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   95668篇
  免费   5494篇
  国内免费   3550篇
耳鼻咽喉   1128篇
儿科学   1528篇
妇产科学   1141篇
基础医学   12830篇
口腔科学   5561篇
临床医学   8376篇
内科学   6323篇
皮肤病学   659篇
神经病学   14918篇
特种医学   3018篇
外国民族医学   8篇
外科学   13864篇
综合类   11471篇
现状与发展   6篇
预防医学   2691篇
眼科学   469篇
药学   6128篇
  27篇
中国医学   9264篇
肿瘤学   5302篇
  2024年   165篇
  2023年   1017篇
  2022年   1729篇
  2021年   2767篇
  2020年   2605篇
  2019年   2200篇
  2018年   2295篇
  2017年   2364篇
  2016年   2547篇
  2015年   2823篇
  2014年   5791篇
  2013年   6167篇
  2012年   5596篇
  2011年   6409篇
  2010年   5198篇
  2009年   4717篇
  2008年   4997篇
  2007年   4971篇
  2006年   4633篇
  2005年   4155篇
  2004年   3659篇
  2003年   3344篇
  2002年   2695篇
  2001年   2396篇
  2000年   2148篇
  1999年   1866篇
  1998年   1636篇
  1997年   1463篇
  1996年   1239篇
  1995年   1082篇
  1994年   985篇
  1993年   896篇
  1992年   830篇
  1991年   709篇
  1990年   678篇
  1989年   600篇
  1988年   555篇
  1987年   476篇
  1986年   484篇
  1985年   688篇
  1984年   619篇
  1983年   426篇
  1982年   448篇
  1981年   376篇
  1980年   342篇
  1979年   184篇
  1978年   142篇
  1977年   140篇
  1976年   90篇
  1974年   89篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
1.
PurposeAccording to the social determinants of health framework, income inequality is a potential risk factor for adverse mental health. However, few studies have explored the mechanisms suspected to mediate this relationship. The current study addresses this gap through a mediation analysis to determine if social support and community engagement act as mediators linking neighbourhood income inequality to maternal anxiety and depressive symptoms within a cohort of new mothers living in the City of Calgary, Canada.MethodsData collected at three years postpartum from mothers belonging to the All Our Families (AOF) cohort were used in the current study. Maternal data were collected between 2012 and 2015 and linked to neighbourhood socioeconomic data from the 2006 Canadian Census. Income inequality was measured using Gini coefficients derived from 2006 after-tax census data. Generalized structural equation models were used to quantify the associations between income inequality and mental health symptoms, and to assess the potential direct and indirect mediating effects of maternal social support and community engagement.ResultsIncome inequality was not significantly associated with higher depressive symptoms (β = 0.32, 95%CI = −0.067, 0.70), anxiety symptoms (β = 0.11, 95%CI = −0.39, 0.60), or lower social support. Income inequality was not associated with community engagement. For the depression models, higher social support was significantly associated with lower depressive symptoms (β = −0.13, 95%CI = −0.15, −0.097), while community engagement was not significantly associated with depressive symptoms (β = 0.059, 95%CI = −0.15, 0.27). Similarly, for the anxiety models, lower anxiety symptoms were significantly associated with higher levels of social support (β = −0.17, 95%CI = −0.20, −0.13) but not with higher levels of community engagement (β = 0.14, 95%CI = −0.14, 0.41).ConclusionThe current study did not find clear evidence for social support or community engagement mediating the relationship between neighbourhood income inequality and maternal mental health. Future investigations should employ a broader longitudinal approach to capture changes in income inequality, potential mediators, and mental health symptomatology over time.  相似文献   
2.
3.
BackgroundThe estimated number of people living with anxiety disorders worldwide is around 264 million and is estimated to have worsened with the recent pandemic of COVID-19. Acupuncture has shown to have excellent therapeutic effects in reducing anxiety.DesignDouble-blinded randomized controlled clinical trial with 56 participants (21–82 years) with anxiety diagnosed by 3 different anxiety scales (BAI, GAD-7 and OASIS). A 30-min acupuncture session was applied once a week for 10 weeks.AimsEvaluate the effectiveness of acupuncture and electroacupuncture in the treatment of anxiety to verify if: (1) People with high anxiety report reduced scores after 5 and 10 sessions; (2) Salivary cortisol levels accompanied the reduced scores; (3) Electroacupuncture treatment is more effective than acupuncture; (4) the treatments is independent of anxiolytic medication.MethodsVolunteers were randomized into 3 groups (control, acupuncture, and electroacupuncture). The results were analyzed by anxiety scales and salivary cortisol tests.ResultsThe findings show an improvement in anxiety, assessed by BAI, GAD-7 and OASIS, after the 5th session of acupuncture (p < 0.05) and electroacupuncture (p < 0.05) and the 10th session for both techniques (p < 0.001). The salivary cortisol values measured in the morning followed this pattern (p < 0.05), although the reduction of the night cortisol values was not statistically significant. Electroacupuncture and acupuncture show similar efficacy. The positive effect after the treatments is independent of anxiolytic medication (p < 0.001).ConclusionAcupuncture and electroacupuncture are effective in treating anxiety on their own or as adjuncts to pharmacological therapy.Trial registration numberNºP445-08/2017 (Unidade de Investigação em Ciências da Saúde);  相似文献   
4.
ObjectiveSpinal cord stimulation (SCS) is an effective treatment in failed back surgery syndrome (FBSS). We studied the effect of preimplantation opioid use on SCS outcome and the effect of SCS on opioid use during a two-year follow-up period.Materials and methodsThe study cohort included 211 consecutive FBSS patients who underwent an SCS trial from January 1997 to March 2014. Participants were divided into groups, which were as follows: 1) SCS trial only (n = 47), 2) successful SCS (implanted and in use throughout the two-year follow-up period, n = 131), and 3) unsuccessful SCS (implanted but later explanted or revised due to inadequate pain relief, n = 29). Patients who underwent explantation for other reasons (n = 4) were excluded. Opioid purchase data from January 1995 to March 2016 were retrieved from national registries.ResultsHigher preimplantation opioid doses associated with unsuccessful SCS (ROC: AUC = 0.66, p = 0.009), with 35 morphine milligram equivalents (MME)/day as the optimal cutoff value. All opioids were discontinued in 23% of patients with successful SCS, but in none of the patients with unsuccessful SCS (p = 0.004). Strong opioids were discontinued in 39% of patients with successful SCS, but in none of the patients with unsuccessful SCS (p = 0.04). Mean opioid dose escalated from 18 ± 4 MME/day to 36 ± 6 MME/day with successful SCS and from 22 ± 8 MME/day to 82 ± 21 MME/day with unsuccessful SCS (p < 0.001).ConclusionsHigher preimplantation opioid doses were associated with SCS failure, suggesting the need for opioid tapering before implantation. With continuous SCS therapy and no explantation or revision due to inadequate pain relief, 39% of FBSS patients discontinued strong opioids, and 23% discontinued all opioids. This indicates that SCS should be considered before detrimental dose escalation.  相似文献   
5.
《Cancer cell》2021,39(9):1214-1226.e10
  1. Download : Download high-res image (204KB)
  2. Download : Download full-size image
  相似文献   
6.
目的:探讨血化瘀方联合针灸治疗对脑梗后遗症患者脑血管血液流变动力学及神经功能的影响。方法:选取2016年1月至2017年1月沈阳市第二中医医院收治脑梗后遗症患者120例作为研究对象,对照组61例患者接受针灸治疗;观察组59例患者接受活血化瘀方联合针灸治疗。2组连续治疗30 d。比较2组患者脑血流流变学指标、神经功能评分、中医证候积分、临床疗效。结果:治疗前2组患者脑部平均血流速度、左侧椎动脉血流量、右侧椎动脉血流量、基底动脉血流量比较,差异无统计学意义(P 0. 05)。治疗后观察组患者脑部平均血流速度、左侧椎动脉血流量、右侧椎动脉血流量、基底动脉血流量大于对照组(P 0. 05)。治疗前2组患者NIHSS评分、MMSE评分比较,差异无统计学意义(P 0. 05)。治疗后观察组患者NIHSS评分显著低于对照组,MMSE评分高于对照组(P 0. 05)。治疗前2组患者头晕目眩、语言謇涩、半身不遂、患侧麻木、舌苔白腻证候评分比较,差异无统计学意义(P 0. 05)。治疗后研究患者头晕目眩、语言謇涩、半身不遂、患侧麻木、舌苔白腻证候评分显著低于对照组(P 0. 05)。2组患者临床疗效比较,差异有统计学意义(Z=-5. 626,P=0. 000)。结论:活血化瘀方联合针灸能改善脑梗后遗症患者脑血管血液流变动力学指标,保护神经功能。  相似文献   
7.
8.
Context: Persons with spinal cord injury (SCI) experience significant challenges when they access primary care and community services.

Design: A provincial summit was held to direct research, education, and innovation for primary and community care for SCI.

Setting: Toronto, Ontario, Canada.

Participants: Key stakeholders (N?=?95) including persons with SCI and caregivers, clinicians from primary care, rehabilitation, and specialized care, researchers, advocacy groups, and policy makers.

Methods: A one-day facilitated meeting that included guest speakers, panel discussions and small group discussions was held to generate potential solutions to current issues related to SCI care and to foster collaborative relationships to advance care for SCI. Perspectives on SCI management were shared by primary care, neurosurgery, rehabilitation, and members of the SCI community

Outcome Measures: Discussions were focused on five domains: knowledge translation and dissemination, application of best practices, communication, research, and patient service accessibility.

Results: Summit participants identified issues and prioritized solutions to improve primary and community care including the creation of a network of key stakeholders to enable knowledge creation and dissemination; an online repository of SCI resources, integrated health records, and a clinical network for SCI care; development and implementation of strategies to improve care transitions across sectors; implementation of effective care models and improved access to services; and utilization of empowerment frameworks to support self-management.

Conclusions: This summit identified priorities for further collaborative efforts to advance SCI primary and community care and will inform the development of a provincial SCI strategy aimed at improving the system of care for SCI.  相似文献   
9.
10.
《Journal of endodontics》2020,46(6):846-857
IntroductionThis study assessed the cleaning, shaping, and disinfection abilities of 2 instrumentation systems in molar root canals using a novel correlative analytical approach.MethodsThe root canals from extracted mandibular and maxillary molars with apical periodontitis were pair matched according to anatomic similarities as determined by micro–computed tomographic analysis and prepared with either XP-endo Shaper (FKG Dentaire, La Chaux-de-Fonds, Switzerland) (n = 16) or Reciproc Blue (VDW, Munich, Germany) (n = 16) instruments and 2.5% sodium hypochlorite irrigation. Pre- and postpreparation micro–computed tomographic scans were used to identify and calculate the unprepared surface areas (shaping), which were histobacteriologically evaluated for the presence of residual bacteria (disinfection) and pulp tissue remnants (cleaning) in each canal third.ResultsUnprepared canal surface areas for XP-endo Shaper and Reciproc Blue in the full canal length were approximately 26% and 19% (P < .05), respectively (30% and 23% in the apical part of the canal, P > .05). Preparation with Reciproc Blue resulted in 37.5% canals free of bacteria in all sections examined and 56% in the apical sections only. XP-endo Shaper resulted in 44% canals free of bacteria in all sections, and 56% in the apical part of the canal only. Pulp tissue remnants were not observed in 31% (all canal sections) and 50% (apical canal sections) of specimens from both instrument systems. No significant differences were observed between instruments when comparing the amount of pulp tissue remnants and the number of cases negative for bacteria and tissue remnants (P > .05).ConclusionsAlthough the Reciproc Blue instrument had superior shaping ability in comparison with XP-endo Shaper, both systems performed similarly in cleaning and disinfecting root canals. Irregular canals and difficult-to-reach areas were not thoroughly cleaned and disinfected by any of the tested systems.  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