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71.
Kazunori Matsui Takayuki Kaneko Yasunori Yaginuma Masaru Ryu 《Journal of Sol-Gel Science and Technology》1997,9(3):273-277
A spin probe TEMPOL (4-hydroxy-2,2,6,6-tetramethylpiperidinyl-1-oxy) was dissolved in a tetraethyl orthosilicate sol-gel reaction
system and measured by electron spin resonance spectroscopy at 295 K. The nitrogen hyperfine coupling constant was from 1.64–1.66
mT in the sol-gel solutions. The values were sensitive to the ethanol-to-water ratio of the solutions. The hyperfine coupling
constant in the xerogels was 1.70 mT, which was almost the same as that in water, indicating that the probe molecules were
trapped in silica pores with water adsorbed on the silica surfaces. The motion of TEMPOL in the xerogels was considerably
slower than in the sol-gel solutions. The local viscosity estimated was from 70–90 cP. The ESR spectra of TEMPOL were altered
during the sol-gel process, indicating that adsorbed water on the silicas surfaces has an important role for trapping organic
molecules in sol-gel glasses. 相似文献
72.
73.
In the presence of a catalytic amount of ammonium chiral borate salt, asymmetric Friedel-Crafts alkylation of indoles with α,β-disubstituted enals proceeded to give the corresponding 1,4-addition products with moderate enantioselectivities. 相似文献
74.
Chul-Joong Kim Hyeon-Yeol Ryu Somin Lee Han-Joo Lee Yoon-Soek Chun Jong-Kyu Kim Chang-Yeon Yu Bimal Kumar Ghimire Jae-Geun Lee 《Molecules (Basel, Switzerland)》2021,26(10)
Wild ginseng has better pharmacological effects than cultivated ginseng. However, its industrialization is limited by the inability to grow wild ginseng on a large scale. Herein, we demonstrate how to optimize ginseng production through cultivation, and how to enhance the concentrations of specific ginsenosides through fermentation. In the study, we also evaluated the ability of fermented cultured wild ginseng root extract (HLJG0701-β) to inhibit acetylcholinesterase (AChE), as well as its neuroprotective effects and antioxidant activity. In in vitro tests, HLJG0701-β inhibited AChE activity and exerted neuroprotective and antioxidant effects (showing increased catalyst activity but decreased reactive oxygen species concentration). In in vivo tests, after HLJG0701-β was orally administered at doses of 0, 125, 250, and 500 mg/kg in an animal model of memory impairment, behavioral evaluation (Morris water maze test and Y-maze task test) was performed. The levels of AChE, acetylcholine (ACh), blood catalase (CAT), and malondialdehyde (MDA) in brain tissues were measured. The results showed that HLJG0701-β produced the best results at a dose of 250 mg/kg or more. The neuroprotective mechanism of HLJG0701-β was determined to involve the inhibition of AChE activity and a decrease in oxidative stress. In summary, both in vitro and in vivo tests confirmed that HJG0701-β administration can lead to memory improvement. 相似文献
75.
Min Gyu Jeong Kai Zhou Soyeon Park HyeongJeon An Yonghoon Kwon Yeonho Chang Do-Hyeon Kim Sung Ho Ryu 《Experimental & molecular medicine》2021,53(2):291
Various repertoires of membrane protein interactions determine cellular responses to diverse environments around cells dynamically in space and time. Current assays, however, have limitations in unraveling these interactions in the physiological states in a living cell due to the lack of capability to probe the transient nature of these interactions on the crowded membrane. Here, we present a simple and robust assay that enables the investigation of transient protein interactions in living cells by using the single-molecule diffusional mobility shift assay (smDIMSA). Utilizing smDIMSA, we uncovered the interaction profile of EGFR with various membrane proteins and demonstrated the promiscuity of these interactions depending on the cancer cell line. The transient interaction profile obtained by smDIMSA will provide critical information to comprehend the crosstalk among various receptors on the plasma membrane.Subject terms: Fluorescence imaging, Super-resolution microscopy, Single-molecule biophysics 相似文献
76.
Byeong Su Gu Dr. Soumen Dutta Yu-Rim Hong Dr. Odongo Francis Ngome Okello Hyeonae Im Seungil Ahn Prof. Dr. Si-Young Choi Prof. Dr. Jeong Woo Han Prof. Dr. Sunmin Ryu Prof. Dr. In Su Lee 《Angewandte Chemie (International ed. in English)》2023,62(31):e202307816
The performance of nanocrystal (NC) catalysts could be maximized by introducing rationally designed heterointerfaces formed by the facet- and spatio-specific modification with other materials of desired size and thickness. However, such heterointerfaces are limited in scope and synthetically challenging. Herein, we applied a wet chemistry method to tunably deposit Pd and Ni on the available surfaces of porous 2D−Pt nanodendrites (NDs). Using 2D silica nanoreactors to house the 2D-PtND, an 0.5-nm-thick epitaxial Pd or Ni layer ( e - Pd or e -Ni ) was exclusively formed on the flat {110} surface of 2D−Pt, while a non-epitaxial Pd or Ni layer ( n - Pd or n -Ni ) was typically deposited at the {111/100} edge in absence of nanoreactor. Notably, these differently located Pd/Pt and Ni/Pt heterointerfaces experienced distinct electronic effect to influence unequally in electrocatalytic synergy for hydrogen evolution reaction (HER). For instance, an enhanced H2 generation on the Pt{110} facet with 2D-2D interfaced e -Pd deposition and faster water dissociation on the edge-located n -Ni overpowered their facet-located counterparts in respective HER catalysis. Therefore, a feasible assembling of the valuable heterointerfaces in the optimal 2D n -Ni/e-Pd/Pt catalyst overcame the sluggish alkaline HER kinetics, with a catalytic activity 7.9 times higher than that of commercial Pt/C. 相似文献
77.
Ryu Sasaki 《Czechoslovak Journal of Physics》2003,53(11):1111-1117
The relationship (resemblance and/or contrast) between quantum and classical integrability in Ruijsenaars-Schneider (R-S) and Calogero-Moser systems is addressed. The classical Calogero and Sutherland systems (based on any root system) at equilibrium have many remarkable properties; for example, the minimum energies, frequencies of small oscillations and the eigenvalues of Lax pair matrices at equilibrium are all integer valued. These are related to the energy eigenvalues of the quantum Calogero and Sutherland systems. Similar features and results hold for the R-S type of integrable systems based on the classical root systems. 相似文献
78.
Koike R Motoyoshiya J Takaguchi Y Aoyama H 《Chemical communications (Cambridge, England)》2003,(6):794-795
A kinetic study of peroxyoxalate chemiluminescence reactions employing 2,4,6-trichlorophenyl N-aryl-N-tosyloxamates supports the 1,2-dioxetanones still bearing the eliminating group as the key intermediates that interact with the fluorophores rather than 1,2-dioxetanedione. 相似文献
79.
Kyukwan Zong Seung Il Shin Dong Ju Jeon Jung No Lee Eung K. Ryu 《Journal of heterocyclic chemistry》2000,37(1):75-78
3‐Aryl‐4‐methoxycarbonylisoxazoles were prepared from the reaction of a variety of substituted benzonitrile oxides with methyl 3‐(p‐nitrobenzoyloxy)acrylate in moderate to good yields. 相似文献
80.
Yanghyun?ByunEmail author Dosang?Joe Jeong?Seog Ryu Seunghun?Yi 《Mathematische Zeitschrift》2003,245(3):435-453
We investigate the possibility of a Lagrangian Whitney trick, a process to remove a pair of intersection points of a self-transverse Lagrangian immersion by a homotopy through Lagrangian immersions. There is a model for which a Lagrangian Whitney trick with compact support works assuming the model satisfies an area-capacity condition. Reduction of more general cases to the model, not necessarily fulfilling the area-capacity requirement, is possible if the given pair of double points admits a suitable symplectic disc and a certain Maslov-Viterbo index is 1. We look into an example to see the actualities of the Maslov-Viterbo index and the area-capacity conditions.
The authors would like to thank the anonymous referee whose suggestions improved remarkably the exposition of the paper. This work was supported by the grant no.R01-2000-000-00004-0 from Korea Science & Engineering Foundation. 相似文献