全文获取类型
收费全文 | 96350篇 |
免费 | 4033篇 |
国内免费 | 208篇 |
专业分类
耳鼻咽喉 | 1440篇 |
儿科学 | 2965篇 |
妇产科学 | 2463篇 |
基础医学 | 13067篇 |
口腔科学 | 2556篇 |
临床医学 | 5832篇 |
内科学 | 22198篇 |
皮肤病学 | 2737篇 |
神经病学 | 7487篇 |
特种医学 | 2046篇 |
外国民族医学 | 2篇 |
外科学 | 12159篇 |
综合类 | 459篇 |
一般理论 | 25篇 |
预防医学 | 10992篇 |
眼科学 | 2225篇 |
药学 | 7318篇 |
中国医学 | 310篇 |
肿瘤学 | 4310篇 |
出版年
2023年 | 535篇 |
2022年 | 310篇 |
2021年 | 1560篇 |
2020年 | 795篇 |
2019年 | 1843篇 |
2018年 | 3239篇 |
2017年 | 1918篇 |
2016年 | 1830篇 |
2015年 | 2107篇 |
2014年 | 2241篇 |
2013年 | 3664篇 |
2012年 | 6240篇 |
2011年 | 6326篇 |
2010年 | 3228篇 |
2009年 | 2299篇 |
2008年 | 5228篇 |
2007年 | 5539篇 |
2006年 | 5380篇 |
2005年 | 5428篇 |
2004年 | 4993篇 |
2003年 | 4637篇 |
2002年 | 4399篇 |
2001年 | 3133篇 |
2000年 | 3342篇 |
1999年 | 2644篇 |
1998年 | 448篇 |
1996年 | 307篇 |
1992年 | 1253篇 |
1991年 | 1155篇 |
1990年 | 1079篇 |
1989年 | 962篇 |
1988年 | 875篇 |
1987年 | 883篇 |
1986年 | 819篇 |
1985年 | 786篇 |
1984年 | 578篇 |
1983年 | 457篇 |
1979年 | 589篇 |
1978年 | 342篇 |
1976年 | 316篇 |
1975年 | 346篇 |
1974年 | 527篇 |
1973年 | 488篇 |
1972年 | 428篇 |
1971年 | 389篇 |
1970年 | 464篇 |
1969年 | 426篇 |
1968年 | 405篇 |
1967年 | 368篇 |
1966年 | 313篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
Bromocriptine (0.5 mg/kg) and apomorphine (0.03 mg/kg) exert moderate aphrodisiac effect in sexually sluggish rats. This effect appears rapidly and reaches its peak within 24 h. Amphetamine (2 mg/kg) acts similarly but with a more rapid onset and offset of the effect. A single dose of (-)deprenyl, a selective inhibitor of MAO-B, exerts a much more potent effect in this test. 相似文献
72.
Melatonin, a pineal hormone, released photoperiodically, was administered systemically in rats, previously implanted with semimicroelectrodes into six different brain structures. The multiunit electrical activity of these structures was recorded for 10 min before and 60 min after melatonin administration in unanesthetized, freely moving rats. Different melatonin doses (100, 200, 500, and 1000 micrograms/kg) produced changes in the electrical activity of all tested structures. However, amygdala, rostral hypothalamus and mesencephalic reticular formation showed the most important changes. The main effect induced by melatonin was a dose-related decrease of the spontaneous electrical activity. The significance of these effects is discussed within the context of the behavioral and endocrinological effects of melatonin. 相似文献
73.
74.
C A González G López-Abente M Errezola A Escolar E Riboli I Izarzugaza M Nebot 《International journal of epidemiology》1989,18(3):569-577
A case-control study on bladder cancer was carried out in four regions of Spain. The study included 497 cases (438 males and 59 females), 583 hospital controls and 530 population controls matched by sex, age and residence. The present paper reports the results of the analyses on occupational history. Among men, an increased risk of bladder cancer was found for textile workers (OR = 1.97, 95% CL 1.2-3.3), mechanics and maintenance workers (OR = 1.86, 95% CL 1.2-2.8), workers in the printing industry (OR = 2.06, 95% CL 1.0-4.3) and for managers (OR = 2.03, 95% CL 1.2-3.5). The risk was highest among those first employed in the textile industry before the age of 25 and prior to 1960. Among mechanics the risk was highest for those who started after the age of 25 and later than 1960. The OR for smokers who had also been employed in one of the high risk occupations was 7.82 (95% CL 4.4-14.0) which is compatible with a multiplicative effect of joint exposure to tobacco and occupational hazards. 相似文献
75.
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
76.
Antonio Rivera Antonio Yáñez Gloria León-Tello Constantino Gil Silvia Giono Eduardo Barba Lilia Cedillo 《BMC musculoskeletal disorders》2002,3(1):15-7
Background
Mycoplasma fermentans has been associated with rheumatoid arthritis. Recently, it was detected in the joints and blood of patients with rheumatoid arthritis, but it is not clear yet how the bacteria enter the body and reach the joints. The purpose of this study was to determine the ability of M. fermentans to induce experimental arthritis in rabbits following inoculation of the bacteria in the trachea and knee joints. 相似文献77.
78.
Cyclodextrin formulation of dorzolamide and its distribution in the eye after topical administration. 总被引:2,自引:0,他引:2
Hakon H Sigurdsson Einar Stefánsson Elínborg Gudmundsdóttir Thór Eysteinsson Margrét Thorsteinsdóttir Thorsteinn Loftsson 《Journal of controlled release》2005,102(1):255-262
Due to limited aqueous solubility of dorzolamide at physiologic pH, the pH of Trusopt eye drops (cont. 2% dorzolamide) has to be kept at about 5.65, and to increase the topical bioavailability of the drug from Trusopt the contact time of the drug with the eye surface is increased by increasing the viscosity of the eye drops to 100 cps. This low pH and high viscosity can lead to local irritation. In this study, dorzolamide hydrochloride was formulated as 2% and 4% low viscosity solutions (viscosity 3 to 5 cps) containing randomly methylated beta-cyclodextrin at pH 7.45. These formulations were evaluated in rabbits. The animals were sacrificed at various time points after topical administration of the drug and the dorzolamide concentration determined in the different parts of the eye. Trusopt was used as a reference standard. The topical availability of dorzolamide from the cyclodextrin-containing eye drops appeared to be comparable to that from Trusopt and the drug reached retina and optic nerve to give measurable concentrations for at least 8 h after administration of the eye drops. 相似文献
79.
80.
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