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   20657篇
  免费   3776篇
  国内免费   1001篇
耳鼻咽喉   94篇
儿科学   110篇
妇产科学   361篇
基础医学   1827篇
口腔科学   455篇
临床医学   2251篇
内科学   2391篇
皮肤病学   132篇
神经病学   1054篇
特种医学   889篇
外国民族医学   6篇
外科学   1903篇
综合类   3801篇
现状与发展   14篇
预防医学   1313篇
眼科学   1049篇
药学   3063篇
  16篇
中国医学   1342篇
肿瘤学   3363篇
  2024年   45篇
  2023年   676篇
  2022年   945篇
  2021年   1381篇
  2020年   1360篇
  2019年   974篇
  2018年   1003篇
  2017年   744篇
  2016年   960篇
  2015年   1228篇
  2014年   1843篇
  2013年   1582篇
  2012年   2109篇
  2011年   2182篇
  2010年   1638篇
  2009年   1226篇
  2008年   754篇
  2007年   1094篇
  2006年   969篇
  2005年   459篇
  2004年   395篇
  2003年   392篇
  2002年   313篇
  2001年   274篇
  2000年   225篇
  1999年   175篇
  1998年   188篇
  1997年   147篇
  1996年   93篇
  1995年   33篇
  1994年   14篇
  1993年   2篇
  1992年   2篇
  1991年   1篇
  1990年   4篇
  1989年   2篇
  1988年   1篇
  1984年   1篇
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
1.
PurposeTo provide means for calculating the dose received by various tissues of the patient, calculate lung shield, and verify received dose using a phantom as a tool for quality assurance for a planned Total Body Irradiation (TBI) procedure in radiotherapy.MethodUsing Microsoft Visual Basic, MATLAB, and Python, a program for Total Body Irradiation Calculation in Radiotherapy (TBICR) is constructed. It uses patient translation and beam zone method for total body irradiation calculations to compute the proper dose received by the patient and determine the lung shield thickness. There are three main user-friendly interfaces in the application. The first one allows the user to upload the TBI topography and estimate the distances needed for TBI calculations. The second one enables the user to count the number of beam zones needed for each point and estimate the effective area (Aeff) for each level. The third interface estimates the velocity required to deliver the relative dose depending on patient separation, Monitor Units (MU), couch speed and travel distance. It allows the user to compute the required lung shield thickness, read any patient's CT DICOM file and acquire dose in any distinct location using machine learning model to predict the dose.ResultsThe TBICR software has been successfully validated by reproducing all of the manual calculations in an exact and timely manner. TBICR generated more accurate results and confirmed the absorbed dose to patient through measurements on Anderson phantom.ConclusionsA computer program for the calculation of total body irradiation (TBI) is described in full. The dose received at each point on the patient, the calculation of lung shield and the determination of the velocity and time required for the couch movement are all made possible using the software. The ease of use, precision, data storage and printing are some important features of the present software.  相似文献   
2.
安宁疗护可提高患者在生命终末阶段的生活质量,减轻患者和家属的身心痛苦。科学合理的安宁疗护准入标准可帮助医护人员识别出需要安宁疗护服务的患者,使其及时获得安宁疗护服务,因此明确安宁疗护的准入标准是推进安宁疗护发展的基础。本文就国内外安宁疗护准入标准的制定方法、具体内容及优缺点进行综述,以期为我国安宁疗护准入标准的构建提供参考。  相似文献   
3.
目的研究糖尿病并发抑郁症患者运动依从性的影响因素,探讨有效的干预措施。方法选择2018年11月-2019年8月天津市公安医院收治的糖尿病患者158例为研究对象,根据抑郁自评量表(CES-D)调查情况分为糖尿病抑郁(DDM)组和糖尿病非抑郁(NDDM)组各79例,采用问卷的形式分析个体化健康教育指导前后患者运动依从性影响因素。结果 NDDM组患者运动依从性量表评分为(78.4±3.3)分,高于DDM组的(52.7±4.1)分;重度抑郁患者较轻度抑郁患者运动治疗依从性明显降低;两组患者个体化健康教育后运动依从性量表评分较教育前均提高,差异均有统计学意义(P<0.01)。不同运动依从性的糖尿病患者性别、婚姻状况、文化程度、家庭支持、医患关系、并发症数量、住院次数、BMI、HbA1c比较差异有统计学意义(P<0.05)。结论抑郁症对糖尿病患者的运动依从性有明显影响,且抑郁程度越重运动依从性越差。个体化健康教育能有效改善糖尿病并发抑郁症患者的运动依从性,值得临床进一步研究。  相似文献   
4.
5.
张瑾  张超 《中国肿瘤临床》2019,46(22):1189-1192
随着临床诊治水平的不断进步,肝细胞性肝癌(hepatocellular carcinoma,HCC)患者的总生存时间获得延长,但是HCC骨转移发生率则显著升高,HCC骨转移的筛查与诊治已成为全球性热点与难点问题。明确HCC骨转移的致病机制有助于临床肿瘤筛查及诊疗手段的提高,血管形成和上皮-间质转化(epithelial mesenchymal transition,EMT)是HCC骨转移的主要致病机制,骨微环境使得HCC骨转移持续发生。明确HCC骨转移的预后因素有利于对此类患者进行早期干预以延长患者总生存期,但目前尚未就HCC骨转移患者的治疗策略达成共识。本文就HCC骨转移分子病理学致病机制的研究进展进行综述,为早期筛查、精准诊断和个体化治疗提供依据。   相似文献   
6.
Many nanoparticles (NPs) have toxic effects on multiple cell lines. This toxicity is assumed to be related to their accumulation within cells. However, the process of internalization of NPs has not yet been fully characterized. In this study, the cellular uptake, accumulation, and localization of titanium dioxide nanoparticles (TiO2 NPs) in rat (C6) and human (U373) glial cells were analyzed using time-lapse microscopy (TLM) and transmission electron microscopy (TEM). Cytochalasin D (Cyt-D) was used to evaluate whether the internalization process depends of actin reorganization. To determine whether the NP uptake is mediated by phagocytosis or macropinocytosis, nitroblue tetrazolium (NBT) reduction was measured and the 5-(N-ethyl-N-isopropyl)-amiloride was used. Expression of proteins involved with endocytosis and exocytosis such as caveolin-1 (Cav-1) and cysteine string proteins (CSPs) was also determined using flow cytometry.TiO2 NPs were taken up by both cell types, were bound to cellular membranes and were internalized at very short times after exposure (C6, 30 min; U373, 2 h). During the uptake process, the formation of pseudopodia and intracellular vesicles was observed, indicating that this process was mediated by endocytosis. No specific localization of TiO2 NPs into particular organelles was found: in contrast, they were primarily localized into large vesicles in the cytoplasm. Internalization of TiO2 NPs was strongly inhibited by Cyt-D in both cells and by amiloride in U373 cells; besides, the observed endocytosis was not associated with NBT reduction in either cell type, indicating that macropinocytosis is the main process of internalization in U373 cells. In addition, increases in the expression of Cav-1 protein and CSPs were observed.In conclusion, glial cells are able to internalize TiO2 NPs by a constitutive endocytic mechanism which may be associated with their strong cytotoxic effect in these cells; therefore, TiO2 NPs internalization and their accumulation in brain cells could be dangerous to human health.  相似文献   
7.
8.
9.
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