137 research outputs found

    The aderoid factors in the development of the Kaliningrad region

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    This article analyses the factors of the development of the Kaliningrad region. Expanding G. M. Fedorov’s complex analysis, the author identifies a new independent class of factors (aderoid factors) that have a significant impact on the regional development and are subject to an independent study. The analysis of aderoid factors makes it possible to create a management system that would change the sign of the factor from minus to plus or vice versa and block the model regression process

    MgB2 thick film with TC = 40.2 K deposited on sapphire substrate

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    We have successfully deposited thick MgB2 film on the (0001) crystalline surface of sapphire by the method of hybrid physical-chemical vapor deposition (HPCVD). The film thickness is about 1.3 micron. It has a dense and interlaced structure. The film surface, shown by SEM, is stacked with MgB2 microcrystals. Transport measurements by the 4-probe technique have demonstrated that its critical temperature is about 40.2 K, with a sharp transition width of 0.15 K. The residual resistivity ratio (RRR) is about 11. By extrapolation, HC2(0) is determined as 13.7 T from the magneto-transport measurement. Also by hysteresis measurement and applying the Bean model, the critical current density is estimated as 5*1010 A/m2 in zero magnetic field. The present work has demonstrated that HPCVD is an effective technique to fabricate the MgB2 thick film with decent superconducting properties. Hence, it is important for the future superconducting application, in particular, as a crucial preliminary stage to fabricate superconducting tape.Comment: 7 pages with 4 figures included, Phys. Stat. Sol. (a) In pres

    Genetic toolbox for controlled expression of functional proteins in Geobacillus spp.

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    Species of genus Geobacillus are thermophilic bacteria and play an ever increasing role as hosts for biotechnological applications both in academia and industry. Here we screened a number of Geobacillus strains to determine which industrially relevant carbon sources they can utilize. One of the strains, G. thermoglucosidasius C56-YS93, was then chosen to develop a toolbox for controlled gene expression over a wide range of levels. It includes a library of semi-synthetic constitutive promoters (76-fold difference in expression levels) and an inducible promoter from the xylA gene. A library of synthetic in silico designed ribosome binding sites was also created for further tuning of translation. The PxylA was further used to successfully express native and heterologous xylanases in G. thermoglucosidasius. This toolbox enables fine-tuning of gene expression in Geobacillus species for metabolic engineering approaches in production of biochemicals and heterologous proteins

    Just Keep Tweeting: Emergency Responder\u27s Social Media Use Before and During Emergencies

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    This study investigates how emergency response organizations use social media during emergency preparedness and response. Using qualitative (interviews and documents) and quantitative (Facebook posts) data, the study identifies several uses of social media in emergency preparedness and emergency management, as well as the organizational context that affects this use. Findings indicate that social media support various purposes of use, including information dissemination, obtaining input from the public and other organizations, and participation by other emergency response organizations. Branding of the organization during the emergency preparedness phase was found to be an important aspect of information dissemination, and helps social media to be useful tool to connect with the public and other organizations during the emergency response phase. Nevertheless, social media use in the emergency response domain still has to overcome leadership and staff adoption barriers

    Critical Current Density and Resistivity of MgB2 Films

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    The high resistivity of many bulk and film samples of MgB2 is most readily explained by the suggestion that only a fraction of the cross-sectional area of the samples is effectively carrying current. Hence the supercurrent (Jc) in such samples will be limited by the same area factor, arising for example from porosity or from insulating oxides present at the grain boundaries. We suggest that a correlation should exist, Jc ~ 1/{Rho(300K) - Rho(50K)}, where Rho(300K) - Rho(50K) is the change in the apparent resistivity from 300 K to 50 K. We report measurements of Rho(T) and Jc for a number of films made by hybrid physical-chemical vapor deposition which demonstrate this correlation, although the "reduced effective area" argument alone is not sufficient. We suggest that this argument can also apply to many polycrystalline bulk and wire samples of MgB2.Comment: 11 pages, 3 figure

    Thickness dependence of the properties of epitaxial MgB2 thin films grown by hybrid physical-chemical vapor deposition

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    We have studied the effect of deposition rate and layer thickness on the properties of epitaxial MgB2 thin films grown by hybrid physical-chemical vapor deposition on 4H-SiC substrates. The MgB2 film deposition rate depends linearly on the concentration of B2H6 in the inlet gas mixture. We found that the superconducting and normal-state properties of the MgB2 films are determined by the film thickness, not by the deposition rate. When the film thickness was increased, the transition temperature, Tc, increased and the residual resistivity, rho0, decreased. Above about 300 nm, a Tc of 41.8 K, a rho0 of 0.28 mikroOhm.cm, and a residual resistance ratio RRR of over 30 were obtained. These values represent the best MgB2 properties reported thus far.Comment: 10 pages, 4 figure

    СЕЛЕКТИВНАЯ ИНТРААРТЕРИАЛЬНАЯ ХИМИОТЕРАПИЯ (СИАХТ) ПРИ ЛЕЧЕНИИ ДЕТЕЙ С ИНТРАОКУЛЯРНОЙ РЕТИНОБЛАСТОМОЙ

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    Treatment of intraocular retinoblastoma is challenging. It requires a multidisciplinary personalized approach that includes focal treatments, chemotherapy, surgery and radiotherapy. Today, the focus of therapy has shifted to eye preservation with the major aim to save the child’s life and to preserve the eyeball as a functioning organ of vision with minimal complications. One of the most promising therapy approaches is selective intra-arterial chemotherapy (IAC), by which a cytostatic agent is given directly into the eye. This treatment modality has been shown to provide survival benefit and improvement of quality of life, reducing toxicity and minimizing side effects.Лечение интраокулярной ретинобластомы является непростой задачей, требующей от врача-онколога мультидисциплинарного, персонализированного подхода, сочетающего в себе лекарственные, хирургические и лучевые методы. Анализ результатов различных научных исследований показывает, что данная проблема не является окончательно решенной, что дает основание считать изучение данного вопроса актуальным. Основное направление сегодня – органосохраняющее лечение, при котором главная цель врача фокусируется не только на спасении жизни ребенка, но и на сохранении глазного яблока как функционирующего органа зрения при минимальных осложнениях. Целенаправленная доставка химиопрепарата в глаз путем селективной интраартериальной химиотерапии (СИАХТ) показала многообещающие результаты. Работы зарубежных авторов показывают, что данный способ лечения обеспечивает повышение выживаемости, увеличение количества сохраненных глаз и улучшение качества жизни, снижая токсичность и минимизируя побочные эффекты

    Critical temperature for first-order phase transitions in confined systems

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    We consider the Euclidean DD-dimensional λϕ4+ηϕ6-\lambda |\phi |^4+\eta |\phi |^6 (λ,η>0\lambda ,\eta >0 ) model with dd (dDd\leq D) compactified dimensions. Introducing temperature by means of the Ginzburg--Landau prescription in the mass term of the Hamiltonian, this model can be interpreted as describing a first-order phase transition for a system in a region of the DD-dimensional space, limited by dd pairs of parallel planes, orthogonal to the coordinates axis x1,x2,...,xdx_1, x_2, ..., x_d. The planes in each pair are separated by distances L1,L2,...,LdL_1, L_2, ..., L_d. We obtain an expression for the transition temperature as a function of the size of the system, % T_c(\{L_i\}), i=1,2,...,di=1, 2, ..., d. For D=3 we particularize this formula, taking L1=L2=...=Ld=LL_1=L_2=... =L_d=L for the physically interesting cases d=1d=1 (a film), d=2d=2 (an infinitely long wire having a square cross-section), and for d=3d=3 (a cube). For completeness, the corresponding formulas for second-order transitions are also presented. Comparison with experimental data for superconducting films and wires shows qualitative agreement with our theoretical expressionsComment: REVTEX, 11 pages, 3 figures; to appear in Eur. Phys. Journal
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