Inhibitory effect of magnosalin derived from Flos magnoliae on tube formation of rat vascular endothelial cells during the angiogenic process

An aqueous water extract of Flos magnoliae, a Japanese Sino-medicine, inhibits angiogenesis in adjuvant-induced mouse pouch granuloma. Magnosalin (MSA) and magnoshinin (MSI), neolignans isolated from magnolia, have a crucial role in the anti-angiogenic effect of magnolia (Kimura et al., Int. Arch. Allergy Appl. Immunol., 93, 365 (1990); Phytother. Res., 6, 209 (1992)). We investigated the effects of these neolignans on tube formation of endothelial cells (EC) cultured in type I collagen gel during the angiogenic process. MSA (0.1-10 microM), MSI (0.23-7 microM) and corticosterone (CS: 0.3-30 microM) inhibited fetal bovine serum (FBS)-stimulated tube formation in a concentration-dependent manner. Their 30% inhibitory concentration (IC30, 95% confidence limits) values were 0.51 (0.20-1.27) for MSA, 8.14 (2.48-26.7) for MSI and 3.65 microM (2.47-5.40) for CS, respectively. MSA and MSI (1-3 microM) also inhibited interleukin (IL)-1 alpha-stimulated tube formation in a concentration-dependent manner. Their IC50 values (95% confidence limits) were 1.22 (1.01-1.47) for MSA and 0.74 microM (0.24-2.31) for MSI against a submaximal concentration (69 pM) of IL-1 alpha-stimulated tube formation. Their inhibitory effects on the action of IL-1 alpha were non-competitive. These results demonstrate that MSA inhibited FBS-stimulated tube formation with a greater potency than MSI. The inhibitory effect of MSA on the action of FBS differed from that on the action of IL-1 alpha.     

Mechanochemical block copolymerization in heterogeneous systems of the solid poly(vinyl chloride) with styrene by ultrasonic irradiation

Summary Mechanochemical block copolymerization in heterogeneous systems of the solid poly(vinyl chloride)-styrene-sodium dodecyl sulfate aqueous solutions has been studied by ultrasonic irradiation at 65 °C. The block copolymerization of styrene was initiated by free radicals produced from the poly(vinyl chloride) particles by ultrasonic waves. The initial rate of the block copolymerization Rp was given by Rp α [Styrene] [Sodium dodecyl sulfate]^1/2. Both copolymer and homopolymer were obtained. For example, when 2.506 g of the poly(vinyl chloride) particles, 24.23 g of styrene, and 54.00 g of sodium dodecyl sulfate aqueous solution (0.500 wt%) were added in the reaction system, the weight proportions of the block copolymer and polystyrene after 60 min were approximately 50 and 20%.     

Diffusion process of amino acids in polymer supports for solid‐phase peptide synthesis as studied by pulsed‐field‐gradient spin‐echo proton nuclear magnetic resonance

The diffusion coefficient (D) values of tert‐butyloxycarbonyl‐glycine, tert‐butyloxycarbonyl‐L ‐tryptophan, tert‐butyloxycarbonyl‐L ‐phenylalanine (Boc‐Phe), and 9‐fluorenylmethoxycarbonyl‐L ‐phenylalanine in Merrifield polystyrene (MPS) gels, poly(ethylene glycol)‐grafted polystyrene (PEG–PS) gels, and crosslinked ethoxylate acrylate (CLEAR) gels, as used in solid‐phase peptide synthesis, were determined by the pulsed‐field‐gradient spin‐echo ¹H‐NMR method. From these experimental results, it was found that the amino acids in MPS gels, PEG–PS gels, and CLEAR gels with N,N‐dimethylformamide‐d₇ (DMF‐d₇) as a solvent had multidiffusion components within a measurement timescale of 10 ms. The D value of Boc‐Phe in polystyrene gels (1% divinylbenzene crosslinked) with tetrahydrofuran‐d₈ was much larger than that in the same gels with DMF‐d₇. Furthermore, the required time in which an amino acid transferred from a reactive site to a reactive site was estimated, within which the solvents and amino acids in the polymer supports diffused in the swollen beads.© 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 413–421, 2003     

Initial Collection Performance of Resin Wool Filters and Estimation of Charge Density

Abstract

A new type of resin wool filter (RWF) that persists the load with oil droplets was developed by Kimura and colleagues. In the present work, the initial collection performances of RWF (A and C) are measured for various particle sizes (0.03, 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3 μm) with different charging states at various filtration velocities (0.05, 0.1, 0.15, and 0.3 m/s). As a result, it is shown that the present RWF impregnated with PTBP resin can attain high collection efficiency (99.999% at filtration velocity of 0.05 m/s) with a pressure drop of less than 30 Pa. The charge density is estimated by applying prediction equations of single-fiber collection efficiencies of electret filters with a dipolar charge distribution because no other prediction equation for RWF are available at present. The experimental single-fiber efficiencies for uncharged particles are successfully predicted by assigning a single value of charge density in the prediction equations for dipolar fibers. The estimated charge density on RWF fibers is 2.1 × 10^{? 4} C/m², which is much higher than those of conventional electret filter media. Therefore, RWF studied in the present work is suitable for the application to respirators as well as room air cleaners.     

An Additional Insight into the Correlation between the Distribution Ratios and the Aqueous Acidity of the TODGA System

Abstract

Extraction of Eu(III) and Am(III) from HNO₃ into the organic solvents using N,N,N′,N′‐tetraoctyl‐diglycolamide (TODGA) was investigated in order to study the detailed extraction reaction. The chemical species: 1:2 for metal:TODGA complex is present in polar diluents. On the other hand, the metal complexes need three or more TODGA molecules to remain stable in non‐polar diluents. The HNO₃ concentration dependence on the distribution ratio suggests that HNO₃ participates in the metal extraction. Infrared spectra indicate that the carbonyl oxygen coordinates with Eu(III), and luminescence lifetimes suggest that there are no water molecules in the inner coordination sphere of the extracted Eu‐complex.     

Synergistic Extraction of Am(III) and Eu(III) by Tris(2‐pyridylmethyl)Amine with Various Anions in 1,2‐Dichloroethane

The extraction equilibria of Am(III) and Eu(III) by using a tripodal ligand, tris(2‐pyridylmethyl)amine (tpa), with various lipophilic anions have been investigated. The extractability of both Am(III) and Eu(III) was increased by the combination of tpa and counteranions due to a synergistic effect. The separation factors between Am(III) and Eu(III) were also increased from 7.6 to 49 by the combination of counteranions and organic solvents. The extraction equilibria of Am(III) and Eu(III) with tpa in 1,2‐dichloroethane were determined by slope analysis. It was found that three anions and one molecule of the ligand coordinated to Am(III) and Eu(III) was extracted regardless of the anions.     

miR-29 Represses the Activities of DNA Methyltransferases and DNA Demethylases

Members of the microRNA-29 (miR-29) family directly target the DNA methyltransferases, DNMT3A and DNMT3B. Disturbances in the expression levels of miR-29 have been linked to tumorigenesis and tumor aggressiveness. Members of the miR-29 family are currently thought to repress DNA methylation and suppress tumorigenesis by protecting against de novo methylation. Here, we report that members of the miR-29 family repress the activities of DNA methyltransferases and DNA demethylases, which have opposing roles in control of DNA methylation status. Members of the miR-29 family directly inhibited DNA methyltransferases and two major factors involved in DNA demethylation, namely tet methylcytosine dioxygenase 1 (TET1) and thymine DNA glycosylase (TDG). Overexpression of miR-29 upregulated the global DNA methylation level in some cancer cells and downregulated DNA methylation in other cancer cells, suggesting that miR-29 suppresses tumorigenesis by protecting against changes in the existing DNA methylation status rather than by preventing de novo methylation of DNA.     

Hydrophilic non-wovens made of cross-linked fully-hydrolyzed poly(vinyl alcohol) electrospun nanofibers

Fully-hydrolyzed poly (vinyl alcohol) (PVA) nanofibers were successfully electrospun from aqueous solutions of PVA in the presence of acetic acid. A continuous spinning of uniform PVA nanofibers proceeded by the addition of acetic acid due to the changes of electronic conductivity and surface tension of aqueous solution of PVA. When cross-linking agent 1 was added to aqueous solution of PVA and subsequent thermal treatment of as-spun nanofibers, chemically cross-linked PVA nanofibers were achieved to resist disintegration in contact with hot water and the tensile mechanical property of nanofiber non-wovens was greatly improved by the formation of cross-linking points. Magnetite was deposited uniformly onto the hydrophilic surface of cross-linked PVA nanofibers and the resulted nanofibers decorated with magnetite showed a magnetic responsiveness. The deposition of magnetite on the PVA nanofibers can generate self-standing magnetic non-wovens.     

Resistance to sulfur poisoning of hot gas cleaning catalysts for the removal of tar from the pyrolysis of cedar wood

In the partial oxidation of tar derived from the pyrolysis of cedar wood, the effect of H₂S addition was investigated over non-catalyst, steam reforming Ni catalyst, and Rh/CeO₂/SiO₂ using a fluidized bed reactor. In the non-catalytic gasification, the product distribution was not influenced by the presence of H₂S. Steam reforming Ni catalyst was effective for the tar removal without H₂S addition, however, the addition of H₂S deactivated drastically. In contrast, Rh/CeO₂/SiO₂ exhibited higher and more stable activity than the Ni catalyst even under the presence of high concentration of H₂S (280 ppm). On the Ni catalyst, the adsorption of sulfur was observed by XPS and Ni species was oxidized during the partial oxidation of tar. In the case of Rh/CeO₂/SiO₂, the adsorption of sulfur was below the detection limit of XPS. This can be related to the self-cleaning of catalyst surface during the circulation in the fluidized bed reactor for the partial oxidation of tar derived from cedar pyrolysis.