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   1123篇
  免费   100篇
  国内免费   4篇
耳鼻咽喉   10篇
儿科学   15篇
妇产科学   5篇
基础医学   71篇
口腔科学   12篇
临床医学   68篇
内科学   626篇
皮肤病学   6篇
神经病学   42篇
特种医学   31篇
外科学   127篇
综合类   17篇
一般理论   2篇
预防医学   51篇
眼科学   23篇
药学   83篇
中国医学   1篇
肿瘤学   37篇
  2023年   5篇
  2022年   12篇
  2021年   41篇
  2020年   32篇
  2019年   44篇
  2018年   49篇
  2017年   47篇
  2016年   40篇
  2015年   44篇
  2014年   57篇
  2013年   43篇
  2012年   76篇
  2011年   67篇
  2010年   43篇
  2009年   48篇
  2008年   79篇
  2007年   69篇
  2006年   60篇
  2005年   49篇
  2004年   59篇
  2003年   48篇
  2002年   39篇
  2001年   21篇
  2000年   15篇
  1999年   17篇
  1998年   17篇
  1997年   9篇
  1996年   8篇
  1995年   4篇
  1992年   3篇
  1991年   2篇
  1990年   3篇
  1989年   2篇
  1988年   4篇
  1987年   2篇
  1985年   8篇
  1984年   9篇
  1983年   3篇
  1982年   14篇
  1981年   6篇
  1980年   4篇
  1979年   2篇
  1978年   2篇
  1977年   4篇
  1976年   1篇
  1975年   4篇
  1973年   3篇
  1972年   1篇
  1970年   3篇
  1968年   1篇
排序方式: 共有1227条查询结果,搜索用时 109 毫秒
11.
12.
13.
Hypertrophic cardiomyopathy (HCM) is the most common genetically transmitted cardiomyopathy. In patients resistant to medical management, myectomy is the surgical procedure of choice to reduce the symptoms of left ventricular outflow obstruction. Two‐dimensional transesophageal echocardiography (2DTEE) has become part of the operative procedure by decreasing the incidence of postoperative complications. However, because of the three‐dimensional geometry of left ventricular outflow tract, it is unable to comprehensively assess the location and severity of the obstruction and to provide accurate guidance during myectomy. In this study, 10 patients with HCM underwent live/real time three‐dimensional transesophageal echocardiography (3DTEE) intra‐operatively to measure the volume of the resected septum. This volume correlated well with the volume of the resected septal muscle directly obtained using a graduating cylinder containing water (r = 0.9, P < 0.000). 3DTEE may be potentially used as an adjunct to guide the surgeon in performing an adequate myectomy with a lower incidence of residual obstruction and complications such as an iatrogenic ventricular septal defect.  相似文献   
14.
Background and aimsPatients with diabetes mellitus (DM) often demonstrate impaired antibody response to influenza/hepatitis B vaccines. Hence, we compared anti-SARS-CoV-2 antibody response in non-severe COVID-19 patients with and without type 2 diabetes mellitus (T2DM).MethodsRecords of non-severe COVID-19 patients admitted at our institution between April 10, 2020 and May 20, 2020 were retrieved. Qualitative detection of total (IgG + IgM) anti-SARS-CoV-2 antibody was performed using electrochemiluminescence immunoassay in plasma samples collected at least 14 days post-polymerase chain reaction (PCR) confirmation of diagnosis.ResultsThirty-one non-severe COVID-19 patients were included. Nine patients (29%) had T2DM with mean HbA1c at admission of 8.3 ± 1.0%. Anti-SARS-CoV-2 antibody was estimated at a median of 16 (14–17) days post-PCR confirmation of COVID-19 diagnosis. Only three patients (10%) were seronegative, and all had T2DM. Patients with T2DM were more likely to have non-detectable anti-SARS-CoV-2 antibodies than those without DM (p = 0.019).ConclusionsCOVID-19 patients with T2DM may not undergo seroconversion even after two weeks of diagnosis. Impaired seroconversion could theoretically increase the risk of reinfections in patients with DM. However, the finding requires validation in large-scale studies involving serial estimations of anti-SARS-CoV-2 antibodies in patients with and without DM.  相似文献   
15.
Objective: The first goal of our study was to investigate major determinants of aortic stiffness in postmenopausal women using an echocardiographic method to calculate global pulse wave velocity (PWVg) rather than the less accurate carotid–femoral pulse wave velocity (PWVc). The second goal was to relate PWVg to the absolute risk of major cardiovascular (CV) events estimated by CV risk factors. Patients and methods: Two hundred forty‐four consecutive women who presented to our heart station were screened. One hundred twenty‐two were postmenopausal, either natural or surgical, whereas 122 were premenopausal. The mean age of the patients was 54 ± 13 years. Individuals were categorized as current smokers, former smokers, or nonsmokers and hypertensive or not. Hypercholesterolemia and diabetes mellitus were defined. Aortic stiffness was assessed by PWVg measured with pulsed Doppler, the interval between the beginning of QRS complex and the foot of the systolic upstroke in the Doppler spectral envelope was calculated at the aortic valve site and at the right common femoral artery. PWVg was calculated between the aortic valve and right common femoral artery by dividing the straight line distance between the two by the transit time. Results: There was a highly significant statistical difference (P < 0.0012) in PWVg between menstruating women and postmenopausal women. Similarly, this difference in PWVg was also noted among the menstruating population (P < 0.0014) when comparing normotensive women and hypertensive women. In postmenopausal women, PWVg was 6.8 m/sec in normotensive women and 7.56 m/sec in hypertensive women (P < 0.007). Conclusion: PWVg was increased in postmenopausal women compared with menstruating women. Systemic hypertension has an independent, but additive effect on aortic stiffness assessed by PWVg. Our study supports the usefulness of the assessment of aortic stiffness as a marker of CV disease and to identify subjects at risk at an early age.  相似文献   
16.
Aorta to pulmonary artery fistula is an uncommon and potentially fatal condition. This case is of a 48‐year‐old Caucasian male with congestive heart failure and multiple aortic valve replacement surgeries who presented with an acquired ascending aortic aneurysm to pulmonary artery fistula diagnosed using two‐dimensional transthoracic echocardiography via nonstandard imaging windows. Three‐dimensional transthoracic echocardiography using live/real time three‐dimensional color Doppler was used to assess the size of the opening of the fistula, providing additional value. This patient was surgically managed and is doing well 8 months postoperation.  相似文献   
17.
Cardiomyopathy refers to a set of diseases that are characterized by myocardial dysfunction. Classically, two-dimensional echocardiography has been used in the diagnosis of these disorders and to help guide their management. Three-dimensional transthoracic echocardiography is now increasingly being used in the diagnosis, management, and prognostication of intrinsic cardiomyopathies. In this article, we summarize the available data on the use of three-dimensional transthoracic echocardiography in various forms of intrinsic cardiomyopathy as well as some of its advantages over traditional two-dimensional transthoracic echocardiography. (Echocardiography 2012;29:76-87)  相似文献   
18.
19.
Two parallel literatures on the physical activity (PA) identity and schema constructs have the potential to supplement traditional social cognitive approaches used for PA promotion. The purpose of this paper was to review schema/identity research and appraise its relationship with PA via meta-analysis followed by thematic analyses of its correlates, as well as its proposed mechanisms on PA. Eligible studies were from English, peer-reviewed published articles that examined identity and/or schema in the context of PA. Searches were completed in June 2015 in five databases. Sixty-two independent data-sets (32 available for meta-analysis), primarily of modest quality, were identified. Results of the random effects meta-analysis showed that the point-estimate between identity/schema and behaviour was r?=?.44 (CI?=?.39?.48), and invariant to selected study characteristics. Thematic review showed that identity/schema was associated with commitment, ability, affective judgments, identified/integrated regulation and social comparison and predicted intention, self-regulatory efficacy, and self-regulation strategy use. It had reliable evidence as a moderator of the intention–behavior relationship, was associated with increases in the speed of processing of relevant information and created negative affect under hypothetical identity–behavior discrepant situations. While this initial research is promising, more rigorous research designs, including interventions to increase identity/schema, are warranted.  相似文献   
20.
PurposeTo assess and compare the long-term outcomes of various endovascular interventions in patients with Budd-Chiari syndrome (BCS).Materials and MethodsIn this single-center retrospective study, 510 consecutive patients with BCS who had undergone a total of 618 endovascular procedures from January 2001 to December 2019 were included. Details of the type of endovascular intervention, technical success, clinical success, patency rate, complications, and survival outcomes were analyzed.ResultsThe overall technical success rate was 96% (593 of 618 procedures; 500 in treatment-naïve patients and 93 repeat interventions for recurrent disease). Endovascular procedures included recanalization procedures (angioplasty and stent placement) in 355 patients (71%) and transjugular intrahepatic portosystemic shunt (TIPS) creation in 145 (29%). Major postprocedure complications occurred in 14 patients (2.8%). Vascular/stent restenosis occurred in 95 patients (19%), and successful repeat intervention was performed in 82 of those 95 (86.3%). An additional 11 of these 82 (13.4%) underwent a third intervention for restenosis. In the recanalization and TIPS groups, the 1- and 5-y cumulative patency rates were 87% and 74% and 95% and 68%, respectively. The 1- and 5-y survival rates were 96% and 89% and 90% and 76%, respectively.ConclusionsEndovascular interventions for BCS are feasible and safe in the majority of patients, with excellent short- and long-term patency and survival rates.  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