Search results for "isole"

Isolement de champignons d’un andosol de Guadeloupe contaminé à la chlordécone : caractérisation de leurs tolérances

2012

The σ B -dependent regulatory sRNA Rli47 represses isoleucine biosynthesis in Listeria monocytogenes through a direct interaction with the ilvA trans…

2019

International audience; The facultative intracellular pathogen Listeria monocytogenes can persist and grow in a diverse range of environmental conditions, both outside and within its mammalian host. The alternative sigma factor Sigma B (sigma(B)) plays an important role in this adaptability and is critical for the transition into the host. While some of the functions of the sigma(B) regulon in facilitating this transition are understood the role of sigma(B)-dependent small regulatory RNAs (sRNAs) remain poorly characterized. In this study, we focused on elucidating the function of Rli47, a sigma(B)-dependent sRNA that is highly induced in the intestine and in macrophages. Using a combinatio…

Isole Minori ed ambiente: lo sviluppo integrato e sostenibile alla luce dei valori di legalità

2014

Telerilevamento e GIS per la valutazione e il monitoraggio delle isole di calore in ambiente urbano

2017

The techniques of spatial analysis and Remote Sensing represent an useful tool for the knowledge and the study of the Urban Heat Island phenomenon (English acronym UHI). In this study, among the different causes that lead to the generation of the event, those regarding physical features of the surface and the presence of different land use/cover such as: the high cover of urban areas and the lack of green areas have been examined. The Remote Sensing techniques allow to create maps of the land use/cover, then, in order to estimate the different in temperature due to the distance to the vegetation, the temperature of the bodies already tested have been compared with a thermal map. In detail t…

2021

Amino acids with small side chains and motifs of small residues in a distance of four are rather abundant in human single-span transmembrane helices. While interaction of such helices appears to be common, the role of the small residues in mediating and/or stabilizing transmembrane helix oligomers remains mostly elusive. Yet, the mere existence of (small)xxx(small) motifs in transmembrane helices is frequently used to model dimeric TM helix structures. The single transmembrane helix of the human carbonic anhydrases XII contains a large number of amino acids with small side chains, and critical involvement of these small amino acids in dimerization of the transmembrane domain has been sugges…

Chromatographic Determination of Thiols After Pre‐column Derivatization witho‐Phthalaldehyde and Isoleucine

2004

Abstract The reaction of primary amines with excess o‐phthalaldehyde (OPA) and thiol yields unique isoindole derivatives that are readily separated by reversed‐phase liquid chromatography. In a previous work, a spectrophotometric procedure was proposed for the assay of N‐acetylcysteine by derivatization with OPA and isoleucine at pH 9.5, with satisfactory results. The chromatographic determination of this and other low molecular‐weight thiols, after isoindole formation with isoleucine, using mobile phases of acetonitrile–water at pH 3 and spectrophotometric detection, is now examined. From the assayed thiols (thioglycolic acid, 3‐mercaptopropionic acid, tiopronin, N‐acetylcysteine, N‐acetyl…

Use of the o-Phthalaldehyde and N-Acetyl-L-Cysteine the Evaluation of Milk Proteins

1991

Abstract o -Phthalaldehyde and N-acetyl-Lcysteine are used in the determination of milk proteins. Three procedures are proposed and compared. One of them is based on reaction of o -phthalaldehyde and N-acetyl-Lcysteine with the intact proteins and the two others on reaction of the reagents with the released amino acids after total acid hydrolysis of the protein samples. When the protein sample is hydrolyzed, calibration is performed either with a hydrolyzed protein standard or with isoleucine. A procedure for the measurement of the degree of enzymatic hydrolysis of milk proteins without separation of the unhydrolyzed protein, which makes use of the same reagents, is also described. In all c…

Determination of the protein and free amino acid content in a sample using o-phthalaldehyde and N-acetyl-L-cysteine

1990

A spectrophotometric method is proposed for determining the protein content in a sample after total acid hydrolysis. In the procedure, free amino acids are caused to react with o-phthalaldehyde and N-acetyl-L-cysteine at pH 9.5, using isoleucine as the reference compound. Correction factors are used to take into account the differences between the molar absorptivities of the amino acid isoindoles and the recoveries of the amino acids after the hydrolysis treatment. The limit of detection was in the range 40-50 micrograms of protein, and the recoveries were usually 101 +/- 3% with a coefficient of variation lower than 4%. The free amino acid content in a partially hydrolysed protein was also…

Risk Assessment of "Other Substances" – L-leucine, L-isoleucine and L-valine, the Branched Chain Amino Acids (BCAA)

2018

ortho-Metalation of aromatic ethers by yttrium alkyl complexes that contain a linked amido-cyclopentadienyl ligand

2003

Abstract The reaction of the half-sandwich alkyl complex [Y(η5:η1-C5Me4CH2SiMe2NtBu)(CH2SiMe3)(THF)] (1) with anisole smoothly gives the ortho-metalation product [Y(η5:η1-C5Me4CH2SiMe2NtBu)(2-C6H4OMe)(THF)] (2). 3- and 4-Methylanisole as well as phenetole analogously undergo ortho-metalation, whereas thioanisole, N,N′-dimethylaniline, fluorobenzene, and trifluorobenzene do not react with yttrium complex 1. 2-Methylanisole reacts with 1 under activation of the ring methyl group to give the 2-methoxybenzyl complex [Y(η5:η1-C5Me4CH2SiMe2NtBu)(CH2C6H4OMe-2)(THF)] (6). A single-crystal X-ray structure analysis of the 2-anisyl complex 2 revealed a four-legged piano-stool configuration with the me…