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Structural Comportment of Extract of Bougainvillea xbuttiana Flower Incorporated in Silica Xerogel Matrix

American Journal of Plant Sciences 2016年第6期7卷 828-833页

作者： José Martínez-Mendoza Erika Espericueta-González Diana Espericueta-González Gerardo Ortega-Zarzosa Azdrubal Lobo Guerrero departamento de Físico-matemáticas Universidad Autónoma de San Luis Potosí San Luis Potosí México Facultad de Ciencias Universidad Autónoma de San Luis Potosí San Luis Potosí México Facultad de Ingeniería Universidad Autónoma de San Luis Potosí San Luis Potosí México Doctorado Institucional de Ciencia e Ingeniería de Materiales Universidad Autónoma de San Luis Potosí San Luis Potosí México Instituto de Física Universidad Autónoma de San Luis Potosí San Luis Potosí México

Measurement of the fluorescence comportment of Bougainvillea xbuttiana flowers embedded in silica xerogels matrix prepared with two different water to tetraethyl-orthosilicate [Si(OC2H5)4] ratio molar of 11 and 5, without heat-treatment, we report the grade of biostability of compound. The structural comportment for the PSI and PSII present in Bougainvillea flower is similar to the structural comportment for these photosystems present in leaves when they are incorporated on inorganic matrix such as silica xerogels. The contribution of the natural pigment of this kind of flower such as betalains which consist of betaxanthins and betacyanins, determines their colors contributed in the range of wavelength from about 550 nm to 660 nm.

关键词： Betalaine Chlorophyll Structure Biostability Sol-Gel

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Thermo-Stability of Natural Products Based on Chlorophyll Species Embedded in Silica Xerogel

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American Journal of Analytical Chemistry 2016年第4期7卷 356-362页

作者： José Martínez-Mendoza Erika Espericueta-González Diana Espericueta González Gerardo Ortega-Zarzosa Azdrubal Lobo Guerrero departamento de Físico-matemáticas Universidad Autónoma de San Luis Potosí San Luis Potosí México Facultad de Ciencias Universidad Autónoma de San Luis Potosí San Luis Potosí México Facultad de Ingeniería Universidad Autónoma de San Luis Potosí San Luis Potosí México Doctorado Institucional de Ciencia e Ingeniería de Materiales Universidad Autónoma de San Luis Potosí San Luis Potosí México Instituto de Física Universidad Autónoma de San Luis Potosí San Luis Potosí México

This work studied the thermostability and the biostability of chlorophyll species obtained from an extract of spinach leaves embedded in a silica xerogel matrix. The analysis was done by monitoring the photosystem II (PSII) using fluorescence spectroscopy. Samples were prepared using the sol gel method with a molar ratio of ethanol/H2O/TEOS of 4:11.6:1. Then, silica xerogel matrix was loaded with an extract of spinach leaves, obtained in dark conditions. The measurement of the fluorescence spectra was done at selected temperatures to the corresponding non-physiological regimen. Results indicate that the PSII band position remains unchanged when heat treatment temperature increases up 200°C. For temperatures above 100?C, the fluorescence intensity diminishes linearly when the temperature increases. The photosystem II embedded in silica xerogel matrix is decomposed at temperatures above 200°C.

关键词： Chlorophyll Structure Biostability Sol-Gel

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Synthesis of Aluminum-doped Zinc Oxide Nanowires Hydrothermally Grown on Plastic Substrate

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Advances in Materials Physics and Chemistry 2012年第4期2卷 56-59页

作者： Concepción Mejía García Elvia Díaz Valdés Ana Ma. Paniagua Mercado Arturo F. Méndez Sánchez José A. Andraca Adame Velumani Subramaniam Josué Romero Ibarra Centro de Nanociencias y Micro y Nanotecnologías del IPN UPALM Luis Enrique Erro S/N México 07738 México departamento de Física Escuela Superior de Física y Matemáticas – IPN Edif. 9 UPALM Col. San Pedro Zacatenco Deleg. GAM México 07738 México depto. de Ing. Eléctrica Sección de Estado Sólido Av. IPN No. 2508 Col. San Pedro Zacatenco México 07360 México

We report the synthesis of undoped ZnO and Al-doped ZnO (ZnO:Al) nanowires grown using a two-step process: (a) preparation of the seed layer, and (b) growth of the nanostructures. In the first step,? 10 mM solutions of zinc acetate dihydrate and 1-propanol were spin coated on polyethylene terephthalate? (PET) substrate at 2000 rpm by 30 s. Vertical nanowires were then grown by dipping the substrates in an equimolar solution of zinc nitrate hexahydrate and hexamethylenetetramine. As doping source, aluminum nitrate nonahydrate powders were added in the solution. In the solutions, Al doping concentrations were established as 0.5 At %, 1.0 At %, 2.0 At % and 3.0 At %, respectively. The hydrothermal process were carried out with a commercially microwave at 140 W power setting. The nanowires were characterized optically and morphologically. XRD patterns show the presence of ZnO, Zn(OH)2 and Zn6Al2O9. Scanning electron microscopy analysis showed that the size of ZnO nanowires was 50 nm in diameter. The undoped ZnO and ZnO:Al nanowires bandgap energy was obtained from optical transmission spectra.

关键词： Nanowires ZnO ZnO:Al Nanowires Spin Coating Hydrothermal Process

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Role of short-term dispersal on the dynamics of Zika virus in an extreme idealized environment

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Infectious Disease Modelling 2017年第1期2卷 21-34页

作者： Victor M.Moreno Baltazar Espinoza derdei Bichara Susan A.Holechek Carlos Castillo-Chavez Simon A.Levin Mathematical Computational and Modeling Sciences CenterArizona State UniversityP.O.Box 873901TempeAZ 85287-3901United States Biodesign Center for Infectious Diseases and Vaccinology Biodesign InstituteArizona State UniversityTempeAZ 85287-5401United States School of Life Sciences Arizona State UniversityTempeAZ 85287-4501United States department of Mathematics and Center for Computational and Applied Mathematics California State UniversityFullertonCA 92831United States departamento the Ingenieria Biomedica Universidad de Los AndesBogotaColombia Rector's Office Yachay Tech UniversityUrcuquiEcuador

In November 2015,El Salvador reported their first case of Zika virus(ZIKV)infection,an event followed by an explosive outbreak that generated over 6000 suspected cases in a period of two *** agencies began implementing control measures that included vector control and recommending an increased use of ***,in response to the alarming and growing number of microcephaly cases in Brazil,the importance of avoiding pregnancies for two years was *** this paper,we explore the role of mobility within communities characterized by extreme poverty,crime and ***,the role of short term mobility between two idealized interconnected highly distinct communities is explored in the context of ZIKV *** make use of a Lagrangian modeling approach within a two-patch setting in order to highlight the possible effects that short-term mobility,within highly distinct environments,may have on the dynamics of ZIKV outbreak when the overall goal is to reduce the number of cases not just in the most affluent areas but *** depend on existing mobility patterns,levels of disease risk,and the ability of federal or state public health services to invest in resource limited areas,particularly in those where violence is *** results of simulations in highly polarized and simplified scenarios are used to assess the role of *** quickly became evident that matching observed patterns of ZIKV outbreaks could not be captured without incorporating increasing levels of *** number of distinct patches and variations on patch connectivity structure required to match ZIKV patterns could not be met within the highly aggregated model that is used in the simulations.

关键词： Vector-borne diseases Zika virus Residence times Multi-patch model

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