全文获取类型
收费全文 | 4310篇 |
免费 | 249篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 116篇 |
儿科学 | 132篇 |
妇产科学 | 87篇 |
基础医学 | 443篇 |
口腔科学 | 100篇 |
临床医学 | 410篇 |
内科学 | 934篇 |
皮肤病学 | 160篇 |
神经病学 | 330篇 |
特种医学 | 172篇 |
外科学 | 857篇 |
综合类 | 46篇 |
一般理论 | 3篇 |
预防医学 | 218篇 |
眼科学 | 101篇 |
药学 | 227篇 |
中国医学 | 2篇 |
肿瘤学 | 247篇 |
出版年
2023年 | 29篇 |
2022年 | 48篇 |
2021年 | 117篇 |
2020年 | 80篇 |
2019年 | 116篇 |
2018年 | 132篇 |
2017年 | 112篇 |
2016年 | 126篇 |
2015年 | 148篇 |
2014年 | 167篇 |
2013年 | 243篇 |
2012年 | 312篇 |
2011年 | 363篇 |
2010年 | 226篇 |
2009年 | 182篇 |
2008年 | 270篇 |
2007年 | 289篇 |
2006年 | 291篇 |
2005年 | 276篇 |
2004年 | 251篇 |
2003年 | 192篇 |
2002年 | 185篇 |
2001年 | 40篇 |
2000年 | 41篇 |
1999年 | 42篇 |
1998年 | 30篇 |
1997年 | 32篇 |
1996年 | 11篇 |
1995年 | 15篇 |
1994年 | 16篇 |
1993年 | 23篇 |
1992年 | 15篇 |
1991年 | 15篇 |
1990年 | 7篇 |
1989年 | 10篇 |
1988年 | 12篇 |
1987年 | 11篇 |
1985年 | 5篇 |
1984年 | 6篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1979年 | 7篇 |
1978年 | 5篇 |
1976年 | 7篇 |
1975年 | 6篇 |
1970年 | 7篇 |
1968年 | 4篇 |
1967年 | 4篇 |
1966年 | 6篇 |
1965年 | 4篇 |
排序方式: 共有4585条查询结果,搜索用时 15 毫秒
71.
García-Cano Lizcano J González Martín JA Taberna Arana L Díaz Ruiz J Morillas Ariño MJ Pérez Sola A 《Anales de medicina interna (Madrid, Spain : 1984)》2002,19(8):409-411
Endoscopic retrograde cholangiopancreatography (ERCP) is an established method to treat bile duct obstruction. Besides, ERCP is one of the most stricking parts of interventional endoscopy and takes advantage of its minimal invasive condition to be applied to a wide variety of patients. We present five patients over 90 years of age who underwent successfully and without complications six therapeutic ERCPs. Endoscopic biliary sphincterotomy, common bile duct stone extraction and plastic stent insertion all were performed uneventfully and solving the biliary obstruction. Therapeutic ERCP is a safe and effective modality to treat bile duct obstruction in patients over 90 years of age. 相似文献
72.
We examined the association between serum trace elements and clinical findings such as number of sensitive tender points, severity of fatigue and functional status in patients with fibromyalgia (FM). Thirty-two patients diagnosed as having FM according to the ACR 1990 criteria and 32 normal healthy controls (NHC) were included in this study. The demographic data, disease duration, number of tender points and accompanying symptoms (fatigue, sleep disorders, headache, paresthesia, irritable bowel syndrome, sicca symptoms, Raynaud's phenomena) of the patients were noted. Visual analog scale (10 cm) was implemented to estimate daily severity of pain and fatigue. Fibromyalgia impact questionnaire was used for functional assessment. Serum selenium (mug/dL) and serum zinc (mug/dL) levels were measured by atomic absorption spectrometer. Serum magnesium (mmol/L) level was measured by the original kits of Abbott Aeroset auto-analyzer. The mean age of patients in FM group and NHC were calculated as 42.9 (SD = 7.7) years and 41.3 (SD = 9.7) years, respectively. Serum levels of zinc (P = 0.001) and magnesium (P = 0.002) were significantly decreased by FM groups, whereas there was no considerable difference with selenium levels of both groups (P > 0.05). Association between serum zinc level and number of tender points (P = 0.008) and that between fatigue and magnesium level (P = 0.003) was found as meaningful. According to the results of this study, it was asserted that serum magnesium and zinc levels may play an important role in the pathophysiology of FM. 相似文献
73.
Barbara D. Fontana Alistair J. Gibbon Madeleine Cleal Ari Sudwarts David Pritchett Maria Elena Miletto Petrazzini Caroline H. Brennan Matthew O. Parker 《Developmental psychobiology》2021,63(1):54-64
Early life stress (ELS) is defined as a short or chronic period of trauma, environmental or social deprivation, which can affect different neurochemical and behavioral patterns during adulthood. Zebrafish (Danio rerio) have been widely used as a model system to understand human neurodevelopmental disorders and display translationally relevant behavioral and stress‐regulating systems. In this study, we aimed to investigate the effects of moderate ELS by exposing young animals (6‐weeks postfertilization), for 3 consecutive days, to three stressors, and analyzing the impact of this on adult zebrafish behavior (16‐week postfertilization). The ELS impact in adults was assessed through analysis of performance on tests of unconditioned memory (free movement pattern Y‐maze test), exploratory and anxiety‐related task (novel tank diving test), and social cohesion (shoaling test). Here, we show for the first time that moderate ELS increases the number of alternations in turn‐direction compared to repetitions in the unconditioned Y‐maze task, suggesting increased working memory, but has no effect on shoal cohesion, locomotor profile, or anxiety‐like behavior. Overall, our data suggest that moderate ELS may be linked to adaptive flexibility which contributes to build “resilience” in adult zebrafish by improving working memory performance. 相似文献
74.
75.
Cardiac arrhythmias during ischemia-reperfusion (I/R) are believed to be related to free radicals generated in the heart especially during the period of reperfusion. The pineal secretory product, melatonin, is known to be a potent free radical scavenger and its pharmacological concentrations have been shown to reduce the I/R-induced arrhythmias in isolated rat hearts. However, the physiological role of melatonin in the prevention of these arrhythmias is unknown. Rats were pinealectomized (Px) or sham-operated (non-Px) (control) 2 months before the I/R studies. To produce arrhythmias, left main coronary artery was occluded for 7 min, followed by 7 min reperfusion, in anesthetized rats. The incidence of mortality resulted from irreversible ventricular fibrillation (VF) was found significantly higher in the Px rats (63%) than in the control group (25%). Melatonin administration (0.4 mg/kg, either before ischemia or reperfusion) to Px rats significantly reduced the incidence of total (irreversible plus reversible) and irreversible VF and returned them to control values. On the other hand, melatonin administration (0.4 and 4 mg/kg) to non-Px rats failed to attenuate the I/R arrhythmias, significantly. These results suggest that physiological melatonin concentrations are important to reduce the I/R-induced VF and mortality, while pharmacological concentrations of melatonin did not increase its beneficial effect on these arrhythmias. As melatonin levels have been reported to decrease with age, melatonin replacement therapy may attenuate the incidence of sudden cardiac death especially in older patients. 相似文献
76.
Olga Amaral Ana Marcão Eugénia Pinto Ari Zimran M.C.Sá Miranda 《Blood cells, molecules & diseases》1997,23(3):415-416
ABSTRACT: A new polymorphism, in intron 7 of glucocerebrosidase gene, has been identified in Gaucher Disease patients. It seems to appear only in Pv1.1-alleles bearing the N370S mutation. This new sub-haplotype was only identified in Portuguese patients, of origins spanning all of the Portuguese continental territory. This finding indicates that, in the Portuguese, mutation N370S has existed in the context of two slightly different haplotypes and thus must be relatively ancient. 相似文献
77.
78.
79.
To assess risk factors related to the development of chronic obstructive pulmonary disease (COPD) including smoking and occupational exposure (OE) to dusts, gases or fumes, we performed a longitudinal 11-year follow-up postal survey. The original study population was a random population sample of 8000 inhabitants of Helsinki aged 20 to 69 years in 1996. Participants of the first postal questionnaire were invited to this follow-up survey in 2007 with 4302 (78%) answers obtained. Cumulative incidence of COPD in 11 years was 3.43% corresponding to an incidence rate of 3.17/1000/year after exclusion of those with self-reported physician-diagnosed COPD and ever COPD in 1996. Smoking and age, but not gender, were associated with incident COPD. Reported family history of COPD increased the cumulative incidence to 8.55% vs 3.04% among those without a family history (p < 0.001). In multivariate analysis, significant independent risk factors for incident COPD were: current smoking in 1996 (OR 4.40 [95% CI 2.89–6.71]), age over 50 (OR 3.42 [95% CI 2.22–5.26]), family history of COPD (OR 2.08 [1.27–3.43]), ever asthma (OR 2.28 [1.35–3.86]), and self-reported OE (OR 2.14 [1.50–3.05]). Occupational exposure to dusts, gases or fumes, assessed both based on self-reported exposure and a job exposure matrix using reported professions, was an independent risk factor for incident COPD. Smoking and OE together yielded an additive effect on incidence of COPD. 相似文献