全文获取类型
收费全文 | 12451篇 |
免费 | 1080篇 |
国内免费 | 525篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 148篇 |
妇产科学 | 107篇 |
基础医学 | 832篇 |
口腔科学 | 154篇 |
临床医学 | 1338篇 |
内科学 | 3271篇 |
皮肤病学 | 141篇 |
神经病学 | 412篇 |
特种医学 | 638篇 |
外国民族医学 | 1篇 |
外科学 | 878篇 |
综合类 | 1524篇 |
现状与发展 | 1篇 |
预防医学 | 589篇 |
眼科学 | 93篇 |
药学 | 1877篇 |
7篇 | |
中国医学 | 1594篇 |
肿瘤学 | 425篇 |
出版年
2024年 | 57篇 |
2023年 | 355篇 |
2022年 | 553篇 |
2021年 | 789篇 |
2020年 | 622篇 |
2019年 | 722篇 |
2018年 | 657篇 |
2017年 | 422篇 |
2016年 | 404篇 |
2015年 | 497篇 |
2014年 | 824篇 |
2013年 | 896篇 |
2012年 | 744篇 |
2011年 | 762篇 |
2010年 | 534篇 |
2009年 | 504篇 |
2008年 | 510篇 |
2007年 | 511篇 |
2006年 | 452篇 |
2005年 | 379篇 |
2004年 | 278篇 |
2003年 | 263篇 |
2002年 | 222篇 |
2001年 | 182篇 |
2000年 | 149篇 |
1999年 | 153篇 |
1998年 | 147篇 |
1997年 | 129篇 |
1996年 | 89篇 |
1995年 | 143篇 |
1994年 | 115篇 |
1993年 | 87篇 |
1992年 | 98篇 |
1991年 | 81篇 |
1990年 | 83篇 |
1989年 | 67篇 |
1988年 | 63篇 |
1987年 | 64篇 |
1986年 | 63篇 |
1985年 | 61篇 |
1984年 | 67篇 |
1983年 | 52篇 |
1982年 | 51篇 |
1981年 | 41篇 |
1980年 | 30篇 |
1979年 | 20篇 |
1978年 | 13篇 |
1977年 | 16篇 |
1976年 | 12篇 |
1975年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
12.
13.
《The Journal of thoracic and cardiovascular surgery》2023,165(1):149-158.e4
BackgroundCoronary artery bypass grafting (CABG) improves survival in patients with heart failure and severely reduced left ventricular systolic function (LVEF). Limited data exist regarding adverse cardiovascular event rates after CABG in patients with heart failure with midrange ejection fraction (HFmrEF; LVEF > 40% and < 55%).MethodsWe analyzed data on isolated CABG patients from the Veterans Affairs national database (2010-2019). We stratified patients into control (normal LVEF and no heart failure), HFmrEF, and heart failure with reduced LVEF (HFrEF) groups. We compared all-cause mortality and heart failure hospitalization rates between groups with a Cox model and recurrent events analysis, respectively.ResultsIn 6533 veterans, HFmrEF and HFrEF was present in 1715 (26.3%) and 566 (8.6%) respectively; the control group had 4252 (65.1%) patients. HFrEF patients were more likely to have diabetes mellitus (59%), insulin therapy (36%), and previous myocardial infarction (31%). Anemia was more prevalent in patients with HFrEF (49%) as was a lower serum albumin (mean, 3.6 mg/dL). Compared with the control group, a higher risk of death was observed in the HFmrEF (hazard ratio [HR], 1.3 [1.2-1.5)] and HFrEF (HR, 1.5 [1.2-1.7]) groups. HFmrEF patients had the higher risk of myocardial infarction (subdistribution HR, 1.2 [1-1.6]; P = .04). Risk of heart failure hospitalization was higher in patients with HFmrEF (HR, 4.1 [3.5-4.7]) and patients with HFrEF (HR, 7.2 [6.2-8.5]).ConclusionsHeart failure with midrange ejection fraction negatively affects survival after CABG. These patients also experience higher rates myocardial infarction and heart failure hospitalization. 相似文献
14.
Mayuko Kinoshita Haruka Kaneko Lizu Liu Masashi Nagao Ryo Sadatsuki 《Modern rheumatology / the Japan Rheumatism Association》2019,29(1):157-164
Objectives: To examine the factors associated with increase in lumbar spine bone mineral density (LS-BMD) by bisphosphonates (BPs) with active vitamin D analog (aVD).Methods: Two independent postmenopausal osteoporotic patients treated by BPs with aVD for 24 months (Study 1: n?=?93, Study 2: n?=?99) were retrospectively analyzed.Results: In Study 1, LS-BMD of the patients significantly increased for 24 m (5.4%, p?.001). A multiple regression analysis among baseline characteristics revealed that serum calcium (sCa: 8.5–10.5?mg/dL) was associated with an increased LS-BMD by treatment (r2: 0.088, p?=?.02). While average sCa of the patients was 9.2?mg/dL before treatment, it increased time-dependently to 9.6?mg/dL for 24 m by treatment. As each patient had their LS-BMD five times during the study, there were four instances of %LS-BMD in each patient, resulting in 372 instances of %LS-BMD in Study 1. The smallest Akaike’s information criterion value for the most appropriate cut-off levels of sCa for %LS-BMD by treatment every 6 m was 9.3?mg/dL. The %LS-BMD by treatment for 6 m during 24 m period in patients with sCa ≥9.3?mg/dL (1.5%) was significantly higher than that in patients with sCa <9.3?mg/dL (0.8%, p?=?.038). The results of Study 2 were similar to those of Study 1, confirming the phenomena observed.Conclusion: sCa was associated with an increased LS-BMD by BPs with aVD. 相似文献
15.
16.
17.
Evaluation of training nurses to perform semi‐automated three‐dimensional left ventricular ejection fraction using a customised workstation‐based training protocol
下载免费PDF全文
![点击此处可从《Journal of clinical nursing》网站下载免费的PDF全文](/ch/ext_images/free.gif)
18.
19.
Ewelina Kazimierczyk Andrzej Eljaszewicz Paula Zembko Ewa Tarasiuk Malgorzata Rusak Agnieszka Kulczynska-Przybik Marta Lukaszewicz-Zajac Karol Kaminski Barbara Mroczko Maciej Szmitkowski Milena Dabrowska Bozena Sobkowicz Marcin Moniuszko Agnieszka Tycinska 《Pharmacological reports : PR》2019,71(1):73-81
Background
Acute myocardial infarction (AMI) causes irreversible myocardial damage and release of inflammatory mediators, including cytokines, chemokines and miRNAs. We aimed to investigate changes in the levels of cytokines (IL-6, TNF-α and IL-10), miRNAs profiles (miR-146 and miR-155) and distribution of different monocyte subsets (CD14++CD16-, CD14++CD16+, CD14+CD16++) in the acute and post-healing phases of AMI.Methods
In eighteen consecutive AMI patients (mean age 56.78?±?12.4 years, mean left ventricle ejection fraction – LVEF: 41.9?±?9.8%), treated invasively, monocyte subsets frequencies were evaluated (flow cytometry), cytokine concentrations were analyzed (ELISA) as well as plasma miRNAs were isolated twice – on admission and after 19.2?±?5.9 weeks of follow-up. Measurements were also performed among healthy volunteers.Results
AMI patients presented significantly decreased frequencies of classical cells in comparison to healthy controls (median 71.22% [IQR: 64.4–79.04] vs. 84.35% [IQR: 81.2–86.7], p?=?0.001) and higher percent of both intermediate and non-classical cells, yet without statistical significance (median 6.54% [IQR: 5.14–16.64] vs. 5.87% [IQR: 4.48–8.6], p?=?0.37 and median 5.99% [IQR: 3.39–11.5] vs. 5.26% [IQR: 3.62–6.2], p?=?0.42, respectively). In AMI patients both, analyzed plasma miRNA concentrations were higher than in healthy subjects (miR-146: median 5.48 [IQR: 2.4–11.27] vs. 1.84 [IQR: 0.87–2.53], p?=?0.003; miR-155: median 25.35 [IQR: 8.17–43.15] vs. 8.4 [IQR: 0.08–16.9], p?=?0.027, respectively), and returned back to the values found in the control group in follow-up. miR-155/miR-146 ratio correlated with the frequencies of classical monocytes (r=0.6, p?=?0.01) and miR-155 correlated positively with the concentration of inflammatory cytokines ? IL-6 and TNF-α.Conclusions
These results may suggest cooperation of both pro-inflammatory and anti-inflammatory signals in AMI in order to promote appropriate healing of the infarcted myocardium. 相似文献20.
《Journal of pharmaceutical sciences》2019,108(7):2500-2504
Accurately predicting the hepatic clearance of compounds using in vitro to in vivo extrapolation (IVIVE) is crucial within the pharmaceutical industry. However, several groups have recently highlighted the serious error in the process. Although empirical or regression-based scaling factors may be used to mitigate the common underprediction, they provide unsatisfying solutions because the reasoning behind the underlying error has yet to be determined. One previously noted trend was intrinsic clearance-dependent underprediction, highlighting the limitations of current in vitro systems. When applying these generated in vitro intrinsic clearance values during drug development and making first-in-human dose predictions for new chemical entities though, hepatic clearance is the parameter that must be estimated using a model of hepatic disposition, such as the well-stirred model. Here, we examine error across hepatic clearance ranges and find a similar hepatic clearance-dependent trend, with high clearance compounds not predicted to be so, demonstrating another gap in the field. 相似文献