全文获取类型
收费全文 | 24307篇 |
免费 | 1636篇 |
国内免费 | 159篇 |
专业分类
耳鼻咽喉 | 262篇 |
儿科学 | 565篇 |
妇产科学 | 441篇 |
基础医学 | 2836篇 |
口腔科学 | 960篇 |
临床医学 | 2216篇 |
内科学 | 5130篇 |
皮肤病学 | 521篇 |
神经病学 | 1562篇 |
特种医学 | 700篇 |
外国民族医学 | 6篇 |
外科学 | 3421篇 |
综合类 | 558篇 |
一般理论 | 18篇 |
预防医学 | 1920篇 |
眼科学 | 998篇 |
药学 | 2304篇 |
中国医学 | 252篇 |
肿瘤学 | 1432篇 |
出版年
2024年 | 23篇 |
2023年 | 279篇 |
2022年 | 579篇 |
2021年 | 1348篇 |
2020年 | 885篇 |
2019年 | 1080篇 |
2018年 | 1317篇 |
2017年 | 916篇 |
2016年 | 991篇 |
2015年 | 1026篇 |
2014年 | 1387篇 |
2013年 | 1613篇 |
2012年 | 2186篇 |
2011年 | 2261篇 |
2010年 | 1314篇 |
2009年 | 1004篇 |
2008年 | 1480篇 |
2007年 | 1349篇 |
2006年 | 1129篇 |
2005年 | 952篇 |
2004年 | 741篇 |
2003年 | 650篇 |
2002年 | 558篇 |
2001年 | 90篇 |
2000年 | 90篇 |
1999年 | 94篇 |
1998年 | 79篇 |
1997年 | 57篇 |
1996年 | 62篇 |
1995年 | 51篇 |
1994年 | 32篇 |
1993年 | 45篇 |
1992年 | 33篇 |
1991年 | 29篇 |
1990年 | 28篇 |
1989年 | 37篇 |
1988年 | 30篇 |
1987年 | 17篇 |
1986年 | 16篇 |
1985年 | 18篇 |
1984年 | 24篇 |
1983年 | 19篇 |
1982年 | 24篇 |
1981年 | 16篇 |
1980年 | 16篇 |
1979年 | 19篇 |
1978年 | 17篇 |
1976年 | 19篇 |
1975年 | 14篇 |
1974年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Effect of Replacement of Wharton Acellular Jelly With FBS on the Expression of Megakaryocyte Linear Markers in Hematopoietic Stem Cells CD34+
下载免费PDF全文
![点击此处可从《Asian Pacific journal of cancer prevention》网站下载免费的PDF全文](/ch/ext_images/free.gif)
zahra Jalili Behnam Emamgolizadeh Hossein Abbaszadeh Shahla JaliliMehdi Derakhshani Mehdi YousefiMehdi TalebiKarim Shams Asenjan Ali Akabr Movassaghpour 《Asian Pacific journal of cancer prevention》2022,23(10):3281-3286
Objective: Animal environments for the growth of stem cells cause the transmission of some diseases and immune problems for the recipient. Accordingly, replacing these environments with healthy environments, at least with human resources, is essential. One of the media that can be used as an alternative to animal serums is Wharton acellular jelly (AWJ). Therefore, in this study, we intend to replace FBS with Wharton jelly and investigate its effect on the expression of megakaryocyte-related genes and markers in stem cells. Materials and Methods: In this study, cord blood-derived CD34 positive HSCs were cultured and expanded in the presence of cytokines including SCF, TPO, and FLT3-L. Then, the culture of expanded CD34 positive HSCs was performed in two groups: 1) IMDM culture medium containing 10% FBS and 100 ng / ml thrombopoietin cytokine 2) IMDM culture medium containing 10% AWJ, 100 ng / ml thrombopoietin cytokine. Finally, CD41 expressing cells were analyzed with the flow cytometry method. The genes related to megakaryocyte lineage including FLI1 and GATA2 were also evaluated using the RT-PCR technique. Results: The expression of CD41, a specific marker of megakaryocyte lineage in culture medium containing Wharton acellular jelly was increased compared to the FBS group. Additionally, the expression of GATA2 and FLI1 genes was significantly increased related to the control group. Conclusion: This study provided evidence of differentiation of CD34 positive hematopoietic stem cells from umbilical cord blood to megakaryocytes in a culture medium containing AWJ. 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.
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7.
8.
9.
10.
Moises Rodriguez-Gonzalez Antonio Moruno Tirado Reza Hosseinpour Jose Santos de Soto 《Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital》2015,42(4):350-356
Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital condition. It responds well to early diagnosis and treatment, but otherwise the prognosis is poor. We present our case series of 12 patients (mean age, 2 ± 2.58 yr; age range, 2 mo–8 yr), emphasizing the diagnostic process and discussing our surgical results. The diagnosis of ALCAPA should be suspected in infants who have dilated cardiomyopathy with electrocardiographic changes that suggest ischemia, and in older children who have isolated mitral regurgitation. When clinical suspicion is high, the results of 2-dimensional echocardiography combined with color-flow Doppler studies in expert hands can establish the diagnosis, thus avoiding angiography in critically ill infants. The treatment of choice in our patients was transfer and reimplantation of the left coronary artery onto the ascending aorta. There were 2 deaths: both were infants in extremis who underwent emergency surgery. An older child with severe ventricular dysfunction was given mechanical ventricular assistance and then heart transplantation. As of this report, all 10 survivors remained well and asymptomatic. 相似文献