Search results for "bama"
showing 10 items of 304 documents
A second pathway of activation of the Torpedo acetylcholine receptor channel
1991
We have studied the interaction of the reversible acetylcholine esterase inhibitor (-)physostigmine (D-eserine) with the nicotinic acetylcholine receptor (nAChR) from Torpedo marmorata electric tissue by means of ligand-induced ion flux into nAChR-rich membrane vesicles and of equilibrium binding. We find that (-) physostigmine induces cation flux (and also binds to the receptor) even in the presence of saturating concentrations of antagonists of acetylcholine, such as D-tubocurarine, alpha-bungarotoxin or antibody WF6. The direct action on the acetylcholine receptor is not affected by removal of the methylcarbamate function from the drug and thus is not due to carbamylation of the receptor…
Spectral and structural studies on Ni(II) dithiocarbamates: Nickel sulfide nanoparticles from a dithiocarbamate precursor
2015
Abstract Three new planar Ni(II) dithiocarbamate complexes; [Ni(4-dpmpzdtc)2] (1), [Ni(4-dpmpzdtc)(PPh3)(NCS)] (2) and [Ni(bupcbzdtc)(PPh3)(NCS)] (3) (where, 4-dpmpzdtc = 4-(diphenylmethyl)piperazinecarbodithioato anion, bupcbzdtc = N-butyl-N-(4-chlorobenzyl))dithiocarbamato anion and PPh3 = triphenylphosphine) with “NiS4” and “NiS2PN” chromophore units were synthesized and characterized by single crystal X-ray structural analysis as well as UV–Vis, IR and NMR (1H, 13C and 31P) spectroscopy. For 2, 1H–1H COSY spectrum was also recorded. Single crystal X-ray structural analysis of 1–3, reveals a slightly distorted square planar geometry in all three complexes wherein the steric and electroni…
A surface hopping algorithm for nonadiabatic minimum energy path calculations
2015
The article introduces a robust algorithm for the computation of minimum energy paths transiting along regions of near-to or degeneracy of adiabatic states. The method facilitates studies of excited state reactivity involving weakly avoided crossings and conical intersections. Based on the analysis of the change in the multiconfigurational wave function the algorithm takes the decision whether the optimization should continue following the same electronic state or switch to a different state. This algorithm helps to overcome convergence difficulties near degeneracies. The implementation in the MOLCAS quantum chemistry package is discussed. To demonstrate the utility of the proposed procedur…
Le sénat : Quel contre-pouvoir ?
2012
Chapitre 13.; International audience; Le renforcement du pouvoir présidentiel est certainement la principale évolution institutionnelle des dix dernières années, à tel point que les observateurs s’accordent à évoquer une « revanche » sur le Watergate. Mais cette évolution n’est pas seulement le résultat d’une tendance historique de la présidence à s’affranchir des contraintes du système politique américain.
tert-Butyl N-benzyl-N-[4-(4-fluorobenzoylmethyl)-2-pyridyl]carbamate
2008
In the crystal structure of the title compound, C25H25FN2O3, the pyridine ring makes dihedral angles of 75.1 (3), 39.4 (3) and 74.6 (3)° with the phenyl ring, the carbamate plane and the 4-fluorophenyl ring, respectively. The phenyl ring makes dihedral angles of 77.2 (3) and 23.6 (3)° with the carbamate plane and the 4-fluorophenyl ring, respectively. The 4-fluorophenyl ring is perpendicular to the carbamate plane, the dihedral angle between them being 89.5 (3)°.
tert-ButylN-(4-methyl-2-pyridyl)carbamate
2008
The crystal structure of the title compound, C11H16N2O2, contains two crystallographically independent molecules forming dimers by pairs of intermolecular N—H...N hydrogen bonds. The two molecules are related by a pseudo-twofold axis. The dihedral angle between the pyridine ring and the carbamate plane differs in the two molecules [12.1 (3) and 3.5 (3)°].
tert-Butyl N-benzyl-N-(4-methyl-2-pyridyl)carbamate
2008
In the crystal structure of the title compound, C18H22N2O2, the pyridine ring makes dihedral angles of 83.71 (6) and 9.2 (1)° with the phenyl ring and the carbamate plane, respectively. The phenyl ring and the carbamate plane are nearly perpendicular to one another, with a dihedral angle of 87.17 (7)°.
Adding the Mureş River Basin (Transylvania, Romania) to the List of Hotspots with High Contamination with Pharmaceuticals
2020
Background: The Mureș River Basin is a long-term heavily polluted watershed, in a situation of climate changes with increasing water flow and related decreasing dilution capacity. Here, a mixture of emerging pollutants such as pharmaceuticals were targeted to reveal potential risks regarding the natural lotic ecosystems. Due to the continuous discharge into the environment, pharmaceuticals are gaining persistent organic pollutant characteristics and are considered emerging pollutants. Based on the hazard quotient, this research highlights the dangerous concentrations of carbamazepine, ibuprofen, furosemide, and enalapril in river water. Results: High levels of four pharmaceutical compounds …
Determination at low ppm levels of dithiocarbamate residues in foodstuff by vapour phase-liquid phase microextraction-infrared spectroscopy
2010
Abstract A methodology based on the vapour phase (VP) generation of carbon disulphide from non-volatile dithiocarbamate compounds has been developed for determination of pesticide residues in foodstuff at low ppm levels. The method involves a selective reaction combined with liquid phase microextraction (LPME) and transmission infrared measurements. The use of a home made transmission cell improved the detection limits (LOD) compared to the use of attenuated total reflectance measurements by a factor of approximately 80. Using the most appropriate experimental conditions for the CS2 generation and LPME preconcentration, the precision of the methodology, expressed as the relative standard de…
Quelle recherche pour l'arôme des vins Bourguignons ?
1997
National audience