Comparative Study of SnO₂ and ZnO Semiconductor Nanoparticles (Synthesized Using <i>Randia echinocarpa</i>) in the Photocatalytic Degradation of Organic Dyes

Symmetry in nanomaterials is essential to know the behavior of their properties. In the present research, the photocatalytic properties of SnO2 and ZnO nanoparticles were compared for the degradation of the cationic dyes Methylene Blue (MB) and Rhodamine B (RB). The nanoparticles were obtained through a green synthesis process assisted by Randia echinocarpa extracts; they were then analyzed through Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) to characterize their structure. Transmission electron microscopy (TEM) was used to identify the morphology and disclose nanoparticle size, and the optical properties were studied through Ultraviolet–visible spectroscopy (UV–Vis). The results show that the synthesized SnO2 and ZnO nanomaterials have quasispherical morphologies with average sizes of 8–12 and 4–6 nm, cassiterite and wurtzite crystal phases, and band gap values of 3.5 and 3.8 eV, respectively. The photocatalytic activity yielded 100% degradation of the MB and RB dyes in 210 and 150 min, respectively. ZnO performed higher photocatalytic degradation of the cationic dyes than SnO2 due to a higher content of Randia echinocarpa extracts remaining after the green synthesis process

Multi-Stage Ensemble-Based System for Glaucomatous Optic Neuropathy Diagnosis in Fundus Images

Recent developments in Computer-aided Diagnosis (CAD) systems as a countermeasure to the increasing number of untreated cases of eye diseases related to visual impairment (such as diabetic retinopathy or age-related macular degeneration) have the potential to yield in low-to-mid income countries a comfortable and accessible alternative to obtaining a general ophthalmological study necessary for follow-up medical attention. In this work, a multi-stage ensemble-based system for the diagnosis of glaucomatous optic neuropathy (GON) is proposed. GON diagnosis is based on a binary classification procedure working in conjunction with a multi-stage block based on image preprocessing and feature extraction. Our preliminary data show similar results compared to current studies considering metrics such as Accuracy, Sensitivity, Specificity, AUC (AUROC), F1score, and the use of Matthews Correlation Coefficient (MCC) as an additional performance metric is proposed

Study on MID-IR Spectroscopy on Whole Blood Samples for Human Glucose Quanitification Applications

The importance of a systematic glucose monitoring in order to keep a steady control for diabetic patients has been established. Several medical studies accept the necessity of exploring alternatives for the traditional digital glucometer, given the pain and discomfort related to the application of this technique, which can lead to a compromised control of the disease. Several efforts based on the application of IR spectroscopy have been done with favorable, yet not conclusive results. Therefore it’s necessary to apply a comprehensive and interdisciplinary study based on the biochemical and optical properties of the glucose in the human body in order to understand the interaction between this substance, its surroundings, and IR light. This study proposes a comprehensive approach of the glucose and IR light interaction, considering and combining important biochemical, physiological and optical properties such as the effect of glucose regulation compounds and data mining based chemometrics techniques. The results of this work would help to define the right parameters, aiming to obtain an optical glucose quantification or classification system, as well as the protocol for the purpose