全文获取类型
收费全文 | 2024篇 |
免费 | 111篇 |
国内免费 | 75篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 171篇 |
妇产科学 | 26篇 |
基础医学 | 240篇 |
口腔科学 | 59篇 |
临床医学 | 251篇 |
内科学 | 490篇 |
皮肤病学 | 73篇 |
神经病学 | 60篇 |
特种医学 | 391篇 |
外科学 | 101篇 |
综合类 | 44篇 |
预防医学 | 89篇 |
眼科学 | 20篇 |
药学 | 84篇 |
2篇 | |
肿瘤学 | 108篇 |
出版年
2023年 | 5篇 |
2022年 | 7篇 |
2021年 | 11篇 |
2020年 | 14篇 |
2019年 | 15篇 |
2018年 | 31篇 |
2017年 | 22篇 |
2016年 | 22篇 |
2015年 | 39篇 |
2014年 | 47篇 |
2013年 | 57篇 |
2012年 | 34篇 |
2011年 | 38篇 |
2010年 | 88篇 |
2009年 | 84篇 |
2008年 | 50篇 |
2007年 | 87篇 |
2006年 | 52篇 |
2005年 | 54篇 |
2004年 | 26篇 |
2003年 | 17篇 |
2002年 | 27篇 |
2001年 | 36篇 |
2000年 | 29篇 |
1999年 | 33篇 |
1998年 | 128篇 |
1997年 | 155篇 |
1996年 | 134篇 |
1995年 | 109篇 |
1994年 | 115篇 |
1993年 | 98篇 |
1992年 | 30篇 |
1991年 | 40篇 |
1990年 | 40篇 |
1989年 | 58篇 |
1988年 | 48篇 |
1987年 | 44篇 |
1986年 | 50篇 |
1985年 | 45篇 |
1984年 | 26篇 |
1983年 | 15篇 |
1982年 | 24篇 |
1981年 | 29篇 |
1980年 | 25篇 |
1979年 | 4篇 |
1978年 | 8篇 |
1977年 | 18篇 |
1976年 | 25篇 |
1975年 | 14篇 |
1966年 | 1篇 |
排序方式: 共有2210条查询结果,搜索用时 15 毫秒
1.
JM Martín† L Calduch† C Monteagudo‡ I Molina† D Ramón† V Alonso† E Jordᆠ《Journal of the European Academy of Dermatology and Venereology》2006,20(4):428-431
Cutaneous plasmacytosis is a rare disorder characterized by a benign proliferation of mature plasma cells that appears as multiple dark-brown to purplish skin lesions, often associated with polyclonal hypergammaglobulinaemia. We present the case of a 55-year-old Caucasian man who suffered from a cutaneous plasmacytosis associated with two different carcinomas. Cutaneous plasmacytosis seems to be a reactive process because most cases reported are not associated with any apparent underlying disease. Nevertheless, because few reported cases were associated with malignancies, screening of additional neoplasms would be justified. 相似文献
2.
JM Vilanova J Figueras-Aloy J Roselló G Gómez E Gelpí R Jiménez 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(5):588-592
The aim of this study was to evaluate the cerebral synthesis of eicosanoids in the asphyctic newborn and to investigate the relation between the prostanoid profiles in cerebrospinal fluid (CSF) and the appearance and severity of hypoxic-ischaemic encephalopathy (HIE). Levels of 6-keto-PGF 1-α, TXB2 , PGE2 and PGF2-α in CSF were measured in 40 full term newborns during the first day of life. Thirty of these newborns had birth asphyxia and were divided into three groups: 10 without HIE, 12 with mild HIE and 8 with moderate-severe HIE. They were compared to a control group of 10 non-hypoxic newborns. Determinations of the metabolites in CSF were performed by RIA and expressed as pg/ml (mean ± SD). The CSF TXB2 (thromboxane A2 metabolite) in asphyxiated newborns was always higher than in the control group (28.12 ± 10.6), and related to the severity of HIE ( p = 0:005): without HIE (50.84 ± 16.4; p = 0:02), mild HIE (80.65 ± 12.64; p ± 0:01) and moderate-severe HIE (178.14 ± 20.5; p < 0:01). The CSF 6-keto-PGF 1-α (prostacyclin metabolite) in asphyxiated newborns was always higher than in the control group (80.55 ± 12.56), but indirectly related to the severity of HIE: without HIE (240.95 ± 28.12; p < 0:01), mild HIE (183.65 ± 30.1; p < 0:01) and moderate-severe HIE (140.55 ± 25.12; p < 0:01). In the moderate-severe HIE group, the increase in TXB2 was higher than the rise in 6-keto-PGF 1-α . 相似文献
3.
4.
5.
6.
7.
T.G. van Kooten J.M. Schakenraad H.C. van der Mei A. Dekker C.J. Kirkpatrick H.J. Busscher 《Medical engineering & physics》1994,16(6):506-512
In this study, human umbilical vein and human saphenous vein endothelial cells were seeded on glass and exposed to fluid shear in a parallel-plate flow chamber. Cell retention, morphology and migration were studied as a function of shear stress and of adhesion time prior to exposure to shear. Three-hour and 24-h adhesion times gave rise to comparable cell retention values after 2 h of flow for both cell types. Cell retention decreased from 85 to 20% as shear stress increased from 88 to 264 dynes cm−2 (8.8 to 26 Pa). Mean spreading areas decreased after the onset of flow, but subsequently stabilized to plateau values, which were smaller at higher shear stresses. Shape factors increased faster to higher values as cells were exposed to higher shear stresses, without any obvious preference in orientation of the cells with respect to the direction of flow. Migration was unidirectional with flow and linear with time. Migration was faster for cells which had adhered for 24 h than for cells which had adhered for 3 h and was accompanied by the presence of fibrillar structures left behind on the surface upstream of migrating cells. It is concluded that after 3 h adhesion to glass, cells have adhered with an adhesion strength that does not substantially increase during the next 21 h. However, during this time changes in cell-substratum interactions seem to occur judging by the differences in, e.g., migration rates. 相似文献
8.
9.
10.
Ralls PW; Johnson MB; Kanel G; Dobalian DM; Colletti PM; Boswell WD Jr; Radin DR; Halls JM 《Radiology》1986,161(2):451-454
FM sonography - a signal-processing technique that uses frequency and phase information as well as amplitude data - shows promise in evaluation of patients with diffuse liver disease. In a prospective blinded review of 37 patients with biopsy-proved liver disease and 42 healthy volunteers, FM sonography was clearly superior to traditional amplitude-based (AM) sonography in distinguishing healthy from diseased subjects. Statistically significant differences were seen in accuracy (FM, 98.7%; AM, 84.8%), sensitivity (FM, 97.3%; AM, 70.3%), and negative predictive value (FM, 97.7%; AM, 78.8%). Our data also suggest that current FM sonographic techniques cannot differentiate among histologic findings associated with different hepatic parenchymal abnormalities. It is unclear, therefore, whether FM imaging can reduce the numbers of patients who require biopsy for diagnosis or the frequency of biopsy procedures in patients with known disease. 相似文献