Navegando por Assunto "Infrared Spectroscopy"

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    ATR-FTIR and Genetic Polymorphism Analysis: Potential Tools in the Diagnosis and Identification of Predisposition to DM2
    Silva, Ivan Saraiva; Diniz, Renata V.; Oliveira, Maria do Socorro Pombo de; Lima, Luciana de; Sibelino, Sônia Khouri; Raniero, Leandro José; Canevari, Renata de Azevedo; Ribeirão Preto
    Type 2 Diabetes Mellitus (DM2) is a multifactorial disorder characterized by insulin resistance or reduced hormonal production, commonly diagnosed in adults. The pre-diabetes stage, reversible if treated, can progress to DM2, leading to serious complications such as vision loss and cardiovascular disease. Currently, conventional diagnostic methods, such as glucose measurement and glycated hemoglobin analysis, require fasting which can be uncomfortable for patients; thus, infrared spectroscopy analysis demonstrates great potential as a tool to facilitate disease diagnosis. Genetic polymorphism analysis, although expensive and time-consuming, offers early insights into predisposition to DM2, becoming an important technique for predicting susceptibility to disease development. Studies on the SNP -866G/A of the UCP2 gene, associated with DM2, indicate the polymorphism as one of the factors that may facilitate disease development. This study evaluates the feasibility of FTIR spectroscopy as an alternative method for DM2 and pre-diabetes diagnosis by analyzing serum collected from 17 patients (9 with elevated glucose and HbA1c levels and 8 controls). The presence of the -866G/A polymorphism in the UCP2 gene was evaluated using the PCR-RFLP technique for group stratification. The ATR-FTIR technique proved effective in separating patients with glucose alterations from those with normal glycemic patterns; however, further studies are needed to correlate the -866G/A polymorphism with DM2 predisposition.
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    Chemical changes induced during heating of acetonitrile-rich ice pre-irradiated by X-rays and its implication in astrochemistry
    (Elsevier) Carvalho, Geanderson Araújo; Pilling, Sergio
    In this work, we investigate the effects induced by the heating of acetonitrile-rich ice from 13 K to 350 K. Before the heating, the sample was irradiated at 13 K by broadband X-rays (6 eV to 2 keV), which trigger the production of new molecules, such as HCN, H2CCNH, CH4 and CH3NC (see Carvalho and Pilling, 2020) and also induced desorption of frozen species to gas-phase. New spectra were collected during heating to investigate whether new species, not present before at lower temperatures, appear due to thermal processing. New infrared bands were identified at temperatures around 120 K and 300 K, from which it was possible to notice the possible presence of HCN/CN radical, ammonia and C2N2. It was also verified that acetonitrile has a thermal desorption peak between 120 K and 200 K, which yields to the vanishing of acetonitrile within the sample for temperatures of 200 K and above. Some infrared features assigned before solely to acetonitrile remain for sample temperatures > 200 K, which indicates the presence of blended species with similar infrared features. From analyzing those blended peaks, we also perceived the possible presence of aminoacetonitrile.