1,887 research outputs found

    Four related benzazepine derivatives in a reaction pathway leading to a benzazepine carboxylic acid : hydrogen-bonded assembly in zero, one, two and three dimensions

    Get PDF
    The authors thank ‘Centro de Instrumentacion Cientıfico-Tecnica of Universidad de Jaen’ and the staff for data collection. AP, SAG and CMS thank Colciencias for financial support (grant No. 1102–521–28229). JC thanks the Consejerıa de Innovacion, Ciencia y Empresa (Junta de Andalucıa, Spain) and the Universidad de Jaen for financial support.(2R*,4S*)-Methyl 2,3,4,5-tetra­hydro-1,4-ep­oxy-1H-benz[b]azepine-2-carboxyl­ate, C12H13NO3, (I), and its reduction product (2R*,4S*)-methyl 4-hy­droxy-2,3,4,5-tetra­hydro-1H-benz[b]azepine-2-carboxyl­ate, C12H15NO3, (II), both crystallize as single enanti­omers in the space group P212121, while the hydrolysis product (2RS,4SR)-4-hy­droxy-2,3,4,5-tetra­hydro-1H-benz[b]azepine-2-carb­oxy­lic acid, C11H13NO3, (III), and the lactone (2RS,5SR)-8-(trifluoromethoxy)-5,6-dihydro-1H-2,5-methanobenz[e][1,4]oxazocin-3(2H)-one, C12H10F3NO3, (IV), both crystallize as racemic mixtures in the space group P21/c. The mol­ecules of compound (IV) are linked into centrosymmetric R22(10) dimers by N-HO hydrogen bonds, and those of compound (I) are linked into chains by C-H(arene) hydrogen bonds. A combination of O-HO and O-HN hydrogen bonds links the mol­ecules of com­pound (III) into sheets containing equal numbers of R44(14) and R44(26) rings, and a combination of C-H(arene) hydrogen bonds and three-centre O-H(N,O) hydrogen bonds links the mol­ecules of compound (II) into a three-dimensional frame­work structure. Comparisons are made with some related compounds.Publisher PDFPeer reviewe

    Spatial deconvolution of spectropolarimetric data: an application to quiet Sun magnetic elements

    Full text link
    Observations of the Sun from the Earth are always limited by the presence of the atmosphere, which strongly disturbs the images. A solution to this problem is to place the telescopes in space satellites, which produce observations without any (or limited) atmospheric aberrations. However, even though the images from space are not affected by atmospheric seeing, the optical properties of the instruments still limit the observations. In the case of diffraction limited observations, the PSF establishes the maximum allowed spatial resolution, defined as the distance between two nearby structures that can be properly distinguished. In addition, the shape of the PSF induce a dispersion of the light from different parts of the image, leading to what is commonly termed as stray light or dispersed light. This effect produces that light observed in a spatial location at the focal plane is a combination of the light emitted in the object at relatively distant spatial locations. We aim to correct the effect produced by the telescope's PSF using a deconvolution method, and we decided to apply the code on Hinode/SP quiet Sun observations. We analyze the validity of the deconvolution process with noisy data and we infer the physical properties of quiet Sun magnetic elements after the deconvolution process.Comment: 14 pages, 9 figure

    Variación de las características mecánicas de armaduras de alta ductilidad B500SD en función de su grado de corrosión / Mechanical properties variation of B500SD high ductility reinforcement regarding its corrosion degree

    Get PDF
    Los efectos de la corrosión sobre las armaduras se manifiestan por la pérdida de sección y la variación de las propiedades mecánicas relacionadas con la ductilidad. En este trabajo se han ensayado a tracción 96 barras de acero B500SD que previamente se han sometido a niveles variables de corrosión. Los resultados muestran que los alargamientos de las barras disminuyen y el cociente entre la tensión máxima y el límite elástico aumenta conforme el nivel de corrosión avanza. A partir del estudio del efecto de entalla y de la distinta constitución metalográfica del acero a nivel de sección debido a su procedimiento de fabricación se pueden explicar los fenómenos anteriores

    Transient-Receptor Potential (TRP) and Acid-Sensing Ion Channels (ASICs) in the Sensory Organs of Adult Zebrafish

    Get PDF
    Sensory information from the aquatic environment is required for life and survival of zebrafish. Changes in the environment are detected by specialized sensory cells that convert different types of stimuli into electric energy, thus originating an organ-specific transduction. Ion channels are at the basis of each sensory modality and are responsible or are required for detecting thermal, chemical, or mechanical stimuli but also for more complex sensory processes as hearing, olfaction, taste, or vision. The capacity of the sensory cells to preferentially detect a specific stimulus is the result of a characteristic combination of different ion channels. This chapter summarizes the current knowledge about the occurrence and localization of ion channels in sensory organs of zebrafish belonging to the superfamilies of transient-receptor potential and acid-sensing ion channels that are involved in different qualities of sensibility superfamilies in the sensory organs of zebrafish. This animal model is currently used to study some human pathologies in which ion channels are involved. Furthermore, zebrafish is regarded as an ideal model to study in vivo the transient-receptor potential ion channels
    corecore