Ionic behavior assessment of surface-active compounds from corn steep liquor by exchange resins

Depending on their ionic nature, biosurfactants can be classified as nonionic, anionic, cationic, or amphoteric. The ionic behavior of biosurfactants is an important characteristic that dictates their use in industrial applications. In this work, a biosurfactant extract obtained from corn steep liquor was subjected to anionic or cationic resins, in order to study the ionic behavior under different operational conditions using response surface methodology. The independent variables included in the study are the dilution of biosurfactant solution, the amount of cationic or anionic resin, and the extraction time, whereas the dependent variables studied consisted of the surface tension of biosurfactant aqueous solution, after contacting with anionic or cationic resin. The results showed that biosurfactant extracted from corn steep liquor is amphoteric, since both resins were able to entrap this biosurfactant, making it particularly suited for use in personal care preparations for sensitive skin.Peer ReviewedPostprint (author's final draft

Evolution of Cluster Ellipticals at 0.2 < z < 1.2 from Hubble Space Telescope Imaging

Two-dimensional surface photometry derived from Hubble Space Telescope imaging is presented for a sample of 225 early-type galaxies (assumed to be cluster members) in the fields of 9 clusters at redshifts $0.17 < z < 1.21$. The 94 luminous ellipticals ($M_{AB}(B)<-20$; selected by morphology alone with no reference to color) form tight sequences in the size-luminosity plane. The position of these sequences shifts, on average, with redshift so that an object of a given size at z=0.55 is brighter by $\Delta M(B)=-0.57 \pm 0.13$ mag than its counterpart (measured with the same techniques) in nearby clusters. At z=0.9 the shift is $\Delta M(B)=-0.96 \pm 0.22$ mag. If the relation between size and luminosity is universal so that the local cluster galaxies represent the evolutionary endpoints of those at high redshift, and if the size-luminosity relation is not modified by dynamical processes then this population of galaxies has undergone significant luminosity evolution since z=1 consistent with expectations based on models of passively evolving, old stellar populations.Comment: 7 pages, 3 figures, and 1 Tabl

Antimicrobial study of biosurfactants from Lactobacillus strains against skin pathogens

[Excerpt] Human skin microflora is composed by resident1 temporarily resident and transient microbial species. Therefore, gram-positive bacteria from the genera Propionibacterium, Staphylococcus, Micrococcus, Corynebaderium and Acinetobacter are the majority microorganisms present in the resident microflora [1 ]. For instance, Staphylococcus epidermidis is the main constituent of skin microflora, which protects the human skin from infections; whereas Staphylococcus aureus is a common transient species, which causes skin infections [2]. Anti-bacterial preservatives such as triclosan, methylparaben or bronopol, among others, are currently used as ingredients in the skin and oral care cosmetic products. However, there is a growing demand for cosmetics free of synthetic preservatives [3]. In this sense, biosurfactants from lactic acid bacteria, which are generally recognized as safe by the American Food and Drug Administration, are natural compounds that exhibit antimicrobial activity and therefore, could be used as an alternative to the chemically synthetized preservatives. The aim of this study was to evaluate the antimicrobial activity of biosurfactants obtained from two different Lactobacillus strains (L. pentosus and L. paracasef) against skin pathogenic microorganisms. [...]Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BI0/04469/2013 unit, COMPETE 2020 (POCl-01-0145-FEDER-006684) and the project RECl/BBB-EBl/0179/2012 (FCOMP-01-0124-FEDER-027462

New approach on the bioconversion of vineyard pruning waste into surface-active compounds by Lactobacillus paracasei

Strategic funding of UID/BIO/04469/2013 unit and project ref RECI/BBB-EBI/0179/2012 (project number FCOMP-01-0124-FEDER-027462) and Xanel Vecino post-doctoral grant (ref SFRH/BPD/101476/2014) funded by Fundação para a Ciência e a Tecnologia, Portuga

Potential applications of multifunctional extract obtained from corn industry in food packaging

[Excerpt] Nowadays, in the food industry exists an increased demand, by the consumers, of natural additives that can replace those chemical additives obtained from non renewable resources. In this work extracts with surfactant and antioxidant properties were obtained from corn steep liquor (CSl) with potential applications in food packaging. the extraction process was carried out using ethyl acetate and the operational conditions consisted of: CSl/ethyl acetate 1:3 (v/v), at 25°C during 45 min with agitation system at 150 rpm. the antioxidant activity of the extract was determined by the dPPh (2,2-diphenyl-1-picrylhydrazyl) radical scavenging method; whereas the surface active properties was evaluated by the wilhelmy plate method in a force tensiometer with a platinum plate (easy dyne k20, kruSS gmbh), at room temperature. Fatty acid composition of extract was analyzed by gas chromatography coupled to a mass spectrometer (Bruker Scion 451-gC). [...

The influence of the medium composition on the biosurfactants produced by Lactobacillus paracasei

[Excerpt] Lactic acid bacteria is an interesting group of microorganisms for the production of biosurfactants. In addition, these bacteria are generally recognized as safe by the American Food and Drug Administration. An example is the Lactobacil/us paracasei that was isolated from a Portuguese dairy industry and has been previously reported by Gudina and collaborators [1] forthe production of biosurfactants.The biosurfactants produced by LAB are cell-bound biosurfactants contrarily to the most well-known extracellular biosurfactants produced by Pseudomonas or Bacillus species. The main bottleneck of their industrial production and application is related with the production and recovery costs. Therefore, many studies are focusing on the use of renewable agroindustrial wastes as carbon sources in the fermentative processes [2]. The aim of this work was the production and characterization of biosurfactants by L. paracasei using a lignocellulosic residue (vineyard pruning waste) as carbon source. The vineyard pruning waste was subjected to a fractionation process to obtain cellulose, which was next submitted to a saccharification step with enzymes in order to convert cellulose in a glucose-based fermentation media. Once this glucose solution was obtained, it was further supplemented with 1 O g/L of yeast extract and 1 O g/L of corn steep liquor. [...]Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BI0/04469/2013 unit, COMPETE 2020 (POCl-01-0145-FEDER-006684) and the project RECl/BBB-EBl/0179/2012 (FCOMP-01-0124-FEDER-02746

Testing models with non-minimal Higgs sector through the decay t->q+WZ

We study the contribution of charged Higgs boson to the rare decay of the top quark t->q+WZ (q=d,s,b) in models with Higgs sector that includes doublets and triplets. Higgs doublets are needed to couple charged Higgs with quarks, whereas the Higgs triplets are required to generate the non-standard vertex HWZ at tree-level. It is found that within a model that respect the custodial SU(2) symmetry and avoids flavour changing neutral currents by imposing discrete symmetries, the decay mode t->b+WZ, can reach a branching ratio of order 0.0178, whereas the decay modes t->(d,s)+WZ, can reach a similar branching ratio in models where flavour changing neutral currents are suppressed by flavour symmetries.Comment: Typeset using REVTEX and EPSF, 5 pag, 2 figure

Osteoporosis transitoria de rodilla en el embarazo

La osteoporosis transitoria o síndrome de edema óseo transitorio es una enfermedad poco frecuente y autolimitada que puede afectar a la mujer embarazada. La etiología es desconocida y su localización más frecuente es la cadera. Presentamos un caso de osteoporosis transitoria de rodilla durante el embarazo, con resolución clínica y radiológica completa tras 10 meses de evolución.Transient osteoporosis or transient bone edema syndrome is a rare, self-limiting disease that can affect pregnant women. The etiology is unknown and most common location is the hips. We present a case of tran - sient osteoporosis of the knee during pregnancy, with complete clinical and radiological resolution after 10 months

Evaluation of the power frequency magnetic field generated by three-core armored cables through 3D finite element simulations

The great expansion in offshore power plants is raising the concern regarding the cumulative effect of the electromagnetic field emissions caused by submarine power cables. In this sense, owners are required to predict these emissions during the permitting and consenting process of new power plants. This is a challenging task, especially in the case of HVAC three-core armored cables due to their complex geometry. Customarily, 2D approaches based on the finite element method (FEM) have been employed for evaluating the magnetic field emissions caused by these cables. However, inaccurate results are obtained since the phase conductors and armor twisting is omitted. This work develops, for the first time in the literature, an in-depth analysis of the magnetic field caused by this type of cable through an ultra-shortened 3D-FEM model, which is also faced to experimental measurements taken on an actual 132 kV, 800 mm2 three-core armored cable. Relevant conclusions are derived regarding the impact of the cable design on the magnetic field emissions, including material properties, as well as single and double-layer armors, presenting the proposed model not only as a valuable tool for predicting purposes, but also for optimizing cable design in terms of magnetic field emissions