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1.
J Imaging ; 9(11)2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37998100

RESUMO

Retinal imaging is a non-invasive technique used to scan the back of the eye, enabling the extraction of potential biomarkers like the artery and vein ratio (AVR). This ratio is known for its association with various diseases, such as hypertensive retinopathy (HR) or diabetic retinopathy, and is crucial in assessing retinal health. HR refers to the morphological changes in retinal vessels caused by persistent high blood pressure. Timely identification of these alterations is crucial for preventing blindness and reducing the risk of stroke-related fatalities. The main objective of this paper is to propose a new method for assessing one of the morphological changes in the fundus through morphometric analysis of retinal images. The proposed method in this paper introduces a novel approach called the arteriovenous length ratio (AVLR), which has not been utilized in previous studies. Unlike commonly used measures such as the arteriovenous width ratio or tortuosity, AVLR focuses on assessing the relative length of arteries and veins in the retinal vasculature. The initial step involves segmenting the retinal blood vessels and distinguishing between arteries and veins; AVLR is calculated based on artery and vein caliber measurements for both eyes. Nine equations are used, and the length of both arteries and veins is measured in the region of interest (ROI) covering the optic disc for each eye. Using the AV-Classification dataset, the efficiency of the iterative AVLR assessment is evalutaed. The results show that the proposed approach performs better than the existing methods. By introducing AVLR as a diagnostic feature, this paper contributes to advancing retinal imaging analysis. It provides a valuable tool for the timely diagnosis of HR and other eye-related conditions and represents a novel diagnostic-feature-based method that can be integrated to serve as a clinical decision support system.

2.
Food Chem Toxicol ; 165: 113177, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35643230

RESUMO

The recent studies evaluated the extensive exploitation of azo dyes as food colorant to improve the texture of food to turn the food to be very attractive. The heavy consumption of the food colorants by the food industries in commonly consumed beverages especially in the soft drinks may become the cause of certain suspected diseases. Amaranth is an azo dye which easily cleaved into amines and is suspected to be mutagen and carcinogen. Thus, the quantification of amaranth through reliable and sensitive sensor is of great importance. The SnO2/rGO nanocomposite has been engineered to be utilized as chemically modified sensor for the low-level quantification of amaranth in soft drinks and water sample. The fabricated nanocomposite materials was characterized through XRD, FTIR, raman and TEM tools which revealed average crystalline size of 23.7 nm, different surface functionalities and internal rectangle shaped morphology. The engineered nanocomposite was electrochemically characterized through electrochemical impedance spectroscopy (EIS) and Tafel plot to evaluate the electrocatalytic properties and charger transfer kinetics of SnO2/rGO/Nafion/GCE. The resistance of bare, GO/GCE and SnO2/rGO/Nafion/GCE was calculated as 812.5 Ω, 1343 Ω and 338 Ω. Certain parameters were optimized such as PBS electrolyte pH 6, scan rate 130 mV/s and potential window (0.4-1.2 V) to carry out sensitive and fluent determination process of amaranth azo dye. For the effectiveness of proposed sensor two calibration ranges were optimized from 1 to 800 nM and 1-60 µM. The LOD for both ranges were calculated as 0.68 nM and 0.0027 µM. Moreover, the anti-interference and stability profile of developed sensor were found phenomenal that suggest the exceptional electrocatalytic performance of SnO2/rGO/Nafion/GCE for amaranth.


Assuntos
Grafite , Nanocompostos , Corante Amaranto , Compostos Azo , Bebidas Gaseificadas , Técnicas Eletroquímicas/métodos , Grafite/química , Nanocompostos/química , Compostos de Estanho
3.
Environ Res ; 212(Pt C): 113372, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35561824

RESUMO

4-aminophenol (4-AP) is one of the major environmental pollutants which is broadly exploited as drug intermediate in the pharmaceutical formulations. The extensive release of 4-AP in the environment without treatment has become a serious issue that has led several health effects on humans. This work describe the determination of 4-AP through a new chemically modified sensor based on polyvinyl alcohol functionalized tungsten oxide/reduced graphene oxide (PVA/WO3/rGO) nanocomposite. The fabricated nanocomposite was characterized through XRD and HR-TEM to confirm the crystalline structure with average size of 35.9 nm and 2D texture with ultra-fine sheets. The electrochemical characterization of fabricated sensor was carried out by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) to ensure the charge transfer kinetics of modified sensor that revealed high conductivity of PVA/WO3/rGO/GCE. Under optimized conditions e.g. scan rate 80 mV/s, phosphate buffer (pH 6) as supporting electrolyte and potential window from -0.2 to 0.8 V, the prepared sensor showed excellent response for 4-AP. The linear dynamic range of developed method was optimized as 0.003-70 µM. The LOD of fabricated sensor based on PVA/WO3/rGO/GCE for 4-AP was calculated as 0.51 nM. The practical application of PVA/WO3/rGO/GCE was tested in real water and pharmaceutical samples. The fabricated sensor presented here, exhibited exceptional stability and sensitivity than the reported sensors and could be effectively used for the monitoring 4-AP without interferences.


Assuntos
Nanocompostos , Álcool de Polivinil , Aminofenóis , Grafite , Humanos , Nanocompostos/química , Óxidos , Preparações Farmacêuticas , Tungstênio
4.
Food Chem Toxicol ; 161: 112843, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35101578

RESUMO

The extensive use of pesticides for better yield of crops have become major human concern over the decades. Pesticides are widely used in the fields to kill weeds and pests on the vegetable and crops to improve the quality and yield of the food knowing the fact that pesticides residue in food are very lethal for human being. Amongst, the hazardous pesticides, mancozeb is widely applied in the protection of crops. Thus the quantification of mancozeb residue is of great importance. This study reports the electrochemical monitoring of mancozeb through tungsten oxide reduced graphene oxide (WO3/rGO) nanocomposite. The engineered nanocomposite was characterized though different analytical tools such as FTIR, XRD and TEM to examine crystallinity, internal texture and the size. The FTIR result confirm the functionalities of GO and WO3/rGO nanocomposite in finger print and functional group region. Through XRD analysis, the size of the WO3/rGO nanocomposite was calculated as 31.6 nm. While the TEM analysis was also exploited to examine the 2D texture of GO and nanometric size of the WO3/rGO. To ensure the conductive nature of the WO3/rGO nanocomposite, the glassy carbon electrode was modified and exploited for cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under the optimal conditions, the modified sensor showed exceptional response for mancozeb. The linear dynamic range was set from 0.05 to 70 µM in BRB buffer of pH 4. The LOD and LOQ for proposed method was calculated as 0.0038 and 0.0115 µM. The analytical applicability of chemically modified sensor was investigated in real matrix of different vegetable samples and the recovery values were observed in acceptable range. The electrochemical examination of present work reveals that WO3/rGO nanocomposite can be an exceptional aspirant for the determination of mancozeb at commercial level.


Assuntos
Técnicas Eletroquímicas/instrumentação , Grafite/química , Maneb/química , Nanocompostos/química , Óxidos/química , Tungstênio/química , Zineb/química , Técnicas Eletroquímicas/métodos , Recuperação e Remediação Ambiental/instrumentação , Recuperação e Remediação Ambiental/métodos , Concentração de Íons de Hidrogênio
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