Effect of Helicobacter Pylori Eradication on Extent of Duodenal Gastric Metaplasia and Grade of Gastritis

The extent of the regression of duodenal gastric metaplasia (DGM) after the eradication of Helicobacter pylori infection is controversial. Therefore, we decided to assess the degree of DGM before, sex weeks and one year after H. pylori eradication. 105 consecutive Helicobacter pylori positive patients with endoscopically proven duodenal ulcer, with DGM and Helicobacter pylori infection were recruited for this study. The diagnosis of Helicobacter pylori infection was based on CLO-test and histology, and DGM was assessed on four bulb biopsies taken before, sex weeks and one year after Helicobacter pylori eradication. Histological assessment of Helicobacter pylori associated gastritis was performed according to the Sydney classification. Follow up study on 98 patients before, six weeks and one year after the eradication of Helicobacter pylori showed that the mean extent of DGM did not change significantly after eradication and did not differ when compared with 14 patients with persisting infection. Our results show that the inflammatory process related to Helicobacter pylori does not play the main role in the development of DGM

Relationship of Gastric Metaplasia and Age, Sex, Smoking and Helicobacter pylori Infection in Patients with Duodenal Ulcer and Duodenitis

Gastric metaplasia is one of the factors in duodenal ulcer appearance. The aim of this study was to investigate the frequency of gastric metaplasia and its connection with age, sex, cigarette smoking and H. pylori infection. In the study 216 patients were included. There were 98 patients with duodenal ulcer, 60 with duodenitis, and 58 healthy control subjects. There was no statistically significant difference in gastric metaplasia frequency according to age and sex. Gastric metaplasia was statistically more significant in patients with duodenal ulcer (p < 0.01). In all the subjects cigarette smoking did not significantly influence gastric metaplasia. In smokers with duodenal ulcer, and those who besides duodenal ulcer and smoking had H. pylori infection gastric metaplasia was more frequent (p < 0.01). However, in patients with duodenal ulcer, there was no statistically significant difference of gastric metaplasia related to H. pylori presence. It may be suggested that H. pylori infection is not of indispensable significance for gastric metaplasia appearance

Breathing solitons in nematic liquid crystals

Dynamical and steady-state behavior of beams propagating in nematic liquid crystals (NLCs) is analyzed. A well-known model for the beam propagation and the director reorientation angle in a NLC cell is treated numerically in space and time. The formation of steady-state soliton breathers in a threshold region of beam intensities is displayed. Below the region the beams diffract, above the region spatiotemporal instabilities develop, as the input intensity and the material parameters are varied. Curiously, the only kind of solitons we could demonstrate in our numerical studies was the breathers. Despite repeated efforts, we could not find the solitons with a steady profile propagating in the NLC model at hand

Self-trapped bidirectional waveguides in a saturable photorefractive medium

We introduce a time-dependent model for the generation of joint solitary waveguides by counter-propagating light beams in a photorefractive crystal. Depending on initial conditions, beams form stable steady-state structures or display periodic and irregular temporal dynamics. The steady-state solutions are non-uniform in the direction of propagation and represent a general class of self-trapped waveguides, including counterpropagating spatial vector solitons as a particular case.Comment: 4 pages, 5 figure

Counterpropagating Matter Waves in Optical Lattices

An investigation of Bose-Einstein condensate in two-dimensional optical lattice potentials, formed by laser beams, is carried out. We are interested in the dynamics of Bose-Einstein condensate in a square optical lattice, where the periodic potential can lead to the stabilization of an otherwise unstable Bose-Einstein condensate. The behavior of Bose-Einstein condensate in optical lattices is described by the nonlinear Gross-Pitaevskii equation, which we treat numerically. By applying the Petviashvili iteration method, we demonstrate the existence of solitonic solutions in the case of counterpropagating matter waves, and analyze their stability

Magnetoelectric properties and low-energy excitations of multiferroic FeCr2 S4

© 2020 American Physical Society. We report on the low-frequency optical excitations in the multiferroic ground state of polycrystalline FeCr2S4 in the frequency range 0.3-3 THz and their changes upon applying external magnetic fields up to 7 T. In the ground state below the orbital-ordering temperature TOO=9 K we observe the appearance of several new modes. By applying the external magnetic field parallel and perpendicular to the propagation direction of the THz radiation, we can identify the strongest absorptions to be of predominantly electric-dipole origin. We discuss these modes as the low-energy electronic excitations of the Fe2+ ions (3d6, S=2) in an tetrahedral S2- environment. The eigenfrequencies and relative intensities of these absorption lines are satisfactorily reproduced by our calculation assuming an effective exchange field of 12.8cm-1 at the Fe2+-ions sites. The direction of the exchange field is found to be slightly tilted out of the ab plane. With our approach we can also describe previously reported results from Mössbauer studies and the order of magnitude of the electric polarization induced by orbital and noncollinear spin ordering

Socio-Demographic Characteristics of Postmenopausal Estrogen Users

The purpose of the paper was to describe general health, socio-economic and demographic characteristics of postmenopausal estrogen users in comparison to nonusers. During years 1994–2000, 717 postmenopausal estrogen users and 235 postmenopausal nonusers were gynecological examined, interweaved with a questionnaire including information on their health, socio-economic and demographic status and compared. Women who had prescription on a hormone replacement minimally 6 months before interview were deemed to be current users, but the controls had not use hormone replacement ever. Hormone replacement users were statistically significant more often smokers, they had better physical activity and better general health than nonusers. Women with surgical menopause were more often hormone replacement users than nonusers. Women with better socio-economic status, higher education and urban population were more likely to use hormone replacement. Single, divorced and widowed women were more likely, but married women were less likely to use hormone replacement. However, more healthy profiles among hormone replacement users may inflate the apparent benefit of treatment. The gynaecologists play a major role in hormone replacement therapy decision- making because of a substantial public health impact

Dancing Light: Counterpropagating Beams in Photorefractive Crystals

A review of work on the dynamical behavior of counterpropagating incoherent laser beams in photorefractive crystals is presented. Numerical study of counterpropagating beams of different type is carried out, in both space and time, using an appropriate theoretical model. The development of patterns in broad hyper-Gaussian counterpropagating beams in saturable Kerr-like media is investigated, by varying the width of beams. Rotational properties of counterpropagating mutually incoherent self-trapped vortex beams in optically induced fixed photonic lattices are also investigated numerically. One of the fundamental quantum mechanical phenomena is observed for the counterpropagating beams in photonic lattices, the tunneling of light from the first to the higher-order bands of the lattice band gap spectrum. The transfer of angular momentum from vortex beams to optically induced photonic lattices is also demonstrated. For the interacting beams it is found that the sum of angular momenta of counterpropagating components is not a conserved quantity, but the difference is. In the fixed lattices there is always a considerable loss of angular momentum

Dancing Light: Counterpropagating Beams in Photorefractive Crystals

A review of work on the dynamical behavior of counterpropagating incoherent laser beams in photorefractive crystals is presented. Numerical study of counterpropagating beams of different type is carried out, in both space and time, using an appropriate theoretical model. The development of patterns in broad hyper-Gaussian counterpropagating beams in saturable Kerr-like media is investigated, by varying the width of beams. Rotational properties of counterpropagating mutually incoherent self-trapped vortex beams in optically induced fixed photonic lattices are also investigated numerically. One of the fundamental quantum mechanical phenomena is observed for the counterpropagating beams in photonic lattices, the tunneling of light from the first to the higher-order bands of the lattice band gap spectrum. The transfer of angular momentum from vortex beams to optically induced photonic lattices is also demonstrated. For the interacting beams it is found that the sum of angular momenta of counterpropagating components is not a conserved quantity, but the difference is. In the fixed lattices there is always a considerable loss of angular momentum