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   22654篇
  免费   2072篇
  国内免费   434篇
耳鼻咽喉   141篇
儿科学   1798篇
妇产科学   91篇
基础医学   6072篇
口腔科学   55篇
临床医学   1524篇
内科学   5154篇
皮肤病学   117篇
神经病学   324篇
特种医学   216篇
外科学   366篇
综合类   3434篇
预防医学   1465篇
眼科学   42篇
药学   2387篇
  21篇
中国医学   1668篇
肿瘤学   285篇
  2024年   6篇
  2023年   341篇
  2022年   418篇
  2021年   813篇
  2020年   912篇
  2019年   847篇
  2018年   739篇
  2017年   869篇
  2016年   892篇
  2015年   884篇
  2014年   1437篇
  2013年   2623篇
  2012年   1336篇
  2011年   1407篇
  2010年   1039篇
  2009年   1022篇
  2008年   994篇
  2007年   1172篇
  2006年   1078篇
  2005年   862篇
  2004年   770篇
  2003年   654篇
  2002年   596篇
  2001年   500篇
  2000年   417篇
  1999年   394篇
  1998年   293篇
  1997年   287篇
  1996年   222篇
  1995年   157篇
  1994年   154篇
  1993年   109篇
  1992年   105篇
  1991年   95篇
  1990年   100篇
  1989年   58篇
  1988年   66篇
  1987年   58篇
  1986年   74篇
  1985年   94篇
  1984年   46篇
  1983年   38篇
  1982年   35篇
  1981年   34篇
  1980年   42篇
  1979年   23篇
  1978年   16篇
  1977年   8篇
  1976年   8篇
  1975年   5篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
BackgroundGastroesophageal reflux may be associated with the worsening of asthma by increasing cough reflex sensitivity. Hull Airway Reflux Questionnaire (HARQ) consists of 14 prevalent reflux-related symptoms. It may be useful in predicting the presence of cough reflex hypersensitivity in asthma.MethodsFrom August 2018 to July 2020, 266 asthmatic patients completed the HARQ. They underwent blood analysis, spirometry, fraction of exhaled nitric oxide (FeNO) measurement, and the capsaicin cough challenge test. Patients were considered to have reflux-related symptoms if their HARQ scores were 13 points or higher. We evaluated the association between reflux-related symptoms and clinical asthma outcomes. Finally, we performed a multivariate analysis to determine the clinical significance of the HARQ for asthma. This study was registered in the University Hospital Medical Information Network (UMIN000040732).ResultsThe mean HARQ scores were 13.1 (standard deviation 12.0). Patients in the high HARQ scores group (HARQ ≥13, n = 105) showed a lower prevalence of atopic predisposition, lower levels of FeNO, heightened capsaicin cough reflex sensitivity, poorer asthma control, and more frequent admissions due to asthma than those in the low HARQ groups (all p values < 0.05). The HARQ was useful in selecting patients with poor controlled asthma and those with severe cough when the cut-off value was set at 13. Multivariate analysis revealed that heightened capsaicin cough reflex sensitivity affected reflux-related symptoms, as well as lower levels of FeNO and younger age.ConclusionsHigher HARQ scores (≥13) may be useful in predicting not only poor asthma condition but also the presence of airway neuronal dysfunction in patients with asthma to some extent.  相似文献   
2.
背景维生素D(VitD)是一种有效的免疫调节剂,其缺乏与支气管哮喘(以下简称哮喘)患者气道炎症、病情加重和预后不良有关。目前,成人哮喘与VitD相关性的研究报道较少,且研究结果并不一致。目的探讨成人哮喘患者血清25-羟维生素D〔25(OH)D〕水平与肺通气功能、最小诱发累积剂量(Dmin)的相关性。方法本研究为回顾性研究。选取新疆医科大学第一附属医院2020年1月至2021年9月收治的179例初诊哮喘患者作为观察组,另选取同期在新疆医科大学第一附属医院进行健康体检的151例健康体检者作为对照组。比较两组受试者血清25(OH)D水平,不同血清25(OH)D水平的哮喘患者肺通气功能指标〔用力肺活量(FVC)、FVC占预计值百分比、第1秒用力呼气容积(FEV1)、FEV1占预计值百分比、FEV1/FVC、FEV1/FVC占预计值百分比、呼气流量峰值(PEF)、PEF占预计值百分比及用力呼出25%肺活量的呼气流量(FEF25)、用力呼出50%肺活量的呼气流量(FEF50)、用力呼出75%肺活量的呼气流量(FEF75)、最大呼气中期流量(MMEF)占预计值百分比〕及Dmin;成人哮喘患者血清25(OH)D水平与Dmin的相关性分析采用Pearson相关分析。结果观察组患者血清25(OH)D水平低于对照组(P<0.05)。不同血清25(OH)D水平的哮喘患者FVC、FVC占预计值百分比、FEV1、FEV1占预计值百分比、FEV1/FVC、FEV1/FVC占预计值百分比、PEF、PEF占预计值百分比、FEF25占预计值百分比、FEF50占预计值百分比、FEF75占预计值百分比及MMEF占预计值百分比比较,差异无统计学意义(P>0.05);血清25(OH)D水平不足、缺乏的哮喘患者Dmin低于血清25(OH)D水平正常的哮喘患者,血清25(OH)D水平缺乏的哮喘患者Dmin低于血清25(OH)D水平不足的哮喘患者(P<0.05)。Pearson相关分析结果显示,成人哮喘患者血清25(OH)D水平与Dmin呈正相关(r=0.300,P<0.001)。结论血清25(OH)D水平与成人哮喘患者肺通气功能无关,但与Dmin呈正相关,故血清25(OH)D水平对评估成人哮喘患者气道高反应性(AHR)具有一定参考价值。  相似文献   
3.
夏小辉 《当代医学》2022,28(6):7-10
目的探究葶苈大枣泻肺汤加味治疗支气管哮喘的效果及患者不良反应。方法回顾性分析2019年1月至2020年6月本院收治的80例支气管哮喘患者的临床资料,按照平衡序贯法分为对照组(n=38)和观察组(n=42)。对照组采用常规西药治疗,观察组在对照组基础上联合葶苈大枣泻肺汤加味治疗,比较两组临床疗效、肺功能情况、临床症状、动脉血气、血清炎症因子及不良反应发生率。结果观察组治疗总有效率为95.2%,明显高于对照组的78.9%(P<0.05)。观察组不良反应发生率为2.3%,低于对照组的15.7%(P<0.05)。治疗后,观察组FVC、FEV1、FEV1/FVC均高于对照组,症状改善时间、住院时间均短于对照组,住院费用低于对照组(P<0.05)。治疗后,观察组SaO2、PaO2高于对照组,PaCO2低于对照组(P<0.05)。治疗后,观察组IL-7、IL-8以ECP均明显低于对照组(P<0.05)。结论在常规西药治疗的基础上联合葶苈大枣泻肺汤开展加味治疗支气管哮喘患者,可有效提升临床疗效及治疗安全性,值得临床推广应用。  相似文献   
4.
目的 探讨儿童哮喘风险评分(PARS)和哮喘预测指数(API)对反复喘息幼儿发生支气管哮喘(哮喘)的预测价值,为儿童哮喘的精准预测提供充分的证据。方法 收集100例1~3岁反复喘息儿童的临床资料,分别进行PARS和API评估,随访观察患儿是否发生哮喘,比较两者单独或联合应用的预测效能。结果 PARS预测反复喘息幼儿发生哮喘的灵敏度和特异度分别为54.55%和86.52%,ROC AUC为0.744 (95% CI 0.578~0.909)。API预测反复喘息幼儿发生哮喘的灵敏度和特异度分别为72.73%和52.81%,ROC曲线下面积为0.628(95% CI 0.460~0.796)。两者联合预测反复喘息幼儿发生哮喘的灵敏度和特异度分别为81.82%和44.94%,ROC曲线下面积为0.634(95% CI 0.474~0.794)。PARS预测反复喘息幼儿发生哮喘的ROC AUC略高于API及联合检测,但组间比较差异均无统计学意义(P均>0.05)。结论 PARS和API用于预测反复喘息幼儿发生哮喘的临床价值相当。  相似文献   
5.
目的研究急性支气管哮喘(BA)经特步他林并布地奈德治疗后白介素-5(IL-5)、白介素-10(IL-10)、肿瘤坏死因子-α(TNF-α)的变化。方法选取2016年1月至2020年12月商丘市中医院收治的122例急性BA患者的临床资料进行分析,根据不同治疗方法分为研究组(n=62,特步他林+布地奈德)和对照组(n=60,特步他林),比较两组临床疗效、肺功能[用力肺活量(FVC)、1秒用力呼气容器(FEV1)、1秒用力呼气容积占用力肺活量的百分比(FEV1/FVC%)、治疗前后IL-5、IL-10、TNF-α变化及不良反应情况。结果研究组总疗效(93.55%)高于对照组(81.67%),差异有统计学意义(P<0.05)。治疗后两组FVC、FEV1、FEV1/FVC%均较治疗前升高,且研究组高于对照组,差异具有统计学意义(P<0.05)。治疗后两组IL-5、TNF-α水平均降低,且研究组低于对照组,两组IL-10水平均上升,且研究组高于对照组,差异有统计学意义(P<0.05)。两组不良反应率比较差异无统计学意义(P>0.05)。结论特步他林与布地奈德联合治疗急性BA的效果显著,能够有效缓解患者的气道炎症反应,促进其肺功能的恢复,且联合用药无不良反应增加。  相似文献   
6.
PurposeStudies conducted primarily among European ancestry women reported 12 breast cancer predisposition genes. However, etiologic roles of these genes in breast cancer among African ancestry women have been less well-investigated.MethodsWe conducted a case-control study in African American women, which included 1117 breast cancer cases and 2169 cancer-free controls, and a pooled analysis, which included 7096 cases and 8040 controls of African descent. Odds ratios of associations with breast cancer risk were estimated.ResultsUsing sequence data, we identified 61 pathogenic variants in 12 breast cancer predisposition genes, including 11 pathogenic variants not yet reported in previous studies. Pooled analysis showed statistically significant associations of breast cancer risk with pathogenic variants in BRCA1, BRCA2, PALB2, ATM, CHEK2, TP53, NF1, RAD51C, and RAD51D (all P < .05). The associations with BRCA1, PALB2, and RAD51D were stronger for estrogen receptor (ER)-negative than for ER-positive breast cancer (P heterogeneity < .05), whereas the association with CHEK2 was stronger for ER-positive than for ER-negative breast cancer.ConclusionOur study confirmed previously identified associations of breast cancer risk with BRCA1, BRCA2, PALB2, ATM, TP53, NF1, and CHEK2 and provided new evidence to extend the associations of breast cancer risk with RAD51C and RAD51D, which was identified previously in European ancestry populations, to African ancestry women.  相似文献   
7.
《Molecular therapy》2022,30(5):1979-1993
  1. Download : Download high-res image (238KB)
  2. Download : Download full-size image
  相似文献   
8.
9.
IntroductionDetailed data on clinical characteristics in children with the omicron strain of SARS-COV-2 are limited.MethodsWe conducted a retrospective observational study of children with COVID-19 at the National Center for Child Health and Development to evaluate the clinical manifestations during and before the emergence of the omicron variant. Only symptomatic patients without underlying diseases were included. Participants were divided into two temporal groups: the “omicron era” (1/2022–2/2022) and the “pre-omicron era,” where the delta variant predominated (7/2021–11/2021). The patients were subclassified into an older vaccine-eligible group (aged 12–17 years), a younger vaccine-eligible group (aged 5–11 years), and a vaccine-ineligible group (aged 0–4 years).ResultsWe compared 113 patients in the omicron era with 106 in the pre-omicron era. Most patients in both eras had non-severe disease, and no patients required mechanical ventilation or died. Among patients aged 0–4 years, sore throat and hoarseness were more common during the omicron era than the pre-omicron era (11.1% vs. 0.0% and 11.1% vs. 1.5%, respectively). Croup syndrome was diagnosed in all patients with hoarseness. Among patients aged 5–11 years, vomiting was more frequent during the omicron era (47.2%) than during the pre-omicron era (21.7%). Cough and rhinorrhea were less common during the omicron era in patients aged 0–4 and 5–11 years, respectively, than during the pre-omicron era.ConclusionsIn children with COVID-19, clinical manifestations differed between the omicron and pre-omicron eras. In the Omicron era, croup syndrome was more frequent in vaccine-ineligible children.  相似文献   
10.
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