全文获取类型
收费全文 | 559篇 |
免费 | 38篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 31篇 |
妇产科学 | 6篇 |
基础医学 | 37篇 |
口腔科学 | 6篇 |
临床医学 | 97篇 |
内科学 | 85篇 |
皮肤病学 | 4篇 |
神经病学 | 62篇 |
特种医学 | 76篇 |
外科学 | 94篇 |
综合类 | 14篇 |
预防医学 | 22篇 |
眼科学 | 2篇 |
药学 | 28篇 |
肿瘤学 | 37篇 |
出版年
2023年 | 4篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 3篇 |
2016年 | 7篇 |
2015年 | 12篇 |
2014年 | 8篇 |
2013年 | 16篇 |
2012年 | 25篇 |
2011年 | 16篇 |
2010年 | 15篇 |
2009年 | 23篇 |
2008年 | 22篇 |
2007年 | 21篇 |
2006年 | 30篇 |
2005年 | 32篇 |
2004年 | 36篇 |
2003年 | 19篇 |
2002年 | 16篇 |
2001年 | 24篇 |
2000年 | 31篇 |
1999年 | 18篇 |
1998年 | 18篇 |
1997年 | 6篇 |
1996年 | 14篇 |
1995年 | 13篇 |
1994年 | 13篇 |
1993年 | 13篇 |
1992年 | 10篇 |
1991年 | 8篇 |
1990年 | 9篇 |
1989年 | 7篇 |
1988年 | 14篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 7篇 |
1975年 | 3篇 |
1973年 | 3篇 |
1971年 | 4篇 |
1968年 | 4篇 |
1967年 | 3篇 |
排序方式: 共有604条查询结果,搜索用时 15 毫秒
61.
Myocardial uptake and biodistribution of newly designed technetium-labelled fatty acid analogues 总被引:2,自引:0,他引:2
Heintz AC Jung CM Stehr SN Mirtschink P Walther M Pietzsch J Bergmann R Pietzsch HJ Spies H Wunderlich G Kropp J Deussen A 《Nuclear medicine communications》2007,28(8):637-645
PURPOSE: In an effort to develop 99mTc-labelled fatty acids (FAs) for myocardial metabolism and flow imaging, several Tc analogues according to the '3+1' and the '4+1' mixed-ligand approach were synthesized and myocardial extraction was evaluated in non-working isolated guinea pig hearts. An example of biodistribution patterns in guinea pigs was determined by using one FA analogue. METHODS: The coordination moieties contain a +5, respectively +3, oxidation state metal core attached to the end position of a FA chain. FA complexes of the '3+1' and the '4+1' mixed-ligand type were prepared and investigated using the isolated heart model. To estimate the diagnostic value of the analogue 99mTc-FAs, the biodistribution of one well-extracted FA was evaluated. RESULTS: The '4+1' FA compounds achieved the highest uptake rates of all the technetium FAs investigated. In particular, the '4+1' 99mTc-C11-FA achieved at least a 2-fold higher ventricular extraction of the applied activity than the established control tracers including omega-(p-[123I]iodophenyl)pentadecanoic FAs (BMIPP and IPPA) and Tc-MIBI. Furthermore, the '4+1' dodecanoic FA derivative and the thiadodecanoic FA derivative showed an extraction comparable to established 123I-labelled tracers. Biodistribution experiments performed for the thiadodecanoic FA derivative indicated a good heart/blood and heart/lung ratio and also a high uptake in the liver. In contrast, '3+1' 99mTc complexes showed a low myocardial extraction rate. Nevertheless, the differentiation in the extraction profile, which depends on the FA chain length and structure, indicates a specific heart uptake of these 99mTc-labelled FA derivatives as well. CONCLUSIONS: The excellent extraction rates found for '4+1' 99mTc-FAs indicate possibly promising structures for innovative myocardial tracers. 相似文献
62.
D Altavilla F Squadrito A Bitto F Polito BP Burnett V Di Stefano L Minutoli 《British journal of pharmacology》2009,157(8):1410-1418
Background and purpose:
The flavonoids, baicalin and catechin, from Scutellaria baicalensis and Acacia catechu, respectively, have been used for various clinical applications. Flavocoxid is a mixed extract containing baicalin and catechin, and acts as a dual inhibitor of cyclooxygenase (COX) and 5-lipoxygenase (LOX) enzymes. The anti-inflammatory activity, measured by protein and gene expression of inflammatory markers, of flavocoxid in rat peritoneal macrophages stimulated with Salmonella enteritidis lipopolysaccharide (LPS) was investigated.Experimental approach:
LPS-stimulated (1 µg·mL−1) peritoneal rat macrophages were co-incubated with different concentrations of flavocoxid (32–128 µg·mL−1) or RPMI medium for different incubation times. Inducible COX-2, 5-LOX, inducible nitric oxide synthase (iNOS) and inhibitory protein κB-α (IκB-α) levels were evaluated by Western blot analysis. Nuclear factor κB (NF-κB) binding activity was investigated by electrophoretic mobility shift assay. Tumour necrosis factor-α (TNF-α) gene and protein expression were measured by real-time polymerase chain reaction and enzyme-linked immunosorbent assay respectively. Finally, malondialdehyde (MDA) and nitrite levels in macrophage supernatants were evaluated.Key results:
LPS stimulation induced a pro-inflammatory phenotype in rat peritoneal macrophages. Flavocoxid (128 µg·mL−1) significantly inhibited COX-2 (LPS = 18 ± 2.1; flavocoxid = 3.8 ± 0.9 integrated intensity), 5-LOX (LPS = 20 ± 3.8; flavocoxid = 3.1 ± 0.8 integrated intensity) and iNOS expression (LPS = 15 ± 1.1; flavocoxid = 4.1 ± 0.4 integrated intensity), but did not modify COX-1 expression. PGE2 and LTB4 levels in culture supernatants were consequently decreased. Flavocoxid also prevented the loss of IκB-α protein (LPS = 1.9 ± 0.2; flavocoxid = 7.2 ± 1.6 integrated intensity), blunted increased NF-κB binding activity (LPS = 9.2 ± 2; flavocoxid = 2.4 ± 0.7 integrated intensity) and the enhanced TNF-α mRNA levels (LPS = 8 ± 0.9; flavocoxid = 1.9 ± 0.8 n-fold/β-actin) induced by LPS. Finally, flavocoxid decreased MDA, TNF and nitrite levels from LPS-stimulated macrophages.Conclusion and implications:
Flavocoxid might be useful as a potential anti-inflammatory agent, acting at the level of gene and protein expression. 相似文献63.
64.
65.
66.
J Termote NE Schalij-Delfos BP Cats D Wittebol-Post BR Hoogervorst HAA Brouwers 《Acta paediatrica (Oslo, Norway : 1992)》1996,85(12):1491-1496
To assess the effect of surfactant replacement therapy (SRT) on the prevalence and severity of retinopathy of prematurity (ROP), we compared data from 160 SRT-treated preterm infants with data from 230 historic controls. The prevalence of ROP was 30.6% in the treatment group and 23.4% in the control group. Severe ROP (stages 3-4) was seen in 6.1% of the infants with ROP in the treatment group and 20.3% of the ROP patients in the control group. Surfactant therapy had no influence on the prevalence of ROP (odds ratio 1.4, 95% confidence interval 0.797-2.459, p = 0.242). However, SRT was associated with a decreased risk for severe ROP, compared to mild ROP (odds ratio 0.226, 95% confidence interval 0.056-0.905, p = 0.036). These data suggest that SRT is associated with a decreased risk for severe ROP. 相似文献
67.
Oscillatory motion of the normal cervical spinal cord 总被引:2,自引:0,他引:2
68.
We describe a simple adaptation of the Water Pik (Teledyne Water Pik, Fort Collins, Colorado) irrigating device which allows vigorous, direct-vision agitation of the bladder wall. Three groups of mongrel dogs were subjected to cystoscopy and either syringe barbotage, half-speed Water Pik irrigation, or full-speed Water Pik irrigation of the bladder wall. Transitional cell counts were then done on centrifuged aliquots of each bladder wash specimen. The average number of transitional cells per high-power field were similar between the control group and the syringe barbotage group (2.5 and 1.5 respectively). However, both the half-speed and the full-speed Water Pik groups demonstrated statistically higher cell counts (5.7 and 13.7) when compared to both the controls and syringe barbotage groups. We conclude that Water Pik irrigation is an effective method to increase cell yield in bladder wash specimens. 相似文献
69.
HY Chan XQ Yao SY Tsang BP Bourreau FL Chan Y Huang . 《Journal of cardiac surgery》2002,17(6):562-562
Background: Calcitonin gene-related peptide (CGRP) is known to have an extremely potent and prolonged vasodilator effect on the coronary arteries. Studies have shown that CGRP increased coronary blood flow and alleviated reperfusion injury in vitro. It is still unknown, however, whether exogenous CGRP has a protective effect on the reperfusion heart associated with cardiopulmonary bypass (CPB). Methods: An in vivo porcine model of CPB was established. Twenty pigs, 10 controls and 10 CGRP used animals (CGRP group), were performed a median sternotomy followed by a standard CPB. All the hearts were arrested for 45 minutes. In the CGRP group, 1mg/kg CGRP was added into the cardioplegia, and another 1mg/kg was reperfused just before the aortic cross-clamp was removed. In both groups, myocardial microvascular perfusion, coronary arterial microvessel diameter and microvessel blood flow were detected by a laser doppler flowmeter and a contact microscope with TV monitor on five consecutive time perioperatively. Result: Myocardial microvascular perfusion was significantly higher and coronary arterial microvessel diameter was larger in the CGRP group on every point of time of reperfusion compared to those in the control group. In the CGRP group, microvessel blood flow also improved significantly than that in the control group during reperfusion. Conclusion: CGRP improves myocardial microcirculation during cardiac ischemia-reperfusion associated with CPB and could become a new, potent myocardial protector. 相似文献
70.