27 research outputs found
Expression of Constitutive Nitric Oxide Synthase Isoforms in Varicose Vein Wall; Preliminary Results
There are conflicting findings in literature about the structural changes of the primary varicose veins. NO (a potent vasodilatator) is synthesized by nitric oxide synthase (NOS). From 3 known NOS isoforms the two are constitutional: eNOS (endothelial NOS) and nNOS (neuronal NOS). 10 varicose and 10 control vein samples were processed by standard light microscopy and immuno-histochemica techniques using rabbit polyclonal antibodies against eNOS and nNOS. Antibodies expression was evaluated semiquantitatively and proved morphometrically by 2D-image analysis. total area of NOS isoforms expressions was determined by color analysis and color digital subtraction. The results showed discontinuous and significantly lower expression of both NOS isoforms the in the tunica media of varicose veins compared with the control group. For the statistical analysis the unpaired t-test was used. Our results suppose lower NO levels in varicose vein wall, deducing that varicose dilatation is due to other mechanism, and they contradict the results of previously published similar works
Bond formation at polycarbonate | X interfaces (X = AlO, TiO, TiAlO) studied by theory and experiments
Interfacial bond formation during sputter deposition of metal oxide thin
films onto polycarbonate (PC) is investigated by ab initio molecular dynamics
simulations and X-ray photoelectron spectroscopy (XPS) analysis of PC | X
interfaces (X = AlO, TiO, TiAlO). Generally, the predicted bond
formation is consistent with the experimental data. For all three interfaces,
the majority of bonds identified by XPS are (C-O)-metal bonds, whereas C-metal
bonds are the minority. Compared to the PC | AlO interface, the PC |
TiO and PC | TiAlO interfaces exhibit a reduction in the measured
interfacial bond density by ~ 75 and ~ 65%, respectively. Multiplying the
predicted bond strength with the corresponding experimentally determined
interfacial bond density shows that AlO exhibits the strongest
interface with PC, while TiO and TiAlO exhibit ~ 70 and ~ 60% weaker
interfaces, respectively. This can be understood by considering the complex
interplay between the metal oxide composition, the bond strength as well as the
population of bonds that are formed across the interface
On the classes of languages accepted by limited context restarting automata
In the literature various types of restarting automata have been studied that are based
on contextual rewriting. A word w is accepted by such an automaton if,
starting from the initial configuration that corresponds to input w, the
word w is reduced to the empty word by a finite number of applications of
these contextual rewritings. This approach is reminiscent of the notion of McNaughton
families of languages. Here we put the aforementioned types of restarting automata into
the context of McNaughton families of languages, relating the classes of languages
accepted by these automata in particular to the class GCSL of growing context-sensitive
languages and to the class CRL of Church–Rosser languages
Residual Stress Distribution Analysis in Advanced Materials by Neutron Diffraction: The Case of Spherical Storage Tank Butt Weld
The two-axis diffractometer SPN-100 at the Center of Accelerators and Nuclear Analytical Methods (CANAM) in Řež, is a neutron diffraction instrument dedicated to residual stress analyses in polycrystalline materials, it has recently been equipped with a new two-dimensional position sensitive detector (2D-PSD) and a six-axis robotic arm for sample positioning. Recent results of strain/stress distribution measurements with the upgraded tools are presented. The measured materials are made of C-Mn unalloyed steel used for spherical storage tank. Welding-induced residual stresses have direct influence on ductility and toughness of both weld metal and heat affected zone of the weld area, which affect the service life time of structures. Normal, transversal and longitudinal components of the stresses obtained in the vicinity of the butt weld from a spherical storage tank were measured by neutron diffraction at CANAM
Residual Stress Distribution Analysis in Advanced Materials by Neutron Diffraction: The Case of Spherical Storage Tank Butt Weld
The two-axis diffractometer SPN-100 at the Center of Accelerators and Nuclear Analytical Methods (CANAM) in Řež, is a neutron diffraction instrument dedicated to residual stress analyses in polycrystalline materials, it has recently been equipped with a new two-dimensional position sensitive detector (2D-PSD) and a six-axis robotic arm for sample positioning. Recent results of strain/stress distribution measurements with the upgraded tools are presented. The measured materials are made of C-Mn unalloyed steel used for spherical storage tank. Welding-induced residual stresses have direct influence on ductility and toughness of both weld metal and heat affected zone of the weld area, which affect the service life time of structures. Normal, transversal and longitudinal components of the stresses obtained in the vicinity of the butt weld from a spherical storage tank were measured by neutron diffraction at CANAM