9 research outputs found

    Platinum Nanoparticle Decorated SiO2 Microfibers as Catalysts for Micro Unmanned Underwater Vehicle Propulsion

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    Micro unmanned underwater vehicles (UUVs) need to house propulsion mechanisms that are small in size but sufficiently powerful to deliver on-demand acceleration for tight radius turns, burst-driven docking maneuvers, and low-speed course corrections. Recently, small-scale hydrogen peroxide (H2O2) propulsion mechanisms have shown great promise in delivering pulsatile thrust for such acceleration needs. However, the need for robust, high surface area nanocatalysts that can be manufactured on a large scale for integration into micro UUV reaction chambers is still needed. In this report, a thermal/electrical insulator, silicon oxide (SiO2) microfibers, is used as a support for platinum nanoparticle (PtNP) catalysts. The mercapto-silanization of the SiO2 microfibers enables strong covalent attachment with PtNPs, and the resultant PtNP–SiO2 fibers act as a robust, high surface area catalyst for H2O2 decomposition. The PtNP–SiO2 catalysts are fitted inside a micro UUV reaction chamber for vehicular propulsion; the catalysts can propel a micro UUV for 5.9 m at a velocity of 1.18 m/s with 50 mL of 50% (w/w) H2O2. The concomitance of facile fabrication, economic and scalable processing, and high performance—including a reduction in H2O2 decomposition activation energy of 40–50% over conventional material catalysts—paves the way for using these nanostructured microfibers in modern, small-scale underwater vehicle propulsion systems

    Platinum Nanoparticle Decorated SiO 2 Microfibers as Catalysts for Micro Unmanned Underwater Vehicle Propulsion

    Get PDF
    Micro unmanned underwater vehicles (UUVs) need to house propulsion mechanisms that are small in size but sufficiently powerful to deliver on-demand acceleration for tight radius turns, burst-driven docking maneuvers, and low-speed course corrections. Recently, small-scale hydrogen peroxide (H2O2) propulsion mechanisms have shown great promise in delivering pulsatile thrust for such acceleration needs. However, the need for robust, high surface area nanocatalysts that can be manufactured on a large scale for integration into micro UUV reaction chambers is still needed. In this report a thermal/electrical insulator, silicon oxide (SiO2) microfibers, are used as a support for platinum nanoparticle (PtNP) catalysts. The mercapto-silanization of the SiO2 microfibers enables strong covalent attachment with PtNPs and the resultant PtNP-SiO2 fibers act as a robust, high surface area catalyst for H2O2 decomposition. The PtNP-SiO2 catalysts are fitted inside a micro UUV reaction chamber for vehicular propulsion; the catalysts can propel a micro UUV for 5.9 meters at a velocity of 1.18 m/s with 50 mL of 50% (w/w) H2O2.The concomitance of facile fabrication, economic and scalable processing, and high performance —including a reduction in H2O2 decomposition activation energy of 40-50% over conventional material catalysts—paves the way for using these nanostructured microfibers in modern, small-scale underwater vehicle propulsion systems

    The epidemiology of mild cognitive impairment (MCI) and Alzheimer’s disease (AD) in community-living seniors: protocol of the MemoVie cohort study, Luxembourg

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    BACKGROUND: Cognitive impairment and Alzheimer’s disease (AD) are increasingly considered a major public health problem. The MemoVie cohort study aims to investigate the living conditions or risk factors under which the normal cognitive capacities of the senior population in Luxembourg (≥ 65 year-old) evolve (1) to mild cognitive impairment (MCI) – transitory non-clinical stage – and (2) to AD. Identifying MCI and AD predictors undeniably constitutes a challenge in public health in that it would allow interventions which could protect or delay the occurrence of cognitive disorders in elderly people. In addition, the MemoVie study sets out to generate hitherto unavailable data, and a comprehensive view of the elderly population in the country. METHODS/DESIGN: The study has been designed with a view to highlighting the prevalence in Luxembourg of MCI and AD in the first step of the survey, conducted among participants selected from a random sample of the general population. A prospective cohort is consequently set up in the second step, and appropriate follow-up of the non-demented participants allows improving the knowledge of the preclinical stage of MCI. Case-control designs are used for cross-sectional or retrospective comparisons between outcomes and biological or clinical factors. To ensure maximal reliability of the information collected, we decided to opt for structured face to face interviews. Besides health status, medical and family history, demographic and socio-cultural information are explored, as well as education, habitat network, social behavior, leisure and physical activities. As multilingualism is expected to challenge the cognitive alterations associated with pathological ageing, it is additionally investigated. Data relative to motor function, including balance, walk, limits of stability, history of falls and accidents are further detailed. Finally, biological examinations, including ApoE genetic polymorphism are carried out. In addition to standard blood parameters, the lipid status of the participants is subsequently determined from the fatty acid profiles in their red blood cells. The study obtained the legal and ethical authorizations. DISCUSSION: By means of the multidisciplinary MemoVie study, new insights into the onset of cognitive impairment during aging should be put forward, much to the benefit of intervention strategies as a whole

    Diagnosis of heterotopic bone marrow in the mediastinum using 52Fe and positron emission tomography.

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    A patient with hereditary spherocytosis was admitted with mediastinal masses on the chest X-ray. 52Fe and positron emission tomography (PET) showed uptake of 52Fe in the masses and established the diagnosis of thoracic extramedullary hematopoiesis

    Accumulation of polymorphonuclear leukocytes in reperfused ischemic canine myocardium: relation with tissue viability assessed by fluorine-18-2-deoxyglucose uptake.

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    Polymorphonuclear leukocytes may participate in reperfusion injury. Whether leukocytes affect viable or only irreversibly injured tissue is not known. Therefore, we assessed the accumulation of 111In-labeled leukocytes in tissue samples characterized as either ischemic but viable or necrotic by metabolic, histochemical, and ultrastructural criteria. Six open-chest dogs received left anterior descending coronary occlusion for 2 hr followed by 4 hr reperfusion. Myocardial blood flow was determined by microspheres and autologous 111In-labeled leukocytes were injected intravenously. Fluorine-18-2-deoxyglucose, a tracer of exogenous glucose utilization, was injected 3 hr after reperfusion. The dogs were killed 4 hr after reperfusion. The risk and the necrotic regions were assessed following in vivo dye injection and postmortem tetrazolium staining. Myocardial samples were obtained in the ischemic but viable, necrotic and normal zones, and counted for 111In and 18F activity. Compared to normal, leukocytes were entrapped in necrotic regions (111In activity: 207 +/- 73%) where glucose uptake was decreased (26 +/- 15%). A persistent glucose uptake, marker of viability, was mainly seen in risk region (135 +/- 85%) where leukocytes accumulation was moderate in comparison to normal zone (146 +/- 44%). Thus, the glucose uptake observed in viable tissue is mainly related to myocytes metabolism and not to leukocytes metabolism

    Platinum Nanoparticle Decorated SiO2 Microfibers as Catalysts for Micro Unmanned Underwater Vehicle Propulsion

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    Micro unmanned underwater vehicles (UUVs) need to house propulsion mechanisms that are small in size but sufficiently powerful to deliver on-demand acceleration for tight radius turns, burst-driven docking maneuvers, and low-speed course corrections. Recently, small-scale hydrogen peroxide (H2O2) propulsion mechanisms have shown great promise in delivering pulsatile thrust for such acceleration needs. However, the need for robust, high surface area nanocatalysts that can be manufactured on a large scale for integration into micro UUV reaction chambers is still needed. In this report, a thermal/electrical insulator, silicon oxide (SiO2) microfibers, is used as a support for platinum nanoparticle (PtNP) catalysts. The mercapto-silanization of the SiO2 microfibers enables strong covalent attachment with PtNPs, and the resultant PtNP–SiO2 fibers act as a robust, high surface area catalyst for H2O2 decomposition. The PtNP–SiO2 catalysts are fitted inside a micro UUV reaction chamber for vehicular propulsion; the catalysts can propel a micro UUV for 5.9 m at a velocity of 1.18 m/s with 50 mL of 50% (w/w) H2O2. The concomitance of facile fabrication, economic and scalable processing, and high performance—including a reduction in H2O2 decomposition activation energy of 40–50% over conventional material catalysts—paves the way for using these nanostructured microfibers in modern, small-scale underwater vehicle propulsion systems.Reprinted with permission from ACS Applied Materials & Interfaces 8 (2016): 30941, doi:10.1021/acsami.6b10047.</p

    Platinum Nanoparticle Decorated SiO2 Microfibers as Catalysts for Micro Unmanned Underwater Vehicle Propulsion

    Get PDF
    Micro unmanned underwater vehicles (UUVs) need to house propulsion mechanisms that are small in size but sufficiently powerful to deliver on-demand acceleration for tight radius turns, burst-driven docking maneuvers, and low-speed course corrections. Recently, small-scale hydrogen peroxide (H2O2) propulsion mechanisms have shown great promise in delivering pulsatile thrust for such acceleration needs. However, the need for robust, high surface area nanocatalysts that can be manufactured on a large scale for integration into micro UUV reaction chambers is still needed. In this report, a thermal/electrical insulator, silicon oxide (SiO2) microfibers, is used as a support for platinum nanoparticle (PtNP) catalysts. The mercapto-silanization of the SiO2 microfibers enables strong covalent attachment with PtNPs, and the resultant PtNP–SiO2 fibers act as a robust, high surface area catalyst for H2O2 decomposition. The PtNP–SiO2 catalysts are fitted inside a micro UUV reaction chamber for vehicular propulsion; the catalysts can propel a micro UUV for 5.9 m at a velocity of 1.18 m/s with 50 mL of 50% (w/w) H2O2. The concomitance of facile fabrication, economic and scalable processing, and high performance—including a reduction in H2O2 decomposition activation energy of 40–50% over conventional material catalysts—paves the way for using these nanostructured microfibers in modern, small-scale underwater vehicle propulsion systems.This article is published as Chen, Bolin, Nathaniel T. Garland, Jason Geder, Marius Pruessner, Eric Mootz, Allison Cargill, Anne Leners et al. "Platinum Nanoparticle Decorated SiO2 Microfibers as Catalysts for Micro Unmanned Underwater Vehicle Propulsion." ACS Applied Materials & Interfaces 8, no. 45 (2016): 30941-30947. DOI:10.1021/acsami.6b10047.</p

    European postgraduate curriculum in geriatric medicine developed using an international modified Delphi technique

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    WOS: 000462615200022PubMed ID: 30423032the European Union of Medical Specialists (UEMS-GMS) recommendations for training in Geriatric Medicine were published in 1993. The practice of Geriatric Medicine has developed considerably since then and it has therefore become necessary to update these recommendations. under the auspices of the UEMS-GMS, the European Geriatric Medicine Society (EuGMS) and the European Academy of Medicine of Ageing (EAMA), a group of experts, representing all member states of the respective bodies developed a new framework for education and training of specialists in Geriatric Medicine using a modified Delphi technique. Thirty-two expert panel members from 30 different countries participated in the process comprising three Delphi rounds for consensus. The process was led by five facilitators. the final recommendations include four different domains: General Considerations on the structure and aim of the syllabus as well as quality indicators for training (6 sub-items), Knowledge in patient care (36 sub-items), Additional Skills and Attitude required for a Geriatrician (9 sub-items) and a domain on Assessment of postgraduate education: which items are important for the transnational comparison process (1 item). the current publication describes the development of the new recommendations endorsed by UEMS-GMS, EuGMS and EAMA as minimum training requirements to become a geriatrician at specialist level in EU member states.EUGMSThe project was supported by EUGMS by a restricted grant in 2017, which was used to support the administrative work during the Delphi procedure
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