• Journal of the Korean Mathematical Society
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• v.60 no.1
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• pp.33-69
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• 2023

Let α ∈ (0, ∞), p ∈ (0, ∞) and q(·) : ℝⁿ → [1, ∞) satisfy the globally log-Hölder continuity condition. We introduce the weak Herz-type Hardy spaces with variable exponents via the radial grand maximal operator and to give its maximal characterizations, we establish a version of the boundedness of the Hardy-Littlewood maximal operator M and the Fefferman-Stein vector-valued inequality on the weak Herz spaces with variable exponents. We also obtain the atomic and the molecular decompositions of the weak Herz-type Hardy spaces with variable exponents. As an application of the atomic decomposition we provide various equivalent characterizations of our spaces by means of the Lusin area function, the Littlewood-Paley g-function and the Littlewood-Paley $g^*_{\lambda}$-function.

• The KIPS Transactions:PartA
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• v.19A no.2
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• pp.73-76
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• 2012

In this paper, we propose an efficient method to extract surface atoms from a protein molecule. Surface atoms are defined as a set of atoms who can contact given probe solvent $P$, where $P$ does not collide with the molecule. The atoms contained in the molecule are represented as a set of spheres with van der Waals radii. The probe solvent also is represented as a sphere. We propose a method to extract the surface atoms by computing the offset surface of the molecule with respect to the radius of $P$. For efficient computation of the offset surface of a molecule, a voxel map is constructed for the offset surfaces of the spheres. Based on GPU (graphic processor unit) acceleration, a data parallel algorithm is used to extract the surface atoms in 42.87 milliseconds for the molecule containing up to 6,412 atoms.

• The Korean Journal of Pesticide Science
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• v.8 no.4
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• pp.265-271
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• 2004

Hydrolytic reactivities of N-phenylphthalimid herbicide flumioxazine (S) were disccused using molecular orbital (MO) theoretical method. It is revealed that below pH 5.0, the protonation $(SH^+)$ to carbonyl oxygens atom $(O_{21})$ of 1,2-dicarboximino group by general acid catalysis $(k_A)$ with hydronium ion $(H_3O^+)$ proceeds via charge controled reaction. Whereas, the specific base catalysis $(k_{OH})$ with hydroxide anion via orbital controled reaction occurs above pH 8.0. We may concluded that in the range of pH $5.0\sim8.0$, the hydrolysis proceeds through nucleophilic addition elimination $(Ad_{N-E})$ reaction, these two reactions occur competitively.

• Journal of the Korean Chemical Society
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• v.47 no.1
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• pp.26-30
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• 2003

The dinuclear $Ag_2[Phen]_2[S_2P(OPr)_2]_2$(phen=1,10-phenanthroline; Pr=propyl), was prepared by the reaction of bis(dipropyldithiophosphato) silver(I) complex with 1,10-phenanthroline ligand, and its structure was determined by X-ray crystallography. The two dipropyldithiophosphato ligands each bridge two silver atoms to form an eight-membered $Ag_2S_4P_2$ ring, while the 1,10-phenanthroline molecule coordinates to a silver atom to complete the local tetrahedral geometry for the metal ion. The Ag-S bond distances are 2.559(1) and 2.567(1)${\AA}$, and the Ag-N bond distances are 2.366(3) and 2.471(3)${\AA}$.

• Bulletin of the Korean Chemical Society
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• v.35 no.9
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• pp.2694-2698
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• 2014

A multisegmented polystyrene (PS) with pH-cleavable ester and carbamate linkages was successfully synthesized by a combination of atom transfer radical polymerization (ATRP) and Cu(I)-catalyzed 1,3-dipolar cycloaddition of azide and alkynes (click chemistry). ATRP was employed to synthesize polystyrene from hydroxyl-terminated initiator using CuBr/N,N,N',N",N"-pentamethyldiethylenetriamine (PMDETA) as the catalyst. The reaction of the resulting PS with sodium azide yielded the azido-terminated polymer. The hydroxyl group in the other end of the polymer was reacted with 4-nitrophenyl chloroformate (NPC), followed by reaction with propargylamine to produce an alkyne end group with a carbamate linkage. The PS with an alkyne group in one end and an azide group in the other end was then self-coupled in the presence of CuBr/2,2'-bipyridyl (bpy) in DMF to yield a desired multisegmented PS. Molecular weight and molecular weight distribution of the self-coupled polymer increased with time, as in the typical step-growth-type polymerization processes. Finally, we demonstrated that the ester and carbamate linkages of the multisegmented PS were hydrolyzed in the presence of HCl to yield individual PS chains.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.5221-5231
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• 2010

The complex formation from Ni(II) ion and 2-(2-Hydroxyethylamino)-2-(hydroxymethyl)-1,3-propanediol(Monotris) in aqueous solution at $25^{\circ}C$ and at ionic strength of 0.10M has been studied potentiometrically. In the Monotris(L) comlex $NiL^{2+}$, hydroxyl oxygen atom as well as the amine nitrogen of the ligand are coordinated to the Ni(II) ion.. The complex $NiL^{2+}$ undergoes further dissociation as the pH is increased forming triply deprotonated dinuclear complex $Ni_2L_2H_{-3}^+$.

• Journal of Integrative Natural Science
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• v.8 no.3
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• pp.192-203
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• 2015

In view of the growing medicinal importance of pyrazole and its derivatives, the single crystal X-ray diffraction study was carried out for the potential active 2-Benzyl-3-[3-(4-bromo-phenyl)-1-phenyl-1H-pyrazol-4yl]-4,6-dioxo-5-phenyl-octahydro-pyrrolo[3,4-C]pyrrole-1-carboxylic acid ethyl ester ($C_{37}H_{31}BrN_4O_4$, H2O). In the title compound are two molecules exist in the asymmetric unit. It crystallizes in the monoclinic space group $P{\hat{i}}$ with unit cell dimension $a=13.361(18){\AA}$, $b=13.424(17){\AA}$ and $c=21.649(2){\AA}$ [${\alpha}=80.745(9)^{\circ}$, ${\beta}=79.770(10)^{\circ}$ and ${\gamma}=60.788(6)^{\circ}$]. The pyrazole ring adopts planar conformation. The sum of the bond angles at nitrogen atom of the pyrazole ring indicates the $Sp^2$ hybridized state. The crystal structure is stabilized by intramolecular C-H...O hydrogen bond interaction.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.6
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• pp.772-781
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• 2012

This study was conducted to examine the development of a new anti-inflammatory substance with potent anti-inflammatory activities that was derived from the Platycodi Radix butanol fraction. To accomplish this, the chemical structures and anti-inflammatory activities of the components were elucidated. Upon column chromatography of the tertiary subfraction, fractions 8-4-1 and 8-4-2 were identified as platycodin D and D3, respectively, following recrystallization, based on melting point (MP), infrared (IR), and positive fast atom bombardment (FAB)-mass and nuclear magnetic resonance (NMR) spectral data. Platycodin D and D3 exhibited strong anti-inflammatory activities in rats when administerd at oral doses of 12 mg/kg and 36 mg/kg, p.o., respectively. Platycodin D and D3 induced inhibitory effects on capillary vascular permeability in rats at oral doses of 16 mg/kg and 24 mg/kg, p.o., respectively, and potent inhibition of leukocyte emigration in a carboxymethyl cellulose (CMC)-pouch when administered at doses of 3 mg/rat and 7 mg/rat, s.c., respectively. These results verified the high antiinflammatory potency of the platycodin D and D3 components in Platycodi Radix.

• Bulletin of the Korean Chemical Society
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• v.23 no.12
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• pp.1778-1784
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• 2002

Novel membrane lipids containing the unusual very long chain fatty $acid{\alpha}{\omega}-1316-dimethyloctacosanedioate$, dimethyl. Ester (DME C30) was isolated and purified from thermophilic anaerobic eubacterium, Thermoanaerobacter ethanolicus. Structures of the lipids containing the bifunctional fatty acyl components were proposed by various analyses such as $^1H,\;^{13}C,\;^{31}P$ nuclear magnetic resonance (NMR), Fourier transform infrared(FTIR) spectroscopy, gas chromatography/mass spectrometry (GC/MS) and fast atom bombardment mass spectrometry (FAB/MS). Combined with the GC/MS, $^1H,\;and\;^{13}C$NMR data, we confirmed that the head groups of the lipids contained the glycerol and/or glucosamine molecules. $^{31}P$ NMR spectrum also showed that the lipids contained phosphate in a phosphodiester linkage. The proposed structures of these novel lipid components were the ones in which two head groups were linked by the membrane spanning fatty acyl component(DME C30)and regular chain fatty acids on glycerol moiety of each head group.

• Bulletin of the Korean Chemical Society
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• v.25 no.12
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• pp.1779-1783
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• 2004

In the present study, we carried out comparative research on the anthraquinones Raman spectrum and on the anthraquinones derivative 1,4-diamino-anthraquinone focusing on change in its intermediate in terms of pH and change in the substituent. WE use the SERS method and employ a silver sol prepared by Creighton et al.'s method. From the analysis of the UV spectrum of the mixture solution of 1,4-diamino-anthraquinone and silver sol, we could see that the 1,4-diamino-anthraquinone physically adsorbs silver sol. In terms of the adsorbing orientation, the adsorption of the nitrogen atom in the amino group is perpendicular to the surface of silver sol according to the surface selection rule. From the structure of the 1,4-diamino-anthraquinone intermediate according to the change of pH, we could see that the C=O bond is strengthened in the acidic state and weakened in the neutral and the alkaline state because of the resonance effect of the amines.