全文获取类型
收费全文 | 209476篇 |
免费 | 9522篇 |
国内免费 | 553篇 |
专业分类
耳鼻咽喉 | 3120篇 |
儿科学 | 6808篇 |
妇产科学 | 4793篇 |
基础医学 | 27639篇 |
口腔科学 | 7145篇 |
临床医学 | 14378篇 |
内科学 | 49848篇 |
皮肤病学 | 5953篇 |
神经病学 | 17122篇 |
特种医学 | 5898篇 |
外国民族医学 | 7篇 |
外科学 | 27177篇 |
综合类 | 1054篇 |
一般理论 | 64篇 |
预防医学 | 19196篇 |
眼科学 | 4626篇 |
药学 | 14290篇 |
中国医学 | 930篇 |
肿瘤学 | 9503篇 |
出版年
2023年 | 1337篇 |
2022年 | 1592篇 |
2021年 | 4632篇 |
2020年 | 2417篇 |
2019年 | 4562篇 |
2018年 | 8506篇 |
2017年 | 5210篇 |
2016年 | 4540篇 |
2015年 | 4750篇 |
2014年 | 5868篇 |
2013年 | 8686篇 |
2012年 | 14277篇 |
2011年 | 15423篇 |
2010年 | 7872篇 |
2009年 | 5824篇 |
2008年 | 12673篇 |
2007年 | 13442篇 |
2006年 | 12650篇 |
2005年 | 12647篇 |
2004年 | 11585篇 |
2003年 | 10895篇 |
2002年 | 10283篇 |
2001年 | 5734篇 |
2000年 | 6530篇 |
1999年 | 4804篇 |
1998年 | 1175篇 |
1997年 | 810篇 |
1996年 | 776篇 |
1995年 | 644篇 |
1994年 | 524篇 |
1993年 | 488篇 |
1992年 | 1861篇 |
1991年 | 1526篇 |
1990年 | 1455篇 |
1989年 | 1198篇 |
1988年 | 1023篇 |
1987年 | 1013篇 |
1986年 | 959篇 |
1985年 | 843篇 |
1984年 | 637篇 |
1983年 | 500篇 |
1979年 | 528篇 |
1975年 | 412篇 |
1974年 | 455篇 |
1973年 | 507篇 |
1972年 | 431篇 |
1971年 | 450篇 |
1970年 | 400篇 |
1969年 | 391篇 |
1968年 | 388篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
Arminda Jorge Félix Lorente Luís Taborda-Barata 《Pediatric allergy and immunology》2006,17(6):466-473
The prevalence of latex allergy has been increasing not only in risk groups but also in the general population, where it is accepted to average 1%. In children, latex sensitization prevalence studies are scarce and involve different population sampling and allergy testing methods, which makes it difficult to compare across studies. Nevertheless, existing studies point towards a low prevalence of latex allergy in children, which still needs to be confirmed in the Portuguese population. Aiming at studying the prevalence of latex sensitization and allergy in a sample of Portuguese children, we studied 182 children from two different hospital outpatient clinics. A standardized questionnaire focusing on atopic background, previous history and allergic signs or symptoms on exposure to latex or fruits was given to all children and parents. Skin prick testing was performed with a battery of common aeroallergens as well as latex. Serum total IgE, Phadiatop, F x 5E and latex-specific IgE were determined in all children. Specific IgE to latex-crossreacting fruits was determined in latex-sensitized children. Based upon the questionnaire, the prevalence of latex allergy would be 0.5%. The prevalence of latex sensitization would be 3.8%, when based solely upon skin prick testing, and 12.1% (>/=0.35 IU/ml) or 6.6% (>/=0.70 IU/ml) when based singly upon determination of latex-specific IgE. When positive results for either test were considered, the prevalence of latex sensitization was 14.3%. All latex-sensitized children were atopic. Sensitivity to latex-crossreacting foodstuffs was demonstrated in 61.5% of latex-sensitized children (16/26). This study shows that the prevalence of latex allergy and sensitization in Portuguese atopic and non-atopic children, as analysed using various diagnostic methods, is similar to that observed in other countries. In addition, the assessment of latex allergy and sensitization should always include skin prick testing and determination of serum IgE. 相似文献
43.
Pilar Nicolás 《Hereditary cancer in clinical practice》2007,5(3):144-152
The specific characteristics of genetic data lead to ethical-legal conflicts in the framework of genetic diagnosis. Several international organisations, including UNESCO and the Council of Europe, have enacted rules referring to the use of genetic information. This paper discusses possible legal and ethical criteria that could be used in genetic testing. 相似文献
44.
45.
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
46.
47.
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
48.
49.
R. San Juan M. Yebra C. Lumbreras F. López-Medrano M. Lizasoain J.C. Meneu J. Delgado A. Andrés J.M. Aguado 《Clinical transplantation》2009,23(5):666-671
Abstract: Long-term prophylaxis against cytomegalovirus (CMV) started immediately after transplantation in (D+/R−) poses a higher risk of late-onset CMV disease. Delayed CMV prophylaxis could allow a transitory exposure of the immune system to CMV, which would let the immune system mount an adequate CMV-specific cytotoxic response in (D+/R−) patients and confer protection against CMV disease. We included all (D+/R−) solid organ transplant recipients (SOT) performed at our institution (January 3/October 6) who received CMV prophylaxis (mainly with oral valganciclovir) during 100 d. In the first period (until December 4), prophylaxis was initiated immediately after transplantation (conventional prophylaxis: CP). Since January 5, it was initiated after 14 d (delayed prophylaxis: DP). Incidence and severity of CMV disease was compared between both groups. A total of 44 SOT recipients were included (CP: 26 and DP: 18). CMV disease was diagnosed in eight patients (18%), seven of 26 (27%) in the CP group, and one of 18 (5.5%) in the DP group (p = 0.07). CMV colitis was reported in five of 26 patients in the CP group (19%), whereas there were no cases of visceral CMV disease in the DP group (p = 0.048). A 14-d delay in the beginning of long-term prophylaxis against CMV in (D+/R−) is safe and could prevent the onset of late-CMV disease. 相似文献