El tratamiento oncológico actúa no sólo en los tejidos enfermos, sino también sobre las células sanas, durante este proceso suelen ocurrir efectos secundarios que pueden aparecer bajo la forma de complicaciones bucales y sistémicas. Son ejemplos mucositis, xerostomía, las infecciones, bacterianas víricas y fúngicas. Objetivo: Evaluar la frecuencia de complicaciones bucales en los niños con cáncer que asistieron a la Facultad de Odontología ntes del tratamiento antineoplásico y seis meses después de haber recibido oncoterapia yentrenamiento, para el control de las mismas. Materiales y métodos: La muestra estuvo constituida por 100 niños con diagnóstico de cáncer que procedían de los diferentes hospitales y clínicas privadas de Caracas y sus alrededores. Se realizó un cuestionario a los representantes que acompañaban al niño, en el momento de la primera visit...

El tratamiento oncológico actúa no sólo en los tejidos enfermos, sino también sobre las células sanas, durante este proceso suelen ocurrir efectos secundarios que pueden aparecer bajo la forma de complicaciones bucales y sistémicas. Son ejemplos mucositis, xerostomía, las infecciones, bacterianas víricas y fúngicas. Objetivo: Evaluar la frecuencia de complicaciones bucales en los niños con cáncer que asistieron a la Facultad de Odontología ntes del tratamiento antineoplásico y seis meses después de haber recibido oncoterapia yentrenamiento, para el control de las mismas. Materiales y métodos: La muestra estuvo constituida por 100 niños con diagnóstico de cáncer que procedían de los diferentes hospitales y clínicas privadas de Caracas y sus alrededores. Se realizó un cuestionario a los representantes que acompañaban al niño, en el momento de la primera visit...

The present study has as main objecuve the search of new materials, among them the porous materials whose diversity of pore diameter confers lO the same specific properties, those that in turn determine a series of applications like adsorbents. catalysts, and shield materials, among others. The investigatíon consists of the synthes1s of macroporous materials by the method Sol-Gel, using reactive of low cost as sodium silicate (silicon source) and includes/understanos the following stages: 1) control of hydrolysis of the inorganic precursors: 2) formatíon oí the rnacrostructure material (hydrothermal synthesis) and 3) elimination of the organic matter by calcinations. The structural characterization and the degree of crystalinidad were made by means of Diffraction of Rays-X (DRX) and Electronic Diffraction of Area Selecta.(DEAS), whereas the morphologic analysis was made through an Ele...

The present study has as main objecuve the search of new materials, among them the porous materials whose diversity of pore diameter confers lO the same specific properties, those that in turn determine a series of applications like adsorbents. catalysts, and shield materials, among others. The investigatíon consists of the synthes1s of macroporous materials by the method Sol-Gel, using reactive of low cost as sodium silicate (silicon source) and includes/understanos the following stages: 1) control of hydrolysis of the inorganic precursors: 2) formatíon oí the rnacrostructure material (hydrothermal synthesis) and 3) elimination of the organic matter by calcinations. The structural characterization and the degree of crystalinidad were made by means of Diffraction of Rays-X (DRX) and Electronic Diffraction of Area Selecta.(DEAS), whereas the morphologic analysis was made through an Ele...

Driven by the demand to understand and quantify the magnetic properties of superconducting materials, the ac- and dc-magnetic susceptibility has emerged as a valuable technique in the superconductivity field; allowed us to quantify: superconducting critical temperature, Meissner and diamagnetic shielding fractions, Curie constant, Curie-Weiss temperature and effective Bohr magnetón.

The edible mushroom Pleurotus ostreatus have been subjected to thermal, chemical and thermal-chemical treatment. The results show that the chemical treatment produces a more effective enzymatic inactivation compared to the other two treatments. Also, the experimental study of fungi dehydration carried out at 55 ° C reveals that the critical moisture content is 10.4 kg water / kg dry solids, the equilibrium moisture is 0.22 kg water / kg of solid .

The edible mushroom Pleurotus ostreatus have been subjected to thermal, chemical and thermal-chemical treatment. The results show that the chemical treatment produces a more effective enzymatic inactivation compared to the other two treatments. Also, the experimental study of fungi dehydration carried out at 55 ° C reveals that the critical moisture content is 10.4 kg water / kg dry solids, the equilibrium moisture is 0.22 kg water / kg of solid .

In April 2011 took place in the world’s first 100 years of the discovery of superconductivity. Super- conductivity has been the focus of fundamental solid state physics, applied sciences and engineering. Today it is possible to use superconducting materials in a first generation of superconducting devices and in the near future in magnetically levitated trains, superconducting wires, quantum computers, new generation mobile phones, new MRI equipment, etc. The group of superconducting ceramic oxide materials belonging to the UNMSM have studied with great interest the YBa2 Cu3 O7 superconducting material, investigating the incorporation of different cations and anions in different atomic sites in the YBa2 Cu3 O7 structure, as well as derivatives of this structure, to understand their structural, chemical and superconducting properties, then proposing new superconducting compounds. We cel...

The main objective of this work to estab1ish the controlled use of heat as a function of the pH in order to destroy all the microorganisms that are this bacterias anaerobic forced thermopiles and essentially mesófilas. The bacteria more resistant esporulada to 1he heat is Clostridium botulinum and it is considered lndicative microorganísm of the sterellization. Another parameter of very important control is the quality of the matter it prevails that it can resist the operations of thermal prcsecution, the classification is made in function to the hat size, weight, color and it forms.

The main objective of this work to estab1ish the controlled use of heat as a function of the pH in order to destroy all the microorganisms that are this bacterias anaerobic forced thermopiles and essentially mesófilas. The bacteria more resistant esporulada to 1he heat is Clostridium botulinum and it is considered lndicative microorganísm of the sterellization. Another parameter of very important control is the quality of the matter it prevails that it can resist the operations of thermal prcsecution, the classification is made in function to the hat size, weight, color and it forms.

En el presente trabajo estudiamos la textura de capas superconductoras de YBa2Cu3O7-da través de la difracción de rayos-X. Las capas fueron crecidas sobre el sustrato monocristalino SrTiO3 (100) mediante la deposición de solución química. Posteriormente se sometió la muestra a tratamientos térmicos en una atmósfera oxidante. Una caracterización mediante difracción de rayos-X revela la presencia de reflexiones (00l) para la fase de YBa2Cu3O7-d con una fracción de granos superconductores orientados eje-c del 70%. Mediciones de la Rocking Curves permiten observar 3 regiones texturizadas fuera del plano del sustrato, con valores de FWHM 0.35°; 0.83° y 1.0°.

Y Ba2Cu3O7 epitaxial superconducting film is consequence of an optimum epitaxial growth process of superconducting grains. Also, the substrate's epitaxy has a direct repercussion on the lm microstructure and its physical properties. Conventional characterization techniques such as: scanning electronic microscopy, and x ray difrraction, allowed us to obtain a quick assessment of epitaxy quality through of texture quantification of the film. We present the results of texture quantification in Y Ba2Cu3O7 superconducting films.

En el presente trabajo estudiamos la textura de capas superconductoras de YBa2Cu3O7-da través de la difracción de rayos-X. Las capas fueron crecidas sobre el sustrato monocristalino SrTiO3 (100) mediante la deposición de solución química. Posteriormente se sometió la muestra a tratamientos térmicos en una atmósfera oxidante. Una caracterización mediante difracción de rayos-X revela la presencia de reflexiones (00l) para la fase de YBa2Cu3O7-d con una fracción de granos superconductores orientados eje-c del 70%. Mediciones de la Rocking Curves permiten observar 3 regiones texturizadas fuera del plano del sustrato, con valores de FWHM 0.35°; 0.83° y 1.0°.

En el presente trabajo, sintesizamos y caracterizamos nanopartículas magnéticas de maghemita & gamma;-Fe2O3utiles para aplicaciones biomédicas. En el proceso químico de co-precipitación, una solución precursora de magnetita fue oxidizada ajustando el pH=3.5 a 80℃ en un ambiente ácido. El diámetro de los granos de las nanopartículas obtenidas de maghemita fueron calculados de las mediciones TEM y muestran nanopartículas de menos de 12 nm de tamaño. Las curvas de magnetización FC y ZFC medidas a 1 kOe indican una temperatura de bloqueo de 95 K. La curva M-H revela una coercitividad de cero a temperatura ambiente. La función paramagnética de Langevin fue usada para ajustar la curva de histéresis a 300 K para estimar el diámetro de los granos en la nanomuestra.

In this work we report the structural and electronic properties of the compound [Y0.8Ca0.2](Ba0.5Sr0.5)2Cu3O7-δ (YCaBaSr) which is a superconductor below the critical temperature TC = 80 K. This compound was prepared using the Sol-Gel method. The structural properties were studied by X-ray diffraction and electronic properties were studied by X-ray Photoemission Spectroscopy (XPS). The results were compared with those ones of the traditional superconductor YBa2Cu3O7-δ (YBCO). The X-ray photoemission spectra were taken at room temperature (normal state) and at 30 K (superconductor state). In the superconductor state, the X-ray photoemission spectra showed a shift in the O 1s. While the position of the Cu3p principal peaks do not change when measuring at 30 K. However, the spectra reveal the appearance of a new peak due to de hybridization of the Cu3d and O2p states. In addition, the Fou...

En este trabajo se reporta las propiedades estructurales y electrónicas del compuesto [Y0.8Ca0.2](Ba0.5Sr0.5)2Cu3O7-δ (YCaBaSr) que es superconductor con temperatura crítica TC = 80 K. El compuesto fue preparado mediante el método Sol-Gel. Las propiedades estructurales y electrónicas de este compuesto se estudiaron mediante difracción de rayos X (DRX) y espectroscopia de fotoemisión de rayos X (XPS) respectivamente. Los resultados fueron comparados con los del superconductor tradicional YBa2Cu3O7- δ (YBCO). Las medidas por XPS se realizaron a temperatura ambiente (en el estado normal) y a 30 K (estado superconductor). En el estado superconductor, los espectros XPS de ambos compuestos muestran corrimiento en el pico O 1s. Mientras que, la posición de los picos principales del Cu 3p no cambian de posición al ser medidos a 30 K y 293 K. Sin embargo, se observa en el espectro la ap...

We present the synthesis of YBa2Cu3O7-x superconductor oxide with critical temperature - 92 K, by Sol-Gel method. The synthesis of this superconducting compound was performed by using oxalate precursor solution which were prepared by dissolving stoichiometric mixtures of the Y(OOCCH3)•4H2O; Ba(OOCCH3)2 and Cu(OOCCH3)2•H2O acetates in an aqueous solution of oxalic acid, HCOO-COOH. The gel obtained was calcined at 860 oC and then fired at 920 oC in oxidizing atmosphere. The characterization of this superconducting ceramic was performed by x-ray diffraction, micro-Raman spectroscopy and SQUID techniques.

We present the synthesis of YBa2Cu3O7-x superconductor oxide with critical temperature - 92 K, by Sol-Gel method. The synthesis of this superconducting compound was performed by using oxalate precursor solution which were prepared by dissolving stoichiometric mixtures of the Y(OOCCH3)•4H2O; Ba(OOCCH3)2 and Cu(OOCCH3)2•H2O acetates in an aqueous solution of oxalic acid, HCOO-COOH. The gel obtained was calcined at 860 oC and then fired at 920 oC in oxidizing atmosphere. The characterization of this superconducting ceramic was performed by x-ray diffraction, micro-Raman spectroscopy and SQUID techniques.

Eating mushrooms are an alternative, which provide high biological and nutritional values, because of their proteins and the high level of their macro nutrients.

En el presente trabajo desarrollamos y adecuamos una tecnología de cultivo y producción de hongos comestibles.