46 research outputs found

    Neodymium doped lanthanide fluoride nanoparticles as contrast agents for luminescent bioimaging and X-ray computed tomography

    Get PDF
    The synthesis of uniform neodymium-doped lanthanum trifluoride nanoparticles with lenticular shape and a mean diameter around 45 nm by using a homogeneous precipitation method is reported. The luminescent properties of the synthesized samples in terms of their emission spectra and emission lifetime are analyzed as a function of the Nd content to find the optimum phosphor and its suitability for luminescent imaging in the second biological window. The X-ray attenuation properties of the optimum phosphor are evaluated to investigate their additional ability as contrast agent for X-ray computed tomography. Finally, the colloidal stability of the obtained nanoparticles in physiological medium and their cytotoxicity are also analyzed to assess their aptness for in vivo bioimaging applications. En este trabajo se ha desarrollado un método de síntesis de nanopartículas uniformes de trifluoruro de lantano dopadas con neodimio, con forma lenticular y un diámetro medio en torno a 45 nm, basado en un proceso de precipitación homogénea en medio acuoso. Las propiedades luminiscentes de las muestras sintetizadas en términos de sus espectros de emisión y tiempo de vida de las emisiones se han analizado en función del contenido de neodimio (Nd) para determinar el nanofósforo óptimo y su idoneidad para la obtención de imágenes luminiscentes en la segunda ventana biológica. Asimismo, se han evaluado las propiedades de atenuación de rayos X del nanofósforo óptimo para valorar su capacidad adicional como agente de contraste para tomografía computarizada de rayos X. Por último, también se han analizado la estabilidad coloidal de las nanopartículas obtenidas en medio fisiológico y su citotoxicidad para determinar su aplicabilidad para la obtención de imágenes biológicas in vivo

    Bimodal Nd-doped luVo4 nanoprobes functionalized with polyacrilic acid for x-ray computed tomography and NIR luminescent imaging

    Get PDF
    Uniform Nd3+-doped LuVO4 nanophosphors have been synthesized for the first time in literature by using a poliol-based method at 120 °C from Nd3+ and vanadate precursors. After optimizing the Nd doping level, these phosphors present intense luminescence in the near-infrared biological windows. The X-ray attenuation capacity of the optimum nanophosphor has been found to be higher than that of a commercial X-ray computed tomography contrast agent. After surface coating with polyacrylic acid, such nanoparticles present high colloidal stability in physiological pH medium and high cell viability. Because of these properties, the developed Nd3+-doped LuVO4 nanoparticles have potential applications as a bimodal probe for NIR luminescent bioimaging and X-ray computed tomography

    Theranostics in Boron neutron capture therapy

    Get PDF
    Boron neutron capture therapy (BNCT) has the potential to specifically destroy tumor cells without damaging the tissues infiltrated by the tumor. BNCT is a binary treatment method based on the combination of two agents that have no effect when applied individually:10B and thermal neutrons. Exclusively, the combination of both produces an effect, whose extent depends on the amount of10B in the tumor but also on the organs at risk. It is not yet possible to determine the10B concentration in a specific tissue using non-invasive methods. At present, it is only possible to measure the10B concentration in blood and to estimate the boron concentration in tissues based on the assumption that there is a fixed uptake of10B from the blood into tissues. On this imprecise assumption, BNCT can hardly be developed further. A therapeutic approach, combining the boron carrier for therapeutic purposes with an imaging tool, might allow us to determine the10B concentration in a specific tissue using a non-invasive method. This review provides an overview of the current clinical protocols and preclinical experiments and results on how innovative drug development for boron delivery systems can also incorporate concurrent imaging. The last section focuses on the importance of proteomics for further optimization of BNCT, a highly precise and personalized therapeutic approach

    Molecular Characterization of Growth Hormone-producing Tumors in the GC Rat Model of Acromegaly

    Get PDF
    D.A.C. was supported by the Nicolás Monardes program of the Andalusian Ministry of Health (C-0015-2014) and by a grant from the Andalusian Ministry of Science and Innovation (CTS-7478). A.S-M and A.L.C were supported by grants from the ISCIII-Subdirección General de Evaluación y Fomento de la Investigación co-funded with Fondos FEDER (PI12/0143 and PI13/02043, respectively) and the Andalusian Regional Government (CTS-444) and a grant from Pfizer Spain. R.L.C. was supported by a grant from Andalusian Ministry of Health (PI0302-2012). R.M.L. was supported by grants from Proyecto de Investigación en Salud (FIS) PI13- 00651 (funded by Instituto de Salud Carlos III), CTS-1406, PI-0639-2012, BIO-0139 (funded by Junta de Andalucía) and by Ayuda Merck Serono 2013. J. P. C. was funded by a grant (BFU2013-43282-R) from Ministerio de Economía y Competitividad. CIBER is an initiative of Instituto de Salud Carlos III, Ministerio de Sanidad, Servicios Sociales e Igualdad, Spain. J.F.M.R. is supported by the “Sara Borrell” program from the Instituto de Salud Carlos III. R.M. Luque and J.P. Castaño have received grants and lecture fees from Ipsen and Novartis. E. Venegas-Moreno and A. Soto-Moreno received grants and lecture fees from Ipsen, Novartis and Pfizer. A. Leal-Cerro received grants from Novartis and Pfizer. David Cano received a grant from Novartis

    Research facilities and highlights at the Centro Nacional de Aceleradores (CNA)

    Get PDF
    The Centro Nacional de Aceleradores is a user-oriented accelerator facility in Seville, Spain. Its main facilities are a 3 MV tandem accelerator, an 18 MeV proton Cyclotron, a tandetron used for AMS, a compact accelerator used for radiocarbon measurements, a 60Co irradiator and a PET/CT scanner. The technical specifications and research applications of these facilities are described. A neutron beam line associated to a charged pulsed beam in the tandem allows for time of flight measurements which determine the neutron energy. The use of an adequate stripper gas in the AMS tandetron permits to measure heavy radionuclides with very low detection levels, allowing to perform environmental studies using these radionuclides as tracers. The use of the microbeam in the tandem accelerator allows to apply the ion beam-induced current technique to investigate the spectroscopic properties and radiation hardness of different semiconductor detectors.European Union, H2020-847594, H2020-654002, H2020-847552, H2020-847594Ministry of Science RTI2018-098117-B-C21, RTC-2017-6369-3, EQC2018-004193-P, EQC2018-004095-P, EQC2018-004166- P, PGC2018-094546-B-I00Junta de Andalucía FEDER US-1261006, US-1263369, P18-RT-190

    On proportionality of the light output of semiconductor scintillators under irradiation by alpha-particles and heavy ions

    No full text
    In the energy range E =2.8...42.2 MeV, the light output S was measured for ZnSe-based scintillators under irradiation with α- particles and heavy ions 81Br. Under such irradiation, the proportionality S(Еα,i) is observed up to energies Еα≤7 MeV. Substantial deviation from linearity in the region of higher energies is explained by different contribution to S from both primary and δ-electrons. Increases were also observed in the values of intrinsic energy resolution with shorter shaping time constants.Виміряно світловий вихід S для сцинтиляторів, заснованих на ZnSe, при опроміненні α-частками і важкими іонами 81Br у діапазоні енергій E =2.8...42.2 МеВ. При опроміненні спостерігалася пропорційність S(Е α ,i) до енергій Еα ≤7 МеВ. Істотне відхилення від лінійності в області більш високих енергій пояснюється різним внеском у S як первинних, так і δ-електронів. Помітний вплив на криву пропорційності і спектри енергії робило легування Te.Измерен световой выход S для сцинтилляторов, основанных на ZnSe, при облучении α-частицами и тяжелыми ионами 81Br в диапазоне энергий E=2.8...42.2 МэВ. При облучении наблюдалась пропорциональность S(Еα,i) до энергий Еα ≤7 МэВ. Существенное отклонение от линейности в области более высоких энергий объясняется различным вкладом в S как первичных, так и и δ-электронов. Заметное влияние на кривую пропорциональности и спектры энергии оказывало легирование Te

    Prolonged oral cannabinoid administration prevents neuroinflammation, lowers β-amyloid levels and improves cognitive performance in Tg APP 2576 mice

    Get PDF
    Background: Alzheimer’s disease (AD) brain shows an ongoing inflammatory condition and non-steroidal antiinflammatories diminish the risk of suffering the neurologic disease. Cannabinoids are neuroprotective and antiinflammatory agents with therapeutic potential. Methods: We have studied the effects of prolonged oral administration of transgenic amyloid precursor protein (APP) mice with two pharmacologically different cannabinoids (WIN 55,212-2 and JWH-133, 0.2 mg/kg/day in the drinking water during 4 months) on inflammatory and cognitive parameters, and on 18F-fluoro-deoxyglucose (18FDG) uptake by positron emission tomography (PET). Results: Novel object recognition was significantly reduced in 11 month old Tg APP mice and 4 month administration of JWH was able to normalize this cognitive deficit, although WIN was ineffective. Wild type mice cognitive performance was unaltered by cannabinoid administration. Tg APP mice showed decreased 18FDG uptake in hippocampus and cortical regions, which was counteracted by oral JWH treatment. Hippocampal GFAP immunoreactivity and cortical protein expression was unaffected by genotype or treatment. In contrast, the density of Iba1 positive microglia was increased in Tg APP mice, and normalized following JWH chronic treatment. Both cannabinoids were effective at reducing the enhancement of COX-2 protein levels and TNF-a mRNA expression found in the AD model. Increased cortical b-amyloid (Ab) levels were significantly reduced in the mouse model by both cannabinoids. Noteworthy both cannabinoids enhanced Ab transport across choroid plexus cells in vitro. Conclusions: In summary we have shown that chronically administered cannabinoid showed marked beneficial effects concomitant with inflammation reduction and increased Ab clearanceThis work was supported by the Spanish Ministry of Science and Technology (SAF 2005-02845 to M.L.C). A.M.M-M. was recipient a fellowship from the Ministry of Education and Scienc

    Compressibility systematics of calcite-type borates : An experimental and theoretical structural study on ABO3 (A = Al, Sc, Fe and In)

    Full text link
    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry C , copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/jp4124259The structural properties of calcite-type orthoborates ABO(3) (A = Al, Fe, Sc, and In) have been investigated at high pressures up to 32 GPa. They were studied experimentally using synchrotron powder X-ray diffraction and theoretically by means of ab initio total-energy calculations. We found that the calcite-type structure remains stable up to the highest pressure explored in the four studied compounds. Experimental and calculated static geometries (unit-cell parameters and internal coordinates), bulk moduli, and their pressure derivatives are in good agreement. The compressibility along the c axis is roughly three times that along the a axis. Our data clearly indicate that the compressibility of borates is dominated by that of the [AO(6)] octahedral group and depends on the size of the trivalent A cations. An analysis of the relationship between isomorphic borates and carbonates is also presented, which points to the potentiality of considering borates as chemical analogues of the carbonate mineral family.This study was supported by the Spanish government MEC under Grant Nos.: MAT2010-21270-C04-01/03/04 and CTQ2009-14596-C02-01, by MALTA Consolider Ingenio 2010 Project (CSD2007-00045), by Generalitat Valenciana (GVA-ACOMP-2013-1012), and by the Vicerrectorado de Investigacion y Desarrollo of the Universidad Politecnica de Valencia (UPV2011-0914 PAID-05-11 and UPV2011-0966 PAID-06-11). We thank ALBA and Diamond synchrotrons for providing beamtime for the XRD experiments. A.M. and P.R-H. acknowledge computing time provided by Red Espanola de Supercomputacion (RES) and MALTA-Cluster. J.A.S. and B.G.-D. acknowledge Juan de la Cierva fellowship and FPI programs for financial support. We are gratefully indebted to Dr. Capponi and Dr. Diehl for supplying us single crystals of AlBO3 and FeBO3, respectively.Santamaría Pérez, D.; Gomis Hilario, O.; Sans, JÁ.; Ortiz, HM.; Vegas, Á.; Errandonea, D.; Ruiz-Fuertes, J.... (2014). Compressibility systematics of calcite-type borates : An experimental and theoretical structural study on ABO3 (A = Al, Sc, Fe and In). Journal of Physical Chemistry C. 118(8):4354-4361. https://doi.org/10.1021/jp4124259S43544361118
    corecore