Search results for " DIP"

Changes in the proton potential and the cellular energetics of Escherichia coli during growth by aerobic and anaerobic respiration or by fermentation.

1998

The energetic parameters of Escherichia coli were analyzed for the aerobic/anaerobic transition. The electrochemical proton potential (delta p) across the cytoplasmic membrane was determined in the steady state of respiration with O2, nitrate, fumarate, dimethylsulfoxide (Me2SO), and for fermentation. With O2, a proton potential of -160 mV was obtained. For anaerobic respiration with nitrate, fumarate or Me2SO, delta p decreased only slightly by about 20 mV in contrast to earlier assumptions, whereas delta p dropped by approximately 40 mV during fermentation. Under all conditions, the membrane potential (delta psi) contributed the major portion to delta p. The cellular ATP levels were highe…

Optimization of a microwave-assisted extraction large-volume injection and gas chromatography–ion trap mass spectrometry procedure for the determinat…

2006

Abstract A sensitive and rapid method for the determination of polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs) and polychlorinated naphthalenes (PCNs) in sediment samples is proposed. The method involving microwave-assisted extraction (MAE) and large-volume injection (LVI) gas chromatography (GC)–ion trap mass spectrometry (ITMS), and the experimental conditions were optimized using the statistical design of experiments (DOE). A Plackett–Burman (P–B) design was chosen to estimate the influence of five factors, such as resonance excitation voltage (EV), isolation time (IT), excitation time (ET), ion source temperature (IST) and electron energy (EE) on the analytical r…

Miniaturized matrix solid phase dispersion procedure and solid phase microextraction for the analysis of organochlorinated pesticides and polybromina…

2009

Abstract This work has developed a miniaturized method based on matrix solid phase dispersion (MSPD) using C18 as dispersant and acetonitrile–water as eluting solvent for the analysis of legislated organochlorinated pesticides (OCPs) and polybrominated diphenylethers (PBDEs) in biota samples by GC with electron capture (GC-ECD). The method has compared Florisil®-acidic Silica and C18 as dispersant for samples as well as different solvents. Recovery studies showed that the combination of C18–Florisil® was better when using low amount of samples (0.1 g) and with low volumes of acetonitrile–water (2.6 mL). The use of SPME for extracting the analytes from the solvent mixture before the injectio…

Use of micellar mobile phases for the chromatographic determination of clorazepate, diazepam, and diltiazem in pharmaceuticals

2001

An ODS-2 column, a micellar mobile phase of high elution strength containing 0.1M sodium dodecyl sulfate and 3% (v/v) butanol, and ultraviolet detection at 230 nm are used for the determination of either of two benzodiazepines (clorazepate and diazepam) and a benzothiazepine (diltiazem) in pharmaceuticals. The procedure is shown to be competitive against conventional chromatography with methanol-water mobile phases, especially for diltiazem. The composition of the micellar mobile phase is selected using a predictive strategy based on an accurate retention model and assisted by computer simulation. Calibration graphs are linear at least in the 2.5 to 20 microg/mL, 4 to 20 microg/mL, and 5 to…

Tests of General Relativity with GW170817

2019

The recent discovery by Advanced LIGO and Advanced Virgo of a gravitational wave signal from a binary neutron star inspiral has enabled tests of general relativity (GR) with this new type of source. This source, for the first time, permits tests of strong-field dynamics of compact binaries in presence of matter. In this paper, we place constraints on the dipole radiation and possible deviations from GR in the post-Newtonian coefficients that govern the inspiral regime. Bounds on modified dispersion of gravitational waves are obtained; in combination with information from the observed electromagnetic counterpart we can also constrain effects due to large extra dimensions. Finally, the polari…

Institutional Dynamics in International Organizations: Lessons from the Recruitment Procedures of the European External Action Service

2014

Author's version of an article in the journal: Organization Studies. Also available from the publisher at: http://dx.doi.org/10.1177/0170840614544558 This article examines how organizational designs develop by proposing a novel theoretical framework that views organizational change as resulting from a dialectic process between interpretive agents. The key claim is that existing formal procedures (such as recruitment processes, our empirical focal point) are subject to involved actors’ interpretive efforts. This results in a bargaining situation based on the interpretations of the principal actors, which may induce a feedback loop whereby the original procedures are amended. The empirical re…

Complexes of diorganotin(IV) with aminoacids and a dipeptide. Synthesis and structural investigations.

2008

The aim of this work is to synthesize complexes of Arginine, effector of recognition, with organotin(IV) ions (R2Sn2+, R =Me, nBu) which are known to possess antitumour, antimicrobial, anti-inflammatory activities. The complexes were investigated by FT-IR and 119Sn Můssbauer.While identical stoichiometries are present for Me2Sn(Arg)2 and Me2Sn(Boc-Arg)2 complexes, 119Sn Můssbauer spectra give a clear evidence of different coordination modes. L-Arginine appears to behave as a chelating ligand through carboxylate and a-NH2 groups in the former, while in Nα-Boc-L-Arginine complex, the Nα-protected amino group being exempted from coordination, only the carboxylate groups are effectors of bondin…

La Dipendenza sessuale.

2009

L'insertion professionnelle des diplômés en France

1984

International audience

Des caractéristiques des équipes de recherche aux pratiques de recrutement en entreprise

1999

International audience