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排序方式: 共有1487条查询结果,搜索用时 15 毫秒
941.
Masahito Shimizu Yohei Shirakami Hiroyasu Sakai Masaya Kubota Takahiro Kochi Takayasu Ideta Tsuneyuki Miyazaki Hisataka Moriwaki 《International journal of molecular sciences》2015,16(3):6124-6139
Hepatocellular carcinoma (HCC), which is a common malignancy worldwide, usually develops in a cirrhotic liver due to hepatitis virus infection. Metabolic syndrome, which is frequently complicated by obesity and diabetes mellitus, is also a critical risk factor for liver carcinogenesis. Green tea catechins (GTCs) may possess potent anticancer and chemopreventive properties for a number of different malignancies, including liver cancer. Antioxidant and anti-inflammatory activities are key mechanisms through which GTCs prevent the development of neoplasms, and they also exert cancer chemopreventive effects by modulating several signaling transduction and metabolic pathways. Furthermore, GTCs are considered to be useful for the prevention of obesity- and metabolic syndrome-related carcinogenesis by improving metabolic disorders. Several interventional trials in humans have shown that GTCs may ameliorate metabolic abnormalities and prevent the development of precancerous lesions. The purpose of this article is to review the key mechanisms by which GTCs exert chemopreventive effects in liver carcinogenesis, focusing especially on their ability to inhibit receptor tyrosine kinases and improve metabolic abnormalities. We also review the evidence for GTCs acting to prevent metabolic syndrome-associated liver carcinogenesis. 相似文献
942.
Koichiro Suekuni Chul Ho Lee Hiromi I. Tanaka Eiji Nishibori Atsushi Nakamura Hidetaka Kasai Hitoshi Mori Hidetomo Usui Masayuki Ochi Takumi Hasegawa Mitsutaka Nakamura Seiko Ohira‐Kawamura Tatsuya Kikuchi Koji Kaneko Hirotaka Nishiate Katsuaki Hashikuni Yasufumi Kosaka Kazuhiko Kuroki Toshiro Takabatake 《Advanced materials (Deerfield Beach, Fla.)》2018,30(13)
Thermoelectric devices convert heat flow to charge flow, providing electricity. Materials for highly efficient devices must satisfy conflicting requirements of high electrical conductivity and low thermal conductivity. Thermal conductivity in caged compounds is known to be suppressed by a large vibration of guest atoms, so‐called rattling, which effectively scatters phonons. Here, the crystal structure and phonon dynamics of tetrahedrites (Cu,Zn)12(Sb,As)4S13 are studied. The results reveal that the Cu atoms in a planar coordination are rattling. In contrast to caged compounds, chemical pressure enlarges the amplitude of the rattling vibration in the tetrahedrites so that the rattling atom is squeezed out of the planar coordination. Furthermore, the rattling vibration shakes neighbors through lone pairs of the metalloids, Sb and As, which is responsible for the low thermal conductivity of tetrahedrites. These findings provide a new strategy for the development of highly efficient thermoelectric materials with planar coordination. 相似文献
943.
Takeshi Nakajima Masanori Ochi Junichi Ida Hiromi Dozono Kiyoto Matsumoto Soshi Watanabe 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2016,38(12):1763-1770
Pyrolysis and steam gasification of methane fermentation residue (MFR) produced from food waste (FW) were performed at two different heating rates. Moreover, unfermented FW and active sludge (AS) were tested. The results of slow heating experiments showed that although MFR contains biologically refractory organic matter, its overall thermal decomposition and gas evolution behaviors were similar to those of AS and, especially, FW. Furthermore, rapid heating experiments demonstrated that total gas yield and gas composition were similar for all three samples at 700°C. However, the effect of an increase in gasification temperature was more significant for MFR. 相似文献
944.
Yoshiyuki Mizushina Isoko Kuriyama Asahi Yamazaki Takahiro Akashi Hiromi Yoshida 《Food chemistry》2013
During the screening of selective DNA polymerase (pol) inhibitors, we isolated cycloartenyl trans-ferulate (CAF), which is a major component of γ-oryzanol, which is a byproduct formed during the production of Japanese rice wine “sake”. CAF selectively inhibited the activity of mammalian A, B, and X pol families, but Y family pols were not affected. CAF did not influence the activities of plant or prokaryotic pols, nor the activity of other DNA metabolic enzymes tested. Individual chemical components of CAF, including cycloartenol (CA) and ferulic acid (FA), did not inhibit pol enzyme activities. CAF suppressed TPA (12-O-tetradecanoylphorbol-13-acetate)-induced inflammation in the mouse ear, but CA and FA did not. The ability to inhibit mammalian pol enzymes in vitro was positively correlated with their propensity to suppress inflammation in vivo. These results suggest that this byproduct formed during the sake-brewing process is useful as an anti-inflammatory agent. 相似文献
945.
Shijie Li Chenguang Wang Noriyuki Kobayashi Mitsuhiro Kubota 《Nanoscale and Microscale Thermophysical Engineering》2017,21(1):1-7
Mg(OH)2 nanoparticles anchored on graphene oxide (GO) were facilely prepared by a hydrothermal method. The main diameter scale of nanoparticles on the graphene sheet was about 25–50 nm shown by transmission electron microscopy characterization results. X-ray diffraction results indicated that the nanoparticles are in accordance with the data on magnesium hydroxide. This material exhibited significantly improved heat storage capacity and a higher hydration rate than pure magnesium oxide, and the introduction of GO leads to greatly increased thermal conductivity of the nanocomposites. As a novel thermochemical heat storage material, Mg(OH)2/GO has huge potential for high-efficiency energy systems. 相似文献
946.
Tsuyoshi Kariya Ryutaro Minami Tsuyoshi Imai Mao Ota Youichi Endo Shin Kubo Takahashi Shimozuma Hiromi Takahashi Yasuo Yoshimura Satoshi Ito Takahashi Mutoh Keishi Sakamoto Yoshika Mitsunaka 《Journal of Infrared, Millimeter and Terahertz Waves》2011,32(3):295-310
A 28 GHz 1 MW with TE8,3 cavity for GAMMA10 tandem mirror and a 77 GHz 1.5 MW gyrotron with TE18,6 for Large Helical Device (LHD) have been developed to upgrade their Electron Cyclotron Heating (ECH) systems. In the 28 GHz gyrotron, the maximum power of 1.05 MW was obtained, which is in agreement with its design target value. And the high efficiency of 40% without collector potential depression (CPD) was obtained with 0.8 MW. In the first and second 77 GHz gyrotrons, 0.8 MW 3.6 sec., 0.3 MW 60 sec operations have been achieved, but several issues due to the stray RF and velocity dispersion have been found, too. In consideration of these, the design improvement was performed to aim at 1.5 MW in the third tube. In the short pulse test, the maximum output power of 1.6 MW and the maximum total efficiency of 49.4% with CPD were obtained. In the long pulse test, the pulse length extended to 5 sec with 1 MW, 1800 sec with 0.1 MW, 1.6 sec with 1.5 MW. Total injection power of 3.1 MW to LHD plasma has been achieved. It is shown that the electron beam pitch factor ?? decreases with increasing of beam current, comparing with the experimental and calculation results. 相似文献
947.
Ohko Y Iuchi K Niwa C Tatsuma T Nakashima T Iguchi T Kubota Y Fujishima A 《Environmental science & technology》2002,36(19):4175-4181
The degradation of 17 beta-estradiol (E2) in water by TiO2 photocatalysis was investigated; concurrently the estrogenic activity of the treated water was evaluated during the photocatalytic reactions by an estrogen screening assay. As a result, 10(-6) M of E2 was totally mineralized to CO2 in 1.0 g L-1 TiO2 suspension under UV irradiation for 3 h. 10 epsilon-17 beta-Dihydroxy-1,4-estradien-3-one and testosterone-like species were elucidated as intermediate products by GC/MS analysis. The mechanisms of E2 degradation by TiO2 photocatalysis were discussed not only experimentally but also theoretically by calculating the frontier electron densities of the E2 molecule. On the basis of the results obtained, it was concluded that the phenol moiety of the E2 molecule, one of the essential functional groups to interact with the estrogen receptor, should be the starting point of the photocatalytic oxidation of E2. This means that the estrogenic activity should be almost lost concurrently with the initiation of the photocatalytic degradation. Actually, the estrogenic activities of the intermediate products were negligible. TiO2 photocatalysis could be applied to water treatment to effectively remove natural and synthetic estrogens without producing biologically active intermediary products. 相似文献
948.
All-solid-state thin-filmed lithium-ion rechargeable batteries composed of amorphous Nb2O5 negative electrode with the thickness of 50–300 nm and amorphous Li2Mn2O4 positive electrode with a constant thickness of 200 nm, and amorphous Li3PO4−xNx electrolyte (100 nm thickness), have been fabricated on glass substrates with a 50 mm × 50 mm size by a sputtering method, and their electrochemical characteristics were investigated. The charge–discharge capacity based on the volume of positive electrode increased with increasing thickness of negative electrode, reaching about 600 mAh cm−3 for the battery with the negative electrode thickness of 200 nm. But the capacity based on the volume of both the positive and negative electrodes was the maximum value of about 310 mAh cm−3 for the battery with the negative electrode thickness of 100 nm. The shape of charge–discharge curve consisted of a two-step for the batteries with the negative electrode thickness more than 200 nm, but that with the thickness of 100 nm was a smooth S-shape curve during 500 cycles. 相似文献
949.
950.
Song Chen Xuetao Shi Hiromi Morita Jie Li Nobuhiro Ogawa Toshiyuki Ikoma Satoshi Hayakawa Yuki Shirosaki Akiyoshi Osaka Nobutaka Hanagata 《Science and Technology of Advanced Materials》2011,12(6)
Silica nanotube fibrous meshes were fabricated as multiple functional matrices for both delivering bone morphological protein-2 (BMP-2) and supporting osteoblast attachment and proliferation. The meshes were fabricated via a collagen-templated sol–gel route and consisted of tubular silica with open ends. BMP-2 was loaded to the meshes by soaking in BMP-2 solution. The meshes effectively enabled the attachment and proliferation of osteoblast MC3T3-E1 cells and delivered bioactive BMP-2 to stimulate cell differentiation. These results demonstrate the potential use of the meshes in bone generation applications. 相似文献