Conference Paper
Nano and micro reoriented domains and their relation with the crystal structure in the new Fe 1.5Zn 1.5B 7O 13Cl boracite
Fecha
2008Registro en:
10.1166/jnn.2011.3438
Autor
Ortiz, G.G.
Benitez-King, G.A.
Rosales-Corral, S.A.
Pacheco-Moises, F.P.
Velazquez-Brizuela, I.E.
Institución
Resumen
Molecular oxygen is toxic for anaerobic organisms but it is also obvious that oxygen is poisonous to aerobic organisms as well, since oxygen plays an essential role for inducing molecular damage. Molecular oxygen is a triplet radical in its ground-stage (.O-O.) and has two unpaired electrons that can undergoes consecutive reductions of one electron and generates other more reactive forms of oxygen known as free radicals and reactive oxygen species. These reactants (including superoxide radicals, hydroxyl radicals) possess variable degrees of toxicity. Nitric oxide (NO ) contains one unpaired electron and is, therefore, a radical. NO is generated in biological tissues by specific nitric oxide synthases and acts as an important biological signal. Excessive nitric oxide production, under pathological conditions, leads to detrimental effects of this molecule on tissues, which can be attributed to its diffusion-limited reaction with superoxide to form the powerful and toxic oxidant, peroxynitrite. Reactive oxygen and nitrogen species are molecular "renegades"; these highly unstable products tend to react rapidly with adjacent molecules, donating, abstracting, or even sharing their outer orbital electron(s). This reaction not only changes the target molecule, but often passes the unpaired electron along to the target, generating a second free radical, which can then go on to react with a new target amplifying their effects. This review describes the mechanisms of oxidative damage and its relationship with the most highly studied neurodegenerative diseases and the roles of melatonin as free radical scavenger and neurocytoskeletal protector. " 2008 Bentham Science Publishers Ltd.",,,,,,"10.2174/157015908785777201",,,"http://hdl.handle.net/20.500.12104/39935","http://www.scopus.com/inward/record.url?eid=2-s2.0-53249154949&partnerID=40&md5=b74f0d9baf3097a5f5ac2d4ef75286c6",,,,,,"3",,"Current Neuropharmacology",,"203 214",,"6",,"Scopus WOS",,,,,,"Alzheimer; Melatonin; Neurodegeneration; NO; Oxidative stress; Parkinson",,,,,,"Cellular and biochemical actions of melatonin which protect against free radicals: Role in neurodegenerative disorders",,"Review"
"41683","123456789/35008",,"Pérez, M.A.G., Instituto de Neurociencias, Universidad de Guadalajara, Mexico, Instituto de Neurociencias, Univ. de Guadalajara, Rayo 2611, Guadalajara, Jal., 44520, Mexico; Loyo, J.R., Instituto de Neurociencias, Universidad de Guadalajara, Mexico; Hernández-González, M., Instituto de Neurociencias, Universidad de Guadalajara, Mexico; Madera-Carrillo, H., Instituto de Neurociencias, Universidad de Guadalajara, Mexico; Corsi-Cabrera, M., Facultad de Psicología, Univ. Nac. Auton. de México, Mexico",,"Perez, M.A.G. Loyo, J.R. Hernandez-Gonzalez, M. Madera-Carrillo, H. Corsi-Cabrera, M.",,"2000",,"Both spontaneous (EEG) and evoked (ERPs) brain electrical activity recording has been very useful in the study of brain functional organization. Its recording and analysis, within a researching approach, is mainly make using computers at the present time. The first step is the EEG signals capture for further analysis. In this work it is presented a computational program (CAPTUSEN). created in Pascal language in order to be able to: capture signals from a polygraph through an analog/digital converter; make an on line and outline selection of free artifact samples and; obtain ERPs through EEG averaging. All these is make in an efficient and cheap way and with great flexibility for being adapted to specific research requirements in this field, therefore CAPTUSEN constitutes an important technical contribution in this research field.",,,,,,,,,"http://hdl.handle.net/20.500.12104/39904","http://www.scopus.com/inward/record.url?eid=2-s2.0-0347607126&partnerID=40&md5=d638b06c2989e6f419aa7839708ead28",,,,,,"1",,"Revista Mexicana de Psicologia",,"77 88",,"17",,"Scopus WOS CLASE",,,,,,"Computerized EEG analysis; EEG acquisition; PREs / Psychology",,"Psicofisiología",,,"CAPTUSEN: un sistema para la adquisición computarizada del EEG y los potenciales relacionados a eventos","CAPTUSEN: A system for the computerized acquisition of EEG and event-related potentials [CAPTUSEN: Un Sistema para la Adquisición Computarizada del EEG y los Potenciales Relacionados a Eventos]",,"Article"
"44801","123456789/35008",,"Ulloa-Godínez, S., Centro Universitario de Ciencias Exactas e Ingeniería, Universidad de Guadalajara, Departamento de Electrónica, Av. Revolución No.1500, Planta baja, S.R. C.P. 44840, Guadalajara, Jalisco, Mexico, Facultad de Ingeniería, Universidad Autónoma de Baja California, Blvd. Benito Juarez s/n col. Insurgentes, Mexicali, Baja California, Mexico; Barrera, A., Centro Universitario de la Ciénega, Universidad de Guadalajara, Laboratorio de Materiales, Av. Universidad No. 1115, Colonia Linda Vista, C.P. 47840, Ocotlán, Jalisco, Mexico; Rosales, I., Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, C.P. 01000 México, D. F., Mexico; Bucio, L., Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20-364, C.P. 01000 México, D. F., Mexico; Castillon, F.F., Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 356, C.P. 22800, Ensenada, Baja California, Mexico; Farias, M.H., Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 356, C.P. 22800, Ensenada, Baja California, Mexico; Siqueiros, J.M., Centro de Nanociencias y Nanotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 356, C.P. 22800, Ensenada, Baja California, Mexico; Campa-Molina, J., Centro Universitario de Ciencias Exactas e Ingeniería, Universidad de Guadalajara, Departamento de Electrónica, Av. Revolución No.1500, Planta baja, S.R. C.P. 44840, Guadalajara, Jalisco, Mexico",,"Ulloa-Godinez, S. Barrera, A. Rosales, I. Bucio, L. Castillon, F.F. Farias, M.H. Siqueiros, J.M. Campa-Molina, J.",,"2011",,"New iron-zinc chlorine single crystals of Fe 1.5Zn 1.5B 7O 13Cl boracite were grown by chemical transport reactions in closed quartz ampoules, at a temperature of 1173 K. The crystal structure was characterized by X-ray powder diffraction (XRD) using the Rietveld refinement method and belongs to the trigonal/rombohedral system with space group R3c (No. 161). The cell parameters were a = 8.5726(1) , c = 21.0116(4) , V = 1337.26(3) 3 and Z = 6. The refinement successfully proceeded and ended with sound merit figure values X 2 = 2.25, R B = 6.12%. Chemical analysis was performed with X-ray energy dispersive spectroscopy (EDS) and X-ray fluorescence (XRF). Ferroelectric nano and micro reoriented domains were found in this material using polarizing optical microscopy (PLM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The examination by TEM showed that in the trigonal/rombohedral system of Fe 1.5Zn 1.5B 7O 13Cl nanodomain structures exist. Thin (50-100 nm) mostly planar domains parallel to (100) were frequently observed in Fe 1.5Zn 1.5B 7O 13Cl boracite. Copyright " 2011 American Scientific Publishers.