全文获取类型
收费全文 | 19325篇 |
免费 | 1252篇 |
国内免费 | 140篇 |
专业分类
耳鼻咽喉 | 169篇 |
儿科学 | 446篇 |
妇产科学 | 372篇 |
基础医学 | 2233篇 |
口腔科学 | 787篇 |
临床医学 | 1864篇 |
内科学 | 4149篇 |
皮肤病学 | 402篇 |
神经病学 | 1188篇 |
特种医学 | 454篇 |
外国民族医学 | 5篇 |
外科学 | 2547篇 |
综合类 | 515篇 |
一般理论 | 15篇 |
预防医学 | 1614篇 |
眼科学 | 748篇 |
药学 | 1839篇 |
中国医学 | 224篇 |
肿瘤学 | 1146篇 |
出版年
2024年 | 22篇 |
2023年 | 230篇 |
2022年 | 562篇 |
2021年 | 1126篇 |
2020年 | 742篇 |
2019年 | 903篇 |
2018年 | 1078篇 |
2017年 | 750篇 |
2016年 | 805篇 |
2015年 | 818篇 |
2014年 | 1091篇 |
2013年 | 1274篇 |
2012年 | 1712篇 |
2011年 | 1770篇 |
2010年 | 1045篇 |
2009年 | 800篇 |
2008年 | 1159篇 |
2007年 | 1022篇 |
2006年 | 867篇 |
2005年 | 732篇 |
2004年 | 584篇 |
2003年 | 479篇 |
2002年 | 413篇 |
2001年 | 55篇 |
2000年 | 65篇 |
1999年 | 64篇 |
1998年 | 56篇 |
1997年 | 46篇 |
1996年 | 45篇 |
1995年 | 39篇 |
1994年 | 22篇 |
1993年 | 36篇 |
1992年 | 27篇 |
1991年 | 23篇 |
1990年 | 22篇 |
1989年 | 20篇 |
1988年 | 18篇 |
1987年 | 10篇 |
1986年 | 13篇 |
1985年 | 12篇 |
1984年 | 19篇 |
1983年 | 17篇 |
1982年 | 16篇 |
1981年 | 12篇 |
1980年 | 12篇 |
1979年 | 13篇 |
1978年 | 10篇 |
1976年 | 10篇 |
1974年 | 9篇 |
1973年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
1.
Defining con-founders that affect the reliability of diagnostic tests for coronavirus disease 2019 is vital to breaking the chain of infection. The elderly population is a higher risk group for the emerging virus. However, gender seems to exert a critical role in modifying the infection risk among women owing to hormonal changes. The menopause transition is an exceptional period for older women where the protective and immunomodulatory effects of the estrogen hormone are lost. Accordingly, attention should be given to postmenopausal women since they will have an increased risk compared to their pre-menopausal peers. 相似文献
2.
3.
4.
5.
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
6.
7.
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8.
9.
10.