Efficiency, Kinetics and Mechanism of 4-Nitroaniline Removal from Aqueous Solutions by Emulsion Liquid Membranes Using Type 1 Facilitated Transport.

4-Nitroaniline (4NA) is a common organic pollutant that is released into the environment during the manufacture and processing of a wide variety of industrial products. This article describes the use of an emulsion liquid membrane process to remove 4NA from aqueous solutions using a type 1 facilitated transport mechanism. Optimization of the removal process was carried out by analyzing the efficiency of 4NA removal from the feed phase and the initial apparent feed/membrane fluxes and permeabilities under different experimental conditions.

Description of conformational ensembles of disordered proteins by residue-local probabilities.

The study of proteins with intrinsically disordered regions (IDRs) has emerged as an active field of research due to their intriguing nature. Although IDRs lack a well-defined folded structure, they play important functional roles in cells, following biological mechanisms different from those of the traditional structured proteins. Consequently, it has been necessary to re-design experimental and theoretical methods in order to face the challenges introduced by the dynamic nature of IDRs.

Comparative Study of 4-Aminophenol Removal from Aqueous Solutions by Emulsion Liquid Membranes Using Acid and Basic Type 1 Facilitations: Optimisation and Kinetics.

The molecule 4-aminophenol (4AP) is recognised as a serious environmental pollutant that enters the environment during the manufacture and processing of a variety of industrial processes and through the degradation of some pharmaceutical products. This paper describes a comparative study of 4AP removal from aqueous solutions by emulsion liquid membranes using acid and basic type 1-facilitated transports. The results are explained by analysing the stripping process through both the different relative acid/basic strength of the hydroxyl and amine groups of the 4AP molecule and the hydrogen-bonding capacity with water of the ionisation products generated by the reaction of 4AP with HCl or NaOH.

Ibuprofen Removal by Graphene Oxide and Reduced Graphene Oxide Coated Polysulfone Nanofiltration Membranes.

The presence of pharmaceutical products, and their metabolites, in wastewater has become a focus of growing environmental concern. Among these pharmaceutical products, ibuprofen (IBU) is one of the most consumed non-steroidal anti-inflammatory drugs and it can enter the environment though both human and animal consumption, because it is not entirely absorbed by the body, and the pharmaceutical industry wastewater. Nanofiltration has been described as an attractive process for the treatment of wastewater containing pharmaceutical products.

Effects of Auriculotherapy on treatment of women with premenstrual syndrome symptoms: A randomized, placebo-controlled clinical trial.

Objective: This study aimed to investigate the effect of auriculotherapy on the intensity of physical and mood Premenstrual syndrome (PMS) symptoms.

Design: Single-blind randomized, placebo-controlled clinical trial.

Setting: Federal University of Parana, Curitiba, Brazil.

Feasibility of Adsorption Kinetic Models to Study Carrier-Mediated Transport of Heavy Metal Ions in Emulsion Liquid Membranes.

Emulsion liquid membranes have been successfully used for the removal of different types of organic and inorganic pollutants by means of carrier-mediated transport mechanisms. However, the models that describe the kinetics and transport of such mechanisms are very complex due to the high number of model parameters. Starting from an analysis of the similarity between the elemental mechanisms of carrier-mediated transport in liquid membranes and of transport in adsorption processes, this paper presents an experimental analysis of the possibility of applying kinetic and mechanistic models developed for adsorption to carrier-mediated transport in emulsion liquid membranes.

Activated Olive Stones as a Low-Cost and Environmentally Friendly Adsorbent for Removing Cephalosporin C from Aqueous Solutions.

In this paper, we describe the removal of cephalosporin C (CPC) from aqueous solutions by adsorption onto activated olive stones (AOS) in a stirred tank. For comparative purposes, several experiments of adsorption onto commercial granular activated carbon were carried out. A quantum study of the different species of cephalosporin C that, depending on the pH, exist in aqueous solution pointed to a favorable mass transfer process during adsorption.

Pertraction of Co(II) through Novel Ultrasound Prepared Supported Liquid Membranes Containing D2EHPA. Optimization and Transport Parameters.

Pertraction of Co(II) through novel supported liquid membranes prepared by ultrasound, using bis-2-ethylhexyl phosphoric acid as carrier, sulfuric acid as stripping agent and a counter-transport mechanism, is studied in this paper. Supported liquid membrane characterization through scanning electron microscopy, energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy shows the impregnation of the microporous polymer support by the membrane phase by the action of ultrasound. The effect on the initial flux of Co(II) of different experimental conditions is analyzed to optimize the transport process.

On the Role of Entropy in the Stabilization of α-Helices.

Protein folding evolves by exploring the conformational space with a subtle balance between enthalpy and entropy changes which eventually leads to a decrease of free energy upon reaching the folded structure. A complete understanding of this process requires, therefore, a deep insight into both contributions to free energy. In this work, we clarify the role of entropy in favoring the stabilization of folded structures in polyalanine peptides with up to 12 residues.

Urethane-Acrylate/Aramid Nanocomposites Based on Graphenic Materials. A Comparative Study of Their Mechanical Properties.

Urethane-acrylate thermoset resins (UATR) are a new type of polymeric matrix that have recently made a strong breakthrough in the composites sector. This is because of their properties, which make them an advantageous alternative to epoxy resins, especially if they are reinforced with high-performance fibers such as aramids. Graphene-based nanocomposites are one of the most dynamic research fields in nanotechnology, because graphenic materials greatly improve the properties of traditional composites.

On the relativistic impulse approximation for the calculation of Compton scattering cross sections and photon interaction coefficients used in kV dosimetry.

We calculate differential and integrated cross sections for the Compton interaction as well as mass attenuation ([Formula: see text]), mass energy-transfer ([Formula: see text]), and mass energy-absorption ([Formula: see text]) coefficients, within the relativistic impulse approximation (RIA) using Compton profiles (CPs) obtained from unrestricted Hartree-Fock electron densities. We investigate the impact of using molecular as opposed to atomic CPs on dosimetric photon interaction coefficients for air, water and graphite, and compare our cross sections to the simpler Waller-Hartree (WH) and Klein-Nishina (KN) formalisms. We find that differences in [Formula: see text] and [Formula: see text] resulting from the choice of CPs within the RIA are small relative to the differences between the RIA, WH, and KN calculations.

Relaxation pathways of the OD stretch fundamental of HOD in liquid HO.

The molecular dynamics with quantum transitions method is used to study the vibrational relaxation of the OD stretching mode of HOD dissolved in liquid HO water at 303 K. All the vibrational modes of the solute and solvent molecules that participate in the relaxation process are described by quantum mechanics, while the rotational and translational degrees of freedom are treated classically. A modification of the water intramolecular SPC/E (Simple Point Charge/Extended) force field providing vibrational frequencies in solution closer to the experimental values is proposed to analyze the influence of the vibrational energy gaps on the relaxation channels.

Conformational Changes of Trialanine in Water Induced by Vibrational Relaxation of the Amide I Mode.

Most of the protein-based diseases are caused by anomalies in the functionality and stability of these molecules. Experimental and theoretical studies of the conformational dynamics of proteins are becoming in this respect essential to understand the origin of these anomalies. However, a description of the conformational dynamics of proteins based on mechano-energetic principles still remains elusive because of the intrinsic high flexibility of the peptide chains, the participation of weak noncovalent interactions, and the role of the ubiquitous water solvent.

Theoretical study of the temperature dependence of the vibrational relaxation of the H2O bend fundamental in liquid water and the subsequent distortion of the hydrogen bond network.

The molecular dynamics with quantum transitions method is used to study the temperature dependence of the relaxation dynamics of the H2O bend fundamental in liquid water in the range from 277 to 348 K and the subsequent variation of the hydrogen bonds network in the liquid. The vibrational bending degrees of freedom of the water molecules are all described by quantum mechanics while the remaining translational and rotational motions are described classically. The participation of the H-bonds in the relaxation process is studied taking into account the dependence of the relaxation lifetimes on the number of H-bonds formed by the initially excited water molecule and the amount of energy transferred into the hindered rotational motions.

Discovery of SAR184841, a potent and long-lasting inhibitor of 11β-hydroxysteroid dehydrogenase type 1, active in a physiopathological animal model of T2D.

Starting from 11β-HSD1 inhibitors that were active ex vivo but with Cyp 3A4 liability, we obtained a new series of adamantane ureas displaying potent inhibition of both human and rodent 11β-HSD1 enzymes, devoid of Cyp 3A4 interactions, and rationally designed to provide long-lasting inhibition in target tissues. Final optimizations lead to SAR184841 with good oral pharmacokinetic properties showing in vivo activity and improvement of metabolic parameters in a physiopathological model of type 2 diabetes.

Increasing stability and transport efficiency of supported liquid membranes through a novel ultrasound-assisted preparation method. Its application to cobalt(II) removal.

A novel ultrasound assisted method for preparing supported liquid membranes is described in this paper. The stability and efficiency of the supported liquid membrane obtained was tested by removing cobalt(II) from aqueous solutions through a facilitated countertransport mechanism using CYANEX 272 as carrier and protons as counterions. The results are compared with those obtained using supported liquid membranes prepared by soaking the polymeric material in the organic solution of the carrier at atmospheric pressure and under vacuum, both for 24h.

Molecular dynamics with quantum transitions study of the vibrational relaxation of the HOD bend fundamental in liquid D2O.

The molecular dynamics with quantum transitions method is used to study the vibrational relaxation of the HOD bend fundamental in liquid D(2)O. All of the vibrational bending degrees of freedom of the HOD and D(2)O molecules are described by quantum mechanics, while the remaining translational and rotational degrees of freedom are described classically. The effect of the coupling between the rotational and vibrational degrees of freedom of the deuterated water molecules is analyzed.

Melatonin prevents the decreased activity of antioxidant enzymes and activates nuclear erythroid 2-related factor 2 signaling in an animal model of fulminant hepatic failure of viral origin.

This work was undertaken to investigate whether treatment with melatonin prevents oxidative stress and changes in the expression and activity of factor erythroid 2-related factor 2 (Nrf2)-mediated antioxidant enzymes in an animal model of fulminant hepatic failure of viral origin. Rabbits were experimentally infected with 2 x 10(4) hemagglutination units of a rabbit hemorrhagic disease virus (RHDV) isolate and received melatonin at two concentrations of 10 mg/kg and 20 mg/kg at 0, 12 and 24 hr postinfection. Blood transaminases, blood lactate dehydrogenase, liver concentration of thiobarbituric reactive acid substances and the liver oxidized to reduced glutathione ratio significantly increased at 36 hr postinfection in infected animals.

Hybrid quantum/classical simulation of the vibrational relaxation of the bend fundamental in liquid water.

The Ehrenfest method with quantum corrections is used to describe the vibrational relaxation of the bend fundamental in liquid water. All the vibrational degrees of freedom of the water molecules are described using quantum mechanics, while the remaining translational and rotational degrees of freedom are described classically. The relaxation time obtained compares well with experiment and with relaxation times calculated using other theoretical approximations.

Full quantum vibrational simulation of the relaxation of the cyanide ion in water using the Ehrenfest method with quantum corrections.

The Ehrenfest method with quantum corrections is used to describe the vibrational relaxation of the cyanide ion in liquid water. All the vibrational degrees of freedom of the system are described using quantum mechanics, including the normal modes of each individual solvent water molecule. The remaining translational and rotational degrees of freedom are described classically.

The Ehrenfest method with quantum corrections to simulate the relaxation of molecules in solution: equilibrium and dynamics.

The use of the Ehrenfest method to simulate the relaxation of molecules in solution is explored. Using the cyanide ion dissolved in water as a test model, the independent trajectory (IT) and the bundle of trajectories (BT) approximations are shown to provide very different results for the time evolution of the vibrational populations of the solute. None of these approximations reproduce the Boltzmann equilibrium vibrational populations accurately.

Oxidative stress induced by Cremophor EL is not accompanied by changes in NF-kappaB activation or iNOS expression.

The effects of polyoxyethylenglycerol triricinoleate 35 (Cremophor EL, CrEL) on markers of oxidative stress, nuclear factor kappa B (NF-kappaB) activation and inducible nitric oxide synthase (iNOS) expression were studied in the liver of male Wistar rats. Animals were randomly divided into three groups. Group Cr1 received, i.

Surface hopping simulation of the vibrational relaxation of I2 in liquid xenon using the collective probabilities algorithm.

A surface hopping simulation of the vibrational relaxation of highly excited I(2) in liquid xenon is presented. The simulation is performed by using the collective probabilities algorithm which assures the coincidence of the classical and quantum populations. The agreement between the surface hopping simulation results and the experimental measurements for the vibrational energy decay curves at different solvent densities and temperatures is shown to be good.