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Search Results: 1 - 10 of 123079 matches for " T Ko?ter "
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HIV-associated idiopathic non-cirrhotic portal hypertension is an underdiagnosed disorder: results of a large cohort study
T Koter,H Rossing,J Schouten,P Taimr
Journal of the International AIDS Society , 2012, DOI: 10.7448/ias.15.6.18314
Abstract: Purpose of the study Idiopathic non-cirrhotic portal hypertension (INCPH) has been reported increasingly in patients with chronic HIV infection. However, several aspects of this disorder remain to be elucidated. The aim of our study was to evaluate the prevalence and risk factors of HIV associated INCPH. Methods All adult HIV patients attending the outpatient clinic between February and September 2011 underwent sonographical spleen size determination and assessment of portosystemic collaterals. Patients with splenomegaly underwent an extensive ultrasound examination. Gastroscopy was performed when additional signs of portal hypertension or collaterals were observed. All children with HIV infection underwent extensive ultrasound examination. INCPH was diagnosed according to the general definition. Differences between INCPH cases (group 1) and HIV patients treated with didanosine (ddI) without portal hypertension (group 2) were assessed at HIV diagnosis, start of ddI and INCPH diagnosis. Summary of results Four out of 1010 screened adult HIV patients were diagnosed with INCPH (prevalence of 4‰). Hundred of the 1010 screened patients were treated with ddI. All INCPH patients were treated with ddI, representing an INCPH prevalence of 4% in patients exposed to ddI. In The Netherlands, 7000 patients were treated with ddI and only 17 are diagnosed with INCPH, suggesting underdiagnosis in 260 patients. No differences in clinical characteristics predictive for the development of INCPH could be demonstrated between group 1 and group 2 at HIV infection or start of ddI treatment. INCPH patients were treated longer with ddI [86 vs. 51 months, p<0.01] and concomitant treatment with ddI and stavudine [21 vs. 4 months, p<0.01]. Corrected for age and duration of follow-up of HIV, active protein c [0.64 vs. 1.13, p<0.01] and active protein s [0.67 vs. 1.01, p<0.01] levels were lower in the INCPH group. None of the 38 children with HIV infection were diagnosed with INCPH. None of these children were ever treated with ddI. Conclusions In our study HIV-associated INCPH only occurred in patients exposed to ddI. Awareness for this disorder is warranted considering the suggested underdiagnosis based on these study results. Risk factors are long term treatment with ddI and concomitant treatment with stavudine and screening for signs of portal hypertension in this subgroup may be recommended. A possible pathophysiological role for thrombophilia remains to be elucidated.
Wear Beahaviour of Nitrided Microstructures of AlSl H13 Dies for Hot Extrusion of Aluminium
Kugler, G.,Turk, R.,Ve?ko-Pirtov?ek, T.,Ter?elj, M.
Metalurgija , 2006,
Abstract: Nitriding of bearing surfaces on dies (tools, AISI H13) for hot extrusion of aluminium is technologically a very sensitive process with regard to achieving a constant quality of the nitrided layers. This study was based on the analysis of microstructure on dies with intentionally prepared deep and narrow gaps which were nitrided by various manufacturers of equipment for gas and ionic nitriding. The manufacturers chose their own nitriding parameters in order to achieve an optimal wear resistant microstructure. The microstructures obtained showed differences with regard to the presence or absence of a compound layer (white layer), its thickness and its e/g' phase ratio (XRD), nitriding depth and microhardness profile. The measured nitriding depths and the maximum microhardness values on nitrided surface layers were quite similar on dies of the same manufacturer, while for different manufacturers these values differed. Differences with regards to compound layer characteristics were also found on the same die. The die samples with these various nitrided microstructures were then laboratory tested for wear resistance using equipment that provides simulation of the tribological conditions during hot extrusion of aluminium. The wear testing results show differences in behaviour of the nitrided samples. The differences in the actual structures, microstructures, hardness, etc. explain the high level of scattering in die life in actual industrial applications.
Utilisation of 2nd generation web technologies in master level vocational teacher training
ter Tóth
Acta Didactica Napocensia , 2009,
Abstract: The Masters level Opportunities and Technological Innovation in Vocational Teacher Education project (project site: http://motivate.tmpk.bmf.hu/) aims to develop the use and management of virtual learning environments in the area of vocational teacher training, drawing on a well established international partnership of institutions providing both technical and educational expertise. This paper gives an overall picture of the first results and products of the collaboration. We touch upon the goals, the assessments and the learning process of using “Multimedia and e-Learning: e-learning methods and tools” module in details. The main cooperative and collaborative devices are presented in virtual learning environment. The communication during collaborative learning, the structured debate on forum and the benefits of collaborative learning in VLE are interpreted at the end of this paper.
Schreier decomposition of loops
ter T. Nagy
Mathematics , 2015,
Abstract: The aims of this paper are to find algebraic characterizations of Schreier loops and explore the limits of the non-associative generalization of the theory of Schreier extensions. A loop can have Schreier decomposition with respect to a normal subgroup if and only if the subgroup is the middle and right nuclear. In this case the conjugation by elements of the loop induces inner automorphisms on the normal subgroup if and only if the subgroup commutes with a suitable left transversal through the identity. Schreier loops which are Schreier extensions of the same loop by the same normal subgroups are characterized.
Mass of the Lightest Higgs Boson in the Minimal Supersymmetric Standard Model with an Additional Singlet
W. T. A. ter Veldhuis
Physics , 1992,
Abstract: An upperbound on the mass of the lightest neutral scalar Higgs boson is calculated in an extended version of the minimal supersymmetric standard model that contains an additional Higgs singlet. We integrate the renormalization group equations of the model, and impose low energy boundary conditions consistent with present experimental results, and ultra-violet conditions following from triviality. Radiative corrections induced by a large top quark Yukawa coupling are included in our analysis, and we find the allowed values for the mass of the Higgs boson as a function of the mass of the top quark. Typically, for a top quark mass $m_t=150\ GeV$, the upper bound on the Higgs boson mass is about $25 \ GeV$ higher than in the minimal model.
Introduction to the Theory of Goyaks (Operator Manifold Approach to Geometry and Particle Physics)
G. T. Ter-Kazarian
Physics , 1995,
Abstract: The question that guides our discussion is "how did the geometry and particles come into being?" To explore this query we suggest the theory of goyaks, which reveals the primordial deeper structures underlying fundamantal concepts of contemporary physics. It address itself to the question of the prime-cause of origin of geometry and basic concepts of particle physics such as the fundamental fields of quarks and leptons with the spins and various quantum numbers, internal symmetries and so on; also basic principles of Relativity, Quantum, Gauge and Color Confinement, which are, as it was proven, all derivative and come into being simultaneously. The substance out of which the geometry and particles are made is a set of new physical structures-the goyaks involved into reciprocal linkage establishing processes. We elaborated a new mathematical framework, which is a still wider generalization of the familiar methods of secondary quantization with appropriate expansion over the geometric objects. One interesting offshoot of it directly leads to the formalism of operator manifold, which framed our discussion throughout this paper. It yields the quantization of geometry, which differs in principle from all earlier studies. Many of the important anticipated properties, basic concepts and principles of particle physics are appeared quite naturally in the framework of suggested theory. It predicts a class of possible models of internal symmetries, which utilize the whole idea of gauge symmetry and reproduce the known phenomenology of electromagnetic, weak and strong interactions. Here we focused our attention mainly on developing the mathematical foundations for our novel viewpoint. We believe that the more realistic final theory of particles and interactions can be found within the
BPS Saturated Domain Walls along a Compact Dimension
R. Hofmann,T. ter Veldhuis
Physics , 2000, DOI: 10.1103/PhysRevD.63.025017
Abstract: Generalized Wess-Zumino models which admit topologically non-trivial BPS saturated configurations along one compact, spatial dimension are investigated in various dimensions of space-time. We show that, in a representative model and for sufficiently large circumference, there are BPS configurations along the compact dimension containing an arbitrary number of equidistant, well-separated domain walls. We analyze the spectrum of the bosonic and fermionic light and massless modes that are localized on these walls. The masses of the light modes are exponentially suppressed by the ratio of the distance between the walls and their width. States that are initially localized on one wall oscillate in time between all the walls. In (2+1) dimensions the ``chirality'' of localized, massless fermions is determined. In the (1+1)-dimensional case we show how the mass of certain classically BPS saturated solitons is lifted above the BPS bound by instanton tunneling.
The exotic eta'pi- Wave in 190 GeV pi-p --> pi-eta'p at COMPASS
T. Schlüter,for the COMPASS Collaboration
Physics , 2011,
Abstract: A sample of 35,000 events of the type pi-p --> eta'pi-p_slow (eta' --> eta pi-pi+, eta --> gamma gamma) with -t>0.1 GeV^2/c^2 was selected from COMPASS 2008 data for a partial-wave analysis. We study the broad P_+ structure known from previous experiments at lower energies, in particular its phase motion relative to the D_+-wave near the a_2(1320) mass and relative to a broad D_+-wave structure at higher mass. We also find the a_4(2040). We compare kinematic plots for the eta'pi^- and eta pi- final states.
Gravitation Gauge Group
G. T. Ter-Kazarian
Physics , 1997,
Abstract: Suggested theory involves a drastic revision of a role of local internal symmetries in physical concept of curved geometry. Under the reflection of fields and their dynamics from Minkowski to Riemannian space a standard gauge principle of local internal symmetries is generalized. The gravitation gauge group is proposed, which is generated by hidden local internal symmetries. The developed mechanism enables one to infer Einstein's equation of gravitation, but only with strong difference from Einstein's theory at the vital point of well-defined energy-momentum tensor of gravitational field and conservation laws. The gravitational interaction as well as general distortion of manifold G(2.2.3) with hidden group U(1) was considered.
Operator Manifold Approach to Geometry and Particle Physics
G. T. Ter-Kazarian
Physics , 1997, DOI: 10.1007/BF00645224
Abstract: The question that guides our discussion is how did the geometry and particles come into being. The present theory reveals primordial deeper structures underlying fundamental concepts of contemporary physics. We begin with a drastic revision of a role of local internal symmetries in physical concept of curved geometry. A standard gauge principle of local internal symmetries is generalized. The gravitation gauge group is proposed, which is generated by hidden local internal symmetries. Last two parts address to the question of physical origin of geometry and basic concepts of particle physics such as the fields of quarks with the spins and various quantum numbers, internal symmetries and so forth; also four basic principles of Relativity, Quantum, Gauge and Color Confinement, which are, as it was proven, all derivative and come into being simultaneously. The most promising aspect of our approach so far is the fact that many of the important anticipated properties, basic concepts and principles of particle physics are appeared quite naturally in the framework of suggested theory.
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