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   2503篇
  免费   396篇
  国内免费   81篇
耳鼻咽喉   15篇
儿科学   105篇
妇产科学   26篇
基础医学   527篇
口腔科学   105篇
临床医学   354篇
内科学   589篇
皮肤病学   63篇
神经病学   62篇
特种医学   37篇
外科学   261篇
综合类   313篇
预防医学   44篇
眼科学   22篇
药学   248篇
中国医学   49篇
肿瘤学   160篇
  2024年   11篇
  2023年   66篇
  2022年   71篇
  2021年   162篇
  2020年   128篇
  2019年   144篇
  2018年   119篇
  2017年   135篇
  2016年   133篇
  2015年   116篇
  2014年   150篇
  2013年   174篇
  2012年   107篇
  2011年   111篇
  2010年   91篇
  2009年   71篇
  2008年   91篇
  2007年   88篇
  2006年   71篇
  2005年   90篇
  2004年   95篇
  2003年   78篇
  2002年   63篇
  2001年   67篇
  2000年   67篇
  1999年   56篇
  1998年   64篇
  1997年   49篇
  1996年   42篇
  1995年   31篇
  1994年   27篇
  1993年   36篇
  1992年   22篇
  1991年   23篇
  1990年   13篇
  1989年   14篇
  1988年   19篇
  1987年   8篇
  1986年   12篇
  1985年   10篇
  1984年   11篇
  1983年   5篇
  1982年   7篇
  1981年   7篇
  1980年   10篇
  1979年   6篇
  1978年   3篇
  1977年   3篇
  1972年   1篇
  1968年   1篇
排序方式: 共有2980条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
《Immunity》2020,52(5):856-871.e8
  1. Download : Download high-res image (236KB)
  2. Download : Download full-size image
  相似文献   
65.
66.
Acute respiratory distress syndrome (ARDS) is characterized by the severe inflammation and destruction of the lung air–blood barrier, leading to irreversible and substantial respiratory function damage. Patients with coronavirus disease 2019 (COVID-19) have been encountered with a high risk of ARDS, underscoring the urgency for exploiting effective therapy. However, proper medications for ARDS are still lacking due to poor pharmacokinetics, non-specific side effects, inability to surmount pulmonary barrier, and inadequate management of heterogeneity. The increased lung permeability in the pathological environment of ARDS may contribute to nanoparticle-mediated passive targeting delivery. Nanomedicine has demonstrated unique advantages in solving the dilemma of ARDS drug therapy, which can address the shortcomings and limitations of traditional anti-inflammatory or antioxidant drug treatment. Through passive, active, or physicochemical targeting, nanocarriers can interact with lung epithelium/endothelium and inflammatory cells to reverse abnormal changes and restore homeostasis of the pulmonary environment, thereby showing good therapeutic activity and reduced toxicity. This article reviews the latest applications of nanomedicine in pre-clinical ARDS therapy, highlights the strategies for targeted treatment of lung inflammation, presents the innovative drug delivery systems, and provides inspiration for strengthening the therapeutic effect of nanomedicine-based treatment.  相似文献   
67.
Although upregulation of CD11b/CD18 receptor, i.e. activation of neutrophils and monocytes, during cardiopulmonary bypass is well documented, the duration of the active state after uncomplicated operation is less understood. We therefore investigated CD11b expression of phagocytes in blood samples collected 2-4, 24, 48 and 72 h after coronary artery bypass grafting. CD11b expression on neutrophils was significantly elevated at 2-4 and 24 hours after operation as compared with baseline. On monocytes, expression peaked at 24 h and returned to baseline by 72 h. Because CD11b is a sensitive marker, effects of different sampling techniques on its expression were also studied. CD11b expression was similar in samples collected with a syringe from arterial or central venous catheter or with open technique from cubital vein. On neutrophils from healthy subjects, sampling with syringe caused small (10%) but statistically significant increase of expression. We conclude that activated neutrophils disappear from circulation within hours after CABG surgery while activated monocytes may continue circulating for 2-3 days, and that CD11b sampling can be done with a syringe.  相似文献   
68.
Activated platelets form platelet–leukocyte aggregates in the circulation in inflammatory diseases. We investigated whether activated platelets in inflamed skin tissues are phagocytized and removed by neutrophils. To investigate the kinetics of platelets and neutrophils, we immunohistochemically examined the spatiotemporal distribution of them in a murine model of 2,4,6-trinitro-1-chlorobenzene (TNCB)-induced dermatitis by using confocal and structured illumination microscopy. Four hours after elicitation, aggregates of CD41-positive platelets were adhered to CD31-positive endothelial cells within the vessels, and CD62P and PF4, markers of activated platelets, were expressed on platelet aggregates. At 8 hour post-elicitation, fragmented CD41-positive platelets were located both inside and outside vessels. Twenty-four hours after elicitation, the number of Ly-6G-positive neutrophils ingesting fragmented CD41-positive platelets outside vessels was increased, and CD62P and PF4 expression on the phagocytosed platelets was no longer observed. Disc-shaped CD41-positive platelets were not found outside vessels at any time during the experiment. Our data revealed that aggregates of activated platelets inside vessels were ingested and removed by neutrophils in the early stage of TNCB-induced dermatitis, suggesting that the process of removal of activated platelets by neutrophils may play an important role not only in the early phase of skin inflammation but also in other types of acute inflammation.  相似文献   
69.
70.
Innate immune mechanisms respond rapidly to bacterial infection. A key cellular component of the innate immune response is the neutrophil, whose cytoplasmic granules contain a variety of antimicrobial proteins and peptides. Among these is the bactericidal/permeability-increasing protein (BPI), a cationic 55 kDa protein whose selective anti-infective action against Gram-negative bacteria is based on its high (nM) affinity for lipopolysaccharide (LPS, or “endotoxin”). Binding of BPI to Gram-negative bacteria results in growth inhibition, serves as an opsonin that enhances phagocytosis of bacteria and inhibits bacteria-induced inflammatory responses by blocking the interaction of LPS with host pro-inflammatory pathways. Expression of BPI appears to be developmentally regulated as human newborns apparently have lower neutrophil BPI levels than adults. BPI expression has also recently been demonstrated in human epithelial cells where it appears to be inducible by endogenous anti-inflammatory lipids (lipoxins). BPI’s potent anti-endotoxic activity against a broad range of Gram-negative bacterial pathogens is manifest in biological fluids and renders it an attractive template for pharmaceutical development. Indeed, rBPI21, an active recombinant protein derived from human BPI, has proven safe in Phase I human trials, shown promise in Phase II trials and has recently completed a Phase III trial for severe meningococcaemia with apparent benefit. Identification and evaluation of additional disease entities characterised by Gram-negative bacteraemia and/or endotoxaemia as possible targets for BPI therapy continues.  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