Microscopic evaluation of vesicles shed by erythrocytes at elevated temperatures

The images of human erythrocytes and vesicles were analyzed by a light microscopy system with spatial resolution of better than 90 nm. The samples were observed in an aqueous environment and required no freezing, dehydration, staining, shadowing, marking, or any other manipulation. Temperature elevation resulted in significant concentration increase of structurally transformed erythrocytes (echinocytes) and vesicles in the blood. The process of vesicle separation from spiculated erythrocytes was video recorded in real time. At a temperature of 37°C, mean vesicle concentrations and diameters were found to be 1.50 ± 0.35 × 10⁶ vesicles per microliter and 0.365 ± 0.065 μm, respectively. The vesicle concentration increased approximately threefold as the temperature increased from 37 to 40°C. It was estimated that 80% of all vesicles found in the blood are smaller than 0.4 μm. Accurate account of vesicle numbers and dimensions suggest that 86% of the lost erythrocyte material is lost not by vesiculation but by another, as yet, unknown mechanism. Microsc. Res. Tech. 76:1163–1170, 2013. © 2013 Wiley Periodicals, Inc.     

The effects of cold storage of table grapes, sulphur dioxide and ethanol on species of black Aspergillus producing ochratoxin A

Table grapes of cv. 'Superior' were sampled from four vineyards during three seasons, for the occurrence of black Aspergillus species that can produce ochratoxin A after storage. The ochratoxin A-producing fungus, Aspergillus carbonarius , was identified in all the samples at harvest and it survived through cold storage. Storage of table grapes for 7 days at 20 °C resulted in occasional increase in the number of isolates recovered from the berries. In contrast, storage for 1 month at 0 °C, with sulphur dioxide (SO₂) generator pads reduced the number of isolates significantly or completely, depending on the dose. Dipping the clusters in ethanol prior to cold storage did not reduce the number of isolates of the Aspergillus niger aggregate after storage. Exposure of A. carbonarius to a final level of 0.4 ppm of SO₂ resulted in fewer fungal colonies than in the control, and the surviving spores developed into fungal colonies that failed to sporulate. These results demonstrate that A. carbonarius is ubiquitous on table grapes before storage and care should be taken to avoid its contamination.     

Increased significance of food wastes: Selective recovery of added-value compounds

A single-step selective separation of two food additives was investigated using alcohol-salt aqueous two-phase systems (ATPS). The selective partitioning of two of the most used additives from a processed food waste material, vanillin and l-ascorbic acid, was successfully accomplished. The results obtained prove that alcohol-salt ATPS can be easily applied as cheaper processes for the selective recovery of valuable chemical products from food wastes and other sources.     

Liquid and gas flow and related phenomena in monolithic catalysts studied by H NMR microimaging

NMR is employed to study liquid and gas flow in a tube and in the channels of shaped catalysts, mass transport during drying of water saturated porous monoliths, and gas adsorption by porous alumina pellets. NMR flow imaging and pulsed field gradient NMR are shown to yield the same average propagators for liquid and gas flow in a straight circular tube. The complicated patterns of gas or liquid flow in shaped reactors are characterized successfully by NMR flow imaging through the detection of all three flow velocity components.     

An investigation of the strength of branch areas in the piping of nuclear power installations

A three-dimensional shell finite-element method and a computer code have been developed in RRC ‘Kurchatov Institute’ for the strength analysis of branch pipe (nozzle) areas, which are among the most critical as regards strength components of pipes in both reactors and other systems. According to the method, the structure under study is broken up into eight-node isoparametric shell-type finite elements, each with eight or 18 integration points. The program was tested with the help of experimental results. The strength analyses of equal and unequal T-pipes were performed. Consideration was given to the variants with loading by pressure and moments (symmetric and asymmetric cases). The effects of fillet wall thickness and radius on the stressed state of the T-pipes were investigated.     

Effect of nanofiller on the behavior of a melt‐drawn HDPE/PA6 microfibrillar composite

Microfibrillar composites (MFCs) with reinforcing fibrils formed in situ by melt drawing were modified by the addition of layered silicates using different mixing protocols, viz simultaneous addition of components, application of respective premade nanocomposites and their combinations. The objective was to combine reinforcement with changes in the final structure, especially the fibril dimensions. The presented results indicate good potential of the nanoclay to enhance the MFC based on the melt‐drawn HDPE/PA6 system. The best mechanical behavior was achieved with the simultaneous addition of all components. The majority of the nanofiller material was contained inside the PA6 fibrils. Both fibrils dimensions and mechanical behavior were significantly affected by the nanofiller migration to the PA6 phase in the course of mixing and melt drawing. Due to a complex effect of the clay, deterioration of mechanical properties was also found. As a result, numerous, in some cases contradictory, effects of nanofillers must be perfectly harmonized to improve the properties of MFCs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41868.