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Sauer T 《Chaos (Woodbury, N.Y.)》1995,5(1):127-132
According to a theorem of Takens [Lecture Notes in Mathematics (Springer-Verlag, Berlin, 1981), Vol. 898], dynamical state information can be reproduced from a time series of amplitude measurements. In this paper we investigate whether the same information can be reproduced from interspike interval (ISI) measurements. Assuming an integrate-and-fire model coupling the dynamical system to the spike train, there is a one-to-one correspondence between the system states and interspike interval vectors of sufficiently large dimension. The correspondence implies in particular that a data series of interspike intervals, formed in this manner, can be forecast from past history. This capability is demonstrated using a nonlinear prediction algorithm, and is found to be robust to noise. A set of interspike intervals measured from a simple neuronal circuit is studied for deterministic structure using a prediction error statistic. (c) 1995 American Institute of Physics. 相似文献
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1,3,4-Oxadiazoles can be rapidly and efficiently synthesized from a variety of carboxylic acids and acid hydrazides in one simple step. The use of commercially available PS-PPh3 resin combined with microwave heating delivered the product 1,3,4-oxadiazoles in high yields and purities. 相似文献
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M. M. Abd-Elmeguid Ch. Sauer U. Köbler W. Zinn 《Zeitschrift für Physik B Condensed Matter》1985,60(2-4):239-248
X-ray diffraction,151Eu Mössbauer effect (ME) and magnetic susceptibility measurements have been performed to investigate the valence behavior and the magnetic interactions of the Eu ions in the intermetallic series Eu(Pd1–x
Au
x
)2Si2 (0x1) as a Forx>0.4 all experimental techniques are in agreement with each other and suggest a divalent 4f
7 ground state of the Eu ion. Belowx=0.4 the different methods lead to different results: while the lattice parameters and the ME isomer shift suggest an instable behavior of the valence the magnetic susceptibility proves a pure divalent 4f
7 ground state. These differences can be explained by assuming a partial extension of the 4f-shell radius such that the localized character of the 4f-electrons is preserved.Dedicated to B. Mühlschlegel on the occasion of his 60th birthday 相似文献
28.
Benzoxazoles or benzimidazoles can be rapidly and efficiently synthesized from a variety of carboxylic acids with 2-aminophenols or 1,2-phenylenediamines in one simple step, respectively. The use of commercially available PS-PPh3 resin combined with microwave heating delivered a variety of benzoxazoles and benzimidazoles in high yields and purities. 相似文献
29.
A total of fifteen substances were identified through thin-layer chromatography, after mild acid hydrolysis of the chloroform extract from the seeds of Dregea volubilis (L.) BENTH . ex HOOK . Of these fifteen substances, eight (B, D, P, O; U, V, H and T) were isolated in crystalline form. Two of these were identical with the known genins drevogenin B (B) and drevogenin D (D). Drevogenin P (P) and the unknown substance O (probably a genin) were isolated for the first time. U proved to be identical with D -cymarose, V with the biose U1 obtained from Asclepias lilacina, and H with (+)-methyl-pachybioside. T was not investigated (probably a sugar derivative). 相似文献
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Bauer O Guerasimova A Sauer S Thamm S Steinfath M Herwig R Janitz M Lehrach H Radelof U 《Rapid communications in mass spectrometry : RCM》2004,18(16):1821-1829
Peptide nucleic acid (PNA) is a novel class of DNA analogues in which the entire sugar-phosphate backbone is replaced by a pseudopeptide counterpart. Owing to its neutral character and the consequent lack of electrostatic repulsion, PNA exhibits very stable heteroduplex formation with complementary nucleic acid that is essentially ionic strength independent and enables hybridization under minimum salt conditions. This feature as well as its superior ion stability and easy ionization compared to DNA renders PNA very attractive for hybridization-based matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) applications. We have developed an approach to DNA characterization that takes advantage of multiplexed PNA hybridizations analyzed by MALDI-TOFMS. Our motivation was the further development of oligonucleotide fingerprinting, an efficient technique for cDNA and genomic DNA library characterization. Through positive 'charge-tagging' of PNA the efficiency of detection in MALDI-TOFMS was considerably enhanced permitting an unparalleled degree of multiplexing. Results from the simultaneous hybridization of 21 charge-tagged PNA hexamer oligonucleotides showed that genomic DNA and cDNA clones are successfully characterized on the basis of their hybridization profiles. The degree of multiplexing achieved may render a significant increase in throughput and hence efficiency of oligonucleotide fingerprinting possible. 相似文献