Andrew Chi Sing Leung

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We have used a biomembrane force probe decorated with P-selectin to form point attachments with PSGL-1 receptors on a human neutrophil (PMN) in a calcium-containing medium and then to quantify the forces experienced by the attachment during retraction of the PMN at fixed speed. From first touch to final detachment, the typical force history exhibited the(More)
A simple micromechanical method has been used to directly measure the force of contraction in single mammalian phagocytes (blood granulocytes) during engulfment of large yeast pathogens. Both the time course of cell spreading over the yeast particle and increase in cell body contractile force were quantitated at three temperatures in the range of 23-35(More)
Many biomolecular bonds exhibit a mechanical strength that increases in proportion to the logarithm of the rate of force application. Consistent with exponential decrease in bond lifetime under rising force, this kinetically limited failure reflects dissociation along a single thermodynamic pathway impeded by a sharp free energy barrier. Using a sensitive(More)
Binding of the plant lectin wheat germ agglutinin (WGA) to erythrocyte membranes causes membrane rigidification. One of our objectives has been to directly measure the effects of WGA binding on membrane rigidity and to relate rigidification to the kinetics and levels of WGA binding. Our other objective has been to measure the strength of adhesion and(More)
We have used a biomembrane force probe decorated with P-selectin to form point attachments with PSGL-1 receptors on a human neutrophil (PMN) in a calcium-containing medium and then to quantify the forces experienced by the attachment during retraction of the PMN at fixed speed. From first touch to final detachment, the typical force history exhibited the(More)
It has been 21 years since the first International Conference on Neural Information Processing (ICONIP) held in Seoul, Korea, and now is the annual conference of the Asia Pacific Neural Network Assembly (APNNA) aiming at providing a platform for the neural processing community to present their researches and to exchange the research ideas. In 2014, ICONIP(More)
It has been over 17 years since the first International Conference on Neural Information Processing (ICONIP) held in Seoul, Korea. ICONIP is organized by the Asia– Pacific Neural Network Assembly (APNNA). The aim of ICONIP is to bring together scientists, practitioners, and students worldwide, especially from the Asia–Pacific region, to discuss the(More)
Using a biomembrane force probe decorated with P-selectin, discrete bonds were formed to PSGL-1 receptors on PMN surfaces and detached at speeds from ~ 1-100 µm/sec. High resolution tracking of the distance between probe tip and PMN revealed an initial elastic deformation that was either terminated by abrupt detachment or interrupted by yield and fluid-like(More)
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