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   8463篇
  免费   609篇
  国内免费   103篇
耳鼻咽喉   64篇
儿科学   215篇
妇产科学   395篇
基础医学   946篇
口腔科学   191篇
临床医学   1038篇
内科学   1704篇
皮肤病学   80篇
神经病学   713篇
特种医学   279篇
外科学   1102篇
综合类   235篇
一般理论   4篇
预防医学   475篇
眼科学   184篇
药学   726篇
中国医学   83篇
肿瘤学   741篇
  2023年   45篇
  2022年   105篇
  2021年   180篇
  2020年   106篇
  2019年   179篇
  2018年   216篇
  2017年   180篇
  2016年   178篇
  2015年   246篇
  2014年   291篇
  2013年   380篇
  2012年   547篇
  2011年   623篇
  2010年   418篇
  2009年   353篇
  2008年   506篇
  2007年   509篇
  2006年   520篇
  2005年   454篇
  2004年   401篇
  2003年   332篇
  2002年   294篇
  2001年   273篇
  2000年   226篇
  1999年   195篇
  1998年   86篇
  1997年   74篇
  1996年   71篇
  1995年   53篇
  1994年   40篇
  1993年   43篇
  1992年   112篇
  1991年   121篇
  1990年   99篇
  1989年   74篇
  1988年   73篇
  1987年   74篇
  1986年   47篇
  1985年   41篇
  1984年   34篇
  1983年   35篇
  1981年   25篇
  1980年   18篇
  1979年   27篇
  1978年   33篇
  1977年   18篇
  1976年   19篇
  1975年   18篇
  1974年   26篇
  1968年   19篇
排序方式: 共有9175条查询结果,搜索用时 15 毫秒
11.
The clinical and ultrasonographic (US) features of 15 cases of mesenteric or omental cyst are herein described. This series included seven male and eight female patients, whose age ranged from 2–89 years. Correct clinical diagnosis was made in two children only, but preoperative US examination accurately demonstrated the lesion in 11 of 13 patients (85%). These cystic lesions usually had a thin wall, internal septations, and fluid content with sedimentation. Enteric duplication cysts had a relatively thick wall merging with the muscle layer of bowel loop, and multiloculation was noted mainly with cystic lymphangiomas or pseudocysts. The diagnostic and surgical management of these lesions are briefly reviewed and their US appearance is illustrated.  相似文献   
12.
13.
The first universal hepatitis B vaccination program for newborns in the world was launched in Taiwan in July 1984. Most studies on the effectiveness of hepatitis B vaccination focused on the seroprevalence of HBs Ag among children under 14 years old. Only few studies focused on the seropositivity of anti-HBs among adolescents aged 15–18 years old. The present study aimed to evaluate the impact of the nationwide hepatitis B vaccination program on the immunity to HBV infection and the necessity of boost among adolescents. In this study including eight annual seroprevalence surveys from 2000 to 2007, 2342 college entrants (1589 15-year-olds in group I and 753 18-year-olds in group II) and 1851 university freshmen (18-year-olds in group III) participated. Subjects identified anti-HBs, HBs Ag and anti-HBc negative were given boost three doses of HBV vaccine. The HBs Ag seroprevalence was 11.6%, 3.5% and 1.0% for participants who were born before 1984, 1984–1986 and after 1986. The anti-HBs-seropositive rates were significantly higher in group II (83.1%) than in group I (53.0%) and group III (53.5%). All 572 participants who were seronegative for anti-HBs, HBs Ag and anti-HBc became anti-HBs-seropositive after catch-up vaccination. It is concluded that the anti-HBs-seropositive rate decreased to 50% in 15 years after vaccination, and boost vaccination was 100% effective. The necessity and age for boost among anti-HBs negative adolescents and the timing of the first immunization should be further evaluated.  相似文献   
14.
Limitations of the Panoramic 200 Optomap.   总被引:7,自引:0,他引:7  
  相似文献   
15.
16.
Extrarenal Wilms tumor occurring in the inguinal canal   总被引:2,自引:0,他引:2  
We report an unusual case of extrarenal Wilms tumor discovered incidentally during routine inguinal orchiopexy. The world literature and embryological implications of Wilms tumor in the inguinal canal are reviewed.  相似文献   
17.
BACKGROUND AND PURPOSE: Marine luminous bacteria were isolated and identified from samples in shallow coastal waters of Taiwan during the relatively warm seasons. METHODS: Identification of the luminous isolates was performed based on differences of phenotypic and genotypic characteristics together with data from phylogenetic analysis. RESULTS: Twenty seven strains of marine luminous bacteria were isolated. They were divided into five types based on differences of phenotypic characteristics. However, they could be clustered into only two genotypes according to the analysis of restriction patterns of polymerase chain reaction-amplified 16S rRNA genes digested with various restriction enzymes. The characterization data together with the 16S rRNA gene-based phylogenetic analysis revealed that the isolates included in phenotype I (seven isolates) could be Photobacterium leiognathi, and those included in phenotypes II-V (twenty isolates) might be classified as Vibrio harveyi. However, phylogeny based on gyrB sequences indicated that phenotypes II-V could be classified into two species, V. harveyi and Vibrio campbellii. CONCLUSION: Culturable luminous bacteria in the shallow coastal waters of Taiwan during the sampling period are dominated by V. harveyi/campbellii and P. leiognathi, and the former species appeared to be more prevalent and numerous than the latter species in general.  相似文献   
18.
A total of 114 patients with various sympathetic disorders underwent endoscopic sympathetic block over different thoracic ganglions by the clipping method. The advantages of this method include the recognition of the clipped level, changeability, and reversibility. However, 4.4% of patients were unilaterally clipped at the wrong level.  相似文献   
19.
20.
Three cases of proved peritoneal carcinomatosis were examined by magnetic resonance imaging (MRI). Air was used to distend the entire gastrointestinal tract via an antegrade method. The findings included seedings along the small intestine, transverse and sigmoid colon, stellate pattern in the mesentery, plaque-like and bulky tumor masses in the mesentery and greater omentum, and focal thickenings along the right subdiaphragmatic parietal peritoneum. Stenosis caused by tumor encasement at the duodenojejunal junction and ileocolic anastomosis were first detected by MRI and later confirmed by barium studies. Ascites was present in all cases. One case showed ascites located only along the left paracolic gutter. This report shows that MRI is also able to demonstrate peritoneal carcinomatosis by using air as a gastrointestinal contrast medium.  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