Synthesis and pigmental properties of titanium phosphates with the addition of urea

As a white pigment, titanium oxide is used for cosmetic application. This oxide is well known to have the photo catalytic activity. Therefore, a certain degree of sebum is decomposed by the ultraviolet radiation in the sunlight. In this work, titanium phosphates were prepared as a novel white pigment. Their chemical composition, powder properties, photo catalytic activity, moisture retention and smooth were studied with the addition of urea. These white pigments had little photo catalytic activity. The addition of urea improved the moisture retention of titanium phosphates. The slipping resistance of samples became small by heating, on the other hand, the roughness of samples became small by the addition of urea.     

Near‐Infrared Fluorescent Silica/Porphyrin Hybrid Nanorings for In Vivo Cancer Imaging

Ring‐shaped silica nanoparticles are synthesized with a high tetrakis(4‐carboxyphenyl)porphyrin (TCPP) content or silica/TCPP hybrid nanorings (HNRs) using a one‐pot sol‐gel reaction with a TCPP‐binding silica precursor for fluorescence imaging of tumor. The shape of the HNRs is a reflection of abundant ring‐shaped TCPP aggregates in the silica matrix. The HNRs are of a size that makes them susceptible to the enhanced permeability and retention effect. For comparison, the TCPP‐doped silica nanoparticles are synthesized using a conventional method. The nanoparticles are spherical in shape because little TCPP is contained in the silica matrix and are designated as TCPP‐containing silica nanospheres (NSs). The absorption bands of the HNRs shift by about 20 nm toward longer wavelengths compared with the TCPP bands. This redshift leads the excitation wavelength of the HNRs into the near‐infrared (NIR) region. Therefore, the HNRs are excited by NIR light to emit strong fluorescence, although the NSs emit no fluorescence. The PEGylated HNRs (PEG‐HNRs) are uncharged and possess a significantly longer blood circulation time than PEG‐NSs. The PEG‐HNRs accumulate in tumor through multiple factors including their size, uncharged surface, unique shape, and long circulation time in blood, resulting in the acquisition of clear images of tumor.     

Metabolism of azo dyes by Lactobacillus casei TISTR 1500 and effects of various factors on decolorization

Lactobacillus casei TISTR 1500 was isolated from soil of a dairy wastewater treatment plant and selected as the most active azo dye degrader of 19 isolates. Growing cells and freely suspended cells of this strain completely degraded methyl orange, thereby decolorizing the medium. The strain stoichiometrically converted methyl orange to N,N-dimethyl-p-phenylenediamine and 4-aminobenzenesulfonic acid, which were identified by HPLC, GC, and GC-MS analyses. The enzyme activity responsible for the cleavage of the azo bond of methyl orange was localized to the cytoplasm of cells grown on modified MRS medium containing methyl orange. The effect of sugars, oligosaccharides, organic acids, metal ions, pHs, oxygen and temperatures on methyl orange decolorization by freely suspended cells was investigated. The optimal conditions for the decolorization of methyl orange by the Lactobacillus casei TISTR 1500 are incubation at 35 degrees C and pH 6 with sucrose provided as the energy source.     

Microbial transformation of aniline derivatives: regioselective biotransformation and detoxification of 2-phenylenediamine by Bacillus cereus strain PDa-1

A bacterial isolate, strain PDa-1, grew well on basal medium supplemented with 2-phenylenediamine, sucrose, and ammonium nitrate and completely transformed 2-phenylenediamine. The isolate was identified as Bacillus cereus. The product formed from 2-phenylenediamine was identified by EI-MS and NMR as 2-aminoacetanilide; whole cells converted 2-phenylenediamine to the product with a 76% molar yield. Whole cells also showed a broad substrate specificity toward 20 of 26 tested arylamines with substituent groups of various size and positions. Especially 2-aminobenzoic acid, 4-aminosalicylic acid, 5-aminosalicylic acid, and 2-aminofluorene were converted completely to the corresponding product with an aminoacetyl group. Cell extracts of strain PDa-1 had a high arylamine N-acetyltransferase activity. The partially purified enzyme converted 2-phenylenediamine to 2-aminoacetanilide. Strain PDa-1 constitutively expressed the enzyme in the absence of 2-phenylenediamine. Effects of 2-phenylenediamine and 2-aminoacetanilide on growth indicated that this enzyme probably plays a role in the detoxification of toxic arylamines in this strain.     

Doppler-free spectroscopy using a continuous-wave optical frequency synthesizer

A continuous-wave (cw) optical frequency synthesizer is demonstrated by using a monolithic-type cw optical parametric oscillator (cw-OPO) and an optical frequency comb. The cw-OPO is phase locked to an optical frequency comb that is phase locked to an atomic clock. The output frequency of the cw-OPO is frequency shifted with an electro-optic modulator, which makes it possible to tune the frequency continuously over 10 GHz. Furthermore, Doppler-free spectroscopy is performed using the optical frequency synthesizer for a cesium D1 line at 895 nm. The observed linewidth of 5 MHz is the natural linewidth of cesium. The center frequency of the line is consistent with a previous report.     

Electron Spin Dynamics in (DMe-DCNQI)2M (M = Li1-x Cu x (x < 0.14), Ag)

The quarter-filled π band systems, (DMe-DCNQI)_2M(M=Li_1-x Cu _x (x ≤ 0.14), Ag) were systematically studied with electron paramagnetic resonance (EPR). The intercolumn spin hopping rate in Li_1-x Cu _x -salt was obtained from the EPR linewidth. The temperature dependence of can be understood with the hole soliton model which also explains the DC conductivity. The π−d mixing of the Cu-salt enhances both and by 10³ times more than the Li-salt, which is consistent with the fact that the only Cu-salt has three-dimensional Fermi surface, but that Ag-salt is one-dimensional in spite of the mixing enhancement of by 10 times more than the Li-salt.     

Impact of NOx reduction on long-term ozone trends in an urban atmosphere

We investigated the relationships between ambient O(3) concentrations and the concentrations of its precursors, NO(x) and NMHC, in Osaka, Japan. The levels of O(x)' (where [O(x)']=[O(3)]+[NO(2)]-0.1x[NO(x)] where the last term accounts for primary emissions of NO(2)) were uniform within the city even in the photochemically active season. We suggested that NO oxidation by peroxy radicals was a minor contributor, and that oxidation of locally emitted NO by background O(3) in the city was the primary control on NO(2) concentrations. Ozone concentrations increased linearly from 1985 to 2002 at a rate of 0.6 ppbv/yr, even though O(x)' concentrations remained constant after the mid 1990s. The trend for O(x)' concentrations could not be explained in terms of an increase in local O(3) production, and the trend was found to reflect background O(3) concentrations in Japan. There was a clear relationship between the NO(2)/O(x)' ratio and NO(x) concentration: the ratio decreased with decreasing NO(x) concentration. As a consequence, O(3) increased with decreasing NO(x) concentration. The reduction of NO(x) emissions was deemed to be an important factor for the recent trend of increasing O(3) concentrations in Osaka City.     

Strain-time effects in low-cycle fatigue of nickel-base heat-resistant alloys at high temperature

A series of strain controlled low-cycle fatigue tests in the simulated high-temperature gas-cooled reactor (HTGR) helium environment were conducted at 900°C on Hastelloy X and its modified version, Hastelloy XR. In those tests the effects of strain rate and hold time on high-temperature low-cycle fatigue behavior were investigated. Decreasing the strain rate led to notable reductions in the fatigue life. In the tests with the trapezoidal strain waveform, the fatigue life was found to be reduced most effectively in tensile hold-time experiments. The tendency was interpreted through the feature of the crack morphology.     

Synthesis of Chiral Polyethers Containing Imidazolidinone Repeating Units and Application as Catalyst in Asymmetric Diels–Alder Reaction

In this study, enantiopure imidazolidinones containing two hydroxyphenyl groups were synthesized, and the Williamson synthesis of the chiral bisphenols thus prepared with dihalides afforded polyethers containing chiral imidazolidinone repeating units. These chiral imidazolidinone polyethers exhibited excellent catalytic activity in the asymmetric Diels–Alder reaction. With the use of these polymeric catalysts, enantioselectivities up to 99% were obtained, higher than those obtained by the corresponding monomeric imidazolidinone catalyst in homogeneous solution. The polymeric catalysts were found to be insoluble in commonly used organic solvents, and they could be repeatedly used without the loss of activity.