The laboratory investigations of the heat transfer properties of wall structures are very significant from the point of view of designing the buildings. In this article measurements and calculations will be presented in order to manifest the effect of the forced and un-forced convection of air at the cold surface of the wall. A steady-state method for measuring the thermal resistance of wall structures with Hukseflux apparatus is presented in this article. The measurements were accomplished through, firstly on an un-insulated inbuilt plaster/brick/plaster wall construction and later it was covered with a 0.013 m thick aerogel layer blanket. Aerogels are nanoporous lightweight materials, were discovered more than 70 years ago. In these years their applications are truly spread over. During the investigations the wall structures were tested without forcing the air to motion, and then measurements were carried both on the insulated and un-insulated wall structures, where the movement of the air was forced by a ventilator from three different directions with the same 1 m/s velocity near the wall.
Authors:P. Olejníková, A. Kaszonyi, M. Šimkovič, B. Lakatoš, M. Kaliňák, M. Valachovičová, and L. Birošová
The human endogenous intestinal microbiota is an essential “organ” in providing nourishment, regulating epithelial development, and instructing innate immunity. Even though lots of scientists have evaluated the content of gut microbiota from various points of view, we examined the content of intestinal microbes in the group of healthy middle aged volunteers (40–60) form Slovakia. We have compared faecal cultivable microbiota of vegetarians and omnivores. We have found that the composition of the human microbiota is fairly stable, and it seems that the major microbial groups on species level that dominate the human intestine are conserved in all individuals regardless of dietary habits. Beside the microbial content we have examined the faecal samples also for the presence of antimicrobial active compounds, potential mutagens, and faecal sterols.
Authors:K. Szentmihályi, A. Blázovics, I. Kocsis, Edit Fehér, B. Lakatos, and Péter Vinkler
The metabolic alteration of fatty liver causes significant changes in the composition of bile fluid secreted by epithelial liver cells. These processes include both organic molecular and inorganic ion content changes in bile juice as well. In this work ion concentration differences of bile fluid in experimental hyperlipidemic rats compared to normal ones were monitored. Fatty liver in young male Wistar albino rats was induced by 2% cholesterol, 20% sunflower oil and 0.5% cholic acid added to the normal food and 3% alcoholic water was administered to rats for 9 days. The development of hyperlipidemy was detected by measuring serum parameters and fatty liver was proved by morphological investigations. The ion concentrations of bile fluid samples were determined by ICP-OES (inductively coupled plasma optical emission spectrometry). The bile fluid samples were digested with a mixture of HNO3 and H2 O2 . The results show that the concentration of calcium and phosphorus in bile juice increased significantly in hyperlipidemic rats compared to the control. Significant concentration changes have also been detected for chromium and manganese. The changes in metal ion metabolism also point to the damage of liver cells owing to metal complex evacuation.
Authors:B. Sági, A. Peti, O. Lakatos, T. Gyimesi, E. Sulyok, I. Wittmann, and Botond Csiky
In this observational study we addressed accelerated arteriosclerosis (AS) in patients with chronic renal failure (CRF) on hemodialysis (HD) by measuring vascular stiffness (VS) parameters and attempted to relate them to pro-inflammatory and protective factors.
96 consecutive patients receiving regular HD were included. 20 adult patients without major renal, cardiovascular or metabolic morbidities served as controls.
AS parameters (carotid-femoral pulse wave velocity – PWV, aortic augmentation index – Aix) were measured by using applanation tonometry (SphygmoCor, AtCor Medical, Sidney). In addition to routine laboratory tests 25(OH) vitamin D3 (vitamin D3) and high-sensitivity C-reactive protein (hsCRP) were quantified by immunometric assay; whereas fetuin-A, α-Klotho, tumor necrosis factor-α (TNF-α) and transforming growth factor-β1 (TGF-β1) were determined by ELISA.
Pro-inflammatory biomarkers (hsCRP, TNF-α and TGF-β1) were markedly elevated (P < 0.01), while anti-inflammatory factors (fetuin-A: P < 0.05, α-Klotho: P < 0.01, vitamin D3: P < 0.01) significantly depressed in HD patients when compared to controls. PWV was significantly affected only by total cholesterol, fetuin-A and dialysis time. Multiple linear regression analyses revealed that several clinical and laboratory parameters were associated with pro- and anti-inflammatory biomarkers rather than VS. The impact of baseline clinical and biochemical variables on outcome measures were also analyzed after three-year follow-up, and it was demonstrated that low levels of vitamin D, α-Klotho protein and fetuin-A were related to adverse cardiovascular outcomes, whereas all-cause mortality was associated with elevated hsCRP and depressed vitamin D.
Our results provide additional information on the pathomechanism of accelerated AS in patients with CRF, and documented direct influence of pro- and anti-inflammatory biomarkers on major outcome measures.