New Lie-Algebraic and Quadratic Deformations of Minkowski Space from Twisted Poincare Symmetries

We consider two new classes of twisted D=4 quantum Poincar\'{e} symmetries described as the dual pairs of noncocommutative Hopf algebras. Firstly we investigate a two-parameter class of twisted Poincar\'{e} algebras which provide the examples of Lie-algebraic noncommutativity of the translations. The corresponding associative star-products and new deformed Lie-algebraic Minkowski spaces are introduced. We discuss further the twist deformations of Poincar\'{e} symmetries generated by the twist with its carrier in Lorentz algebra. We describe corresponding deformed Poincar\'{e} group which provides the quadratic deformations of translation sector and define the quadratically deformed Minkowski space-time algebra.Comment: LaTeX 16 pages. The version which appear in PL

Charakterystyka właściwości biomechanicznych ścian aorty brzusznej

Background. The structure of the aorta wall is well adapted to withstand the mechanical loads caused by arterial blood pressure. The most important structural components of the aortic wall are elastin and collagen fibres. Elastin and collagen fibres allow reversible deformation of, and give mechanical strength to, the aorta. Alterations in composition cause changes in the mechanical properties of the aortic wall. Hence, the main aim of this study is the biomechanical assessment and preliminary histological study of the abdominal aortic wall. Material and methods. Specimens were cut from the materials obtained during autopsies, taking research standards into consideration, which were then examined in order to determine the directional material properties. The second part of the materials was intended for histological analysis. Results. It was appreciable that the mechanical strength of the aortic wall is higher in the transversal than in the longitudinal direction, which has a vital meaning for the correct functioning of the organism, and it makes the vessel able to perform reversible deformation under the influence of pulsatile blood pressure. This ability is strongly dependent on the structural composition of the aortic wall. Conclusions. Structural alterations due to atherosclerotic lesions of various degrees lead to a significant increase of stiffness and decrease of mechanical strength of the walls of abdominal aorta.Wstęp. Struktura ścian aorty jest przystosowana do stawiania oporu mechanicznym obciążeniom, które wywoływane są przez ciśnienie tętnicze. Najważniejszymi elementami strukturalnymi ścian aorty są włókna elastynowe i kolagenowe. Odpowiadają one za odwracalne odkształcanie się ścian aorty oraz ich mechaniczną wytrzymałość. Dlatego też głównym celem tej pracy jest ocena biomechaniczna oraz analiza histologiczna ścian aorty brzusznej. Materiał i metody. Z materiału pobranego podczas sekcji zwłok wycinano próbki w celu określenia właściwości mechanicznych ścian aorty brzusznej. Pozostałą część materiału przeznaczono do analiz histologicznych. Wyniki. Odnotowano, że mechaniczna wytrzymałość ścian aorty jest większa w kierunku obwodowym niż wzdłużnym. Cecha ta ma kluczowe znaczenie dla poprawnego funkcjonowania organizmu dzięki zdolności naczynia do odwracalnego odkształcania się pod wpływem tętniczego przepływu krwi w naczyniu. Zdolność ta silnie zależy od struktury naczynia. Wnioski. Zmiany strukturalne spowodowane przez miażdżycę prowadzą do znaczącego wzrostu sztywności i obniżenia wytrzymałości mechanicznej ścian aorty brzusznej

Infekcyjne zapalenie wsierdzia - wciąż wielkie wyzwanie. Opis dwóch przypadków

Abstract: We present two patients with aortic valve disease who developed acute infective endocarditis. In both patients the disease started with infection of the upper respiratory tract. The patients were treated with antibiotics due to pneumonia. The diagnosis of infective endocarditis was established 4 months and 9 weeks after the onset of infection. The first patient died whereas the second underwent successful aortic valve replacement

Antimicrobial Photodynamic Inactivation: An Alternative for Group B <i>Streptococcus</i> Vaginal Colonization in a Murine Experimental Model

Background: Streptococcus agalactiae, referred to as Group B Streptococcus (GBS), is a prominent bacterium causing life-threatening neonatal infections. Although antibiotics are efficient against GBS, growing antibiotic resistance forces the search for alternative treatments and/or prevention approaches. Antimicrobial photodynamic inactivation (aPDI) appears to be a potent alternative non-antibiotic strategy against GBS. Methods: The effect of rose bengal aPDI on various GBS serotypes, Lactobacillus species, human eukaryotic cell lines and microbial vaginal flora composition was evaluated. Results: RB-mediated aPDI was evidenced to exert high bactericidal efficacy towards S. agalactiae in vitro (>4 log10 units of viability reduction for planktonic and >2 log10 units for multispecies biofilm culture) and in vivo (ca. 2 log10 units of viability reduction in mice vaginal GBS colonization model) in microbiological and metagenomic analyses. At the same time, RB-mediated aPDI was evidenced to be not mutagenic and safe for human vaginal cells, as well as capable of maintaining the balance and viability of vaginal microbial flora. Conclusions: aPDI can efficiently kill GBS and serve as an alternative approach against GBS vaginal colonization and/or infections

Materials characterization of TiO2TiO_2 nanotubes decorated by Au nanoparticles for photoelectrochemical applications

The structural and chemical modification of TiO(2) nanotubes (NTs) by the deposition of a well-controlled Au deposit was investigated using a combination of X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Scanning Transmission Electron Microscopy (STEM), Raman measurements, UV-Vis spectroscopy and photoelectrochemical investigations. The fabrication of the materials focused on two important factors: the deposition of Au nanoparticles (NPs) in UHV (ultra high vacuum) conditions (1–2 × 10(−8) mbar) on TiO(2) nanotubes (NTs) having a diameter of ∼110 nm, and modifying the electronic interaction between the TiO(2) NTs and Au nanoparticles (NPs) with an average diameter of about 5 nm through the synergistic effects of SMSI (Strong Metal Support Interaction) and LSPR (Local Surface Plasmon Resonance). Due to the formation of unique places in the form of “hot spots”, the proposed nanostructures proved to be photoactive in the UV-Vis range, where a characteristic gold plasmonic peak was observed at a wavelength of 580 nm. The photocurrent density of Au deposited TiO(2) NTs annealed at 650 °C was found to be much greater (14.7 μA cm(−2)) than the corresponding value (∼0.2 μA cm(−2)) for nanotubes in the as-received state. The IPCE (incident photon current efficiency) spectral evidence also indicates an enhancement of the photoconversion of TiO(2) NTs due to Au NP deposition without any significant change in the band gap energy of the titanium dioxide (E(g) ∼3.0 eV). This suggests that a plasmon-induced resonant energy transfer (PRET) was the dominant effect responsible for the photoactivity of the obtained materials