Sequential application of activated sludge and phytoremediation with aquatic macrophytes on tannery effluents: in search of a complete treatment.

Tannery effluents with a high organic matter load (indicated by their COD level) have to be treated before they are discharged, so as to minimize their negative impact on the environment. Using field mesocosm systems, this study evaluated the feasibility of treating such effluents through bioaugmentation with activated sludge, followed by phytoremediation with aquatic macrophytes (Lemnoideae subfamily). Regardless of its quality, the activated sludge was able to remove approximately 77% of the COD from effluents with a low initial organic load (up to 1500 mg/L). The macrophytes then enhanced removal (up to 86%), so the final COD values were permissible under the current legislation for effluent discharge. When the initial organic load in the undiluted effluents was higher (around 3000 mg/L), the COD values obtained after consecutive bioaugmentation and phytoremediation were close to the legally allowed limits (583 mg/L), which highlights the potential of phytoremediation as a tertiary treatment. This treatment also brought total coliform counts down to legally acceptable values, without plant biomass decreasing over time. Moreover, the plant biomass remained viable and capable of high COD removal efficiency (around 75%) throughout two additional reuse cycles. These findings indicate that the efficiency of the biological treatments assayed here depends largely on the initial organic load in the tannery effluents. In any case, the sequential application of activated sludge and aquatic macrophytes proved to be a successful alternative for remediation.

On-line enantioseparation of chlorpheniramine using ß-cyclodextrin and carbon nanotubes after multivariate optimization.

Multiwalled carbon nanotubes are evaluated here as solid phase extraction (SPE) sorbent aiming to (±)-chlorpheniramine (CPA) enantioresolution with fluorimetric detection. ß-cyclodextrin (CD) was added to the racemate and solutions with HCl and sodium dodecyl sulfate (SDS) in different proportions were assayed as eluents to achieve the separation between both enantiomers. The overall methodology involved a flow injection (FI) strategy enabling high sample throughput and low reagents consumption making it suitable for drug routine quality control. An adequate enantioresolution (2.08) with satisfactory responses for both (R)-CPA (peak area=285) and (S)-CPA (peak area=380) was achieved applying the proposed FI-SPE strategy under the optimized conditions [ß-CD] = 1.0 mmol L(-1), [HCl] = 1.0 × 10(-2) mol L(-1), [SDS] = 4.0 × 10(-4) mol L(-1) and eluent flow rate = 8.0 rpm.

Determination of sildenafil by preconcentration on surfactant coated polymeric resin followed by spectrofluorimetry.

The illicit addition of phosphodiesterase type-5 (PDE-5) inhibitors like sildenafil (Viagra) in product offered as herbal medicine or dietary supplement for male erectile dysfunction has concerned authorities in recent times. In this paper, we proposed a sensitive surfactant-coated Amberlite XAD™ resin for sildenafil preconcentration method with spectrofluorimetric detection. Retention capacity of micellar coated XAD resin for sildenafil was studied and the obtained eluate was measured by spectrofluorometer at excitation and emission wavelengths of 350 and 430 nm, respectively. This method allowed the detection of sildenafil at 0.15 ng/mL with linear range of 0.0003-7.0 µg/mL. The method has been successfully applied to the analysis of some local commercially available herbal medicines and urine.

Los Adolescentes y la Cultura de la Informática: Un Fenómeno Creciente / dolescents and Cultural Informatics: A Growing Phenomenon

Las Tecnologías de la Información y Comunicación (TICs) han avanzado en los últimos años modificando el estilode vida del hombre. Los objetivos fueron determinar la prevalencia y el tiempo dedicado al uso de las TICs en adolescentes, y la asociación con exceso de peso. Estudio descriptivo, de corte transversal, n= 649 adolescentes de 12 a 14 años concurrentes a escuelas públicas y privadas de Corrientes seleccionadas por conveniencia. Se utilizó una encuesta estructurada, de elección múltiple, y en terreno se registraron variables de peso y talla.Todos los integrantes de la muestra estudiada utilizan TICs y el tiempo de uso aumenta en forma exponencial conla edad de los adolescentes. Internet (70%), TV (67%) y Celular (59%). Observamos uso superior a 2 hs. en 57% de adolescentes de 12 años; en 63% de los de 13 años y en el 71% de los de 14 años de edad. Más de la mitad de aquellos con sobrepeso (66%) y de los adolescentes con peso adecuado (64%) utiliza las TICs por un tiempo superior a 2 hs/ día (Odds= 1,08).Encontramos asociación entre exceso de peso y tiempo destinado al uso de las TICS. Los pediatras enfrentan el desafío de promover el juego creativo y las actividades deportivas para prevenir el uso excesivo de las TICs y sus repercusiones en la salud de niños y adolescentes...

In vitro-in vivo antifungal evaluation and structure-activity relationships of 3H-1,2-dithiole-3-thione derivatives.

As part of our project devoted to the search of new antifungal agents, we report here the in vitro-in vivo antifungal evaluations and a structure-activity relationship (SAR) study of 17 thione derivatives. Some compounds of this series exhibited remarkable antifungal activity against a broad spectrum of pathogenic opportunistic fungi. SAR studies provide a useful information for the determination of the minimum structural requirements for producing the biological response.

Resentimiento y condición socioeconómica: una investigación en estudiantes de secundaria / Resentment and Social Class: A Research Study in Secondary School Adolescents

Se reporta un estudio de resentimiento en 152 adolescentes, hombres y mujeres de condición socioeconómica alta y baja, estudiantes de secundaria. Hubieron diferencias estadísticamente significativas con altos niveles de resentimiento entre adolescentes de nivel socioeconómico bajo.

A study of resentment on 152 male and female secondary school adolescents, of low and high social class, in Lima, is reported. Significative statiscal differences were found, with higher levels of resentment in low-social class adolescents.