Examinando por Autor "Morales, D."

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    Hundred joules plasma focus device as a potential pulsed source for in vitro cancer cell irradiation
    (American Institute of Physics Inc., 2017-08) Jain, J.; Moreno, J.; Andaur, R.; Armisen, R.; Morales, D.; Marcelain, K.; Avaria, G.; Bora, B.; Davis, S.; Pavez, C.; Soto, L.
    Plasma focus devices may arise as useful source to perform experiments aimed to study the effects of pulsed radiation on human cells in vitro. In the present work, a table top hundred joules plasma focus device, namely "PF-400J", was adapted to irradiate colorectal cancer cell line, DLD-1. For pulsed x-rays, the doses (energy absorbed per unit mass, measured in Gy) were measured using thermoluminescence detectors (TLD-100 dosimeters). The neutron fluence and the average energy were used to estimate the pulsed neutron doses. Fifty pulses of x-rays (0.12 Gy) and fifty pulses of neutrons (3.5 μGy) were used to irradiate the cancer cells. Irradiation-induced DNA damage and cell death were assessed at different time points after irradiation. Cell death was observed using pulsed neutron irradiation, at ultralow doses. Our results indicate that the PF-400J can be used for in vitro assessment of the effect of pulsed radiation in cancer cell research.
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    Ion emission study using visible spectroscopy and ToF method in a plasma focus device of two kilojoules
    (Institute of Physics Publishing, 2015-03) Moreno, J.; Morales, D.; Avaria, G.; Cuadrado, O.; Soto, L.
    Different studies have been developed in order to understand the dynamics and processes involved in the particle emission from plasma focus devices operating in the kilo joule range. The use of chemical compound gasses and noble gas mixtures has proven to produce different charged particles, as well as increase the neutron yield from deuterium plasma discharges. Nevertheless, the processes and parameters involved in these discharges are not fully understood. In this work we will present results of visible spectroscopy and “time-of flight” observations of the different ion species and ionization levels obtained in a 2kJ plasma focus device, when using deuterium or hydrogen with small percentage impurities.
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    Prolonged AT1R activation induces CaV1.2 channel internalization in rat cardiomyocytes
    (Nature Publishing Group, 2017-12) Hermosilla, T.; Encina, M.; Morales, D.; Moreno, C.; Conejeros, C.; Alfaro-Valdés, H.M.; Lagos-Meza, F.; Simon, F.; Altier, C.; Varela, D.
    The cardiac L-type calcium channel is a multi-subunit complex that requires co-assembling of the pore-forming subunit CaV1.2 with auxiliary subunits CaVα2δ and CaVβ. Its traffic has been shown to be controlled by these subunits and by the activation of various G-protein coupled receptors (GPCR). Here, we explore the consequences of the prolonged activation of angiotensin receptor type 1 (AT1R) over CaV1.2 channel trafficking. Bioluminescence Resonance Energy Transfer (BRET) assay between β-arrestin and L-type channels in angiotensin II-stimulated cells was used to assess the functional consequence of AT1R activation, while immunofluorescence of adult rat cardiomyocytes revealed the effects of GPCR activation on CaV1.2 trafficking. Angiotensin II exposure results in β-arrestin1 recruitment to the channel complex and an apparent loss of CaV1.2 immunostaining at the T-tubules. Accordingly, angiotensin II stimulation causes a decrease in L-type current, Ca2+ transients and myocyte contractility, together with a faster repolarization phase of action potentials. Our results demonstrate that prolonged AT1R activation induces β-arrestin1 recruitment and the subsequent internalization of CaV1.2 channels with a half-dose of AngII on the order of 100 nM, suggesting that this effect depends on local renin-angiotensin system. This novel AT1R-dependent CaV1.2-trafficking modulation likely contributes to angiotensin II-mediated cardiac remodeling.