Search results for "Orbit"
showing 10 items of 1104 documents
Protein Biomarkers of Bovine Defective Meats at a Glance: Gel-Free Hybrid Quadrupole-Orbitrap Analysis for Rapid Screening
2021
An understanding of biological mechanisms that could be involved in the stress response of animal cattle prior to slaughter is critical to create effective strategies aiming at the production of high-quality meat. The sarcoplasmic proteome of directly extracted samples from normal and high ultimate pH (pHu) meat groups was studied through a straightforward gel-free strategy supported by liquid chromatography hybrid quadrupole-Orbitrap high-resolution mass spectrometry (LC-HRMS) analysis. A stepped proteomic pipeline combining rapid biomarker hunting supported by qualitative protein Mascot scores followed by targeted label-free peptide quantification revealed 26 descriptors that characterize…
Versatile, sensitive liquid chromatography mass spectrometry – Implementation of 10 μm OT columns suitable for small molecules, peptides and proteins
2016
AbstractWe have designed a versatile and sensitive liquid chromatographic (LC) system, featuring a monolithic trap column and a very narrow (10 μm ID) fused silica open tubular liquid chromatography (OTLC) separation column functionalized with C18-groups, for separating a wide range of molecules (from small metabolites to intact proteins). Compared to today’s capillary/nanoLC approaches, our system provides significantly enhanced sensitivity (up to several orders) with matching or improved separation efficiency, and highly repeatable chromatographic performance. The chemical properties of the trap column and the analytical column were fine-tuned to obtain practical sample loading capacities…
Reflexions about imaging technique and examination protocol
2004
Computed tomography as imaging technique is established since decades, especially in examinations of the orbit. New technical development of multi-slice helical CT requires new attention, concerning radiation burden. Always asked is the use of contrast material in orbital examination. Indications and contraindications are discussed.
Chelation of a proton by oxidized diphosphines
2012
Abstract The chelation of a proton by oxidized diphosphines is studied for the first time both experimentally and theoretically. As a proof of concept the rare case where two different H-bond systems exist in one compound, H[7,8-(OP i Pr 2 ) 2 -7,8- nido -C 2 B 9 H 10 ] is reported. Based on NBO, QTAIM and ELF calculations, the P–O⋯H + ⋯O–P interactions were characterized as strong hydrogen bonds.
Intramolecular Communication in Anionic Oxidized Phosphanes through a Chelated Proton
2015
Oxidation of the 1,2-(PR2 )2 -1,2-closo-C2 B10 H10 (R=Ph, iPr) platform with hydrogen peroxide in acetone is a two-step procedure in which partial deboronation of the closo cluster and oxidation of the phosphorus atoms occur. Based on NMR spectroscopic and kinetic data, we demonstrate that the phosphorus atoms are oxidized in the first step, followed by cluster deboronation. DFT calculations and natural-bond orbital (NBO) analysis were used to obtain insight into the electronic structures of diphosphane ortho-carborane derivatives.
Molecular orbital studies on the mechanism of catalytic isomerization of xylenes III. Protonation channels
1981
Abstract The isoenergetic lines of the interaction energy between a bare proton and ortho-, meta- , and para -xylene have been calculated in order to detect both the best approaching channel and the preferred protonation positions. The channels found direct the protonation to the following ring positions: 4 and 5 for o -xylene, 4 and 6 for m -xylene, and 2 equivalents for p -xylene. The overall interaction energy determines the protonation positions on each isomer and the most important contributions to it are the electrostatic term in o -xylene, the polarization term in p -xylene, and both terms equally in m -xylene. These results are in agreement with the experimental findings and appear …
A G2(MP2) theoretical study of substituent effects on H3BNHnCl3−n (n= 3-0) donor-acceptor complexes
2008
Abstract The complexation energies of H3BNHnCl3−n (n= 3-0) complexes and the proton affinities of NHnCl3−n compounds have been computed at the G2(MP2) level of theory. G2(MP2) results show that the successive chlorine substitution on the ammonia decreases both the basicity of the NHnCl3−n ligands and the stability of H3BNHnCl3−n complexes. The findings are interpreted in terms of the rehybridisation of the nitrogen lone-pair orbital. The NBO partitioning scheme shows that the variation of the N-H and N-Cl bond lengths, upon complexation, is due to variation of “s” character in these bonds.
Singular quadratic Lie superalgebras
2012
In this paper, we give a generalization of results in \cite{PU07} and \cite{DPU10} by applying the tools of graded Lie algebras to quadratic Lie superalgebras. In this way, we obtain a numerical invariant of quadratic Lie superalgebras and a classification of singular quadratic Lie superalgebras, i.e. those with a nonzero invariant. Finally, we study a class of quadratic Lie superalgebras obtained by the method of generalized double extensions.
A criterion for zero averages and full support of ergodic measures
2018
International audience; Consider a homeomorphism $f$ defined on a compact metric space $X$ and a continuous map $\phi\colon X \to \mathbb{R}$. We provide an abstract criterion, called control at any scale with a long sparse tail for a point $x\in X$ and the map $\phi$, which guarantees that any weak* limit measure $\mu$ of the Birkhoff average of Dirac measures $\frac1n\sum_0^{n-1}\delta(f^i(x))$ s such that $\mu$-almost every point $y$ has a dense orbit in $X$ and the Birkhoff average of $\phi$ along the orbit of $y$ is zero.As an illustration of the strength of this criterion, we prove that the diffeomorphisms with nonhyperbolic ergodic measures form a $C^1$-open and dense subset of the s…
A note on homoclinic solutions of (p,q)-Laplacian difference equations
2019
We prove the existence of at least two positive homoclinic solutions for a discrete boundary value problem of equations driven by the (p,q) -Laplace operator. The properties of the nonlinearity ensure that the energy functional, corresponding to the problem, satisfies a mountain pass geometry and a Palais–Smale compactness condition.