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1.
Atsuo Kuniba Tomoki Nakanishi Zengo Tsuboi 《Communications in Mathematical Physics》2002,227(1):155-190
We study a class of systems of functional equations closely related to various kinds of integrable statistical and quantum
mechanical models. We call them the finite and infinite $Q$-systems according to the number of functions and equations. The
finite Q-systems appear as the thermal equilibrium conditions (the Sutherland–Wu equation) for certain statistical mechanical systems.
Some infinite Q-systems appear as the relations of the normalized characters of the KR modules of the Yangians and the quantum affine algebras.
We give two types of power series formulae for the unique solution (resp. the unique canonical solution) for a finite (resp.
infinite) Q-system. As an application, we reformulate the Kirillov–Reshetikhin conjecture on the multiplicities formula of the KR modules
in terms of the canonical solutions of Q-systems.
Received: 2 August 2001 / Accepted: 27 December 2001 相似文献
2.
3.
Tertiary structure changes in DNA duplexes, induced by Hoechst 33258 binding, have been examined by the use of atomic force microscopy. Besides minor groove binding, which is an established mode of binding for this drug, Hoechst 33258 has now been found to show another binding mode, which causes an unwinding of the duplex. When the drug concentration is as high as 0.5 microg/ml, the Hoechst 33258 molecule seems to function as a clamp for two DNA chains and forms a condensate. The condensate was found to have a toroidal shape. By surveying more than 100 microscopic images of such condensates formed in I microg/ml drug solution, a mechanism of toroidal condensate formation has been proposed. 相似文献
4.
Rapid method for preparing a beta-glucan-specific sensitive fraction from Limulus (Tachypleus tridentatus) amebocyte lysate 总被引:1,自引:0,他引:1
By separating Limulus amebocyte lysate by cation-exchange chromatography with an SP-Toyopearl 650C column, a fraction insensitive to endotoxin, yet specifically sensitive to beta-glucan, was successfully obtained in the unadsorbed portion. This fraction showed beta-glucan dose-dependent clotting enzyme activity, although no sensitivity to endotoxin. This beta-glucan-dependent reaction showed no interference in the presence of endotoxin, with the fraction also showing sensitivity towards various kinds of beta-glucan, i.e. curdlan, pachyman, laminaran and lichenan. The sensitivity towards curdlan was approximately 10(-10) g/ml. 相似文献
5.
Minoru Isobe Prof. Dr. Masakuni Kurono Dr. Katsunori Tsuboi Dr. Akira Takai Prof. Dr. 《化学:亚洲杂志》2007,2(3):377-385
We have accomplished the synthesis of 13C‐labeled tautomycin at the C18, C19, C21, and C22 positions starting from 100 % [13C]triethylphosphonoacetate for the purpose of elucidating the dynamics and conformation of the C17–C26 moiety. NMR spectroscopy of 13C‐labeled tautomycin revealed strong binding with protein phosphatase type 1 and new features in the 13C NMR spectrum, such as the very small three‐bond coupling constants (2J). 相似文献
6.
Furusho Y Oku T Hasegawa T Tsuboi A Kihara N Takata T 《Chemistry (Weinheim an der Bergstrasse, Germany)》2003,9(12):2895-2903
A dynamic covalent approach to disulfide-containing [2]- and [3]rotaxanes is described. Symmetrical dumbbell-shaped compounds with two secondary ammonium centers and a central located disulfide bond were synthesized as components of rotaxanes. The rotaxanes were synthesized from the dumbbell-shaped compounds and dibenzo-[24]crown-8 (DB24C8) with catalysis by benzenethiol. The yields of isolated rotaxanes reached about 90 % under optimized conditions. A kinetic study on the reaction forming [2]rotaxane 2 a and [3]rotaxane 3 a suggested a plausible reaction mechanism comprising several steps, including 1) initiation, 2) [2]rotaxane formation, and 3) [3]rotaxane formation. The whole reaction was found to be reversible in the presence of thiols, and thermodynamic control over product distribution was thus possible by varying the temperature, solvent, initial ratio of substrates, and concentration. The steric bulk of the end-capping groups had almost no influence on rotaxane yields, but the structure of the thiol was crucial for reaction rates. Amines and phosphines were also effective as catalysts. The structural characterization of the rotaxanes included an X-ray crystallographic study on [3]rotaxane 3 a. 相似文献
7.
Y Inamori M Ogawa H Amino M Tsuboi S Yamaguchi H Tsujibo S Takemura 《Chemical & pharmaceutical bulletin》1990,38(7):2045-2046
The diethylstilbestrol-related compounds 3,3'-dihydroxy-alpha, beta-diethyldiphenylethane (I), diethylstilbestrol (II) and hexestrol (III) showed hypotensive effects on spontaneously hypertensive rats (SHR) and antifungal activities against all Fusarium oxysporum sp. tested. As previously reported, I had strong hypotensive action on normotensive rats at the dose of 10 mg/kg, while II and III showed weak hypotensive effects on these rats at the same dose. In this work, all three compounds also had hypotensive actions on SHR at the same dose. I showed the strongest hypotensive effect (-80.0 +/- 5.0 mmHg, 10 mg/kg, i.v.) on both SHR and normotensive rats. The three compounds also had antifungal activities against five kinds of Fusarium oxysporum sp. tested. Especially, II strongly inhibited the growth of Fusarium oxysporum f. sp. raphani IFO-9972 (minimum inhibitory concentration (MIC): 1.0 micrograms/ml). 相似文献
8.
9.
Dr. Yuichi Kobayashi Yuji Takashima Yuuya Motoyama Yukari Isogawa Kyosuke Katagiri Atsuki Tsuboi Dr. Narihito Ogawa 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(11):3779-3785
The regioselectivity (r.s.) and enantiospecificity (e.s.) of the substitution reactions of secondary propargylic alcohol derivatives using reagents derived from ArMgBr and Cu salts were studied. First, the picolinate, 3-methylpicolinate, and diethylphosphonate derivatives of Ph(CH2)2CH(OH)C≡CTMS were reacted with PhMgBr/CuCN in ratios of 2.5:2.7–2.5:0.25. The use of 2.5:0.25 ratio in THF/DME (6:1) at 0 °C for 1 h afforded the α-substitution product from the phosphate with ≥98 % r.s. and 99 % e.s. CuBr⋅Me2S gave similar selectivity. The reaction system was then applied to phosphates derived from R1CH(OH)C≡CR2 and ArMgBr to obtain synthetically sufficient r.s. and e.s. values with R2=TMS, Ph, whereas iPr was borderline in terms of size as an R1 substituent. The presence of a substituent at the o-position of Ar marginally affected the selectivity. We also found that the use of PhMgBr/Cu(acac)2 in a 2:1 ratio in THF produced the γ-substitution products (allenes) with high r.s. and e.s. 相似文献
10.
Absorption and photoluminescence (PL) spectra, PL quantum efficiency, and PL lifetime have been investigated on bis(8-hydroxyquinoline)
zinc (Znq2) and magnesium (Mgq2) in solutions and powder. Znq2 and Mgq2 have the lowest-energy absorption band at 376 and 396 nm in acetonitrile solution, respectively, and emission band with peak
at 555 and 480 nm. The PL quantum efficiency is 0.03 and 0.45 for Znq2 and Mgq2 in the solution, respectively, while 0.45 and 0.36 in powder. Unlike the case of powders, two PL lifetimes are obtained in
solutions. The longer lifetime is attributed to molecule having interaction with its neighboring molecule, while the shorter
one to the isolated single molecule. 相似文献