Packaging materials with tailor made light transmission properties for food protection

Packaging material with optimal light barrier properties can prevent food quality deterioration. For dairy products, wavelength in the visible region between 400–450 nm and 600–650 nm should be blocked out due to the content of chlorophyll in dairy products. Six low density polyethylene blown films were formulated with the combination of four different pigments and additives: green, yellow, silver additive, and optical brightener, in addition to four reference samples. All films were transparent. Optical properties and light transmission were measured for each film, and microscopy analyses were used to investigate the surface topography. The sample containing high concentration of both green and yellow pigments had the lowest value in gloss and transmittance. This film blocked the light below 450 nm and transmitted 10% at 600–650 nm. Optical brightener had an effect only on visual appearance but not on light transmission properties. Samples containing silver additive were more intense green and gave a higher light transmission in blue region (380–500 nm) and lower in red region (600–700 nm) compared with samples without silver additive. These developed films can be applied in dairy products and other food products in the future. POLYM. ENG. SCI., 52:2015–2024, 2012. © 2012 Society of Plastics Engineers     

Effects of orally administered yeast‐derived beta‐glucans: A review

Yeast‐derived beta‐glucans (Y‐BG) are considered immunomodulatory compounds suggested to enhance the defense against infections and exert anticarcinogenic effects. Specific preparations have received Generally Recognized as Safe status and acceptance as novel food ingredients by European Food Safety Authority. In human trials, orally administered Y‐BG significantly reduced the incidence of upper respiratory tract infections in individuals susceptible to upper respiratory tract infections, whereas significant differences were not seen in healthy individuals. Increased salivary IgA in healthy individuals, increased IL‐10 levels in obese subjects, beneficial changes in immunological parameters in allergic patients, and activated monocytes in cancer patients have been reported following Y‐BG intake. The studies were conducted with different doses (7.5–1500 mg/day), using different preparations that vary in their primary structure, molecular weight, and solubility. In animal models, oral Y‐BG have reduced the incidence of bacterial infections and levels of stress‐induced cytokines and enhanced antineoplastic effects of cytotoxic agents. Protective effects toward drug intoxication and ischemia/reperfusion injury have also been reported. In conclusion, additional studies following good clinical practice principles are needed in which well‐defined Y‐BG preparations are used and immune markers and disease endpoints are assessed. Since optimal dosing may depend on preparation characteristics, dose‐response curves might be assessed to find the optimal dose for a specific preparation.     

Proton exchange membrane water electrolysis with short-side-chain Aquivion membrane and IrO2 anode catalyst

A series of three membrane types has been screened for medium temperature solid polymer electrolyte water electrolysis in membrane electrode assemblies coated with 2 mg cm⁻² of iridium oxide as a catalyst for the oxygen evolution reaction, synthesised via a hydrolysis method from the hexachloroiridic acid precursor, and deposited on the membrane either directly by spray deposition or by decal transfer. The short-side-chain perfluorosulfonic acid Aquivion^® ionomer of equivalent weight 870 meq g⁻¹, in membranes of thickness 120 μm, gives higher water electrolysis performance at 120 °C than a composite membrane of Aquivion^® with zirconium phosphate, while a sulfonated ether-linked polybenzimidazole, sulfonated poly-[(1-(4,4′-diphenylether)-5-oxybenzimidazole)-benzimidazole], shows promising performance and no transport limitations up to 2 A cm⁻². The lowest cell voltage was observed at 120 °C for an MEA prepared using spray-coating directly on the Aquivion^® membrane, 1.57 V at 1 A cm⁻².     

Fatigue assessment of as‐built and heat‐treated Inconel 718 specimens produced by additive manufacturing including notch effects

The fatigue behaviour of notched and unnotched specimens produced by additively manufactured Inconel 718 were analysed in the as‐built and heat‐treated conditions. The surfaces display high roughness and defects acting as fatigue initiation sites. In the as‐built condition, fine subgrains were found, while in in the heat‐treated state, the subgrains were removed and the dislocation density recovered. SN‐curves are predicted based on tensile properties, hardness and defects obtained by fractography, using the ‐method.     

Nested PCR assay for detection of granulocytic ehrlichiae

A sensitive and specific nested PCR assay was developed for the detection of granulocytic ehrlichiae. The assay amplifies the 16S rRNA gene and was used to examine acute-phase EDTA-blood and serum samples obtained from seven humans with clinical presentations compatible with human granulocytic ehrlichiosis. Five of the seven suspected cases were positive by the PCR assay using DNA extracted from whole blood as the template, compared with a serologic assay that identified only one positive sample. The PCR assay using DNA extracted from the corresponding serum samples as the template identified three positive samples. The sensitivity of the assay on human samples was examined, and the limit of detection was shown to be fewer than 2 copies of the 16S rRNA gene. The application of the assay to nonhuman samples demonstrated products amplified from template DNA extracted from Ixodes scapularis ticks collected in Rhode Island and from EDTA-blood specimens obtained from white-tailed deer in Maryland. All PCR products were sequenced and identified as specific to granulocytic ehrlichiae. A putative variant granulocytic ehrlichia 16S rRNA gene sequence was detected among products amplified from both the ticks and the deer blood specimens.     

A semi-empirical model for stress relaxation including primary and secondary creep stages

A universal creep law which incorporates both primary and secondary creep has been used to develop a semi-empirical model for stress relaxation. The modelling was performed by comparing computer simulated relaxation curves with experimental data. Contrary to most models for stress relaxation, the results indicate that relaxation life should be divided into two stages, a primary stage with increasing internal stress and a secondary stage during which the internal stress falls as the applied stress decreases.     

Potential for nitrate—N loss in central Alberta soils

Incubation experiments were conducted to determine the influence of soil type, soil depth and tillage-straw treatment on the capacity for NO₃-N loss under anaerobic incubation. In Experiment 1 with 14 cultivated surface soil samples, there were substantial NO₃-N losses in all soils regardless of the total organic carbon content. The total organic carbon content of these soils ranged from 21 to 55 g C kg^–1. Experiment 2 showed that the rate of NO₃-N loss decreased with depth of soil, but when glucose was added the rate of NO₃-N loss increased markedly and all of the added NO₃-N disappeared within less than a week. In Experiment 3, the soil under zero tillage where straw was retained gave slightly higher rate of NO₃-N loss than the soil from conventional tillage treatment. (Scientific Paper No. 628)     

Advances in ophthalmological photodynamic therapy

Photodynamic therapy is a new experimental therapeutic technique which is attracting increasing attention. Its biopharmacological basis of action is the specific interaction of a photosensitizing compound with the cellular elements of pathological lesions. The photosensitizer is thought to enter specifically into the pathologic cells, where it accumulates. The lesion is then irradiated with a sensitizing laser-beam of specific wave-length to activate the photosensitizer, which then becomes a generator of free oxygen radicals. These radicals destroy the sensitizer-harboring pathological cells. The advantage of specifically destroying pathological lesions without affecting surrounding normal tissue is obvious. Recently, many experimental studies have been conducted to test the usefulness of photodynamic therapy for ocular disorders, mainly advanced age-related macular degeneration and uveal melanoma. Results so far are encouraging.