Search results for " Spectra"
showing 10 items of 709 documents
Verschiedenartige Additionsreaktionen von 2-Cyano-2-propylradikalen an p-Tolylmethacrylat und 4-Cyclohexylphenylmethacrylat
1976
Durch Umsetzung von p-Tolylmethacrylat oder 4-Cyclohexylphenylmethacrylat in stark verdunnter, siedender Benzollosung mit einem sehr grosen Uberschus an 2,2′-Azoisobutyronitril wurden die erwarteten Additionsprodukte mit 2-Cyano-2-propylradikalen (1) erhalten, namlich p-Tolyl- bzw. 4-Cyclohexylphenyl-[4-cyano-2-(2-cyano-2-propyl)-2,4-dimethyl]valerianat (3a bzw. 3b) mit rund 50% Ausbeute. Daneben wurden p-Tolyl- bzw. 4-Cyclohexylphenyl-(4-cyano-4-methyl-2-methylen)valerianat (4a bzw. 4b), p-Tolyl- bzw. 4-Cyclohexylphenyl-[4-cyano-2(2-cyano-2-methyl-1-propyl)-4-methyl]valerianat (5a bzw. 5b), p-Tolyl- bzw. 4-Cyclohexylphenyl-(4-cyano-2,4-dimethyl)valerianat (6a bzw. 6b) und p-Tolyl- bzw. 4-C…
Metabolite identification in human liver needle biopsies by high-resolution magic angle spinning1H NMR spectroscopy
2006
High-resolution magic angle spinning (HR-MAS) 1 H NMR spectroscopy of intact human liver needle biopsies has not been previously reported. HR-MAS NMR spectra collected on 17 specimens with tissue amounts between � 0.5 and 12 mg showed very good spectral resolution and signal-to-noise ratios. One-dimensional 1 H spectra revealed many intense signals corresponding to cellular metabolites. In addition, some high molecular weight metabolites, such as glycogen and mobile fatty acids, could be observed in some spectra. Resonance assignments for 22 metabolites were obtained by combining the analysis of three different types of 1D 1 H spectral editing, such as T2 filtering or the nuclear Overhauser…
Synchronization to metrical levels in music depends on low-frequency spectral components and tempo
2016
Previous studies have found relationships between music-induced movement and musical characteristics on more general levels, such as tempo or pulse clarity. This study focused on synchronization abilities to music of finely-varying tempi and varying degrees of low frequency spectral change/flux. Excerpts from six classic Motown/R&B songs at three different tempos (105, 115, and 130 BPM) were used as stimuli in this experiment. Each was then time-stretched by a factor of 5% with regards to the original tempo, yielding a total of 12 stimuli that were presented to 30 participants. Participants were asked to move along with the stimuli while being recorded with an optical motion capture system.…
Individual and common antigen-recognition sites of liver-derived T cells in patients with autoimmune hepatitis.
2003
Autoimmune hepatitis (AIH) is characterized by dense T-cell infiltrations in the liver tissue, but little is known how T cells influence the pathogenesis. To address this question, the distribution of T-cell receptor variable beta-chain (TCR Vbeta) transcripts of peripheral blood and liver-infiltrating T cells from previously untreated patients with newly diagnosed acute exacerbated AIH was investigated. Furthermore, the lengths and sequences of complementary-determining region 3 (CDR3) were studied. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis and CDR3 spectratyping revealed multiple clonal expansions of liver-infiltrating T cells but not peripheral T cells within vari…
Instantaneous transfer entropy for the study of cardio-respiratory dynamics
2015
Measures of transfer entropy have been proposed to quantify the directional coupling and strength between two complex physiological variables. Particular attention has been given to nonlinear interactions within cardiovascular and respiratory dynamics as influenced by the autonomic nervous system. However, standard transfer entropy estimates have shown major limitations in dealing with issues concerning stochastic system modeling, limited observations in time, and the assumption of stationarity of the considered physiological variables. Moreover, standard estimates are unable to track time-varying changes in nonlinear coupling with high resolution in time. Here, we propose a novel definitio…
Quantifying the contribution of arm postural tremor to the outcome of goal-directed pointing task by displacement measures.
2004
A method for quantifying the outcome of goal-directed postural pointing was presented and used for relating the tremor output to the oscillations of single arm landmarks. The displacement of reflective markers placed on shoulder, upper arm, forearm, and hand were measured by an optoelectronic motion capture system in nine subjects holding a laser penlight pointed at a target. The high signal-to-noise ratio of the measured displacement series (from 7:1 for shoulder marker to 30:1 for hand marker) demonstrated the feasibility of the proposed system to carry out tremor analysis. The track of the laser emission on the target, reconstructed from penlight displacements, was studied as the outcome…
Aminoacid zwitterions in solution : Geometric, energetic, and vibrational analysis using density functional theory-continuum model calculations
1998
Glycine and alanine aminoacids chemistry in solution is explored using a hybrid three parameters density functional (B3PW91) together with a continuum model. Geometries, energies, and vibrational spectra of glycine and alanine zwitterions are studied at the B3PW91/6-31+G∗∗ level and the results compared with those obtained at the HF and MP2/6-31+G∗∗ levels. Solvents effects are incorporated by means of an ellipsoidal cavity model with a multipolar expansion (up to sixth order) of the solute’s electrostatic potential. Our results confirm the validity of the B3PW91 functional for studying aminoacid chemistry in solution. Taking into account the more favorable scaling behavior of density funct…
A coincidence-point problem of Perov type on rectangular cone metric spaces
2017
We consider a coincidence-point problem in the setting of rectangular cone metric spaces. Using alpha-admissible mappings and following Perov's approach, we establish some existence and uniqueness results for two self-mappings. Under a compatibility assumption, we also solve a common fixed-point problem.
Reaction products and pathways in the selective oxidation of C-2-C-4 alkanes on MoVTeNb mixed oxide catalysts
2010
[EN] The catalytic properties of MoVTeNbO catalysts during the selective oxidation of short chain alkanes and olefins (C-2-C-4) have been comparatively studied The main reaction products have been ethylene from ethane acrylic acid from propane maim anhydride from n-butane and methacrolein from isobutane FTIR studies of the adsorption of the main reaction products i e olefins and aldehydes over MoVTeNbO catalyst has been carried out Accordingly the reaction pathway is explained on the basis of the characteristics of the alkane fed the stability and reactivity of both the intermediates and the reaction products and the nature of the catalytic sites involved in each reaction (C) 2010 Elsevier …
Enantiodifferentiation of acyclic phosphonium salts in chiral liquid crystalline solutions
2006
Abstract The enantiodifferentiation of acyclic phosphonium salts bearing a stereogenic centre, whether on the phosphorus atom or on one of its substituents, was investigated by 2 H–{ 1 H}, 13 C–{ 1 H} and 31 P–{ 1 H} NMR in chiral liquid crystals composed of a polypeptide dissolved in an organic solvent. For the first time, the enantiomers of P-chirogenic phosphorus compounds were discriminated in these anisotropic media, affording good to excellent separation of the signals, allowing the determination of their proportion. While 31 P–{ 1 H} NMR spectra showed no chiral separation, 2 H–{ 1 H} NMR was efficient in the enantiodifferentiation of an isotopically labelled compound. Better still, …