Intrathalline Metabolite Profiles in the Lichen <Emphasis Type="Italic">Argopsis friesiana</Emphasis> Shape Gastropod Grazing Patterns

Lichen-gastropod interactions generally focus on the potential deterrent or toxic role of secondary metabolites. To better understand lichen-gastropod interactions, a controlled feeding experiment was designed to identify the parts of the lichen Argopsis friesiana consumed by the Subantarctic land snail Notodiscus hookeri. Besides profiling secondary metabolites in various lichen parts (apothecia, cephalodia, phyllocladia and fungal axis of the pseudopodetium), we investigated potentially beneficial resources that snails can utilize from the lichen (carbohydrates, amino acids, fatty acids, polysaccharides and total nitrogen). Notodiscus hookeri preferred cephalodia and algal layers, which had high contents of carbohydrates, nitrogen, or both. Apothecia were avoided, perhaps due to their low contents of sugars and polyols. Although pseudopodetia were characterized by high content of arabitol, they were also rich in medullary secondary compounds, which may explain why they were not consumed. Thus, the balance between nutrients (particularly nitrogen and polyols) and secondary metabolites appears to play a key role in the feeding preferences of this snail.     

Effect of <Emphasis Type="Italic">Punica granatum</Emphasis> peel and <Emphasis Type="Italic">Melia azedarach</Emphasis> bark extracts on durability of European beech and maritime pine

A method to improve wood durability using natural extracts was evaluated. Wood deterioration is a condition caused by several abiotic and biotic factors including fungal contamination. To date, approaches aiming at the reduction of these contaminants mainly involve the use of chemicals agents. Natural products could represent an alternative strategy. Aqueous extracts of Punica granatum L. (pomegranate) peel and Melia azedarach L. barks were evaluated as antifungal agents to improve natural durability of beech wood and maritime pine. To evaluate the effect of treatments under simulated accelerated ageing of wood by natural conditions, impregnation and leaching tests were performed. Results demonstrated that samples impregnated with pomegranate or M. azedarach solutions notably increased the biological resistance of wood in a dose-dependent manner. These results were confirmed by the reduction in weight losses in treated samples even after 6 weeks of fungal exposure. Moreover, after leaching tests, 20 and 7% (w/v) of pomegranate and M. azedarach extract solutions were demonstrated as the better concentrations to enhance wood durability. Total phenol content and characterization of the phenolic compounds in both, natural extracts and wood samples were analyzed by Folin–Ciocalteu assay and HPLC-DAD. In conclusion, it was demonstrated that the present method can be considered as an effective treatment to increase wood durability while it proposes the valorization of natural extractives in wood industry.     

Mobilization of peripheral blood progenitor cells after induction chemotherapy (THP-doxorubicin-vinorelbine-cyclophosphamide-fluorouracil) and granulocyte colony-stimulating factor in breast cancer

Fermentations of Streptomyces sp. E/784 produce low levels of the novel C-30 alkylthio-substituted ansamycin antibiotics naphthomycins J (9) and I (10), in addition to the more abundant C-30 hydroxylated analogues actamycin (1) and naphthomycin D (2) and C-30 chlorinated analogues naphthomycins H (3) and A (4). The addition of N-acetyl-L-cysteine to the fermentation medium substantially increases the production of the thionaphthomycins J and I at the expense of their chloro analogues H and A. Other thiols and thiol progenitors are similarly utilised, including N-acetyl-L-cysteine methyl ester which affords the known naphthomycin F (8) and its novel 2-demethyl homologue (7). The formation of thioansamycins from chloroansamycins and thiols in vivo is probably non-enzymic since similar conversions can be effected in vitro.     

Study of rosin softening point through thermal treatment for a better understanding of maritime pine exudation

The temperature of pine rosin softening point was studied to better understand the phenomenon of resin exudation on the surface of pine boards. This problem may decrease strongly the aesthetical performance of wood used outside and is an important concern for the industry. To perform a reliable measurement of rosin properties with a small amount of sample, differential scanning calorimetry (DSC) and thermo mechanical analysis (TMA) techniques were investigated and the results compared. DSC curves on industrial rosin and acetone rosin extractives from maritime pine show a behavior similar to a glass transition in polymers. TMA measurements carried out on the same industrial rosin showed that the softening point is in the midpoint of the transition phase observed by DSC. The softening point temperature is about 45 °C for industrial rosin and about 50 °C for rosin extractives from maritime pine boards. These values are significantly lower than those usually found on other rosins measured by the ASTM E28-14 standard using the ring-and-ball method. When using heat treatment, it was observed for the first time that the thermal history of the sample can change its softening point temperature. With these results, it could be possible to develop a new strategy to reduce rosin exudation for exterior wood siding.     

Distribution of varietal thiol precursors in the skin and the pulp of Melon B. and Sauvignon Blanc grapes

In order to examine varietal thiol precursors in both the skin and the pulp of grapes, two grape varieties, Melon B. and Sauvignon Blanc, were considered. We found that cysteinylated and glutathionylated precursors of 3-mercapto-1-hexanol and 4-methyl-4-mercapto-2-pentanone were preferentially in skin. In the Sauvignon Blanc variety, precursors were detected both in the skin and the pulp, while in Melon B., only S-3-(1-hexanol)glutathione was detected in pulp, any other precursors being exclusively found in skin. During an industrial pressing cycle, extraction of thiol precursors was enhanced at the end of the cycle (highest pressures), thus producing more varietal thiols in the resulting wines. Cold prefermentation skin contact did not influence the concentration of the measured precursors in Sauvignon Blanc must. Nevertheless, the release of thiol in resulting wines increased significantly between 1 and 7 days of cold prefermentation skin contact. This increase could be due to the formation of other thiol precursors, such as S-3-(1-hexanal)glutathione or S-3-(1-hexanal)cysteine, during prefermentative operations.     

Flow of short-glass-fiber-filled thermoplastics in channels of circular of thin rectangular cross-section

A pressure-flow-type modular rheonmeter was developed specifically for the stuidy of the flow of unfilled thermoplastic melts and for the same melts with particles of relatively large dimensions in channels of shapes and dimensions encompassing those encountered in the injections molding of commercial parts. Experimental results are reported here for the case of polypropylene with 20 and 40 percent by weight of short glass fibers. The handling of the wide range of data, suing the concept of an end correctuion(Bagley plot), led to a reasonably unique viscosity vs. Shear-rate relationship for each material and confirmed that fibers have little effect on such a relationship for the range of shear rates involved in commercial processing. End effects were examined systematically for the wide range of shear rates and geometries, and the data, although difficult to correlate at present, should prove useful to rheologists trying to elucidate the flow in such areas.     

Recovery (spring-back) of polyethylene from an imposed bend

Measurements have been made of the recovery of polyethylene samples from bending deformations of varying severity. The amount of spring-back from a severe bend is quite different for different densities (degrees of crystallinity), especially at short times after release, being much greater for lower-density polyethylenes. Short-term spring-back measurements thus afford a simple and rapid means of determining the approximate density. Immediate recovery is small, 5 to 15 percent, and is in rough accord with expectations for elastic-plastic solids. A major protracted recovery process follows. It is accelerated by raising the temperature, in reasonable agreement with the WLF relation for segmental mobility. It is therefore attributed to retarded molecular motions in the amorphous fraction. Final recovery is greater for lower-density materials, but it is incomplete even after very long times or for mild degrees of bending. Thus, some irreversible processes appear to take place, even when bending strains as low as 3 percent are imposed.     

Dimensioning a full color LED microdisplay for augmented reality headset in a very bright environment

This paper focuses on the dimensioning of a very bright full color 10 μm‐pitch light‐emitting device (LED) microdisplay for avionics application. Starting from the specifications of head‐mounted display to be used in an augmented reality optical system, a theoretical approach is proposed that enables predicting the specifications of the main technology building blocks entering into the microdisplay manufacturing process flow. By taking into account various material and technological parameters, kept as realistic as possible, it is possible to assess the feasibility of a very bright LED microdisplay (1 Mcd/m² full white) and to point out the main limitations. The theoretical specifications are then compared with the technical results obtained so far in the framework of the H2020 Clean Sky “HILICO” project. It shows that 350 000 cd/m² of white emission may be accessible with the present gallium nitride (GaN)‐micro‐LED technology provided a color conversion solution with stable external quantum efficiency of 30% is available. Beyond such level of luminance, the inherent limitations of driving circuit (4 V, 15 μA per pixel) commands working with materials enabling higher external quantum efficiency (EQE). In particular, 10‐μm‐pitch micro‐LEDs with electroluminescence EQE of 15% and color conversion EQE approaching 60% are needed, opening the way to future challenging material and technology research developments.