One-year weekly survey of noroviruses and enteric adenoviruses in the Tone River water in Tokyo metropolitan area, Japan

To investigate the actual fluctuations in the concentrations of noroviruses (NoVs) GI and GII, and enteric adenoviruses (EAdVs) in river water and its relationship with the number of acute infectious gastroenteritis patients, one-year weekly quantitative monitoring of NoVs GI and GII and EAdVs was performed in the Tone River in Japan where the surface water is utilized for the main production of drinking water for the Tokyo Metropolitan Area from October 2009 to September 2010. Noroviruses GI and GII and EAdVs were detected in 28 (54%), 33 (63%), and 23 (44%) of the 52 samples (1 L each), respectively. The concentrations of NoVs GI and GII and EAdVs fluctuated strongly and were more abundant in winter and early spring. The concentration of NoVs GI was transiently greater than 10,000 copies/L. The number of acute infectious gastroenteritis patients in the upper river basin was highly correlated with all the viral concentrations, while general microbial indicator data such as turbidity and heterotrophic plate count were independent of viral concentration as suggested in previous studies. To the best of our knowledge, this is the first study that clearly shows the strong correlation of the number of gastroenteritis with virus contamination in lower river basin.     

Removal of radioactive iodine and cesium in water purification processes after an explosion at a nuclear power plant due to the Great East Japan Earthquake

The presence of radionuclides at five water purification plants was investigated after an explosion at a nuclear power plant hit by the Great East Japan Earthquake on 11 March 2011. Radioactive iodine (¹³¹I) and cesium (¹³⁴Cs and ¹³⁷Cs) were detected in raw water in Fukushima and neighboring prefectures. ¹³¹I was not removed by coagulation-flocculation-sedimentation. ¹³¹I was removed by granular activated carbon (GAC) and powdered activated carbon (PAC) at a level of about 30%-40%, although ¹³¹I was not removed in some cases. This was also confirmed by laboratory-scale experiments using PAC. The removal percentages of ¹³¹I in river and pond waters by 25 mg dry/L of PAC increased from 36% to 59% and from 41% to 48%, respectively, with chlorine dosing before PAC. ¹³⁴Cs and ¹³⁷Cs were effectively removed by coagulation at both a water purification plant and in laboratory-scale experiments when turbidity was relatively high. In contrast, ¹³⁴Cs and ¹³⁷Cs in pond water with low turbidity were not removed by coagulation. This was because ¹³⁴Cs and ¹³⁷Cs in river water were present mainly in particulate form, while in pond water they were present mainly as cesium ions (¹³⁴Cs⁺ and ¹³⁷Cs⁺). However, the removal of ¹³⁴Cs and ¹³⁷Cs in pond water by coagulation increased markedly when ¹³⁴Cs and ¹³⁷Cs were mixed with sediment 24 h before coagulation.     

Nanoscale epitaxial growth control of oxide thin films by laser molecular beam epitaxy—towards oxide nanoelectronics

The nanoscale growth control of oxide thin films, such as ferroelectric and magnetic materials, were explored by a novel technique based on nanoscale substrate engineering as well as atomic layer control via laser molecular beam epitaxy (laser-MBE). Atomic-scale analysis of the terminating layer of perovskite oxide films was performed by in situ coaxial impact-collision ion scattering spectroscopy. The novel heteroepitaxies that could be attained were: (1) the termination-regulated molecular layer-by-layer epitaxy of BaTiO₃ and La_0.7Sr_0.3MnO₃ thin films and (2) the step-decoration epitaxy resulting in the nanowire or nanodot structures of magnetic oxides such as (Mn, Zn) ferrite on ultrasmooth sapphire substrates with straight atomic steps.     

Antimicrobial resistance of Salmonella enterica serovar Typhimurium isolated from cattle in Japan

The antimicrobial susceptibility of 144 Salmonella enterica serovar Typhimurium isolates collected from all over Japan between 1973 and 1998 were investigated. All the isolates exhibited resistance to four or more antimicrobials and 22 resistance patterns were observed. Isolates showing resistance patterns to ampicillin (A), chloramphenicol (C), streptomycin (S), sulfonamides (Su) and tetracycline (T), which are typical resistance patterns for S. Typhimurium DT104 (DT104), were predominant. Thirty-six of the 68 isolates that exhibited resistance to five or more antimicrobials (ACSSuT+) were identified as DT104 by phage typing. Another 103 S. Typhimurium strains gathered from cattle between 1977 and 1999 in a limited area of Japan were analyzed for molecular epidemiological studies. Results using fluorescent amplified-fragment length polymorphism and pulsed-field gel electrophoresis suggest that clonal exchange of S. Typhimurium among cattle in Japan has occurred since 1992, and that contemporary strains show a remarkable degree of homogeneity with DT104 at a molecular level. The clonal replacement by DT104 affected the antimicrobial resistance pattern of S. Typhimurium from cattle in Japan.     

Effect of solvent evaporation rate on surface composition in fluoro‐copolymer/acrylate‐copolymer blend films

The relationship between the surface composition and the rate of solvent evaporation (R) in blend films of poly(vinylidene fluoride‐co‐hexafluoroacetone) (P(VDF‐HFA)) and poly(2‐ethylhexyl acrylate‐co‐acrylic acid‐co‐vinyl acetate) (P(2EHA‐AA‐VAc)) has been investigated. P(VDF‐HFA), a low‐surface tension component, was concentrated on the surface when R was relatively high. In contrast, when R was relatively low, P(2EHA‐AA‐VAc), a low‐density component, was concentrated on the surface. Therefore, it is speculated that the factors dominating surface enrichment in polymer blends were changed from surface tension differences to density differences between the components when R was decreased. In addition, the affinity between components and substrate strongly affects the dominant factors determining the surface composition. © 2001 Society of Chemical Industry     

Multi-thousand kilometer optical soliton data transmissionexperiments at 5 Gb/s using an electroabsorption modulator pulsegenerator

We have demonstrated the transmission of data-coded optical soliton pulse at the bit-rate of 5 Gb/s over a few thousand kilometers. Ultra-short optical pulses generated with a sinusoidally driven electroabsorption modulator and a DFB-LD that were approximately hyperbolic-secant squared shape were transmitted through the fiber. Both recirculating loop transmission lines and straight transmission lines were used for the experiments. The pulse width was maintained well over 6,000 km transmission in the recirculating loop experiment. Three-thousand-km stable transmission was achieved using a straight-line setup at the bit-rate of 5 Gb/s, although the average fiber chromatic dispersion deviated slightly from the optimum value. The results indicate the possibility of the soliton transmission system for multi-thousand-km optical communication systems     

A single-chip CMOS analog/digital mixed NTSC decoder

A single-chip CMOS LSI that integrates all analog-to-digital (A/D), digital-to-analog (D/A), peripheral, and digital signal processing circuits necessary for a digital National Television System Committee (NTSC) signal decoder is described. The LSI chip accepts composite NTSC video signals in analog form, digitizes them using the on-chip A/D converter, converts them to component RGB signals, and then converts the signals to analog form by using the on-chip D/A converters. The development of circuits that maximize use of the input digital data is discussed. A 6-b A/D circuit is used to reduce the circuit size. Circuits that help maintain acceptable picture quality despite 6-b resolution were developed. Besides analog NTSC signal input and RGB signal output, the IC can also input and output digital NTSC signals, Y/C (luminance, chrominance) signals, and RGB signals. Applications of the LSI are presented     

The experimental study of the effect of fiber chromatic dispersionupon IM-DD ultra-long distance optical communication systems withEr-doped fiber amplifiers using a 1000 km fiber loop

We have evaluated the transmission performance difference of ultra-long distance optical communication systems with Er-doped fiber amplifier repeaters due to fiber chromatic dispersion effect. A 1000 km fiber loop with 31 Er-doped fiber amplifiers was used for the experiments. We have changed the system zero dispersion wavelength by changing the length of the normal single-mode fiber at the end of the fiber loop, and measured the bit-error-rate after transmission. Comparison of the longest transmission distance and the width of the 9000 km transmissible window were discussed for various system zero dispersion wavelengths. The results have shown that the difference between the gain peak wavelength of the amplifier chain and the system zero dispersion wavelength caused degradation of the system performance, and the degree of the degradation was almost symmetrical from the gain peak wavelength     

A new materials processing—hydrothermal processing

Summary The hydrothermal processing has emerged as the new materials processing for powder preparation. This describes definition, history, advantages, characteristics of the powder, ideal and hydrothermal powder.     

CD48 expression on leukocytes in infectious diseases: flow cytometric analysis of surface antigen

BACKGROUND: The function of CD48, one of the pan leukocyte cell surface antigens, is not yet well understood. CD48 was recently shown to enhance the CD40-mediated activating signal to B lymphocytes. As CD48 is one of the activation antigens of monocytes, neutrophils and lymphocytes, a change of its expression on the cells could be expected in infectious diseases. METHODS AND RESULTS: Leukocytes from 27 healthy controls and 97 patients with various infectious diseases were stained with anti CD48 antibody and analyzed by flow cytometry. On monocytes and neutrophils, the CD48 expression was increased in all of the patients with varicella, measles, rubella, infectious mononucleosis, streptococcus tonsillitis, sepsis and appendicitis. On lymphocytes, a significant increase of CD48 was also detected in the patients with the same diseases, except those with sepsis or appendicitis. The normalization of increased CD48 expression was confirmed on monocytes at the convalescent phase. CONCLUSION: These data suggest that CD48 expression on leukocytes reflects the disease activity of infectious diseases, especially of viral infections.