G6PD deficiency in Latin America: systematic review on prevalence and variants

Plasmodium vivax radical cure requires the use of primaquine (PQ), a drug that induces haemolysis in glucose-6-phosphate dehydrogenase deficient (G6PDd) individuals, which further hampers malaria control efforts. The aim of this work was to study the G6PDd prevalence and variants in Latin America (LA) and the Caribbean region. A systematic search of the published literature was undertaken in August 2013. Bibliographies of manuscripts were also searched and additional references were identified. Low prevalence rates of G6PDd were documented in Argentina, Bolivia, Mexico, Peru and Uruguay, but studies from Curaçao, Ecuador, Jamaica, Saint Lucia, Suriname and Trinidad, as well as some surveys carried out in areas of Brazil, Colombia and Cuba, have shown a high prevalence (> 10%) of G6PDd. The G6PD A-202A mutation was the variant most broadly distributed across LA and was identified in 81.1% of the deficient individuals surveyed. G6PDd is a frequent phenomenon in LA, although certain Amerindian populations may not be affected, suggesting that PQ could be safely used in these specific populations. Population-wide use of PQ as part of malaria elimination strategies in LA cannot be supported unless a rapid, accurate and field-deployable G6PDd diagnostic test is made available

ZrO2 thin film grafted on silica gel surface: Preparation and Cr(VI) adsorption property

ZrO2THIN FILM GRAFTED ON SILICA GEL SURFACE: PREPARATION AND Cr(VI) ADSORPTION PROPERTY. The present experiment describes in easy procedure for obtaining SiO2/ZrO2 by reacting ZrOCl2 with SiO2 with the following characteristics: S-BEC = 500 m(2) g(-1) and an average pore diameter of 6 nm. The material obtained presented 1.3 wt% ZrO2 content corresponding to 140 mumol g(-1). The average density of ZrO2 onto SiO2/ZrO2 matrix is 2.8x10(-11) mol cm(-2). The adsorption isotherm for Cr(VI) showed a maximum of adsorption value (200 mumol g(-1)) at pH 2. The adsorption can be described by the reaction: =Zr(OH)(2) + 2HCrO(4) . + 2H(+) reversible arrow [(=Zr(OH2+)(2)) (HCrO4.)(2)]. Above the zero point of charge, i.e. pH > 5.5 due to the surface charge inversion, desorption of Cr(VI) occurs according to the reaction: [(=Zr(OH2+)(2)) (HCrO4.)(2)] + 60H reversible arrow (=ZrO2)(2.) + 6H(2)O + 2CrO(4)(2-).25349950

Methylene blue-zirconium phosphate-cellulose acetate hybrid membrane film attached to a platinum electrode and its application in electrocatalytic oxidation of NADH

Highly dispersed zirconium phosphate was prepared by reacting a cellulose acetate membrane film containing zirconium oxide (ZrO2 = 6.3 wt.%; 0.50 mmol g(-1) of the zirconium atom per gram of the material) with phosphoric acid. The resulting membrane film was reacted with methylene blue (MB) by an ion exchange reaction. The amount of the dye bonded to the surface was 0.15 mmol g(-1). High power decoupling magic angle spinning (HPDEC-MAS) P-31 NMR data indicated that Zr(HPO4)(2) is the species present on the membrane surface. Cyclic voltammetry experiments of the MB dye adsorbed onto CelZrP, carried out on a thin membrane of the material fixed on a platinum disk electrode, were obtained. The midpoint potential (E-m) of CelZrP/MB was -0.15 V The solution pH practically did not affect the midpoint potential of the adsorbed dye between pH 3 and 7. The modified electrode presented a reproducible response and it was chemically stable under various oxidation-reduction cycles. The electrode proved to be efficient to mediate the transfer for NADH oxidation. The apparent Michaelis-Menten constant, K-M(app), for the modified electrode showed an efficient interaction between dye and NADH. (C) 2002 Elsevier Science B.V. All rights reserved.87349850

A platinum electrode coated with a copper (II) aminopropyl complex-cellulose acetate membrane and its use for dissolved oxygen reduction

Highly dispersed Al2O3 in a cellulose acetate membrane, resulting in an organic-inorganic hybrid material, Cel/Al2O3, was prepared. It was further modified by attaching an organofunctional group by reacting with the precursor reagent (EtO)(3)Si(CH2)(3)NH(CH2)(2)NH2. The resulting organofunctionalized material was reacted with CuCl2 in ethanolic solution forming a distorted tetragonal coordinated complex Cel/Al2O3/(SiL)(2)CuCl2 [L = -(CH2)(3)NH(CH2)(2)NH2], as shown by the UV-Vis absorption spectrum. The quantities of attached organofunctional groups and of adsorbed metal were 0.41 and 0.12 mmol per gram of the material, respectively. Cyclic voltammetric (CV) experiments, carried out on a thin membrane of the material fixed on a platinum disk, showed two cathodic current peaks, one at 0.10 and another at -0.35 V, versus SCE, both due to the Cu(II) --> Cu(I) reduction process. The differences in the equilibrium coordination geometry around the metal complexes of Cu(II) and Cu(I) are responsible for the doubled peaks. In a dissolved oxygen solution, an enhancement of the cathodic peak currents was observed due to a catalytic oxygen reduction. The electrode response towards dissolved oxygen concentrations showed a linear correlation between concentrations of 1.9 and 12.1 mg l(-1), indicating the potential use of the material to make an oxygen sensor. (C) 2003 Elsevier B.V. All rights reserved.2214167117518

Aluminum phosphate dispersed on a cellulose acetate fiber surface - Preparation, characterization and application for Li+, Na+ and K+ separation

Cellulose acetate fibers with supported highly dispersed aluminum phosphate were prepared by reacting aluminum-containing cellulose acetate (Al2O3 = 3.5 wt.%; 1.1 mmol g(-1) aluminum atom per gram of the material) with phosphoric acid. Solid-state NMR spectra (CPMAS P-31 NMR) data indicated that HPO42- is the species present on the fiber surface. The specific concentration of acidic centers, determined by ammonia gas adsorption, is 0.50 mmol g(-1). The ion exchange capacities for Li+, Na+ and K+ ions were determined from ion exchange isotherms at 298 K and showed the following values (in mmol g(-1)): Li+ = 0.03, Na+ = 0.44 and K+ = 0.50. The H+/Li+ exchange corresponds to the model of the ideal ion exchange with a small value of the corresponding equilibrium constant K = 1.1 x 10(-2), Due to the strong cooperative effect, the H+/Na+ and H+/K+ ion exchange is non-ideal. These ion exchange equilibria were treated with the use of models of fixed bi- or tridentate centers, which consider the surface of the sorbent as an assemblage of polyfunctional sorption centers. Both the observed ion exchange capacities with respect to the alkaline metal ions and the equilibrium constants were discussed by taking into consideration the sequence of the ionic hydration radii for Li+, Na+ and K+. The matrix affinity order for the ions decreases as the hydration radii of the cations increase, i.e. Li+ > Na+ > K+. The high values of the separation factors SNa+/(Li+) and SK+/Li+ (up to several hundred) provide quantitative separation of Na+ and K+ from Li+ from a mixture containing these three ions. (C) 2002 Elsevier Science B.V. All rights reserved.477230531

Preparation and characterization of the cobaloxime complex and its use in fabrication of a modified electrode. An electrochemical experiment for undergraduate course

PREPARATION AND CHARACTERIZATION OF THE COBALOXIME COMPLEX AND ITS USE IN FABRICATION OF A MODIFIED ELECTRODE. AN ELECTROCHEMICAL EXPERIMENT FOR UNDERGRADUATE COURSE. The present experiment describes the preparation, characterization of n-butyl(pyridil)cobaloxime complex and its electrochemical property. The infrared and uv-visible absorption spectra were used to characterize the complex obtained. The infrared spectrum of the compound showed characteristics bands that indicated the formation of the Co-C chemical bond formation. The electronic absorption spectrum in acetonitrile showed transition bands attributed to pi-pi*, metal-to-ligand charge transfer, d-d transitions and charge transfer Co-C. The electrochemical property was investigated by the pulse differential voltammetry technique. Two oxidation processes: Co(I)/Co(II) at -423 mV and Co(II)/Co(III) at 752 mV were observed.26694394

Home care for persons with AIDS: a case-control study to identify determinants of referral to a hospital-based scheme

We conducted a multicenter, hospital-based case-control study to identify specific characteristics of AIDS patients which determine referral to hospital care at home. The cases were patients referred to a hospital-based home care scheme, in the metropolitan area of Rome, during 1997. Each case was matched with two controls. Social, demographic and clinical characteristics were collected at referral. Univariate and multivariate analysis were performed. In the study period, 119 cases and 238 controls were recruited. In logistic regression analysis, social characteristics were not found to affect referral to the hospital-at-home scheme. A severely impaired functional status--assessed by the Functional Independent Measure--identified by a score below 100 (Odds Ratio [OR]=15.2, 95% confidence interval [CI] 2.8-82.7), and the need for prolonged intravenous therapy (OR=12.4, 95% CI=3.3-46.3) were the only two independent predictors of home-care referral. We conclude that home care, even in a period when new potent combination antiretroviral therapies are widely available, is an important integrated service component for persons with AIDS with severe functional impairment or requiring intravenous therapy