Nitric oxide synergistically enhances DNA strand breakage induced by polyhydroxyaromatic compounds, but inhibits that induced by the Fenton reaction

This paper deals with the muscle force of the cervical spine in patients with cervical syndrome compared to the muscle activity in non-patients. It has thus been observed that both the flexors' and the extensors' force of the cervical spine is much greater in non-patients (the flexors' P < 0.01 and the extensors' P < 0.01). The precise measurements having been carried out by a dynamometer. The groups being tested comprised 50 persons each, 25 men and 25 women. The average age of the patients group was 43.1 years, namely between 21 and 57 years, while that of the non-patients group was 42.3 years, between 24 and 56 years. As regards the professional engagement of both groups and, accordingly, the strain on the cervical spine and the corresponding musculature, they were approximately the same.     

The T cell-directed CC chemokine TARC is a highly specific biological ligand for CC chemokine receptor 4

Thymus and activation-regulated chemokine (TARC) is a recently identified CC chemokine that is expressed constitutively in thymus and transiently in stimulated peripheral blood mononuclear cells. TARC functions as a selective chemoattractant for T cells that express a class of receptors binding TARC with high affinity and specificity. To identify the receptor for TARC, we produced TARC as a fusion protein with secreted alkaline phosphatase (SEAP) and used it for specific binding. By stably transfecting five orphan receptors and five known CC chemokine receptors (CCR1 to -5) into K562 cells, we found that TARC-SEAP bound selectively to cells expressing CCR4. TARC-SEAP also bound to K562 cells stably expressing CCR4 with a high affinity (Kd = 0.5 nM). Only TARC and not five other CC chemokines (MCP-1 (monocyte chemoattractant protein-1), RANTES (regulated upon activation, normal T cells expressed and secreted), MIP-1alpha (macrophage inflammatory protein-1alpha), MIP-1beta, and LARC (liver and activation-regulated chemokine)) competed with TARC-SEAP for binding to CCR4. TARC but not RANTES or MIP-1alpha induced migration and calcium mobilization in 293/EBNA-1 cells stably expressing CCR4. K562 cells stably expressing CCR4 also responded to TARC in a calcium mobilization assay. Northern blot analysis revealed that CCR4 mRNA was expressed strongly in human T cell lines and peripheral blood T cells but not in B cells, natural killer cells, monocytes, or granulocytes. Taken together, TARC is a specific functional ligand for CCR4, and CCR4 is the specific receptor for TARC selectively expressed on T cells.     

Oxidation kinetics for <Emphasis Type="Italic">cis</Emphasis>-9,<Emphasis Type="Italic">trans</Emphasis>-11 and <Emphasis Type="Italic">trans</Emphasis>-10,<Emphasis Type="Italic">cis</Emphasis>-12 isomers of CLA

The autoxidation processes of the cis-9,trans-11 (c9,t11) and trans-10,cis-12 (t10,c12) isomers of CLA were separately observed at ca. 0% RH and different temperatures. The t10,c12 CLA oxidized faster than the c9,t11 isomer at all tested temperatures. The first half of the oxidation process of t10,c12 CLA obeyed an autocatalytic-type rate expression, but the latter half followed first-order kinetics. On the other hand, the entire oxidation process of c9,t11 CLA could be expressed by the autocatalytic-type rate expression. The apparent activation energies and frequency factors for the autoxidation of the isomers were estimated from the rate constants obtained at various temperatures based on the Arrhenius equation. The apparent activation energies for the CLA isomers were greater than those for the nonconjugated n−6 and n−3 PUFA or their esters. However, the enthalpyentropy compensation held during the autoxidation of both the CLA and PUFA. This suggested that the autoxidation mechanisms for the CLA and PUFA were essentially the same.     

Poly(pyridine-2,5-diyl)–CuCl2 catalyst for synthesis of dimethyl carbonate by oxidative carbonylation of methanol: catalytic activity and corrosion influence

A -conjugated polymer, poly(pyridine-2,5-diyl) (PPy) was investigated as a support for CuCl₂ in the synthesis of dimethyl carbonate by oxidative carbonylation of methanol. The PPy–CuCl₂ adduct had high catalytic activity which was comparable to that of the homogeneous CuCl₂ catalyst. The adduct caused corrosion of stainless-steel vessels only to minor extent, compared with the homogeneous CuCl₂ catalyst. This PPy–CuCl₂ catalyst was easily recycled by filtration and showed a similar catalytic activity in the third time use. The presence of the -conjugated system in PPy, through which electrons can move, may bring about the high catalytic activity for the oxidative carbonylation of methanol, which involves Cu(II)/Cu(I) redox processes.     

Carbon fiber from natural biopolymer Bombyx mori silk fibroin with iodine treatment

Carbon fibers were prepared from silk fibers after an iodine treatment and the carbon yield, fiber morphology, structure and mechanical properties were investigated. A single or multi-step carbonization process was used for the preparation. In the single step process, silk fibroin (SF) fibers were heated from 25 to 800 °C with a heating rate of 5 °C min⁻¹ under Ar atmosphere. However, the carbon fiber obtained was partially melted and was too fragile to handle. For better performance, SF fibers were treated with iodine vapor at 100 °C for 12 h and untreated and iodinated SF fibers were heated from 25 to 800 °C by a multi-step carbonization process, which was defined based on the optimum thermal degradation rate of silk. In this multi-step process, the carbon fibers obtained from iodinated SF were structurally intact and stable in appearance, and the carbon yield achieved was ca. 36 wt.%, much higher than the value for untreated SF. X-ray diffraction, Raman spectroscopy and transmission electron microscopic observation revealed that the obtained carbon fibers from both untreated and iodinated SFs had a basically amorphous structure. The strength of carbon fibers prepared from iodinated SF using the multi-step carbonization was considerably increased compared to that of untreated SF. According to viscoelastic measurement, by heating above 280 °C the iodine introduced intermolecular cross-linking of the SF, and its melt flow was inhibited which produced a higher yield and better performance of the carbon fiber.     

Fractionation and enrichment of CLA isomers by selective esterification with Candida rugosa lipase

A commercial product of CLA contains almost equal amounts of cis-9,trans-11 (c9,t11)-CLA and trans-10,cis-12 (t10,c12)-CLA. We attempted to enrich the two isomers by a two-step selective esterification using Candida rugosa lipase that acted on c9,t11-CLA more strongly than on t10,c12-CLA. An FFA mixture containing CLA isomers was esterified with an equimolar amount of lauryl alcohol in a mixture of 20% water and the lipase. When the esterification of total FA reached 50%, two isomers were fractionated in a good yield: t10,c12-CLA was enriched in FFA, and c9,t11-CLA was recovered in lauryl esters. The FFA were esterified again to enrich t10,c12-CLA. At 27.3% esterification of total FA, the t10,c12-CLA content in FFA increased to 64.8 wt% with 89.3% recovery: The ratio of the content of t10,c12-CLA to that of two isomers was 95.9%. Lauryl esters obtained by the single esterification were employed for enrichment of c9,t11-CLA. After the esters were hydrolyzed, the resulting FFA were esterified again with lauryl alcohol. At 62.0% esterification of total FA, the c9,t11-CLA content in lauryl esters increased to 73.3 wt% with 79.4% recovery: The ratio of the content of c9,t11-CLA to that of two isomers was 95.6%. In a 600-g-scale purification, molecular distillation was effective in separating the reaction mixture into lauryl alcohol, FFA, and lauryl ester fractions.     

Sharpness and noise characteristics of a half‐mirror stereoscopic display

Stereoscopic displays are becoming popular in entertainment and industrial applications. We characterize the spatial resolution and noise properties of a stereoscopic display with a half‐mirror and passive polarizing glasses. The upper display images reflected off the mirror have slightly degraded sharpness and reduced high spatial‐frequency noise resulting in modulation transfer functions (MTFs) of 0.59 and 0.50 at the Nyquist frequency with corresponding noise power spectra (NPS) values of 4.79 × 10^?6 and 5.17 × 10^?6 mm² at 10 mm^?1 in the horizontal and vertical directions. These results are compared to the characteristics of the individual displays with MTF values of 0.64 and 0.53 and NPS values of 6.24 × 10^?6 and 5.87 × 10^?6 mm². The polarizing glasses cause minimal reduction in sharpness and high‐frequency noise. The MTFs in the upper images observed with glasses are decreased to 0.54 and 0.47, while the NPS are decreased to 2.86 × 10^?6 and 2.01 × 10^?6 mm². When both displays are turned on and using the mirror and glasses, the observed luminance for each eye is increased from the luminance of the individual displays owing to crosstalk. We find that sharpness and noise are not affected by the interaction between the displays at the particular geometry tested in this study.     

Hydrogen‐bonding interaction between poly(ε‐caprolactone) and low‐molecular‐weight amino compounds

The specific interactions between several low‐molecular‐weight diamino compounds and poly(ε‐caprolactone) (PCL) have been investigated by FT‐IR. It was found that PCL and 3,3′‐diaminodiphenylmethane (3,3′‐DADPM) interact through strong intermolecular hydrogen bonds in the blend. Thermal and mechanical properties of PCL/3,3′‐DADPM blends were investigated by DSC and tensile measurements, respectively. The glass transition temperature of the blend increases while both the melting point and the elongation‐at‐break of the blend decrease with the increase of 3,3′‐DADPM content. Besides 3,3′‐DADPM, several other low‐molecular‐weight compounds containing two amino groups, such as o‐phenylenediamine or 1,6‐diaminohexane, were also added into PCL and the corresponding blend systems were investigated by FT‐IR and DSC. The effect of the chemical structure of the additives on the properties of PCL is discussed. © 2001 Society of Chemical Industry     

Microwave-assisted steam distillation for simple determination of polychlorinated biphenyls and organochlorine pesticides in sediments

A novel sample extraction technique for polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) analysis using microwave-heating device is developed. In this study, microwave-assisted extraction (MAE) and steam distillation techniques were combined. Desorption of the anatytes from solid matrixes was accelerated with water vapor which was generated by microwave irradiation. A sample holder in a commercial microwave extraction cell kept the sample from direct contact with the organic solvent for analytes trapping during the treatment process. Therefore, relatively clean extracts were obtained with small amount of solvents. Without any cleanup steps, the obtained extract could be analyzed with gas chromatograph/mass spectrometers (GC/MS). Six PCB congeners (PCB15, 28, 70, 101, 180, 194, 209) and three OCPs (gamma-HCH, 4,4'-DDE, 4,4'-DDD) in two marine sediment samples (a sediment collected from a bay of Kyusyu Island, Japan, and a certified reference material NIST SRM1944) were analyzed by using this microwave-assisted steam distillation (MASD) technique and another extraction method (exhaustive steam distillation, MAE, and Soxhlet extraction); and comparisons of the results are shown in this report. Although recovery yields of highly chlorinated biphenyls (PCB180, 194, 209) and relatively polar OCPs (gamma-HCH, 4,4'-DDD) were low (30-60%) compared with other analytes (PCB15, 28, 70, 101, 4,4'-DDE; recovery, 80-100%), use of isotope labeled internal standards for the MASD technique gave comparable results with the values obtained by other extraction methods and the certified values in the samples.     

Influence of Bile Salts on the Permeability Through the Nasal Mucosa of Rabbits of Insulin in Comparison with Dextran Derivatives

The nasal drug absorption and the effect of absorption promoters have been studied in rabbits. Nasal mucosa excised from rabbits was mounted as a flat sheet in an in vitro chamber. The result indicates that the change in the porosity of the membrane by pretreatment with bile salts increased the permeability coefficient of sodium chloride in the nasal membrane. The permeabilities of dextran derivatives were enhanced by pretreatment with sodium glycocholate (GC). The permeability coefficient (P) of fluorescein isothiocyanate diethylaminoethyl dextran