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   969篇
  免费   139篇
  国内免费   9篇
耳鼻咽喉   15篇
儿科学   93篇
妇产科学   14篇
基础医学   89篇
口腔科学   39篇
临床医学   146篇
内科学   220篇
皮肤病学   9篇
神经病学   52篇
特种医学   162篇
外科学   127篇
综合类   35篇
预防医学   43篇
眼科学   1篇
药学   19篇
中国医学   5篇
肿瘤学   48篇
  2021年   10篇
  2020年   6篇
  2019年   6篇
  2018年   35篇
  2017年   42篇
  2016年   36篇
  2015年   33篇
  2014年   36篇
  2013年   61篇
  2012年   29篇
  2011年   24篇
  2010年   58篇
  2009年   53篇
  2008年   28篇
  2007年   27篇
  2006年   18篇
  2005年   14篇
  2004年   13篇
  2003年   12篇
  2002年   10篇
  2001年   19篇
  2000年   17篇
  1999年   11篇
  1998年   61篇
  1997年   54篇
  1996年   55篇
  1995年   49篇
  1994年   29篇
  1993年   40篇
  1992年   17篇
  1991年   19篇
  1990年   19篇
  1989年   18篇
  1988年   25篇
  1987年   21篇
  1986年   15篇
  1985年   10篇
  1984年   12篇
  1983年   16篇
  1982年   3篇
  1981年   16篇
  1980年   8篇
  1978年   2篇
  1977年   10篇
  1976年   9篇
  1975年   3篇
  1968年   1篇
  1965年   1篇
  1947年   1篇
  1938年   1篇
排序方式: 共有1117条查询结果,搜索用时 15 毫秒
1.
Lipomas are common benign tumours that can occur in most parts of the body. Lipomas arising from the deep temporal fat pad, found between the two layers of the deep temporal fascia, are rare, however; there has been only one documented case report to our knowledge. We describe a second case arising from the temporal fat pad in a patient treated at our unit, having previously reported the first one, and discuss the relevant anatomy and management.  相似文献   
2.
3.
A healthy diet is essential to attain genetically determined peak bone mass and maintain optimal skeletal health across the adult lifespan. Despite the importance of nutrition for bone health, many of the nutritional requirements of the skeleton across the lifespan remain underexplored, poorly understood, or controversial. With increasingly aging populations, combined with rapidly changing diets and lifestyles globally, one anticipates large increases in the prevalence of osteoporosis and incidence of osteoporotic fractures. Robust, transparent, and reproducible nutrition research is a cornerstone for developing reliable public health recommendations to prevent osteoporosis and osteoporotic fractures. However, nutrition research is often criticized or ignored by healthcare professionals due to the overemphasis of weak science, conflicting, confusing or implausible findings, industry interests, common misconceptions, and strong opinions. Conversely, spurious research findings are often overemphasized or misconstrued by the media or prominent figures especially via social media, potentially leading to confusion and a lack of trust by the general public. Recently, reforms of the broader discipline of nutrition science have been suggested and promoted, leading to new tools and recommendations to attempt to address these issues. In this perspective, we provide a brief overview of what has been achieved in the field on nutrition and bone health, focusing on osteoporosis and osteoporotic fractures. We discuss what we view as some of the challenges, including inherent difficulties in assessing diet and its change, disentangling complex interactions between dietary components and between diet and other factors, selection of bone-related outcomes for nutrition studies, obtaining evidence with more unbiased designs, and perhaps most importantly, ensuring the trust of the public and healthcare professionals. This perspective also provides specific recommendations and highlights new developments and future opportunities for scientists studying nutrition and bone health. © 2021 American Society for Bone and Mineral Research (ASBMR).  相似文献   
4.
5.
6.
7.
8.
Global cerebral hypoperfusion may be involved in the aetiology of brain atrophy; however, long-term longitudinal studies on this relationship are lacking. We examined whether reduced cerebral blood flow was associated with greater progression of brain atrophy. Data of 1165 patients (61 ± 10 years) from the SMART-MR study, a prospective cohort study of patients with arterial disease, were used of whom 689 participated after 4 years and 297 again after 12 years. Attrition was substantial. Total brain volume and total cerebral blood flow were obtained from magnetic resonance imaging scans and expressed as brain parenchymal fraction (BPF) and parenchymal cerebral blood flow (pCBF). Mean decrease in BPF per year was 0.22% total intracranial volume (95% CI: –0.23 to –0.21). Mean decrease in pCBF per year was 0.24 ml/min per 100 ml brain volume (95% CI: –0.29 to –0.20). Using linear mixed models, lower pCBF at baseline was associated with a greater decrease in BPF over time (p =0.01). Lower baseline BPF, however, was not associated with a greater decrease in pCBF (p =0.43). These findings indicate that reduced cerebral blood flow is associated with greater progression of brain atrophy and provide further support for a role of cerebral blood flow in the process of neurodegeneration.  相似文献   
9.
10.
背景 冠状动脉无复流是影响急性ST段抬高型心肌梗死(STEMI)患者急诊经皮冠状动脉介入治疗(PCI)效果的重要因素,影响患者预后,增加死亡风险。寻求有效的药物提高PCI手术效果,降低术中无复流的发生率具有重要意义。目的 探讨冠状动脉内直接注入比伐芦定联合静脉泵入对比单静脉泵入比伐芦定对急性STEMI患者术中无复流的影响及其安全性和短期临床预后观察。方法 选取2017年6月-2019年1月于新疆医科大学附属中医医院明确诊断为急性STEMI发病12 h内并行PCI的住院患者110例,随机分为冠状动脉内直接注入联合静脉泵入比伐芦定组(观察组,n=55)和单纯静脉泵入比伐芦定组(对照组,n=55)。比较两组术中、术后观察指标〔病变血管支数、梗死相关血管(IRA)、术前靶血管TIMI血流分级、Gensini评分、门-球(D-to-B)时间、血栓抽吸例数、支架植入数量、后扩张、术后应用血管紧张素转换酶抑制剂(ACEI)或血管紧张素Ⅱ受体拮抗剂(ARB)比例、术后应用β-受体阻滞剂比例〕、疗效评价指标〔术中植入支架即刻造影IRA的校正的TIMI帧数计数(CTFC),无复流/慢血流发生率,术后4 h内心电图ST段回落程度,术后24 h的肌酸激酶同工酶(CK-MB),术后24 h左心室射血分数(LVEF)〕、30 d内主要心血管不良事件(MACE)发生率;采用多因素Logistic回归分析探讨冠状动脉内直接注入比伐芦定联合静脉泵入对部分疗效指标的影响。结果 两组患者术中、术后观察指标比较,差异无统计学意义(P>0.05)。两组PCI术中即刻CTFC、无复流/慢血流发生率及ST段回落情况比较,差异有统计学意义(P<0.05)。多因素Logistic回归分析结果显示,冠状动脉内直接注入比伐芦定联合静脉泵入治疗急性STEMI,可以降低患者术中CTFC〔OR=0.423,95%CI(0.321,0.656),P=0.005〕,是术后无复流/慢血流〔OR=0.431,95%CI(0.262,0.812),P=0.002〕的保护因素,并促进术后4 h内心电图ST段的回落〔OR=1.532,95%CI(0.627,2.517),P=0.003〕。结论 冠状动脉内直接注入比伐芦定联合静脉泵入可降低STEMI患者术后无复流发生率,可降低心力衰竭及死亡风险,且安全性良好,可改善患者短期临床预后。  相似文献   
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