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  • 11
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 66 (1995), S. 5148-5152 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Perfect crystals in transmission (Laue) geometry can be used effectively for x-ray monochromators, and moreover, perfect Laue crystals show an interesting focusing effect when the incident beam is white and divergent. This focusing is directly dependent on the incident beam divergence and on the diffraction profile width of the crystal. The aim of this work is to study whether this property can be used for focusing a synchrotron x-ray beam, and to obtain quantitatively the dimensions of the resulting monochromatic beam. We have experimentally measured the size of an undulator beam after diffraction from a diamond crystal in Laue geometry, and we analyze and explain the results by comparison with ray-tracing simulations. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 12
    Electronic Resource
    Electronic Resource
    Oxford, UK; Malden, USA : Blackwell Publishing Ltd/Inc.
    Wound repair and regeneration 13 (2005), S. 0 
    ISSN: 1524-475X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Antimicrobial peptides are major components of the innate defense system that present microbicidal activity against gram positive and negative bacteria, yeast, and some enveloped viruses. The human cathelicidin LL-37 is expressed in skin upon wounding and, in addition to its role in antimicrobial defense, it has also been previously demonstrated that this peptide might be involved in reepithelization. We have generated an adenoviral vector containing the complete sequence of LL-37 along with an Ires-GFP expression cassette. The efficacy of this vector was probed by testing the conditioned medium from adenoviral transduced keratinocytes in preventing bacterial growth. We have studied the in vitro effects of LL-37 on HK migration and proliferation. In addition, we have efficiently transduced human skin grafts (in immunodeficient mice) using an in vivo gene transfer approach and we are currently testing the involvement of this peptide in wound repair.
    Type of Medium: Electronic Resource
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  • 13
    ISSN: 1524-475X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: SPARC (secreted protein, acidic and rich in cysteine), a matricellular glycoprotein, modulates the interactions of cells with the extracellular matrix. Studies in null-mice revealed a role of SPARC in wound healing. Here we examined the effect of SPARC in a skin-humanized mouse wound healing model. This model is based in the regeneration of human skin onto the back of nude mice by transplantation of a dermo-epidermal equivalent. The regenerated human skin was excisionally wounded with biopsy punches. At the moment of wounding an adenoviral vector encoding the cDNA for SPARC was intradermally injected. We are currently assessing the effects of in vivo gene transfer of SPARC at the wound site in the healing process. Criticals events of wound healing including reepithelialization, regeneration of dermoepidermal junction and dermal remodeling were studied at different time points postwounding.
    Type of Medium: Electronic Resource
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  • 14
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Mosaic crystals provide an interesting choice for synchrotron radiation monochromators under certain conditions. They show a wider and lower reflectivity curve than perfect crystals, but a higher integrated reflectivity. Some mosaic crystals such as graphite or beryllium could be considered as monochromators or premonochromators for third generation synchrotron radiation machines (Sincrotrone Trieste, European Synchrotron Radiation facility, etc.). In order to assess these possibilities, we have implemented a new mosaic crystal part in the ray tracing code SHADOW. The effect of the random distribution of the crystallites in a mosaic crystal can be analyzed efficiently with a Monte Carlo method. Taking into account the random distribution of the crystal planes, modeled as a Gaussian of standard deviation κ, it is possible to reproduce the well known focusing and defocusing properties of these crystals. For reflectivity calculations we have implemented in the computer code the Mosaic Crystals Theory of Zachariasen. As secondary extinction is not negligible in mosaic crystals, we have also included the penetration effect of the x-ray beam inside the crystal.
    Type of Medium: Electronic Resource
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  • 15
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 63 (1992), S. 936-940 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Asymmetrically cut crystals are interesting for use in synchrotron radiation monochromators because of their good energy resolution characteristics and their focusing properties. Ray tracing codes, such as SHADOW, are very efficient in the design and development of new optical devices. In order to determine the convenience of using asymmetrically cut crystals for x-ray monochromators, SHADOW has been extended to include these kinds of crystals. The physical approach to ray tracing asymmetrically cut crystals is based on the coexistence of two periodic structures. One of these is the bulk periodic structure of the Bragg planes. Such a structure determines the existence of a rocking curve near the Bragg condition, and is implemented in SHADOW following the Darwin–Prins formalism of the dynamical theory of diffraction. The second periodic structure is a one-dimensional grating on the crystal surface, formed by the truncation of the lattice planes with the surface. This grating is responsible for the focusing properties of these crystals and plays an essential role in determining the trajectory of the rays. The combination of an asymmetric crystal and a nonplanar surface can be easily achieved by bending (Johann case) to provide improved properties. More complex cases such as the ground-bent crystals (i.e., Johansson geometry) can be considered as a particular case of asymmetrical crystals in which the angle between the Bragg planes and the surface change along the crystal surface. All these cases have been implemented in SHADOW.
    Type of Medium: Electronic Resource
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  • 16
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 464 (1986), S. 0 
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
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  • 17
    Electronic Resource
    Electronic Resource
    Oxford, UK and Malden, USA : Blackwell Publishing Ltd.
    Creativity and innovation management 14 (2005), S. 0 
    ISSN: 1467-8691
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Economics
    Notes: This paper posits an antecedents and consequences model of constructive conflict (or the benefits derived from cross-functional conflict). The managers of a sample of innovating Spanish firms perceive positive changes when the parties in conflict: (1) exchange information to solve problems; (2) emphasize their common interests; and (3) make an effort to maintain good relations. The results of the study also indicate that collaborating to seek a solution to conflicts between areas indirectly influences the new product programme performance through constructive conflict.
    Type of Medium: Electronic Resource
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  • 18
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 72 (2001), S. 3291-3303 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A novel, compact, large field, and spectrally tunable imaging x-ray microscope is presented. It is based on the use of an isotropic point x-ray source and a spherically curved crystal. The x-ray beam intensity is modulated by the object attenuation, then monochromatized and enlarged using a spherical crystal and, finally, imaged using a detector downstream from the crystal. We demonstrate by ray tracing simulations that this system allows microscopy studies with high spatial resolution, high magnification ratios, and large field of view. Microscopes using this model can be easily built using different x-ray sources, like conventional x-ray tube generators, x rays emitted by laser-generated plasmas or x-pinch plasmas, and also synchrotron radiation when used in combination with other condenser optics. Preliminary experiments are presented to demonstrate the feasibility of the proposed setup. High resolution (∼4 μm) monochromatic (δλ/λ∼10−5–10−3) images over a large field of view (few mm2) were recorded in the spectral range 8–14 Å using a laser-generated plasma source and a spherical mica crystal. Compared to x-ray crystal imagers used in relation with plasma sources, the new configuration produces high quality stigmatic images working at many different Bragg angles, thus improving the spectral tunability and allowing a more flexible design. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 19
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Addiction 90 (1995), S. 0 
    ISSN: 1360-0443
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine , Psychology
    Notes: A regional survey on peoples' attitudes towards drugs was conducted in the fall of 1992 on 2500 individuals aged 14–70 years. The great majority of those surveyed considered the taking of heroin (98%), cocaine (95.9%) and amphetamines (94.7%) to be “very risky” for one's health. These percentages were considerably lower in the case of tobacco (41.3%) and alcohol (26.7%). Those surveyed pointed to‘heroin’(35.6%),‘all illegal drugs’(27%),‘legal drugs’(17.2%) and‘cocaine’(14.2%) as the most dangerous drugs for society. The study shows how alcohol and tobacco are perceived by Spaniards as less dangerous than illegal drugs.
    Type of Medium: Electronic Resource
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  • 20
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 33 (2000), S. 1023-1030 
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: Section topographs recorded at different spatial locations and at different rocking angles of a highly oriented pyrolytic graphite (HOPG) crystal allow three-dimensional maps of the local angular-dependent scattering power to be obtained. This is performed with a direct reconstruction from the intensity distribution on such topographs. The maps allow the extraction of information on local structural parameters such as size, form and internal mosaic spread of crystalline domains. This data analysis leads to a new method for the characterization of mosaic crystals. Perspectives and limits of applicability of this method are discussed.
    Type of Medium: Electronic Resource
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