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Evaluation of natural iron mineral as possible collectors of arsenic and fluoride
Get PDF"En este trabajo se caracterizó y evaluó la remoción de arsénico y fluoruro sobre óxidos de hierro naturales de bajo y alto contenido de Fe, colectados de las principales minas de hierro en operación en México. De los seis materiales evaluados, dos interactúan eficientemente con arsénico y fluoruro. Las isotermas de adsorción de ambos aniones ajustan por el modelo de Langmuir, y las cinéticas de adsorción son lentas para ambos aniones. Se evalúo el efecto de la presencia de arsénico en la capacidad de adsorción de fluoruro, y viceversa. Además, se determinó el efecto del pH y de los aniones coexistentes en agua natural sobre la capacidad de adsorción de arsénico y fluoruro sobre los óxidos de hierro naturales.""Natural iron oxides of low and high Fe content were characterized and evaluated to remove arsenic and fluoride from water. These iron oxides were collected from the main iron ore mines in operation in Mexico. Of the six materials evaluated, two eectively interacted with arsenic and fluoride. Adsorption isotherms of both anions adjusted to the Langmuir model, and adsorption kinetics for both anions were slow. The eect of the presence of arsenic in the fluoride adsorption capacity, and vice verse, was evaluated. Moreover, the eect of pH and the presence of coexisting anions in natural water were determined on the adsorption capacity of arsenic and fluoride on natural iron oxides.
Amaranth protein improves lipid profile and insulin resistance in a diet-induced obese mice model
Get PDF"Amaranth has been claimed as functional food, but its function on obesity-related disorder is not fully known. The aim of this study was to analyse the effect of amaranth protein intake on blood lipids profile and insulin resistance in diet-induced obese mice. The effect of soybean protein was also analysed for comparative purposes. C57BL-6 mice were fed for eight weeks with regular or high fat diet. Amaranth or soybean protein isolates (10 mg/kg) were supplied via oral administration. Changes in body weight, adipose tissue, total cholesterol, triglycerides, insulin, a glucose tolerance test, as well as the expression of lipid metabolism-related genes were measured. Our results have shown that amaranth protein induces a decrease in plasma insulin in mice fed with a regular diet, whereas a decrease in triglycerides was observed in mice fed with high fat diet. Furthermore, down-regulation of Tnf-? and Res, suggested the inhibition of inflammation state. The present study demonstrates that amaranth protein, but not soybean protein, improves the obese mice health, and the hormonal modulation (Lep, Fasn, Lpl) could lead to new mechanism of action by which amaranth consumption exerts its beneficial health effect.
Bioelectrochemical changes during the early stages of chalcopyrite interaction with Acidithiobacillus Thiooxidans and Leptospirillum sp.
Get PDF"A bioelectrochemical study of charge transfer in the biofilm-chalcopyrite interface was performed to investigate the effect of surficial reduced sulfur species (RSS), in the form of non-stochiometric compounds or polysulfides (Sn2?) and elemental sulfur (S0) on a biofilm structure, during the earliest stages (1, 12 and 24 h) of chalcopyrite biooxidation by Acidithiobacillus thiooxidans alone and adding Leptospirillum sp. The surface of massive chalcopyrite electrodes was exposed to the bacteria, which were analyzed electrochemically, spectroscopically, and microscopically. At the studied earlier times, charge transfer and significant differences in the biofilm structure were detected, depending on the presence of Leptospirillum sp. acting on A. thiooxidans biofilms. Such differences were a consequence of a continuous chalcopyrite pitting and promoting changes in biofilm hydrophobicity. A. thiooxidans modifies the reactive properties of RSS and favors an acidic dissolution, which shifts into ferric dissolution when Leptospirillum sp. is present. A. thiooxidans allows H+ and Fe3+ diffusion, and Leptospirillum sp. enables to surpass the charge transfer (reactivity) barrier between the mineral interface and the ions. The observed changes of hydrophobicity on the interface are associated to ions and electrons activity and transfer. Finally, a model of S0 biooxidation by A. thiooxidans alone or with Leptospirillum sp. is proposed
Non-alternating knots: alternation and dealternating numbers
Get PDFTesis (Doctorado en Control y Sistemas Dinámicos)"In this thesis we give formulae to obtain the HOMFLY-PT polynomial of certain oriented 3-tangles and links formed by the closure of them. Also we show formulae for the Conway-Alexander polynomial. We propose a construction to form non-alternating links and give a condition over this construction to obtain only knots. For this construction, the formulae for Conway-Alexander polynomial are explicit and non-recursive. Hence these formulae are easy to implement. The families of the constructed knots contain the first non-alternating knots: 8_19, 8_20, 8_21, 9_42.
Furthermore, by using the Alexander polynomial, some infinite families of non-alternating prime knots, which have alternation number equal to one are given. More specifically, these knots with one crossing change yield 2-bridge knots or the trivial knot. Furthermore, the knots are hyperbolic except for the only two torus knots with alternation number one: 8_19 and 10_124.
On the other hand, for each positive integer n we will prove, by using Khovanov homology, that a family of infinitely many hyperbolic prime knots has alternation number 1, dealternating number equal to n, braid index equal to n+3 and Turaev genus equal to n.""En esta tesis proponemos fórmulas para obtener el polinomio HOMFLY-PT de ciertos 3- ovillos orientados y de enlaces formados con estos 3-ovillos. También mostramos fórmulas para los polinomios de Conway y Alexander. Proponemos una construcción para formar enlaces no alternantes y damos una condición en esta construcción para obtener nudos. Las fórmulas de Conway y Alexander son explícitas y no recursivas, por lo que son fáciles de implementar. Las familias contienen los primeros nudos no alternantes: 819, 820, 821, 942. Además, mostramos familias infinitas de nudos primos con número de alternancia igual a
uno. Más específicamente estos nudos después de un cambio de cruce se vuelven nudos de dos puentes o el nudo trivial. Además, los nudos son hiperbólicos excepto por los dos únicos nudos tóricos con número de alternancia uno, que son 819 y 10124. Por otra parte, para cada entero positivo n probaremos, usando homología de Khovanov, que existe una familia infinita de nudos hiperbólicos primos con número de alternancia igual a uno, número de dealternancia igual a n, índice de trenza igual a n+3 y genero de Turaev igual a n.
Palabras clave: Nudos no alternantes, invariantes polinomiales, número de alternancia, número de dealternancia."CONACYT(262229
Expression analysis of the Arabidopsis thaliana AtSpen2 gene, and its relationship with other plant genes encoding Spen proteins
Get PDF"Proteins of the Split ends (Spen) family are characterized by an N-terminal domain, with one or more RNA recognition motifs and a SPOC domain. In Arabidopsis thaliana, the Spen protein FPA is involved in the control of flowering time as a component of an autonomous pathway independent of photoperiod. The A. thaliana genome encodes another gene for a putative Spen protein at the locus At4g12640, herein named AtSpen2. Bioinformatics analysis of the AtSPEN2 SPOC domain revealed low sequence similarity with the FPA SPOC domain, which was markedly lower than that found in other Spen proteins from unrelated plant species. To provide experimental information about the function of AtSpen2, A. thaliana plants were transformed with gene constructs of its promoter region with uidA::gfp reporter genes; the expression was observed in vascular tissues of leaves and roots, as well as in ovules and developing embryos. There was absence of a notable phenotype in knockout and overexpressing lines, suggesting that its function in plants might be specific to certain endogenous or environmental conditions. Our results suggest that the function of Atspen2 diverged from that of fpa due in part to their different transcription expression pattern and divergence of the regulatory SPOC domain.
Reducción enzimática por alcohol deshidrogenasa TA1316 proveniente de Thermoplasma acidophilum
No full text"In this work we present the NADH-dependent Ta1316 alcohol dehydrogenese (ADH) characterization for its reducingreaction in the presence of aldehydes, ketones and keto-esters. In the presence of 2 mM acetaldehyde, Ta1316 ADHshowed a remarkable thermal activity, displaying activity at temperatures up tp 90”C and low pH with a requirement ofZ+2to reach its maximum activity. In contrast to other characterized ADHs, Ta1316 ADH reduces methyl pyruvate, analpha-ketoester as its preferred substrate. We conclude that Ta1316 ADH’s principalfunction is the reduction of substratesand is potentially an enzyme that can be used in biotechnology, as erll as in industrial applications. ""En este trabajo presentamos la caracterización de la actividad enzimática reductora de la enzima alcohol deshidrogenasa (ADH) Ta1316 dependiente de NADH en presencia de aldehídos, cetonas y ceto ́esteres. La ADH Ta1316 mostr ́o estabilidadt ́ermica notable con actividad m ́axima a temperatura de 90”C y pH ac ́ıdico en presencia del cofactor Zn+2y acetaldeh ́ıdo2 mM. En contraste con otras ADHs caracterizadas, Ta1316 es capaz de reducir metil-piruvato, un alfa-cetoéster como susustrato preferido. Concluimos que la función principal de la Ta1316 ADH es la reducción de sustratos y es una enzima que podría ser utilizada potencialmente en aplicaciones biotecnológicas e industriales.
Generalized Thomas-Fermi equations as the Lampariello class of Emden-Fowler equations
Get PDF"A one-parameter family of Emden-Fowler equations defined by Lampariello's parameter p which, upon using Thomas-Fermi boundary conditions, turns into a set of generalized Thomas-Fermi equations comprising the standard Thomas-Fermi equation for p = 1 is studied in this paper. The entire family is shown to be non integrable by reduction to the corresponding Abel equations whose invariants do not satisfy a known integrability condition. We also discuss the equivalent dynamical system of equations for the standard Thomas-Fermi equation and perform its phase-plane analysis. The results of the latter analysis are similar for the whole class. (C) 2016 Elsevier B.V. All rights reserved.
Análisis del papel de la proteína EPL1 de Trichoderma atroviride en la resistencia a patógenos en Arabidopsis thaliana
Get PDF"Las plantas son organismos sésiles que se encuentran expuestas a diversos tipos de estrés abiótico o biótico. Para sobrevivir han evolucionado mecanismos de defensa que les ayudan a protegerse del ambiente; por ejemplo relaciones benéficas con habitantes de la rizósfera, como es el caso de los hongos del género Trichoderma. Estos hongos han sido ampliamente estudiados por los beneficios que ofrecen a las plantas. Se ha demostrado que la interacción de algunas especies de Trichoderma con las plantas promueve su crecimiento, desarrollo e incluso la resistencia a patógenos. Uno de los mecanismos para promover las respuestas de defensa es a través de elicitores. EPL1 es un elicitor secretado por Trichoderma atroviride que pertenece a la familia de las cerato-plataninas y que se ha descrito que está involucrado en la resistencia a enfermedades en las plantas. El siguiente trabajo se divide en dos capítulos. En el primero se analizó el papel protector que confiere la sobreexpresión de EPL1 en plantas de Arabidopsis contra patógenos. Nuestros datos apuntan a que la expresión de TaEPL1 produce una acumulación de ROS y la inducción de genes relacionados a defensa, incluso antes de la interacción con organismos patógenos, además produce resistencia a enfermedades causadas por Pseudomonas syringae y Botrytis cinerea, principalmente en la línea transgénica EPL1-3. En el segundo capítulo se describe la importancia de determinar la localización intracelular de la proteína EPL1 y su conformación como dímero en plantas. Se espera que estos resultados aporten información transcendente que ayude a inferir la forma de acción de la proteína para activar las respuestas de defensa de la planta. ""Plants are sessile organisms that are exposed to different kinds of abiotic or abiotic
stress. To overcome these, plants have evolved complex defense mechanisms
that help them to protect themselves from the environment; for example, they have
developed benefit relationships with rhizosphere inhabitants like fungi of the
Trichoderma genus. These fungi have been widely studied due to the benefits they
give to the plants. It has been shown that some Trichoderma-plant interaction
promotes plant growth, development and even pathogen resistance. One of the
mechanisms by which the Trichoderma genus fungi induce defense responses is
through elicitors. EPL1 is an elicitor secreted by Trichoderma atroviride that
belongs to the Cerato-platanin protein family and it has been described to be
involved in plant disease resistance. The present work is divided into two chapters.
In the first Chapter, the protective role of the EPL1 overexpression in Arabidopsis
plants against plant pathogens was analyzed. Our data provides evidence that
TaEPL1 expression produces ROS accumulation and induction of defense-related
genes, even before of the plant-pathogen interaction, as well as it confers disease
resistance to Pseudomonas syringae and Botrytis cinerea, especially in the EPL1-3
transgenic plant. The second chapter describes the importance of the
determination of the EPL1 protein intracellular localization and the dimer
conformation in vegetal cells. It is to be expected that this results offer some insight
about the TaEPL1 protein function in the activation of the plant defense responses.
Synthesis of protonated titanate nanotubes tailored by the washing step: Effect upon acid properties and photocatalytic activity
Get PDF"In this work, the acid and photocatalytic properties of titanate nanotubes (NTs) were surveyed. The surface acidity of the NTs was characterized by FTIR with lutidine and pyridine. The photocatalytic degradation of phenol in aqueous suspension was performed to test the photocatalytic properties of the NTs. The results were compared with those obtained from commercial TiO2. NTs were prepared by hydrothermal treatment of TiO2 nanoparticles in a NaOH aqueous solution. During the washing step, three different acid agents (HCl, H2SO4, and HNO3) were used. TiO2 nanoparticles were synthesized previously by the sol-gel method. The photocatalytic materials were characterized by FTIR, XRD, XPS, SBET, UV–vis, and HRTEM.
It was found that the used acid agent significantly affected the amount and type of acid sites. Brönsted acid sites were favored by the use of HNO3. Lewis acid sites were promoted when HCl was employed during the washing step, which is in contrast with the results obtained using the other acids chosen in this work. Besides, the use of HCl promoted the H2Ti3O7 phase. The acid phase H2Ti4O9·H2O was favored when HNO3 was used and H2SO4 formed the H2Ti2O4·(OH)2 acid phase. The presence of Cl, S, and N species on the NTs was not found. Furthermore, Na+ ions were completely removed from the surface of the NTs, which were exchanged by H+ ions.
It was found, in general, that the three catalysts presented a relatively high photocatalytic activity to remove phenol. However, NTs washed with HNO3 (NT-HNO3) displayed the best photocatalytic activity compared to the other NTs. After 200 min, NT-HNO3 reached a phenol degradation yield close to 100%. Commercial TiO2 presented a phenol degradation yield close to 60%. It could be concluded that the acid phase (H2Ti4O9·H2O) and concentration of Brønsted acid sites promoted the photocatalytic activity of NT-HNO3.
Magnetic, thermal and magnetocaloric properties of Ni50Mn35In14.5B0.5 ribbons
Get PDF"The structural, thermal, magnetic, and magnetocaloric properties of Ni50Mn35In14.5B0.5 melt-spun ribbons have been investigated using room-temperature x-ray diffraction (XRD), differential scanning calorimetry (DSC), and magnetization measurements. Magnetic and structural transitions were found to coincide in temperature leading to large magnetocaloric effects associated with the first-order magnetostructural phase transition. In comparison to the bulk Ni50Mn35In14.5B0.5 alloys, both the martensitic transition temperature (TM) and Curie temperature (TC) shifted to lower temperatures. The MCE parameters were found to be comparable to those reported for bulk Ni50Mn35In14.5B0.5 Heusler alloys and Ni48Mn39In13-xBx ribbons. A comparison of magnetic properties and magnetocaloric effects in Ni50Mn35In14.5B0.5 alloys as a ribbon and in their bulk form has been shown in detail. The roles of the magnetic and structural changes on the transition the temperatures of the ribbons are discussed.