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Ishihara K.,Tokushima Bunri University | Nakaoka M.,Tokushima Prefectural Industrial Technology Center
American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP | Year: 2015

Vortices occur when gas flow passes through a duct with a tube bank of heat exchangers, such as a gas heater and/or a boiler. Very high level noise called a "self-sustained tone" occurs due to the interference of the vortices and the sound field in the duct. In general, baffle plates are used to suppress the self-sustained tone. However, it is difficult to use them effectively, because insertion conditions are vague. Then, perforated plates are used in both sides of the duct walls to suppress the self-sustained tones. Because we thought that the perforated plate might have acoustic damping and resonance mode of the duct perpendicular direction to the flow may be suppressed by its damping effect, when the self-sustained tone occurred. Some experiments were carried out to examine the suppression effect of the perforated plates installed. As a result, the suppression effect appeared in all cases. The purpose of this study is to clarify the effectiveness of the perforated plates for self-sustained tones. Copyright © 2015 by ASME.


Nakamura M.,Tokushima University | Hayashi K.,Tokushima University | Hayashi K.,EcoTopia Science Institute | Nakano M.,Tokushima University | And 4 more authors.
ACS Nano | Year: 2015

An in vitro imaging system to evaluate the stealth function of nanoparticles against mouse macrophages was established using fluorescent organosilica nanoparticles. Surface-functionalized organosilica nanoparticles with polyethylene glycol (PEG) were prepared by a one-step process, resulting in a brush-type PEG layer. A simultaneous dual-particle administration approach enabled us to evaluate the stealth function of nanoparticles with respect to single cells using time-lapse fluorescent microscopic imaging and flow cytometry analyses. Single-cell imaging and analysis revealed various patterns and kinetics of bare and PEGylated nanoparticle uptake. The PEGylated nanoparticles revealed a stealth function against most macrophages (PEG-sensitive macrophages); however, a stealth function against certain macrophages (PEG-insensitive macrophages) was not observed. We identified and characterized the PEG-resistant macrophages that could take up PEGylated nanoparticles at the same level as bare nanoparticles. © 2015 American Chemical Society.


Hayashi K.,Tokushima University | Nakamura M.,Tokushima University | Miki H.,Tokushima University | Ozaki S.,Tokushima Prefectural Central Hospital | And 4 more authors.
Advanced Functional Materials | Year: 2014

Physical therapies including photodynamic therapy (PDT) and photothermal therapy (PTT) can be effective against diseases that are resistant to chemotherapy and remain as incurable malignancies (for example, multiple myeloma). In this study, to enhance the treatment efficacy for multiple myeloma using the synergetic effect brought about by combining PDT and PTT, iodinated silica/porphyrin hybrid nanoparticles (ISP HNPs) with high photostability are developed. They can generate both 1O2 and heat with irradiation from a light-emitting diode (LED), acting as photosensitizers for PDT/PTT combination treatment. ISP HNPs exhibit the external heavy atom effect, which significantly improves both the quantum yield for 1O 2 generation and the light-to-heat conversion efficiency. The in vivo fluorescence imaging demonstrates that ISP HNPs, modified with folic acid and polyethylene glycol (FA-PEG-ISP HNPs), locally accumulate in the tumor after 18 h of their intravenous injection into tumor-bearing mice. The LED irradiation on the tumor area of the mice injected with FA-PEG-ISP HNPs causes necrosis of the tumor tissues, resulting in the inhibition of tumor growth and an improvement in the survival rate. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Tsutsumi R.,Tokushima University | Yoshida T.,Tokushima University | Nii Y.,Tokushima Prefectural Industrial Technology Center | Okahisa N.,Tokushima Prefectural Industrial Technology Center | And 8 more authors.
Nutrition and Metabolism | Year: 2014

Background: Obesity is a major risk factor for insulin resistance, type 2 diabetes, and stroke. Flavonoids are effective antioxidants that protect against these chronic diseases. In this study, we evaluated the effects of sudachitin, a polymethoxylated flavonoid found in the skin of the Citrus sudachi fruit, on glucose, lipid, and energy metabolism in mice with high-fat diet-induced obesity and db/db diabetic mice. In our current study, we show that sudachitin improves metabolism and stimulates mitochondrial biogenesis, thereby increasing energy expenditure and reducing weight gain. Methods. C57BL/6 J mice fed a high-fat diet (40% fat) and db/db mice fed a normal diet were treated orally with 5 mg/kg sudachitin or vehicle for 12 weeks. Following treatment, oxygen expenditure was assessed using indirect calorimetry, while glucose tolerance, insulin sensitivity, and indices of dyslipidemia were assessed by serum biochemistry. Quantitative polymerase chain reaction was used to determine the effect of sudachitin on the transcription of key metabolism-regulating genes in the skeletal muscle, liver, and white and brown adipose tissues. Primary myocytes were also prepared to examine the signaling mechanisms targeted by sudachitin in vitro. Results: Sudachitin improved dyslipidemia, as evidenced by reduction in triglyceride and free fatty acid levels, and improved glucose tolerance and insulin resistance. It also enhanced energy expenditure and fatty acid β-oxidation by increasing mitochondrial biogenesis and function. The in vitro assay results suggest that sudachitin increased Sirt1 and PGC-1α expression in the skeletal muscle. Conclusions: Sudachitin may improve dyslipidemia and metabolic syndrome by improving energy metabolism. Furthermore, it also induces mitochondrial biogenesis to protect against metabolic disorders. © 2014 Tsutsumi et al.; licensee BioMed Central Ltd.


Hayashi K.,Tokushima University | Nakamura M.,Tokushima University | Sakamoto W.,EcoTopia Science Institute | Yogo T.,EcoTopia Science Institute | And 2 more authors.
Chemistry of Materials | Year: 2011

Conifer foliage-like rutile TiO2 nanoparticles (CFR NPs), spherical anatase TiO2 NPs (SA NPs), and a mixture of CFR and SA NPs were synthesized in aqueous solution at low temperature. Furthermore, sea urchin-like nanostructures combining SA and CFR NPs, which were designated as anatase/rutile nanostructures (A/R NSs), were produced through the self-assembly of jack bean urease (JBU). The specific surface area of the A/R NSs was considerably larger than those of the CFR NPs, SA NPs, and commercial TiO 2 (P25). In addition, the amount of reactive oxygen species (ROS) yielded from the A/R NSs was significantly higher than that yielded from CFR NPs, SA NPs, and P25 because of the large surface area of the A/R NSs and a synergistic effect caused by the integration of anatase and rutile phases. The A/R NSs showed no cytotoxicity at concentrations <100 μg/mL, although CFR NPs, SA NPs, and P25 were cytotoxic, probably because of their size and shape. Using the high surface area and the superior photocatalytic activity of the A/R NSs, macrophages were effectively destroyed by UV irradiation for the purpose of treating atherosclerosis. Macrophages were killed more effectively by the A/R NSs than P25. Furthermore, different mechanisms of cell destruction resulting from UV irradiation, A/R NSs, and a combination of both were investigated. The death of cells treated with A/R NSs and exposed to UV irradiation was induced primarily by apoptosis rather than necrosis; cells that were not treated with the NSs died mainly from necrosis. © 2011 American Chemical Society.


Nishino H.,Tokushima University | Asano T.,Tokushima University | Taniguchi Y.,Tokushima University | Yoshida K.,Tokushima University | And 3 more authors.
Japanese Journal of Applied Physics | Year: 2011

In this paper, we present a novel method of accurately estimating pipe wall thickness by detecting the minute difference in the angular wave number of a circumferential (C-) Lamb wave. A C-Lamb wave circling along a circumference of a pipe is transmitted and received by a pair of noncontact air-coupled ultrasonic transducers. For the accurate detection of the angular wave number, a large number of tone-burst cycles are used so as to superpose the C-Lamb wave on itself along its circumferential orbit. In this setting, the amplitude of the superposed region changes considerably with the angular wave number, from which the wall thickness can be estimated. This method is very useful to monitor the integrity of piping in high-temperature environments because of its noncontact nature. The principle of the method and experimental verification are shown. © 2011 The Japan Society of Applied Physics.


Hayashi K.,Tokushima University | Nakamura M.,Tokushima University | Makita Y.,Japan National Institute of Advanced Industrial Science and Technology | Fujiwara R.,Aichi Institute of Technology | And 2 more authors.
Materials Letters | Year: 2011

Sea urchin-shaped rutile nanostructures (SUR NSs) with abundant {110} surfaces are synthesized at 60 °C under atmospheric pressure. The SUR NSs were ∼ 420 nm in diameter and contain a number of needle-like rutile single crystals grown parallel to the (110) face from a single nucleus in a radial fashion. The photocatalytic activity of the SUR NSs is significantly higher than that of commercial rutile nanoparticles with the same specific surface area. This demonstrates that {110} facets are effective in enhancing photoactivity. © 2011 Elsevier B.V. All Rights Reserved.


PubMed | Saitama University, Tokushima Prefectural Industrial Technology Center and Tokushima University
Type: | Journal: Nutrition & metabolism | Year: 2014

Obesity is a major risk factor for insulin resistance, type 2 diabetes, and stroke. Flavonoids are effective antioxidants that protect against these chronic diseases. In this study, we evaluated the effects of sudachitin, a polymethoxylated flavonoid found in the skin of the Citrus sudachi fruit, on glucose, lipid, and energy metabolism in mice with high-fat diet-induced obesity and db/db diabetic mice. In our current study, we show that sudachitin improves metabolism and stimulates mitochondrial biogenesis, thereby increasing energy expenditure and reducing weight gain.C57BL/6J mice fed a high-fat diet (40% fat) and db/db mice fed a normal diet were treated orally with 5mg/kg sudachitin or vehicle for 12weeks. Following treatment, oxygen expenditure was assessed using indirect calorimetry, while glucose tolerance, insulin sensitivity, and indices of dyslipidemia were assessed by serum biochemistry. Quantitative polymerase chain reaction was used to determine the effect of sudachitin on the transcription of key metabolism-regulating genes in the skeletal muscle, liver, and white and brown adipose tissues. Primary myocytes were also prepared to examine the signaling mechanisms targeted by sudachitin in vitro.Sudachitin improved dyslipidemia, as evidenced by reduction in triglyceride and free fatty acid levels, and improved glucose tolerance and insulin resistance. It also enhanced energy expenditure and fatty acid -oxidation by increasing mitochondrial biogenesis and function. The in vitro assay results suggest that sudachitin increased Sirt1 and PGC-1 expression in the skeletal muscle.Sudachitin may improve dyslipidemia and metabolic syndrome by improving energy metabolism. Furthermore, it also induces mitochondrial biogenesis to protect against metabolic disorders.


Tsuboi R.,Keio University | Kakinuma Y.,Keio University | Aoyama T.,Keio University | Ogawa H.,Tokushima Prefectural Industrial Technology Center | Hamada S.,Taga Denki Co.
Procedia CIRP | Year: 2012

This paper deals with the use of two types of ultrasonic-assisted micromachining methods for obtaining longer tool life and higher machining efficiency in the micromachining of hard and brittle materials. USV drilling is drilling that is aided by ultrasonic vibration in the direction axial to the tool. Cavitation machining is a method is aided by ultrasonic vibration of the cutting fluid. We investigated the effects of USV, cavitation, and their combination on the micro drilling of SiC. Experimental results clearly showed an improvement in tool life and a reduction in tool wear. Furthermore, the accuracy was improved. © 2012 The Authors.


Higaino T.,Keio University | Aoyama T.,Keio University | Ogawa H.,Tokushima Prefectural Industrial Technology Center
Proceedings of the 8th International Conference on Leading Edge Manufacturing in 21st Century, LEM 2015 | Year: 2015

The problems associated with machining CFRTP (carbon fiber reinforced thermoplastics) are short tool life and burrs. In this study, side milling tests are carried out dry and with two types of coolants liquefied carbon dioxide (LCO2) and liquefied nitrogen (LN2). The workpiece material is a composite material made of carbon fibers and polyetheretherketon (CF/PEEK) Cutting force, surface integrity and tool wear are evaluated, and the elastic modulus of the CF/PEEK is examined. The use of liquefied nitrogen as a coolant suppresses burrs effectively. There is no significant difference in tool wear between the dry and cryogenic conditions. The finished surface roughness increases with the cutting length, and milling with liquefied nitrogen shows the highest surface roughness. The elastic modulus of CF/PEEK under cryogenic condition is higher than that at room temperature.

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