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   2735篇
  免费   143篇
  国内免费   7篇
耳鼻咽喉   47篇
儿科学   139篇
妇产科学   325篇
基础医学   300篇
口腔科学   42篇
临床医学   242篇
内科学   664篇
皮肤病学   22篇
神经病学   207篇
特种医学   65篇
外科学   407篇
综合类   9篇
一般理论   3篇
预防医学   122篇
眼科学   80篇
药学   101篇
中国医学   3篇
肿瘤学   107篇
  2024年   4篇
  2023年   19篇
  2022年   34篇
  2021年   77篇
  2020年   53篇
  2019年   87篇
  2018年   83篇
  2017年   60篇
  2016年   86篇
  2015年   80篇
  2014年   117篇
  2013年   130篇
  2012年   215篇
  2011年   216篇
  2010年   128篇
  2009年   111篇
  2008年   185篇
  2007年   181篇
  2006年   199篇
  2005年   162篇
  2004年   164篇
  2003年   111篇
  2002年   108篇
  2001年   22篇
  2000年   26篇
  1999年   20篇
  1998年   21篇
  1997年   14篇
  1996年   12篇
  1995年   7篇
  1994年   8篇
  1993年   7篇
  1992年   9篇
  1991年   9篇
  1990年   18篇
  1989年   7篇
  1988年   9篇
  1987年   8篇
  1986年   7篇
  1985年   12篇
  1984年   12篇
  1983年   11篇
  1982年   3篇
  1981年   6篇
  1976年   3篇
  1975年   4篇
  1974年   3篇
  1972年   5篇
  1970年   2篇
  1967年   3篇
排序方式: 共有2885条查询结果,搜索用时 15 毫秒
71.
BACKGROUND & AIMS: We tested whether the attenuation of experimental colitis by live probiotic bacteria is due to their immunostimulatory DNA, whether toll-like receptor (TLR) signaling is required, and whether nonviable probiotics are effective. METHODS: Methylated and unmethylated genomic DNA isolated from probiotics (VSL-3), DNAse-treated probiotics and Escherichia coli (DH5 alpha) genomic DNA were administered intragastrically (i.g.) or subcutaneously (s.c.) to mice prior to the induction of colitis. Viable or gamma-irradiated probiotics were administered i.g. to wild-type mice and mice deficient in different TLR or in the adaptor protein MyD88, 10 days prior to administration of dextran sodium sulfate (DSS) to their drinking water and for 7 days thereafter. RESULTS: Intragastric and s.c. administration of probiotic and E. coli DNA ameliorated the severity of DSS-induced colitis, whereas methylated probiotic DNA, calf thymus DNA, and DNase-treated probiotics had no effect. The colitis severity was attenuated to the same extent by i.g. delivery of nonviable gamma-irradiated or viable probiotics. Mice deficient in MyD88 did not respond to gamma-irradiated probiotics. The severity of DSS-induced colitis in TLR2 and TLR4 deficient mice was significantly decreased by i.g. administration of gamma-irradiated probiotics, whereas, in TLR9-deficient mice, gamma-irradiated probiotics had no effect. CONCLUSIONS: The protective effects of probiotics are mediated by their own DNA rather than by their metabolites or ability to colonize the colon. TLR9 signaling is essential in mediating the anti-inflammatory effect of probiotics, and live microorganisms are not required to attenuate experimental colitis because nonviable probiotics are equally effective.  相似文献   
72.
Objective:There is strong evidence supporting internet-delivered cognitive behaviour therapy (iCBT) and consequently growing demand for iCBT in Canada. Transdiagnostic iCBT that addresses both depression and anxiety is particularly promising as it represents an efficient method of delivering iCBT in routine care. The Online Therapy Unit, funded by the Saskatchewan government, has been offering transdiagnostic iCBT for depression and anxiety since 2013. In this article, to broadly inform implementation efforts, we examined trends in utilization, patient characteristics, and longitudinal improvements for patients receiving transdiagnostic iCBT over 6 years.Methods:Patients who completed telephone screening between November 2013 and December 2019 were included in this observational study. Patients provided demographics and mental health history at screening and completed measures at pre-treatment, post-treatment and at 3- to 4-month follow-up. Treatment engagement and satisfaction were assessed.Results:A total of 5,321 telephone screenings were completed and 4,283 of patients were accepted for treatment over the 6-year period (80.5% acceptance). The most common reason for referral to another service was high suicide risk/severe symptoms (47.1%). Examination of trends showed growing use of transdiagnostic iCBT over time (37% increase per year). There was remarkable stability in patient characteristics across years. Most patients were concurrently using medication (57.3%) with 11.9% reporting using iCBT while on a waiting list for face-to-face treatment highlighting the importance of integrating iCBT with other services. Consistent across years, large improvements in depression and anxiety symptoms were found and maintained at 3- to 4-month follow-up. There was strong patient engagement with iCBT and positive ratings of treatment experiences.Conclusions:As there is growing interest in iCBT in Canada, this large observational study provides valuable information for those implementing iCBT in terms of likely user characteristics, patterns of use, and improvements. This information has potential to assist with resource allocation and planning in Canada and elsewhere.  相似文献   
73.
ObjectiveTo evaluate the significance of sonographic perinephric fluid collection on the emergent management of patients with acute urinary stone obstruction.MethodsWe conducted a prospective study with retrospective analysis. Since January 2016 through July 2017, patients admitted to our tertiary hospital's emergency department (ED) with suspected symptomatic urinary stones underwent ultrasound evaluation. Images were prospectively interpreted by experienced radiologist who analyzed each case for the following imaging features: hydronephrosis, perinephric fluid and urethral stone identification. The presence and measurements of perinephric fluid were re-evaluated by second radiologist who was blinded for the first reader's measurements. Retrospective analysis was conducted to evaluate for an association between perinephric fluid collection and the following outcome variables: need for analgesics, the number of doses of analgesics and the amount of morphine (mg) in the ED, elevation of creatinine levels, hospitalization and need for urological interventions.ResultsThe need for analgesics, the number of doses of analgesics and the amount of morphine were significantly associated with the presence of perinephric fluid (p < 0.05). The odds ratio for the need for analgesics was 3.8 in the presence of any perinephric fluid, and 8.9 in the presence of moderate/severe perinephric fluid. No other patient outcome variables were found to be significantly associated with the presence of perinephric fluid (p > 0.05).ConclusionsThis study shows a correlation between sonographic evidence of perinephric fluid and more severe pain. Therefore, an emergency physician can consider the evidence of perinephric fluid, in acute urethral stone obstruction, a predictor for more severe pain.  相似文献   
74.
Focal segmental glomerulosclerosis (FSGS) is a scarring process associated with chronic low‐grade inflammation ascribed to toll‐like receptor (TLR) activation and monocyte migration. We developed synthetic, small‐molecule lecinoxoids, VB‐201 and VB‐703, that differentially inhibit TLR‐2‐ and TLR‐4‐mediated activation and monocyte migration. The efficacy of anti‐inflammatory lecinoxoid treatment on FSGS development was explored using a 5/6 nephrectomy rat model. Five‐sixths of nephrectomized rats were treated with lecinoxoids VB‐201, VB‐703 or PBS, for 7 weeks. Upon sacrifice, albumin/creatinine ratio, glomerulosclerosis, fibrosis‐related gene expression and the number of glomerular and interstitial monocyte were evaluated. Treatment of nephrectomized rats with lecinoxoids ameliorated glomerulosclerosis. The percentage of damaged glomeruli, glomerular sclerosis and glomeruli fibrotic score was significantly reduced following VB‐201 and VB‐703 treatment. VB‐703 attenuated the expression of fibrosis hallmark genes collagen, fibronectin (FN) and transforming growth factor β (TGF‐β) in kidneys and improved albumin/creatinine ratio with higher efficacy than did VB‐201, but only VB‐201 significantly reduced the number of glomerular and interstitial monocytes. These results indicate that treatment with TLR‐2, and more prominently, TLR‐4 antagonizing lecinoxioids, is sufficient to significantly inhibit FSGS. Moreover, inhibiting monocyte migration can also contribute to treatment of FSGS. Our data demonstrate that targeting TLR‐2‐TLR‐4 and/or monocyte migration directly affects the priming phase of fibrosis and may consequently perturb disease parthogenesis.  相似文献   
75.
76.
77.
78.
79.
OBJECTIVE: Most of the data supporting the use of atypical antipsychotics (AA) is based on studies in young adult patients. The present study is an open-label naturalistic follow-up study of olanzapine treatment vs. haloperidol for elderly chronic schizophrenia patients. MEHTOD: 20 patients (mean age 72.7+/-5.9 years, mean disease duration 33.1+/-12.0 years) who met the DSM-IV criteria for schizophrenia were randomly assigned to olanzapine (n=10) or haloperidol (n=10) treatment during acute exacerbation. Primary outcome measure was rating on the Clinical Global Impression (CGI) scale and the Positive and Negative Symptom Scale (PANSS). RESULTS: Between-group differences were computed using analysis of covariance. PANSS Total score decreased from 84 at baseline to 65 after treatment with olanzapine while decreased only from 79 to 74 with haloperidol treatment (F= 6.66, P=.02). PANSS Negative subscale decreased from 19 at baseline to 15 with olanzapine treatment while increased (deteriorated) from 18 to 20 with haloperidol treatment (F=23.37, P=.0003). CGI decreased from baseline with both olanzapine and haloperidol treatments (1.1 vs. 0.4) but the decrease in the olanzapine group was significantly greater (F=4.63, P=.05). Mean weight increased in both groups but without statistical difference between groups. CONCLUSIONS: In elderly chronic schizophrenia patients, olanzapine treatment is superior to haloperidol in reducing negative symptoms as well as less induction of extrapyramidal symptoms (EPS).  相似文献   
80.
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