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排序方式: 共有172条查询结果,搜索用时 31 毫秒
1.
We developed two DNA-conjugated polymers, one based on polyallylamine and the other on polyacrylic acid, for use in DNA chips. A 30-mer single-stranded DNA probe and thioctic acid were covalently attached to polyallylamine as sidechains. The same single-stranded DNA and 3-(pyridyldithio)propionyl hydrazide were covalently attached to polyacrylic acid as sidechains. Both DNA-conjugated polymers could be specifically immobilized onto a gold sensor substrate by a self-assembly technique. The interactions between fully matched DNA and each DNA-conjugated polymer were investigated by surface plasmon resonance. A gold surface modified with either DNA-conjugated polymer recognized fully matched DNA much better than unmatched DNA. The hybridization selectivity and efficiency of DNA-conjugated polyallylamine was optimized by adjusting the pH so as to reduce the effects of cationic polymer sidechains. The hybridization selectivity and efficiency of DNA-conjugated polymers were higher than those of a conventional immobilized thiol-based DNA. The coating of DNA-conjugated polymers reduced nonspecific adsorption of DNA by the gold substrate. DNA-conjugated polyacrylic acid was more selective toward fully matched DNA than was DNA-conjugated polyallylamine. Therefore, DNA-conjugated polymers show promise for application in novel DNA chips. 相似文献
2.
We developed DNA-conjugated polymer for DNA chip fabrication. A 30 mer probe DNA and disulfide bridges were covalently attached to the polymer side chain. The DNA-conjugated polymer can be specifically adsorbed on a gold substrate surface by a self-assembly technique. The interaction between fully matched DNA and DNA-conjugated polymer was investigated by surface plasmon resonance (SPR) technique. The DNA-conjugated polymer-modified gold surface highly recognized fully matched DNA, rather than unmatched DNA. Therefore, DNA-conjugated polymer can be used for novel DNA chip fabrication. 相似文献
3.
The synthesis and properties of novel anthracene-bridged porphyrin dimers having an oxomolybdenum(V) porphyrin unit, H(2)(DPA)[Mo(V)O(OMe)] (1) and (DPA)[Mo(V)O(OMe)][Zn(II)(MeOH)] (2), and the relevant monomer porphyrin complexes Mo(V)O(MPP)OMe (3) and Zn(II)(MPP) (4) are presented. An oxomolybdenum(V) unit was introduced into one of the two porphyrins in DPA to give 1, which has a free-base porphyrin unit. By introducing a zinc(II) ion to the free-base part, a mixed-metal complex of 2 was prepared and isolated. The structure of 2 was analyzed by X-ray crystallography (2.(7)/(6)CH(2)Cl(2), triclinic, P(-)1 (no. 2), a = 15.2854(12) A, b = 19.9640(15) A, c = 13.6915(12) A, alpha = 90.968(3), beta = 113.108(4), gamma = 96.501(4), Z = 2, R1 = 9.9, wR2 = 19.2). The structure of 2 demonstrated that a methanol is stably coordinated to the Zn(II) ion with the aid of a hydrogen bond to the methoxo ligand on the Mo(V) ion in the binding pocket of DPA. The electrochemical measurements of 2 suggested that the methanol was kept in the pocket of DPA in solution even at the reduced state of the molybdenum ion. 相似文献
4.
Makoto Wakeshima Nobuyuki Taira Aya Tobo Yasuo Yamaguchi 《Journal of solid state chemistry》2003,174(1):159-164
Magnetic and electrical properties are investigated for quaternary neodymium sulfides BaNd2TS5 (T=Co, Zn) through the specific heat, neutron diffraction, and electrical conductivity measurements. Their electrical conductivities show semiconductive behavior, which follows the Arrhenius temperature dependence with the activation energy of Ea=1.46 eV for BaNd2ZnS5 and Ea=1.19 eV for BaNd2CoS5. The specific heat of BaNd2ZnS5 has a λ-type anomaly at 2.8 K due to the antiferromagnetic ordering of the Nd3+ moments and a Schottky-type anomaly at around 60 K, which results from the crystal field splitting of the 4I9/2 ground state of the Nd3+ ion. The specific heat of BaNd2CoS5 shows two λ-type anomalies at 5.7 K due to the antiferromagnetic ordering of Nd3+ and at 58 K due to the antiferromagnetic ordering of Co2+. The latter overlaps with the Schottky-type anomaly due to the crystal field splitting of the Nd3+ ion. Neutron diffraction measurements for BaNd2CoS5 show that a magnetic arrangement of the Co2+ moments has a collinear antiferromagnetic structure, while that of the Nd3+ moments has a noncollinear one. 相似文献
5.
Du YZ Hiratsuka Y Taira S Eguchi M Uyeda TQ Yumoto N Kodaka M 《Chemical communications (Cambridge, England)》2005,(16):2080-2082
A new nano-biomachine has been created from microtubules (MTs) and hetero-bifunctional polymer particles bearing pyruvate kinase, which is propelled on glass surfaces coated with kinesin by use of self-supplying ATP. 相似文献
6.
Hydrogen bond complex stability between adenine (A) and hydrogen bond equivalents of uracil: 2-pyridone derivatives (UX
X2O) and 3-oxo-1,2,6-thiadiazine-1,1-dioxide derivatives (UX
SO2) was studied, and as the result, the hydrogen bond energy of UX
X2O-A and a complex of UXX
SO2-A, was about 1.5 kcal/mol more stable than that of the corresponding adenine-uracil derivatives complex, respectively. The energy difference between the imide tautomer and enol tautomer was smaller than those of uracil derivatives. UF
SO2 can form a stable complex with A, and its imide tautomer is stable. 相似文献
7.
A zwitterionic trichloroplatinum(II) complex PtCl3(4,4′-bpy-N-nBu) (1) was prepared by an aqueous reaction of [4,4′-bpy-N-nBu]Cl with K2PtCl4, and was characterized by 1H-n.m.r. and IR spectroscopy as well as elemental analysis. Dissolving (1) into dmso-d
6 at 25 °C yields a mixture of the complexes, cis-PtCl2(4,4′-bpy-N-nBu)(dmso-d
6) (2-cis), trans-PtCl2(4,4′-bpy-N-nBu)(dmso-d
6) (2-trans), [4,4′-bpy-N-nBu]Cl and PtCl2(dmso-d
6)2. Ratio of the products in the dmso-d
6 solution changed depending on the temperature and the total concentration of the complexes. These compounds are in equilibrium
via isomerization reaction between (2-cis) and (2-trans) and via displacement reaction of the alkylbipyridinium ligand of
(2-cis) and (2-trans) with dmso-d
6 to form [4,4′-bpy-N-nBu]Cl and PtCl2(dmso-d
6)2. 相似文献
8.
9.
An Okinawan soft coral Cespitularia sp. has proven to be a good source of cytotoxic metabolites having a carbon skeleton of the seco-type variety of xenicin. This soft coral yielded alcyonolide, the major constituent, and other related compounds, all of which have proven to be cytotoxic. Reinvestigation of the cytotoxic ethyl acetate extracts of the coral yielded two new alcyonolide congeners, trisnorditerpenoid 1 and diterpenoid 2, possessing the same carbon skeleton. Their structures were elucidated by a detailed analysis of spectroscopic data (1D, 2D NMR, and MS). Metabolites 1 and 2 showed cytotoxicity against HCT116 cells (IC50 6.04 and 47.0 μM, respectively) and a dose dependent, anti-inflammatory effect in LPS/IFN-γ-stimulated inflammatory RAW 264.7 macrophage cells. 相似文献
10.