A verification test result of islanding operation of a microgrid configured with new energy generators and a study of improvement of voltage control

Verification test results of the isolated operation of a microgrid configured with some new energy generators at Aichi EXPO 2005 showed stable controllability without a rotating machine. However, improvement of voltage fluctuation with changing reactive power of loads had been hoped for. Some improvements of system voltage control had been implemented on the microgrid moved to Central Japan Airport City. This paper presents the results of verification testing of the improvement of voltage fluctuation in isolated operation with PAFC output power compensation control by NaS batteries, and also presents a simulation study of further improvement of the voltage control strategies of PAFC inverters. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 176(2): 41–52, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21096     

MicroRNA Expression Profiles in Superficial Esophageal Squamous Cell Carcinoma before Endoscopic Submucosal Dissection: A Pilot Study

Esophageal squamous cell carcinoma (ESCC) has a poor prognosis when diagnosed at an advanced stage, and early detection and treatment are essential to improve survival. However, intraobserver and interobserver variation make the diagnosis of superficial ESCC difficult, and suitable biomarkers are urgently needed. Here, we compared the microRNA (miRNA) expression profiles of superficial ESCC tissues and adjacent normal tissues obtained immediately before esophageal endoscopic submucosal dissection. We found that ESCC and normal tissues differed in their miRNA expression profiles. In particular, miR-21-5p and miR-146b-5p were significantly upregulated and miR-210-3p was significantly downregulated in tumor tissues compared with normal tissues. We also detected significant associations between miRNA expression and ESCC invasion depth and lymphovascular invasion. The same differential expression of miR-21-5p, miR-146b-5p, and miR-210-3p was detected in ESCC cell lines compared with normal esophageal epithelial cells in vitro. However, transfection of ESCC cells with miR-210-3p and miR-21-5p mimics or inhibitors had partial effects on cell proliferation and invasion in vitro. These results indicate that miRNA expression is significantly deregulated in superficial ESCC, and suggest that the potential contribution of differentially expressed miRNAs to the malignant phenotype should be further investigated.     

Identification of a Putative β-Arrestin Superagonist of the Growth Hormone Secretagogue Receptor (GHSR)

Ghrelin is a pleiotropic feeding hormone which also has a pivotal role in the central nervous system. Upon the activation of its receptor, growth hormone secretagogue receptor (GHSR), the Gα_q/11-mediated and the β-arrestin-mediated signaling pathways are activated. As the β-arrestin pathway is a potential drug target, there is a strong need for β-arrestin-biased GHSR modulators. Activation of the β-arrestin pathway should inhibit the Gα_q/11-mediated calcium flux through internalization of the receptor. Hence, we used the antagonistic activity in the calcium assay as the first screening for the β-arrestin activation. By conducting the second screening assay for the β-arrestin activation based on extracellular signal regulated kinase (ERK) 1/2 phosphorylation, we discovered a putative β-arrestin-biased superagonist. The activity of the compound was not completely blocked with the competitive antagonist, which implies that the effect is mediated, at least partly, by allosteric binding of the compound.     

Acceleration of graphitization on carbon nanofibers prepared from bacteria cellulose dispersed in ethanol

Bacteria cellulose is composed of pure cellulose nanofibrils with about 30–60 nm width. The original conglomerate of bacteria cellulose was dispersed in ethanol or distilled water and filtered, and paper like sheets were prepared. The conglomerate itself and the sheets were carbonized and then heat-treated at 3100 °C. The development of graphite structure by the heat treatment was observed for these sheets, especially for that derived from the nanofibrils dispersed in ethanol, while the heat-treated conglomerate exhibited the nature of nongraphitizing carbon. The difference in graphitizability seems to be attributed to graphitization behavior on the surface of nongraphitizing carbon.     

GABA(γ-氨基丁酸)的功能性

γ-氨基丁酸(GABA)富含于蔬菜、水果及发酵食品中,是日常摄取的氨基酸的一种。作为抑制性神经物质在人的大脑中枢神经系统中起作用。关于GABA的功能性,以前曾报道其具有抑制血压上升作用,但是在日常生活中摄取的GABA的量很少,所以,光从食物中很难获取能发挥其功能性的需要量。因此,我们注重研究有饮食生活经验的发酵食品中的微生物,开发了由微生物发酵的高效GABA生产技术。而且,经过一系列试验确认了GABA的有效作用,如抗压力作用等新功能。     

Nationwide survey of salmonella prevalence in environmental dust from layer farms in Japan

A nationwide survey was conducted to determine Salmonella prevalence in airborne dust from layer farms. Of the 4,090 layer farms in Japan, 203 were surveyed and 48 (23.6%) of these were positive for Salmonella. Salmonella isolation rates were higher in the eastern (24.3%), central (25.6%), western (23.9%), and southern (27.5%) prefectures than they were in the northern (13.3%) prefecture. We recovered 380 Salmonella isolates and identified 34 different Salmonella serovars. Salmonella Infantis was the most prevalent serovar (42 [11.1%] of 380), followed by Salmonella Agona (39 [10.3%] of 380), Salmonella Mbandaka (37 [9.7%] of 380), Salmonella Cerro (32 [8.4%] of 380), Salmonella Thompson (29 [7.6%] of 380), and Salmonella Braenderup (27 [7.1%] of 380). Of the 380 isolates, 273 (71.8%) were resistant to more than one antibiotic. Salmonella Infantis (41 [97.6%] of 42), Salmonella Agona (38 [97.4%] of 39), and Salmonella Mbandaka (34 [91.9%] of 37) showed the highest resistance rates. We found 18 different resistance patterns and the most common (179 [47.1%] of 273) was resistant to dihydrostreptomycin. One of the 13 Salmonella Hadar isolates was resistant to eight antibiotics. To investigate characteristics of Salmonella Agona, Salmonella Infantis, and Salmonella Mbandaka isolates across different prefectures, we performed pulsed-field gel electrophoresis by using XbaI and BlnI. The Salmonella Agona and Salmonella Mbandaka dendrograms were grouped into seven clusters, with 80 and 70% similarity, respectively. Because the Salmonella Infantis dendrogram showed low similarity, there is a possibility of genetic diffusion of this serovar across Japan. This report is the first to describe Salmonella contamination in airborne dust from layer farms in Japan. Our findings should be useful for future Salmonella infection monitoring and control.     

Synthesis of bimetallic gold-silver alloy nanoclusters by simple mortar grinding

A macroscale quantity of bimetallic Au-Ag alloy nanoclusters was achieved through sequential reduction by simple mortar grinding. The chitosan biopolymer was used as both a stabilizing and reducing agent. These nanoclusters exhibit excellent catalytic activity toward the reduction of 4-nitrophenol.