全文获取类型
收费全文 | 18646篇 |
免费 | 1069篇 |
国内免费 | 98篇 |
专业分类
耳鼻咽喉 | 133篇 |
儿科学 | 370篇 |
妇产科学 | 343篇 |
基础医学 | 3075篇 |
口腔科学 | 389篇 |
临床医学 | 1500篇 |
内科学 | 3343篇 |
皮肤病学 | 728篇 |
神经病学 | 2015篇 |
特种医学 | 1270篇 |
外科学 | 2379篇 |
综合类 | 86篇 |
一般理论 | 6篇 |
预防医学 | 788篇 |
眼科学 | 311篇 |
药学 | 1866篇 |
中国医学 | 23篇 |
肿瘤学 | 1188篇 |
出版年
2023年 | 66篇 |
2022年 | 132篇 |
2021年 | 211篇 |
2020年 | 199篇 |
2019年 | 234篇 |
2018年 | 251篇 |
2017年 | 249篇 |
2016年 | 329篇 |
2015年 | 418篇 |
2014年 | 513篇 |
2013年 | 650篇 |
2012年 | 1005篇 |
2011年 | 1151篇 |
2010年 | 699篇 |
2009年 | 711篇 |
2008年 | 1158篇 |
2007年 | 1225篇 |
2006年 | 1178篇 |
2005年 | 1160篇 |
2004年 | 1146篇 |
2003年 | 1195篇 |
2002年 | 1159篇 |
2001年 | 263篇 |
2000年 | 178篇 |
1999年 | 257篇 |
1998年 | 305篇 |
1997年 | 258篇 |
1996年 | 228篇 |
1995年 | 197篇 |
1994年 | 182篇 |
1993年 | 183篇 |
1992年 | 138篇 |
1991年 | 125篇 |
1990年 | 114篇 |
1989年 | 118篇 |
1988年 | 126篇 |
1987年 | 105篇 |
1986年 | 83篇 |
1985年 | 90篇 |
1984年 | 111篇 |
1983年 | 97篇 |
1982年 | 105篇 |
1981年 | 104篇 |
1980年 | 112篇 |
1979年 | 65篇 |
1978年 | 70篇 |
1977年 | 86篇 |
1976年 | 65篇 |
1975年 | 63篇 |
1974年 | 73篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
The pharmacokinetics of 14C-bonnecor after intravenous and oral administration was studied. The bioavailability was 70%. It was shown that administration of doses in the range of from 3 to 43 mg/kg as well as the repeated use of bonnecor failed to influence the pharmacokinetic parameters. 相似文献
43.
44.
M L Ganikos C McNeil J B Braslow E B Arkin D Klaus E E Oberley M F White 《Public health reports (Washington, D.C. : 1974)》1994,109(5):626-631
The chasm between the supply and demand of donated organs and tissues continues to grow despite widespread public awareness of transplantation and numerous efforts to educate the public about organ donation. It is fast becoming a significant public health problem in this country. The need for more effective public education is well documented in the literature on transplantation and is a primary objective of organizations in the transplant field. In response to this need, the Division of Organ Transplantation in the Health Resources and Services Administration of the Public Health Service initiated a project to examine the nature and scope of donation education initiatives throughout the country, to identify shortcomings, and to suggest ways the Federal Government could contribute to the effectiveness of public education in organ and tissue donation. The project resulted in the development of a protocol that also is applicable to other health education programs. Its major steps consisted of assessing the status of donation-related public education in the United States, identifying existing needs in donation education by applying principles learned from other public health education programs, and identifying roles that could be assumed to help strengthen the American public''s commitment to organ and tissue donation. These roles, which could be adopted by an transplant-related organization, were as broker of knowledge, producer of educational strategies, energizer through communications research, and catalyst by bringing together other groups. This approach to needs assessment and planning may provide useful insights both for those concerned with transplants and for professionals conducting education campaigns related to other public health issues. 相似文献
45.
46.
David S. K. Lu Shantanu Sinha John Lucas Keyvan Farahani Robert Lufkin Klaus Lewin 《Journal of magnetic resonance imaging : JMRI》1997,7(2):303-308
The purpose of this study was to test the feasibility of MR-guided percutaneous ethanol ablation of liver tissue on a .2-T open MR scanner. Needles were placed by MR guidance first into an ex vivo sheep liver and then into livers of three anesthetized pigs, and injection of 10 ml of 96% alcohol was performed. T1 fast low-angle shot (FLASH), T2 turbo spin echo (TSE), and T1 spin echo (SE) images were obtained after incremental volumes of injection. In one pig, simultaneous injection of saline into normal liver was also performed with subsequent pathological correlation. Ethanol-infiltrated liver was hypointense to liver on all sequences, whereas saline caused no tissue signal changes on T1 SE and either isointense or hyperintense changes on T2 TSE images. Pathological examination confirmed ethanol-induced acute liver changes as compared with the control. MR guidance of needle placement and monitoring of ethanol effects on liver tissue is feasible. This may have implications for potential MR-guided hepatic tumor ablation. 相似文献
47.
Klaus Hurrelmann 《Zeitschrift fur Gesundheitswissenschaften》1994,2(3):282-288
48.
The combined effects of the oligoamine RE 1492 with the NO-donor RE 2047 or ASA, ticlopidine, pentoxifylline and BM 14515 were determined in vitro (Born-test and in vivo (rat thrombosis model). The effects in vitro were supra additive but over independent. In vivo all combinations showed over additive and over independent inhibition of thrombus formation. The best results were obtained with a combination of 10 mg/kg RE 1492C and 10 mg/kg RE 2047. It inhibited thrombus formation in arterioles (A) by 79 % and 36 % in venoles (V). The combined effect of RE 1492C and pentoxifylline 10 mg/kg each was 62% (A) or 32% (V), respectively. 相似文献
49.
Friedrich Längle M.D. Thomas Soliman M.D. Nikolaus Neuhold M.D. Gerold Widhalm M.D. Bruno Niederle M.D. Sebastian Roka K. Kaserer M.D. Wolfgang Blauensteiner M.D. Karl Dam M.D. Martin Clodi M.D. Juan Flores M.D. Almute Loidl M.D. Bernhard Schwarzlmüller M.D. Eva Huber M.D. Gerald Jahl Klaus Wamprechtshammer Rudolf Roka M.D. 《World journal of surgery》1994,18(4):583-587
Patients treated for sporadic and hereditary medullary thyroid carcinoma (MTC) have varying rates of persistent disease, recurrence, and survival. The aim of this study was to correlate the immunoreactivity of the monoclonal antibody CD15 (LeuM1) to initial clinical findings and the outcome of treatment. The primary tumors of 75 patients with sporadic MTC, 7 with hereditary disease, and 3 members of MEN 2A families were studied. Of these subjects 74 (87%) showed no or little immunoreactivity (<15% positive cells; score 0) in most tumors. The remaining 13% had surgery for tumors with more than 15% cells with positive staining (score I). There was no correlation between LeuM1 immunoreactivity and sex, age, and type of MTC. There was, however, a significant correlation with the pTNM classification and UICC staging. The prognosis for patients with score 0 was significantly better than score 1 patients. CD15 immunoreactivity appears to be a predictive factor in sporadic and hereditary MTC. Lymph node dissection seems to be more successful in patients with score 0 tumors than in those with score 1 tumors. The question of reoperation in patients with recurrence of disease (especially with biochemical recurrence or persistence) should be discussed on the basis of CD15 immunoreactivity.
Members and institutions are listed in Table 1. 相似文献
Resumen Los pacientes tratados para carcinoma medular, esporádico y hereditario, de la glándula tiroides (CMT) exhiben grandes variaciones en las tasas de enfermedad persistente, recidiva y sobrevida. El propósito del presente estudio fue establecer la correlación entre la inmunorreactividad del anticuerpo CD15 (LeuM1) y los hallazgos clínicos iniciales, así como con el resultado final del tratamiento.Se estudiaron los tumores primarios de 75 pacientes con CMT esporádico, de siete con enfermedad hereditaria y de 3 miembros de familias con síndrome NEM2A.Setenta y cuatro pacientes (87%) exhibieron ninguna o muy baja inmunorreactividad (menos de 15% de células positivas; puntaje 0) en la mayoría de los tumores. El 13% restante fue sometido a cirugía por tumores con más de 15% de las células con coloración positiva (puntaje 1). No se evidenció correlación entre la inmunorreactividad LeuM1 y el sexo, edad o tipo del CMT. Sin embargo, sí apareció una correlación significativa con la clasificiación pTNM y la estadificación de la UICC. El pronóstico de los pacientes con puntaje 0 resultó significativamento mejor que el de los pacientes con puntaje 1.La inmunorreactividad CD15 parece ser un factor de predicción de pronóstico en el CMT esporádico y familiar. La disección ganglionar parece ser más exitosa en pacientes con tumores de puntaje 0 que en los que portan tumores con puntaje 1.El interrogante en cuanto a reoperación en pacientes con recidiva de la enfermedad (especialmente cuando hay recidiva o persistencia bioquímica) debe ser considerada con base en la inmunorreactividad CD15.
Résumé Les taux de maladie persistante, de récidive et de survie chez des patients traités pour cancer médullaire sporadique et héréditaire de la thyroïde (CMT) sont très variables. Le but de cette étude a été de corréler l'immunoréactivité des anticorps monoclonaux CD15 (LeuM1) à des données cliniques initiales et l'évolution finale du traitement des CMT. On a étudié 75 patients ayant un CMT primitif, sept ayant une maladie héréditaire, et trois membres d'une famille MEN 2A. Soixante quatre patients (87%) avaient peu ou pas d'immunoréactivité (moins de 15% de cellules positive: score = 0). Les 13% restants ont eu une chirurgie pour les tumeurs ayant un pourcentage > 15 (score = 1). Il n'y avait aucune corrélation entre l'immunoréactivité LeuM1 et le sexe, l'âge et le type de CMT. Il y avait, en revanche, une corrélation significative entre la classification pTMN et le stage UICC. Le pronostic des patients ayant un score = 0 était significativement meilleur que celui des patients ayant un score = 1. L'immunoréactivité CD15 apparaît comme étant un facteur pronostique des CMT. Le curage lymphatique
Members and institutions are listed in Table 1. 相似文献
50.
Angela Ohlemacher Rainer Schenk Hans Peter Weitzel Nikolai Tyutyulkov Maria Tasseva Klaus Müllen 《Macromolecular chemistry and physics.》1992,193(1):81-93
The energy gaps of poly(p-arylenevinylene)s with phenylene, naphthylene and anthrylene subunits are determined by extrapolating the UV/VIS spectroscopic data of the oligomers. The band structure of the three polymers was theoretically investigated. The topology-, geometry- and correlation-factors were determined upon which the energy spectra of this class of one-dimensional π-electron systems depend. 相似文献