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Why Quantitative Variables Should Not Be Recoded as Categorical

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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

Analysis of the deformation of Composite Materials of Scrapes of Tire and Latex with Temperature Variation

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Journal of Chemistry and Chemical Engineering 2012年第1期6卷 39-47页

作者： Elmo Thiago lins Coeuras Ford Rubens Maribondo do Nascimento Jose Ubiragi de Lima Mendes antonio Torres Marques Celeste Margarida Correia Pereira Technological Center Campus Universitfrio Federal University of Rio Grande do Norte Lagoa Nova-Natal-RN 59072-790Brazil Faculty of Engineering University of Porto Porto 4200-465 Portugal Institute of Mechanical Engineering and Industrial Administration University of Porto Porto 4200-465 Portugal

The great major applications of thermal isolation are in the strip of drops and averages temperatures （up to 180 ℃）, which is used from aggressive materials to the nature, such as glass wool, rock wool, polystyrene, EPS among others. In spite of the effectiveness in the retention of the flow of heat, such materials possess considerable cost and they are discarded for long years to be decomposed. In that context, to adapt to the world politics about the preservation of the environment, a study began with intention of developing a material composite with thermal properties, originating from insulating industrial residues. In this research, the behavior of this composite was analyzed, when it submitted traction efforts. For this, a term-mechanic was used （DMA）, where the composite was differentiated under variation temperatures. It was also certain that the gradient temperature of the composite was the source of heat, the conductivity and thermal diffusion. Consequently, the function of the answers of the system was possible to be observed with the deformation of the composite with the tension and temperature variation, as well as the temperature gradient for each proportion of the composite.

关键词： Composite latex deformation.

Comparison Study between Ultra-Chopper and Divide &Conquer Techniques

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Open Journal of Ophthalmology 2022年第2期12卷 201-207页

作者： Wilson Takashi Hida Andre lins de Medeiros Patrick Tzelikis Celso Takashi Nakano antonio Francisco Pimenta Motta Pedro Carricondo Marcelo Colombo Barboza Cesar Vilar Walton Nose Hospital Oftalmológico de Brasília Brasília Brasil Renato Ambrosio Eye Research Center Brasília Brasil

Background: Hard brunescent nuclei are difficult to chop with traditional techniques, because leathery tough strands may connect the posterior surface and span across the fragments, which poses a challenge to completely divide the nuclei. The ultra-chopping technique was designed to mitigate this issue. Purpose: To compare the intraoperative parameters between Ultra-Chopper and Divide & Conquer Techniques. Setting: This study was performed at Hospital Oftalmológico de Brasília, Brasília, DF, Brazil. Patients and Methods: A prospective, randomized and comparative study. Patients with the diagnosis of dense cataract and surgical extraction programmed were divided into two groups: Ultra-Chopper and Divide & Conquer. Intraoperative data were collected and submitted for the statistical analysis. Results: 36 eyes were included, 19 eyes with Ultra-Chopper and 17 eyes with Divide & Conquer. Groups were statistically equivalent in age and nucleus density. There were no surgical complications. Torsional time and cumulative dissipated energy were significantly reduced in the ultra-chopper group. The ultra-chopper group had less total case time, fluid usage and aspiration (ASP) time. Conclusion: The ultra-chopper tech- nique can reduce ultrasound energy dissipation during cataract surgery, and decrease case time, fluid usage and ASP time.

关键词： Ultra-Chopper Cataract Aspiration

Evaluation of the Effectiveness of Preloaded IOL Injectors in Surgical Time

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Open Journal of Ophthalmology 2021年第4期11卷 339-347页

作者： Wilson Takashi Hida Leonardo da Cunha Silva Braga Danilo Varela Kniggendorf Celso Takashi Nakano antonio Francisco Pimenta Motta Andre lins de Medeiros Walton Nosé Hospital Oftalmológico de Brasília Brasília Brasil Centro de Estudos Oftalmológicos Renato Ambrósio Brasília Brasil UNIFESP S&#227 o Paulo Brasil

Background: The implantation of the intraocular lens (IOL) is still subject to error and complication, as it can result in traumatic opening of the IOL leading to rupture of the posterior capsule and zonular dialysis, it takes time to train paramedic teams to assemble such IOLs with the manual injectors. Moreover, there is a potential risk of comtamination and endophthalmitis as there is manipulation of the IOL and cartridge. The preloaded IOLs tend to reduce those unwanted results and may optimize the surgical time. Purpose: The aim of this study is to compare the effectiveness and implantation time between three injectors and three intraocular lenses, two pre-loaded and one conventional. Methodology: Videos of thirty patients undergoing cataract surgery from december 2019 to december 2020 at the Hospital Oftalmológico de Brasília (HOB), Brasília, Brazil were included in this observational, analytical retrospective study, non randomized. All patients had their surgeries recorded, from which the time of injection and opening of the intraocular lens (IOL) was extracted, 20 eyes were implanted with preloaded intraocular lens, and 10 eyes with conventional IOL implant. The patients were divided into three groups with similar eye characteristics. The first received the AutonoMeTM (CE) injector with the Clareon® IOL, the second the IsertTM injector (I) with the Hoya® IOL, and the third was injected with Johnson & Johnson Platinum 1 Series injector used to deliver Sensar

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

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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