161 research outputs found
Estado de nutrición en escolares de la Escuela Primaria Emiliano Zapata, de la colonia Lomas Altas, Toluca Estado de México, 2013
Evaluación de hidrolizados de granos de sorgo y granos de destilería secos con solubles para la producción de transglutaminasa microbiana
Sorghum grains can be used as a source of fermentable sugars to reduce the culture media cost for microbial growth of Streptomyces and the
production of microbial transglutaminase (MTGase). In the production of ethanol from corn, dried distillers grains with solubles (DDGSs)
are generated as waste. The aim of this work is to elucidate the biotechnological production of transglutaminase by Streptomyces
mobaraensis NRRL-3191 grown in a medium containing sorghum grains hydrolysates and DDGS is feasible. The results showed that
casein has a great effect on the production of MTGase while DDGS did not show any significant effect on the range of study. The model
obtained predicts 0.66 U/mL of MTGase activity using enzymatic hydrolysates of sorghum grains supplemented with yeast extract (2 g/L),
DDGS (2 g/L), and casein (19.5 g/L)Los granos de sorgo se pueden utilizar como fuente de azúcares fermentables para reducir los costes de medios de cultivo para el
crecimiento microbiano de Streptomyces y la producción de transglutaminasa microbiana (MTGasa). En la producción de etanol a partir de
maíz, se generan como residuos granos de destilería secos con solubles (DDGS). El objetivo de este trabajo fue determinar si la producción
biotecnológica de transglutaminasa por Streptomyces mobaraensis NRRL-3191 cultivados en un medio que contiene hidrolizados de granos
de sorgo y DDGS es factible. Los resultados mostraron que la caseína tiene un gran efecto en la producción de MTGasa mientras que
DDGS no mostraron un efecto significativo en el intervalo de estudio. El modelo obtenido predice 0.66 U/mL de actividad MTGase usando
hidrolizados enzimáticos de granos de sorgo suplementados con extracto de levadura (2 g/L), DDGS (2 g/L) y caseína (19,5 g/L)A scholarship from CONACyT and IPN (Mexico) to G. C. Rodríguez-Castillejos is gratefully acknowledged. The authors are grateful for the financial support from the co-ordinator of
Fundación Produce A.C.S
Composición y dinámica del fitoplancton en un lago urbano hipertrófico
Taxonomic composition and temporal fluctuation of the phytoplankton community inhabiting the urban, hypertrophic shallow lake Tezozomoc, D.F. was analyzed. Water samples were taken monthly at the littoral and limnetic areas of the lake, from September 2003 to August 2004. Temperature, pH, dissolved oxygen, conductivity (K25), chlorophyll a, and nutrients (N and P) concentrations were measured. Phytoplankton was identified and counted including the fraction smaller than 2 µm. Fifty phytoplankton species were identified, being Chlorophyta the dominant group. Two species belonging to the genus Microcystis showed high abundances in the lake from September to December 2003. Merismopedia punctata, Selenastrum minutum, Chlamydomonas globosa and Monoraphidium caribeum, as well as picophytoplankton, were dominant. Environmental and biological data clearly reflected two different seasons in the lake: one cold and dry season (September to March) and the second, warm and wet (April to August). Along the first season, mean values of water temperature (17.6 ºC), nutrients (P-PO4 = 2.21, N-NO3 = 0.4 mg L-1) and chlorophyll a (200 ?g L-1) were lower, while K25 (985 µS cm-1) and dissolved oxygen (10.1 mg L-1) concentrations were the higher. Dominant species along the period were C. globosa, Cyclotella meneghiniana, M. griffithii, Cryptomonas ovata and Microcystis spp. The second period had the higher mean values of water temperature (21 ºC), nutrients concentration (P-PO4 = 3.31, N-NO3 = 3.3 mg L-1) and clorophyll a (295 ?g L-1), while K25 (808 µS cm-1) and dissolved oxygen concentrations (6.8 mg L-1) decreased. S. minutum, M. caribeum, Chlorogonium minimum and the picophytoplankton were dominant. Identified species and the environmental conditions values indicated the hypertrophic state of the Tezozomoc lake.Se presenta la composición y dinámica anual del fitoplancton del somero e hipertrófico Lago Tezozomoc, D.F. Se realizaron muestreos mensuales de superficie en la zona litoral y limnética del lago, durante septiembre de 2003 a agosto de 2004. Se midieron temperatura, pH, oxígeno disuelto, conductividad (K25), clorofila a y nutrimentos (N y P). El fitoplancton se identificó y se cuantificó, incluyendo el de talla menor a 2 µm. Se encontraron 50 especies, las Chlorophyta fueron el grupo más abundante y con mayor número de especies. Entre septiembre y diciembre del 2003, dos especies de Microcystis fueron muy abundantes en el lago. Merismopedia punctata, Selenastrum minutum, Chlamydomonas globosa, Monoraphidium caribeum y el picofitoplancton fueron dominantes. Se distinguieron dos épocas: una fría y seca (septiembre a abril) y otra cálida y lluviosa (mayo a agosto). Durante la primera, se registró un menor promedio de temperatura (17.6 ºC), concentración de nutrimentos (P-PO4 = 2.21, N-NO3 = 0.4 mg L-1) y clorofila a (200 ?g L-1), mientras que la K25 (985 µS cm-1) y el oxígeno disuelto (10.1 mg L-1) fueron más elevados, predominando C. globosa, Cyclotella meneghiniana, Monoraphidium griffithii, Cryptomonas ovata y Microcystis spp. En la segunda, la temperatura promedio se incrementó (21 ºC), lo mismo que los nutrimentos (P-PO4 = 3.31, N-NO3 = 3.3 mg L-1) y la clorofila a (295 ?g L-1), disminuyendo la K25 (808 µS cm-1) y el oxígeno disuelto (6.8 mg L-1). Las especies dominantes fueron S. minutum, M. caribeum, Chlorogonium minimum y el picoplancton. Las especies presentes y las condiciones ambientales indicaron claramente el estado hipertrófico del lag
Photovoltaic Glass Waste Recycling in the Development of Glass Substrates for Photovoltaic Applications
Because of the increasing demand for photovoltaic energy and the generation of end-of-life
photovoltaic waste forecast, the feasibility to produce glass substrates for photovoltaic application
by recycling photovoltaic glass waste (PVWG) material was analyzed. PVWG was recovered from
photovoltaic house roof panels for developing windows glass substrates; PVWG was used as the main
material mixed with other industrial waste materials (wSG). The glass was casted by air quenching,
annealed, and polished to obtain transparent substrates samples. Fluorine-doped tin oxide (FTO) was
deposited as back contact on the glass substrates by spray pyrolysis. The chemical composition of the
glass materials was evaluated by X-ray fluorescence (XRF), the thermal stability was measured by
differential thermal analysis (DTA) and the transmittance was determined by UV-VIS spectroscopy.
The surface of the glass substrates and the deposited FTO were observed by scanning electron
microscopy (SEM), the amorphous or crystalline state of the specimens were determined by X-ray
diffraction (XRD) and the sheet resistance was evaluated by the four-point probe method. The sheet
resistance of the deposited FTO on the wSG substrate was 7.84 ± 3.11 Ω/, lower than that deposited
on commercial soda-lime glass (8.48 ± 3.67 Ω/), meaning that this material could present improved
conduction of the produced electrons by the photovoltaic effect. This process may represent an
alternative to produce glass substrates from waste materials that could be destined for photovoltaic
applications, especially the production of ecological photovoltaic windows
Activation of Peptidylarginine Deiminase in the Salivary Glands of Balb/c Mice Drives the Citrullination of Ro and La Ribonucleoproteins
The goal of the present study was to determine whether peptidylarginine deiminase PAD2 and PAD4 enzymes are present in Balb/c mouse salivary glands and whether they are able to citrullinate Ro and La ribonucleoproteins. Salivary glands from Balb/c mice were cultured in DMEM and supplemented with one of the following stimulants: ATP, LPS, TNF, IFNγ, or IL-6. A control group without stimulant was also evaluated. PAD2, PAD4, citrullinated peptides, Ro60, and La were detected by immunohistochemistry and double immunofluorescence. PAD2 and PAD4 mRNAs and protein expression were detected by qPCR and Western blot analysis. PAD activity was assessed using an antigen capture enzyme-linked immunosorbent assay. LPS, ATP, and TNF triggered PAD2 and PAD4 expression; in contrast, no expression was detected in the control group (p < 0 001). PAD transcription slightly increased in response to stimulation. Additionally, PAD2/4 activity modified the arginine residues of a reporter protein (fibrinogen) in vitro. PADs citrullinated Ro60 and La ribonucleoproteins in vivo. Molecular stimulants induced apoptosis in ductal cells and the externalization of Ro60 and La ribonucleoproteins onto apoptotic membranes. PAD enzymes citrullinate Ro and La ribonucleoproteins, and this experimental approach may facilitate our understanding of the role of
posttranslational modifications in the pathophysiology of Sjögren’s syndrome
Progression of the Total and Individual Capsaicinoids Content in the Fruits of Three Different Cultivars of Capsicum chinense Jacq.
The evolution of individual and total capsaicinoids content in three pepper varieties
of Capsicum chinense Jacq. (‘Bode’ (B), ‘Habanero’ (H), and ‘Habanero Roxo’ (Hr)) during fruit
ripening was studied. The five major capsaicinoids (nordihydrocapsaicin, capsaicin, dihydrocapsaicin,
homocapsaicin, and homodihydrocapsaicin) were extracted using ultrasound-assisted extraction
and the extracts were analysed by ultra-performance liquid chromatography with fluorescence
detection (UHPLC-Fl). The plants were grown in a glasshouse and sampled every 7 days until
over-ripening. As expected, the results indicated that the total capsaicinoids content increases during
the ripening of pepper fruits. The maximum contents of capsaicinoids were reached at different fruit
development stages depending on the cultivar. The ‘Habanero Roxo’ pepper presented the greatest
total capsaicinoids content (3.86 mg g1 fresh weigh, F.W.), followed by the ‘Habanero’ pepper
(1.33 mg g1 F.W.) and ‘Bode’ pepper (1.00 mg g1 F.W.). In all the samples, capsaicin represented
more than 80% of the total capsaicinoids content. Due to the high variability observed in the evolution
of capsaicinoids content over the ripening process, this work intends to contribute to the existing
knowledge on this aspect in relation to the quality of peppers
Maximization of the Likelihood Function of Probability Distributions using Genetic Algorithms
[ES] Tradicionalmente, para obtener los parámetros de una función de distribución con el método de máxima verosimilitud se acostumbra igualar a cero la derivada del logaritmo de la función de verosimilitud y resolver el sistema de ecuaciones no lineales que resulta. La popularidad del procedimiento se debe a su sencillez; sin embargo, cuando la función de verosimilitud no es suficientemente regular, puede llevar a obtener un valor muy alejado del máximo Por ese motivo, en este documento se presenta el uso de un algoritmo genético que permite encontrar los parámetros de la función de distribución (con los que se maximiza directamente la función de verosimilitud, o su logaritmo), sin recurrir a la derivada de los logaritmos de dicha función. Se halló buena concordancia de los resultados respecto a los obtenidos usando un software de uso frecuente en México, para el caso las funciones Gumbel y Gumbel de dos poblaciones. [EN] Traditionally, to get the parameters of a distribution function with the maximum likelihood method is usually equaled to zero the derivative of the logarithm of the likelihood function and then the resulting non-linear system of equations is solved. The popularity of the procedure is due to its simplicity; however, when the likelihood function is not regular enough, can lead to obtain a value very far away from the maximum sought. This document presents the use of a genetic algorithm that allows to find the parameters of the distribution function by directly maximizing the likelihood function, or its logarithm, without need to resort to the derivative of the logarithms of the function. The results are compared with those obtained using a software frequently used in Mexico, for the case functions Gumbel and Gumbel of two populations.Fuentes Mariles, OA.; Arganis Juárez, ML.; Domínguez Mora, R.; Fuentes Mariles, GE.; Rodríguez Vázquez, K. (2015). Maximización de la función de Verosimilitud de Distribuciones de Probabilidad usando Algoritmos Genéticos. Ingeniería del agua. 19(1):17-29. https://doi.org/10.4995/ia.2015.3225OJS1729191Arganis-Juárez, M.L., Domínguez-Mora, R., González-Villarreal, F., Carrizosa-Elizondo, E., Esquivel-Garduño, G., Hollands, A.J., Ramírez-Salazar, L.E. (2009). Estudio Integral de la Cuenca Alta del Río Grjialva. Actualización de Avenidas de Diseño. Para CFE. Informe Final.Baker, J.E. (1985). Adaptive Search Selection Methods for Genetic Algorithms, in Proceedings of the First International Conference on Genetic Algorithms (Grefenstette, ed), Lawrence Erlbaum, 101-111.Clark, C., Whu, Y.Z. (2006). Integrated hydraulic model and genetic algorithm optimization for informed analysis of a real water system. Asce 8th Annual International Symposium On Water Distribution System Analysis, Cincinnati, August 27-30, Ohio.Domínguez-Mora, R., Carrizosa-Elizondo, E., Fuentes-Mariles, G.E., Arganis-Juárez, M.L. (2000). Estudio de diferentes aspectos sobre el funcionamiento de la obra de excedencias del Proyecto Hidroeléctrico, la Angostura, Chiapas y actualización de la hidrología para el sistema de presas del Río Grijalva. "Estudio Hidrológico de la Cuenca alta del Río Grijalva". Para CFE. Informe final.Domínguez-Mora, R., Fuentes-Mariles, G.E., Arganis-Juárez, M.L. (2004). Optimación de los parámetros de la función de distribución doble gumbel usando algoritmos genéticos en una serie de gastos máximos anuales. XXI Congreso Latinoamericano de Hidráulica, Sao Paulo, Brasil.Domínguez-Mora, R., Arganis-Juárez, M.L., Carrizosa-Elizondo, E., Fuentes-Mariles, G.E., Echeverri, C.A. (2006). Determinación de Avenidas de Diseño y Ajuste de los Parámetros del Modelo de Optimización de las Políticas de Operación del Sistema de Presas del Río Grijalva. Para CFE. Informe Final.Escalante-Sandoval, C., Reyes-Chávez, L. (2002). Técnicas Estadísticas en Hidrología. Facultad de Ingeniería. Universidad Nacional Autónoma de México.Fuentes-Mariles, O.A., Fuentes-Mariles, G.E., Domínguez-Mora, R. (2005). Optimación de los parámetros de algunas funciones de distribución de probabilidad de gastos máximos anuales usando un algoritmo genético simple. 4a. Conferencia Iberoamericana en Sistemas Cibernética e Informática, Cicsi, Orlando, Flo., Usa, Vol. 2, 156-159.Fuentes-Mariles, O.A. Domínguez-Mora, R., Fuentes-Mariles, G.E., Arganis-Juárez, M.L., Rodríguez-Vázquez, K. (2006). Estimación de los parámetros de funciones de distribución empleadas en hidrología usando ecuaciones de máxima verosimilitud y algoritmos genéticos. XXII Congreso Latinoamericano De Hidráulica, Ciudad Guayana, Venezuela.Goldberg, D.E. (1989). Genetic Algorithms in Search, Optimization and Machine Learning. Addison-Wesley, USA.González-Villarreal, F. (1970). Contribución al análisis de frecuencias de valores extremos de los gastos máximos en un río. Serie Azul, Instituto de Ingeniería, UNAM.Gumbel, E.J. 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Expression of CCR5, CXCR4 and DC-SIGN in Cervix of HIV-1 Heterosexually Infected Mexican Women
Background: A number of studies have demonstrated that receptor and co-receptor expression levels which may affect viral entry, promoting cervical HIV infection. The aim was to evaluate the expression levels of CCR5, CXCR4 and DC-SIGN mRNA in a sample of heterosexually HIV infected Mexican women. Methods: We enrolled twenty-six HIV heterosexual infected women attending a local infectious diseases medical unit. RNA was isolated from the cervix and gene expression analysis was performed using real-time PCR. Results: Expression rates for mRNA of CCR5 (median 1.82; range 0.003–2934) were higher than those observed for CXCR4 (0.79; 0.0061–3312) and DC-SIGN (0.33; 0.006–532) receptors (p < 0.05). A high correlation was found between the mRNA expression levels of these three receptors (rs = 0.52 to 0.85, p < 0.01). Conclusion: Levels of expression of the tested chemokine receptors in the cervix are different from each other and also vary from woman to woman, and seem to support the suggestion that chemokine receptor expression in genital tissues may be playing a role in the HIV transmission
Optimization of an Ultrasound-Assisted Extraction Method Applied to the Extraction of Flavonoids from Moringa Leaves (Moringa oleifera Lam.)
Interest in phenolic compounds has recently increased due to their potential as antioxidant agents. Moringa leaves (Moringa oleifera) have a high content of phenolic compounds, which presents them as a promising source for the extraction of these compounds. However, it is necessary to use analytical techniques to identify and quantify their actual compound content to determine the quality of the raw material and the potential of the final product. Ultrasound assisted extraction is a green, rapid and environmentally friendly extraction technique that produces high quality extracts from natural products. Hence, the aim of this research is to optimize the variables of the ultrasound-assisted extraction (UAE) process for the extraction of moringa leaves using response surface methodology (RSM) to extract the main flavonoids using methanol as the extraction solvent. A Box-Behnken design (BBD) has been used to evaluate the effect of the ultrasound extraction process variables. Finally, the optimal extraction time in the range between 2 and 30 min was determined. The results revealed that the methanol concentration was the most influential variable. The optimal extraction time was established at 15 min. Six of the main flavonoids were quantified by UHPLC-DAD and identified by UHPLC-QToF-MS. The results confirmed that UAE is an efficient method for the extraction and subsequent analysis and quality control of the flavonoids that can be found in moringa leaves
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