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   9774篇
  免费   1084篇
  国内免费   490篇
耳鼻咽喉   60篇
儿科学   135篇
妇产科学   205篇
基础医学   1142篇
口腔科学   119篇
临床医学   1338篇
内科学   1436篇
皮肤病学   87篇
神经病学   508篇
特种医学   425篇
外国民族医学   3篇
外科学   877篇
综合类   1622篇
现状与发展   3篇
一般理论   3篇
预防医学   600篇
眼科学   192篇
药学   1183篇
  11篇
中国医学   578篇
肿瘤学   821篇
  2024年   54篇
  2023年   176篇
  2022年   401篇
  2021年   585篇
  2020年   483篇
  2019年   390篇
  2018年   388篇
  2017年   339篇
  2016年   282篇
  2015年   505篇
  2014年   652篇
  2013年   505篇
  2012年   779篇
  2011年   813篇
  2010年   471篇
  2009年   390篇
  2008年   459篇
  2007年   446篇
  2006年   507篇
  2005年   505篇
  2004年   271篇
  2003年   266篇
  2002年   217篇
  2001年   179篇
  2000年   203篇
  1999年   191篇
  1998年   104篇
  1997年   103篇
  1996年   86篇
  1995年   64篇
  1994年   70篇
  1993年   29篇
  1992年   65篇
  1991年   55篇
  1990年   40篇
  1989年   46篇
  1988年   33篇
  1987年   32篇
  1986年   16篇
  1985年   18篇
  1984年   18篇
  1983年   6篇
  1982年   10篇
  1981年   7篇
  1979年   10篇
  1978年   16篇
  1973年   10篇
  1972年   6篇
  1967年   7篇
  1966年   5篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
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   
2.
Erosive pustular dermatosis of the scalp (EPDS) is an uncommon chronic inflammatory response to scalp trauma that usually resolves with cicatricial alopecia. It most commonly affects elderly patients with a history of actinic damage. Herein, we describe a 16‐year‐old girl with acrofacial dysostosis type 1 presenting after surgery with crusting purulent scalp lesions, whose clinical presentation and histopathologic findings were consistent with EPDS. A review of the literature on EPDS in children is also detailed.  相似文献   
3.
4.
5.
目的:探讨甲状旁腺激素(PTH)对大鼠牵张成骨(DO)过程中ONC、OPN、C-FOS、COL1、VEGF、RUNX2、ALP基因表达的影响。方法30只雄性大鼠制备大鼠下颌骨DO模型。随机分5组,每组6只。第1组(只有牵张无PTH),术后8周取材,应用HE染色及微CT检测,以确定成骨情况。第2组(有牵张无PTH),第3组(有牵张有PTH),第4组(无牵张有PTH),第5组(对照组:无牵张无PTH)。2、3、4组及对照组术后1周取材,RT-PCR测定ONC、OPN、C-FOS、COL1、VEGF、RUNX2、ALP基因的表达。结果第1组,新骨形成,骨质充满牵张区,骨质连续,大鼠建模成功。RT-PCR检测结果显示,2、3、4组与对照组比较,OPN、COL1、RUNX2、ALP基因表达有明显提高(P<0.05),其中第3组最为明显。ONC、C-FOS、VEGF基因2、3、4组与对照组比较差异无统计学意义(P>0.05)。结论 PTH在 DO 过程中,间歇性给以 PTH的作用只有在牵张期发挥作用,其对 OPN、COL1、RUNX2、ALP基因表达能够获得理想的协同作用。  相似文献   
6.
涎腺导管内癌(intraductal carcinoma,IDC)是一种主要发生在腮腺,在导管内或囊内生长为主的罕见肿瘤,但也可伴浸润性生长,生物学行为相对惰性。具有独特的形态学、免疫表型及分子遗传学特征。主要包括4种亚型:闰管型、顶浆分泌型、闰管-顶浆分泌混合型和嗜酸型。闰管型多数存在NCOA4-RET融合,个别存在STRN-ALK融合;混合型存在TRIM27-RET融合,顶浆分泌型具有PIK3CA和HRAS突变或TP53缺失;嗜酸型具有TRIM33-RET融合或BRAF V600E突变。目前多数观点认为与涎腺导管癌不同,即使存在浸润,仍具有良好的预后,罕见复发和淋巴结转移,无远处转移。因此精准诊断对于临床治疗的选择极其重要。  相似文献   
7.
Pediatric dermatology is one of the smallest subspecialties, and expanding the availability of care is of great interest. Teledermatology has been proposed as a way to expand access and improve care delivery, but no current assessment of pediatric teledermatology exists. The objective of the current study was to assess usage and perspectives on pediatric teledermatology. Surveys were distributed electronically to all 226 board‐certified U.S. pediatric dermatologists; 44% (100/226) responded. Nearly all respondents (89%) have experience with teledermatology. Formal teledermatology reimbursement success rates have increased to 35%. Respondents were positive about teledermatology's present and future prospects, and 41% want to use teledermatology more often, although they viewed teledermatology as somewhat inferior to in‐person care regarding accuracy of diagnosis and appropriation of management plans. Significant differences were found between formal teledermatology users and nonusers in salary structure, practice environment, sex, and region. Substantial increases in pediatric teledermatology have occurred in the last 5 to 10 years, and there remains cause for optimism for teledermatology's future. Concerns about diagnostic confidence and care quality indicate that teledermatology may be best for care of patients with characteristic clinical presentations or management of patients with established diagnoses.  相似文献   
8.
目的研究阴道锥体训练联合生物反馈盆底肌治疗尿失禁老年人的临床疗效及对盆底肌的影响。方法选取84例从2016年9月至2018年3月本院收治的尿失禁老年患者进行研究,以随机抽签法将其均分为联合组及对照组,每组42例。对照组予以常规盆底肌训练治疗,联合组则予以阴道锥体训练联合生物反馈盆底肌治疗。对比两组在临床疗效、治疗前后盆底肌力情况、治疗前后尿动力学参数指标水平以及生活质量变化情况等方面的差异。结果联合组与对照组在总有效率方面比较,前者高于后者(P<0.05)。治疗后联合组盆底肌力分级为Ⅳ级、Ⅴ级的人数占比相比对照组较高(P<0.05)。治疗后联合组与对照组在VLPP、PMUC水平方面比较,前者高于后者(P<0.05)。治疗后联合组与对照组I-QOL评分相比治疗前较高,且联合组相比对照组较高(P<0.05)。结论阴道锥体训练联合生物反馈盆底肌治疗老年尿失禁患者的疗效显著,有利于促进盆底肌力的恢复,且有效改善患者尿动力学参数,提高生活质量,具有较高的临床推广应用价值。  相似文献   
9.
Abstract

Background: This study aims to compare the effectiveness of inhaled prostacyclin or its analoguesversus nitric oxide (NO) in treating pulmonary hypertension (PH) after cardiac or pulmonary surgery remains unclear.

Methods: PubMed, Cochrane, and Embase databases were searched for literature published prior to December 2019 using the following keywords: inhaled, nitric oxide, prostacyclin, iloprost, treprostinil, epoprostenol, Tyvaso, flolan, and pulmonary hypertension. Randomized controlled trials and multiple-armed prospective studies that evaluated inhaled NO versus prostacyclin (or analogues) in patients for perioperative and/or postoperative PH after either cardiac or pulmonary surgery were included. Retrospective studies, reviews, letters, comments, editorials, and case reports were excluded.

Results: Seven studies with a total of 195 patients were included. No difference in the improvement of mean pulmonary arterial pressure (pooled difference in mean change= ?0.10, 95% CI: ?3.98 to 3.78, p?=?.959) or pulmonary vascular resistance (pooled standardized difference in mean change= ?0.27, 95% CI: ?0.60 to 0.05, p?=?.099) were found between the two treatments. Similarly, no difference was found in other outcomes between the two treatments or subgroup analysis.

Conclusions: Inhaled prostacyclin (or analogues) was comparable to inhaled NO in treating PH after cardiac or pulmonary surgery.
  • Key messages
  • This study compared the efficacy of inhaled prostacyclin or its analogues versus inhaled NO to treat PH after surgery. The two types of agent exhibited similar efficacy in managing MPAP, PVR, heart rate, and cardiac output was observed.

  • Inhaled prostacyclin may serve as an alternative treatment option for PH after cardiac or pulmonary surgery.

  相似文献   
10.
目的应用6σ理论对肿瘤标志物项目的分析性能进行评价,并初步确定各项目的质量目标。 方法收集本实验室2018年1至12月室内质控数据和国家卫生健康委临床检验中心室间质量评价结果,以生物学变异导出的质量规范和国家室间质量评价标准作为允许总误差(TEa)计算6项肿瘤标志物的σ水平,并依据质量目标选择流程图和肿瘤标志物分析性能验证图评价肿瘤标志物的分析性能,进而为肿瘤标志物选择合适的质量目标。 结果应用不同层级的生物学变异导出的质量规范和国家室间质量评价标准,肿瘤标志物项目的σ水平存在显著差异;依据质量目标选择流程图:选择生物学变异导出的"适当的"质量规范作为CA125项目的质量目标,选择生物学变异导出的"最低的"质量规范作为t-PSA、CEA、AFP、CA199和CA153项目的质量目标。 结论6σ能够客观评价肿瘤标志物的分析性能,并为实验室质量目标的选择提供重要的参考价值。  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