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The catalytic activity of horseradish peroxidase (HRP) in the presence of hydrogen peroxide has been investigated for the fluorescent derivatization of kynurenic acid under conditions with no exposure to light. Non-fluorescent kynurenic acid was converted into a fluorescent compound (Ex: 367 nm, Em: 470 nm) with HRP in the presence of hydrogen peroxide, and the optimum conditions of this fluorescent derivatization were investigated. Moreover, this fluorescent derivatization was developed for a spectrofluorometric determination of trace amounts of kynurenic acid by measuring the fluorescence intensity of the fluorescent compound. The calibration curve obtained was linear from 1.0 to 10.0 nmol of kynurenic acid in a 1.0 mL sample solution. The relative standard deviation at 5.0 nmol of kynurenic acid was 5.71% (n=5). By adjusting the bandwidths for both the excitation and emission to 15 nm, the calibration curve was also linear in the range between 0.1 to 1.0 nmol of kynurenic acid in a 1.0 mL sample solution. This method was applied to the fluorometric determination of trace amounts of kynurenic acid in the control sera. 相似文献
74.
Akihito Wachi 《Letters in Mathematical Physics》2006,77(2):155-168
We construct central elements in the universal enveloping algebra using column-determinants for the split realization of the orthogonal Lie algebra. Our central elements are quite new and simple, though they are closely related to what Howe and Umeda gave for the orthogonal Lie algebra under the different realization as the alternating matrices. 相似文献
75.
Kohji Tashiro Sobiroh Kariyo Akihito Nishimori Takashi Fujii Seishi Saragai Shinsuke Nakamoto Tatsuya Kawaguchi Akikazu Maatsumoto Orapin Rangsiman 《Journal of Polymer Science.Polymer Physics》2002,40(6):495-506
The development of a bench‐top‐type system for simultaneous measurement of X‐ray diffraction and Raman spectra has been made to investigate structural changes in the phase transitions of chain molecules such as polyethylene, n‐alkane, and so forth from various viewpoints. For the X‐ray diffraction measurement an imaging plate or a charge‐coupled device camera was used as a two‐dimensional detector. For the Raman spectral measurement a miniature Raman spectrometer was used with optical fibers for the irradiation of incident laser beams and collection of scattered signals. For example, in the heating process of the n‐C30H62 sample, the phase transition from orthorhombic‐to‐hexagonal lattices could be detected clearly by the X‐ray and Raman measurements. By comparing these two different types of data in detail, an intimate relationship between conformational disordering and rotational motion of molecular chains is detected more clearly than before. Also, similar discussion can be made for the orthorhombic‐to‐hexagonal phase transition of the geometrically constrained polyethylene sample occurring immediately below the melting point. Another example concerns the structural change in the photoinduced solid‐state polymerization of cis,cis‐diethylmuconate single crystal. From the shifts in the X‐ray reflection position and Raman frequency characteristic of the produced polymer, it was found that the molecular deformation of the polymer chains and lattice strain was induced in the early stage of the polymerization reaction. For the ferroelectric‐phase transition of vinylidene fluoride copolymer, the simultaneous measurement was made for collecting triple information of small‐angle and wide‐angle X‐ray scatterings and Raman spectra to know the relationship between the structural change in the crystal lattice and the morphological change in the lamellar stacking mode. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 495–506, 2002; DOI 10.1002/polb.10112 相似文献
76.
Nobuo Shinozaki Masaaki Sibuya Kunio Tanabe 《Annals of the Institute of Statistical Mathematics》1972,24(1):193-203
Summary Direct methods for computing the Moore-Penrose inverse of a matrix are surveyed, classified and tested. It is observed that
the algorithms using matrix decompositions or bordered matrices are numerically more stable. 相似文献
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79.
Sugihara T Kuwahara K Wakabayashi A Takao H Imagawa H Nishizawa M 《Chemical communications (Cambridge, England)》2004,(2):216-217
Nitric oxide reacts efficiently with alkynyllithium at low temperature producing 1,2,3-oxadiazole 3-oxides in good yields. 相似文献
80.
Ab initio path integral molecular dynamics simulation of M(+)(H(3)O(2)(-)) (M = Li, Na, and K) has been carried out to analyze how the structure and dynamics of a low-barrier hydrogen-bonded Zundel anion, H(3)O(2)(-), can be affected by the counter alkali metal cation, M(+). Our simulation predicts that the quantum proton transfer in Zundel anion can be strongly coupled to the motion of counter cation located nearby. A smaller cation can induce larger structural distortion of the Zundel anion fragment making the proton transfer barrier higher, and hence, lower the vibrational excitation energy. It is also argued that a large H∕D isotope effect is present. 相似文献