Phenolic extracts of cachaça aged in different woods and quantifying antioxidant activity and antifungal properties

The antioxidant and antifungal activities of the phenolic compounds in different alcoholic extracts of aged cachaça were evaluated. The physico‐chemical analyses were performed in the Laboratório de Qualidade de Aguardente of the Universidade Federal de Lavras according to the methods of the Ministério Agricultura Pecuária e abastecimento. Total phenol content was determined by the Folin–Ciocalteu method, quantification of these compounds was performed by HPLC and antioxidant activities were determined by methods involving inhibition of the DPPH (1,1‐diphenyl‐2 picrylhydrazyl) radical, the β‐carotene/linoleic acid system, ABTS (2,2 azinobis‐[3‐ethyl‐6‐benzothiazolinesulfonic acid]) radical, reducing power and thiobarbituric acid. Determination of antifungal activity was accomplished through the technique of dissemination in discs using Aspergillus carbonarius, Aspergillus niger, Aspergillus flavus, Penicillium commune and Penicillium cladosporoides fungi at the Laboratório de Micologia de Alimentos. The values obtained for the phenolic compounds ranged from 0.41 to 9.69 mg L^?1; syringaldehyde, vanillic acid and gallic acid were predominant. A satisfactory antioxidant activity was observed in all of the tests with the alcoholic extracts. A moderate activity against P. commune and P. cladosporoides, but no inhibition of the growth of A. carbonarius, A. niger or A. flavus was observed. Copyright © 2016 The Institute of Brewing & Distilling     

Influence of processing on the antioxidant capacity and bioactive compounds in jellies from different blackberry cultivars

The effect of thermal processing and the berry cultivar has been the subject of several studies, to serve as a basis for the least possible loss of bioactive compounds and antioxidant capacity. In Brazil, there are numerous blackberry cultivars under cultivation, and in this context, the aim of this work was to study how the bioactive compound contents and antioxidant capacity of blackberry jelly were influenced by the cultivars (Guarani, Brazos, Comanche, Tupy, Cherokee, Caingangue and Choctaw). Analysis was made of 7 fresh blackberry cultivars and 7 blackberry jelly formulations. Analysis of antioxidant activity, total phenolics, total anthocyanins and ascorbic acid was performed. It was verified that the contribution of the heat sensitive antioxidants compounds is considerable in all blackberry cultivars, and the degradation of these compounds was significantly different between the different blackberry cultivars. The Brazos and Caingangue cultivars stand out as undergoing the lowest losses in processing, resulting in jellies richer in bioactive compounds and higher antioxidant capacity.     

Effects of supercritical and liquid carbon dioxide extraction on hemp (Cannabis sativa L.) seed oil

The increase in the popularity of hemp-based products is mainly linked to the presence of non-psychoactive cannabinoids that provide relief from aches, pain and anxiety. In this study, hemp seed oils were produced by two innovative and environmentally friendly extraction techniques: supercritical and liquid carbon dioxide (CO₂) extraction. The chemical composition of the two oils was analysed and compared with that of a control oil obtained by solvent (n-hexane) extraction. Both oils obtained by liquid and supercritical CO₂ extraction presented interesting compositions: they contained large amounts of cannabinoids, polyphenols and tocopherols and were less oxidised than the control and contained a large amount of hexanal, which provided a pleasant aroma. The maximum cannabinoid content was found in the oil obtained by liquid CO₂ extraction (71.51 mg of cannabidiol per kg of oil and 113.92 mg of cannabinol per kg of oil). Carotenoids were prevalent in the oil obtained by supercritical CO₂ extraction (61.00 mg kg⁻¹ of oil).     

Sorption behavior of the MgH2–Mg2FeH6 hydride storage system synthesized by mechanical milling followed by sintering

The hydrogen sorption behavior of the Mg₂FeH₆–MgH₂ hydride system is investigated via in-situ synchrotron and laboratory powder X-ray diffraction (SR-PXD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), particle size distribution (PSD) and volumetric techniques. The Mg₂FeH₆–MgH₂ hydride system is obtained by mechanical milling in argon atmosphere followed by sintering at high temperature and hydrogen pressure. In-situ SR-PXD results show that upon hydriding MgH₂ is a precursor for Mg₂FeH₆ formation and remained as hydrided phase in the obtained material. Diffusion constraints preclude the further formation of Mg₂FeH₆. Upon dehydriding, our results suggest that MgH₂ and Mg₂FeH₆ decompose independently in a narrow temperature range between 275 and 300 °C. Moreover, the decomposition behavior of both hydrides in the Mg₂FeH₆–MgH₂ hydride mixture is influenced by each other via dual synergetic-destabilizing effects. The final hydriding/dehydriding products and therefore the kinetic behavior of the Mg₂FeH₆–MgH₂ hydride system exhibits a strong dependence on the temperature and pressure conditions.     

Thymus Extracellular Matrix-Derived Scaffolds Support Graft-Resident Thymopoiesis and Long-Term In Vitro Culture of Adult Thymic Epithelial Cells

The thymus provides the physiological microenvironment critical for the development of T lymphocytes, the cells that orchestrate the adaptive immune system to generate an antigen-specific response. A diverse population of stroma cells provides surface-bound and soluble molecules that orchestrate the intrathymic maturation and selection of developing T cells. Forming an intricate 3D architecture, thymic epithelial cells (TEC) represent the most abundant and important constituent of the thymic stroma. Effective models for in and ex vivo use of adult TEC are still wanting, limiting the engineering of functional thymic organoids and the understanding of the development of a competent immune system. Here a 3D scaffold is developed based on decellularized thymic tissue capable of supporting in vitro and in vivo thymopoiesis by both fetal and adult TEC. For the first time, direct evidences of feasibility for sustained graft-resident T-cell development using adult TEC as input are provided. Moreover, the scaffold supports prolonged in vitro culture of adult TEC, with a retained expression of the master regulator Foxn1. The success of engineering a thymic scaffold that sustains adult TEC function provides unprecedented opportunities to investigate thymus development and physiology and to design and implement novel strategies for thymus replacement therapies.     

Assessment of Microvessel Permeability in Murine Atherosclerotic Vein Grafts Using Two-Photon Intravital Microscopy

Plaque angiogenesis and plaque hemorrhage are major players in the destabilization and rupture of atherosclerotic lesions. As these are dynamic processes, imaging of plaque angiogenesis, especially the integrity or leakiness of angiogenic vessels, can be an extremely useful tool in the studies on atherosclerosis pathophysiology. Visualizing plaque microvessels in 3D would enable us to study the architecture and permeability of adventitial and intimal plaque microvessels in advanced atherosclerotic lesions. We hypothesized that a comparison of the vascular permeability between healthy continuous and fenestrated as well as diseased leaky microvessels, would allow us to evaluate plaque microvessel leakiness. We developed and validated a two photon intravital microscopy (2P-IVM) method to assess the leakiness of plaque microvessels in murine atherosclerosis-prone ApoE3*Leiden vein grafts based on the quantification of fluorescent-dextrans extravasation in real-time. We describe a novel 2P-IVM set up to study vessels in the neck region of living mice. We show that microvessels in vein graft lesions are in their pathological state more permeable in comparison with healthy continuous and fenestrated microvessels. This 2P-IVM method is a promising approach to assess plaque angiogenesis and leakiness. Moreover, this method is an important advancement to validate therapeutic angiogenic interventions in preclinical atherosclerosis models.     

Poly(hydroxybutyrate-co-hydroxyvalerate) microspheres loaded with atrazine herbicide: screening of conditions for preparation,physico-chemical characterization,and in vitro release studies

Due to their widespread use in agriculture as well as in urban areas, agricultural chemicals are globally some of the most commonly encountered substances in waters. The objective of this study is to develop (including preparation and characterization) a new modified release system for the herbicide atrazine, employing poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) microspheres. The microspheres were prepared by the emulsification/solvent evaporation method, emulsifying an organic phase (atrazine and PHBV dissolved in chloroform) into an aqueous phase containing polyvinyl alcohol (PVA) as surfactant, under stirring, and then evaporating the solvent. A 2^4-1 fractional factorial design, investigating the influence of four variables at two levels, was performed to obtain formulations with optimized association efficiencies. There was a greater dependence of association efficiency on PVA concentration (negative) and the mass of polymer (positive) with lesser influence of both stirring speed and organic phase volume. The size of the particles was assessed using scanning electron microscopy, which showed that the particles were rough-surfaced spheres. The results obtained are promising, since the formulations presented encapsulation efficiency near 25% and the release kinetics profile of atrazine was altered when it was encapsulated in the microparticles, indicating that these systems may be efficient in reducing the environmental impact caused by the herbicide, hence making it safer to use.     

Protein adsorption on titanium dioxide: Effects on double layer and semiconductor space charge region studied by EIS

The semiconductor properties of an n-type TiO₂ oxide surface and its modification by protein adsorption using electrochemical impedance spectroscopy (EIS) were studied. Impedance spectra under steady state conditions were obtained as a function of electrode potential and human serum albumin (HSA) concentration in solution. The effect of the adsorption potential on the EIS response was also analyzed (E_ads −0.70, −0.50 and −0.080 V vs. saturated calomel electrode). The impedance spectra were modeled using different equivalent circuits, and data analysis were performed by data fitting in the whole frequency range, as well as in the low and high frequency ranges. The electric representation that better fit experimental data consisted of two equivalent subcircuits composed by a combination of constant phase elements (cpe₁ and cpe₂) and resistances (R_s and R₁). The cpe₁ element represented the distributed capacity in the semiconductor oxide. The cpe₂ element was associated with diffusional processes. We have analyzed EIS data based on a theoretical calculation of interface apparent capacitance (C_app) from the cpe₁ parameters (Q₁ and ?₁) and resistance elements. The changes in capacitance, produced by the presence of HSA, were associated to changes in the space charge layer capacitance of the semiconductor, as a result of the energy band bending near the surface. The values obtained for the R₁ element from the theoretical fitting procedures (in the high and whole frequency range) were correlated to the electric resistance inherent to the semiconductor properties having a value of 6.10³ Ω cm².     

Photoluminescent and antimicrobial properties of silver-doped indium hydroxide synthesized by one-step microwave-assisted hydrothermal method

Silver-doped indium hydroxide In_(1-x)(OH)₃:_xAg (with x = 0, 1, 2, 4, and 8 mol%) of Ag nanoparticles were synthesized by the microwave-assisted hydrothermal (MAH) method at 140°C for 30 minutes. These nanoparticles were characterized by X-ray diffraction (XRD), fourier transformed infrared (FT-IR) spectroscopy, and optical diffuse reflectance. Photoluminescence (PL) spectra were acquired with a 350 nm beam of a krypton ion laser as an excitation source. The antibacterial activities of the samples were evaluated against gram negative Escherichia coli bacteria and gram positive Staphylococcus aureus bacteria using the disc diffusion method. The results showed that all diffraction peaks present in XRD patterns could be indexed to the cubic lattice related to the In(OH)₃ phase. Broadband photoluminescence behavior in visible range spectra was observed for all samples with a maximum peak centered in the blue and green regions. The antibacterial activities showed that In_(1-x)(OH)₃: _xAg nanoparticles have a promising bactericide that can be used for deactivating microbes.     

Local boron environment in B-doped nanocrystalline diamond films

Thin films of heavily B-doped nanocrystalline diamond (B:NCD) have been investigated by a combination of high resolution annular dark field scanning transmission electron microscopy and spatially resolved electron energy-loss spectroscopy performed on a state-of-the-art aberration corrected instrument to determine the B concentration, distribution and the local B environment. Concentrations of ～1 to 3 at.% of boron are found to be embedded within individual grains. Even though most NCD grains are surrounded by a thin amorphous shell, elemental mapping of the B and C signal shows no preferential embedding of B in these amorphous shells or in grain boundaries between the NCD grains, in contrast with earlier work on more macroscopic superconducting polycrystalline B-doped diamond films. Detailed inspection of the fine structure of the boron K-edge and comparison with density functional theory calculated fine structure energy-loss near-edge structure signatures confirms that the B atoms present in the diamond grains are substitutional atoms embedded tetrahedrally into the diamond lattice.