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Abstract  

The aim of this study is to understand some properties and thermal behavior of blood, giving a possible alternative tool which differs from the traditional blood diagnostic methods, and to improve investigations in hematology and artificial bloods. Wistar rat blood samples (WRBS); SHR rat blood samples (SHRBS) and human blood samples (HBS) were analyzed. TG curves showed two decomposition stages for HBS at around 100 and 230C (T onset), while three mass degradation stages for WRBS (70, 110, 270C) and SHRBS (70, 120, 270C) could be observed. DSC peaks showed five endotherms for HBS at 65, 82, 194, 201 and 309C and three endotherms for WRBS at 83, 184 and 313C.

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Abstract  

The thermal behavior of the kidney, heart and liver of spontaneous hypertension rats (SHR) were studied by thermogravimetry (TG) and differential thermal analysis (DTA). SHR are, by far, the most widely used rat model in the study of heart diseases in mammals, because they develop chronic hypertension, which leads to heart failure during their lives. TG curves showed two steps for all samples: at 800C less residues remained for an SHR kidney (4.01.8%) than for an SHR heart (6.90.4) and liver samples (7.51.9%). It probably happened due to the presence of inorganic substances such as iron, calcium, magnesium, potassium and sodium. DTA curves depicted three endothermic events for kidney (70, 120 and 310C), heart (85, 250 and 300C) and liver samples (70, 250 and 310C), indicating protein denaturation, as well as protein degradation and fat degradation, respectively. TG/DTG/DTA profiles of organs samples showed peculiarities that permit correlation between them. These methods might serve as a simple alternative to investigations over these vital organs.

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Journal of Thermal Analysis and Calorimetry
Authors: C. G. Mothé, T. Carestiato, M. B. Aguila, and C. A. Mandarim-de-Lacerda

Summary Hypertension is a major and growing public health problem. It is responsible for the mortality of millions of people around world, and is increasing each year. Nevertheless, the understanding of the relationship between the composition of the heart's cells, hypertension and health diseases is still very incomplete. The present study focuses on the evaluation of the attributes of some hearts of Spontaneous Hypertension Rats (SHR), comparing with SHR which received additional amounts of polysaccharide (SHR+P) and with wistar rats (normal blood pressure) by Thermal Analysis. Some differences could be seen between groups, as the residue content after 800°C was different for rats from different groups, and of wistar rats hearts samples showed 5.3±0.3& of residues vs. 8.3±1.5& of the SHR. DSC profiles for wistar rats showed one intense endothermic event at 160°C, with enthalpy transition of 450 J g-1 and more three small events. Thermal analyses curves also showed some differences between freezing and no freezing samples, probably associated to the denaturation of proteins and degradation of organic materials.

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