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   19490篇
  免费   1467篇
  国内免费   430篇
耳鼻咽喉   158篇
儿科学   193篇
妇产科学   137篇
基础医学   3292篇
口腔科学   557篇
临床医学   1841篇
内科学   2623篇
皮肤病学   807篇
神经病学   1350篇
特种医学   715篇
外国民族医学   3篇
外科学   1284篇
综合类   1946篇
现状与发展   7篇
预防医学   1950篇
眼科学   871篇
药学   2078篇
  25篇
中国医学   524篇
肿瘤学   1026篇
  2024年   91篇
  2023年   472篇
  2022年   721篇
  2021年   1000篇
  2020年   887篇
  2019年   702篇
  2018年   657篇
  2017年   672篇
  2016年   679篇
  2015年   772篇
  2014年   1314篇
  2013年   1363篇
  2012年   1128篇
  2011年   1212篇
  2010年   905篇
  2009年   886篇
  2008年   897篇
  2007年   810篇
  2006年   647篇
  2005年   597篇
  2004年   543篇
  2003年   488篇
  2002年   403篇
  2001年   353篇
  2000年   258篇
  1999年   228篇
  1998年   238篇
  1997年   212篇
  1996年   173篇
  1995年   181篇
  1994年   166篇
  1993年   128篇
  1992年   140篇
  1991年   137篇
  1990年   126篇
  1989年   94篇
  1988年   113篇
  1987年   116篇
  1986年   78篇
  1985年   146篇
  1984年   133篇
  1983年   99篇
  1982年   107篇
  1981年   79篇
  1980年   75篇
  1979年   45篇
  1978年   28篇
  1977年   20篇
  1976年   23篇
  1974年   11篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
目的:探讨加速儿童髋关节一过性滑膜炎疾病的愈合.方法:随机性分析2005年1月~2006年4月共100例髋关节一过性滑膜炎患儿的治疗效果,把病人随机分为治疗组及对照组.治疗组按常规方法治疗加TDP灯局部照射,对照组仅按常规方法治疗.结果:治疗1周后,治疗组B超检查增厚滑膜厚度变化差值、关节腔间隙宽度变化值、关节腔积液好转率、"4"字试验阴性率均明显优于对照组(P<0.05).结论:TDP灯用于治疗儿童髋关节一过性滑膜炎能加速疾病愈合,提高治疗效果.  相似文献   
12.
本文将聚乙二醇(PEG)比浊法和固相酶联免疫法(ELISA)结合,建立了—较灵敏的免疫复合物(IC)直接固相吸附抗原特异性检测法。利用牛清蛋白(BSA)为已知抗原组份的IC模型,分别对IC直接固相吸附的条件和影响因素、方法的灵敏度、重复性等进行了研究。结果发现IC在解离状态下直接固相吸附后的抗原特异性检测灵敏度明显高于未解离者。该法具有简单易行,灵敏度较高、适于临床测定大量血清样品等优点。  相似文献   
13.
BACKGROUND: Based on good results in the treatment of superficial skin tumours, since the early 1990s topical photodynamic therapy with aminolaevulinic acid (ALA PDT) has been used for disseminated, inflammatory dermatoses including psoriasis. However, there is still a lack of well-documented trials. OBJECTIVE: A prospective randomized, double-blind phase I/II intrapatient comparison study was conducted in 12 patients to investigate whether topical ALA PDT is an effective treatment for chronic plaque-type psoriasis. METHODS: In each patient three psoriatic plaques were randomly treated with a light dose of 20 J/cm(2) and 0.1%, 1% and 5% ALA, respectively. Treatment was conducted twice a week until complete clearance or for a maximum of 12 irradiations. Therapeutic efficacy was assessed by weekly determination of the psoriasis severity index (PSI). RESULTS: The mean percentage improvement was 37.5%, 45.6% and 51.2% in the 0.1%, 1% and 5% ALA-treated groups, respectively. Irradiation had to be interrupted several times because of severe burning and pain sensation. CONCLUSION: Topical ALA PDT did not prove to be an appropriate treatment option for plaque-type psoriasis due to disappointing clinical efficacy, the time-consuming treatment procedure and its unfavourable adverse event profile.  相似文献   
14.
Osteolysis induced by ultrahigh molecular weight polyethylene wear debris has been recognized as the major cause of long-term failure in total joint arthroplasties. In a previous study, the prevalence of intraoperatively identified osteolysis during primary revision surgery was much higher in mobile bearing knee replacements (47%) than in fixed bearing knee replacements (13%). We postulated that mobile bearing knee implants tend to produce smaller sized particles. In our current study, we compared the particle size and morphology of polyethylene wear debris between failed mobile bearing and fixed bearing knees. Tissue specimens from interfacial and lytic regions were extracted during revision surgery of 10 mobile bearing knees (all of the low contact stress (LCS) design) and 17 fixed bearing knees (10 of the porous-coated anatomic (PCA) and 7 of the Miller/Galante design). Polyethylene particles were isolated from the tissue specimens and examined using both scanning electron microscopy and light-scattering analyses. The LCS mobile bearing knees produced smaller particulate debris (mean equivalent spherical diameter: 0.58 microm in LCS, 1.17 microm in PCA and 5.23 microm in M/G) and more granular debris (mean value: 93% in LCS, 77% in PCA and 15% in M/G).  相似文献   
15.
Concern about short- and long-term ultraviolet radiation (particularly UVB) damage to the eye has led to increased research in this area. Numerous studies have confirmed the pathogenic enhancing roles of reflected ultraviolet (UV) and visible radiation in our environment. There is concern that conventional sunglasses do not protect the eye adequately from reflected rays (albedo), especially on the lateral aspect, from behind and from below. Using eye models and computer ray tracing methods, the pathways of oblique rays incident at the temporal peripheral cornea have been plotted by Maloof, Ho and Coroneo.1 These rays are refracted and focused and theoretically can result in up to 20 times the concentration of incident irradiance at the nasal anterior chamber angle and nasal equatorial cortex of the crystalline lens. The purpose of this study was to determine the limits of angular subtense of the incident peripheral light which is refracted in this manner in human subjects and to investigate the relation between corneal shape and certain ocular parameters to the limits. A statistically significant positive correlation was found between temporal entrance angle and anterior chamber depth (r = 0.70, P< 0.0006). The entrance angle ranged from 15 degrees to 30 degrees and was located 10 degrees to 45 degrees posterior to the coronal plane. Our results support Maloof and colleagues' predictions for the implication of focused peripheral UV and high intensity visible radiation in the pathogenesis of pterygium and cortical cataract and emphasise the need for lateral eye protection in conditions of high ultraviolet albedo.  相似文献   
16.
应用我室建立的化学发光自显影技术检测鸭沙门氏菌。用酶标抗体与硝酸纤维素膜上固定的细菌结合,再同发光底物溶液作用,使X线胶片感光,根据胶片上的黑斑进行半定量,可检出100个菌。其检测特异性好,约2小时即可出报告。  相似文献   
17.
基于DSP的远程监护终端系统的研究   总被引:4,自引:0,他引:4  
阐述一种基于DSP的远程家庭监护终端的程序设计。包括心电的采集,用小波变换完成QRS波的检测,最后将心电波形数据和检测结果通过互联网传输到医院的心电服务器上。  相似文献   
18.
In a randomized cross-over design, 7 patients with winter depression were treated with a week of a bright (1700 lx) dawn simulation (0400 to 0600) and a week of standard bright (1700 lx) morning (0600 to 0800) light therapy. The Hamilton Rating Scale for Depression scores decreased significantly for the standard light therapy (18.9 to 6.6) but not for the bright dawn therapy (18.0 to 11.3). Early morning awakening was a frequent side effect with the bright dawn simulation. Although dawn simulation at a lower illuminance may be an effective treatment, the bright dawn used in this study showed only a nonsignificant trend to lower depression ratings. The illuminance of dawn simulation should be adjusted to minimize side effects.  相似文献   
19.
基于多分辨率分析的心电图QRS波检测   总被引:4,自引:1,他引:3  
从多分辨率分析出发,构造出一个用于心电图R波检测的滤波器,并在此滤波器的基础上提出了一种新的R波检测算法。本文详细论述了滤波器的构造方法和新的R波检测算法的原理及在实现中采用的一些策略,经MIT-BIH标准心律失常数据库验证,该算法对于各种干扰尤其是肌电干扰具有很强的抑制能力。算法实现简单,计算量小,在ECG信号的脱机和实时处理程序中均可使用。  相似文献   
20.
基因定量检测已经成为研究基因组变异以及由于基因重组所引起的相关疾病的重要手段。大片段的基因组的重复和缺失可以引起致病突变。使用PCR和测序等定性检测方法很难探测到杂合状态的缺失和重复,因此探寻高效、可靠、灵敏的基因定量检测方法是当务之急。在过去的几年中已经相继出现了一些自动高效的技术方法。现在可用的基因定量方法大致可以分成3类:DNA印迹技术,细胞遗传学方法和以PCR扩增为基础的定量。本文对基因定量的最新进展作一综述,探讨其优缺点以期对定量研究方法的选择有所帮助。  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