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排序方式: 共有292条查询结果,搜索用时 15 毫秒
231.
Dr. Ryosuke Ueki Ayaka Ueki Naoto Kanda Prof. Shinsuke Sando 《Angewandte Chemie (International ed. in English)》2016,55(2):579-582
Oligonucleotide‐based hepatocyte growth factor (HGF) mimetics are described. A DNA aptamer to Met, a cognate receptor for HGF, was shown to induce Met activation when used in dimer form. The most potent aptamer dimer, ss‐0, which was composed solely of 100‐mer single‐stranded DNA, exhibited nanomolar potency. Aptamer ss‐0 reproduced HGF‐induced cellular behaviors, including migration and proliferation. The present work sheds light on oligonucleotides as a novel chemical entity for the design of growth factor mimetics. 相似文献
232.
Sparham C Van Egmond R O'Connor S Hastie C Whelan M Kanda R Franklin O 《Journal of chromatography. A》2008,1212(1-2):124-129
A method is described for the analysis of decamethylcyclopentasiloxane (D(5)) in river water and treated waste water using headspace gas chromatography/mass spectrometry. Internal standard addition to samples and field blanks was carried out in the field to provide both a measure of recovery and to prevent any exposure of samples to laboratory air, which contained background levels of D(5). Measured levels of D(5) were typically in the range <10-29ngL(-1) in the River Great Ouse (UK) with slightly higher levels in the River Nene (UK). The measured concentration of D(5) in treated waste water varied between 31 and 400ngL(-1), depending on the type of treatment process employed. 相似文献
233.
Kumiko?Yamamoto Hironobu?Yasui Tomoki?Bo Tohru?Yamamori Wakako?Hiraoka Toshihide?Yamasaki Ken-ichi?Yamada Osamu?InanamiEmail authorView authors OrcID profile 《Applied magnetic resonance》2018,49(8):837-851
Our recent report demonstrated that genotoxic stimuli enhance mitochondrial energy metabolism in various tumor cell lines. However, the mitochondrial response against genotoxic stimuli has not been fully elucidated. In this study, to investigate mitochondrial functions in X-irradiated cells, the oxygen consumption rate (OCR) in human cervical adenocarcinoma HeLa cells was examined by electron spin resonance (ESR) spectroscopy with lithium 5,9,14,18,23,27,32,36-octa-n-butoxy-2,3-naphthalocyanine. ESR oximetry demonstrated that basal respiration, ATP-linked respiration, proton leak, maximal respiration, and reserve capacity increased in HeLa cells 24 h after X-irradiation. However, a flow cytometric analysis using MitoTracker Green showed that mitochondrial mass also increased following X-irradiation. When the OCR was standardized to the mitochondria membrane mass, the radiation-induced increases in the respiratory parameters disappeared. This finding indicated that the radiation-induced increase in cellular OCR was explained by an increase in mitochondrial mass but not by the activation of mitochondrial respiratory-related enzymes. In addition, mitochondrial semiquinone radicals at g?=?2.004 were detected by low-temperature (110 K) ESR spectroscopy. The ESR signal intensity of semiquinone radicals was enhanced by X-irradiation, suggesting an increase in the electron flow in the electron transport chain. These data will be important to understand the mechanism of radio-sensitization by mitochondria-targeting reagents in tumor cells. 相似文献
234.
Biodegradation of formaldehyde by a formaldehyde-resistant bacterium isolated from seawater 总被引:3,自引:0,他引:3
Yamazaki Tomohioko Tsugawa Wakako Sode Koji 《Applied biochemistry and biotechnology》2001,91(1-9):213-217
A formaldehyde-tolerantbacterium designated as a DM-2 strain was used to biodegrade formaldehyde. The cells, precultivated
in the presence of 400 ppm of formaldehyde, were able to degrade formaldehyde in a minimal medium supplemented with up to
400 ppm of formaldehyde in the presence of 3% NaCl. The rate of formaldehyde degradation achieved, in this study was 45 ppm/h
when the DM-2 culture's optical density at 660 nm was 1.2. 相似文献
235.
Yoshihiko Amano Kouichi Nozaki Takashi Araki Hideki Shibasaki Shigenori Kuga Takahisa Kanda 《Cellulose (London, England)》2001,8(4):267-274
We have investigated the reactivities of various cellulases onribbon-type bacterial cellulose (BC I) and band-shaped bacterial cellulose (BCII) so as to clarify the properties of different cellulases. BC I waseffectively hydrolyzed by exo-type cellulases from different fungi from twicetofour times as much as BC II, but endo-type cellulases showed little differencein reactivity on those substrates. One of the endo-type cellulases, EG II fromTrichoderma reesei, degraded BC II more rapidly thanexo-type cellulases even in the production of reducing sugars. The degree ofpolymerization (DP) of BC II was rapidly decreased by endo-type cellulases atanearly stage, while exo-type cellulases did not cause the decrease of DP atthe initial stage, though the decrease of DP was observed after an incubation of24 h. All exo-type cellulases adsorbed on BC I and BC II,whileendo-type cellulases except for EG II adsorbed slightly on both substrates. Itwas interesting to observe EG II adsorbed on BC I but not on BC II. It issuggested that the adsorption of enzyme on cellulose is important for thedegradation of BC I, but not for BC II. It is proposed that the ratio of aspecific activity of each enzyme between BC I and BC II represents thedifference in the mode of action of cellulase. Furthermore, the K
RW value, which we can calculate from thedecrease of DP/reducing sugar produced, is effective for discriminating themode of action of cellulase, especially the evaluation of randomness in thehydrolysis of cellulose by endo- and exo-type cellulases. 相似文献
236.
HAN Yun-Cheng Nobuyuki Chiga Yu Fujii Kenta Putatsukawa Osamu Hashimoto Kentaro Hirose Takatsugu Ishikawa Hiroki Kanda Masashi Kaneta Daisuke Kawama Yue Ma Kazushige Maeda Tomofumi Maruta Nayuta Maruyama Akihiko Matsumura Youhei Miyagi Koji Miwa Satoshi N. Nakamura Hajime Shimizu Koutarou Shirotori Koutaku Suzuki Tadaaki Tamae Hirokazu Tamura Kyo Tsukada WANG Tie-Shan Hirohito Yamazaki 《中国物理C(英文版)》2010,34(1)
The energy of tagged photons, which were provided from the internal photon tagging system of the Laboratory of Nuclear Science, Tohoku University, has been calibrated using the d(γ,π-pp) reaction. Charged pions and protons in the final state were detected with the Neutral Kaon Spectrometer (NKS2). Photon energies were obtained from the reaction of d(γ,π-pp). The derived photon energy was consistent with the design of the tagger system and the previous measurement using electron-positron pair production. The consistency demonstrates the performance of NKS2 and the capability of the photon energy calibration using d(γ,π-pp). 相似文献
237.
Y. Oki K. Kondo Y. Kanda T. Miura 《Journal of Radioanalytical and Nuclear Chemistry》1999,239(3):501-505
Aerosol-size distributions of218Po were determined for the accelerator tunnel air sampled during machine operation and for the basement air of a concrete
building, where the number and the size distribution of non-radioactive aerosols are greatly different from each other. The218Po distributions depended very much on the size distributions of ambient non-radioactive aerosols, and could be well explained
by an attachment model of218Po to ambient non-radioactive aerosols. 相似文献
238.
Tomohiko Yamazaki Wakako Tsugawa Koji Sode 《Applied biochemistry and biotechnology》1999,77(1-3):325-335
We previously reported a novel glucose dehydrogenase (GDH) showing two peaks in the optimum temperature for the reaction at
around 45°C and at around 75°C. Each peak derived from hetero-oligomeric enzyme, constructed from two distinct peptides with
an α-subunit (MWs 67,000) and β-subunit (MWs 43,000), and a single peptide enzyme containing an α-subunit alone. The function
of the two subunits in the thermostable co-factor binding GDH was investigated. The results of spectroscopic analyses indicated
that the α-subunit contained an unknown co-factor showing specific fluorescence spectra like pyrroloquinoline quinone (PQQ),
and the β-subunit was cytochrome c. Moreover, the results of a urea denaturation and reconstitution experiment suggested that the dissociation of the hetero-oligomeric
complex to a single peptide was reversible. The kinetic parameter analyses for glucose and the electron mediator also suggested
that the β-subunit was responsible for electron transfer from the catalytic center of the α-subunit to the electron mediator. 相似文献
239.
Duyen Minh Pham Yasushi Miyata Takanori Awata Masashi Nakatake Chung Fang Zhang Keiji Kanda Satoshi Ogawa Shozo Ohta Shinya Yagi Arata Katayama 《Surface and interface analysis : SIA》2019,51(2):226-233
Carbon-binding state of humin (HM, a non-conductive insoluble organo-mineral humic substance) was successfully characterized for the first time by synchrotron-radiation–based X-ray photoelectron spectroscopy (XPS). Four sample preparation techniques—HM on double-sided carbon tape, indium sheet, copper mesh, and in pellet formed from the mixture of HM and copper powder (Cu) at different mixing ratios (1:1, 1:2, and 1:6 v/v)—were compared. The results show that HM samples prepared using the first three methods had significant charge buildup, which made the interpretation of the XPS spectra impossible because of the shifts in the binding energy of C 1s XPS spectra. Pellets of HM:Cu mixture enhanced the electrical conductivity and reduced charge buildup on the sample surface. Pellets prepared with HM:Cu ratio of 1:1 (v/v) provided the minimum charge buildup and high sensitivity with difference in C 1s spectra regardless of the observing position. The C 1s spectra, estimated by the subtraction of the carbon contamination in Cu, showed the resolution of CC (284.0 eV), C C/C H (285.1 eV), C O (286.3 eV), CO (287.3 eV), and OC O (288.3 eV) and three additional peaks of CF (289.3 eV), CF2 (290.2 eV), and CF3 (291.4 eV). Soft X-ray absorption spectroscopic (XAS) analysis further proved the existence of fluoride (F 1s) in HM structure. The detection of fluorinated carbon in HM showed a great advancement of XPS compared with other conventional analyses. X-ray with the incident angle of 0° provided the smallest (nearly negligible) energy shift in the C 1s spectra of HM and did not damage the surface of the sample. 相似文献
240.
A. Kanda 《Monatshefte für Mathematik》1912,23(1):347-348
Ohne Zusammenfassung 相似文献