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   1198篇
  免费   91篇
  国内免费   2篇
耳鼻咽喉   9篇
儿科学   54篇
妇产科学   22篇
基础医学   216篇
口腔科学   39篇
临床医学   139篇
内科学   237篇
皮肤病学   15篇
神经病学   114篇
特种医学   20篇
外科学   114篇
综合类   6篇
预防医学   82篇
眼科学   56篇
药学   87篇
中国医学   13篇
肿瘤学   68篇
  2024年   2篇
  2023年   20篇
  2022年   54篇
  2021年   80篇
  2020年   47篇
  2019年   71篇
  2018年   66篇
  2017年   61篇
  2016年   65篇
  2015年   63篇
  2014年   60篇
  2013年   87篇
  2012年   124篇
  2011年   124篇
  2010年   59篇
  2009年   39篇
  2008年   60篇
  2007年   53篇
  2006年   43篇
  2005年   27篇
  2004年   37篇
  2003年   19篇
  2002年   15篇
  2001年   3篇
  2000年   2篇
  1999年   1篇
  1998年   1篇
  1997年   2篇
  1996年   1篇
  1994年   2篇
  1988年   1篇
  1982年   1篇
  1981年   1篇
排序方式: 共有1291条查询结果,搜索用时 15 毫秒
1.
2.
We assessed the occurrence of atypical adenomatous hyperplasia (AAH) in whole lung lobes with primary cancer lesions. Following surgical resection, tissue specimens were sliced to a thickness of 4 mm (3,641 specimens from 61 cases; mean = 59.7 specimens per case). A total of 119 AAH foci were found and an association was evident in 25 (57%) of 44 adenocarcinomas, 3 (30%) of 10 squamous cell carcinomas, and 2 (29%) of 7 other lung cancers. Histologic evaluation showed that 108 AAH foci were categorized as low-grade and the other 11 as high-grade AAH. These 11 foci of high-grade AAH were present in 7 patients with adenocarcinoma, and in 1 patient there was a synchronous double primary lung adenocarcinoma. High-grade AAH was closely associated with bronchioloalveolar carcinoma (BAC) type adenocarcinoma, and low-grade AAH with non-BAC adenocarcinoma. The mean +/- SD Ki-67 labeling index in high-grade AAH (3.5%+/-2.9%) was significantly higher than for the low-grade index (1.4%+/-1.6%). We propose that foci of high- but not low-grade AAH may be potential precursor lesions of lung adenocarcinoma, especially with the BAC component.  相似文献   
3.
4.
BackgroundAcute exacerbations of chronic obstructive pulmonary disease (AECOPD) are serious complications that often require immediate intervention in an emergency department (ED). The aim of this study was to investigate the effect of intravenous magnesium sulphate as an adjuvant in the treatment of AECOPD in the ED.MethodsIn a double-blind, randomized clinical trial, a total of 60 patients with AECOPD presenting to the ED of Imam Khomeini Hospital in Sari, Iran, were included. The study was conducted between September 2016 and February 2018. Eligible patients were randomly allocated into two groups of intervention and control. Patients in the intervention and control groups received intravenous infusion of magnesium sulfate (2 gr) or normal saline over 30 minutes, respectively. For all patients, Borgdyspnea score, forced expiratory volume in one second (FEV1) result and clinical variables of interest were evaluated before the beginning of the intervention, and also 45 minutes and 6 hours after the commencement of intervention.ResultsRegardless of time of evaluation, pulse rate (PR), respiratory rate (RR) and Borg score in intervention group was lower than control group. Also, FEV1 and SPO2 were greater in intervention group compared to control group. However, these differences were not statistically significant (between-subject differences or group effect) (p<0.001). The trends of FEV1, SPO2, PR, RR and Borg score were similar between two groups of study (no interaction effect; P>0.05).ConclusionAccording to the results of this study, it seems that using intravenous magnesium sulfate has no significant effect on SPO2, FEV1, RR, and PR of patients with AECOPD who presented to ED.  相似文献   
5.
6.
The aim of this paper is twofold. Firstly, to investigate the potential benefits of online health communities (OHCs) for informal caregivers by conducting a systematic literature review. Secondly, to identify the relationship between the potential benefits of OHCs and resilience factors of older adults. Performing a thematic analysis, we identified the potential benefits of OHCs for informal caregivers of older adults, including two salient themes: (a) caregivers sharing and receiving social support and (b) self and moral empowerment of caregivers. Then, we uncovered how these potential benefits can support resilience of older adults. Our findings show that sharing and receiving of social support by informal caregivers, and self and moral empowerment of informal caregivers in OHCs, can support four resilience factors among older adults, including self-care, independence, altruism and external connections. This review enables a better understanding of OHCs and Gerontology, and our outcomes also challenge the way healthcare and aged-care service providers view caregivers and older adults. Furthermore, the identified gap and opportunities would provide avenues for further research in OHCs.  相似文献   
7.
Non-small cell lung cancer (NSCLC) is one of the most common types of cancer in the world and has a 5-year survival rate of ~20%. Immunotherapies have shown promising results leading to durable responses, however, they are only effective for a subset of patients. To determine the best therapeutic approach, a thorough and in-depth profiling of the tumour microenvironment (TME) is required. The TME is a complex network of cell types that form an interconnected network, promoting tumour cell initiation, growth and dissemination. The stroma, immune cells and endothelial cells that comprise the TME generate a plethora of cytotoxic or cytoprotective signalling pathways. In this review, we discuss immunotherapeutic targets in NSCLC tumours and how the TME may influence patients' response to immunotherapy.  相似文献   
8.
9.
10.
Many multiple sclerosis (MS) patients with normal pure tone threshold suffer from difficulties in their hearing especially speech perception in background noise, which is possibly because of incompetence of central auditory processing in this group. Three audiologic tests including gap in noise test (GIN), duration pattern sequence test (DPST) and word discrimination score (WDS) were used for comparing a number of aspects of central auditory processing between patients with MS and normal subjects. Approximate threshold and percent of correct answers in GIN test, percent of correct answers in DPST test and monosyllabic discrimination in WDS test were obtained through cross-sectional non-invasive study conducted on 26 subjects with relapsing-remitting multiple sclerosis who had mean age of 28.9 (SD 4.1) years, and 26 18–40-year-old ones with normal hearing and mean age of 27.7 (SD 5.2). Results of this study demonstrate increased approximate threshold and reduction of percent of correct answers obtained from GIN test in patients with multiple sclerosis (Pv = 0.0001). Furthermore in patients with MS, the average of correct answers in DPST was lower than normal subjects and finally performance of MS subjects in WDS test in quiet environment was correlated with GIN threshold (r = ?/624, Pr = /003). Results of the present study showed that patients with MS had defect in aspects of central auditory processing consisting of temporal resolution, auditory pattern and the memory for auditory task and difficulty in discrimination of speech in noisy environment that are related to the involvement of central nervous system.  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