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891.
Hiroyuki Tsuda Katsumi Fukamachi Jiegou Xu Kazunori Sekine Shigetoshi Ohkubo Nobuo Takasuka Masaaki Iigo 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2006,82(7):208-215
Increasing attention is being paid to chemopreventive agents for individuals at high risk of cancer. We have concentrated on bovine lactoferrin (bLF), an 80 kDa iron-binding glycoprotein known to have anti-microbial and immunoprotective effects. Lactoferrin is particularly abundant in colostrum, and is also present in tears, saliva and seminal and uterine secretions. However, only little is known regarding its influence on carcinogenesis. We have shown preventive effects of bLF and its fragment peptide, lactoferricin (bLFcin), consisting of a 25 amino acid sequence without iron binding capacity, on chemically-induced colon carcinogenesis in the rat and transplanted carcinoma cell metastasis in the mouse. The mechanisms are wide-spectrum, including elevation of caspase-1 and IL-18 in the small intestine, enhancement of the cell killing activity of cytotoxic T and natural killer (NK) cells, and anti-inflammatory and anti-angiogenic effects. It also inhibits the induction of liver CYP1A2, a carcinogen activating enzyme, and induces apoptosis in the colon epithelium of carcinogen treated rats. Thus, bLF possesses multi-functional potential to suppress carcinogenesis and is a good candidate for practical application in humans. 相似文献
892.
893.
Tatsumi Y Naga T Nakashima H Murahashi T Kurosawa H 《Chemical communications (Cambridge, England)》2004,(12):1430-1431
A series of 1,4-diphenyl-1,3-butadiene multinuclear palladium sandwich complexes are synthesized by stepwise growth of palladium chains within a sandwich framework. 相似文献
894.
Novel molecular recognition via fluorescent resonance energy transfer using a biotin-PEG/polyamine stabilized CdS quantum dot 总被引:2,自引:0,他引:2
Nagasaki Y Ishii T Sunaga Y Watanabe Y Otsuka H Kataoka K 《Langmuir : the ACS journal of surfaces and colloids》2004,20(15):6396-6400
A novel functionally PEGylated quantum dot (QD) was prepared by a coprecipitation method in the presence of the biotin-PEG/polyamine block copolymer. When CdCl2 and Na2S were mixed in aqueous media in the presence of the biotin-PEG-b-poly(2-(N,N-dimethylamino)ethyl methacrylate) [biotin-PEG/PAMA], a CdS QD with a size of ca. 5 nm was prepared. The polyamine segment was anchored on the surface of the formed CdS nanoparticle, whereas the PEG segment was tethered on the surface to form a hydrophilic palisade, thus improving the dispersion stability in aqueous media even under a high salt concentration condition. An effective fluorescent resonance energy transfer (FRET) was observed by the specific interaction of the biotin-PEG/PAMA stabilized CdS QD with TexasRed-labeled streptavidin of the physiological ionic strength of 0.15 M. The extent of the energy transfer was in proportion to the concentration of the TexasRed-streptavidin. This FRET system using the PEGylated CdS QD coupled with fluorescent-labeled protein can be utilized as a highly sensitive bioanalytical system. 相似文献
895.
Oxidation of 3-hydroxypiperidine with iodosylbenzene in water afforded 2-pyrrolidinone directly in good yields. The reaction probably involves oxidative Grob fragmentation yielding imino aldehyde, which upon hydrolysis produces 2-pyrrolidinone via a cyclization-oxidation sequence. 相似文献
896.
897.
898.
Takeshi Yagi Naofumi Kuboki Yoshihisa Suzuki Naotaka Uchino Kazunori Nakamura Kazuaki Yoshida 《Optical Review》1997,4(5):596-600
A new fiber-optic ammonia sensor utilizing rectangular-cladding eccentric-core fiber and a sensitive film containing an indicator dye is demonstrated. The sensitive film is a SiO2-GeO2 gel film including an indicator dye of bromocresol purple or bromocresol green, which is dip-coated by a sol-gel technique. The attenuation of this sensor changes depending on the concentration of ammonia at the wavelength range of 500–700 nm. This sensor can detect several ppm of gaseous ammonia. Various factors determining the sensitivity to detect the ammonia gas and time response of the sensor are also studied. 相似文献
899.
The eight nickel(II) complexes with 16-ethyl-5,6,7,8,9,14-hexahydrodibenzo[b, i][1,4,8,11]tetraazacyclotetradecine and a counter anion have been synthesized and their spectroscopic properties were studied. The δ N-H values of NiLCl and NiLBr are observed in a more downfield range than those of NiLPF6, NiLBF4 and NiLClO4 in acetonitrile and nitromethane solutions. The plot of δ N-H against molar conductance is found to be approximately linear. The N-H stretching modes of NiLBF4, NiLPF6 and NiLClO4 shift to lower frequency and those of NiLCl, NiLBr and NiLI shift to higher frequency upon metal-coordination. 相似文献
900.
T. Kurosawa A. Morinaga T. Sakurai K. Tanaka 《Applied physics. B, Lasers and optics》1984,34(2):49-53
The S/N ratio of the beat note obtained from the frequency mixing between a 32 THz CO2 laser, a 10.7 THz H2O laser and a 22 GHz klystron is measured as a function of incident power of both lasers and the klystron on the W-Ni point contact diode. A maximum S/N ratio of 36 dB is obtained. It is found that the S/N ratio arises from the product of the contributions due to the incident power and the fifth coefficient of the current-voltage characteristic of the W-Ni diode. These characteristics are discussed qualitatively. 相似文献