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   594篇
  免费   39篇
  国内免费   5篇
耳鼻咽喉   18篇
儿科学   23篇
妇产科学   5篇
基础医学   60篇
口腔科学   3篇
临床医学   54篇
内科学   85篇
皮肤病学   11篇
神经病学   25篇
特种医学   13篇
外科学   41篇
综合类   45篇
预防医学   116篇
眼科学   26篇
药学   53篇
中国医学   10篇
肿瘤学   50篇
  2023年   7篇
  2022年   25篇
  2021年   54篇
  2020年   21篇
  2019年   25篇
  2018年   23篇
  2017年   14篇
  2016年   14篇
  2015年   22篇
  2014年   16篇
  2013年   28篇
  2012年   38篇
  2011年   46篇
  2010年   18篇
  2009年   21篇
  2008年   37篇
  2007年   40篇
  2006年   29篇
  2005年   21篇
  2004年   25篇
  2003年   16篇
  2002年   22篇
  2001年   13篇
  2000年   10篇
  1999年   7篇
  1998年   2篇
  1997年   4篇
  1996年   3篇
  1995年   4篇
  1994年   3篇
  1992年   4篇
  1991年   5篇
  1990年   1篇
  1989年   1篇
  1987年   7篇
  1974年   1篇
  1969年   1篇
  1966年   10篇
排序方式: 共有638条查询结果,搜索用时 15 毫秒
1.
The great majority of traumatic brain injury (TBI) is of mild severity, with Glasgow Coma Scores (GCS) of 13-15, post-traumatic amnesia of less than 48 hours and brief, if any, hospitalization. All mild TBI admissions to hospital were provided with education in the form of a brief interview and a brochure on minor head trauma from the National Head Injury Foundation. Seventy-seven insured individuals with mild TBI were contacted by phone between 1 and 3 months post-injury to determine the frequency and severity of post-traumatic symptoms and the rate of return to work (RTW). Twenty-six per cent of those contacted had subjective complaints; 88% had returned to work or school; 16% of those returning did so with some symptoms. Only 45% of symptomatic individuals sought medical consultation for their condition when offered. Education about post-traumatic symptoms from the onset may provide sufficient reassurance to most individuals that future use of medical services is seen as unnecessary. Rate of RTW is relatively higher than reported in previous studies of mild TBI.  相似文献   
2.
采用随机对照的方法,对氯丙咪嗪、氯丙嗪、氯丙咪嗪并氯丙嗪治疗91例精神分裂症伴发的强迫症状的治疗剂量、起效时间、疗效、副作用进行了研究。结果:氯丙咪嗪的平均治疗量163.68±17.76mg/d,氯丙嗪的平均治疗量756.75±26.57mg/d。氯丙咪嗪,氯丙咪嗪并氯丙嗪治疗精神分裂症的强迫症状疗效显著优于氯丙嗪(P<0.01)。起效时间为1周。氯丙嗪组和氯丙咪嗪并氯丙嗪组的锥体外系副作用比氯丙咪嗪组显著。  相似文献   
3.
针对医学微生物学实验线上教学面临的诸多难题,本研究采取线上直播+操作视频+虚拟实验的授课模式,通过操作视频和虚拟实验弥补了操作上的缺口;考核模式采用紧扣操作流程的主观型思考题+实验设计+文献综述(围绕传统实验由于条件所限无法开展的临床检验重头技术或新技术,如质谱分析、荧光定量PCR、G实验等展开)的模式,从而可以较大限度了解学生对教学目标的掌握程度和综合应用、创新性思维等能力。学生调查问卷显示,大部分学生对线上实验教学模式持肯定态度,学生作业的完成质量表明大部分学生学习效果良好。  相似文献   
4.
The recent introduction of digital film scanners in the medical-scientific field provided everyone dealing with light-microscopy an easy method to obtain low-power photomicrographs from entire histological sections. Direct scanning of the common microscope slide allows the easy creation of high quality images. The digital images obtained may be improved or retouched using dedicated software and then printed on paper or film. The required instrumentation is relatively unexpensive and neither skilled staff nor expertise of photographic techniques is required. This reduces costs and saves time. The obtained images may be employed in histopathology, embryology, histochemistry, image analysis and telepathology, and are suitable for scientific papers, educational purposes and lecturing, as well as for daily reporting. The authors bring their personal experience in this field, making also a complete literature review on the topic.  相似文献   
5.
Sarcoidosis (SA) is a systemic granulomatous disorder of unknown etiology characterized by T helper 1-type inflammatory responses at sites of disease with signs of B cell hyperactivity. Like rheumatoid arthritis and diabetes, an infectious etiology has frequently been postulated but no single infectious trigger definitively identified. Polymorphic alleles at SLC11A1 have previously been associated with susceptibility to both the putative infectious agents and to these autoimmune disorders. We therefore investigated its candidacy as a genetic determinant of SA in Poland in an association-based study comparing 86 SA patients with 85 tuberculosis (TB) patients and 93 control subjects. The functional promoter (GT)(n) polymorphism and four of 10 other single nucleotide or insertion/deletion polymorphisms genotyped across SLC11A1 were informative in our sample. Consistent with previous autoimmune disease studies, allele 3 at the functional (GT)(n) promoter region repeat polymorphism was significantly associated with SA when compared with healthy controls (odds ratio 1.68; 95% CI: 1.01-2.81; P=0.04) or with TB patients (odds ratio 1.69; 95% CI: 1.042-0.78; P=0.03).  相似文献   
6.
The cholinomimetic activity of Cimetidine and Ranitidine has been demonstrated by several authors. In the aim to better understand the phenomenon, we analyse the miniature end-plate current decay time. The prolongation of the decay phase of the synaptic current induced by the "selective" H2-antagonist Ranitidine, and to a lesser extent and at higher concentrations by Cimetidine, resembles that of the cholinesterase inhibitors. These agents usually prolong the quantal conductance change having little or no effect on the channel lifetime. The results of our previous experiments, which data were obtained by analyzing the "voltage" events, either spontaneous or evoked, of a classic frog preparation, showed a marked alteration of the temporal parameters. These effects, obtained at higher drug concentrations than those used in the present work, are now better defined by deriving extracellularly the "current" events. The results are also compared with those obtained by assaying the cholinesterase inhibitor Eserine, under the same experimental conditions.  相似文献   
7.
Twenty patients underwent resections for head and neck cancer. The reconstructive procedure used was the free forearm flap with microsurgical technique on 22 occasions. The free forearm flap was used in its simple or composite form, with double or manifold islands, with a segment of the radius for mandible reconstruction or with two islands joined solely by the vascular pedicle, constituting what the authors call "tandem flap", with excellent results. The procedure does not replace conventional ones, but the authors believe it should be regarded as one of the choice flaps by surgeons dedicated to this special field.  相似文献   
8.
From 1983 through 1989, 141 untreated patients with Hodgkin's disease underwent CT of the abdomen. They subsequently underwent staging laparotomy plus splenectomy and multiple biopsies of liver and lymph nodes, at the Institute of Radiology and Hematology, University "La Sapienza", Rome. CT results were compared with surgical findings to evaluate CT sensitivity, specificity, and overall accuracy. The cases from this series were divided into two groups depending on the characteristics of the CT scanners employed. From 1983 to 1985, 78 patients were examined with 2nd-generation CT units; from 1986 to 1989, 63 patients underwent CT performed with 3rd-generation scanners. The results from the two groups were analyzed according to these parameters. A total number of 622 biopsies were performed, of spleen, liver, and lymph nodes. CT sensitivity, specificity, and overall accuracy were: 22.9% (group I) vs 43.7% (group II), 83.1% vs 92%, and 68.4% vs 81.2% for lymph nodes; 28.1% vs 36.3%, 93.5% vs 98%, and 66.7% vs 87.3% for the spleen, and 12.5% vs 42.8%, 97.1% vs 98.2%, and 88.5% vs 92.1% for the liver. Our results demonstrate an obvious increase in reliability with newer units, even though a high percentage of false-negatives were still observed in our series, which caused understaging in 19.4% of cases vs 24.4% in group I.  相似文献   
9.
10.
Hydatidiform moles (HM) are characterized by an abnormal proliferating trophoblast with a potential for a malignant transformation. Similar to other human tumors, trophoblastic pathogenesis is likely a multistep process involving several molecular and genetic alterations. The study was performed to investigate the expression patterns of c-erbB-2 and Bcl-2 oncoproteins, p53, p21WAF1/CIP1 and p63 tumor suppressor proteins and Ki-67 cell proliferation marker in HM.We conducted a retrospective study of 220 gestational products, including 39 hydropic abortions (HA), 41 partial HM (PHM) and 140 complete HM (CHM). The expression of c-erbB-2, Bcl-2, p53, p21WAF1/CIP1, p63 and Ki-67 was investigated by immunohistochemistry on archival tissues. c-erbB-2 expression was observed in three PHM and 10 CHM. Bcl-2 immunostaining was significantly higher in PHM (61%) and CHM (70.7%) compared with HA (7.7%, p?=? 0.001 and p?<? 0.0001, respectively). p53 expression was stronger in CHM (73.6%) compared with PHM (24.4%, p < 0.0001) and HA (12.8%, p < 0.0001). p21WAF1/CIP1 staining was observed as well in molar and non-molar gestations (p?>? 0.05). p63 immunoexpression was significantly described in CHM (85.7%) and PHM (78%) compared with HA (10.2%, p < 0.0001 and p = 0.0001, respectively). Ki-67 was significantly expressed in CHM (72.1%) compared with HA (46.2%, p = 0.005).Altered expression of Bcl-2, p53, p63 and Ki-67 reflects the HM pathological development. Immunohistochemical analysis is beneficial to recognize the HM molecular and pathogenic mechanisms. Furthermore, it could serve as a useful adjunct to conventional methods for refining HM diagnosis.  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