检索结果-南通市图书馆

Why Quantitative Variables Should Not Be Recoded as Categorical

Journal of Applied Mathematics and Physics 2019年第7期7卷 1519-1530页

作者： Antonio Fernandes Caio Malaquias Dalson Figueiredo Enivaldo da Rocha rodrigo lins Department of Political Science Federal University of Pernambuco (UFPE) Recife Brazil

The transformation of quantitative variables into categories is a common practice in both experimental and observational studies. The typical procedure is to create groups by splitting the original variable distribution at some cut point on the scale of measurement (e.g. mean, median, mode). Allegedly, dichotomization improves causal inference by simplifying statistical analyses. In this article, we address some of the adverse consequences of recoding quantitative variables into categories. In particular, we provide evidence that categorization usually leads to inefficient and biased estimates. We believe that considerable progress in our understanding of data analysis can occur if scholars follow the recommendations presented in this article. The recodification of quantitative variables as categorical is a poor methodological strategy, and scientists must stay away from it.

关键词： Dichotomization Inefficiency Bias

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Investigation of the Grain Growth Evolution in the AISI 304H Austenitic Stainless Steel

引用

Journal of Mechanics Engineering and Automation 2016年第2期6卷 95-99页

作者： rodrigo Pinto de Siqueira Jose Flavio Silveira Feiteirat Dionisio Jos6 Rodrigues da Costa and Jefferson Fabricio Cardoso lins Department of Mechanical Engineering Fluminense Federal University Volta Redonda 27255-125 Brazil

The austenitic stainless steels usually present an excellent combination of corrosion resistance and mechanical properties such as ductility in the annealed condition and high yield strength after cold deformation. Solution annealing in the AISI 304H is recommended before deformation process in order to improve ductility. However, long annealing during solution annealing can cause GG （grain growth） or AGG （abnormal grain growth） in the AISI 304H. In these cases, ductility is strongly decreased. Therefore, GG or AGG must be avoided during solution annealing. In this article, grain growth during solution annealing of the AISI 304H samples was determined. Samples of the AISI 304H were annealed at 1,100 ℃ for solution-annealing times varying from 15 min to 180 min. The results show that AGG took place for samples annealed at 1,100 ℃ for 30 min. In this condition, grain size reached 70 ± 10 μm. After annealing solution at 1,100 ℃ for 180 min, grain size reached 120 ~ 20 μm. In summary, the results shown that solution annealing at 1,100 ℃ even for relatively short annealing promotes the prompt increase of the grain size.

关键词： AISI 304H austenitic stainless steel solution annealing grain growth abnormal grain growth.

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Shrinking Lung Detected on Computed Tomography:Pictorial Essay of the Main Findings of the Image

引用

Open Journal of Medical Imaging 2018年第2期8卷 17-24页

作者： Francisco Barbosa de Araújo Neto Tiago Castello Branco Lyra Rita Karine Veras Gomes de Mello Vinícius Martins Valois Tiago Bezerra Albano Antonio Fernando lins de Paiva rodrigo Caruso Chate Cesar Higar Nomura Department of Radiology of the Medical School of the University of Sao Paulo Sao PauloBrazil Department of Radiology of the Hospital Israelita Albert Einstein(HIAE) Sao PauloBrazil Department of Radiology of the Hospital Heliopolis Sao PauloBrazil Cardiology Institute of the Clinic Hospital of the Medicine School of the University of Sao Paulo Sao PauloBrazil

Shrinking lung refers to a rare complication of systemic lupus erythematosus and is characterized by unexplained dyspnea, a restrictive pattern in lung function tests, and elevation of the diaphragmatic hemicuples. It is postulated to have a predilection for female involvement and occurs mainly during late stages of the disease. Chest X-rays usually show small, diaphragmatic lungs. Occasional basal atelectasis may be present. Chest tomography usually shows reduced lung volumes with diaphragmatic elevation, occasional basal atelectasis, without severe pulmonary or pleuropulmonary disease. Shrinking lung can cause significant morbidity and occasional mortality. There is no definitive therapy, while corticosteroids may decrease symptoms and improve lung function in some patients. The objective of this study was to describe the main imaging findings in Shrinking Lung, an important pulmonary alteration in lupus patients. We highlight the characteristics observed on radiography and computed tomography, with an emphasis on computed tomography. It is important that every radiologist is prepared to recognize these findings and understand the possible clinical repercussions.

关键词： Chest Tomography Pulmonary Diseases Systemic Lupus Erythematosus Shrinking Lung

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Quality of Life for People with Parkinson’s Disease in Relation to Their Oral Health

引用

Open Journal of Stomatology 2018年第11期8卷 312-318页

作者： Phablo Glewber Torres Bezerra Samuel rodrigo de Andrade Veras Camila Caroline da Silva Renato Mariano da Silva Deivison Edson Pereira da Silva Eduardo Borges da Costa Leite Maria das Gracas Wanderley de Sales Coriolano Carla Cabral dos Santos Accioly lins Federal University of Pernambuco RecifeBrazil Department of Prosthodontics and Oral and Maxillofacial Surgery Federal University of PernambucoRecifeBrazil Department of Anatomy Federal University of PernambucoRecifeBrazil

The present study aimed to evaluate the correlation between the oral health status and the quality of life for people with Parkinson’s disease. The Decayed, Missing, Filled (DMFT) index and the quality of life questionnaire for people with Parkinson’s disease (Parkinson’s Disease Questionnaire-39) were used as evaluation instruments. Sixty-two people with a clinical diagnosis of Parkinson’s disease between stages 1 and 3, age between 46 and 86 years, of both sexes, with an average time of disease evolution of 7 years, participated in the study. Data were evaluated using the Pearson’s correlation test, and one-way ANOVA (p < 0.05). The mean DMFT obtained was 23;there was no correlation between the DMFT values and the total score of the Parkinson’s Disease Questionnaire-39 neither in its domains, nor between the DMFT and the stages of Parkinson’s disease (p = 0.61). We found that the oral health of parkinsonians is deficient due to the high number of missing teeth, but their perception of quality of life is favorable despite their motor limitations related to mobility, and activities of daily living.

关键词： Parkinson’s Disease Quality of Life DMFT Index

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：