Arbuscular Mycorrhizal Fungi and Plant Growth-Promoting Pseudomonads Increases Anthocyanin Concentration in Strawberry Fruits (Fragaria x ananassa var. Selva) in Conditions of Reduced Fertilization

Anthocyanins are a group of common phenolic compounds in plants. They are mainly detected in flowers and fruits, are believed to play different important roles such as in the attraction of animals and seed dispersal, and also in the increase of the antioxidant response in tissues directly or indirectly affected by biotic or abiotic stress factors. As a major group of secondary metabolites in plants commonly consumed as food, they are of importance in both the food industry and human nutrition. It is known that arbuscular mycorrhizal (AM) fungi can influence the plant secondary metabolic pathways such as the synthesis of essential oils in aromatic plants, of secondary metabolites in roots, and increase flavonoid concentration. Plant Growth-Promoting Bacteria (PGPB) are able to increase plant growth, improving plant nutrition and supporting plant development under natural or stressed conditions. Various studies confirmed that a number of bacterial species living on and inside the root system are beneficial for plant growth, yield and crop quality. In this work it is shown that inoculation with AM fungi and/or with selected and tested Pseudomonas strains, under conditions of reduced fertilization, increases anthocyanin concentration in the fruits of strawberry.     

High-frequency asymptotic formulation for prompt response of parabolic reflector antennas

This work presents some important concepts for the temporal characterization of reflector antennas based on the determination of the transient antenna response together with a useful definition of the early-time antenna radiation pattern. The concepts are useful in the analysis and design of reflector antennas intended for high resolution radars and for high capacity digital, and UWB communication systems.     

Simulation of methanol-to-olefin reaction over SAPO-34 catalysts with different particle sizes: Formation of active sites and deactivation

Conversion profiles of methanol-to-olefin (MTO) reaction over SAPO-34 catalysts with different particle sizes were simulated using two kinetic models. The MTO reaction was assumed to consist of three steps: the formation of hexamethylbenzene (HMB), the production of lower olefins over HMB and the further condensation of HMB to polyaromatic hydrocarbons. To reflect the effect of particle size on the MTO reaction, only the space near the external particle surface was considered to be available for HMB formation in Model I, whereas an effectiveness factor and a deactivation function were introduced in Model II. The simulated conversion profiles of the MTO reaction by both models successfully confirmed the presence of an induction period and deactivation, but Model II showed a better agreement between the experimental and simulated results because of its inclusion of the deactivation function and its consideration for the gradient of methanol concentration.     

Application of solvent dye in the field of biodiesel preservation

In this study, biodiesel (OSRB) from degummed oilseed radish oil (OSR) was obtained by transesterification, and the effect on its thermal stability of a binary compound containing a conventional antioxidant and a solvent dye was evaluated. A combination of the traditional antioxidant tert-butylhydroquinone (TBHQ) and a solvent dye, so-called CI Solvent Blue 35 (SB-35), was prepared and incorporated into OSR and OSRB prior to analysis. The acid value, peroxide value, and induction period were measured, and it was found that TBHQ and SB-35 were highly effective in stabilising OSR and OSRB when used in combination. The TBHQ/SB-35 blend had strong antioxidation activity, even at very low concentrations, when compared with the addition of the individual compounds. In summary, the results showed that a TBHQ/SB-35 blend may be successfully used as an alternative additive for improving oil and biodiesel preservation.     

Addition of α‐tocopherol on poly(lactic acid): Thermal,mechanical, and sorption properties

This work investigates the effect of the addition of a well‐known antioxidant, α‐tocopherol in poly (lactic acid) flexural and barrier properties. For that purpose, films of poly(lactic acid) enriched with 0, 2.2, and 4.4% of α‐tocopherol were prepared. Differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis were used to characterize the changes in the mechanical and thermal properties. The sorption of oxygen and carbon dioxide in the prepared enriched films of poly(lactic acid) was measured at different temperatures between 283 and 313 K and pressures up to atmospheric pressure using a Quartz Crystal Microbalance. Although no significant changes were found in the mechanical and thermal properties, the addition of α‐tocopherol promotes an increasing in the oxygen sorption and the convex shape of the isotherms indicate a strong interaction gas‐polymer. Regarding the sorption of carbon dioxide, no pronounced effect was found. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Eupafolin,a flavonoid isolated from Artemisia princeps,induced apoptosis in human cervical adenocarcinoma HeLa cells

Although eupafolin, a flavone found in Artemisia princeps Pampanini, has been shown to inhibit the growth of several human cancer cells, its mode of action is poorly understood. In this study, we investigated the pro‐apoptotic activities of eupafolin in human cervical carcinoma HeLa cells. It was found that eupafolin induced apoptosis in a dose‐dependent manner, as evidenced by DNA fragmentation and the accumulation of positive cells for annexin V. In addition, eupafolin triggered the activations of caspases‐3, ‐6, ‐7, ‐8, and ‐9 and the cleavages of their substrates, such as, poly (ADP‐ribose) polymerase and lamin A/C. Furthermore, treatment with eupafolin resulted in a loss of mitochondrial membrane potential (ΔΨ_m), increased the release of cytochrome c to the cytosol, and altered the expression levels of B‐cell lymphoma 2 (Bcl‐2) family proteins. Interestingly, caspase‐8, an initiator caspase, was activated after the loss of ΔΨ_m and the activations of caspases‐3 and ‐9. Moreover, treatment with z‐DEVD‐fmk (a specific caspase‐3 inhibitor) and the overexpression of Bcl‐2 prevented eupafolin‐stimulated caspase‐8 activation. Altogether, these results suggest that the eupafolin‐induced apoptosis in HeLa cells is mediated by caspase‐dependent pathways, involving caspases‐3, ‐9, and ‐8, which are initiated by the Bcl‐2‐dependent loss of ΔΨ_m.     

Photon and fast neutron dosimetry using aluminium oxide thermoluminescence dosemeters

Al(2)O(3):Mg,Y thermoluminescence (TL) dosemeters were used to measure photon and fast neutron doses in a fast neutron beam recently implemented at the Portuguese Research Reactor, Nuclear and Technological Institute, Portugal. The activation of Al(2)O(3):Mg,Y by fast neutrons provides information about the fast neutron component by measuring the activity of the reaction products and the self-induced TL signal. Additionally, the first TL reading after irradiation determines the photon dose. The elemental composition of the dosemeters was determined by instrumental neutron activation analysis and by particle induced X-ray emission. Results demonstrate that Al(2)O(3):Mg,Y is an adequate material to discriminate photon and fast neutron fields for reactor dosimetry purposes.     

Dosimetry at the Portuguese research reactor using thermoluminescence measurements and Monte Carlo calculations

This work presents an extensive study on Monte Carlo radiation transport simulation and thermoluminescent (TL) dosimetry for characterising mixed radiation fields (neutrons and photons) occurring in nuclear reactors. The feasibility of these methods is investigated for radiation fields at various locations of the Portuguese Research Reactor (RPI). The performance of the approaches developed in this work is compared with dosimetric techniques already existing at RPI. The Monte Carlo MCNP-4C code was used for a detailed modelling of the reactor core, the fast neutron beam and the thermal column of RPI. Simulations using these models allow to reproduce the energy and spatial distributions of the neutron field very well (agreement better than 80%). In the case of the photon field, the agreement improves with decreasing intensity of the component related to fission and activation products. (7)LiF:Mg,Ti, (7)LiF:Mg,Cu,P and Al(2)O(3):Mg,Y TL detectors (TLDs) with low neutron sensitivity are able to determine photon dose and dose profiles with high spatial resolution. On the other hand, (nat)LiF:Mg,Ti TLDs with increased neutron sensitivity show a remarkable loss of sensitivity and a high supralinearity in high-intensity fields hampering their application at nuclear reactors.     

Degradation behavior of hydrophilized PLGA scaffolds prepared by melt-molding particulate-leaching method: Comparison with control hydrophobic one

Porous PLGA/PVA scaffolds as hydrophilized PLGA scaffolds for tissue engineering applications were fabricated by a novel melt-molding particulate leaching method (non-solvent method). The prepared scaffolds exhibited highly porous and open-cellular pore structures with almost same surface and interior porosities (pore size, 200–300 μ m; porosity, about 90%). The in vitro degradation behavior of the PLGA and PLGA/PVA scaffolds was compared at 37^∘C in PBS (pH 7.4) with and without the solution change everyday to see the effect of solution pH as well as scaffold hydrophilicity on the degradation behavior. The changes in dimension, molecular weight, mechanical properties (maximum load and modulus), and morphology of the scaffolds were examined with degradation time. The degradation behavior of the PLGA and PLGA/PVA scaffolds was further investigated in vivousing a rat model (subcutaneously implantation). It was observed that both PLGA and PLGA/PVA scaffolds in decreasing pH condition (PBS no change) showed faster degradation than those in constant pH condition (PBS change everyday), owing to the enhanced intramolecular depolymerization by the increment of chain hydrophilicity caused by carboxylate groups as well as the autocatalysis of carboxylic acids accumulated in the solution by the cleavage of PLGA backbone ester bonds. The scaffolds in vivo condition also showed faster degradation than those in vitro, probably due to the aid of foreign body giant cells or enzymes. The PLGA/PVA scaffold showed slightly faster degradation than the PLGA scaffold for both in vitro and in vivo conditions. Author to whom all correspondence should be addressed.     

Scientific and technological fundamentals for the development of the controlled short-circuiting MIG/MAG welding process: a review of the literature. Part 2 of 3. Metal droplet formation,shield gases,penetration mechanisms,heat input and economical aspects

The second part of this series deals with the metal transfer modes of most interest to the MIG/MAG process, regarding the development of the controlled short-circuiting MIG/MAG welding process (CCC). The primary intention is to study pulsed arc and short-circuiting arc welding, both of which are the basis for the CCC. Also in relation to the metal transfer dynamics, the drop formation and the forces acting on it are reviewed. To provide a more complete understanding, aspects regarding shielding gases are described, including economic issues. Since they are important characteristics for any weld, information concerning short-circuiting MIG/MAG welding penetration and heat input are also provided.