Stone-Wales Rearrangement Pathways from the Hinge-Opened [2+2] C60 Dimer to Ipr C120 Fullerenes. Vibrational Analysis of Intermediates

Abstract

Possibility of the previously proposed hinge-opened product 2 of [2+2] C₆₀, dimer 1 transforming itself into IPR C₁₂₀ fullerenes by a series of generalized Stone-Wales (GSW) rearrangements has been tested by seeking all topologically acceptable pathways with the help of a graphical search program. the first IPR isomer 4 appeared after 20 GSW steps from the wide-bridged dumb-bell shaped precursor 3. More than 1,000 C₁₂₀ fullerene structures were generated during subsequent ten GSW steps, but the outstanding T _d C₁₂₀ global minimum 5 was not reached. Semiempirical vibrational calculations predict characteristic transition in the vibrational spectra in the course of rearrangement pathway.     

V–I characteristics of solid polymer electrolytic (SPE) dehumidifier

Measurements of the V–I characteristics of a solid polymer electrolytic (SPE) dehumidifier were done using a modified SPE dehumidifier with four electrodes which included two electrodes to carry the main current and the other two electrodes to measure the voltages applied to the electrical double layer, which are the boundary voltages between the electrodes and the SPE membrane. The measured results were analyzed using the Butler-Volmer equation to examine the validity of the measurements. The current flowing in the dehumidifier is produced by the decomposition of water near the anode. Therefore, under a steady-state condition, the current should be proportional to the supply rate of water to the anode. On the other hand, a two-layer model for the SPE dehumidifier presented in our previous article showed that the current flowing in the dehumidifier was roughly proportional to the water content in the vicinity of the anode. These results were introduced for interpretation of the V–I measurements of the SPE dehumidifier. It was concluded that the dehumidifier current was expressed in the form of a Butler-Volmer equation as a function of the electrode boundary voltages which were the voltages across the boundary between the electrodes and the SPE membrane. An experimental formula for the current under a steady-state condition was developed as a function of the water content near the anode and the boundary voltages.     

Antioxidative activities of some peptides isolated from hydrolyzed potato protein extract

Three peptides (5A, 5C and 6C), purified from potato protein hydrolysate fractions, possessed antioxidative activities. Isolation and purification were carried out using gel permeation chromatography and successive reverse-phase HPLC. These three peptide fractions were sequenced and identified as Phe-Gly-Glu-Arg, Phe-Asp-Arg-Arg and Phe-Gly-Glu-Arg-Arg, respectively. The fractions 5A, 5C and 6C inhibited linoleic acid oxidation by 55.3%, 58.5% and 61.7% using β-carotene decolorization assay system, while the inhibition ratio was 32.1%, 93.0% and 93.4% in the ferric thiocyanate assay system, respectively. The peptide fractions 5A, 5C and 6C also repressed lipid oxidation by 24.2%, 14.7% and 26.4% in the erythrocyte membrane ghost assay system, respectively. Oral administration of 100 mg/kg of body weight of the chemically synthesized peptides, 5A, 5C and 6C to rats (male Wistar) 30 min prior to ethanol injection reduced ethanol-induced gastric mucosal damage by 67.9%, 57.0% and 60.3%, respectively. Conclusively, these peptides have shown real potent antioxidative activities and could further be investigated for potential use as food additives.     

Oral intake of Lactobacillus delbrueckii subsp. bulgaricus OLL1073R-1 prevents collagen-induced arthritis in mice.

Oral intake of some lactic acid bacteria can have beneficial effects on the host by activating immune responses and enhancing resistance to infection by pathogens. In this study, effects of Lactobacillus sp. on the development of autoimmune disease were examined in mice with collagen-induced arthritis (CIA). CIA, a model of some types of rheumatoid arthritis (RA), can be induced in DBA/1J mice by immunizing them with bovine type II collagen (bCII). Oral intake of skimmed milk (SM) fermented with Lactobacillus delbrueckii subsp. bulgaricus OLL1073R-1 (SM/OLL1073R-1) was found to markedly inhibit the development of CIA in these mice, compared with a control group fed the control foodstuff. The inhibitory effect of SM fermented with L. delbrueckii subsp. bulgaricus OLLI 102 (SM/OLL1102) or fresh SM was weaker than that of SM/ OLL1073R-1. A deMan Rogosa Sharpe (MRS) broth culture of OLL1073R-1 without any major components of SM had the same inhibitory effect as SM/OLL1073R-1, suggesting that the inhibitory effect of SM/OLL1073R-1 is attributable not only to SM components but also to OLL1073R-1 cells, their metabolites, or both. We found that SM/OLL1073R-1 and SM caused reduced secretion of the cytokine IFN-gamma by lymph node cells (LNCs) in response to bCII. However, SM/OLL1102 did not affect the secretion of IFN-gamma. A polysaccharide fraction secreted by OLL1073R-1 also exhibited the inhibitory effects on both development of CIA and secretion of IFN-gamma.     

Size dependence of crystallization within spherical microdomain structures

We have investigated the size dependence of crystallization within spherical microdomains formed in various poly(ε-caprolactone)-block-polybutadiene diblock copolymers (PCL-b-PB). The crystallinity (χ) and melting temperature (T_m) of the PCL block are considerably lower than those of PCL homopolymer, and χ decreases steadily and T_m decreases only slightly with decreasing radius of PCL spheres (R) for a series of PCL-b-PB with a same molecular weight (M_n). When PCL-b-PB is compared with the similar R but different M_n, χ is significantly different, suggesting that the sphere size is not the unique factor to control crystallization within spherical microdomains.     

Influence of cocations on catalytic activity of copper ion-exchanged ZSM-5 zeolite for reduction of nitric oxide with ethene in the presence of oxygen

The coexistence of alkaline earth (Ca and Sr) and transition metal (Fe, Co and Ni) cations with Cu ions in ZSM-5 zeolite is effective in the promotion of the maximum activity and the expansion of the active temperature range for the reduction of nitric oxide with ethene in the presence of excess oxygen.     

Vesicles from sucrose fatty acid esters

It has been confirmed, from observations with an electron microscope after staining negatively with aqueous uranyl acetate solutions and using a flourescent microscope, that sucrose fatty acid esters form closed vesicles. The range of particle size of the vesicle, consisting of chromatographically fractionated sucrose dilaurate, was apparently 70–700 nm in the longer diameter of individual vesicles based on the transmission electron microscopic (TEM) observation. The weight-average particle size was 424 nm as shown by means of the photon-correlation method. The amounts of 6-carboxyfluorescein trapped in the vesicles of sucrose fatty acid esters were determined, and it was ascertained that the volumes of the central water phase depended upon the acyl chain lengths of fatty acid residues. Further, the effect of the additives [cholesterol and dicetyl phosphate (DCP) was examined. As an example, the vesicle of sucrose stearate had a central water phase of 1.7 one water/mol ester, and showed a slow release of 6-carboxyfluorescein from the central water phase after preparation of the vesicle.