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Search Results: 1 - 10 of 465376 matches for " María Ysabel García "
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Determinación de paraquat en orina utilizando un sistema de inyección en flujo continuo Determination of paraquat in urine samples by flow-injection analysis
José Rafael Luna,María Luisa Di Bernardo,María Ysabel García,Fernando Ovalles
Acta bioqu?-mica cl?-nica latinoamericana , 2008,
Abstract: El paraguat es un herbicida que pertenece al grupo de los biperidilos. Su determinación cuantitativa en orina es muy importante para diagnosticar la supervivencia de pacientes intoxicados. Muchos centros hospitalarios utilizan pruebas semicuantitativas para la determinación de paraquat en muestras biológicas. Sin embargo, éstas suelen carecer de precisión y exactitud. Por tanto, el desarrollo de métodos alternativos simples, exactos, precisos y accesibles podría resultar muy útil en instituciones hospitalarias. Sobre la base de estas consideraciones, se propone un método de análisis por inyección en flujo y detección espectrofotométrica para la determinación cuantitativa de paraquat en muestras de orina. La determinación se basa en la formación de un producto coloreado (600 nm) posterior a la reducción de paraquat con glucosa en un medio alcalino, mediante un sistema en línea. Bajo las condiciones óptimas de operación, la ley de Beer se cumple en el intervalo 1-50 μg mL-1 de paraquat con un coeficiente de correlación >0,999. La frecuencia de análisis fue de 12 h-1 con una desviación estándar relativa del 2,8% para una solución muestra que contiene 10 μg mL-1 de paraquat (n=3). El estudio de recuperación osciló entre 97,9 y 102,1%. El método analítico fue aplicado satisfactoriamente al análisis de muestras de dos pacientes intoxicados con paraquat. Paraguat is a herbicide beloging to the bipyridinium group.The quantitative determination of paraquat in urine of humans is very important to diagnose survival of intoxicated patients. Many hospitals use semi-quantitative tests for determining paraquat in biological samples. However, they often lack precision and accuracy. Therefore, the development of simple, precise, accurate and accessible alternative methods could be very useful in hospital institutions. Based on these considerations, a flow-injection spectrophotometric procedure is proposed for paraquat determination in urine samples. The determination is based on the formation of a coloured product (600 nm) after on-line reduction of paraquat with glucose in alkaline medium. Under optimal conditions of operation, Beer's law is obeyed in a concentration range of 1-50 μg mL-1 of paraquat with a correlation coefficient >0.999. The analytical frequency was 12 h-1 and the relative standard deviation was 2.8% for a sample solution containing 10 μg mL-1 paraquat (n=3). Recovery studies were between 97.9 and 102.1%. The analytical method was satisfactorily applied in the analyses of samples from two intoxicated patients.
Determinación y estandarización de plomo en sangre en operarios de estaciones de servicio del Estado Mérida Blood lead determination and standardization in petrol station workers in the State of Merida
Laura Molina,María Luisa Di Bernardo,Carlos Rondón,María Ysabel García
Acta bioqu?-mica cl?-nica latinoamericana , 2007,
Abstract: En este trabajo se ha determinado el contenido de plomo (Pb) en sangre en operarios de estaciones de servicio de la ciudad de Mérida (Venezuela) y en un grupo de personas no expuestas ocupacionalmente. Las muestras de sangre provenientes de sujetos de ambos sexos n=21 (controles) y n=65 (personal expuesto) fueron procesadas por absorción atómica con atomización electrotérmica (ETAAS). Las concentraciones obtenidas de 15,27±9,62 y 83,74±28,95 μg/L para los grupos denominados como control y expuesto respectivamente, muestran diferencias altamente significativas que evidencian una exposición directa al Pb, por cuanto los valores del grupo expuesto ocupacional son más de 5 veces superiores a los del grupo control. Los resultados obtenidos también muestran que valores iguales o superiores a 54,79 μg/L son indicadores de exposición directa al Pb, permitiendo establecer valores de tolerancia entre los intervalos de 24,89 y 112,69 μg/L. Estos valores de referencia se encuentran por debajo de lo descripto por Burguera y cols. (1997), lo cual podría atribuirse al reemplazo gradual de la gasolina con plomo, en los últimos a os, que ha llevado a una disminución de un 27% en los niveles de plomo en sangre, en comparación con un estudio similar realizado en esta misma ciudad en el a o 1997. In this work the lead (Pb) content in blood was determined in petrol station workers in the city of Merida-Venezuela and in a group of people not occupationally exposed. The blood samples coming from subjects of both sexes n=21 controls and n=65 exposed workers were processed by atomic absorption with electrothermal atomization (ETAAS). The 15.27±9.62 and 83.74±28.95 μg/L concentrations obtained for the group referred to as control and exposed respectively show highly significant differences that evidence a direct exposure to Pb, since the values of the occupationally exposed group are more than 5 times higher than those of the control group. The results obtained also show that values equal to or higher than 54.79 μg/L are indicative of direct exposure to Pb, making it possible to establish tolerance values between the 24.89 and 112.69 μg/L intervals. These reference values are below what was reported by Burguera et al (1997) which could be attributed to the gradual substitution of gasoline for lead that has originated a 27% decrease in lead levels in blood, if compared with a similar study carried out in the same city in 1997.
Evaluation of the hair matrix as valid for the determination of mercury pollution in artisanal miners Bolivar State- Venezuela.
María Luisa Di Bernardo,María Ysabel García,Karina Isabel Zago,José R Luna
RETEL : Revista de Toxicología en Línea , 2010,
Abstract: Mercury (Hg) elementary metal or, is used in the extraction of gold and silver, in dental amalgams and a great variety of elements of measurement of temperature and pressure in medicine and the industry (1). The determination of Hg in different biological matrices, mainly in blood, urine and hair, it is important to value the contamination of Hg coming from the environment or the labor atmosphere. The volatileness and easy skin absorption of the metal and most of the mercury compounds, turn to him into a toxic difficult to control, reason why it is necessary that, besides applying strict measures of industrial hygiene, frequent biological controls become of exhibition (2). The study was carried out in 32 workers of both sorts (22 men and 10 women) exposed to elementary Hg, all artisan miners of the State Bolivar-Venezuela. With ages averages of 36±14 years. Also one needed 20 individuals (12 men and 8 women) not exhibited labor, that we denominated group Control. One determined in urine and Hg hair to them. The existing correlations between both matrices studied, as well as the tinned effect of the fish consumption, products, and inlays, habits to smoke, exposure time, dye use or creams for the hair among others. Knowing that the plans of toxic metals and until of illegal drugs disappear of the urine, but the evidence remains catched in the hair. The hair has the advantage to count in the long term on memory. It is a permanent file, like the ring of the trees. The hair absorbs toxic minerals through its roots of the sanguineous torrent. The substance remains as grows the hair at a speed of 1, 25 cm per month. A length of hair of 7, 5 cm of the portion more close to the hairy leather offers a history of 6 months. In resistance, the toxic mineral can later not show to a track in the urine only few hours or few days (3-6). This work tries to demonstrate if it exists or not a correlation in both studied and evaluated matrices.Giving rise to a matrix alternating and significant or on the contrary, to reject it when it is tried to evaluate poisoning and exhibition.
Uso de glucosa como agente reductor en la determinación semicuantitativa de paraquat en orina
José Rafael Luna,María Luisa Di Bernardo,María Ysabel García,Carlos Ya?ez
RETEL : Revista de Toxicología en Línea , 2007,
Abstract: Paraquat belongs to the Bipyridylium family of herbicides. It is widely used for green weed control since interferes with the mechanism of photosynthesis. The absorption by the intact skin and the respiratory tract is lower than ingestion. Paraquat is highly toxic via ingestion. Precisely, oral administration with either suicidal intent or accidentally is by far the commonest route of entry. The acute toxicological effects depend on the amount ingested. The absorbed paraquat is distributed via the bloodstream to practically all organs and tissues of the body, but it is excreted rapidly by the kidney. In some cases, before prescribing a treatment for people poisoned by paraquat, a spot test may be needed in order to confirm its diagnosis. Survival depends on the accuracy and timeliness of the diagnosis. There is a known spot test for paraquat in the urine which is available on hospitals and emergency centers. This qualitative test is based on the reduction of paraquat to a blue complex in the presence of alkali and sodium dithionite. The main disadvantage of this test is the instability of the blue radical ion in presence of oxygen. In the present research the aforementioned urine color test was reproduced but substituting sodium dithionite by glucose. Glucose was used as reducing agent in order to develop a semi-quantitative method with competitive advantages over the official method. Glucose is cheap, stable and nontoxic. Paraquat reacts with glucose in alkaline medium to yield a blue chromogen with higher stability than that one obtained using sodium dithionite. The colored complex is formed after incubation in water bath. Results showed that the colored complex is stable up to 12 hours and is paraquat-glucose concentration dependent. The proposed qualitative method could be used as a rapid and routinely color test for paraquat in urine samples for a quick confirmation of paraquat poisoning.
Assesment of some hematological and biochemical parameters as biomarkers of occupational exposure to lead, in Mérida, Venezuela
Carlos Yánez,María Luisa Di Bernardo,María Ysabel García,Nurby Ríos
RETEL : Revista de Toxicología en Línea , 2008,
Abstract: We studied 150 people exposed to lead, between 20 and 50 years’old to assess some hematologic and biochemical abnormalities. They were classify in two groups: Group A (controls occupational non-exposed, n=55) and Group B (occupational exposed, n=95). People from Group B work in shops and retailers with vinyl paintings, workshops and automobile paint, printing graphics, workshops oil change, car wash and lubrication and blacksmithing workshops of the Libertador Municipality of Mérida State with a time of exposure between 3 months and 10 years. Both groups were taken blood samples for determination of serum lead by Electrothermal Atomic Absorption Spectrometry (ETAAS) and testing Hematological and biochemical. There were statistically significant differences (p <0.05) between the two groups. Workers with high percentages of basophilic stippling were associated with higher serum levels of the metal. In this review, basophilic stippling and corpuscular volume were good biomarkers of exposure to the metal and we postulated to be useful when a toxicology laboratory has not infrastructure for accurate diagnosis. It is a methodology bioanalytical routine, safe, reliable and inexpensive.
Determinación de paraquat en orina utilizando un sistema de inyección en flujo continuo
Luna,José Rafael; Di Bernardo,María Luisa; García,María Ysabel; Ovalles,Fernando; Calderón,Laura;
Acta bioqu?-mica cl?-nica latinoamericana , 2008,
Abstract: paraguat is a herbicide beloging to the bipyridinium group.the quantitative determination of paraquat in urine of humans is very important to diagnose survival of intoxicated patients. many hospitals use semi-quantitative tests for determining paraquat in biological samples. however, they often lack precision and accuracy. therefore, the development of simple, precise, accurate and accessible alternative methods could be very useful in hospital institutions. based on these considerations, a flow-injection spectrophotometric procedure is proposed for paraquat determination in urine samples. the determination is based on the formation of a coloured product (600 nm) after on-line reduction of paraquat with glucose in alkaline medium. under optimal conditions of operation, beer's law is obeyed in a concentration range of 1-50 μg ml-1 of paraquat with a correlation coefficient >0.999. the analytical frequency was 12 h-1 and the relative standard deviation was 2.8% for a sample solution containing 10 μg ml-1 paraquat (n=3). recovery studies were between 97.9 and 102.1%. the analytical method was satisfactorily applied in the analyses of samples from two intoxicated patients.
Aminas biógenas y bacterias en salchichón tipo milano: Efecto del tiempo de almacenamiento
Izquierdo,Pedro; Allara,María; García,Aiza; Torres,Gabriel; Rojas,Evelin; Pi?ero,María Ysabel;
Revista Científica , 2006,
Abstract: free aminoacids presence, decarboxilating bacteria, temperature and storage time may induce biogenic amine formation. the objective of this research was to determine storage time effect on biogenic amine and bacteria presence in milano type sausage. nine (9) complete sausages of three brands (3 units per brand) were used, two months from expiration date. samples were analyzed 60, 30 and 0 days before expiration. biogenic amines were determined by means of liquid chromatography (hplc), lactic acid bacteria (lab), enterococci (entc) and enterobacteria (entb) according to icmsf. in brand 1 a significant diminishment (p < 0.05) in lab number, brand 2 remain stable, meanwhile brand 3 raised significantly (p < 0.05) between first and second sampling, and kept this values until expiration date. there were no significant differences in entc of brands 1 and 3, but in brand 2, the number raised, and significant differences (p < 0.05) between first and later dates were found. brand and storage time and interaction between them had a significant effect (p < 0.05) on biogenic amine content, entc and lab. lab was higher than entc during storage. entb were not found. tiramine, histamine, cadaverin and putrescine were detected; tiramine and histamine concentrations could produce a food poisoning in susceptible individuals.
Determinación y estandarización de plomo en sangre en operarios de estaciones de servicio del Estado Mérida
Molina,Laura; Di Bernardo,María Luisa; Rondón,Carlos; García,María Ysabel; Carrero,Pablo; Luna,José Rafael; Salazar,José Gregorio; Morales,Alexis; Hernández,Yajaira; Pe?a,Jesús;
Acta bioqu?-mica cl?-nica latinoamericana , 2007,
Abstract: in this work the lead (pb) content in blood was determined in petrol station workers in the city of merida-venezuela and in a group of people not occupationally exposed. the blood samples coming from subjects of both sexes n=21 controls and n=65 exposed workers were processed by atomic absorption with electrothermal atomization (etaas). the 15.27±9.62 and 83.74±28.95 μg/l concentrations obtained for the group referred to as control and exposed respectively show highly significant differences that evidence a direct exposure to pb, since the values of the occupationally exposed group are more than 5 times higher than those of the control group. the results obtained also show that values equal to or higher than 54.79 μg/l are indicative of direct exposure to pb, making it possible to establish tolerance values between the 24.89 and 112.69 μg/l intervals. these reference values are below what was reported by burguera et al (1997) which could be attributed to the gradual substitution of gasoline for lead that has originated a 27% decrease in lead levels in blood, if compared with a similar study carried out in the same city in 1997.
Relation between Human Chorionic Gonadotropin and Thyroid Hormones in Preeclampsia  [PDF]
María I. Camejo, Ysabel C. Casart
Open Access Library Journal (OALib Journal) , 2014, DOI: 10.4236/oalib.1100652
Abstract: Aim: Alterations in thyroid function with a simultaneous increase of hCG in some pregnancy diseases have been reported. However, the relationship between thyroid hormones and hCG during preeclampsia is not yet evaluated. In this study we determined serum levels of hCG, TSH, free T3 (fT3) and free T4 (fT4) in normal pregnant woman and in patients with preeclampsia and evaluated the correlation between these hormones. Methods: Blood samples were taken from 20 healthy pregnant women as control and from 20 patients with severe preeclampsia. Total hCG was measured by enzyme immunoassays. Serum concentrations of TSH, fT3 and fT4 were determined by chemiluminiescence method. Result: The average values of hCG were higher in the group with preeclampsia, but no statistically significant differences in relation to control group were observed. Likewise, no differences in serum concentrations of TSH, fT3 and fT4 between the control group and the group with preeclampsia were observed. Additionally, no correlation was observed between TSH, T3 and T4 with hCG. Conclusion: No correlation was observed between hCG and thyroid hormones. The different forms of hCG present in normal pregnancy and during preeclampsia could have different ways of stimulating the TSH receptor, which may be reflected in thyroid function.
Can Character Solve Our Problems? Character Qualities and the Imagination Age  [PDF]
María García Alvarez
Creative Education (CE) , 2018, DOI: 10.4236/ce.2018.92012
Abstract: The emergence of new technology, incorporation of AI to the work floor and rapid pace of change and complexity around us, contribute to the need for a more sophisticated set of skills as key elements for the 21st century and centuries to come. This paper defends the idea that in the Imagination Age we will require more than just the mastery of traditional foundational literacies. Educational institutions should shift the focus towards the training of character qualities. Meta-competencies directly linked with character will provide students with the ability to deal with complex environments. While the importance of character qualities in education is not new, it will become more relevant to prepare the future generations. Educational institutions are urged to rethink their own methods and roles to prepare students to live and collaborate together with new forms of intelligence.
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