High current-density anodic electro-dissolution in flow-injection systems for the determination of aluminium, copper and zinc in non-ferroalloys by flame atomic absorption spectrometry

An automatic Procedure with a high current-density anodic electrodissolution unit (HDAE) is proposed for the determination of aluminium, copper and zinc in non-ferroalloys by flame atonic absorption spectrometry, based on the direct solid analysis. It consists of solenoid valve-based commutation in a flow-injection system for on-line sample electro-dissolution and calibration with one multi-element standard, an electrolytic cell equipped with two electrodes (a silver needle acts as cathode, and sample as anode), and an intelligent unit. The latter is assembled in a PC-compatible microcomputer for instrument control, and far data acquisition and processing. General management of the process is achieved by use of software written in Pascal. Electrolyte compositions, flow rates, commutation times, applied current and electrolysis time mere investigated. A 0.5 mol l(-1) HNO3 solution was elected as electrolyte and 300 A/cm(2) as the continuous current pulse. The performance of the proposed system was evaluated by analysing aluminium in Al-allay samples, and copper/zinc in brass and bronze samples, respectively. The system handles about 50 samples per hour. Results are precise (R.S.D < 2%) and in agreement with those obtained by ICP-AES and spectrophotometry at a 95% confidence level.

Evaluation of different rhodium modifiers and coatings on the simultaneous determination of As, Bi, Pb, Sb, Se and of Co, Cr, Cu, Fe, Mn in milk by electrothermal atomic absorption spectrometry

Different kinds of modifiers and coatings on the integrated platform of transversely heated graphite atomizer (THGA) have been tested for the simultaneous determination of two group of elements: the first, the more volatile, formed by arsenic, bismuth, lead, antimony and selenium; the second, the less volatile, formed by cobalt, chromium, cupper, iron and manganese in milk by electrothermal atomic absorption spectrometry. Different Rh-modifiers were studied, such as Rh-coated platforms (Rh), carbide plus rhodium coated platforms (W-Rh, Zr-Rh), carbide-coated platforms (W and Zr) with co-injection of RhCl3, solutions and uncoated platforms with injection of solutions of Pd(NO3)(2), Mg(NO3)(2), and RhCl3. Milk samples were diluted 1:10 in 1.0% HNO3 and injected into the tube. The mass of modifier deposited and co-injected in the tube and the use of end capped tubes were also evaluated in order to improve the electrothermal behavior of analytes. Integrated platform pretreated with W plus co-injection RhCl3 for first group and pretreated with W-Rh for second group were elected. For 20 mu L injected samples the analytical curves in the 5.0-20.0 mu g L-1 concentration range have good linear correlation coefficients (r > 0.998). Relative standard deviations (n = 12) are < 6% and the calculated characteristic masses are between 5 pg and 62 pg.

Resonant x-ray diffraction as a tool to calculate mixed valence ratios: Application to Prussian Blue materials

An approach is proposed here to calculate mixed valence ratios in molecular compounds. Synchrotron x-ray powder diffraction experiments were conducted to determine the Fe(+3)/Fe(+2) ratio in Prussian Blue compounds, which were elected as an example of the use of this approach. As a result, a resonant x-ray diffraction measurement provided direct evidence that the vacant [Fe(CN)(6)] group was randomly absent from similar to 31% of the structure, which was indicated by structural differences caused by variations in the anomalous dispersion term. These findings are very important for a deeper understanding of the changes occurring in properties during in situ compositional variations. (c) 2008 American Institute of Physics.

Avaliação da eficiência dos métodos Direto, COPROTEST e Rugai no diagnóstico da estrongiloidíase

Strongyloidiasis, a relatively common parasitism in tropical and sub-tropical areas, is the result of the infection by the smaller nematode, the Strongyloides stercoralis. Humans can be infected by this parasite, which has in its vital cycle free-life forms of male and female individuals able to live in the ground, and with another step necessary parasitism in the intestinal wall. The diagnostic of the infection is routinely done by the microscopic observation of the larva in stool samples and the high sensibility of urn method over another one allows an trustable and efficient diagnostic. The efficiency of three methods (Direct, COPROTEST and Rugai) used in the Parasitology Sector of the NAC-LACAL in Araraquara (SP) to diagnosis the strongiloidiasis were evaluated. A number of 2346 samples of stool of patients from NAC-LACAL and Nestor Goulart Reis Hospital were analyzed in the period between August and December of 2002. The Rugai Method with an positivity index of 65 % was elected as the most efficient of thee ones.

Evaluation of Ir-based modifiers in the simultaneous determination of As, Bi, Pb, Sb, and Se in milk by graphite furnace atomic absorption spectrometry

Different modifiers (IrCl3, W+IrCl3, Zr+IrCl 3) and coatings (Ir, W-Ir, Zr-Ir) were evaluated for the simultaneous determination of arsenic, bismuth, lead, antimony, and selenium in milk by graphite furnace atomic absorption spectrometry using the 'end-capped' transversely heated graphite atomizer (THGA). Integrated platform, pretreated with Zr-Ir as permanent modifier, was elected as the optimum surface modification resulting in up to 250 firings. Two additional recoatings were possible without significant changes in the analytical performance (750 firings). For 20 μL of matrix-matched standard solutions using diluted (1:10) milk samples, typical correlation coefficients between integrated absorbance and analyte concentration (5.00-20.0 μg/L) was always better than 0.999. The levels of the analytes found in commercial milk samples were lower than the limit of detection: 2.9 μg/L As, 2.9 μg/L Bi, 1.8 μg/L Pb, 1.9 μg/L Sb, and 2.5 μg/L Se. Recoveries were found within the following intervals: 88-114% for As, 89-118% for Bi, 89-113% for Pb, 91-115% for Sb, and 92-115% for Se. The relative standard deviations (n = 12) were ≤2% (As), ≤ 5% (Bi), ≤ 1.4% (Pb), ≤ 3% (Sb), and 5% (Se), and the respective calculated characteristic masses were 54 pg As, 55 pg Bi, 40 pg Pb, 56 pg Sb, and 51 pg Se.

Proteção miocárdica ao coração hipertrofiado: O eterno desafio

The myocardial protection allowed great advance in cardiac surgery, decreasing the mortality and making more feasible complex surgeries. Latterly, the patient population elected for cardiac procedures has been changing towards elderly patients with ventricular function depressed and myocardial hypertrophy. The myocardial hypertrophy condition represents a great challenge since the beginning of the cardiac surgery. Several techniques have been described to protect the myocardial hypertrophy, however with no satisfactory results. In this manuscript we present the state of the art technique of myocardial protection.

Women's contribution to equality in Latin America and the Caribbean

Includes bibliography

Foreign investment in Mexico after economic reform

Includes bibliography

Macroeconomic volatility and social vulnerability in Brazil: the Cardoso government (1995-2002) and perspectives

Includes bibliography

Open regionalism and economic integration

Includes bibliography

Is peripheral blood cell balanced altered by the use of fresh frozen bone block allografts in lateral maxillary ridge augmentation?

Background: The relationship between the immune response and red and white blood cell homeostasis is cited in literature, but no studies regarding the balance of these cell populations following maxillary bone-graft surgeries can be found. Aim: The aim of this study was to evaluate the possible impairments in the blood cell balance following fresh-frozen allogeneic bone-graft augmentation procedures in patients who needed maxillary reconstruction prior to implants. Material and Methods: From 33 patients elected to onlay bone grafting procedures, 20 were treated with fresh-frozen bone allografts and 13 with autologous bone grafts. Five blood samples were collected from each patient in a 6-month period (baseline: 14, 30, 90, and 180 days postsurgery), and the hematological parameters (erythrogram, leukogram, and platelets count) were accessed. Results: All evaluated parameters were within the reference values accepted as normal, and significant differences were found for the eosinophils count when comparing the treatments (30 days, p=.035) and when comparing different periods of evaluation (allograft-treated group, baseline×180 days, p≤.05 and 90×180 days, p≤.01; autograft-treated group, 30×90 days, p≤.05 and 30×180 days, p≤.05). Conclusions: Both autologous and fresh-frozen allogeneic bone grafts did not cause any impairment in the red and white blood cell balance, based on quantitative hemogram analysis, in patients subjected to maxillary reconstruction. © 2011 Wiley Periodicals, Inc.

Visualização de Afinidades Entre Parlamentares Mediante Dados de Votações no Senado Brasileiro

The expansion of citizen participation in the public sphere depends directly of access information on the performance of elected representatives, especially with regard to their voting decisions during their terms. The Information Science can assist in this process, proposing and evaluating models of access to such information that may be obtained from data to be provided by the official websites from legislative, in levels federal, state and municipal. It is proposed in this paper to analyze the process of collecting and using of data about votes of senators in order to promote the use of this model in other spheres. From analyzed data a affinity matrix was developed to identifying the relationship between each of the parliamentary with others, based on the similarities of the decisions taken in all the open votes. It was also analyzed the development of initial visualizations and the extension of the scope of the search through the application of data obtained in all the affinities between parliamentarians and to obtain an average affinity between parties, enabling new dimensions of analysis to the data collected. The preparation of the full matrix of relations of affinity among parliamentarians can provide a new horizon of possibilities for developing new forms of visualization and analysis, increasing the visibility of parliamentary actions with society.

Draft programme of regional statistical work for Latin America and the Caribbean, July 2005-June 2007

Includes bibliography

Clinical similarities and histological diversity comparing fresh frozen onlay bone blocks allografts and autografts in human maxillary reconstruction

Background: In the absence of autologous bone for harvesting, fresh-frozen bone allografts turned into an alternative for bone reconstruction procedures. Purpose: The purpose of this study was to make a histological analysis of fresh-frozen onlay bone allografts (ALs), compared with autografts, in patients who needed maxillary reconstruction prior to dental implants placement. Materials and Methods: Twelve patients with bone deficiencies (width inferior to 4mm) in the sites where the implants were planned were enrolled in the study. From these, six were elected to be treated with autogenous (AT) bone grafts and six with fresh-frozen bone AL. This last group included the patients who had absence of a convenient amount of bone in donor sites. Each patient received from one to six graft blocks, totalling to 12 ATs and 17 ALs. Seven months after grafting procedures, biopsies of the grafts were made using 2-mm internal diameter trephine burs, and processed for histological analysis. One biopsy was retrieved from each patient. Results: Clinically, all grafts were found to be firm in consistency and well-incorporated to the receptor bed. Histological analysis showed a large amount of necrotic bone surrounded by few spots of new-formed bone in the AL group, suggesting low rate of graft remodeling. In the AT group, an advanced stage of bone remodeling was seen. Conclusions: Human fresh-frozen bone block AL showed clinical compatibility for grafting procedures, although associated to slow remodeling process. Further studies are needed to define, at long term, the remodeling process chronology the clinical longitudinal results for fresh-frozen bone AL. Copyright © 2013 Wiley Periodicals, Inc.

A emergência do marcador discursivo assim sob a óptica da gramaticalização: um caso de multifuncionalidade e (inter)subjetivização

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)