The strong CO ligand vibrations of an octahedral complex, [Re (CO)(bpy)(CHCN)], in acetonitrile are observed at 2040 and 1932 cm. Facial rhenium tricarbonyl systems offer very strong and isolated CO vibrations with the potential for interactions between these vibrations. This work first identifies the dominant ion-pair species using attenuated total reflection infrared (ATR-IR) absorption spectra on a dilution series and then determines the strength of these CO ligand vibrations (as isolated vibrations) with a combination of ATR-IR and etalon-based measurements that determine the absolute complex index of refraction of the solution.
View Article and Find Full Text PDFA new method is established using an etalon cavity to assist in the determination of the wavelength-dependent complex index of refraction of a solution throughout the mid-infrared range. The results are used to study the cavity-vibration polaritons of PF in acetonitrile. Mixed states are formed by placing solution inside a pair of parallel plate mirrors with a wavelength-scale spacing, .
View Article and Find Full Text PDFEtalons are pairs of parallel plate mirrors with wavelength-scale spacing that exhibit cavity modes, giving transmission maxima (fringes) due to constructive interference. Infrared transmission measurements as a function of angle were used to determine the effective mass of etalon cavity modes using a gap filled with air and then liquid carbon tetrachloride. The air-filled etalon gives results in agreement with pure photon expectations established herein.
View Article and Find Full Text PDFJ Invest Dermatol
March 2022
The family of autoinflammatory diseases (AIDs) continues to expand and now includes over 40 genetically defined disorders. Their defining feature is a dysregulated inflammatory innate immune response. Many AIDs have overlapping clinical characteristics, and dermatological manifestations are common.
View Article and Find Full Text PDFThis work is the first report on nonzero molecular vibration-vibration coupling in an infrared cavity-vibration experiment. Vibration-vibration coupling strength is determined as a cavity mode of parallel spaced mirrors (etalon mode or fringe) is angle-tuned in the region between two vibrations of liquid acetonitrile which are Fermi coupled, namely, a CN stretch dominated vibration and a nearby combination band dominated by the symmetric CH bend and C-C stretch. All other infrared cavity-vibration work to date involving more than one vibration has used a value of zero for vibration-vibration coupling; however, this work starts with Fermi coupled vibrations and reveals that there are changes in the vibration-vibration coupling and cavity-vibration couplings as the cavity mode is angle-tuned between the interacting vibrations.
View Article and Find Full Text PDFHeart conditions in which the tricuspid valve (TV) faces either increased volume or pressure stressors are associated with premature valve failure. Mechanistic studies to improve our understanding of the underlying pathophysiology responsible for the development of premature TV failure are lacking. Due to the inability to conduct these studies in humans, an animal model is required.
View Article and Find Full Text PDFPost-natal maturation of the myocardium starts shortly after birth and could affect how clinicians should provide hemodynamic support during this transition. Our aim was to assess the impact of post-natal maturation on tolerance to tachycardia with altered loading condition in a piglet model. We report three series of experimentations.
View Article and Find Full Text PDFThe complexity and scale of the sources, types and environmental impacts of persistent solid waste pollution (PSWP) continue to overwhelm the capabilities of government and private efforts to control it. Global cumulative production of virgin plastics is expected to quadruple by 2050 with a concomitant doubling of plastic waste. All nations must take significant steps to realize eventual mitigation of PSWP.
View Article and Find Full Text PDFObjectives: This study describes procedural and 1-year outcomes of the 16 mm Melody PB1016 valve in patients with dysfunctional RVOT conduits.
Background: The Melody PB1016 is a standard Melody valve produced from a 16 mm bovine jugular vein and is intended for deployment up to 20 mm.
Methods: This is a prospective, non-randomized, multicenter study of the procedural and short-term outcomes of Melody PB1016 TPV replacement within dysfunctional RVOT conduits.
Background: In adult humans and pig models, strain rate (SR) correlates strongly with invasive measures of contractility but does not demonstrate a force-frequency relationship, which is a fundamental behavior of myocardial contraction. Given the considerable maturational changes of the myocardium from fetal stages to adulthood, extrapolation of adult findings to the young heart may not be appropriate. We sought to evaluate the SR response of the immature heart to increased heart rate (HR) and inotropic stimulation.
View Article and Find Full Text PDFWe hypothesized that an automated speech- recognition-inspired classification algorithm could differentiate between the heart sounds in subjects with and without pulmonary hypertension (PH) and outperform physicians. Heart sounds, electrocardiograms, and mean pulmonary artery pressures (mPAp) were recorded simultaneously. Heart sound recordings were digitized to train and test speech-recognition-inspired classification algorithms.
View Article and Find Full Text PDFThis work characterizes collections of infrared spectra of individual dust particles of ∼4 µm size that were obtained from three very different environments: our lab air, a home air filter, and the 11 September 2001 World Trade Center event. Particle collection was done either directly from the air or by placing dust powder from various samples directly on the plasmonic mesh with 5 µm square holes as air is pumped through the mesh. This arrangement enables the recording of "scatter-free" infrared absorption spectra of individual particles of size comparable to the probing wavelengths whose vibrational signatures are otherwise dominated by scattering and dispersive line shape distortions.
View Article and Find Full Text PDFDoppler studies at rest suggest left ventricular (LV) diastolic function rapidly improves from the neonate to infant. Whether this translates to its response to hemodynamic challenges is uncertain. We sought to explore the impact of early LV maturation on its ability to tolerate atrial tachycardia.
View Article and Find Full Text PDFBackground: Automatic detection of the 1st (S1) and 2nd (S2) heart sounds is difficult, and existing algorithms are imprecise. We sought to develop a wavelet-based algorithm for the detection of S1 and S2 in children with and without pulmonary arterial hypertension (PAH).
Method: Heart sounds were recorded at the second left intercostal space and the cardiac apex with a digital stethoscope simultaneously with pulmonary arterial pressure (PAP).
The enthalpy and Gibbs free energy thermodynamical potentials of single walled carbon nanotubes were studied of all types (armchairs, zig-zags, chirals (), and chiral ()). Bulk values of these thermodynamic potentials were obtained using a previously demonstrated robust method based on semi-empirical PM3 calculations and an extrapolated cluster approach. Those values were used to study the relationship between the thermodynamic potentials and the diameter of the nanotube.
View Article and Find Full Text PDFWe studied digital stethoscope recordings in children undergoing simultaneous catheterization of the pulmonary artery (PA) to determine whether time-domain analysis of heart sound intensity would aid in the diagnosis of PA hypertension (PAH). Heart sounds were recorded and stored in .wav mono audio format.
View Article and Find Full Text PDFThe postnatal survival of patients with congenital cardiac defects such as hypoplastic left heart syndrome (HLHS) is dependent on the patency of the ductus arteriosus and the presence of an unrestrictive atrial septal defect (ASD). We report a six week old infant with HLHS and tricuspid valve regurgitation with restrictive ASD. Transfemoral balloon atrial septostomy provided temporary relief but further attempts were not possible.
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