Intercellular Transport of Nanomaterials is Mediated by Membrane Nanotubes In Vivo

So‐called membrane nanotubes are cellular protrusions between cells whose functions include cell communication, environmental sampling, and protein transfer. It has been previously reported that systemically administered carboxyl‐modified quantum dots (cQDs) are rapidly taken up by perivascular macrophages in skeletal muscle of healthy mice. Expanding these studies, it is found, by means of in vivo fluorescence microscopy on the mouse cremaster muscle, rapid uptake of cQDs not only by perivascular macrophages but also by tissue‐resident cells, which are localized more than 100 μm distant from the closest vessel. Confocal microscopy on muscle tissue, immunostained for the membrane dye DiI, reveals the presence of continuous membranous structures between MHC‐II‐positive, F4/80‐positive cells. These structures contain microtubules, components of the cytoskeleton, which clearly colocalize with cQDs. The cQDs are exclusively found inside endosomal vesicles. Most importantly, by using in vivo fluorescence microscopy, this study detected fast (0.8 μm s^?1, mean velocity), bidirectional movement of cQDs in such structures, indicating transport of cQD‐containing vesicles along microtubule tracks by the action of molecular motors. The findings are the first to demonstrate membrane nanotube function in vivo and they suggest a previously unknown route for the distribution of nanomaterials in tissue.     

An expert protein loop refinement protocol by molecular dynamics simulations with restraints

Protein structure prediction (PSP) is a long standing problem in structural biology and bioinformatics. Within the PSP problem loop refinement is a major bottleneck. In this article we report the latest version of the CReF expert predictor system for the PSP problem with emphasis on loop refinement of the approximate 3-D structure 1ZDD_P of the Z34C mini protein predicted by CReF. We designed a loop refinement protocol based on seven molecular dynamics (MD) simulations runs at different temperatures. We found that, by letting the loop residues move freely during dynamics at 325 K and restraining the internal coordinates of the correctly predicted helical structures, while allowing them to move relative to each other, the refinement protocol was very effective in predicting an accurate loop conformation in the first 100 ps of a 1000 ps MD simulation. The quality of the predictions was confirmed by the RMSD between refined and experimental structures which varied from 0.6 to 1.3 Å. In addition, stereochemical analyses showed that 100% of all residues of the refined 1ZDD_P, including those in the loop, populates the most favorable core regions of the Ramachandran plot. Our study suggests that the proposed protocol may be suitable to refine more complex mini proteins with different classes and architectures.     

Estimate of the electric energy generating potential for different sources of biogas in Brazil

The increasing interest in the recuperation of the biogas coming from organic residues, associated with its energetic use is a subject that has been widely discussed. Biogas was merely seen as a sub-product obtained from anaerobic decomposition (without oxygen) of organic residue. In the paper is carried out an evaluation of the quantities of organic residues coming out from the sugar and alcohol industry (vinasse), urban solid and liquid wastes (garbage and sewage) and livestock residues (bovine and swine manure) in Brazil. Finally the electricity generation potential of biogas out of the evaluated sources of organic residues in Brazil is estimated. The results of this study indicate that the potential regarding the production of biogas out of the aforementioned organic residues of electricity production using could meet an energy demand of about 1.05 to 1.13 %. Constraints for biogas energy utilization are identified and discussed.     

Effect of temperature on structural properties of Aloe vera (Aloe barbadensis Miller) gel and Weibull distribution for modelling drying process

Aloe vera (Aloe barbadensis Miller) gel was dried at five inlet temperatures 50, 60, 70, 80 and 90 °C, in a convective dryer with a constant air flow of 2.0 ± 0.2 m/s. Rehydration ratio, water holding capacity, texture, microstructure and total polysaccharide content were evaluated. Drying kinetics was estimated using the Weibull distribution (r² > 0.97 and Chi-square < 0.0009). Values of scale and shape parameters ranged from 90.94 to 341.06 (min) and 1.43 to 1.49, respectively. Furthermore, the influence of temperature on the model parameters as well as on the quality attributes was analysed using a least significant difference test (p-value < 0.05). These effects were more evident for the long drying period (e.g. 810 min at 50 °C). However, minor alterations in the structural properties and total polysaccharide content were produced at drying temperatures of 60–70 °C, resulting in a high quality gel.     

Sediment Oxygen Demand and Nutrient Fluxes for a Tropical Reservoir in Singapore

Sediment oxygen demand (SOD) and nutrient flux studies were conducted for a tropical reservoir in Singapore in order to determine the approximate SOD and nutrient release rates from the sediments. SOD values obtained from laboratory experiments ranged from 1.4 to 3.3?g?O2/m2-day. Similar results were also obtained by calculating SOD values from in situ DO measurements taken in the field. The nutrient flux study was performed in the laboratory at a constant temperature of 25°C in oxic and anoxic columns. Except for nitrate+nitrite, higher nutrient release rates were generally observed under anoxic conditions. The ammonium release rate was 0.06?g?O2/m2-day under oxic conditions and 0.117?g?O2/m2-day under anoxic conditions. The nitrate flux rate was 0.17?g?O2/m2-day under oxic conditions but was negligible under anoxic conditions. Orthophosphate flux results were negative throughout the oxic incubation implying that sediments acted as a sink. The release rate of orthophosphate was 0.007?6?g?O2/m2-day under anoxic conditions.     

Surface tension studies of additives in acrylic resin-based powder coatings using the Wilhelmy balance technique

A modified Wilhelmy balance technique using thin fibers as solid probes has been applied to study the effect of silicone additives in acrylic resin-based powder coatings on the surface tension of non-reactive binder systems. By measuring the temperature dependence of the surface tension in the temperature range between 140 and 180°C, it could be shown that the silicone additives investigated had a very different surface activity in the molten acrylic resin. Due to the high accuracy of the measuring technique and the good reproducibility of the experiments the influence of different additive concentrations on the surface tension was detectable even at very low concentrations (below 1 wt.%).

Compared to the pure powder coating binder which has a surface tension of about 30 mN/m the values decreased between 2–15 mN/m depending on the type of the silicone additive. In addition, the temperature coefficient −(dγ/dT) of the surface tension of the binder melt was changed. In the case of two additives, the surface tension of the powder coating and its temperature coefficient were lowered considerably. This effect of additives is desirable to reach good wetting and leveling of the powder coating.     

Use of grape by‐product as a source of dietary fibre and phenolic compounds in sourdough mixed rye bread

The study evaluated the effect of grape by‐products (GP) on the chemical composition, soluble (SDF) and insoluble (IDF) dietary fibre, phenolic compounds and antioxidant activity (AA) and organoleptic characteristics of sourdough mixed rye bread. The following samples of sourdough mixed rye bread were prepared: control bread (BC) and breads with GP at four different levels: 4%, 6%, 8% and 10%. Addition of GP significantly improves dietary fraction contents, as bread with a 10% addition of GP accounts for 39% and 37% higher contents of IDF and SDF than BC. The assay of radical‐scavenging activity and reducing ability showed that GP addition greatly enhanced antioxidant properties of mixed rye breads. Profiles of phenolic compounds of supplemented breads were dominated by procyanidin B1 and B2, catechin, epicatechin, caffeic acid and myricetin. With an increase in the level of GP, the hardness and gumminess of the bread significantly increase. Although both BC and supplemented breads showed common volatile compound profiles, there were slight differences in the concentrations of those components. Sensory evaluation of GP‐enhanced breads revealed that a maximum of 6% GP could be incorporated to prepare acceptable products.     

Juice from king palm (Archontophoenix alexandrae) leaf sheathes: chemical characterisation and use in soft drink formulation

The heart of palm is a food extracted from several species of palm trees. Only 10–20% of the raw material is transformed into canned hearts of palm, therefore this agro‐industry generates a large quantity of solid residue. The aim of this work was to extract and characterise a juice produced from this solid residue. This extract is compared with the traditional fruit juices (orange and pineapple juices), obtaining higher contents of minerals, such as magnesium (22.80 mg/100 g) and potassium (276.90 mg/100 g), phenolic compounds (gallic, 3,4‐dihydroxybenzoic, chlorogenic, syringic and caffeic acids) and high free radical scavenging capacity (expressed as 2,2‐diphenyl‐1‐picrylhydrazyl), which suggest high antioxidant activity. Additionally, a new soft drink was formulated using this king palm juice as its main ingredient. The soft drink samples formulated with this juice had high sensory acceptability and high intention of consumption, which suggests an important and low‐cost application for this industrial residue.     

Assessment of personal hygiene and practices of food handlers in municipal public schools of Natal,Brazil

The aim of this study was to assess the hygiene practices of food handlers in municipal schools of Natal, Brazil, where 27 public schools were evaluated, using a checklist and microbiological analysis of hands. It was found that 74.1% of the handlers did not receive periodic training, 51.9% did not undergo annual health examinations and 100% did not practice proper hand hygiene, a situation that reflected significantly (p < 0.05) in hand contamination, in which fecal coliforms were detected on 55.6% of the hands analyzed. It was concluded that the schools studied did not have appropriate hygienic conditions, suggesting the need for interventions that ensure the quality of school food served to the children.