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791.
T Hida Y Yatabe H Achiwa H Muramatsu K Kozaki S Nakamura M Ogawa T Mitsudomi T Sugiura T Takahashi 《Canadian Metallurgical Quarterly》1998,58(17):3761-3764
Cyclooxygenase (COX)-2 expression was immunohistochemically examined in 59 human lung cancers as well as in normal and premalignant lung specimens. In contrast to scattered weak reactivity seen in normal peripheral airway epithelial cells, markedly up-regulated COX-2 expression was detected in about one-third of atypical adenomatous hyperplasias and carcinoma in situ specimens, and a significant increase in COX-2 expression was observed in 70% of invasive adenocarcinoma cases. Interestingly, the proportion of adenocarcinoma cells with marked COX-2 expression was much greater in lymph node metastases than in the corresponding primary tumors. In contrast, small cell carcinomas showed virtually negligible expression, and squamous cell carcinomas showed infrequent and low expression. These findings suggest that an increase in COX-2 expression may be associated with the development of adenocarcinomas and possibly with acquisition of an invasive and metastatic phenotype. 相似文献
792.
Tomoaki Okuda Kazuki Okamoto Zhenxing Shen Zongquan Huo 《The Science of the total environment》2010,408(8):1909-1914
In this study, we measured polycyclic aromatic hydrocarbons (PAHs) in aerosols in Xi'an, China from 2005 to 2007, by using a modified Soxhlet extraction followed by a clean-up procedure using automated column chromatography followed by HPLC/fluorescence detection. The sources of PAHs were apportioned by using the positive matrix factorization (PMF) method. The PM10 concentration in winter (161.1 ± 66.4 μg m− 3, n = 242) was 1.5 times higher than that in summer (110.9 ± 34.7 μg m− 3, n = 248). ΣPAH concentrations, which are the sum of the concentrations of all detected PAHs, in winter (344.2 ± 149.7 ng m− 3, n = 45) was 2.5 times higher than that in summer (136.7 ± 56.7 ng m− 3, n = 24) in this study. These strong seasonal variations in atmospheric PAH concentration are possibly due to coal combustion for residential heating. According to the source apportionment with PMF method in this study, the major sources of PAHs in Xi'an are categorized as (1) mobile sources such as vehicle exhaust that constantly contribute to PAH pollution, and (2) stationary sources such as coal combustion that have a large contribution to PAH pollution in winter. 相似文献
793.
Xingzhong Guo Jie Song Yixiu Lvlin Kazuki Nakanishi Kazuyoshi Kanamori Hui Yang 《Science and Technology of Advanced Materials》2015,16(2)
Monolithic macroporous zirconia (ZrO2) derived from ionic precursors has been successfully fabricated via the epoxide-mediated sol-gel route accompanied by phase separation in the presence of propylene oxide (PO) and poly(ethylene oxide) (PEO). The addition of PO used as an acid scavenger mediates the gelation, whereas PEO enhances the polymerization-induced phase separation. The appropriate choice of the starting compositions allows the production of a macroporous zirconia monolith with a porosity of 52.9% and a Brunauer–Emmett–Teller (BET) surface area of 171.9 m2 · g−1. The resultant dried gel is amorphous, whereas tetragonal ZrO2 and monoclinic ZrO2 are precipitated at 400 and 600 °C, respectively, without spoiling the macroporous morphology. After solvothermal treatment with an ethanol solution of ammonia, tetragonal ZrO2 monoliths with smooth skeletons and well-defined mesopores can be obtained, and the BET surface area is enhanced to 583.8 m2 · g−1. 相似文献
794.
Kazuki Heishima Takashi Mori Yukie Ichikawa Hiroki Sakai Yuki Kuranaga Takayuki Nakagawa Yuiko Tanaka Yasuhiko Okamura Mikio Masuzawa Nobuhiko Sugito Mami Murakami Nami Yamada Yukihiro Akao Kohji Maruo 《International journal of molecular sciences》2015,16(10):25377-25391
Malignant endothelial proliferative diseases including human angiosarcoma (AS) and canine hemangiosarcoma (HSA) are serious diseases with a grave prognosis. Establishing liquid biopsy-based biomarkers for screening has definite clinical utility; however, plasma miRNAs up- or down-regulated in these sarcomas have been unclear. For identifying possible diagnostic plasma miRNAs for these sarcomas, we investigated whether plasma miR-214 and miR-126, which miRNAs play important roles in angiogenesis and tumorigenesis, were elevated in malignant endothelial proliferative diseases. For this investigation, human angiosarcoma and canine hemangiosarcoma cell lines and clinical plasma samples of canine hemangiosarcoma were examined by performing miRNA qRT-PCR. We report here that human angiosarcoma and canine hemangiosarcoma cell lines over-secreted miR-214 and miR-126 via microvesicles; in addition, their levels in the plasma samples from canines with hemangiosarcoma were increased. Moreover, the surgical resection of primary tumors decreased the levels of plasma miR-214 and miR-126. Our findings suggest that these malignant endothelial proliferative diseases over-secreted miR-214 and miR-126, thus suggesting that these miRNAs have potential as diagnostic biomarkers for malignant endothelial proliferative diseases in canine and possible in human angiosarcoma. 相似文献
795.
Yoshihide Watanabe Akihiko Asano Koji Banno Koji Yokota Masahiro Sugiura 《Catalysis Today》2001,69(1-4):209-216
A model of NOx selective reduction by hydrocarbon (HC) was developed, which takes into account the adsorption and desorption of HC. The model was applied for predicting the performance of a De–NOx catalytic reactor, working under transient conditions such as a legislative driving cycle. Diesel fuel was used as a supplemental reductant.
The behavior of HC and NOx reactions and HC adsorption and desorption has been simulated successfully by our numerical approach under the transient conditions of the simulated Japanese 10–15 driving cycle. Our model is expected to optimize the design of selective diesel NOx reduction systems using a diesel fuel as a supplemental reductant. 相似文献
796.
Kazuki Tajima Hiromi HottaYasusei Yamada Masahisa OkadaKazuki Yoshimura 《Solar Energy Materials & Solar Cells》2011,95(12):3370-3376
Mg-Ni thin films as a switchable mirror material are promising for application in energy-saving windows because they can change their state between reflective and transparent by hydrogenation and dehydrogenation. In our previous work, we found that electrochromic switchable mirror glass based on a Mg4Ni thin film is affected by environmental factors such as temperature and humidity. In this work, we investigated the effects of the environment on the optical switching properties of electrochromic switchable mirrors with Mg-Ni thin films of various compositions suitable for a broad range of applications and operating environments. When the mirror devices were kept in a simulated environment with a constant temperature 40 °C and a constant relative humidity of 80%, controlled by a thermostat/humidistat bath, their optical switching properties degraded. The degradation was found to be related to the change in the Mg-Ni thin films into nonmetallic states of oxides and hydroxides. The device with a Mg6Ni thin film kept in the bath for 7 days showed no optical switching property. The mechanism of degradation in the bath was strongly affected by the composition of the Mg-Ni thin-film optical switching layer. The device constructed with an optical switching layer having high magnesium content degraded more rapidly in the test. 相似文献
797.
Katsuki Hayashi Kazuki Mitsui Tatsuki Shimizu Rikiya Kado Takumi Umada Akio Koike Satoshi Yoshida Seiji Inaba Akira Saitoh 《Journal of the American Ceramic Society》2023,106(3):1732-1738
The well-known Makishima–Mackenzie relationship, consisting of two terms of the dense packing structure and dissociation energy regarding bonding in constituent oxides, enables fabricating oxide glasses with ultrahigh Young's modulus (∼140 GPa) and a small coefficient of thermal expansion (CTE) (∼4 ppm/K). The effects of increasing MgO and Ta2O5 contents in an MgO–Ta2O5–Al2O3–SiO2–B2O3 glass system using a conventional melt-quenching method are revealed. The essential oxides of Al2O3 and Ta2O5 are primarily suitable for dense packing structures dominated by a large coordination number of oxygens. The substitution of CaO by MgO results in high dissociation energy when the glass composition falls in the peraluminous regime (Al2O3/[MgO + CaO] > 1). A small CTE is realized by increasing the molar ratio of Al2O3/MgO. According to magic-angle spinning-nuclear magnetic resonance spectra, mechanically and thermally functional oxide glasses depend on their structures. These findings facilitate the development of glass substrate applications without thermal dilatation. 相似文献
798.
Hidetoshi Miyazaki Kazuki Eguchi Mako Tsuruda 《International Journal of Applied Ceramic Technology》2023,20(3):1571-1575
Si2N2O, which shows high radiative cooling ability, was mixed and hardened with ordinary Portland cement to prepare cement specimens having radiative cooling abilities. The bulk cement specimens were prepared with diameters of 50 mm and two different thicknesses of 3 and 10 mm, and Si2N2O powder were mixed with 2 and 10 wt%. The temperatures of the blank specimen (without radiative cooling Si2N2O powder) and the cement composite specimens were measured in a thermostatic chamber maintained at ambient temperature, and the radiative cooling abilities of the specimens were evaluated. The obtained specimens showed a radiative cooling ability in the range 0.077–0.92 W/m2; thus, the results of this study suggested the possibility of a cement composite with passive cooling property. 相似文献
799.
Hiroki Fukumoto Kazuki Shiitsuka Keisuke Yamada Shigeyuki Yamada Tsutomu Konno Toshio Kubota Tomohiro Agou 《Polymer International》2022,71(1):117-123
The intramolecular oxidative photocyclization of 1,2-diarylhexafluorocyclopentene ( 1 ) under light irradiation (λ = 365 nm) provided hexafluorocyclopentene-fused phenanthrene with formyl groups ( 2 ) in moderate yield. The copolymerization of 2 with tetraethyl(2,5-bis(dodecyloxy)-1,4-phenylene)bis(methylene)diphosphonate by the Horner–Wadsworth–Emmons reaction gave a fluorine-containing poly(phenylene vinylene), Polymer-2, in 41% yield. For comparison, a diphenylethene-type copolymer, Polymer-1, was also prepared analogously. The number-average molecular weights of Polymer-1 and Polymer-2 were 8900 and 3300 g mol?1, respectively. The copolymers showed high thermal stability, as revealed by their thermogravimetric analysis. UV–visible spectra of the copolymers in CHCl3 showed π–π* transition peaks at around 420 nm, and the peaks shifted to longer wavelengths by ca 10 nm for samples in film form. The photoluminescence spectra of Polymer-1 and Polymer-2 exhibited peaks at 542 and 560 nm in CHCl3, respectively, whereas the photoluminescence intensity of Polymer-2 was very low in the solid state, presumably owing to the partial aggregation of the polymer molecules. © 2021 Society of Industrial Chemistry. 相似文献
800.
Hiroki Nakano Kazuki Shiina Hirofumi Tomiyama 《International journal of molecular sciences》2021,22(8)
The cumulative number of cases in the current global coronavirus disease 19 (COVID-19) pandemic, caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has exceeded 100 million, with the number of deaths caused by the infection having exceeded 2.5 million. Recent reports from most frontline researchers have revealed that SARS-CoV-2 can also cause fatal non-respiratory conditions, such as fatal cardiovascular events. One of the important mechanisms underlying the multiple organ damage that is now known to occur during the acute phase of SARS-CoV-2 infection is impairment of vascular function associated with inhibition of angiotensin-converting enzyme 2. To manage the risk of vascular dysfunction-related complications in patients with COVID-19, it would be pivotal to clearly elucidate the precise mechanisms by which SARS-CoV-2 infects endothelial cells to cause vascular dysfunction. In this review, we summarize the current state of knowledge about the mechanisms involved in the development of vascular dysfunction in the acute phase of COVID-19. 相似文献