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   47655篇
  免费   3850篇
  国内免费   1037篇
耳鼻咽喉   287篇
儿科学   920篇
妇产科学   1415篇
基础医学   4492篇
口腔科学   916篇
临床医学   5271篇
内科学   6850篇
皮肤病学   324篇
神经病学   1766篇
特种医学   1698篇
外国民族医学   12篇
外科学   4440篇
综合类   7773篇
现状与发展   1篇
预防医学   6909篇
眼科学   375篇
药学   5045篇
  104篇
中国医学   1923篇
肿瘤学   2021篇
  2023年   639篇
  2022年   988篇
  2021年   1848篇
  2020年   1828篇
  2019年   1551篇
  2018年   1624篇
  2017年   1578篇
  2016年   1652篇
  2015年   1619篇
  2014年   3242篇
  2013年   3323篇
  2012年   3030篇
  2011年   3248篇
  2010年   2451篇
  2009年   2240篇
  2008年   2226篇
  2007年   2312篇
  2006年   1915篇
  2005年   1713篇
  2004年   1466篇
  2003年   1205篇
  2002年   1094篇
  2001年   950篇
  2000年   824篇
  1999年   767篇
  1998年   606篇
  1997年   610篇
  1996年   594篇
  1995年   529篇
  1994年   508篇
  1993年   399篇
  1992年   409篇
  1991年   366篇
  1990年   310篇
  1989年   302篇
  1988年   261篇
  1987年   211篇
  1986年   197篇
  1985年   256篇
  1984年   221篇
  1983年   135篇
  1982年   190篇
  1981年   162篇
  1980年   147篇
  1979年   128篇
  1978年   102篇
  1977年   91篇
  1976年   86篇
  1975年   89篇
  1974年   60篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
In clear cell renal cell carcinoma (ccRCC), glycolysis is enhanced mainly because of the increased expression of key enzymes in glycolysis. Hence, the discovery of new molecular biomarkers for glycolysis may help guide and establish a precise system of diagnosis and treatment for ccRCC. Expression profiles of 1079 tumor samples of ccRCC patients (including 311 patients treated with everolimus or nivolumab) were downloaded from public databases. Proteomic profiles of 232 ccRCC samples were obtained from Fudan University Shanghai Cancer Center (FUSCC). Biological changes, tumor microenvironment and prognostic differences were explored between samples with various glycolysis characteristics. There were significant differences in CD8+ effector T cells, epithelial-to-mesenchymal transition and pan-fibroblast TGFb between the Low and High glyScore groups. The tumor mutation burden of the Low glyScore group was lower than that of the High glyScore group. And higher glyScore was significantly associated with worse overall survival (OS) in 768 ccRCC patients (P < .0001). External validation in FUSCC cohort also indicated that glyScore was of strong ability for predicting OS (P < .05). GlyScore may serve as a biomarker for predicting everolimus response in ccRCC patients due to its significant associations with progression-free survival (PFS). And glyScore may also predict overall survival in patients treated with nivolumab. We calculated the glyScore in ccRCC and the defined glyScore was of strong ability for predicting OS. In addition, glyScore may also serve as a biomarker for predicting PFS in patients treated with everolimus and could predict OS in patients treated with nivolumab.  相似文献   
2.
3.
4.
Stones in the common bile duct (CBD) are reported worldwide, and this condition is majorly managed through endoscopic retrograde cholangiopancreatography (ERCP). CBD stone recurrence is an important issue after endoscopic stone removal. Therefore, it is essential to identify its risk factors to determine the necessity of regular follow-up in patients who underwent endoscopic removal of CBD stones. The authors identified that the S and polyline morphological subtypes of CBD were associated with increased stone recurrence. New morphological subtypes of CBD presented by the authors can be important risk predictors of recurrence after endoscopic stone removal. Furthermore, the new morphological subtypes of CBD may predict the risk of residual CBD stones or technical difficulty in CBD stone removal. Further studies with a large sample size and longer follow-up durations are warranted to examine the usefulness of the newly identified morphological subtypes of CBD in predicting the outcomes of ERCP for CBD stone removal.  相似文献   
5.
AimTo examine the effectiveness of a Humanoid Diagram Teaching Strategy (HDTS) on care capabilities and retention of novice nurses.BackgroundGuiding novice nurses in clinical practice is a matter of concern and the use of diagrams in assisting the learning process and to promote learning efficiency has been acknowledged.DesignThis is a quasi-experimental study with asynchronous repeated measurements for the experimental and control groups.MethodsThe study was conducted in a medical centre in southern Taiwan with 24 novice nurses. The intervention, Humanoid Diagrams Teaching Strategy, contained three parts: the head and neck; trunk; and limbs. The HDTS was applied three time weekly. Each session lasted approximately 30 min and the training lasted 4 weeks. The effectiveness of HDTS was measured using Mini-CEX, CbD and retention rates in the 3rd and 6th months of novice nurses’ experience.ResultsAfter the HDTS, although increases in mini-CEX and CbD scores in the experimental group were greater than the control group, these differences were not statistically significant after considering the time interaction. But the 3rd month and 6th month novice nurses’ retention rates were statistically significantly different by comparing the differences under the time interaction effects in both groups.ConclusionsThe Humanoid Diagram Teaching Strategy is an effective tool for preceptors to use in assisting novice nurses in learning, improving their nursing care knowledge and technical skills and to increase their retention rate.  相似文献   
6.
Following adoption of moderately hypofractionated radiotherapy as a standard for localised prostate cancer, ultrahypofractioned radiotherapy delivered in five to seven fractions is rapidly being embraced by clinical practice and international guidelines. However, the question remains: how low can we go? Can radiotherapy for prostate cancer be delivered in fewer than five fractions? The current review summarises the evidence that radiotherapy for localised prostate cancer can be safely and effectively delivered in fewer than five fractions using high dose rate brachytherapy or stereotactic body radiotherapy. We also discuss important lessons learned from the single-fraction high dose rate brachytherapy experience.  相似文献   
7.
《Vaccine》2022,40(24):3380-3388
BackgroundWe evaluated the safety and immunogenicity of NVX-CoV2373, a recombinant SARS-CoV-2 nanoparticle vaccine, in healthy Japanese participants.MethodsThis phase 1/2, randomized, observer-blind, placebo-controlled trial conducted in Japan (two sites), enrolled healthy Japanese adults aged ≥ 20 years with no history/risk of SARS-CoV-2 infection and no prior exposure to other approved/investigational SARS-CoV-2 vaccines or treatments. Participants were stratified by age (< 65 or ≥ 65 years) and randomized to receive two doses of either NVX-CoV2373 (5 μg SARS-CoV-2 rS; 50 μg Matrix-M1) or placebo, 21 days apart. Primary outcomes were safety and immunogenicity assessed by serum IgG antibody levels against SARS-CoV-2 rS protein on day 36. Herein, we report the primary data analysis at 4 weeks after the second dose, ahead of 12-month follow-up completion (data cut-off: 8 May 2021).ResultsBetween 12 February 2021 and 17 March 2021, 326 subjects were screened, and 200 participants enrolled and randomized: NVX-CoV2373, n = 150; placebo, n = 50. Solicited adverse events (AEs) through 7 days after each injection occurred in 121/150 (80.7%) and 11/50 (22.0%) participants in the NVX-CoV2373 and placebo arms, respectively. In the NVX-CoV2373 arm, tenderness and injection site pain were the most frequently reported solicited AEs after each vaccination, irrespective of age. Robust immune responses occurred with NVX-CoV2373 (n = 150) by day 36: IgG geometric mean fold rise (95% confidence interval) 259 (219, 306); seroconversion rate 100% (97.6, 100). No such response occurred with placebo (n = 49).ConclusionTwo doses of NVX-CoV2373 given with a 21-day interval demonstrated acceptable safety and induced robust anti-SARS-CoV-2 immune responses in healthy Japanese adults. Funding: Takeda Pharmaceutical Company Limited and Japan Agency for Medical Research and Development (AMED). ClinicalTrials.gov identifier: NCT04712110.  相似文献   
8.
目的 分析南京市某国际高中学生艾滋病知识知晓率及其影响因素,为制定高中生艾滋病健康教育策略提供依据。方法 对南京市某国际高中所有学生开展纸质问卷调查,统计分析艾滋病知识知晓率及其影响因素。 共纳入171名高中生为调查对象,艾滋病和梅毒的知识知晓率分别为56.1%和46.8%;有过性行为的占14.6%,其艾滋病知识知晓率最高为32.0%,(χ2=10.799,P=0.005);有吸毒史的学生占9.3%,其艾滋病知识知晓率最高为31.2%,(χ2=21.062,P<0.001);梅毒知识知晓者与不知晓者的艾滋病知识知晓率差异具有统计学意义(χ2=21.716,P<0.001)。 该国际高中学生性病和艾滋病知识知晓率较低,对高中生开展毒品危害教育和性病艾滋病防治应作为健康教育工作重点。  相似文献   
9.
ObjectiveNew-onset postoperative atrial fibrillation (POAF) after cardiac surgery is common, with rates up to 60%. POAF has been associated with early and late stroke, but its association with other cardiovascular outcomes is less known. The objective was to perform a meta-analysis of the studies reporting the association of POAF with perioperative and long-term outcomes in patients with cardiac surgery.MethodsWe performed a systematic review and a meta-analysis of studies that presented outcomes for cardiac surgery on the basis of the presence or absence of POAF. MEDLINE, EMBASE, and the Cochrane Library were assessed; 57 studies (246,340 patients) were selected. Perioperative mortality was the primary outcome. Inverse variance method and random model were performed. Leave-one-out analysis, subgroup analyses, and metaregression were conducted.ResultsPOAF was associated with perioperative mortality (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.58-2.33), perioperative stroke (OR, 2.17; 95% CI, 1.90-2.49), perioperative myocardial infarction (OR, 1.28; 95% CI, 1.06-1.54), perioperative acute renal failure (OR, 2.74; 95% CI, 2.42-3.11), hospital (standardized mean difference, 0.80; 95% CI, 0.53-1.07) and intensive care unit stay (standardized mean difference, 0.55; 95% CI, 0.24-0.86), long-term mortality (incidence rate ratio [IRR], 1.54; 95% CI, 1.40-1.69), long-term stroke (IRR, 1.33; 95% CI, 1.21-1.46), and longstanding persistent atrial fibrillation (IRR, 4.73; 95% CI, 3.36-6.66).ConclusionsThe results suggest that POAF after cardiac surgery is associated with an increased occurrence of most short- and long-term cardiovascular adverse events. However, the causality of this association remains to be established.  相似文献   
10.
《Vaccine》2022,40(34):4933-4941
Subunit influenza vaccine only formulated with surface antigen proteins has better safety profiles relative to split-virion influenza vaccine. Compared to the traditional quadrivalent split-virion influenza vaccine, a novel quadrivalent subunit influenza vaccine is urgently needed in China. We completed a phase 3, randomized, double-blind, active-controlled, non-inferiority clinical study at two sites in Henan Province, China. Eligible volunteers were split into four age cohorts (3–8 years, 9–17 years, 18–64 years, and ≥ 65 years, based on their dates of birth) and randomly assigned (1:1) to the subunit and the split-virion ecNAIIV4 groups. All volunteers were intramuscularly administered a single vaccine dose at baseline, and children aged 3–8 years received a boosting dose at day 28. And the immune response was evaluated by measuring hemagglutinin-inhibition antibody titers against the four vaccine strains in blood samples. Safety profiles had nonsignificant differences between the study groups in ≥ 3 years cohort. Most adverse reactions post-vaccination, both local and systemic, were mild to moderate and resolved within 3 days. And no serious adverse events occurred. The immunogenicity of the trial vaccine was non-inferior to the comparator. Further, a two-dose vaccine series can provide better seroprotection than that of a one-dose series in children aged 3–8 years, with clinically acceptable safety profiles.Clinical Trials Registration. ChiCTR2100049934.  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