Pak-Wing Fok

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The morphological relaxation of faceted crystal surfaces is studied via a continuum approach. Our formulation includes (i) an evolution equation for the surface slope that describes step line tension, g1, and step repulsion energy, g3; and (ii) a condition at the facet edge (a free boundary) that accounts for discrete effects via the collapse times, t(n),(More)
  • Pak-Wing Fok
  • Mathematical medicine and biology : a journal of…
  • 2012
Plaques are fatty deposits that grow mainly in arteries and develop as a result of a chronic inflammatory response. Plaques are characterized as 'vulnerable' when they have large internal regions of necrosis and are heavily infiltrated by macrophages. The particular composition of a vulnerable plaque renders it susceptible to rupture, which releases(More)
Pak-Wing Fok,1 Rodolfo R. Rosales,2 and Dionisios Margetis3 1Applied and Computational Mathematics, California Institute of Technology, Pasadena, California 91125, USA 2Department of Mathematics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA 3Department of Mathematics and Institute for Physical Science and Technology, University(More)
Pak-Wing Fok,1,2 Rodolfo R. Rosales,3 and Dionisios Margetis4 1Applied and Computational Mathematics, California Institute of Technology, Pasadena, California 91125, USA 2Department of Biomathematics, University of California–Los Angeles, Los Angeles, California 90095, USA 3Department of Mathematics, Massachusetts Institute of Technology, Cambridge,(More)
We investigate the dynamics of a one-dimensional asymmetric exclusion process with Langmuir kinetics and a fluctuating wall. At the left-hand boundary, particles are injected onto the lattice; from there, the particles hop to the right. Along the lattice, particles can adsorb or desorb, and the right-hand boundary is defined by a wall particle. The(More)
Atherosclerotic plaque can cause severe stenosis in the artery lumen. Blood flow through a substantially narrowed artery may have different flow characteristics and produce different forces acting on the plaque surface and artery wall. The disturbed flow and force fields in the lumen may have serious implications on vascular endothelial cells, smooth muscle(More)
A crystal lattice with a small miscut from the plane of symmetry has a surface which consists of a series of atomic height steps separated by terraces. If the surface of this crystal is not in equilibrium with the surrounding medium, then its evolution is strongly mediated by the presence of these steps, which act as sites for attachment and detachment of(More)
Damaged or mismatched bases in DNA can be repaired by base excision repair enzymes (BER) that replace the defective base. Although the detailed molecular structures of many BER enzymes are known, how they colocalize to lesions remains unclear. One hypothesis involves charge transport (CT) along DNA [Yavin et al., Proc. Natl. Acad. Sci. U.S.A. 102, 3546(More)
A charge transport (CT) mechanism has been proposed in several articles to explain the localization of base excision repair (BER) enzymes to lesions on DNA. The CT mechanism relies on redox reactions of iron-sulfur cofactors that modify the enzyme's binding affinity. These redox reactions are mediated by the DNA strand and involve the exchange of electrons(More)