全文获取类型
收费全文 | 8064篇 |
免费 | 427篇 |
国内免费 | 45篇 |
专业分类
耳鼻咽喉 | 27篇 |
儿科学 | 122篇 |
妇产科学 | 106篇 |
基础医学 | 1256篇 |
口腔科学 | 270篇 |
临床医学 | 885篇 |
内科学 | 1649篇 |
皮肤病学 | 309篇 |
神经病学 | 1010篇 |
特种医学 | 500篇 |
外科学 | 908篇 |
综合类 | 48篇 |
一般理论 | 4篇 |
预防医学 | 342篇 |
眼科学 | 100篇 |
药学 | 469篇 |
中国医学 | 16篇 |
肿瘤学 | 515篇 |
出版年
2023年 | 42篇 |
2022年 | 71篇 |
2021年 | 124篇 |
2020年 | 81篇 |
2019年 | 103篇 |
2018年 | 137篇 |
2017年 | 117篇 |
2016年 | 105篇 |
2015年 | 175篇 |
2014年 | 234篇 |
2013年 | 345篇 |
2012年 | 498篇 |
2011年 | 542篇 |
2010年 | 337篇 |
2009年 | 322篇 |
2008年 | 540篇 |
2007年 | 537篇 |
2006年 | 567篇 |
2005年 | 583篇 |
2004年 | 506篇 |
2003年 | 505篇 |
2002年 | 486篇 |
2001年 | 106篇 |
2000年 | 62篇 |
1999年 | 92篇 |
1998年 | 127篇 |
1997年 | 103篇 |
1996年 | 89篇 |
1995年 | 72篇 |
1994年 | 58篇 |
1993年 | 58篇 |
1992年 | 40篇 |
1991年 | 37篇 |
1990年 | 22篇 |
1989年 | 23篇 |
1988年 | 28篇 |
1987年 | 23篇 |
1986年 | 20篇 |
1985年 | 31篇 |
1984年 | 20篇 |
1983年 | 19篇 |
1982年 | 44篇 |
1981年 | 30篇 |
1980年 | 20篇 |
1978年 | 26篇 |
1977年 | 19篇 |
1973年 | 17篇 |
1970年 | 17篇 |
1913年 | 22篇 |
1912年 | 18篇 |
排序方式: 共有8536条查询结果,搜索用时 15 毫秒
21.
The main mechanism of possible cardioprotection by estrogens appears to be a direct effect on the vasculature, resulting in an improvement of endothelial function and inhibition of atherogenesis. Numerous observational and experimental studies have demonstrated a positive correlation between estrogens and various biochemical markers surrogating direct vascular effects. In general, most markers are influenced in a similar way by oral and transdermal hormone therapy, although oral therapy may have a faster and more pronounced effect. The main difference between oral and transdermal administration may be confined to markers that are mainly or exclusively produced in the liver. Clinical studies demonstrate that progestogen addition can have an impact on the beneficial estrogen-induced changes of biochemical markers. Concerning the effects of tibolone, inconsistent data have been found. Overall, tibolone-induced beneficial changes on the various biochemical markers appear to be less marked compared with those of hormone therapy. The few data available on the direct effects of androgens on the vascular wall indicate a less favorable action of androgens on biochemical markers than of estrogens. The practical relevance of marker measurements is currently under discussion. Although evidence strongly supports some of these markers as predictors of acute events, it remains to be established whether modifying circulating levels of these markers will influence outcomes. 相似文献
22.
23.
Wilson's disease tremor is associated with magnetic resonance imaging lesions in basal ganglia structures. 总被引:1,自引:0,他引:1
Martin Südmeyer Andreas Saleh Lars Wojtecki Mathias Cohnen Joachim Gross Markus Ploner Harald Hefter Lars Timmermann Alfons Schnitzler 《Movement disorders》2006,21(12):2134-2139
Wilson's disease (WD) is an inherited disorder of copper metabolism yielding marked motor deficits, including a severely disabling tremor. As a structural correlate of the disease, a variety of cerebral abnormalities has been revealed. However, the relationship between motor deficits and cerebral lesions has remained largely unknown. Here, we investigated correlation between WD tremor and cerebral magnetic resonance imaging (MRI) findings. Cerebral MRI abnormalities in 6 symptomatic WD patients were compared to findings in 6 asymptomatic WD patients and 10 healthy controls. All patients were treated with long-term copper chelating therapy. Motor symptoms including tremor were determined by Unified Parkinson's Disease Rating Scale Part III (UPDRS-III). MRI findings in symptomatic WD patients revealed significant symmetric T2*-weighted hypointense signal alterations of globus pallidus, head of the caudate nucleus, and substantia nigra. In contrast, MRI of asymptomatic WD patients did not differ from healthy controls. Correlation analysis revealed a significant positive correlation between MRI basal ganglia lesions and UPDRS action tremor score. Our results demonstrate for the first time that Wilson's disease tremor is associated with lesions of the globus pallidus, the head of the caudate nucleus, and the substantia nigra. 相似文献
24.
Elisabeth M Weiss Edith Stadelmann Christian G Kohler Colleen M Brensinger Karen A Nolan Herbert Oberacher Walther Parson Florian Pitterl Harald Niederst?tter Georg Kemmler Hartmann Hinterhuber Josef Marksteiner 《Journal of the International Neuropsychological Society》2007,13(5):881-887
The catechol-O-methyltransferase (COMT) Val158Met polymorphism modulates executive functions and working memory and recent neuroimaging studies implicate an association with emotional processing. We examined the relationship between the COMT Val158Met polymorphism and facial emotion recognition and differentiation in 100 healthy individuals. Compared to Met homozygosity, Val homozygosity was associated with better and faster recognition of negative facial expressions such as anger and sad. Our study provides evidence for a possible influence of the COMT polymorphism on emotion recognition abilities in healthy subjects. Additional research is needed to further define the neurocognitive phenotypes associated with COMT polymorphisms. 相似文献
25.
A 54-year old man presented with multiple pulmonary emboli and an incidental finding of a huge left ventricular thrombus. Transthoracic echo images demonstrated a globally dilated heart with very poor left ventricular function. It was elected to manage the patient medically, and he was commenced on warfarin therapy, resulting in completed resolution of the thrombus over 10 weeks. No underlying cause was found and he did not experience any further embolic events. This illustrates a rare case of a large ventricular thrombus in a patient with no underlying risk factors. 相似文献
26.
Thomas W Stief Ola Ijagha Bettina Weiste Ileana Herzum Harald Renz Martin Max 《Blood coagulation & fibrinolysis》2007,18(2):179-186
This laboratory study tested new methods to analyze hemostasis alterations in septic patients. Samples of ethylenediamine tetraacetic acid (EDTA) plasma and citrated plasma were collected from 62 patients with clinical diagnosis of sepsis. Additionally, a subset of EDTA-plasma samples from each patient was stabilized 1 + 1 with 2.5 mol/l arginine, pH 8.6, to conserve the real hemostasis activation state. EDTA-arginine plasma, EDTA plasma and citrated plasma samples were tested in duplicate. The patients at admission to the intensive care unit had 36 +/- 26 (normal, 0.8 +/- 0.2) ng/ml global endotoxin reactivity, 188 +/- 66% (normal, 100 +/- 20%) fibrinogen function, 179 +/- 66% (normal, 100 +/- 20%) fibrinogen antigen, 4.0 +/- 3.6 (normal, 0.049 +/- 0.025) microg/ml D-dimer, 313 +/- 307% (normal, 100 +/- 30%) plasmin-antiplasmin complex, 8.7 +/- 11.4 (normal, 1.1 +/- 0.7) U/ml plasminogen activator inhibitor-1, 12.1 +/- 10.5 (normal, 1.3 +/- 0.4) ng/ml thrombin-antithrombin III complex, 173 +/- 62% (normal, 100 +/- 20%) thrombin, 568 +/- 225 (normal, 140 +/- 42) pg/ml tissue factor, and 2.56 +/- 2.48 (normal, 0.19 +/- 0.04) microg/ml soluble intercellular adhesion molecule-1. Endotoxin (lipopolysaccharide and/or beta-glucan) reactivity (EDTA plasma), fibrinogen function + antigen + ratio and plasminogen activator inhibitor-1 (citrated plasma), and D-dimer, soluble intercellular adhesion molecule-1, thrombin activity (EDTA-arginine-stabilized plasma) presented large aberrations in septic patients when compared with normal values and may therefore be particularly interesting as markers of hemostasis alteration. Whether the observed alterations are of clinical significance has to be determined in well defined patient groups. 相似文献
27.
28.
29.
Harald zur Hausen 《Medizinische Klinik》1998,93(2):63-64
Ohne Zusammenfassung 相似文献
30.
Four new findings of the biochemistry and biology of the essential n–6 and n–3 fatty acids have recently been demonstrated. These findings will augment current knowledge as to the role of the essential fatty acids in human health. 相似文献