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   41060篇
  免费   2924篇
  国内免费   679篇
耳鼻咽喉   232篇
儿科学   1734篇
妇产科学   1159篇
基础医学   5776篇
口腔科学   1179篇
临床医学   2865篇
内科学   8346篇
皮肤病学   678篇
神经病学   3185篇
特种医学   1939篇
外国民族医学   4篇
外科学   5777篇
综合类   2597篇
预防医学   2578篇
眼科学   402篇
药学   3454篇
  26篇
中国医学   802篇
肿瘤学   1930篇
  2023年   556篇
  2022年   739篇
  2021年   1518篇
  2020年   1516篇
  2019年   2447篇
  2018年   2321篇
  2017年   1570篇
  2016年   1127篇
  2015年   1160篇
  2014年   2032篇
  2013年   2051篇
  2012年   1418篇
  2011年   1562篇
  2010年   1253篇
  2009年   1378篇
  2008年   1234篇
  2007年   1120篇
  2006年   1057篇
  2005年   859篇
  2004年   777篇
  2003年   783篇
  2002年   568篇
  2001年   524篇
  2000年   494篇
  1999年   440篇
  1998年   321篇
  1997年   283篇
  1996年   233篇
  1995年   203篇
  1994年   185篇
  1993年   132篇
  1992年   111篇
  1991年   120篇
  1990年   98篇
  1989年   99篇
  1988年   92篇
  1987年   71篇
  1985年   1006篇
  1984年   1791篇
  1983年   1099篇
  1982年   1226篇
  1981年   1192篇
  1980年   984篇
  1979年   880篇
  1978年   801篇
  1977年   684篇
  1976年   790篇
  1975年   558篇
  1974年   496篇
  1973年   552篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
Defects of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) protein affect the homeostasis of chloride, bicarbonate, sodium, and water in the airway surface liquid, influencing the mucus composition and viscosity, which induces a severe condition of infection and inflammation along the whole life of CF patients. The introduction of CFTR modulators, novel drugs directly intervening to rescue the function of CFTR protein, opens a new era of experimental research. The review summarizes the most recent advancements to understand the characteristics of the infective and inflammatory pathology of CF lungs.  相似文献   
3.
田玥  邹健 《现代肿瘤医学》2022,(23):4377-4382
胃癌作为临床最常见的肿瘤之一,常因确诊疾病较晚而影响治疗效果,胃镜活检后的病理虽然作为确诊的金标准,但是由于此方式过程痛苦,操作复杂,费用较高,且具有侵入性,可能会导致患者拒绝操作而难普及于临床,因此积极找寻胃癌有效的监测指标十分必要。近年来,很多学者研究维生素与胃癌的相关关系,并试图通过摄取某些维生素降低胃癌发生率,延缓病情及改善预后,也有通过检测血清中维生素的水平给早期胃癌的诊断提供帮助。本文就同型半胱氨酸、维生素D、维生素C、维生素E、维生素B12及叶酸在胃癌中的作用机制,及其在血清中水平与胃癌关系的相关研究进展进行简要综述,为临床胃癌诊疗提供新思路。  相似文献   
4.
《Value in health》2022,25(2):178-184
ObjectivesThe ALIC4E trial has shown that oseltamivir reduces recovery time while increasing the risk of nausea. This secondary analysis of the ALIC4E trial aimed to determine the gain in quality-adjusted life-years (QALYs) associated with adding oseltamivir to usual primary care in patients presenting with influenza-like illness (ILI).MethodsPatients with ILI were recruited during the influenza season (2015-2018) in 15 European countries. Patients were assigned to usual care with or without oseltamivir through stratified randomization (age, severity, comorbidities, and symptom onset). Patients’ health status was valued with the EQ-5D and visual analog scale (VAS) for up to 28 days. Average EQ-5D and VAS scores over time were estimated for both treatment groups using one-inflated beta regression in children (<13 years old) and adults (≥13 years old). QALY gain was calculated as the difference between the groups. Sensitivity analysis considered the value set to convert EQ-5D answers to summary scores and the follow-up period.ResultsIn adults, oseltamivir gained 0.0006 (95% confidence interval 0.0002-0.0010) QALYs, whereas no statistically significant gain was found in children (14-day follow-up, EQ-5D). QALY gains were statistically significant in patients aged ≥65 years, patients without relevant comorbidities, or patients experiencing symptoms for ≤48 hours. Using VAS and accounting for 28-day follow-up resulted in higher QALY gain.ConclusionsQALY gain owing to oseltamivir is limited compared with other diseases, and its clinical meaningfulness remains to be determined. Further analysis is needed to evaluate whether QALY gain and its impact on ILI treatment cost render oseltamivir cost-effective.  相似文献   
5.
目的探讨维持性血液透析(MHD)患者血清维生素D水平对下肢肌力减退的预测作用。 方法横断面研究设计,选择2018年9月至10月于战略支援部队特色医学中心血液净化中心的95例MHD患者,检测其血清25-羟维生素D3[25(OH)D3]水平,采用5次站立-坐下实验(5-STS)评价其下肢肌力。根据5-STS完成时间将MHD患者分为下肢肌力正常组(n=85)与减退组(n=10),比较两组患者人口学特征、实验室指标。采用多因素Logistic回归分析下肢肌力减退的影响因素,绘制受试者工作特征(ROC)曲线分析上述因素预测MHD患者发生下肢肌力减退的特异度和敏感度。 结果95例MHD患者血清25(OH)D3水平为11.00~99.50 nmol/L,中位数31.23(19.90~43.30)nmol/L;5-STS完成时间为3.55 s~18.71 s,中位数9.81(7.12,12.43)s,下肢肌力减退者10例(10.53%)。多因素Logistic回归分析显示,血清25(OH)D3是MHD患者下肢肌力减退的保护性因素[OR=0.761,95%CI(0.592~0.978),P=0.033]。进一步ROC曲线分析显示,25(OH)D3对应的ROC曲线下面积为0.815,其预测MHD患者发生下肢肌力减退的敏感度为80.00%,特异度为80.00%。 结论MHD患者血清25(OH)D3水平普遍较低,下肢肌力减退者更为明显;血清维生素D水平对MHD患者是否存在下肢肌力减退具有较好的预测价值。  相似文献   
6.
7.
BackgroundVitamin D is essential in the host defense against tuberculosis (TB). Suboptimal vitamin D status is common in the hemodialysis population. Hemodialysis patients have an increased risk compared to the general population latent tuberculosis infection (LTBI). However, the association between vitamin D deficiency and LTBI in this population remains unclear.Materials and methodsWe conducted a cross-sectional study between March and May 2017. Interferon-gamma release assay (IGRA) through QuantiFERON-TB Gold In-Tube was used to assess LTBI. Plasma 25-hydroxycholecalciferol (25-OHD) levels were measured by Elecsys Vitamin D Total assay. Suboptimal vitamin D levels included vitamin D insufficiency 20–29 ng/mg and vitamin D deficiency <20 ng/mL. Predictors for LTBI were analyzed.ResultsA total of 287 participants were enrolled. The suboptimal vitamin D level was 31.4% (90/287), which including the vitamin D deficiency was 13.9% (40/287). A total of 49.1% (141/287) people received nutritional vitamin D supplementation. The prevalence of IGRA positivity in this study was 25.1% (72/287). There was no significant difference in vitamin D concentrations or the proportion of vitamin D supplementation among the IGRA-positive and IGRA-negative groups (p = 0.789 and 0.496, respectively). In multivariate analysis, age >65 years old (odds ratio (OR), 1.89; 95% CI, 1.08–3.31; p = 0.026) and TB history (OR, 3.51; 95% CI, 1.38–8.91; p = 0.008) were independent predictors of IGRA positivity.ConclusionThis is the first study to report that vitamin D deficiency was not associated with IGRA positivity in a hemodialysis population. Aging and TB history were both independent predictors for LTBI.  相似文献   
8.
9.
目的:观察应用3D打印技术指导下的尺神经沟扩大成形术结合尺神经原位松解,术后给予针刺促进神经康复来治疗中重度肘管综合征的临床疗效。方法:自2016年4月—2019年3月,对40例由于肘关节退行性病变引起的尺神经沟骨赘生成造成尺神经卡压的中重度肘管综合征患者,根据其术前肘关节CT平扫三维重建应用3D打印技术打印肘关节模型,根据我院骨科人员提出的"肘管指数"概念,经电脑辅助计算尺神经沟正常尺寸并制作个性化的磨骨"试模",术中原位松解尺神经沟后,将尺神经牵至后方保护,切开关节囊,根据磨骨"试模"大小应用磨钻打磨扩大加深尺神经沟,尺神经松解后重新还纳入扩大的肘管内,重建弓状韧带缝回,术后在常规预防感染,营养神经治疗的同时,应用针刺的方法进行治疗,取穴以尺神经走行手太阳小肠经穴位为主,10天为1个疗程,针刺3个疗程,每疗程结束后休息3天。结果:40例患者术后伤口均一期愈合,未见血肿形成,其中1例患者因恐惧针刺而中途放弃针灸治疗。所有患者术后得到随访,随访时间12~18个月,平均13.6个月。将术后12个月与术前的运动感觉传导速度、两点辨别觉、握力、侧方捏力(占对侧百分比)进行比较,均有明显提高,有统计学差异(P0.05)。根据中华医学会手外科分会上肢部分功能评定试用标准评价手部功能:优28例,良10例,可1例,差1例,优良率95%。结论:应用3D打印技术指导下的肘管扩大成形术+尺神经原位松解,术后结合中医针灸治疗中重度肘管综合征,有一定的临床疗效。  相似文献   
10.
The selection and implementation of a plan for maxillary surgery is of the utmost importance in achieving the desired outcome for the patient undergoing two-jaw orthognathic surgery. Some splint-based and splintless methods, accompanied by computer-assisted techniques, are helpful in improving surgical plan implementation. However, randomized controlled trials focused on this procedure are lacking. This study included 61 patients who underwent bimaxillary surgeries. The patients were randomly assigned to a conventional resin occlusal splint (CROS) group, a digital occlusal splint (DOS) group, or a digital templates (DT) group, in a 1:1:1 ratio. The mean linear distance between the planned and actual postoperative positions of eight selected points on the surfaces of the maxillary teeth was selected as the outcome measure. The distance was significantly smaller in the DT group (1.17 ± 0.66 mm) when compared to both the CROS group (2.55 ± 0.95 mm, P < 0.05) and DOS group (2.15 ± 1.12 mm, P < 0.05). However, the difference between the CROS group and DOS group was not statistically significant. These findings indicate that using digital templates results in the best performance in transferring the surgical plan to the operation environment as compared to the other two types of splints. This suggests that the application of digital templates could provide a reliable treatment option.  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