Model for grain boundary sliding and its relevance to optimal structural superplasticity Part 2 - Evidence for cooperative grain/interphase boundary sliding and plane interface formation

A Zn-22 wt-% Al alloy was superplastically deformed in the optimal range to obtain experimental evidence based on scanning electron and transmission electron microscopy for mesoscopic grain/interphase boundary sliding and plane interface formation that facilitates the cooperative boundary sliding process. It was seen that such localised shear surfaces had formed in the entire specimen bulk in an interconnected manner. At boundaries that formed part of a cooperative shear surface the triple junctions had migrated to a near 1800 orientation. Mesoscopic grain/interphase boundary sliding appeared to be accommodated by local boundary migration brought about by diffusion at intercrystalline boundaries and lattice dislocation motion at interphase interfaces in accordance with the requirements of the model presented in Part 1

Dissolution of the second phase particles in the course of the equal channel angular pressing of diluted Cu-Cr-Zr alloy

Changes of properties and the second phase particles' distribution in diluted CuCrZr alloy in the course of equal channel angular pressing (ECAP) and post-deformation annealing are investigated. To decrease the concentration of alloying elements dissolved in the copper matrix, samples of the alloy were thermally aged prior to the ECAP. Temperature of annealing, 450 degrees C, was the same as the one used for the subsequent post-deformation aging, and the time of annealing was long enough to reach a practically equilibrium state. The enthalpy release rate curve of the ECAP-processed sample, unlike the one for the initial state exhibits an exopeak in the temperature range 440..470 degrees C, which is typical for breakdown of the solid solution in alloys of this system. The post-deformation aging causes a significant increase in the tensile strength as compared to the value immediately after the ECAP. This increase can be related only to the dispersion strengthening that is confirmed by the observation of higher density of particles after the aging. These facts unambiguously indicate that the solid solution at the aging temperature is supersaturated, i.e. its concentration increased in the course of the ECAP due to the deformation-induced dissolution of the second phases. This conclusion agrees with the behavior of the electrical conductivity that noticeably decreases upon the ECAP and recovers its initial value after the aging. As the density of structural defects is significantly different in the initial and final states, the observed decrease can be related only to the lattice distortion due to dissolved foreign atoms.Ufa State Petr Technol Univ, 1 Kosmonavtov Str, Ufa 450062, RussiaBASHNIPINEFT, 86-1 Lenina Str, Ufa 450006, RussiaRAS, Inst Met Superplast Problems, 39 Khalturina Str, Ufa 450001, RussiaRAS, Inst Mol & Crystal Phys, 71 Prospect Oktyabrya, Ufa 450000, RussiaRAS, Inst Problems Mech Engn, 85 Belinsky Str, Nizhnii Novgorod 603024, RussiaUniv Fed Sao Paulo, Rua Talim 330, BR-12231280 Sao Jose Dos Campos, SP, BrazilBeijing Aeronaut Mfg Technol Res Inst, POB 863, Beijing 100024, Peoples R ChinaUniv Fed Sao Paulo, Rua Talim 330, BR-12231280 Sao Jose Dos Campos, SP, BrazilWeb of Scienc

The Role of Lactobacillus reuteri DSMZ17648 for Helicobacter pylori eradication therapy

Aim of review. To analyze the options of application of Lactobacillus reuteri DSMZ17648 (Pylopass™) within Helicobacter pylori eradication. Summary. H. pylori eradication therapy is considered as one of the optional spheres for clinical application of probiotic medications. According to available data certain strains of probiotics are effective in decreasing of gastrointestinal adverse effects rates, associated with eradication therapy while the other can potentiate the efficacy of H. pylori eradication itself. L. reuteri strain DSM17648 which was chosen from over 700 wildtype strains of Lactobacillus spp. possess the ability for selective adhesion to H. pylori in vivo in the gastric media. DSM17648 strain of L. reuteri form coaggregates with various H. pylori strains and serotypes both in vivo and in vitro. It was revealed that lyophilizate of this strain (PylopassTM) blocks adhesion of H. pylori to epithelial cells as well. Clinical trials demonstrate the effect of PylopassTMon gastric mucosa colonization by H. pylori according to the 13C urea breath test data and as well the increase in H. pylori eradication rate when the productis added the to triple therapy modes. Conclusion. Potential of PylopassTM combination to various H. pylori eradication therapy modes is a subject offutnet multicenter randomized clinical trials for assessment of optimal combination to antibiotic drugs, treatment duration and adverse effect rates. The value of monotherapy by this metabiotic at chronic H. pyloriassociated gastritis is a subject of further studies

The Role of Lactobacillus reuteri DSMZ17648 for Helicobacter pylori eradication therapy (Review of literature and advisory council resolution, February 28, 2018)

Aim of review. To analyze the options of application of Lactobacillus reuteri DSMZ17648 (Pylopass™) within Helicobacter pylori eradication. Summary. H. pylori eradication therapy is considered as one of the optional spheres for clinical application of probiotic medications. According to available data certain strains of probiotics are effective in decreasing of gastrointestinal adverse effects rates, associated with eradication therapy while the other can potentiate the efficacy of H. pylori eradication itself. L. reuteri strain DSM17648 which was chosen from over 700 wildtype strains of Lactobacillus spp. possess the ability for selective adhesion to H. pylori in vivo in the gastric media. DSM17648 strain of L. reuteri form coaggregates with various H. pylori strains and serotypes both in vivo and in vitro. It was revealed that lyophilizate of this strain (PylopassTM) blocks adhesion of H. pylori to epithelial cells as well. Clinical trials demonstrate the effect of PylopassTMon gastric mucosa colonization by H. pylori according to the 13C urea breath test data and as well the increase in H. pylori eradication rate when the productis added the to triple therapy modes. Conclusion. Potential of PylopassTM combination to various H. pylori eradication therapy modes is a subject offutnet multicenter randomized clinical trials for assessment of optimal combination to antibiotic drugs, treatment duration and adverse effect rates. The value of monotherapy by this metabiotic at chronic H. pyloriassociated gastritis is a subject of further studies