全文获取类型
收费全文 | 2409篇 |
免费 | 177篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 34篇 |
儿科学 | 150篇 |
妇产科学 | 95篇 |
基础医学 | 295篇 |
口腔科学 | 31篇 |
临床医学 | 298篇 |
内科学 | 592篇 |
皮肤病学 | 19篇 |
神经病学 | 162篇 |
特种医学 | 53篇 |
外科学 | 335篇 |
综合类 | 25篇 |
一般理论 | 6篇 |
预防医学 | 118篇 |
眼科学 | 63篇 |
药学 | 192篇 |
中国医学 | 7篇 |
肿瘤学 | 121篇 |
出版年
2023年 | 7篇 |
2022年 | 22篇 |
2021年 | 52篇 |
2020年 | 50篇 |
2019年 | 40篇 |
2018年 | 48篇 |
2017年 | 33篇 |
2016年 | 36篇 |
2015年 | 51篇 |
2014年 | 85篇 |
2013年 | 105篇 |
2012年 | 153篇 |
2011年 | 156篇 |
2010年 | 87篇 |
2009年 | 77篇 |
2008年 | 152篇 |
2007年 | 163篇 |
2006年 | 147篇 |
2005年 | 180篇 |
2004年 | 159篇 |
2003年 | 152篇 |
2002年 | 137篇 |
2001年 | 37篇 |
2000年 | 23篇 |
1999年 | 39篇 |
1998年 | 41篇 |
1997年 | 22篇 |
1996年 | 18篇 |
1995年 | 12篇 |
1994年 | 16篇 |
1993年 | 17篇 |
1992年 | 22篇 |
1991年 | 13篇 |
1990年 | 11篇 |
1989年 | 11篇 |
1988年 | 15篇 |
1987年 | 17篇 |
1986年 | 19篇 |
1985年 | 28篇 |
1984年 | 18篇 |
1983年 | 9篇 |
1982年 | 18篇 |
1981年 | 14篇 |
1980年 | 7篇 |
1979年 | 11篇 |
1978年 | 11篇 |
1973年 | 5篇 |
1972年 | 4篇 |
1913年 | 4篇 |
1841年 | 4篇 |
排序方式: 共有2596条查询结果,搜索用时 78 毫秒
1.
Gil Bolotin Frederik H. van der Veen Roberto Lorusso Tamir Wolf Robert Sachner Rona Shofti Jan J. Shreuder Gideon Uretzky 《European journal of cardio-thoracic surgery》2002,21(6):975-980
Objective: Descending and ascending aortomyoplasty are two surgical procedures intended to induce hemodynamic benefits similar to those of the intra-aortic-balloon-pump (IABP). To date, there have been no studies comparing the two surgical techniques. The objective of this study was to compare coronary blood flow augmentation and afterload reduction as produced by descending and ascending aortomyoplasty counterpulsation Methods: Twenty-two mongrel dogs (18–35 kg) underwent IABP application (n=7), descending (n=8), or ascending (n=7) aortomyoplasty. Left anterior descending (LAD) coronary artery blood flow was measured using a Transonic Doppler flow probe. Left ventricular pressure as well as aortic pressures proximal and distal to either the aortomyoplasty site or the IABP position were monitored continuously. Results: Descending aortomyoplasty induced higher elevation in the LAD blood flow during assisted beats (27% from 10.8±4 to 13.8±6 ml/min, P<0.001) than that induced by either ascending aortomyoplasty (19% from 11.7±5 to 14±5 ml/min, P<0.001) or IABP counterpulsation (18% from 8.6±3 to 10.2±4 ml/min, P<0.001). Conversely, while ascending aortomyoplasty reduced the left ventricular end-diastolic pressure by 16% (from 60±18 to 50±22 mmHg, P<0.001), similar to the 16% after load reduction achieved by the IABP counterpulsation, descending aortomyoplasty failed to induce afterload reduction. Conclusions: Descending aortomyoplasty produces higher coronary blood flow augmentation than either ascending aortomyoplasty or IABP. However, afterload reduction comparable to that achieved by IABP was observed only with ascending aortomyoplasty and not with descending aortomyoplasty. 相似文献
2.
Safety of gadolinium during pregnancy 总被引:4,自引:0,他引:4
3.
4.
Eliezer Lahat MD Joseph Barr MD Baruch Klin MD Zvi Dvir MD Tzvy Bistrizer MD Gideon Eshel MD 《Pediatric neurology》1996,15(4):299-301
Mild head injuries are very common among young children. Often, these injuries are followed by a variety of subjective complaints termed posttraumatic syndrome. Posturography (balance test) was performed immediately after the trauma in 21 children who had sustained mild head injury. Significant difference in performance was observed in head-injured children in all subparts of the test as compared with a control group. We conclude that posturography may serve as a simple cost-effective method in qualifying the posttraumatic imbalance. 相似文献
5.
Gideon Fait MD Dan Grisaru MD Michael Shenhav MD Michael J. Kupfermine MD Joseph B. Lessing MD M. Reuben Peyser MD Ariel Jaffa MD 《The Australian & New Zealand journal of obstetrics & gynaecology》1997,37(2):174-176
Summary: One hundred five women with a documented pregnancy of 41 weeks' gestation or more, admitted for induction of labour by balloon catheter with extra-amniotic saline instillation, were retrospectively compared to 196 women admitted in spontaneous labour at the same gestational age, with regard to mode of delivery. The success rate of the induction group was 97.1%. The mode of delivery did not differ significantly between the 2 groups. The Caesarean section rates were 11.4% in the induction group versus 9.7% in the spontaneous group. The mode of delivery after induction of labour by balloon catheter with extra-amniotic saline instillation and simultaneously commenced intravenous oxytocin infusion, in pregnancies of 41 weeks or more, is similar to that of spontaneous deliveries at the same gestational age. 相似文献
6.
OBJECTIVE: To study microvasculature and hemorrhage within the arterial wall. DESIGN: Human autopsy specimens of the arch of the aorta, the carotid, brachiocephalic, subclavian and coronary arteries perfused with liquid casting material and maintained at physiological pressure until the material had set. MAIN RESULTS: Evidence of dense microvasculature and other phenomena which have the morphological appearance of 'hemorrhage' within the arterial wall, coupled with calcified matter and other impressions made on the cast by atherosclerotic plaques. CONCLUSIONS: The findings lend support to suggestions in the literature that neovascularization may play a role in the pathogenesis of coronary atherosclerosis and its sequelae, that hemorrhage into the intima may be due to rupture of capillaries which are derived from the coronary lumen, and that an increase in microvasculature occurs in the immediate vicinity of localized atherosclerotic lesions. 相似文献
7.
8.
Efrat Rorman Chen Stein Zamir Irena Rilkis Hilla Ben-David 《Reproductive toxicology (Elmsford, N.Y.)》2006,21(4):458
Toxoplasma gondii (T. gondii) is the cause of toxoplasmosis. Primary infection in an immunocompetent person is usually asymptomatic. Serological surveys demonstrate that world-wide exposure to T. gondii is high (30% in US and 50–80% in Europe). Vertical transmission from a recently infected pregnant woman to her fetus may lead to congenital toxoplasmosis. The risk of such transmission increases as primary maternal infection occurs later in pregnancy. However, consequences for the fetus are more severe with transmission closer to conception. The timing of maternal primary infection is, therefore, critically linked to the clinical manifestations of the infection. Fetal infection may result in natural abortion. Often, no apparent symptoms are observed at birth and complications develop only later in life. The laboratory methods of assessing fetal risk of T. gondii infection are serology and direct tests.Screening programs for women at childbearing age or of the newborn, as well as education of the public regarding infection prevention, proved to be cost-effective and reduce the rate of infection.The impact of antiparasytic therapy on vertical transmission from mother to fetus is still controversial. However, specific therapy is recommended to be initiated as soon as infection is diagnosed. 相似文献
9.
Gal Ophir Ninette Amariglio Jasmine Jacob-Hirsch Ran Elkon Gideon Rechavi Daniel M. Michaelson 《Neurobiology of disease》2005,20(3):519-718
Apolipoprotein E4 (apoE4), the major genetic risk factor of Alzheimer's disease (AD), is associated with enhanced brain inflammation. Genome-wide gene expression profiling was employed to study the effects of apoE genotype on hippocampal gene expression in LPS-treated mice, transgenic for either apoE4 or the AD benign allele, apoE3. This revealed that the expression of inflammation-related genes following intracerebroventricular injection of LPS was significantly higher and more prolonged in apoE4 than in apoE3 transgenic mice. Clustering analysis revealed gene clusters which responded differently in apoE4 and apoE3 mice and were significantly enriched in NF-kappaB response elements. Direct measurement of NF-kappaB-regulated genes revealed that their extent of activation was greater in the apoE4 mice. Immunohistochemistry experiments revealed that microglial and NF-kappaB activation were more pronounced in apoE4 than in apoE3 mice. These findings suggest that the increased brain inflammation in apoE4 mice is related to disregulation of NF-kappaB signaling pathway. 相似文献
10.
Effect of the glucocorticoid receptor antagonist RU 38486 on muscle protein breakdown in sepsis 总被引:4,自引:0,他引:4
The role of glucocorticoids in muscle catabolism during sepsis was tested with the glucocorticoid receptor antagonist RU 38486. Sepsis was induced in male Sprague-Dawley rats (40 to 60 gm) by cecal ligation and puncture (CLP). Other animals underwent sham operation. Two hours before CLP or sham operation, rats received RU 38486 (5 mg/kg) or a corresponding volume of vehicle by gavage. Sixteen hours after CLP or sham operation, protein synthesis rate was determined by measuring incorporation of 14C-phenylalanine into protein in incubated extensor digitorum longus muscles. Total and myofibrillar protein breakdown rates were determined by measuring net release of tyrosine and 3-methylhistidine, respectively. The protein synthesis rate was approximately 30% lower in rats with sepsis than in sham operated rats and was not affected by treatment with RU 38486. The total protein breakdown rate was increased by approximately 70% and myofibrillar protein degradation was increased more than fivefold in muscle from rats with sepsis. Treatment with RU 38486 resulted in a 28% reduction of total and a 44% reduction of myofibrillar protein breakdown in rats with sepsis but did not affect proteolysis in muscle from sham-operated animals. The results support a role of glucocorticoids in accelerated muscle proteolysis during sepsis. It is not clear whether glucocorticoids are the only required mediator or they interact with other substances to induce muscle protein breakdown during sepsis. 相似文献