Electronic Cooling via Interlayer Coulomb Coupling in Multilayer Epitaxial Graphene

In van der Waals bonded or rotationally disordered multilayer stacks of two-dimensional (2D) materials, the electronic states remain tightly confined within individual 2D layers. As a result, electron-phonon interactions occur primarily within layers and interlayer electrical conductivities are low. In addition, strong covalent in-plane intralayer bonding combined with weak van der Waals interlayer bonding results in weak phonon-mediated thermal coupling between the layers. We demonstrate here, however, that Coulomb interactions between electrons in different layers of multilayer epitaxial graphene provide an important mechanism for interlayer thermal transport even though all electronic states are strongly confined within individual 2D layers. This effect is manifested in the relaxation dynamics of hot carriers in ultrafast time-resolved terahertz spectroscopy. We develop a theory of interlayer Coulomb coupling containing no free parameters that accounts for the experimentally observed trends in hot-carrier dynamics as temperature and the number of layers is varied.Comment: 54 pages, 15 figures, uses documentclass{achemso}, M.T.M. and J.R.T. contributed equally to this wor

Gluon Fusion: A Probe of Higgs Sector CP Violation

We demonstrate that CP violation in the Higgs sector, \eg\ of a multi-doublet model, can be directly probed using gluon-gluon collisions at the SSC. % requires phyzzx.tex macro packageComment: UCD-93-

Single center experience on dosing and adverse events of recombinant factor seven use for bleeding after congenital heart surgery

There are limited data on the relationship between the administered dose of recombinant factor seven (rFVIIa) and the development of adverse clinical outcomes after congenital heart surgery. This single institution case series reports on dosing, adverse events, and blood product usage after the administration of rFVIIa in the congenital heart surgery patient population. A retrospective review identified 16 consecutive pediatric patients at an academic, free-standing, children’s hospital who received rFVIIa to curtail bleeding following congenital heart surgery between April 2004 and June 2012. Patients were assessed for survival to hospital discharge versus in-hospital mortality and the presence or absence of a major neurological event during inpatient hospitalization. The median age at surgery was 6.8 months (range: 3 days–42 years). Seven patients (44%) survived to hospital discharge and nine patients (56%) died. The cause of mortality included major neurological events (44%), uncontrolled bleeding (33%), and sepsis (23%). Eight patients (50%) required extracorporeal membrane oxygenation support following congenital heart surgery. The median cumulative rFVIIa dose administered was 97 mcg/kg, and the median cumulative amount of blood products administered was 452 ml/kg. In conclusion, this case series underscores the need to prospectively evaluate the effect that rFVIIa has on patient survival and the incidence of adverse events, including thrombotic and major neurological events, in congenital heart surgery patients. Ideally, a randomized, multicenter study would provide the sufficient numbers of patients and events to test these relationships

Risk Factors for Major Early Adverse Events Related to Cardiac Catheterization in Children and Young Adults With Pulmonary Hypertension: An Analysis of Data From the IMPACT (Improving Adult and Congenital Treatment) Registry.

BACKGROUND: Cardiac catheterization is the gold standard for assessment and follow-up of patients with pulmonary hypertension (PH). To date, there are limited data about the factors that influence the risk of catastrophic adverse events after catheterization in this population. METHODS AND RESULTS: A retrospective multicenter cohort study was performed to measure risk of catastrophic adverse outcomes after catheterization in children and young adults with PH and identify risk factors for these outcomes. All catheterizations in children and young adults, aged 0 to 21 years, with PH at hospitals submitting data to the IMPACT (Improving Adult and Congenital Treatment) registry between January 1, 2011, and December 31, 2015, were studied. Using mixed-effects multivariable regression, we assessed the association between prespecified subject-, procedure-, and center-level covariates and the risk of death, cardiac arrest, or mechanical circulatory support during or after cardiac catheterization. A total of 8111 procedures performed in 7729 subjects at 77 centers were studied. The observed risk of the composite outcome was 1.4%, and the risk of death before discharge was 5.2%. Catheterization in prematurely born neonates and nonpremature infants was associated with increased risk of catastrophic adverse event, as was precatheterization treatment with inotropes and lower systemic arterial saturation. Secondary analyses demonstrated the following: (1) increasing volumes of catheterization in patients with PH were associated with reduced risk of composite outcome (odds ratio, 0.8 per 10 procedures; CONCLUSIONS: Young patients with PH are a high-risk population for diagnostic and interventional cardiac catheterization. Hospital experience with PH is associated with reduced risk, independent of total catheterization case volume

Intermediate-Term Results of Extracorporeal Membrane Oxygenation Support Following Congenital Heart Surgery

Background: Although there are considerable data regarding in-hospital results of congenital heart surgery patients requiring post-operative extracorporeal membrane oxygenation support, there is limited information on intermediate-term outcomes. Methods: A single institution retrospective review of 25 consecutive post-operative congenital heart surgery patients who required extracorporeal membrane oxygenation and survived to hospital discharge between January 2003 and June 2008. Survival was estimated by the Kaplan-Meier method. Results: At a median follow-up of 3.3 years (interquartile range: 1.2-5.9 years), there was 1 death which occurred at 6 months post-surgery. Kaplan-Meier estimated survival at 3 years was 95% (95% confidence interval: 90-100%). Indications for extracorporeal membrane oxygenation included extracorporeal cardiopulmonary resuscitation (48%), systemic hypoxia (4%), post-operative low cardiac output syndrome (28%), and intra-operative failure to wean off of cardiopulmonary bypass (20%). Following extracorporeal membrane oxygenation support, 65% of patients had unplanned cardiac re-interventions (3 requiring operative interventions, 6 requiring percutaneous interventions, and 4 requiring both), and 47% required unplanned hospitalizations. 29% developed neurological deficits, and 12% developed chronic respiratory failure. No patients developed renal failure. Overall systemic ventricular function normalized in 83% of patients, whereas 17% had persistent mild-to-moderate systemic ventricular dysfunction. Conclusions: Intermediate-term patient survival of extracorporeal membrane oxygenation following congenital heart surgery is encouraging. However, neurological impairment and unplanned cardiac re-interventions remain significant concerns. Further delineation of risk factors to improve patient outcomes is warranted

Guidance of sentinel lymph node biopsy decisions in patients with T1-T2 melanoma using gene expression profiling.

AIM: Can gene expression profiling be used to identify patients with T1-T2 melanoma at low risk for sentinel lymph node (SLN) positivity? PATIENTS & METHODS: Bioinformatics modeling determined a population in which a 31-gene expression profile test predicted \u3c5% SLN positivity. Multicenter, prospectively-tested (n = 1421) and retrospective (n = 690) cohorts were used for validation and outcomes, respectively. RESULTS: Patients 55-64 years and ≥65 years with a class 1A (low-risk) profile had SLN positivity rates of 4.9% and 1.6%. Class 2B (high-risk) patients had SLN positivity rates of 30.8% and 11.9%. Melanoma-specific survival was 99.3% for patients ≥55 years with class 1A, T1-T2 tumors and 55.0% for class 2B, SLN-positive, T1-T2 tumors. CONCLUSION: The 31-gene expression profile test identifies patients who could potentially avoid SLN biopsy

NLO Higgs boson production plus one and two jets using the POWHEG BOX, MadGraph4 and MCFM

We present a next-to-leading order calculation of Higgs boson production plus one and two jets via gluon fusion interfaced to shower Monte Carlo programs, implemented according to the POWHEG method. For this implementation we have used a new interface of the POWHEG BOX with MadGraph4, that generates the codes for generic Born and real processes automatically. The virtual corrections have been taken from the MCFM code. We carry out a simple phenomenological study of our generators, comparing them among each other and with fixed next-to-leading order results.Comment: 27 pages, 21 figure