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151.
Yuji Shimada Akio Sugihara Hirofumi Nakano Tomomi Yokota Toshihiro Nagao Sadao Komemushi Yoshio Tominaga 《Journal of the American Oil Chemists' Society》1996,73(11):1415-1420
An attempt was made to produce structured lipids containing essential fatty acid by acidolysis with 1,3-positional specificRhizopus delemar lipase. The lipase was immobilized on a ceramic carrier by coprecipitation with acetone and then was activated by shaking
for 2 d at 30°C in a mixture of 5 g safflower or linseed oil, 10 g caprylic acid, 0.3 g water and 0.6 g of the immobilized
enzyme. The activated enzyme was transferred into the same amount of oil/caprylic acid mixture without water, and the mixture
was shaken under the same conditions as for the activation. By this reaction, 45–50 mol% of the fatty acids in oils were exchanged
for caprylic acid, and the immobilized enzyme could be reused 45 and 55 times for safflower and linseed oils, respectively,
without any significant loss of activity. The triglycerides were extracted withn-hexane after the acidolysis and then were allowed to react again with caprylic acid under the same conditions as mentioned
above. When acidolysis was repeated three times with safflower oil as a starting material, the only products obtained were
1,3-capryloyl-2-linoleoylglycerol and 1,3-capryloyl-2-oleoyl-glycerol, with a ratio of 86∶14 (w/w). Equally, the products
from linseed oil were 1,3-capryloyl-2-α-linolenoyl-glycerol, 1,3-caprylol-2-linoleoyl-glycerol, and 1,3-capryloyl-2-oleoly-glycerol
(60∶22∶18, w/w/w). All fatty acids at the 1,3-positions in the original oils were exchanged for caprylic acid by the repeated
acidolyses, and the positional specificity ofRhizopus lipase was also confirmed to be strict. 相似文献
152.
Yomi?Watanabe Yoshie?Yamauchi-Sato Toshihiro?Nagao Takaya?Yamamoto Kentaro?Tsutsumi Akio?Sugihara Yuji?ShimadaEmail author 《Journal of the American Oil Chemists' Society》2003,80(9):909-914
We attempted to produce MAG of CLA through lipase-catalyzed esterification of a FFA mixture containing CLA (referred to as
FFA-CLA) with glycerol. Screening of lipases showed that MAG-CLA was produced efficiently at 5°C with Penicillium camembertii, Rhizopus oryzae, and Candida rugosa lipases. Among them, C. rugosa lipase was selected because the lipase is widely used as a catalyst for oils and fats processing. The reaction was conducted
with agitation of a 300-g mixture of FFA-CLA/glycerol (1∶5, mol/mol), a 200-U/g mixture of C. rugosa lipase, and 2% water. When the reaction was conducted at 30°C, the esterification scarcely proceeded, owing to inhibition
of the reaction by glycerol. But the reaction at 5°C eliminated the inhibition and produced MAG efficiently: The degree of
esterification reached 93.8% after 58 h, and MAG content in the reaction mixture was 88.4 wt%. To reduce the reaction time,
the reactor was connected with a vacuum pump after 24 h, and the reaction was continued with dehydration at 5 mm Hg. The degree
of esterification reached 94.7% after 24 h of dehydration (48 h in total), and MAG content increased to 93.0 wt%. Candida rugosa lipase acted a little more strongly on cis-9, trans-11 CLA than on trans-10,cis-12 CLA, but the contents of the two isomers in MAG obtained from a 48-h reaction were the same as the contents in FFA-CLA. 相似文献
153.
Y. Abe T. Ozai Y. Kuno Y. Nagao T. Misono 《Journal of Inorganic and Organometallic Polymers》1992,2(1):143-149
The synthesis and properties of polymethylsilazanes were investigated. Controlled ammonolysis of methyl(triisocyanato)silane (MTIS) at the molar ratios NH3/MTIS=4 and 6 gave polymethylsilazanes3 and4, which were soluble in tetrahydrofuran (THF) and dimethyl sulfoxide (DMSO) but insoluble when isolated as powders. The concentrated polymer solution showed spinnability and film formation. Thermogravimetric analysis of3 and4 showed weight losses of 67 and 16%, respectively. Species4 may be a precursor for silicon/carbon/nitrogen ceramics. 相似文献
154.
Qiang Xu Wei Pan Jingdong Wang Chunlei Wan Longhao Qi Hezhuo Miao Kazutaka Mori Taiji Torigoe 《Journal of the American Ceramic Society》2006,89(1):340-342
A series of rare-earth zirconate Ln2 Zr2 O7 ceramics (Ln=Dy, Er, and Yb) with a fluorite structure (F-Ln2 Zr2 O7 ) were prepared by pressureless sintering from zirconia and rare-earth oxide powders at 1600°C for 10 h in air. The microstructure experiments were performed by X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The thermal conductivity and thermal expansion of these ceramics were evaluated using a steady-state laser heat-flux technique and high-temperature dilatometry, respectively. The XRD and SEM results demonstrate that Ln2 Zr2 O7 ceramics with a single fluorite phase are synthesized and no other phases are found. The results of thermal conductivity show that their thermal conductivities (1.3–1.9 W/(m·K), 20°–800°C) are as low as those of the referenced Ln2 Zr2 O7 ceramics (Ln=La, Nd, Sm, and Gd) with pyrochlore structure (P-Ln2 Zr2 O7 ). It is concluded that rare-earth zirconate ceramics with a fluorite structure can be considered as candidate materials for future thermal barrier coatings. 相似文献
155.
Takahiro Sasai Nobuko Saigusa Akihiko Ito Ramakrishna Nemani Kazuhito Ichii Taku M. Saitoh Kazutaka Murakami Takehisa Oikawa 《Remote sensing of environment》2011,115(7):1758-1771
The terrestrial carbon cycle is strongly affected by natural phenomena, terrain heterogeneity, and human-induced activities that alter carbon exchange via vegetation and soil activities. In order to accurately understand terrestrial carbon cycle mechanisms, it is necessary to estimate spatial and temporal variations in carbon flux and storage using process-based models with the highest possible resolution. We estimated terrestrial carbon fluxes using a biosphere model integrating eco-physiological and mechanistic approaches based on satellite data (BEAMS) and observations with 1-km grid resolution. The study area is the central Far East Asia region, which lies between 30° and 50° north latitude and 125° and 150° east longitude. Aiming to simulate terrestrial carbon exchanges under realistic land surface conditions, we used as many satellite-observation datasets as possible, such as the standard MODIS, TRMM, and SRTM high-level land products. Validated using gross primary productivity (GPP), net ecosystem production (NEP), net radiation and latent heat with ground measurements at six flux sites, the model estimations showed reasonable seasonal and annual patterns. In extensive analysis, the total GPP and NPP were determined to be 2.1 and 0.9 PgC/year, respectively. The total NEP estimation was + 5.6 TgC/year, meaning that the land area played a role as a carbon sink from 2001 to 2006. In analyses of areas with complicated topography, the 1-km grid estimation could prove to be effective in evaluating the effect of landscape on the terrestrial carbon cycle. The method presented here is an appropriate approach for gaining a better understanding of terrestrial carbon exchange, both spatially and temporally. 相似文献
156.
Yokoo M Kawai N Hironaka Y Nakamura KG Kondo K 《The Review of scientific instruments》2007,78(4):043904
A diagnostic system has been developed to obtain spatial and temporal profiles of shock front. A two-stage light-gas gun is used to accelerate impactors in velocity range with 4-9 km/s. The system consists of the Faraday-type electromagnetic sensors to measure impactor velocity, optical system with high-speed streak camera to measure shock-wave velocities, and the delay trigger system with self-adjustable pre-event pulse generator. We describe the specifications and performance of this system and data-analysis technique on the tilt and distortion of the shock front. Finally, we obtained the Hugoniot data of copper for system demonstration. 相似文献
157.
Structural study of nanometer-sized iron crystallites in single crystalline iron–mgo composite films
Nobuo Tanaka Masaru Nagao Fukio Yoshizaki Kazuhiro Mihama 《Microscopy research and technique》1989,12(3):272-280
Single crystalline composite films of iron and MgO are prepared by a simultaneous vacuum deposition technique. The structures of the composite films, especially of the iron crystallites embedded, are studied by high-resolution electron microscopy and nanometer-area electron diffraction. The α-iron (b.c.c.) crystallites of 1 nm in size are epitaxially embedded in single crystalline MgO films, the orientation being (011 )[100]Fe/(001)[100]Mgo and (001)[11 0]Fe//(001)[100]Mgo. A heat treatment of the as-grown films at 500–1,000°C brings about a phase transformation of the crystallites from α-iron to γ-iron (f.c.c.), followed by a grain growth of α-iron and finally the growth of the spinel, MgFe2O4. The γ-iron crystallites transformed are circular plates and have strains at the periphery to accommodate the surrounding MgO-matrix. The magnetic property of the composite films is also reported. 相似文献
158.
159.
Yukino Ogura Kazuko Tajiri Nobuyuki Murakoshi DongZhu Xu Saori Yonebayashi Siqi Li Yuta Okabe Duo Feng Yuzuno Shimoda Zoughu Song Haruka Mori Zixun Yuan Kazutaka Aonuma Masaki Ieda 《International journal of molecular sciences》2021,22(2)
Neutrophils are recruited into the heart at an early stage following a myocardial infarction (MI). These secrete several proteases, one of them being neutrophil elastase (NE), which promotes inflammatory responses in several disease models. It has been shown that there is an increase in NE activity in patients with MI; however, the role of NE in MI remains unclear. Therefore, the present study aimed to investigate the role of NE in the pathogenesis of MI in mice. NE expression peaked on day 1 in the infarcted hearts. In addition, NE deficiency improved survival and cardiac function post-MI, limiting fibrosis in the noninfarcted myocardium. Sivelestat, an NE inhibitor, also improved survival and cardiac function post-MI. Flow cytometric analysis showed that the numbers of heart-infiltrating neutrophils and inflammatory macrophages (CD11b+F4/80+CD206low cells) were significantly lower in NE-deficient mice than in wild-type (WT) mice. At the border zone between intact and necrotic areas, the number of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive apoptotic cells was lower in NE-deficient mice than in WT mice. Western blot analyses revealed that the expression levels of insulin receptor substrate 1 and phosphorylation of Akt were significantly upregulated in NE-knockout mouse hearts, indicating that NE deficiency might improve cardiac survival by upregulating insulin/Akt signaling post-MI. Thus, NE may enhance myocardial injury by inducing an excessive inflammatory response and suppressing Akt signaling in cardiomyocytes. Inhibition of NE might serve as a novel therapeutic target in the treatment of MI. 相似文献
160.
Kawakubo Masateru Moriyama Daichi Yamasaki Yuzo Abe Kohtaro Hosokawa Kazuya Moriyama Tetsuhiro Triadyaksa Pandji Wibowo Adi Nagao Michinobu Arai Hideo Nishimura Hiroshi Kadokami Toshiaki 《Magma (New York, N.Y.)》2022,35(6):911-921
Magnetic Resonance Materials in Physics, Biology and Medicine - We propose a deep learning-based fully automatic right ventricle (RV) segmentation technique that targets radially reconstructed... 相似文献