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1.
Makoto Kimura Kasumi Kashikura Satomi Yokoi Yumiko Koiwa Yoshikazu Tokuoka Norimichi Kawashima 《Optical Review》2005,12(3):207-210
We determined photodynamic therapy (PDT) efficacy using a flash wave (FW) and a continuous wave (CW) light, of which the fluence rate was 70 W/cm2, for murine thymic lymphoma cells (EL-4) cultivated in vitro. The irradiation frequency and the pulse width of the FW light were in the range of 1–32 Hz and less than one millisecond, respectively. 5-Aminolevulinic acid-induced protoporphyrin IX (ALA-PpIX) was used as a photosensitizer. When EL-4 with ALA administration was irradiated by the light for 4 h (irradiation fluence: 1.0J/cm2), the survival rate of EL-4 by the FW light was lower than that by the CW light, except for the FW light with irradiation frequency of 32 Hz, and decreased gradually with decreasing irradiation frequency. Moreover, the FW light, especially at lower irradiation frequency, was superior to the CW light for the generation of singlet oxygen in an aqueous PpIX solution. Therefore, thehigher PDT efficacy for EL-4 of the FW light would be caused by the greater generation of singlet oxygen in the cells. 相似文献
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Zhang W Sato K Kato A Jia YM Hu XG Wilson FX van Well R Horne G Fleet GW Nash RJ Yu CY 《Organic letters》2011,13(16):4414-4417
Total synthesis of the proposed structure of (-)-hyacinthacine C(5) and its epimers at C6 and C7 is described. A key step of the synthesis was the construction of the bicyclic pyrrolizidine system by means of a nucleophilic addition of a dithiane to a cyclic nitrone followed by a Cope-House cyclization. 相似文献
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The photopatternability of various silyl hydride containing organosilicone resins containing the photobase generators N‐methylnifedipine or O‐(2‐nitrobenzyl)‐N‐octyl carbamate have been examined, with the goal of identifying potential photopatternable compositions with high thermal stability after cure. Two different categories of silicone resins have been prepared from combinations of diphenylsiloxane and methyl and hydrogen silsesquioxane units and a combination of phenyl and hydrogen silsesquioxane monomer units. The photobase generators were incorporated into these resins at concentrations up to 10 weight percent. UV‐irradiation of micrometer thick silicone resin‐photobase films through a photomask, under an air atmosphere, yielded micrometer scale features after development. Photopatternable compositions have been identified with photosensitivities of less than 50 mJ/cm2. The photopatterning process is believed to proceed by base‐catalyzed reaction of resin‐based silanol groups with neighboring silyl hydride groups to yield thermally stable siloxane crosslinks. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
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Kazunobu Toshima Ken-ichi Kasumi Kanako Kawahara Shuichi Matsumura 《Tetrahedron》2004,60(25):5331-5339
Novel α- and β-stereocontrolled glycosidations using a heterogeneous solid acid, sulfated zirconia (SO4/ZrO2), as an activator have been developed. The glycosidations of manno- and 2-deoxyglucopyranosyl α-fluorides with several alcohols using SO4/ZrO2 in MeCN proceeded α-stereoselectively, while those with the same activator in the presence of MS 5A in Et2O occurred with β-stereoselectivity. Thus, both the α- and β-manno- and 2-deoxyglucopyranosides were effectively obtained by the present glycosidations. 相似文献
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Kasumi H Solomentsev YE Guelcher SA Anderson JL Sides PJ 《Journal of colloid and interface science》2000,232(1):111-120
Theory suggests that thermocapillary flow about neighboring bubbles in liquids on hot walls pulls the bubbles together. A temperature gradient perpendicular to the wall establishes a surface tension gradient at the bubble-liquid interface, which in turn sustains a shear stress gradient that pumps adjacent fluid away from the wall. Neighboring bubbles are mutually entrained in this flow and also respond thermophoretically to lateral temperature gradients in the temperature near field. The theory predicts that the aggregation velocity scales with the temperature gradient, the radius of the bubbles, the derivative of the surface tension with respect to temperature, and the reciprocal of the liquid's viscosity. Bubble aggregation experiments under controlled conditions were performed to test the theory. Scaling the experimental bubble trajectories according to the theory substantially collapses all of the data onto a master curve when the interbubble separation is greater than 3 radii, which suggests that the theory is correct. Calculated velocities agree with the experimental results when hindrance of bubble motion due to the wall is included. Values for the parameter that describes the hindrance effect are obtained from fitting the data to the theory, from independent measurements, and from direct hydrodynamic calculation. The results of the three determinations agree within 15% of the possible range of the value of the parameter. Copyright 2000 Academic Press. 相似文献
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Daisuke Tanaka Satoru Yoneda Yoko Yamashiro Akihiro Sakatoku Takuro Kayashima Kasumi Yamakawa Shogo Nakamura 《Applied biochemistry and biotechnology》2012,168(2):327-338
A psychrotrophic Pseudomonas sp. TK-3 was isolated from dirty and cool stream water in Toyama, Japan from which we cloned and characterized the bacterial lipase LipTK-3. The sequenced DNA fragment contains an open reading frame of 1,428?bp that encoded a protein of 476 amino acids with an estimated molecular mass of 50,132?Da. The lipase showed high sequence similarity to those of subfamily ??.3 lipase and had a conserved GXSXG motif around the catalytic Ser residue. Its optimal temperature was 20?C25?°C, lower than in most other subfamily ??.3 lipases. The lipase exhibited about 30?% of maximal activity at 5?°C. The optimal pH value was 8.0. The activity was strongly inhibited by EDTA and was highly dependent on Ca2+. Tricaprylin and p-nitrophenyl caprylate were the most favorable substrates among the triglycerides and p-nitrophenyl esters, respectively. LipTK-3 also showed high activity towards natural substrates including edible vegetable oils and animal fats. Furthermore, LipTK-3 was very active and stable in the presence of several detergents, metal ions, and organic solvents. This cold-adapted lipase may prove useful for future applications. 相似文献
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Tomoki Saka Toru Okaki Shohei Ifuku Yukiko Yamashita Kasumi Sato Shota Miyawaki Akiko Kamori Atsushi Kato Isao Adachi Yasuhiro Tezuka Peter G. Kiria Osamu Onomura Daishiro Minato Kenji Sugimoto Yuji Matsuya Naoki Toyooka 《Tetrahedron》2013
Synthesis and inhibitory activities against α-l-fucosidase of phenylalkyl-substituted polyhydroxypiperidines have been described. Among the newly synthesized compounds, 2,4,6-trichloro derivative (16q) showed very high inhibitory activity against α-l-fucosidase with IC50 value of 0.005 μM, and Ki values of 0.0011 μM, respectively. 相似文献
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Muto R Chiba J En'yo H Fukao Y Funahashi H Hamagaki H Ieiri M Ishino M Kanda H Kitaguchi M Mihara S Miwa K Miyashita T Murakami T Nakura T Naruki M Ozawa K Sakuma F Sasaki O Sekimoto M Tabaru T Tanaka KH Togawa M Yamada S Yokkaichi S Yoshimura Y 《Physical review letters》2007,98(4):042501
Invariant mass spectra of e(+) e(-) pairs have been measured in 12 GeV p + A reactions to detect possible in-medium modification of vector mesons. Copper and carbon targets are used to study the nuclear-size dependence of e(+) e(-) invariant mass distributions. A significant excess on the low-mass side of the phi meson peak is observed in the low betagamma(= beta/square root(1-beta(2))) region of phi mesons (betagamma < 1.25) with copper targets. However, in the high betagamma region (betagamma > 1.25), spectral shapes of phi mesons are well described by the Breit-Wigner shape when experimental effects are considered. Thus, in addition to our earlier publications on rho/omega modification, this study has experimentally verified vector meson mass modification at normal nuclear density. 相似文献