2,772 research outputs found

    Response to Borg and Bergermaier

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43704/1/11205_2004_Article_BF00300658.pd

    721-6 Pulmonary Balloon Valvuloplasty: Effective Palliation for Infants with Tetralogy of Fallot and Small Pulmonary Arteries

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    Infants with tetralogy of Fallot (TOF) and small pulmonary arteries (PAs) may need palliation to improve pulmonary blood flow and allow growth of the PAs prior to complete repair. Shunts may become occluded, distort the PAs or cause pulmonary overcirculation. As an alternative palliation, we performed pulmonary balloon valvuloplasty (PBV) on infants with TOF and small PAs.20 infants, ages 1.8±1.5 mo and weights 4.1±1.6kg, undervvent PBV as initial palliation for persistent cyanosis or “spells”. 4/20 pts were intubated prior to or for PBV All pts had pre and post-PBV angiograms. In all pts, single balloon valvuloplasty was performed. The ratio of balloon: pulmonary valve annulus (PVA) diameter was 1.51±0.32. Post-PBV, there was no change in the PYA diameter (5.2±1.1mm vs 5.6 + 1.1mm; p=0.1) or PA branch diameter(4.1±1.6mm vs 4.5±1.7mm, p>0.05). The systemic 02 saturation increased from 81±8% to 93±6%. (p<0.001)7/20 pts undervvent follow-up (F/U) cath 8.2±2.4 mo post-PBV Compared to pre-PBV measurements, the PYA diameter increased from 5.2 ± 1.1mm to 7.1±1.4mm (p<0.03) and the McGoon ratio increased from 1.4±0.4 to 2.1±0.3 (p<0.02).Of the 20 pts, 11 pts undervvent corrective surgery 8.0±3.1 mo post-PBV with no surgical deaths; 5 pts remain in stable condition awaiting surgery; 3 pts required shunt placement 9-66 days post-PBV; 1 pt died due to other congenital anomalies.ConclusionsPulmonary balloon valvuloplasty promotes growth of the PAs and PYA in infants with TOF and small PAs, offering a safe and effective alternative palliation for infants who are not yet candidates for complete repair

    Effects of airway obstruction and hyperinflation on electrocardiographic axes in COPD

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    Background: COPD influences cardiac function and morphology. Changes of the electrical heart axes have been largely attributed to a supposed increased right heart load in the past, whereas a potential involvement of the left heart has not been sufficiently addressed. It is not known to which extent these alterations are due to changes in lung function parameters. We therefore quantified the relationship between airway obstruction, lung hyperinflation, several echo- and electrocardiographic parameters on the orientation of the electrocardiographic (ECG) P, QRS and T wave axis in COPD. Methods: Data from the COPD cohort COSYCONET were analyzed, using forced expiratory volume in 1 s (FEV1), functional residual capacity (FRC), left ventricular (LV) mass, and ECG data. Results: One thousand, one hundred and ninety-five patients fulfilled the inclusion criteria (mean ± SD age: 63.9 ± 8.4 years; GOLD 0–4: 175/107/468/363/82). Left ventricular (LV) mass decreased from GOLD grades 1–4 (p = 0.002), whereas no differences in right ventricular wall thickness were observed. All three ECG axes were significantly associated with FEV1 and FRC. The QRS axes according to GOLD grades 0–4 were (mean ± SD): 26.2° ± 37.5°, 27.0° ± 37.7°, 31.7° ± 42.5°, 46.6° ± 42.2°, 47.4° ± 49.4°. Effects of lung function resulted in a clockwise rotation of the axes by 25°-30° in COPD with severe airway disease. There were additional associations with BMI, diastolic blood pressure, RR interval, QT duration and LV mass. Conclusion: Significant clockwise rotations of the electrical axes as a function of airway obstruction and lung hyperinflation were shown. The changes are likely to result from both a change of the anatomical orientation of the heart within the thoracic cavity and a reduced LV mass in COPD. The influences on the electrical axes reach an extent that could bias the ECG interpretation. The magnitude of lung function impairment should be taken into account to uncover other cardiac disease and to prevent misdiagnosis

    Effects of airway obstruction and hyperinflation on electrocardiographic axes in COPD

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    BackgroundCOPD influences cardiac function and morphology. Changes of the electrical heart axes have been largely attributed to a supposed increased right heart load in the past, whereas a potential involvement of the left heart has not been sufficiently addressed. It is not known to which extent these alterations are due to changes in lung function parameters. We therefore quantified the relationship between airway obstruction, lung hyperinflation, several echo- and electrocardiographic parameters on the orientation of the electrocardiographic (ECG) P, QRS and T wave axis in COPD.MethodsData from the COPD cohort COSYCONET were analyzed, using forced expiratory volume in 1s (FEV1), functional residual capacity (FRC), left ventricular (LV) mass, and ECG data.ResultsOne thousand, one hundred and ninety-five patients fulfilled the inclusion criteria (meanSD age: 63.9 +/- 8.4years;GOLD 0-4: 175/107/468/363/82). Left ventricular (LV) mass decreased from GOLD grades 1-4 (p=0.002), whereas no differences in right ventricular wall thickness were observed. All three ECG axes were significantly associated with FEV1 and FRC. The QRS axes according to GOLD grades 0-4 were (mean +/- SD): 26.2 degrees +/- 37.5 degrees, 27.0 degrees +/- 37.7 degrees, 31.7 degrees +/- 42.5 degrees, 46.6 degrees +/- 42.2 degrees, 47.4 degrees +/- 49.4 degrees. Effects of lung function resulted in a clockwise rotation of the axes by 25 degrees-30 degrees in COPD with severe airway disease. There were additional associations with BMI, diastolic blood pressure, RR interval, QT duration and LV mass.Conclusion Significant clockwise rotations of the electrical axes as a function of airway obstruction and lung hyperinflation were shown. The changes are likely to result from both a change of the anatomical orientation of the heart within the thoracic cavity and a reduced LV mass in COPD. The influences on the electrical axes reach an extent that could bias the ECG interpretation. The magnitude of lung function impairment should be taken into account to uncover other cardiac disease and to prevent misdiagnosis

    The number of ways to label a structure

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    It has been observed that the number of different ways in which a graph with p points can be labelled is p ! divided by the number of symmetries, and that this holds regardless of the species of structure at hand. In this note, a simple group-theoretic proof is provided.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45724/1/11336_2005_Article_BF02289423.pd

    Lunar surface mechanical properties — Surveyor 1

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    Engineering telemetry data and lunar surface photographs by Surveyor 1 have been evaluated for information on the mechanical properties of the lunar surface material at the Surveyor 1 landing site. Based primarily on photographic evidence, estimates of soil density, cohesion, and other soil characteristics are presented. Also, the mechanisms in which the lunar material is believed to have failed under the footpad impacts are discussed. Because dynamic soil reactions cannot be interpreted directly from the available data, a comparative study using computer-simulated landings was initiated. Preliminary results of this study, which is still in progress, are presented

    Probing the Early Stages of Low-Mass Star Formation in LDN 1689N: Dust and Water in IRAS 16293-2422A, B, and E

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    We present deep images of dust continuum emission at 450, 800, and 850 micron of the dark cloud LDN 1689N which harbors the low-mass young stellar objects (YSOs) IRAS 16293-2422A and B (I16293A and I16293B) and the cold prestellar object I16293E. Toward the positions of I16293A and E we also obtained spectra of CO-isotopomers and deep submillimeter observations of chemically related molecules with high critical densities. To I16293A we report the detection of the HDO 1_01 - 0_00 and H2O 1_10 - 1_01 ground-state transitions as broad self-reversed emission profiles with narrow absorption, and a tentative detection of H2D+ 1_10 - 1_11. To I16293E we detect weak emission of subthermally excited HDO 1_01 - 0_00. Based on this set of submillimeter continuum and line data we model the envelopes around I16293A and E. The density and velocity structure of I16293A is fit by an inside-out collapse model, yielding a sound speed of a=0.7 km/s, an age of t=(0.6--2.5)e4 yr, and a mass of 6.1 Msun. The density in the envelope of I16293E is fit by a radial power law with index -1.0+/-0.2, a mass of 4.4 Msun, and a constant temperature of 16K. These respective models are used to study the chemistry of the envelopes of these pre- and protostellar objects. The [HDO]/[H2O] abundance ratio in the warm inner envelope of I16293A of a few times 1e-4 is comparable to that measured in comets. This supports the idea that the [HDO]/[H2O] ratio is determined in the cold prestellar core phase and conserved throughout the formation process of low-mass stars and planets.Comment: 61 pages, 17 figures. Accepted for publication in ApJ. To get Fig. 13: send email to [email protected]

    Plasma Dynamics

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    Contains reports on four research projects.National Science Foundation (Grant GK-37979X)U.S. Atomic Energy Commission (Contract AT(11-1)-3070
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