Doctor en química con experiencia en Cristales líquidos, materiales fotoconductores, catálisis fotoquímica, fotosensibilizadores y terapia fotodinámica. Responsable de proyectos en Biomateriales que incluyen extractos de productos naturales o nanopartículas metálicas, con actividad biológica, especialmente para el tratamiento de tuberculosis, úlceras (leishmania cutánea), quemaduras, y lesiones a la piel en general. Igualmente ejecuto proyectos multidisciplinarios sobre la terapia fotodinamica del cancer y Tratamiento de efluentes industriales
A morphological and microscopic study of the paste from Nasca pottery has been performed. A stere... more A morphological and microscopic study of the paste from Nasca pottery has been performed. A stereo microscope (x20) and a digital camera were used to study the morphology of the paste while a transmission electron microscope and electron diffraction were used for the study of the microcrystal presents in the paste. The main component of the paste were determined and also some insight about the quality of the paste preparation and calcinations.
Universidad Nacional Mayor de San Marcos, Organismo Internacional de Energia Atomica, Instituto P... more Universidad Nacional Mayor de San Marcos, Organismo Internacional de Energia Atomica, Instituto Peruano de Energia Nuclear.
RESUMEN Se ha aplicado diversas dosis (0-20 kGy) de radiación gamma a muestras de harina de maca ... more RESUMEN Se ha aplicado diversas dosis (0-20 kGy) de radiación gamma a muestras de harina de maca (Lepidium meyenii walp) amarilla, blanca y morada para descontaminarlas. La dosis de radiación gamma necesaria para eliminar los aerobios mesófilos fue 12-15 kGy mientras que para eliminar hongos fue necesario 1-8 kGy, dependiendo del tipo de ecotipo. Se determinó la actividad antioxidante de las muestras irradiadas por el método de neutralización del radical DPPH. Los valores de IC50 de las muestras estudiadas indican que la radiación gamma no modifica sustancialmente la actividad antioxidante de los extractos acuosos de maca amarilla, blanca y morada. En cambio, la actividad antioxidante de los extractos hidroalcohólicos de maca amarilla irradiada disminuye notoriamente, mas no así la de los otros ecotipos. Palabras clave: Maca, radiación gamma, descontaminación, actividad antioxidante. ABSTRACT Various doses (0-20 kGy) of gamma radiation have been applied to samples of maca (Lepidium ...
Se han obtenido hidrogeles de quitosano con alcohol polivinílico (PVA) utilizando radiación gamma... more Se han obtenido hidrogeles de quitosano con alcohol polivinílico (PVA) utilizando radiación gamma. Se presenta un análisis preliminar del tipo de interacción entre las cadenas de quitosano y del PVA en estos hidrogeles. El quitosano en solución disminuye rápidamente su peso molecular por efecto de la radiación gamma, mientras que el PVA en solución acuosa forma hidrogeles luego de ser irradiadas a dosis mayores a 5 kGy. Sin embargo, las mezclas de quitosano y PVA forman hidrogeles en los cuales estos polímeros no se degradan significativamente, y forman hidrogeles estables. Presentamos evidencias que sugieren que las cadenas de PVA y quitosano están entrecruzadas covalentemente. Esto se explica en términos de reactividad de los radicales formados por radiación gamma.
The present work studies the improvement of the physical properties wood-polymer composites obtai... more The present work studies the improvement of the physical properties wood-polymer composites obtained by means of infiltration in vacuum of styrene-polyester, methyl methacrylate, and their mixtures. The polymerization was done by gamma radiation and microwaves. Capirona, Oje Blanco and Cumala woods, were used in this study. The polymerization by microwaves depends on the working power. High power produces bubbles, deformation and fractures of the obtained polymer. The minimum dose to provoke the polymerization by gamma radiation is 14 kGy. The wood-polymer composites show low water absorption in comparison with the non-treated wood.
The antioxidant activity, total polyphenol content and antimicrobial activity of different extrac... more The antioxidant activity, total polyphenol content and antimicrobial activity of different extracts from dragon's blood, Croton lechleri, powder have been evaluated. The fractions obtained with ethanol, methanol, water-alcohol solution and ethyl acetate treatment have different characteristics. The ethanol fraction has the highest antioxidant activity, while the original latex has the highest content of total polyphenols. However, the water-alcohol solution has higher antimicrobial activity against S. aureus.
Various doses (0-20 kGy) of gamma radiation have been applied to samples of maca (Lepidium meyeni... more Various doses (0-20 kGy) of gamma radiation have been applied to samples of maca (Lepidium meyenii walp) flour, yellow, white and purple ecotypes, to decontaminate them. The gamma radiation dose required to eliminate the aerobic mesophiles was 12-15 kGy while it was necessary to applied 1-8 kGy to kill fungi, depending on the ecotype of Maca. We have determined the antioxidant activity of the irradiated samples by the method of neutralization of DPPH radical. IC50 values of the studied samples indicate that gamma radiation does not substantially alter the antioxidant activity of aqueous extracts of maca yellow, white and purple. In contrast, the antioxidant activity of hydroalcoholic extracts of irradiated maca yellow decrease sharply, but not the other ecotypes.
TiO2-doped polyvinyl alcohol films (PVA) have been prepared from a suspension of TiO2 nanoparticl... more TiO2-doped polyvinyl alcohol films (PVA) have been prepared from a suspension of TiO2 nanoparticles in PVA 10% water solution. The suspension was stabilized by ultrasound
Chitosan-polyvinyl(alcohol) films containing dragon’s blood (Croton lechleri) hydro alcoholic, al... more Chitosan-polyvinyl(alcohol) films containing dragon’s blood (Croton lechleri) hydro alcoholic, alcoholic and aqueous extract have been prepared and their antimicrobial properties against S. aureus, E. coli and P. aeruginosa have been evaluated. These films as well as the latex exhibit activity against S. aureus only and have potential application as wound healing material.
The preparation of an oligomeric complex obtained from the reaction of 1,1'-bis(octadecyl)-2,... more The preparation of an oligomeric complex obtained from the reaction of 1,1'-bis(octadecyl)-2,2'-benzimidazole and CoCl2 is reportad. This oligomero has been characterized by UV-visible spectroscopy, FT-IR and 1 H-RMN. The elemental analysis does not throw a defined relation between cobalt and the ligand. The oligomeric complex undergoes decomposition when heating according to ose analysis.
Hydrogels of poly(vinyl alcohol) (PVA) – poly(vinyl pyrrolidone) (PVP) has been obtained using ga... more Hydrogels of poly(vinyl alcohol) (PVA) – poly(vinyl pyrrolidone) (PVP) has been obtained using gamma radiation, 10-30 kGy. The PVP films exhibit a greater swelling degree than those of PVA, 1600 and 350% respectively. In contrast the PVA films are those that arrive at their point of saturation faster than those from PVP, being those of PVA-PVP those that present a quite slow swelling. Transparent hydrogels with good adhesiveness and good mechanical properties were obtained. These properties show that these films have a good potential to be used as polymeric matrix in skin disordered treatment.
The intracellular localization of a lipophilic alkyl long-chain tetraphenylporphyrin in electrocy... more The intracellular localization of a lipophilic alkyl long-chain tetraphenylporphyrin in electrocytes, Psammobatis extenta (Rajidae) is described. In contrast to the usual case, this porphyrin derivative was localized in electromotor nerves and in nuclei chromatin of electrocytes. Both structures exhibited intense fluorescence. However, the mitochondria were slightly fluorescent. These data are discussed in relation to electrocyte death in a weak electric fish. Additionally, the electron probe X-ray microanalysis suggest the activation of the chloride and cationic channels.
Third World Academy of Science (TWAS) por el financiamiento parcial de este trabajo que cubre un ... more Third World Academy of Science (TWAS) por el financiamiento parcial de este trabajo que cubre un aspecto del proyecto de investigacion: “Leishmanicidal effects of Croton lechlery extract desorbed from a biopolymer”.
Instituto Peruano de Energia Nuclear - Organismo Internacional de Energia Atomica (OIEA) Proyecto... more Instituto Peruano de Energia Nuclear - Organismo Internacional de Energia Atomica (OIEA) Proyecto: CRP PER13058.
Revista Peruana De Quimica E Ingenieria Quimica, 2003
... de electrocitos tratados con 1 en: a) xiieno-EtOH-buffer imidazol yb) CHCI3 (x1C0) 2.3 Cambio... more ... de electrocitos tratados con 1 en: a) xiieno-EtOH-buffer imidazol yb) CHCI3 (x1C0) 2.3 Cambios morfológicos de los electrocitos La Figura 3a muestra una micrografia SEM de la cara no inervada ... 1-18. [17]EM Schwiebert, L. Cid-Soto, D. Stafford, M. Carter, С Blaisdell, P.Zeitlin ...
A morphological and microscopic study of the paste from Nasca pottery has been performed. A stere... more A morphological and microscopic study of the paste from Nasca pottery has been performed. A stereo microscope (x20) and a digital camera were used to study the morphology of the paste while a transmission electron microscope and electron diffraction were used for the study of the microcrystal presents in the paste. The main component of the paste were determined and also some insight about the quality of the paste preparation and calcinations.
Universidad Nacional Mayor de San Marcos, Organismo Internacional de Energia Atomica, Instituto P... more Universidad Nacional Mayor de San Marcos, Organismo Internacional de Energia Atomica, Instituto Peruano de Energia Nuclear.
RESUMEN Se ha aplicado diversas dosis (0-20 kGy) de radiación gamma a muestras de harina de maca ... more RESUMEN Se ha aplicado diversas dosis (0-20 kGy) de radiación gamma a muestras de harina de maca (Lepidium meyenii walp) amarilla, blanca y morada para descontaminarlas. La dosis de radiación gamma necesaria para eliminar los aerobios mesófilos fue 12-15 kGy mientras que para eliminar hongos fue necesario 1-8 kGy, dependiendo del tipo de ecotipo. Se determinó la actividad antioxidante de las muestras irradiadas por el método de neutralización del radical DPPH. Los valores de IC50 de las muestras estudiadas indican que la radiación gamma no modifica sustancialmente la actividad antioxidante de los extractos acuosos de maca amarilla, blanca y morada. En cambio, la actividad antioxidante de los extractos hidroalcohólicos de maca amarilla irradiada disminuye notoriamente, mas no así la de los otros ecotipos. Palabras clave: Maca, radiación gamma, descontaminación, actividad antioxidante. ABSTRACT Various doses (0-20 kGy) of gamma radiation have been applied to samples of maca (Lepidium ...
Se han obtenido hidrogeles de quitosano con alcohol polivinílico (PVA) utilizando radiación gamma... more Se han obtenido hidrogeles de quitosano con alcohol polivinílico (PVA) utilizando radiación gamma. Se presenta un análisis preliminar del tipo de interacción entre las cadenas de quitosano y del PVA en estos hidrogeles. El quitosano en solución disminuye rápidamente su peso molecular por efecto de la radiación gamma, mientras que el PVA en solución acuosa forma hidrogeles luego de ser irradiadas a dosis mayores a 5 kGy. Sin embargo, las mezclas de quitosano y PVA forman hidrogeles en los cuales estos polímeros no se degradan significativamente, y forman hidrogeles estables. Presentamos evidencias que sugieren que las cadenas de PVA y quitosano están entrecruzadas covalentemente. Esto se explica en términos de reactividad de los radicales formados por radiación gamma.
The present work studies the improvement of the physical properties wood-polymer composites obtai... more The present work studies the improvement of the physical properties wood-polymer composites obtained by means of infiltration in vacuum of styrene-polyester, methyl methacrylate, and their mixtures. The polymerization was done by gamma radiation and microwaves. Capirona, Oje Blanco and Cumala woods, were used in this study. The polymerization by microwaves depends on the working power. High power produces bubbles, deformation and fractures of the obtained polymer. The minimum dose to provoke the polymerization by gamma radiation is 14 kGy. The wood-polymer composites show low water absorption in comparison with the non-treated wood.
The antioxidant activity, total polyphenol content and antimicrobial activity of different extrac... more The antioxidant activity, total polyphenol content and antimicrobial activity of different extracts from dragon's blood, Croton lechleri, powder have been evaluated. The fractions obtained with ethanol, methanol, water-alcohol solution and ethyl acetate treatment have different characteristics. The ethanol fraction has the highest antioxidant activity, while the original latex has the highest content of total polyphenols. However, the water-alcohol solution has higher antimicrobial activity against S. aureus.
Various doses (0-20 kGy) of gamma radiation have been applied to samples of maca (Lepidium meyeni... more Various doses (0-20 kGy) of gamma radiation have been applied to samples of maca (Lepidium meyenii walp) flour, yellow, white and purple ecotypes, to decontaminate them. The gamma radiation dose required to eliminate the aerobic mesophiles was 12-15 kGy while it was necessary to applied 1-8 kGy to kill fungi, depending on the ecotype of Maca. We have determined the antioxidant activity of the irradiated samples by the method of neutralization of DPPH radical. IC50 values of the studied samples indicate that gamma radiation does not substantially alter the antioxidant activity of aqueous extracts of maca yellow, white and purple. In contrast, the antioxidant activity of hydroalcoholic extracts of irradiated maca yellow decrease sharply, but not the other ecotypes.
TiO2-doped polyvinyl alcohol films (PVA) have been prepared from a suspension of TiO2 nanoparticl... more TiO2-doped polyvinyl alcohol films (PVA) have been prepared from a suspension of TiO2 nanoparticles in PVA 10% water solution. The suspension was stabilized by ultrasound
Chitosan-polyvinyl(alcohol) films containing dragon’s blood (Croton lechleri) hydro alcoholic, al... more Chitosan-polyvinyl(alcohol) films containing dragon’s blood (Croton lechleri) hydro alcoholic, alcoholic and aqueous extract have been prepared and their antimicrobial properties against S. aureus, E. coli and P. aeruginosa have been evaluated. These films as well as the latex exhibit activity against S. aureus only and have potential application as wound healing material.
The preparation of an oligomeric complex obtained from the reaction of 1,1'-bis(octadecyl)-2,... more The preparation of an oligomeric complex obtained from the reaction of 1,1'-bis(octadecyl)-2,2'-benzimidazole and CoCl2 is reportad. This oligomero has been characterized by UV-visible spectroscopy, FT-IR and 1 H-RMN. The elemental analysis does not throw a defined relation between cobalt and the ligand. The oligomeric complex undergoes decomposition when heating according to ose analysis.
Hydrogels of poly(vinyl alcohol) (PVA) – poly(vinyl pyrrolidone) (PVP) has been obtained using ga... more Hydrogels of poly(vinyl alcohol) (PVA) – poly(vinyl pyrrolidone) (PVP) has been obtained using gamma radiation, 10-30 kGy. The PVP films exhibit a greater swelling degree than those of PVA, 1600 and 350% respectively. In contrast the PVA films are those that arrive at their point of saturation faster than those from PVP, being those of PVA-PVP those that present a quite slow swelling. Transparent hydrogels with good adhesiveness and good mechanical properties were obtained. These properties show that these films have a good potential to be used as polymeric matrix in skin disordered treatment.
The intracellular localization of a lipophilic alkyl long-chain tetraphenylporphyrin in electrocy... more The intracellular localization of a lipophilic alkyl long-chain tetraphenylporphyrin in electrocytes, Psammobatis extenta (Rajidae) is described. In contrast to the usual case, this porphyrin derivative was localized in electromotor nerves and in nuclei chromatin of electrocytes. Both structures exhibited intense fluorescence. However, the mitochondria were slightly fluorescent. These data are discussed in relation to electrocyte death in a weak electric fish. Additionally, the electron probe X-ray microanalysis suggest the activation of the chloride and cationic channels.
Third World Academy of Science (TWAS) por el financiamiento parcial de este trabajo que cubre un ... more Third World Academy of Science (TWAS) por el financiamiento parcial de este trabajo que cubre un aspecto del proyecto de investigacion: “Leishmanicidal effects of Croton lechlery extract desorbed from a biopolymer”.
Instituto Peruano de Energia Nuclear - Organismo Internacional de Energia Atomica (OIEA) Proyecto... more Instituto Peruano de Energia Nuclear - Organismo Internacional de Energia Atomica (OIEA) Proyecto: CRP PER13058.
Revista Peruana De Quimica E Ingenieria Quimica, 2003
... de electrocitos tratados con 1 en: a) xiieno-EtOH-buffer imidazol yb) CHCI3 (x1C0) 2.3 Cambio... more ... de electrocitos tratados con 1 en: a) xiieno-EtOH-buffer imidazol yb) CHCI3 (x1C0) 2.3 Cambios morfológicos de los electrocitos La Figura 3a muestra una micrografia SEM de la cara no inervada ... 1-18. [17]EM Schwiebert, L. Cid-Soto, D. Stafford, M. Carter, С Blaisdell, P.Zeitlin ...
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