全文获取类型
收费全文 | 1380篇 |
免费 | 62篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 64篇 |
妇产科学 | 22篇 |
基础医学 | 134篇 |
口腔科学 | 27篇 |
临床医学 | 123篇 |
内科学 | 381篇 |
皮肤病学 | 110篇 |
神经病学 | 36篇 |
特种医学 | 207篇 |
外科学 | 126篇 |
综合类 | 29篇 |
一般理论 | 1篇 |
预防医学 | 79篇 |
眼科学 | 6篇 |
药学 | 51篇 |
中国医学 | 3篇 |
肿瘤学 | 50篇 |
出版年
2020年 | 7篇 |
2019年 | 9篇 |
2018年 | 7篇 |
2017年 | 14篇 |
2016年 | 19篇 |
2015年 | 23篇 |
2014年 | 29篇 |
2013年 | 71篇 |
2012年 | 19篇 |
2011年 | 16篇 |
2010年 | 52篇 |
2009年 | 60篇 |
2008年 | 24篇 |
2007年 | 35篇 |
2006年 | 28篇 |
2005年 | 35篇 |
2004年 | 18篇 |
2003年 | 16篇 |
2002年 | 25篇 |
2001年 | 23篇 |
2000年 | 16篇 |
1999年 | 26篇 |
1998年 | 84篇 |
1997年 | 72篇 |
1996年 | 78篇 |
1995年 | 50篇 |
1994年 | 63篇 |
1993年 | 52篇 |
1992年 | 15篇 |
1991年 | 16篇 |
1990年 | 22篇 |
1989年 | 43篇 |
1988年 | 42篇 |
1987年 | 34篇 |
1986年 | 29篇 |
1985年 | 26篇 |
1984年 | 23篇 |
1983年 | 12篇 |
1982年 | 21篇 |
1981年 | 19篇 |
1980年 | 13篇 |
1979年 | 17篇 |
1978年 | 14篇 |
1977年 | 16篇 |
1976年 | 16篇 |
1975年 | 12篇 |
1973年 | 14篇 |
1972年 | 9篇 |
1971年 | 7篇 |
1957年 | 7篇 |
排序方式: 共有1475条查询结果,搜索用时 15 毫秒
991.
Depression leads to a poorer quality of life (QOL) which is a determinant of healthy ageing. Cost-effective solutions for enhancing QOL in the older population are much needed in China, with its rapidly ageing population. We conducted a randomized controlled trial involving 112 community-dwelling older participants with mild to moderate depression, to evaluate the effect of Tai Chi with music on QOL (57 in intervention group, 55 in control group). WHO Quality of Life-BREF was used to measure QOL at baseline and at every month for three months. Following the adjustments for sociodemographic data, the effect of intervention on QOL was assured (F = 25.145, P < 0.001, ηp2= 0.435, F = 18.696, P < 0.001, ηp2= 0.364, F = 17.473, P< 0.001, ηp2= 0.348, and F = 29.576, P < 0.001, ηp2= 0.475 for physical, psychological, social, and environment domains respectively). This intervention represents an economically viable solution to better QOL and healthy ageing in a highly populous developing nation. 相似文献
992.
993.
目的:建立上颈椎三维有限元模型,以期应用于临床相关的生物力学实验研究中。方法:实验于2005-05/2006-01在南方医科大学解剖及生物力学实验室完成。选取2例自愿参与实验的健康青年男性,均经医院伦理委员会批准,且受试者知情同意。复习病史并行X射线平片检查排除枕颈部疾患。通过对正常人的CT薄层扫描获得原始DICOM图像数据,采用CAD数据处理技术进行计算机三维重建,改良建立的模型导入ANSYS9.0软件进行计算机模拟仿真生物力学研究。结果:所建模型外观清晰逼真,几何相似性好。所建的上颈椎有限元模型能够通过验证,与体外生物力学实验结果基本吻合,可进一步行各种上颈椎有限元力学分析。结论:为临床对枕颈交界区有限元三维模型的建立提供了一种便捷而精确的方法,对计算机分析及研究该模型局部结构在各种受力情况下的生物力学表现创造条件。 相似文献
994.
Unilateral Stimulation of Prelemniscal Radiations for the Treatment of Acral Symptoms of Parkinson's Disease: Long‐Term Results 下载免费PDF全文
995.
STUDY OBJECTIVES: To describe the outcome of patients with status asthmaticus (SA) treated in a medical ICU with positive pressure ventilation (PPV), and to identify those factors associated with increased length of hospital stay. DESIGN: Retrospective chart review. SETTING: University-based hospital in Chicago, IL. PATIENTS: All patients admitted with SA and treated with PPV over a 5-year period. RESULTS: The first ICU admission for each of 78 patients was analyzed. Fifty-six patients underwent endotracheal intubation (ETI) during the hospitalization, while 22 patients were treated with noninvasive PPV alone. Three patients died. The median hospital length of stay was 5.5 days. Cox regression analysis revealed the following factors to be independently associated with increased length of hospital stay: female gender (p < 0.01), ETI (p < 0.01), the administration of neuromuscular blockers for > 24 h (p < 0.01), inhaled corticosteroid use prior to ICU admission (p = 0.01), and increasing APACHE (acute physiology and chronic health evaluation) II score (p < 0.01). CONCLUSIONS: This study suggests that while the mortality associated with SA treated with contemporary methods of PPV is low, certain factors, including female gender, ETI, and the prolonged use of neuromuscular blockade, are associated with an increased length of hospital stay. The development of respiratory failure despite preadmission use of inhaled corticosteroids is also associated with prolonged hospitalization. 相似文献
996.
Turner W. Rentz Jr LCDR MC USNR C. Stratton Warden LT MC USNR F. J. Garcia LCDR MC USNR Dr. Paul J. Kovalcik CDR MC USNR 《Digestive diseases and sciences》1979,24(4):316-318
Summary A 17-year-old male with Crohn's disease involving the terminal ileum and cecum developed an umbilical fistula in the absence of previous surgery. While on intravenous hyperalimentation he developed an enterovesical fistula and was successfully treated by surgical resection. This combination of an enterovesical and umbilical fistula has not been previously reported. An aggressive approach to treatment is suggested. 相似文献
997.
Stromal cells from human long-term marrow cultures are mesenchymal cells that differentiate following a vascular smooth muscle differentiation pathway 总被引:20,自引:2,他引:20
In human long-term marrow cultures connective tissue-forming stromal cells are an essential cellular component of the adherent layer where granulomonocytic progenitors are generated from week 2 onward. We have previously found that most stromal cells in confluent cultures were stained by monoclonal antibodies directed against smooth muscle- specific actin isoforms. The present study was carried out to evaluate the time course of alpha-SM-positive stromal cells and to search for other cytoskeletal proteins specific for smooth muscle cells. It was found that the expression of alpha-SM in stromal cells was time dependent. Most of the adherent spindle-shaped, vimentin-positive stromal cells observed during the first 2 weeks of culture were alpha- SM negative. On the contrary, from week 3 to week 7, most interdigitated stromal cells contained stress fibers whose backbone was made of alpha-SM-positive microfilaments. In addition, in confluent cultures, other proteins specific for smooth muscle were detected: metavinculin, h-caldesmon, smooth muscle myosin heavy chains, and calponin. This study confirms the similarity between stromal cells and smooth muscle cells. Moreover, our results reveal that cells in vivo with the phenotype closest to that of stromal cells are immature fetal smooth muscle cells and subendothelial intimal smooth muscle cells; a cell subset with limited development following birth but extensively recruited in atherosclerotic lesions. Stromal cells very probably derive from mesenchymal cells that differentiate along this distinctive vascular smooth muscle cell pathway. In humans, this differentiation seems crucial for the maintenance of granulomonopoiesis. These in vitro studies were completed by examination of trephine bone marrow biopsies from adults without hematologic abnormalities. These studies revealed the presence of alpha-SM-positive cells at diverse locations: vascular smooth muscle cells in the media of arteries and arterioles, pericytes lining capillaries, myoid cells lining sinuses at the abluminal side of endothelial cells or found within the hematopoietic logettes, and endosteal cells lining bone trabeculae. More or less mature cells of the granulocytic series were in intimate contact with the thin cytoplasmic extensions of myoid cells. Myoid cells may be the in vivo counterpart of stromal cells with the above-described vascular smooth muscle phenotype. 相似文献
998.
Platelet transfusions from donors matched for cross-reactive antigens have been shown to be effective in providing hemostasis in alloimmunized thrombocytopenic patients. A significant number of these transfusions, however, fail to provide posttransfusion platelet recoveries. We investigated incompatibility in the Bw4/bw6 system as a possible explanation for these failures. The Bw4/Bw6 system is a biallelic antigen system closely associated with HLA-B. HLA-B locus antigens that are cross-reactive frequently differ in their Bw4/Bw6 specificity. Posttransfusion platelet recoveries from 21 alloimmunized thrombocytopenic patients homozygous for Bw4 or Bw6 and transfused with both Bw4/Bw6 compatible and incompatible platelets were analyzed. The mean 1-hr posttransfusion recovery was 84% following Bw4/Bw6-compatible platelets versus 52% with Bw4/Bw6-incompatible platelets (p less than 0.02). Twenty-four hours following transfusion, mean recoveries were 44% and 24%, respectively, (p less than 0.01). A subgroup of 8 patients (38%) was identified who had markedly lower responses following Bw4/Bw6- incompatible transfusions as compared to Bw4/Bw6-compatible transfusions (mean recoveries: 1 hr--compatible 100%, incompatible 27%, p less than 0.001; 24 hr--compatible 45%, incompatible 7%, p less than 0.01). These data suggest that the Bw4/Bw6 antigen system has clinical significance for some patients requiring platelet transfusion therapy and, when appropriate, should be considered in the selection of donors. 相似文献
999.
We evaluated neutrophil adhesive function in patients undergoing chronic hemodialysis using either prostacyclin or heparin as antithrombotic agents. Patients underwent successive hemodialyses with prostacyclin (4 ng/kg/min) and heparin. There were no significant differences noted in neutrophil adhesive function during either dialysis: transient neutropenia developed in each case; impaired neutrophil adhesiveness to plastic developed during both dialyses; neutrophil aggregation was diminished when compared to predialysis responses during both dialyses. Furthermore, the number of circulating Fc-receptor-bearing neutrophils fell significantly during both prostacyclin and heparin hemodialysis. Our study demonstrates that substitution of prostacyclin for heparin in doses that do not cause hypotension, does not prevent neutropenia or alter the diminished neutrophil adhesiveness that occurs during heparin hemodialysis. 相似文献
1000.