首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   35560篇
  免费   2479篇
  国内免费   125篇
耳鼻咽喉   406篇
儿科学   1093篇
妇产科学   724篇
基础医学   4433篇
口腔科学   746篇
临床医学   4801篇
内科学   6484篇
皮肤病学   507篇
神经病学   3357篇
特种医学   1074篇
外国民族医学   1篇
外科学   4724篇
综合类   402篇
一般理论   35篇
预防医学   3763篇
眼科学   685篇
药学   2442篇
  1篇
中国医学   32篇
肿瘤学   2454篇
  2023年   164篇
  2022年   278篇
  2021年   756篇
  2020年   424篇
  2019年   794篇
  2018年   835篇
  2017年   616篇
  2016年   686篇
  2015年   830篇
  2014年   1241篇
  2013年   1667篇
  2012年   2677篇
  2011年   2606篇
  2010年   1442篇
  2009年   1293篇
  2008年   2414篇
  2007年   2482篇
  2006年   2453篇
  2005年   2372篇
  2004年   2244篇
  2003年   1953篇
  2002年   1933篇
  2001年   340篇
  2000年   304篇
  1999年   371篇
  1998年   435篇
  1997年   345篇
  1996年   293篇
  1995年   257篇
  1994年   224篇
  1993年   228篇
  1992年   183篇
  1991年   194篇
  1990年   174篇
  1989年   178篇
  1988年   165篇
  1987年   146篇
  1986年   153篇
  1985年   137篇
  1984年   174篇
  1983年   149篇
  1982年   153篇
  1981年   146篇
  1980年   119篇
  1979年   109篇
  1978年   117篇
  1977年   87篇
  1975年   76篇
  1974年   70篇
  1973年   82篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Advancing nanomedicines from concept to clinic requires integration of new science with traditional pharmaceutical development. The medical and commercial success of nanomedicines is greatly facilitated when those charged with developing nanomedicines are cognizant of the unique opportunities and technical challenges that these products present. These individuals must also be knowledgeable about the processes of clinical and product development, including regulatory considerations, to maximize the odds for successful product registration. This article outlines these topics with a goal to accelerate the combination of academic innovation with collaborative industrial scientists who understand pharmaceutical development and regulatory approval requirements—only together can they realize the full potential of nanomedicines for patients.  相似文献   
3.
4.
5.

Background

The optimal noninvasive test (NIT) for patients with diabetes and stable symptoms of coronary artery disease (CAD) is unknown.

Objectives

The purpose of this study was to assess whether a diagnostic strategy based on coronary computed tomographic angiography (CTA) is superior to functional stress testing in reducing adverse cardiovascular (CV) outcomes (CV death or myocardial infarction [MI]) among symptomatic patients with diabetes.

Methods

PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) was a randomized trial evaluating an initial strategy of CTA versus functional testing in stable outpatients with symptoms suggestive of CAD. The study compared CV outcomes in patients with diabetes (n = 1,908 [21%]) and without diabetes (n = 7,058 [79%]) based on their randomization to CTA or functional testing.

Results

Patients with diabetes (vs. without) were similar in age (median 61 years vs. 60 years) and sex (female 54% vs. 52%) but had a greater burden of CV comorbidities. Patients with diabetes who underwent CTA had a lower risk of CV death/MI compared with functional stress testing (CTA: 1.1% [10 of 936] vs. stress testing: 2.6% [25 of 972]; adjusted hazard ratio: 0.38; 95% confidence interval: 0.18 to 0.79; p = 0.01). There was no significant difference in nondiabetic patients (CTA: 1.4% [50 of 3,564] vs. stress testing: 1.3% [45 of 3,494]; adjusted hazard ratio: 1.03; 95% confidence interval: 0.69 to 1.54; p = 0.887; interaction term for diabetes p value = 0.02).

Conclusions

In diabetic patients presenting with stable chest pain, a CTA strategy resulted in fewer adverse CV outcomes than a functional testing strategy. CTA may be considered as the initial diagnostic strategy in this subgroup. (PROspective Multicenter Imaging Study for Evaluation of Chest Pain [PROMISE]; NCT01174550)  相似文献   
6.
Osteogenesis imperfecta (OI) is a collagen-related bone disorder characterized by fragile osteopenic bone and muscle weakness. We have previously shown that the soluble activin receptor type IIB decoy (sActRIIB) molecule increases muscle mass and improves bone strength in the mild to moderate G610C mouse model of OI. The sActRIIB molecule binds multiple transforming growth factor-β (TGF-β) ligands, including myostatin and activin A. Here, we investigate the musculoskeletal effects of inhibiting activin A alone, myostatin alone, or both myostatin and activin A in wild-type (Wt) and heterozygous G610C (+/G610C) mice using specific monoclonal antibodies. Male and female Wt and +/G610C mice were treated twice weekly with intraperitoneal injections of monoclonal control antibody (Ctrl-Ab, Regn1945), anti-activin A antibody (ActA-Ab, Regn2476), anti-myostatin antibody (Mstn-Ab, Regn647), or both ActA-Ab and Mstn-Ab (Combo, Regn2476, and Regn647) from 5 to 16 weeks of age. Prior to euthanasia, whole body composition, metabolism and muscle force generation assessments were performed. Post euthanasia, hindlimb muscles were evaluated for mass, and femurs were evaluated for changes in microarchitecture and biomechanical strength using micro–computed tomography (μCT) and three-point bend analyses. ActA-Ab treatment minimally impacted the +/G610C musculoskeleton, and was detrimental to bone strength in male +/G610C mice. Mstn-Ab treatment, as previously reported, resulted in substantial increases in hindlimb muscle weights and overall body weights in Wt and male +/G610C mice, but had minimal skeletal impact in +/G610C mice. Conversely, the Combo treatment outperformed ActA-Ab alone or Mstn-Ab alone, consistently increasing hindlimb muscle and body weights regardless of sex or genotype and improving bone microarchitecture and strength in both male and female +/G610C and Wt mice. Combinatorial inhibition of activin A and myostatin more potently increased muscle mass and bone microarchitecture and strength than either antibody alone, recapturing most of the observed benefits of sActRIIB treatment in +/G610C mice. © 2022 American Society for Bone and Mineral Research (ASBMR).  相似文献   
7.
8.
Researchers interested in measuring neighborhood‐level effects should understand how “neighborhood” is defined within nursing sciences and other sciences, and the inherent strengths and weaknesses of current research methodologies. This concept analysis provides clarity around the concept of neighborhood within the context of health, analyzes the current state of development of the neighborhood concept, and proposes areas for future nursing research. Using the Rodger's Method of analysis, the concept of neighborhood within nursing and public health research is described based on existing literature. The concept's attributes, related concepts, antecedents, and consequences are given from the literature. Comparisons of the use of neighborhood are made between nursing, public health, sociology, and other sciences. The evolution of the concept of neighborhood throughout history is described, and important implications for future research are discussed.  相似文献   
9.
Quality of Life Research - This study investigated the PROMIS Self-Efficacy Measure for Managing Chronic Conditions (PROMIS-SE) domain distributions and examined the factor structure of the...  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号