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Breast cancer is a prevalent malignancy characterized by the uncontrolled growth of glandular epithelial cells, which can metastasize through the blood and lymphatic systems. Microcalcifications, small calcium deposits within breast tissue, are critical markers for early detection of breast cancer, especially in non-palpable carcinomas. These microcalcifications, appearing as small white spots on mammograms, are challenging to identify due to potential confusion with other tissues. This study hypothesizes that a hybrid feature extraction approach combined with Convolutional Neural Networks (CNNs) can significantly enhance the detection and localization of microcalcifications in mammograms. The proposed algorithm employs Gabor, Prewitt, and Gray Level Co-occurrence Matrix (GLCM) kernels for feature extraction. These features are input to a CNN architecture designed with maxpooling layers, Rectified Linear Unit (ReLU) activation functions, and a sigmoid response for binary classification. Additionally, the Top Hat filter is used for precise localization of microcalcifications. The preprocessing stage includes enhancing contrast using the Volume of Interest Look-Up Table (VOI LUT) technique and segmenting regions of interest. The CNN architecture comprises three convolutional layers, three ReLU layers, and three maxpooling layers. The training was conducted using a balanced dataset of digital mammograms, with the Adam optimizer and binary cross-entropy loss function. Our method achieved an accuracy of 89.56%, a sensitivity of 82.14%, and a specificity of 91.47%, outperforming related works, which typically report accuracies around 85-87% and sensitivities between 76 and 81%. These results underscore the potential of combining traditional feature extraction techniques with deep learning models to improve the detection and localization of microcalcifications. This system may serve as an auxiliary tool for radiologists, enhancing early detection capabilities and potentially reducing diagnostic errors in mass screening programs.
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This study presents the design, simulation, and prototype creation of a quadruped robot inspired by the Acinonyx jubatus (cheetah), specifically designed to replicate its distinctive walking, trotting, and galloping locomotion patterns. Following a detailed examination of the cheetah's skeletal muscle anatomy and biomechanics, a simplified model of the robot with 12 degrees of freedom was conducted. The mathematical transformation hierarchy model was established, and direct kinematics were simulated. A bio-inspired control approach was introduced, employing a Central Pattern Generator model based on Wilson-Cowan neural oscillators for each limb, interconnected by synaptic weights. This approach assisted in the simulation of oscillatory signals for relative phases corresponding to four distinct gaits in a system-level simulation platform. The design phase was conducted using CAD software (SolidWorks 2018), resulting in a 1:3-scale robot mirroring the cheetah's actual proportions. Movement simulations were performed in a virtual mechanics software environment, leading to the construction of a prototype measuring 35.5 cm in length, 21 cm in width, 27 cm in height (when standing), and weighing approximately 2.1 kg. The experimental validation of the prototype's limb angular positions and trajectories was achieved through the image processing of video-recorded movements, demonstrating a high correlation (0.9025 to 0.9560) in joint angular positions, except for the knee joint, where a correlation of 0.7071 was noted. This comprehensive approach from theoretical analysis to practical implementation showcases the potential of bio-inspired robotics in emulating complex biological locomotion.
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A composite material composed of anodized aluminum oxide (AAO), carbon (C), and magnesium oxide (MgO) was developed for CO2 capture applications. Inspired by the bryophyte organism, the AAO/C/MgO composite mirrors two primary features of these species-(1) morphological characteristics and (2) elemental composition-specifically carbon, oxygen, and magnesium. The synthesis process involved two sequential steps: electroanodization of aluminum foil followed by a hydrothermal method using a mixture of glucose and magnesium chloride (MgCl2). The concentration of MgCl2 was systematically varied as the sole experimental variable across five levels-1 mM, 2 mM, 3 mM, 4 mM, and 5 mM-to investigate the impact of MgO formation on the samples' chemical and physical properties, and consequently, their CO2 capture efficiency. Thus, scanning electron microscopy analysis revealed the AAO substrate's porous structure, with pore diameters measuring 250 ± 30 nm. The growth of MgO on the AAO substrate resulted in spherical structures, whose diameter expanded from 15 nm ± 3 nm to 1000 nm ± 250 nm with increasing MgCl2 concentration from the minor to major concentrations explored, respectively. X-ray photoelectron spectroscopy (XPS) analysis indicated that carbon serves as a linking agent between AAO and MgO within the composite. Notably, the composite synthesized with a 4 mM MgCl2 concentration exhibited the highest CO2 capture efficiency, as determined by UV-Vis absorbance studies using a sodium carbonate solution as the CO2 source. This efficiency was quantified with a 'k' constant of 0.10531, significantly higher than those of other studied samples. The superior performance of the 4 mM MgCl2 sample in CO2 capture is likely due to the optimal density of MgO structures formed on the sample's surface, enhancing its adsorptive capabilities as suggested by the XPS results.
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Breast cancer is a significant health concern for women, emphasizing the need for early detection. This research focuses on developing a computer system for asymmetry detection in mammographic images, employing two critical approaches: Dynamic Time Warping (DTW) for shape analysis and the Growing Seed Region (GSR) method for breast skin segmentation. The methodology involves processing mammograms in DICOM format. In the morphological study, a centroid-based mask is computed using extracted images from DICOM files. Distances between the centroid and the breast perimeter are then calculated to assess similarity through Dynamic Time Warping analysis. For skin thickness asymmetry identification, a seed is initially set on skin pixels and expanded based on intensity and depth similarities. The DTW analysis achieves an accuracy of 83%, correctly identifying 23 possible asymmetry cases out of 20 ground truth cases. The GRS method is validated using Average Symmetric Surface Distance and Relative Volumetric metrics, yielding similarities of 90.47% and 66.66%, respectively, for asymmetry cases compared to 182 ground truth segmented images, successfully identifying 35 patients with potential skin asymmetry. Additionally, a Graphical User Interface is designed to facilitate the insertion of DICOM files and provide visual representations of asymmetrical findings for validation and accessibility by physicians.
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A reliable process for the formation of nanoporous ZnO films supported on amorphous quartz and (100) silicon substrates via the processing of ZnO/Zn precursor films is reported. The process is based on the sublimation mechanism of Zn implemented in a novel ZnO/Zn precursor film to produce a nanoporous film. A scanning electron microscopy analysis of the nanoporous ZnO films' surfaces revealed the presence of ZnO nano-features with round tips; in contrast, the nanoporous ZnO films supported on (100) Si substrates showed hexagonal nut-like nanostructures. The crystallite size of the nanoporous ZnO films decreased as the sublimation temperature was increased. X-ray photoelectron spectroscopy studies demonstrated that formations of oxygen vacancies were produced during the processing stages (as the main structural lattice defects in the ZnO nanoporous films). The analysis of the photoluminescence response confirmed that the active deep-level centers were also related to the oxygen vacancies generated during the thermal processing of the ZnO/Zn precursor films. Finally, a qualitative mechanism is proposed to explain the formation of nanoporous ZnO films on quartz and crystalline Si substrates. The results suggest that the substrates used have a strong influence on the nanoporous ZnO structures obtained with the Zn-sublimation-controlled process.
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Resumen Objetivo: Disminuir la brecha del conocimiento de la Enfermedad de Kawasaki (EK) y dar herramientas al personal médico por medio de la descripción de la demografía, presentación clínica, los hallazgos de laboratorio, la frecuencia de lesiones coronarias y desenlaces en 2 instituciones de salud en Bogotá, Colombia. Metodología: Estudio observacional retrospectivo mediante la revisión de historias clínicas de los códigos CIE-10 de paciente pediátricos donde se evaluaron características demográficas, presentación clínica, datos paraclínicos (incluidos hallazgos ecocardiográficos), tratamiento recibido y respuesta a este, en pacientes admitidos entre junio de 2015 y junio de 2020. Resultados: Se incluyeron 36 pacientes entre 3 meses y 15 años. La edad media de los pacientes fue de 2.9 años, siendo la EK más frecuente en niños en una rela ción 2:1. El 61.1% presentó EK completa o clásica, el 30.5% EK incompleta y el 8.3% EK atípica. Todos los pacientes recibieron inmunoglobulina intravenosa antes del día 10 del curso de la enfermedad, con remisión de la fiebre antes de 12 horas luego de la administración. La incidencia de compromiso coronario fue de 30.6%. Conclusiones: La Enfermedad de Kawasaki tiene un curso clínico característico que afecta especialmente a niños menores de 5 años. Es una entidad clínica que, al ser reconocida con mayor frecuencia por pediatras, permite instaurar diagnóstico y tratamiento tempranos evitando complicaciones y secuelas a mediano y largo plazo.
Abstract Objective: To reduce the knowledge gap about Kawasaki Disease (KD) and to provide tools to medical personnel through the description of demographics, clinical presentation, laboratory findings, frequency of coronary lesions and outcomes in 2 health institutions in Bogota Colombia. Methodology: Retrospective observational study by reviewing the clinical records of the ICD-10 codes of pediatric patients where demographic characteristics, clinical presentation, paraclinical data (including echocardiographic findings), treatment received and response to it were evaluated, in patients admitted between June 2015 and June 2020. Results: The mean age of the patients was 2.9 years, being KD more frequent in boys a 2:1 ratio. 61.1% had complete or classic KD, 30.5% had incomplete KD, and 8.3% atypical KD. All patients received intravenous immunoglobulin before day 10 of the course of the disease, with remission of fever within 12 hours after administration. The incidence of coronary compromise was 30.6%. Conclusions: KD has a characteristic clinical course that especially affects children under 5 years. A more frequent recognition of this clinical entity by pediatricians, allows for an early diagnosis and treatment avoiding complications and sequelae in the medium and long term.
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INTRODUCTION: An exponential increase in thyroid cancer has been reported in Mexico with 12,122 new cases in 2018 it represents the most common endocrinological cancer described by the World Health Organization. Attributing it local and distant metastatic lesions, being unusual the orbital condition. CLINICAL CASE: A 56-year-old woman diagnosed with chronic myeloid leukemia 19 years ago, presented with left eye proptosis and tearing, headaches, worsening left facial neuralgia. CONCLUSIONS: In these cases, the surgical treatment is essential to improve patient's symptoms and quality of life.
INTRODUCCIÓN: En México existe un aumento exponencial del cáncer de tiroides, con 12,122 nuevos casos en 2018, representando el cáncer endocrinológico más frecuente descrito por la Organización Mundial de la Salud. Se le atribuyen lesiones metastásicas locales y a distancia, siendo una presentación inusual la afección orbitaria. CASO CLÍNICO: Mujer de 56 años diagnosticada de leucemia mieloide crónica hace 19 años, que acude por cefalea, proptosis e hiperemia conjuntival con limitación a la abducción, y dolor facial izquierdo. CONCLUSIONES: En estos casos, el tratamiento quirúrgico es indispensable para mejorar la sintomatología y la calidad de vida del paciente.
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Neoplasias Orbitales , Neoplasias de la Tiroides , Femenino , Humanos , México , Persona de Mediana Edad , Calidad de Vida , Neoplasias de la Tiroides/cirugíaRESUMEN
Introducción: a nivel internacional hay una búsqueda de donadores debido a una demanda creciente mientras que éstos son pocos. Dentro de la cultura de la donación existen los factores sociales y psicológicos que influyen directamente en la decisión de la familia de un potencial donador por muerte encefálica. Objetivo: identificar cuáles son las experiencias de la familia ante la condición potencial de donación de órganos en pacientes con muerte encefálica en una institución de tercer nivel. Material y métodos: estudio mixto cuanti-cualitativo retrospectivo, transversal realizado en una institución de tercer nivel, por medio de una familia (el responsable) con un integrante donador por muerte encefálica. Análisis: estadística descriptiva con valores porcentuales, en Spss 23 previo, diseño de base de datos con variables sociodemográficas y de actitud. Resultados: el 51.8 % de la población tuvo el diagnóstico de hemorragia subaracnoidea; seguida del 18.4 % con diagnóstico de tumor cerebral. Y un 9.6% diagnosticados con evento vascular cerebral. Destaca un 1.8 % con diagnóstico de criptocosis cerebral. La investigación revela que el 53.5 % de la población es femenina y el 46.5 % masculina, en la relación con el índice de donación el 43.3 % de los hombres aceptan la donación a diferencia del 23 % de las mujeres que se convierten en donadoras. Conclusiones: las experiencias de los familiares de donadores por muerte encefálica reflejan disposición para donar. Sin embargo, es evidente que se requiere una evaluación de las condiciones emocionales del familiar, en el momento de sugerirle la posibilidad de autorizar la donación.
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Humanos , Muerte Encefálica , Donaciones , Consentimiento InformadoRESUMEN
ABSTRACT Objective: To describe our experience on a case series treated with minimal invasive techniques in spine surgery, with short-term follow-up and identify complications. Methods: A prospective analysis was performed on 116 patients operated on by the same team from September 2015 to June 2016. Evaluating the short-term follow-up we registered the surgical time, bleeding, complications, hospital stay, pre- and postoperatively neurological status, as well as scales of disability and quality of life. Demographic and surgical procedure data were analyzed with SPSS version 20 program. Results: A total of 116 patients with a mean age of 49.7 + 15.7 (21-85 years) underwent surgery being 76 (65%) with lumbar conditions and 37 (32%) with cervical conditions. The most common procedures were tubular discectomies (31), tubular bilateral decompression (17), lumbar MI-TLIFs (7), and anterior cervical discectomy and fusion (35). The mean blood loss was 50.6 cc, the hospital stay was 1.7 day, pre- and postoperative pain VAS were 7.4 % and 2.3%, respectively, pre- and postoperative Oswestry (ODI) were 64.6% and 13.1%, respectively, pre- and postoperative SF-36 of 37.8% and 90.3%. There were no major complications, except for a surgical wound infection in diabetic patient and three incidental durotomies, one of these being a contained fistula, treated conservatively. Conclusions: The current tendency towards minimally invasive surgery has been justified on multiple studies in neoplastic and degenerative diseases, with the preservation of the structures that support the spine biomechanics. The benefits should not replace the primary objectives of surgery and its usefulness depends on the skills of the surgeon, pathology and the adequate selection of the techniques. We found that the tubular access allows developing techniques such as discectomy, corpectomy and fusion without limiting exposure, avoiding manipulation of adjacent structures, reducing complications and being feasible in a public hospital.
RESUMO Objetivo: Descrever nossa experiência em uma série de casos tratados por técnicas minimamente invasivas de cirurgia da coluna, o acompanhamento a curto prazo e identificar complicações. Métodos: Realizou-se análise prospectiva de 116 pacientes operados pela mesma equipe, de setembro de 2015 até junho de 2016. Avaliando o acompanhamento a curto prazo, foram registrados tempo cirúrgico, hemorragia, complicações, estadia hospitalar, estado neurológico pré e pós-operatório, além de escalas de incapacidade e qualidade de vida. Os dados demográficos e sobre o procedimento cirúrgico foram analisados com o programa SPSS versão 20. Resultados: Um total de 116 pacientes com média de idade de 49,7 + 15,7 (21 a 85 anos) foram operados, sendo 76 (65%) com afecção lombar e 37 (32%) com afecção cervical. Os procedimentos mais comuns foram discotomias tubulares (31), descompressão bilateral tubular (17), MI-TLIF (7) lombares; discotomia e artrodese anterior (35). O sangramento médio foi de 50,6 cm3, o tempo de hospitalização foi 1,7 dia, a escala EVA pré-cirúrgica foi 7,4 e a pós-cirúrgica 2,3, Oswestry (ODI) pré-cirúrgico de 64,6% e pós-cirúrgico de 13,1%, SF-36 pré-cirúrgico de 37,8% e pós-cirúrgico de 90,3%. Não houve grandes complicações, exceto uma infecção da ferida cirúrgica em paciente diabética e três durotomias incidentais um dos pacientes com fístula, uma delas contida, tratada de modo conservador. Conclusões: A tendência atual da cirurgia minimamente invasiva tem sido justificada em vários estudos sobre neoplasia e doenças degenerativas, preservando as estruturas da biomecânica da coluna vertebral. Os benefícios não devem substituir os objetivos primários e sua utilidade depende das habilidades do cirurgião, da patologia e do uso seletivo das técnicas. Constatamos que o acesso tubular permite desenvolver a técnica de discotomia, fusão e corpectomia sem limite de exposição, evitando manipulação de estruturas adjacentes, reduzindo as complicações e sendo viável em hospitais públicos.
RESUMEN Objetivo: Describir nuestra experiencia en una serie de casos tratados mediante técnicas mínimamente invasivas en cirugía de columna, su seguimiento a corto plazo e identificar las complicaciones. Métodos: Se realizó un análisis prospectivo en 116 pacientes intervenidos por el mismo equipo desde septiembre de 2015 a junio de 2016. Evaluando el seguimiento a corto plazo, se registró tiempo quirúrgico, sangrado, complicaciones, estancia hospitalaria, estado neurológico pre y post operatorio además de escalas de discapacidad y calidad de vida. Los datos demográficos y del procedimiento quirúrgico fueron analizados con el programa SPSS versión 20. Resultados: Un total de 116 pacientes con edad promedio de 49,7 + 15,7 (21 a 85 años), fueron intervenidos siendo 76 (65%) patologías lumbares y 37 (32%) cervicales. Los procedimientos más comunes fueron discectomías tubulares (31), descompresión bilateral tubular (17), MI-TLIF (7) lumbares; discectomía y artrodesis anterior (35). El promedio de sangrado fue 50,6 cc, estancia hospitalaria 1,7 día, escala EVA prequirúrgica 7,4 y posquirúrgica 2,3, Oswestry (ODI) prequirúrgico 64,6% y posquirúrgico 13,1%, SF-36 prequirúrgico 37,8% y posquirúrgico 90,3%. No hubo complicaciones mayores, excepto una infección de herida quirúrgica en paciente diabética y 3 durotomías incidentales, una de estas con fístula contenida, de manejo conservador. Conclusiones: La tendencia actual de la cirugía mínimamente invasiva se ha justificado en múltiples estudios en patología tumoral y degenerativa, con la conservación de estructuras para biomecánica de la columna. Los beneficios no deben reemplazar los objetivos primarios y su utilidad depende de las habilidades del cirujano, la patología, y el uso selectivo de las técnicas. Encontramos que el acceso tubular permite desarrollar la técnica de discectomía, fusión y corpectomía sin limitar la exposición, evitando manipulación de estructuras adyacentes, disminuyendo complicaciones y siendo factible en un hospital público.
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Procedimientos Quirúrgicos Mínimamente Invasivos , Enfermedades de la Columna Vertebral/cirugía , Estudios Prospectivos , Resultado del TratamientoRESUMEN
BACKGROUND: Multiple myeloma is a plasmatic cell neoplasm that is characterized by skeletal destruction, renal failure, anemia and hypercalcemia. The skull plasmacytomas represent less than 1% of the head and neck tumors, they can be the primary lesion or occur as a secondary manifestation of multiple myeloma in 20-30% of the patients, or they can even manifest several years later after the diagnosis of plasmacytoma. Although some of the lesions may be surgically accessible, the aggressive natural behavior will complicate the evolution of the patients. We present two cases of Mexican women with intracranial plasmacytomas, one of them associated with multiple myeloma. CLINICAL CASES: The first case was a 24 year-old woman diagnosed with a multiple myeloma with plasmacytic-plasmablastic bone infiltration that was removed in 90%. She presented a local recurrence that required a second intervention for removal. The second case was a 62 year-old female with a malignant intracranial tumor of plasma cells that was totally resected. Both patients received adjuvant treatment based on chemotherapy and radiation therapy with favorable results. The patients died at 5 and 1.5 years respectively due to renal failure secondary to systemic disease. CONCLUSIONS: We propose chemotherapy and radiation therapy as an essential part of treatment for this condition, as the aggressive behavior of the neoplasms can complicate the evolution, despite being surgically accessible.
Antecedentes: el mieloma múltiple es una neoplasia de células plasmáticas caracterizada por destrucción ósea, insuficiencia renal, anemia e hipercalcemia. Los plasmacitomas de los huesos del cráneo representan menos de 1% de los tumores de cabeza y cuello. Se manifiestan como lesión primaria o secundaria a mieloma múltiple en 20-30%, incluso pueden aparecer varios años después del diagnóstico. Los autores comunicamos dos casos de pacientes mexicanas con lesiones plasmocíticas intracraneales, asociadas con mieloma múltiple.Casos clínicos: el primer caso es el de una paciente de 24 años de edad, con diagnóstico de mieloma múltiple e infiltración ósea que fue extirpado en 90%. Experimentó una recidiva local que requirió otra intervención para su remoción. El segundo caso es el de una mujer de 62 años de edad con un tumor intracraneal de células plasmáticas que se resecó en su totalidad. Ambas recibieron terapia adyuvante con quimio y radioterapia con resultados favorables. Las pacientes fallecieron a los 5 y 1.5 años, respectivamente, por insuficiencia renal como consecuencia de la enfermedad sistémica. Conclusiones: se propone a la quimioterapia y radioterapia como parte esencial del tratamiento de este tumor porque su comportamiento natural agresivo puede complicar la evolución, a pesar de ser accesibles quirúrgicamente.