334 research outputs found
De Storyville a Broadway
Molina Foix, JA. (1996). De Storyville a Broadway. Nosferatu. Revista de cine. (21):68-73. http://hdl.handle.net/10251/40977.ImportaciĂłn Masiva68732
Low temperature degradation behaviour of 10Ce-TZP/Al2O3 bioceramics obtained by microwave sintering technology
Zirconia is one of the most used ceramics, especially for biomedical applications, due to its exceptional mechanical properties. However, it is commonly known that its properties can be diminished owing to a low temperature degradation (LTD). This phenomenon consists on a spontaneous phase transformation, from tetragonal to monoclinic, under certain conditions, which is accelerated when the samples are exposed under high levels of humidity at a temperature range between 20-300 ÂșC. In addition to the fact that the monoclinic phase presents worse mechanical properties than the tetragonal one, there is a volume change of 4% between phases that gives rise to defects in the material as microcracks. Due to this reason, zirconia prostheses failed catastrophically inside the human body between 1999 and 2001 (1). Previous researches reveal that Al2O3 addition suppress the propagation of phase transformation (2). Thus, the aim of the present work is to study the hydrothermal ageing of zirconia doped with ceria and toughened with alumina (10Ce-TZP/Al2O3) composite, which has been sintered by microwave employing two different frequencies: 2.45 and 5.8 GHz. Microwave heating technology is based on the absorption of electromagnetic radiation by the material, which allows the sample to be heated. So far, most microwave heating equipments use 2.45 GHz; accordingly, the novelty of this study is to employ a frequency of 5.8 GHz and to investigate its effect on LTD. LTD is carried out in an autoclaved in steam at 120 ÂșC and 1.2 bar, because these conditions accelerate the hydrothermal aging process (3). In order to characterize the degraded samples, micro-Raman spectroscopy, AFM, nanoindentation technique and electronic microscopy have been performed.
References
1. Norton, M. R., Yarlagadda, R., Anderson, G. H. J. Bone Joint Surg. Br., 2002, 84âB, 631â635.
2. Fabbri, P., Piconi, C., Burresi, E., Magnani, G., Mazzanti, F., Mingazzini, C. Dent. Mater., 2014.
3. Presenda, Ă., Salvador, M. D., Moreno, R., Borrell, A. J. Am. Ceram. Soc., 2015, 98, 3680â3689
Amylin impairment of insulin effects on glycogen synthesis and phosphoenolpyruvate carboxykinase gene expression in rat primary cultured hepatocytes
Numerical analysis of microwave heating cavity: Combining electromagnetic energy, heat transfer and fluid dynamics for a NaY zeolite fixed-bed
[EN] Three-dimensional mathematical model was developed for a rectangular TE10n microwave heating cavity system, working at 2.45 GHz. Energy/heat, momentum equations were solved together with Maxwell's electromagnetic field equations using comm. MULTIPHYSICS (R) simulation environment. The dielectric properties, epsilon' and epsilon '', of NaY zeolite (Si/Al = 2.5) were evaluated as a function of temperature. Considering these values, the microwave heating of a porous fixed-bed made of dry NaY zeolite was simulated. Electric field distribution, axial and radial temperature profiles and temperature evolution with time were obtained. The zeolite fixed bed was heated up to 180 degrees C in 5 min, with 30 W power. The fixed-bed temperature evolution under non-steady state conditions showed the same trend as the one observed experimentally with only an average deviation of 10.3%. The model was used to predict microwave heating of other materials improving energy efficiency of the microwave cavity. Furthermore, the developed model was able to predict thermal runaway for zeolites.Financial support from the European Research Council ERC-Advanced Grant HECTOR-267626 is gratefully acknowledged. Hakan Nigar acknowledges financial support from the Spanish Ministry of Education for the FPU grant (Formacion del Profesorado Universitario - FPU12/06864), and also for the academic short stay grant (Estancia Breve - FPU2016) at the Delft University of Technology, Delft, The Netherlands.Nigar, H.; Sturm, GSJ.; GarcĂa-Baños, B.; Penaranda-Foix, FL.; CatalĂĄ Civera, JM.; Mallada, R.; Stankiewicz, A.... (2019). Numerical analysis of microwave heating cavity: Combining electromagnetic energy, heat transfer and fluid dynamics for a NaY zeolite fixed-bed. Applied Thermal Engineering. 155:226-238. https://doi.org/10.1016/j.applthermaleng.2019.03.117S22623815
Expression of Glycogen Phosphorylase Isoforms in Cultured Muscle from Patients with McArdle's Disease Carrying the p.R771PfsX33 PYGM Mutation
Mutations in the PYGM gene encoding skeletal muscle glycogen phosphorylase (GP) cause a metabolic disorder known as McArdle's disease. Previous studies in muscle biopsies and cultured muscle cells from McArdle patients have shown that PYGM mutations abolish GP activity in skeletal muscle, but that the enzyme activity reappears when muscle cells are in culture. The identification of the GP isoenzyme that accounts for this activity remains controversial
The impact of chorionicity on pregnancy outcome and neurodevelopment at 2 years old among twins born preterm: the EPIPAGE-2 cohort study
OBJECTIVE
To compare the shortâ and midâterm outcomes of preterm twins by chorionicity of pregnancy.
DESIGN
Prospective nationwide populationâbased EPIPAGEâ2 cohort study.
SETTING
546 maternity units in France, between March and December 2011.
POPULATION
A total of 1700 twin neonates born between 24 and 34 weeks of gestation.
METHODS
The association of chorionicity with outcomes was analysed using multivariate regression models.
MAIN OUTCOME MEASURES
First, survival at 2âyear corrected age with or without neurosensory impairment, and second, perinatal, shortâ, and midâterm outcomes (survival at discharge, survival at discharge without severe morbidity) were described and compared by chorionicity.
RESULTS
In the EPIPAGE 2 cohort, 1700 preterm births were included (850 twin pregnancies). In all, 1220 (71.8%) were from dichorionic (DC) pregnancies and 480 from monochorionic (MC) pregnancies. MC pregnancies had three times more medical terminations than DC pregnancies (1.67 versus 0.51%, P < 0.001), whereas there were three times more stillbirths in MC than in DC pregnancies (10.09 versus 3.78%, P < 0.001). Both twins were alive at birth in 86.6% of DC pregnancies compared with 80.0% among MC pregnancies (P = 0.008). No significant difference according to chorionicity was found regarding neonatal deaths and morbidities. Likewise, for children born earlier than 32 weeks, the 2âyear followâup neurodevelopmental results were not significantly different between DC and MC twins.
CONCLUSIONS
This study confirms that MC pregnancies have a higher risk of adverse outcomes. However, the outcomes among preterm twins admitted to neonatal intensive care units are similar irrespective of chorionicity
Characterization method of dielectric properties of free falling drops in a microwave processing cavity and its application in microwave internal gelation
[EN] Microwave internal gelation (MIG) is a chemical process proposed for the production of nuclear particle fuel. The internal gelation reaction is triggered by a temperature increase of aqueous droplets falling by gravity by means of non-contact microwave heating. Due to the short residence time of a solution droplet in a microwave heating cavity, a detailed knowledge of the interaction between microwaves and chemical solution (shaped in small drops) is required. This paper describes a procedure that enables the measurement of the dielectric properties of aqueous droplets that freely fall through a microwave cavity. These measurements provide the information to determine the optimal values of the parameters (such as frequency and power) that dictate the heating of such a material under microwaves.This work is a part of the PINE (Platform for Innovative Nuclear FuEls) project which targets the development of an advanced production method for Sphere-Pac fuel and is financed by the Swiss Competence Center for Energy and Mobility. The work has been also financed by the European Commission through contract no 295664 regarding the FP7 PELGRIMM Project, as well as contract no 295825 regarding the FP7-ASGARD Project. MC-S would like to thank the ITACA research team (UPV Valencia, Spain) and the EMPA Thun (Switzerland) for their support in the measurements and Carl Beard (PSI, Switzerland) for the help provided in respect with CST simulations. The work of FLP-F was supported by the Conselleria d'Educacio of the Generalitat Valenciana for economic support (BEST/2012/010).Cabanes Sempere, M.; CatalĂĄ Civera, JM.; Penaranda-Foix, FL.; Cozzo, C.; Vaucher, S.; Pouchon, MA. (2013). Characterization method of dielectric properties of free falling drops in a microwave processing cavity and its application in microwave internal gelation. Measurement Science and Technology. 24(9). https://doi.org/10.1088/0957-0233/24/9/095009S24
Adenovirus-mediated delivery into myocytes of muscle glycogen phosphorylase, the enzyme deficient in patients with glycogen-storage disease type V
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