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   3080篇
  免费   380篇
  国内免费   86篇
耳鼻咽喉   207篇
儿科学   30篇
妇产科学   3篇
基础医学   267篇
口腔科学   753篇
临床医学   191篇
内科学   162篇
皮肤病学   46篇
神经病学   118篇
特种医学   66篇
外国民族医学   2篇
外科学   437篇
综合类   520篇
预防医学   47篇
眼科学   21篇
药学   87篇
  1篇
中国医学   360篇
肿瘤学   228篇
  2024年   10篇
  2023年   61篇
  2022年   100篇
  2021年   136篇
  2020年   145篇
  2019年   133篇
  2018年   110篇
  2017年   109篇
  2016年   144篇
  2015年   126篇
  2014年   193篇
  2013年   214篇
  2012年   190篇
  2011年   210篇
  2010年   144篇
  2009年   153篇
  2008年   161篇
  2007年   165篇
  2006年   143篇
  2005年   109篇
  2004年   107篇
  2003年   102篇
  2002年   68篇
  2001年   61篇
  2000年   44篇
  1999年   30篇
  1998年   41篇
  1997年   43篇
  1996年   27篇
  1995年   27篇
  1994年   18篇
  1993年   21篇
  1992年   24篇
  1991年   18篇
  1990年   19篇
  1989年   17篇
  1988年   17篇
  1987年   8篇
  1986年   10篇
  1985年   14篇
  1984年   18篇
  1983年   9篇
  1982年   12篇
  1981年   9篇
  1980年   8篇
  1979年   7篇
  1978年   5篇
  1975年   1篇
  1974年   2篇
  1973年   1篇
排序方式: 共有3546条查询结果,搜索用时 15 毫秒
11.
目的:研究开He患者的舌位置有无特征性变异。方法:利用舌背碘油造影方法,增加头颅侧位定位X线片上舌背的显影效果,在头颅侧位定位X线片上以舌体在固有口腔内的相对位置确定舌体的位置,通过开He与正常He者知位置的团体t检验比较,找出开He患者的舌位置变异特性。结果:开He患者与正常He者比较,舌根部与悬雍垂之间的间隙增大,舌背部与腭表面之间的间隙减小,舌尖部更靠近牙齿,结论:开He个体相对于正常He个体舌位置有向前,向上的变化特点,这可能是开He的病因之一。  相似文献   
12.
Summary Surgery for highly placed basilar bifurcation aneurysms is one of the most difficult operations in neurosurgery. Specific surgical techniques have been developed including the temporopolar, zygomatic, transzygomatic subtemporal, transclinoid trans-sellar transcavernous, and trans third ventricular approaches. The authors present some technical advances which have been developed for the transcristagalli translamina terminalis approach for the treatment of this aneurysm.  相似文献   
13.
14.
An extensive examination of the tongue was performed at autopsy in 20 consecutive patients who had died with AIDS. Abnormalities in the tongue were detected in 18 (90%) of the cases; the commonest lesions were ulceration (11), candidosis (8) and small foci of hyperkeratosis (10). The most extensive lesions were caused by Aspergillus infection (1), non-Hodgkin's lymphoma juxtaposed with Kaposi's sarcoma (1), herpetic infection (1) and candidosis (5). The disease causing death was identified in the tongue in two cases. There was a surprisingly low prevalence of oral hairy leukoplakia. which may be related to anti-viral or retroviral therapy.  相似文献   
15.
We report a case of an infantile myofibromatosis with hemangiopericytoma-like features arising in the tongue of a 5-month-old female infant. Many authors now classify neoplasms as infantile myofibromatosis that were previously called infantile hemangiopericytoma. The ultrastructural features of our tumor illustrate its biphasic nature and provide a possible explanation for its histogenesis. Infantile myofibromatosis, including those diagnosed as infantile hemangiopericytomas, rarely arise in any intraoral location. Despite the generally good prognosis associated with these neoplasms, complete surgical excision is recommended to avoid recurrences.  相似文献   
16.
表皮生长因子影响肿瘤患者舌苔变化的分子机制研究   总被引:12,自引:0,他引:12  
目的 研究表皮生长因子(EGF)对食管癌细胞Eca-109细胞周期及表皮生长因子受体(EGF-R)表达的影响,探讨EGF促进肿瘤患者舌苔增厚的分子机制。方法 应用流式细胞术,检测EGF-R的表达和细胞周期。结果 EGF能明显促进Eca-109细胞膜上EGF-R的表达,使细胞增殖活性大大增强。结论EGF有是通过促进EGF-R的表达影响舌苔形成。  相似文献   
17.
The aim of this study was to investigate cell kinetics and ultrastructural changes during carcinogenesis using a hamster 9,10-dimethyl-1,2-benzanthracene (DMBA)-induced tongue cancer model. Five squamous cell carcinomas, five dysplastic epithelia, seven hyperplastic epithelia, and four normal epithelia were obtained from 21 hamster tongues by applying 1.0% acetone solution of DMBA on the left lingual mucosa after scratching with a root canal broach. Ultrastructural examination revealed that the number of microvilli increased, whereas that of desmosomes decreased during carcinogenesis. Cell proliferation was analyzed by means of 5-bromodeoxyuridine (BrdU) immunohistochemistry and in situ hybridization (ISH) for histone H3 mRNA. The BrdU and histone H3 mRNA labeling indices (LIs) were lowest for normal epithelium, higher for hyperplastic and dysplastic epithelia, and highest for squamous cell carcinoma. Cytoplasmic histone H3 mRNA and nuclear BrdU were localized in virtually identical areas of serial sections. The correlation coefficient for the relationship between these two LIs was 0.97 (P 0.001). These results suggest that the assessment of cell proliferation using H3 mRNA ISH will be a useful technique for investigating biological behavior during carcinogenesis.  相似文献   
18.
Renal biopsies and post-mortem kidneys were examined for segmental lesions at glomerular tips, consisting of adhesion of the tuft to Bowman's capsule with an area of intra-capillary foam cells or hyaline material or sclerosed material. Of 72 consecutive renal biopsies showing membranous nephropathy, 46 (64 per cent) had tip changes. Such changes were correlated with the presence of acute tubular damage and with later stages of the nephropathy, but otherwise seemed unrelated to any particular clinical or pathological feature. Fourteen other patients were identified whose renal biopsies showed tip changes in glomeruli that had segmental or global mesangial hypercellularity not of a well-recognized type such as IgA nephropathy. These patients had persistent proteinuria unresponsive to steroids. Tip changes were also seen in several miscellaneous conditions including IgA nephropathy and diabetic glomerulosclerosis. These findings demonstrate that tip changes are seen in many disorders of the kidney associated with proteinuria and represent a previously unrecognized common response of the glomerulus to some insult, the glomerular tip lesion, as originally defined, is distinguished by the apparent normality of tufts except for the tip changes and can be regarded as presumed minimal change nephropathy plus tip changes and when tip changes are seen, the most important factor determining the prognosis is the condition of the rest of the glomerular tuft.  相似文献   
19.
The laboratory workload, microbiological techniques and aetiology of catheter-related infections in European hospitals are mostly unknown. The present study (ESGNI-005) comprised a 1-day (22 October 2001), laboratory-based, point-prevalence survey based on a questionnaire completed by microbiology laboratories in European (European Union (EU) and non-EU) hospitals. Also included were questions requesting retrospective information for the year 2000. In total, 151 hospitals from 26 European countries participated, of which 78.1% were teaching institutions. Overall, the estimated population served by these institutions was 121,363,800, and the estimated number of admissions during 2000 was 6,712,050. The total number of catheter tips processed during 2000 was 142,727, or 21/1,000 admissions, of which 23.7% were considered to be positive in the institutions using semiquantitative or quantitative techniques. Overall, EU centres received significantly more catheter tip samples/1,000 admissions and had a significantly higher rate of 'positivity' (p < 0.0001) than non-EU centres. Of the institutions surveyed, 11.4% (7.2% in EU countries and 23.7% in non-EU countries; p 0.04) used only qualitative techniques for catheter tip sample processing. On the day of the study, 167 microorganisms were recovered from significant catheter tip cultures (122 patients), of which Gram-positive bacteria represented 70.7%, Gram-negative bacteria 22.2%, and yeasts 7.2%. The five most common microorganisms were coagulase-negative staphylococci, Staphylococcus aureus, Candida spp., Enterococcus spp. and Pseudomonas spp. Overall, 19% of catheter tip cultures were polymicrobial. In the case of S. aureus, 40% of isolates were resistant to oxacillin, as were 63.4% of coagulase-negative staphylococcus isolates. Of 37 Gram-negative isolates, 35% were resistant to cefotaxime, 31% to ceftazidime, and 27% to ciprofloxacin. Imipenem and cefepime had the lowest reported rates of resistance (11%).  相似文献   
20.
目的:探讨前臂游离皮瓣在舌-口底软组织缺损修复与重建中的临床意义。方法:随机选择资料完整的住院患者59例进行回顾性分析。结果:全部病例术后愈合良好,随访1-14年总成功率达81.4%,患者语言,吞咽等功能较满意。结论:前臂游离皮瓣具有血运丰富,解剖恒定,厚度适中,容易折叠,便于操作等优点,是舌一口底软组织缺损修复与重建的理想材料。  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