315 research outputs found
Unusual Hybrid Closure of Ventricular Septal Defects
A planned combined perventricular and “open heart” surgical closure of multiple ventricular septal defects had to be modified
intraoperatively due to a technical fault disabling echocardiographic guidance. Through an atriotomy, device closure of a muscular
defect and patch closure of a perimembranous ventricular septal defect were performed. In unusual situations, collaboration of
the surgical and interventional team is crucial
Catheter, MRI and CT Imaging in Newborns with Pulmonary Atresia with Ventricular Septal Defect and Aortopulmonary Collaterals: Quantifying the Risks of Radiation Dose and Anaesthetic Time
Catheter, MRI and CT Imaging in Newborns with Pulmonary Atresia with Ventricular Septal Defect and Aortopulmonary Collaterals: Quantifying the Risks of Radiation Dose and Anaesthetic Time
Radiative Decay of Vector Quarkonium: Constraints on Glueballs and Light Gluinos
Given a resonance of known mass, width, and J^{PC}, we can determine its
gluonic branching fraction, b(R->gg), from data on its production in radiative
vector quarkonium decay, V -> gamma+R. For most resonances b(R->gg) is found to
be O(10%), consistent with being q-qbar states, but we find that both
pseudoscalars observed in the 1440 MeV region have b(R->gg) ~ 1/2 - 1, and
b(f_0^{++}->gg) ~ 1/2. As data improves, b(R->gg) should be a useful
discriminator between q-qbar and gluonic states and may permit quantitative
determination of the extent to which a particular resonance is a mixture of
glueball and q-qbar. We also examine the regime of validity of pQCD for
predicting the rate of V -> gamma+eta_gluino, the ``extra'' pseudoscalar bound
state which would exist if there were light gluinos. From the CUSB limit on
peaks in Upsilon -> gamma X, the mass range 3 GeV < m(eta_gluino) < 7 GeV can
be excluded. An experiment must be significantly more sensitive to exclude an
eta_gluino lighter than this.Comment: 36pp (inc figs),RU-94-04. (Replaces original which didn't latex
correctly and didn't have figures.
Indications for stenting of coarctation of the aorta in children under 3 months of age
Introduction: Coarctation of the aorta in children under 3 months of age is usually treated surgically. However, there are clinical scenarios in which stenting of native or recurrent coarctation may become necessary in this age group. Case reports: Four cases illustrate possible indications: left ventricular dysfunction increasing the operative risk, thrombus formation after coarctation surgery, patient size (i.e. in premature babies), and retrograde arch obstruction after hybrid palliation of hypoplastic left heart syndrome. In all babies, coarctation stenting was carried out successfully without complications. Conclusion: Coarctation stenting can be carried out safely in small children. Usually, the stent has to be removed or redilated later. Results are encouraging
Acute coronary ischemia during alcohol withdrawal: a case report
<p>Abstract</p> <p>Introduction</p> <p>The potential of alcohol withdrawal to cause acute coronary events is an area that needs the urgent attention of clinicians and researchers.</p> <p>Case presentation</p> <p>We report the case of a 52-year-old heavy-alcohol-using Sri Lankan man who developed electocardiogram changes suggestive of an acute coronary event during alcohol withdrawal. Despite the patient being asymptomatic, subsequent echocardiogram showed evidence of ischemic myocardial dysfunction. We review the literature on precipitation of myocardial ischemia during alcohol withdrawal and propose possible mechanisms.</p> <p>Conclusions</p> <p>Alcohol withdrawal is a commonly observed phenomenon in hospitals. However, the number of cases reported in the literature of acute coronary events occurring during withdrawal is few. Many cases of acute ischemia or sudden cardiac deaths may be attributed to other well known complications of delirium tremens. This is an area needing the urgent attention of clinicians and epidemiologists.</p
Meson Decay Constants from Isospin Mass Splittings in the Quark Model
Decay constants of and mesons are estimated within the framework of a
heavy-quark approach using measured isospin mass splittings in the , ,
and states to isolate the electromagnetic hyperfine interaction between
quarks. The values MeV and MeV are
obtained. Only experimental errors are given; possible theoretical ambiguities,
and suggestions for reducing them, are noted.Comment: 7 pages, LaTeX, EFI-92-3
Catheter, MRI and CT Imaging in Newborns with Pulmonary Atresia with Ventricular Septal Defect and Aortopulmonary Collaterals: Quantifying the Risks of Radiation Dose and Anaesthetic Time
A comprehensive understanding of the native pulmonary blood supply is crucial in newborns with pulmonary atresia with ventricular septal defect and aortopulmonary collaterals (PA/VSD/MAPCA). We sought to describe the accuracy in terms of identifying native pulmonary arteries, radiation dose and anaesthetic time associated with multi-modality imaging in these patients, prior to their first therapeutic intervention. Furthermore, we wanted to evaluate the cumulative radiations dose and anaesthetic time over the study period. Patients with PA/VSD/MAPCA diagnosed at < 100 days between 2004 and 2014 were identified. Cumulative radiation dose and anaesthetic times were calculated, with imaging results compared with intraoperative findings. We then calculated the cumulative risks to date for all surviving children. Of 19 eligible patients, 2 had echocardiography only prior to first intervention. The remaining 17 patients underwent 13 MRIs, 4 CT scans and 13 cardiac catheterization procedures. The mean radiation dose was 169 mGy cm2 (47–461 mGy cm2), and mean anaesthetic time was 111 min (33–185 min). 3 children had MRI only with no radiation exposure, and one child had CT only with no anaesthetic. Early cross-sectional imaging allowed for delayed catheterisation, but without significantly reducing radiation burden or anaesthetic time. The maximum cumulative radiation dose was 8022 mGy cm2 in a 6-year-old patient and 1263 min of anaesthetic at 5 years. There is the potential to generate very high radiation doses and anaesthetic times from diagnostic imaging alone in these patients. As survival continues to improve in many congenital heart defects, the important risks of serial diagnostic imaging must be considered when planning long-term management
Deep inelastic production at HERA in the -factorization approach and its consequences for the nonrelativistic QCD
In the framework of the -factorization approach, we analyse the
inclusive and inelastic production of particles in deep inelastic
scattering. We take into account both colour-singlet and colour-octet
production channels. We inspect the sensitivity of theoretical predictions to
the choice of model parameters. Our theoretical results agree reasonably well
with recent experimental data collected by the collaboration H1 at HERA.Comment: 14 pages, 6 figure
Upsilonium polarization as a touchstone in understanding the proton dynamics in QCD
In the framework of the k_t-factorization approach, the production of
\alpha$ are presented. We argue
that measuring the polarization of quarkonium states can serve as a crucial
test discriminating two competing theoretical approaches to parton dynamics in
QCD.Comment: 8 pages, 2 figure
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