全文获取类型
收费全文 | 3796篇 |
免费 | 256篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 63篇 |
妇产科学 | 54篇 |
基础医学 | 459篇 |
口腔科学 | 325篇 |
临床医学 | 353篇 |
内科学 | 990篇 |
皮肤病学 | 76篇 |
神经病学 | 184篇 |
特种医学 | 198篇 |
外科学 | 572篇 |
综合类 | 22篇 |
预防医学 | 253篇 |
眼科学 | 21篇 |
药学 | 196篇 |
中国医学 | 12篇 |
肿瘤学 | 282篇 |
出版年
2023年 | 28篇 |
2022年 | 59篇 |
2021年 | 124篇 |
2020年 | 86篇 |
2019年 | 92篇 |
2018年 | 121篇 |
2017年 | 91篇 |
2016年 | 101篇 |
2015年 | 131篇 |
2014年 | 145篇 |
2013年 | 183篇 |
2012年 | 278篇 |
2011年 | 247篇 |
2010年 | 173篇 |
2009年 | 188篇 |
2008年 | 243篇 |
2007年 | 205篇 |
2006年 | 207篇 |
2005年 | 211篇 |
2004年 | 207篇 |
2003年 | 167篇 |
2002年 | 162篇 |
2001年 | 29篇 |
2000年 | 19篇 |
1999年 | 40篇 |
1998年 | 54篇 |
1997年 | 52篇 |
1996年 | 45篇 |
1995年 | 36篇 |
1994年 | 34篇 |
1993年 | 27篇 |
1992年 | 26篇 |
1991年 | 18篇 |
1990年 | 23篇 |
1989年 | 28篇 |
1988年 | 18篇 |
1987年 | 20篇 |
1986年 | 18篇 |
1985年 | 10篇 |
1984年 | 16篇 |
1983年 | 10篇 |
1982年 | 11篇 |
1981年 | 11篇 |
1980年 | 20篇 |
1979年 | 8篇 |
1978年 | 7篇 |
1977年 | 11篇 |
1976年 | 11篇 |
1975年 | 4篇 |
1969年 | 4篇 |
排序方式: 共有4077条查询结果,搜索用时 15 毫秒
31.
Glenn L Sia Su Clara Mae R Mariano Nikki Shayne A Matti Gliceria B Ramos 《亚太热带病杂志(英文版)》2012,2(1):51-54
ObjectiveTo assess the parasitic infestation of vegetables in selected markets in Metro Manila, Philippines.MethodsA total of 80 vegetables were purchased from public and private markets in Munoz, Quezon City, and Alabang, Muntinlupa City. Vegetables were washed, and the washings were collected and examined for parasitic organisms.ResultsIn all vegetables examined, 36 of 80 (45.0%) were infested with parasitic organisms. Vegetables obtained from Muntinlupa City showed that 17 of 40 (42.5%) have parasitic infestation as compared with those obtained from Quezon City with 19 of 40 (47.5%). Significant differences on the parasitic organisms existed between the public and private markets and between the two locations (P<0.05).ConclusionsFindings indicate that vegetables can be potential source of parasitic infection. There is a need to be vigilant in ensuring that foodstuffs sold in our market systems are safe and fit for consumption. 相似文献
32.
33.
José Saura Llamas María Nieves Martínez Garre María Elena Sebastián Delgado María Ángeles Martínez Navarro Mariano Leal Hernández Susana Blanco Sabio Antonio Martínez Pastor 《Atencion primaria / Sociedad Espa?ola de Medicina de Familia y Comunitaria》2013,45(6):297-306
ObjectiveTo evaluate the performance and quality of the 10 groups of training tasks envisaged in the portfolio training model undertaken by all residents of the Primary Care Teaching Unit in Murcia.DesignA cross-sectional study was conducted on the portfolios provided and completed by all residents in May 2011.ParticipantsAll residents who were in training at that time (131).MethodTen groups of training tasks were established from those recommended by the National Commission for the specialty. The performance of each one in each of the portfolios was evaluated, and the compliance for each training task was calculated. The quality of the performance of each of the tasks was given a score, 0 points (very poor) to 10 points (excellent).ResultsAs regards compliance, the tasks that were most performed were: filling in the Resident book correctly and using the resident skills guide, both with 99.24%, followed by reflection reports on the training visits. All tasks had a compliance rate higher than 67%. The mean percentage of compliance was 86.49%. All tasks obtained an average score greater than 7 (outstanding). The overall mean score was 7,8 points.ConclusionsThe level of perfomance of the tasks set out in the portfolio by the residents was very satisfying. It is necessary to continue working on improving the performance of the portfolio. 相似文献
34.
35.
The regulation of hemopoiesis in long-term bone marrow cultures. II. Stimulation and inhibition of stem cell proliferation 总被引:6,自引:1,他引:6
The isolation of a DNA synthesis inhibitor (NBME fraction IV) and stimulator (RBME fraction III) specific for the hemopoietic stem cell (CFU-s) from freshly isolated normal adult and regenerating murine bone marrow, respectively, has been well documented. We have utilized long- term liquid bone marrow cultures in a further analysis of the role of these factors in the regulation of CFU-s proliferation. Our results show that shortly after feeding, at a time when the cultured CFU-s are actively proliferating, high levels of the hemopoietic stem cell proliferation stimulator fraction III can be isolated from the culture medium. In contrast, the presence of essentially noncycling CFU-s found in cultures fed 8-10 days previously correlates with high levels of the hemopoietic stem cell inhibitor fraction IV. These results suggest that a certain balance between these factors determines CFU-s proliferation in the long-term cultures. In support of this, DNA synthesis in actively cycling CFU-s in the long-term cultures is inhibited for at least 3 days by the addition of excess NBME fraction IV (inhibitor). Furthermore, DNA synthesis in noncycling cultured CFU-s is stimulated for at least 5 days by the addition of RBME fraction III (stimulator). 相似文献
36.
Jelinek J; Fairbairn LJ; Dexter TM; Rafferty JA; Stocking C; Ostertag W; Margison GP 《Blood》1996,87(5):1957-1961
A human O6-alkylguanine-DNA-alkyltransferase (ATase) cDNA-containing retrovirus was used to infect murine long-term primary bone marrow cultures. High levels of ATase expression were obtained, and colony- forming cells of the granulocyte-macrophage lineage from the cultures transduced with the human ATase retrovirus were three times more resistant to the alkylating agent, N-methyl-N-nitrosourea (MNU), than control cultures. Furthermore, expression of the human ATase protected long-term hematopoiesis, measured as the output of progenitor cells to the nonadherent fraction of the culture, against the cytotoxic effects of repeated exposures to MNU. These results clearly show that a human ATase cDNA-containing retrovirus can be used to infect long-term primary bone marrow cultures and that this attenuates their sensitivity to nitrosoureas. 相似文献
37.
Juan M. Díaz-Tocados María E. Rodríguez-Ortiz Yolanda Almadén Carmen Pineda Julio M. Martínez-Moreno Carmen Herencia Noemi Vergara M. Victoria Pendón-Ruiz de Mier Rafael Santamaría Cristian Rodelo-Haad Antonio Casado-Díaz Víctor Lorenzo Catarina Carvalho João M. Frazão Arnold J. Felsenfeld William G. Richards Escolástico Aguilera-Tejero Mariano Rodríguez Juan R. Muñoz-Castañeda 《Kidney international》2019,95(5):1064-1078
38.
39.
Romina C. De Lucca Patricio L. Dutrey Mariano E. Villarino Angela M. Ubios 《Experimental and toxicologic pathology》2009,61(4):347-352
Not only workers employed at industrial plants are exposed to intoxication with the element they manipulate, the population at large is also at risk of suffering health problems caused by contaminating wastes inadequately treated for their safe disposal. As a result certain toxic substances, such as hexavalent chromium,has reached the general population including children. The present study sought to evaluate the effect of intoxication with hexavalent chromium on body and mandibular growth and tooth eruption in suckling Wistar rats. Potassium dichromate was administered by gavage in a dose of 6.25 or 12.5 mg/kg body weight (b.w.) to one of the two groups of 4-day-old Wistar rats during 10 days. Our results showed that the effects of chromium are dose-dependent. Morphometric studies of body growth showed lower body weight in both experimental groups and shorter tail length in animals receiving 12.5 mg/kg b.w. dose of chromium, compared with controls. All parameters of mandibular growth were lower in the experimental group receiving 12.5 mg/kg b.w. of chromium. Differences in tooth eruption were observed at the level of the first molar in animals receiving 12.5 mg/kg and of the second molar in those receiving 6.25 mg/kg b.w. of chromium. Chromium was found to affect all the studied parameters. 相似文献
40.
Saura D Campos JV Villegas M Picó F de la Morena G Valdés-Chávarri M 《International journal of cardiology》2008,129(1):e7-e9
Heart–hand syndromes show substantial clinical and genetic heterogeneity. The unusual case of a patient with a heart–hand syndrome consisting of preaxial polydactylia, postaxial syndactylia, parachute mitral valve, mild subaortic stenosis, and double outlet right ventricle is presented and discussed. The importance of distinguishing Holt–Oram syndrome from its phenocopies and other heart–hand syndromes is underlined. 相似文献