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   23753篇
  免费   2345篇
  国内免费   740篇
耳鼻咽喉   248篇
儿科学   377篇
妇产科学   183篇
基础医学   2934篇
口腔科学   587篇
临床医学   2774篇
内科学   3029篇
皮肤病学   379篇
神经病学   2519篇
特种医学   760篇
外国民族医学   1篇
外科学   1425篇
综合类   3742篇
一般理论   1篇
预防医学   2261篇
眼科学   336篇
药学   3098篇
  26篇
中国医学   1280篇
肿瘤学   878篇
  2024年   29篇
  2023年   442篇
  2022年   712篇
  2021年   1311篇
  2020年   1213篇
  2019年   949篇
  2018年   901篇
  2017年   1019篇
  2016年   989篇
  2015年   975篇
  2014年   1700篇
  2013年   1853篇
  2012年   1632篇
  2011年   1709篇
  2010年   1221篇
  2009年   1223篇
  2008年   1130篇
  2007年   1022篇
  2006年   879篇
  2005年   781篇
  2004年   625篇
  2003年   590篇
  2002年   465篇
  2001年   432篇
  2000年   346篇
  1999年   316篇
  1998年   236篇
  1997年   182篇
  1996年   201篇
  1995年   159篇
  1994年   158篇
  1993年   149篇
  1992年   123篇
  1991年   127篇
  1990年   113篇
  1989年   116篇
  1988年   117篇
  1987年   97篇
  1986年   78篇
  1985年   88篇
  1984年   89篇
  1983年   63篇
  1982年   65篇
  1981年   36篇
  1980年   37篇
  1979年   35篇
  1978年   30篇
  1977年   18篇
  1976年   18篇
  1975年   19篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
目的:给予不同年龄结节性甲状腺肿合并甲状腺癌患者实施甲状腺超声检查,对相应的超声检查特征展开分析。方法:选择2018年6月~2019年6月的114例患者为对象,所有患者均被确诊为结节性甲状腺肿合并甲状腺癌,并且利用甲状腺二维超声及多普勒超声对患者进行检查,依据患者年龄阶段均分为两组,每组中各纳入57例患者,年龄超过60岁以上的患者为老年组;年龄在60岁以下的患者为中青年组,对比两组患者的血流相关指标与钙化情况数据。结果:老年组中的平均收缩期流速、阻力指数等数据明显低于中青年组,且比较后P<0.05,具有临床可比较意义。老年组中钙化的总例数为21例,总钙化率占比为36.84%,中青年组中钙化的总例数为38例,总钙化率占比为66.67%,前者数据显著低于后者钙化率,P<0.05。结论:在对结节性甲状腺肿合并甲状腺癌患者实施超声检查后,中青年组患者的病灶呈现低回声、高回声以及伴微小钙化、血流分布以内部血流为主、血流阻力大的特点明显高于老年组,能够显著提升诊断效果,为日后的临床治疗提供了图像依据。  相似文献   
2.
We carried out a longitudinal study on the associations between residential greenness and depression risk in urban areas in Finland. Residential greenness indicators were estimated within various buffer sizes around individuals' home locations (selected n = 14424) using time-series of normalized differential vegetation index (NDVI) and CORINE land cover data (CLC). We estimated individuals’ cumulative exposure to residential greenness over a 5-years and 14-years follow-up. We used doctor-diagnosed depression and Beck Depression Inventory for depression assessment. Our multi-logistic model showed an inverse association between residential greenness and depression, implying lowered depression risk for individuals with higher residential greenness. The association was particularly evident when using NDVI-based residential greenness (within a buffer of 100 m radius) and doctor-diagnosis depression data, adjusted with individual-level covariates. The odds ratio was 0.56 (95% CI 0.33 to 0.96) for the 5-years follow-up, and 0.54 (95% CI 0.30 to 0.98) for the 14-years follow-up. The associations between CLC-based total residential green space and depression varied across the different buffer sizes. In general, all the associations depended on the type of depression assessment, quality of greenness indicators, and the spatial scale of analysis. The associations also varied across the socio-demographic groups and neighborhood socioeconomic disadvantage level.  相似文献   
3.
BackgroundIn order to avoid excessive treatment of thyroid nodules in the clinic, it is necessary to find a simple and practical analysis method to comprehensively and accurately reflect benign or malignant thyroid nodules. This study aimed to construct and validate a comprehensive and reliable network-based predictive model using a variety of imaging and laboratory criteria for thyroid nodules to stratify the risk of malignancy prior to surgery.MethodsWe retrospectively analyzed data from patients who underwent surgical treatment for thyroid nodules at the Thyroid and Breast Diagnosis and Treatment Center of Weifang Hospital of Traditional Chinese Medicine between January 2018 and December 2020. Binary logical regression analysis was performed to predict whether nodules were malignant or benign. The developmental dataset included 457 patients (January 2018–December 2020). The validation set included separate data points (n = 225, January 2018–December 2020).ResultsIn this study, criteria that showed significant predictive value for malignant nodules included TI-RADS: 4b (p = 0.065); Bethesda IV, Bethesda V, Bethesda VI (P < 0.0001); BRAFV600E mutation (P < 0.0001); Calcitonin>5 pg/ml (p = 0.0037); and FNA-Tg>30 ng/ml (p = 0.0003). A 10-grade risk scoring system was developed. The risk of malignancy risk ranged from 2.06% to 100% and was positively associated with increasing risk grade. The areas under the receiver-operating characteristic curve of the development and validation sets were 0.972 and 0.946, respectively.ConclusionA simple, comprehensive and reliable web-based predictive model was designed using a variety of imaging and laboratory criteria to stratify thyroid nodules by probability of malignancy.  相似文献   
4.
杨旭  朱德兵  王巍炜  唐明伟 《西部医学》2022,34(9):1329-1334+1341
目的 分析术前SCC、CYFRA21-1与肺鳞癌临床病理特征、预后之间的关系。方法 收集2017年3月~2018年4月在云南省肿瘤医院确诊的肺鳞癌患者100例为观察组,确诊为肺良性肿瘤患者90名为肺良性肿瘤组、以及正常人群90名为健康人群组。通过电化学发光法对SCC、CYFRA21-1两种指标进行检测。检测SCC、CYFRA21-1含量,分析在肺鳞癌中表达的临床意义。结果 SCC、CYFRA21-1在肺鳞癌中比在肺良性肿瘤、健康人群中含量要高,差异有统计学意义(P<0.001),并且敏感性均高于其他两组;男性患者的SCC、CYFRA21-1含量高于女性患者,差异具有统计学意义(P<0.05);SCC、CYFRA21-1含量在年龄≥60岁的含量高于<60岁患者,差异无统计学意义(P>0.05);有吸烟史患者的SCC含量高于无吸烟史患者,差异无统计学意义(P>0.05)。CYFRA21-1在吸烟史患者中高表达,差异有统计学意义(P<0.05);SCC、CYFRA21-1在有淋巴结转移、远处转移、肿瘤直径≥5 cm、病理分期为晚期时高表达,差异具有统计学意义(P<0.05);SCC、CYFRA21-1阳性患者OS、PFS比阴性患者短;SCC、CYFRA21-1两者之间呈正相关,相关系数(r)为0.630。结论 SCC、CYFRA21-1在肺鳞癌中表达上调;SCC、CYFRA21-1与性别之间存在某种内在联系;SCC、CYFRA21-1与肺鳞癌的TNM分期呈正相关;SCC、CYFRA21-1阳性患者OS、PFS比阴性患者短;SCC、CYFRA21-1两者之间呈正相关,相关系数(r)为0.630。  相似文献   
5.
《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   
6.
目的分析瘀热型慢性前列腺炎(CP)临床症状与心理性因素及性功能的相关性。方法收集2020年6月至2021年6月在南京市江宁中医院泌尿外科门诊诊治的91例瘀热型CP患者的临床资料进行回顾性分析,使用美国国立卫生研究院慢性前列腺炎症状指数评分表(NIH-CPSI)、中医证候量表、7项广泛性焦虑障碍量表(GAD-7)、抑郁症筛查量表(PHQ-9)、疼痛灾难化量表(PCS)、国际勃起功能评分表(IIEF-5)和早泄诊断量表(PEDT)对患者进行评估,对量表评定结果进行Pearson相关性分析和多元线性回归分析。结果(1)症状量表:NIH-CPSI总分与中医量表总分、GAD-7总分呈正相关,中医证候量表总分与CPSI、GAD-7、PHQ-9、PCS、PEDT总分呈正相关(P<0.05);CPSI总分随中医量表总分递增而升高,中医证候量表总分随CPSI疼痛症状、PHQ-9总分递增而升高(P<0.05)。(2)情绪量表:GAD-7总分与CPSI、中医证候量表总分、排尿症状、PHQ总分、PEDT总分呈正相关,PHQ-9总分与中医证候量表总分、疼痛及排尿症状、PCS总分、PEDT总分呈正相关,PCS总分与中医证候量表总分及疼痛症状分值呈正相关(P<0.05);GAD-7总分随PHQ-9总分递增而升高;PHQ-9总分随中医证候量表排尿症状、GAD-7、PCS分值递增而升高;PCS总分随中医证候量表疼痛症状、PHQ-9分值递增而升高(P<0.05)。(3)性功能量表:IIEF-5总分与中医证候量表疼痛分值呈负相关,PEDT总分与中医证候量表总分及疼痛症状、GAD-7、PHQ-9分值呈正相关(P<0.05);IIEF-5总分随中医证候量表疼痛症状分值递减而升高(P<0.05)。结论瘀热型CP患者表现为以疼痛为主,伴随排尿异常、情绪异常、认知障碍和性功能障碍的系列症状,同时使用中医证候量表及CPSI评估能较好的反映其病情的严重程度。  相似文献   
7.
目的探讨乙肝相关性肝癌临床病理学特征与溶血磷脂酸(LPA)和高敏C反应蛋白(hs-CRP)表达的相关性。方法选取2019年1月至2020年1月间河南省驻马店市中心医院收治的198例乙肝相关性肝癌患者作为乙肝组,198例酒精相关性肝癌患者作为酒精组。两组患者都进行血清hs-CRP和LPA表达检测,调查患者的病理学特征并进行相关性分析。结果乙肝组患者血清hs-CRP和LPA含量均高于酒精组,差异均有统计学意义(均P <0.05)。两组患者血清ALP、AFP、ALT、AST和GGT含量比较,差异均无统计学意义(P> 0.05)。乙肝组不同临床分期和组织学分化患者的血清hs-CRP和LPA含量比较,差异均有统计学意义(均P <0.05)。乙肝组患者的临床分期和组织学分化与血清hs-CRP和LPA表达均存在相关性,差异均有统计学意义(均P <0.05)。患者的临床分期和组织学分化均为影响hs-CRP和LPA表达的重要因素,差异均有统计学意义(均P <0.05)。结论相对于酒精相关性肝癌,乙肝相关性肝癌的血清hs-CRP和LPA呈现高表达,与患者的临床病理学特征存在相关性。  相似文献   
8.
9.
PurposeThe purpose of this study was to make a systematic review and meta-analysis to determine the stent diameter (8 mm vs. 10 mm) that conveys better safety and clinical efficacy for transjugular intrahepatic portosystemic shunt (TIPS).Materials and methodsFour databases were used to identify clinical trials published from inception until March 2020. Data were extracted to estimate and compare one-year and three-year overall survivals, hepatic encephalopathy, variceal rebleeding, and shunt dysfunction rates between patients with 8 mm covered stents and those with 10 mm covered stents.ResultsFive eligible studies were selected, which included 489 patients (316 men, 173 women). The 8 mm covered stent group had higher efficacy regarding one-year or three-year overall survival (odds ratio [OR], 2.88; P = 0.003) and (OR, 1.81; P = 0.04) and lower hepatic encephalopathy (OR, 0.69; P = 0.04) compared with 10 mm covered stent group. There were no significant differences in variceal rebleeding rate (OR 0.80; P = 0.67). However, shunt dysfunction was lower in 10 mm covered stent group (OR, 2.26; P = 0.003).ConclusionsOur results suggest that the use of 8 mm covered stents should be preferred to that of 10 mm covered stents for TIPS placement when portal pressure is frequently monitored.  相似文献   
10.
目前在中医界已发布的冠心病痰湿证辨证标准是以主症、次症形式定性地给出,存在主观性较强的问题。本文引入约束隐结构分析,该方法将主症、次症的语义作为约束条件加入隐结构分析过程,得到含有主症、次症语义约束的定量化中医证候辨证规则。使用该方法对冠心病痰湿证患者556条无标签数据的分析,得到其约束隐结构模型,最后建立定量化痰湿证辨证规则,舌胖边有齿痕(3.16)、苔腻(3.12)、苔白滑(4.72)、胸闷(1.73)、脉濡或滑(6.04);次症:肢体困重(0.48)、口黏(0.63)、体胖(0.49)、大便粘滞(1.38)、脘腹痞满(0.97)、面色晦浊(0.79)、嗜睡(1.18)、纳差(1.07)。与经典隐结构模型得到规则和中医界已发布的定性化辨证规则相比,约束隐结构得到的规则客观性强,具有可重复性。在证候类大小、规则的量化合理度上较好地反映了主症、次症的特点,得到的规则切合中医实际,为冠心病痰湿证辨证标准的定量化研究提供帮助和参考。  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