Supercritical carbon dioxide extraction of pelletized Jalapeño peppers

The effects of process pressure (220–500 bar) and temperature (35–65 °C) on yield and extract quality of pelletized Jalapeño peppers (Capsicum annuum L) treated with supercritical carbon dioxide (ScCO₂) were studied. Compaction was inadequate when using whole air‐dried pepper flakes conditioned to high moisture as raw material, which resulted in high porosity pellets and low bed densities. Thus, reference pellet samples were produced from Jalapeño pepper flakes that were finely ground and conditioned to low moisture. Pressures ≥290 bar did not affect cumulative extraction of reference pellet samples at 45 °C. On the other hand, the extraction rate of reference pellet samples at 360 bar increased with process temperature, as a result of increments in solubility, improvements in mass transfer properties, and/or improvements in solute desorption from the solid matrix. With regard to pretreatment, finely ground pepper samples were extracted in half the time of reference pellets (120 versus 270 min) at 360 bar and 45 °C; increasing sample moisture prior to pelletization increased extraction yield; and decreasing particle size prior to pelletization increased extraction rate slightly. These results suggest that sample moisture is partially co‐extracted by ScCO₂, and that the extraction rate of pelletized Jalapeño peppers is controlled by internal mass transfer mechanisms. Chlorophyllian pigments were removed in the final stages of the extraction process. Furthermore, pigment extraction increased with process pressure at 45 °C, and it increased slightly with process temperature at 360 bar. On the other hand, the concentration of capsaicinoids in extract samples remained constant during ScCO₂ extraction. Copyright © 2003 Society of Chemical Industry     

Can positive emotion influence problem-solving attitudes among suicidal adults?

A client's mood can hinder or enhance treatment and its effectiveness. Positive emotions can encourage exploration and experimentation, and they may have the long-term effect of resource building. The purpose of the present study was to assess this perspective as applied to the treatment of suicidal individuals. The authors found that patients prone to positive moods, as compared with those less prone to such moods, displayed more positive problem-solving attitudes following treatment for suicidal symptoms, and, partly as a function thereof, displayed enhanced treatment response. These findings suggest that clinicians may improve their chances of achieving successful treatment outcomes if they present skill-building treatments during windows of positive mood for the client, rather than in times of crisis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Patterns of hemispheric perceptual asymmetries: Left hemispatial biases predict changes in anxiety and positive affect in undergraduate women.

Consistent with the tripartite model of anxiety and depression, hemispheric asymmetries may be differentially associated with depressive and anxious symptoms. Indeed, research has demonstrated that asymmetries do exist when examining hernispatial biases in both anxious and depressed individuals; however, the magnitude and direction of these asymmetries has been variable. The Chimeric Faces Task was used here to measure these asymmetries, along with measures for current and future levels of anxiety and depression. Results indicated that (a) increased left hemispatial biases at Time 1 predict increased anxiety (i,e., physiological hyperarousal) at Time 2 among 63 female undergraduate students (aged 18-47 yrs) and (b) decreased left hernispatial biases at Time 1 predict decreased positive affectivity at Time 2 among the same participants. The possibility that hemispatial biases represent a vulnerability to future anxiety and depression is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Correlation analysis between phenolic levels of Brazilian propolis extracts and their antimicrobial and antioxidant activities

Propolis extracts are currently used for the treatment of oronasal infections and as antioxidant agents. Ethanolic commercial Brazilian propolis extracts were assayed for their ability to inhibit the growth of Staphylococcus aureus and also for their ability to scavenge DPPH radicals. These activities were correlated with their total phenolic and flavonoid levels. In one group of extracts there was a strong linear relationship between total phenol contents and the measured activities, while in the other group this relationship was weaker. It was also found that flavonoid levels had a greater influence on the antioxidant activity of these extracts than on their antimicrobial profiles.     

Interference risk and the function of dynamic shifts in calling in the gray treefrog (Hyla versicolor).

Male gray treefrogs call to attract females under challenging acoustic conditions. At higher chorus densities, there is considerable background noise and a good chance that a male's calls will often be overlapped by calls of other individuals. Call overlap may reduce the probability of mating because females prefer calls with internal pulse structure that is not obscured. With increases in acoustic stimulation, males lengthen call duration while simultaneously reducing call rate such that "pulse effort" changes little. In our study, we tested the "interference risk hypothesis." This proposes that males change call duration so that, on average, there will be a sufficient number of pulses and interpulse intervals clear of acoustic interference per call to attract a female. However, female choice experiments employing call alternatives of different durations, rates, intensity levels, and degrees of call overlap refuted this hypothesis. Our results leave open the possibilities that the dynamic shift in the two components of pulse effort are related to the problem of call detection in a noisy environment or are responses by males to the perceived threat of competition for females. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ordered arrays of polymeric nanopores by using inverse nanostructured PTFE surfaces

We present a simple, efficient, and high-throughput methodology for the fabrication of ordered nanoporous polymeric surfaces with areas in the range of cm(2). The procedure is based on a two-stage replication of a master nanostructured pattern. The process starts with the preparation of an ordered array of poly(tetrafluoroethylene) (PTFE) free-standing nanopillars by wetting self-ordered porous anodic aluminum oxide templates with molten PTFE. The nanopillars are 120?nm in diameter and approximately 350?nm long, while the array extends over cm(2). The PTFE nanostructuring process induces surface hydrocarbonation of the nanopillars, as revealed by confocal Raman microscopy/spectroscopy, which enhances the wettability of the originally hydrophobic material and facilitates its subsequent use as an inverse pattern. Thus, the PTFE nanostructure is then used as a negative master for the fabrication of macroscopic hexagonal arrays of nanopores composed of biocompatible poly(vinylalcohol). In this particular case, the nanopores are 130-140?nm in diameter and the interpore distance is around 430?nm. Features of such characteristic dimensions are known to be easily recognized by living cells. Moreover, the inverse mold is not destroyed in the pore array demolding process and can be reused for further pore array fabrication. Therefore, the developed method allows the high-throughput production of cm(2)-scale biocompatible nanoporous surfaces that could be interesting as two-dimensional scaffolds for tissue repair or wound healing. Moreover, our approach can be extrapolated to the fabrication of almost any polymer and biopolymer ordered pore array.     

Variation of the lipids and fatty acids in marine shrimps consumed in Venezuela

There are three marine shrimp species in the Venezuelan internal market, two of them are native species, from fisheries, Farfantapenaeus brasiliensis and Litopenaeus schmitti, and one is an exotic species and farmed, L. vannamei. The objectives of this paper were to determine the possible variation of lipid content and fatty acid composition of these species, even under different culture conditions (e.g. feed used). The lipid content in all the species are higher (5 to 10 times) that the data from previous papers deal with marine shrimps, ranged from 4.8 to 10.9%, suggesting that its impact in the human health should be reviewed. At the same time, there were detected differences between the lipid content and fatty acids composition of the species. Wild L. schmitti had the highest lipid content (10.9%), following by wild F. brasiliensis (9.0%), cultured L. schmitti (4.8% to 7.1%) and cultured L. vannamei (5.1% to 6.2%). On the other hand, L. schmitti fed on commercial feed had the highest proportion of EPA and/or DHA, following by L. vannamei fed on the experimental feed, wild L. schmitti and fed with the experimental feed and wild F. brasiliensis.     

Lithium clusters on graphene surface and their ability to adsorb hydrogen molecules

This research describes the theoretical study of the adsorption of lithium clusters on graphene and the ability to capture hydrogen molecules. The results of the studied structures showed that the [Li₁C₅₄H₁₈]⁺ system is capable of accepting three hydrogen molecules showing adsorption energies of 0.12 eV. On the other hand, it is important to note that in [Li_nC₅₄H₁₈] n = 2–6 systems, the lithium atoms that do not interact with the graphene surface, they can adsorb up to four hydrogen molecules. The [Li₆C₅₄H₁₈]4H₂ system presented a higher adsorption energy value of 0.31 eV. Finally, the Li–H₂ interactions were characterized by a NBO analysis, which showed that hydrogen atoms are the donors and lithium atoms are the acceptors.     

Perspectives on the utilization of waste fat from beef cattle and fowl for biodiesel production in Mexico

The purpose of this research was to perform a preliminary inventory of the waste fat generated from beef cattle and fowl in Mexico that could be used for biodiesel production. Additionally, the CO₂ emissions reduction that could be achieved by using the potential biodiesel to replace an energy‐equivalent amount of fossil diesel was assessed. Based on national reports for the year 2014, it was estimated that the non‐edible fat from beef cattle and fowl annually generated in Mexico is sufficient to produce 216.0 kt of biodiesel, which would furnish 8379 TJ. This amount is equivalent to 1.5% of the energy annually consumed in Mexico as fossil diesel for road transport. The potential 216.0 kt of animal fat‐based biodiesel that can be produced annually could replace 198.3 kt of fossil diesel and thus allow a reduction in the WTW (well to wheels) emissions of 592.3 kt CO₂, which represents 1.5% of the WTW CO2 emitted from the combustion of the fossil diesel used for road transportation in Mexico in the year 2014. © 2016 Society of Chemical Industry