Cu2+ -mediated assembly of the minor groove binders on the DNA template with sequence selectivity

The ligands (Bpy-H, 5) have been designed to connect the Hoechst33258 skeleton for DNA binding and 2,2'-bipyridine for Cu(2+) complexation. It has been revealed that the new Hoechst ligand long Bpy-H (5L) having a long linker exhibits Cu(2+)-mediated assembly on the DNA template having two A(3)T(3) sites in a selective manner depending on the length of the linker of the ligand as well as on the distance between the two A(3)T(3) sites of DNA. [reaction: see text]     

A multigrid‐based shifted Laplacian preconditioner for a fourth‐order Helmholtz discretization

In this paper, an iterative solution method for a fourth‐order accurate discretization of the Helmholtz equation is presented. The method is a generalization of that presented in (SIAM J. Sci. Comput. 2006; 27 :1471–1492), where multigrid was employed as a preconditioner for a Krylov subspace iterative method. The multigrid preconditioner is based on the solution of a second Helmholtz operator with a complex‐valued shift. In particular, we compare preconditioners based on a point‐wise Jacobi smoother with those using an ILU(0) smoother, we compare using the prolongation operator developed by de Zeeuw in (J. Comput. Appl. Math. 1990; 33 :1–27) with interpolation operators based on algebraic multigrid principles, and we compare the performance of the Krylov subspace method Bi‐conjugate gradient stabilized with the recently introduced induced dimension reduction method, IDR(s). These three improvements are combined to yield an efficient solver for heterogeneous problems. Copyright © 2009 John Wiley & Sons, Ltd.