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   1775篇
  免费   127篇
  国内免费   11篇
耳鼻咽喉   17篇
儿科学   82篇
妇产科学   27篇
基础医学   183篇
口腔科学   74篇
临床医学   235篇
内科学   246篇
皮肤病学   19篇
神经病学   87篇
特种医学   210篇
外国民族医学   1篇
外科学   242篇
综合类   88篇
预防医学   178篇
眼科学   12篇
药学   130篇
中国医学   24篇
肿瘤学   58篇
  2022年   12篇
  2021年   17篇
  2020年   17篇
  2019年   15篇
  2018年   29篇
  2017年   20篇
  2016年   19篇
  2015年   21篇
  2014年   53篇
  2013年   79篇
  2012年   77篇
  2011年   82篇
  2010年   59篇
  2009年   56篇
  2008年   78篇
  2007年   90篇
  2006年   45篇
  2005年   49篇
  2004年   52篇
  2003年   42篇
  2002年   29篇
  2001年   35篇
  2000年   31篇
  1999年   32篇
  1998年   73篇
  1997年   56篇
  1996年   50篇
  1995年   36篇
  1994年   35篇
  1993年   33篇
  1992年   36篇
  1991年   24篇
  1990年   32篇
  1989年   41篇
  1988年   48篇
  1987年   35篇
  1986年   43篇
  1985年   52篇
  1984年   23篇
  1983年   24篇
  1982年   20篇
  1981年   16篇
  1980年   14篇
  1979年   28篇
  1978年   20篇
  1977年   15篇
  1976年   20篇
  1975年   17篇
  1970年   9篇
  1969年   9篇
排序方式: 共有1913条查询结果,搜索用时 0 毫秒
101.
BACKGROUND: The evaluation of thyroid nodules by fine-needle aspiration has been the standard for almost 30 years, despite significant shortcomings in sensitivity and specificity. Recent data from our laboratory have suggested that molecular profiling permits the discrimination of specific types of thyroid nodules. These studies were undertaken to determine whether molecular profiling can discriminate between benign and malignant thyroid nodules with the necessary sensitivity and specificity required of a screening test. METHODS: Molecular profiles of 11 papillary thyroid carcinomas, 13 follicular variant of papillary thyroid carcinomas, 9 follicular thyroid carcinomas, and 26 benign tumors (follicular adenomas and hyperplastic nodules) were analyzed by oligonucleotide microarray analysis. A gene list was created based on 45 samples. Seventeen samples were then added to the analysis as unknowns. A hierarchical clustering analysis was performed on all 62 samples to examine the groups for potential differences and the ability of the gene list to distinguish tumor types. RESULTS: Cluster analysis of all 62 samples produced 2 distinct groups, 1 containing the carcinomas and 1 containing the benign lesions. The sensitivity for a diagnosis of cancer was 91.7% with a specificity of 96.2% (3 follicular variant of papillary thyroid carcinomas clustered with the benign lesions). The cancer gene profiles contained both known cancer-associated genes (MET, galectin-3) and previously unidentified genes. CONCLUSIONS: Molecular profiling readily distinguishes between benign and malignant thyroid tumors with excellent sensitivity and specificity. Elucidated genes may provide insight into the molecular pathogenesis of thyroid cancer. Gene profiling may significantly enhance the evaluation of thyroid nodules in the future.  相似文献   
102.
103.
104.
Exploring how rising family dissolutions affect adopted children, the authors investigated 2 competing viewpoints: (a) a double jeopardy hypothesis, positing adoptees are susceptible to heightened risks of adjustment problems because of a compounding of parental losses, versus (b) a buffering hypothesis, suggesting early birth parent losses buffer an adoptee's ability to accept parental loss from divorce. With data from the 1994 National Longitudinal Study of Adolescent Health (Add Health, 2003), the authors compared adaptations of adolescent adoptees living with 1 adoptive parent (n=143) with those of children living in step- or single-parent biological families (n=7,457) in a nationally representative sample. Results were mixed, showing some support for both hypotheses and mostly nonsignificant differences on the largest number of behavioral comparisons made.  相似文献   
105.
OBJECTIVE: To determine the effect of a cognitive and behavioral skills building intervention delivered via a small group or correspondence on improvement in total diet quality. DESIGN: Randomized, controlled trial comparing 2 intervention groups with a usual care (UC) group. PARTICIPANTS: Generally healthy men (n = 35) and women (n = 63); mean age = 49.6 years (range = 29 to 71 years). INTERVENTION: 20-session behavioral and cognitive skills curriculum to train participants to improve personal dietary habits that were inconsistent with public health guidelines. One group (weekly meeting [WM]) met in small groups with 2 cofacilitators. A correspondent (CR) group received the curriculum via mail and an interactive study Web site. The UC group received a copy of a consumer nutrition book. MAIN OUTCOME MEASURE: Modified Healthy Eating Index (MHEI) score derived from 9 components of the US Department of Agriculture's Healthy Eating Index. RESULTS: The WM group significantly improved their MHEI score compared with the CR (P =.04) and UC (P =.002) groups. The CR group's improvement in MHEI score was not significantly different from that of the UC group (P =.19). CONCLUSIONS AND IMPLICATIONS: A behaviorally focused intervention can improve overall diet quality, especially if delivered through small-group meetings.  相似文献   
106.
107.
刑事警察心理健康调查分析   总被引:2,自引:0,他引:2  
①目的了解刑事警察的心理健康状况,为心理干预提供依据。②方法对济宁市刑警队员进行症状自评量表(Symptom Checklist 90.SCL-90)、焦虑自评量表(Self—rating Anxiety state,SAS)、抑郁自评量表(Self—rating Depression scale,SDS)评定。③结果济宁市刑警队员的SCL-90、SAS、SDS量表评分与全国常模相比存在显著性差异。④结论。刑事警察职业是一种特殊职业,该职业对队员的心理健康有显著的影响,这种影响随着从事刑警工作时间的不同而改变。  相似文献   
108.
目的探讨黄芪注射液抗肝纤维化及对TGF-β1、Col-Ⅰ表达的影响。方法将35只SD大鼠随机分为正常对照组、CCl4诱导肝纤维化模型组和黄芪干预组。至造模第10周,处死所有大鼠,采用PV免疫组化方法检测Col-Ⅰ在各组肝组织中的表达,ELISA法检测TGF-β1在各组血清中的表达。结果经CCl4诱导成功建立大鼠肝纤维化模型,随着肝纤维化程度的进展,肝组织中Col-Ⅰ和血清中TGF-β1表达明显增强。在正常对照组、黄芪干预组和肝纤维化模型组肝组织中Col-Ⅰ表达的平均光密度值分别为0.298、0.315、0.503,模型组与前两组比较差异均有显著性(P〈0.01),而黄芪干预组与正常组肝组织比较差异无统计学意义(P〉0.05)。在正常对照组、黄芪干预组和肝纤维化模型组大鼠血清中TGF-β1表达含量分别为491.29pg/L、629.91pg/L、959.09pg/L,呈递增趋势。模型组与前两组比较差异均有显著性(P〈0.01),黄芪干预组与正常组比较其表达含量无显著差异(P〉0.05)。结论黄芪注射液可以显著抑制实验性肝纤维化大鼠模型的肝纤维化,这种抑制作用可能与抑制I型胶原蛋白及TGF-β1的表达有关。  相似文献   
109.
A newly developed murine monoclonal antibody, DS6, immunohistochemically reacts with an antigen, CA6, that is expressed by human serous ovarian carcinomas but not by normal ovarian surface epithelium or mesothelium. CA6 has a limited distribution in normal adult tissues and is most characteristically detected in fallopian tube epithelium, inner urothelium and type 2 pneumocytes. Pre-treatment of tissue sections with either periodic acid or neuraminidase from Vibrio cholerae abolishes immunoreactivity with DS6, indicating that CA6 is a neuraminidase-sensitive and periodic acid-sensitive sialic acid glycoconjugate ("sialoglycotope"). SDS-PAGE of OVCAR5 cell lysates has revealed that the CA6 epitope is expressed on an 80 kDa non-disulfide-linked glycoprotein containing N-linked oligosaccharides. Two-dimensional non-equilibrium pH gradient gel electrophoresis indicates an isoelectric point of approximately 6.2 to 6.5. Comparison of the immunohistochemical distribution of CA6 in human serous ovarian adenocarcinomas has revealed similarities to that of CA125; however, distinct differences and some complementarity of antigen expression were revealed by double-label, 2-color immunohistochemical studies. The DS6-detected CA6 antigen appears to be distinct from other well-characterized tumor-associated antigens, including MUC1, CA125 and the histo-blood group-related antigens sLea, sLex and sTn.  相似文献   
110.
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