Treatment of volatile organic compounds by biofiltration with and without percolation : kinetic and characterization studies

The objectives of this work are related to the kinetic study and characterization of air treatment biofilters with and without percolation which were packed with inert packing materials in order to treat methanol, ethanol and toluene vapours.The thesis is divided into three sections.The first section contains a bibliographic introduction to biofiltration and an experimental study.The review of experimental work shows that methanol, ethanol and toluene can be treated in biofilters with or without percolation. In the experimental study of this section, ethanol is treated in a biotrickling filter at low nitrogen concentrations in the nutrient solution and high removal efficiencies are obtained. In this study, experimental protocols for maintaining the biofilter and controlling the biomass content in the packing bed were developed.The second section is composed of two experimental studies for characterizing biofilters with and without percolation in order to treat methanol. A methodology for calculating the biomass accumulated in the packing bed of a biofilter is among the new experimental protocols developed in this study. In the case of biotrickling filter, methodologies for determining the partition coefficient of methanol and the biomass production rate were developed.The role of the biofilm and the nutrient solution on bioflter performance was also analyzed.The studies of this section lead to a better comprehension of methanol biodegradation in biofilters.The third section contains two kinetic studies for biofilters with and without percolation. In the first study, a new experimental methodology is proposed to calculate microkinetic parameters related to microbial growth in a biofilter. In the second study, the microkinetic and macrokinetic behaviors of methanol and toluene biodegradation are compared.The influence of operating conditions on microbial growth and elimination capacity is also analyzed. This study includes the identification of energy indicators of biofilters with and without percolation, which could be used in energy balances and for estimating the temperature of packing bed

Complete Genome Sequence of Border Disease Virus Genotype 3 Strain Gifhorn

The complete genome sequence of the genotype 3 border disease virus strain Gifhorn has been determined; this strain was originally isolated from pigs. This represents the consensus sequence for the virus used to produce the bacterial artificial chromosome (BAC) cDNA clone pBeloGif3, which yields a virus that is severely attenuated in cell culture

Análisis de la política de dividendos, su impacto en los ingresos fiscales de empresas no financieras, supervisadas por la SMV - Lima Metropolitana, periodo 2018

El presente trabajo de investigación sobre el “Análisis de la política de dividendos y su impacto en los ingresos fiscales de empresas no financieras supervisadas por la SMV periodo 2018, en Lima Metropolitana., tuvo como objetivo general precisar el impacto en los ingresos fiscales, que tiene el análisis de la política de dividendos. La hipótesis que se consideró en este trabajo de investigación es el análisis significativo de la política de dividendos impacta en los ingresos fiscales de las empresas no financieras supervisadas por la SMV- Lima Metropolitana, periodo 2018. La presente investigación fue descriptiva – correlacional, de método cuantitativo, de diseño no experimental de corte transversal. Se seleccionó una muestra de 29 de 120 empleados del área contable y financiera (asistentes, contadores y gerentes del rubro contable, financiero y tributario). Se utilizó un cuestionario de recolección de datos y la escala de Likert, con 17 preguntas. Se concluyó que la política de dividendos impacta significativamente en los ingresos fiscales de las empresas no financieras supervisadas por la SMV. Además, el plan de acción y los dividendos impactan significativamente en los ingresos fiscales, de las empresas no financieras supervisadas por la SMV- periodo 2018, en Lima Metropolitana.Tesi

El género, un factor determinante en el riesgo de somnolencia

Los trastornos del sue˜no constituyen un grupo numeroso y heterogéneo de procesos. A nivel mundial se estima que la prevalencia de trastornos del sue˜no oscila entre 35 y 45% de la población adulta mayor de 18 a˜nos. Estudios previos realizados en la Cd de México han demostrado una somnolencia excesiva diurna en el 18%, de los cuales 19% fueron mujeres y 17% hombres por lo que el objetivo de este proyecto es detectar en una población adulta del valle de Toluca, el riesgo de somnolencia. Métodos: Se empleó un instrumento validado: escala de somnolencia de Epworth que tiene por objeto evaluar la magnitud de la somnolencia diurna frente a ocho situaciones de la vida diaria. Resultados: De los 227 sujetos analizados, se encontró que 76 de ellos (33.4%): 44 hombres (19.4% del total) y 27 mujeres (11.9% del total) tenían somnolencia excesiva. Se dividió a la población en dos grupos: mayores o iguales a 50 a˜nos de edad y 49 a˜nos o menos. Al comparar el riesgo Hombre-Mujer se encontró un valor de O.R. de 4.1 en los hombres de 50 a˜nos o más, mientras que en el género femenino fue de 1.0. Al establecer una separación con los sujetos que tenían entre 9 y 11 puntos de la escala de Epworth, se demostró que el riesgo seguía siendo elevado en OR = 4.0 Conclusiones: En la población estudiada el género masculino tiene un riesgo cuatro veces mayor que la mujer de presentar somnolencia excesiva diurna. © 2014 Universidad Autónoma del Estado de México. Publicado por Masson Doyma México S.A. Todos los derechos reservados

Single dose of diclofenac or meloxicam for control of pain, facial swelling, and trismus in oral surgery

Background: Postoperative pain associated with removal of mandibular third molars has been documented from moderate to severe during the first 24 hours after surgery, with pain peaking between 6 and 8 hours when a conventional local anesthetic is used. Dental pain is largely inflammatory, and evidence-based medicine has shown that nonsteroidal anti-inflammatory drugs are the best analgesics for dental pain. The aim of this study was to compare the analgesic, anti-inflammatory and anti-trismus effect of a single dose of diclofenac and meloxicam after mandibular third molar extraction. Material and Methods: A total of 36 patients were randomized into two treatment groups, each with 18 patients, using a series of random numbers: Group A, was administered 100 mg of diclofenac; and Group B, 15 mg of meloxicam. Drugs were administered orally 1 hour prior to surgery. We evaluated pain intensity, analgesic consumption, swelling, as well as trismus. Results: The results of this study showed that patients receiving 15 mg of meloxicam had less postoperative pain ( P =0.04) and better aperture than those receiving 100 mg of diclofenac ( P =0.03). The meloxicam group presented less swelling than diclofenac group; however, significant statistical differences were not observed. Conclusions: Data of this double-blind, randomized, parallel-group clinical trial demonstrated that patients receiving 15 mg of preoperative meloxicam had a better postoperative analgesia and anti-trismus effect compared with who were given 100 mg of diclofenac after third molar extractions

Factores de riesgo asociados a la seroprevalencia de lentivirus en rebaños ovinos y caprinos del noreste de México

A cross-sectional study was conducted with the purpose of determinate the risk factors associated with the serological frequency of small ruminant lentivirus (SRLV) in sheep and goats from northeastern Mexico. From 128 herds, 71 of goats, 32 of sheep and 25 mixed herds (goats + sheep), 768 individual sera were collected from animals ≥1 yr old. From each herd, 4 to 5 serum samples were mixed and analyzed by ELISA to identify antibodies against SRLV glycoprotein 135. Samples were obtained from randomly selected animals in 2019 and 2020. A questionnaire was applied to the producers and the data were analyzed to determine the risk factors associated with herd seropositivity by logistic regression. The proportion of seropositive herds, overall, was estimated at 50.6 %. According to the type of herd, seropositivity in goat herds was 62.0 %, in sheep herds 25.4 % and 50.2 % in mixed herds. The risk factors associated with the presence of antibodies against SRLV were the presence of animals with arthritis, veterinary care, reuse of needles, nerve alterations, low pregnancy rate, type of herd and mastitis. Serological frequency indicates a high endemicity of SRLV in small ruminant herds from northeastern Mexico.Se realizó un estudio transversal con el propósito de determinar los factores de riesgo asociados a la frecuencia serológica de Lentivirus de los pequeños rumiantes (LvPR) en ovinos y caprinos del noreste de México. De 128 rebaños, 71 de caprinos, 32 de ovinos y 25 mixtos (caprinos + ovinos), se recolectaron 768 sueros individuales de animales ≥1 año de edad. De cada rebaño 4 a 5 muestras de suero fueron mezcladas y analizadas por ELISA para identificar anticuerpos contra la glucoproteína 135 del LvPR. Las muestras se obtuvieron de animales seleccionados al azar en los años 2019 y 2020. Se aplicó un cuestionario a los productores y los datos se analizaron para determinar los factores de riesgo asociados a la seropositividad del rebaño mediante regresión logística. La proporción de rebaños seropositivos en general fue estimada en 50.6 %. Acorde al tipo de rebaño la seropositividad en rebaños caprinos fue de 62.0 %, en ovinos de 25.4 % y de 50.2 % en rebaños mixtos. Los factores de riesgo asociados a la presencia de anticuerpos contra el LvPR fueron presencia de animales con artritis, asistencia veterinaria, reutilizar agujas, alteraciones nerviosas, bajo índice de preñez, tipo de rebaño y mastitis. La frecuencia serológica indica una alta endemicidad del LvPR en rebaños de pequeños rumiantes del noreste de México

"In Vitro Color Stability Evaluation of Three Polished and Unpolished Nanohybrid Resin Composites Immersed in a 0.12% Chlorhexidine-Based Mouthwash at Different Times"

"The use of chlorhexidine-based mouthwashes on resin composites with rough surfaces can cause discoloration which compromises the esthetic of patients. The present study aimed to evaluate the in vitro color stability of Forma (Ultradent Products, Inc., South Jordan), Tetric N-Ceram (Ivoclar Vivadent, Schaan, Liechtenstein) and Filtek Z350XT (3M, ESPE, St. Paul, MN, USA) resin composites, with and without polishing, after being immersed in a 0.12% chlorhexidine (CHX)-based mouthwash at different times. The present in vitro experimental and longitudinal study used 96 nanohybrid resin composite blocks (Forma, Tetric N-Ceram and Filtek Z350XT) 8 mm in diameter and 2 mm thick, evenly distributed. Each resin composite group was divided into two subgroups (n = 16) with and without polishing and then immersed in a 0.12% CHX-based mouthwash for 7, 14, 21 and 28 days. Color measurements were performed with a calibrated digital spectrophotometer. Nonparametric tests were used to compare independent (Mann–Whitney U and Kruskal–Wallis) and related (Friedman) measures. In addition, the Bonferroni post hoc correction was used considering a significance level of p < 0.05. All polished and unpolished resin composites presented color variation < 3.3 when immersed for up to 14 days in 0.12% CHX-based mouthwash. The polished resin composite with the lowest color variation (∆E) values over time was Forma, and the one with the highest values was Tetric N-Ceram. When comparing the color variation (∆E) over time, it was observed that the three resin composites, with and without polishing, presented a significant change (p < 0.001), although these changes in color variation (∆E) were evident from 14 days between each color acquisition (p < 0.05). The unpolished Forma and Filtek Z350XT resin composites showed significantly more color variation than the same polished ones at all times when immersed in a 0.12% CHX-based mouthwash for 30 s daily. In addition, every 14 days, all three resin composites with and without polishing showed a significant color change, while, every 7 days, color stability was maintained. All the resin composites showed clinically acceptable color stability when exposed for up to 14 days to the above-mentioned mouthwash.