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SEM, AFM and CLSM microscopic techniques as tools for characterization of cellulose, polyaluminum and aluminum recovered from Tetra Pak packaging

CARLOS EDUARDO BARRERA DIAZ Liliana Ivette Ávila Córdoba FERNANDO UREÑA NUÑEZ GONZALO MARTINEZ BARRERA VICTOR VARELA GUERRERO LILIANA ROSALES HERNANDEZ (2017)

In this chapter, the characterization of the morphological features of sub-products of Tetra Pak packaging using SEM, AFM and CLSM microscopic techniques is presented. In a first step, the separation of the components of the Tetra Pak was done using hydropulping mechanical process; the principal obtained products include cellulose, aluminium and polyethylene+aluminum. The last one called Polyaluminum. After this, the morphological analysis was obtained. The results show that such microscopy techniques are adequate for describe the high degree of purity of the components after recycling.

Book part

SEM AFM CLSM Microscopy Cellulose Polyaluminum Tetra Pak BIOLOGÍA Y QUÍMICA

Efecto de la metformina sobre marcadores bioquímicosmoleculares y secreción de exosomas en células HUH7 con resistencia a insulina.

JOSE MANUEL VILLALVA PEREZ (2020)

Liver-specific insulin resistance is associated with the development of the main challenges in metabolism resulting in dyslipidemia, hyperinsulinemia and hyperglycemia. In vitro models developed for researching the hepatic insulin resistance are limited and employed cell lines without similar characteristics to primary human hepatocytes.

Master thesis

Insulin resistance Huh7 cells Metformin insulin resistance biomarkers BIOLOGÍA Y QUÍMICA QUÍMICA BIOQUÍMICA

ANALYSIS OF HYBRID PEROVSKITE FILMS (MAPbI3) FABRICATED BY THE ONE AND TWO-STEPS METHODS

Diana Marcela Montoya (2021)

"In this work, the one-step and the two-step methods were used to deposit MAPbI3 perovskite films. For both methods, there are several variables to control the perovskite formation and film quality. The influence of anti-solvent, the time for its addition, and the annealing temperature on the features of perovskite films were studied for the one-step method. The temperature for deposition of the inorganic film was studied for the close-spaced sublimation method, and the time that MAI-solution remains onto the PbI2 film before the spin process began was studied for spin-coating with sequential deposition methods."

Doctoral thesis

Perovskite Solar cells MAPbI3 CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA ÓPTICA ÓPTICA

Increased micronuclei and nuclear abnormalities in buccal mucosa and oxidative damage in saliva from patients with chronic and aggressive periodontal diseases

BLANCA PATRICIA LAZALDE RAMOS (2014)

Background and objective

Periodontal disease is a chronic bacterial infection characterized by connective tissue breakdown and alveolar bone destruction because of inflammatory and immune response caused by periodontopathogens and long-term release of reactive oxygen species. A high number of reactive oxygen species result in periodontal tissue damage through multiple mechanisms such as lipid peroxidation, protein denaturation and DNA damage. The aim of this study was to evaluate DNA and oxidative damage in subjects with chronic or aggressive periodontitis and healthy controls.

Material and methods

Buccal mucosa cells and whole saliva were collected from 160 subjects, who were divided into three groups: subjects with chronic periodontitis (CP) (n = 58), subjects with aggressive periodontitis (AgP) (n = 42) and a control group (n = 60). DNA damage was determined by counting micronuclei (MN) and nuclear abnormalities (NAs) in exfoliated cells, including binucleated cells, cells with nuclear buds and karyolitic, karyorrhectic, condensed chromatin and pyknotic cells. The degree of oxidative stress was determined by quantifying 8-hydroxy-2'-deoxyguanosine (8-OHdG) in whole saliva.

Results

Subjects with CP or AgP presented significantly more ( p < 0.05) MN and NAs and higher levels of 8-OHdG ( p < 0.05) compared with the control group.

Conclusion

Our results indicate that subjects with periodontitis (CP or AgP) exhibited an increase in the frequency of MN, NAs and 8-OHdG, which is directly related to DNA damage. In addition, a positive correlation exists between oxidative stress produced by periodontitis disease and MN.

Producción Científica de la Universidad Autónoma de Zacatecas UAZ

Article

BIOLOGÍA Y QUÍMICA Periodontal disease chronic bacterial infection Buccal mucosa cells

Evaluation of phthalates exposition in sirtuin transcription in HepG2 cells and its toxicity in human hematopoietic stem cells

Evaluación de la exposición de ftalatos en la transcripción de sirtuinas en células HepG2 y su toxicidad en células madre hematopoyéticas humanas

ANA KAREN GUTIERREZ GARCIA (2020)

"Plasticizers are substances incorporated into plastic polymers to increase their flexibility and workability. Phthalic acid esters (phthalates) were developed for use as plasticizers in the 1920´s and more than 8 million tons of plasticizers are sold globally every year, representing the 70% of all current industrial plasticizers. Phthalates are not covalently bound to the plastic polymer and can migrate to the environment. Therefore, humans are exposed to these compounds; its exposure has been associated with delays in fertility, increased risk of allergies, asthma, obesity, diabetes and cancer. Due to the potential hazard to human health and the environment, several international health and environment organizations have classified phthalates as priority pollutants. Therefore, the cytotoxicity of diisononyl phthalate (DINP) was evaluated on sirtuin expression in HepG2 cells and its effect on the levels of reactive oxygen species (ROS). Results showed that 1 μg/mL DINP significantly down-regulated Sirt1, Sirt2, Sirt3, and Sirt5 gene expression. Furthermore, protein levels of Sirt1 and Sirt3 were significantly down-accumulated by 1 μg/mL DINP. On the other hand, 100 μg/mL DINP doubled the levels of lysine acetylation proteins as well as reactive oxygen species (ROS). Also, the effect of four phthalates: dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), diethyl phthalate (DEP) and diethylhexyl phthalate (DEHP) was evaluated on the in vitro expansion of human hematopoietic cells. For this, 0.5 x 106 cells/mL were exposed to concentrations ranging from 0.1 to 100 µg/mL and the total cell expansion was determined after 14 days of culture in IMDM-cytokines medium. The control cultures attained 1.31 ± 0.21 x 106 cell/mL, whereas the cultures exposed to DBP, BBP and DEHP showed a reduction from 23 to 81%, 17 to 69% and 15 to 93.5%, respectively."

"Los plastificantes son sustancias incorporadas en polímeros plásticos para

aumentar su flexibilidad y maleabilidad. Los ésteres de ácido ftálico (ftalatos) se

desarrollaron para su uso como plastificantes en la década de 1920 y cada año se

venden más de 8 millones de toneladas de plastificantes en todo el mundo,

representando el 70% de todos los plastificantes industriales actuales. Los ftalatos

no están unidos covalentemente al polímero plástico y pueden migrar al medio

ambiente. Por lo tanto, los humanos están expuestos a estos compuestos; su

exposición se ha asociado con retrasos en la fertilidad, un mayor riesgo de alergias,

asma, obesidad, diabetes y cáncer. Debido al peligro potencial para la salud

humana y el medio ambiente, varias organizaciones internacionales de salud y

medio ambiente han clasificado los ftalatos como contaminantes prioritarios. Por lo

tanto, evaluamos la citotoxicidad del diisononil ftalato (DINP), su efecto sobre la

expresión de sirtuinas en células HepG2 y su efecto sobre los niveles de especies

reactivas de oxígeno (ROS). Los resultados mostraron que 1 μg/mL DINP disminuyó

significativamente la expresión de los genes Sirt1, Sirt2, Sirt3 y Sirt5. Además, los

niveles de proteínas de Sirt1 y Sirt3 fueron significativamente disminuidos por 1

μg/mL DINP. Por otro lado, 100 μg/mL DINP duplicaron los niveles de proteínas de

acetilación en lisina, así como las especies reactivas de oxígeno. Además,

evaluamos el efecto de cuatro ftalatos dibutil ftalato (DBP), bencil butil ftalato (BBP),

dietil ftalato (DEP) y dietilhexil ftalato (DEHP) en la expansión in vitro de células

hematopoyéticas humanas. Para esto, 0.5 x 106 células/mL se expusieron a

concentraciones que oscilaban entre 0.1 y 100 µg/mL de ftalatos y se determinó la

expansión celular total después de 14 días de cultivo en medio IMDM-citocinas. Los

cultivos control alcanzaron 1.31 ± 0.21 x 106 cell/mL mientras, que los cultivos

expuestos a DBP, BBP y DEHP mostraron una reducción del 23 al 81%, del 17 al

69% y del 15 al 93.5%, respectivamente."

Doctoral thesis

HepG2 cells Hematopoietic stem cells Phthalates Toxicity BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA MOLECULAR BIOLOGÍA MOLECULAR

IPI-SA3-C4, population of human preadipose cells with multipotent differentiation capability. Characterization as a model system for in vitro adipogenesis and optimization of its culture conditions

CLAUDIA GRISELDA CARDENAS LEON (2020)

"The most commonly in vitro model systems used for adipose tissue studies are murine cell lines, which have genetic and metabolic differences with the human adipocytes. To date, there is not a general in vitro model to study the human adipose tissue, because adipogenic human cell lines have a low adipogenic potential and their use is limited. This thesis includes two reports: the first one describes the characterization of a human subcutaneous adipose stromal cell population, “IPI-SA3-C4”, while the second one deals with the optimization of the culture medium for growing these cells. The IPI-SA3-C4 population is composed of non-tumorigenic diploid cells with high proliferative potential as well as strong adipogenic, osteogenic, and chondrogenic differentiation capabilities. In the second report, we proved that a dilution 1:1 of L15 and mTeSR1 culture media allow us to expand the life span of these cells by 20%, while retains their adipogenic capacity and normal diploid karyotype. Thus, this work describes the IPI-SA3-C4 cells as a new in vitro model system suitable but transient to study the human adipose tissue as well a cell culture strategy assuring high in vitro expansion of normal adult mesenchymal stromal cells useful for basic and translational research."

"Los modelos in vitro más utilizados para el estudio del tejido adiposo son líneas celulares de origen múrido, las cuales presentan diferencias genéticas y metabólicas respecto a los adipocitos humanos. Hasta ahora no hay un modelo in vitro de adipogénesis humana de uso generalizado, porque las líneas celulares adiposas humanas descritas habitualmente tienen un bajo potencial adipogénico y su uso es limitado. Este trabajo de tesis resultó en dos reportes: El primero describe la caracterización de una población de células estromales adiposas subcutáneas humanas, “IPI-SA3-C4”, en tanto que el segundo trata de la optimización del medio de cultivo para el crecimiento de estas células. La población IPI-SA3-C4 está constituida por células diploides, no tumorigénicas, con alto potencial proliferativo y con una fuerte capacidad de diferenciación adipogénica, osteogénica y condrogénica. En el segundo reporte probamos que una mezcla 1:1 de medios de cultivo L15 y mTeSR1 permiten expandir la esperanza de vida de estas células en un 20%, al tiempo que mantiene su capacidad adipogénica y su cariotipo diploide normal. Así, este trabajo describe las células IPI-SA3-C4 como un modelo in vitro adecuado aunque transitorio para estudiar el tejido adiposo humano y una estrategia de cultivo celular que permite la alta expansión in vitro de células estromales mesenquimales adultas normales con utilidad para investigación básica y traslacional."

Doctoral thesis

Human subcutaneous preadipocytes Cellular model Adipogenesis Osteogenesis Chondrogenesis Adipose-derived stromal cells mTesR1 hTERT Senescence MEDICINA Y CIENCIAS DE LA SALUD MEDICINA Y CIENCIAS DE LA SALUD

Modification of Ceiba pentandra cellulose for drug release applications

SILVIA ARGELIA PERAZA KU JOSE MANUEL CERVANTES UC Beatriz Escobar Morales Jorge Alonso Uribe Calderón (2020)

Tubular fibers (raw and wax-free) from Ceiba pentandra (CP) were cross-linked with butane-1,2,3,4-tetracarboxylic acid (BTCA) at different concentrations to obtain a porous biodegradable medium for drug release applications. Chlorhexidine diacetate (CHX) was added to the cross-linked fibers for drug release studies. The Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy results indicated that the cross-linked fibers with a 5:1 fiber:BTCA ratio presented the higher cross-linking density. CHX was added at different concentrations (8% and 16% wt/wt); the elemental analysis indicated that CHX was loaded up to 7.99 wt%. In vitro studies showed a burst release of CHX within the first 3 h. CHX release kinetics was described using several models, with the Korsmeyer–Peppas equation, which adjusted better to the experimental data. The results indicated that the CP fibers are a feasible material for drug release applications.

Article

CEIBA PENTANDRA CHLORHEXIDINE DIACETATE CELLULOSE CROSS-LINKING DRUG RELEASE INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE MATERIALES RESISTENCIA DE MATERIALES RESISTENCIA DE MATERIALES

Propuesta de diseño de un sistema para la generación de energía eléctrica a partir de la generación de hidrógeno in situ empleando residuos de aluminio y la conversión del calor de desecho producido en energía eléctrica

ALBERTO ARTURO OSORIO SANDOVAL (2019)

RESUMEN

En el presente trabajo se muestran los resultados del diseño de una planta piloto a escala laboratorio para la producción de hidrógeno a partir la reacción exotérmica de la hidrolisis de aluminio, acoplada a una celda de combustible de intercambio protónico (PEMFC).

La materia prima alimentada al proceso consiste en una solución de hidróxido de sodio y aluminio proveniente de latas de desecho.

El hidróxido de sodio permite retirar la capa de óxido que pasiva al metal; proceso conocido como activación alcalina.

El diseño se basó en el análisis del balance de masa y energía, su comprobación experimental y los requerimientos de combustible de la PEMFC, adicionalmente se consideró el aprovechamiento del calor liberado por la reacción mediante el efecto Seebeck.

La planta está integrada por un contenedor que abastece solución de hidróxido de sodio a un reactor tipo batch, el cual entrega el gas producido a una columna de adsorción de NaOH.

Los tres componentes funcionan como sistema de almacenamiento temporal del combustible en tanto es entregado a una presión regulada y bajo demanda a la PEMFC.

El contenedor de 0.45 L almacena solución al 4.13 M suficiente para hacer reaccionar 10 g de aluminio que producirá 12 L NTP (Normal Temperature and Pressure) de hidrógeno.

El reactor de 2.1 L tiene la forma de un prisma rectangular para acoplar a su superficie placas Peltier que funcionan como convertidores de calor a electricidad.

La propuesta se construirá en versión planta piloto a escala laboratorio en acero inoxidable para evaluar la eficiencia energética global de la planta.

ABSTRACT

This work shows results of a pilot plant designed to laboratory scale to produce hydrogen from a hydrolysis of aluminum exothermic reaction, coupled to a proton exchange membrane fuel cell (PEMFC).

The raw material fed in this process consists in sodium hydroxide solution and the aluminum came from wasted cans.

Sodium hydroxide allows to remove the oxide layer that passivates the metal; Process known as alkaline activation.

The design was based in mass and energy balance analysis, its experimental verification and fuel requirements of the PEMFC, the exploitation of the heat released by reaction through the Seebeck effect was also considered.

The plant is composed by a container that supplies hydroxide sodium solution to the batch reactor, which delivers the gas produced to an adsorption column of NaOH.

These three components work as a temporary storage system of the fuel while it is provided at a regulated pressure and demand to the PEMFC.

The container of 0.45 L stores solutions at 2.13 M which is enough to react with 10 g of aluminum to produce 12 L of hydrogen into NTP.

The 2.1 L reactor is shaped into a rectangular prism to place in its surface Peltier plates that work as converters of heat to electricity.

Master thesis

INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS PEM fuel cells, Hydrolysis of aluminum, wasted aluminum cans, hydrogen production plant, Sebeek effect