Dynamics of self assembly of magnetized disks rotating at the liquid-air interface

This paper is a theoretical study of dynamic self assembly in a system of millimeter-sized magnetized disks floating at a liquid-air interface and spinning under the influence of a rotating magnetic field. Equations of motions are derived that account for the hydrodynamic and magnetic forces acting in the system. Numerical integration of these equations predicts formation of ordered structures of spinning disks; the simulated structures reproduce the patterns observed experimentally.

Combinatorial computational method gives new picomolar ligands for a known enzyme

Combinatorial small molecule growth algorithm was used to design inhibitors for human carbonic anhydrase II. Two enantiomeric candidate molecules were predicted to bind with high potency (with R isomer binding stronger than S), but in two distinct conformations. The experiments verified that computational predictions concerning the binding affinities and the binding modes were correct for both isomers. The designed R isomer is the best-known inhibitor (K(d) approximately 30 pM) of human carbonic anhydrase II.

Dynamic, self-assembled aggregates of magnetized, millimeter-sized objects rotating at the liquid-air interface: macroscopic, two-dimensional classical artificial atoms and molecules

This paper describes self-assembly of millimeter-sized, magnetized disks floating on a liquid-air interface, and rotating under the influence of a rotating external magnetic field. Spinning of the disks results in hydrodynamic repulsion between them, while the rotating magnetic field produces an average confining potential acting on all disks. The interplay between hydrodynamic and magnetic interactions leads to the formation of patterns. Theoretical analysis of hydrodynamic and magnetic forces indicates that the interactions in this system are similar to those acting in systems of finite numbers of particles behaving classically ("classical artificial atoms"). Macroscopic artificial atoms and molecules are described, and the rules governing their morphologies outlined.

Modeling the kinetics of acylation of insulin using a recursive method for solving the systems of coupled differential equations

This paper describes a theoretical method for solving systems of coupled differential equations that describe the kinetics of complicated reaction networks in which a molecule having multiple reaction sites reacts irreversibly with multiple equivalents of a ligand (reagent). The members of the network differ in the number of equivalents of reagent that have reacted, and in the patterns of sites of reaction. A recursive algorithm generates series, asymptotic, and average solutions describing this kinetic scheme. This method was validated by successfully simulating the experimental data for the kinetics of acylation of insulin.

Beam redirection and frequency filtering with transparent elastomeric diffractive elements

A new, to our knowledge, type of optical device capable of beam redirection and frequency filtering is described. It is based on a transparent elastomeric binary diffraction grating. When light is passed through the device the intensities of the diffraction orders can be modulated by compression of the elastomer in the direction perpendicular to the plane of the grating. Selective filtering of the component frequencies of two-component light (lambda = 543.5 nm and lambda = 632.8 nm) has been demonstrated. Experimental observations are in agreement with theoretical calculations quantifying the performance of the device.