50 research outputs found

    Structure of 2-Methyl-5,6,7-triphenyl-6,7-dihydropyrazolo[2,3-\u3cem\u3ea\u3c/em\u3e]pyrimidine

    Get PDF
    C25H21N3, Mr = 363.46, monoclinic, P21/n, a = 9.245 (2), b = 23.502 (5), c = 9.340 (2) Å, β= 103.50(3)°, V=1973.3(2) Å3, Z=4, Dx= 1.220 (2) g cm-3, λ (Mo Kα )= 0.71069 Å, μ = 0.068 cm-1, F(000) = 768, T= 292 K, R = 0.091 for 1442 unique observed reflections. The dihydropyrimidine ring adopts a distorted sofa conformation. The aryl substituents on the saturated C atoms have an axial orientation

    Structure of 5-nitro-2-tosylaminobenzaldehyde di(morpholin-4-yl)aminal Complex with Carbon Tetrachloride

    Get PDF
    The 5-nitro-2-tosylaminobenzaldehyde di(morpholin-4-yl)aminal forms a stable complex with carbon tetrachloride in the crystal phase. X-ray structural study of this complex indicates an essentially shortened intermolecular contact of 2.89 Å between the oxygen atom of the nitro group and one of the chlorine atom of the CCI4 molecule. Quantum-chemical calculations by semiempirical AMI method showed that the formation of such complex did not cause considerable decrease of system energy or change of charge distribution in molecules. It was supposed that this associate has van der Waals character

    2,3,4,6,7,8,9,10-Octa­hydro­pyrimido[1,2-a]azepin-1-ium 2-cyano-1-(2,6-dimethylanilino)-2-(phenyl­sulfonyl)ethenethiol­ate

    Get PDF
    In the title compound, C9H17N2 +·C17H15N2O2S2 −, the Csp 2—N bonds in the tetra­hydro­pyrimidine ring of the cation are delocalized. The negative charge is localized on the S atom of the thione group. Cations and anions are linked by N—H⋯S inter­molecular hydrogen bonds

    Rationing of medical care: how medical care to be distributed in conditions of limited resources

    Get PDF
    Background. Rationing of health care—restricting patients’ access to potentially beneficial health care interventions through non-market instruments—is a natural feature of all health care systems as they operate under resource constraints. The purpose of this study is to characterize rationing practices and the attitude of doctors themselves to it, with an emphasis on comparing Russia and the United States and on changes in the perception of rationing during the COVID-19 pandemic. Methods. We conducted a bibliometric analysis of publications in the medical scientific literature since 1989 on the issue of rationing of medical care. To characterize rationing practices in Russia and the United States and the attitudes of doctors towards them, we used data from published studies and data from semi-structured in-depth interviews with 28 Russian doctors. Results. Despite the increasing frequency of publications related to the topic of resource allocation over the past 20 years, studies using the term “rationing” are rare. Both Russia and the USA have practices of explicit and implicit rationing. In Russia they are more diverse and widespread. In both countries, doctors prefer implicit rationing and do not want open discussion of these issues. The practice of rationing is institutionalized. In Russian medical organizations its most common form is a chain of permissions for the use of resources. But most doctors believe they are not rationing care. The pandemic briefly brought the topic of rationing into the public sphere, but then its discussion was limited. The probable reason is that medical practice during the pandemic was carried out within the previous legal framework. Professional organizations have developed several recommendations for rationing, but their usefulness and level of acceptance by professionals and the public is unclear. Conclusions The transition from implicit to explicit rationing is extremely difficult, but is necessary to ensure equitable patient access to scarce medical resources and the effective functioning of health care systems. A major barrier to the explicit and informed use of rationing instrument is the limited public acceptance of it and the reluctance of professional communities to make public decisions that maximize public benefit by prioritizing access to effective interventions

    Experimental Method of Temperature and Strain Discrimination in Polymer Composite Material by Embedded Fiber-Optic Sensors Based on Femtosecond-Inscribed FBGs

    Get PDF
    Experimental method of temperature and strain discrimination with fiber Bragg gratings (FBGs) sensors embedded in carbon fiber-reinforced plastic is proposed. The method is based on two-fiber technique, when two FBGs inscribed in different fibers with different sensitivities to strain and/or temperature are placed close to each other and act as a single sensing element. The nonlinear polynomial approximation of Bragg wavelength shift as a function of temperature and strain is presented for this method. The FBGs were inscribed with femtosecond laser by point-by-point inscription technique through polymer cladding of the fiber. The comparison of linear and nonlinear approximation accuracies for array of embedded sensors is performed. It is shown that the use of nonlinear approximation gives 1.5–2 times better accuracy. The obtained accuracies of temperature and strain measurements are 2.6–3.8°C and 50–83 με in temperature and strain range of 30–120°C and 0–400 με, respectively

    Revealing Josephson vortex dynamics in proximity junctions below critical current

    Get PDF
    Made of a thin non-superconducting metal (N) sandwiched by two superconductors (S), SNS Josephson junctions enable novel quantum functionalities by mixing up the intrinsic electronic properties of N with the superconducting correlations induced from S by proximity. Electronic properties of these devices are governed by Andreev quasiparticles [1] which are absent in conventional SIS junctions whose insulating barrier (I) between the two S electrodes owns no electronic states. Here we focus on the Josephson vortex (JV) motion inside Nb-Cu-Nb proximity junctions subject to electric currents and magnetic fields. The results of local (Magnetic Force Microscopy) and global (transport) experiments provided simultaneously are compared with our numerical model, revealing the existence of several distinct dynamic regimes of the JV motion. One of them, identified as a fast hysteretic entry/escape below the critical value of Josephson current, is analyzed and suggested for low-dissipative logic and memory elements.Comment: 11 pages, 3 figures, 1 table, 43 reference
    corecore