1,605 research outputs found

    Organizational and Technical Support for Remote Work of Employees in the Conditions of Industrial Production Diversification

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    The article is devoted to the analysis of a very relevant topic at present: the process of transferring employees (employees) of an organization (company, firm, Department etc.) to a remote (remote) mode of operation, and thus creating a so-called virtual office. For the most part, the translation algorithm and organizational and technical support of the virtual office creation process are typical (universal). However, there is certain specificity in the organization and implementation of this process in relation to engineering organizations and high-tech industrial enterprises, due to the peculiarities of their activities in modern conditions of diversification of industrial production at the enterprises of the defense-industrial complex

    Аминирование эпоксидов как удобный способ синтеза липофильных полиаминов

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    Objectives. Alkylated derivatives of polyamines are able to block the growth of cancer cells due to their embedding into the polyamine biosynthesis mechanisms. The study aimed to synthesize lipophilic derivatives of norspermine or triethylenetetramine based on the formation of a C–N bond during the opening of the oxirane ring by primary amines to expand a number of synthetic polyamine derivatives with antitumor activity.Methods. The starting compounds—glycidol alcoholate or epichlorohydrin—were reacted with hexadecyl bromide or sodium hexadecanolate to give glycidyl hexadecyl ether. The key reaction for the preparation of lipophilic polyamines was the amination of lipophilic epoxides with polyamines in the presence of calcium triflate. Acylation of the hydroxyl group formed during the opening of oxirane was carried out by the action of 4-dimethylaminopyridine and acetic anhydride. The introduction of an alkyl substituent in the presence of sodium hydride led to intramolecular cyclization with the formation of an oxoazolidine cycle. The regioselectivity of the oxirane ring opening reaction at the C(1) position of glycerol was confirmed by two-dimensional heteronuclear {1H,13C} nuclear magnetic resonance spectroscopy.Results. An approach to the synthesis of novel lipophilic polyamines based on the catalytic amination of epoxides was developed and tested. Compounds based on norspermine and triethylentetramine containing a hydroxyl group at the C(2) atom of the glycerin backbone were obtained. For norspermine derivatives, the hydroxyl group was modified: an acetyl substituent was introduced and a derivative containing an oxoazolidine cycle was obtained.Conclusions. The obtained lipophilic polyamines can be considered as potential antitumor agents, for which cytotoxicity against various cancer cells will be evaluated in the future.Цели. Алкилированные производные полиаминов способны блокировать рост раковых клеток за счет встраивания в механизмы биосинтеза полиаминов. Цель исследования – синтезировать новые липофильные производные норспермина или триэтилентетрамина, основанные на формировании связи C–N при раскрытии оксиранового кольца первичными аминами, для расширения ряда синтетических производных полиаминов, обладающих противоопухолевой активностью.Методы. Исходные соединения – алкоголят глицидола или эпихлоргидрин – вводили во взаимодействие с гексадецилбромидом или гексадецилатом натрия, получая гексадецилглицидиловый эфир. Ключевой реакцией получения липофильных полиаминов являлось аминирование липофильных эпоксидов полиаминами в присутствии трифлата кальция. Ацилирование гидроксильной группы, образовавшейся в ходе раскрытия оксирана, проводили действием 4-диметиламинопиридина и уксусного ангидрида. Введение алкилильного заместителя в присутствии гидрида натрия приводило к внутримолекулярной циклизации с образованием оксоазолидинового цикла. Региоселективность реакции раскрытия оксиранового цикла по C(1) положению глицерина подтверждали двумерной гетероядерной {1H,13C} спектроскопией ядерного магнитного резонанса.Результаты. Разработан и апробирован подход к синтезу новых липофильных полиаминов, основанный на каталитическом аминирование эпоксидов. Получены соединения на основе норспермина и триэтилентетрамина, содержащие гидроксильную группу при С(2) атоме глицеринового остова. Для производных норспермина проведена модификация гидроксильной группы: введен ацетильный заместитель и получено производное, содержащее оксоазолидиновый цикл.Выводы. Полученные липофильные полиамины можно рассматривать как потенциальные противоопухолевые агенты, для которых в дальнейшем будет проведена оценка цитотоксичности против различных раковых клеток

    Measurement of the CKM angle γ from a combination of B±→Dh± analyses

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    A combination of three LHCb measurements of the CKM angle γ is presented. The decays B±→D K± and B±→Dπ± are used, where D denotes an admixture of D0 and D0 mesons, decaying into K+K−, π+π−, K±π∓, K±π∓π±π∓, K0Sπ+π−, or K0S K+K− final states. All measurements use a dataset corresponding to 1.0 fb−1 of integrated luminosity. Combining results from B±→D K± decays alone a best-fit value of γ =72.0◦ is found, and confidence intervals are set γ ∈ [56.4,86.7]◦ at 68% CL, γ ∈ [42.6,99.6]◦ at 95% CL. The best-fit value of γ found from a combination of results from B±→Dπ± decays alone, is γ =18.9◦, and the confidence intervals γ ∈ [7.4,99.2]◦ ∪ [167.9,176.4]◦ at 68% CL are set, without constraint at 95% CL. The combination of results from B± → D K± and B± → Dπ± decays gives a best-fit value of γ =72.6◦ and the confidence intervals γ ∈ [55.4,82.3]◦ at 68% CL, γ ∈ [40.2,92.7]◦ at 95% CL are set. All values are expressed modulo 180◦, and are obtained taking into account the effect of D0–D0 mixing

    Measurement of the ratio of branching fractions BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma)

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    The ratio of branching fractions of the radiative B decays B0 -> K*0 gamma and Bs0 -> phi gamma has been measured using 0.37 fb-1 of pp collisions at a centre of mass energy of sqrt(s) = 7 TeV, collected by the LHCb experiment. The value obtained is BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma) = 1.12 +/- 0.08 ^{+0.06}_{-0.04} ^{+0.09}_{-0.08}, where the first uncertainty is statistical, the second systematic and the third is associated to the ratio of fragmentation fractions fs/fd. Using the world average for BR(B0 -> K*0 gamma) = (4.33 +/- 0.15) x 10^{-5}, the branching fraction BR(Bs0 -> phi gamma) is measured to be (3.9 +/- 0.5) x 10^{-5}, which is the most precise measurement to date.Comment: 15 pages, 1 figure, 2 table

    Differential branching fraction and angular analysis of the decay B0→K∗0μ+μ−

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    The angular distribution and differential branching fraction of the decay B 0→ K ∗0 μ + μ − are studied using a data sample, collected by the LHCb experiment in pp collisions at s√=7 TeV, corresponding to an integrated luminosity of 1.0 fb−1. Several angular observables are measured in bins of the dimuon invariant mass squared, q 2. A first measurement of the zero-crossing point of the forward-backward asymmetry of the dimuon system is also presented. The zero-crossing point is measured to be q20=4.9±0.9GeV2/c4 , where the uncertainty is the sum of statistical and systematic uncertainties. The results are consistent with the Standard Model predictions

    Measurement of the relative rate of prompt χc0, χc1 and χc2 production at √s=7TeV

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    Prompt production of charmonium χc0, χc1 and χc2 mesons is studied using proton-proton collisions at the LHC at a centre-of-mass energy of √s=7TeV. The χc mesons are identified through their decay to J/ψγ, with J/ψ→μ+mu− using photons that converted in the detector. A data sample, corresponding to an integrated luminosity of 1.0fb−1 collected by the LHCb detector, is used to measure the relative prompt production rate of χc1 and χc2 in the rapidity range 2.0<y<4.5 as a function of the J/ψ transverse momentum from 3 to 20 GeV/c. First evidence for χc0 meson production at a hadron collider is also presented

    Search for the decay Bs0→D*∓π±

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    A search for the decay Bs0→D*∓π± is presented using a data sample corresponding to an integrated luminosity of 1.0  fb-1 of pp collisions collected by LHCb. This decay is expected to be mediated by a W-exchange diagram, with little contribution from rescattering processes, and therefore a measurement of the branching fraction will help us to understand the mechanism behind related decays such as Bs0→π+π- and Bs0→DD- . Systematic uncertainties are minimized by using B0→D*∓π± as a normalization channel. We find no evidence for a signal, and set an upper limit on the branching fraction of B(Bs0→D*∓π±)<6.1(7.8)×10-6 at 90% (95%) confidence level

    Measurements of the branching fractions of B+→ppK+ decays

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    The branching fractions of the decay B+ → pp̄K+ for different intermediate states are measured using data, corresponding to an integrated luminosity of 1.0 fb-1, collected by the LHCb experiment. The total branching fraction, its charmless component Mpp̄ < 2.85 GeV/c2 and the branching fractions via the resonant cc̄ states η c(1S) and ψ(2S) relative to the decay via a J/ψ intermediate state are [Equation not available: see fulltext.] Upper limits on the B + branching fractions into the η c(2S) meson and into the charmonium-like states X(3872) and X(3915) are also obtained

    Study of DJ meson decays to D+π−, D0π+ and D∗+π− final states in pp collisions

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    A study of D+π−, D0π+ and D∗+π− final states is performed using pp collision data, corresponding to an integrated luminosity of 1.0 fb−1, collected at a centre-of-mass energy of 7 TeV with the LHCb detector. The D1(2420)0 resonance is observed in the D∗+π− final state and the D∗2(2460) resonance is observed in the D+π−, D0π+ and D∗+π− final states. For both resonances, their properties and spin-parity assignments are obtained. In addition, two natural parity and two unnatural parity resonances are observed in the mass region between 2500 and 2800 MeV. Further structures in the region around 3000 MeV are observed in all the D∗+π−, D+π− and D0π+ final states

    Observation of Bc+→J/ψDs+ and Bc+→J/ψDs*+ decays

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    The decays Bc+→J/ψDs+ and Bc+→J/ψDs*+ are observed for the first time using a dataset, corresponding to an integrated luminosity of 3  fb-1, collected by the LHCb experiment in proton-proton collisions at center-of-mass energies of √s=7 and 8 TeV. The statistical significance for both signals is in excess of 9 standard deviations. The following ratios of branching fractions are measured to be B(Bc+→J/ψDs+)/B(Bc+→J/ψπ+)=2.90±0.57±0.24, B(Bc+→J/ψDs*+)/B(Bc+→J/ψDs+)=2.37±0.56±0.10, where the first uncertainties are statistical and the second systematic. The mass of the Bc+ meson is measured to be mBc+=6276.28±1.44(stat)±0.36(syst)  MeV/c2, using the Bc+→J/ψDs+ decay mode
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