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   8074篇
  免费   486篇
  国内免费   35篇
耳鼻咽喉   68篇
儿科学   281篇
妇产科学   192篇
基础医学   1243篇
口腔科学   173篇
临床医学   717篇
内科学   1660篇
皮肤病学   246篇
神经病学   859篇
特种医学   167篇
外科学   626篇
综合类   67篇
一般理论   3篇
预防医学   659篇
眼科学   184篇
药学   769篇
中国医学   11篇
肿瘤学   670篇
  2024年   6篇
  2023年   58篇
  2022年   174篇
  2021年   349篇
  2020年   203篇
  2019年   215篇
  2018年   280篇
  2017年   195篇
  2016年   275篇
  2015年   273篇
  2014年   318篇
  2013年   462篇
  2012年   688篇
  2011年   668篇
  2010年   352篇
  2009年   301篇
  2008年   481篇
  2007年   524篇
  2006年   500篇
  2005年   459篇
  2004年   481篇
  2003年   407篇
  2002年   382篇
  2001年   48篇
  2000年   45篇
  1999年   43篇
  1998年   50篇
  1997年   51篇
  1996年   39篇
  1995年   23篇
  1994年   26篇
  1993年   22篇
  1992年   17篇
  1991年   17篇
  1990年   14篇
  1989年   17篇
  1988年   10篇
  1987年   6篇
  1986年   7篇
  1985年   9篇
  1984年   9篇
  1983年   12篇
  1982年   13篇
  1981年   9篇
  1980年   6篇
  1978年   6篇
  1977年   7篇
  1976年   4篇
  1975年   4篇
  1974年   6篇
排序方式: 共有8595条查询结果,搜索用时 31 毫秒
91.
BACKGROUND: Despite a recent decline in smoking behavior in many European countries, lung cancer rates remain high, especially in Central and Eastern Europe. This paper aims to describe trends in smoking behavior and lung cancer incidence and mortality, including histopathological classification of lung cancer, in a Central European country: Austria. METHODS: Using data from the Austrian Central Cancer Registry, we calculated age-standardized incidence, histopathology-specific incidence, and age-standardized and birth cohort-specific mortality rates for all lung cancer cases in Austria. Using national survey data, we estimated prevalence of smoking in the Austrian population. Our analysis covers the time period from 1970 to 2009. RESULTS: In 2009, lung cancer incidence rates were 41.3/100,000 and 18.5/100,000 and mortality rates were 36.3/100,000 and14.5/100,000, for males and females, respectively. Male lung cancer rates declined but increased steadily in females over the past three decades. In 2009, the most common histological type is adenocarcinoma, which reflects a shift from predominantly squamous cell carcinoma and large cell carcinoma in the mid 1980s. In 2009, 27?% of men and 19?% of women were smokers, which represent a rise of smoking rates in women, especially in younger women, and a decline in the men. CONCLUSIONS: While in Austrian men the lung cancer rates, in accordance with their decreasing prevalence of smoking, declined over the past 30 years, the increasing smoking prevalence and lung cancer rates in women remain a public health concern. Antismoking laws and public health initiatives to curtail smoking habits are needed in Austria, especially targeting younger women.  相似文献   
92.
93.
AimTo evaluate the microleakage of recently available glass ionomer based restorative materials (GC Fuji IX GP, GC Fuji VII, and Dyract) and compare their microleakage with the previously existing glass ionomer restorative materials (GC Fuji II LC) in primary and permanent teeth.MethodOne hundred and fifty (75 + 75) non-carious deciduous and permanent teeth were restored with glass ionomer based restorative materials after making class I cavities. Samples were subjected to thermocycling after storing in distilled water for 24 h. Two coats of nail polish were applied 1 mm short of restorative margins and samples sectioned buccolingually after storing in methylene blue dye for 24 h. Microleakage was assessed using stereomicroscope.ResultSignificant differences (P < 0.05) were found when inter group comparisons were done. Except when GC Fuji VII (Group III) was compared with GC Fuji II LC (Group II) and Dyract (Group IV), non-significant differences (P > 0.05) were observed. It was found that there was no statistically significant difference when the means of microleakage of primary teeth were compared with those of permanent teeth.ConclusionsGC Fuji IX GP showed maximum microleakage and GC Fuji VII showed least microleakage.  相似文献   
94.
The enantiomeric contents of monoterpenes have been determined in essential oils from the following species: Pinus cembra, Pinus nigra, Pinus pinaster, Pinus montana, Pinus sylvestris, Abies alba and Abies sibirica. A gas chromatographic method with a formamide solution of a-cyclodextrin as a stationary phase was applied for the separation and determination of enantiomers.  相似文献   
95.
For the prevention of postoperative ocular infections prophylactic topical antibiotics are routinely used. Studies evaluating comparative difference between single dose versus multiple dose administration on aqueous humour concentration of moxifloxacin are lacking. This study compared the aqueous humour concentration of moxifloxacin following its topical administration in rabbit eyes with two dose regimens. Twelve albino rabbits were divided into two groups. In group-1, two drops were administered thrice (total six drops) at 2 min intervals, in both the eyes; in group-2, two drops of moxifloxacin were administered three times a day for three days and also two h before aqueous humour collection i.e. on fourth day. Mean aqueous humour concentrations were calculated and compared using Student''s ‘t’ test and P<0.05 was considered significant. Moxifloxacin concentration in aqueous humour in group-1 was 23.79 μg/ml and in group-2 was 42.08 μg/ml. Both dosing regimens produced substantially higher aqueous concentrations than the known minimum inhibitory concentration for most bacteria. Moxifloxacin concentration in aqueous humour with multiple instillations is significantly higher than single instillation (P<0.05), which is adequate to cover ciprofloxacin-resistant gram-negative bacteria. Repeated topical moxifloxacin administration achieved significantly higher aqueous humour concentrations than single administration.  相似文献   
96.
97.
T-cell acute lymphoblastic leukemia (T-ALL) is a rare, aggressive and heterogeneous malignancy originating from T-cell precursors. The mechanisms of T-ALL pathogenesis related to non-protein coding part of the genome are currently intensively studied. miRNAs are short, non-coding molecules acting as negative regulators of gene expression which shape phenotype of cells in a complex and context-specific manner. miRNAs may act as oncogenes or tumor suppressors; several miRNAs have been related to drug resistance and treatment response in various malignancies.Here we present the review of the state-of-the-art knowledge on the role of miRNAs in T-ALL pathogenesis, with detailed overview of the studies reporting on miRNAs with oncogenic and tumor suppressor potential. We discuss whether miRNAs might be considered candidate biomarkers of prognosis in T-ALL and leukemia subtype-specific markers. We also describe experimental approaches and a typical workflow applied in research on the involvement of miRNAs in oncogenesis.  相似文献   
98.
99.
100.
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