Investigation of the epitaxial growth of AIIIBV-N heterostructures for solar cell applications

The InGaAsN/GaAs heterostructures proposed in 1996 by Kondow et al. have been successfully used in telecom laser constructions on GaAs substrate. Additionally, the InGaAsN with a bandgap of 1 eV are lattice matched to both GaAs and Ge for the nitrogen and indium contents of around 3 % and 9 %, respectively. These features make this semiconductor an ideal candidate for high-efficiency multijunction solar cells (MJSCs) based on the Ge/InGaAsN/GaAs/InGaP structure. The growth technology of the GaAsN alloy-based diluted nitrides is very difficult because of the large miscibility gap between GaAs and GaN. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2097

High antigen levels induce an exhausted phenotype in a chronic infection without impairing T cell expansion and survival.

Chronic infections induce T cells showing impaired cytokine secretion and up-regulated expression of inhibitory receptors such as PD-1. What determines the acquisition of this chronic phenotype and how it impacts T cell function remain vaguely understood. Using newly generated recombinant antigen variant-expressing chronic lymphocytic choriomeningitis virus (LCMV) strains, we uncovered that T cell differentiation and acquisition of a chronic or exhausted phenotype depend critically on the frequency of T cell receptor (TCR) engagement and less significantly on the strength of TCR stimulation. In fact, we noted that low-level antigen exposure promotes the formation of T cells with an acute phenotype in chronic infections. Unexpectedly, we found that T cell populations with an acute or chronic phenotype are maintained equally well in chronic infections and undergo comparable primary and secondary expansion. Thus, our observations contrast with the view that T cells with a typical chronic infection phenotype are severely functionally impaired and rapidly transition into a terminal stage of differentiation. Instead, our data unravel that T cells primarily undergo a form of phenotypic and functional differentiation in the early phase of a chronic LCMV infection without inheriting a net survival or expansion deficit, and we demonstrate that the acquired chronic phenotype transitions into the memory T cell compartment

Synergistic Reversal of Intrahepatic HCV-Specific CD8 T Cell Exhaustion by Combined PD-1/CTLA-4 Blockade

Viral persistence is associated with hierarchical antiviral CD8 T cell exhaustion with increased programmed death-1 (PD-1) expression. In HCV persistence, HCV-specific CD8 T cells from the liver (the site of viral replication) display increased PD-1 expression and a profound functional impairment that is not reversed by PD-1 blockade alone. Here, we report that the inhibitory receptor cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) is preferentially upregulated in PD-1+ T cells from the liver but not blood of chronically HCV-infected patients. PD-1/CTLA-4 co-expression in intrahepatic T cells was associated with a profound HCV-specific effector dysfunction that was synergistically reversed by combined PD-1/CTLA-4 blockade in vitro, but not by blocking PD-1 or CTLA-4 alone. A similar effect was observed in circulating HCV-specific CD8 T cells with increased PD-1/CTLA-4 co-expression during acute hepatitis C. The functional response to combined blockade was directly associated with CTLA-4 expression, lost with CD28-depletion and CD4-independent (including CD4+FoxP3+ Tregs). We conclude that PD-1 and CTLA-4 pathways both contribute to virus-specific T cell exhaustion at the site of viral replication by a redundant mechanism that requires combined PD-1/CTLA-4 blockade to reverse. These findings provide new insights into the mechanisms of virus-specific T cell dysfunction, and suggest that the synergistic effect by combined inhibitory receptor blockade might have a therapeutic application against chronic viral infection in vivo, provided that it does not induce autoimmunity

Liver Is Able to Activate Naïve CD8+ T Cells with Dysfunctional Anti-Viral Activity in the Murine System

The liver possesses distinct tolerogenic properties because of continuous exposure to bacterial constituents and nonpathogenic food antigen. The central immune mediators required for the generation of effective immune responses in the liver environment have not been fully elucidated. In this report, we demonstrate that the liver can indeed support effector CD8+ T cells during adenovirus infection when the T cells are primed in secondary lymphoid tissues. In contrast, when viral antigen is delivered predominantly to the liver via intravenous (IV) adenovirus infection, intrahepatic CD8+ T cells are significantly impaired in their ability to produce inflammatory cytokines and lyse target cells. Additionally, intrahepatic CD8+ T cells generated during IV adenovirus infection express elevated levels of PD-1. Notably, lower doses of adenovirus infection do not rescue the impaired effector function of intrahepatic CD8+ T cell responses. Instead, intrahepatic antigen recognition limits the generation of potent anti-viral responses at both priming and effector stages of the CD8+ T cell response and accounts for the dysfunctional CD8+ T cell response observed during IV adenovirus infection. These results also implicate that manipulation of antigen delivery will facilitate the design of improved vaccination strategies to persistent viral infection

Progressive Activation of CD127+132− Recent Thymic Emigrants into Terminally Differentiated CD127−132+ T-Cells in HIV-1 Infection

AIM: HIV infection is associated with distortion of T-cell homeostasis and the IL-7/IL7R axis. Progressive infection results in loss of CD127+132- and gains in CD127-132+ CD4+ and CD8+ T-cells. We investigated the correlates of loss of CD127 from the T-cell surface to understand mechanisms underlying this homeostatic dysregulation. METHODS: Peripheral and cord blood mononuclear cells (PBMCs; CBMC) from healthy volunteers and PBMC from patients with HIV infection were studied. CD127+132-, CD127+132+ and CD127-132+ T-cells were phenotyped by activation, differentiation, proliferation and survival markers. Cellular HIV-DNA content and signal-joint T-cell receptor excision circles (sjTRECs) were measured. RESULTS: CD127+132- T-cells were enriched for naïve cells while CD127-132+ T-cells were enriched for activated/terminally differentiated T-cells in CD4+ and CD8+ subsets in health and HIV infection. HIV was associated with increased proportions of activated/terminally differentiated CD127-132+ T-cells. In contrast to CD127+132- T-cells, CD127-132+ T-cells were Ki-67+Bcl-2(low) and contained increased levels of HIV-DNA. Naïve CD127+132- T-cells contained a higher proportion of sjTRECs. CONCLUSION: The loss of CD127 from the T-cell surface in HIV infection is driven by activation of CD127+132- recent thymic emigrants into CD127-132+ activated/terminally differentiated cells. This process likely results in an irreversible loss of CD127 and permanent distortion of T-cell homeostasis

Theoretical and technological aspects of intelligent systems: problems of artificial intelligence

Theoretical and technological aspects of intelligent systems: problems of artificial intelligence / Denys Frolov, Wojciech Radziewicz, Volodymyr Saienko and etc. // International journal of computer science and network security. – 2021. – Vol . 21, No 5. – P. 35-38. -DOI :https://doi.org/10.22937/IJCSNS.2021.21.5.6.Досліджено підходи до визначення і розуміння штучного інтелекту. Розглянуто штучний інтелект в антропологічному вимірі. Наголошено на важливості системного підходу як методологічної основи проектування інтелектуальної системи. Визначено структурно-функціональні компоненти інтелектуальної системи; інтелектуальні системи в технологічному аспекті. Розкрито проблеми та перспективи відносин у системі «людина – інтелектуальна система".The article discusses approaches to the definition and understanding of artificial intelligence, research directions in the field of artificial intelligence; artificial intelligence in the anthropological dimension; the importance of the systems approach as a methodological basis for the design of intelligent systems; structural and functional components of intelligent systems; intelligent systems in the technological aspect; problems and prospects of relations in the system "man - intellectual system".Исследованы подходы к определению и пониманию искусственного интеллекта. Рассмотрен искусственный интеллект в антропологическом измерении. Отмечено важность системного подхода как методологической основы проектирования интеллектуальной системы. Определены структурно-функциональные компоненты интеллектуальной системы; интеллектуальные системы в технологическом аспекте. Раскрыты проблемы и перспективы отношений в системе «человек – интеллектуальная система»

Inhibitory Receptors Are Expressed by Trypanosoma cruzi-Specific Effector T Cells and in Hearts of Subjects with Chronic Chagas Disease

We had formerly demonstrated that subjects chronically infected with Trypanosoma cruzi show impaired T cell responses closely linked with a process of T cell exhaustion. Recently, the expression of several inhibitory receptors has been associated with T cell dysfunction and exhaustion. In this study, we have examined the expression of the cytotoxic T lymphocyte antigen 4 (CTLA-4) and the leukocyte immunoglobulin like receptor 1 (LIR-1) by peripheral T. cruzi antigen-responsive IFN-gamma (IFN-γ)-producing and total T cells from chronically T. cruzi-infected subjects with different clinical forms of the disease. CTAL-4 expression was also evaluated in heart tissue sections from subjects with severe myocarditis. The majority of IFN-γ-producing CD4+ T cells responsive to a parasite lysate preparation were found to express CTLA-4 but considerably lower frequencies express LIR-1, irrespective of the clinical status of the donor. Conversely, few IFN-γ-producing T cells responsive to tetanus and diphtheria toxoids expressed CTLA-4 and LIR-1. Polyclonal stimulation with anti-CD3 antibodies induced higher frequencies of CD4+CTAL-4+ T cells in patients with severe heart disease than in asymptomatic subjects. Ligation of CTLA-4 and LIR-1 with their agonistic antibodies, in vitro, reduces IFN-γ production. Conversely, CTLA-4 blockade did not improved IFN-γ production in response to T. cruzi antigens. Subjects with chronic T. cruzi infection had increased numbers of CD4+LIR-1+ among total peripheral blood mononuclear cells, relative to uninfected individuals and these numbers decreased after treatment with benznidazole. CTLA-4 was also expressed by CD3+ T lymphocytes infiltrating heart tissues from chronically infected subjects with severe myocarditis. These findings support the conclusion that persistent infection with T. cruzi leads to the upregulation of inhibitory receptors which could alter parasite specific T cell responses in the chronic phase of Chagas disease

Exploiting iterative compilation in the software layer of embedded systems optimization

Artykuł dotyczy wykorzystania kompilacji iteracyjnej do optymalizacji warstwy programowej systemów wbudowanych. W oparciu o autorskie narzędzie WIZUTIC zminejszono czas przetwarzania algorytmu szyfrowania DES. Danymi wejściowymi kompilatora są programy sekwencyjne, wynikami programy zrównoleglone zgodnie ze standardem OpenMP oraz zoptymalizowane pod względem lokalności danych. Parametrem kompilacji iteracyjnej jest rozmiar bloku dla transformacji pętli programowej-tiling.Embedded systems are special-purpose computers that perform one or few dedicated tasks. They are mostly part of larger electronic devices, such as communication devices, home appliances, office automation, business equipment, automobiles, etc. Complexity of computers has grown tremendously in recent years, because multi-core processors are in widespread use. Parallelized programs must be run on multi-core processors to use the most of its computing power. Exploiting parallel compilers for automatic parallelization of sequential programs accelerates design processes and reduces costs of the designed systems. In this paper there is described a WIZUTIC iterative compiler developed by the Faculty of Computer Science and Information Technology of the West Pomeranian University of Technology. It uses the source code of PLUTO parallel compiler developed at the Ohio State University by Uday Bondhugula. A simulated annealing algorithm is used for finding optimization passes for the given program features. Parameters that are changed in each iteration are tile sizes of loop transformation tiling. Experimental tests are described and the speed-up results obtained for the DES encryption algorithm are given

Iteracyjny kompilator zrównoleglający oraz optymalizujący lokalność danych

Complexity of computers has grown tremendously in recent years, because, among others, multi-processor and multi-core architectures are in widespread use. Parallelized programs should run on multi-core processors to use the most of its computing power. Exploiting parallel compilers for automatic parallelization and data locality optimization of sequential programs reduces costs of software. In this paper there is described the WIZUTIC Compiler Framework developed in the Faculty of Computer Science and Information Technology of the West Pomeranian University of Technology. The application uses the source code of the PLUTO parallel compiler developed in the Ohio State University by Uday Bondhugula. The simulated annealing method and the Bees algorithm are used for finding proper transformations of the source code for given program features. The experimental study results using the Data Encryption Standard (DES) algorithm are described and the speed-ups of encryption and decryption processes are presented.W artykule przedstawiono autorski kompilator zrównoleglający oraz optymalizujący lokalność danych- WIZUTIC oraz jego wykorzystanie do skrócenia czasu przetwarzania algorytmu szyfrowania DES. Do utworzenia kompilatora WIZUTIC transformującego kod źródłowy zapisany w języku C ze źródła do źródła wykorzystano kody źródłowe kompilatora PLUTO autorstwa Uday'a Bondhuguli służącego do optymalizacji lokalności danych z zastosowaniem transformacji tiling oraz zrównoleglenia pętli programowych z wykorzystaniem gruboziarnistej równoległości. W procesie kompilacji wykorzystano technikę kompilacji iteracyjnej oraz dwie metody optymalizacji: symulowane wyżarzanie (SA) oraz algorytm pszczół (BA) służące do określenia odpowiedniego rozmiaru bloku transformacji tiling. Przedstawiono wyniki badań eksperymentalnych dla algorytmu DES pracującego w trybie ECB. Badania przeprowadzona z zastosowaniem maszyny 8-procesorowej Quad Core Intel Xeon Processor Model E7310, kompilatora GCC GNU z wykorzystaniem standardu OpenMP w wersji 3.0 oraz narzędzia do profilowania kodu Intel VTune