全文获取类型
收费全文 | 168653篇 |
免费 | 7519篇 |
国内免费 | 557篇 |
专业分类
耳鼻咽喉 | 2666篇 |
儿科学 | 4938篇 |
妇产科学 | 3873篇 |
基础医学 | 23007篇 |
口腔科学 | 5997篇 |
临床医学 | 10793篇 |
内科学 | 41034篇 |
皮肤病学 | 5250篇 |
神经病学 | 13918篇 |
特种医学 | 3828篇 |
外国民族医学 | 4篇 |
外科学 | 19966篇 |
综合类 | 1041篇 |
一般理论 | 47篇 |
预防医学 | 16456篇 |
眼科学 | 3662篇 |
药学 | 11985篇 |
中国医学 | 952篇 |
肿瘤学 | 7312篇 |
出版年
2023年 | 1084篇 |
2022年 | 1908篇 |
2021年 | 4553篇 |
2020年 | 2303篇 |
2019年 | 4269篇 |
2018年 | 6109篇 |
2017年 | 3605篇 |
2016年 | 3562篇 |
2015年 | 3997篇 |
2014年 | 5332篇 |
2013年 | 7549篇 |
2012年 | 11815篇 |
2011年 | 12694篇 |
2010年 | 6677篇 |
2009年 | 5274篇 |
2008年 | 9843篇 |
2007年 | 10367篇 |
2006年 | 9577篇 |
2005年 | 9500篇 |
2004年 | 8449篇 |
2003年 | 7891篇 |
2002年 | 7305篇 |
2001年 | 4655篇 |
2000年 | 5193篇 |
1999年 | 4105篇 |
1998年 | 960篇 |
1997年 | 745篇 |
1996年 | 631篇 |
1995年 | 544篇 |
1994年 | 445篇 |
1993年 | 382篇 |
1992年 | 1628篇 |
1991年 | 1345篇 |
1990年 | 1215篇 |
1989年 | 1025篇 |
1988年 | 895篇 |
1987年 | 820篇 |
1986年 | 828篇 |
1985年 | 710篇 |
1984年 | 523篇 |
1983年 | 433篇 |
1979年 | 471篇 |
1978年 | 319篇 |
1975年 | 321篇 |
1974年 | 413篇 |
1973年 | 402篇 |
1972年 | 348篇 |
1971年 | 379篇 |
1970年 | 336篇 |
1969年 | 362篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Summary In cases where a reconstruction of defects in the larynx, oral cavity, the pharynx or in the ear region has been performed using skin flaps, a temporary fistula is formed at the point of entry.This fistula can be closed later after the flap has taken and the flap pedicle dissected.We would like to demonstrate with some examples that with the use of deepithelisation it is possible to achieve a primary wound closure. This way no temporary fistula results and additional surgery is avoided in many cases.Furthermore flap deepithelisation offers a way to bring good vascularised tissue under the skin and cover subcutaneous defects, for example those after radiotherapy.
Die Veröffentlichung des Manuskripts soll in Laryngol Rhinol Otol (Stuttg) erfolgen 相似文献
Die Veröffentlichung des Manuskripts soll in Laryngol Rhinol Otol (Stuttg) erfolgen 相似文献
92.
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
93.
The study concerned the effects of acute and chronic clomipramine administration to male rats on exploratory activity in a novel environment (hole-board) and on immobility in the forced swimming test. Acute clomipramine administration did not alter either exploratory activity on a hole-board as measured 3 or 20 h after drug administration, or immobility in the forced swimming test as measured 20 h after drug administration. Approximately 20 h after the last injection of clomipramine, the rats chronically treated with the drug showed reduced exploratory activity on the hole-board. In contrast, chronic clomipramine treatment significantly increased the activity in the forced swimming test. The effects of the drug on exploratory and forced swimming activities persisted for 14 days after the cessation of clomipramine administration. These data indicate that chronic clomipramine administration exerted profound and long-lasting effects on central nervous system function. The long-lasting action of the drug on behaviour in the forced swimming test might explain the long-term beneficial effect of antidepressant drugs in counteracting behavioral depression. 相似文献
94.
95.
A. Jaén J. Sunyer X. Basagaña S. Chinn† J. P. Zock J. M. Antó‡ P. Burney† 《Clinical and experimental allergy》2002,32(12):1713-1719
BACKGROUND: The role of atopy in the evolution to chronic obstructive disease remains controversial. AIM: We aimed to assess the association between individual sensitization to common allergens and lung function. METHOD: We analysed data from 12,687 subjects aged 20 to 44 years, from 34 centres in 15 countries participating in the European Community Respiratory Health Survey (ECRHS). Participants performed a blood test, lung function test, methacholine challenge, and answered an administered questionnaire. The relationships between specific IgE, FEV1 and FEV1/FVC ratio were assessed for each study centre stratified by sex, followed by random effects meta-analysis. RESULTS: Asthmatics sensitized to house dust mite had a lower FEV1 (-119 mL in women and -112 mL in men) and FEV1/FVC ratio (-1.95%, and -2.48%) than asthmatics without sensitization. Asthmatics sensitized to cat had a lower FEV1 (statistically significant for women only) and a lower FEV1/FVC ratio. Asthmatic women sensitized to grass had a lower FEV1 and a lower ratio, and those sensitized to Cladosporium had a lower FEV1. A weak association was found with sensitization to cat and to Cladosporium among non-asthmatic women, which disappeared after adjusting for BHR. CONCLUSION: We conclude that atopy was related to a lower lung function, which was only apparent among asthmatics. This relationship was explained by specific sensitization to cat and to house dust mite, the latter being homogeneous across areas. 相似文献
96.
97.
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
98.
99.
100.
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