Relocation of active acetylcholinesterase to liposome-gel conjugate

Relocation of a glycosylphosphatidylinositol (GPI)-anchored protein acetylcholinesterase (AChE) in its enzymatically active form from proteovesicles containing human erythrocyte ghost membrane proteins onto a liposome-gel conjugate was examined. Liposomes of 1,2-dimyristoylphosphatidylcholine (DMPC) were immobilized on Sephacryl S-1000 gel that was chemically modified to bear hydrophobic octyl moieties. Upon coincubation of the liposome-gel conjugate with freely suspended proteovesicles prepared from erythrocyte ghosts, 50% of the AChE left the proteovesicles and immobilized onto the liposome-gel conjugate in 18 h. When the proteovesicles were immobilized and interacted with freely suspended plain liposomes, approximately 2% of the AChE appeared in the liposome fraction. The relocation of AChE apparently possesses strong preference for the liposome-gel conjugate, suggesting that the hydrophobic moieties on the gel could assist the relocation.     

Exact diagonalization studies on two-band minimal model for iron-based superconductors

In order to explore a superconducting mechanism on iron-based superconductors, we numerically study a two-band minimal model considering two degenerate d_xz and d_yz orbitals on Fe atom. We perform exact diagonalization on a two-band and two-leg square ladder totally composed of 10 lattice sites, which is computationally equivalent to 4-leg 20-sites square-Hubbard-ladder. Consequently, we find that a robust pairing occurs in a wide parameter range when the intra-orbital repulsive interaction becomes smaller than the inter-orbital one. Moreover, the obtained binding energy can grow into much larger value than that obtained in the single band Hubbard model depending on the parameter range.     

Multibaric-multithermal ensemble molecular dynamics simulations

We present new generalized-ensemble molecular dynamics simulation algorithms, which we refer to as the multibaric-multithermal molecular dynamics. We describe three algorithms based on (1) the Nosé thermostat and the Andersen barostat, (2) the Nosé-Poincaré thermostat and the Andersen barostat, and (3) the Gaussian thermostat and the Andersen barostat. The multibaric-multithermal simulations perform random walks widely both in the potential-energy space and in the volume space. Therefore, one can calculate isobaric-isothermal ensemble averages in wide ranges of temperature and pressure from only one simulation run. We test the effectiveness of the multibaric-multithermal algorithm by applying it to a Lennard-Jones 12-6 potential system.     

In-Line Reactions and Ionizations of Vaporized Diphenylchloroarsine and Diphenylcyanoarsine in Atmospheric Pressure Chemical Ionization Mass Spectrometry

We propose detecting a fragment ion (Ph₂As⁺) using counter-flow introduction atmospheric pressure chemical ionization ion trap mass spectrometry for sensitive air monitoring of chemical warfare vomiting agents diphenylchloroarsine (DA) and diphenylcyanoarsine (DC). The liquid sample containing of DA, DC, and bis(diphenylarsine)oxide (BDPAO) was heated in a dry air line, and the generated vapor was mixed into the humidified air flowing through the sampling line of a mass spectrometer. Humidity effect on the air monitoring was investigated by varying the humidity of the analyzed air sample. Evidence of the in-line conversion of DA and DC to diphenylarsine hydroxide (DPAH) and then BDPAO was obtained by comparing the chronograms of various ions from the beginning of heating. Multiple-stage mass spectrometry revealed that the protonated molecule (MH⁺) of DA, DC, DPAH, and BDPAO could produce Ph₂As⁺ through their in-source fragmentation. Among the signals of the ions that were investigated, the Ph₂As⁺ signal was the most intense and increased to reach a plateau with the increased air humidity, whereas the MH⁺ signal of DA decreased. It was suggested that DA and DC were converted in-line into BDPAO, which was a major source of Ph₂As⁺.

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Photo‐Induced Anomalous Deformation of Poly(N‐Isopropylacrylamide) Gel Hybridized with an Inorganic Nanosheet Liquid Crystal Aligned by Electric Field

Poly‐(N‐isopropylacrylamide) (PNIPA) hydrogel films doped with uniaxially aligned liquid crystalline (LC) nanosheets adsorbed with a dye are synthesized and its anomalous photothermal deformation is demonstrated. The alignment of the nanosheet LC at the cm‐scale is easily achieved by the application of an in‐plane or out‐of‐plane AC electric field during photo‐polymerization. A photoresponsive pattern is printable onto the gel with μm‐scale resolution by adsorption of the dye through a pattern‐holed silicone rubber. When the gel is irradiated with light, only the colored part is photothermally deformed. Interestingly, the photo‐irradiated gel shows temporal expansion along one direction followed by anisotropic shrinkage, which is an anomalous behavior for a conventional PNIPA gel.

     

Effect of geometrical imperfections on swelling-induced buckling patterns in gel films with a square lattice of holes

In this study, we investigate the effect of geometrical imperfections on swelling-induced buckling patterns in gel films with a square lattice of holes. Finite element analysis is performed using the inhomogeneous field theory of polymeric gels in equilibrium proposed by Hong et al. (2009). Periodic units consisting of 2 × 2 and 10 × 10 unit cells are analyzed under a generalized plane strain assumption. Geometrical imperfections are introduced using randomly oriented elliptical holes. The 2 × 2 unit cells show that the resulting buckling patterns are sensitive to imperfections; three different buckling patterns are obtained, and the most dominant one is the diamond plate pattern observed in experiments, which cannot be described using the model without imperfections. The 10 × 10 unit cells reveal that random imperfections are responsible for inducing homogeneous transformation into the diamond plate pattern. Furthermore, domain wall formation is simulated using a 10 × 10 unit cell model containing two elliptic holes.     

Oxidative dimerization of aromatic amines using tBuOI: entry to unsymmetric aromatic azo compounds

It's all the hype: An oxidative dimerization reaction of aromatic amines utilizing tert-butyl hypoiodite (tBuOI) under mild reaction conditions leads to aromatic azo compounds. The method allows access to unsymmetric aromatic azo compounds, which are difficult to prepare by conventional synthetic methods, in a selective manner.     

Study of multiple-stacking growth of 1.55 μm InAs columnar quantum dots with modulated tensile-strained InGaAsP barrier layers

An investigation was performed of columnar InAs quantum dots (CQDs) with modulated tensile-strained InGaAsP barriers in which the amount of tensile strain in the upper parts was higher than in the lower parts, the dots being deposited on an InP substrate grown by metalorganic vapor phase epitaxy. The smaller tensile strain of the barrier layers in the lower parts made the photoluminescence (PL) wavelength longer while the larger tensile strain of the barrier layers in the upper parts increased the strain compensation of the CQDs. Compared to CQDs with uniformly tensile-strained barriers, 1.55 μm emission was obtained at a higher average strain of barrier layers. By utilizing modulated tensile-strained barriers, triple-stacking of 12-fold CQDs with a PL wavelength of 1.55 μm using 30-nm-thick spacer layers was achieved with good crystallinity, indicating suitability for fabrication of high density CQDs.     

Spatial competition and collaboration networks

We model the formation of collaboration networks among firms that are located in a circular city as a two-stage game. In the first stage, the firms form collaboration links, and in the second stage, they engage in price competition. If two firms form a link, their production costs in the second stage are reduced. The second stage is a generalization of Salop??s (Bell J Econ 10(1):141?C156, 1979) circular city model. We provide a complete characterization of equilibrium prices of the model. We show that a firm prefers forming a link with a more distant firm if the cost-reducing effects are the same. We discuss the stability and social efficiency of the collaboration networks. When link costs are small, there is no conflict between efficiency and stability of networks. When link costs are significant, there is a conflict between efficiency and stability of networks. We also examine the average distances between linked firms.     

Coherent interactions of dyes assembled on DNA

The optical behavior of an organized dye assembly is different from that of the isolated dye; this difference is explained using molecular exciton theory. The theory predicts that mutual orientation, the number of dyes in the cluster, and combinations of different dyes should display given characteristic spectroscopic behaviors due to coherent interactions. Comparison of theoretical predictions with experimental results has been limited so far. One of the reasons is the absence of a rigid and well-organized system that can control the orientation and size of the dye assembly. Recently, the DNA duplex has been used to assemble chromophores in a programmed manner. Use of DNA allows organized dye assembly with a given size and particular orientation. In this review, we evaluate the spectroscopic behavior of the H-type aggregate based on molecular exciton theory and compare it with actual dye assembly with DNA duplex. Furthermore, we demonstrate the importance of coherent interactions on the observed optical properties of dyes assembled in a DNA duplex.