全文获取类型
收费全文 | 632350篇 |
免费 | 36930篇 |
国内免费 | 18902篇 |
专业分类
耳鼻咽喉 | 6025篇 |
儿科学 | 16123篇 |
妇产科学 | 8378篇 |
基础医学 | 69183篇 |
口腔科学 | 13739篇 |
临床医学 | 56372篇 |
内科学 | 106795篇 |
皮肤病学 | 9973篇 |
神经病学 | 38292篇 |
特种医学 | 20894篇 |
外国民族医学 | 79篇 |
外科学 | 77147篇 |
综合类 | 67994篇 |
现状与发展 | 48篇 |
一般理论 | 15篇 |
预防医学 | 39087篇 |
眼科学 | 10697篇 |
药学 | 83132篇 |
241篇 | |
中国医学 | 29746篇 |
肿瘤学 | 34222篇 |
出版年
2023年 | 8037篇 |
2022年 | 19115篇 |
2021年 | 24518篇 |
2020年 | 16922篇 |
2019年 | 26402篇 |
2018年 | 24057篇 |
2017年 | 18645篇 |
2016年 | 17020篇 |
2015年 | 20291篇 |
2014年 | 35255篇 |
2013年 | 37496篇 |
2012年 | 36005篇 |
2011年 | 35040篇 |
2010年 | 30069篇 |
2009年 | 29889篇 |
2008年 | 28591篇 |
2007年 | 29137篇 |
2006年 | 26159篇 |
2005年 | 20965篇 |
2004年 | 14969篇 |
2003年 | 13558篇 |
2002年 | 11325篇 |
2001年 | 10331篇 |
2000年 | 9493篇 |
1999年 | 8073篇 |
1998年 | 7867篇 |
1997年 | 6946篇 |
1996年 | 6394篇 |
1995年 | 6289篇 |
1994年 | 5866篇 |
1993年 | 4802篇 |
1992年 | 4305篇 |
1991年 | 4125篇 |
1990年 | 3690篇 |
1989年 | 3240篇 |
1988年 | 3121篇 |
1987年 | 2728篇 |
1985年 | 7695篇 |
1984年 | 9342篇 |
1983年 | 7296篇 |
1982年 | 7840篇 |
1981年 | 7186篇 |
1980年 | 6205篇 |
1979年 | 5956篇 |
1978年 | 4792篇 |
1977年 | 3762篇 |
1976年 | 4036篇 |
1975年 | 3009篇 |
1974年 | 2828篇 |
1973年 | 2523篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
《The Journal of thoracic and cardiovascular surgery》2023,165(1):94-103.e24
ObjectiveNew-onset postoperative atrial fibrillation (POAF) after cardiac surgery is common, with rates up to 60%. POAF has been associated with early and late stroke, but its association with other cardiovascular outcomes is less known. The objective was to perform a meta-analysis of the studies reporting the association of POAF with perioperative and long-term outcomes in patients with cardiac surgery.MethodsWe performed a systematic review and a meta-analysis of studies that presented outcomes for cardiac surgery on the basis of the presence or absence of POAF. MEDLINE, EMBASE, and the Cochrane Library were assessed; 57 studies (246,340 patients) were selected. Perioperative mortality was the primary outcome. Inverse variance method and random model were performed. Leave-one-out analysis, subgroup analyses, and metaregression were conducted.ResultsPOAF was associated with perioperative mortality (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.58-2.33), perioperative stroke (OR, 2.17; 95% CI, 1.90-2.49), perioperative myocardial infarction (OR, 1.28; 95% CI, 1.06-1.54), perioperative acute renal failure (OR, 2.74; 95% CI, 2.42-3.11), hospital (standardized mean difference, 0.80; 95% CI, 0.53-1.07) and intensive care unit stay (standardized mean difference, 0.55; 95% CI, 0.24-0.86), long-term mortality (incidence rate ratio [IRR], 1.54; 95% CI, 1.40-1.69), long-term stroke (IRR, 1.33; 95% CI, 1.21-1.46), and longstanding persistent atrial fibrillation (IRR, 4.73; 95% CI, 3.36-6.66).ConclusionsThe results suggest that POAF after cardiac surgery is associated with an increased occurrence of most short- and long-term cardiovascular adverse events. However, the causality of this association remains to be established. 相似文献
2.
3.
中药生产过程质量控制关键技术研究进展 总被引:10,自引:8,他引:2
中医药发展已上升到国家战略层面,在医药行业贯彻实施"中国制造2025"战略的新形势下,中药生产过程质量控制是中药工业需要加快突破的关键领域之一。对中药生产过程质量控制领域在工艺设计、分析检测、过程建模、制造装备等方面的关键共性问题进行解析,综述了中药生产过程质量控制体系中工艺过程理解、生产过程实时分析方法开发、过程控制策略建立3个方面的研究进展;并结合企业研究实践,介绍了质量源于设计(quality by design,Qb D)、过程分析技术(process analytical technology,PAT)、实验设计(design of experiment,DOE)、多变量统计分析等关键技术在上述3个研究方向中的应用进展,分析了实际工业应用的难点问题并对其应用前景进行展望,旨在为中药企业应用和提升生产过程质量控制技术提供参考。 相似文献
4.
Itay Zmora Yonit Wiener-Well Evan Avraham Alpert 《The American journal of emergency medicine》2019,37(5):1006.e5-1006.e7
Background
Purulent bacterial pericarditis is a rare and potentially fatal disease. The course may be fulminant, and the presentation may pose a diagnostic challenge.Case report
An otherwise healthy 75-year-old male was brought to the emergency department in a state of general deterioration, confusion, and shock. Bedside ultrasound showed a significant pericardial effusion. His condition quickly deteriorated and the resuscitation included emergent bedside pericardiocentesis. The drainage was purulent and later cultures grew out Streptococcus pneumoniae.Why should an emergency physician be aware of this?
Purulent pericarditis is extremely rare but should be considered in the patient with a fulminant infectious process (particularly pneumonia) and signs of pericardial effusion. Treatment should include appropriate antibiotics and early drainage. 相似文献5.
6.
《Archives of Cardiovascular Diseases》2022,115(10):505-513
Central illustration: cumulative major adverse cardiac events (MACE) and bioresorbable vascular scaffold (BVS) thrombosis rates after 1, 2, 3, 4 and 5 years. 相似文献
7.
《Diagnostic and interventional imaging》2020,101(9):555-564
PurposeThe purpose of this study was to determine whether computed tomography (CT)-based machine learning of radiomics features could help distinguish autoimmune pancreatitis (AIP) from pancreatic ductal adenocarcinoma (PDAC).Materials and MethodsEighty-nine patients with AIP (65 men, 24 women; mean age, 59.7 ± 13.9 [SD] years; range: 21–83 years) and 93 patients with PDAC (68 men, 25 women; mean age, 60.1 ± 12.3 [SD] years; range: 36–86 years) were retrospectively included. All patients had dedicated dual-phase pancreatic protocol CT between 2004 and 2018. Thin-slice images (0.75/0.5 mm thickness/increment) were compared with thick-slices images (3 or 5 mm thickness/increment). Pancreatic regions involved by PDAC or AIP (areas of enlargement, altered enhancement, effacement of pancreatic duct) as well as uninvolved parenchyma were segmented as three-dimensional volumes. Four hundred and thirty-one radiomics features were extracted and a random forest was used to distinguish AIP from PDAC. CT data of 60 AIP and 60 PDAC patients were used for training and those of 29 AIP and 33 PDAC independent patients were used for testing.ResultsThe pancreas was diffusely involved in 37 (37/89; 41.6%) patients with AIP and not diffusely in 52 (52/89; 58.4%) patients. Using machine learning, 95.2% (59/62; 95% confidence interval [CI]: 89.8–100%), 83.9% (52:67; 95% CI: 74.7–93.0%) and 77.4% (48/62; 95% CI: 67.0–87.8%) of the 62 test patients were correctly classified as either having PDAC or AIP with thin-slice venous phase, thin-slice arterial phase, and thick-slice venous phase CT, respectively. Three of the 29 patients with AIP (3/29; 10.3%) were incorrectly classified as having PDAC but all 33 patients with PDAC (33/33; 100%) were correctly classified with thin-slice venous phase with 89.7% sensitivity (26/29; 95% CI: 78.6–100%) and 100% specificity (33/33; 95% CI: 93–100%) for the diagnosis of AIP, 95.2% accuracy (59/62; 95% CI: 89.8–100%) and area under the curve of 0.975 (95% CI: 0.936–1.0).ConclusionsRadiomic features help differentiate AIP from PDAC with an overall accuracy of 95.2%. 相似文献
8.
9.
Alexandra Katsimardou Konstantinos Imprialos Konstantinos Stavropoulos Alexandros Sachinidis Michalis Doumas 《Expert opinion on pharmacotherapy》2020,21(10):1241-1252
ABSTRACT
Introduction
Type 1 diabetes mellitus (T1DM) is a chronic, autoimmune disease that is characterized by total absence of insulin production. Hypertension is a common comorbidity in T1DM with complex pathophysiology, while it is also a well-recognized risk factor for the development of cardiovascular disease (CVD), as well as other microvascular diabetic complications. 相似文献10.
Qiaojie Wang Karan Goswami Noam Shohat Arash Aalirezaie Jorge Manrique Javad Parvizi 《The Journal of arthroplasty》2019,34(5):947-953