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   6933篇
  免费   337篇
  国内免费   51篇
耳鼻咽喉   36篇
儿科学   152篇
妇产科学   55篇
基础医学   232篇
口腔科学   136篇
临床医学   1885篇
内科学   706篇
皮肤病学   37篇
神经病学   169篇
特种医学   270篇
外国民族医学   1篇
外科学   640篇
综合类   949篇
预防医学   1224篇
眼科学   98篇
药学   463篇
  44篇
中国医学   125篇
肿瘤学   99篇
  2024年   10篇
  2023年   163篇
  2022年   262篇
  2021年   406篇
  2020年   379篇
  2019年   318篇
  2018年   270篇
  2017年   236篇
  2016年   212篇
  2015年   256篇
  2014年   619篇
  2013年   534篇
  2012年   569篇
  2011年   561篇
  2010年   426篇
  2009年   347篇
  2008年   340篇
  2007年   302篇
  2006年   249篇
  2005年   159篇
  2004年   130篇
  2003年   115篇
  2002年   92篇
  2001年   62篇
  2000年   38篇
  1999年   37篇
  1998年   26篇
  1997年   36篇
  1996年   30篇
  1995年   20篇
  1994年   20篇
  1993年   9篇
  1992年   7篇
  1991年   6篇
  1990年   7篇
  1989年   5篇
  1988年   6篇
  1987年   5篇
  1986年   4篇
  1985年   7篇
  1984年   9篇
  1983年   6篇
  1982年   11篇
  1981年   2篇
  1980年   7篇
  1979年   4篇
  1977年   1篇
  1973年   1篇
排序方式: 共有7321条查询结果,搜索用时 15 毫秒
1.
2.
3.
ObjectiveThe objective of this study was to reduce errors in a pathologic specimen with the help of a protocol systematizing the pathology specimen management process in the operating room.Materials and methodThis quasi-experimental study was carried out in the operating room unit of a research and training hospital. A protocol systematizing the process of specimen management in secure surgical pathology and prepared in light of the current literature was used as an intervention, and the effectiveness of the protocol was tested.ResultsIt was determined that the rate of adverse events decreased from .3226% (68 of 21,078) to .032% (6 of 18,706) after the protocol systematizing the surgical pathology specimen management process prepared by the researchers, and the protocol was found to be effective by 90% (P = .03).ConclusionBased on the data obtained in this study, we recommend the use of a pathologic specimen management protocol in the operating room.  相似文献   
4.
5.
PurposeTo compare morphological imaging features and CT texture histogram parameters between grade 3 pancreatic neuroendocrine tumors (G3-NET) and neuroendocrine carcinomas (NEC).Materials and methodsPatients with pathologically proven G3-NET and NEC, according to the 2017 World Health Organization classification who had CT and MRI examinations between 2006-2017 were retrospectively included. CT and MRI examinations were reviewed by two radiologists in consensus and analyzed with respect to tumor size, enhancement patterns, hemorrhagic content, liver metastases and lymphadenopathies. Texture histogram analysis of tumors was performed on arterial and portal phase CT images. images. Morphological imaging features and CT texture histogram parameters of G3-NETs and NECs were compared.ResultsThirty-seven patients (21 men, 16 women; mean age, 56 ± 13 [SD] years [range: 28-82 years]) with 37 tumors (mean diameter, 60 ± 46 [SD] mm) were included (CT available for all, MRI for 16/37, 43%). Twenty-three patients (23/37; 62%) had NEC and 14 patients (14/37; 38%) had G3-NET. NECs were larger than G3-NETs (mean, 70 ± 51 [SD] mm [range: 18 - 196 mm] vs. 42 ± 24 [SD] mm [range: 8 - 94 mm], respectively; P = 0.039), with more tumor necrosis (75% vs. 33%, respectively; P = 0.030) and lower attenuation on precontrast (30 ± 4 [SD] HU [range: 25-39 HU] vs. 37 ± 6 [SD] [range: 25-45 HU], respectively; P = 0.002) and on portal venous phase CT images (75 ± 18 [SD] HU [range: 43 - 108 HU] vs. 92 ± 19 [SD] HU [range: 46 - 117 HU], respectively; P = 0.014). Hemorrhagic content on MRI was only observed in NEC (P = 0.007). The mean ADC value was lower in NEC ([1.1 ± 0.1 (SD)] × 10−3 mm2/s [range: (0.91 - 1.3) × 10−3 mm2/s] vs. [1.4 ± 0.2 (SD)] × 10−3 mm2/s [range: (1.1 - 1.6) × 10−3 mm2/s]; P = 0.005). CT histogram analysis showed that NEC were more heterogeneous on portal venous phase images (Entropy-0: 4.7 ± 0.2 [SD] [range: 4.2-5.1] vs. 4.5 ± 0.4 [SD] [range: 3.7-4.9]; P = 0.023).ConclusionPancreatic NECs are larger, more frequently hypoattenuating and more heterogeneous with hemorrhagic content than G3-NET on CT and MRI.  相似文献   
6.
PurposeThe purpose of this study was to determine whether computed tomography (CT)-based machine learning of radiomics features could help distinguish autoimmune pancreatitis (AIP) from pancreatic ductal adenocarcinoma (PDAC).Materials and MethodsEighty-nine patients with AIP (65 men, 24 women; mean age, 59.7 ± 13.9 [SD] years; range: 21–83 years) and 93 patients with PDAC (68 men, 25 women; mean age, 60.1 ± 12.3 [SD] years; range: 36–86 years) were retrospectively included. All patients had dedicated dual-phase pancreatic protocol CT between 2004 and 2018. Thin-slice images (0.75/0.5 mm thickness/increment) were compared with thick-slices images (3 or 5 mm thickness/increment). Pancreatic regions involved by PDAC or AIP (areas of enlargement, altered enhancement, effacement of pancreatic duct) as well as uninvolved parenchyma were segmented as three-dimensional volumes. Four hundred and thirty-one radiomics features were extracted and a random forest was used to distinguish AIP from PDAC. CT data of 60 AIP and 60 PDAC patients were used for training and those of 29 AIP and 33 PDAC independent patients were used for testing.ResultsThe pancreas was diffusely involved in 37 (37/89; 41.6%) patients with AIP and not diffusely in 52 (52/89; 58.4%) patients. Using machine learning, 95.2% (59/62; 95% confidence interval [CI]: 89.8–100%), 83.9% (52:67; 95% CI: 74.7–93.0%) and 77.4% (48/62; 95% CI: 67.0–87.8%) of the 62 test patients were correctly classified as either having PDAC or AIP with thin-slice venous phase, thin-slice arterial phase, and thick-slice venous phase CT, respectively. Three of the 29 patients with AIP (3/29; 10.3%) were incorrectly classified as having PDAC but all 33 patients with PDAC (33/33; 100%) were correctly classified with thin-slice venous phase with 89.7% sensitivity (26/29; 95% CI: 78.6–100%) and 100% specificity (33/33; 95% CI: 93–100%) for the diagnosis of AIP, 95.2% accuracy (59/62; 95% CI: 89.8–100%) and area under the curve of 0.975 (95% CI: 0.936–1.0).ConclusionsRadiomic features help differentiate AIP from PDAC with an overall accuracy of 95.2%.  相似文献   
7.
目的探讨案例教学法在消化内科见习课的教学效果和体会。方法选取2017年10月—2017年12月在消化内科进行见习课的2015级39-40班护理本科学生44例(全部为女生),抓阄分成对照组(22人)和试验组(22人),对照组给予传统的带教方法,试验组给予案例教学法教学,比较两组护生在理论、技能、综合能力和对带教满意度方面有无差异。两组学生在性别、年龄、专业前的课程成绩比较,差异无统计学意义(均P>0.05)。结果观察组在理论考核成绩、操作考核成绩、教学满意度等方面均高于对照组。结论案例教学法能提高护理教学的教学效果,增加学生的理论、操作能力,提高护理临床思维能力,提升学生的学习主动性和积极性。  相似文献   
8.
The aim of this study was to analyse the effect of body mass index (BMI), both low and high values, on the perioperative complication rate in patients with oral squamous cell carcinoma (OSCC). The medical records of 259 patients operated between 2014 and 2017 for OSCC were reviewed. Univariate and multivariate analyses were performed. Sixty of the 259 patients developed 87 complications. Low or high BMI was not associated with the perioperative complication rate. A longer operating time and increased blood loss were associated with a higher perioperative complication rate and higher Clavien–Dindo grade. Low BMI, American Society of Anesthesiologists score 2 and 3, a longer operating time, and increased blood loss were associated with a longer hospital stay. Low BMI was associated with a longer hospital stay. Neither low nor high BMI was associated with the perioperative complication rate. A longer operating time and increased blood loss were associated with a higher perioperative complication rate and higher Clavien–Dindo grade.  相似文献   
9.
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