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   269511篇
  免费   16941篇
  国内免费   7198篇
耳鼻咽喉   3039篇
儿科学   9158篇
妇产科学   5088篇
基础医学   22768篇
口腔科学   5339篇
临床医学   30691篇
内科学   43411篇
皮肤病学   3758篇
神经病学   14288篇
特种医学   14729篇
外国民族医学   29篇
外科学   36793篇
综合类   27194篇
一般理论   6篇
预防医学   19244篇
眼科学   5812篇
药学   29882篇
  146篇
中国医学   9005篇
肿瘤学   13270篇
  2023年   2641篇
  2022年   4676篇
  2021年   9118篇
  2020年   6958篇
  2019年   12235篇
  2018年   6845篇
  2017年   6633篇
  2016年   8125篇
  2015年   11076篇
  2014年   20864篇
  2013年   19113篇
  2012年   21707篇
  2011年   18927篇
  2010年   17104篇
  2009年   16450篇
  2008年   15078篇
  2007年   15262篇
  2006年   12970篇
  2005年   9058篇
  2004年   5280篇
  2003年   4798篇
  2002年   3822篇
  2001年   3234篇
  2000年   2801篇
  1999年   2058篇
  1998年   2235篇
  1997年   2079篇
  1996年   1814篇
  1995年   1982篇
  1994年   1818篇
  1993年   1459篇
  1992年   1621篇
  1991年   1443篇
  1990年   1466篇
  1989年   1387篇
  1988年   1204篇
  1987年   1068篇
  1986年   967篇
  1985年   1993篇
  1984年   2109篇
  1983年   1483篇
  1982年   1641篇
  1981年   1561篇
  1980年   1397篇
  1979年   1181篇
  1978年   922篇
  1977年   898篇
  1976年   807篇
  1975年   530篇
  1974年   535篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
目的探讨通过下食管括约肌(lower esophageal sphincter,LES)扩张建立咽喉反流性疾病(laryngophyngeal reflux disease,LPRD)模型的可行性。方法18只新西兰白兔随机分为实验组10只和对照组8只,对实验组动物进行LES测压定位后,使用球囊对LES进行注水扩张,对照组同法置入球囊,但不进行球囊注水。扩张前1周及扩张后2周行咽喉及食管下段pH监测,LES平均静息压检测;扩张前1周、扩张后2周及8周行喉镜检查,进行喉镜下反流体征评分;扩张后8周处死动物,对其喉部及食管下段黏膜取材,光镜下观察其病理变化。结果扩张后pH监测验证实验组造模成功8只(80.0%,8/10),实验组扩张前咽喉酸反流时间百分比(%)、反流事件数(次)、反流最长时间(s)分别为0(0,0)、0(0,0)、0(0,0),扩张后分别为17.5(8.2,29.4)、3(1,5.5)、17.2(10.2,30.8),较扩张前增加,差异有统计学意义(P<0.01)。实验组扩张前食管下段pH监测酸反流时间百分比、反流事件数、反流最长时间分别为0(0,0.7)、0(0,1)、0(0,1.2),扩张后分别为23.1(4.8,49.5)、3(1,6)、25.9(11.5,56.8),较扩张前增加,差异有统计学意义(P<0.01)。实验组扩张前LES压力28.0±5.6 mmHg,较扩张后(17.2±3.3 mmHg)升高,差异有统计学差异(P=0.001);实验组扩张前RFS评分3.1±1.2分,扩张后2周为3.6±1.4分,扩张后8周为8.6±2.5分,扩张前和扩张后2周差异无统计学意义(P=0.482),但扩张前与扩张后8周差异有统计学意义(P=0.005)。病理检查示实验组喉部及食管黏膜均可观察到不同程度慢性炎症。结论食管下括约肌球囊扩张可安全、有效地建立LPRD动物模型。  相似文献   
3.
IntroductionOur aim was to describe practices in multimodal pain management at US children's hospitals and evaluate the association between non-opioid pain management strategies and pediatric patient-reported outcomes (PROs).MethodsData were collected as part of the 18-hospital ENhanced Recovery In CHildren Undergoing Surgery (ENRICH-US) clinical trial. Non-opioid pain management strategies included use of preoperative and postoperative non-opioid analgesics, regional anesthetic blocks, and a biobehavioral intervention. PROs included perioperative nervousness, pain-related functional disability, health-related quality of life (HRQoL). Associations were analyzed using multinomial logistic regression models.ResultsAmong 186 patients, 62 (33%) received preoperative analgesics, 186 (100%) postoperative analgesics, 81 (44%) regional anesthetic block, and 135 (73%) used a biobehavioral intervention. Patients were less likely to report worsened as compared to stable nervousness following regional anesthetic block (relative risk ratio [RRR]:0.31, 95% confidence interval [CI]:0.11–0.85), use of a biobehavioral technique (RRR:0.26, 95% CI:0.10–0.70), and both in combination (RRR:0.08, 95% CI:0.02–0.34). There were no associations of non-opioid pain control modalities with pain-related functional disability or HRQoL.ConclusionUse of postoperative non-opioid analgesics have been largely adopted, while preoperative non-opioid analgesics and regional anesthetic blocks are used less frequently. Regional anesthetic blocks and biobehavioral interventions may mitigate postoperative nervousness in children.Level of evidenceIII.  相似文献   
4.
BackgroundPerianal abscesses and anal fistulas are common. The principle of intention-to-treat has not been considered in previous systemic reviews. Thus, the comparison between primary and post-recurrence management was confused, and the recommendation of primary treatment is obscure. The current study aims to identify the optimal initial treatment for pediatric patients.MethodsUsing PRISMA guidelines, studies were identified from MEDLINE, EMBASE, PubMed, Cochrane Library, and Google Scholar without any language or study design restriction. The inclusion criteria include original articles or articles with original data, studies of management for a perianal abscess with or without anal fistula, and patient age of <18 years. Patients with local malignancy, Crohn's disease, or other underlying predisposing conditions were excluded. Studies without analyzing recurrence, case series of <5, and irrelevant articles were excluded in the screening stage. Of the 124 screened articles, 14 articles had no full texts or detailed information. Articles written in a language other than English or Mandarin were translated by Google Translation first and confirmed with native speakers. After the eligibility process, studies that compared identified primary managements were then included in the qualitative synthesis.ResultsThirty-one studies involving 2507 pediatric patients met the inclusion criteria. The study design consisted of two prospective case series of 47 patients and retrospective cohort studies. No randomized control trials were identified. Meta-analyses for recurrence after initial management were performed with a random-effects model. Conservative treatment and drainage revealed no difference (Odds ratio [OR], 1.222; 95% Confidential interval [CI]: 0.615–2.427, p = 0.567). Conservative management had a higher risk of recurrence than surgery without statistical significance (OR 0.278, 95% CI: 0.109–0.707, p = 0.007). Compared with incision/drainage, surgery can prevent recurrence remarkably (OR 4.360, 95% CI: 1.761–10.792, p = 0.001). Subgroup analysis of different approaches within conservative treatment and operation was not performed for lacking information.ConclusionStrong recommendations cannot be made due to the lack of prospective or randomized controlled studies. However, the current study based on real primary management supports initial surgical intervention for pediatric patients with perianal abscesses and anal fistula to prevent recurrence.Level of evidenceType of study: Systemic review; Evidence level: Level II.  相似文献   
5.
目的探究腰丛联合坐骨神经阻滞复合小剂量丙泊酚麻醉对老年股骨粗隆间骨折患者麻醉效果的影响。方法选取本院2017年8月至2019年11月收治的94例老年股骨粗隆间骨折患者,按照随机数字表法分为对照组(n=48)和观察组(n=46)。对照组行蛛网膜下腔阻滞麻醉复合腰硬外麻醉,观察组行腰丛联合坐骨神经阻滞复合小剂量丙泊酚麻醉。比较两组手术不同时间段血流动力学指标[平均动脉压(MAP)及心率(HR)]情况。结果 T1、T2、T3、T4时段,观察组MAP及HR水平均高于对照组,差异有统计学意义(P<0.05)。结论老年股骨粗隆间骨折患者经腰丛联合坐骨神经阻滞复合小剂量丙泊酚麻醉更有利于稳定术中血流动力学指标。  相似文献   
6.
ObjectiveTo explore the effects of the levels of glutamine(Glx) and glutamate(Glu) on the early identification of neurobiochemical abnormalities in high-risk people with schizophrenia through Meta-analysis.  相似文献   
7.
认知障碍是指记忆、语言、理解和判断等一个或多个方面的功能障碍,包括轻度认知障碍和各种类型的痴呆症。痴呆症是认知障碍最严重的表现,是一种导致患者日常生活、社会交往和工作能力发生显著变化的综合征。阿尔茨海默病(AD)是最常见的痴呆症类型,其次是血管性痴呆(VD)和其他神经退行性痴呆[1]。已知年龄与认知功能的退化密切相关。  相似文献   
8.
目的探讨小儿肠胃康颗粒联合酪酸梭菌活菌散治疗小儿消化不良性腹泻的临床疗效及安全性。方法104例小儿消化不良性腹泻患儿,依据随机抽签法分为对照组与观察组,各52例。对照组采用小儿肠胃康颗粒治疗,观察组采用小儿肠胃康颗粒联合酪酸梭菌活菌散治疗。对比两组症状改善时间、治疗效果及不良反应发生情况。结果观察组腹泻、腹部疼痛及食欲下降改善时间分别为(1.93±1.05)、(2.05±1.06)、(2.47±1.04)d,均短于对照组的(4.88±1.49)、(3.62±1.55)、(3.63±1.15)d,差异有统计学意义(P<0.05)。观察组治疗总有效率为94.23%,高于对照组的76.92%,差异有统计学意义(P<0.05)。观察组不良反应发生率为1.92%,低于对照组的13.46%,差异有统计学意义(P<0.05)。结论小儿肠胃康颗粒联合酪酸梭菌活菌散治疗小儿消化不良性腹泻疗效显著,且安全性较高,值得临床合理推行实践。  相似文献   
9.
郑茂  邹玉  王洁莹  况南珍  傅颖媛 《安徽医药》2022,26(11):2198-2202
目的探讨瑞香素(DAP)通过含半胱氨酸的天冬氨酸蛋白水解酶(caspase)通路对胶原诱导性关节炎(CIA)大鼠成纤维样滑膜细胞(FLS)增殖与凋亡的影响。方法体外培养 CIA-FLS,选取对数生长期细胞以不同浓度 DAP(0、5、10、20、40、80 mg/  相似文献   
10.
In this paper, we argue that understanding and addressing the problem of poor-quality medical products requires a more interdisciplinary approach than has been evident to date. While prospective studies based on rigorous standardized methodologies are the gold standard for measuring the prevalence of poor-quality medical products and understanding their distribution nationally and internationally, they should be complemented by social science research to unpack the complex set of social, economic, and governance factors that underlie these patterns. In the following sections, we discuss specific examples of prospective quality surveys and of social science studies, highlighting the value of cross-sector partnerships in driving high-quality, policy-relevant research in this area.  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