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   67067篇
  免费   7892篇
  国内免费   2522篇
耳鼻咽喉   126篇
儿科学   1900篇
妇产科学   290篇
基础医学   6301篇
口腔科学   362篇
临床医学   5809篇
内科学   13293篇
皮肤病学   239篇
神经病学   298篇
特种医学   2779篇
外国民族医学   96篇
外科学   5498篇
综合类   12762篇
现状与发展   13篇
预防医学   2655篇
眼科学   173篇
药学   6243篇
  36篇
中国医学   3946篇
肿瘤学   14662篇
  2024年   217篇
  2023年   1264篇
  2022年   2117篇
  2021年   3397篇
  2020年   3141篇
  2019年   2657篇
  2018年   2569篇
  2017年   3007篇
  2016年   3116篇
  2015年   3274篇
  2014年   4611篇
  2013年   4744篇
  2012年   4261篇
  2011年   4533篇
  2010年   3641篇
  2009年   3381篇
  2008年   3382篇
  2007年   3601篇
  2006年   3168篇
  2005年   2787篇
  2004年   2197篇
  2003年   1762篇
  2002年   1472篇
  2001年   1323篇
  2000年   1034篇
  1999年   824篇
  1998年   741篇
  1997年   700篇
  1996年   609篇
  1995年   464篇
  1994年   476篇
  1993年   352篇
  1992年   369篇
  1991年   300篇
  1990年   282篇
  1989年   213篇
  1988年   222篇
  1987年   196篇
  1986年   177篇
  1985年   157篇
  1984年   130篇
  1983年   85篇
  1982年   116篇
  1981年   87篇
  1980年   87篇
  1979年   61篇
  1978年   44篇
  1977年   40篇
  1976年   26篇
  1975年   26篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.

Background

Lung ultrasound can accelerate the diagnosis of life-threatening diseases in adults with respiratory symptoms.

Objective

Systematically review the accuracy of lung ultrasonography (LUS) for emergency diagnosis of pneumonia, acute heart failure, and exacerbation of chronic obstructive pulmonary disease (COPD)/asthma in adults.

Methods

PubMed, Embase, Scopus, Web of Science, and LILACS (Literatura Latino Americana e do Caribe em Ciências da Saúde; until 2016) were searched for prospective diagnostic accuracy studies. Rutter-Gatsonis hierarchical summary receiver operating characteristic method was used to measure the overall accuracy of LUS and Reitsma bivariate model to measure the accuracy of the different sonographic signs. This review was previously registered in PROSPERO (Centre for Reviews and Dissemination, University of York, York, UK; CRD42016048085).

Results

Twenty-five studies were included: 14 assessing pneumonia, 14 assessing acute heart failure, and four assessing exacerbations of COPD/asthma. The area under the summary receiver operating characteristic curve of LUS was 0.948 for pneumonia, 0.914 for acute heart failure, and 0.906 for exacerbations of COPD/asthma. In patients suspected to have pneumonia, consolidation had sensitivity of 0.82 (95% confidence interval [CI] 0.74–0.88) and specificity of 0.94 (95% CI 0.85–0.98) for this disease. In acutely dyspneic patients, modified diffuse interstitial syndrome had sensitivity of 0.90 (95% CI 0.87–0.93) and specificity of 0.93 (95% CI 0.91–0.95) for acute heart failure, whereas B-profile had sensitivity of 0.93 (95% CI 0.72–0.98) and specificity of 0.92 (95% CI 0.79–0.97) for this disease in patients with respiratory failure. In patients with acute dyspnea or respiratory failure, the A-profile without PLAPS (posterior-lateral alveolar pleural syndrome) had sensitivity of 0.78 (95% CI 0.67–0.86) and specificity of 0.94 (95% CI 0.89–0.97) for exacerbations of COPD/asthma.

Conclusion

Lung ultrasound is an accurate tool for the emergency diagnosis of pneumonia, acute heart failure, and exacerbations of COPD/asthma.  相似文献   
72.
目的 观察自拟温润方治疗风寒袭肺型急性咳嗽病的临床疗效。方法 64例风寒袭肺型急性咳嗽病患者,随机分为对照组(31例)和治疗组(33例)。对照组患者给予复方甘草口服溶液治疗,治疗组患者给予温润方治疗。比较两组患者治疗前和治疗3、6 d后的中医症状评分以及临床疗效。结果 治疗3、6 d后,两组患者咳嗽、咯痰、恶风、咽痒、鼻塞、流涕、鼻干、口干咽燥症状评分均低于治疗前,差异均具有统计学意义(P<0.05)。治疗组患者治疗3 d后咳嗽、咽痒、鼻干、口干咽燥症状评分分别为(2.18±0.98)、(1.15±0.81)、(0.60±0.61)、(0.81±0.71)分,均低于对照组的(3.04±1.62)、(1.68±0.96)、(0.96±0.67)、(1.37±0.86)分,差异均具有统计学意义(P<0.05);治疗组患者治疗6 d后咳嗽、咽痒、鼻干、口干咽燥症状评分分别为(0.54±0.51)、(0.42±0.48)、(0.40±0.46)、(0.47±0.51)分,均低于对照组的(1.12±0.76)、(1.11±0.98)、(0.88±0.98)、(1.01±0.92)分,差异均具有统计学意义(P<0.05)。两组患者治疗3、6 d后咯痰、恶风、鼻塞、流涕症状评分比较,差异无统计学意义(P>0.05)。治疗3 d后,治疗组治疗总有效率90.9%高于对照组的71.0%,差异具有统计学意义(P<0.05)。治疗6 d后,治疗组患者治疗总有效率93.9%与对照组的90.3%比较,差异无统计学意义(P>0.05)。结论 在风寒袭肺型急性咳嗽病治疗中,温润方在缓解咳嗽以及部分次症方面明显优于复方甘草口服溶液,起效更快。  相似文献   
73.
Acute lung injury (ALI) is a major cause of sepsis-induced acute respiratory failure. Emodin has been considered to play a protective role for acute lung edema in cecal ligation and puncture (CLP)-induced sepsis model. In this study we aimed to investigate whether emodin could improve CLP-induced lung sepsis via regulating aquaporin (AQP) and tight junction (TJ), inflammatory factors, and pulmonary apoptosis. The results showed that sepsis-induced pulmonary pathological changes were significantly improved after emodin treatment. Emodin was found to upregulate AQP and TJ expression in the CLP model. Meanwhile, inflammatory cytokine release and pulmonary apoptosis was remarkably reduced after emodin treatment in lung sepsis. Our data demonstrated that emodin could suppresse inflammation, restore pulmonary epithelial barrier and reduce mortality in CLP-induced ALI, suggesting the potential therapeutic application of emodin in sepsis.  相似文献   
74.

Background

We have recently shown that human epididymis protein 4 (HE4) levels correlate with the severity of cystic fibrosis (CF) lung disease. However, there are no data on how HE4 levels alter in patients receiving CFTR modulating therapy.

Methods

In this retrospective clinical study, 3 independent CF patient cohorts (US-American: 29, Australian: 12 and Irish: 19 cases) were enrolled carrying at least one Class III CFTR CF-causing mutation (p.Gly551Asp) and being treated with CFTR potentiator ivacaftor. Plasma HE4 was measured by immunoassay before treatment (baseline) and 1–6?months after commencement of ivacaftor, and were correlated with FEV1 (% predicted), sweat chloride, C-reactive protein (CRP) and body mass index (BMI).

Results

After 1?month of therapy, HE4 levels were significantly lower than at baseline and remained decreased up to 6?months. A significant inverse correlation between absolute and delta values of HE4 and FEV1 (r?=??0.5376; P?<?.001 and r?=??0.3285; P?<?.001), was retrospectively observed in pooled groups, including an independent association of HE4 with FEV1 by multiple regression analysis (β?=??0.57, P?=?.019). Substantial area under the receiver operating characteristic curve (ROC-AUC) value was determined for HE4 when 7% mean change of FEV1 (0.722 [95% CI 0.581–0.863]; P?=?.029) were used as classifier, especially in the first 2?months of treatment (0.806 [95% CI 0.665–0.947]; P?<?.001).

Conclusions

This study shows that plasma HE4 levels inversely correlate with lung function improvement in CF patients receiving ivacaftor. Overall, this potential biomarker may be of value for routine clinical and laboratory follow-up of CFTR modulating therapy.  相似文献   
75.
We used the dual capability of hyperpolarized 129Xe for spectroscopy and imaging to develop new measures of xenon diffusing capacity in the rat lung that (analogously to the diffusing capacity of carbon monoxide or DLCO) are calculated as a product of total lung volume and gas transfer rate constants divided by the pressure gradient. Under conditions of known constant pressure breath-hold, the volume is measured by hyperpolarized 129Xe MRI, and the transfer rate is measured by dynamic spectroscopy. The new quantities (xenon diffusing capacity in lung parenchyma (DLXeLP)), xenon diffusing capacity in RBCs (DLXeRBC), and total lung xenon diffusing capacity (DLXe)) were measured in six normal rats and six rats with lung inflammation induced by instillation of fungal spores of Stachybotrys chartarum. DLXeLP, DLXeRBC, and DLXe were 56 +/- 10 ml/min/mmHg, 64 +/- 35 ml/min/mmHg, and 29 +/- 9 ml/min/mmHg, respectively, for normal rats, and 27 +/- 9 ml/min/mmHg, 42 +/- 27 ml/min/mmHg, and 16 +/- 7 ml/min/mmHg, respectively, for diseased rats. Lung volumes and gas transfer times for LP (TtrLP) were 16 +/- 2 ml and 22 +/- 3 ms, respectively, for normal rats and 12 +/- 2 ml and 35 +/- 8 ms, respectively, for diseased rats. Xenon diffusing capacities may be useful for measuring changes in gas exchange associated with inflammation and other lung diseases.  相似文献   
76.
目的探讨螺旋CT对于监测中央型肺癌术后局部复发及胸内淋巴结转移的价值。方法回顾性地对55例110人次中央型肺癌术后胸部增强螺旋CT资料进行分析。结果支气管残端或吻合口复发9例,12人次。胸内淋巴结26例33人次淋巴结短径≥1 cm,其中14例结合临床及CT诊断为淋巴结转移。结论对中央型肺癌术后复发的监测,螺旋CT是最好手段之一,但对肿大淋巴结性质的评价有一定局限性。  相似文献   
77.
目的 探讨肺上沟癌的临床特点及放疗疗效和不良反应。方法 回顾性分析 3 3例肺上沟癌住院病人的临床特征和常规放疗的疗效。结果 肺上沟癌占原发性支气管肺癌的 2 9% ,常见症状为 :患侧肩、背和上肢疼痛 ( 78 8% ) ,后 1,2 ,3肋骨或椎骨破坏( 5 7 6% ) ,Horner’s综合征 ( 3 6 7% ) ;少见的症状为 :咳嗽 ( 2 7% ) ,咯血 ( 9% ) ;中位生存期为 8 4月 ;1,3 ,5年生存率分别为 3 5 6% ,12 3 % ,4 6% ;放疗反应可耐受。结论 肺上沟癌相当少见 ,其临床特征基本符合pancoast综合症 ,本病预后差 ,但放疗可缓解疼痛 ,提高生存质量。  相似文献   
78.
Aim:To investigate the clinical characteristics of patients with Peyronie's disease(PD)and diabetes mellitus(DM).Methods:During an 8-year period,a total of 307 men seen at our outpatient clinic were diagnosed with PD.Clinicalcharacteristics,penile deformities and the erectile status of patients with PD and DM together(n=102)were retro-spectively analyzed and compared to patients with PD alone with no risk factors for systemic vascular diseases(n=97).Results:The prevalence of PD among men with DM and sexual dysfunction was 10.7%.The mean ageof diabetic patients with PD was(55.9±8.9)years;in the no risk factor group it was(48.5±9.0)years(P<0.05).The median duration of DM was 5 years.The majority of diabetic patients with PD(56.0%)presented in the chronicphase(P<0.05),and they were more likely to have a severe penile deformity(>60°)than the no risk factor group(P<0.05).In the diabetic group,the most common presenting symptom was penile curvature(81.4 %),followedby a palpable nodule on the shaft of the penis(22.5%)and penile pain with erection(14.7 %).A total of 19.6 % ofpatients were not aware of their penile deformities in the diabetic group.Erectile function,provided by history and inresponse to intracavernosal injection and a stimulation test,was significantly diminished in patients with PD and DM(P<0.05).Conclusion:DM probably exaggerates the fibrotic process in PD.Diabetic patients with PD have ahigher risk of severe deformity and erectile dysfunction(ED).PD seems to be a silent consequence of DM andshould be actively sought in diabetic men.(Asian J Androl 2006 Jan;8:75-79)  相似文献   
79.
外科治疗ⅢA期N2非小细胞肺癌的预后分析及临床意义   总被引:7,自引:0,他引:7  
目的 探讨影响ⅢA期N2非小细胞肺癌(NSCLC)预后的因素,并分析经手术治疗不同亚组病人的生存率差异。方法 分析1997年1月至2000年1月146例手术治疗的ⅢA期N2 NSCLC病人的可能影响预后因素:病理类型、肿瘤位置、肿瘤大小、手术方式、临床N2情况,N2转移组数及个数、术后辅助治疗等,并用Kaplan-Meier曲线及Logr ank检验生存率差异,Cox单因素、多因素分析各因素对生存率的影响。结果 ⅢA期N2 NSCLC病人的3年和5年生存率分别为19.86%和14.56%。单因素分析示肿瘤位置、临床N2情况、N2转移组数及个数是影响生存率的因素;多因素分析示肿瘤大小、临床N2情况,N2转移组数和肿瘤位置影响预后。右肺下叶肿瘤单组或单个N2转移,预后最好。结论 纵隔N2转移淋巴结的大小、个数和组数是影响术后生存率主要因素。手术前未发现N2转移(mN2),有1组N2转移(N2h),N2转移数少于4个者手术治疗效果好。右肺下叶肿瘤发生单组N2淋巴结转移预后好。  相似文献   
80.
机械通气治疗小儿急性肺损伤   总被引:1,自引:0,他引:1  
目的:探讨小儿急性肺损伤(ALI)的临床治疗。方法:对本院综合ICU1998年4月至2002年4月发生的22例小儿ALI的临床治疗情况进行回顾性分析。结果:本组22例小儿ALI采用呼吸末正压机械通气(PEEP)联合大剂量甲基强的松龙冲击治疗,有效率为86.36%;3例死亡,死亡率为13.64%,死于多器官功能不全综合征(MODS)。结论:机械通气治疗小儿ALI应选择最佳PEEP,动态监测动脉血气指标和X线胸片,在综合治疗基础上加用大剂量甲基强的松龙冲击治疗能收到较好的疗效。  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