Bidimensional measurement of an underwater sediment surface using a 3D-Scanner

The application of laser technologies to experimental fluvial hydraulics is a relatively new field with a promising future. In the area of sediment transport, these technologies will be used here to describe the evolution of an underwater sediment bed profile. This paper presents the application of a three-dimensional laser scanner (3D-Scanner), which measures elevation through the intersection of the laser beam with the sediment surface, correcting the effect of its refraction as it enters the water. Results were compared with those obtained with a particle image velocimetry (PIV) in recording the longitudinal profile of the bed. In this way, the utility of this high-precision, continuous and non-intrusive technique has been demonstrated in fluvial hydraulic studies with sediment transport.     

Cooperative games and cost allocation problems

The objective of this paper is to provide a general view of the literature of applications of transferable utility cooperative games to cost allocation problems. This literature is so large that we concentrate on some relevant contributions in three specific areas: transportation, natural resources and power industry. We stress those applications dealing with costs and with problems arisen outside the academic world.     

Highly Efficient and Directional Homo‐ and Heterodimeric Energy Transfer Materials Based on Fluorescently Derivatized α,γ‐Cyclic Octapeptides

Cyclic octapeptides composed of α‐amino acids alternated with cis‐3‐aminocycloalkanecarboxylic acids, self‐assemble as drumlike dimers through β‐sheet‐like, backbone‐to‐backbone hydrogen bonding. Heterodimerization appears to be significantly more favored than homodimerization, and this represents a novel approach for the design and fabrication of highly stable heterodimeric assemblies. A multicomponent equilibrium network based on fluorescently derivatized self‐assembling α,γ‐cyclic octapeptides has been successfully used to form light‐harvesting/light‐converting ensembles with a distinctive organization of donor and acceptor units able to act as efficient artificial photosystems.     

Electronic interpretation of conformational preferences in benzyl derivatives and related compounds

Quantum Theory of Atoms in Molecules (QTAIM) analysis on B3LYP/6-311++G(2d,2p) 6d electron densities of five benzyl derivatives (C(6)H(5)-CH(2)X; X = F, Cl, OH, SH, NH(2)) and seven related fluorides of furan, pyrrole, and naphthalene indicates that the preference for perpendicular or gauche conformation exhibited by these compounds is related to the diminution of the steric repulsion between the heteroatom at the substituent and the closest hydrogen in the ring. The electron density reorganization can be satisfactorily explained on the basis of these repulsive interactions, while no evidence of larger hyperconjugative delocalization is observed in the preferred conformations.     

Interaction of the cationic peptide bactenecin with mixed phospholipid monolayers at the air-water interface

The initial mechanism by which antimicrobial peptides target microbes occurs via electrostatic interactions; however, the mechanism is not well understood. We investigate the interaction of the antimicrobial peptide bactenecin with a 50:50 w:w% 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dimyristoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (DMPG) phospholipid mixture at the air-water interface with different NaCl concentrations (0.01, 0.05, 0.1, 0.5 M) in the subphase. A larger shift of DPPC:DMPG isotherms was obtained for 0.1 M salt concentration at lower and higher pressures, demonstrating the influence of the negative charge of DMPG molecules and the screening of the electrostatic interaction by the salt concentration. Raman spectroscopy of monolayers demonstrated the presence of cysteine-cysteine bridges in bactenecin loops. The peptide adsorption in DPPC:DMPG monolayers observed by AFM images suggests a self-assembled aggregation process, starting with filament-like networks. Domains similar to carpets were formed and pore structures were obtained after a critical peptide concentration, according to the carpet model.     

A Review of Potential Use of Amazonian Oils in the Synthesis of Organogels for Cosmetic Application

New strategies for the delivery of bioactives in the deeper layers of the skin have been studied in recent years, using mainly natural ingredients. Among the strategies are organogels as a promising tool to load bioactives with different physicochemical characteristics, using vegetable oils. Studies have shown satisfactory skin permeation, good physicochemical stability mainly due to its three-dimensional structure, and controlled release using vegetable oils and low-molecular-weight organogelators. Within the universe of natural ingredients, vegetable oils, especially those from the Amazon, have a series of benefits and characteristics that make them unique compared to conventional oils. Several studies have shown that the use of Amazonian oils brings a series of benefits to the skin, among which are an emollient, moisturizing, and nourishing effect. This work shows a compilation of the main Amazonian oils and their nutraceutical and physicochemical characteristics together with the minority polar components, related to health benefits, and their possible effects on the synthesis of organogels for cosmetic purposes.