Impact of oxidoreduction potential and of gas bubbling on rheological properties of non-fat yoghurt

The aim of this work was to study the effect of different gaseous conditions on the physico-chemical properties of yoghurt. Four conditions of oxidoreduction potential (Eh₇), +433 mV (milk gassed with air), +405 mV (ungassed milk), +283 mV (milk gassed with N2) and ?349 mV (milk gassed with N₂–H₂) were applied to milk. The rheological properties and microstructure of these yoghurts were determined by measuring apparent viscosity, whey separation (WS) and using confocal laser scanning microscopy. Exopolysaccharide (EPS) production by lactic acid bacteria (LAB) was also studied, and production was increased for extreme Eh₇ values: the highest values were obtained for air (oxidizing condition) and for N₂–H₂ (reducing condition). Yoghurts made under bubbled N₂–H₂ clearly led to low WS with higher gel aggregation and a lower proportion of pores.     

Interpersonal subtypes and change of interpersonal problems in the treatment of patients with generalized anxiety disorder: A pilot study.

Interpersonal problems are highly relevant to the treatment of generalized anxiety disorder (GAD) patients. Previous studies using the Inventory of Interpersonal Problems identified several interpersonal subtypes in GAD patients. In this study, we wanted to replicate earlier findings of interpersonal subtypes in GAD. We investigated whether these interpersonal subtypes are characterized by different types of interpersonal problems and different levels of interpersonal distress, and we further examined whether they differed with regard to improvement of interpersonal problems after short-term treatment. This study is based on results from a randomized controlled trial that investigated short-term treatments in GAD outpatients. For secondary analysis, interpersonal subtypes were identified by cluster analysis and Inventory of Interpersonal Problems profiles were calculated for both the total sample (N = 52) and the interpersonal subtypes using the Structural Summary Method for Circumplex Data. This study confirmed previous results demonstrating the existence of interpersonal subtypes in GAD. Four interpersonal subtypes were identified: Overly Nurturant, Intrusive, Socially Avoidant, and Nonassertive. Short-term treatment significantly improved interpersonal problems (d = 0.46) within the total GAD sample. Interestingly, the effect sizes of the four clusters differed considerably (d = 0.19–1.24) and the clusters displayed different changes in the two circumplex axes Dominance and Nurturance. Our study indicates that change of interpersonal problems needs to be specifically analyzed, even within homogenous diagnostic groups. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Growth and structure of aggregates of heat-denatured β-Lactoglobulin

Summary The aggregation of the globular protein β-lactoglobulin after heat-denaturation was studied in aqueous solution at pH 7 using static and dynamic light scattering. The structure of the aggregates is self-similar with fractal dimension 2.0. Size exclusion chromatography and dynamic light scattering measurements show that the aggregates have a broad size distribution. Initially clusters of about 85 proteins and 15 nm radius are formed which are the elementary units of the larger fractal aggregates. At low ionic strength the formation of the larger aggregates is impeded by electrostatic interactions.
The structure of the aggregates is independent of the concentration and the temperature. The rate of aggregation has an Arrhenius temperature dependence with an activation energy of about 350 kJ/mol weakly dependent on the concentration. The apparent reaction order of the aggregation is 1.5. In the mixture both variants A and B have the same aggregation rate. The gel time increases with decreasing concentration and diverges at about 0.7g L⁻¹. At lower concentration the aggregate growth stagnates when all protein has aggregated.     

Nuclear magnetic resonance analysis of protein–DNA interactions

Recent methodological and instrumental advances in solution-state nuclear magnetic resonance have opened up the way to investigating challenging problems in structural biology such as large macromolecular complexes. This review focuses on the experimental strategies currently employed to solve structures of protein–DNA complexes and to analyse their dynamics. It highlights how these approaches can help in understanding detailed molecular mechanisms of target recognition.     

A histomorphometric comparison of the muscular tissue reaction to stainless steel,pure titanium and titanium alloy implant materials

Thein vivo tissue reaction to titanium and titanium-based alloys using quantitative histomorphometry was investigated. According to the guidelines for biomaterials testing suggested by ISO, 2 mm × 6 mm cylindrical specimens of chemically pure (CP) Ti, TiO₂, electrolytically coated Ti, Ti6Al4V, TiO₂-coated Ti6Al4V, TiN physical vapour deposition-coated Ti6Al4V and Ti5Al2.5Fe were implanted in the paravertebral muscles of rats, for 1–52 weeks, 316L stainless steel being used as a control implant material. After PMMA embedding, electrochemical dissolution of the implants, microtome sectioning and Masson's trichrome staining, the tissue reaction was assayed using a semi-automatic method based on the digitization of both the encapsulating membrane contours and the different cell types located within it. All materials induced a close tissue reaction. There was no statistical difference between the tested materials regarding the time-evolution of the inflammatory cells. However, when comparing CP Ti with 316L, a significant difference was found in the fibrocyte kinetics: in the short term, fibrocyte densities were lower for 316L, while beyond 12 weeks, they exhibited higher values than CP Ti. To a lesser extent, a similar observation was made when comparing CP Ti with Ti5Al12.5Fe. No statistical difference was found in the comparison of CP Ti with Ti6Al4V. The membrane thickness was identical for all tested materials and appeared not to be time-dependent.     

Nanoparticle-Mediated Pulmonary Drug Delivery: A Review

Colloidal drug delivery systems have been extensively investigated as drug carriers for the application of different drugs via different routes of administration. Systems, such as solid lipid nanoparticles, polymeric nanoparticles and liposomes, have been investigated for a long time for the treatment of various lung diseases. The pulmonary route, owing to a noninvasive method of drug administration, for both local and systemic delivery of an active pharmaceutical ingredient (API) forms an ideal environment for APIs acting on pulmonary diseases and disorders. Additionally, this route offers many advantages, such as a high surface area with rapid absorption due to high vascularization and circumvention of the first pass effect. Aerosolization or inhalation of colloidal systems is currently being extensively studied and has huge potential for targeted drug delivery in the treatment of various diseases. Furthermore, the surfactant-associated proteins present at the interface enhance the effect of these formulations by decreasing the surface tension and allowing the maximum effect. The most challenging part of developing a colloidal system for nebulization is to maintain the critical physicochemical parameters for successful inhalation. The following review focuses on the current status of different colloidal systems available for the treatment of various lung disorders along with their characterization. Additionally, different in vitro, ex vivo and in vivo cell models developed for the testing of these systems with studies involving cell culture analysis are also discussed.     

Red Fluorescent Turn‐On Ligands for Imaging and Quantifying G Protein‐Coupled Receptors in Living Cells

Classical fluorescence‐based approaches to monitor ligand–protein interactions are generally hampered by the background signal of unbound ligand, which must be removed by tedious washing steps. To overcome this major limitation, we report here the first red fluorescent turn‐on probes for a G protein‐coupled receptor (oxytocin receptor) at the surface of living cells. The peptide ligand carbetocin was conjugated to one of the best solvatochromic (fluorogenic) dyes, Nile Red, which turns on emission when reaching the hydrophobic environment of the receptor. We showed that the incorporation of hydrophilic octa(ethylene glycol) linker between the pharmacophore and the dye minimized nonspecific interaction of the probe with serum proteins and lipid membranes, thus ensuring receptor‐specific turn‐on response. The new ligand was successfully applied for background‐free imaging and quantification of oxytocin receptors in living cells.     

Modeling of multicomponent diffusion in high temperature flows

Three methods for computing diffusive mass transfer in non-reactive high temperature flows are compared. Results show that the widely used effective binary approximation may lead to large errors (up to 70%) in the evaluation of the mass fluxes, reflecting, therefore, on the solution of the species conservation equations. Two other approaches, the consistent effective binary diffusion due to Ramshaw, hereafter called the Ramshaw's approximation, and the linearized method are shown to reproduce accurately the mass transfer obtained with the exact formulation for multicomponent high temperature flows in isotherm conditions. When temperature gradients are imposed, the linear approximation leads to important errors (up to 40%) on the mass flux calculation.