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   84446篇
  免费   5482篇
  国内免费   2130篇
耳鼻咽喉   367篇
儿科学   2193篇
妇产科学   902篇
基础医学   5992篇
口腔科学   365篇
临床医学   10662篇
内科学   17236篇
皮肤病学   247篇
神经病学   3501篇
特种医学   5677篇
外国民族医学   10篇
外科学   17697篇
综合类   13383篇
预防医学   2289篇
眼科学   518篇
药学   6207篇
  41篇
中国医学   2500篇
肿瘤学   2271篇
  2024年   52篇
  2023年   1182篇
  2022年   1594篇
  2021年   2791篇
  2020年   2911篇
  2019年   2551篇
  2018年   2495篇
  2017年   2416篇
  2016年   2564篇
  2015年   2839篇
  2014年   5585篇
  2013年   6133篇
  2012年   4548篇
  2011年   5038篇
  2010年   4316篇
  2009年   4321篇
  2008年   4449篇
  2007年   4571篇
  2006年   4209篇
  2005年   3641篇
  2004年   3044篇
  2003年   2582篇
  2002年   2206篇
  2001年   2033篇
  2000年   1560篇
  1999年   1318篇
  1998年   1183篇
  1997年   1144篇
  1996年   930篇
  1995年   1019篇
  1994年   889篇
  1993年   771篇
  1992年   689篇
  1991年   577篇
  1990年   481篇
  1989年   443篇
  1988年   395篇
  1987年   358篇
  1986年   273篇
  1985年   362篇
  1984年   303篇
  1983年   173篇
  1982年   213篇
  1981年   182篇
  1980年   146篇
  1979年   126篇
  1978年   128篇
  1977年   79篇
  1976年   83篇
  1975年   51篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
ObjectiveNew-onset postoperative atrial fibrillation (POAF) after cardiac surgery is common, with rates up to 60%. POAF has been associated with early and late stroke, but its association with other cardiovascular outcomes is less known. The objective was to perform a meta-analysis of the studies reporting the association of POAF with perioperative and long-term outcomes in patients with cardiac surgery.MethodsWe performed a systematic review and a meta-analysis of studies that presented outcomes for cardiac surgery on the basis of the presence or absence of POAF. MEDLINE, EMBASE, and the Cochrane Library were assessed; 57 studies (246,340 patients) were selected. Perioperative mortality was the primary outcome. Inverse variance method and random model were performed. Leave-one-out analysis, subgroup analyses, and metaregression were conducted.ResultsPOAF was associated with perioperative mortality (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.58-2.33), perioperative stroke (OR, 2.17; 95% CI, 1.90-2.49), perioperative myocardial infarction (OR, 1.28; 95% CI, 1.06-1.54), perioperative acute renal failure (OR, 2.74; 95% CI, 2.42-3.11), hospital (standardized mean difference, 0.80; 95% CI, 0.53-1.07) and intensive care unit stay (standardized mean difference, 0.55; 95% CI, 0.24-0.86), long-term mortality (incidence rate ratio [IRR], 1.54; 95% CI, 1.40-1.69), long-term stroke (IRR, 1.33; 95% CI, 1.21-1.46), and longstanding persistent atrial fibrillation (IRR, 4.73; 95% CI, 3.36-6.66).ConclusionsThe results suggest that POAF after cardiac surgery is associated with an increased occurrence of most short- and long-term cardiovascular adverse events. However, the causality of this association remains to be established.  相似文献   
3.
The coronavirus disease 2019 pandemic presented challenges for urology patients to receive care in the format of a traditional clinic visit. For renal cancer patients, active surveillance and postintervention surveillance are the standard components of management. Telehealth, which was defined as a televideo encounter via the BlueJeans (Verizon) platform (a telehealth platform), was used to ensure continuity of care. Telehealth using the televideo modality was shown to be an effective model of care delivery to provide an optimal patient experience with ease of use.  相似文献   
4.
PurposeTo study, from a U.S. payer’s perspective, the economic consequences of drug-coated balloon (DCB) versus standard percutaneous transluminal angioplasty (PTA) use for the treatment of stenotic lesions in dysfunctional hemodialysis arteriovenous fistulae.Materials and MethodsCost differences between DCBs and PTA at year 1 and beyond were calculated via 2 methods. The first approach used the mean absolute number of trial-observed access circuit reinterventions through 12 months (0.65 ± 1.05 vs 1.05 ± 1.18 events per patient for DCBs and PTA, respectively) and projected treatment outcomes to 3 years. The second approach was based on the trial-observed access circuit primary patency rates at 12 months (53.8% vs 32.4%) and calculated the cost difference on the basis of previously published Medicare cost for patients who maintained or did not maintain primary patency. Assumptions regarding DCB device prices were tested in sensitivity analyses, and the numbers needed to treat were calculated.ResultsUsing the absolute number of access circuit reinterventions approach, the DCB strategy resulted in an estimated per-patient savings of $1,632 at 1 year and $4,263 at 3 years before considering the DCB device cost. The access circuit primary patency approach was associated with a per-patient cost savings of $2,152 at 1 year and $3,894 at 2.5 years of follow-up. At the theoretical DCB device reimbursement of $1,800, savings were $1,680 and $2,049 at 2.5 and 3 years, respectively. The one-year NNT of DCB compared to PTA was 2.48.ConclusionsEndovascular therapy for arteriovenous access stenosis with the IN.PACT AV DCB can be expected to be cost-saving if longer follow-up data confirm its clinical effectiveness.  相似文献   
5.
目的探讨超微经皮肾镜取石术(UMP)应用于直径1.5~2.5 cm肾及输尿管上段结石患者中的安全性和有效性。方法回顾性分析2018年6月-2020年6月宿迁市第一人民医院收治的60例直径为1.5~2.5 cm肾及输尿管上段结石患者的临床资料,均采用UMP治疗,分析患者手术时间、住院时间、手术成功率、结石清除率、并发症发生率及额外镇痛药使用情况。结果60例患者均一期建立通道并顺利完成手术。所有患者均未行单通道手术,未接受输血,无毗邻脏器损伤(肠道、肝脏和脾脏等),无血气胸发生;存在尿外渗或者有明显症状的腹膜后灌注液患者3例(5.0%),均行保守治疗好转;发热(体温高于38℃)5例(8.3%),均对症治疗后好转;无感染性休克患者。手术时间为35~98 min,平均(56.1±21.3)min;术后住院天数为3~8 d,平均(4.1±1.8)d;术后立即评估结石清除率为85.0%(51/60),术后1个月评估结石清除率为91.7%(55/60);术后镇痛药使用率为15.0%(9/60)。结论UMP是治疗直径1.5~2.5 cm肾及输尿管上段结石安全、有效的治疗方法之一,值得临床推广。  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.
PurposeTo evaluate the midterm outcomes of percutaneous transluminal renal angioplasty (PTRA) for pediatric renovascular hypertension (RVH).Materials and MethodsThe clinical data of patients who underwent PTRA for RVH in the authors’ hospital from 2012 to 2019 were retrospectively analyzed. Postprocedural blood pressure, glomerular filtration rate (GFR) of the affected kidney, restenosis, and complications were closely monitored.ResultsPTRA was performed in a total of 30 children (20 boys and 10 girls), with a mean age of 7.3 years ± 0.7 (range, 40 days to 13.9 years) and a mean weight of 25.0 kg ± 2.3 (range, 3.4–53 kg). The median follow-up period was 26.5 months (range, 1 month to 7.5 years). Technical success was achieved in 26 (86.7%) of the 30 patients. Restenosis developed in 3 patients (10.0%). Only 1 patient underwent stent implantation, and the stent fractured 8 months later, requiring further intervention. There were no other complications. In terms of clinical benefit of blood pressure control after the initial PTRA procedure, 15 patients (50%) were cured and 7 patients (23.3%) showed improvement. There was no significant difference in the etiology, lesion location, and lesion length between patients with clinical benefit and failure (P = .06, P = .202, and P = .06, respectively). GFR of the affected kidney was significantly improved from 19.9 mL/min ± 11.2 to 38.1 mL/min ± 11.9 at the 6-month follow-up after PTRA (P < .001).ConclusionsThe overall results of PTRA for pediatric RVH caused by different etiologies are promising. PTRA not only provided a clinical benefit of blood pressure control in 73.3% of the patients but also significantly improved the function of the affected kidney.  相似文献   
8.
目的 建立妊娠11~13+6周子宫动脉多普勒参数在低危人群中的正常参考值,同时评估其对不良妊娠结局的预测价值。方法 收集2019年6月至2021年6月于我院行产前超声检查的妊娠11~13+6周孕妇,根据妊娠结局分组。收集两侧子宫动脉多普勒指标,包括搏动指数(PI)、阻力指数(RI)、舒张早期是否有切迹,以及孕妇基本临床资料和胎儿出生信息,将以上相关参数进行统计学分析。结果 最终纳入800例孕妇,包括正常妊娠结局组740例和不良妊娠结局组60例。两组孕妇体质量指数(BMI)、分娩孕周和胎儿出生体质量比较,差异均有统计学意义(均P<0.05)。随着孕周的增加,子宫动脉两侧平均搏动指数(mPI)、平均阻力指数(mRI)和两侧舒张早期切迹检出率均呈逐渐下降的趋势。ROC曲线分析显示,mPI、mRI及两侧舒张早期切迹预测妊娠结局的曲线下面积(AUC)分别为0.542、0.574、0.521,三者联合预测妊娠结局的AUC为0.648;孕妇BMI、年龄mPI、mRI及两侧舒张早期切迹预测妊娠结局的AUC为0.751。结论 建立了低危人群在妊娠11~13+6周子宫动脉多普勒参数的正常参考值范围。在妊娠11~13+6周单纯应用子宫动脉多普勒参数预测妊娠结局的价值有限,将子宫动脉参数与临床相关指标结合可提高对不良妊娠结局的预测价值。  相似文献   
9.
10.
Diabetic foot ulcer is a devastating complication of diabetes mellitus and significant cause of mortality and morbidity all over the world and can be complex and costly. The development of foot ulcer in a diabetic patient has been estimated to be 19%-34% through their lifetime. The pathophysiology of diabetic foot ulcer consist of neuropathy, trauma and, in many patients, additional peripheral arterial disease. In particular, diabetic neuropathy leads to foot deformity, callus formation, and insensitivity to trauma or pressure. The standard algorithms in diabetic foot ulcer management include assessing the ulcer grade classification, surgical debridement, dressing to facilitate wound healing, off-loading, vascular assessment (status and presence of a chance for interventional vascular correction), and infection and glycemic control. Although especially surgical procedures are sometimes inevitable, they are poor predictive factors for the prognosis of diabetic foot ulcer. Different novel treatment modalities such as nonsurgical debridement agents, oxygen therapies, and negative pressure wound therapy, topical drugs, cellular bioproducts, human growth factors, energy-based therapies, and systematic therapies have been available for patients with diabetic foot ulcer. However, it is uncertain whether they are effective in terms of promoting wound healing related with a limited number of randomized controlled trials. This review aims at evaluating diabetic foot ulcer with regard to all aspects. We will also focus on conventional and novel adjunctive therapy in diabetic foot 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