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   661篇
  免费   57篇
  国内免费   5篇
耳鼻咽喉   4篇
儿科学   23篇
妇产科学   22篇
基础医学   98篇
口腔科学   22篇
临床医学   94篇
内科学   139篇
皮肤病学   12篇
神经病学   30篇
特种医学   9篇
外科学   59篇
综合类   2篇
一般理论   1篇
预防医学   70篇
眼科学   5篇
药学   70篇
中国医学   4篇
肿瘤学   59篇
  2023年   8篇
  2022年   20篇
  2021年   35篇
  2020年   14篇
  2019年   25篇
  2018年   36篇
  2017年   21篇
  2016年   13篇
  2015年   24篇
  2014年   32篇
  2013年   35篇
  2012年   49篇
  2011年   66篇
  2010年   32篇
  2009年   32篇
  2008年   41篇
  2007年   31篇
  2006年   27篇
  2005年   35篇
  2004年   44篇
  2003年   32篇
  2002年   26篇
  2001年   2篇
  2000年   1篇
  1999年   3篇
  1998年   5篇
  1997年   1篇
  1996年   5篇
  1995年   3篇
  1994年   2篇
  1993年   3篇
  1992年   1篇
  1990年   2篇
  1989年   1篇
  1987年   1篇
  1986年   1篇
  1984年   3篇
  1983年   2篇
  1982年   1篇
  1980年   2篇
  1979年   1篇
  1973年   1篇
  1972年   1篇
  1971年   1篇
  1965年   1篇
  1962年   1篇
排序方式: 共有723条查询结果,搜索用时 578 毫秒
61.
62.
Hev b 6.02 (hevein), identified as a major allergen from natural rubber latex (NRL), is involved in the latex-fruit syndrome and also acts as a pathogenesis defense-related protein. Its 3D structure has been solved at high resolution, and its linear epitopes have already been reported. However, information about conformational epitopes is still controversial, even though it is relevant for an accurate diagnosis and treatment, as well as for the study of allergen-antibody molecular interactions. We sought to analyze the B-cell epitopes of Hev b 6.02 at a molecular and structural level, using specific recombinant antibodies. We obtained a murine monoclonal antibody (mAb 6E7) and three human single chain fragments (scFvs A6, H8, and G7) anti-Hev b 6.02 that were able to compete for hevein binding with serum IgEs from latex allergic patients. In vitro assays showed that the mAb 6E7 and scFv H8 recognized the area of Hev b 6.02 where the aromatic residues are exposed; while the scFv G7 defined the amino and carboxy-terminal regions that lie close to each other, as a different epitope. The structural modeling of the Hev b 6.02-scFv H8 and Hev b 6.02-scFv G7 complexes revealed the putative regions of two conformational epitopes. In one of these, the aromatic residues, as well as polar side chains are important for the interaction, suggesting that they are part of a dominant conformational epitope also presented on the Hev b 6.02-IgE interactions. Antibodies recognizing this important allergen have potential to be used to diagnose and ultimately treat latex allergy.  相似文献   
63.
Women with epilepsy (WWE)’s knowledge of the interaction between antiepileptic drugs (AEDs) and oral contraceptives (OCs) and the potential teratogenicity of AEDs has received limited study. We conducted a cross-sectional questionnaire study (English or Spanish) among young WWE (18–44 years) to assess demographic characteristics, current AED use, and knowledge of AED interactions with OCs and teratogenicity. We used the Food and Drug Administration’s classification system to categorize each AED’s teratogenic potential. Participants (n = 148) had a mean age of 32 years (SD 8); 32% spoke Spanish and described themselves as Hispanic. Among women prescribed a cytochrome p450-inducing AED, 65% were unaware of decreased OC efficacy. Forty percent of those prescribed Category D AEDs were unaware of potential teratogenic effects. WWE have limited knowledge of the potential interaction between AEDs and OCs and the teratogenic effects of AEDs. Educational efforts should highlight the reproductive health effects of AEDs in WWE.  相似文献   
64.
Dendrimers are polymeric compounds with highly branched structures and functionally tunable peripheral groups. Because of their low polydispersity, high degree of molecular uniformity, and precisely controlled structure, dendrimers are excellent models for demonstrating a variety of biological activities. With the attachment of metals ions and/or metals, metallodendrimers or dendrimer nanocomposites, respectively, provide diverse characters for a variety of applications. Functionalization with additional moieties, such as targeted peptides or chromophores, yields metallodendrimers that can find powerful applications and exceed the capabilities of nondendritic molecules or small molecule analogs. This review introduces the background of metallodendrimers and dendrimer nanocomposites. Biomedical applications of metallodendrimers and dendrimer nanocomposites will be discussed, including biomimetic catalysts, imaging contrast agents (especially for MRI imaging), or biomedical sensors and therapeutic agents.  相似文献   
65.
BACKGROUND: The clearance of D+ red blood cells (RBCs) from the circulation in D- individuals mediated by passively administered anti-D occurs by opsonization with the antibody and subsequent removal in the spleen. Few data exist on the kinetics of clearance of large volumes of D+ RBCs from the maternal circulation by anti-D in clinical cases of massive fetomaternal hemorrhage (FMH). CASE REPORT: A 33-year-old D- woman delivered a D+ female infant by emergency cesarean section for suspected fetal anemia. A massive FMH, initially estimated to be approximately 142 mL of RBCs, was found. In addition to the standard dose of intramuscular (IM) anti-D (300 microg) given immediately after delivery, 2700 microg of anti-D was administered intravenously (IV). The clearance of D+ fetal cells from the maternal circulation was monitored by flow cytometry in samples obtained on a daily basis using anti-D. The mother had no detectable anti-D 6 months after delivery. RESULTS: No clearance of fetal cells was apparent after the insufficient dose of IM anti-D. The IV administration of anti-D caused accelerated clearance of D+ fetal RBCs with a t1/2 of 24.5 hours. D+ reticulocytes comprised 4.2 percent of all D+ cells in the maternal circulation at delivery suggesting acute fetal blood loss. CONCLUSIONS: The approach used in this report allowed a detailed analysis of the kinetics related to the clearance of fetal D+ RBCs. Simultaneous measurements of fetal reticulocytes and fetal RBCs in maternal blood may establish the timing of an FMH.  相似文献   
66.
ABSTRACT The purposes of this methodological study were to factor analyze the short form of the Tilden Interpersonal Relationship Inventory (IPRI) for early adolescents, and to assess construct validity of the social support and conflict subscales with early adolescents. The sample consisted of 147 early adolescents, aged 12–14, who completed instrument packets in classrooms in a suburban middle school. Data obtained on the IPRI were subjected to principal components factor analysis with Varimax rotation. The two factors that emerged are consistent with the theories underlying the instrument. Factor I was social support, and had a coefficient α reliability of .90. Factor II was conflict, and had a coefficient α reliability of .86. Construct validity was assessed by testing hypotheses derived from theoretical propositions linking support or conflict to general humor, self-esteem, and symptom patterns; the results of the hypotheses were statistically significant and in the predicted direction. The findings indicate that the social support and conflict subscales of the IPRI have evidence of reliability and validity for early adolescents.  相似文献   
67.
BACKGROUND: Small cell lung cancer (SCLC) is a very aggressive disease, with poor survival rates despite standard treatment with combination chemotherapy with or without radiotherapy. Further insights into the molecular biology of this malignant tumour are needed to improve the therapeutic approaches and outcome. KIT protein is expressed in SCLC, and its kinase activity has been implicated in the pathophysiology of many tumours, including SCLC. The purpose of this study was to evaluate the prevalence of KIT expression in patients with SCLC and its prognostic value. METHODS: We performed an inmunohistochemical analysis of 204 SCLC samples to determine KIT protein expression. The relationship between KIT expression and clinicopathological parameters was evaluated. Univariate and multivariate analyses were performed to define its prognostic significance. RESULTS: KIT expression was observed in 149 of 204 tumour tissues (73%). KIT expression was associated with advanced disease and with decreased incidence of bone metastases. No significant differences were observed for time to disease progression (TTP) (9.1% versus 6.2% at 3 years, p=0.6) or overall survival (OS) (10.7% versus 6.9% at 3 years, p=0.37) among patients with KIT positive versus negative tumours, respectively. Multivariate analysis showed that sex, tumour stage, albumin levels and response to therapy were the only independent predictors for survival. CONCLUSION: KIT protein is expressed in a high percentage of SCLC tumours. In our study population, however, the expression of KIT had no significant impact on survival.  相似文献   
68.
69.
70.
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