284 research outputs found
High-speed Internal Finishing of Capillary Tubes by Magnetic Abrasive Finishing
AbstractIn magnetic abrasive finishing, the development of a multiple pole-tip system using a partially heat-treated magnetic tool allows the finishing of multiple regions simultaneously in capillary tubes and thus improves the finishing efficiency. To further reduce the processing time required, a new high-speed machine is fabricated. This paper describes the development of the high-speed multiple pole-tip finishing equipment, which is capable of rotating the spindle up to 30000 min-1, and the effects of tube rotational speed on abrasive motion during the finishing experiments. Also, the finishing mechanisms of the high-speed machine are clarified
Suppression of cell cycle progression by Jun dimerization protein (JDP2) involves down-regulation of cyclin A2
We report here a novel role for Jun dimerization protein-2 (JDP2) as a regulator of the progression of normal cells through the cell cycle. To determine the role of JDP2 in vivo, we generated Jdp2 knock-out (Jdp2KO) mice by targeting exon 1 to disrupt the site of initiation of transcription. The healing of wounded skin of Jdp2KO mice proceeded more rapidly than that of control mice and more proliferating cells were found at wound margins. Fibroblasts derived from embryos of Jdp2KO mice proliferated more rapidly and formed more colonies than wild-type fibroblasts. JDP2 was recruited to the promoter of the gene for cyclin A2 (ccna2) at a previously unidentified AP-1 site. Cells lacking Jdp2 had elevated levels of cyclin A2 mRNA. Moreover, reintroduction of JDP2 resulted in repression of transcription of ccna2 and of cell cycle progression. Thus, transcription of the gene for cyclin A2 appears to be a direct target of JDP2 in the suppression of cell proliferation
Uniform Internal Finishing of SUS304 Stainless Steel Bent Tube Using a Magnetic Abrasive Finishing Process
Heat Transfer And Pressure Drop Characteristics Of Water Flow Boiling In Internally Enhanced Tubes
Flow boiling is a critical process for many thermal conversion processes such as HVAC&R, water heating, power generation, and desalination applications. The goal of this paper is to enhance the in-tube heat transfer for flow boiling of water and thus improve the efficiency of the boiler. This paper presents an experimental investigation of the heat transfer and pressure drop characteristics for water under forced convection and boiling conditions inside both smooth and enhanced tubes. The results in the smooth copper tube are compared with several relevant correlations and the findings have been used as a baseline. The two-phase heat transfer and pressure drop performance of the water flow boiling in the internally enhanced tube is investigated, and the influence of internal surface pattern on the thermal characteristics is discussed. The relations of the heat transfer coefficient with mass flux, heat flux and vapor quality are analyzed, and the findings have been summarized
酢酸摂取と運動が脂肪代謝と運動耐久性に及ぼす影響
Previously, we found that acetic acid had effects on lipid metabolism in skeletal muscles and has functions that work against obesity and obesity-linked type 2 diabetes through the activation of AMPactivated protein kinase (AMPK). During exercise, AMPK is activated in skeletal muscle according to exercise intensity and it increases fatty acid oxidation. The purpose of this study was to investigate the interactive effects of chronic intake of acetic acid and exercise training on lipid metabolism and endurance performance. Six-week-old SD rats were randomly assigned to four groups: water-injected (rest-water), acetic acid-injected (rest-ace), exercise-trained after injection of water (water-ex), and exercise-trained after injection of acetic acid (ace-ex) for 4 weeks. Body weight (BW) in rest-ace and ace-ex groups was significantly lower than rest-water group. Exercise-training groups showed an increase of exercise capacity, by the addition of intake of acetic acid, lipid oxidation was promoted during exercise tolerance test. Skeletal muscle of rats treated with acetic acid and exercise training led to higher expressions of cytochrome c (cycs), and tended to stimulate expressions of peroxisome proliferator-activated receptor coactivator 1-α (PGC1-α ) and MHC1 genes than those of rest-water group. Those results indicate that treatments both of exercise training and intake of acetic acid contribute to enhancement of lipid metabolism and improvement of exercise capacity.これまで我々は、酢酸の摂取が骨格筋内のAMP活性化プロテインキナーゼ(AMPK)の活性化を介して脂質代謝と肥満、肥満に関連した2型糖尿病の予防に効果があることを示唆してきた。AMPKは運動によって骨格筋で活性化し、脂肪酸酸化を促進する。この研究は、4週間の継続的な酢酸摂取と運動トレーニングが運動中の脂肪代謝と運動耐久性に及ぼす影響について調べることを目的とした。 6週齢のSD系雄ラットを安静期に水を摂取するrest-water群、酢酸を摂取するrest-ace群、運動前に水を摂取するwater-ex群、運動前に酢酸を摂取するace-ex群に無作為に分け実験を行った。酢酸を継続的に摂取すると水摂取に比較して腹腔内脂肪量の減少と体重増加の抑制がみられた。また継続的な酢酸摂取および運動トレーニングにより、耐久性運動下でのグルコース利用の抑制および脂肪酸酸化の促進が見られた。酢酸摂取および運動トレーニング群の腓腹筋では、MHCIおよびcytochrome c等の遅筋線維マーカー遺伝子が増加していた。継続的な酢酸摂取と運動トレーニングにより、脂肪代謝と運動耐久性の向上が示唆された
チュウトウド コウネツセイ サイキン Geobacillus stearothermophilus セイイク オンド ヘンイカブ ニ オケル タンパクシツ ハツゲン カイセキ
Optimum growth of moderately thermophile Geobacillus stearothermophilus (Bst) has been observed at 55ºC, and suppressed by the downshift to lower temperature. In order to understand the relationship between growth temperature and protein expression, we made Bst mutant strains which were adapted to lower temperature (30ºC) compared with wild type strain, and then we examined their protein expression under various growth temperatures. When they were cultured at 55ºC, different expression patterns of six proteins (P1-P6) were observed between wild type and mutant strains, whereas five proteins (A1-A5) were found only in mutant strains cultured at 37ºC. Furthermore, expression of five proteins (DS1-DS5) was increased according to the downshift of growth temperature to 37ºC. Among all 16 proteins, abundant three proteins (P1, DS3, and DS5) were electroblotted to PVDF membrane, followed by analyzed N-terminal amino acid sequences. As a result, it was suggested that P1 must be Surface-layer protein A (sbsA), whereas DS3 and DS5 were unknown proteins
POLISHING CHARACTERISTICS OF TRANSPARENT POLYCRYSTALLINE YAG CERAMICS USING MAGNETIC FIELD-ASSISTED FINISHING
ABSTRACT Transparent polycrystalline yttrium aluminum garnet (YAG) ceramics have garnered an increased level of interest for highpower laser applications due to their ability to be manufactured in large sizes, and doped in relatively substantial concentrations when compared to traditional single-crystalline gain media. However, surface characteristics have a direct effect on the lasing ability of these materials, and a lack of a fundamental understanding of the polishing mechanisms of these ceramics remains a challenge for their utilization. The aim of this paper is to study the polishing characteristics of YAG ceramics using magnetic field-assisted finishing (MAF). An experimental setup was developed, through the refinement of the MAF process, for YAG ceramic workpieces. Using this equipment with diamond abrasives, the YAG ceramic surfaces were polished to subnanometer scale. Polishing trials with fine diamond abrasive and colloidal silica were then performed on this sub-nanometer surface and the material removal mechanisms were analyzed. Polishing with 0-0.1 m diameter diamond abrasive caused increasing roughness with polishing time due to the continuous cycle of relatively substantial chipping followed by minor smoothing. Polishing with colloidal silica caused valleys to widen with increased polishing time and the grain structure of the ceramic influenced the material removal
アミトロール テイコウセイ ダイチョウキン カブ ニオケル タンパクシツ ハツゲン カイセキ
It was reported that the E.coli mutant strain exhibited the resistance against amitrole (AT) which had used as a pesticide and inhibits the bacterial growth. In order to elucidate the mechanism on the AT-resistance in E.coli, we prepared the E.coli mutant strain by treating with chemical mutagen, MNNG, and then selected the AT-resistant E. coli strain. The obtained mutant strain was possible for proliferating even in the M9 minimal medium containing 2 mg/ml AT. Therefore, we examined the expressed proteins in the mutant strain, which was cultured under various conditions. As a result, it was suggested the expression of 22 kDa protein (P1) was suppressed as the AT concentration was increased in M9 medium. By the amino acid sequence analysis, it was proved that P1 must be alkyl hydroperoxide reductase C22 protein (ahpC). On the other hand, the expression of P2 protein in mutant strain has increased in the M9 medium containing 2mg/ml AT, and partial amino acid sequence of P2 was consistent with zinT (yodA) protein. From these results, it is likely that the amitrole-resistance in E.coli might be regulated by soxRS regulon, not oxy R, like adaptation for the oxidative stress
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