全文获取类型
收费全文 | 105392篇 |
免费 | 8081篇 |
国内免费 | 384篇 |
专业分类
耳鼻咽喉 | 1169篇 |
儿科学 | 2626篇 |
妇产科学 | 1732篇 |
基础医学 | 15108篇 |
口腔科学 | 2242篇 |
临床医学 | 10840篇 |
内科学 | 22177篇 |
皮肤病学 | 1862篇 |
神经病学 | 11330篇 |
特种医学 | 4319篇 |
外国民族医学 | 6篇 |
外科学 | 14949篇 |
综合类 | 1280篇 |
一般理论 | 75篇 |
预防医学 | 8155篇 |
眼科学 | 1739篇 |
药学 | 7134篇 |
中国医学 | 135篇 |
肿瘤学 | 6979篇 |
出版年
2023年 | 574篇 |
2022年 | 455篇 |
2021年 | 2237篇 |
2020年 | 1407篇 |
2019年 | 2110篇 |
2018年 | 2568篇 |
2017年 | 1894篇 |
2016年 | 2269篇 |
2015年 | 2629篇 |
2014年 | 3433篇 |
2013年 | 4525篇 |
2012年 | 7022篇 |
2011年 | 7079篇 |
2010年 | 4161篇 |
2009年 | 3796篇 |
2008年 | 6196篇 |
2007年 | 6704篇 |
2006年 | 6234篇 |
2005年 | 6142篇 |
2004年 | 5707篇 |
2003年 | 5108篇 |
2002年 | 5067篇 |
2001年 | 1880篇 |
2000年 | 1793篇 |
1999年 | 1676篇 |
1998年 | 1246篇 |
1997年 | 1014篇 |
1996年 | 818篇 |
1995年 | 817篇 |
1994年 | 698篇 |
1993年 | 647篇 |
1992年 | 1150篇 |
1991年 | 1072篇 |
1990年 | 1007篇 |
1989年 | 972篇 |
1988年 | 860篇 |
1987年 | 803篇 |
1986年 | 834篇 |
1985年 | 826篇 |
1984年 | 667篇 |
1983年 | 582篇 |
1982年 | 556篇 |
1981年 | 450篇 |
1980年 | 387篇 |
1979年 | 514篇 |
1978年 | 398篇 |
1977年 | 361篇 |
1975年 | 325篇 |
1974年 | 359篇 |
1973年 | 342篇 |
排序方式: 共有10000条查询结果,搜索用时 392 毫秒
81.
82.
83.
Computer competition analysis of 3H-DHA (3H-dihydroalprenolol, a nonselective beta-adrenergic radioligand) binding in the presence of unlabeled metoprolol (a beta 1-selective antagonist) indicates the existence of both beta 1- and beta 2-adrenergic receptor subtypes in the rat placenta and confirms previous reports that both beta-adrenoceptors are present in adult rat cortex. In the fetal brain (20th day of gestation), however, only beta 1-receptors were detected. Pregnant rats were chronically exposed to methadone from day 7 to day 20 of gestation via implanted osmotic minipumps (6.3-9.0 mg/kg/day). This treatment schedule did not induce a change in the affinity and density of either beta-receptor subtype in the placental, fetal and maternal brain homogenates. The results are discussed in terms of the reported monoaminergic and opiate receptor functional interactions. 相似文献
84.
85.
P M Battey J T Fulenwider R B Smith L G Martin M T Stewart G D Perdue 《Southern medical journal》1987,80(4):479-482
Peripheral arterial thromboembolism and thrombosis of arterial grafts continue to threaten viability of extremities. Percutaneous intra-arterial thrombolysis (IAT) and angiodilatation have afforded limb salvage in some of these patients. Proper patient selection appears to be the hallmark of success with IAT. During a recent three-year period, we used IAT in 32 extremities in 28 patients who had acute arterial insufficiency. Before IAT, 16 extremities were painful at rest, and 16 had incapacitating claudication. The overall success rate was 38%, but some degree of thrombolysis occurred in 88%. Limb salvage was achieved in 27 of 32 extremities (84%). Only five of 17 limbs (29%) with arterial graft thrombosis required no operation or an operation of lesser magnitude than predicted before IAT. Of six extremities with native arterial embolism, four (67%) were completely cleared with IAT. Major complications occurred in eight cases (25%), with two IAT-related deaths (6%). This study suggests that IAT is best reserved for individuals with acute limb ischemia caused by arterial embolus, those whose degree of ischemia would tolerate a 24-hour trial of IAT, and those whose femoral or tibial runoff is not likely to require remedial operation. 相似文献
86.
87.
Scott E Strome Elizabeth Martin Dallas Flies Dianne Khurana Diva Salomao Koji Tamada Andrei I Chapoval Jan L Kasperbauer Kerry D Olsen Lieping Chen 《Otolaryngology--head and neck surgery》2002,126(2):180-187
OBJECTIVES: CD62L was evaluated as a determinant of human pre-effector T cells. STUDY DESIGN AND SETTING: Phenotype and cytokine secretion profiles of CD62L cells were determined based on activation status. RESULTS: CD62L(Low) T cells demonstrated significantly higher secretion of interleukin (IL)-10 and interferon (IFN)-gamma than did CD62L(High) T cells. After activation, the majority of cells expressed high levels of the CD62L surface marker. Postactivation levels of IL-10 production remained elevated or unchanged. In a murine B16 melanoma model, freshly isolated CD62L(Low) tumor draining lymph nodes (TDLN) T cells showed increased secretion of IL-2 and IL-4 but not of IL-10 or IFN-gamma. The surface expression of CD62L and cytokine secretion patterns were maintained after activation with concomitant increases in IL-10. CONCLUSION: Our results provide evidence that CD62L(Low) T cells in TDLNs of progressively growing squamous cell carcinoma of the head and neck differ phenotypically and functionally from those of mouse origin. SIGNIFICANCE: Characterization of this human CD62L(Low) T cell population provides initial insight regarding novel surface markers in TDLN T cells that might correlate with antitumor reactivity. 相似文献
88.
89.
90.
Ronald Martin Jaime Williams Thomas Hadjistavropoulos Heather D Hadjistavropoulos Michael MacLean 《Revue canadienne de recherche en sciences infirmières》2005,37(2):142-164
The literature suggests that pain in the elderly, especially among seniors with dementia, is under-assessed and under-treated.This qualitative study solicited the perspectives of seniors, front-line nursing staff, nursing-home administrators, and informal caregivers of seniors with dementia on the current status of pain assessment and management. The views of these participants complement the research findings reported in the literature. While some of their explanations and potential solutions concerning under-treatment of pain in seniors echo views that have been presented in the literature, the participants also pointed to factors and avenues that have been given less formal consideration (e.g., systemic barriers to effective assessment and treatment of pain).They also highlighted the need for pain-control strategies beyond medication. The implications of these findings are discussed. 相似文献