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31.
Ohno O Chiba T Todoroki S Yoshimura H Maru N Maekawa K Imagawa H Yamada K Wakamiya A Suenaga K Uemura D 《Chemical communications (Cambridge, England)》2011,47(46):12453-12455
Novel sesquiterpene alkaloids, halichonines A (1), B (2), and C (3), were identified from the marine sponge Halichondria okadai Kadota. By spectroscopic analyses and synthesis, their structures were revealed to include a 6,6-bicyclic ring system and two prenylated amine moieties. In addition, 2 induced apoptosis in HL60 human leukemia cells. 相似文献
32.
Secondary amines react with carbon disulphide to form stable dialkyldithiocarbamates at high pH in aqueous Triton X-100 solution. The formation rates of dimethyl-, diethyl-, di-n-propyl-, diisopropyl-, di-n-butyl- and diisobutyldithiocarbamates and pyrrolidinedithiocarbamate were measured by a stopped-flow spectrophotometric method. The reaction rates were a function of the pH of the solution and depended on the size and structure of the amines. The rate of isoalkylamines was far slower than that of the n-alkyl analogues. Individual concentrations of amines were determined in a mixture of di-n- and diisopropylamine and in a mixture of diiso- and di-n-butylamine. 相似文献
33.
Shuko Yokoyama Toshiyuki Yokoyama Tsutomu Araki Takahisa Hayashi Norihito Suzuki 《Optical Review》1998,5(3):179-184
Frequency of a 532 nm emission line of a diode-laser-pumped Nd:YAG laser is stabilized by lock of the output line to the linear absorption line of iodine molecules. The stabilization method is very simple utilizing the frequency shift caused with an acousto-optic modulator. The laser frequency was stabilized at the zero-crossing point of the second-derivative of the dispersion curve. Instability obtained by the error signal is affected by the phase-characteristics of detectors, which results in 3*10-8. 相似文献
34.
35.
Shinji Fukuhara 《Journal of Number Theory》2006,117(1):87-105
We introduce higher-dimensional Dedekind sums with a complex parameter z, generalizing Zagier's higher-dimensional Dedekind sums. The sums tend to Zagier's higher-dimensional Dedekind sums as z→∞. We show that the sums turn out to be generating functions of higher-dimensional Apostol-Zagier sums which are defined to be hybrids of Apostol's sums and Zagier's sums. We prove reciprocity law for the sums. The new reciprocity law includes reciprocity formulas for both Apostol and Zagier's sums as its special case. Furthermore, as its application we obtain relations between special values of Hurwitz zeta function and Bernoulli numbers, as well as new trigonometric identities. 相似文献
36.
Structure of β-MAPI, a novel proteinase inhibitor produced by Streptomyces nigrescens WT-27, is determined as 1. 相似文献
37.
38.
Yasuhiro Maeda Masaki Yumoto Norihito Saito Takayo Ogawa Kazuo Kurokawa Akihiko Nakano Masafumi Yamashita Satoshi Wada 《Optical Review》2010,17(3):305-308
We have achieved a rapid and random wavelength tuned picosecond pulsed laser and a widely tunable UV-blue picosecond pulsed
laser by using the intracavity second harmonic generation of the laser. The tuning range was from 384 to 434 nm with picosecond
pulse oscillation. In addition, we demonstrated biological imaging using a fluorescent protein excited by the widely tunable
UV-blue picosecond pulsed laser. We found that the laser is suitable for biological imaging using the fluorescent protein
as an excitation light source without damages. 相似文献
39.
The molecular conformation and melting behavior of triblock position isomers H(CH(2))(k)(OCH(2)CH(2))(4)O(CH(2))(12)(-)(k)H (abbreviated as C(k)E(4)C(12)(-)(k)) with k = 6-11 have been studied by infrared spectroscopy and differential scanning calorimetry (DSC), with focus on the effect of the position of an oligo(oxyethylene) block in the molecule. The analysis of infrared spectra has revealed that the stable molecular form changes from a fully planar structure (gamma form) to a planar/helical/planar structure (beta form) with a change of the position of the tetrakis(oxyethylene) block from the center to the end of the molecule. The DSC measurements have shown that the melting points of the gamma-form solid decrease and the melting points of the beta-form solid increase with a shift of the tetrakis(oxyethylene) block toward the terminal of the molecule. The stabilities of the two molecular forms change over between k = 8 and 9. C(8)E(4)C(4) and C(9)E(4)C(3) exhibit contrasting conformational behavior with temperature; when the temperature is increased, the metastable beta form of C(8)E(4)C(4) transforms into the stable gamma form, while the metastable gamma form of C(9)E(4)C(3) transforms into the stable beta form. The metastable gamma form with a planar oligo(oxyethylene) block is a new finding in the present work. The experimental results of the stabilities of molecular forms are explained by the relative stabilities of partial crystal lattices formed by the alkyl and oligo(oxyethylene) blocks. 相似文献
40.
Shinji Fukuhara 《Mathematische Annalen》2010,346(4):769-794
Dedekind symbols are generalizations of the classical Dedekind sums (symbols). There is a natural isomorphism between the
space of Dedekind symbols with Laurent polynomial reciprocity laws and the space of modular forms. We will define a new elliptic
analogue of the Apostol–Dedekind sums. Then we will show that the newly defined sums generate all odd Dedekind symbols with
Laurent polynomial reciprocity laws. Our construction is based on Machide’s result (J Number Theory 128:1060–1073, 2008) on
his elliptic Dedekind–Rademacher sums. As an application of our results, we discover Eisenstein series identities which generalize
certain formulas by Ramanujan (Collected Papers of Srinivasa Ramanujan, pp. 136–162. AMS Chelsea Publishing, Providence, 2000),
van der Pol (Indag Math 13:261–271, 272–284, 1951), Rankin (Proc R Soc Edinburgh Sect A 76:107–117, 1976) and Skoruppa (J
Number Theory 43:68–73, 1993). 相似文献