全文获取类型
收费全文 | 27346篇 |
免费 | 1371篇 |
国内免费 | 71篇 |
专业分类
耳鼻咽喉 | 656篇 |
儿科学 | 1142篇 |
妇产科学 | 405篇 |
基础医学 | 2982篇 |
口腔科学 | 552篇 |
临床医学 | 1713篇 |
内科学 | 7290篇 |
皮肤病学 | 1089篇 |
神经病学 | 1889篇 |
特种医学 | 713篇 |
外科学 | 4180篇 |
综合类 | 117篇 |
一般理论 | 6篇 |
预防医学 | 2236篇 |
眼科学 | 766篇 |
药学 | 1570篇 |
中国医学 | 69篇 |
肿瘤学 | 1413篇 |
出版年
2023年 | 141篇 |
2022年 | 100篇 |
2021年 | 601篇 |
2020年 | 271篇 |
2019年 | 700篇 |
2018年 | 1076篇 |
2017年 | 641篇 |
2016年 | 543篇 |
2015年 | 583篇 |
2014年 | 625篇 |
2013年 | 993篇 |
2012年 | 1763篇 |
2011年 | 1951篇 |
2010年 | 1035篇 |
2009年 | 753篇 |
2008年 | 1606篇 |
2007年 | 1768篇 |
2006年 | 1613篇 |
2005年 | 1653篇 |
2004年 | 1486篇 |
2003年 | 1463篇 |
2002年 | 1425篇 |
2001年 | 1086篇 |
2000年 | 1355篇 |
1999年 | 990篇 |
1998年 | 135篇 |
1997年 | 90篇 |
1996年 | 103篇 |
1995年 | 66篇 |
1994年 | 44篇 |
1993年 | 49篇 |
1992年 | 332篇 |
1991年 | 245篇 |
1990年 | 201篇 |
1989年 | 151篇 |
1988年 | 153篇 |
1987年 | 154篇 |
1986年 | 120篇 |
1985年 | 110篇 |
1984年 | 83篇 |
1983年 | 62篇 |
1981年 | 31篇 |
1979年 | 54篇 |
1976年 | 31篇 |
1974年 | 31篇 |
1973年 | 34篇 |
1972年 | 29篇 |
1971年 | 27篇 |
1970年 | 25篇 |
1968年 | 28篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
D Mezzano G E del Pino M Montesinos M E García E Aranda A Foradori 《Thrombosis and haemostasis》1991,66(2):254-258
Thrombocytopenia was induced in mongrel dogs by two mechanisms: immunologically, by intravenous injection of heterologous antiplatelet antibody, and non-immunologically, by circulating the blood through glass beads in anesthetized animals. The platelet content of 5-HT was monitored before and during the recovery of the blood platelet counts. This period is associated with the normalization of the mean platelet survival time and with a progressive increase in the mean age of the circulating platelet population. A continuous increment in platelet 5-HT closely followed the increase in platelet counts in both models of thrombocytopenia, and a strong correlation was found between the platelet age and 5-HT content. These findings support the concept that platelets accumulate 5-HT during their physiological aging process, contradicting the notion that a negative balance in 5-HT content results at the end of their physiological lifespan in circulation. These results are not in conflict with the concept that circulating platelets release and re-uptake 5-HT. 相似文献
22.
T López-Alburquerque A García Miguel J J Ruiz Ezquerro J de Portugal Alvarez 《Journal of neurology, neurosurgery, and psychiatry》1987,50(4):428-434
The nerve action potential at the elbow and somatosensory evoked potentials (SEPs) at the scalp were recorded over 30 minutes of tourniquet-induced limb ischaemia in 10 diabetic patients and 10 controls. According to the SEP changes, an increased resistance to nerve ischaemia in diabetic patients was observed. The pathways involved in SEP conduction are discussed. 相似文献
23.
E García-Gómez S Vaca A Pérez-Méndez J Ibarra-Caballero V Pérez-Márquez V R Tenorio E Negrete-Abascal 《Avian pathology》2005,34(5):426-429
Gallibacterium anatis (previously named Pasteurella haemolytica-like) is considered a normal inhabitant of genital and upper respiratory tracts of healthy chickens, but it is also associated with different pathological conditions. Secreted metalloproteases from field and reference G. anatis cultures were obtained by methanol precipitation and were characterized. Proteins of molecular mass higher than 100 kDa showing proteolytic activity were observed in 10% polyacrylamide gels copolymerized with 1% bovine casein. They were active at alkaline pH, and inhibited by ethylenediamine tetraacetic acid. Their activity was stable at 50 degrees C, but partially inhibited at 60 degrees C, and totally inhibited at higher temperatures. Secreted proteins were able to degrade chicken IgG after 24 h of incubation, and cross-reacted with a polyclonal antibody against purified protease from Actinobacillus pleuropneumoniae. Secreted metalloproteases could play a role in infections caused by G. anatis. 相似文献
24.
25.
26.
Prevalence of Artemisia species pollinosis in western Poland: impact of climate change on aerobiological trends, 1995-2004. 总被引:2,自引:0,他引:2
A Stach H García-Mozo J C Prieto-Baena M Czarnecka-Operacz D Jenerowicz W Silny C Galán 《Journal of investigational allergology & clinical immunology》2007,17(1):39-47
BACKGROUND: Artemisia species pollen represents a major cause of allergy in Central Europe. Variations in the pollen season, the influence of climate variables and the prevalence of pollinosis to it were analyzed in Poznan, in western Poland between 1995 and 2004. METHODS: A Hirst volumetric spore trap was used for atmospheric sampling. Pollination date trend analysis and Spearman correlation tests were performed. Skin prick tests (SPT) and allergen specific immunoglobulin (lg)E antibody measurements were performed in 676 and 524 patients, respectively. RESULTS: The Artemisia species pollen season grew longer due to a clear advance in the starting day and only a slightly earlier end point; the peak day also came slightly earlier. Rainfall in the first fortnight of July highly influenced pollen season severity. Temperature was directly correlated with daily Artemisia species pollen levels; relative humidity was inversely correlated. Twelve percent of patients had a positive SPT reaction to Artemisia species. Their symptoms were rhinitis and conjunctivitis (15%), atopic dermatitis (15%), chronic urticaria (14.3%), bronchial asthma (2.4%), and facial and disseminated dermatitis (1.3%). Elevated specific IgE concentrations were detected in the sera of 10.1% of patients. CONCLUSIONS: Artemisia species pollen is an important cause of pollinosis in western Poland. Pollen season intensity is highly influenced by rainfall in the previous weeks. Trends towards earlier season starts and longer duration, possibly caused by climate change, may have an impact on the allergic population. 相似文献
27.
L García-Marcos I Carvajal Urue?a A Escribano Montaner M Fernández Benítez S García de la Rubia E Tauler Toro V Pérez Fernández C Barcina Sánchez 《Journal of investigational allergology & clinical immunology》2007,17(4):249-256
OBJECTIVE: To study the effect of seasons on the health-related quality of life (HRQL) of asthmatic children. METHODS: Four groups of asthmatic children 7 to 14 years old were recruited by pediatricians during each season of the year. Their HRQL was assessed by means of the Paediatric Asthma Quality of Life Questionnaire (PAQLQ). Other factors surveyed were asthma severity, atopy, medical treatment, immunotherapy, obesity, parental smoking, and anti-allergic measures. RESULTS: The mean (SD) overall PAQLQ score was highest in summer at 6.2 (1.0) and lowest in autumn at 5.5 (1.2). The same trend was found for domains in summer and autumn, respectively: symptoms, 6.2 (1.0) vs 5.4 (1.4); emotions, 6.5 (0.8) vs 6.0 (1.0); and activities, 5.9 (1.4) vs. 5.0 (1.5). Factors such as male gender (odds ratio [OR], 0.60; 95% confidence interval [CI], 0.41-0.87), being on immunotherapy (OR, 0.59; 95% CI, 0.38-0.92), living in an urban environment (OR, 0.56; 0.33-0.93), and residing on the northern coast of Spain along the Bay of Biscay (OR, 0.56; 0.36-0.89) were independent protective factors against having a total PAQLQ score in the lower tertile. Conversely, being recruited in a primary care setting (OR, 1.55; 1.01-2.38) and having more severe asthma were risks for being in the lower tertile. CONCLUSIONS: Irrespective of the severity of the disease, season has a significant influence on the HRQL of asthmatic children. 相似文献
28.
29.
L Crespo J Graus F García-Hoz R Bárcena L Gil Grande V F Moreira J M Milicua J Sánchez J Blázquez 《Revista española de enfermedades digestivas》2007,99(11):667-670
Hepatic encephalopathy is a reversible state of altered cognition that may occur in patients with acute or chronic liver disease or porto-systemic shunt, and in which known neurological or psychiatric signs may develop. Nitrogenated substances from intestinal digestion reach the brain without being cleared by their passage through the liver due to the presence of porto-systemic shunt. We report two cases of patients with porto-systemic shunt diagnosed with recurrent chronic hepatic encephalopathy refractory to conventional medical treatment. They were satisfactorily treated with shunt embolization using interventionist radiology techniques. 相似文献