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Aportes, problemáticas y desafíos que la noción de ciudadanía movilizada por el Movimiento de Diversidad Sexual y sus fragmentos LTGBI y lesbofeminista antirracista decolonial significan a la radicalización del pluralismo
(Universidad de Chile, 2016)
podría ocultar lógicas de poder que reactualizan las tramas coloniales. De esta forma identificar los aportes, problemáticas y desafíos que la noción de ciudadanía que movilizan representa a la radicalización del pluralismo, puede significar un apoyo a la...
Estimación del potencial geotérmico de pozos profundos de acuerdo con la demanda energético-térmica en Magallanes
(Universidad de Chile, 2020)
, y se aplicó un modelo de
transferencia de calor cuyos resultados se validaron en base a datos de un sistema geotermal similar
(Prenzlau, Alemania). Paralelamente se calculó la demanda térmica en cada sitio y se evaluó la
capacidad de los pozos de...
suplirla en cuanto a límites de temperatura y cantidad de calor en kW. Los resultados muestran que para un pozo el potencial geotérmico varía entre 220 y 390 kW con un caudal de flujo de 1 kg/s, temperatura de entrada de 45°C y temperatura de fondo...
suplirla en cuanto a límites de temperatura y cantidad de calor en kW. Los resultados muestran que para un pozo el potencial geotérmico varía entre 220 y 390 kW con un caudal de flujo de 1 kg/s, temperatura de entrada de 45°C y temperatura de fondo...
Bienestar y satisfacción subjetiva (BB. SS) fortalecimiento de capacidades (FC) en la evaluación de políticas públicas de la dirección de presupuestos del ministerio de hacienda de Chile (DIPRES).
(Universidad de Chile, 2012-06-26)
, pautas de entrevistas realizadas.
1.1. Formulación y planteamiento del problema
Muchas sociedades han definido como uno de sus objetivos fundamentales el progreso.
La pregunta que surge es ¿qué se entiende por progreso? Es un concepto con múltiples...
. Millán sostiene, que en sus inicios, para observarlo y analizarlo, era necesario elegir un objeto observable y cuantificable. Surgía la necesidad de construir formas de medir el desempeño social, para lo que se seleccionó la riqueza, medida a través...
. Millán sostiene, que en sus inicios, para observarlo y analizarlo, era necesario elegir un objeto observable y cuantificable. Surgía la necesidad de construir formas de medir el desempeño social, para lo que se seleccionó la riqueza, medida a través...
Desarrollo de estrategias analíticas de microextracción de compuestos estrogénicos desde matrices líquidas para ser evaluados por cromatografía líquida con analizador de tiempo de vuelo y detector de masas (LC-TOF/MS)
(Universidad de Chile, 2020)
altamente ionizables compatibles con la espectrometría de masas en modo positivo. Se utilizó un analizador de tiempo de vuelo (TOF) y un analizador de triple cuadrupolo (QqQ) acoplados a espectrometría de masas, donde se obtuvieron los productos...
The estrogens are compounds of natural and synthetic origin that have been recently studied as endocrine disruptors. In humans the estrogens have produced symptoms as: breast and prostate cancer, reproductive tract disorders and low sperm count, among others, while in aquatic organisms have been detected problems of feminization, infertility, hermaphrodism and even death. Estrone (E1), 17β-estradiol (E2) and estriol (E3) are the most abundant estrogens in the organism; they are related with the biological functions as growth and reproductive cycles, in humans and animals. In this last function, the synthetic estrogen 17α-ethinylestradiol (EE2) is used as the main active compound in contraceptive methods, although its use also has been reported to promote the growth of animals. On the other hand are the hydroxylated metabolites of E1 and E2 as 2-hydroxyestrone (2-OHE1), 4-hydroxyestrone (4-OHE1), 2-hydroxyestradiol (2-OHE2) and 4-hydroxyestradiol (4-OHE2) called catechol estrogens, as well as the hydroxylated metabolite 16α-hydroxyestrone (16-OHE1), all last compounds have been correlated with the development of different types of cancers, through their transformation to semi quinones and finally quinones, capable of forming adducts with DNA and producing mutations in the organisms. The objective of this research was to develop analytical methodologies that allow extract sex hormones E1, E2, EE2 and E3 and their hydroxylated metabolites from wastewater samples and biological samples such as urine and milk, and then determined sensitively and selectively by liquid chromatography, coupled to mass spectrometry (LC-MS). For the determination, a derivatization methodology with dansyl chloride was developed to obtain estrogen derivatives with highly ionizable amine functional groups in positive mode by using mass spectrometry for the detection. A time of flight analyzer (TOF) and a triple quadrupole analyzer (QqQ) coupled to mass spectrometry were used, the derivatized products were obtained with m/z signals corresponding to the form [M+H]+ for EE2, E1, E2, E3, 16-OHE1 and the form [M+2H]2+ for 2-OHE1, 4-OHE1, 2-OHE2 and 4-OHE2. These last signals not previously reported were more intense, from 4 times more than [M+H]+ forms for 2-OHE1, 4-OHE1, 2-OHE2 and 4-OHE2, reported previously. The estrogens were separated in chromatographic runs of 10 min, showing linearity for all analytes with correlation coefficients greater than 0.994. Different extraction techniques were used depending on the matrix studied. In aqueous samples the techniques rotating disk sorption extraction (RDSE) and solid-phase extraction (SPE) were used. Through RDSE it was possible to develop a methodology for the extraction of estrogens from wastewater using styrene-divinylbenzene (e-DVB) as a sorbent phase, obtaining recoveries between 79 and 118% with RSD values lower than 17%. The limits of detection (LOD) and quantification (LOQ) of the method were between 0.001 and 0.012 μg·L-1 and between 0.004 and 0.038 μg·L-1, respectively. The methodology was applied on two effluents from WWTP in the Región Metropolitana of Santiago, E1 was quantified in concentrations of 0.012±0.003 μg·L-1 and 0.013±0.001 μg·L-1, while E2 and EE2 were detected in concentrations of below the LOQ. When using SPE with C18, recoveries in drinking water and effluent were obtained over 86% with RSD values between 3 and 16%, while the detection and quantification limits of the method were between 0.002 and 0.017 μg·L-1 and between 0.006 and 0.058 μg·L-1. A sample of WWTP effluent was analyzed by detecting and quantifying E1 and E2 in concentrations of 0.007±0.001 μg·L-1 and 0.041±0.010 μg·L-1, respectively.For the extraction of estrogens from milk samples, the QuEChERS citrate methodology was used, and for clean up the extract, SPE was used with the divinylbenzene-co-N-vinylpyrrolidone copolymer sorbent, recoveries between 90 and 123% with RSD values lower than 18% were obtaining. The LOD and LOQ of the QuEChERS methodology coupled to SPE were between 0.02 and 0.13 μg·L-1 and between 0.05 and 0.53 μg·L-1, respectively. The methodology was applied to samples of commercial milk, lactating cow's milk and cow's milk with 7 months gestation, being able to determine the presence of E1 in a concentration of 0.094 μg·L-1 in milk of cow's in gestation. On the other hand, an enzymatic hydrolysis methodology was applied to milk samples obtained from commercial stores, and E1 could be found in 3 analyzed samples, being at a concentration below the limit of quantification in non-hydrolyzed samples and in concentrations between 0.086 and 1.3 μg·L-1. For urine samples, RDSE was used for the extraction of estrogens and simultaneously to primary secondary amine (PSA) was used to reduce the quantity of interferences from this matrix. The extraction methodology was optimized and validated, showing recoveries between 72 and 130% and RSD values less than 17%. The LOD and LOQ were between 0.10 and 0.13 μg·L-1 and between 0.30 and 0.50 μg·L-1, respectively. The methodology was used to analyze urine samples of women of 29, 35 and 53 years old, 2 pregnant women with 27 and 28 weeks of gestation, and of a man of 29 years old. Treatment with the enzyme β-glucuronidase was applied prior to extraction, in order to determine the total amount of estrogen and without enzymatic treatment to determine the free amount of estrogen. The 9 estrogens studied were detected in the different samples analyzed, in individual concentrations ranging from 0.9 to 73 μg·L-1 in the free form, between 0.5 and 1542 μg·L-1 in the conjugated form obtaining concentration until 1615 μg·L-1 in total per analyte. The highest concentrations were found in the urine samples of pregnant women, with E3 being the estrogen found in the highest concentration. It was concluded that the developed methodologies allowed to determine 8 natural and 1 synthetic estrogens by simple and fast methodologies with good levels of linearity, selectivity, sensitivity, accuracy and precision in the three matrices analyzed, where the RDSE technique was adequate for estrogen extraction in complex matrices of a mainly polar nature such as water and urine, while QuEChERS proved to be an efficient methodology for the extraction of estrogens from complex matrices of a mostly non-polar nature. The RDSE technique showed figures of merit similar to other techniques with extensive development such as SPE, while the QuEChERS methodology allowed the extraction of estrogens from milk at levels comparable to other investigations, allowing quantify E1 in the analyzed milk samples. Liquid chromatography coupled to mass spectrometry was a fundamental technique in the detection, confirmation and quantification of these compounds, due to the ability to separate compounds with similar physicochemical properties and to the sensitive and selective determination that was possible in samples of high complexity. It was determined that urine is an important source of estrogen contamination, since through the urine estrogens reach wastewater, which are subsequently discharged into the environment and can affect aquatic fauna and other species that have direct interaction with these waters On the other hand, humans could be incorporating estrogens into our organisms through milk, since if it is extracted in cattle that are in the 3rd trimester of pregnancy, hormonal levels could be around 1000 times higher than in a bovine in normal conditions...
The estrogens are compounds of natural and synthetic origin that have been recently studied as endocrine disruptors. In humans the estrogens have produced symptoms as: breast and prostate cancer, reproductive tract disorders and low sperm count, among others, while in aquatic organisms have been detected problems of feminization, infertility, hermaphrodism and even death. Estrone (E1), 17β-estradiol (E2) and estriol (E3) are the most abundant estrogens in the organism; they are related with the biological functions as growth and reproductive cycles, in humans and animals. In this last function, the synthetic estrogen 17α-ethinylestradiol (EE2) is used as the main active compound in contraceptive methods, although its use also has been reported to promote the growth of animals. On the other hand are the hydroxylated metabolites of E1 and E2 as 2-hydroxyestrone (2-OHE1), 4-hydroxyestrone (4-OHE1), 2-hydroxyestradiol (2-OHE2) and 4-hydroxyestradiol (4-OHE2) called catechol estrogens, as well as the hydroxylated metabolite 16α-hydroxyestrone (16-OHE1), all last compounds have been correlated with the development of different types of cancers, through their transformation to semi quinones and finally quinones, capable of forming adducts with DNA and producing mutations in the organisms. The objective of this research was to develop analytical methodologies that allow extract sex hormones E1, E2, EE2 and E3 and their hydroxylated metabolites from wastewater samples and biological samples such as urine and milk, and then determined sensitively and selectively by liquid chromatography, coupled to mass spectrometry (LC-MS). For the determination, a derivatization methodology with dansyl chloride was developed to obtain estrogen derivatives with highly ionizable amine functional groups in positive mode by using mass spectrometry for the detection. A time of flight analyzer (TOF) and a triple quadrupole analyzer (QqQ) coupled to mass spectrometry were used, the derivatized products were obtained with m/z signals corresponding to the form [M+H]+ for EE2, E1, E2, E3, 16-OHE1 and the form [M+2H]2+ for 2-OHE1, 4-OHE1, 2-OHE2 and 4-OHE2. These last signals not previously reported were more intense, from 4 times more than [M+H]+ forms for 2-OHE1, 4-OHE1, 2-OHE2 and 4-OHE2, reported previously. The estrogens were separated in chromatographic runs of 10 min, showing linearity for all analytes with correlation coefficients greater than 0.994. Different extraction techniques were used depending on the matrix studied. In aqueous samples the techniques rotating disk sorption extraction (RDSE) and solid-phase extraction (SPE) were used. Through RDSE it was possible to develop a methodology for the extraction of estrogens from wastewater using styrene-divinylbenzene (e-DVB) as a sorbent phase, obtaining recoveries between 79 and 118% with RSD values lower than 17%. The limits of detection (LOD) and quantification (LOQ) of the method were between 0.001 and 0.012 μg·L-1 and between 0.004 and 0.038 μg·L-1, respectively. The methodology was applied on two effluents from WWTP in the Región Metropolitana of Santiago, E1 was quantified in concentrations of 0.012±0.003 μg·L-1 and 0.013±0.001 μg·L-1, while E2 and EE2 were detected in concentrations of below the LOQ. When using SPE with C18, recoveries in drinking water and effluent were obtained over 86% with RSD values between 3 and 16%, while the detection and quantification limits of the method were between 0.002 and 0.017 μg·L-1 and between 0.006 and 0.058 μg·L-1. A sample of WWTP effluent was analyzed by detecting and quantifying E1 and E2 in concentrations of 0.007±0.001 μg·L-1 and 0.041±0.010 μg·L-1, respectively.For the extraction of estrogens from milk samples, the QuEChERS citrate methodology was used, and for clean up the extract, SPE was used with the divinylbenzene-co-N-vinylpyrrolidone copolymer sorbent, recoveries between 90 and 123% with RSD values lower than 18% were obtaining. The LOD and LOQ of the QuEChERS methodology coupled to SPE were between 0.02 and 0.13 μg·L-1 and between 0.05 and 0.53 μg·L-1, respectively. The methodology was applied to samples of commercial milk, lactating cow's milk and cow's milk with 7 months gestation, being able to determine the presence of E1 in a concentration of 0.094 μg·L-1 in milk of cow's in gestation. On the other hand, an enzymatic hydrolysis methodology was applied to milk samples obtained from commercial stores, and E1 could be found in 3 analyzed samples, being at a concentration below the limit of quantification in non-hydrolyzed samples and in concentrations between 0.086 and 1.3 μg·L-1. For urine samples, RDSE was used for the extraction of estrogens and simultaneously to primary secondary amine (PSA) was used to reduce the quantity of interferences from this matrix. The extraction methodology was optimized and validated, showing recoveries between 72 and 130% and RSD values less than 17%. The LOD and LOQ were between 0.10 and 0.13 μg·L-1 and between 0.30 and 0.50 μg·L-1, respectively. The methodology was used to analyze urine samples of women of 29, 35 and 53 years old, 2 pregnant women with 27 and 28 weeks of gestation, and of a man of 29 years old. Treatment with the enzyme β-glucuronidase was applied prior to extraction, in order to determine the total amount of estrogen and without enzymatic treatment to determine the free amount of estrogen. The 9 estrogens studied were detected in the different samples analyzed, in individual concentrations ranging from 0.9 to 73 μg·L-1 in the free form, between 0.5 and 1542 μg·L-1 in the conjugated form obtaining concentration until 1615 μg·L-1 in total per analyte. The highest concentrations were found in the urine samples of pregnant women, with E3 being the estrogen found in the highest concentration. It was concluded that the developed methodologies allowed to determine 8 natural and 1 synthetic estrogens by simple and fast methodologies with good levels of linearity, selectivity, sensitivity, accuracy and precision in the three matrices analyzed, where the RDSE technique was adequate for estrogen extraction in complex matrices of a mainly polar nature such as water and urine, while QuEChERS proved to be an efficient methodology for the extraction of estrogens from complex matrices of a mostly non-polar nature. The RDSE technique showed figures of merit similar to other techniques with extensive development such as SPE, while the QuEChERS methodology allowed the extraction of estrogens from milk at levels comparable to other investigations, allowing quantify E1 in the analyzed milk samples. Liquid chromatography coupled to mass spectrometry was a fundamental technique in the detection, confirmation and quantification of these compounds, due to the ability to separate compounds with similar physicochemical properties and to the sensitive and selective determination that was possible in samples of high complexity. It was determined that urine is an important source of estrogen contamination, since through the urine estrogens reach wastewater, which are subsequently discharged into the environment and can affect aquatic fauna and other species that have direct interaction with these waters On the other hand, humans could be incorporating estrogens into our organisms through milk, since if it is extracted in cattle that are in the 3rd trimester of pregnancy, hormonal levels could be around 1000 times higher than in a bovine in normal conditions...
Caracterización de nuevos lazo péptidos producidos por Streptomyces SP. HST28
(Universidad de Chile, 2018)
El estudios de Streptomyces, bacterias Gram positivas del filo Actinobacteria y cosmopolitas (encontradas en diferentes tipos de ambientes), ha llevado al descubrimiento de un gran número de metabolitos secundarios con potencial terapéutico. Uno de...
Identificar oportunidades de inversión para proyectos inmobiliarios residenciales para los segmentos C3 y C2 en la comuna de Puente Alto
(Universidad de Chile, 2019)
el mercado residencial está desarrollando proyectos de viviendas de
extensión con un precio promedio de UF 4.349 ubicados preferentemente en el sector
oriente de la comuna y los desarrollos de viviendas en altura con un precio promedio de UF
2...
del año 2018, Puente Alto es la comuna con mayor déficit habitacional del país alcanzando las 22.441 viviendas, situando a las autoridades locales y a sus habitantes en un escenario altamente complejo por los volúmenes involucrados. Otra...
del año 2018, Puente Alto es la comuna con mayor déficit habitacional del país alcanzando las 22.441 viviendas, situando a las autoridades locales y a sus habitantes en un escenario altamente complejo por los volúmenes involucrados. Otra...
Avances hacia la construcción y reconfiguración de la periferia urbana de la comuna 21 de la ciudad de Santiago de Cali, Colombia, inclusionaria para la población en situación de desplazamiento forzado -PSD
(Universidad de Chile, 2013)
herramienta de desarrollo. 30
2.1.3 El urbanismo como disciplina en Colombia. 32
3. APROXIMACIÓN AL FENÓMENO DEL DESPLAZAMIENTO FORZADO 37
3.1 GENERALIDADES DEL DESPLAZAMIENTO FORZADO 37
3.1.1 El desplazamiento como un choque de intereses. 37
3.1.2 El...
vivienda social del Estado. 111 Foto 15. Condiciones de vida calificadas como excelentes por el 2.3% de los encuestados, antiguos desplazados integrados a la vida de la ciudad de Cali. 111 Foto 16. Vista general de un área destinada a...
vivienda social del Estado. 111 Foto 15. Condiciones de vida calificadas como excelentes por el 2.3% de los encuestados, antiguos desplazados integrados a la vida de la ciudad de Cali. 111 Foto 16. Vista general de un área destinada a...
Empresas de trabajo temporal, un equilibrio entre flexibilización y precarización
(Universidad de Chile, 2007)
Primeramente analizaremos algunas consideraciones generales acerca de las empresas de trabajo temporal, desarrollando conceptualmente el fenómeno del Trabajo Temporal y trazando un deslinde con otras figuras con las que suele confundirse. En el...
Segmentación del mercado laboral juvenil en Chile: tendencias y modalidades de la década 2010-2019
(Universidad de Chile, 2021)
de Empleo se realiza un ejercicio descriptivo comparativo en el periodo, para luego explorar el cúmulo de dimensiones en un análisis de correspondencias múltiples para el año 2019. La evidencia muestra una estructuración desigual y asimétrica del...
Diseño de una red óptima de tratamiento de residuos sólidos domiciliarios para minimizar impactos ambientales y económicos de la comuna de la Granja
(Universidad de Chile, 2019)
reducido, que cuenta con contenedores en lugares de
acceso público como plazas, supermercados, iglesias, condominios, entre otros. En dichos
lugares la ciudadanía realiza una entrega de sus residuos separados. Aquí no se realiza un
pretratamiento.
3
d...
volumétrico respecto a la generación de residuos totales. Además, a partir del funcionamiento actual de la comuna, se propone la instalación de nuevos puntos limpios y/o plantas de tratamiento de pirólisis y/o de combustión. De esta manera, se propone un...
volumétrico respecto a la generación de residuos totales. Además, a partir del funcionamiento actual de la comuna, se propone la instalación de nuevos puntos limpios y/o plantas de tratamiento de pirólisis y/o de combustión. De esta manera, se propone un...