

Summary

Clinical trials have shown that zoledronic acid was more effective than other bisphosphonates in the treatment of Paget disease. We retrospectively reviewed remission and relapse statuses of 12 patients with Paget disease. Remission was achieved in all patients after treatment. We recommend zoledronic acid in the first-line treatment of Paget disease.

Introduction

Paget disease is a disease of bone of unknown etiology with increased bone turnover that results in defective bone microarchitecture and bone deformity. Bisphosphonates are used in symptomatic Paget disease of bone. Clinical trials have shown that zoledronic acid was more effective than other bisphosphonates in the treatment of Paget disease.

Methods

In this study, we retrospectively reviewed the remission and relapse statuses of 12 patients with Paget disease of bone who were seen as outpatients between October 2011 and October 2013.We evaluated alkaline phosphates, osteocalcin, and deoxypyridinoline levels measured before and at 6th, 12th, and 18th months of treatment.

Results

Pretreatment and posttreatment values for alkaline phosphates, deoxypyridinoline, and osteocalcin were as follows: 473?±?256 U/L, 14.99?±?7.63 mmol/L, 21.09?±?3.18 ng/ml, and 82?±?13 U/L, 5.14?±?1.11 mmol/L, and 8.57?±?4.31 ng/ml. Remission was achieved in all patients after treatment. The levels indicated that remission continued at 12th and 18th months of treatment. There was statistically significant difference between pretreatment and posttreatment values. No statistically significant difference between the levels measured at 6th, 12th, and 18th months of treatment was detected.

Conclusion

We recommend zoledronic acid in the first-line treatment of Paget disease of bone in achieving and maintaining remission.  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