Search results for "circular"

AMYLOID AGGREGATION IN CONCANAVALIN A AT HIGH PH STUDIED BY LIGHT SCATTERING, FLUORESCENCE AND CIRCULAR DICHROISM SPECTROSCOPY

2008

The frontier between cell and organelle: genome analysis of Candidatus Carsonella ruddii

2007

Background Bacterial symbioses are widespread among insects. The early establishment of such symbiotic associations has probably been one of the key factors for the evolutionary success of insects, since it may have allowed access to novel ecological niches and to new imbalanced food resources, such as plant sap or blood. Several genomes of bacterial endosymbionts of different insect species have been recently sequenced, and their biology has been extensively studied. Recently, the complete genome sequence of Candidatus Carsonella ruddii, considered the primary endosymbiont of the psyllid Pachpsylla venusta, has been published. This genome consists of a circular chromosome of 159,662 bp and…

Polarization-domain-wall complexes in fiber lasers

2013

To study the possible build-up of polarization-domain-walls (PDWs) in fiber laser cavities, an erbium-doped fiber ring laser was used and a wide range of vector polarization dynamics that can be selected at a given pump power, by using the degrees of freedom of two intracavity polarization controllers (PC) was investigated. A simple theoretical model that explains polarization switching in fiber ring lasers featuring a normally dispersive cavity with a typical, moderate, level of birefringence is presented. Such polarization dynamics, based on a special class of polarization-domain-wall structures, agrees qualitatively well with experimental observations. The paper stresses on the complex a…

Hamiltonian tools for the analysis of optical polarization control

2011

Import JabRef; International audience; The study of the polarization dynamics of two counterpropagating beams in optical fibers has recently been the subject of a growing renewed interest, from both the theoretical and experimental points of view. This system exhibits a phenomenon of polarization attraction, which can be used to achieve a complete polarization of an initially unpolarized signal beam, almost without any loss of energy. Along the same way, an arbitrary polarization state of the signal beam can be controlled and converted into any other desired state of polarization, by adjusting the polarization state of the counterpropagating pump beam. These properties have been demonstrate…

Enhanced β-turn conformational stability of tripeptides containing Δphe in cis over trans configuration

2013

Conformations of three pairs of dehydropeptides with the opposite configuration of the Delta Phe residue, Boc-Gly-Delta(Z/E)Phe-Phe-p-NA (Z- p -NA and E- p -NA), Boc-Gly-Delta(Z/E)Phe-Phe-OMe (Z-OMe and E-OMe), and Boc-Gly-Delta(Z/E)Phe-Phe-OH (Z-OH and E-OH) were compared on the basis of CD and NMR studies in MeOH, TFE, and DMSO. The CD results were used as the additional input data for the NMR-based calculations of the detailed solution conformations of the peptides. It was found that Z- p -NA, E- p -NA, Z-OMe, and Z-OH adopt the beta-turn conformations and E-OMe and E-OH are unordered. There are two overlapping type III beta-turns in Z- p -NA, type II' beta-turn in E- p -NA, and type II …

Influence of solvents on conformation of dehydropeptides

2013

Abstract Structural investigations of dehydropeptides containing (Z)-dehydrophenylalanine in solvents characterized by different polarity are discussed. The conformational analysis are based on spectroscopic methods (NMR, CD), molecular modeling techniques and in case of the tripeptide, ab initio methods. The results of temperature experiment indicate, that the only conformation of the investigated hexapeptide 3 is stabilized by intramolecular hydrogen bonds. Depending on the length of the peptide chain, the polarity of solvent influences on arrangement of the side chain of the amino acids or of the main chain of the peptide.

Tuning the pH-Switch of Supramolecular Polymer Carriers for siRNA to Physiologically Relevant pH

2017

The preparation of histidine enriched dendritic peptide amphiphiles and their self-assembly into multicomponent pH-switchable supramolecular polymers is reported. Alternating histidine and phenylalanine peptide synthons allow the assembly/disassembly to be adjusted in a physiologically relevant range of pH 5.3-6.0. Coassembly of monomers equipped with dendritic tetraethylene glycol chains with monomers bearing peripheral primary amine groups leads to nanorods with a tunable cationic surface charge density. These surface functional supramolecular polycations are able to reversibly bind short interfering RNA (siRNA). The nanorod-like supramolecular polymers, their complexation with siRNA, and…

A feasibility study of table salt production from seawater reverse osmosis brine

2022

Design e ficodindia : per uno sviluppo locale sostenibile

2017

L’articolo descrive il rapporto tra il design e un prodotto dell’agroalimentare siciliano, il ficodindia di Roccapalumba, per uno sviluppo economico e territoriale nel rispetto dell’ambiente. A tal fine il ficodindia è considerato risorsa in grado di avviare delle innovazioni, come la valorizzazione degli scarti e la relazione tra gli attori locali. Nell’articolo, per generare una seconda vita agli scarti, si è studiato il ciclo di vita del ficodindia e tra i vari output si è considerato la potatura dei cladodi da cui si è ricavato una fibra, utilizzata in modo innovativo e secondo una visione locale, puntando sul patrimonio culturale e sulle tradizioni. The article describes the relationsh…

Design and Agrifood for new sustainable local development

2019

This paper is about the relationship between design and the prickly pear of Roccapalumba (Sicily), a product of the agrifood chain, considering it as a resource able to start innovative strategies for waste recycling and for a sustainable local economy. The study examines the entire life cycle of prickly pear and, among the various outputs, considers the cladodes to obtain cellulosic fibres, mucilage for cosmetics and for restoration of cultural heritage, the flowers for infusions and the fruit seeds for an oil with nutraceutical properties to generate a second life of the prickly pear. This will lead to economic and environmental benefits in the territory, creating a network of companies w…