全文获取类型
收费全文 | 392篇 |
免费 | 5篇 |
国内免费 | 12篇 |
专业分类
儿科学 | 21篇 |
妇产科学 | 5篇 |
基础医学 | 20篇 |
口腔科学 | 5篇 |
临床医学 | 27篇 |
内科学 | 68篇 |
皮肤病学 | 18篇 |
神经病学 | 1篇 |
特种医学 | 155篇 |
外科学 | 66篇 |
综合类 | 3篇 |
预防医学 | 7篇 |
药学 | 4篇 |
中国医学 | 1篇 |
肿瘤学 | 8篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 1篇 |
2016年 | 4篇 |
2015年 | 1篇 |
2014年 | 7篇 |
2013年 | 12篇 |
2012年 | 13篇 |
2011年 | 5篇 |
2010年 | 9篇 |
2009年 | 9篇 |
2008年 | 3篇 |
2007年 | 13篇 |
2006年 | 8篇 |
2005年 | 7篇 |
2004年 | 9篇 |
2003年 | 7篇 |
2002年 | 8篇 |
2001年 | 4篇 |
2000年 | 5篇 |
1999年 | 6篇 |
1998年 | 15篇 |
1997年 | 22篇 |
1996年 | 25篇 |
1995年 | 15篇 |
1994年 | 17篇 |
1993年 | 11篇 |
1992年 | 7篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 22篇 |
1988年 | 13篇 |
1987年 | 18篇 |
1986年 | 17篇 |
1985年 | 20篇 |
1984年 | 13篇 |
1983年 | 7篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 6篇 |
排序方式: 共有409条查询结果,搜索用时 15 毫秒
41.
DD Cohen C Voss MJD Taylor DM Stasinopoulos A Delextrat GRH Sandercock 《Acta paediatrica (Oslo, Norway : 1992)》2010,99(7):1065-1072
Aims: The aims of this study were to evaluate patterns of handgrip (HG) strength in relation to gender and age in English schoolchildren and to compare this with existing data and produce reference data for this population. Methods: The HG of 7147 English schoolchildren (3773 boys and 3374 girls) aged 10–15.9 years was measured using a portable Takei handgrip dynamometer (Takei Scientific Instruments Co. Ltd, Tokyo, Japan). Centile data were produced using the Generalized Additive Models for Location, Scale and Shape. Z‐scores were generated using existing data for European children. Age and gender interactions were analysed using analysis of covariance. Results: In boys and girls, significant increases in HG were found between every age‐group (p < 0.001). Boys were significantly stronger than girls at every age (p < 0.001) and the boys’ age‐related increase was significantly greater than the girls’ (p < 0.001). Conclusion: This study provides reference data for handgrip strength in English schoolchildren. Handgrip strength in English children is broadly similar to existing European data, after adjusting for mass and stature. These data could be used for clinical or athletic screening of low and high strength in this population. 相似文献
42.
43.
44.
GY MINUK N ASSY LX DING T GAUTHIER DD PASHNIAK 《Journal of gastroenterology and hepatology》1997,12(1):54-57
Quinolone antibiotics inhibit eukaryotic as well as prokaryotic cell growth and protein synthesis. To determine whether these properties adversely affect hepatic growth and recovery following surgical resection, five groups of healthy, adult male rats (n = 7–8/group) were treated for 10 days with equal volumes of either ofloxacin (50 mg/kg), fleroxacin (25mg/kg), ciprofloxacin (25 mg/kg), norfloxacin (15mg/kg) or sterile saline (controls) prior to 70% partial hepatectomy (PH) and daily thereafter until death. Restituted liver mass, DNA and protein synthesis rates were determined at 24, 48 and 72 h PH. The results of the study revealed that all parameters of hepatic regeneration were similar in the five study groups at each time interval. To ensure that an effect on hepatic regeneration was not dose-dependent, additional experiments were performed where 1, 10 and 100 mg/kg ciprofloxacin was administered and DNA synthesis was measured 24 h post-PH. Once again, the results were similar to sterile saline-treated controls. These findings suggest that the quinolone antibiotics are unlikely to have an adverse effect on hepatic recovery following surgical resection of the liver and are safe to use in that setting. 相似文献
45.
46.
H Yalcin DD Balci E Ucar N Ozcelik C Tasci†† E Seyfeli F Akgul F Yalcin 《Journal of the European Academy of Dermatology and Venereology》2009,23(7):798-802
Background Psoriasis is associated with a premature atherosclerosis due to the chronic inflammatory process. To evaluate the effect of disease process on myocardial perfusion, we planned to perform 99mTc-MIBI myocardial perfusion single photon emission computed tomography (SPECT) in patients with psoriasis.
Methods The study group consisted of 28 psoriasis patients (17 men, 11 women), aged 18-76 years, and mean age 41.2 ± 14.1 years. The patients were selected among those who were older than 18 years and longer than 10 years of disease duration with more than two times of systemic treatment. All patients underwent 99mTc-MIBI myocardial perfusion SPECT with the same day protocol.
Results We detected various risk factors including smoking habits in 7, family history of cardiovascular disease in 4, hypertension in 1, hyperlipidemia in 9 patients. We completed myocardial perfusion SPECT for each patient and found normal perfusion pattern in SPECT images.
Conclusion We detected that myocardial perfusion is preserved in the patients with psoriasis. The majority of acute heart attacks are caused by noncritical coronary stenosis and this may be an explanation for increased cardiovascular risk in these patients despite normal coronary perfusion. 相似文献
Methods The study group consisted of 28 psoriasis patients (17 men, 11 women), aged 18-76 years, and mean age 41.2 ± 14.1 years. The patients were selected among those who were older than 18 years and longer than 10 years of disease duration with more than two times of systemic treatment. All patients underwent 99mTc-MIBI myocardial perfusion SPECT with the same day protocol.
Results We detected various risk factors including smoking habits in 7, family history of cardiovascular disease in 4, hypertension in 1, hyperlipidemia in 9 patients. We completed myocardial perfusion SPECT for each patient and found normal perfusion pattern in SPECT images.
Conclusion We detected that myocardial perfusion is preserved in the patients with psoriasis. The majority of acute heart attacks are caused by noncritical coronary stenosis and this may be an explanation for increased cardiovascular risk in these patients despite normal coronary perfusion. 相似文献
47.
48.
Factor V and factor VIII are homologous cofactors in the blood coagulation cascade that have the domain structure A1-A2-B-A3-C1-C2, of which the B domain has extensively diverged. In transfected COS-1 monkey cells, expression of factor VIII is approximately 10-fold less efficient than that of factor V, primarily because of inefficient protein secretion and, to a lesser extent, reduced mRNA expression. To study the functional significance and effect of the B domain on expression and activity, chimeric cDNAs were constructed in which the B domains of factor V and factor VIII were exchanged. Expression of a factor VIII chimera harboring the B-domain of factor V yielded a fully functional factor VIII molecule that was expressed twofold more efficiently than wild-type factor VIII because of increased mRNA expression. Thus, sequences within the factor VIII B domain were not responsible for the inefficient secretion of factor VIII compared with factor V. Expression of a factor V chimera harboring the B domain of factor VIII was slightly reduced compared with wild-type factor V, although the secreted molecule had significantly reduced procoagulant activity correlating with dissociated heavy and light chains and resistance to thrombin activation. Interestingly, the factor V chimera containing the factor VIII B domain was efficiently activated by Russell's viper venum (RVV). A factor V B domain deletion (residues 710- 1545) molecule also exhibited significantly reduced procoagulant activity caused by resistance to thrombin cleavage and activation, although this molecule was activatable by RVV. These results show that, in contrast to factor VIII, thrombin activation of factor V requires sequences within the B domain. In addition, thrombin activation of factor V occurs through a different mechanism than activation by RVV. 相似文献
49.
Neutrophils have been implicated in the pathogenesis of several inflammatory lung disorders including asthma, emphysema, and adult respiratory distress syndrome. The precursors of these destructive cells are thought to be marginating neutrophils that, although intravascular, remain intimately associated with endothelium, resisting the shearing forces of flowing blood. The purposes of this study were (1) to examine a method for quantitating marginating lung neutrophils, (2) to assess the adherence of marginating neutrophils to normal lung endothelium, and (3) to determine the reversibility of neutrophil-endothelial cell adherence. Rats were anesthetized and ventilated, and their lungs were exposed through a median sternotomy. The left lung was tied off with blood in situ and the right lung was perfused intraarterially with colloid for 2 minutes. In separate experiments, both left and right lungs were perfused intraarterially with colloid for 25 minutes. Myeloperoxidase, a neutrophil granule enzyme, was related to lung neutrophils. Dithionite-sensitive optical density (DSOD) was related to lung hemoglobin. Marginating lung neutrophils were quantitated by measuring the peroxidase activity of normal blood-perfused lung (myeloperoxidase assay) and subtracting from it the fraction of activity corresponding to the lung blood content (DSOD). The marginating neutrophil pool was identified by 2.1 units myeloperoxidase (5 x 10(6) neutrophils) per gm wet lung. Although the marginating pool was depleted by 54% during 2 minutes of lung colloid perfusion, lung erythrocytes (DSOD) were decreased by a significantly greater 93% (p less than 0.05). Lungs perfused with colloid for 25 minutes had negligible remaining myeloperoxidase activity. We conclude that (1) marginating lung neutrophils can be quantitated with the myeloperoxidase and DSOD assays, (2) marginating neutrophils are relatively adherent to normal lung endothelium compared with intravascular erythrocytes, and (3) the adherence of marginating neutrophils is fully reversible. 相似文献
50.
Duodenal hematoma: the ring sign in MR imaging 总被引:1,自引:1,他引:0
Proper management of duodenal hematoma requires that an accurate diagnosis be made using noninvasive radiological methods. Conventional imaging may be nonspecific if there is no history of trauma or coagulopathy. Two cases of duodenal hematoma that were imaged by magnetic resonance (MR) and computed tomography (CT) are described. In both cases the hematoma had a well-defined concentric ring configuration on MR images, a finding which helped establish the diagnosis. MR imaging may provide tissue-specific characterization of duodenal hematomas. 相似文献