Pacing Clin Electrophysiol
December 2024
Background: In addition to the pulmonary vein, the superior vena cava (SVC) is an important focus of atrial fibrillation (AF). However, SVC isolation may cause serious complications, and appropriate settings and techniques for SVC isolation are lacking.
Methods: This study enrolled 86 consecutive patients with AF who underwent SVC isolation.
We have demonstrated that the near-infrared and infrared absorptions in the 8000-3200 cm(-1) region of an OH group of 2-nonanol, 1-nonanol, etc., in n-heptane are excellently separated by subtraction without any serious interference down to very low concentrations at which OH groups are completely free. The separated sharp absorptions are assigned to the fundamental, combination, and overtone bands that are concerned with the OH stretching of free OH.
View Article and Find Full Text PDFFirst, we developed quantitative analytical methods of water in poly(methyl methacrylate) (PMMA) in various hydrated states by utilizing the first combination and OH stretching bands of water at about 5240 and 3630 cm-1, respectively. Next, we investigated how the state of water depended on its quantity or the mole ratio of water to the CO (denoted as the H2O/CO ratio), which only interacts with water in PMMA, mainly on the basis of the band feature of the OH stretching bands. Below the H2O/CO ratio of 0.
View Article and Find Full Text PDFWe characterized near-infrared spectra of the CH2 sequence in CH2X2 (X=halogen), CH2ClCHCl2, and CH3(CH2)5CH3. Each near-infrared absorption in the region from 3500 to 10,000 cm-1 is consistently assigned to one of the five different combination or overtone groups, in the order of increasing frequency, of the {[v(CH)]+[delta(CH)]} (A), {[v(CH)]+[2delta(CH)]} (B), [2v(CH)] (C), {[2v(CH)]+[delta(CH)]} (D), and [3v(CH)] (E) types, where v(CH) and delta(CH) denote the CH stretching and CH deformation normal modes, respectively. Each group has its own characteristic frequency zone.
View Article and Find Full Text PDFIn the present report we studied spectral characteristics of the near-infrared combination and overtone bands of CH vibrations of a CH sequence. The near-infrared bands of the CH in CHX3 (X, halogen), which were interpreted in terms of the CH stretching and CH deformation fundamentals without any ambiguity, typically showed how the frequency and intensity of a combination or an overtone depend on the vibrational excited state. In the CH-C-CH of CHX2CX2CHX2, the vibrations of one CH are isolated from those of the other CH, and the combination and overtone bands were similarly interpreted as those of the CH, although each of the combination bands was split into two because of non-degeneracy of the CH deformation.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
November 2005
We studied the influence of hydrogen bonding on the fundamental and overtone bands of the OH-stretching vibration of each OH group in the intramolecularly hydrogen-bonded OH(I)::OH(II) pair in 1,2-, 1,3- and 1,4-diols. The hydrogen bonding between the two OH groups significantly increases in strength from the five-membered ring of a 1,2-diol to the seven-membered ring of a 1,4-diol. Although the hydrogen bonding does not affect the vibrational property of the OH(II) (or acceptor), it significantly influences the OH(I) (or donor).
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
December 2005
We studied the influence of intermolecular interactions on the first combination band between the OH-stretching and -deformation vibrations of the water that is dissolved in organic and polymeric materials. The water has two types. The first type occurs in the matrix in which water-interactive functional groups are densely distributed.
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