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   582篇
  免费   18篇
儿科学   36篇
妇产科学   28篇
基础医学   64篇
口腔科学   17篇
临床医学   41篇
内科学   104篇
皮肤病学   3篇
神经病学   54篇
特种医学   56篇
外科学   77篇
综合类   4篇
一般理论   2篇
预防医学   34篇
眼科学   3篇
药学   30篇
肿瘤学   47篇
  2023年   3篇
  2022年   13篇
  2021年   19篇
  2020年   7篇
  2019年   21篇
  2018年   10篇
  2017年   6篇
  2016年   8篇
  2015年   14篇
  2014年   19篇
  2013年   32篇
  2012年   29篇
  2011年   40篇
  2010年   13篇
  2009年   20篇
  2008年   43篇
  2007年   32篇
  2006年   21篇
  2005年   19篇
  2004年   23篇
  2003年   16篇
  2002年   21篇
  2001年   19篇
  2000年   13篇
  1999年   9篇
  1998年   6篇
  1997年   3篇
  1996年   4篇
  1995年   2篇
  1994年   5篇
  1993年   7篇
  1992年   5篇
  1991年   13篇
  1990年   9篇
  1989年   6篇
  1988年   5篇
  1987年   12篇
  1986年   6篇
  1985年   9篇
  1984年   6篇
  1983年   7篇
  1979年   4篇
  1978年   3篇
  1976年   3篇
  1943年   2篇
  1930年   2篇
  1899年   1篇
  1898年   1篇
  1897年   1篇
  1896年   1篇
排序方式: 共有600条查询结果,搜索用时 31 毫秒
101.
102.

Purpose

To investigate the prognostic value of posttreatment 18F-FDG PET/CT in patients with locally advanced cervical cancer (LACC) treated with concomitant chemoradiation therapy (CCRT). The secondary aim was to assess the possible role of intensity-based and volume-based PET parameters including SUVmax, SUVmean, MTV and TLG, and clinical parameters including age, pathology, FIGO stage and nodal involvement as factors predicting response to treatment.

Methods

This retrospective study included 82 patients affected by LACC treated with CCRT. All patients underwent 18F-FDG PET/CT both before and after treatment. The posttreatment PET/CT scans were used to classify patients as complete metabolic responders (CMR) or non-complete metabolic responders (N-CMR) according to the EORTC criteria. Kaplan-Meier analysis was used to evaluate differences in overall survival (OS) between the CMR and N-CMR groups. Student’s t test, Pearson’s chi-squared test and logistic regression were used to investigate the possible value of PET and clinical parameters as predictors of metabolic response to therapy.

Results

Kaplan­Meier analysis showed a highly significant difference in OS between the CMR and N-CMR groups (log-rank test p?<?0.0001). Significant independent predictors of response to therapy were MTV (p?=?0.019, odds ratio?=?1.015, 95% CI?=?1.002–1.028, Nagelkerke R2?=?0.110), TLG (p?=?0.045, odds ratio?=?1.001, 95% CI?=?1.000–1.002, Nagelkerke R2?=?0.081) and nodal involvement (p?=?0.088, odds ratio?=?2.361, 95% CI?=?0.879–6.343, Nagelkerke R2?=?0.051).

Conclusion

18F-FDG PET/CT-based response assessment using the EORTC criteria reliably predicts OS in LACC patients treated with CCRT. In our cohort of patients, pretreatment MTV and TLG and nodal involvement were predictors of response to therapy. MTV was the best predictor of response. However, its additional risk value seems to be low (MTV odds ratio?=?1.015).
  相似文献   
103.
Deletions of the Y chromosome are a significant cause of spermatogenic failure. Three major deletion intervals have been defined and termed AZFa, AZFb and AZFc. Here, we report an unusual case of a proximal AZFb deletion that includes the Y chromosome palindromic sequence P4 and a novel heat shock factor (HSFY). This deletion neither include the genes EIF1AY, RPS4Y2 nor copies of the RBMY1 genes. The individual presented with idiopathic azoospermia. We propose that deletions of the testis-specific HSFY gene family may be a cause of unexplained cases of idiopathic male infertility. This deletion would not have been detected using current protocols for Y chromosome microdeletion screens, therefore we recommend that current screening protocols be extended to include this region and other palindrome sequences that contain genes expressed specifically in the testis.  相似文献   
104.
One hundred subjects positive for anti-human immunodeficiency virus (HIV) antibodies were tested for anti-Leishmania antibodies by the indirect immunofluorescent antibody test (IFAT) and the direct agglutination test (DAT). Subjects were subsequently followed for two years to monitor the onset of visceral leishmaniasis. Fifteen subjects were positive for anti-Leishmania antibodies in either one or both tests. Eleven were positive only by IFAT, one only by DAT, and three by both tests. During the two-year follow-up period, nine subjects developed visceral leishmaniasis; of these, six were serologically positive, four by IFAT alone and two by both tests. The results indicate that IFAT and DAT have a similar specificity but that IFAT has a higher sensitivity and a greater diagnostic significance.  相似文献   
105.
A recent issue in the EU legislation is the evaluation of the toxicologically-equivalent contribution of dioxin-like polychlorobiphenyls (DL-PCBs) in addition to that coming from polychlorodibenzodioxins (PCDDs) and polychlorodibenzofurans (PCDFs) as contaminants in foods for a total of 29 congeners. This fact is determining the need to revise analytical criteria both for confirmatory and screening analysis. In this work, a modeling was developed to check the reliability of the outcomes of the DR CALUX bioassay when applied to farm milk samples characterized by large differences in congener patterns. To reproduce some field conditions where DL-PCB contributions up to 90% of total WHO-TEQs (HRGC-HRMS assessment) were recorded in dairy products, goat milk samples from a common bulk were fortified at different TEQ levels with mixtures containing either PCDDs and PCDFs or non-ortho substituted DL-PCBs. Fortification ranged approximately 4.5-15 pgWHO-TEQ/g fat. Based on the results, DR CALUX relative potency value (REP) of DL-PCB 126 was estimated 0.061 against the canonical WHO-TEF of 0.1. The value of 0.061 together with the other DR CALUX REPs from the literature for the remaining 28 congeners were used to model DR CALUX response (C-TEQs) in milk samples with different congener patterns. The theoretical underestimation of DR CALUX data could be mitigated by correcting the latter with the linear correlation experimentally obtained between C-TEQs and the WHO-TEQs. Under these conditions, the use as calibrants of reference samples with different analytical patterns could help those laboratories involved in a high throughput routine to set the most appropriate decision limits to optimize screening output.  相似文献   
106.
The Autism Genome Project (AGP) Consortium recently reported genome‐wide significant association between autism and an intronic single nucleotide polymorphism marker, rs4141463, within the MACROD2 gene. In the present study we attempted to replicate this finding using an independent case–control design of 1,170 cases with autism spectrum disorder (ASD) (874 of which fulfilled narrow criteria for Autism (A)) from five centers within Europe (UK, Germany, the Netherlands, Italy, and Iceland), and 35,307 controls. The combined sample size gave us a non‐centrality parameter (NCP) of 11.9, with 93% power to detect allelic association of rs4141463 at an alpha of 0.05 with odds ratio of 0.84 (the best odds ratio estimate of the AGP Consortium data), and for the narrow diagnosis of autism, an NCP of 8.9 and power of 85%. Our case–control data were analyzed for association, stratified by each center, and the summary statistics were combined using the meta‐analysis program, GWAMA. This resulted in an odds ratio (OR) of 1.03 (95% CI 0.944–1.133), with a P‐value of 0.5 for ASD and OR of 0.99 (95% CI 0.88–1.11) with P‐value = 0.85 for the Autism (A) sub‐group. Therefore, this study does not provide support for the reported association between rs4141463 and autism. © 2011 Wiley‐Liss, Inc.  相似文献   
107.
108.
109.
110.
The aim of this study was to identify whether age at onset (AAO) identifies Bipolar Disorder (BD) subtypes, and to test whether the subgroups were confirmed by different clinical profiles. Admixture analysis was applied to determine a model that best fit the observed distribution of AAO in 964 BD patients. Three distributions of AAO were identified, and age means were 16.1 (S.D. 4.2), 25.4 (S.D. 2.5) and 32.2 (S.D. 9.5) years. A significant increased rate of suicide attempts, Bipolar I (BD I) caseness, and depressive onset was observed in the early-onset group when compared to those with later-onset by means of χ2. Findings from extant studies and our results are remarkably consistent in showing that BD can be subdivided into three groups based on AAO distributions, and that early-onset is associated with higher rates of suicide attempts.  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