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Biomedical subjects

K E Paul

Publications and source records attributed to K E Paul.

4 recordsLinked to original sources
PubMed2001

Self-assembly of 10-microm-sized objects into ordered three-dimensional arrays.

This paper describes the self-assembly of small objects--polyhedral metal plates with largest dimensions of 10 to 30 microm--into highly ordered, three-dimensional arrays. The plates were fabricated using photolithography and electrodeposition techniques, and the faces of the plates were functionalized to be hydrophobic or hydrophilic using self-assembled monolayers (SAMs). Self-assembly occurs in water through capillary interactions between thin films of a hydrophobic liquid (a liquid prepolymer adhesive) coated onto the hydrophobic faces of the plates; coalescence of the adhesive films reduces the interfacial free energy of the system and drives self-assembly. By altering the size and surface-patterning of the plates, the external morphologies of the aggregates were varied. Curing the adhesive furnished mechanically stable aggregates that were characterized by scanning electron microscopy (SEM). For assemblies formed by plates partially composed of a sacrificial material, a subsequent etching step furnished fully open, three-dimensional microstructures. This work validates the use of capillary interactions for three-dimensional mesoscale self-assembly in the 10-microm-size regime and opens new avenues for the fabrication of complex, three-dimensional microscructures.

Electroplating↗
PubMed1998

Cardiac malposition, redistribution of fetal cardiac output, and left heart hypoplasia reduce survival in neonates with congenital diaphragmatic hernia requiring extracorporeal membrane oxygenation.

OBJECTIVE: To evaluate cardiac position, left ventricular (LV) mass, and distribution of fetal cardiac output in infants with congenital diaphragmatic hernia (CDH) who required extracorporeal membrane oxygenation (ECMO), and in control subjects. STUDY DESIGN: Echocardiograms were performed on 23 neonates with CDH shortly after birth, and repeated within 5 days of repair on ECMO in 21 infants,aand on 12 infants receiving ECMO for other diagnoses, and on 10 healthy, term neonates. Cardiac angle between the midline saggital plane and the interventriculak septum was measured, and deviation from normal (45 degrees) was determined. The ratio of cross-sectional areas (proportional to flows) across the pulmonary (PV) and aortic (AV) valves was determined (PV2/AV2) in 19 infants with CDH and in the healthy control subjects. RESULTS: Thirteen (57%) infants with CDH survived and 10 (43%) died, with no difference in cardiac deviation before surgical repair (35 +/- 13 degrees vs Cardiac deviation persisted after repair in nonsurvivors (27 +/- 14 degrees vs 800.01 and LV mass was significantly less (1.68 +/- 0.39 vs 3.05 +/- 1.20 gm/kg, p00.0005). Neonates requiring ECMO for other diagnoses and well term babies did not have cardiac angle deviations; both these groups had a greater LV mass than did the infants with CDH. The PV2/AV2 flow ratios were higher in infants with CDH (median, 1.73; range, 1.25 to 16.50) compared with those of the healthy infants (0.96, 0.79 to 1.69, p < 0.0002). CONCLUSIONS: Cardiac malposition persisted despite CDH repair in nonsurvivors with low LV mass, and fetal cardiac output was redistributed away from the left ventricle. Lung hypoplasia with reduced pulmonary flow returning to the left atrium and altered left atrial hemodynamics may result in LV hypoplasia

Abnormalities, Multiple↗
PubMed1995

Recognition, stabilization, and early management of infants with critical congenital heart disease presenting in the first days of life.

The incidence of infants born with congenital heart disease (CHD) is about 0.8% of all live births. Out of this at-risk population, approximately one-third will develop life-threatening symptoms of critical CHD within the first few days of life. These infants present the neonatal team with a variety of challenges, and require early identification along with proper stabilization and treatment to survive. The neonatal nurse plays a vital role in recognizing the first signs and symptoms of cardiac distress. This article discusses the most common life-threatening congenital cardiac lesions, reviews their pathophysiology, and outlines the initial medical and nursing management. A through understanding of these concepts can help the nurse improve patient outcomes.

Heart Defects, Congenital↗