Diabetes is a recognized risk factor of heart disease. The abnormalities related to a decreased heart performance probably arise at cellular and molecular levels already in the asymptomatic phase of diabetes. However, the early alterations initiating a sequence of events that culminates in the clinical signs have not been fully elucidated yet. This review deals with some biophysical methods applied to investigation of left ventricular myocytes in rats with streptozotocin diabetes, as well as our most important findings concerning diabetes-induced cell changes which cannot be captured by other techniques. The observed decrease in sarcolemmal membrane fluidity is causatively associated with increased glycation and glycoxidation. On the other hand, an increase in the mitochondrial membrane fluidity may be attributed to augmented energy transduction through the membranes. We reported for the first time concurrent measurements of membrane potential and dynamics, and respiratory chain activities in rat heart mitochondria, as well as calcium transients in the myocytes from diabetic hearts together with the assessed quantitative relationships among these variables. We were able to detect some significant alterations that may underlie myocyte dysfunction and subsequent remodeling of the heart. We suppose that not all these changes reflect mechanisms leading to pathology; some may represent adaptive and compensatory responses to diabetes., I. Waczulíková ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
The paper deals with the use of the luminiscence phenomenon of epoxy resins to obtain an estimation of basic technological variables such as the storage temperature of the mixed resin and an estimation of the end of the crosslinking reaction in the state of the material that allows manipulation with the product. To obtain a description of the curing reaction kinetics, it was necessary to measure the fluorescence spectra over time and to create a mathematical model. From the processed data we obtained the value of the highest storage temperature for a particular epoxy system (EPOXY 1200 + P11), when the reaction stops t = -0.7 °C and we also determined the potential barrier value for the given chemical reaction w0 = 158 meV. The obtained results are an interesting possibility to use a non-contact optical method for controlling the curing processes in the production of composite products (e.g. aircraft wings in an autoclave) and their automation. and Článek se zabývá využitím jevu luminiscence u epoxidových pryskyřic k získání odhadu základních technologických veličin, jako jsou teplota skladování zamíchané pryskyřice a odhad ukončení síťovací reakce ve stavu materiálu, který umožňuje manipulaci s výrobkem. Kzískání popisu kinetiky vytvrzovací reakce bylo nutno naměřit fluorescenční spektra v závislosti na čase a následně vytvořit matematický model. Ze zpracovaných dat jsme pro konkrétní epoxidový systém (EPOXY 1200+P11) získali hodnotu nejvyšší skladovací teploty t=-0,7 °C, kdy se reakce zastaví, a navíc jsme určili hodnotu potenciálové bariéry pro danou chemickou reakci w0 = 158 meV. Získané výsledky jsou zajímavou možností využití nekontaktní optické metody pro řízení vytvrzovacích postupů při výrobě kompozitových výrobků (například křídel letadel v autoklávu) a jejich automatizaci.