• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.28-28
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• 2003

To discover new drugs more quickly and more efficiently, pharmaceutical companies and biotechnology firms are increasingly turning to the genomics and the structural proteomics technologies. Structural-proteomics can provide a foundation for this through the determination and analysis for protein structure on a genomics scale. Among many structures determined by CGI, we will present with the representative examples drawn from our work on novel structures or complex structures of the disease-related proteins. The alpha subunit of Hypoxia-inducible factor (HIF) is targeted for degradation under normoxic conditions by an ubiquitin-ligase complex that recognizes a hydroxylated proline residue in HIF, Hydroxylation is catalysed by HIF prolyl 4-hydroxylases (HIFPH) which are Fe(II) and 2-oxoglutarate (2-OG) dependent oxygenases. Here, we discuss the first crystal structure of the catalytic domain of HIFPH in complexes, with the Fe(II)/2-OG at 1.8 ${\AA}$. These structures suggest that the L1 region (residues 236-253), which is also conserved in mammals, form a ‘lid’ that closes over the active site. The structural and mutagenesis analyses allow us to provide a focus for understanding cellular responses to hypoxia and a target for the therapeutic manipulation.

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.818-826
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• 1995

The present study was undertaken to investigate the crystal growth onto enamel mineral and synthetic hydroxyapatite seeds in media resembling the enamel fluid composition. Effects of fluoride at low concentrations on the precipitation were also examined in a benchtop crystal growth model adopting a miniaturized reaction column. X-ray diffraction and Fourier transform infrared spectroscopy(FTIR), as well as chemical analyses, were employed for characterization of both seed materials before and after experimentation. Remarkable findings were that (1) both biological and synthetic seeds at the same total surface areas yielded rather similar precipitation rates at all levels of fluoride concentration in solution and (2) the precipitation rate was accelerated in a manner depending on fluoride concentrations in media. FTIR differential analysis disclosed that the precipitating phase was characterized as poorly crystallized apatite, which incorporated subtle carbonate. Most of the fluoride ions in soution were readily incorporated into crystals. The overall results support the view that the seeded crystal growth model is of value to gain insight into the mechanism of enamel crystal growth under fluoride regimens.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.85-92
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• 2007

This paper presents a design optimization of a new Advanced Active Blade Twist (AATR-II) blade incorporating single crystal Macro Fiber Composites (MFC) and conducts vibratory loads reduction analysis using an obtained optimal blade configuration. Due to the high actuation performance of the single crystal MFC, the AATR blade may reduce the helicopter vibration more efficiently even with a lower input-voltage as compared with the previous ATR blades. The design optimization provides the optimal cross-sectional configuration to maximize the tip twist actuation when a certain input-voltage is given. In order to maintain the properties of the original ATR blade, various constraints and bounds are considered for the design variables selected. After the design optimization is completed successfully, vibratory load reduction analysis of the optimized AATR-II blade in forward flight condition is conducted. The numerical result shows that the hub vibratory loads are reduced significantly although 20% input-voltage of the original ATR blade is used.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.34 no.3
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• pp.98-102
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• 2024

In this study, the crystal characteristics of commercial AlN powders with sizes of "㎛" and "nm" were selected through XRD analysis and then sintered at different temperatures through an induction heating furnace to investigate the optimized sintering temperature and physical properties. The sintering temperature was 1,500, 1,700, and 1,900℃ in the N₂ atmosphere, and the optimized sintering temperature conditions were established for the sintered AlN pellets using SEM, XRD, and Raman analysis. Additionally, impedance analysis was performed to confirm the electrical properties of the optimized AlN pellet without sintering additives.

• Analytical Science and Technology
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• v.18 no.5
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• pp.381-385
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• 2005

The title compound, $\{H_2NCH_2CH_2NH_2CH_2CH_2\}\{Cu(H_2O)_6\}(SO_4)_2$, I, has been synthesized under solvo/hydrothermal conditions and their crystal structure analyzed by X-ray single crystallography. Compound I crystallizes in the monoclinic system, $P2_1/n$ space group with a = 6.852(1), b = 10.160(2), $c=11.893(1){\AA}$, ${\beta}=92.928(8)^{\circ}$, $V=826.9(2){\AA}^3$, Z = 2, $D_x=1.815g/cm^3$, $R_1=0.031$ and ${\omega}R_2=0.084$. The crystal structure of the piperazine templated Cu(II)-sulfate demonstrate zero-dimensional compound constituted by doubly protonated piperazine cations, hexahydrated copper cations and sulfate anions. The central Cu atom has a elongated octahedral coordination geometry. The crystal structure is stabilized by three-dimensional networks of the intermolecular $O_{water}-H{\cdots}O_{sulfate}$ and $N_{pip}-H{\cdots}O_{sulfate}$ hydrogen bonds between the water molecules and sulfate anions and protonated piperazine cations. Based on the results of thermal analysis, the thermal decomposition reaction of compound I was analyzed to have three distinctive stages.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.2
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• pp.84-88
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• 2021

The change of the photoluminescence properties of La2O3-CaF2-Al2O3-SiO2 glass-ceramics doped with rare earth material, that is used as laser and optical sensors, was analyzed according to heat treatment temperature. The heat treatment conditions for fabricating glass-ceramics were obtained through non-isothermal thermal analysis, and X-ray diffraction analysis was performed to determine the degree of crystal growth and kinds of crystal phases generated according to the heat treatment temperature. Using Scherrer's equation, it was predicted that crystals with a size of 25~40 nm would be generated inside the glass-ceramics. Photoluminescence (PL) analysis showed that the specimens heat-treated at 660℃ to 670℃ for 1 hour had the highest PL intensity. Also, from the CIE color coordinate analysis, all glass-ceramics specimens emitted red-orange light regardless of the heat treatment condition.

• Journal of Pharmaceutical Investigation
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• v.39 no.3
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• pp.173-176
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• 2009

A new crystal form of valsartan dipotassium was isolated by recrystallization using the one-pot method. The new crystal form was identified as a monohydrate form ($C_{24}H_{27}N_5O_3K_2.H_2O$) and characterized by diffential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and X-ray powder diffractometry (PXRD). The new crystal data demonstrated to be clearly different from those known for the tetrahydrate form ($C_{24}H_{27}N_5O_3K_2.4H_2O$). It was observed that the monohydrate of vasartan dipotassium salt was completely dissolved in water within 1 hour and its dissolution rate was much faster than anhydrous free form of valsartan.

• Journal of Integrative Natural Science
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• v.8 no.4
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• pp.250-257
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• 2015

The crystal structure of the potential active 3-(4-ethylphenyl)-3H-chromeno[4,3-c]isoxazole-3a(4H)-carbonitrile ($C_{19}H_{16}N_2O_2$) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the monoclinic space group $P2_1/c$ with unit cell dimension a=6.6869 (8) ${\AA}$, b=15.8326 (19) ${\AA}$ and c= 15.237 (2) ${\AA}$ [${\alpha}=90^{\circ}$, ${\beta}=100.663^{\circ}$ and ${\gamma}=90^{\circ}$]. In the structure chromene, isoxazole and carboxylate are almost coplanar each other. All geometrical parameters revelled that chromene ring of pyran ring adopt sofa conformation. The crystal packing is stabilized by intermolecular C-H...N and C-H...O hydrogen bond interaction.

• Journal of Integrative Natural Science
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• v.8 no.3
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• pp.184-191
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• 2015

The crystal structure of the potential active methyl-3-phenyl-3H-chromeno[4,3-c]isoxazole-3a(4H)-carboxylate ($C_{18}H_{15}NO_4$) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the orthorombic space group $P2_12_12_1$ with unit cell dimension $a=9.8320(17){\AA}$, $b=9.9890(18){\AA}$ and $c=15.588(3){\AA}$ [${\alpha}=90^{\circ}$, ${\beta}=90^{\circ}$ and ${\gamma}=90^{\circ}$]. In the structure chromene, isoxazole and carboxylate are almost coplanar each other. All geometrical parameters revelled that chromene ring of pyran ring adopt sofa conformation. The crystal packing is stabilized by intermolecular C-H...O and C-H...N hydrogen bond interaction.

• Journal of Integrative Natural Science
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• v.9 no.4
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• pp.255-260
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• 2016

The crystal structure of the saliciline derivatives N,N'-bis(3-chloro-2-methylsalicylidene)-1,4-butanediamine ($C_{20}H_{22}Cl_2N_2O_2$) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the triclinic space group $P{\bar{i}}$ with unit cell dimension $a=4.6085(3){\AA}$, $b=5.9747(3){\AA}$ and $c=5.9747(3){\AA}$ [${\alpha}=83.889(4)^{\circ}$, ${\beta}=86.744(5)^{\circ}$ and ${\gamma}=82.085(5)^{\circ}$]. The title compound is essentially planar conformation. The compound lies across a crystallographic inversion centre and adopts E configurations with respect to the C-N bonds. The crystal packing of the molecules of compound is stabilized through weak O-H...N intra molecular interactions