首页 | 官方网站   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   4149470篇
  免费   341021篇
  国内免费   13618篇
医药卫生   4504109篇
  2021年   50552篇
  2020年   35447篇
  2019年   58375篇
  2018年   73584篇
  2017年   55888篇
  2016年   61939篇
  2015年   74944篇
  2014年   109317篇
  2013年   174458篇
  2012年   120458篇
  2011年   125935篇
  2010年   125115篇
  2009年   126482篇
  2008年   112288篇
  2007年   119641篇
  2006年   128426篇
  2005年   123604篇
  2004年   123887篇
  2003年   114302篇
  2002年   102992篇
  2001年   148976篇
  2000年   143413篇
  1999年   131884篇
  1998年   64264篇
  1997年   60363篇
  1996年   58494篇
  1995年   59106篇
  1994年   53308篇
  1993年   49560篇
  1992年   95618篇
  1991年   92537篇
  1990年   88873篇
  1989年   86609篇
  1988年   79749篇
  1987年   78315篇
  1986年   73655篇
  1985年   72804篇
  1984年   61345篇
  1983年   55003篇
  1982年   45560篇
  1981年   42662篇
  1980年   40037篇
  1979年   52740篇
  1978年   43694篇
  1977年   38443篇
  1976年   35887篇
  1975年   35953篇
  1974年   39170篇
  1973年   37439篇
  1972年   35147篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.

The exercise pressor reflex is a feedback mechanism engaged upon stimulation of mechano- and metabosensitive skeletal muscle afferents. Activation of these afferents elicits a reflex increase in heart rate, blood pressure, and ventilation in an intensity-dependent manner. Consequently, the exercise pressor reflex has been postulated to be one of the principal mediators of the cardiorespiratory responses to exercise. In this updated review, we will discuss classical and recent advancements in our understating of the exercise pressor reflex function in both human and animal models. Particular attention will be paid to the afferent mechanisms and pathways involved during its activation, its effects on different target organs, its potential role in the abnormal cardiovascular response to exercise in diseased states, and the impact of age and biological sex on these responses. Finally, we will highlight some unanswered questions in the literature that may inspire future investigations in the field.

  相似文献   
73.
74.
Journal of Neuro-Oncology - Craniopharyngiomas are locally-aggressive tumors arising along the hypothalamic-pituitary axis. Treatment is nuanced as a result of their proximity and adherence to...  相似文献   
75.
When hospitals first encountered coronavirus disease 2019 (COVID-19), there was a dearth of therapeutic options and nearly 1 in 3 patients died from the disease. By the summer of 2020, as deaths from the disease declined nationally, multiple single-center studies began to report declining mortality of patients with COVID-19. To evaluate the effect of COVID-19 on hospital-based mortality, we searched the Vizient Clinical Data Base for outcomes data from approximately 600 participating hospitals, including 130 academic medical centers, from January 2017 through December 2020. More than 32 million hospital admissions were included in the analysis. After an initial spike, mortality from COVID-19 declined in all regions of the country to under 10% by June 2020 and remained constant for the remainder of the year. Despite this, inpatient, all-cause mortality has increased since the beginning of the pandemic, even those without respiratory failure. Inpatient mortality has particularly increased in elderly patients and in those requiring intubation for respiratory failure. Since June 2020, COVID-19 kills one in every 10 patients admitted to the hospital with this diagnosis. The addition of this new disease has raised overall hospital mortality especially those who require intubation for respiratory failure.  相似文献   
76.
Network meta-analyses (NMAs) simultaneously estimate the effects of multiple possible treatment options for a given clinical presentation. For allergists to benefit optimally from NMAs, they must understand the process and be able to interpret the results. Through a worked example published in Pediatric Allergy and Immunology, we summarize how to identify credible NMAs and interpret them with a focus on recent innovations in the GRADE approach (Grading of Recommendations Assessment, Development, and Evaluation). NMAs build on traditional systematic reviews and meta-analyses that consider only direct paired comparisons by including indirect evidence, thus allowing the simultaneous assessment of the relative effect of all pairs of competing alternatives. Our framework informs clinicians of how to identify credible NMAs and address the certainty of the evidence. Trustworthy NMAs fill a critical gap in providing key inferences using direct and indirect evidence to inform clinical decision making when faced with more than two competing courses of treatment options. This document will help allergists to identify trustworthy NMAs to enhance patient care.  相似文献   
77.
78.
79.
80.
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-23

京公网安备 11010802026262号