全文获取类型
收费全文 | 15491篇 |
免费 | 936篇 |
国内免费 | 54篇 |
专业分类
耳鼻咽喉 | 126篇 |
儿科学 | 464篇 |
妇产科学 | 288篇 |
基础医学 | 2153篇 |
口腔科学 | 344篇 |
临床医学 | 1330篇 |
内科学 | 3641篇 |
皮肤病学 | 303篇 |
神经病学 | 1526篇 |
特种医学 | 474篇 |
外国民族医学 | 1篇 |
外科学 | 2007篇 |
综合类 | 125篇 |
一般理论 | 4篇 |
预防医学 | 1175篇 |
眼科学 | 314篇 |
药学 | 930篇 |
中国医学 | 39篇 |
肿瘤学 | 1237篇 |
出版年
2023年 | 144篇 |
2022年 | 287篇 |
2021年 | 560篇 |
2020年 | 312篇 |
2019年 | 446篇 |
2018年 | 516篇 |
2017年 | 369篇 |
2016年 | 384篇 |
2015年 | 423篇 |
2014年 | 592篇 |
2013年 | 787篇 |
2012年 | 1241篇 |
2011年 | 1206篇 |
2010年 | 743篇 |
2009年 | 573篇 |
2008年 | 980篇 |
2007年 | 977篇 |
2006年 | 854篇 |
2005年 | 908篇 |
2004年 | 801篇 |
2003年 | 661篇 |
2002年 | 653篇 |
2001年 | 183篇 |
2000年 | 120篇 |
1999年 | 139篇 |
1998年 | 116篇 |
1997年 | 106篇 |
1996年 | 93篇 |
1995年 | 84篇 |
1994年 | 76篇 |
1993年 | 61篇 |
1992年 | 71篇 |
1991年 | 51篇 |
1990年 | 70篇 |
1989年 | 48篇 |
1988年 | 55篇 |
1987年 | 43篇 |
1986年 | 61篇 |
1985年 | 45篇 |
1984年 | 42篇 |
1983年 | 57篇 |
1982年 | 46篇 |
1981年 | 32篇 |
1980年 | 34篇 |
1979年 | 33篇 |
1977年 | 28篇 |
1976年 | 27篇 |
1975年 | 25篇 |
1974年 | 31篇 |
1972年 | 25篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Very preterm children are at increased risk of reduced processing speed at 5 years of age,predicted by typical complications of prematurity and prenatal smoking 下载免费PDF全文
2.
Renaud Snanoudj Nassim Kamar Elisabeth Cassuto Sophie Caillard Marie Metzger Pierre Merville Antoine Thierry Isabelle Jollet Philippe Grimbert Dany Anglicheau Marc Hazzan Gabriel Choukroun Bruno Hurault De Ligny Bénedicte Janbon Vincent Vuiblet Anne Devys Yann Le Meur Michel Delahousse Jean-Luc Taupin 《Kidney international》2019,95(6):1471-1485
3.
4.
5.
Quantitatively distinct requirements for signaling-competent cell spreading on engineered versus natural adhesion ligands. 总被引:1,自引:0,他引:1
Gabriel P Richman David A Tirrell Anand R Asthagiri 《Journal of controlled release》2005,101(1-3):3-12
To design synthetic microenvironments that elicit desired cell behaviors, we must better understand the molecular mechanisms by which cells interact with candidate biomaterials. Using cell lines with distinct alpha5beta1 integrin expression profiles, we demonstrate that this integrin mediates cell spreading on substrata coated with genetically engineered artificial extracellular matrix (aECM) proteins containing the RGD sequence (RGD-containing aECM protein [aRGD]) but lacking the PHSRN synergy site. Furthermore, aRGD-mediated adhesion stimulates an intracellular focal adhesion kinase (FAK) signal that is indicative of integrin tethering. Although both aRGD and the natural ECM protein fibronectin (FN) support alpha5beta1 integrin-mediated cell spreading, quantitative single-cell analysis revealed that aRGD-mediated spreading requires ten-fold greater threshold amount of integrin expression than FN-mediated spreading. Our analysis demonstrates that aRGD-based substrata mediate both biophysical (cell spreading) and biochemical (FAK signaling) events via the alpha5beta1 integrin, albeit with efficacy quantitatively distinct from that of natural ECM proteins that possess the full spectrum of adhesion and synergy domains. 相似文献
6.
Johannes Woitzik Elke Lassel Ulf C. Schneider Helmut Schroeck Rudolf Graf 《Experimental neurology》2009,218(1):41-350
Lesion evolution during focal cerebral ischemia may depend on flow restrictions or on accumulation of toxic mediators within the infarct and expansion of these factors to the periinfarct region. So far, the precise contribution of flow dependent versus spreading-mediated impairment of viable periinfarct tissue has not been determined. Therefore, we measured lesion expansion, flow restrictions and glutamate distribution on serial brain sections at different time points after experimental focal ischemia.Permanent focal ischemia was induced by occlusion of the right middle cerebral artery in male rats and the flow reduction was subsequently measured at 1, 12 and 24 h using iodo[14C]antipyrine autoradiography. Additionally, the necrotic volume was determined on serial brain sections and the glutamate content was measured in tissue samples from adjacent microdissections.Twelve hours after focal ischemia no noteworthy viable areas with blood flow restrictions of 20-40 ml 100 g− 1 min− 1 existed but at 24 h the necrotic tissue exceeded the hemodynamically compromised region by 40 ± 21 mm3 (24%). Furthermore, at 12 and 24 h the glutamate content was elevated in areas surrounding the infarct.Relevant flow restrictions are detectable only during early stages of infarct maturation, whereas the propagation of secondary factors may be the predominant mechanism for delayed infarct evolution. 相似文献
7.
Andrea Berger Michelle Sadeh Gabriel Tzur I Avinoam Shuper Liora Kornreich Dov Inbar Ian J Cohen Shalom Michowiz Isaac Yaniv Shlomi Constantini Eli Vakil 《Journal of the International Neuropsychological Society》2005,11(4):482-487
Cerebellar involvement in motor and non-motor sequence learning was examined with serial reaction time tasks (SRT). Our sample consisted of 8 children and adolescents who had undergone surgical removal of a benign posterior fossa tumor (PFT) during childhood. None of them had undergone chemotherapy or cranial radiation therapy (CRT). Ages ranged from 1-11 years at surgery and 9-17 years at testing. The children were tested not earlier than 2.5 years after surgery (M = 5.9 years), enabling brain plasticity and recovery of functions. Their performance was compared with a matched control sample. The PFT group was not impaired in the implicit learning of sequences, as reflected in their performance in blocks with a repeated sequence, both before and after a random block. However, in the perceptual task, their performance deteriorated more than that of the control group when a random block was introduced, suggesting that it was more difficult for the patients to respond flexibly or change their response set when encountering changing task demands. These results are in line with another study by our group on task switching with the same patients. 相似文献
8.
9.
10.