Inhibitory effect of anthraquinones isolated from the Noni (Morinda citrifolia) root on animal A-, B- and Y-families of DNA polymerases and human cancer cell proliferation

During the course of our studies to develop new uses for the Noni (Morinda citrifolia) root, 10 anthraquinones, rubiadin (1), rubiadin 1-methyl ether (2), lucidin (3), damnacanthol (4), 1,3-dihydroxy-2-methoxymethylanthraquinone (5), 3-hydroxy-1-methoxy-2-methoxymethylanthraquinone (6), nordamnacanthal (7), damnacanthal (8), sorandidiol (9) and morindone (10), were isolated. Compounds 5, 6, 7, 8 and 10 exhibited remarkable inhibition against the activities of animal pols, and compound 10 was the strongest inhibitor in the anthraquinones investigated. Among mammalian pols, compound 10 inhibited the pol activities of A- (pol γ), B- (pols α, δ and ε) and Y- (pols η, ι and κ) families, but did not influence the activities of X-family pols (pols β, λ and terminal deoxynucleotidyl transferase). The tendency of pol inhibition showed a positive correlation with the suppression of human colon cancer cell HCT116 growth. These results suggested that the Noni root containing anthraquinones may be used as an anticancer functional food.     

Extractive solubilization, structural change, and functional conversion of cytochrome c in ionic liquids via crown ether complexation

This article reports on the extraction behavior of heme proteins from an aqueous phase into ionic liquids (ILs) with dicyclohexano-18-crown-6 (DCH18C6), and the structure-function relationship of cytochrome c (Cyt-c) dissolved in ILs. We have found that DCH18C6 enables transfer of Lys-rich proteins into ILs via supramolecular complexation. The hydrophobicity and functional groups of ILs have a great influence on protein partitioning, and a hydroxyl group-containing IL with DCH18C6 is capable of the quantitative partitioning of Cyt-c. On the other hand, protein transfer using conventional organic solvents is negligibly small. UV-visible, CD, and resonance Raman spectroscopic characterizations indicate that the sixth ligand Met 80 in the heme group of the Cyt-c-DCH18C6 complex in IL is replaced by other amino acid residues of the peptide chain and that a non-natural, six-coordinate, low-spin ferric heme structure is induced in IL. Solubilization of Cyt-c in IL causes the environmental change of the heme vicinity of Cyt-c, which triggers the functional conversion of Cyt-c from an electron-transfer protein to peroxidase. The Cyt-c-DCH18C6 complex in IL provides remarkably high peroxidase activity compared with native Cyt-c, because of enhancement of the affinity for H2O2.     

IR and XPS Studies on the Surface Structure of Poled ZnO–TeO2 Glasses with Second-Order Nonlinearity

The effect of thermal/electrical poling on the surface structure of 30ZnO·70TeO₂ glass has been investigated by means of IR reflectance and X-ray photoelectron spectroscopy (XPS). All the poled glasses exhibit a common characteristic that the second-order nonlinearity is induced preferentially in an anode-side surface region. The reflectance from the anode-side glass surface at around 635 cm^{− 1} assignable to the vibrational mode of the Te–O_ax bond, where ax stands for the axial position of the TeO₄ trigonal bipyramid, is smaller in comparison with both as-annealed and cathode-side surfaces. The XPS analysis of the anode-side surface shows a depletion of Zn²⁺ ions and penetration of Na⁺ ions from the borosilicate glass which was placed between the sample and the anode during poling. These results suggest that the poling brings about both the breaking of the tellurite glass network and compositional changes at the anode-side surface below which the second-order nonlinearity is preferentially induced.     

A 53° twisted-nematic cell for a color reflective liquid-crystal display

Abstract— A 53° twisted-nematic cell for a color reflective liquid-crystal display was developed. It has a mirror electrode inside the panel on the TFT substrate, a twisted-nematic alignment structure, an RGB color filter, a single polarizer, and a light-control film covering the panel. Its advantages include gray-scale capability, low driving voltage, and a wide viewing angle. We discuss the Δn?d, the twist angle, and the front-light control film.     

Quick change of ion species of heavy-ion microbeam by cocktail beam acceleration technique with the JAEA AVF cyclotron

A heavy-ion microbeam with hundreds of MeV energy is utilized for research in biotechnology and materials science at the JAEA AVF cyclotron facility. Beam users need microbeams providing a wide range of the LET. We have to change ion species and/or energy in order to vary the LET widely. However, it takes much time to develop a new microbeam of different ion species step by step using a flat-top acceleration system. A cocktail beam acceleration technique is frequently used to change the ion species and energy quickly. The cocktail beam acceleration has been first applied to the microbeam formation for quick change of the ion species. As a result, we have succeeded to reduce considerably microbeam changing time to within 30 min between a 520 MeV ⁴⁰Ar¹⁴⁺ and a 260 MeV ²⁰Ne⁷⁺. No deterioration of the microbeam spot size has been confirmed using a SE image of a copper grid.     

Fabrication of nanowires by varying energy microbeam lithography using heavy ions at the TIARA

In TIARA facility of Japan Atomic Energy Agency (JAEA) Takasaki, we have produced three-dimensional micro/nano-structures with high aspect ratio using cross linking process based on negative resist such as SU-8 by a technique of mask less ion beam lithography. By bombarding high energy heavy ions such as 450 MeV Xe²³⁺ to SU-8, on the other hand, it appeared that a nanowire could be produced just with a single ion hitting. Then we tried to produce nanowires, of which both ends were fixed in the three-dimensional structure. This paper shows a preliminary experiment for this purpose using a combination of 15 MeV Ni⁴⁺ ion microbeam patterning and the 450 MeV ¹²⁹Xe²³⁺ hitting on SU-8.     

Transport parameters and solubility coefficients of polymers at their glass transition temperatures

Many parameters of polymers exhibit breaks when temperature passes through glass transition. It is also often assumed that fractional free volume (FFV) at the glass transition temperature (T_g) has a standard value (the isofree volume concept). As gas diffusion (D) and permeability (P) coefficients depend on FFV, and mechanism of sorption and permeation is different above and below T_g, a question can be asked if D and P parameters of various gases in polymers have standard values at corresponding T_g, and, if not, how the values of D(T_g) and P(T_g) vary with T_g in different polymers. To examine this problem, two approaches were used: (1) extrapolation to T_g of numerous P and D values measured at ambient temperatures; (2) an analysis of direct data obtained in different polymers at their T_g. In both cases, qualitatively similar results were obtained: the D(T_g) and P(T_g) values increase with growing T_g independently of the nature of gas. Permselectivity P_i(T_g)/P_j(T_g) and selectivity of diffusion D_i(T_g)/D_j(T_g) are reduced when T_g increases. The dependence of the solubility coefficients S(T_g) = D(T_g)/P(T_g) is much weaker than those of D(T_g) and P(T_g). This conclusion was confirmed by the results of direct measurements of S in a wide range of temperature including T_g for several gas/polymer systems. An analysis of the results of positron annihilation studies of free volume in polymers led to the conclusion that the observed increases in the D(T_g) and P(T_g) values with T_g are caused mainly by thermal activation of diffusion processes at T_g. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1691–1705, 2000     

Life cycle assessment and economical evaluation of superconducting magnetic energy storage systems in a power system

In recent years, the introduction of superconducting magnetic energy storage systems (SMES) into a power system is drawing considerable research effort because of their high efficiency rate and large storage capacity characteristics. In this paper, the introduction of SMES into a power system and its effects on energy and on environmental issues are addressed. The analysis results show that the introduction of SMES can considerably cut down CO₂ emissions without increasing the production cost if it substitutes for the operation of thermal plants during peak load period. However, to achieve this, nuclear plants are also needed for charging purposes. Thus, an algorithm to find the best generation mix, subject to CO₂ emissions constraints and nuclear plant introduction constraints, is proposed. The inclusion of nuclear plant constraints increases the coal consumption, hence CO₂ emissions. Nevertheless, in most of the analyzed cases, the introduction of SMES could attain important cost savings and environmental conservation. © 2000 Scripta Technica, Electr Eng Jpn, 131(1): 32–44, 2000     

Rosmarinic Acid and Sodium Citrate Have a Synergistic Bacteriostatic Effect against Vibrio Species by Inhibiting Iron Uptake

Background: New strategies are needed to combat multidrug-resistant bacteria. The restriction of iron uptake by bacteria is a promising way to inhibit their growth. We aimed to suppress the growth of Vibrio bacterial species by inhibiting their ferric ion-binding protein (FbpA) using food components. Methods: Twenty spices were selected for the screening of FbpA inhibitors. The candidate was applied to antibacterial tests, and the mechanism was further studied. Results: An active compound, rosmarinic acid (RA), was screened out. RA binds competitively and more tightly than Fe³⁺ to VmFbpA, the FbpA from V. metschnikovii, with apparent K_D values of 8 μM vs. 17 μM. Moreover, RA can inhibit the growth of V. metschnikovii to one-third of the control at 1000 μM. Interestingly, sodium citrate (SC) enhances the growth inhibition effect of RA, although SC only does not inhibit the growth. The combination of RA/SC completely inhibits the growth of not only V. metschnikovii at 100/100 μM but also the vibriosis-causative pathogens V. vulnificus and V. parahaemolyticus, at 100/100 and 1000/100 μM, respectively. However, RA/SC does not affect the growth of Escherichia coli. Conclusions: RA/SC is a potential bacteriostatic agent against Vibrio species while causing little damage to indigenous gastrointestinal bacteria.