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   421篇
  免费   28篇
  国内免费   5篇
耳鼻咽喉   1篇
儿科学   2篇
妇产科学   2篇
基础医学   54篇
口腔科学   19篇
临床医学   74篇
内科学   15篇
皮肤病学   1篇
神经病学   7篇
特种医学   29篇
外科学   24篇
综合类   31篇
预防医学   59篇
药学   81篇
中国医学   26篇
肿瘤学   29篇
  2024年   3篇
  2023年   13篇
  2022年   19篇
  2021年   14篇
  2020年   11篇
  2019年   14篇
  2018年   14篇
  2017年   15篇
  2016年   19篇
  2015年   10篇
  2014年   34篇
  2013年   29篇
  2012年   40篇
  2011年   40篇
  2010年   20篇
  2009年   24篇
  2008年   15篇
  2007年   26篇
  2006年   15篇
  2005年   13篇
  2004年   13篇
  2003年   7篇
  2002年   8篇
  2001年   6篇
  2000年   5篇
  1999年   5篇
  1998年   5篇
  1997年   5篇
  1996年   1篇
  1995年   2篇
  1992年   3篇
  1991年   1篇
  1987年   1篇
  1985年   2篇
  1975年   1篇
  1973年   1篇
排序方式: 共有454条查询结果,搜索用时 15 毫秒
1.
李云  王凡 《安徽医学》2019,40(6):603-605
目的研究滑轨CT不同配准方式对肺癌大分割调强放疗摆位误差的影响。方法选取2016年10月至2017年10月在安徽医科大学第一附属医院放疗科就诊的肺癌患者24例,每周行滑轨CT扫描所得图像与原计划图像行灰度、骨性、手动3种模式在线配准,得出X、Y、Z轴3个方向平移误差,并进行统计分析。结果灰度配准、骨性配准和手动配准方式测量的X、Y、Z轴摆位误差分别为(0. 21±0. 16)、(0. 29±0. 15)、(0. 37±0. 22) cm,(0. 27±0. 16)、(0. 35±0. 25)、(0. 29±0. 19) cm,(0. 18±0. 12)、(0. 28±0. 16)、(0. 23±0. 14) cm,结果显示Y轴平移误差最大,其次为X轴,Z轴最小,且3组数据的差异有统计学意义(P <0. 05)。其中灰度模式在X、Y、Z轴上平移误差较骨性模式均缩小,灰度模式在X、Z轴上平移误差较手动模式有所缩小,差异有统计学意义(P <0. 05)。结论肺癌患者行图像引导大分割调强放疗时,应用滑轨CT中的灰度模式可缩小摆位误差。  相似文献   
2.
Reproductive toxicity testing is characterized by high animal use. For registration of pharmaceutical compounds, developmental toxicity studies are usually conducted in both rat and rabbits. Efforts have been underway for a long time to design alternatives to animal use. Implementation has lagged, partly because of uncertainties about the applicability domain of the alternatives.  相似文献   
3.
目的了解双休日试行免挂号费的周门诊量变化情况,为加强门诊管理提供依据。方法对医院信息系统数据库中的2007年1月~8月与2006年1月~8月门诊量、门诊收入、入院人数数情况按周进行分类统计,并通过走访医师、导医、挂号员、病人了解情况。结果某医院双休日实行免挂号费后门诊量增长明显,但存在虚高现象,原因也比较多。结论双休日免挂号费政策深受群众欢迎,但要高度重视免费号所带来的门诊量虚高现象,改进双休日免挂号费的管理制度,加强监管。  相似文献   
4.
目的分析门诊挂号现状,提高预约挂号比例,解决老百姓"挂号难"的问题。方法通过现有门诊挂号的三种模式,开展调查,对统计数据进行对比分析。结果窗口挂号仍然是患者多年养成的就医习惯占99.42%;电话预约挂号占0.24%;网络预约挂号约占0.34%。结论改变患者多年养成的就医习惯,需要引导患者转变就医挂号观念,疏导患者就医挂号合理性,医院加大宣传力度,探索有效的预约挂号方法,提高预约挂号比例,减轻挂号窗口压力,缩短患者就诊时间,控制和减少院内交叉感染,真正解决"挂号难"的问题,提高预约挂号率。  相似文献   
5.
Computer assisted navigation systems are frequently used in spine surgery to improve the accuracy of pedicle screw placement. The 7D Surgical System utilizes optical topographic imaging (OTI) with a camera positioned directly above the surgical field to perform rapid registration from a pre-operative CT scan onto anatomical landmarks with zero intra-operative radiation exposure. This current technology requires an open approach with well-exposed bony anatomy, raising concerns about using the 7D Surgical System in revision surgery, where typical anatomical landmarks may be altered, missing, or obscured by prior hardware. To overcome this, the 7D Surgical System is capable of registering off prior hardware. Here, we present the first published report of 7D Surgical System’s registration off prior hardware in a revision spinal fusion. The registration was accurate, and the workflow was easy and efficient with one registration required for 3 levels of instrumentation and discectomy/corpectomy. This demonstrates that the 7D Surgical System can be used in revision cases with altered, missing, or obscured anatomy.  相似文献   
6.
7.
《Toxicology in vitro》2014,28(4):571-587
The knowledge-based search engine Go3R, www.Go3R.org, has been developed to assist scientists from industry and regulatory authorities in collecting comprehensive toxicological information with a special focus on identifying available alternatives to animal testing. The semantic search paradigm of Go3R makes use of expert knowledge on 3Rs methods and regulatory toxicology, laid down in the ontology, a network of concepts, terms, and synonyms, to recognize the contents of documents. Search results are automatically sorted into a dynamic table of contents presented alongside the list of documents retrieved. This table of contents allows the user to quickly filter the set of documents by topics of interest. Documents containing hazard information are automatically assigned to a user interface following the endpoint-specific IUCLID5 categorization scheme required, e.g. for REACH registration dossiers. For this purpose, complex endpoint-specific search queries were compiled and integrated into the search engine (based upon a gold standard of 310 references that had been assigned manually to the different endpoint categories). Go3R sorts 87% of the references concordantly into the respective IUCLID5 categories. Currently, Go3R searches in the 22 million documents available in the PubMed and TOXNET databases. However, it can be customized to search in other databases including in-house databanks.  相似文献   
8.
BackgroundSurgical navigation requires precise registration of the pre-operative image dataset to the patient in the operation theatre. Different marker-based and marker-free registration techniques are available, each of them with advantages and disadvantages regarding precision and clinical handling. In this model study, the precision of two dental splint techniques for marker-based registration is analyzed.Materials and methodsA synthetic full-size human skull was registered with its cone beam computed tomography dataset using (a) a dentally-mounted “rapid” occlusal splint with five titanium screws directly attached to the splint, (b) an “extender”, a dentally-mounted occlusal splint with similar fiducials fixed to an extension of the splint. The target registration error was measured for 170 landmarks distributed over the viscero- and neurocranium in 10 repeats per splint type using the Vector Vision2 (BrainLAB AG, Heimstetten, Germany) navigation system. Statistical and graphical evaluations were performed per anatomical region.ResultsIn the periorbital region, the rapid splint, with an average deviation of 1.50 mm (SD = 0.439) showed greater accuracy than the extender with 1.76 mm (SD = 0.525). The viscerocranial results for both splints were similar (extender 1.84 mm, SD = 0.559, rapid occlusal splint 1.86 mm, SD = 0.686). In the cranial vault region, registration with the extender (2.33 mm, SD = 0.685) proved to be more precise than with the rapid splint (2.86 mm, SD = 0.929).ConclusionsDue to the more compact dimension of the rapid occlusal splint, errors close to the splint were smaller compared to the extender technique. The advantage of greater distances between the registration fiducials on the extender is particularly important in areas such as the orbital roof, the cranial vault, and the lateral skull base.  相似文献   
9.
10.
Three‐dimensional (3D) printing technology, virtual reality, and augmented reality technology have been used to help surgeons to complete complex total hip arthroplasty, while their respective shortcomings limit their further application. With the development of technology, mixed reality (MR) technology has been applied to improve the success rate of complicated hip arthroplasty because of its unique advantages. We presented a case of a 59‐year‐old man with an intertrochanteric fracture in the left femur, who had received a prior left hip fusion. After admission to our hospital, a left total hip arthroplasty was performed on the patient using a combination of MR technology and 3D printing technology. Before surgery, 3D reconstruction of a certain bony landmark exposed in the surgical area was first performed. Then a veneer part was designed according to the bony landmark and connected to a reference registration landmark outside the body through a connecting rod. After that, the series of parts were made into a holistic reference registration instrument using 3D printing technology, and the patient's data for bone and surrounding tissue, along with digital 3D information of the reference registration instrument, were imported into the head‐mounted display (HMD). During the operation, the disinfected reference registration instrument was installed on the selected bony landmark, and then the automatic real‐time registration was realized by HMD through recognizing the registration landmark on the reference registration instrument, whereby the patient's virtual bone and other anatomical structures were quickly and accurately superimposed on the real body of the patient. To the best of our knowledge, this is the first report to use MR combined with 3D printing technology in total hip arthroplasty.  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