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   24969篇
  免费   2069篇
  国内免费   710篇
耳鼻咽喉   245篇
儿科学   88篇
妇产科学   266篇
基础医学   525篇
口腔科学   179篇
临床医学   2006篇
内科学   2939篇
皮肤病学   202篇
神经病学   288篇
特种医学   314篇
外国民族医学   4篇
外科学   5407篇
综合类   4738篇
预防医学   968篇
眼科学   162篇
药学   2368篇
  38篇
中国医学   5036篇
肿瘤学   1975篇
  2024年   95篇
  2023年   596篇
  2022年   1077篇
  2021年   1388篇
  2020年   1213篇
  2019年   857篇
  2018年   775篇
  2017年   922篇
  2016年   1153篇
  2015年   995篇
  2014年   2383篇
  2013年   1906篇
  2012年   2205篇
  2011年   1883篇
  2010年   1514篇
  2009年   1305篇
  2008年   1182篇
  2007年   1134篇
  2006年   891篇
  2005年   742篇
  2004年   564篇
  2003年   439篇
  2002年   386篇
  2001年   331篇
  2000年   260篇
  1999年   226篇
  1998年   185篇
  1997年   158篇
  1996年   132篇
  1995年   135篇
  1994年   128篇
  1993年   76篇
  1992年   48篇
  1991年   62篇
  1990年   44篇
  1989年   48篇
  1988年   41篇
  1987年   32篇
  1986年   48篇
  1985年   30篇
  1984年   39篇
  1983年   15篇
  1982年   26篇
  1981年   17篇
  1980年   13篇
  1979年   13篇
  1978年   11篇
  1977年   9篇
  1976年   5篇
  1973年   4篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
目的 了解我国老年人中医证候分布特征,为中医药辨治老年人提供参考依据。方法 系统检索中国知识基础设施(CNKI)、中文科技期刊数据库(CCD)、万方数据资源系统数据库(CSPD),纳入研究对象为老年人的临床流行病学调查研究文献,对其调查目的、调查疾病及调查结果等进行描述统计。结果 ①最终纳入168篇文献,其中2010至2020年之间发表138篇(82.14%);调查地区涵盖全国28个省市自治区,共纳入43948例老年人,累计覆盖340个研究中心;②主要研究结果显示,老年人中医证候阴虚阳亢证(10.05%)>血瘀证(9.5%)>痰浊(湿)证(8.91%)>阴阳两虚证(4.98%)>痰瘀互结证(4.96%);单元证分布阴虚证(14.70%)>痰证(11.22%)>气虚证(7.15%)>肾虚证(4.72%)>血瘀证(4.18%);涉及病变脏腑肾>肝>脾>肺>心。结论 根据统计结果,可以看出老年人证候分布虚证多于实证,虚证中又以阴虚证、气虚证最为多见,实证常见血瘀证、痰浊(湿)证等,且多见痰瘀互结证;老年人五脏皆损,其中又以肾、肝、脾功能失调最为突出。  相似文献   
2.
目的 应用可视化方法分析代谢组学在中医药领域的现状及趋势。方法 检索中国知网数据库(CNKI)和Web of Science 核心合集数据库2021年3月15日之前收录的中医药领域代谢组学研究的相关文献,应用CiteSpace软件对纳入的文献进行关键词、作者、研究机构等内容进行可视化分析。结果 共纳入中文文献247篇,英文文献350篇。文献数量在波动中迅速上升。中、英文文献作者合作网络显示,张爱华是中医药领域代谢组学研究发文量最多的作者,并形成了核心研究团队。发文机构显示,中国医学科学院是该领域的重要研究机构,机构间合作紧密。中、英文文献关键词分析显示,研究内容主要集中在核磁共振、代谢标记物、冠心病、质谱技术、代谢通路等相关领域。结论 中医药领域代谢组学研究的热点主要为中医药治疗代谢性疾病的机制研究。研究趋势为卵泡代谢组学研究及中药有效成分的研究。  相似文献   
3.
BackgroundLiver resection is commonly performed for hepatic tumors, however preoperative risk stratification remains challenging. We evaluated the performance of contemporary prediction models for short-term mortality after liver resection in patients with and without cirrhosis.MethodsThis retrospective cohort study examined National Surgical Quality Improvement Program data. We included patients who underwent liver resections from 2014 to 2019. VOCAL-Penn, MELD, MELD-Na, ALBI, and Mayo risk scores were evaluated in terms of model discrimination and calibration for 30-day post-operative mortality.ResultsA total 15,198 patients underwent liver resection, of whom 249 (1.6%) experienced 30-day post-operative mortality. The VOCAL-Penn score had the highest discrimination (area under the ROC curve [AUC] 0.74) compared to all other models. The VOCAL-Penn score similarly outperformed other models in patients with (AUC 0.70) and without (AUC 0.74) cirrhosis.ConclusionThe VOCAL-Penn score demonstrated superior predictive performance for 30-day post-operative mortality after liver resection as compared to existing clinical standards.  相似文献   
4.
5.
BackgroundTraditional Chinese medicine (TCM) has been proven to played a great important role on the treatment of COVID-19. As one of the drugs recommended in Chinese guidelines, Lianhua Qingwen Granules or Capsules (LQ) are widely used.This systematic review and meta-analysis amis to evaluate the clinical efficacy of LQ on the treatment of COVID-19.MethodsSeven databases (PubMed, EMBASE, CENTRAL, CNKI, VIP, CBM and Wanfang) were searched to include all appropriate clinical trials that explore the efficacy of LQ on the treatment of COVID-19.ResultA total of 3 trials including 245 COVID-19 patients were eventually enrolled.Compared with the control group,the LQ group showed great significant difference on reducing the rate of clinical change to severe or critical condition[RR = 0.38, 95 %CI (0.17,0.85), P < 0.05]and the fever time (SMD =-0.57,95 %CI (-0.96,-0.17), P<0.05),as well as the significant improvement on the disappearance rate of the clinical symptoms: fever [RR = 1.36,95 %CI (1.14,1.61), P < 0.05],cough[RR = 1.99,95 %CI (1.39,2.86), P < 0.05],fatigue[RR = 1.52,95 %CI (1.15,2.01), P < 0.05] and anhelation [RR = 4.18,95 %CI (1.99,8.81), P < 0.05], but no significance on expectoration[RR = 2.46,95 %CI (0.81,7.51), P < 0.05].ConclusionThe clinical application of LQ on the treatment of COVID-19 has significant efficacy in improving clinical symptoms and reducing the rate of clinical change to severe or critical condition. Nevertheless, due to the limited quantity and quality of the included studies, more and higher quality trials with more observational indicators are expected to be published.  相似文献   
6.
PurposeTo review and to compare indirectly the outcomes of minimally invasive therapies for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia.Materials and MethodsA literature search via Medline and Cochrane Central databases was completed for randomized control studies published between January 2000 to April 2020 for the following therapies: Rezum, Urolift, Aquablation, and prostatic artery embolization (PAE). Data on the following variables were included: International prostate symptom score (IPSS), maximum urinary flow rate, quality of life, and postvoid residual (PVR). Standard mean differences between treatments were compared through a meta-analysis using transurethral resection of the prostate (TURP) to assess differences in treatment effect.ResultsThere was no significant difference in outcomes between therapies for IPSS at the 3, 6, and 12-month follow ups. Although outcomes for Rezum were only available out to 3 months, there were no consistently significant differences in outcomes when comparing Aquablation versus PAE versus Rezum. TURP PVR was significantly better than Urolift at 3, 6, and 12 months. No significant differences in minor or major adverse events were noted.ConclusionAlthough significant differences in outcomes were limited, Aquablation and PAE were the most durable at 12 months. PAE has been well studied on multiple randomized control trials with minimal adverse events while Aquablation has limited high quality data and has been associated with bleeding-related complications.  相似文献   
7.
《Digestive and liver disease》2022,54(11):1486-1493
BackgroundCold snare polypectomy (CSP) is a promising technique for the removal of sessile serrated polyps (SSPs) ≥ 10 mm. However, the efficacy and safety of this technique remain undetermined.AimsWe aimed to comprehensively evaluate the efficacy and safety of CSP for SSPs ≥ 10 mm.MethodsPubMed, EMBASE, Web of Science and Cochrane Library were searched up to January 2021.ResultsA total of 10 studies consisting of 1727 SSPs (range, 10–40 mm) from 1021 patients were included. The overall rates of technical success, adverse events (AEs) and residual SSPs were 100%, 0.7% and 2.9%, respectively. Subgroup analysis showed that the rates of technical success and AEs were comparable between CSP and cold endoscopic mucosal resection (EMR) (99.9% vs. 100% and 1.3% vs. 0.5%, respectively), between the proximal and distal colon (100% vs. 99.9% and 0.3% vs. 0, respectively), and between polyps of 10–19 mm and ≥20 mm (99.8% vs. 100% and 0.9% vs. 0, respectively). However, subgroup analysis showed that the rate of residual SSPs was slightly lower in CSP compared with cold EMR (1.3% vs. 3.9%), as well as in polyps of 10–19 mm compared with those ≥20 mm (3.1% vs. 4.7%).ConclusionCSP was an effective and safe technique for removing SSPs ≥ 10 mm.  相似文献   
8.
目的 系统评价中药治疗哮喘-慢阻肺(ACO)的疗效与安全性。方法 全面检索PubMed、Cochrane Library、Web of Science、中国知网、万方、维普、中国医学文献数据库,纳入有关中医药治疗ACO的随机对照试验(RCT),运用Cochrane手册对纳入研究的方法学质量进行评估,采用Review Manager 5.3进行Meta分析。结果 共纳入32项RCT,包括2688例ACO患者,其中试验组1361例,对照组1327例。Meta分析结果显示,中医药可以显著改善ACO患者的中医证候疗效[RR=1.19,95% CI(1.13,1.25),P<0.00001]、CAT评分[MD=-3.62,95% CI(-4.37,-2.87),P<0.00001]、ACT评分[MD=3.42,95% CI(2.23,4.62),P<0.00001],、中医证候总积分[MD=-3.61,95% CI(-4.83,-2.39),P<0.00001]、FEV1[MD=0.59,95% CI(0.08,1.10),P=0.02]、FEV1%[MD=8.61,95% CI(5.20,12.1),P<0.00001]、FEV1/FVC[MD=6.52,95% CI(4.24,8.80),P<0.00001]、6 min步行实验[MD=41.18,95% CI(22.15,60.21),P<0.0001]、急性发作次数[MD=-2.46,95% CI(-3.62,-1.13),P<0.0001]。所有研究均未报道严重不良反应。结论 中药治疗ACO,可以显著提高临床疗效,改善患者的肺功能且具有较好安全性,但是需要更高质量、多样本、多中心的随机对照试验进一步确认。  相似文献   
9.
目的 基于临床信息系统分析总结真实世界的数据,采用数据挖掘的方法探讨中医药治疗糖尿病肾病的用药规律。方法 收集2018年1月-2020年12月上海中医药大学附属曙光医院宝山分院健康信息系统确诊的糖尿病肾病的门诊或住院患者的诊疗信息,建立Excel数据库,采用Excel 2010软件统计高频药物的四气、五味、归经及功效;使用SPSS Modeler 18.0软件中的Apriori算法分析关联规则,采用web节点建构药对关联网状图;运用SPSS 25统计软件进行因子分析。结果 本研究最终纳入477例接受中药饮片治疗的DKD患者,在1203条方剂信息中,涉及中药462种;使用频数排名前5位的中药分别是黄芪、黄精、石斛、山茱萸、麦冬;使用频数前5类的中药类别分别是补气药、补阴药、清热燥湿药、活血调经药、息风止痉药;在30味高频药物中,苦、甘、辛药味最为常见;药性寒、温数量接近;归脾经、肝经、肺经、肾经居多;关联规则提示,药物组合中置信度最高的组合为地龙-当归-僵蚕,因子分析共得到5个有效因子,累积贡献率为47.33%。结论 中医药治疗DKD在补益气血阴阳的同时,兼顾对瘀血、湿邪和痰饮的治疗,结合证型,可考虑使用黄芪、黄精、石斛、山茱萸、麦冬、金蝉花等药物的使用,清热燥湿药物如黄连、黄芩、黄柏可适当加入,为使邪有去处,大黄、车前子或可增添疗效。  相似文献   
10.
ObjectiveTo systematically evaluate the clinicopathological and prognostic value of extra-hepatic bile duct resection (EHBDR) in the surgical management of patients with gallbladder carcinoma (GBC), especially in non-jaundiced patients.MethodsPubMed, EMBASE and the Cochrane Library were searched up to March 1st 2021 for comparative studies between bile duct resected and non-resected groups. RevMan5.3 and Stata 13.0 software were used for the statistical analyses.ResultsEHBDR did not correlate with a better overall survival (OS) (P = 0.17) or disease-free survival (P = 0.27). No survival benefit was also observed in patients with T2N1 (P = 0.4), T3N0 (P = 0.14) disease and node-positive patients (P = 0.75), rather, EHBDR was even harmful for patients with T2N0 (P = 0.01) and node-negative disease (P = 0.02). Significantly higher incidences of recurrent disease (P = 0.0007), postoperative complications (P < 0.00001) and positive margins (P = 0.02) were detected in the bile duct-resected group. The duration of postoperative hospital stay between the two groups was comparable (P = 0.58). Selection bias was also detected in our analysis that a significantly higher proportion of advanced lesions with T3-4 or III-IV disease was observed in the bile duct-resected group (P < 0.00001). EHBDR only contributed to a greater lymph yield (P = 0.01).ConclusionEHBDR has no survival advantage for patients with GBC, especially for those with non-jaundiced disease. Considering the unfairness of comparing OS between jaundiced patients receiving EHBDR with non-jaundiced patients without EHBDR, we could only conclude that routine EHBDR in non-jaundiced patients is not recommended and future well-designed studies with more specific subgroup analyses are required for further validation.  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