Publications by authors named "Mark Plunkett"

High-entropy alloy (HEA) nanoparticles (NPs) exhibit unusual combinations of functional properties. However, their scalable synthesis remains a significant challenge requiring extreme fabrication conditions. Metal salts are often employed as precursors because of their low decomposition temperatures, yet contain potential impurities.

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Background: In addition to being associated with aortopathy, a bicuspid aortic valve (BAV) has been posed to be a risk factor for the dilation of the pulmonary autograft in the aortic position. The aim of this study is to assess the association between the subtype of native aortic valve leaflet fusion (right and noncoronary leaflets [R/N] vs right and left leaflets [R/L]) and autograft dilation and valve dysfunction after the Ross procedure.

Methods: We performed a retrospective review of 43 patients with BAV who underwent a Ross procedure in our center from 1993 to 2013.

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The World Society for Pediatric and Congenital Heart Surgery has endorsed the establishment of an international platform for the exchange of knowledge and experience for those that treat patients with a congenital heart defect. On January 1, 2017, the release of the World Database for Pediatric and Congenital Heart Surgery opened a new era in evaluation of treatment with congenital heart defects. The contribution of data from countries with established congenital surgical databases will greatly enhance the efforts to provide the most accurate measure of overall surgical outcomes across the globe.

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We recently demonstrated scalable manufacturing of boron nitride nanotubes (BNNTs) directly from hexagonal BN (hBN) powder by using induction thermal plasma, with a high-yield rate approaching 20 g/h. The main finding was that the presence of hydrogen is crucial for the high-yield growth of BNNTs. Here we investigate the detailed role of hydrogen by numerical modeling and in situ optical emission spectroscopy (OES) and reveal that both the thermofluidic fields and chemical pathways are significantly altered by hydrogen in favor of rapid growth of BNNTs.

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Background: Management of a ventricular septal defect (VSD) at time of coarctation of the aorta (CoA) repair remains controversial, with recent studies advocating concomitant repair of both defects. We evaluated the surgical management and mortality for patients undergoing CoA repair associated with a VSD.

Methods: We retrospectively reviewed data submitted to the Pediatric Cardiac Care Consortium of patients undergoing repair of CoA from 1982 to 2007.

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Objectives: The Avalon Elite (Macquet, Rastatt, Germany) double-lumen cannula can provide effective cavopulmonary assistance in a Fontan (total cavopulmonary connection) sheep model, but it requires strict alignment. The objective was to fabricate and test a newly designed paired umbrella double-lumen cannula without alignment requirement.

Methods: The paired membrane umbrellas were designed on the double-lumen cannula to bracket infusion blood flow toward the pulmonary artery.

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Boron nitride nanotubes (BNNTs) exhibit a range of properties that are as compelling as those of carbon nanotubes (CNTs); however, very low production volumes have prevented the science and technology of BNNTs from evolving at even a fraction of the pace of CNTs. Here we report the high-yield production of small-diameter BNNTs from pure hexagonal boron nitride powder in an induction thermal plasma process. Few-walled, highly crystalline small-diameter BNNTs (∼5 nm) are produced exclusively and at an unprecedentedly high rate approaching 20 g/h, without the need for metal catalysts.

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Our goal was to develop a less invasive total cavopulmonary connection (TCPC) sheep model for testing total cavopulmonary assist (CPA) devices. Thirteen sheep underwent a right fourth intercostal lateral thoracotomy. In series I (n = 6), a polytetrafluoroethylene (PTFE) extracardiac conduit (ECC) was connected to inferior vena cava (IVC) and superior vena cava (SVC) by end-to-side anastomosis.

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Congenital diaphragmatic hernia (CDH) presenting beyond the neonatal period is commonly perceived to be rare. With reported frequencies of 2.6% to 20% of all CDH, it may be an overlooked cause of mortality.

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We report on an acute myocardial injury caused by thrombotic emboli during off-pump bilateral sequential lung transplantation in a 15-year-old female patient with end-stage cystic fibrosis. A few minutes after reperfusion of the right (second sequential) allograft, the patient developed hemodynamic collapse, including hypotension, acute akinesis of the anterior and lateral myocardial walls, and severe mitral regurgitation. Thrombus was noted within the left atrium and ventricle on intraoperative transesophageal echocardiogram.

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Background: Mechanical circulatory support is a highly effective technology to maintain organ perfusion in patients with cardiogenic shock as a bridge to transplantation. Although implantation of a left ventricular assist device alone is often the preferred configuration, patients with biventricular failure and significant end-organ dysfunction often require biventricular assistance.

Methods: Between January 2000 and September 2008, 80 patients with severe biventricular failure were accepted for heart transplantation and received a pneumatic biventricular assist devices as a bridge to transplant.

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Background: We are developing a total cavopulmonary support system for failing Fontan physiology using the percutaneous Wang-Zwische double-lumen cannula (DLC).

Methods: We developed a sheep model of failing Fontan physiology through a right thoracotomy in 5 sheep. An extracardiac conduit was anastomosed to the inferior vena cava and superior vena cava, and a graft was applied to connect the conduit and the right pulmonary artery (PA) to create total vena cava-to-PA diversion, excluding the right heart.

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Objectives: To evaluate the incidence of atrial tachy-arrhythmia (AT) recurrence following conversion from right atrial-pulmonary artery (RA-PA) Fontan to total cavopulmonary connection (TCPC) in adults.

Background: AT is a recognized sequel of Fontan palliation, especially in RA-PA Fontans, and is associated with significant morbidity. While catheter ablation achieves fairly reliable short-term success with low morbidity, conversion to TCPC with arrhythmia surgery is a highly effective treatment option for the classical Fontan patients with incessant AT.

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Anomalous origin of a pulmonary artery from the ascending aorta (AORPA) is a rare congenital cardiac malformation that needs prompt surgical repair; otherwise it is associated with poor prognosis. We describe 3 cases of AORPA that successfully underwent complete surgical correction without extracorporeal circulation.

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Salivary films coating oral surfaces are critically important for oral health. This study focuses on determining the underlying nature of this adsorbed film and how it responds to departures from physiological conditions due to changes in ionic strength. Under physiological conditions, it is found that pre-adsorbed in vitro salivary film on hydrophobic surfaces is present as a highly hydrated viscoelastic layer.

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Truncal valve insufficiency is a significant risk factor for post-operative mortality following repair of truncus arteriosus. The surgical management of dysplastic and insufficient truncal valves remains an operative challenge. We report the cases of two infants with type 2 truncus arteriosus and severely dysplastic and insufficient quadricuspid truncal valves.

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Background: Heart transplantation in the elderly is increasingly common. In the mid-1990s, 25% of recipients in our program were >62 years of age. We evaluated outcomes from one institution with the hypothesis that older recipients may be at higher risk of major complications associated with immunosuppression.

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Article Synopsis
  • The Fontan operation, first described in 1971, has evolved significantly over the past 40 years through various medical and surgical approaches.
  • The text examines a patient's journey with a single ventricle, detailing the history and implications of the Fontan procedure, including its indications and potential complications.
  • It emphasizes the use of cardiac computed tomography with angiography as an effective noninvasive method for assessing the unique complexities of Fontan circulation.
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Purpose/objectives: Each year in the United States, more than 4.4 million patients with chest pain (DRG 143) present to emergency departments. Many of these admissions do not have documented justification to support an acute inpatient admission.

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Background: Pulmonary artery reconstruction remains a challenging clinical problem. We sought to evaluate the use of intraoperative stenting in conjunction with open heart surgical repairs.

Methods: We retrospectively analyzed data from 22 patients between 1998 and 2003 who underwent intraoperative pulmonary artery stenting.

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This chapter describes the structure/function relationships of the right ventricle (RV), and shows how the geometry of the helical ventricular myocardial band model defines spatial geometry of the free wall and septum that underlie dynamic action. Myocardial fiber orientation is the keynote to performance in health and disease. The transverse geometry of the RV free wall allows constriction (bellows-type motion), whereas oblique septal fiber orientation and midline septal position is essential for ventricular twisting, the vital mechanism for RV ejection against increased pulmonary vascular resistance.

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