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   63731篇
  免费   5999篇
  国内免费   4821篇
医药卫生   74551篇
  2024年   83篇
  2023年   947篇
  2022年   1516篇
  2021年   3201篇
  2020年   2484篇
  2019年   2170篇
  2018年   2302篇
  2017年   2036篇
  2016年   1941篇
  2015年   3091篇
  2014年   3720篇
  2013年   3158篇
  2012年   4955篇
  2011年   5471篇
  2010年   3517篇
  2009年   2582篇
  2008年   3292篇
  2007年   3444篇
  2006年   3348篇
  2005年   3465篇
  2004年   2208篇
  2003年   2101篇
  2002年   1753篇
  2001年   1398篇
  2000年   1574篇
  1999年   1615篇
  1998年   1077篇
  1997年   1008篇
  1996年   750篇
  1995年   707篇
  1994年   673篇
  1993年   394篇
  1992年   473篇
  1991年   426篇
  1990年   365篇
  1989年   312篇
  1988年   232篇
  1987年   220篇
  1986年   168篇
  1985年   114篇
  1984年   66篇
  1983年   59篇
  1982年   43篇
  1981年   31篇
  1980年   14篇
  1979年   23篇
  1978年   4篇
  1977年   3篇
  1975年   4篇
  1973年   8篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Diffuse large B-cell lymphoma (DLBCL) is a clinically aggressive and heterogenous disease. Although most patients can be cured by immunochemotherapy, 30% to 40% patient will ultimately develop relapsed or refractory disease. Here, we investigated the molecular landscapes of patients with diverse responses to R-CHOP. We performed capture-based targeted sequencing on baseline samples of 105 DLBCL patients using a panel consisting of 112 lymphoma-related genes. Subsequently, 81 treatment-naïve patients with measurable disease and followed for over 1 year were included for survival analysis. Collectively, the most commonly seen mutations included IGH fusion (69%), PIM1(33%), MYD88 (29%), BCL2 (29%), TP53 (29%), CD79B (25%) and KMT2D (24%). Patients with TP53 mutations were more likely to have primary refractory disease (87.0% vs 50.0%, P = .009). For those with TP53 disruptive mutations, 91.7% patients were in the primary refractory group. Interestingly, BCL-2 somatic hypermutation was only seen in patients without primary refractory disease (P = .014). In multivariate analysis, BCL-2 amplification (hazard ratio [HR] = 2.94, P = .022), B2M mutation (HR = 2.99, P = .017) and TP53 mutation (HR = 3.19, P < .001) were independently associated with shorter time to progression (TTP). Furthermore, TP53 mutations was correlated with worse overall survival (P = .049). Next, we investigated mutation landscape in patients with wild-type (WT) TP53 (n = 58) and found that patients harboring MYD88 L265P had significantly inferior TTP than those with WT or non-265P (P = .046). Our study reveals the mutation spectrum of treatment-naive Chinese DLBCL patients. It also confirms the clinical significance of TP53 mutations and indicates the prognostic value of MYD88 L265P in TP53 WT patients.  相似文献   
52.
我国新型冠状病毒肺炎(Corona Virus Disease,COVID-19)疫情到目前为止还在持续。现有流行病学显示人群对新型冠状病毒(2019 novel coronavirus,2019-nCoV)普遍易感,有基础疾病或60岁以上患者是COVID-19重症病例的高危人群。对于罕见病,尤其是对呼吸道感染易感而且一旦患病极易加重、甚至危及生命的神经肌肉病患儿,如何加强防护和进行居家康复,目前需要更多的关注。因此,中华医学会儿科学分会内分泌遗传代谢学组、中华医学会儿科学分会神经学组、中华医学会儿科学分会康复学组和《中华实用儿科临床杂志》编辑委员会以婴幼儿最常见的神经肌肉病-脊髓性肌萎缩症(spinal muscular atrophy,SMA)为例,根据国家卫生健康委员会发布的相关疾病诊治方案和SMA多学科管理专家共识,结合儿童COVID-19的临床特点,制定了以SMA为代表的神经肌肉病患儿COVID-19的防控建议以及疫情期间康复训练和用药指导的专家建议,以指导合并COVID-19的神经肌肉病患儿的诊治及其居家管理、康复。  相似文献   
53.
天麻素是从兰科植物天麻的块茎中提取分离而得,现已人工合成。天麻素药理作用广泛,如镇痛、镇静安眠、促智、保护神经元、降血压、抗惊厥、抗癫痫、抗氧化、抗衰老、改善微循环等,且安全、无明显毒副作用,其相关制剂在临床上亦被广泛用于心脑血管及神经精神系统疾病,如头痛、冠心病、高血压、后循环缺血性眩晕、突发性耳聋、癫痫、神经衰弱及脑卒中等。考虑到天麻素临床治疗上述疾病常与其他药物或治疗方法联用,故其体内过程及其药代动力学性质不容忽视。目前,有关天麻素综述多集中于药理作用和临床应用方面,而其药代动力学综述鲜见报道。随着天麻素药代动力学研究日渐深入,本研究将从其样品前处理、测定方法、药物ADME过程及影响体内过程的因素等方面较系统全面地对天麻素近年来的药代动力学研究作一综述,以期对天麻素制剂工艺及临床联合配伍应用有所裨益。  相似文献   
54.
55.
国内药事管理专业起步较晚,对该领域人才需求突出;中医药行业药事管理专业人才培养及储备尤为重要。从药事管理学科背景出发,结合中医药行业特点,以北京中医药大学为例;提出中医药院校在药事管理专业教育中,应让学生传承中国传统文化,重视以哲学思维为引领,培养以人为本及融合中庸之道的管理能力,掌握中医药理论+通识管理的特色专业课程知识,具备继承不泥古、创新不离宗等综合素质。  相似文献   
56.
Resident and inflammatory macrophages are essential effectors of the innate immune system. These cells provide innate immune defenses and regulate tissue and organ homeostasis. In addition to their roles in diseases such as cancer, obesity and osteoarthritis, they play vital roles in tissue repair and disease rehabilitation. Macrophages and other inflammatory cells are recruited to tissue injury sites where they promote changes in the microenvironment. Among the inflammatory cell types, only macrophages have both pro-inflammatory(M1) and anti-inflammatory(M2) actions, and M2 macrophages have four subtypes. The co-action of M1 and M2 subtypes can create a favorable microenvironment, releasing cytokines for damaged tissue repair. In this review, we discuss the activation of macrophages and their roles in severe peripheral nerve injury. We also describe the therapeutic potential of macrophages in nerve tissue engineering treatment and highlight approaches for enhancing M2 cell-mediated nerve repair and regeneration.  相似文献   
57.
Background:Colon cancer is a common malignant tumor of the gastrointestinal tract. Therefore, a clear diagnosis is particularly important for the treatment of colon cancer. Ultrasound and spiral computed tomography (CT) can both be used in the diagnosis, but each has its own advantages and disadvantages, which could cause confusion in clinical choice. The purpose of this study was to systematically evaluate the practicability of spiral CT and ultrasound in the diagnosis of colon cancer.Methods:A systematic search was performed by retrieving on English databases (PubMed, Embase, Web of Science, the Cochrane Library) and Chinese databases (CNKI, Wanfang, Weipu [VIP], CBM). Besides, manually search for Google and Baidu academic of diagnostic experimental study of ultrasound and spiral CT in the diagnosis of Colon Cancer. The retrieval time limit was from the establishment of the database to October 2020. Two researchers independently extracted and evaluated the quality of the data in the included study. A meta-analysis was performed using Meta Disc1.4 and RevMan5.3 software.Results:Sensitivity, specificity, positive Likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were used to determine the diagnostic efficacy of ultrasonography and helical CT in colorectal cancer.Conclusions:This study will compare the practicability of CT and ultrasound in the diagnosis of colon cancer and provide reliable evidence-based basis for clinicians to choose the appropriate or best evidence-based basis.Ethics and dissemination:The private information from individuals will not be published. This systematic review also will not involve endangering participant rights. Ethical approval is not required. The results may be published in a peer-reviewed journal or disseminated in relevant conferences.OSF Registration number:DOI 10.17605/OSF.IO/WAJHQ  相似文献   
58.
59.
This study aimed to examine the association between floods and the morbidity of dysentery and to quantify the burden of dysentery due to floods in Nanning, China. A generalized additive mixed model was conducted to assess the relationship between monthly morbidity of dysentery and floods from 2004 to 2010. The years lived with disability (YLDs) of dysentery attributable to floods were then estimated based on the WHO framework of the burden of disease study for calculating the potential impact fraction. The relative risk (RR) of floods on the morbidity of dysentery was 1.44 (95% confidence interval [CI] = 1.18–1.75). The models suggest that a potential 1-day rise in flood duration may lead to 8% (RR = 1.08, 95% CI = 1.04–1.12) increase in the morbidity of dysentery. The average attributable YLD per 1,000 of dysentery caused by floods were 0.013 in males, 0.005 in females, and 0.009 in persons. Our study confirms that floods have significantly increased the risk and the burden of dysentery in the study area. Public health action should be taken to prevent and control the potential risk of dysentery after floods. Vulnerable groups such as males and children should be paid more attention.  相似文献   
60.
研究生科学道德和学风建设是学位与研究生教育的重要组成部分。针对近年来科学研究和学术活动中各种违背科学道德和学术规范的行为时有发生,国家教育部对研究生科学道德和学风建设日益重视,因此构建研究生的科学道德和学风教育质量管理体系具有十分重要的意义。实现研究生科学道德和学风教育质量体系的方针和目标需具备三个要素,即教育实践的模式(集主题教育、方法学习、学术实践三位一体)、有效性评价机制和绩效考核机制。此外,尚需建立体系优化机制,以适应各种内外部因素的变化,保持体系的更新和优化。  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-23

京公网安备 11010802026262号