Ion-channel-like behavior in lipid bilayer membranes at the melting transition

It is well known that at the gel-liquid phase transition temperature a lipid bilayer membrane exhibits an increased ion permeability. We analyze the quantized currents in which the increased permeability presents itself. The open time histogram shows a "-3/2" power law which implies an open-closed transition rate that decreases like $k(t) \propto t^{-1}$ as time evolves. We propose a "pore freezing" model to explain the observations. We discuss how this model also leads to the $1/f^{\alpha}$ noise that is commonly observed in currents across biological and artificial membranes.Comment: 5 pages, 4 figure

Solitons in iterated \phi^4 model

W pracy skoncentrowano się na omówieniu iterowanego modelu \phi^4. Wprowadzono niezbędne do tego pojęcia z klasycznej teorii pola skalarnego, w szczególności z potencjałem \phi^4. Następnie omówiono solitony w tym przypadku i jego rozszerzenie o pole "impurity". Opisano konstrukcję modelu iterowanego, ze szczególnym uwzględnieniem niskich k-cykli. W ramach własnych obliczeń otrzymano numeryczne rozwiązania równań 3-cyklu reprezentujące układy od dwóch do pięciu (anty)kinków.This thesis focuses on discussing the iterated \phi^4 model. The classical field theory concepts necessary for this matter are introduced, especially the \phi^4 potential. Then the solitons in this case and its extension by an impurity field are discussed. The construction of the iterated model is described, with particular emphasis on low k-cycles. As part of my own calculations, numerical solutions of the 3-cycle equations are obtained, representing systems from two to five (anti)kinks

Wrodzona przepuklina oponowa wewnątrznosowa u noworodka : opis przypadku

Background: Meningocele or meningocephalocele is a rare defect, which consists in the displacement of the structures of the brain or/and meninges through a congenital cavity in the cranium. Depending on the location, there are hernias of the skull vault and base or external and internal hernias. Some of them can cause breathing disorders in children. Case Report: We described a case of an eutrophic, full-term newborn boy with breathing disorders. A laryngological examination found a tumor of the left nasal meatus, from which a sample was collected for histopathological study. Due to a cyst revealed under the lesion and pulsation of the tumor, it was decided to include imaging examinations into the diagnostic process. Computed tomography (CT) showed a mass of meningocele type, which was confirmed in magnetic resonance imaging (MRI). Results: In case of breathing disorders and a suspected mass in the nasal meatus in a newborn, a congenital meningocele or menigocephalocele should be assumed. This constitutes a contraindication to sampling of the lesion, without prior imaging tests (CT and/or MRI)

Biological Potential and Chemical Profile of European Varieties of Ilex

Plants of the genus Ilex are widespread throughout the world, with its best-known representative being Ilex paraguraiensis from South America. The European species Ilex aquifolium shows similarities in its terpenoid, sugar and phenolic acid profiles. Using aqueous extracts of Ilex aquifolium as a supplement in Wistar rats showed that, despite the lack of caffeine, it had strong hypocholesterolemic effects. In addition, a reduction in oxidative lipid degradation and a decrease in hepatic steatosis in histopathological studies were observed. The results of this study suggest that extracts from the European species Ilex aquifolium may have potential as an alternative treatment for hyperlipidemia