Earticle

We provide a complete proof that the existence of a system of parameters, which is a reduction of the maximal ideal, is essential in Koh-Lee's conjecture.

Haemoglobin is an interesting physiologically significant protein composed of specific functional prosthetic haem and globin moieties. In recent decades, there has been substantial interest in attempting to understand the structural basis and functional diversity of avian haemoglobins (Hbs). Towards this end, purification, crystallization, preliminary X-ray diffraction and molecular-replacement studies have been carried out on Amaurornis phoenicurus Hb. Crystals were grown by the hanging drop vapor-diffusion method using PEG 2000 and NaCl as precipitants. The crystals belonged to the primitive monoclinic system P21, with unit-cell parameters a = 65.33 Å, b = 93.14 Å, c = 98.54 Å, β = 100.48o; a complete data set was collected to a resolution of 2.6 Å. The Matthews coefficient of 2.30 Å3 Da-1 for the crystal indicated the presence of two α2β2 tetramers in the asymmetric unit.

The crystal structure of the potential active 4,6-dimethyl-9-phenyl-8,12-dioxa-4,6-diazatetracyclo [8.8.0.02,7.013,18] octadeca-2(7),13,15,17-tetraene-3,5,11-trione 2-ethoxyphenyl (2E)-but-2-enoate (C22H18N2O5) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the monoclinic space group P121/c1 with unit cell dimension a=15.2039(8), b=12.3888(6) and c= 9.8162(5) [alpha & gamma=90o beta=98.113(2)]. In the structure fused pyrone and pyran rings each adopt a sofa/envelop conformation. The crystal structure is stabilized by intramolecular CH... O hydrogen bond interaction.

Human P-gp is a protein responsible for the multidrug resistance (MDR) and causes failure of cancer chemotherapy. Till date no X-ray crystal structure is reported for this membrane protein, which hampers active research in the field. We performed homology modeling to develop three dimensional (3D) model of P-gp, and docking studies of the verapamil and curcumin have been performed to gain insight into the interaction mechanism between inhibitors and P-gp. It was identified that the inhibitors docked into the upper part of P-gp and interacted through the hydrophobic interactions.

In this study, in order to investigate how consecutive treatments of glass surface with HF acid and water vapor/Ar plasma affect the quality of 3-aminopropyltriethoxysilane self-assembled monolayer (APS-SAM), poly(3,4- ethylenedioxythiophene) (PEDOT) thin films were vapor phase-polymerized immediately after spin coating of FeCl3 and poly- urethane diol-mixed oxidant solution on the monolayer surfaces prepared at various treatment conditions. For the film characterization, various poweful tools were used, e.g., FE-SEM, an optical microscope, four point probe, and a contact angle analyzer. The characterization revealed that HF treatment is not desirable for the synthesis of a high quality PEDOT thin film via vapor phase polymerization method. Rather, sole treatment with plasma noticeably improved the quality of APS -SAM on glass surface. As a result, a highly dense and smooth PEDOT thin film was grown on uniform oxidant film- coated APS monolayer surface.

In this study, in order to investigate how consecutive treatments of glass surface with HF acid and water vapor/Ar plasma affect the quality of 3-aminopropyltriethoxysilane self-assembled monolayer (APS-SAM), poly(3,4- ethylenedioxythiophene) (PEDOT) thin films were vapor phase-polymerized immediately after spin coating of FeCl3 and poly-urethane diol-mixed oxidant solution on the monolayer surfaces prepared at various treatment conditions. For the film characterization, various poweful tools were used, e.g., FE-SEM, an optical microscope, four point probe, and a contact angle analyzer. The characterization revealed that a well prepared APS-SAM on a glass surface treated with water vapor/Ar plasma is very useful for uniform coating of FeCl3 and DUDO mixed oxidant solution, regardless of HF treatment. On the other hand, a bare glass surface without APS-SAM but treated with HF and water vapor/Ar plasma generally led to a very poor oxidant film. As a result, PEDOT films vapor phase-polymerized on APS-SAM surfaces are far superior to those on bare glass surfaces in the quality and electrical characteristics aspects.

Amyloid-β peptide (Aβ), implicated in Alzheimer's disease, associates into the fibrils that deposit in senile plaque. The 39~43 amino acid long peptide assemble into various species which could be regulated by chaperone molecules. Despite extensive progress, the results are conflicting; for example, both reduction and enhancement of Aβ cytotoxicity by chaperone have been reported. And the relationship of Aβ structural species with chaperone, and further its implication in cytotoxicity remain to be elucidated. To address this question and to understand the underlying mechanism(s), in this study, the effect of a chaperone molecule, DnaK, on Aβ structure and its effect on cytotoxicity were investigated under several different conditions. A significant amount of oligomeric species of Aβ that is believed to be more toxic among Aβ structures was accumulated at 0.01~0.1 ratio of DnaK/abeta42, while such accumulation was not observed with higher ratio, where the oligomers appeared in the form of complexes with the chaperone molecules. Importantly, accumulation of these Aβ oligomers exerted enhanced toxicity concomitantly and, in contrast, cytoprotection was observed at excess molar of DnaK. In all conditions, fibrillar forms were markedly inhibited. Further, fibrillization kinetics indicated that DnaK might affect on nucleation step, while circular dichroism spectroscopy demonstrated that DnaK delayed overall β- sheet formation. Taken together, results indicate that the chaperone influences Aβ structural transition from oligomer to fibrillar structures as well as from monomer to oligomer with variable rates, and as results, it decreased or increased the amount of Aβ oligomer as well as the cytotoxicity.

N-terminal kinase-like (NTKL) protein was initially identified as a protein binding to protein kinase B (PKB, also known as Akt). Though NTKL-BP1 (NTKL-binding protein 1) has been identified as an NTKL binding protein, its functions related to binding have not yet been elucidated. Here, a new alternative spliced variant of NTKL and its association with integrin β1 is described, in addition to the kinase activity of NTKL and its substrate candidates. Although the phosphorylation of the candidates must be further confirmed using other experimental methods, the observation that NTKL can phosphorylate ROCK1, DYRK3, and MST1 indicates that NTKL may act as a signaling protein to regulate actin assembly, cell migration, cell growth, and to facilitate differentiation and development in an integrin- associated manner.

Three types of functionalized flexible optical composite films based on Bragg structure porous silicon interferometer have been successfully fabricated by casting a toluene solution of polystyrene onto the free-standing porous silicon. The optical properties of composite films are measured. Surface functionalization of porous silicon is determined by FT-IR measurement. Reflectance and transparence properties of composite films are measured for the possible application of tunable optical filter and indicate that the transmission peak occurred at the identical location where the reflection peak appeared.

For the mean vector of a p-variate normal distribution (p ≥ 4), the optimal estimation within the class of modified James-Stein type decision rules under the quadratic loss is given when the underlying distribution is that of a variance mixture of normals and when the norm II θ - θ1 II it known.