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171.
M Takagi D Delia L Chessa S Iwata T Shigeta Y Kanke K Goi M Asada M Eguchi C Kodama S Mizutani 《Canadian Metallurgical Quarterly》1998,58(21):4923-4929
We examined the regulation of apoptosis, radiosensitivity, and spindle checkpoint in response to DNA-damaging agents in ataxia telangiectasia (AT)-derived lymphoblastoid cell lines (AT-LCLs), which lack AT mutated (ATM) protein expression. In addition to the previous findings that AT-LCLs are defective in regulation of cell cycle at the G1, S, and G2-M checkpoints in response to X-ray irradiation (X-IR) and are highly sensitive to X-IR (J. Biol. Chem., 271: 20486-20493, 1996), we showed for the first time that AT-LCLs were defective in X-IR-associated spindle checkpoint control. The cells were also resistant to early apoptosis as much as LCLs derived from patients with Li-Fraumeni syndrome (LFS-LCLs). Terminal deoxynucleotidyl transferase-mediated nick end labeling assay of LCLs, however, demonstrated a significant increase in apoptotic cells among AT-LCLs cultured over a longer period after X-IR. These findings were in contrast to those of LFS-LCL, which showed very little increase in terminal deoxynucleotidyl transferase-mediated nick end labeling-positive population, even in cells with hyperploidy. Thus, although early apoptosis and cell cycle controls in response to DNA damage are disrupted in both ATM and p53 mutations, cells from AT patients are much more susceptible to late-onset apoptosis than those of LFS. These differences may depend on the level of accumulation of DNA damage and/or threshold that triggers late-onset cell death in ATM or p53 mutations. Our findings allow a better understanding of the role of ATM in p53-dependent and independent signal transduction pathways in response to DNA damaging agents. 相似文献
172.
Pd-Ag thin films were prepared by the RF sputtering method on a Pyrex glass substrate to give monophasic alloys. Oxidation of allylic alcohols using the films gave selectively , -unsaturated carbonyl compounds in the presence of O2; highly dispersed Pd species on Ag, Pd7Ag93 showed 95% selectivity for acrolein from allyl alcohol at 473 K. 相似文献
173.
Gd(x)Y(1-x)Ca4O(BO3)3 (GdYCOB) is a promising nonlinear optical crystal that shows high effective nonlinearity d(eff), noncritical phase matching, and high chemical stability. We report on the fabrication and characteristics of a monolithic wavelength converter, which generates ultraviolet light by the incidence of a 1.064 microm near-infrared laser. The converter consists of GdYCOB for third-harmonic generation, KTiOPO4 (KTP) for second-harmonic generation, and a wave plate. GdYCOB has the advantage of an extremely wide angular acceptance bandwidth, whereas KTP exhibits a high effective nonlinear coefficient and a broad temperature bandwidth. Consequently the combination of these crystals results in highly efficient and stable ultraviolet conversion for constructing a compact and robust ultraviolet laser. 相似文献
174.
The sex pheromones of four Plusiinae species in the family Noctuidae, Ctenoplusia albostriata (CA), Macdunnoughia purissima (MP), Syngrapha ain (SA), and Diachrysia stenochrysis (DS) were identified by GC-EAD and GC-MS analyses. These were subsequently evaluated by a series of field trials in different ecological habitats. CA females produced (Z)-5-decenyl acetate (I), (Z)-7-dodecenyl acetate (II), and (Z)-7-dodecen-1-ol (III) in a ratio of 2:100:13. While the antennae of CA males responded to all three components, neither I nor III was essential to capture males. The MP females produced II, III, and (Z)-5-dodecenyl acetate (IV) in a ratio of 100:80:20, and this blend captured the most MP males. Compounds II and III were also identified from SA females, and mixtures ranging from 4:1 to 2:3 were equally attractive to males. DS females only produced one active compound, (Z)-7-decenyl acetate (V), and DS is the first Plusiinae species identified as using only the ω3-compound and none of ω5-compounds, such as II and III, which are common components of Plusiinae pheromones. Using previously published chemical and biosynthetic data, together with the finding from this study, we propose a classification of the Plusiinae sex pheromones. 相似文献
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177.
Saburo Hosokawa Yukihiro Hayashi Seiichiro Imamura Kenji Wada Masashi Inoue 《Catalysis Letters》2009,129(3-4):394-399
Ceria colloidal particles with a mean crystallite size of 2 nm were synthesized by a solvothermal reaction. The Ru/CeO2 catalyst prepared from the CeO2 colloids exhibited higher activity than the catalyst prepared from Ce(NO3)3. Temperature-programmed reduction analysis indicated that the reduction of surface Ce4+ was accelerated by highly dispersed Ru species on the CeO2 particles and occurred at low temperatures. The single component CeO2 sample prepared by the coagulation of the CeO2 colloid was more easily reduced and re-oxidized than the CeO2 sample prepared by the precipitation method from Ce(NO3)3. The higher activity of Ru/CeO2 prepared from the CeO2 colloids came from the inherent nature of the CeO2 support itself. 相似文献
178.
Nobutaka Maeda Takaaki Matsushima Masashi Kotobuki Toshihiro Miyao Hiroyuki Uchida Hisao Yamashita Masahiro Watanabe 《Applied Catalysis A: General》2009,370(1-2):50-53
Pt–Fe/mordenite (4 wt% Pt–0.5 wt% Fe) powder catalysts were wash-coated onto ceramic straight-channel monoliths by using silica- and/or alumina-sol as a binder, and were evaluated for the preferential oxidation of carbon monoxide (PROX) in a hydrogen-rich gas. In a synthetic reformate gas (1% CO, 1% O2, 5% H2O, 20% CO2, and balance H2), the CO concentration was reduced to less than 20 ppm at temperatures ranging from 100 to 130 °C. After a certain period of the PROX reaction, condensation of H2O in the pores of the mordenite-support occurred over the monolithic catalyst, which was wash-coated with alumina-sol, in the lower temperature range (100–120 °C), resulting in a rapid increase in CO concentration. The monolithic catalyst wash-coated with silica-sol, however, showed an excellent tolerance against H2O condensation and offered a stable catalytic performance, maintaining a CO concentration of ca. 20 ppm for 200 h. The H2O-tolerant characteristic was attributed to the relatively small adsorption amount of H2O over the silica-modified monolithic catalyst. 相似文献
179.
Masatoshi Kitakaze Ryota Chijimatsu Andrea Vecchione Toru Kitagawa Yuichiro Doki Hidetoshi Eguchi Hideshi Ishii 《International journal of molecular sciences》2021,22(14)
The recent advances in deciphering the human genome allow us to understand and evaluate the mechanisms of human genome age-associated transformations, which are largely unclear. Genome sequencing techniques assure comprehensive mapping of human genetics; however, understanding of gene functional interactions, specifically of time/age-dependent modifications, remain challenging. The age of the genome is defined by the sum of individual (inherited) and acquired genomic traits, based on internal and external factors that impact ontogenesis from the moment of egg fertilization and embryonic development. The biological part of genomic age opens a new perspective for intervention. The discovery of single cell-based mechanisms for genetic change indicates the possibility of influencing aging and associated disease burden, as well as metabolism. Cell populations with transformed genetic background were shown to serve as the origin of common diseases during extended life expectancy (superaging). Consequently, age-related cell transformation leads to cancer and cell degeneration (senescence). This article aims to describe current advances in the genomic mechanisms of senescence and its role in the spatiotemporal spread of epithelial clones and cell evolution. 相似文献
180.
Hata E Katsuda K Kobayashi H Nishimori K Uchida I Higashide M Ishikawa E Sasaki T Eguchi M 《Journal of dairy science》2008,91(2):564-569
The aim of this study was to clarify the epidemiological association and bacteriological characteristics of human and animal Staphylococcus aureus isolates. Pulsed-field gel electrophoresis showed that pulsotypes (PT) of isolates from bulk milk differed from PT from human isolates, suggesting that there is no epidemiological association between isolates from these 2 sources. The absence of a common PT could result from the lack of contact between the sources. Methicillin-resistant S. aureus from human secretions and S. aureus from bulk milk in Japan consisted of 1 and 2 dominant clusters, respectively, whereas methicillin-susceptible S. aureus from humans consisted of assorted clusters. Isolates belonging to the dominant clusters showed the coagulase serotype, the capsule serotype, detection of exotoxin genes, and antimicrobial susceptibility. Isolates from bulk milk did not show the penicillin-binding protein 2a gene, and 252 of 275 isolates belonging to the 2 dominant clusters of bulk milk were susceptible to ampicillin, cefazolin, erythromycin, chloramphenicol, oxacillin, and vancomycin. Moreover, the LukM/LukF′-PV leukotoxin gene was detected in 233 of 275 isolates belonging to the dominant clusters in bulk milk isolates. These results support the hypothesis that a number of factors play a role in the adaptation of S. aureus isolates to specific hosts. 相似文献