全文获取类型
收费全文 | 20830篇 |
免费 | 1298篇 |
国内免费 | 142篇 |
专业分类
耳鼻咽喉 | 188篇 |
儿科学 | 518篇 |
妇产科学 | 381篇 |
基础医学 | 2367篇 |
口腔科学 | 789篇 |
临床医学 | 1978篇 |
内科学 | 4449篇 |
皮肤病学 | 429篇 |
神经病学 | 1261篇 |
特种医学 | 485篇 |
外国民族医学 | 5篇 |
外科学 | 2876篇 |
综合类 | 509篇 |
一般理论 | 15篇 |
预防医学 | 1695篇 |
眼科学 | 786篇 |
药学 | 2068篇 |
中国医学 | 233篇 |
肿瘤学 | 1238篇 |
出版年
2024年 | 21篇 |
2023年 | 243篇 |
2022年 | 607篇 |
2021年 | 1159篇 |
2020年 | 753篇 |
2019年 | 904篇 |
2018年 | 1093篇 |
2017年 | 762篇 |
2016年 | 825篇 |
2015年 | 835篇 |
2014年 | 1135篇 |
2013年 | 1328篇 |
2012年 | 1816篇 |
2011年 | 1856篇 |
2010年 | 1086篇 |
2009年 | 842篇 |
2008年 | 1245篇 |
2007年 | 1119篇 |
2006年 | 956篇 |
2005年 | 822篇 |
2004年 | 649篇 |
2003年 | 541篇 |
2002年 | 449篇 |
2001年 | 90篇 |
2000年 | 108篇 |
1999年 | 111篇 |
1998年 | 60篇 |
1997年 | 61篇 |
1996年 | 50篇 |
1995年 | 43篇 |
1994年 | 30篇 |
1993年 | 46篇 |
1992年 | 55篇 |
1991年 | 48篇 |
1990年 | 42篇 |
1989年 | 47篇 |
1988年 | 45篇 |
1987年 | 23篇 |
1986年 | 30篇 |
1985年 | 33篇 |
1984年 | 39篇 |
1983年 | 32篇 |
1982年 | 19篇 |
1981年 | 21篇 |
1980年 | 17篇 |
1979年 | 31篇 |
1978年 | 20篇 |
1976年 | 19篇 |
1974年 | 19篇 |
1973年 | 16篇 |
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
1.
2.
3.
4.
Aaron Pitzele Mohammad Rahimi Eric Armbrecht 《The journal of maternal-fetal & neonatal medicine》2015,28(15):1770-1773
Objective: To determine whether packed red blood cell (PRBC) transfusion affects post-prandial superior mesenteric artery blood flow velocities (SMA BFVs) in very-low birth weight (VLBW) neonates and if so, at what time point after transfusion restoration of previous SMA BFV patterns occurs.Design/Methods: VLBW pre-term neonates, older than 14 days and tolerating bolus enteral feedings administered every 3?h were enrolled in this prospective observational study. Pulsed Doppler ultrasound was used to measure pre- and post-prandial (at 45?min) time-averaged mean, peak and end diastolic velocities (TAMV, PSV, EDV) immediately before and after 15?ml/kg of PRBC transfusion was given over 3?h; patent ductus arteriosus (PDA) status was also evaluated. Subsequent pre- and post-prandial SMA BFVs were recorded 24 and 48?h after the transfusion.Results: Pre- and post-prandial measurements were obtained for 21 out of 25 enrolled infants. Post-prandial SMA BFVs were attenuated during the feedings immediately after transfusion; at 24 and 48?h after transfusion, changes in post-prandial SMA BFVs were similar to those measured prior to transfusion; the presence of the PDA did not affect results.Conclusions: PRBC transfusion blunted SMA BFV responses to feedings immediately after the transfusion with normalization observed 24?h post-transfusion. 相似文献
5.
Ahmed M. Abu El-Asrar Ajmal Ahmad Eef Allegaert Mohammad Mairaj Siddiquei Priscilla W. Gikandi Gert De Hertogh 《Ocular immunology and inflammation》2020,28(4):575-588
ABSTRACT
Purpose
To investigate the expression of IL-11 and its receptor IL-11Rα and to quantify density of CD163+ M2 macrophages in proliferative diabetic retinopathy (PDR). 相似文献6.
7.
8.
Purpose: To describe how central venous access devices (CVADs) are utilized for ambulatory oncology patients and to evaluate the rate of complications. Method: Single institution retrospective study of oncology patients with CVADs who received systemic treatment at the Walker Family Cancer Centre (WFCC) between 1 January and 31 December 2018. Results: A total of 480 CVADS were placed in 305 patients, of which 408 (85%) were peripherally inserted central catheters (PICCs) and 72 (15%) were implanted vascular access devices (PORTs). The incidence of early and late complications was 9% and 24%, respectively. For the entire cohort, the rate of venous thromboembolism (VTE) was 16%, of which 9% were CVAD-related thrombosis (CRTs) and 7% were distant VTE. The CRT rates were similar for PICCs and PORTs (9% vs. 7%). A total of 6% of CVADs were complicated by infection (i.e., localized infections and bacteremia), with a total infection rate of 0.43 and 0.26 per 1000 indwelling days for PICCs and PORTs, respectively. The incidence of central line associated bloodstream infections (CLABSI) was greater for PICCs than PORTs, at a rate of 0.22 compared with 0.08 per 1000 indwelling days, respectively. The premature catheter removal rate was 26% for PICCs and 18% for PORTs. PORTs required more additional hospital visits. Conclusions: PICCs were utilized more frequently than PORTs and had a higher rate of premature removal. The rates of VTE and CRT were similar for both CVAD types. PORTs had a lower rate of infection per 1000 indwelling days. However, the management of PORT related complications required more visits to the hospital and oncology clinic. 相似文献
9.
10.