Toy model of the Nucleon - Nucleon potential

We start from a system of six interacting constituent quarks and examine how the picture of two nucleons can change when substructure of the nucleons are taken into account.Comment: 9 pages, 6 figures, proceedings of the international conference "Nuclear Structure and Related Topics

Correlations in self-bound systems of identical fermions

A method for the calculation of translationally invariant wave functions for systems of identical fermions with arbitrary potential of pair interaction is developed. It is based on the well-known result that the essential dynamic part of the Hamiltonian for the system of identical particles is the Reduced Hamiltonian operator describing relative movement of two particles inside the system. The eigenfunctions of this operator take into account all correlations caused by interaction. These eigenfunctions are basic for the construction of the components (i.e. the functions with a lower degree of antisymmetry) of the system wave functions. The main problem of this approach appears to be antisymmetrization of the components. The developed universal algorithm for antisymmetrization gives a possibility to perform this operation in a simple way and keep numerical approximations under control.Comment: 20 pages REVTeX, submitted to Lithuanian J. Phy

Evidence for diagnosis of early chronic pancreatitis after three episodes of acute pancreatitis : a cross-sectional multicentre international study with experimental animal model

Chronic pancreatitis (CP) is an end-stage disease with no specific therapy; therefore, an early diagnosis is of crucial importance. In this study, data from 1315 and 318 patients were analysed from acute pancreatitis (AP) and CP registries, respectively. The population from the AP registry was divided into AP (n=983), recurrent AP (RAP, n=270) and CP (n=62) groups. The prevalence of CP in combination with AP, RAP2, RAP3, RAP4 and RAP5+was 0%, 1%, 16%, 50% and 47%, respectively, suggesting that three or more episodes of AP is a strong risk factor for CP. Laboratory, imaging and clinical biomarkers highlighted that patients with RAP3+do not show a significant difference between RAPs and CP. Data from CP registries showed 98% of patients had at least one AP and the average number of episodes was four. We mimicked the human RAPs in a mouse model and found that three or more episodes of AP cause early chronic-like morphological changes in the pancreas. We concluded that three or more attacks of AP with no morphological changes to the pancreas could be considered as early CP (ECP).The new diagnostic criteria for ECP allow the majority of CP patients to be diagnosed earlier. They can be used in hospitals with no additional costs in healthcare.Peer reviewe

Ultrafast relaxation of photoexcited carriers in semiconductor quantum wires: A Monte Carlo approach

A detailed analysis of the cooling and thermalization process for photogenerated carriers in semiconductor quantum wires is presented. The energy relaxation of the nonequilibrium carrier distribution is investigated for the ‘‘realistic'' case of a rectangular multisubband quantum-wire structure. By means of a direct ensemble Monte Carlo simulation of both the carrier and the phonon dynamics, all the nonlinear phenomena relevant for the relaxation process, such as carrier-carrier interaction, hot-phonon effects, and degeneracy, are investigated. The results of these simulated experiments show a significant reduction of the carrier-relaxation process compared to the bulk case, which is mainly due to the reduced efficiency of carrier-carrier scattering; on the contrary, the role of hot-phonon effects and degeneracy seems to be not so different from that played in bulk semiconductors

Junction profiles of sub keV ion implantation for deep sub-quarter micron devices

Junction profiles of sub keV ion implantation for deep sub-quarter micron device

Photoemission study of LT-GaAs

The electronic structure of GaAs (100) grown by low-temperature molecular beam epitaxy was investigated by means of photoemission spectroscopy. Slight differences are found in the valence band spectra of GaAs layers grown at different As-2/Ga flux ratios. Analysis of As 3d core level spectra does not indicate qualitative differences in respect to high temperature grown GaAs (100) layers. The Ga 3d core level spectra include a new component in comparison to the spectra of high temperature grown GaAs. The origin of this component is attributed to high density of As antisites in low-temperature grown GaAs. (C) 2004 Elsevier B.V. All rights reserved