RESUMO
Introducción: La posición del tercer molar mandibular durante su erupción puede influir en el resultado del tratamiento de ortodoncia o que se necesita recurrir a este nuevamente. Objetivo: Describir la posición de los terceros molares mandibulares durante su erupción en pacientes que recibieron tratamiento ortodóncico en el consultorio Desing Dental en la ciudad de Santo Domingo de los Tsáchilas, Ecuador. Método: se realizó un estudio descriptivo transversal, el universo lo constituyeron el total de pacientes que recibieron tratamiento ortodóncico en edades comprendidas entre 13 y 33 años¸ el muestreo fue aleatorio simple y la muestra quedó conformado por 23 pacientes, 11 del sexo masculino y 12 del femenino. La recolección de la información se realizó a través de la revisión documental de los informes radiográficos mediante una guía confeccionada para este fin. Los resultados se presentaron en tablas y fueron contrastados con los de otras investigaciones. Se respetaron los principios éticos. Resultados: La posición de los terceros molares más común según edad y sexo fue: para el sexo masculino de 11 pacientes, 2 presentaron la vertical, 8 la mesioangular y 1 la horizontal; mientras que, en el sexo femenino con una muestra de 12 pacientes: 2 pacientes presentaron la posición vertical, 8 la mesioangular y 2 la distoangular. Conclusiones: La posición más frecuente de los terceros molares durante su erupción en los pacientes con tratamiento de ortodoncia fue la posición mesioangular.
Introduction: The position of mandibular third molar during its eruption can influence on the outcome of orthodontic treatment or the need to turn to an orthodontic treatment again. Objective: To describe the position of mandibular third molars during eruption in patients who received orthodontic treatment at the dental office Desing Dental, in the city of Santo Domingo de los Tsáchilas, Ecuador. Method: A cross-sectional descriptive study was carried out; the universe was constituted by the total of patients who received orthodontic treatment, patients between 13 and 33 years of age; the sampling applied was simple random and the sample selected gathered 23 patients, 11 male and 12 female. The information collected was obtained throught a documentary review of the radiographic reports, using a guide prepared for this purpose. The outcomes were presented in tables and were contrasted with those of other investigations. Ethical principles were respected. Results: The most common position of the third molars according to age and sex was as follow: From the 11 male patients, in 2 of them the position was vertical, 8 mesioangular and 1 horizontal; whereas in the 12 female patients, in two of them the position was vertical, 8 mesioangular and 2 distoangular. Conclusions: The most frequent position of third molars during eruption in patients undergoing orthodontic treatment was the mesioangular position.
Introdução: A posição do terceiro molar inferior durante sua erupção pode influenciar no resultado do tratamento ortodôntico ou que seja necessário recorrer a ele novamente. Objetivo: Descrever a posição dos terceiros molares inferiores durante sua erupção em pacientes que receberam tratamento ortodôntico no consultório Desing Dental na cidade de Santo Domingo de los Tsáchilas, Equador. Método: Foi realizado um estudo descritivo transversal, o universo foi constituído pelo número total de pacientes que receberam tratamento ortodôntico entre 13 e 33 anos, a amostragem foi aleatória simples e a amostra foi composta por 23 pacientes, 11 masculinos e 12 femininos. A coleta de informações foi realizada por meio da revisão documental dos laudos radiográficos utilizando um roteiro elaborado para esse fim. Os resultados foram apresentados em tabelas e contrastados com os de outras investigações. Os princípios éticos foram respeitados. Resultados: A posição mais comum dos terceiros molares de acordo com idade e sexo foi: para o sexo masculino de 11 pacientes, 2 apresentaram a vertical, 8 a mesioangular e 1 a horizontal; enquanto, no sexo feminino com uma amostra de 12 pacientes: 2 pacientes apresentaram a posição vertical, 8 a mesioangular e 2 a distoangular. Conclusões: A posição mais frequente dos terceiros molares durante sua erupção em pacientes com tratamento ortodôntico foi a posição mesioangular.
RESUMO
In this study, a novel, simple, and highly sensitive analytical procedure for the quantitative evaluation of oxygenated and nitrated polycyclic aromatic hydrocarbons in volcanic ash samples based on dispersive solid-liquid microextraction (DSLME) coupled to ultra high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed. Diverse chemometric tools were applied to optimize DSLME working conditions. Thus, a linear calibration curve for all the target analytes in the concentration range from 0.01 to 100 µg g-1 (r2 > 0.994) was obtained. The limits of detection for all the compounds were between 14.6 and 56.0 pg g-1, with high reproducibility (relative standard deviation (RSD) was below 8.1% for all the analytes). Additionally, recoveries ranged from 94.2 to 100%. The applicability of the method was evaluated and the feasibility of the existence of nitrated and oxygenated-PAHs in volcanic ashes at ultra-trace levels was demonstrated, which reveals an unknown source of distribution of these pollutants to the environment. Graphical Abstract.
Assuntos
Nitratos , Hidrocarbonetos Policíclicos Aromáticos , Limite de Detecção , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem , Erupções VulcânicasRESUMO
A new simple methodology is proposed for chlorsufuron (CS) traces quantification based upon enhancement of rhodamine B (RhB) fluorescent signal. Experimental variables that influence fluorimetric sensitivity have been studied and optimized. The zeroth order regression calibration was linear from 0.866 to 35.800µgL(-1) CS, with a correlation coefficient of 0.99. At optimal experimental conditions, a limit of detection of 0.259µgL(-1) and a limit of quantification of 0.866µgL(-1) were obtained. The method showed good sensitivity and adequate selectivity and was applied to the determination of trace amounts of CS in plasma, serum and water samples with satisfactory results analyzed by ANOVA test. The proposed methodology represents an alternative to traditional chromatographic techniques for CS monitoring in complex samples, using an accessible instrument in control laboratories.
Assuntos
Poluentes Ambientais/análise , Corantes Fluorescentes/química , Praguicidas/análise , Rodaminas/química , Sulfonamidas/análise , Triazinas/análise , Água Potável/análise , Poluentes Ambientais/sangue , Poluentes Ambientais/química , Poluentes Ambientais/urina , Feminino , Fluorescência , Água Subterrânea/análise , Humanos , Leite Humano/química , Praguicidas/sangue , Praguicidas/química , Praguicidas/urina , Plasma/química , Soro/química , Espectrometria de Fluorescência , Sulfonamidas/sangue , Sulfonamidas/química , Sulfonamidas/urina , Triazinas/sangue , Triazinas/química , Triazinas/urinaRESUMO
A novel method for preconcentration and electrochemical detection of zinterol in bovine urine samples was developed. In order to improve the limit of detection, the surface of a screen-printed carbon electrode was modified with electrodeposited metal copper nanoparticles. The experimental electrodeposition optimization was performed using a central composite design (CCD), involving the variables: precursor concentration, potential and time applied. Copper nanoparticles were characterized by transmission electron microscopy, scanning electron microscopy, cyclic voltammetry, and energy dispersive X-ray spectroscopy. Mesoporous shuttle-like copper oxide nanoparticles were used for the preconcentration step to avoid interferences with many compounds present in the sample matrix. The optimal working conditions for the preconcentration approach were found by means of both two-level fractional factorial and CCD designs. The obtained enhancement factor for a sample volume of 30 mL was 35 fold. The calibration curve showed linearity between 0.5 and 45 ng mL(-1) and the limit of detection was 0.16 ng mL(-1). The intra and inter assay coefficients of variability were below 4% and 5%; respectively.
Assuntos
Agonistas Adrenérgicos beta/urina , Cobre/química , Etanolaminas/urina , Aditivos Alimentares/análise , Nanopartículas Metálicas/química , Agonistas Adrenérgicos beta/química , Ração Animal , Animais , Carbono/química , Bovinos , Eletroquímica , Eletrodos , Etanolaminas/química , Aditivos Alimentares/química , Inocuidade dos Alimentos , CarneRESUMO
A preconcentration system has been developed to determine inorganic selenium species. Selenium was retained by a column filled with polyvinyl chloride (PVC) with lanthanum hydroxide co-precipitation. Speciation was achieved by selective photoreduction previous Se preconcentration. The retention pH was optimized at 10.0. Two multivariate calibrations and a central composite design were employed for optimization of the system. Sample, reagents and acid flow rates are significant variables affecting the system. Employing HG-ICP-OES as detection, the optimized system reached a detection limit of 0.03µg/L, and an enhancement factor of 14875 (25 for preconcentration system, 595 for hydride generation). To verify the method' accuracy, two certified reference materials, BCR® 414 Plankton & IRMM-804 Rice Flour, were analysed. The system was applied to inorganic selenium speciation in several Argentinean beverages to estimate their selenium contribution to diet.
Assuntos
Bebidas/análise , Espectrometria de Massas/métodos , Compostos de Selênio/análise , Compostos de Selênio/isolamento & purificação , Extração em Fase Sólida/métodos , Argentina , Calibragem , Limite de Detecção , Selênio/análiseRESUMO
An on-line preconcentration procedure using solid phase extraction (SPE) for the determination of copper in different water samples by inductively coupled plasma optical emission spectrometry (ICP-OES) is proposed. The copper was retained on a minicolumn filled with ethyl vinyl acetate (EVA) at pH 8.0 without using any complexing reagent. The experimental optimization step was performed using a two-level full factorial design. The results showed that pH, sample loading flow rate, and their interaction (at the tested levels) were statistically significant. In order to determine the best conditions for preconcentration and determination of copper, a final optimization of the significant factors was carried out using a central composite design (CCD). The calibration graph was linear with a regression coefficient of 0.995 at levels near the detection limit up to at least 300 µg L(-1). An enrichment factor (EF) of 54 with a preconcentration time of 187.5 s was obtained. The limit of detection (3σ) was 0.26 µg L(-1). The sampling frequency for the developed methodology was about 15 samples/h. The relative standard deviation (RSD) for six replicates containing 50 µg L(-1) of copper was 3.76%. The methodology was successfully applied to the determination of Cu in tap, mineral, river water samples, and in a certified VKI standard reference material.