675 research outputs found
Determination of Penetration Depth of Transverse Spin Current in Ferromagnetic Metals by Spin Pumping
Spin pumping in nonmagnetic/ferromagnetic metal multilayers is studied both
theoretically and experimentally. We show that the line widths of the
ferromagnetic resonance (FMR) spectrum depend on the thickness of the
ferromagnetic metal layers, which must not be in resonance with the oscillating
magnetic field. We also show that the penetration depths of the transverse spin
current in ferromagnetic metals can be determined by analyzing the line widths
of their FMR spectra. The obtained penetration depths in NiFe, CoFe and CoFeB
were 3.7 [nm], 2.5 [nm] and 12.0 [nm], respectively.Comment: 4 pages, 2 figures
Survey of Newly-found Nitrile Hydratase-Producing Microorganisma Grown at Higher Temperatures
We surveyed some novel nitrile hydratase-producing microorganisms through the enrichment culture technique at higher temperatures. We isolated several spore-forming filamentous bacteria from soil samples. One of them, strain 45A40 exhibited the highest nitrile hydratase activity. Based on taxonomical studies, strain 45A40 was identifind to be genus Streptomyces. It was the first example of a Streptomyces strain exhibiting high nitrile hydratase acitivity. We optimized the culture conditions of Streptomyces 45A40 to enhance the nitrile hydratase activity. The formation of nitrile hydratase was constitutive and was highly enhanced by the addition of cobalt ions. The enzyme acted on various nitriles and showed low Km value for 3-cyanopuridine. The enzyme exhibited tolerance against a high concentration of 3-cyanopyridine ; however, its heat stability was not outstanding.二トリルヒドラターゼは、温和な条件下で二トリルを水和し、極めて効率的にアミドを生産蓄積する反応を触媒することから、ポリマーの原料であるアクリルアミドの工場生産に応用されてきた(Fig.1(1)).またごく最近、ビタミン剤として家畜の飼料添加に用いられるニコチンアミドの工業生産にも本酵素の水和反応プロセスが応用されるようになった(Fig.1(2))1-3).本酵素は今日のバイオインダストリーにおいて、最もポテンシャルの高い酵素の一つであると言える。現在、アクリルアミド、ニコチンアミドの工場生産は、長澤ら4-6)によって確立された方法、即ちRhodococcus rhodochrous J1をコバルトイオンと尿素を添加した培地で培養し、著量の二トリルヒドラターゼを誘導生成させた菌体を直接触媒的に用いる生産プロセスが実用化されている。これまで二トリル分解菌の分離は、二トリルが一般的に低沸点で揮発性であることから、30℃以下の温度域で集積培養し、分離することが一派的であった。これまで報告されている高活性を示す二トリルヒドラターゼ生成菌としては、Pseudomonas属7), Rhodococcus属6,8)の細菌が知られている。新規二トリルヒドラターゼ生成菌の探索を目的として、今回、我々は比較的高沸点の二トリル化合物を単一炭素、窒素源として用いてこれまで試みられなかった37℃-50℃の中高温度域で集積培養を行う新たな二トリル分解菌の探索を試みた
Sodium benzoate attenuates 2,8-dihydroxyadenine nephropathy by inhibiting monocyte/macrophage TNF-α expression
Sodium benzoate (SB), a known D-amino acid oxidase (DAO) enzyme inhibitor, has an anti-inflammatory effect, although its role in renal damage has not been explored. 2,8-dihydroxyadenine crystal induced chronic kidney disease, in which TNF-α is involved in the pathogenesis, was established by oral adenine administration in C57BL/6JJcl mice (AdCKD) with or without SB to investigate its renal protective effects. SB significantly attenuated AdCKD by decreasing serum creatinine and urea nitrogen levels, and kidney interstitial fibrosis and tubular atrophy scores. The survival of AdCKD mice improved 2.6-fold by SB administration. SB significantly decreased the number of infiltrating macrophages observed in the positive F4/80 immunohistochemistry area and reduced the expression of macrophage markers and inflammatory genes, including TNF-α, in the kidneys of AdCKD. Human THP-1 cells stimulated with either lipopolysaccharide or TNF-α showed increased expression of inflammatory genes, although this was significantly reduced by SB, confirming the anti-inflammatory effects of SB. SB exhibited renal protective effects in AdCKD in DAO enzyme deficient mice, suggesting that anti-inflammatory effect of SB was independent of DAO enzyme activity. Moreover, binding to motif DNA sequence, protein level, and mRNA level of NF-κB RelB were significantly inhibited by SB in AdCKD kidneys and lipopolysaccharide treated THP-1 cells, respectively. We report that anti-inflammatory property of SB is independent of DAO enzymatic activity and is associated with down regulated NF-κB RelB as well as its downstream inflammatory genes such as TNF-α in AdCKD
Using NU-KNIT® for hemostasis around recurrent laryngeal nerve during transthoracic esophagectomy with lymphadenectomy for esophageal cancer
BACKGROUND: We thought that using electrocautery for hemostasis caused recurrent laryngeal nerve palsy. We reflected the prolonged use of electrocautery and employed NU-KNIT® to achieve hemostasis nearby the recurrent laryngeal nerve. We assessed that using NU-KNIT® hemostasis prevented or not postoperative recurrent laryngeal nerve palsy, retrospectively. The present study was evaluated to compare using electrocautery hemostasis with using NU-KNIT® hemostasis during lymphadenectomy along recurrent laryngeal nerve. The variables compared were morbidity rate of recurrent laryngeal nerve palsy, operation time, and blood loss. RESULTS: We use NU-KNIT® to achieve hemostasis without strong compression. This group is named group N. On the other hand, we use electrocautery to achieve hemostasis. This group is named group E. Complication rate of recurrent laryngeal nerve palsy was higher in group E (55.6%) than group N (5.3%) (p = 0.007). CONCLUSIONS: Even hemostasis using NU-KNIT® was slightly more time-consuming than using electrocautery, we concluded that it would be useful to prevent recurrent laryngeal nerve palsy
Systematic Evaluation and Mechanistic Investigation of Antioxidant Activity of Fullerenols Using -Carotene Bleaching Assay
Antioxidant activity of hydroxylated fullerenes, so-called fullerenols, against lipid peroxyl radical was evaluated by -carotene bleaching assay. All samples showed moderate to high antioxidant activity (%AOA), especially for C 60 (OH) 12 (70.1) and C 60 (OH) 44 (66.0) as compared with 8, 24, 26, and 36 hydroxylated ones (31.7-62.8). The detection of the possible products was conducted in the model reaction of both fullerenols and C 60 with methyl linoleate by MALDI-TOF-MS. These results suggested that the two possible mechanisms, such as C-addition to double bonds and H-abstraction from -OH groups, are involved in the present radical scavenging reaction
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