全文获取类型
收费全文 | 1917篇 |
免费 | 127篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 53篇 |
儿科学 | 80篇 |
妇产科学 | 33篇 |
基础医学 | 331篇 |
口腔科学 | 17篇 |
临床医学 | 145篇 |
内科学 | 292篇 |
皮肤病学 | 133篇 |
神经病学 | 244篇 |
特种医学 | 33篇 |
外科学 | 119篇 |
综合类 | 8篇 |
一般理论 | 1篇 |
预防医学 | 220篇 |
眼科学 | 22篇 |
药学 | 167篇 |
中国医学 | 4篇 |
肿瘤学 | 152篇 |
出版年
2024年 | 3篇 |
2023年 | 16篇 |
2022年 | 42篇 |
2021年 | 61篇 |
2020年 | 34篇 |
2019年 | 51篇 |
2018年 | 54篇 |
2017年 | 40篇 |
2016年 | 57篇 |
2015年 | 55篇 |
2014年 | 63篇 |
2013年 | 106篇 |
2012年 | 162篇 |
2011年 | 134篇 |
2010年 | 79篇 |
2009年 | 68篇 |
2008年 | 121篇 |
2007年 | 128篇 |
2006年 | 124篇 |
2005年 | 131篇 |
2004年 | 115篇 |
2003年 | 93篇 |
2002年 | 123篇 |
2001年 | 19篇 |
2000年 | 12篇 |
1999年 | 12篇 |
1998年 | 17篇 |
1997年 | 10篇 |
1996年 | 16篇 |
1995年 | 12篇 |
1994年 | 7篇 |
1993年 | 4篇 |
1992年 | 9篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 7篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1978年 | 4篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1971年 | 3篇 |
1970年 | 2篇 |
1962年 | 2篇 |
1960年 | 2篇 |
排序方式: 共有2054条查询结果,搜索用时 15 毫秒
991.
992.
Jandó G Mikó-Baráth E Markó K Hollódy K Török B Kovacs I 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(27):11049-11052
Although there is a great deal of knowledge regarding the phylo- and ontogenetic plasticity of the neocortex, the precise nature of environmental impact on the newborn human brain is still one of the most controversial issues of neuroscience. The leading model-system of experience-dependent brain development is binocular vision, also called stereopsis. Here, we show that extra postnatal visual experience in preterm human neonates leads to a change in the developmental timing of binocular vision. The onset age of binocular function, as measured by the visual evoked response to dynamic random dot correlograms (DRDC-VEP), appears to be at around the same time after birth in preterm (4.07 mo) and full-term (3.78 mo) infants. To assess the integrity of the visual pathway in the studied infants, we also measured the latency of the visual-evoked response to pattern reversal stimuli (PR-VEP). PR-VEP latency is not affected by premature birth, demonstrating that the maturation of the visual pathway follows a preprogrammed developmental course. Despite the immaturity of the visual pathway, clearly demonstrated by the PR-VEP latencies, our DRCD-VEP data show that the visual cortex is remarkably ready to accept environmental stimulation right after birth. This early plasticity makes full use of the available extra stimulation time in preterm human infants and results in an early onset of cortical binocularity. According to our data, the developmental processes preceding the onset of binocular function are not preprogrammed, and the mechanisms turning on stereopsis are extremely experience-dependent in humans. 相似文献
993.
Edyta P?ońska-Go?ciniak Piotr Lipiec Patrizio Lancellotti Andrzej Szyszka Zbigniew G?sior Ilona Kowalik Andrzej Gackowski Piotr Go?ciniak Karina Wierzbowska-Drabik Jaros?aw D. Kasprzak 《Archives of Medical Science》2013,9(3):434-439
Introduction
The aim of this multicenter, prospective study was to evaluate the long-term prognostic value of low-dose dobutamine stress echocardiography (LDDSE) in patients with aortic stenosis (AS) and depressed left ventricular (LV) function.Material and methods
The study group comprised 39 patients (34 male, mean age 59 ±13 years) with AS (peak gradient > 25 mm Hg), LV ejection fraction (LVEF) ≤ 45% and low transaortic gradient (peak gradient ≤ 45 mm Hg, mean gradient ≤ 35 mm Hg). The qualification for subsequent therapeutic procedures was based on generally accepted indications. All patients underwent LDDSE and coronary angiography. Twelve months after LDDSE patients underwent control resting echocardiography and clinical evaluation.Results
Twenty-seven (69.2%) patients had preserved contractile reserve. In this subgroup, true-severe AS was diagnosed in 12 patients, whereas pseudo-severe AS was found in 15 patients. Nine patients with true-severe AS, 2 patients with pseudo-severe AS and 7 patients without contractile reserve were referred for surgical treatment. The independent risk factors of death during follow-up were: aortic valve area (AVA) at peak stress < 0.8 cm2 (OR 1.4; p = 0.003) and LVEF at rest < 35% (OR 6.8; p = 0.05). The independent risk factors of composite end-point (death or myocardial infarctions or pulmonary edema) were: AVA at stress < 0.8 cm2 (OR 4.0; p = 0.03), absence of AVA increase during LDDSE (OR 5.7; p = 0.005), absence of contractile reserve (OR 4.5; p = 0.01) and presence of significant CAD (OR 6.9; p = 0.02).Conclusions
In patients with AS and depressed LVEF, LDDSE is a useful tool for long-term risk stratification. 相似文献994.
Study objectives
Our study explored if bedtimes influenced school performance and motivation, as well as the odds ratio (OR) for health-related concerns in adolescents.Methods
The School Health Promotion Study was based on an anonymous self-report questionnaire conducted in 90% of the municipalities in Finland. The study was conducted during 2008 and 2010 in Southern Finland, Eastern Finland, and Lapland, and during 2009 and 2011 in Western Finland, Northern Finland, and Åland. Several indicators were used to measure school performance and motivation. Accidents and health-related complaints, such as depressive symptoms, sleep quality, neck or shoulder pains, lower back pains, stomachaches, anxiety or nervousness, irritation or tantrums, headaches, and tiredness or dizziness were analyzed in relation to the usual bedtime. Our study had a relatively large sample size (N = 384,076), consisting of students in the eighth and the ninth grades of secondary schools and the first and the second grades of upper secondary and vocational schools (ages 14–20 years) in Finland.Results
All of the various indicators used to assess school performance and motivation suggest that the later the bedtime of adolescents, the lower their school performance and their motivation. Similarly later bedtimes increase the OR for depressive symptoms and other negative health consequences in adolescents as well as a tendency towards accidents. All of these problems were emphasized in students with bedtimes of 11:30 PM and later.Conclusions
Late bedtimes, especially those after 11:30 PM, indicate poor sleep which deteriorates school performance and motivation and increases the OR for depressive symptoms and other health-related issues in adolescents. 相似文献995.
Kajikawa MM Jármy-Di Bella ZI Focchi GR Dornelas J Girão MJ Sartori MG 《International urogynecology journal》2012,23(4):467-472
Introduction and hypothesis
The purpose of this study was to evaluate the expression of estrogen receptor alpha (ERα) on the neovaginal tissue of patients with Mayer–Rokitansky–Kuster–Hauser (MRKH) syndrome submitted to modified Abbé-McIndoe neovaginoplasty using oxidized regenerated cellulose. 相似文献996.
Maarten van Vliet Ilona W. M. Verburg Mark van den Boogaard Nicolette F. de Keizer Niels Peek Nicole M. A. Blijlevens Peter Pickkers 《Intensive care medicine》2014,40(9):1275-1284
Purpose
To explore trends over time in admission prevalence and (risk-adjusted) mortality of critically ill haematological patients and compare these trends to those of several subgroups of patients admitted to the medical intensive care unit (medical ICU patients).Methods
A total of 1,741 haematological and 60,954 non-haematological patients admitted to the medical ICU were analysed. Trends over time and differences between two subgroups of haematological medical ICU patients and four subgroups of non-haematological medical ICU patients were assessed, as well as the influence of leukocytopenia.Results
The proportion of haematological patients among all medical ICU patients increased over time [odds ratio (OR) 1.06; 95 % confidence interval (CI) 1.03–1.10 per year; p < 0.001]. Risk-adjusted mortality was significantly higher for haematological patients admitted to the ICU with white blood cell (WBC) counts of <1.0 × 109/L (47 %; 95 % CI 41–54 %) and ≥1.0 × 109/L (45 %; 95 % CI 42–49 %), respectively, than for patients admitted with chronic heart failure (27 %; 95 % CI 26–28 %) and with chronic liver cirrhosis (38 %; 95 % CI 35–42 %), but was not significantly different from patients admitted with solid tumours (40 %; 95 % CI 36–45 %). Over the years, the risk-adjusted hospital mortality rate significantly decreased in both the haematological and non-haematological group with an OR of 0.93 (95 % CI 0.92–0.95) per year. After correction for case-mix using the APACHE-II score (with WBC omitted), a WBC <1.0 × 109/L was not a predictor of mortality in haematological patients (OR 0.86; 95 % CI 0.46–1.64; p = 0.65). We found no case–volume effect on mortality for haematological ICU patients.Conclusions
An increasing number of haematological patients are being admitted to Dutch ICUs. While mortality is significantly higher in this group of medical ICU patients than in subgroups of non-haematological ones, the former show a similar decrease in raw and risk-adjusted mortality rate over time, while leukocytopenia is not a predictor of mortality. These results suggest that haematological ICU patients have benefitted from improved intensive care support during the last decade. 相似文献997.
998.
999.
1000.
Lenderink AF Zoer I van der Molen HF Spreeuwers D Frings-Dresen MH van Dijk FJ 《International archives of occupational and environmental health》2012,85(3):229-251