Spray-dried whey protein/lactose/soybean oil emulsions. 1. Surface composition and particle structure

Emulsions made of whey protein, lactose and soybean oil were spray-dried and the chemical surface composition of the dried powders estimated by electron spectroscopy for chemical analysis. In particular, the ability of whey protein to encapsulate fat was highlighted. Additionally, the structure of the spray-dried powder particles was studied by scanning electron microscopy. The powders were examined after storage in both dry and humid atmospheres (relative humidity 75%, 4 days). It was found that the ability of whey protein to encapsulate soybean oil is rather low compared with sodium caseinate, with a large part of the powder surface covered by fat after spray-drying. After storage in humid atmosphere there is a release of encapsulated oil onto the powder surface in most cases, and an increase in fat coverage. The release offat onto the powder surfaces causes the particle structure to change dramatically for powders containing a critical amount of lactose. Such powders agglomerate and lose structure completely. In comparison, powders containing no lactose storage under humid conditions also cause a release of fat onto the powder; however, in this case particle structure remains intact. Powders containing only a small amount of lactose, up to ~25% of emulsion dry weight, do not exhibit the release of fat onto the powder surfaces after storage under humid conditions and the structure of these powder particles does not change. The presence of lactose in whey protein-stabilized emulsions, however, does not increase fat encapsulation by whey protein, as reported earlier for sodium caseinate-stabilized emulsions that were spray-dried. During spray-drying of whey protein/lactose solutions there is a strong overrepresentation of surface-active whey protein on the powder surface. Whey protein coverage increases even further when the powders are stored under humid conditions, also making them lose structure.     

The role of tissue microstructure and water exchange in biophysical modelling of diffusion in white matter

Biophysical models that describe the outcome of white matter diffusion MRI experiments have various degrees of complexity. While the simplest models assume equal-sized and parallel axons, more elaborate ones may include distributions of axon diameters and axonal orientation dispersions. These microstructural features can be inferred from diffusion-weighted signal attenuation curves by solving an inverse problem, validated in several Monte Carlo simulation studies. Model development has been paralleled by microscopy studies of the microstructure of excised and fixed nerves, confirming that axon diameter estimates from diffusion measurements agree with those from microscopy. However, results obtained in vivo are less conclusive. For example, the amount of slowly diffusing water is lower than expected, and the diffusion-encoded signal is apparently insensitive to diffusion time variations, contrary to what may be expected. Recent understandings of the resolution limit in diffusion MRI, the rate of water exchange, and the presence of microscopic axonal undulation and axonal orientation dispersions may, however, explain such apparent contradictions. Knowledge of the effects of biophysical mechanisms on water diffusion in tissue can be used to predict the outcome of diffusion tensor imaging (DTI) and of diffusion kurtosis imaging (DKI) studies. Alterations of DTI or DKI parameters found in studies of pathologies such as ischemic stroke can thus be compared with those predicted by modelling. Observations in agreement with the predictions strengthen the credibility of biophysical models; those in disagreement could provide clues of how to improve them. DKI is particularly suited for this purpose; it is performed using higher b-values than DTI, and thus carries more information about the tissue microstructure. The purpose of this review is to provide an update on the current understanding of how various properties of the tissue microstructure and the rate of water exchange between microenvironments are reflected in diffusion MRI measurements. We focus on the use of biophysical models for extracting tissue-specific parameters from data obtained with single PGSE sequences on clinical MRI scanners, but results obtained with animal MRI scanners are also considered. While modelling of white matter is the central theme, experiments on model systems that highlight important aspects of the biophysical models are also reviewed.     

Exploring the Ion Channel TRPV2 and Testicular Macrophages in Mouse Testis

The cation channel TRPV2 is known to be expressed by murine macrophages and is crucially involved in their functionality. Macrophages are frequent cells of the mouse testis, an immune-privileged and steroid-producing organ. TRPV2 expression by testicular macrophages and possible changes associated with age or inflammation have not been investigated yet. Therefore, we studied testes of young adult and old wild-type (WT) and AROM⁺ mice, i.e., transgenic mice overexpressing aromatase. In these animals, inflammatory changes are described in the testis, involving active macrophages, which increase with age. This is associated with impaired spermatogenesis and therefore AROM⁺ mice are a model for male infertility associated with sterile inflammation. In WT animals, testicular TRPV2 expression was mapped to interstitial CD206⁺ and peritubular MHC II⁺ macrophages, with higher levels in CD206⁺ cells. Expression levels of TRPV2 and most macrophage markers did not increase significantly in old mice, with the exception of CD206. As the number of TRPV2⁺ testicular macrophages was relatively small, their possible involvement in testicular functions and in aging in WT mice remains to be further studied. In AROM⁺ testis, TRPV2 was readily detected and levels increased significantly with age, together with macrophage markers and TNF-α. TRPV2 co-localized with F4/80 in macrophages and further studies showed that TRPV2 is mainly expressed by unusual CD206⁺MHC II⁺ macrophages, arising in the testis of these animals. Rescue experiments (aromatase inhibitor treatment and crossing with ERαKO mice) restored the testicular phenotype and also abolished the elevated expression of TRPV2, macrophage and inflammation markers. This suggests that TRPV2⁺ macrophages of the testis are part of an inflammatory cascade initiated by an altered sex hormone balance in AROM⁺ mice. The changes in testis are distinct from the described alterations in other organs of AROM⁺, such as prostate and spleen. When we monitored TRPV2 levels in another immune-privileged organ, namely the brain, we found that levels of TRPV2 were not elevated in AROM⁺ and remained stable during aging. In the adrenal, which similar to the testis produces steroids, we found slight, albeit not significant increases in TRPV2 in both AROM⁺ and WT mice, which were associated with age. Thus, the changes in the testis are specific for this organ.     

Emulsion preparation with modified oat bran: Optimization of the emulsification process for microencapsulation purposes

The objective of this study was to develop an oil in water (o/w) emulsion using modified oat bran (MOB). Test emulsions containing 5% rapeseed oil were prepared by varying the content of MOB and maintaining the solid content constant (20%) by using corn syrup solids (DE34) as filler. A central composite (CC) design was applied as a tool to obtain a stable and low viscosity emulsion. The effect of concentration of MOB, homogenization pressure and homogenization time on the emulsion stability (at 25 °C for 26 h), viscosity and particle size were determined. The concentration of MOB in the recipe significantly influenced the emulsion properties whereas the homogenization pressure and the homogenization time had no statistically significant influence on the emulsion properties. Further experiments, however, showed that increasing the homogenization pressure decreased the emulsion viscosity. Emulsions prepared using a MOB concentration of 1.55% and homogenized at 60 MPa for 10 min, exhibited excellent stability, low viscosity, small enough mean particle size and narrow particle size distribution. Modified oat bran containing deamidated oat protein possesses an excellent capability to form stable emulsions which might be suitable for microencapsulation.     

Integrated treatment of PAH contaminated soil by soil washing, ozonation and biological treatment

The aim of the study was to optimise three different treatment methods and to find out if the integration of soil washing, ozonation and biological treatment could be a feasible method for the remediation of aged oil contaminated with PAHs. Three different ozone doses and soil washing were studied in different pHs in order to assess their effect to the degradation and enhancement of biodegradability of PAH in the soil and water phase. Main target of the study was to find out a method with which the PAH concentrations could be decreased below the Finnish guideline level for total PAHs. In this case, the initial concentration of PAHs was 1200 mg kg(-1) and therefore almost 85% degradation of PAHs was required. Any of the methods studied was not able to reach this target level alone, but by several combinations of the methods studied achieved 90% reduction of PAHs. The consumption of ozone was 5-10 times lower in the integrated treatments of soil washing, ozonation and biological treatment than without prewashing.     

VIRTUAL REALITY FOR IMMERSIVE DATA INTERACTION

In a time shaped by technological developments dissolving the boundaries between the real and the virtual world, we are challenged to newly define the potentials of virtual and mixed reality in the field of landscape architecture. Critical analyses of the primary application areas of these technologies show that the current focus mostly lies on the optimization of 3D visualization and navigation in virtual space. Within professional practice, mixed reality tools are increasingly being used to test and communicate design decisions, for marketing purposes, and more often, within the smart building industry as well. Thus far, the incorporation of immersive environments in landscape architecture is lacking research on human-centered data interaction and the perception of space. At Aalto University, Finland, the team of Pia Fricker, Professor of Practice for Computational Methodologies in Landscape Architecture and Urbanism, researches new immersive co-design methodologies to introduce new meaningful trajectories for participatory processes. Mixed reality applications are thus extended beyond common and conventional uses to help create multidisciplinary immersive interactive spaces using data informed processes. The research and teaching results showcased in the article address international discourse on the larger theme of “Digital Humanism — Big Data and Human-Centered Design.”     

Utilizing Formate as an Energy Carrier by Coupling CO2 Electrolysis with Fuel Cell Devices

Electrochemical reduction of CO₂ to useful chemicals can change the role of CO₂ from harmful waste to a valuable feedstock. Despite a lot of progress in the alkaline electrochemical conversion of CO₂ to formate, there is still a lack of potential applications for the generated aqueous formate solution. Here, the general ability of formate to be used as an energy or hydrogen carrier is discussed and compared to well‐known energy storage chemicals. Concepts to employ formate solution as an energy carrier by combining CO₂ electrolysis with the reconversion of formate into electricity via a direct formate fuel cell or catalytic decomposition to H₂ combined with a proton exchange membrane fuel cell are demonstrated.     

Shear-load carrying capacities of the distal rat femora after osteotomy fixed with self-reinforced polyglycolic acid and poly-L-lactic acid pins

Distal femora of 40 rats were osteotomized and fixed with self-reinforced polyglycolide (SR-PGA) and self-reinforced polylactide (SR-PLLA) pin 2.0 mm in diameter and 15 mm in length. The shear-load carrying capacities of the osteotomized bones were compared with each other and with the intact control rat distal femora of the same age of 20 pairs. The follow-up times were 1, 3, 6, 12, 24, 36, 48, and 52 weeks. After killing all operated and control femora were examined macroscopically and radiographically. The shear-load carrying capacities reached their highest values at 24 weeks in the SR-PGA-fixed specimens, after that decreasing to the level where they remained. In the SR-PLLA-fixed specimens the strength values of the pins increased after three weeks, but there was a decrease at 24 weeks. After that the shear-load carrying capacities started to raise because of the influence of the healed osteotomy. In the control bones the shear-load carrying capacities were weaker than in the SR-PGA-and SR-PLLA-fixed specimens except at three weeks, as the osteotomies had not yet healed. During the whole follow-up period the mean shear-load carrying capacity of the SR-PGA-fixed specimens was 199.1 N, in the SR-PLLA-fixed specimens 214.6 N, the corresponding value of the control specimens being 148.2 N.     

Investigations on grape skin colours for the purpose of legislative regulation

Zusammenfassung Zehn im Handel erhältliche Farbstoffe der Traubenschalen wurden auf ihren gesamten roten Farbstoffgehalt und auf die Pigmentqualität untersucht. Die Pigmentqualität wurde über Spektren bestimmt und die Absorption bei verschiedenen pH-Werten bzw. Wellenlängen abgelesen. Die Pigmentqualität wurde auch spektrophotometrisch nach Bleichen mit Sulfit und nach Säulenfraktionierung der Monomere, der roten und gelb-braunen Polymere bestimmt. Eine Formel zur Berechnung des Gehaltes des gesamten roten Farbstoffes von Auszügen aus Traubenschalen wird angegeben. Diese Formel stützt sich auf die WerteE _1cm ^1% =500 als maximale Absorption bei rund 520 nm im Puffer von pH 1. Die Formel wird in der nationalen dänischen Vorschrift über den Lebensmittelfarbstoff der Traubenschalen zur Bestimmung des Gehalts an rotem Farbstoff angewendet. Es wurden große Variationen im Farbstoffgehalt und auch in der Pigmentqualität der Handelserzeugnisse gefunden. Mögliche Identitätstests, wie DC und Farbreaktionen für Farbstoffe und Traubenschalen, wurden ebenfalls untersucht.

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Investigations on grape skin colours for the purpose of legislative regulation

Summary Ten commercially available grape skin colouring agents were examined with regard to total red colour content and pigment quality. The pigment quality of the colour preparations was studied by recording their visible absorbance spectra at different pH values. Pigment quality was also estimated from spectra after sulphite bleaching and after column chromatographic fractionation into monomers, and red and brown-yellow polymers.A formula for calculating the total red colour content of grape skin preparations is given, based on the valueE _1cm ^1% =500 for the maximal absorptivity at about 520 nm in buffer at pH 1. This formula has been adopted in the Danish national specification for grape skin colours. Considerable variations between the commercial preparations were found regarding anthocyanin colour content as well as pigment quality. Identification of grape skin preparations by TLC and colour reactions was also studied.