全文获取类型
收费全文 | 10269篇 |
免费 | 493篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 151篇 |
儿科学 | 384篇 |
妇产科学 | 185篇 |
基础医学 | 1463篇 |
口腔科学 | 214篇 |
临床医学 | 643篇 |
内科学 | 2776篇 |
皮肤病学 | 304篇 |
神经病学 | 824篇 |
特种医学 | 277篇 |
外科学 | 1433篇 |
综合类 | 68篇 |
一般理论 | 1篇 |
预防医学 | 875篇 |
眼科学 | 141篇 |
药学 | 497篇 |
中国医学 | 53篇 |
肿瘤学 | 498篇 |
出版年
2023年 | 48篇 |
2022年 | 142篇 |
2021年 | 359篇 |
2020年 | 138篇 |
2019年 | 301篇 |
2018年 | 353篇 |
2017年 | 215篇 |
2016年 | 178篇 |
2015年 | 212篇 |
2014年 | 298篇 |
2013年 | 398篇 |
2012年 | 649篇 |
2011年 | 661篇 |
2010年 | 392篇 |
2009年 | 328篇 |
2008年 | 532篇 |
2007年 | 536篇 |
2006年 | 551篇 |
2005年 | 553篇 |
2004年 | 523篇 |
2003年 | 523篇 |
2002年 | 458篇 |
2001年 | 383篇 |
2000年 | 419篇 |
1999年 | 323篇 |
1998年 | 96篇 |
1997年 | 56篇 |
1996年 | 66篇 |
1995年 | 66篇 |
1994年 | 53篇 |
1993年 | 42篇 |
1992年 | 107篇 |
1991年 | 109篇 |
1990年 | 84篇 |
1989年 | 87篇 |
1988年 | 59篇 |
1987年 | 81篇 |
1986年 | 73篇 |
1985年 | 44篇 |
1984年 | 40篇 |
1983年 | 32篇 |
1982年 | 18篇 |
1979年 | 22篇 |
1977年 | 17篇 |
1975年 | 12篇 |
1974年 | 17篇 |
1970年 | 18篇 |
1969年 | 16篇 |
1967年 | 10篇 |
1966年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
141.
142.
Aresté N Amor J Cambil T Salgueira M Sánchez-Palencia R Páez C Gómez O Palma A 《Nefrología : publicación oficial de la Sociedad Espa?ola Nefrologia》2003,23(Z2):64-68
Calcitriol deficiency and phosphorus retention are mechanisms involved in the pathogenesis of renal hyperparathyroidism. The aim of this study was to evaluate the effect of dietary phosphorus restriction versus calcium carbonate treatment for one month on PTH and calcitriol levels in patients with mild renal failure. We studied two groups of patients: Group I: 21 patients (14M/7F); mean age 61 years old; mean glomerular filtration rate 51 ml/min. Their diet contained phosphorus 700 mg/day. Group II: 30 patients (21M/9F); mean age 58; mean glomerular rate 56 ml/min. They were divided in two subgroups: 18 patients treated with calcium carbonate 2.5 g/day and 12 patients with 5 g/day. Serum PTH, calcitriol, 25(OH)D3, calcium, phosphorus and urinary excretion of calcium and phosphorus were measured before and after a 30 day period. The low phosphorus diet (Group I) resulted in a significant decrease in PTH levels (81.3 +/- 35 vs 71 +/- 39 pg/ml, p < 0.05) and significant increase in calcitriol levels (22.4 +/- 4.4 vs 33.4 +/- 7.5 pg/ml, p < 0.05). In our study calcium carbonate treatment (Group II) had no effect on PTH and calcitriol levels. 相似文献
143.
Daniel Zúiga-Núez Pablo Barrias Gloria Crdenas-Jirn M. Soledad Ureta-Zaartu Camilo Lopez-Alarcn F. Eduardo Morn Vieyra Claudio D. Borsarelli Emilio I. Alarcon Alexis Aspe 《RSC advances》2018,8(4):1927
Coumarin compounds have been described as anti-inflammatories, and chemotherapeutic agents as well as antioxidants. However, the origin of the antioxidant activity of non phenolic coumarins remains obscure. In the present report, we demonstrate that non-phenolic 7-dialkyl-aminocoumarins may also have significant antioxidant properties against free radicals derived from 2,2′-azobis(2-amidinopropane) dihydrochloride under aerobic conditions. This atypical behaviour is due to the presence of traces of very reactive hydroxycinnamic acid-type compounds. Changing functional groups at the C-3 and C-4 positions shifts the reactivity of the compounds from peroxyl to alkoxyl free radicals. Kinetic and theoretical studies based on Density Functional Theory support the formation of reactive hydroxycinnamic acid and directly link the antioxidant behaviour of the compounds to hydrogen atom transfer.Relevant antioxidant properties of non-phenolic 7-dialkyl-aminocoumarins against free radicals derived from 2,2′-azobis(2-amidinopropane) dihydrochloride under aerobic conditions have been experimentally and theoretically demonstrated. 相似文献
144.
145.
Hernández-Díaz Yazmín González-Castro Thelma Beatriz Tovilla-Zárate Carlos Alfonso López-Narváez María Lilia Genis-Mendoza Alma Delia Castillo-Avila Rosa Giannina Ramos-Méndez Miguel Ángel Juárez-Rojop Isela Esther 《Metabolic brain disease》2021,36(8):2415-2424
Metabolic Brain Disease - Schizophrenia is a debilitating mental illness. Levels of oxytocin have been proposed as a biomarker of schizophrenia; however, the observed levels of oxytocin in... 相似文献
146.
Mena-Vázquez Natalia Jimenez-Núñez Francisco Gabriel Godoy-Navarrete Francisco Javier Manrique-Arija Sara Aguilar-Hurtado María Carmen Romero-Barco Carmen María Ureña-Garnica Inmaculada Espildora F. Padin-Martín María Isabel Fernández-Nebro Antonio 《Clinical rheumatology》2021,40(6):2377-2385
Clinical Rheumatology - To analyze the diagnostic utility of lung ultrasound (US) to detect interstitial lung disease (ILD) in rheumatoid arthritis (RA) patients comparing with high-resolution... 相似文献
147.
Holz F. Carrillo G. G. Núñez Peña E. G. Martinez Martinez A. A. Rivera de la Peña Jiménez I. G. Virgen Ramon Bonilla Verhoff M. A. Birngruber Christoph G. 《International journal of legal medicine》2022,136(4):1199-1199
International Journal of Legal Medicine - 相似文献
148.
149.
Angiosarcoma of the small intestine: an immunoperoxidase study 总被引:3,自引:0,他引:3
N G Ordó?ez G W del Junco A G Ayala N Ahmed 《The American journal of gastroenterology》1983,78(4):218-221
A case of multifocal angiosarcoma of the small intestine is reported. These tumors often contain areas of solid sheets of cells and may be confused with poorly differentiated carcinoma or other sarcomas, as was the tumor in the reported case. Factor VIII-related antigen was demonstrated in biopsy samples by the peroxidase antiperoxidase method, showing the tumor to be an angiosarcoma. We conclude that the demonstration of factor VIII-related antigen in the neoplastic cells is an important aid in the diagnosis of angiosarcoma. 相似文献
150.