Photocatalytic oxidation of low concentration 2,4-D solution with new TiO2 fiber catalyst in a continuous flow reactor.

Environmental pollution by low concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D) is a concern these days due to ever increasingly stringent regulations. Photocatalysis with immobilized TiO2 fiber is a promising oxidation method. Laboratory experiments on photocatalytic degradation of 0.045 mmol l(-1) 2,4-D with the world's first high-strength TiO2 fiber catalyst were carried out in a continuous flow reactor in which the degradations were, in general, similar to those with high 2,4-D concentrations investigated elsewhere. Degradation and mineralization of 2,4-D were significantly enhanced with no initial pH adjustments. The rate constants for total organic carbon (TOC) without pH adjustment were about two-fold bigger than the pH adjustment cases. CO2 gas measurement and carbon mass-balance were carried out for the first time, where about 34% organic carbon converted into CO2 gas during four-hour oxidation. 2,4-Dichlorophenol (2,4-DCP), phenol, benzyl alcohol and two unknowns (RT = 2.65 and 3.78 min.) were detected as aromatic intermediates while Phenol was the new aromatic in HPLC analysis. Dechlorination efficiencies were high (> 70%) in all the cases, and more than 90% efficiencies were observed in chloride mass balance. Bigger flow rates and solution temperature fixed at 20 degrees C without pH adjustment greatly enhanced 2,4-D mineralization. These results can be an important basis in applying the treatment method for dioxin-contaminated water and wastewater.     

Selection of parameters in the design of real-time spectral analysis

A new analytical method with high speed processing in the time-frequency domain is presented. In this method, sine and cosine waves with an established frequency and multiple periods are used, and we call these waves “cutting-out waves.” We all the frequency the “established frequency,” and we call the number of periods of the cutting-out wave the “number of periods.” The inner product of the cutting-out wave and the signal are calculated, and a signal element with a frequency near the established frequency is detected. We call the unit that detects the signal element an “auditory cell.” There are many auditory cells, and they have an established frequency which differs very little. The design of this method is the arrangement of the auditory cells. There are three parameters in the design, and these parameters are a sampling frequency, the number of periods, and the increasing rate of the established frequencies. In this article, we show the selection of these parameters.     

Proteomics integrated with Escherichia coli vector-based vaccines and antigen microarrays reveals the immunogenicity of a surface sialidase-like protein of Propionibacterium acnes

Proteomics is a powerful tool for the identification of proteins, which provides a basis for rational vaccine design. However, it is still a highly technical and time‐consuming task to examine a protein's immunogenicity utilizing traditional approaches. Here, we present a platform for effectively evaluating protein immunogenicity and antibody detection. A tetanus toxin C fragment (Tet‐c) was used as a representative antigen to establish this platform. A cell wall‐anchoring sialidase‐like protein (SLP) of Propionibacterium acnes was utilized to assess the efficacy of this platform. We constructed an Escherichia coli vector‐based vaccine by overexpressing Tet‐c or SLP in E. coli and utilized an intact particle of E. coli itself as a vaccine (E. coli Tet‐c or SLP vector). After ultraviolet (UV) irradiation, the E. coli vector‐based vaccines were administered intranasally into imprinting control region mice without adding exogenous adjuvants. For antibody detection, we fabricated antigen microarrays by printing with purified recombinant proteins including Tet‐c and SLP. Our results demonstrated that detectable antibodies were elicited in mice 6 weeks after intranasal administration of UV‐irradiated E. coli vector‐based vaccines. The antibody production of Tet‐c and SLP was significantly elevated after boosting. Notably, the platform with main benefits of using E. coli itself as a vaccine carrier provides a critical template for applied proteomics aimed at screening novel vaccine targets. In addition, the novel immunogenic SLP potentially serves as an antigen candidate for the development of vaccines targeting P. acnes‐associated diseases.     

Full Band Monte Carlo Study for Two-Dimensional Hole Transport in Strained Si p-MOSFETs

Transport properties of the two-dimensional hole gas in inversion layer of strained Si/SiGe p-MOSFETs are investigated using the full-band Monte Carlo simulator based on the nonlocal pseudopotential calculation. The hole mobility is significantly enhanced by the strain in the case of Ge content of ≥20%. Moreover, we also present the high-field transport characteristics of 2D holes. In contrast to the low-field mobility, the hole saturation velocity does not significantly enhanced by the strain.     

Detection of Leuconostoc strains at a meat processing plant using polymerase chain reaction

To simplify the labor-intensive conventional routine testing of samples to detect Leuconostoc at a meat processing plant, we developed polymerase chain reaction (PCR) primers specific for Leuconostoc from 16S rRNA gene sequences. These primers did not detect other common lactic acid bacteria such as Lactobacillus plantarum, Lact. sake, Lact. fermentum, Lact. acidophilus and Weissella viridescens. PCR with this primer detected all Leuconostoc species tested (Leu. mesenteroides subsp. mesenteroides, Leu. pseudomesenteroides, Leu. carnosum, Leu. lactic, Leu. citreum, Leu. amelibiosum, Leu. gelidum), except for Leu. fallax, and no other lactic acid bacteria on agarose gel electrophoresis. The method could identify areas contaminated with Leuconostoc in a large-scale industrial meat processing plant. Of 69 samples analyzed, 34 were positive for Leuconostoc according to the conventional culture method (isolation of LAB producing dextran) and PCR, whereas 29 were negative according to both. Six samples were culture-negative but positive by PCR. No false negative results were generated by PCR. The method is rapid and simple, is useful for routinely monitoring areas contaminated with Leuconostoc in meat processing plants, and could help to prevent the spoilage of meat products.     

Ferromagnetic Correlations in Ca-Doped Sr2RuO4: 87Sr NMR Study

Magnetic properties on Sr_2–x Ca _x RuO₄ have been investigated by a microscopic probe of ⁸⁷Sr-NMR in order to understand the magnetic character on spin-triplet superconductor of Sr₂RuO₄, which has multibands on the Fermi surface. With substituting Ca for Sr which gives rise to crystal distortion, the Knight shift (K) and the nuclear spin-lattice relaxation rate divided by temperature (1/T _{1 T}) increases progressively up to x=1.5. The Korringa relation from K and 1/T ₁ T becomes smaller, indicative of development of ferromagnetic fluctuations with increasing Ca content. This suggests that the q-independent spin fluctuations originating from the 2-dimensional band are changed to the ferromagnetic ones by the Ca doping.     

Real‐time spectral analysis

For signal analysis, the Fourier transform and the linear prediction methods are the main approaches. In recent years, the wavelet transform, which gives an expression in the time–frequency domain, has been attracting attention. In the wavelet transform, scale and shift operations are used to analyze regional waves in the signal. In this paper, we propose a new method for signal analysis. Instead of the wavelet, short sine waves and cosine waves which have slightly different frequencies and phases established beforehand are used. These frequencies and phases play the same role as wavelets in analyzing regional waves in the signal. However, our proposed method is different from the wavelet transform because it does not use multiresolution analysis. In conventional spectral analysis methods, all data are prepared beforehand and calculations are performed by using these data. In the proposed method, the spectrum is updated whenever new signal data come in. We show that the amount of calculation is markedly reduced and that real‐time spectral analysis can be achieved. Finally, we present an analysis of Japanese vocal sounds using the proposed method. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 161(1): 43–50, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20504