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141.
Various copolymides were prepared from two acid dianhydrides (BPDA, 3,3′,4,4′-biphenyl tetracarboxylic dianhydride; PMDA, pyromelitic dianhydride) and two diamines (PPD, p-phenylene diamine; ODA, 4,4′-oxydianiline). The thermal and mechanical properties of these polyimides were examined in detail. By appropriately selecting the ratios of the acid dianhydride component and the diamine component, polyimide films having desirable mechanical and thermal characteristics can be obtained. Further, it was proved that there is a correlation between the properties and the compositions of the copolyimides and that the properties could be estimated from the compositions by the use of multiple regression analysis. © 1996 John Wiley & Sons, Inc. 相似文献
142.
Bhupesh C. Roy Motonobu Goto Akio Kodama Tsutomu Hirose 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1996,67(1):21-26
Essential oils and cuticular waxes were extracted from peppermint leaves with supercritical carbon dioxide in a semicontinuous-flow extractor. The effects of CO2 flow rate and pressure on the extraction rate were studied within the flow rate range of (4·1–9·8) × 10−5 kg s−1 and the pressure range of 10–30 MPa. Flow rate effect indicated that the intraparticle diffusion resistance was not dominant in this process. The extraction rate of cuticular waxes increased remarkably with the pressure, whereas that of essential oils was almost constant as compared with cuticular waxes. The concentration of cuticular waxes at the exit of the extractor was close to the solubility of triacontane while that of essential oils was much lower than the solubility of 1-menthol. 相似文献
143.
Shan Liu Jumpei Washio Satoko Sato Yuki Abiko Yuta Shinohara Yuri Kobayashi Haruki Otani Shiori Sasaki Xiaoyi Wang Nobuhiro Takahashi 《International journal of molecular sciences》2022,23(2)
Metformin is a metabolic disruptor, and its efficacy and effects on metabolic profiles under different oxygen and nutrient conditions remain unclear. Therefore, the present study examined the effects of metformin on cell growth, the metabolic activities and consumption of glucose, glutamine, and pyruvate, and the intracellular ratio of nicotinamide adenine dinucleotide (NAD+) and reduced nicotinamide adenine dinucleotide (NADH) under normoxic (21% O2) and hypoxic (1% O2) conditions. The efficacy of metformin with nutrient removal from culture media was also investigated. The results obtained show that the efficacy of metformin was closely associated with cell types and environmental factors. Acute exposure to metformin had no effect on lactate production from glucose, glutamine, or pyruvate, whereas long-term exposure to metformin increased the consumption of glucose and pyruvate and the production of lactate in the culture media of HeLa and HaCaT cells as well as the metabolic activity of glucose. The NAD+/NADH ratio decreased during growth with metformin regardless of its efficacy. Furthermore, the inhibitory effects of metformin were enhanced in all cell lines following the removal of glucose or pyruvate from culture media. Collectively, the present results reveal that metformin efficacy may be regulated by oxygen conditions and nutrient availability, and indicate the potential of the metabolic switch induced by metformin as combinational therapy. 相似文献
144.
Tae Oike Yoshihito Sekiguchi Yuya Yoshimoto Takahiro Oike Ken Ando Wenchao Gu Yasushi Sasaki Takashi Tokino Akira Iwase Tatsuya Ohno 《International journal of molecular sciences》2022,23(1)
Radiotherapy is a definitive treatment for early-stage cervical cancer; however, a subset of this disease recurs locally, necessitating establishment of predictive biomarkers and treatment strategies. To address this issue, we performed gene panel-based sequencing of 18 stage IB cervical cancers treated with definitive radiotherapy, including two cases of local recurrence, followed by in vitro and in silico analyses. Simultaneous mutations in KRAS and SMAD4 (KRASmt/SMAD4mt) were detected only in a local recurrence case, indicating potential association of this mutation signature with radioresistance. In isogenic cell-based experiments, a combination of activating KRAS mutation and SMAD4 deficiency led to X-ray resistance, whereas either of these factors alone did not. Analysis of genomic data from 55,308 cancers showed a significant trend toward co-occurrence of mutations in KRAS and SMAD4. Gene Set Enrichment Analysis of the Cancer Cell Line Encyclopedia dataset suggested upregulation of the pathways involved in epithelial mesenchymal transition and inflammatory responses in KRASmt/SMAD4mt cancer cells. Notably, irradiation with therapeutic carbon ions led to robust killing of X-ray-resistant KRASmt/SMAD4mt cancer cells. These data indicate that the KRASmt/SMAD4mt signature is a potential predictor of radioresistance, and that carbon ion radiotherapy is a potential option to treat early-stage cervical cancers with the KRASmt/SMAD4mt signature. 相似文献
145.
Makoto Tanaka Mikio Taguchi Tsuysohi Takahama Toru Sawada Shigeru Kuroda Takao Matsuyama Shinya Tsuda Akio Takeoka Shoichi Nakano Hiroshi Hanafusa Yukinori Kuwano 《Progress in Photovoltaics: Research and Applications》1993,1(2):85-92
A new solar cell structure named HIT (Heterojunction with Intrinsic Thin layer) has been developed based on new artificially constructed junction (ACJ) technology. In this structure a non-doped a-Si thin layer was inserted between the p(a-Si)/n(c-Si) heterojunction, improving the output characteristics and achieving a conversion efficiency of 18.1%. This structure was applied to cast polycrystalline silicon solar cells of a practical size. A high conversion efficeincy of 13.6% was obtained with a cell size of 10 cm × 10 cm using various technologies, including hydrogen plasma passivation. 相似文献
146.
Masato Nishikuni Tsuyoshi Takahama Shingo Okamoto Kunimoto Ninomiya Hidenori Nishiwaki Shinya Tsuda Akio Takeoka Michotoshi Ohnishi Shoichi Nakano Yukinori Kuwano 《Progress in Photovoltaics: Research and Applications》1994,2(3):211-219
A new approach to high-performance a-Si solar cells was studied. a-Si films prepared at a high substrate temperature (> 250°C) have a higher absorption coefficient and a low Si H2 bond density. the effect of deposition temperature on the open-circuit voltage (Voc) has been investigated systematically for glass/SnO2 Ipin/metal and glass/metal/nip/indium tin oxide (ITO) structure a-Si solar cells. The Voc is found to depend strongly on the thermal history of the p/i interface. A short-circuit current of 19.5 mA/cm−−2 was achieved for an a-Si solar cell using an a-Si i-layer with a thickness of 4000 Å, which was prepared at a substrate temperature of 270°C. 相似文献
147.
Ninomiya Yuma Sasaki Hideaki Yoshikawa Takeshi Maeda Masafumi 《Metallurgical and Materials Transactions B》2019,50(1):407-415
Metallurgical and Materials Transactions B - The dissolution and passivation of pure Cu and Cu-5 wt pct Ag anodes in H2SO4-CuSO4 electrolyte were investigated by a direct... 相似文献
148.
Perfluorinated surfactants in surface, subsurface water and microlayer from Dalian Coastal waters in China 总被引:5,自引:0,他引:5
Two predominant perfluorinated compounds (PFCs), Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), in surface water (SW, 0-20 cm), subsurface water (SSW, > 30 cm depth), and sea surface microlayer (SML, 50 microm thickness) were measured from Dalian Coastal waters in China. The SML samples were collected using glass-plate dipping method. Analysis of the PFCs was conducted through solid-phase extraction, followed by LC/MS-SIM. The PFC's concentrations in SW samples were consistent with previously reported data in this region. Significantly higher concentrations of PFCs were found in SML samples than corresponding SSW samples. The enrichment factors (EF = C(SML)/C(SSW)) for PFOS were as high as 24-109 atthree near-shore sites. The concentration in SW was also generally higher than corresponding SSW samples, giving C(SW)/C(SSW) mean ratios of 1.5 and 1.4 for PFOS and PFOA, respectively. This apparent enrichment of PFCs in surface water, especially in the microlayer, has implications for designing measurement techniques, understanding their distributions, and sea spray-mediated transport in the environment. 相似文献
149.
Nongluk Sriwilaijaroen Akio Kadowaki Yuriko Onishi Nobuki Gato Makoto Ujike Takato Odagiri Masato Tashiro Yasuo Suzuki 《Food chemistry》2011
Fruit-juice concentrate of Japanese apricot (Prunus mume Sieb. et Zucc.) has been shown to be effective against influenza A infection in MDCK cells. In this study, we isolated five components from the fruit-juice concentrate of Japanese apricot, 5-(hydroxymethyl)-2-formylfuran (HMF), 1-[5-(2-formylfuryl)methyl]dihydrogen 2-hydroxypropane-1,2,3-tricarboxylate (mumefural, MF), 2-[5-(2-formylfuryl)methyl]dihydrogen 2-hydroxypropane-1,2,3-tricarboxylate (MF‘), 1-[5-(2-formylfuryl)methyl]hydrogen 1-hydroxyethane-1,2-dicarboxylate (MA1) and 2-[5-(2-formylfuryl)methyl]hydrogen 1-hydroxyethane-1,2-dicarboxylate (MA2), and investigated their inhibitory activities against the novel influenza A/Narita/1/2009 (H1N1) pandemic virus hemagglutinin and neuraminidase functions, which are essential for viral attachment and budding, respectively. An hemagglutination inhibition assay indicated that MF and MF‘ were effective at minimum hemagglutination concentrations of 3.1 and 6.3 mM, respectively. An inhibition study for sialidase activity of the neuraminidase spike showed that MF was the most active anti-sialidase compound with an IC50 value of 0.21 ± 0.01 mM, followed by MA2 (IC50, 0.71 ± 0.09 mM), MA1 (IC50, 1.64 ± 0.31 mM) and MF‘(IC50, 1.62 ± 0.22 mM). Furthermore, MF was shown to inhibit the growth of the pandemic virus in a dose-dependent manner (62 ± 3% inhibition at 5 mM). The results suggest that MF, a citric acid ester linked to HMF at the 1-position of the propane backbone, might be a lead compound for the development of anti-influenza A inhibitors. 相似文献
150.
Amakura Y Tsutsumi T Iida T Nakagawa R Hori T Tobiishi K Uchibe H Nakamura M Yanagi T Kono Y Toyoda M Sasaki K Maitani T 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2005,46(4):148-152
To examine dioxin contamination in commercial baby foods in Japan, congener analyses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (Co-PCBs) were performed on 102 varieties of baby foods obtained from supermarkets in 2001-2002. The toxic equivalent quantity (TEQ) levels for dioxins in samples ranged from < 0.001 to 0.135 pg-TEQ/g wet weight when undetected or trace levels of congeners were taken as zero. Among 102 samples tested, 26 samples exceeded 0.010 pg-TEQ/g. The highest TEQ value was for "sardine, vegetables" (0.135 pg-TEQ/g), followed by "Japanese radish (daikon), sardine" (0.080 pg-TEQ/g). Thus, dioxins were detected at low levels in baby foods containing animal products such as fishes and/or dairy products. 相似文献