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   10942篇
  免费   594篇
  国内免费   1033篇
耳鼻咽喉   105篇
儿科学   131篇
妇产科学   164篇
基础医学   1737篇
口腔科学   136篇
临床医学   708篇
内科学   2085篇
皮肤病学   113篇
神经病学   546篇
特种医学   234篇
外科学   937篇
综合类   1630篇
现状与发展   37篇
一般理论   10篇
预防医学   717篇
眼科学   446篇
药学   1202篇
  3篇
中国医学   335篇
肿瘤学   1293篇
  2024年   34篇
  2023年   154篇
  2022年   68篇
  2021年   101篇
  2020年   73篇
  2019年   61篇
  2018年   70篇
  2017年   52篇
  2016年   60篇
  2015年   87篇
  2014年   222篇
  2013年   159篇
  2012年   1718篇
  2011年   1905篇
  2010年   400篇
  2009年   215篇
  2008年   1131篇
  2007年   1031篇
  2006年   974篇
  2005年   896篇
  2004年   735篇
  2003年   606篇
  2002年   493篇
  2001年   305篇
  2000年   378篇
  1999年   216篇
  1998年   125篇
  1997年   51篇
  1996年   31篇
  1995年   21篇
  1994年   14篇
  1993年   7篇
  1992年   9篇
  1991年   6篇
  1990年   5篇
  1989年   25篇
  1988年   21篇
  1987年   18篇
  1986年   11篇
  1985年   21篇
  1984年   18篇
  1983年   14篇
  1982年   9篇
  1981年   11篇
  1980年   2篇
  1979年   4篇
  1978年   1篇
  1960年   1篇
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
1.
归纳我国脑卒中后抑郁(PSD)护理研究的热点和前沿,分析其研究的阶段特征及趋势。方法 计算机检索我国PSD护理研究的相关文献,时间范围为2010—2019年,利用CiteSpace软件进行知识图谱绘制及可视化分析。结果 于中国知网数据库检索到2010—2019年发表的PSD护理研究文献共779篇,论文年发表数均在60篇以上。纳入文献的高频关键词频次居前5位的依次为脑卒中、抑郁、心理护理、PSD及护理,关键词共现图谱中网络节点数N=423,连线数量E=1 390,网络密度D=0.0 156,节点最大的是脑卒中。纳入文献最早出现的突现词是护理干预,紧接着是心理护理干预,之后在2016年、2017年相继出现了生活能力和心理状态,并持续到现在,成为研究前沿。在PSD护理研究领域总发文数在2篇及以上的作者为核心作者,共64位核心作者,核心作者共计发文139篇,还未形成核心作者群。结论 现阶段我国护理研究越来越重视脑卒中后患者抑郁的问题,且将提出较多行之有效的具体护理干预措施,并在内容上越来越注重护理人文关怀。  相似文献   
2.
Dr.Spampinato gave an insightful comment on "Mesenchymal stem cell secretome to control inflammation in allergic conjunctivitis" (1).Dr.Spampinato proposed that it is key to get the complete knowledge of mesenchymal stem cell (MSC) secretome composition in order to better understand MSC secretome and to achieve the best therapeutic effect of MSC secretome for clinic setting.This comment is highly significant and important.  相似文献   
3.
Objective:Pancreatic ductal adenocarcinoma(PDAC)is a deadly malignancy,due in large part to its resistance to conventional therapies,including radiotherapy(RT).Despite RT exerting a modest antitumor response,it has also been shown to promote an immunosuppressive tumor microenvironment.Previous studies demonstrated that focal adhesion kinase inhibitors(FAKi)in clinical development inhibit the infiltration of suppressive myeloid cells and T regulatory(T regs)cells,and subsequently enhance effector T cell infiltration.FAK inhibitors in clinical development have not been investigated in combination with RT in preclinical murine models or clinical studies.Thus,we investigated the impact of FAK inhibition on RT,its potential as an RT sensitizer and immunomodulator in a murine model of PDAC.Methods:We used a syngeneic orthotopic murine model to study the effect of FAKi on hypofractionated RT.Results:In this study we showed that IN10018,a small molecular FAKi,enhanced antitumor response to RT.Antitumor activity of the combination of FAKi and RT is T cell dependent.FAKi in combination with RT enhanced CD8+T cell infiltration significantly in comparison to the radiation or FAKi treatment alone(P<0.05).FAKi in combination with radiation inhibited the infiltration of granulocytes but enhanced the infiltration of macrophages and T regs in comparison with the radiation or FAKi treatment alone(P<0.01).Conclusions:These results support the clinical development of FAKi as a radiosensitizer for PDAC and combining FAKi with RT to prime the tumor microenvironment of PDAC for immunotherapy.  相似文献   
4.
The formation of insoluble aggregates of beta - amyloid peptide ( A ) within the brain extracellular fluid is a critical event in the etiology of Alzheimer's disease (AD). In theory, an unbalanced A kinetics can be due to its over production, inadequate metabolic cleaning, or an improper balance of import or export of A or related molecules at brain barriers. We investigated the role of the choroid plexus, which forms a barrier between blood and brain cerebrospinal fluid ( CSF), in regulating A in the CSF. A uptake from CSF was determined as its volume of distribution ( VD ) into isola- ted rat choroid plexus tissue by using [^125I] A 1-40 and along with a extracellular space marker [^14C ] sucrose. The choroid plexus exhibited a definite capacity in sequestering [^125I] A 1-40 from the surrounding CSF. Uptake of [^125I] A by the choroid plexus was saturable, time - and temperature - dependent, and not ttffected by addition of transthyretin or apolipoprotein E3. Studies with cultured monolayers of primary choroid epithelial cells indicated that A permeability across cells, corrected by [ ^14C] sucrose, was greater from the CSF -facing membrane than from the blood -facing membrane. Similarly, cellular accumulation of [ ^125 I ] A was concentrative from both directions and was greater from the CSF -facing membrane. Quantitative real- time RT- PCR, immunodetection and enzyme activity assays further revealed the presence of several key enzymes involved in A production, e. g. , amyloid precursor protein and beta - secretase, and in A metabolism and alternate processing, e. g. , insulin degrading enzyme, endothelin - converting enzyme - 1, neprilysin and alpha - secretase. Overall, these results suggest the choroid plexus selectively cleanses A from the CSF by an undetermined mechanism (s) ; moreover, it has the capacity to degrade A , suggesting a vital role of this tissue in maintaining A homeostasis. The perspectives of drug development for treatment of AD by reducing A from brain extracellular fluid as a new strategy will be discussed.  相似文献   
5.
Three-dimensional diffusion tensor tract (DTT) is the newest imaging to describe the structure of white matter fiber in three-dimensions, it has great significance in dividing the concrete anatomic site of gray and white matter lesions, displaying the correlation with fibrous band and judging clinical prognosis, which is incomparable by other imagings.OBJECTTVE: To observe the conditions of corticospinal tract (CST) in acute cerebral ischemic stroke patients,and analyze the relationship between motor function and the severity of CST injury.DESIGN: A case-control observation.SETTTNG: Department of Medical Imaging, Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA.PARTTCTPANTS: Fifteen patients with acute cerebral infarction were selected from Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA from February to December in 2005. They all suffered from acute attack and motor disorder of hemiplegic limbs to different extent, and were conformed by CT or MRI.There were 9 males and 6 females, aging 16-87 years old, the median age was 51.7 years, and all were right handed. Fifteen right-handed normal subjects, who were matched by age and sex with the patients in the cerebral infarction group, were selected from the relatives of patients and physicians of the Imaging Department as the control group. All the subjects were informed and agreed with the study.METHODS: The patients with acute cerebral infarction and subjects in the control group received MR diffusion tensor imaging (DTI) with GE 1.5 T nuclear magnetic resonance system, fiber tracking with the software of dTV- Ⅱ. Fractional anisotropy (FA) maps and three-dimensional tractography of bilateral CST of all patients were created. Displacement, continuity and destroy of fibrous bands were observed. At the same time, muscle strength of ipsilateral hand of patients with cerebral infarction was measured with Brunnstrom standard. The correlation between the severity of CST injury and the muscle strength of ipsilateral hand was analyzed with spearman correlation analysis.MAIN OUTCOME MEASURES: ① FA values in the infarcted sites and those in the contralateral corresponding sites of patients with cerebral infarction; ② CST manifestations in the patients with cerebral infarction and the control group.RESULTS: All the 30 testees were involved in the analysis of results. ① The FA values in infarcted sites of white matter were significantly lower than those in the contralateral ones (t =4.570, P < 0.001 ). ② In the control group, bilateral CST were reconstructed, they originated from precentral gyrus, went downwards to internal capsule, and extended to pontine and medulla oblongata, each fiber had good uniformity in continuous form. In the patients with cerebral infarction, the forms of contralateral CST were consistent with those in the control group with good continuity. Due to the involvement by the infarcted site to different extents, the ipsilateral CST manifested as continuous interruption and loss of uniformity in anatomic structure and form. The CST involvements were divided into three grades: integrated CST for grade I (n =2); integrated CST but compressed or displaced for grade 2 (n =5); interrupted CST for grade 3 (n =8). ③ The severity of CST injury was obviously correlated with the muscle strength of the ipsilateral hand (r=0.888, P< 0.05=.CONCLUSION: ① CST is injured to different extents in patients with acute cerebral infarction, and the severity of injury is associated with muscle strength. It is indicated that it can be used to judge the prognosis of rehabilitative treatment. ②DTT can directly display the status of pyramidal tract more three-dimensionally.  相似文献   
6.
通过对西北地区军队医院文献信息资源的全面调查和统计分析,掌握各医院文献信息资源的现状及地理分布,提出了搞好文献资源建设的发展思路,处理好分工与协作的几个关系,并就医学文献数据库的开发建设、数字化图书馆的建设以及开展形式多样的信息服务进行了论述。此外,还对兰州军区中外文生物医学期刊联合目录的编制及建立电子图书馆等工作进行了介绍。  相似文献   
7.
中药足浴按摩对闭塞性动脉硬化患者肢体血流图的影响   总被引:1,自引:0,他引:1  
中药足浴按摩对闭塞性动脉硬化患者肢体血流图的影响潘金友1杨慧萍1郑萍2肢体闭塞性动脉硬化(arteriosclerosisobliterans,ASO)是老年性动脉退行性非炎症性疾病,由于高脂血症、高血压、糖尿病和血液流动产生的应力作用因素〔1〕,使...  相似文献   
8.
Objective To establish C57BL/6J embryonic stem (ES) cell lines with potential germ- line contribution Methods ES cells were isolated from blastocyst inner cell mass of C5 7BL/6J mice, and cultured for 15 passages, and then injected into blastococels of ICR mice blastocysts to establish chimeric mice. Results Three ES cell lines (mC57ES1,mC57ES3, mC57ES7) derived from the inner cell mass of C57BL/6J mice blastocysts were established. They were characteristic of undifferentiated state, including normal XY karyotype, expression of a specific cell surface marker “stage-specific embryonic antigen-I” and alkaline phosphatase in continuous passage. When injected into immunodeficient mice, mC57ES1 cells consistently differentiated into derivatives of all three embryonic germ layers. When mC57ES1 cells were transferred into ICR mice blastocysts, 4 chimeric mice have been obtained. One male of them revealed successful germ-line transmission. Conclussion We have obtained C57BL/6J ES cell lines with a potential germ-line contribution, which can be used to generate transgenic and gene knock-out mice.  相似文献   
9.
阳维德  郑萍 《华夏医学》2004,17(5):829-831
经皮冠状动脉介入治疗已成为治疗冠心病的重要手段之一,但术后再狭窄仍是介入心脏病学面临的难题。现论述雷帕霉素的一般药理特性和雷帕霉素洗脱支架预防再狭窄的基础研究、临床试验等方面的研究进展。并探讨了可能存在的问题。  相似文献   
10.
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