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   66019篇
  免费   6039篇
  国内免费   4938篇
耳鼻咽喉   660篇
儿科学   710篇
妇产科学   623篇
基础医学   7805篇
口腔科学   1121篇
临床医学   8713篇
内科学   9793篇
皮肤病学   603篇
神经病学   3632篇
特种医学   2550篇
外国民族医学   34篇
外科学   6938篇
综合类   11251篇
现状与发展   16篇
一般理论   1篇
预防医学   4512篇
眼科学   1886篇
药学   6881篇
  59篇
中国医学   3389篇
肿瘤学   5819篇
  2024年   218篇
  2023年   1103篇
  2022年   2770篇
  2021年   3470篇
  2020年   2560篇
  2019年   2205篇
  2018年   2343篇
  2017年   2064篇
  2016年   1955篇
  2015年   3136篇
  2014年   3767篇
  2013年   3193篇
  2012年   4995篇
  2011年   5507篇
  2010年   3542篇
  2009年   2608篇
  2008年   3318篇
  2007年   3474篇
  2006年   3369篇
  2005年   3478篇
  2004年   2219篇
  2003年   2109篇
  2002年   1764篇
  2001年   1407篇
  2000年   1582篇
  1999年   1618篇
  1998年   1080篇
  1997年   1017篇
  1996年   761篇
  1995年   709篇
  1994年   678篇
  1993年   395篇
  1992年   474篇
  1991年   426篇
  1990年   366篇
  1989年   313篇
  1988年   232篇
  1987年   227篇
  1986年   170篇
  1985年   114篇
  1984年   66篇
  1983年   59篇
  1982年   43篇
  1981年   31篇
  1980年   14篇
  1979年   23篇
  1978年   4篇
  1977年   3篇
  1975年   4篇
  1973年   8篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Open in a separate window OBJECTIVESPreoperative selection bias led to the inability to generalize the proposed benefit of subxiphoid uniportal video-assisted thoracoscopic surgery (SVATS) as having less postoperative pain than uniportal intercostal VATS. So, we conducted this prospective, single-blinded, randomized controlled trial to investigate the hypothesis that SVATS may have less early postoperative pain than UVATS in patients who undergo major lung resection for early-stage lung cancer.METHODSA total of262 patients were randomly allocated between 2 groups (each with 131 patients), the first being the UVATS group and the second being the SVATS group. The values indicated on the numerical rating scale (NRS) of pain were collected at 24 h and 48 h during rest and during coughing. In addition, different perioperative variables were analysed and compared between the 2 groups.RESULTSMultiple linear regression analysis showed that the type of surgical approach was a significant predictor of the postoperative NRS values. The postoperative NRS pain values were significantly lower in the SVATS group after 24 h during rest and coughing and after 48 h during coughing. Postoperatively, patients in the SVATS group got out of bed significantly earlier [16.37 (2.54) vs 18.05 (3.29) h, p < 0.001]. The SVATS group showed a significantly higher rate of intraoperative arrhythmia [20 (15.3%) vs 3 (2.3%) patients, p = 0.03].CONCLUSIONSSVATS major pulmonary resection in early-stage lung cancer is associated with less early postoperative pain than the UVATS approach. Operating on patients with cardiac problems using the SVATS approach is still a limiting factor for randomization due to the potential compression on the heart with resulting arrhythmia.Clinical trial registrationThe trial was registered under clinical trials.gov Identifier: NCT03331588. https://clinicaltrials.gov/ct2/show/NCT03331588.  相似文献   
992.
为了更好地完成中毒事件的应急处置,加强各级中毒救治基地之间的联系,提高专业人员应对各类中毒事件的快速处置能力,国家拨专款建立了化学中毒救治基地远程会诊系统。该系统基于Web技术,采用B/S和C/S混合模式,将视频、音频、录播等硬件、软件进行集成,实现视频会诊、现场指导、信息共享、远程教学等多功能的平台系统,丰富了国家化学中毒医疗救治基地之间的沟通方式,最大限度的满足了中毒事件处理的需求。  相似文献   
993.
994.
ObjectiveTo compare the clinical efficacy of performing simple plate fixation with that using a plate combined with fracture end fixation to investigate the necessity of fracture end fixation outside the plate in cases of oblique fracture of the middle clavicle.MethodsThis was a retrospective follow‐up study of patients with middle clavicle oblique fractures (Robinson types 2A1 and 2A2) between 2015 and 2020. Patients were divided into two groups according to their treatment options: the simple plate fixation (SPF) group (n = 79; 43 men and 36 women; average age, 46.37 ± 14.54 years) and the plate combined with fracture local fixation (PLFP) group (n = 81; 36 men and 45 women; average age, 48.42 ± 12.55 years). Intraoperative blood loss, operation time, postoperative fracture healing time, postoperative shoulder function score (Constant–Murley and disabilities of the arm, shoulder, and hand [DASH] scores), clinical complications, and postoperative subjective satisfaction were compared between the two groups.ResultsOne hundred sixty patients with a sufficient follow‐up period were included in the final analysis: 79 in the SPF group (follow‐up time: 16.24 ± 3.94 months) and 81 in the PLFP group (follow‐up time: 16.15 ± 3.43 months). Age, sex, body mass index, follow‐up duration, fracture classification, and cause of injury were not significantly different between the two groups. There was no significant difference in blood loss, Constant–Murley and DASH scores, follow‐up period, and postoperative subjective satisfaction between the two groups (P > 0.05). The fracture healing time was shorter in the PLFP group than in the SPF group (4.41 ± 0.99 vs. 4.87 ± 1.60 months, P < 0.05), but the operation duration was longer in the PLFP group than in the SPF group (65.48 ± 16.48 min, P < 0.05). There were seven (complication rate, 8.86%) and five (complication rate, 6.17%) cases that had complications in the SPF and PLFP groups, respectively. There was no significant difference in the complication rates between the two groups (P > 0.05).ConclusionAlthough the healing time was shorter in the PLFP group than in the SPF group, the clinical efficiency of the two methods in the treatment of oblique fracture of the middle clavicle was similar.  相似文献   
995.
急性期精神分裂症返回抑制时间进程的初步研究   总被引:1,自引:0,他引:1  
目的探讨急性期精神分裂症返回抑制时间进程的基本属性。方法30例健康志愿者及41例符合ICD-10精神分裂症诊断标准的急性期患者分别接受线索-靶子实验。靶子位置的2个水平分别为线索化位置和非线索化位置。线索开始呈现到靶子开始呈现的时间间隔(stimulus onsetasynchrony,SOA)的9个水平分别为300ms,400ms,500ms,600ms,700ms,800ms,1200ms,1500ms和2500ms。记录被试的反应时和错误率。结果(1)经重复测量方差分析,发现分组因素的主效应显著(P=0.000),健康对照组的平均反应时(365ms)短于精神分裂症患者的平均反应时(521ms)。靶子位置的主效应显著(P=0.000),靶子在线索化位置的反应时(458ms)长于非线索化位置的反应时(428ms)。SOA主效应不显著(P=0.338)。分组和SOA之间、分组和靶子位置之间、SOA和靶子位置之间以及分组、SOA和靶子位置之间的交互作用均不显著(P均〉0.05)。(2)健康对照组在所有SOA水平上靶子在线索化位置的反应时均长于非线索化位置的反应时,差异均达非常显著性(P均〈0.01)。(3)精神分裂症患者在所有SOA水平上靶子在线索化位置的反应时均长于非线索化位置的反应时,其中SOA为400ms,700ms和2500ms时,差异有显著性(P〈0.05);SOA为600ms,800ms,1200ms和1500ms时,差异有非常显著性(P〈0.01);而SOA为300ms和500ms时,差异无显著性(P〉0.05)。结论正常人自SOA300ms以后就出现稳定的返回抑制,而急性期精神分裂症患者的返回抑制延迟出现,SOA600ms以后出现稳定的返回抑制。  相似文献   
996.
目的探讨典型和非典型抗精神病药物合并碳酸锂治疗双相情感障碍躁狂发作患者的疗效。方法将94例双相情感障碍躁狂发作患者分为典型抗精神病药物组(43例)和非典型抗精神病药物组(51例),进行为期8周的疗效比较。采用Bech-Rafaelsen躁狂量表(BRMS)、临床大体印象量表(CGI)、副反应量表(TESS)以及药物依从性量表分别于入组前和入组第1、2、4、6和8周末时进行评定。结果治疗结束时,两组BRMS评分较入组时均显著减低(P〈0.01);临床总有效率:典型抗精神病药物组83.7%,非典型抗精神病药物组82.3%;两组疗效差异无显著性。非典型药物组的不良反应较典型组少,药物依从性较典型组高。结论非典型抗精神病药物治疗双相情感障碍躁狂发作的疗效肯定,不良反应较少,安全性高,依从性好,适合临床应用。  相似文献   
997.
ObjectiveThis study aims to assess the proportions of complex regional pain syndrome type I (CRPS I) in radial head fracture patients undergoing unilateral arthroplasty and to explore associated factors.MethodsThis is a prospective observational study. From March 2016 to May 2019, a total of 221 adult patients with radial head fracture patients were included in consecutive studies and completed the 1‐year follow‐up. All patients were treated by unilateral arthroplasty. At each follow‐up visit, the visual analogue scale was used to measure patients'' pain level. Occurrence of CRPS I, which was diagnosed by Budapest criteria, was the main outcome collected at baseline and the 1‐, 3‐, 6‐, and 9‐month follow‐ups. The baseline data were collected before surgery and included demographic and clinical data. Independent t‐tests and χ 2 tests were used as univariate analyses to compare the baseline data of patients with and without CRPS I. Multivariate analysis (Backword‐Wald) was used to identify factors independently associated with CRPS I.ResultsThe proportion of CRPS I cases among radial head fracture patients undergoing unilateral arthroplasty was 11% (n = 24). A total of 19 (79%) patients were diagnosed with CRPS I within 1 month after surgery. Multivariable logistic regression analysis revealed that female gender (odds ratios [OR]: 1.537; 95% confidence interval [CI]: 1.138–2.072), age younger than 60 years (OR: 1.682; 95% CI: 1.246–2.267), moderate and severe Mayo Elbow Performance Score (MEPS) pain (OR: 3.229; 95% CI: 2.392–4.351) and anxiety (OR: 83.346; 95% CI: 61.752–112.320) were independently associated with CRPS I.ConclusionsThis exploratory study reported that the incidence of CRPS I developing after radial head arthroplasty was 11%. Female sex, younger age, moderate and severe MEPS pain and anxiety patients seems more likely to develop CRPS I.  相似文献   
998.
目的 分析山西营养与慢性病家庭队列人群BMI与总死亡率的关系。方法 以"2002年中国居民营养与健康状况调查"山西省调查人群为基线建立队列,于2015年12月至2016年3月对研究对象进行随访调查,对逝者进行死因回顾调查。2002年基线信息完整的≥ 18岁研究对象7 007人,随访到5 360人,随访率为76.5%。将研究对象按BMI分为8组,计算死亡率,以死亡率最低组作为参照,采用Cox比例风险回归模型估计全人群、分性别、年龄(≥ 60岁、<60岁)的各组死亡风险比(HR)及95% CI,模型调整基线年龄、性别、吸烟、饮酒、文化程度等因素,并进行敏感性分析。结果 共随访67 129人年,平均随访12.5年,死亡615人,队列总死亡率为916/10万人年。BMI为26.0~27.9 kg/m2组死亡率最低,以该组为参照组,多因素调整后,BMI<18.5、18.5~19.9、22.0~23.9和≥ 30.0 kg/m2组的死亡风险明显升高,调整HR值(95% CI)分别为1.90(1.26~2.86)、1.68(1.15~2.45)、1.49(1.08~2.06)和1.72(1.07~2.76)。对于≥ 60岁老年人,BMI<18.5 kg/m2组的死亡风险明显升高,调整HR值(95% CI)为1.94(1.20~3.15)。结论 BMI ≤ 19.9、22.0~23.9及≥ 30.0 kg/m2均会增加全因死亡风险。除关注肥胖外,低体重营养不良造成的老年人高死亡风险应特别引起重视。  相似文献   
999.
孔圣枕中丹对痴呆动物模型抗凋亡作用及机制的研究   总被引:1,自引:0,他引:1  
目的:研究孔圣枕中丹抗痴呆动物模型海马神经元细胞凋亡的作用及机制。方法:将50只Wister大鼠随机分为正常组、模型组、脑复康组、孔圣枕中丹低剂量组、高剂量组,每组10只。除正常组外,将其余大鼠制成血管性痴呆大鼠模型。给大鼠灌胃后,采用流式细胞技术检测神经元凋亡率及bcl-2的表达,采用免疫组织化学法观察p53的表达。结果:孔圣枕中丹、脑复康均能降低血管性痴呆大鼠脑海马神经元凋亡率和bcl-2表达,提高p53表达,两组比较无显著性差异。结论:孔圣枕中丹能抑制神经元细胞凋亡,其机制可能与增强p53表达、降低bcl-2表达有关。  相似文献   
1000.
Vascular air embolism (VAE) is a rare complication of percutaneous nephrolithotomy. Paradoxical air embolization resulting from VAE may be more likely to occur in patients with an atrial-septal defect, such as patent foramen ovale. Here, the case of a female patient with VAE that occurred during percutaneous nephrolithotomy is presented. Although the patient was diagnosed with patent foramen ovale, she recovered well without any severe paradoxical air embolization symptoms. To our knowledge, this is the first report of VAE with paradoxical air embolization that occurred in a patient with patent foramen ovale during percutaneous nephrolithotomy that was conducted without pneumopyelography.  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