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   6053篇
  免费   527篇
  国内免费   116篇
耳鼻咽喉   39篇
儿科学   133篇
妇产科学   60篇
基础医学   1408篇
口腔科学   96篇
临床医学   435篇
内科学   1227篇
皮肤病学   95篇
神经病学   348篇
特种医学   139篇
外科学   712篇
综合类   503篇
现状与发展   2篇
预防医学   221篇
眼科学   79篇
药学   344篇
  3篇
中国医学   57篇
肿瘤学   795篇
  2024年   6篇
  2023年   101篇
  2022年   121篇
  2021年   237篇
  2020年   239篇
  2019年   219篇
  2018年   197篇
  2017年   236篇
  2016年   227篇
  2015年   294篇
  2014年   425篇
  2013年   464篇
  2012年   295篇
  2011年   373篇
  2010年   273篇
  2009年   282篇
  2008年   265篇
  2007年   302篇
  2006年   269篇
  2005年   228篇
  2004年   184篇
  2003年   172篇
  2002年   168篇
  2001年   142篇
  2000年   128篇
  1999年   106篇
  1998年   112篇
  1997年   69篇
  1996年   61篇
  1995年   87篇
  1994年   63篇
  1993年   48篇
  1992年   54篇
  1991年   39篇
  1990年   24篇
  1989年   19篇
  1988年   20篇
  1987年   22篇
  1986年   13篇
  1985年   18篇
  1984年   13篇
  1983年   8篇
  1982年   11篇
  1981年   13篇
  1980年   13篇
  1979年   9篇
  1978年   6篇
  1977年   8篇
  1976年   5篇
  1974年   2篇
排序方式: 共有6696条查询结果,搜索用时 17 毫秒
1.
2.
3.
Left ventricular noncompaction (LVNC) is a genetically heterogeneous cardiomyopathy, with familial and sporadic forms, but genetic testing only identifies a pathogenic mutation in a minority of cases. The main complications are heart failure, embolism and dysrhythmias. Herein we report a familial case of LVNC associated with a mutation in the MYH7 gene and review the literature regarding controversies in LVNC. A 50-year-old woman was referred to the cardiology clinic for palpitations. She underwent echocardiography and cardiac magnetic resonance imaging that revealed mild left ventricular systolic dysfunction and LVNC criteria. She had several episodes of non-sustained ventricular tachycardia and received an implantable cardioverter-defibrillator (ICD). Genetic testing revealed the c.1003G>C (p.Ala335Pro) mutation in the MYH7 gene. Familial screening showed clear genotype-phenotype cosegregation, which provided strong evidence for the pathogenic role of this mutation. To the best of our knowledge, this is the first report of LVNC associated with the p.Ala335Pro mutation in the MYH7 gene. This mutation has been described in hypertrophic cardiomyopathy, suggesting that the same pathogenic sarcomere mutation may be associated with different cardiomyopathies. This case also highlights the current difficulties regarding decisions on ICD implantation for primary prevention of sudden cardiac death in LVNC.  相似文献   
4.
5.
BackgroundA widened temporal window of integration (TWI) in audiovisual processing has been detected for children with autism spectrum disorder. However, research indicates a narrowing of this TWI and an associated change in audiovisual integration in the course of development.MethodsTo further elucidate audiovisual integration processes in adulthood, we compared adult participants with Asperger’s Syndrome (AS) to healthy controls (HC) by using the sound-induced double flash illusion. For a better understanding of underlying neural mechanisms, event-related potentials were measured via electroencephalography (EEG).ResultsThe number of reported sound-induced flash illusions indicated audiovisual integration. A similar TWI size for both, participants with AS and HC, was found. Additionally, enhanced P2 amplitudes were detected for participants with AS compared to HC.ConclusionResults indicate an involvement of attentional processes in audiovisual perception in participants with AS.  相似文献   
6.
目的 研究118例孕足月产妇催产中采用双针刺疗法联合米索前列醇的效果对其宫颈成熟的影响。方法 选取2019年6月-2020年6月在我院就诊的足月催产患者118例,按照随机数字分配法分为米索前列醇治疗组和联合治疗组,各59例。米索前列醇治疗组给予米索前列醇片进行治疗,联合治疗组在米索前列醇治疗组的基础上给予双针刺疗法针刺双侧合谷、三阴交穴位。统计两组患者宫颈成熟、子宫活动力、宫口扩张速度、出血量、产程、分娩方式、新生儿情况及催产效率。结果 联合治疗组宫颈口扩张、宫颈管消退、先露位置、宫颈硬度、宫口位置指标均大于米索前列醇治疗组,有统计学差异(P < 0.05)。联合治疗组子宫活动力、宫口扩张速度均大于米索前列醇治疗组,产时出血量、产后2 h出血量均低于米索前列醇治疗组,有统计学差异(P < 0.05)。联合治疗组第一产程、第二产程、第三产程、总产程均小于米索前列醇治疗组,有统计学差异(P < 0.05)。联合治疗组阴道分娩患者例数多于米索前列醇治疗组,剖宫产患者例数少于米索前列醇治疗组,有统计学差异(P < 0.05)。联合治疗组催产效率高于米索前列醇治疗组,有统计学差异(P < 0.05)。结论 双针刺疗法联合米索前列醇在足月产妇催产中应用能促进患者宫颈成熟,减少产后出血量,缩短产程,促进阴道分娩,催产效率高。  相似文献   
7.
The sortilin-related receptor 1 (SORL1) gene has been the subject of many studies focusing on frequent polymorphisms, which is associated with increased risk for Alzheimer’s Disease (AD). By whole-exome sequencing (WES), we identified two pathogenic missense mutations c.579C > G (p.F193L) and c.1397A > G (p.N466S) in SORL1. The two mutations were located in the same protein domain, and the two unrelated probands both had an onset of memory problems at less than 65 years of age, but their clinical manifestations and cranial imaging are different. The protein structure and function affected by these mutations were predicted using bioinformatics analysis, which suggested they were pathogenic. 3D protein structural analysis revealed that these amino acid substitutions might result in instability of protein structure and adverse intramolecular interactions. These findings suggest that both F193L and N466S should be thought as potential causative mutations in early-onset Alzheimer’s disease (EOAD) patients. Further functional studies are warranted to evaluate their roles in the pathogenesis of AD.  相似文献   
8.
Anthrax is a zoonotic infection caused by the gram-positive, aerobic, spore-forming bacterium Bacillus anthracis. Depending on the origin of the infection, serious health problems or mortality is possible. The virulence of B. anthracis is reliant on three pathogenic factors, which are secreted upon infection: protective antigen (PA), lethal factor (LF), and edema factor (EF). Systemic illness results from LF and EF entering cells through the formation of a complex with the heptameric form of PA, bound to the membrane of infected cells through its receptor. The currently available anthrax vaccines have multiple drawbacks, and recombinant PA is considered a promising second-generation vaccine candidate. However, the inherent chemical instability of PA through Asn deamidation at multiple sites prevents its use after long-term storage owing to loss of potency. Moreover, there is a distinct possibility of B. anthracis being used as a bioweapon; thus, the developed vaccine should remain efficacious and stable over the long-term. Second-generation anthrax vaccines with appropriate adjuvant formulations for enhanced immunogenicity and safety are desired. In this article, using protein engineering approaches, we have reviewed the stabilization of anthrax vaccine candidates that are currently licensed or under preclinical and clinical trials. We have also proposed a formulation to enhance recombinant PA vaccine potency via adjuvant formulation.  相似文献   
9.
目的 比较改良眶隔法和传统睑板法切开重睑术中的应用效果及对术后重睑形态、瘢痕发生率、角膜暴露率的影响。方法 选取2020年3月-2021年3月首都医疗爱育华医院收治的80例单睑患者,采用随机数字表法将其分对照组和观察组,各40例。对照组接受传统睑板法切开重睑术,观察组接受改良眶隔法切开重睑术,比较两组术后重睑形态、瘢痕发生率、角膜暴露率、并发症发生率。结果 观察组总有效率高于对照组,差异有统计学意义(P<0.05);观察组GAIS评分高于对照组,VAS评分低于对照组,差异有统计学意义(P<0.05);观察组右侧角膜暴露率增加值、左侧角膜暴露率增加值高于对照组,差异有统计学意义(P<0.05);观察组并发症发生率为5.00%,低于对照组的22.50%,差异有统计学意义(P<0.05)。结论 相比于传统睑板法切开重睑术,改良眶隔法切开重睑术不会过度增加术后角膜暴露率,术后瘢痕发生率更低,重睑形态更理想,患者接受度更高。  相似文献   
10.
《Indian heart journal》2022,74(4):302-306
BackgroundThe alarming rise in prevalence of hypertension warrants psychosocial methods supplementing pharmacotherapy for better management and prevention of cardiac emergencies. The objective of the study was to assess the differential impact of the form and frequency of knowledge intervention on management of primary hypertension.Materials and methodThe study was conducted on 256 hypertensive patients recruited through purposive sampling at health centers in Hyderabad, India. Pretest post-test control group quasi-experimental design was adopted for the study. There were two forms of the knowledge intervention, namely ‘Direct Interaction’ and ‘Audio-Visual’. Each form was presented in two frequencies namely ‘single exposure’ and ‘double exposure’. The four groups were labelled as Direct Intervention Single (DIS), Direct Intervention Double (DID), Audio-Visual Single (AVS) and Audio-Visual Double (AVD). Adherence and management of hypertension were assessed at baseline and six weeks post experiment. Analysis of Covariance (ANCOVA) was applied using IBM SPSS Statistics version 20.ResultsANCOVA followed by Bonferroni Multiple Group Comparison Test revealed significant differences between the four intervention groups and control group on adherence (p< .001). In case of hypertension management significant differences were observed between Control group and DIS, DID (p < .001), Control and AVS (p < .01). Control group did not differ from AVD.ConclusionThere was a positive impact of Knowledge Intervention on adherence and management of hypertension. Double exposure in audio visual form was counterproductive in hypertension management.  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