Is otolith microchemistry (Sr: Ca and Ba:Ca ratios) useful to identify Mugil curema populations in the southeastern Caribbean Sea? / A microquímica do otólito é um indicador do habitat de Mugil curema no sudeste do Mar Caribenho?

Abstract The aim of the present study was to evaluate the potential use of otolith microchemistry (Sr:Ca and Ba:Ca ratios) to identify silver mullet, Mugil curema, populations in Southeastern Caribbean Sea. Fish samples were collected in 7 areas of Nueva Esparta State (Venezuela). The otolith Sr:Ca and Ba:Ca ratios and water Sr:Ca were determined (by ICP-OES and EDTA volumetric method). Otoliths Sr:Ca and Ba:Ca ratios and Sr:Ca partition coefficient of mullets in Cubagua island (south of the State) were significantly different from ratios in La Guardia (north of the State). A discriminant analysis of otolith Sr:Ca and Ba:Ca ratios separated Cubagua Island from La Guardia values. These results suggest the existence of different mullet groups in the Southeastern Caribbean Sea. For this, the simultaneous use of Sr:Ca and Ba:Ca ratios could be a potential tool to identify populations in the study area.

Resumo O objetivo do presente estudo foi avaliar o potencial uso da microquímica do otólito (razões Sr:Ca e Ba:Ca) para identificar distintas populações de tainha, Mugil curema, no sudeste do mar caribenho. Os peixes foram coletados em 7 áreas do estado de Nueva Esparta (Venezuela). As razões Sr:Ca e Ba:Ca do otólito e a razão Sr:Ca da água foram determinadas (pelo ICP-OES e EDTA método volumétrico). As razões de Sr:Ca e Ba:Ca dos otólitos e o coeficiente de partição das tainhas da Ilha Cubagua (sul do estado) foram significativamente diferentes das razões de La Guardia (norte do estado). A análise discriminante das razões de Sr:Ca e Ba:Ca dos otólitos separa os valores da Ilha Cubagua e de La Guardia. Estes resultados sugerem a existência de diferentes grupos de Mugil curema no sudeste do mar Caribenho e que o uso simultâneo das razões Sr:Ca e Ba:Ca poderiam ser uma potencial ferramenta para identificar as populações da área de estudo.

Determination of 24 elements in human hair by ICP-MS using microwave digestion / 法医学杂志

OBJECTIVE@#To establish an inductively coupled plasma-mass spectrometry (ICP-MS) method for determination of 24 elements in human hair.@*METHODS@#The samples were digested with microwave digestion instrument. ICP-MS was applied to determine 24 elements in human hair using indium (115In) as an internal standard. The established method was applied to determine element concentration in normal group (56 samples) and heroin abuse group (10 samples).@*RESULTS@#The limits of detection ranged from 0.000 3 microg/g to 10.14 microg/g. Measured value of the standard materials were basically consistent with the standard value. The contents of magnesium, gallium and barium in hair of heroin addicts decreased after rehabilitation treatment.@*CONCLUSION@#The method is sensitive and accurate for determination of 24 elements in human hair.

Optical density and chemical composition of microfilled and microhybrid composite resins

This study evaluated the optical density of two microfilled and two microhybrid resins, as well as the composition of these materials with regard to their optical density. Cavities prepared in 12 2-mm- or 4-mm-thick acrylic plastic plates were filled with Z250 (3M-ESPE), A110 (3M-ESPE), Charisma (Heraeus-Kulzer) and DurafillVS (Heraeus-Kulzer). The resin increments (2-mm-thick) were light-cured for 40 s. Three 0.12-s radiographic exposures were made of each #2 acrylic plastic plate. DenOptix system optical plates were used to obtain the digital images. Three readings of the composite resin surface were made in each radiograph, totalizing 216 readings. The mean of highest and lowest grey-scale values was obtained. Two specimens of each composite resin were prepared for SEM analysis of the chemical elements related to optical density, using energy dispersive x-ray analysis (EDX). The results were subjected to Shapiro-Wilk's test, ANOVA, Tukey's test at 1 percent level of significance and Pearson's correlation. The mean grey-scale values at 2 mm and 4 mm were: Z250 = 154.27a and 185.33w; A110 = 46.77b and 63.05y; Charisma = 163.40c and 200.46z; DurafillVS = 43.92b and 58.99x, respectively. Pearson's test did not show any positive correlation between optical density and percentage weight of optical density chemical elements. It was concluded that the microhybrid resins had higher optical density means than the microfilled resins; among the evaluated resins, Charisma had the highest optical density means.

Investigacao quimica dos medicamentos homeopaticos pertencentes aos diferentes "Grupos Boyd": analise cromatografica do grupo VI / Chemical investigation of homeopathic medicines pertainig to differents \"Boyd's Groups\": chromatographical analyse of group VI

Dando prosseguimento ao estudo dos chamados grupos Boyd, os autores analisaram o grupo VI por meio de cromatografia ascendente em placas de celulose microcristalina. Detectaram a presenca dos seguintes ions: Mg+2 em vinte e cinco (25) tinturas analisadas, Ca+2 em dez (10), Ba+2 em tres (03) e Zn+2 em uma (01)

Investigacao quimica dos medicamentos homeopaticos pertencentes aos diferentes grupos Boyd 2. Pesquisa de cationtes nos medicamentos do grupo II de Boyd / Chemical investigation of homeopathic drugs belonging to different Boyd Groups 2. Cantion investigation in Boyd Group II drugs

Dando prosseguimento ao estudo dos chamados grupos Boyd, os autores analisaram o grupo II por meio de cromatografia em camada delgada. Detectaram os seguintes ions nas amostras analisadas: Ca+2, Mg+2 e Ba+2.