18 research outputs found

    Surface impedance of superconductive thin films as a function of frequency in microwave range

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    We report measurements of the complex resistivity in YBCOYBCO and MgB2MgB_2 thin films over a continuous frequency spectrum in the microwave range, making use of a Corbino disk geometry. The paper mainly focuses on the extraction of the resistivity from raw data, displaying data analisys procedure and its limits of validity. We obtain and show resistivity curves as a function of frequency and temperature denoting a frequency dependent widening of the superconductive transition.Comment: 8 pages, Latex, 5 figure

    Glucose pulse. A simple method to estimate the amount of glucose oxidized during exercise in type 1 diabetic patients

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    In type 1 diabetic patients, exercise contributes to enhance insulin sensitivity and may help, together with diet and insulin therapy, to achieve and maintain better metabolic control. Fat and carbohydrates are the main substrates for energy production in skeletal muscle during aerobic exercise in well-fed humans, with their relative contribution to total energy production being a function of exercise intensity. Below the anaerobic threshold, both oxygen consumption and heart rate during exercise increase linearly as a function of exercise intensity. On the basis of these relationships, the aim of the present study was to verify the possibility of using heart rate to estimate the amount of glucose oxidized during exercise in type 1 diabetic patients as well as in a control group of healthy subjects. This study shows that heart rate can be a useful physiological parameter to be used to estimate the amount of glucose oxidized during exercise

    Seismostratigraphy and recent sedimentary evolution of an asymmetric extensional basin at the Western arm of the Magallanes-Fagnano transform system

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    In 1995, in the frame of the PNRA (Progetto Nazionale di Ricerche in Antartide) the Dipartimento di Scienze Geologiche, Ambientaie e Marine (DISGAM \u2013 University of Trieste) performed a marine geological survey within the Pacific entrance of the Magellan Strait with the aim a) to verify the occurrence and effects of the Magellan Fault along the western part of the South America-Scotia plate boundary; and b) to investigate the sedimentary architecture of the sequences of this sector of the Strait, with particular interest to those recording the Pleistocene glacial events. The survey consisted of 290km of intermediate resolution multichannel seismic reflection profiles and three gravity cores. These data were acquired in a marine enlargement of the Magellan Strait north of Isla Desolacion, between Cabo Pilar and Isla Tamar with the R/V OGS Explora (Fig. 1). The analysed data were integrated by a high-resolution seismic line acquired all along the sStrait in 1991 and by other three cores collected during different surveys in 1991 and 1995. The present work summarize the previous report of Bartole et al. (2000) and provide new results obtained by recent analyses of the seismic and sampling data

    3D-Printed Reinforcement Scaffolds with Targeted Biodegradation Properties for the Tissue Engineering of Articular Cartilage.

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    Achieving regeneration of articular cartilage is challenging due to the low healing capacity of the tissue. Appropriate selection of cell source, hydrogel, and scaffold materials are critical to obtain good integration and long-term stability of implants in native tissues. Specifically, biomechanical stability and in vivo integration can be improved if the rate of degradation of the scaffold material matches the stiffening of the sample by extracellular matrix secretion of the encapsulated cells. To this end, a novel 3D-printed lactide copolymer is presented as a reinforcement scaffold for an enzymatically crosslinked hyaluronic acid hydrogel. In this system, the biodegradable properties of the reinforced scaffold are matched to the matrix deposition of articular chondrocytes embedded in the hydrogel. The lactide reinforcement provides stability to the soft hydrogel in the early stages, allowing the composite to be directly implanted in vivo with no need for a preculture period. Compared to pure cellular hydrogels, maturation and matrix secretion remain unaffected by the reinforced scaffold. Furthermore, excellent biocompatibility and production of glycosaminoglycans and collagens are observed at all timepoints. Finally, in vivo subcutaneous implantation in nude mice shows cartilage-like tissue maturation, indicating the possibility for the use of these composite materials in one-step surgical procedures

    A microwave broadband technique to measure the complex resistivity of HTS thin films

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    We propose a new broadband swept frequency technique to measure the complex resistivity of high Tc superconducting thin films in the microwave range (from a few GHz up to 50 GHz). A coaxial cable connects the sample to a vector network analyzer which performs reflection measurements; the film and the coaxial end are separated by a short section of circular waveguide. The absence of direct electrical contact between the sample and the coaxial core simplifies realization and avoids contact instability with large temperature variations. We provide an electromagnetic analysis of the coaxial to cylindrical transition (CCT) and find a closed form relation between the measured quantities and the film resistivity. Finally, we present some experimental results obtained for an YBa2Cu3O7-δ thin film using the described method

    Heart failure and severe pulmonary hypertension caused by distal detachment of the valve conduit 16 years after the Cabrol composite graft procedure.

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    We report the case of a patient who underwent Cabrol composite graft procedure for ascending aorta aneurysm and aortic regurgitation. Sixteen years later he developed progressive dyspnea and a left-to-right shunt caused by distal detachment of the valve conduit with persistence of the perigraft space-right atrial fistula visualized with echocardiography. Our case shows that late manifestations of surgical complications of the Cabrol procedure may occur and transesophageal echocardiography may allow a comprehensive assessment in these patients. However, because surgical management of ascending aorta aneurysms has changed in the last decades a detailed knowledge of the surgical technique used is mandatory for adequate interpretation of transesophageal echocardiographic results

    Heart failure and severe pulmonary hypertension caused by distal detachment of the valve conduit 16 years after the Cabrol composite graft procedure

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    We report the case of a patient who underwent Cabrol composite graft procedure for ascending aorta aneurysm and aortic regurgitation. Sixteen years later he developed progressive dyspnea and a left-to-right shunt caused by distal detachment of the valve conduit with persistence of the perigraft space-right atrial fistula visualized with echocardiography. Our case shows that late manifestations of surgical complications of the Cabrol procedure may occur and transesophageal echocardiography may allow a comprehensive assessment in these patients. However, because surgical management of ascending aorta aneurysms has changed in the last decades a detailed knowledge of the surgical technique used is mandatory for adequate interpretation of transesophageal echocardiographic result
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