全文获取类型
收费全文 | 819篇 |
免费 | 35篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 63篇 |
儿科学 | 38篇 |
妇产科学 | 3篇 |
基础医学 | 75篇 |
口腔科学 | 10篇 |
临床医学 | 53篇 |
内科学 | 194篇 |
皮肤病学 | 19篇 |
神经病学 | 6篇 |
特种医学 | 313篇 |
外科学 | 22篇 |
综合类 | 12篇 |
预防医学 | 18篇 |
眼科学 | 3篇 |
药学 | 32篇 |
中国医学 | 1篇 |
肿瘤学 | 14篇 |
出版年
2021年 | 7篇 |
2020年 | 6篇 |
2019年 | 3篇 |
2018年 | 8篇 |
2016年 | 4篇 |
2015年 | 11篇 |
2014年 | 8篇 |
2013年 | 11篇 |
2012年 | 4篇 |
2011年 | 8篇 |
2010年 | 15篇 |
2009年 | 17篇 |
2008年 | 10篇 |
2007年 | 27篇 |
2006年 | 9篇 |
2005年 | 14篇 |
2004年 | 11篇 |
2003年 | 10篇 |
2002年 | 10篇 |
2001年 | 10篇 |
2000年 | 9篇 |
1999年 | 18篇 |
1998年 | 47篇 |
1997年 | 39篇 |
1996年 | 58篇 |
1995年 | 43篇 |
1994年 | 34篇 |
1993年 | 38篇 |
1992年 | 11篇 |
1991年 | 12篇 |
1990年 | 12篇 |
1989年 | 33篇 |
1988年 | 37篇 |
1987年 | 30篇 |
1986年 | 25篇 |
1985年 | 39篇 |
1984年 | 20篇 |
1983年 | 22篇 |
1982年 | 26篇 |
1981年 | 27篇 |
1980年 | 12篇 |
1979年 | 6篇 |
1978年 | 6篇 |
1977年 | 26篇 |
1976年 | 18篇 |
1975年 | 14篇 |
1971年 | 2篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1967年 | 1篇 |
排序方式: 共有876条查询结果,搜索用时 0 毫秒
91.
Surface shield: device to reduce personnel radiation exposure 总被引:2,自引:0,他引:2
Young AT; Morin RL; Hunter DW; Nelson KL; Cardella JF; Castaneda-Zuniga WR; Amplatz K 《Radiology》1986,159(3):801-803
A simple device is described that can reduce personnel exposure from scatter radiation by up to 75%. The device consists of an oblong piece of shielding (0.75-mm lead equivalent) that is taped to the side of the patient during percutaneous renal stone removal and other interventional procedures. Contrary to other shields and barriers, this does not interfere with access to the patient. Scatter exposure data from phantom studies are presented and the rationale for surface shielding discussed. 相似文献
92.
93.
RA Parker J Himmelfarb N Tolkoff-Rubin P Chandran RL Wingard RM Hakim 《American journal of kidney diseases》1998,32(3):432-443
Despite several decades of clinical experience, the mortality rate for patients with acute renal failure (ARF) requiring dialysis remains high, and the evaluation of the patients prognosis has been difficult. To date, the Acute Physiology and Chronic Health Evaluation II (APACHE II) scoring system has been used more frequently for prediction in studies of ARF than any other scoring system, but has not been prospectively validated in controlled multicenter studies of this entity. In a multicenter, prospective, controlled trial evaluating the use of biocompatible hemodialysis membranes (BCMs) in patients with ARF, we evaluated the extent to which the APACHE II scoring system, based on the physiological variables in the 24 hours before the onset of dialysis and the presence or absence of oliguria, is predictive of outcome. Analysis of survival and recovery of renal function for the 153 patients treated in this study show that APACHE II scores are predictive both of survival and recovery of renal function, whether analyzed separately by type of dialysis membrane used (BCM or bioincompatible [BICM]) or for both groups combined (all P < 0.01). There was no evidence of a significant center effect or interaction of APACHE II score with dialysis membrane in our study. After adjusting for the APACHE II score, there was a positive effect of the BCM on both probability of survival (P < 0.05) and recovery of renal function (P < 0.01). In patients dialyzed with BCMs, oliguria at onset of dialysis had an adverse effect on both survival and recovery of renal function (both P < 0.01). Receiver operator curves (ROCs) using APACHE II score and the use of BCMs in nonoliguric patients yielded a statistically significant improvement versus the use of APACHE II score alone in the area under the curve (AUC) for survival (0.747 to 0.801; P < 0.05) and recovery of renal function (0.712 to 0.775; P < 0.05). We conclude that the use of the APACHE II score determined at the time of initiation of dialysis for patients with ARF is a statistically significant predictor of patient survival and recovery of renal function. The use of the APACHE II score measured at the time of dialysis initiation, especially when modified by the presence or absence of oliguria, should help in predicting outcome when evaluating interventions for patients with ARF. 相似文献
94.
In vitro and in vivo selectin-blocking activities of sulfated lipids and sulfated sialyl compounds 总被引:2,自引:0,他引:2
Mulligan MS; Warner RL; Lowe JB; Smith PL; Suzuki Y; Miyasaka M; Yamaguchi S; Ohta Y; Tsukada Y; Kiso M; Hasegawa A; Ward PA 《International immunology》1998,10(5):569-575
There is accumulating evidence that sulfated lipids, sulfated
oligosaccharides and other sulfated compounds are reactive with selectins
in a manner that interferes with selectin interactions with their natural
ligands. In the report we describe the ability of sulfated lipids
(sulfatides and gangliosides) and multimeric forms of sulfated sialic acid
to block binding of P- and E-selectin-Ig to neutrophils. The in vivo
ability of these compounds to block lung injury in rats following i.v.
infusion of purified cobra venom factor (CVF), which induces injury that is
L- and P-selectin dependent, was also determined as well as effects on
recruitment of neutrophils, as measured by lung myeloperoxidase. There was
a significant correlation between the ability of sulfated lipids and sialyl
compounds to interfere in vitro with P-selectin-Ig binding to neutrophils
and to protect against P-selectin-dependent acute lung injury induced by
CVF. The biological effects of these sulfated compounds were also
associated with diminished accumulation of neutrophils. The protective
effects of these compounds may be linked to their ability to interfere with
P- selectin binding to counter-receptors on neutrophils.
相似文献
95.
Murakami T; Baron RL; Peterson MS; Oliver JH rd; Davis PL; Confer SR; Federle MP 《Radiology》1996,200(1):69
96.
97.
狭叶獐牙菜的两个新环烯醚单萜甙 总被引:9,自引:1,他引:8
本文报道狭叶獐牙菜(Swertia angustifolia)中两个新的环烯醚单萜甙的结构。分别命名为狭叶獐牙菜苦甙(angustiamarin,Ⅰ)和狭叶獐牙菜甙(angustioside,Ⅱ),此外还鉴定了獐牙菜甙(sweroside,Ⅲ),獐牙菜苦甙(swertiamarin,Ⅳ)和表优士特莫甙(epi-eustomoside,Ⅴ)。 相似文献
98.
99.
Effect of protein A of Staphylococcus aureus on the binding of monomeric and polymeric IgG to Fc receptor-bearing cells. 总被引:1,自引:0,他引:1 下载免费PDF全文
The effect of protein A of Staphylococcus aureus (SpA) on the binding of rabbit IgG to the Fc receptors of mouse lymphocytes and macrophages was found to correlate with the aggregation of the IgG ligands. After binding anti-erythrocyte IgG complexed with SpA, the cells were able to attach to and kill erythrocyte indicator cells with a higher efficiency than lymphoid cells treated with anti-erythrocyte IgG alone. The amount of anti-peroxidase IgG which can be bound to effector cells was not changed by reaction with SpA. In contrast, the binding to cells of IgG-coated erythrocytes and of anti-peroxidase IgG complexed with peroxidase was substantially reduced by reaction with SpA. The results are compatible with the presence of two distinct Fc receptors, one for cytophilic monomeric IgG and another for polymeric (antigen-complexed) IgG. 相似文献
100.