Cell docking inside microwells within reversibly sealed microfluidic channels for fabricating multiphenotype cell arrays

We present a soft lithographic method to fabricate multiphenotype cell arrays by capturing cells within an array of reversibly sealed microfluidic channels. The technique uses reversible sealing of elastomeric polydimethylsiloxane (PDMS) molds on surfaces to sequentially deliver various fluids or cells onto specific locations on a substrate. Microwells on the substrate were used to capture and immobilize cells within low shear stress regions inside channels. By using an array of channels it was possible to deposit multiple cell types, such as hepatocytes, fibroblasts, and embryonic stem cells, on the substrates. Upon formation of the cell arrays on the substrate, the PDMS mold could be removed, generating a multiphenotype array of cells. In addition, the orthogonal alignment and subsequent attachment of a secondary array of channels on the patterned substrates could be used to deliver fluids to the patterned cells. The ability to position many cell types on particular regions within a two dimensional substrate could potentially lead to improved high-throughput methods applicable to drug screening and tissue engineering.     

Differential Forms in Synthetic Differential Supergeometry

We present a basic theory of differential formsin synthetic differential supergeometry. Exteriordifferential calculus is developed, and Cartan's threemagic formulas as well as a variant of de Rham's theorem are established.     

Characteristic responses of a semiconductor gas sensor depending on the frequency of a periodic temperature change

A novel gas-sensing system based on a dynamic nonlinear response is reported to enhance the selectivity toward sample gases using a single detector. A periodic temperature change was applied to a semiconductor gas sensor and the resulting conductance of the sensor was evaluated by fast Fourier transformation (FFT). The dynamic nonlinear response to the sample gases was further characterized depending on the frequency of the temperature change. The characteristic sensor response under the application of a temperature change was theoretically simulated by considering the kinetics of gas molecules on the semiconductor surface.     

Discovery of Hexagonal Structured Pd–B Nanocrystals

We report on hexagonal close-packed (hcp) palladium (Pd)–boron (B) nanocrystals (NCs) by heavy B doping into face-centered cubic (fcc) Pd NCs. Scanning transmission electron microscopy–electron energy loss spectroscopy and synchrotron powder X-ray diffraction measurements demonstrated that the B atoms are homogeneously distributed inside the hcp Pd lattice. The large paramagnetic susceptibility of Pd is significantly suppressed in Pd–B NCs in good agreement with the reduction of density of states at Fermi energy suggested by X-ray absorption near-edge structure and theoretical calculations.     

Monte carlo simulations for blue-phase structure in liquid crystals

Blue-phase liquid crystals form three-dimensional structures in a self-organizing manner and are similar to living tissue structures such as the teeth of mice and collagen tissues. This study presents numerical results regarding the conditions under which blue-phase liquid crystals occur. The Monte Carlo simulations are performed by employing an improved Lennard–Jones potential that considers anisotropy and chirality. The conditions for the formation of the blue phase, which vary with respect to the chirality, are examined first. The relationship between the anisotropic parameters and the chiral parameter for the formation of the blue phase is discussed. Identical blue-phase structures are obtained, even when the cell size and molecular number are varied drastically. This discussion is useful for considering the scale-up problem, which is almost always a difficult issue for molecular-scale simulations.     

Peripherally Monomial-Preserving Maps between Uniform Algebras

Let and be uniform algebras and p(z,w) = z^mwⁿ a twovariable monomial. We characterize maps T from certain subsets of into such that holds for all f and g in the domain of T; peripherally monomial-preserving maps. Furthermore and are proved to be isometrical isomorphic as Banach algebras. If the greatest common divisor of m and n is 1, then T is extended to an isometrical linear isomorphism; a weighted composition operator. An example of peripherally monomial-preserving surjections between uniform algebras which is not linear, nor multiplicative, nor injective is given when the greatest common divisor is strictly greater than 1. The first, third and fourth authors were partly supported by the Grantsin-Aid for Scientific Research, The Ministry of Education, Science, Sports and Culture, Japan.     

Measurement of the group refractive index of air by two-wavelength interferometry

The group refractive index of air at 3.44 μm is directly measured with an accuracy of 2 × 10^-7 using two-wavelength simultaneous interferometry with a 3.51- and 3.37-μm simultaneous operation He-Xe laser.     

Selective oxidation of hydroxy groups of phenylthio and phenylseleno alcohols

Various kinds of alcohols bearing phenylthio or phenylseleno moiety were converted into the corresponding carbonyl compounds in good to excellent yields by treating with dimesityl diselenide and $\text{tert}$-butyl hydroperoxide.