89 research outputs found

    Quantumness in decoherent quantum walk using measurement-induced disturbance

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    The classicalization of a decoherent discrete-time quantum walk on a line or an n-cycle can be demonstrated in various ways that do not necessarily provide a geometry-independent description. For example, the position probability distribution becomes increasingly Gaussian, with a concomitant fall in the standard deviation, in the former case, but not in the latter. As another example, each step of the quantum walk on a line may be subjected to an arbitrary phase gate, without affecting the position probability distribution, no matter whether the walk is noiseless or noisy. This symmetry, which is absent in the case of noiseless cyclic walk, but is restored in the presence of sufficient noise, serves as an indicator of classicalization, but only in the cyclic case. Here we show that the degree of quantum correlations between the coin and position degrees of freedom, quantified by a measure based on the disturbance induced by local measurements (Luo, Phys. Rev. A 77, 022301 (2008)), provides a suitable measure of classicalization across both type of walks. Applying this measure to compare the two walks, we find that cyclic quantum walks tend to classicalize faster than quantum walks on a line because of more efficient phase randomization due to the self-interference of the two counter-rotating waves. We model noise as acting on the coin, and given by the squeezed generalized amplitude damping (SGAD) channel, which generalizes the generalized amplitude damping channel.Comment: 8 pages with 8 figures, Published versio

    The research of antibacterial properties of decamethoxin, decasan, horosten

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    The study of Staphylococcus resistance to the antibacterial drugs Decamethoxin, Decasan, Horosten remains an important medical problem. The aim of this study was to investigate the antistaphylococcal properties of Decamethoxin, Decasan, Horosten. It has been proven that qaterinary ammonium antiseptic drugs (Decamethoxin, Decasan, Horosten) have high antistaphylococcal properties. The bactericidal activity of Decamethoxin has been shown to be stable under adverse pH conditions of different microbial loading. Different concentrations of Decamethoxine have been shown to cause the formation of resistant variants of Staphylococcus, which lose the ability to form pigments and enzymes

    Magnetic exchange interaction in a pair of orbitally degenerate ions: Magnetic anisotropy of [Ti2Cl9]−3

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    The theory of the kinetic exchange in a pair of orbitally degenerate ions developed by the authors [J. Phys. Chem. A 102, 200 (1998)] is applied to the case of face-shared bioctahedral dimer (overall D3h-symmetry). The effective kinetic exchange Hamiltonian is found for a 2T2–2T2 system taking into account all relevant transfer pathways and charge-transfer crystal field states. The influence of different transfer integrals involved in the kinetic exchange on the energy pattern and magnetic properties of the system is examined. The role of other related interactions (trigonal crystal field, spin–orbit coupling) is also discussed in detail. Using the pseudoangular momentum representation and the technique of the irreducible tensor operators of R3-group we give a general outlook on the nontrivial symmetry properties of the effective Hamiltonian for the D3h-pair, and on the magnetic anisotropy arising from the orbital interactions specific for the case of orbital degeneracy. The magnetic properties of the binuclear unit [Ti2Cl9]−3 in Cs3Ti2Cl9 are discussed with a special emphasis on the magnetic anisotropy experimentally observed in this system. The existing exchange models for [Ti2Cl9]−3 and the concept of the effective Hamiltonian are discussed in the context of the present [email protected] ; [email protected] ; [email protected] ; [email protected]

    Topological structures of adiabatic phase for multi-level quantum systems

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    The topological properties of adiabatic gauge fields for multi-level (three-level in particular) quantum systems are studied in detail. Similar to the result that the adiabatic gauge field for SU(2) systems (e.g. two-level quantum system or angular momentum systems, etc) have a monopole structure, the curvature two-forms of the adiabatic holonomies for SU(3) three-level and SU(3) eight-level quantum systems are shown to have monopole-like (for all levels) or instanton-like (for the degenerate levels) structures.Comment: 15 pages, no figures. Accepted by J.Phys.

    Field induced single ion magnet based on a quasi octahedral Co ii complex with mixed sulfur oxygen coordination environment

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    Synthesis and characterization of structure and magnetic properties of the quasi octahedral complex pipH2 [Co TDA 2] 2H2O I , pipH22 piperazine dication, TDA2 amp; 8722; thiodiacetic anion are described. X ray diffraction studies reveal the first coordination sphere of the Co II ion, consisting of two chelating tridentate TDA ligands with a mixed sulfur oxygen strongly elongated octahedral coordination environment. SQUID magnetometry, frequency domain Fourier transform FD FT THz EPR spectroscopy, and high level ab initio SA CASSCF NEVPT2 quantum chemical calculations reveal a strong easy plane type magnetic anisotropy D amp; 8776; 54 cm amp; 8722;1 of complex I. The complex shows field induced slow relaxation of magnetization at an applied DC field of 1000 O

    The experience of launching a psychological hotline across 21 countries to support Ukrainians in wartime

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    The current work and further steps of the psychological hotline launched by the National Psychological Association of Ukraine (NPA) are discussed along with a call for action to mental health professionals worldwide. Design/methodology/approach – This paper describes the training and support of the NPA’s hotline staff as well as reflections on the hotline’s work from June 2022 to April 2023. Findings – With broad international support, the NPA’s psychological hotline currently operates in 21 countries providing psychological assistance and referrals to other service providers within Ukraine and abroad. We propose further steps of its work, including international collaboration. Originality/value – Providing citizens of Ukraine with broad public access to evidence-based remote psychological support through NPA’s hotlines is a high priority considering the war’s negative impact on mental health diverse and the limited capacity of the state mental health system. Keywords: crisis interventions, psychological hotline, psychological first aid, Russian invasion, Russian-Ukrainian war, war-related traum

    Integrative Analysis of Epigenetic Modulation in Melanoma Cell Response to Decitabine: Clinical Implications

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    Decitabine, an epigenetic modifier that reactivates genes otherwise suppressed by DNA promoter methylation, is effective for some, but not all cancer patients, especially those with solid tumors. It is commonly recognized that to overcome resistance and improve outcome, treatment should be guided by tumor biology, which includes genotype, epigenotype, and gene expression profile. We therefore took an integrative approach to better understand melanoma cell response to clinically relevant dose of decitabine and identify complementary targets for combined therapy. We employed eight different melanoma cell strains, determined their growth, apoptotic and DNA damage responses to increasing doses of decitabine, and chose a low, clinically relevant drug dose to perform whole-genome differential gene expression, bioinformatic analysis, and protein validation studies. The data ruled out the DNA damage response, demonstrated the involvement of p21Cip1 in a p53-independent manner, identified the TGFβ pathway genes CLU and TGFBI as markers of sensitivity to decitabine and revealed an effect on histone modification as part of decitabine-induced gene expression. Mutation analysis and knockdown by siRNA implicated activated β-catenin/MITF, but not BRAF, NRAS or PTEN mutations as a source for resistance. The importance of protein stability predicted from the results was validated by the synergistic effect of Bortezomib, a proteasome inhibitor, in enhancing the growth arrest of decitabine in otherwise resistant melanoma cells. Our integrative analysis show that improved therapy can be achieved by comprehensive analysis of cancer cells, identified biomarkers for patient's selection and monitoring response, as well as targets for improved combination therapy

    The significance of epigenetic alterations in lung carcinogenesis

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