Millikelvin magnetic relaxation measurements of alpha-Fe2O3 antiferromagnetic particles

In this paper we report magnetic relaxation data for antiferromagnetic alpha-Fe2O3 particles of 5 nm mean diameter in the temperature range 0.1 K to 25 K. The average spin value of these particles S=124 and the uniaxial anisotropy constant D=1.6x10^-2 K have been estimated from the experimental values of the blocking temperature and anisotropy field. The observed plateau in the magnetic viscosity from 3 K down to 100 mK agrees with the occurrence of spin tunneling from the ground state Sz = S. However, the scaling M vs Tln(nu t) is broken below 5 K, suggesting the occurrence of tunneling from excited states below this temperature.Comment: 4 pages (two columns), 4 figure

Comprehensive diagnosis in patients with morbid obesity; candidates for bariatric surgery and suggestions for preoperative treatment

Indexación: Scopus; Scielo.Objetivo El propósito del estudio fue analizar y describir las características psicológicas, metabólicas, antropométricas y de condición física de obesos candidatos a cirugía bariátrica, para determinar la intervención preoperatoria. Material y Métodos La población está conformada por 24 obesos candidatos a cirugía bariátrica; cinco hombres y 19 mujeres entre 21 y 60 años. La muestra es de tipo no-probabilística, con sujetos elegidos de manera no aleatoria por conveniencia y voluntarios. Se evaluaron variables psicológicas, antropométricas, metabólicas y de condición física. Resultados La edad promedio de los participantes corresponde a 41,0 años. En el estudio se evidencian bajos niveles en alegría empática. Los síntomas ansiosos presentaron un nivel medio: El 62,5 % presentó depresión mínima, el 29,1 % depresión leve, y el 8,4 % depresión modera. El peso corporal tuvo un promedio de 99,1 kilogramos, la talla de 1,6 metros, el Índice de Masa Coporal (IMC) de 39,3, el porcentaje de masa grasa un promedio de 41,1 y el contorno cintura de 118,0 centímetros. Con respecto a los valores plasmáticos (mg/dl) se obtuvo: colesterol total 192,9, colesterol LDL 120,0, colesterol HDL 43,3, triglicéridos 182,3, Glicemia a 105,9; y la distancia recorrida en seis minutos fue de 511,9 metros. Conclusiones Los resultados aportan información para determinar mejores estrategias de intervención preoperatorias, cambiando así los estilos de vida de los pacientes; logrando que la pérdida de peso post operatoria se sostenga en el tiempo.Objective The purpose of the study was to analyze and describe the psychological, metabolic, anthropometric and physical condition of obese candidates for bariatric surgery. This is in order to determine the preoperative intervention. Material and Methods The population is made up of 24 obese candidates for bariatric surgery; five men and 19 women between 21 and 60 years old. The sample type is non-probabilistic, with non-randomised subjects chosen conveniently and volunteers. Psychological, anthropometric, metabolic and physical condition variables were evaluated. Results The average age of participants corresponds to 41.0 years old. Low levels of empathic joy were observed. Anxiety symptoms presented an intermediate level: 62,5 % presented minimal depression, 29,1 % presented slight depression, and 8,4 % presented considerable depression. Body weight averaged 99.1 kg, height 1.6 meters, Body Mass Index (BMI) 39.3, the percentage of fat mass and contour waist averaged 41.1 118.0 centimeters in that order. With regards to plasma levels (mg / dl), the following were obtained: total cholesterol 192.9, 120.0 LDL cholesterol, HDL cholesterol, 43.3, 182.3 triglycerides, glycerin to 105.9; and distance covered in 6 minutes was 511.9 meters. Conclusions The results provide information to determine best Preoperative intervention strategies; changing the lifestyles of patients, keeping the postoperative weight.http://www.scielo.org.co/pdf/rsap/v19n4/0124-0064-rsap-19-04-00527.pd

Bisphenol A degradation and mineralization by the Fenton and the Photo-Fenton process

The performance of the Fenton and photo-Fenton processes for the degradation and mineralization of Bisphenol A was investigat-ed. A parameterized kinetic model was suitably fitted to the exper-imental data in order to determine two performance parameters related to the global equilibrium conversion and kinetic rate of the process. Further analysis allowed selecting those process condi-tions (iron and hydrogen peroxide load) that maximize the process performance. The Fenton process clearly proved to more efficient-ly degrade Bisphenol A under irradiation. The highest conversion rates were achieved with only the stoichiometric hydrogen perox-ide load and the appropriate iron load (i.e. total Bisphenol A elimination and 90 % TOC decay).Postprint (published version

Abatement of the fluorinated antidepressant fluoxetine (Prozac) and its reaction by-products by electrochemical advanced methods

The degradation of the fluorinated antidepressant fluoxetine, as hydrochloride, was comparatively studied in sulfate medium at pH 3.0 by anodic oxidation with electrogenerated H2O2 (AO-H2O2), electro-Fenton (EF) and photoelectro-Fenton (PEF). Experiments were performed with 100 mL solutions in an undivided tank reactor equipped with a Pt, RuO2-based or boron-doped diamond (BDD) anode and an air-diffusion cathode for continuous H2O2 production. The BDD anode showed higher mineralization rate due to the great production of physisorbed BDD(¿OH), which has larger reactivity to oxidize the drug and intermediates. The degradation rate was enhanced by EF with 0.50 mM Fe2+ due to the additional production of ¿OH in the bulk from Fenton's reaction. The degradation was even faster using PEF owing to the additional photolytic action of UVA radiation. The most effective process was PEF with a BDD anode achieving 94% mineralization at 300 min. The fluoxetine decay followed a pseudo-first-order kinetics, being quicker in the order: AO-H2O2 < EF < PEF. The effect of the current density and drug concentration on the mineralization rate and fluoxetine decay was clarified. Oxidation of fluoxetine by hydroxyl radicals yielded four aromatic by-products, as found by GC-MS. Additionally, a chloroaromatic compound was identified as a result of the reaction of active chlorine, which was formed in situ from the oxidation of chloride ion at the BDD anode. Four short-chain linear carboxylic acids, being oxalic and formic acid more abundant, were identified. In PEF, fluorine atoms of fluoxetine were completely released as fluoride ion, whereas the initial nitrogen was converted to nitrate ion in all cases. A reaction pathway for fluoxetine mineralization by the electrochemical advanced methods is finally proposed

Born too early and too small: higher order cognitive function and brain at risk at ages 8–16

Prematurity presents a risk for higher order cognitive functions. Some of these deficits manifest later in development, when these functions are expected to mature. However, the causes and consequences of prematurity are still unclear. We conducted a longitudinal study to first identify clinical predictors of ultrasound brain abnormalities in 196 children born very preterm (VP; gestational age 32 weeks) and with very low birth weight (VLBW; birth weight 1500 g). At ages 8–16, the subset of VP-VLBW children without neurological findings (124) were invited for a neuropsychological assessment and an MRI scan (41 accepted). Of these, 29 met a rigorous criterion for MRI quality and an age, and gender-matched control group (n = 14) was included in this study. The key findings in the VP-VLBW neonates were: (a) 37% of the VP-VLBW neonates had ultrasound brain abnormalities; (b) gestational age and birth weight collectively with hospital course (i.e., days in hospital, neonatal intensive care, mechanical ventilation and with oxygen therapy, surgeries, and retinopathy of prematurity) predicted ultrasound brain abnormalities. At ages 8–16, VP-VLBW children showed: a) lower intelligent quotient (IQ) and executive function; b) decreased gray and white matter (WM) integrity; (c) IQ correlated negatively with cortical thickness in higher order processing cortical areas. In conclusion, our data indicate that facets of executive function and IQ are the most affected in VP-VLBW children likely due to altered higher order cortical areas and underlying WMThis study was supported by the Spanish Government Institute Carlos III (FIS Pl11/02860), Spanish Ministry of Health to MM-L, and the University of Castilla-La Mancha mobility Grant VA1381500149

Sonochemical synthesis of CuO nanostructures and their morphology dependent optical and visible light driven photocatalytic properties

A controlled synthesis of CuO nanostructures with various morphologies were successfully achieved by presence/absence of low frequency (42 kHz) ultrasound with two different methods. The size, shape and morphology of the CuO nanostructures were tailored by altering the ultrasound, mode of addition and solvent medium. The crystalline structure and molecular vibrational modes of the prepared nanostructures were analysed through X-ray diffraction and FTIR measurement, respectively which confirmed that the nanostructures were phase pure high-quality CuO with monoclinic crystal structure. The morphological evaluation and elemental composition analysis were done using TEM and EDS attached with SEM, respectively. Furthermore, we demonstrated that the prepared CuO nanostructures could be served as an effective photocatalyst towards the degradation of methyl orange (MO) under visible light irradiation. Among the various nanostructures, the spherical shape CuO nanostructures were found to have the better catalytic activities towards MO dye degradation. The catalytic degradation performance of MO in the presence of CuO nanostructures showed the following order: spherical\nanorod \layered oval \nanoleaf \triangular \shuttles structures. The influence of loading and reusability of catalyst revealed that the efficiency of visible light assisted degradation of MO was effectively enhanced and more than 95 % of degradation was achieved after 3 cycle

Sonophotocatalytic mineralization of Norflurazon in aqueous environment

Norflurazon (4-chloro-5-(methylamino)-2-[3- trifluoromethyl)phenyl]pyridazin-3(2H)-one; C12H9ClF3N3O) is an excellent weed controlling agent being practiced in the agricultural lands. The excessive addition or the undissolved Norflurazon (maximum solubility 28 mg/L at 25 C) enters into the aquatic environment and causes the adverse effects associated with its high concentration. To avoid the perilous effects, visible light assisted photocatalysis set-up coupled with the 42 kHz ultrasound producing bath type sonicator is used to completely mineralize the Norflurazon. TiO2, ZnO and gold loaded zinc oxide nanocatalysts were utilized to study the mineralization of Norflurazon. AueZnO shows the greater efficiency for the sonophotocatalytic removal of Norflurazon among the various nanocatalysts employed to study the mineralization. The order of Norflurazon mineralization was sonophotocatalysis > sonocatalysis > photocatalysis. The additive effect was achieved for the sonophotocatalytic degradation. The high performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometric (LCMS) analyses were employed to identify the various intermediates produced during the mineralization. The identification of four pseudo molecular ions and various intermediates using the LCMS analysis evidently suggests the sonophotocatalytic degradation was preceded in various decay pathways. A suitable mechanism has been proposed for the sonophotocatalytic mineralization of Norflurazo