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Energy dispersive X-ray spectroscopy (EDS) is a powerful technical tool used in the biomedical field to investigate the proportion of chemical elements of interest in research, such as heavy metal bioaccumulation and the enzymatic cofactors and nanoparticle therapy in various pathologies. However, the correct evaluation of the proportion of the elements is subject to some factors, including the method of sample preservation. In this study, we seek to investigate the effect of biological tissue preservation methods on the proportion of chemical elements obtained by the EDS methodology. For such, we used EDS to measure the proportion of chemical elements with biomedical interest in preserved livers, using three common methods for preserving biological tissues: (a) freezing, (b) paraformaldehyde fixative solution, and (c) Karnovsky solution. We found an increased level of sodium and reduced contents of potassium and copper in samples fixed in fixative solutions, when compared to frozen samples (p < 0.05). Our data indicate that preservation methods can change the proportion of chemical elements in biological samples, when measured by EDS. Frozen preservation should be preferred to retain the actual chemical content of samples and allow a correct assessment of the proportion of their elements.

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We describe the assembly of a hybrid electrophoresis device that contains fused silica capillaries interconnected to a microfabricated interface in a cross format for the determination of inorganic cations in biological samples. The sample transport in the proposed hybrid device was performed under gated injection mode and the separations were monitored with a capacitively coupled contactless conductivity detector. The capillary extremities were inserted into polypropylene tubes to create solution reservoirs. Sensing electrodes were produced using stainless-steel hypodermic needles previously cut with 2.0 mm length. The running composition and injection time were optimized and the best results were found using 50 mmol/L lactic acid, 20 mmol/L histidine and 3 mmol/L 18-crown-6 ether, and an electrokinetic injection time of 15 s. The separation of six inorganic cations was achieved with baseline resolution, and efficiencies were between 9.1 × 103 and 5.4 × 104 plates/m. The proposed hybrid device was explored for determining the concentration levels of inorganic cations in urine, saliva, and tear samples, employing Li+ as an internal standard. The achieved results were in good agreement with the data reported in the literature. The reliability of the proposed method ranged from 93 to 98%, thus suggesting satisfactory accuracy for bioanalytical applications.

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Honey is the most popular bee product used by man, with nutritional and medicinal purposes. Its great diversity is attributed to numerous factors (bee type, visited flora, environment, and management). The quality of honey is controlled with routine parameters (free acidity, diastase activity, reducing sugars, ash, water, hydroxymethyfurfural, and sucrose contents). Besides the biochemical quality control, a functional profile is also important for pharmacological applications. In this work, bioactive indicators such as the antioxidant activity, flavonoid and polyphenol contents were evaluated by spectrophotometry, and correlated to the content of six bioelements (Ca, Cu, Fe, Mg, Mn, Zn) measured by atomic absorption spectroscopy, tandem FI-FAAS, in 14 unifloral Czech honeys. The antioxidant activity was 43.13 ± 53.72 mmoles TEAC/100 g honey. The flavonoid content was 5.18 ± 4.19 mg QE/100 g, and the polyphenol content was 45.38 ± 27.20 mg GAE/100 g. Buckwheat honey showed the highest values for these indicators of bioactivity, the acacia honeys the lowest, and the rest of the honeys were comprised between both of them. Honey content of bioelements was 138.19 ± 55.57 ppm Ca (min 77.11 - max 261.65), 0.33 ± 0.41 ppm Cu (min 0.00 - max 1.37), 2.95 ± 1.10 ppm Fe (min 1.34 - max 5.36), 35.08 ± 29.59 ppm Mg (min 8.76 - 128.06), 4.93 ± 3.99 ppm Mn (min 0.34 - max 11.31), 1.07 ± 0.56 ppm Zn (min 0.49 - max 2.52). The antioxidant activity of honey was significantly correlated to its content of cupper, iron, magnesium, manganese and zinc, but was not correlated to calcium.

La miel de abejas es el producto apícola más popular utilizado por el hombre, con fines nutricionales y medicinales. Su gran diversidad se atribuye a numerosos factores (tipo de abeja, flora visitada, ambiente, y manejo). La calidad de la miel se controla con parámetros de rutina: acidez libre, actividad de la diastasa, azúcares reductores, cenizas, humedad, hidroximetilfurfural, sacarosa aparente. Junto con el control de calidad bioquímica, también es importante su perfil funcional para aplicaciones farmacológicas. En este trabajo se evaluaron indicadores de bioactividad como la actividad antioxidante, el contenido de flavonoides y de polifenoles por espectrofotometría, y se correlacionaron con el contenido de seis bioelementos (Ca, Cu, Fe, Mg, Mn, Zn) determinados por espectroscopía de absorción atómica, IF acoplada a EAA con llama, en 14 mieles uniflorales checas. La actividad antioxidante fue 43.13 ± 53.72 mmoles TEAC/100 g miel. El contenido de flavonoides fue 5.18 ± 4.19 mg EQ/100 g, y el de polifenoles fue 45.38 ± 27.20 mg EAG/100 g. La miel de trigo sarraceno mostró los mayores valores en estos indicadores de bioactividad, las mieles de acacia los más bajos, y en el resto de las mieles estuvieron comprendidos entre ambos. El contenido de bioelementos en la miel fue 138.19 ± 55.57 ppm Ca (min 77.11 - max 261.65), 0.33 ± 0.41 ppm Cu (min 0.00 - max 1.37), 2.95 ± 1.10 ppm Fe (min 1.34 - max 5.36), 35.08 ± 29.59 ppm Mg (min 8.76 - 128.06), 4.93 ± 3.99 ppm Mn (min 0.34 - max 11.31), 1.07 ± 0.56 ppm Zn (min 0.49 - max 2.52). La actividad antioxidante de la miel se correlacionó significativamente con su contenido de cobre, hierro, magnesio, manganeso y zinc, pero no se correlacionó con el contenido de calcio.

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Two of the main items from which to retrieve data in anthropology are teeth and bones. Identification of trace elements in their composition allows valuable information to be obtained about alimentary habits and community life conditions of groups and individuals. Conventional methods used to determine the presence of trace elements require sample preparation, with partial or total destruction of the pieces, which in most cases are unique. In this work we show the possibilities of laser-induced breakdown spectroscopy (LIBS) as a nearly nondestructive tool in anthropology and paleontology for the measurement of the presence and distribution of trace elements in teeth. We applied LIBS to the determination of strontium and magnesium in dentin and enamel of Neolithic, middle age, and modern Homo sapiens teeth. Mg/Ca and Sr/Ca distribution maps of dentin and enamel in modern teeth were created using the data obtained. Ablation threshold fluences of dentin and enamel were also measured using the photoacoustic signal induced by laser ablation. Significant variations were found in the Mg/Ca and Sr/Ca ratios in the tooth dental tissue and between the teeth of the groups and individuals studied. These results can be useful for evolutionary anthropology studies as they can provide information regarding early nutrition, seasonality, and residential mobility.

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Honey is the most popular bee product used by man, with nutritional and medicinal purposes. Its great diversity is attributed to numerous factors (bee type, visited flora, environment, and management). The quality of honey is controlled with routine parameters (free acidity, diastase activity, reducing sugars, ash, water, hydroxymethyfurfural, and sucrose contents). Besides the biochemical quality control, a functional profile is also important for pharmacological applications. In this work, bioactive indicators such as the antioxidant activity, flavonoid and polyphenol contents were evaluated by spectrophotometry, and correlated to the content of six bioelements (Ca, Cu, Fe, Mg, Mn, Zn) measured by atomic absorption spectroscopy, tandem FI-FAAS, in 14 unifloral Czech honeys. The antioxidant activity was 43.13 +/- 53.72 micromoles TEAC/100 g honey. The flavonoid content was 5.18 +/- 4.19 mg QE/100 g, and the polyphenol content was 45.38 +/- 27.20 mg GAE/100 g. Buckwheat honey showed the highest values for these indicators of bioactivity, the acacia honeys the lowest, and the rest of the honeys were comprised between both of them. Honey content of bioelements was 138.19 +/- 55.57 ppm Ca (min 77.11-max 261.65), 0.33 +/- 0.41 ppm Cu (min 0.00-max 1.37), 2.95 +/- 1.10 ppm Fe (min 1.34-max 5.36), 35.08 +/- 29.59 ppm Mg (min 8.76-128.06), 4.93 +/- 3.99 ppm Mn (min 0.34-max 11.31), 1.07 +/- 0.56 ppm Zn (min 0.49-max 2.52). The antioxidant activity of honey was significantly correlated to its content of cupper, iron, magnesium, manganese and zinc, but was not correlated to calcium.

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An all-in-one version of a capacitively coupled contactless conductivity detector is introduced. The absence of moving parts (potentiometers and connectors) makes it compact (6.5 cm(3)) and robust. A local oscillator, working at 1.1 MHz, was optimized to use capillaries of id from 20 to 100 microm. Low noise circuitry and a high-resolution analog-to-digital converter (ADC) (21 bits effective) grant good sensitivities for capillaries and background electrolytes currently used in capillary electrophoresis. The fixed frequency and amplitude of the signal generator is a drawback that is compensated by the steady calibration curves for conductivity. Another advantage is the possibility of determining the inner diameter of a capillary by reading the ADC when air and subsequently water flow through the capillary. The difference of ADC reading may be converted into the inner diameter by a calibration curve. This feature is granted by the 21-bit ADC, which eliminates the necessity of baseline compensation by hardware. In a typical application, the limits of detection based on the 3sigma criterion (without baseline filtering) were 0.6, 0.4, 0.3, 0.5, 0.6, and 0.8 micromol/L for K(+), Ba(2+), Ca(2+), Na(+), Mg(2+), and Li(+), respectively, which is comparable to other high-quality implementations of a capacitively coupled contactless conductivity detector.

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OBJECTIVE: To assess the effects of evaporation and pasteurization of human milk on its biochemical and immunological composition and on its osmolarity. METHODS: The samples of mature human milk were categorized into four study groups: in natura human milk, pasteurized human milk, human milk evaporated at 70% of the baseline volume and human milk pasteurized and evaporated at 70%, with 12 different samples of milk in each group. The samples were used to determine the concentrations of sodium, potassium, calcium, phosphorus, magnesium, protein, fat, lactose, immunoglobulin A and osmolarity. RESULTS: The pasteurization of human milk did not show statistically significant changes in the concentration of sodium, potassium, calcium, phosphorus, magnesium, protein, fat, lactose, or in osmolarity; however, it showed remarkable reduction in the mean concentration of immunoglobulin A. Evaporation had a mean increase of 38% in the concentration of sodium, potassium, calcium, phosphorus, magnesium, protein, fat and lactose and mean reduction of 45% in the concentration of immunoglobulin A, without significant change in osmolarity in unprocessed milk. CONCLUSION: By evaporation at 70% of the baseline value of human milk, it is possible to obtain human milk that meets the nutritional requirements recommended for preterm infants, except for calcium and phosphorus.

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OBJETIVO: Avaliar os efeitos da evaporação e da pasteurização do leite humano na sua composição bioquímica e imunológica e em sua osmolaridade. MÉTODOS: As amostras de leite humano maduro foram divididas em quatro grupos de estudo: leite humano in natura, leite humano pasteurizado, leite humano evaporado a 70 por cento do volume inicial e leite humano pasteurizado e evaporado a 70 por cento, com 12 diferentes amostras de leite em cada grupo. Das amostras dos grupos, foram dosadas as concentrações de sódio, potássio, cálcio, fósforo, magnésio, proteína, gordura, lactose, imunoglobulina A e osmolaridade. RESULTADOS: A pasteurização do leite humano não mostrou alterações estatisticamente significantes na concentração dos elementos sódio, potássio, cálcio, fósforo, magnésio, proteína, gordura, lactose, nem na osmolaridade; no entanto, mostrou redução significante na concentração média de imunoglobulina A. A evaporação mostrou aumento estatisticamente significativo de 38 por cento em média na concentração dos elementos sódio, potássio, cálcio, fósforo, magnésio, proteína, gordura e lactose e redução média de 45 por cento na concentração da imunoglobulina A, sem alteração significativa da osmolaridade em relação ao leite sem processamento. CONCLUSÃO: Através da evaporação a 70 por cento do volume inicial do leite humano, pode ser obtido leite humano com condições de satisfazer as necessidades nutricionais preconizadas para o recém-nascido pré-termo, com exceção do cálcio e do fósforo.

OBJECTIVE: To assess the effects of evaporation and pasteurization of human milk on its biochemical and immunological composition and on its osmolarity. METHODS: The samples of mature human milk were categorized into four study groups: in natura human milk, pasteurized human milk, human milk evaporated at 70 percent of the baseline volume and human milk pasteurized and evaporated at 70 percent, with 12 different samples of milk in each group. The samples were used to determine the concentrations of sodium, potassium, calcium, phosphorus, magnesium, protein, fat, lactose, immunoglobulin A and osmolarity. RESULTS: The pasteurization of human milk did not show statistically significant changes in the concentration of sodium, potassium, calcium, phosphorus, magnesium, protein, fat, lactose, or in osmolarity; however, it showed remarkable reduction in the mean concentration of immunoglobulin A. Evaporation had a mean increase of 38 percent in the concentration of sodium, potassium, calcium, phosphorus, magnesium, protein, fat and lactose and mean reduction of 45 percent in the concentration of immunoglobulin A, without significant change in osmolarity in unprocessed milk. CONCLUSION: By evaporation at 70 percent of the baseline value of human milk, it is possible to obtain human milk that meets the nutritional requirements recommended for preterm infants, except for calcium and phosphorus.

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Concentrations of calcium, magnesium, sodium and potassium were determined in 55 samples of mature human milk from Canary women and 5 samples of powdered infant formula. According to the literature our data fell within the normal intervals described for each kind of milk. The mean concentration of Ca, Mg, Na y K of powdered infant formula was higher than those concentrations found in the human milks. Significant differences among the concentrations of Ca, Mg and Na for the milks of the considered mothers were observed. Only the Ca intakes for infants fed with human milk were lower than those requirements recommended by the Food and Nutrition Board (1989). However, the infants fed with powdered infant formula had an adequate intake of all the studied metals. A progressive decrease of the Na, K and Ca concentrations with the lactation stage was observed. Maternal age, parity and sex of the newborns did not affect the metal concentrations significantly.

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Concentrations of calcium, magnesium, sodium and potassium were determined in 55 samples of mature human milk from Canary women and 5 samples of powdered infant formula. According to the literature our data fell within the normal intervals described for each kind of milk. The mean concentration of Ca, Mg, Na y K of powdered infant formula was higher than those concentrations found in the human milks. Significant differences among the concentrations of Ca, Mg and Na for the milks of the considered mothers were observed. Only the Ca intakes for infants fed with human milk were lower than those requirements recommended by the Food and Nutrition Board (1989). However, the infants fed with powdered infant formula had an adequate intake of all the studied metals. A progressive decrease of the Na, K and Ca concentrations with the lactation stage was observed. Maternal age, parity and sex of the newborns did not affect the metal concentrations significantly.

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