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   387551篇
  免费   24777篇
  国内免费   8010篇
耳鼻咽喉   4271篇
儿科学   10644篇
妇产科学   7518篇
基础医学   31082篇
口腔科学   8962篇
临床医学   42741篇
内科学   49669篇
皮肤病学   5093篇
神经病学   20985篇
特种医学   8788篇
外国民族医学   312篇
外科学   41015篇
综合类   58056篇
现状与发展   12篇
一般理论   30篇
预防医学   40177篇
眼科学   5539篇
药学   36238篇
  401篇
中国医学   33754篇
肿瘤学   15051篇
  2023年   5877篇
  2022年   9977篇
  2021年   14653篇
  2020年   13497篇
  2019年   20049篇
  2018年   17649篇
  2017年   14065篇
  2016年   11163篇
  2015年   10466篇
  2014年   24959篇
  2013年   25345篇
  2012年   21507篇
  2011年   22954篇
  2010年   19960篇
  2009年   18180篇
  2008年   16141篇
  2007年   15651篇
  2006年   13611篇
  2005年   11701篇
  2004年   9501篇
  2003年   8305篇
  2002年   6531篇
  2001年   5809篇
  2000年   4813篇
  1999年   4167篇
  1998年   3385篇
  1997年   3232篇
  1996年   2801篇
  1995年   2680篇
  1994年   2594篇
  1993年   2065篇
  1992年   2093篇
  1991年   1806篇
  1990年   1587篇
  1989年   1427篇
  1988年   1337篇
  1987年   1157篇
  1985年   4605篇
  1984年   5970篇
  1983年   4450篇
  1982年   4586篇
  1981年   4380篇
  1980年   3837篇
  1979年   3537篇
  1978年   3097篇
  1977年   2231篇
  1976年   2687篇
  1975年   2095篇
  1974年   1830篇
  1973年   1667篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
201.
目的 分析子宫腺肌症可能对患者造成的心理影响,探讨子宫腺肌症患者的心理护理方法,观察护理效果。方法 将62例子宫腺肌症患者随机分配为常规护理干预组和心理护理干预组,每组31例。对常规护理干预组患者,实施常规护理干预措施。对心理护理干预组患者,在常规护理干预措施的基础上,进一步对其实施针对性的心理护理干预措施。结果 心理护理干预组患者的焦虑自评量表(SAS)评分、抑郁自评量表(SDS)评分,以及睡眠质量自评量表(SRSS)各维度评分,都明显低于常规护理干预组,差异具有统计学意义。心理护理干预组患者的生活质量综合评定量表(GQOLI-74)各维度评分,要显著的高于常规护理干预组,差异同样具有统计学意义。结论 应重视并切实做好对子宫腺肌症患者的心理护理工作,这能够有效缓解患者的焦虑、抑郁情绪,提高患者的心理健康水平,改善患者的水平及生活质量。  相似文献   
202.
舌癌患者手术及放化疗后会出现构音障碍、吞咽困难、口腔黏膜炎、口干、营养不良等并发症,使患者生存质量下降,甚至导致肿瘤的复发转移,影响生存期,单一方法往往顾此失彼。依托于中国中医科学院西苑医院肿瘤康复基地,杨宇飞教授在国内外调研考察基础上,结合中国国情,构建了一种“门诊多学科肿瘤康复模式”,在舌癌康复方面,以患者为中心,以中医肿瘤内科为主导,多学科共同参与,结合康复科、口腔科、营养科、药剂科等各科优势,形成全程个体化规范序贯康复方案,对患者及早进行康复,在放疗前进行预防性干预尤其重要,使患者能够快速缓解手术和放疗的不良反应,患者获益明显。现取两个典型案例总结其舌癌多学科康复的经验,以期为舌癌的康复提供借鉴。  相似文献   
203.
204.
目的 研究凉血通瘀方对高血压大鼠急性脑出血模型脑组织miRNA表达的影响,对差异表达的miRNA靶基因进行分析,探索凉血通瘀方可能的药效机制。方法 将自发性高血压大鼠随机分成对照组(B)和实验组(C)。适应性饲养一周后,C组灌胃凉血通瘀方,B组灌胃等体积生理盐水,连续5天,每天1次。构建脑出血模型后收集脑组织,借助全转录组测序技术获得miRNA表达量,与miRBase数据库比对获取已知miRNA,使用miRDeep2预测新miRNA。差异分析软件为DESeq2,筛选阈值为|log2FC| ≥1 并且P <0.05。对显著差异表达的miRNA进行靶基因预测,对靶基因进行GO功能、KEGG通路富集和PPI网络分析。结果 实验组和对照组对比,共发现21个显著差异表达的miRNA,上调有9个,下调有12个,共预测得到1243个有统计学意义的靶基因。GO富集分析发现,生物过程中突触囊泡分泌的调节、神经递质分泌的调节和神经递质运输的调节占前三位,神经元投射终点、全膜、质膜区域和细胞投射则是主要的细胞成分。分子功能分别为小GTPase绑定、底物特异性跨膜转运蛋白活性和离子跨膜转运体活性。通路分析结果显示,靶基因在癌证通路、pI3K-Akt信号通路、人类乳头瘤病毒感染、神经活性配体-受体相互作用和MAPK通路等分布广泛。采用STRING网站和Cytoscape软件,根据MCC算法筛选出ADRA2C、CASR、CCL28、CCR1、DRD2、GNAT3、GRM2、DYNC1LI1、GABBR1、GNAI1等核心靶基因。结论 凉血通瘀方对脑出血急性期鼠脑组织内miRNA的表达有重要影响;显著差异表达miRNAs可能通过靶向核心基因调控凉血通瘀方干预急性脑出血的病理过程及预后。  相似文献   
205.
ObjectiveThe objective of this study was to investigate the association between morphological variation and postsurgical pulmonary vein (PV) stenosis (PPVS) in patients with cardiac total anomalous pulmonary venous connection (TAPVC).MethodsThis single-center, retrospective study included 168 pediatric patients who underwent surgical repair of cardiac TAPVC from 2013 to 2019 (connection to the coronary sinus [CS], n = 136; connection directly to the right atrium [RA], n = 32). Three-dimensional computed tomography modeling and geometric analysis were performed to investigate the morphological features; their relevance to the PPVS was examined.ResultsThe connection type had no association with PPVS (CS type: 18% vs right atrial type: 19%; P = .89) but there was a higher incidence of PPVS in patients with a single PV orifice than > 1 orifice (P < .001). Confluence-to-total PV area ratio (hazard ratio, 4.78, 95% CI, 1.86-12.32; P = .001) and length of drainage route (hazard ratio, 1.22; 95% CI, 1.14-1.31; P < .001) had a 4- and 1-fold increase in the risk for PPVS in the CS type after adjustment for age and preoperative pulmonary venous obstruction. In the right atrial type, those with anomalous PV return to the RA roof were more likely to develop PPVS than to the posterior wall of the RA (P < .001).ConclusionsThe number of inter-junction PV orifice correlated with PPVS development in cardiac TAPVC. The confluence-to-total PV ratio, length of drainage route, and anomalous PV return to the RA roof are important predictors for PPVS. Morphological subcategorization in this clinical setting can potentially assist in surgical decision-making.  相似文献   
206.
207.
208.
BackgroundA venous leg ulcer is a chronic leg wound caused by poor venous blood circulation in the lower limbs. It is a recurring condition causing pain, malodour, reduced mobility, and depression. Randomised controlled trials evaluating treatments for venous leg ulcers provide important evidence to inform clinical decision-making. However, for findings to be useful, outcomes need to be clinically meaningful, consistently reported across trials, and fully reported. Research has identified the large number of outcomes reported in venous leg ulcer trials, impacting both synthesis of results, and clinical decision-making. To address this, a core outcome set will be developed. A core outcome set is an agreed standardised set of outcomes which should be, as a minimum, measured and reported in all trials which evaluate treatment effectiveness for a given indication. A core outcome set has the potential to reduce research waste, improve the utility of RCTs, reduce reporting bias, facilitate treatment comparisons across different sources of evidence and expedite the production of systematic reviews, meta-analyses and evidence-based clinical guidelines.AimThe aim of this project is to develop a core outcome set for research evaluating the effectiveness of interventions for treating venous leg ulceration.MethodsThrough a scoping review of the literature on venous leg ulceration, we will firstly identify a list of candidate outcome domains (broad categories in relation to what is being measured) from randomised controlled trials and qualitative research, and outcomes (specific methods in relation to what is being measured). In two further stages, we will use the resulting lists of outcome domains and outcomes to design two online surveys. A range of stakeholders will be invited to participate in the surveys and they will be asked to indicate which outcome domains and outcomes are most important and should be considered as core in future research reports.  相似文献   
209.
目的 利用网络药理学和分子对接技术研究石菖蒲抗癫痫的有效成分及作用机制。方法 运用中药系统药理数据库及分析平台检索石菖蒲有效成分及主要靶点,通过GeneCards数据库收集癫痫疾病的相关潜在作用靶点,运用Cytoscape.3.7.1和 String绘制石菖蒲-癫痫靶点互作关系图,运用Metascape数据库进行GO和KEGG信号通路富集分析。运用AutoDock Vina 1.1.2软件对石菖蒲主要有效成分与癫痫相关靶标进行分子对接验证;通过构建戊四唑诱导的癫痫模型初步评价石菖蒲提取物及潜在有效成分的抗癫痫作用。结果 由 TCMSP 筛选得到4个有效成分及76个主要靶点。癫痫疾病以“Score”大于1.5分进行筛选得到3685个靶标。GO富集分析得到BP条目10个,细胞CC条目9个,MF条目10个(P<0.01),主要涉及核受体活性、离子通道活性、激素结合、神经递质受体活性、蛋白激酶活性、钙调蛋白结合等。KEGG 富集得到14条通路,主要涉及c型凝集素受体信号通路、雌激素信号通路、Ca2+信号通路、逆行内源性大麻素信号通路等。分子对接结果显示,桉脂素、山奈酚和8-异戊烯基山奈酚与癫痫关键靶标GABRA2、PPARG等具有良好的结合活性。动物实验结果表明,石菖蒲水提取物及主要潜在有效成分桉脂素和山奈酚在PTZ致小鼠癫痫模型上显示出较好的抗癫痫活性。结论 本研究通过动物实验验证了石菖蒲提取物和潜在有效成分的抗癫痫活性,并且运用网络药理学和分子对接技术探讨了其抗癫痫作用机制,发现石菖蒲可通过多个成分如桉脂素、山奈酚、8-异戊烯基山奈酚,多靶点如GABAA、PPARG等,多条通路如雌激素信号通路、钙信号通路对机体产生协调效应从而抑制癫痫的发作。该研究提示石菖蒲治疗癫痫具有多成分、多靶点、多通路特点,为石菖蒲的进一步研究提供数据支撑。  相似文献   
210.
Matrix metalloproteinase-11 (MMP11) is an enzyme with proteolytic activity against matrix and nonmatrix proteins. Although most MMPs are secreted as inactive proenzymes and are later activated extracellularly, MMP11 is activated intracellularly by furin within the constitutive secretory pathway. It is a key factor in physiological tissue remodeling and its alteration may play an important role in the progression of epithelial malignancies and other diseases. TCGA colon and colorectal adenocarcinoma data showed that upregulation of MMP11 expression correlates with tumorigenesis and malignancy. Here, we provide evidence that a germline variant in the MMP11 gene (NM_005940: c.232C>T; p.(Pro78Ser)), identified by whole exome sequencing, can increase the tumorigenic properties of colorectal cancer (CRC) cells. P78S is located in the prodomain region, which is responsible for blocking MMP11's protease activity. This variant was detected in the proband and all the cancer-affected family members analyzed, while it was not detected in healthy relatives. In silico analyses predict that P78S could have an impact on the activation of the enzyme. Furthermore, our in vitro analyses show that the expression of P78S in HCT116 cells increases tumor cell invasion and proliferation. In summary, our results show that this variant could modify the structure of the MMP11 prodomain, producing a premature or uncontrolled activation of the enzyme that may contribute to an early CRC onset in these patients. The study of this gene in other CRC cases will provide further information about its role in CRC development, which might improve patient treatment in the future.  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