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   1683636篇
  免费   126004篇
  国内免费   3711篇
耳鼻咽喉   21730篇
儿科学   55675篇
妇产科学   46152篇
基础医学   239629篇
口腔科学   48715篇
临床医学   150229篇
内科学   330517篇
皮肤病学   38654篇
神经病学   130328篇
特种医学   63801篇
外国民族医学   242篇
外科学   256674篇
综合类   38868篇
一般理论   532篇
预防医学   123296篇
眼科学   40017篇
药学   123188篇
  7篇
中国医学   4351篇
肿瘤学   100746篇
  2019年   13504篇
  2018年   19955篇
  2017年   15244篇
  2016年   16551篇
  2015年   19004篇
  2014年   26289篇
  2013年   38083篇
  2012年   52847篇
  2011年   55537篇
  2010年   32774篇
  2009年   30721篇
  2008年   51625篇
  2007年   54798篇
  2006年   55245篇
  2005年   52564篇
  2004年   50756篇
  2003年   48102篇
  2002年   46278篇
  2001年   91728篇
  2000年   93474篇
  1999年   76624篇
  1998年   18792篇
  1997年   16280篇
  1996年   16420篇
  1995年   16640篇
  1994年   15236篇
  1993年   14010篇
  1992年   57336篇
  1991年   55282篇
  1990年   52966篇
  1989年   50753篇
  1988年   46130篇
  1987年   44934篇
  1986年   42219篇
  1985年   39991篇
  1984年   29319篇
  1983年   24848篇
  1982年   13845篇
  1981年   12331篇
  1979年   25479篇
  1978年   17531篇
  1977年   14850篇
  1976年   13833篇
  1975年   14515篇
  1974年   17603篇
  1973年   16915篇
  1972年   15670篇
  1971年   14436篇
  1970年   13422篇
  1969年   12516篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
Modified-release opioids are often prescribed for the management of moderate to severe acute pain following total hip and knee arthroplasty, despite recommendations against their use due to increasing concerns regarding harm. The primary objective of this multicentre study was to examine the impact of modified-release opioid use on the incidence of opioid-related adverse events compared with immediate-release opioid use, among adult inpatients following total hip or knee arthroplasty. Data for total hip and knee arthroplasty inpatients receiving an opioid analgesic for postoperative analgesia during hospitalisation were collected from electronic medical records of three tertiary metropolitan hospitals in Australia. The primary outcome was the incidence of opioid-related adverse events during hospital admission. Patients who received modified with or without immediate-release opioids were matched to those receiving immediate-release opioids only (1:1) using nearest neighbour propensity score matching with patient and clinical characteristics as covariates. This included total opioid dose received. In the matched cohorts, patients given modified-release opioids (n = 347) experienced a higher incidence of opioid-related adverse events overall, compared with those given immediate-release opioids only (20.5%, 71/347 vs. 12.7%, 44/347; difference in proportions 7.8% [95%CI 2.3–13.3%]). Modified-release opioid use was associated with an increased risk of harm when used for acute pain during hospitalisation after total hip or knee arthroplasty.  相似文献   
3.
Renal cell cancer (RCC) represents 2%-3% of all adulthood cancers and is the most common malignant neoplasm of the kidney (90%). In the mid-nineties of the last century, the standard of treatment for patients with metastatic RCC was cytokines. Sunititib and pazopanib were registered in 2007 and 2009, respectively, and have since been the standard first-line treatment for metastatic clear cell RCC (mccRCC). Renal cell cancer is a highly immunogenic tumor with tumor infiltrating cells, including CD8+ T lymphocytes, dendritic cells, natural killer cells (NK) and macrophages. This observation led to the design of new clinical trials in which patients were treated with immunotherapy. With the growing evidence that proangiogenic factors can have immunomodulatory effects on the host’s immune system, the idea of combining angiogenic drugs with immunotherapy has emerged, and new clinical trials have been designed. In the last few years, several therapeutic options have been approved [immunotherapy and immunotherapy/tyrosine kinase inhibitors (TKI)] for the first-line treatment of mccRCC. Nivolumab/ipilimumab is approved for the treatment of patients with intermediate and poor prognoses. Several checkpoint inhibitors (pembrolizumab, nivolumab, avelumab) in combination with TKI (axitinib, lenvatinib, cabozantinib) are approved for the treatment of patients regardless of their International mRCC Database Consortium prognostic group and PD-L1 expression. There is no specific and ideal biomarker that could help in selecting the ideal patient for the appropriate first-line treatment.  相似文献   
4.
Neuroscience and Behavioral Physiology - We present here results from analysis of the formation of brain bioelectrical activity in children and adolescents living in the northern region of Russia...  相似文献   
5.
6.
7.
Microbial co-infections are another primary concern in patients with coronavirus disease 2019 (COVID-19), yet it is an untouched area among researchers. Preliminary data and systematic reviews only show the type of pathogens responsible for that, but its pathophysiology is still unknown. Studies show that these microbial co-infections are hospital-acquired/nosocomial infections, and patients admitted to intensive care units with invasive mechanical ventilation are highly susceptible to it. Patients with COVID-19 had elevated inflammatory cytokines and a weakened cell-mediated immune response, with lower CD4+ T and CD8+ T cell counts, indicating vulnerability to various co-infections. Despite this, there are only a few studies that recommend the management of co-infections.  相似文献   
8.
9.
10.
Tobacco smoking is associated with a substantially increased risk of postoperative complications. The peri-operative period offers a unique opportunity to support patients to stop tobacco smoking, avoid complications and improve long-term health. This systematic review provides an up-to-date summary of the evidence for tobacco cessation interventions in surgical patients. We conducted a systematic search of randomised controlled trials of tobacco cessation interventions in the peri-operative period. Quantitative synthesis of the abstinence outcomes data was by random-effects meta-analysis. The primary outcome of the meta-analysis was abstinence at the time of surgery, and the secondary outcome was abstinence at 12 months. Thirty-eight studies are included in the review (7310 randomised participants) and 26 studies are included in the meta-analysis (5969 randomised participants). Studies were pooled for subgroup analysis in two ways: by the timing of intervention delivery within the peri-operative period and by the intensity of the intervention protocol. We judged the quality of evidence as moderate, reflecting the degree of heterogeneity and the high risk of bias. Overall, peri-operative tobacco cessation interventions increased successful abstinence both at the time of surgery, risk ratio (95%CI) 1.48 (1.20–1.83), number needed to treat 7; and 12 months after surgery, risk ratio (95%CI) 1.62 (1.29–2.03), number needed to treat 9. More work is needed to inform the design and optimal delivery of interventions that are acceptable to patients and that can be incorporated into contemporary elective and urgent surgical pathways. Future trials should use standardised outcome measures.  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