Effect of Capsicum carotenoids on growth and aflatoxins production by Aspergillus flavus isolated from paprika and chilli

The aim of this study was to determine the effect of a carotenoid mixture (Capsantal FS-30-NT), containing capsanthin and capsorubin, on growth and aflatoxins (AF) production of AF-producing Aspergillus flavus isolates.     

Electrospun composite poly(lactic acid)/polyaniline nanofibers from low concentrations in CHCl3: Making a biocompatible polyester electro-active

Nanofibers of poly(lactic acid) (PLA) blended with polyaniline (PANi) were fabricated via electrospinning at much lower PLA concentrations (∼1wt%) in CHCl₃ than reported before using a more efficient technique of preparing the solutions. The polymer nanofibers had diameters in the range 10 nm–300 nm. Nanofibers prepared with a 3 wt% PLA/PANi solution were conducting and were used to fabricate a diode which was electrically characterized and exhibited a low turn-on voltage and a rectification ratio of 500. The device characteristics were analyzed using the standard thermionic emission model of a Schottky junction and yielded an ideality factor of 1.6 and a barrier height of 0.49 eV. Using a simple circuit, the diode was able to rectify a low frequency alternating current signal with an efficiency of 10%. The ability to engineer insulating PLA into nanofibers that are electro-active extends the range of applications of this biocompatible and biodegradable polyester to include electronic devices that have reduced toxicity.     

Optimization of the silane treatment of cellulosic fibers from eucalyptus wood using response surface methodology

Viscose cellulosic fibers from eucalyptus wood were treated with organosilanes to introduce specific functionalities on the fibers and enhance their wettability and adhesion with phenolic matrices in composites. Modeling procedures were employed to optimize the conditions of the treatments of the fibers with the silanes (3‐aminopropyl) trimethoxysilane (APS) and 3‐(2‐aminoethylamino) propyltrimethoxysilane (AAPS). The analyzed responses were relative intensities of the bands 1565/897 and 1120/897 cm⁻¹, measured by Fourier transform infrared spectroscopy, and the silicon amount incorporated into the cellulosic fibers, which was determined by energy dispersive X‐ray analysis. In addition, surface morphology of the silane treated fibers was observed using scanning electron microscopy. The treatments of the cellulosic fibers with 2.2% APS for 120 min and 1.5% AAPS for 100 min were selected as optimums. According to contact angle measurements, both treatments enhanced the wettability between the fibers and a resol‐type phenolic resin, revealing the possible use of the silane treated fibers as reinforcement in phenolic composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42157.     

Ni/Al Multilayers Produced by Accumulative Roll Bonding and Sputtering

Journal of Materials Engineering and Performance - Ni/Al multilayers are known to transform into NiAl in a highly exothermic and self-sustaining reaction. The fact that this reaction has a high...     

Investigation of carbon dioxide photoreduction process in a laboratory-scale photoreactor by computational fluid dynamic and reaction kinetic modeling

The production of solar fuels via the photoreduction of carbon dioxide to methane by titanium oxide is a promising process to control greenhouse gas emissions and provide alternative renewable fuels. Although several reaction mechanisms have been proposed, the detailed steps are still ambiguous, and the limiting factors are not well defined. To improve our understanding of the mechanisms of carbon dioxide photoreduction, a multiphysics model was developed using COMSOL. The novelty of this work is the computational fluid dynamic model combined with the novel carbon dioxide photoreduction intrinsic reaction kinetic model, which was built based on three-steps, namely gas adsorption, surface reactions and desorption, while the ultraviolet light intensity distribution was simulated by the Gaussian distribution model and Beer-Lambert model. The carbon dioxide photoreduction process conducted in a laboratory-scale reactor under different carbon dioxide and water moisture partial pressures was then modeled based on the intrinsic kinetic model. It was found that the simulation results for methane, carbon monoxide and hydrogen yield match the experiments in the concentration range of 10⁻⁴ mol·m^–3 at the low carbon dioxide and water moisture partial pressure. Finally, the factors of adsorption site concentration, adsorption equilibrium constant, ultraviolet light intensity and temperature were evaluated.     

Raft crystals of poly(isoprene)-block-poly(ferrocenyldimethylsilane) and their surface wetting behavior during melting as observed by AFM and NanoTA

We report on the morphology evolution during heating and melting of lamellar poly(isoprene)-block-poly(ferrocenyldimethylsilane) (PI₇₆-b-PFDMS₇₆) raft crystals deposited at the native oxide surface of silicon (SiO₂) or at a highly ordered pyrolytic graphite (HOPG) surface, studied by in situ temperature controlled atomic force microscopy. Crystals deposited on hydrophilic SiO₂ surfaces revealed an irreversible decrease in length at temperatures of up to tens of degrees above their expected melting temperature, while maintaining their platelet-like structure. Crystals deposited on hydrophobic HOPG surfaces initially decreased in length below their expected melting temperature, while at 120 °C and above a typical molten morphology was observed. In addition, the irreversible formation of a PI₇₆-b-PFDMS₇₆ wetting layer around the crystals was observed upon increasing the temperature. These observations in the morphological behavior upon heating emphasize the role of interfacial energy between a surface deposited block copolymer based macromolecular nanostructure and its supporting substrate.     

Epoxidation reaction of trimethylolpropane with epichlorohydrin: Kinetic study of chlorohydrin formation

The kinetics of the reaction between trimethylolpropane (TMP) and epichlorohydrin (ECH) were studied. A mechanism is proposed which involves the synthesis of chlorohydrins, a previous stage which then leads to epoxy resin formation. From this mechanism a set of three coupled non-linear differential equations, (each equation corresponds to each chlorohydrin) was derived and numerical solutions were obtained using a Monte-Carlo method. The concentrations of chlorohydrins determined by this method (41.7, 35.7, and 22.5%) compare well with the experimental GPC results (42.7, 34.7, and 22.6%). The corresponding rate constants for the formation of the chlorohydrins were obtained.     

Polypropylene/low density polyethylene blends with short glass fibers. II: Effect of compounding method on mechanical properties

Polypropylene/low density polyethylene blend matrices have been reinforced with short glass fibers in order to study their tensile, flexural, and impact behavior. Two-roll milling and twin-screw extrusion compounding methods were used to incorporate the fiber within the polymer matrices, and standard test samples were prepared by injection molding. The effects of matrix composition and fiber concentration on mechanical properties were investigated keeping in mind the matrix and fiber morphology, the latter being intimately dependent upon the compounding method employed.     

CircRNAs as Potential Blood Biomarkers and Key Elements in Regulatory Networks in Gastric Cancer

Gastric cancer (GC) is the fifth most common type of cancer and the third leading cause of cancer death in the world. It is a disease that encompasses a variety of molecular alterations, including in non-coding RNAs such as circular RNAs (circRNAs). In the present study, we investigated hsa_circ_0000211, hsa_circ_0000284, hsa_circ_0000524, hsa_circ_0001136 and hsa_circ_0004771 expression profiles using RT-qPCR in 71 gastric tissue samples from GC patients (tumor and tumor-adjacent samples) and volunteers without cancer. In order to investigate the suitability of circRNAs as minimally invasive biomarkers, we also evaluated their expression profile through RT-qPCR in peripheral blood samples from patients with and without GC (n = 41). We also investigated the predicted interactions between circRNA-miRNA-mRNA and circRNA-RBP using the KEGG and Reactome databases. Overall, our results showed that hsa_circ_0000211, hsa_circ_0000284 and hsa_circ_0004771 presented equivalent expression profiles when analyzed by different methods (RNA-Seq and RT-qPCR) and different types of samples (tissue and blood). Further, functional enrichment results identified important signaling pathways related to GC. Thus, our data support the consideration of circRNAs as new, minimally invasive biomarkers capable of aiding in the diagnosis of GC and with great potential to be applied in clinical practice.     

Effect of dietary inclusion of goat milk on the bioavailability of zinc and selenium in rats

The effects of dietary inclusion of freeze-dried goat and cow milk on the utilization of zinc and selenium, and on the metabolic fate of zinc, were studied in transected (control) and resected rats (resection of 50% of the distal small intestine). Intestinal resection reduced the apparent digestibility coefficient and zinc retention in the cow milk diet, whereas these biological indices were similar in transected (control) and resected rats with standard (without milk) and goat milk diets. The apparent digestibility coefficient and retention of selenium were not affected by intestinal resection in the animals fed with the three diets studied. In transected (control) and resected rats, the apparent digestibility coefficient and retention of zinc and selenium were higher for the goat milk diet than for the other two diets. Zinc deposits in the organs, expressed as microg/g dry weight were in order of decreasing concentrations: femur, testes, sternum, liver, kidney, heart, spleen, longissimus dorsi muscle and brain. Deposits were greatest with the goat milk diet, followed by the standard diet and were lowest for the rats given the cow milk diet, both for transected (control) and resected animals. We conclude that consumption of the goat milk diet produces a greater bioavailability of zinc and selenium and a greater deposit of zinc in key organs, for both the transected (control) and the resected rats, with respect to the standard diet and the cow milk diet.