Search results for "Cholin"
showing 10 items of 1261 documents
Una prospettiva storica e pedagogica sulle Lingue dei Segni: riflessioni psicolinguistiche
2021
Da oltre 50 anni, da quando W. Stokoe negli anni '60 individuò in USA i parametri di articolazione delle lingue dei Segni (cfr. Stokoe, 1981), si assiste ad un sempre maggiore interesse nei confronti delle lingue visivo-gestuali delle comunità di sordi, grazie anche agli sviluppi nel campo della psicolinguistica, delle neuroscienze, e delle nuove tecnologie che consentono indagini sul linguaggio e sul funzionamento cerebrale impensabili sino a qualche tempo fa. Può forse sorprendere che, in una prospettiva storica, all'interno del dibattito linguistico-filosofico si può riscontrare un analogo interesse per i sordi e le loro forme di comunicazione soltanto nella seconda metà del sec. XVIII e…
Sequential Effects of Phonological Priming in Visual Word Recognition
2005
International audience; Two masked priming experiments were conducted to examine phonological priming of bisyllabic words in French, and in particular, whether it operates sequentially or in parallel. Bisyllabic target words were primed by pseudowords that shared either the first or the second phonological syllable of the target. Overlap of the first syllable only-not the second-produced facilitation in both the lexical decision and the naming tasks. These findings suggest that, for polysyllabic words, phonological codes are computed sequentially during silent reading and reading aloud.
Supramolecular Eutecto Gels: Fully Natural Soft Materials
2018
The obtainment of materials featured by high environmental compatibility is one of the main goals of modern research. On this subject, we herein report the first example of supramolecular gel in deep eutectic solvents. In particular, we prepared gels of the L-amino acids isoleucine and tryptophan in choline chloride/phenylacetic acid 1:2. All gel components are readily available and nontoxic. Gels have been fully characterized by standard gelation tests, rheology, X-ray diffraction, morphology and gelation kinetics. Data collected show that gels properties depend on the gelator nature. In particular, gel phases exhibit strong colloidal forces and, this high mechanical resistance, together w…
Environmentally Friendly Eutectogels Comprising l-amino Acids and Deep Eutectic Solvents: Efficient Materials for Wastewater Treatment.
2020
Current concerns for sustainability and the environment make low-impact materials desirable for environmental remediation and, in particular wastewater treatment. We obtained supramolecular gels of l-amino acids in the deep eutectic solvent formed by choline chloride and phenylacetic acid. After gel characterization, and investigating gel-sol transition temperatures, gelation kinetics, rheological properties, and morphology, the gels were applied as sorbents to remove cationic dyes from aqueous solutions. The effects of the pH, dye nature, volume, and concentration of wastewater were analyzed, and the best result was obtained with a l-phenylalanine-based eutectogel. It can be reused for at …
Using partial-orders for detecting faults in concurrent systems
1998
The paper suggests test derivation approaches to obtain test suites for concurrent systems based on the concept of fault coverage criteria in opposition to structural test coverage criteria. Using a partial-order model, called Mazurkiewicz Trace Machine (MTM), for test derivation, the state explosion problem can be alleviated. The derived test suites are characterized by their small size compared to test suites from traditional test derivation approaches and exhibit a defined degree of fault coverage according to certain fault models. The fault models of concurrent systems considered in the paper are based on the most common faults, acceptance, refusal, and transfer faults. A scenario of te…
Low Levels of Acetylcholine Receptor Delta-Subunit Message and Protein in Human Thymus Suggests the Occurrence of ‘Triplet Receptors’ in Thymic Myoid…
2000
Myasthenia gravis (MG) is an autoimmune disease caused by autoantibodies against the acetylcholine receptor (AChR) at the neuromuscular junction [1]. The muscular AChR has been extensively characterized [2], but whether the muscular AChR plays a role during the initiation of MG is unknown [3]. The muscular AChR is a pentameric ion channel composed of 4 different subunits [2, 4]. The fetal AChR expressed during intrauterine life and after denervation of adult muscle exhibits an α2βδγ composition, while the adult AChR expressed after birth in innervated muscle exhibits an α2βδγ composition [4]. The α-subunit contains the main epitopes recognized by MG autoantibodies [2]. The human muscle AChR…
A chemiluminescence flow-based procedure for determination of carbaryl in natural waters exploiting multicommutation and enzymatic reaction
2007
A chemiluminescence procedure for the determination of carbaryl in natural waters using acetylcholinesterase and choline oxidase is described. The flow system designed to implement multicommutation approach controlled by microcomputer comprised five solenoid valves, two columns with immobilized enzymes on controlled pore glass beads and chemiluminometric flow cell. In the best experimental conditions a linear response ranging from 25 to 700 µg L-1 carbaryl was obtained. Water samples were spiked with carbaryl in order to access the accuracy and recoveries between 95 and 101% were obtained for a concentration level ranging from 25 to 100 µg L-1 carbaryl. Detection limit and variation coeffic…
Detergent Properties Influence the Stability of the Glycophorin A Transmembrane Helix Dimer in Lysophosphatidylcholine Micelles
2012
AbstractDetergents might affect membrane protein structures by promoting intramolecular interactions that are different from those found in native membrane bilayers, and fine-tuning detergent properties can be crucial for obtaining structural information of intact and functional transmembrane proteins. To systematically investigate the influence of the detergent concentration and acyl-chain length on the stability of a transmembrane protein structure, the stability of the human glycophorin A transmembrane helix dimer has been analyzed in lyso-phosphatidylcholine micelles of different acyl-chain length. While our results indicate that the transmembrane protein is destabilized in detergents w…
Low-Q peak in X-ray patterns of choline-phenylalanine and homophenylalanine: a combined effect of chain and stacking
2016
Abstract In this contribution we report for the first time the X-ray patterns of choline-phenylalanine and choline-homophenylalanine ionic liquids. The presence of a low Q peak in both systems is another evidence that a long alkyl chain is not always needed to establish a nanodomain segregation in the liquid sufficient to be revealed by the diffraction experiment. These new data are compared with the diffraction patterns and the theoretical calculations of other choline-aminoacid ionic liquids recently reported. A significant role might be played by the stacking interactions between aromatic rings.
Acyl-Chain Mismatch Driven Superlattice Arrangements in DPPC/DLPC/Cholesterol Bilayers
2010
Fluorescence and infrared spectroscopy and cholesterol oxidase activity were employed to investigate the effect of phosphatidylcholine (PC) acyl chain length mismatch on the lateral organizations of lipids in liquid-ordered dipalmitoyl-PC/dilauroyl-PC/cholesterol (DPPC/DLPC/CHOL) bilayers. Plots of steady-state fluorescence emission anisotropy of diphenylhexatriene (DPH) labeled PC (DPH-PC) embedded in the DPPC/DLPC/CHOL bilayers revealed significant peaks at several DPPC mole fractions (Y(DPPC)) when the cholesterol mole fraction (X(CHOL)) was fixed to particular values. Analogously, the DPH-PC anisotropy peaked at several critical X(CHOL)'s when Y(DPPC) was fixed. Acyl chain C-H and C hor…