全文获取类型
收费全文 | 12403篇 |
免费 | 745篇 |
国内免费 | 42篇 |
专业分类
耳鼻咽喉 | 117篇 |
儿科学 | 346篇 |
妇产科学 | 250篇 |
基础医学 | 1651篇 |
口腔科学 | 312篇 |
临床医学 | 1075篇 |
内科学 | 3128篇 |
皮肤病学 | 140篇 |
神经病学 | 1168篇 |
特种医学 | 354篇 |
外国民族医学 | 1篇 |
外科学 | 1730篇 |
综合类 | 117篇 |
一般理论 | 3篇 |
预防医学 | 959篇 |
眼科学 | 223篇 |
药学 | 639篇 |
中国医学 | 33篇 |
肿瘤学 | 944篇 |
出版年
2023年 | 119篇 |
2022年 | 245篇 |
2021年 | 498篇 |
2020年 | 264篇 |
2019年 | 383篇 |
2018年 | 439篇 |
2017年 | 310篇 |
2016年 | 295篇 |
2015年 | 334篇 |
2014年 | 483篇 |
2013年 | 645篇 |
2012年 | 1016篇 |
2011年 | 950篇 |
2010年 | 597篇 |
2009年 | 444篇 |
2008年 | 742篇 |
2007年 | 763篇 |
2006年 | 640篇 |
2005年 | 679篇 |
2004年 | 606篇 |
2003年 | 485篇 |
2002年 | 513篇 |
2001年 | 153篇 |
2000年 | 108篇 |
1999年 | 126篇 |
1998年 | 82篇 |
1997年 | 74篇 |
1996年 | 69篇 |
1995年 | 72篇 |
1994年 | 58篇 |
1993年 | 43篇 |
1992年 | 65篇 |
1991年 | 46篇 |
1990年 | 62篇 |
1989年 | 40篇 |
1988年 | 47篇 |
1987年 | 38篇 |
1986年 | 55篇 |
1985年 | 40篇 |
1984年 | 38篇 |
1983年 | 52篇 |
1982年 | 37篇 |
1981年 | 30篇 |
1980年 | 30篇 |
1979年 | 29篇 |
1977年 | 25篇 |
1976年 | 22篇 |
1975年 | 21篇 |
1974年 | 29篇 |
1972年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
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
2.
3.
4.
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
5.
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
6.
7.
8.
9.
A coupled chromogenic reaction (based on an agar overlay combining NADH, pyruvate kinase, lactate dehydrogenase, phosphoenolpyruvate, ATP, and kanamycin sulfate with thiazolyl blue-phenazine methosulfate for detection of NADH consumption) was optimized for the detection of aminoglycoside phosphotransferases (APHs). When used after analytical isoelectrofocusing of bacterial extracts from APH-producing strains, this method revealed one band in each of two strains with a genetically confirmed APH (3′) I and two bands in another strain with both APH (3′) I and APH (3′) VI, whereas no bands were detected in susceptible control strains or in aminoglycoside-resistant microorganisms without APH genes. 相似文献
10.
Gabriel Mircescu Dimitrie Capsa Maria Covic Mirela Gherman Caprioara Gheorghe Gluhovschi Ovidiu Golea Nicolae Ursea Liliana Garneata Vasile Cepoi Nicolae Constantinovici Adrian Covic 《Nephrology, dialysis, transplantation》2004,19(12):2971-2980
INTRODUCTION. This report describes the current status of nephrology and renal replacement therapy (RRT) in Romania, a country with previously limited facilities, highlighting national changes in the European context. METHODS: Trends in RRT development were analysed in 2003, on a national basis, using the same questionnaires as in previous surveys (1991, 1995). Survival data and prognostic risk factors were calculated retrospectively from a large representative sample of 2284 patients starting RRT between January 1, 1995 and December 31, 2001 (44% of the total RRT population investigated). RESULTS: In 2003, RRT incidence [128 per million population (p.m.p.)] and prevalence (250 p.m.p.) were six and five times higher, respectively, than in 1995. The annual rate of increase in the stock of RRT patients (11%) was supported mainly by an exponential development of the continuous ambulatory peritoneal dialysis (CAPD) population (+600%), while the haemodialysis (HD) growth rate was stable (+33%) and renal transplantation made a marginal contribution. Renal care infrastructure followed the same trend: nephrology departments (+100%) and nephrologists (+205%). The characteristics of RRT incident patients changed accordingly to current European epidemiology (increasing age and prevalence of diabetes and nephroangiosclerosis). The estimated overall survival of RRT patients in Romania was 90.6% at 1 year [confidence interval (CI) 89.4-91.8] and 62.2% at 5 years (CI 59.4-65.0). Patients' survival was negatively influenced (Cox regression analysis) by age >65 years (P < 0.001), lack of pre-dialysis monitoring by a nephrologist [P = 0.01, hazards ratio (HR) = 0.8], severe anaemia, lack of erythropoetin treatment (P < 0.001, HR = 0.6), and co-morbidity, e.g. cardiovascular diseases (P < 0.001, HR = 1.8) and diabetes mellitus (P < 0.001, HR = 2.2). CONCLUSIONS: Although the rate of increase in RRT patient stock in 1996-2003 in Romania was the highest in Europe, the prevalence remained below the European mean. As CAPD had the greatest expansion, followed by HD, an effective transplantation programme must be set up to overcome the imbalance. The quality of RRT appears to be good and survival was similar to that in other registries. Further evolution implies strategies of prevention, based on national surveys, supported by the Romanian Renal Registry. 相似文献