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   861篇
  免费   57篇
  国内免费   12篇
耳鼻咽喉   4篇
儿科学   35篇
妇产科学   9篇
基础医学   106篇
口腔科学   38篇
临床医学   107篇
内科学   215篇
皮肤病学   25篇
神经病学   49篇
特种医学   84篇
外科学   90篇
综合类   26篇
一般理论   1篇
预防医学   81篇
眼科学   3篇
药学   28篇
中国医学   1篇
肿瘤学   28篇
  2023年   5篇
  2021年   10篇
  2020年   8篇
  2019年   11篇
  2018年   16篇
  2017年   8篇
  2016年   19篇
  2015年   10篇
  2014年   14篇
  2013年   29篇
  2012年   21篇
  2011年   22篇
  2010年   36篇
  2009年   35篇
  2008年   29篇
  2007年   34篇
  2006年   26篇
  2005年   23篇
  2004年   23篇
  2003年   21篇
  2002年   10篇
  2001年   16篇
  2000年   23篇
  1999年   16篇
  1998年   33篇
  1997年   35篇
  1996年   36篇
  1995年   26篇
  1994年   22篇
  1993年   20篇
  1992年   19篇
  1991年   16篇
  1990年   14篇
  1989年   17篇
  1988年   22篇
  1987年   27篇
  1986年   14篇
  1985年   15篇
  1984年   15篇
  1983年   9篇
  1982年   13篇
  1981年   8篇
  1979年   10篇
  1978年   9篇
  1977年   23篇
  1976年   11篇
  1975年   5篇
  1974年   7篇
  1970年   7篇
  1968年   6篇
排序方式: 共有930条查询结果,搜索用时 15 毫秒
51.
52.
53.
Because of their evolving nature and inherent scientific uncertainties, outbreaks of emerging infectious diseases can be associated with considerable fear in the general public or in specific communities, especially when illness and deaths are substantial. Mitigating fear and discrimination directed toward persons infected with, and affected by, infectious disease can be important in controlling transmission. Persons who are feared and stigmatized may delay seeking care and remain in the community undetected. This article outlines efforts to rapidly assess, monitor, and address fears associated with the 2003 severe acute respiratory syndrome (SARS) epidemic in the United States. Although fear, stigmatization, and discrimination were not widespread in the general public, Asian-American communities were particularly affected.  相似文献   
54.
55.
56.
Prostaglandins (PGs) act locally to maintain cellular homeostasis and stimulate stress response signaling pathways. These cellular effects are diverse and are tissue-dependent. PGE(2), and the synthetic analogue, 11-deoxy,16,16-dimethyl PGE(2) (DDM-PGE(2)), protect renal proximal tubular epithelial (LLC-PK1) cells against cellular injury induced by the potent nephrotoxic and nephrocarcinogenic metabolite of hydroquinone, 2,3,5-tris-(glutathion-S-yl)hydroquinone. Although this cytoprotective response (in LLC-PK1 cells) is mediated through a thromboxane or thromboxane-like receptor coupled to AP-1 signaling pathways, the mechanism of cytoprotection is unknown. In this study, we utilized HPLC-electrospray ionization tandem mass spectrometric (ESI MS/MS) and matrix-assisted laser desorption ionization time-of-flight mass spectrometric (MALDI TOF) analysis of proteins isolated from DDM-PGE(2)-stimulated LLC-PK1 cells to identify candidate cytoprotective proteins. DDM-PGE(2) selectively stimulated the synthesis of several proteins in LLC-PK1 cells. Peptide sequencing by ESI-MS/MS of in-gel tryptic protein digests revealed the identity of eight proteins: endothelial actin binding protein, myosin, elongation factor 2 (EF-2), elongation factor 1alpha-1 (EF-1alpha), heat shock protein 90beta (HSP90beta), glucose-regulated protein 78 (GRP 78), membrane-organizing extension spike protein, and actin. Both ESI-MS/MS and MALDI-MS analysis resulted in the same protein identification. Western analysis confirmed the temporal induction of the majority of these proteins, including EF-2, EF-1alpha, HSP90beta, GRP78, and actin. The collective expression of these proteins suggests that DDM-PGE(2)-mediated cytoprotection may involve alterations in cytoskeletal organization and/or stimulation of an endoplasmic reticulum (ER) stress response. The present studies provide insights into potential downstream targets of PG signaling.  相似文献   
57.
Severe congenital neutropenia (SCN), a heterogeneous disorder that includes Kostmann syndrome, predisposes to myelodysplasia and acute myelogenous leukemia. Recently identified heterozygous mutations in the gene ELA2, encoding neutrophil elastase on human chromosome 19pter, account for the majority of autosomal dominant cases of SCN, including those demonstrating neoplastic progression. The involvement of the serine protease neutrophil elastase, localized to the granules of neutrophils and monocytes, implies an unexpected role for proteolytic regulation of hematopoiesis. Continued elucidation of the clinical features, molecular genetics, and biochemistry is likely to provide insight into novel pathways of leukemia induction with attendant prospects for new avenues of therapy.  相似文献   
58.
Although the pursuit of Medicare certification has been one of the most controversial events in hospice history no study has examined its impact using data from a defined population of hospices before, during, and after federal legislation was enacted. This paper revisits the debate over the changing role of volunteers using such a longitudinal data source. Over time, as the patient population grew, aggregate levels of volunteers and professional staff increased. However, the ratios of professional staff and volunteers to patients reveal that regardless of certification status, hospices retained more professional staff per patient and fewer volunteers per patient over time. These data suggest hospices, particularly certified organizations, have transitioned from voluntary organizations to professionally staffed organizations with a strong volunteer component. The most important issue for future research is whether the observed changes have affected the quality of hospice care.  相似文献   
59.
60.
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