全文获取类型
收费全文 | 26662篇 |
免费 | 2747篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 239篇 |
儿科学 | 766篇 |
妇产科学 | 683篇 |
基础医学 | 3711篇 |
口腔科学 | 616篇 |
临床医学 | 3140篇 |
内科学 | 5450篇 |
皮肤病学 | 375篇 |
神经病学 | 2573篇 |
特种医学 | 815篇 |
外科学 | 3525篇 |
综合类 | 615篇 |
一般理论 | 16篇 |
预防医学 | 2774篇 |
眼科学 | 481篇 |
药学 | 2336篇 |
1篇 | |
中国医学 | 30篇 |
肿瘤学 | 1287篇 |
出版年
2021年 | 381篇 |
2019年 | 363篇 |
2018年 | 426篇 |
2017年 | 340篇 |
2016年 | 334篇 |
2015年 | 392篇 |
2014年 | 567篇 |
2013年 | 829篇 |
2012年 | 1199篇 |
2011年 | 1229篇 |
2010年 | 708篇 |
2009年 | 593篇 |
2008年 | 1086篇 |
2007年 | 1261篇 |
2006年 | 1159篇 |
2005年 | 1213篇 |
2004年 | 1075篇 |
2003年 | 1149篇 |
2002年 | 1041篇 |
2001年 | 756篇 |
2000年 | 753篇 |
1999年 | 658篇 |
1998年 | 311篇 |
1997年 | 253篇 |
1996年 | 241篇 |
1995年 | 271篇 |
1994年 | 257篇 |
1993年 | 221篇 |
1992年 | 572篇 |
1991年 | 528篇 |
1990年 | 507篇 |
1989年 | 498篇 |
1988年 | 453篇 |
1987年 | 455篇 |
1986年 | 410篇 |
1985年 | 472篇 |
1984年 | 413篇 |
1983年 | 328篇 |
1982年 | 313篇 |
1981年 | 264篇 |
1980年 | 266篇 |
1979年 | 385篇 |
1978年 | 319篇 |
1977年 | 234篇 |
1976年 | 276篇 |
1975年 | 234篇 |
1974年 | 301篇 |
1973年 | 310篇 |
1972年 | 267篇 |
1971年 | 233篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
61.
Anne M Lewis Sheelu Varghese Hui Xu H Richard Alexander 《Journal of translational medicine》2006,4(1):48
The tumor microenvironment consists of tumor, immune, stromal, and inflammatory cells which produce cytokines, growth factors,
and adhesion molecules that promote tumor progression and metastasis. Of particular interest in this setting is interleukin-1
(IL-1), a pleiotropic cytokine with numerous roles in both physiological and pathological states. It is known to be up regulated
in many tumor types and has been implicated as a factor in tumor progression via the expression of metastatic and angiogenic
genes and growth factors. A number of studies have reported that high IL-1 concentrations within the tumor microenvironment
are associated with a more virulent tumor phenotype. Solid tumors in which IL-1 has been shown to be up regulated include
breast, colon, lung, head and neck cancers, and melanomas, and patients with IL-1 producing tumors have generally bad prognoses.
The exact mechanisms by which IL-1 promotes tumor growth remain unclear, though the protein is believed to act via induction
of pro-metastatic genes such as matrix metalloproteinases and through the stimulation of adjacent cells to produce angiogenic
proteins and growth factors such as VEGF, IL-8, IL-6, TNFα, and TGFβ. The IL-1 receptor antagonist (IL-1ra) is a naturally
occurring inhibitor to IL-1 and acts by binding to the IL-1 receptor without activating it. The protein has been shown to
decrease tumor growth, angiogenesis, and metastases in murine xenograft models. Our focus in this review is to summarize the
known data on the role of IL-1 in tumor progression and metastasis and the use of IL-1 inhibition as a novel therapeutic approach
in the treatment of solid organ malignancies. 相似文献
62.
In this study, the cost and health outcomes of a psychiatric consultation letter to primary care physicians caring for a sample of patients diagnosed with somatization disorder, a psychiatric condition associated with multiple, unexplained medical complaints, was assessed. To accommodate the small sample size of 73 patients, outcome effects were calculated using panel analysis. Study patients were randomized to a consultation or noconsultation group, and were repeatedly assessed at equal time intervals. Data were analyzed using parsimonious regression models derived from economic theory. During the 1-year follow-up period, a psychiatric consultation letter was associated with a 12% reduction in health care costs ($455 per patient within first year), with no evidence of deterioration in physical, mental, or general health. Less powerful t-test comparisons between treated and control groups lead to different conclusions. Reasons for these differences are discussed. 相似文献
63.
D E Fleischer F al-Kawas S Benjamin J H Lewis J Kidwell 《Gastrointestinal endoscopy》1992,38(4):411-414
In 1989, the American Society for Gastrointestinal Endoscopy released a quality assurance monograph in which a procedure review process was outlined. The major elements of the program for quality assurance in gastrointestinal endoscopy included: (1) procedure reports, (2) an endoscopic unit record, and (3) a procedure review. This study was designed to use the procedure review process to determine the incidence of complications, to identify quality assurance issues, and to determine whether audits and/or studies would result from this process. To make a meaningful interpretation as to what constitutes an important complication, a classification to define potential problems was established. Using this classification, a complication was identified in 64 of 3287 procedures (1.9%). These complications were discussed in a monthly morbidity and mortality conference. Additionally, 21 quality assurance issues were identified that led to four studies addressing these quality assurance issues. 相似文献
64.
65.
66.
67.
68.
Bruce E. Lewis Colin Sumida Ming H. Hwang Henry S. Loeb 《Catheterization and cardiovascular interventions》1992,26(4):295-299
Four selected cases of emergent IABP insertion in PV patients are presented. After angiographic documentation of critical iliac stenosis, conservative peripheral angioplasty was performed prior to IABP insertion. No patient experienced a peripheral ischemic event associated with IABP use. © 1992 Wiley-Liss, Inc. 相似文献
69.
70.
In the absence of clinically positive regional nodes, any value of prophylactic dissection in malignant melanomas depends on accurate preoperative determination of the pathway of lymphatic drainage. We report on the use of noninvasive radionuclide lymphoscintigraphy in the determination of regional patterns of lymph node drainage in patients with melanomas. Ten patients were studied; treatment was altered by test results in 2. Eleven node groups were excised in 7 patients. There have been no metastatic melanomas found in any nodal basins not detected by lymphoscintigraphy 23 to 42 months after operation. 相似文献