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41.
Raman Spectroscopic Investigations of Coordination Polymeric Metal Tricyanmethanides The Raman spectra of 3d-metal tricyanmethanides M{C(CN)3}2 as well as of [Ni{C(CN)3}2py2] are investigated. The observed Raman lines are assigned, characteristic variations of position and intensity of these lines are discussed. 相似文献
42.
43.
Abstract— Irradiation of thin films consisting of 4,5',8-trimethylpsoralen (TMP), adenosine and small amounts of alcohols led to TMP-alcohol photoadducts in addition to TMP-adenosine photoadducts. Four TMP-ethanol and two TMP-methanol adducts have been separated and characterized. Covalent bonds were formed between the 4-carbon of TMP and the α-carbon to the hydroxy group in the alcohols. The TMP-alcohol photoadducts were formed only in the TMP film containing small amounts of alcohol and adenosine. Furthermore, no photoadduct of TMP and ribose was detected upon photolysis of a TMP-ribose film, suggesting that the adenine moiety plays a specific role in the reaction. The interaction of adenosine with psoralens in a dry film may be related to the DNA sequence selectivity observed for the photoreaction of psoralens with DNA. 相似文献
44.
Chang CH Liao JD Chen JJ Ju MS Lin CC 《Langmuir : the ACS journal of surfaces and colloids》2004,20(26):11656-11663
Alkanethiolate self-assembled monolayers (SAMs) of varied chain lengths were adsorbed upon Au-coated nerve microelectrodes and employed as protein-resistant spacers. The microelectrode spiraled as a cuff type can be used for restoring motor function via electrical stimulation on the peripheral nerve system; however, an increase of electrode impedance might occur during implantation. In this work, a thin-film SAMs treatment upon Au/polyimide (PI) surface of the microelectrode provided a hydrophobic characteristic, which retarded protein adsorption at the initial stage and subsequent pileup (or thickening) process. The protein-resistant effect exhibited comparable SAMs of different chain lengths adsorbed upon Au/PI surfaces. The increase of electrode impedance as a function of protein deposition time was mainly correlated with the addition of reactance that was associated with the pileup thickness of the deposited protein. Particularly, the SAMs-modified surface was capable to detach a significant portion of the accumulated protein from the protein-deposited SAMs/Au/PI, whereas the protein-deposited layers exhibited firm adhesion upon Au/PI surface. It is therefore very promising to apply thin-film SAMs adsorbed upon Au-coated surface for bioinvasive devices that have the need of functional electrical stimulations or sensing nerve signals during chronic implantation. 相似文献
45.
Ju Tao LIU Xiao Hong WANG Jing Fu LIU Faculty of Chemistry Northeast Normal University Changchun 《中国化学快报》2004,15(7):859-862
A novel vanadate decamer, involving all vanadium atoms present in +5 oxidation and one formhydroxamic acid dimer cation readical, has been synthesized. The single-crystal X-ray diffraction shows that the orange crystal is formed in the triclinic system, space group Pi, a = 8. 4960 (17), b = 10.447 (2), c = 11.299 (2) A, α= 68. 82 (3)°,β= 87.35 (3)°, γ = 66.97(3)°. V = 855. 3(3) A3, Z = 8, R1 = 0. 0857, wR2=0. 2551. X-ray crystallographic and packing in superlattice studies showed that the crystal structure was constructed by electrostatic attraction of O-H…O hydrogen bonds between formhydroxamic acid dimer cation and decavanadate polyanion. Formhydroxamic acid dimer is got through controlling the condition of the reaction using formhydroxamic acid. 相似文献
46.
Takashi Kato Ju Kumanotani 《Journal of polymer science. Part A, Polymer chemistry》1969,7(6):1455-1465
Previously, the formation of urushiol quinone from urushiol was demonstrated in the laccase-catalyzed oxidation process of the sap of the Japanese lacquer tree (Rhus vernicifera D.C.) or of lacquer formed from it. This paper presents the results of the investigation on the participation of urushiol quinone in the oxidative polymerization and crosslinking of the sap or the lacquer. The polymeric urushiol was obtained by the fractionation of the mildly oxidized sap (Japanese lacquer), and a specific dimeric urushiol was isolated from it by thin-layer chromatography (TLC). Structural analysis of the dimer illustrated that it has a conjugated triene structure and may be formed by a coupling reaction between urushiol quinone and a triolefinic component of urushiol. Further support for this was given by the spectroscopic study of the reaction between 4-tert-butyl-o-quinone and the triolefinic component of dimethylurushiol, and by the isolation and identification of the coupling product between them. 相似文献
47.
Shu Xia LIU* Chun Mei WANG Hong Ju ZHAI De Hui LI En Bo WANG Institute of Polyoxometalate Chemistry Department of Chemistry Northeast Normal University Changchun 《中国化学快报》2004,15(2):216-219
Heteropolyoxometalates are a large family of potent medicines due to their excellent antiviral and antitumor activity 1-4, while their application in clinic meets great difficulties for their toxicity 5. How to synthesize heteropolyoxometalate medicines possessing high activity and low toxicity has become the focus in heteropolyoxometalate medicine research. Previously reported polyoxometalates showing medical activities are all salts simple Na+, K+ or NH4+ etc. inorganic cations, in which o… 相似文献
48.
Jae Hyung Park Yong Woo Cho Yoen Ju Son Kwangmeyung Kim Hesson Chung Seo Young Jeong Kuiwon Choi Chong Rae Park Rang-Woon Park In-San Kim Ick Chan Kwon 《Colloid and polymer science》2006,284(7):763-770
An anthracycline drug, adriamycin, was chemically conjugated onto the backbone of glycol chitosan via an acid-labile cis-aconityl linkage. The physicochemical characteristics of the glycol chitosan–adriamycin (GC–ADR) conjugates were investigated by dynamic light scattering, atomic force microscopy, and fluorescence spectroscopy. The GC–ADR conjugates were capable of forming nano-sized self-aggregates in an aqueous medium, when the adriamycin content in the conjugate was in the range of 2.0–5.0 wt.%. The self-aggregates were spherical in shape, and had mean diameters of 238–304 nm, depending on the adriamycin content. The critical aggregation concentrations of the conjugates, estimated by the fluorescence quenching method, were as low as 1.0–2.5×10−2 mg/ml. The size of self-aggregates was not affected by the polymer concentration in the range from 50 to 2,000 μg/ml, and was maintained up to 8 days in phosphate-buffered saline (pH 7.4), indicating high colloidal stability. The release of adriamycin from self-aggregates was significantly dependent on the pH of the medium due to the cis-aconityl linkage; e.g., the amount of adriamycin released for 4 days was 7.3±0.3% at pH 7, whereas it was 29.3±1.9% at pH 4. The cell viability results demonstrated that free adriamycin shows more potent cytotoxicity than the conjugates, primarily attributed to the sustained release of adriamycin from self-aggregates. In conclusion, the self-aggregates, formed by GC–ADR conjugates, might be useful for the site-specific delivery of adriamycin in a sustained manner. 相似文献
49.
R. Ramanauskas L. Gudavičiūtė A. Kaliničenko R. Juškėnas 《Journal of Solid State Electrochemistry》2005,9(12):900-908
The influence of pulse plating parameters on the surface morphology, grain size, lattice imperfection and corrosion properties
of Zn–Ni alloy has been studied. The coatings were electrodeposited in an alkaline cyanide-free solution. AFM was applied
for surface morphology examination, XRD measurements were carried out for phase composition and texture analysis, electron
probe microanalysis was used for alloy chemical composition studies, while electrochemical techniques were applied for corrosion
performance evaluation. The pulse plated Zn–Ni coatings appeared to consist of the γ-Zn21Ni5 phase and the composition of the alloy depended on the plating parameters. The grain size, lattice imperfection and homogeneity
of grain distribution were established to be the main factors determining corrosion behaviour of the coating.
Presented at the 4th Baltic Conference on Electrochemistry, Greifswald, March 13–16, 2005 相似文献
50.
纳米级金膜微电极的制作,表征及异相催化反应 总被引:1,自引:0,他引:1
报道了纳米级金膜微电极的制作方法,用XPS及SEM对电极表面进行了表征,考察了该电极的循环伏安及计时电流特性,在聚吡咯修饰微带金电极上成功地实现了葡萄糖氧化酶和电子传递媒体Fe(CN)6^3-的同时固定,并研究了GOD/Fe(CN)6^3-/PPy微酶电极对葡萄糖的响应,稳态响应电流与葡萄糖浓度之间存在Michealis-Menten动力学特征。 相似文献