Silvana Moreira

Associação entre concentrações séricas de minerais, índices antropométricos e ocorrência de diarréia entre crianças de baixa renda da região metropolitana do Rio de Janeiro

OBJECTIVE: The objective of this study was to evaluate the association among blood serum concentrations of iron, zinc, copper, nutritional status and occurrence of diarrhea in children from a low-income community in Duque de Caxias, Rio de Janeiro. METHODS: This is a cross-sectional study that evaluated 104 children aging from 1 to 5 years, selected in the months of April and December 2004, by the project Vila Rosario. The socioeconomic profile of the families and health of the children were assessed, including the occurrence of diarrhea. Nutritional assessment included weight, height/length, weight-for-age and height-for-age indices expressed in Z-scores and classification of the nutritional status based on these indices. Serum concentrations of zinc, iron and copper were determined in a sub-sample (n=59) by synchrotron total reflection x-ray fluorescence. RESULTS: The children lived in crowded households with unsatisfactory sanitary conditions and were from low-income families. The prevalence of diarrhea in the last moth was 55.7%; 28.4% of the children were underweight and 4.9% were stunted. Iron, zinc and copper deficiencies in the sample were 13.0%, 7.5% and 8.9% respectively. There was no significant association between nutritional indicators and serum concentration of the minerals. Blood serum levels of zinc in children without diarrhea were significantly higher than among those with diarrhea. CONCLUSION: Episodes of diarrhea can compromise blood serum levels of zinc in children.

Elemental mapping of teeth using μSRXRF

Human teeth were analysed by X-ray microfluorescence analysis using synchrotron radiation (μSRXRF). The aim of this work was to study the elemental distribution for Ca, Zn and Sr along the dental regions, enamel, dentine and pulp from patterns of relative fluorescence intensities. The measurements were performed in standard geometry of 45° incidence, exciting with a white beam and using a conventional system collimation (orthogonal slits) in the XRF beamline at the Synchrotron Light National Laboratory (Campinas, Brazil). The results show that Ca distribution is quite constant and it is independent of the tooth type and individuals characteristics. An increase of the Zn concentration was found for the pulp region and for untreated carious areas. Ca and Sr distributions show a similar behavior.

Analysis of Medicinal Plants and Crude Extracts by Synchrotron Radiation Total Reflection X-Ray Fluorescence

Abstract Plants and aqueous extracts of Alternanthera maritima (aerial parts and roots), Alternanthera brasiliana and Alternanthera tenella colla (total plant) were selected for analysis of metals bioaccumulation. The synchrotron radiation total reflection X-ray fluorescence (SRTXRF) was used for excitation of the samples and a Si(Li) detector for the detection of the characteristic X-rays emitted by the sample elements. The elements P, S, K, Ca, Ti, Mn, Fe, Cu, Zn, Rb, and Sr were detected in all samples. Further-more Al, Si, Cl, Ni, Br, Rb, Cd, Sn, Sb, Hg, and Pb in Alternanthera maritima samples; Si, Co, Cd, Sn, Sb, and Ce in Alternanthera brasiliana and Al, Si, Co, Ni, Br, Cd, Sn, Sb, and Ce in Alternanthera tenella colla were found. The concentration obtained in the samples for K-shell lines varied from 1.63 µg g−1 for Ni to 3.34 × 105 µg g−1for K, and for L-shell the values ranged from 1.64 x 101 µg g−1 for Cd to 6.71 × 102 µg g−1 for Sn.

X-ray fluorescence with synchrotron radiation to elemental analysis of lead and calcium content of primary teeth.

Primary teeth were analyzed by micro-SRXRF. The aim of this study was to determine the elemental distribution of lead and calcium in different regions of primary incisor of children living in a notoriously contaminated area (Santo Amaro da Purificação, Bahia State, Brazil). The measurements were performed in standard geometry of 45 degrees incidence, exciting with a white beam and using a conventional system collimation (orthogonal slits) in the XRF beamline at the Synchrotron Light National Laboratory (Campinas, Brazil).

Determination of Trace Elements in Alternanthera brasiliana and Pfaffia glabrata by SRTXRF: Application in Environmental Pollution Control

Abstract Aiming at environmental control, we report the use of synchrotron radiation total reflection x‐ray fluorescence (SRTXRF) analysis as a technique for trace elements determination in plants. The analyses were performed in two species (total plant) of Amaranthaceae family: Alternanthera brasiliana from four sites and Pfaffia glabrata from a single site. Some elements, such as P, S, K, Ca, Mn, Fe, Cu, Zn, Sr, and Pb were detected in all samples, and the elements Cl, Ti, Cr, Co, Ni, Br, Rb, Sr, Cd, Sn, Sb, and Ba were detected in some samples. The limit of detection (LOD) varied from 0.315 (Cu) to 121.4 (P) µg g−1.

Anatomical variations in primary teeth microelements with known differences in lead content by micro-Synchrotron Radiation X-Ray Fluorescence (μ-SRXRF) – A preliminary study

Shed teeth have been proposed as trace element biomarkers. This study determined variations in the spatial distribution of Ca, K, Zn, Pb, Mn, Cu, and Sr in four anatomical locations: superficial enamel (SE, 0-10μm), subsuperficial enamel (SSE, 10-30μm), primary dentin (PD), and secondary dentin (SD). Five primary incisors were analyzed by micro Synchrotron Radiation X-Ray Fluorescence (μ-SRXRF). Two teeth had low concentrations of lead in the SE (<250μg/g), while three contained very high lead concentrations in the SE (>2000μg/g). Teeth were sliced, and five spot measurements (20μm beam diameter) were accomplished in each location. The data are shown as absolute values and as the ratio between the different elements and Ca. The distribution of K was close to that of Ca. Zn was the third most abundant element, with the highest levels being found in the SE and SD and low levels detected in the PD. Increasing Sr levels were found progressing from the enamel to the dentin, with the highest levels being found in the SD, a distribution that was unique. Pb, Mn, and Cu exhibited a similar trend, with higher signals for these elements detected in the SE. This study provides preliminary data on the heterogeneous distribution of different elements in the tooth, highlighting the importance of the first 10μm of the SE for determination of some elements, such as Zn, Pb, Mn, and Cu.

Study of the Metals Absorption in Culture Corn Irrigated with Domestic Sewage by SR‐TXRF

Abstract The main objective of this work was to evaluate the absorption of metals coming from the domestic sewage supplied through an irrigation system by furrows. For this, the culture corn (Zea mays L.) (AG 405‐AGROCERES) was irrigated by two different treatments: irrigation with domestic sewage and water. After the vegetative growth, the collected plants were divided into two parts: grains and leaves. These different parts were subjected to the digestion procedure in an open system and then analyzed by total reflection X‐ray fluorescence analysis with synchrotron radiation (SR‐TXRF). It was observed that the concentration of metals in the plants irrigated with sewage was higher than in the plants irrigated with water. The results indicate that the absorption of metals, in the leaves and spikes, is directly related to the application rate of water irrigation. But, in the case of the irrigation with domestic sewage, a larger absorption of metals was observed when the plant was irrigated with 180L application rate, so much for the leaves as for the spike.

Heavy Metals in Groundwater using Synchrotron Radiation Total Reflection X-Ray Analysis

Abstract The environmental pollution problem has increased due to industrial and population growth. São Paulo and Campinas are examples of large urban centers that have grown in a disorderly manner and, today, present contamination problems which have also reached the groundwater. In order to obtain information about levels of heavy metals in groundwater, analyses were carried out with samples from well monitoring at Landfill Pirelli in Campinas and in some supplying wells in the Campinas region which are, in their majority, wells of industrial supply. The analytical technique used for achievement of the analysis is total reflection X‐ray fluorescence with synchrotron radiation. All measurements were performed at Synchrotron Light Source Laboratory, located in Campinas, São Paulo, Brazil. The determined elements in this research were Al, Fe, Mn, Cu, Cr, Ni, Zn, Ba, and Pb. The results were compared with the maximum permitted values (MPV) established by the Brazilian Health Department and, for Landfill Pirelli, the concentrations were higher than the permitted values for Ba and Pb, as was expected, because this landfill received residues during many years without control. In well supply, as in State University of Campinas (UNICAMP), elements such as Cr and Pb were not expected, so the monitoring of these wells is necessary in order to verify if these elements continue to be detected with values above the permitted values. The same elements were also detected in other supplying wells in the Campinas metropolitan region. For lead (Pb), values above the maximum were observed in 15 wells. The detection limits obtained varyied from 0.10 µg · L−1 to 7.91 µg · L−1 and were in agreement with the values presented by other analytical techniques.

X-ray transmission microtomography using synchrotron radiation

This work reports the feasibility of a non-destructive synchrotron radiation X-ray transmission imaging technique development at Brazilian synchrotron light source. The quality control image parameters (spatial and density resolution and noise) are given and microtomograms presented. Microtomograms of biomedical samples are presented. The tomography system was mounted into the XRF beamline that uses a high-intensity white beam with 12 keV effective energy, and maximum width and height equals to 11 and 1 mm, respectively. The detector used to collect the data was a 512-pixel Hamamatsu linear array with width of 50 μm (36 μm of sensitivity length) and cooled by a Peltier junction, causing the temperature falling down to 15°C. The samples were placed over a computer controlled table with 0.5° angular resolution and turned around the center covering 360°. To reconstruct the sample a parallel beam filtered back-projection algorithm was used.

SRTXRF Analysis in Different Pharmaceutical Forms of Diclofenac Sodium

Abstract The quality of medicine depends upon the production processes and on chemical, physical, and physical‐chemical properties of the drug (i.e., the active ingredient) and pharmaceutical excipients used in the formulation. The presence of impurities can inhibit the process of dissolution of medicine and the formulation components, among them metals, can be associated with the clinical effectiveness and bioavailability. The purpose of this work was to verify the presence of trace metals in different batches and pharmaceutical forms of diclofenac sodium using synchrotron radiation total reflection X‐ray fluorescence analysis (SRTXRF). Different batches of medicines from six laboratories were analyzed. The results indicated variation in individual masses of the commercial medicine and in the nature and concentrations of the trace elements detected. Elements measured include Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, and Sr. The SRTXRF shows high sensitivity for the elements considered; it is, therefore, ideal for elemental characterization in solid pharmaceutical products.