RESUMO

Three dimensional magnetic textures are a cornerstone in magnetism research. In this work, we analyze the stabilization and dynamic response of a magnetic hopfion hosted in a toroidal nanoring with intrinsic Dzyaloshinskii-Moriya interaction simulating FeGe. Our results evidence that unlike their planar counterparts, where perpendicular magnetic anisotropies are necessary to stabilize hopfions, the shape anisotropy originated on the torus symmetry naturally yields the nucleation of these topological textures. We also analyze the magnetization dynamical response by applying a magnetic field pulse to differentiate among several magnetic patterns. Finally, to understand the nature of spin wave modes, we analyze the spatial distributions of the resonant mode amplitudes and phases and describe the differences among bulk and surface modes. Importantly, hopfions lying in toroidal nanorings present a non-circularly symmetric poloidal resonant mode, which is not observed in other systems hosting hopfions.

RESUMO

BACKGROUND: Considerable numbers of individuals present low vision, blindness, illiteracy and other conditions that could possibly impair their identification of medications, such as eye drops. Through helping these individuals to identify their eye drops, they can achieve greater autonomy. Misidentification can be avoided through use of multisensory sleeves that can be adapted to most eye drop bottles. Correct use of eye drops is important for preventing progression of diseases like glaucoma that could potentially lead to blindness. OBJECTIVE: To develop bottle sleeves to aid in identification of eye drops and then interview a group of possible users to evaluate the acceptance of the solution. DESIGN AND SETTING: Cross-sectional survey performed at an ophthalmological clinic in São Paulo (SP), Brazil. METHODS: We describe the development of multisensory sleeves to assist in identification of eye drops. To assess the acceptance of this solution, we interviewed 18 patients who were currently using three or more types of eye drops. RESULTS: We developed four prototypes for eye drop bottle sleeves and conducted an acceptance test on them. Most of the patients who answered the survey about the sleeves were elderly. Most (95%) reported believing that the sleeves would help reduce the risk of mixing up eye drops with other medications that also dispense drops. They also believed that these would increase their autonomy in using eye drops. CONCLUSION: The solution presented was well accepted and may help increase safety in using eye drops through preventing misidentification.

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RESUMO

Evaluate whether texture analysis associated with machine learning approaches could differentiate between malignant and benign lymph nodes. A total 18 patients with lung cancer were selected, with 39 lymph nodes, being 15 malignant and 24 benign. Retrospective computed tomography scans were utilized both with and without contrast medium. The great differential of this work was the use of 15 textures from mediastinal lymph nodes, with five different physicians as operators. First and second order statistical textures such as gray level run length and co-occurrence matrix were extracted and applied to three different machine learning classifiers. The best machine learning classifier demonstrated a variability of less than 5% among operators. The support vector machine (SVM) classifier presented 95% of the area under the ROC curve (AUC) and 89% of sensitivity for sequences without contrast medium. SVM classifier presented 93% of AUC and 86% of sensitivity for sequences with contrast medium. Texture analysis and machine learning may be helpful in the differentiation between malign and benign lymph nodes. This study can aid the physician in diagnosis and staging of lymph nodes and potentially reduce the number of invasive analysis to histopathological confirmation.

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RESUMO

El síndrome de dificultad respiratoria (SDR) del recién nacido persiste como una de las principales causas de morbilidad y mortalidad en neonatos prematuros. A pesar que la evidencia científica reciente cuestiona la utilidad de las pruebas para evaluar la madurez pulmonar fetal para determinar el momento más adecuado para el parto en ciertas complicaciones obstétricas, existe un conjunto de indicaciones relativas en las cuales una prueba no invasiva puede encontrar aplicación. El objetivo del presente trabajo es revisar los trabajos publicados en la literatura sobre el empleo de la ecografía como método para predecir la morbilidad respiratoria neonatal, utilizando la evaluación Doppler de la arteria pulmonar y el análisis cuantitativo de la textura ecográfica del pulmón fetal.

Respiratory distress syndrome (RDS) of the newborn remains a major cause of morbidity and mortality in preterm infants. Although the latest scientific evidence questions the utility of fetal lung maturity testing to determine the most suitable moment for delivery in certain obstetrical complications, there is a set of relative indications in which a non-invasive test can find application. The aim ofthis paper is to review studies published on the use of ultrasound as a method to predict neonatal respiratory morbidity, using both Doppler evaluation ofthe pulmonary artery and ultrasound quantitative analysis of fetallung texture.

RESUMO

Se presenta el proceso de caracterización implementado para la obtención de descriptores visuales que representan el contenido visual de imágenes digitales de biopsias de cuello uterino infectadas con el Virus del Papiloma Humano (VPH), en las que se capturan tejidos con lesiones conocidas como Condiloma Plano Viral. A partir de la construcción de una base de datos de imágenes de biopsias de cuello uterino y el análisis e implementación de técnicas de filtrado que resaltan la información relacionada a las texturas contenidas en los tejidos que captura cada imagen y de técnicas de extracción de características que describen el contenido de las imágenes; se propone un conjunto de características que describen el contenido de las imágenes a partir de modificaciones propias de la Transformada Discreta de Wavelets y el cálculo de la Matriz de Coocurrencia, donde este conjunto de características propuesto proporcionó un porcentaje promedio de recuperación del 80% en imágenes microscópicas de cuello uterino infectadas con el VPH, sobre las cuales no se conocen sistemas CBIR desarrollados. Finalmente, se determina el porcentaje de recuperación promedio a partir del uso de métricas de similaridad basadas en la norma LP.

The purpose of this work is to report the characterization process implemented to obtain visual descriptors representing visual content of digital images of cervical biopsies infected with Human Papilloma Virus (HPV). Positive biopsies with infected tissues present lesions known as Condyloma Plano Viral. A database of images of cervical biopsies was constructed in addition to the implementation of techniques that enhance the texture information and describe the content of images. This work proposed a set of features to describe the content of images from custom modifications of Discrete Wavelet Transform and the calculation of the Co-occurrence Matrix. This proposed feature set provided an average recovery rate of 80% in microscopic images of the cervix infected with HPV, from which CBIR systems have not been developed. Finally, this work determines the average recovery rate from the use of similarity metrics based on the standard LP.

Neste trabalho é apresentado o processo implementado de caracterização para a obtenção de descrições visuais que representam o conteúdo visual de imagens digitais de biópsias cervicais infectadas com Papilomavírus Humano (HPV), capturadas em lesões de tecidos conhecidas como Condiloma Plano Viral. A partir da construção de uma base de dados de imagens de biópsias do colo uterino, análise e implementação de técnicas de filtragem de características que descrevem o conteúdo das imagems, propõe-se um conjunto de características que descrevem o conteúdo das imagens a partir de modificações próprias da Transformada Discreta de Wavelets e o cálculo da Matriz de co-ocorrência, onde o conjunto de características propostas resultou numa porcentagem média de 80% de recuperação nas imagens microscópicas de colo uterino infectado com o VPH, sobre as quais não se percebe o desenvolvimento dos sistemas CBIR. Finalmente, a taxa de recuperação média foi determinada a partir da utilização de métricas de similaridade com base na indicação de LP.