Age-related waning of in vitro Interferon-γ levels against r32kDaBCG in BCG vaccinated children

Background  

Mycobacterium bovis BCG vaccine has displayed inconsistent efficacy in different trials conducted in various geographical regions. Nevertheless, it significantly reduces the risk of severe childhood tuberculosis and continues to be used to prevent tuberculosis in many countries. Many studies revealed that efficacy of vaccine wanes with age. Most of the studies were based on in vivo and in vitro responses to tuberculin. With the advent of newer tests such as in vitro interferon-γ assays and identification of potent immunogenic mycobacterial proteins there is a need to corroborate the observations. This study aims at ascertaining the need for a booster at a later age as indicated by in vitro release of IFN-γ while evaluating Ag85A as an antigen.     

Cyclic Groups as Autocommutator Groups

This article classifies the groups X whose autocommutator subgroup [X, Aut(X)] is isomorphic to ? and the finite groups X for which [X, Aut(X)] ? C _p has a prime number p of elements.     

Trapping of Rb atoms by ac electric fields

We demonstrate trapping of an ultracold gas of neutral atoms in a macroscopic ac electric trap. Three-dimensional confinement is obtained by switching between two saddle-point configurations of the electric field. Stable trapping is observed in a narrow range of switching frequencies around 60 Hz. The dynamic confinement of the atoms is directly visualized at different phases of the ac switching cycle. We observe about 10(5) Rb atoms in the 1 mm3 large and several microkelvins deep trap with a lifetime of approximately 5 s.     

Amplitude point-spread function measurement of high-NA microscope objectives by digital holographic microscopy

We present here a three-dimensional evaluation of the amplitude point-spread function (APSF) of a microscope objective (MO), based on a single holographic acquisition of its pupil wavefront. The aberration function is extracted from this pupil measurements and then inserted in a scalar model of diffraction, allowing one to calculate the distribution of the complex wavefront propagated around the focal point. The accuracy of the results is compared with a direct measurement of the APSF with a second holographic system located in the image plane of the MO. Measurements on a 100 x 1.3 NA MO are presented.     

Formulation of Topical Dosage Forms Containing Synthetic and Natural Anti-Inflammatory Agents for the Treatment of Rheumatoid Arthritis

Topical anti-inflammatory and analgesic effect for the treatment of rheumatoid arthritis is of major interest because of their fewer side effects compared to oral therapy. The purpose of this study was to prepare different types of topical formulations (ointments and gels) containing synthetic and natural anti-inflammatory agents with different excipients (e.g.,: surfactants, gel-forming) for the treatment of rheumatoid arthritis. The combination of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs), diclofenac sodium, a topical analgesic agent methyl salicylate, and a lyophilized extract of Calendula officinalis with antioxidant effect were used in our formulations. The aim was to select the appropriate excipients and dosage form for the formulation in order to enhance the diffusion of active substances and to certify the antioxidant, analgesic, and anti-inflammatory effects of these formulations. To characterize the physicochemical properties of the formulations, rheological studies, and texture profile analysis were carried out. Membrane diffusion and permeability studies were performed with Franz-diffusion method. The therapeutic properties of the formulations have been proven by an antioxidant assay and a randomized prospective study that was carried out on 115 patients with rheumatoid arthritis. The results showed that the treatment with the gel containing diclofenac sodium, methyl salicylate, and lyophilized Calendula officinalis as active ingredients, 2-propenoic acid homopolymer (Synthalen K) as gel-forming excipient, distilled water, triethanolamine, and glycerol had a beneficial analgesic and local anti-inflammatory effect.     

On possible microscopic origins of the swelling of neutral lipid bilayers induced by simple salts

It was recently suggested that the swelling of neutral multilipid bilayers upon addition of a salt can be simply explained only by the electrolyte screening of the van der Waals attractions, while assuming that the hydration force and the repulsion due to thermal undulations of membranes are unaffected by the salt. While we agree that the screening of the van der Waals interactions plays a role, we suggest that the increase in the hydration force upon addition of a salt has also to be taken into account. In a statistical model, which accounts for the membrane undulations, parameters could be found to explain the multibilayer swelling even when the van der Waals attraction is considered unaffected by the electrolyte screening. These results point out that the decrease by a factor of three of the Hamaker constant upon addition of a salt, suggested recently to be responsible for the swelling of neutral multilipid bilayers, is perhaps too large, and a smaller decrease in Hamaker constant, coupled with the above mentioned effects might explain the swelling.     

Combined quantum mechanical and molecular mechanical simulations of one- and two-electron reduction potentials of flavin cofactor in water, medium-chain acyl-CoA dehydrogenase, and cholesterol oxidase

Flavin adenine dinucleotide (FAD) is a common cofactor in redox proteins, and its reduction potentials are controlled by the protein environment. This regulation is mainly responsible for the versatile catalytic functions of flavoenzymes. In this article, we report computations of the reduction potentials of FAD in medium-chain acyl-CoA dehydrogenase (MCAD) and cholesterol oxidase (CHOX). In addition, the reduction potentials of lumiflavin in aqueous solution have also been computed. Using molecular dynamics and free-energy perturbation techniques, we obtained the free-energy changes for two-electron/two-proton as well as one-electron/one-proton addition steps. We employed a combined quantum mechanical and molecular mechanical (QM/MM) potential, in which the flavin ring was represented by the self-consistent-charge density functional tight-binding (SCC-DFTB) method, while the rest of the enzyme-solvent system was treated by classical force fields. The computed two-electron/two-proton reduction potentials for lumiflavin and the two enzyme-bound FADs are in reasonable agreement with experimental data. The calculations also yielded the pKa values for the one-electron reduced semiquinone (FH*) and the fully reduced hydroquinone (FH2) forms. The pKa of the FAD semiquinone in CHOX was found to be around 4, which is 4 units lower than that in the enzyme-free state and 2 units lower than that in MCAD; this supports the notion that oxidases have a greater ability than dehydrogenases to stabilize anionic semiquinones. In MCAD, the flavin ring interacts with four hydrophobic residues and has a significantly bent structure, even in the oxidized state. The present study shows that this bending of the flavin imparts a significant destabilization (approximately 5 kcal/mol) to the oxidized state. The reduction potential of lumiflavin was also computed using DFT (M06-L and B3LYP functionals with 6-31+G(d,p) basis set) with the SM6 continuum solvation model, and the results are in good agreement with results from explicit free-energy simulations, which supports the conclusion that the SCC-DFTB/MM computation is reasonably accurate for both 1e(-)/1H+ and 2e(-)/2H+ reduction processes. These results suggest that the first coupled electron-proton addition is stepwise for both the free and the two enzyme-bound flavins. In contrast, the second coupled electron-proton addition is also stepwise for the free flavin but is likely to be concerted when the flavin is bound to either the dehydrogenase or the oxidase enzyme.     

Computational study of the Zr4+ tetranuclear polymer, [Zr4(OH)8(H2O)16]8+

The Zr(4+) tetramer, [Zr(4)(OH)(8)(H(2)O)(16)](8+), is thought to be the major component of the Zr(4+) polymer system in aqueous solution, present as a dominant ionic cluster species compared to other Zr(4+) clusters under various experimental conditions. Despite widespread applications of zirconium, the structure and dynamics of the tetramer in aqueous solution are not well understood. We conducted a combination of ab initio molecular dynamics and quantum mechanical studies in the gas phase and aqueous solution and related our results to the available experimental data to provide atom-level information on the behavior of this species in aqueous solution. Our simulations indicate that the tetramer structure is stable on the picosecond time scale in an aqueous environment and that it is of a planar form, comprising eight-coordinated Zr(4+) ions with an antiprism/irregular dodecahedron ligand arrangement. In combination with our studies of Zr(4+) dimer and trimer clusters, our results provide detailed geometrical information on structural motifs for building zirconium polymers and suggest a possible polymerization path.     

A novel software tool for copolymer characterization by coupling of liquid chromatography with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

The results of copolymer characterization by coupling of chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) techniques and subsequent calculation of copolymer composition using a novel software tool 'MassChrom2D' are presented. For high-resolution mass analysis copolymer samples were fractionated by means of liquid adsorption chromatography (LAC). These fractions were investigated off-line by MALDI-TOF MS. Various mono-n-butyl ethers of polyethylene oxide-polypropylene oxide copolymers (PEO-co-PPO) were investigated. As well as the copolymer composition presented in two-dimensional plots, the applied approach can give additional hints on specific structure-dependent separation conditions in chromatography.     

Additive property of secondary relaxation processes in di-n-octyl and di-isooctyl phthalates: signature of non-Johari-Goldstein relaxation

Broadband dielectric spectroscopy was used to study relaxation dynamics of supercooled di-n-octyl phthalate, di-isooctyl phthalate, and their mixtures. Additionally, low temperature measurements were performed to investigate the nature of the secondary relaxation processes in both glass formers. The authors found that the secondary relaxation observed in the mixture is the additive sum of the secondary relaxations of the two components. This experimental evidence indicates that these secondary relaxation processes are intramolecular in origin, and they are non-Johari-Goldstein secondary relaxations.