Effective mass of cavity-vibration polaritons formed in etalons with liquid carbon tetrachloride.

Etalons 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. Liquids with vibrations having strong infrared transition intensity (vibrational strong coupling mode) can strongly perturb the pattern of transmission resonances, creating mixed states of infrared cavity modes and molecular vibrations, i.e., cavity-vibration polaritons. The effective mass of one cavity-vibration polariton close to the strong vibration of carbon tetrachloride is 4.36 times heavier than the pure photon cavity mode expectation, i.e., the mass factor vs pure light. The mass factors are largest when closest to the strong vibrational frequency, and they converge to the one far away from the strong vibration. This work gives quantitative values of the effective mass of cavity-vibration polariton states and is a diagnostic for the mixing of vibrations with etalon transmission.

Implantation of the Melody transcatheter pulmonary valve PB1016 in patients with dysfunctional right ventricular outflow tract conduits.

OBJECTIVES: 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. Data from eight centers were included in the analysis. RESULTS: During the study period, 39 patients underwent attempted Melody TPVR. Of the 39 patients, 30 underwent successful Melody TPVR. The majority of patients underwent placement of one or more stents prior to TPVR. There was a significant reduction in peak conduit pressure gradient following TPVR (38 mmHg vs. 11 mmHg, P < 0.001). There were three cases of confined conduit tears successfully treated with covered stents or the valve itself. Repeat catheterization was performed in one patient for early re-obstruction that was successfully treated with balloon valvuloplasty. At recent follow-up, there were no cases of more than mild valve regurgitation and the mean pulmonary valve gradient by echocardiogram remained reduced relative to pre-TPVR implant measurements (33.5 mmHg vs. 15.2 mmHg). There were no cases of valve stent fracture or endocarditis reported at the 1-year follow-up. CONCLUSIONS: Our analysis of TPVR with the PB1016 valve in RVOT conduits showed it to be safe and effective and can be performed in a wide range of conduit sizes with preserved valve function. ClinicalTrials.gov Identifier: NCT02347189.

Hyperoxia Reduces Oxygen Consumption in Children with Pulmonary Hypertension.

High inspired oxygen concentration (FiO2 > 0.85) is administered to test pulmonary vascular reactivity in children with pulmonary hypertension (PH). It is difficult to measure oxygen consumption (VO2) if the subject is breathing a hyperoxic gas mixture so the assumption is made that baseline VO2 does not change. We hypothesized that hyperoxia changes VO2. We sought to compare the VO2 measured by a thermodilution catheter in room air and hyperoxia. A retrospective review of the hemodynamic data obtained in children with PH who underwent cardiac catheterization was conducted between 2009 and 2014. Cardiac index (CI) was measured by a thermodilution catheter in room air and hyperoxia. VO2 was calculated using the equation CI = VO2/arterial-venous oxygen content difference. Data were available in 24 subjects (males = 10), with median age 8.3 years (0.8-17.6 years), weight 23.3 kg (7.5-95 kg), and body surface area 0.9 m2 (0.4-2.0 m2). In hyperoxia compared with room air, we measured decreased VO2 (154 ± 38 to 136 ± 34 ml/min/m2, p = 0.007), heart rate (91 [Formula: see text] 20 to 83 [Formula: see text] 21 beats/minute, p=0.005), mean pulmonary artery pressure (41 [Formula: see text] 16 to 35 [Formula: see text] 14 mmHg, p=0.024), CI (3.6 [Formula: see text] 0.8 to 3.3 [Formula: see text] 0.9 L/min/m2, p = 0.03), pulmonary vascular resistance (9 [Formula: see text] 6 to 7 [Formula: see text] 3 WU m2, p = 0.029), increased mean aortic (61 [Formula: see text] 11 to 67 [Formula: see text] 11 mmHg, p = 0.005), pulmonary artery wedge pressures (11 [Formula: see text] 8 to 13 [Formula: see text] 9 mmHg, p = 0.006), and systemic vascular resistance (12 [Formula: see text] 6 to 20 [Formula: see text] 7 WU m2, p=0.001). Hyperoxia decreased VO2 and CI and caused pulmonary vasodilation and systemic vasoconstriction in children with PH. The assumption that VO2 remains unchanged in hyperoxia may be incorrect and, if the Fick equation is used, may lead to an overestimation of pulmonary blood flow and underestimation of PVRI.

Postnatal neonatal myocardial adaptation is associated with loss of tolerance to tachycardia: a simultaneous invasive and noninvasive assessment.

Doppler 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. As tachycardia reduces filling time, we hypothesized that the neonatal LV would be less tolerant of atrial tachycardia. Landrace cross piglets of two age groups (1-3 days; NPs; 14-17 days, YPs; n = 7/group) were instrumented for an atrial pacing protocol (from 200 to 300 beats/min) and assessed by invasive monitoring and echocardiography. NPs maintained their LV output and blood pressure, whereas YPs did not. Although negative dP/dt in NPs at baseline was lower than that of YPs (-1,599 ± 83 vs. -2,470 ± 226 mmHg/s, respectively, P = 0.007), with increasing tachycardia negative dP/dt converged between groups and was not different. Both groups had similar preload reduction during tachycardia; however, NPs maintained shortening fraction while YPs decreased (NPs: 35.4 ± 1.4 vs. 31.8 ± 2.2%, P = 0.35; YPs: 31.4 ± 0.8 vs. 22.9 ± 0.8%, P < 0.001). Contractility measures did not differ between groups. Peak LV twist and untwisting rate also did not differ; however, NPs tended to augment LV twist through increased apical rotation and YPs through increasing basal rotation (P = 0.009). The NPs appear more tolerant of atrial tachycardia than the YPs. They have at least similar diastolic performance, enhanced systolic performance, and different LV twist mechanics, which may contribute to improved tachycardia tolerance of NPs.

Cardiac catheterization in children with pulmonary hypertensive vascular disease.

The risks associated with cardiac catheterization in children with pulmonary hypertension (PH) are increased compared with adults. We reviewed retrospectively all clinical data in children with PH [mean pulmonary artery pressure (mean PAp) ≥25 mmHg and pulmonary vascular resistance index (PVRI) ≥3 Wood units m(2)] undergoing cardiac catheterization between 2009 and 2014. Our strategy included a team approach, minimal catheter manipulation and sildenafil administration prior to extubation. Adverse events occurring within 48 h were noted. Seventy-five patients (36 males), median age 4 years (0.3-17) and median weight 14.6 kg (2.6-77 kg), underwent 97 cardiac catheterizations. Diagnoses included idiopathic or heritable pulmonary arterial hypertension (PAH) (29 %), PAH associated with congenital heart disease (52 %), left heart disease (5 %) and lung disease (14 %). Mean PAp was 43 ± 19 mmHg; mean PVRI was 9.7 ± 6 Wood units m(2). There were no deaths or serious arrhythmias. No patient required cardiac massage. Three patients who suffered adverse events had suprasystemic PAp (3/3), heritable PAH (2/3), decreased right ventricular function (3/3), and pulmonary artery capacitance index <1 ml/mmHg/m(2) (3/3) and were treatment naïve (3/3). No patient undergoing follow-up cardiac catheterization suffered a complication. In 45 % of cases, the data acquired from the follow-up cardiac catheterization resulted in an alteration of therapy. Three percent of children with PH undergoing cardiac catheterization suffered adverse events. However, there were no intra or post procedural deaths and no one required cardiac massage or cardioversion. Follow-up cardiac catheterization in patients receiving pulmonary hypertensive targeted therapy is safe and provides useful information.

Percutaneous transhepatic stenting of a restrictive atrial septal communication in hypoplastic left heart syndrome.

The 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. A transhepatic venous approach to stent the atrial communication was technically successful. This approach may be the only access for certain infant cardiac catheterization interventions, permitting the use of a large delivery system (≥ 8 Fr).

Predicting High-Risk Fetal Cardiac Disease Anticipated to Need Immediate Postnatal Stabilization and Intervention with Planned Pediatric Cardiac Operating Room Delivery.

BACKGROUND: Distances between delivery and cardiac services can make the care of fetuses with cardiac disease at risk of acute cardiorespiratory instability at birth a challenge. In 2013 we implemented a fetal echocardiography-based algorithm targeting fetuses considered high risk for acute cardiorespiratory instability at ≤2 hours of birth for delivery in our pediatric cardiac operating room of our children's hospital, and, herein, examine our experience. METHODS AND RESULTS: We reviewed maternal and postnatal medical records of all fetuses with cardiac disease encountered January 2013 to March 2022 considered high risk for acute cardiorespiratory instability. Secondary analysis was performed including all fetuses with diagnoses of d-transposition of the great arteries/intact ventricular septum (d-TGA/IVS) and hypoplastic left heart syndrome (HLHS) encountered over the study period. Forty fetuses were considered high risk for acute cardiorespiratory instability: 15 with d-TGA/IVS and 7 with HLHS with restrictive atrial septum, 4 with absent pulmonary valve syndrome, 3 with obstructed anomalous pulmonary veins, 2 with severe Ebstein anomaly, 2 with thoracic/intracardiac tumors, and 7 others. Pediatric cardiac operating room delivery occurred for 33 but not for 7 (5 with d-TGA/IVS, 2 with HLHS with restrictive atrial septum). For high-risk cases, fetal echocardiography had a positive predictive value of 50% for intervention/extracorporeal membrane oxygenation/death at ≤2 hours and 70% at ≤24 hours. Of "low-risk" cases, 6/46 with d-TGA/IVS and 0/45 with HLHS required intervention at ≤2 hours. Fetal echocardiography for predicting intervention/extracorporeal membrane oxygenation/death at ≤2 hours had a sensitivity of 67%, specificity 93%, and positive and negative predictive values of 80% and 87%, respectively, for d-TGA/IVS, and 100%, 95%, 71%, and 100% for HLHS, respectively. CONCLUSIONS: Fetal echocardiography can predict the need for urgent intervention in a majority with d-TGA/IVS and HLHS and in half of the entire spectrum of high-risk cardiac disease.

Spectral challenges of individual wavelength-scale particles: strong phonons and their distorted lineshapes.

Beyond our own interest in airborne particulate matter, the prediction of extinction and absorption spectra of single particles of mixed composition has wide use in astronomy, geology, atmospheric sciences, and nanotechnology. Single particle spectra present different challenges than traditional spectroscopic approaches. To quantify the amount of a material in a bulk sample (molecules in solution or the gas phase), one might employ the Beer-Lambert law assuming a simple slab-type assay geometry and averaging over orientation, whereas with single particles one might have a specific orientation and require a nonlinear, Mie-like particle theory. The complicating single particle issues include: strong and broad scattering at wavelengths similar to the particle size, phonon lineshape phase shifting, particle shape effects, distortion of transition lineshapes by strong vibrational bands, bi- and trirefringence, crystal orientation effects including dispersion, and composition mixtures. This work uses a combination of three-dimensional finite difference time domain (3D-FDTD) calculations and experimental infrared spectra on single, crystalline quartz particles to illustrate some of the challenges--in particular the distortion of lineshapes by strong phonons that lie within a range of strong scattering. It turns out that many mineral dust components in the inhalable size range have strong phonons. A Mie-Bruggeman model for single particle spectra is presented to isolate the effects of strong phonons on lineshapes which has utility for analysing the spectra of single, mixed-composition particles. This model will ultimately enable the determination of volume fractions of components in single particles that are mixtures of many materials with strong phonons, as are the dust particles breathed into people's lungs.

Infrared spectral model for subwavelength particles of mixed composition based on the spectra of individual particles with calibration data for airborne dust.

A Mie-Bruggeman spectral model is presented which predicts the orientationally averaged, infrared spectra of individual mixed-composition particles or the average spectrum of collections of such particles. The model uses parameters extracted from sets of individual particle spectra of pure materials known to be in subject mixtures. The spectra of both calibrants and subject particles were recorded by trapping size-selected particles in the holes of plasmonic metal mesh. Calibrating data is presented for quartz, calcite, dolomite, three clays, gypsum, polyethylene, and living organic material (yeast cells). The individual particle spectra of these calibrants are averaged to account for crystal orientation effects, fit by a Mie theory model, and tabulated herein as dielectric functions of each component. The component dielectric functions are combined in this model with Bruggeman effective medium theory producing a spectral prediction for mixed-composition particles. The Mie-Bruggeman model was used to analyze the composition of dust from our lab air [K. E. Cilwa et al. J. Phys. Chem. C 2011, 115, 16910] based on the average spectrum of the dust particles. The model does a reasonable job of characterizing the dust in our laboratory air exhibiting promise for future applications. This work presents the model and illustrates potential; however, much more work will be required before its accuracy as a quantitative analytical method is established.

Etalon-Assisted Determination of the Complex Index of Refraction of a Solution for the Study of Strong Cavity-Vibrational Coupling of PF6- in Acetonitrile.

A 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 PF6- in acetonitrile. Mixed states are formed by placing solution inside a pair of parallel plate mirrors with a wavelength-scale spacing, i.e., within an etalon, such that there are cavity states that are angle-tuned into resonance with the strong P-F vibrations. The dominant ν3 vibrations of PF6- consist of nearly triply degenerate oscillations of the partial-positively charged phosphorous against antisymmetric concerted motions of different sets of fluorine atoms with partial negative charges. These vibrations are dominant even though the solute is 29 times less concentrated than the solvent on a molar basis. The first part of the paper describes the method of determining the complex index of refraction of the solution from a combination of etalon transmission maxima and the attenuated total reflection (ATR) absorption spectrum of the solution. The results are presented as an analytical function including a sum of 37 vibrational contributions. Absolute integrated isolated band intensities were determined to be 463 ± 4, 462 ± 7, and 266 ± 4 km/mol for the three ν3 PF6- vibrations at 841.4, 847.4, and 854.0 cm-1, respectively, which sum to 1191 ± 9 km/mol for the ν3 band. Then, the results are used to simulate the measured etalon transmission using the transfer matrix (TM) method with and without the ν3 target vibrations. The etalon transmission simulations reconstruct the position of cavity modes in the absence of target vibrations. They provide input data for the testing of simple quantum mechanical models for the interaction of vibrations with cavity modes and the interactions of vibrations with other vibrations within the molecule and between solute and solvent. The model shows that the nearly degenerate ν3 vibrations interact with each other with a vibration-vibration coupling of 33 ± 5 cm-1. This is comparable to the cavity-vibration coupling of 30.4 ± 2.9 cm-1 of the two strongest vibrations of PF6-.

Etalon-Assisted Study of the Strong CO Ligand Vibrations of the fac-[Re(CO)3(bpy)(CH3CN)]+ Octahedral Complex.

The strong CO ligand vibrations of an octahedral complex, fac-[Re (CO)3(bpy)(CH3CN)]+, in acetonitrile are observed at 2040 and 1932 cm-1. 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. Finally, the etalon experiments are modeled to study the interaction between vibrations, which is a property not embedded in the solution's complex index of refraction. The ATR-IR spectra are accomplished on a dilution series as well as a larger set of spectra as these solutions evaporated. The A'(1) CO ligand band at 2040 cm-1 is fit with a sum of three Lorentzian functions characterizing the distribution of free, solvent-separated, and contact ion pairs of this octahedral complex vs concentration. The other CO ligand band at 1932 cm-1 is broader and complicated by the dynamics of vibrational interactions, the unresolved splitting of the A'(2) and A″ CO vibrations, and ion-pair speciation. The etalon transmission measurements vs angle were on a 0.029 M solution, and Rabi splittings of 19 and 38 cm-1 were observed for the A'(1) CO vibration and the unresolved A'(2) + A″ CO vibrations, respectively. The great strength of the CO ligand vibrations is evident despite the use of a dilute solution. Integrated band intensities are reported in comparison to hybrid density functional calculations for isolated vibrations. Then, the observed Rabi splittings are modeled to obtain the coupling strength of the CO ligand vibration with etalon cavity modes and with each other. In summary, this work develops a method to determine the concentration of these solutions from the ATR-IR spectrum, characterizes the ion-pairing, shows that the index of refraction is not constant in the IR spectral region of interest, and develops an interaction Hamiltonian that characterizes cavity-vibration and vibration-vibration coupling.

Autoinflammation: Interferonopathies and Other Autoinflammatory Diseases.

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. Autoinflammatory features have also been recognized in more common dermatological conditions such as psoriasis. Furthermore, there is an increasing understanding that immunodeficiencies, autoimmune disorders, and even some allergic disorders share overlapping autoinflammatory features. The discovery that certain somatic mutations, arising within the bone marrow and restricted to the myeloid cell lineage can cause acquired AID heralds a new era of discoveries in this field.

Changing Vibration Coupling Strengths of Liquid Acetonitrile with an Angle-Tuned Etalon.

This 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 CH3 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. The ability to change fundamental vibrational dynamics within a cavity is an exciting result which helps to build a foundation for understanding molecular vibrational dynamics in parallel plate etalon cavities.

OCT: A Modality for Identifying Stent Failure in Pediatric Patients With Angiographically Silent Coronary Arteries.

We present the case of a 16-year-old patient with anomalous left coronary artery from the left pulmonary artery requiring percutaneous coronary intervention in infancy who presented with ventricular fibrillation arrest. A coronary angiogram revealed 40% narrowing of the stent relative to the remainder of the left main coronary artery. Optical coherence tomography was performed and revealed an area stenosis of 70% relative to the native left main coronary artery. The patient had outgrown the stent. (Level of Difficulty: Advanced.).

Modifying infrared scattering effects of single yeast cells with plasmonic metal mesh.

The scattering effects in the infrared (IR) spectra of single, isolated bread yeast cells (Saccharomyces cerevisiae) on a ZnSe substrate and in metal microchannels have been probed by Fourier transform infrared imaging microspectroscopy. Absolute extinction [(3.4±0.6)×10(-7) cm(2) at 3178 cm(-1)], scattering, and absorption cross sections for a single yeast cell and a vibrational absorption spectrum have been determined by comparing it to the scattering properties of single, isolated, latex microspheres (polystyrene, 5.0 µm in diameter) on ZnSe, which are well modeled by the Mie scattering theory. Single yeast cells were then placed into the holes of the IR plasmonic mesh, i.e., metal films with arrays of subwavelength holes, yielding "scatter-free" IR absorption spectra, which have undistorted vibrational lineshapes and a rising generic IR absorption baseline. Absolute extinction, scattering, and absorption spectral profiles were determined for a single, ellipsoidal yeast cell to characterize the interplay of these effects.

Effects of Early Myocardial Postnatal Maturation on Tolerance to Atrial Tachycardia With Altered Loading Conditions: An in vivo Swine Model.

Post-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. Methods: We report three series of experimentations. Six groups of landrace cross neonatal piglets (NP) (1-3 days) and young piglets (YP) (14-17 days) were assigned to tachycardia (NP, YP), tachycardia and hypervolemia (NPV, YPV) or tachycardia and increased afterload (NPA, YPA) groups (n = 7/group). Under anesthesia, a pressure catheter was placed in the left ventricle and pacing wire in the right atrium. NPV and YPV groups had 60 ml/kg of normal saline infused over 20 min. NPA and YPA had balloon sub-occlusion of the descending aorta. Heart rate was increased by 10 bpm increments to 300 bpm. Left ventricular output was measured by echocardiography. Results: NP maintained left ventricular output throughout the pacing protocol but it decreased in the YP (p < 0.001). With volume loading both NPV and YPV maintained their output with tachycardia. Although increased afterload resulted in reduced output during tachycardia in NPA (p = 0.005), there was no added impact on output in YPA. Interestingly, 4 of 7 NPV had significant desaturation at 300 bpm (baseline 99.7% vs. 300 bpm 87.9%, p = 0.04), associated with a right to left shunt through the patent foramen ovale which resolved immediately on cessation of pacing. Conclusions: Early post-natal maturation is associated with improved myocardial tolerance to increased afterload and poor tolerance of tachycardia, the latter of which may be alleviated by increasing intravascular volume. These data could translate into the development of better strategies to optimize cardiac output at these early development ages.

A Novel Right Ventricular Volume and Pressure Loaded Piglet Heart Model for the Study of Tricuspid Valve Function.

Heart 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. In this manuscript, we describe the protocols for a novel chronic recovery infant piglet heart model for the study of changes in the TV when placed under combined volume and pressure stress. In this model, volume loading of the right ventricle and the TV is achieved through the disruption of the pulmonary valve. Then pressure loading is accomplished through the placement of a pulmonary artery band. The success of this model is assessed at four weeks post intervention surgery through echocardiography, intracardiac pressure measurement, and pathologic examination of the heart specimens.