全文获取类型
收费全文 | 2088篇 |
免费 | 339篇 |
国内免费 | 39篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 117篇 |
妇产科学 | 25篇 |
基础医学 | 187篇 |
口腔科学 | 27篇 |
临床医学 | 327篇 |
内科学 | 634篇 |
皮肤病学 | 62篇 |
神经病学 | 195篇 |
特种医学 | 293篇 |
外科学 | 241篇 |
综合类 | 49篇 |
预防医学 | 93篇 |
眼科学 | 35篇 |
药学 | 96篇 |
中国医学 | 1篇 |
肿瘤学 | 67篇 |
出版年
2023年 | 54篇 |
2022年 | 14篇 |
2021年 | 29篇 |
2020年 | 92篇 |
2019年 | 20篇 |
2018年 | 93篇 |
2017年 | 74篇 |
2016年 | 77篇 |
2015年 | 63篇 |
2014年 | 97篇 |
2013年 | 129篇 |
2012年 | 62篇 |
2011年 | 54篇 |
2010年 | 87篇 |
2009年 | 114篇 |
2008年 | 55篇 |
2007年 | 57篇 |
2006年 | 61篇 |
2005年 | 37篇 |
2004年 | 28篇 |
2003年 | 27篇 |
2002年 | 28篇 |
2001年 | 46篇 |
2000年 | 25篇 |
1999年 | 41篇 |
1998年 | 86篇 |
1997年 | 101篇 |
1996年 | 80篇 |
1995年 | 74篇 |
1994年 | 53篇 |
1993年 | 56篇 |
1992年 | 31篇 |
1991年 | 19篇 |
1990年 | 35篇 |
1989年 | 55篇 |
1988年 | 48篇 |
1987年 | 40篇 |
1986年 | 23篇 |
1985年 | 28篇 |
1984年 | 24篇 |
1983年 | 11篇 |
1982年 | 18篇 |
1981年 | 14篇 |
1980年 | 15篇 |
1979年 | 10篇 |
1978年 | 12篇 |
1977年 | 15篇 |
1976年 | 11篇 |
1975年 | 15篇 |
1957年 | 10篇 |
排序方式: 共有2466条查询结果,搜索用时 15 毫秒
61.
62.
Frank J. Molnar MSc MDCM Sophiya Benjamin MBBS MD Stacey A. Hawkins BA MA CPG PhD Student Melanie Briscoe OT Sabeen Ehsan MBBS MD MHI 《Journal of the American Geriatrics Society》2020,68(10):2207-2213
Every year, millions of patients worldwide undergo cognitive testing. Unfortunately, new barriers to the use of free open access cognitive screening tools have arisen over time, making accessibility of tools unstable. This article is in follow-up to an editorial discussing alternative cognitive screening tools for those who cannot afford the costs of the Mini-Mental State Examination and Montreal Cognitive Assessment (see www.dementiascreen.ca ). The current article outlines an emerging disruptive “free-to-fee” cycle where free open access cognitive screening tools are integrated into clinical practice and guidelines, where fees are then levied for the use of the tools, resulting in clinicians moving on to other tools. This article provides recommendations on means to break this cycle, including the development of tool kits of valid cognitive screening tools that authors have contracted not to charge for (i.e., have agreed to keep free open access). The PRACTICAL.1 Criteria ( PRACTI cing C linician A ccessibility and L ogistical Criteria Version 1 ) are introduced to help clinicians select from validated cognitive screening tools, considering barriers and facilitators, such as whether the cognitive screening tools are easy to score and free of cost. It is suggested that future systematic reviews embed the PRACTICAL.1 criteria, or refined future versions, as part of the standard of review. Methodological issues, the need for open access training to insure proper use of cognitive screening tools, and the need to anticipate growing ethnolinguistic diversity by developing tools that are less sensitive to educational, cultural, and linguistic bias are discussed in this opinion piece. J Am Geriatr Soc 68:2207–2213, 2020. 相似文献
63.
Shalender Bhasin MB BS Thomas G. Travison PhD Todd M. Manini PhD Sheena Patel MS Karol M. Pencina PhD Roger A. Fielding PhD Jay M. Magaziner PhD Anne B. Newman MD MPH Douglas P. Kiel MD Cyrus Cooper DM FMedSci Jack M. Guralnik MD PhD Jane A. Cauley Dr.PH Hidenori Arai MD PhD Brian C. Clark PhD Francesco Landi MD PhD Laura A. Schaap PhD Suzette L. Pereira PhD Daniel Rooks PhD Jean Woo MD PhD Linda J. Woodhouse PhD Ellen Binder MD Todd Brown MD Michelle Shardell PhD Quian-Li Xue PhD Ralph B. DʼAgostino Sr PhD Denise Orwig PhD Greg Gorsicki PhD Rosaly Correa-De-Araujo MD PhD Peggy M. Cawthon PhD 《Journal of the American Geriatrics Society》2020,68(7):1410-1418
64.
Wen?YanEmail author David?Polidori Lynn?Yieh Jianing?Di Xiaodong?Wu Veronica?Moreno Lina?Li Celia?P.?Briscoe Nigel?Shankley G.?Lynis?Dohm Walter?J.?Pories 《Obesity surgery》2014,24(11):1969-1974
Changes in gastrointestinal peptide release may play an important role in improving glucose control and reducing body weight following Roux-en-Y gastric bypass (RYGB), but the impact of low caloric intake on gut peptide release post-surgery has not been well characterized. The purpose of this study was to assess the relationships between low caloric intake and gut peptide release and how they were altered by RYGB. Obese females including ten normoglycemic (ON) and ten with type 2 diabetes mellitus (T2DM) (OD) were studied before, 1 week, and 3 months after RYGB. Nine lean, normoglycemic women were studied for comparison. Subjects were given three separate mixed meal challenges (MMCs; 75, 150, and 300 kcal). Plasma glucagon-like peptide 1 (GLP-1) and peptide YY (PYY) were analyzed. Prior to surgery, only minimal increases in GLP-1 and PYY were observed in response to the MMCs. After surgery, the peak GLP-1 concentration was progressively elevated in response to increasing meal sizes. The meal sizes had a statistically significant impact on elevation of GLP-1 incremental areas under the curve (ΔAUC) in both ON and OD at 1 week and 3 months post-surgery visits (p?<?0.05 for all comparisons). The PYY ?AUC was also significantly increased in a meal size-dependent manner in both ON and OD at both post-surgery visits (p?<?0.05 for all comparisons). Meal sizes as small as 75–300 kcal, which cause minimal stimulation in GLP-1 or PYY release in the subjects before RYGB, are sufficient to provide statistically significant, meal size-dependent increases in the peptides post-RYGB both acutely and after meaningful weight loss occurred. 相似文献
65.
66.
Krishna Prasad Gourav MD DM Subhrashis Guha Niyogi MD Vikram Halder MS Sunder Negi MD DM Avneet Singh MD 《Echocardiography (Mount Kisco, N.Y.)》2020,37(7):1114-1115
Patients with large sub-pulmonic ventricular septal defect (VSD) present early as a results of their complications. Some present late, due to the restriction of VSD by the right coronary cusp (RCC) due to its prolapse. In this report, we present a rare case of sub-pulmonic VSD in a 33-year-old man who developed a sub-pulmonic stenosis due to the prolapse of the RCC into the right ventricular outflow tract. 相似文献
67.
Oleksandr Danylenko MD PhD Elena Surkova MD PhD Roxy Senior MD DM Wei Li MD PhD 《Echocardiography (Mount Kisco, N.Y.)》2020,37(8):1315-1317
Accurate assessment of etiology of mitral regurgitation (MR) is one of the key steps in the decision-making process and further clinical management of patients with severe MR. Our clinical case illustrates the added value of three-dimensional echocardiography (3DE) in assessment of mitral valve morphology and identification of an unexpected mechanism of MR which was not previously diagnosed using conventional echocardiography. 3DE helped to choose appropriate management strategy in this patient. 相似文献
68.
69.
70.
Epstein-Barr virus lymphoproliferation after bone marrow transplantation 总被引:16,自引:7,他引:16
We review 15 cases of secondary B-cell lymphoproliferative disorders that occurred among 2,475 patients who received allogeneic bone marrow transplants (BMTs) at the Fred Hutchinson Cancer Research Center (Seattle) between 1969 and 1987. The histopathologic findings in 14 of the 15 patients spanned a wide spectrum of lymphoproliferative lesions. One patient had features characteristic of angioimmunoblastic lymphadenopathy. Epstein-Barr virus (EBV) genomic sequences were identified by Southern blot analysis in each of the 13 patients evaluated. Ten of the 12 lesions evaluated originated in donor cells. In two patients, who had mixed chimerism after transplantation, the lesions originated in host cells. The combined evidence from immunoglobulin light chain staining and the analysis of immunoglobulin heavy chain gene rearrangement indicated that the lesions in most patients represented polyclonal proliferations that gave rise to clonal subpopulations. The results indicate an overall actuarial incidence of 0.6% for this complication in BMT recipients. Anti-CD3 monoclonal antibody (MoAb) treatment of acute graft-v-host disease (GVHD) and T cell depletion of the donor marrow were statistically significant risk factors, and GVHD appeared to play a contributing role, particularly in the setting of human leukocyte antigen (HLA) disparity. Two patients had no identifiable risk factors. Prophylaxis or treatment with acyclovir had no detectable effect in the patients; all but two died with uncontrolled lymphoproliferation. 相似文献