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   7519篇
  免费   564篇
  国内免费   49篇
耳鼻咽喉   99篇
儿科学   204篇
妇产科学   202篇
基础医学   1074篇
口腔科学   722篇
临床医学   669篇
内科学   1711篇
皮肤病学   246篇
神经病学   777篇
特种医学   92篇
外科学   594篇
综合类   47篇
一般理论   1篇
预防医学   694篇
眼科学   108篇
药学   445篇
中国医学   45篇
肿瘤学   402篇
  2024年   13篇
  2023年   132篇
  2022年   247篇
  2021年   441篇
  2020年   260篇
  2019年   358篇
  2018年   391篇
  2017年   255篇
  2016年   292篇
  2015年   358篇
  2014年   444篇
  2013年   512篇
  2012年   729篇
  2011年   728篇
  2010年   381篇
  2009年   282篇
  2008年   518篇
  2007年   429篇
  2006年   314篇
  2005年   319篇
  2004年   242篇
  2003年   225篇
  2002年   150篇
  2001年   14篇
  2000年   6篇
  1999年   18篇
  1998年   25篇
  1997年   9篇
  1996年   9篇
  1995年   5篇
  1994年   7篇
  1993年   1篇
  1992年   2篇
  1991年   4篇
  1990年   1篇
  1989年   2篇
  1987年   4篇
  1986年   1篇
  1984年   1篇
  1978年   2篇
  1969年   1篇
排序方式: 共有8132条查询结果,搜索用时 15 毫秒
141.
142.
143.

Background:

Preclinical and clinical data suggest that cannabidiol (CBD), a major non-psychotomimetic compound from Cannabis sativa, induces antipsychotic-like effects. However, the antipsychotic properties of repeated CBD treatment have been poorly investigated. Behavioral changes induced by repeated treatment with glutamate N-methyl-D-aspartate receptor (NMDAR) antagonists have been proposed as an animal model of schizophrenia-like signs. In the present study, we evaluated if repeated treatment with CBD would attenuate the behavioral and molecular modifications induced by chronic administration of one of these antagonists, MK-801.

Methods:

Male C57BL/6J mice received daily i.p. injections of MK-801 (0.1, 0.5, or 1mg/kg) for 14, 21, or 28 days. Twenty-four hours after the last injection, animals were submitted to the prepulse inhibition (PPI) test. After that, we investigated if repeated treatment with CBD (15, 30, and 60mg/kg) would attenuate the PPI impairment induced by chronic treatment with MK-801 (1mg/kg; 28 days). CBD treatment began on the 6th day after the start of MK-801 administration and continued until the end of the treatment. Immediately after the PPI, the mice brains were removed and processed to evaluate the molecular changes. We measured changes in FosB/ΔFosB and parvalbumin (PV) expression, a marker of neuronal activity and a calcium-binding protein expressed in a subclass of GABAergic interneurons, respectively. Changes in mRNA expression of the NMDAR GluN1 subunit gene (GRN1) were also evaluated. CBD effects were compared to those induced by the atypical antipsychotic clozapine.

Results:

MK-801 administration at the dose of 1mg/kg for 28 days impaired PPI responses. Chronic treatment with CBD (30 and 60mg/kg) attenuated PPI impairment. MK-801 treatment increased FosB/ΔFosB expression and decreased PV expression in the medial prefrontal cortex. A decreased mRNA level of GRN1 in the hippocampus was also observed. All the molecular changes were attenuated by CBD. CBD by itself did not induce any effect. Moreover, CBD effects were similar to those induced by repeated clozapine treatment.

Conclusions:

These results indicate that repeated treatment with CBD, similar to clozapine, reverses the psychotomimetic-like effects and attenuates molecular changes observed after chronic administration of an NMDAR antagonist. These data support the view that CBD may have antipsychotic properties.  相似文献   
144.
Introduction: Diabetic sensorimotor polyneuropathy (DSP) affects 50% of diabetes patients and is painful in about 26%. Although disease-modifying therapies are not available for DSP, symptomatic treatments for painful diabetic neuropathy (PDN) are effective.

Areas covered: We performed a MEDLINE search on PubMed using the search terms: treatment diabetic neuropathy and treatment PDN. This review outlines the problem posed by DSP, the clinical presentation and the characterization of PDN. A discussion of disease-modifying interventions, including the benefits of strict glycemic control, is followed by a focus on interventions for PDN including antidepressants, anticonvulsants and other treatments.

Expert opinion: Disease modification in DSP remains an unmet need in clinical medicine affecting a large percentage of the population with concomitant healthcare costs. Strict glycemic control and attention to potential risk factors such as hypertension, hyperlipidemia and obesity may minimize DSP. Many patients benefit from treatment of their painful symptoms with anticonvulsants or antidepressants, but all are associated with significant side effects that limit their usefulness. There is a need for treatments of PDN with fewer side effects and more effective pain relief.  相似文献   

145.
While the new Coronavirus Disease 2019 (COVID-19) pandemic rapidly spread across the world, South America was reached later in relation to Asia, Europe and the United States of America (USA). Brazil concentrates now the largest number of cases in the continent and, as the disease speedily progressed throughout the country, prompt and challenging operational strategies had to be taken by institutions caring for COVID-19 and non-COVID-19 patients in order to assure optimal workflows, triage, and management. Although hospitals in the USA, Europe and Asia have shared their experience on this subject, little has been discussed about such strategies in South America or by the perspective of outpatient centers, which are paramount in the radiology field. This article shares the guidelines adopted early in the pandemic by a nationwide outpatient healthcare center composed by a network of more than 200 patient service centers and nearly 2,000 radiologists in Brazil, discussing operational and patient management strategies, staff protection, changes adopted in the fellowship program, and the effectiveness of such measures.  相似文献   
146.
BackgroundIndividuals with severe hypercholesterolemia are at a high risk of developing atherosclerotic cardiovascular disease (ASCVD). Many of them have familial hypercholesterolemia (FH).ObjectivesTo assess from a patient perspective the degree of awareness about severe hypercholesterolemia, especially FH, ASCVD risk perception, cascade screening performance, and treatment of individuals participating in a routine health evaluation program.MethodsFrom a database of 70,000 Brazilian individuals evaluated between 2006 and 2016, 1,987 (2.8%) met the inclusion criteria (age ≥ 18 years and LDL-C ≥ 190 mg/dL or ≥ 160 mg/dL, respectively, if not in use of statins or on statin therapy). Two-hundred individuals were randomly invited to complete an extensive questionnaire. FH was diagnosed if suspected by the attending physician.ResultsAlthough 97% of the sample (age 48±9 years; 16% women; 95% college/university education; 88% primary prevention; LDL-C 209±47 mg/dL) had severe hypercholesterolemia, only 18% and 29.5% believed to be at high ASCVD risk and reported knowledge of their recommended LDL-C goal, respectively. Fifty-eight percent reported being informed that high cholesterol could be a family disease, 24.5% (n = 49) had ever heard about FH, and merely 14% (n = 29) had been previously identified as suspected of having FH (age at FH diagnosis 35±12 years; 79% and 31% diagnosed, respectively, > 30 and > 40 years old). Only 2.5% underwent genetic tests, 17% underwent cascade screening, and 17% were not in use of pharmacological treatment.ConclusionsAn important gap in risk perception, cholesterol management, and aspects related to FH was encountered in individuals with severe hypercholesterolemia. (Arq Bras Cardiol. 2021; [online].ahead print, PP.0-0)  相似文献   
147.
148.
149.
Clinical Rheumatology - Resistance training (RT) is well tolerated and has shown promise for decreasing fatigue. However, the effects of RT have never been examined in primary Sjogren’s...  相似文献   
150.
Children with cancer and HSCT recipients are at high risk for common viral infections. We sought to define the viral etiology of ARI and identify risk factors. Nasal wash samples were collected from pediatric hematology–oncology patients and HSCT recipients with ARI during the 2003–2005 winter seasons. Real‐time RT‐PCR was performed to detect Flu A, influenza B, RSV, PIV 1‐3, human MPV, and HRV. HRV specimens were sequenced and genotyped. Seventy‐eight samples from 62 children were included. Viruses were detected in 31 of 78 samples (40%). HRV were detected most frequently, in 16 (52%) including five HRVC; followed by seven (22%) RSV, five (16%) Flu A, four (13%) MPV, and two (6%) PIV2. There was a trend toward higher risk of viral infection for children in day care. Only 8% of the study children had received influenza vaccine. HRV, including the recently discovered HRVC, are an important cause of infection in pediatric oncology and HSCT patients. Molecular testing is superior to conventional methods and should be standard of care, as HRV are not detected by conventional methods.  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