887 research outputs found

    Measurement Of Quasiparticle Transport In Aluminum Films Using Tungsten Transition-Edge Sensors

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    We report new experimental studies to understand the physics of phonon sensors which utilize quasiparticle diffusion in thin aluminum films into tungsten transition-edge-sensors (TESs) operated at 35 mK. We show that basic TES physics and a simple physical model of the overlap region between the W and Al films in our devices enables us to accurately reproduce the experimentally observed pulse shapes from x-rays absorbed in the Al films. We further estimate quasiparticle loss in Al films using a simple diffusion equation approach.Comment: 5 pages, 6 figures, PRA

    Infections associated with mesh repairs of abdominal wall hernias : Are antimicrobial biomaterials the longed-for solution?

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    The incidence of mesh-related infection after abdominal wall hernia repair is low, generally between 1 and 4%; however, worldwide, this corresponds to tens of thousands of difficult cases to treat annually. Adopting best practices in prevention is one of the keys to reduce the incidence of mesh-related infection. Once the infection is established, however, only a limited number of options are available that provides an efficient and successful treatment outcome. Over the past few years, there has been a tremendous amount of research dedicated to the functionalization of prosthetic meshes with antimicrobial properties, with some receiving regulatory approval and are currently available for clinical use. In this context, it is important to review the clinical importance of mesh infection, its risk factors, prophylaxis and pathogenicity. In addition, we give an overview of the main functionalization approaches that have been applied on meshes to confer anti-bacterial protection, the respective benefits and limitations, and finally some relevant future directions. (C) 2018 Elsevier Ltd. All rights reserved.Peer reviewe

    Expression, purification and in vitro biological activity from human recombinant BMP-2 produced by a novel approach

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    Bone morphogenetic proteins have promoted great biomedical interest due to their ability in inducing new bone formation when used as powerful osteoinductive components of several late-stage bone grafting products. Recombinant human bone morphogenetic protein-2 (rhBMP-2) is obtained from mammalian cell expressing systems in low amounts or from bacteria inclusion bodies after timeconsuming refolding methods. Thus, there is a need to establish novel approaches for producing rhBMP-2 in high yields by simple and cheap procedures.Portuguese Foundation for Science and Technolog y, FCT (PhD Grant to PC Bessa , SFRH/BD/17049/2004). This work was also partially supported by the European STREP HIPPOCRATES (NMP3 - CT - 2003 - 505758) and carried out under the scope of European NoE EXPERTISSUES (NMP3 - CT - 2004 - 500283).info:eu-repo/semantics/publishedVersio

    A novel approach for the production of human recombinant BMP-2 for bone tissue engineering applications

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    Bone tissue engineering has been an increasing field of research during the last years. The ideal approach for a regenerative application would consist in the use of cells from the patient, scaffolding materials and differentiation growth factors. Bone morphogenetic protein-2 (BMP-2) is one such growth factors with a strong ability to induce new bone and cartilage formation and has been used as a powerful osteoinductive component of several late-stage tissue engineering products for bone grafting. In this work, we aimed at obtaining high yields of human recombinant BMP-2 in a stable, pure and biologically active form by use of a new bacteria expression system that circumvents the disadvantages of conventional recombinant protein preparation methods and to perform a study of the stability conditions and the functionality of these peptides in vitro in human mesenchymal stem cells and C2C12 murine cell line.info:eu-repo/semantics/publishedVersio

    Intra-arterial tert-Butyl-Hydroperoxide Infusion Induces an Exacerbated Sensory Response in the Rat Hind Limb and is Associated with an Impaired Tissue Oxygen Uptake

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    The objective of this study was to investigate oxidative stress and oxygen extraction mechanisms in an animal model of continuous intra-arterial infusion of a free radical donor and in an in vitro model using isolated mitochondria. tert-Butyl-hydroperoxide (tert-BuOOH, 25 mM) was infused for 24 h in the left hind limb of rats to induce soft tissue damage (n = 8). After 7 days, we assessed local sensory response, tissue oxygen consumption, oxygen radicals, and antioxidant levels. In vitro mitochondrial function was measured after stimulation of isolated mitochondria of skeletal muscle cells with increasing doses of tert-BuOOH. tert-BuOOH infusion resulted in an increased skin temperature (p = 0.04), impaired function, and a significantly increased pain sensation (p = 0.03). Venous oxygen saturation levels (p = 0.01) and the antioxidant ceruloplasmin (p = 0.04) were increased. tert-BuOOH inhibited mitochondrial function in vitro. Induction of free radical formation in the rat hind limb results in an exacerbated sensory response and is associated with impaired oxygen extraction, which likely results from mitochondrial dysfunction caused by free radicals

    Expression, purification and in vitro biological activity from human recombinant BMP-2 produced by a novel approach

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    Bone tissue engineering has been an increasing field of research during the last years. The ideal approach for a regenerative application would consist in the use of cells from the patient, scaffolding materials and differentiation growth factors. Bone morphogenetic protein-2 (BMP-2) is one such growth factors with a strong ability to induce new bone and cartilage formation and has been used as a powerful osteoinductive component of several late-stage tissue engineering products for bone grafting. In this work, we aimed at obtaining high yields of human recombinant BMP-2 in a stable, pure and biologically active form by use of a new bacteria expression system that circumvents the disadvantages of conventional recombinant protein preparation methods and to perform a study of the stability conditions and functionality of these peptides in vitro in human mesenchymal stem cells and C2C12 murine cell line.Portuguese Foundation for Science and Technology, FCT (PhD Grant to PC Bessa, to PC Bessa, SFRH/BD/17049/2004 SFRH/BD/17049/2004 ). This work was ). This work was also partially supported by the European STREP HIPPOCRATES (NMP3 also partially supported by the European STREP HIPPOCRATES (NMP3--CTCT--2003 2003--505758) and carried out under the scope of 505758) and carried out under the scope of European NoE EXPERTISSUES (NMP3 European NoE EXPERTISSUES (NMP3--CTCT- -2004 2004 --500283). 500283info:eu-repo/semantics/publishedVersio
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