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   1170篇
  免费   137篇
  国内免费   6篇
耳鼻咽喉   34篇
儿科学   51篇
妇产科学   37篇
基础医学   165篇
口腔科学   10篇
临床医学   178篇
内科学   187篇
皮肤病学   30篇
神经病学   143篇
特种医学   21篇
外科学   123篇
综合类   13篇
一般理论   1篇
预防医学   159篇
眼科学   16篇
药学   73篇
肿瘤学   72篇
  2023年   17篇
  2022年   7篇
  2021年   28篇
  2020年   42篇
  2019年   55篇
  2018年   48篇
  2017年   49篇
  2016年   33篇
  2015年   38篇
  2014年   58篇
  2013年   90篇
  2012年   108篇
  2011年   104篇
  2010年   51篇
  2009年   36篇
  2008年   72篇
  2007年   70篇
  2006年   58篇
  2005年   55篇
  2004年   55篇
  2003年   38篇
  2002年   43篇
  2001年   5篇
  2000年   8篇
  1999年   6篇
  1998年   5篇
  1995年   2篇
  1994年   7篇
  1993年   2篇
  1992年   17篇
  1991年   7篇
  1990年   10篇
  1989年   3篇
  1988年   10篇
  1987年   6篇
  1985年   7篇
  1984年   6篇
  1983年   7篇
  1982年   4篇
  1981年   3篇
  1979年   2篇
  1974年   3篇
  1973年   4篇
  1972年   6篇
  1971年   2篇
  1968年   3篇
  1966年   2篇
  1963年   2篇
  1943年   2篇
  1881年   4篇
排序方式: 共有1313条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
The in vitro MultiFlow® DNA Damage Assay multiplexes γH2AX, p53, phospho-histone H3, and polyploidization biomarkers into a single flow cytometric analysis. The current report describes a tiered sequential data analysis strategy based on data generated from exposure of human TK6 cells to a previously described 85 chemical training set and a new pharmaceutical-centric test set (n = 40). In each case, exposure was continuous over a range of closely spaced concentrations, and cell aliquots were removed for analysis following 4 and 24 hr of treatment. The first data analysis step focused on chemicals' genotoxic potential, and for this purpose, we evaluated the performance of a machine learning (ML) ensemble, a rubric that considered fold increases in biomarkers against global evaluation factors (GEFs), and a hybrid strategy that considered ML and GEFs. This first tier further used ML output and/or GEFs to classify genotoxic activity as clastogenic and/or aneugenic. Test set results demonstrated the generalizability of the first tier, with particularly good performance from the ML ensemble: 35/40 (88%) concordance with a priori genotoxicity expectations and 21/24 (88%) agreement with expected mode of action (MoA). A second tier applied unsupervised hierarchical clustering to the biomarker response data, and these analyses were found to group certain chemicals, especially aneugens, according to their molecular targets. Finally, a third tier utilized benchmark dose analyses and MultiFlow biomarker responses to rank genotoxic potency. The relevance of these rankings is supported by the strong agreement found between benchmark dose values derived from MultiFlow biomarkers compared to those generated from parallel in vitro micronucleus analyses. Collectively, the results suggest that a tiered MultiFlow data analysis pipeline is capable of rapidly and effectively identifying genotoxic hazards while providing additional information that is useful for modern risk assessments—MoA, molecular targets, and potency. Environ. Mol. Mutagen. 60:513–533, 2019. © 2019 Wiley Periodicals, Inc.  相似文献   
5.
The risk of vulvar squamous cell carcinoma (VSCC) in patients with high‐grade vulvar intraepithelial neoplasia (VIN) is considered lower in high‐grade squamous intraepithelial lesion (HSIL) compared to differentiated VIN (dVIN), but studies are limited. Our study investigated both the incidence of high‐grade VIN and the cumulative incidence of VSCC in patients with HSIL and dVIN separately. A database of women diagnosed with high‐grade VIN between 1991 and 2011 was constructed with data from the Dutch Pathology Registry (PALGA). The European standardized incidence rate (ESR) and VSCC risk were calculated, stratified for HSIL and dVIN. The effects of type of VIN (HSIL vs dVIN), age and lichen sclerosis (LS) were estimated by Cox regression. In total, 1148 patients were diagnosed with high‐grade VIN between 1991 and 2011. Between 1991‐1995 and 2006‐2011, the ESR of HSIL increased from 2.39 (per 100 000 woman‐years) to 3.26 and the ESR of dVIN increased from 0.02 to 0.08. The 10‐year cumulative VSCC risk was 10.3%; 9.7% for HSIL and 50.0% for dVIN (log rank P < .001). Type of VIN, age and presence of LS were independent risk factors for progression to VSCC, with hazard ratios of 3.0 (95% confidence interval [CI] 1.3‐7.1), 2.3 (95% CI 1.5‐3.4) and 3.1 (95% CI 1.8‐5.3), respectively. The incidence of high‐grade VIN is rising. Because of the high cancer risk in patients with dVIN, better identification and timely recognition are urgently needed.  相似文献   
6.
Objective: Computerized neuropsychological assessments are increasingly used in clinical practice, population studies of cognitive aging and clinical trial enrichment. Subtle, but significant, performance differences have been demonstrated across different modes of test administration and require further investigation.

Method: Participants included cognitively unimpaired adults aged 50 and older from the Mayo Clinic Study of Aging who completed the Cogstate Brief Battery and Cogstate’s Groton Maze Learning Test (GMLT) on an iPad or a personal computer (PC) in the clinic. Mode of administration differences and test–retest reliability coefficients were examined across 3 cohorts: a demographically matched test–retest cohort completing PC and iPad administrations the same day (N?=?168); a test naïve cohort comparing baseline PC (n?=?1820) and iPad (n?=605) performance; and a demographically matched longitudinal cohort completing 3 Cogstate visits over 15 months on either the PC (n?=63) or iPad (n?=63).

Results: Results showed a small but statistically significant and consistent finding for faster performance on PC relative to iPad for several Cogstate Brief Battery measures. Measures of accuracy generally did not differ or differences were very small. The GMLT showed faster performance and higher total errors on iPad. Most Cogstate variables showed no difference in the rate of change across PC and iPad administrations.

Conclusions: There are small, but significant, differences in performance when giving the same cognitive tests on a PC or an iPad. Future studies are needed to better understand if these small differences impact the clinical interpretation of results and research outcomes.  相似文献   
7.
CD19 chimeric antigen receptor T (CAR T)-cell therapy with axicabtagene ciloleucel (axi-cel) for relapsed or refractory (R/R) large B-cell lymphoma (LBCL) may lead to durable remissions, however, prolonged cytopenias and infections may occur. In this single center retrospective study of 85 patients, we characterized immune reconstitution and infections for patients remaining in remission after axi-cel for LBCL. Prolonged cytopenias (those occurring at or after day 30 following infusion) were common with ≥grade 3 neutropenia seen in 21 of 70 (30%) patients at day 30 and persisting in 3 of 31 (9.7%) patients at 1 year. B cells were undetectable in 30 of 34 (88.2%) patients at day 30, but were detected in 11 of 19 (57.9%) at 1 year. Median immunoglobulin G levels levels reached a nadir at day 180. By contrast, CD4 T cells decreased from baseline and were persistently low with a median CD4 count of 155 cells/mL at 1 year after axi-cel (n=19, range: 33– 269). In total, 23 of 85 (27.1%) patients received intravenous immunoglobulins after axi-cel, and 34 of 85 (40%) received granulocyte-colony stimulating factor. Infections in the first 30 days occurred in 31 of 85 (36.5%) patients, of which 11 of 85 (12.9%) required intravenous antibiotics or hospitalization (“severe”) and were associated with cytokine release syndrome, neurotoxicity, tocilizumab use, corticosteroid use, and bridging therapy on univariate analyses. After day 30, seven severe infections occurred, with no late deaths due to infection. Prolonged cytopenias are common following axi-cel therapy for LBCL and typically recover with time. Most patients experience profound and prolonged CD4 T-cell immunosuppression without severe infection.  相似文献   
8.
9.
10.
ABSTRACT

This systematic review synthesizes current evidence to determine how subjective cognitive impairment (SCI) relates to physical, cognitive, and social activity participation in older adults. Nine peer-reviewed articles were reviewed and appraised for evidence quality. Most were cross-sectional and had high methodological quality. Higher levels of SCI were almost universally associated with lower levels of physical and social activity participation. These findings suggest that older adults who report higher SCI engage in fewer activities. Examining these relationships longitudinally is an important next step to determine whether SCI precedes withdrawing from activities in older adults.  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