• Bulletin of the Korean Chemical Society
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• v.15 no.6
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• pp.460-465
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• 1994

New silicon-monosubstituted (${\eta}^4$-2,3,4,5-tetraphenyl-l-silacyclopentadiene)transi tion metal complexes are described. (7-Alkyl-7-silanorbornadienyl)MLn(Alkyl=Methyl: MLn=CpRu$(CO)_2$: Alkyl=Methyl: MLn=CpNi(CO): Alkyl=Ethyl: MLn=CpNi(CO)) complexes were prepared from the corresponding silole-transition metal complexes with dimethylacetylenedicarboxylate. Cycloaddition products were obtained with 2,3-dimethyl-1,3-butadiene, 2,3-butanedione, and 1,4-benzoquinone through the ruthenium-substituted silylene. We have determined the crystal structure of (1-methyl-2,3,4,5-tetraphenyl-l-silacyclopentadien yl)cyclopentadienyldicarbonylruthenium by using graphite monochromated Mo-Ka radiation. The compound was crystallized in the monoclinic space group $P2_{1/c}$ with a = 9.838(l), b = 15.972(3), c = 18.327(3) ${\AA}$, and ${\beta}= 94.28(l)^{circ}$. The ruthenium moiety CpRu$(CO)_2$ on silicon is in an axial position.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.285-286
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• 2012

We combine data from two all-sky surveys, the Swift/Burst Alert Telescope 22 Month Source Catalog and the AKARI Point Source Catalogue, in order to study the connection between the hard X-ray (> 10 keV) and infrared (IR) properties of local active galactic nuclei (AGN). We find two photometric diagnostics are useful for source classification: one is the X-ray luminosity vs. IR color diagram, in which type 1 radio-loud AGN are well isolated from other AGN. The second one uses the X-ray vs. IR color-color diagram as a redshift-independent indicator for identifying Compton-thick (CT) AGN. Importantly, CT AGN and starburst galaxies in composite systems can also be separated in this plane based upon their hard X-ray fluxes and dust temperatures. This diagram may be useful as a new indicator to classify objects in new surveys such as with WISE and NuSTAR.

• Journal of The Korean Astronomical Society
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• v.49 no.6
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• pp.255-259
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• 2016

We estimate the fractal dimension of the ${\rho}$ Ophiuchus Molecular Cloud Complex, associated with star forming regions. We selected a cube (${\upsilon}$, l, b) database, obtained with J = 1-0 transition lines of $^{12}CO$ and $^{13}CO$ at a resolution of 22" using a multibeam receiver system on the 14-m telescope of the Five College Radio Astronomy Observatory. Using a code developed within IRAF, we identified slice-clouds with two threshold temperatures to estimate the fractal dimension. With threshold temperatures of 2.25 K ($3{\sigma}$) and 3.75 K ($5{\sigma}$), the fractal dimension of the target cloud is estimated to be D = 1.52-1.54, where $P{\propto}A^{D/2}$, which is larger than previous results. We suggest that the sampling rate (spatial resolution) of observed data must be an important parameter when estimating the fractal dimension, and that narrower or wider dispersion around an arbitrary fit line and the intercepts at NP = 100 should be checked whether they relate to firms noise level or characteristic structure of the target cloud. This issue could be investigated by analysing several high resolution databases with different quality (low or moderate sensitivity).

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.55.2-56
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• 2016

The spin states of asteroids is regarded as an important clue to understand not only the physical property of an individual object but also the dynamical evolution of the of the population as a whole. Single asteroids can be broadly classified into two separate groups according to their rotational states; Principal Axis (PA) and Non-Principal Axis (NPA) rotators. To date, lightcurve observations have been carried out mostly for PA asteroids. However, discovery of NPA objects has recently been increased due to new observing techniques, and this is the reason why rotational properties of NPA rotators became an issue. As a DEEP-South pilot study for NPA, we selected two targets, 5247 Krolv (1982 UP6) and 14764 Kilauea (7072 P-L) considering their Principal Axis Rotation (PAR) code and visibility. Observations were made between Jan. and Feb. 2016 for 17 nights employing Korea Microlensing Telescope Network (KMTNet) 1.6 m telescopes installed at SSO and SAAO using DEEP-South TO (Target of Opportunity) mode. To obtain lightcurves, we conducted time-series photometry using Johnson-Cousins R-filter. Multi-band photometry was also made with BVRI filters at the same time, for taxonomy. Their preliminary lightcurves and approximate mineralogy will be presented.

• Korean Journal of Crystallography
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• v.11 no.1
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• pp.42-45
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• 2000

The complex [Zn(L)Cl](H₂O)(ClO₄) (1) (L=3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,O/sup 1.18/,O/sup 7.12/]docosane) has been prepared and characterized by X-ray crystallography. 1 crystallizes in the monoclinic space group P2₁/c, with a=8.883(1), b=19.319(9), c=15.124(2)Å, β=101.65(1)°, V=2542.0(13) ų, Z=4, R₁(wR₂) for 4457 observed reflections of [I>2σ(I)] was 0.0640(0.1557). The coordination geometry around the zinc is a distorted square-pyramid with four nitrogen atoms of the macrocycle occupying the basal sites(Zn-N/sub av/=2.131(2)Å) and a chloride atom at the axial position with the Zn-Cl distance of 2.315(2)Å.

• Korean Journal of Crystallography
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• v.11 no.3
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• pp.133-136
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• 2000

The molecular structure of [Cd(L)Cl]Cl·2H₂O(1)(L=3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0/sup 1.18/,0/sup 7.12/]docosane) has been determined by X-ray diffraction. Crystallographic dta for 1: triclinic space group P1, a=9.671(1), b=10.784(1), c=12.679(2)Å, α=112.31(1), β=99.49(1), γ=93.95(1)°, V=1230.6(3)ų, Z=2, R=0.0779. The coordination of the cadmium atom is a distorted square-pyramid with four secondary amines of the macrocycle occupying the basal sites (Cd-N/sub av/=2.300(3)Å) and a terminal chlorine atom at the axial position with a Cd-Cl(1) distance of 2.463(2)Å.

• Journal of applied mathematics & informatics
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• v.23 no.1_2
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• pp.321-327
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• 2007

We say that a triangle ${\Delta}$ tiles the polygon ${\rho}\;if\;{\rho}$ can be decomposed into finitely many non-overlapping triangles similar to ${\Delta}$. Let ${\rho}$ be a parallelogram with angles ${\delta}\;and\;{\pi}-{\delta}\;(0<{\delta}{\leq}{\pi}/2)$ and let ${\Delta}$ be a triangle with angles ${\alpha};{\beta},\;{\gamma}\;({\alpha}{\leq}{\beta}{\leq}{\gamma})$. We prove that if ${\Delta}$ tiles ${\rho}$ then either ${\delta}{\in}\;({\alpha},\;{\beta},\;{\gamma},\;{\pi}-{\gamma},\;{\pi}-2{\gamma})\;or\;dimL_{\rho}=dimL_{{\Delta}}$. We also prove that for every parallelogram P, and for every integer n $(where\;n{\geq}2,\;n{\neq}3)$ there is a triangle ${\Delta}$ so that n similar copies of ${\Delta}\;tile\;{\rho}$.

• Restorative Dentistry and Endodontics
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• v.17 no.1
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• pp.55-68
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• 1992

Periapical lesions are developed as a result of inflammatory response to irritants from root canal system. Clinicians remove these irritants from root canal system and seal the root canal space to induce healing of the periapical lesions. Immunopathologic responses may play an important role in development and progression of periapical lesions and periapical lesions contain immunocompetent cells. The purposes of the present study were to analys and to compare the distribution of the immunocompetent cells in the human periapical lesions according to the stage of endodontic treatment using indirect immunoperoxdase technique. Obtained 94 human periapical lesions were devided into four groups: Group 1 : no endodontic treatment(28 samples) Group 2 : root canal enlarged and irrigated(28 samples) Group 3 : root canal filled(29 samples) Group 4: unknown(9 samples) Monoclonal antibodies to examine target cells were UCHL-1 for T lymphocytes(1 : 200, Dakopatt, Denmark), L26 for B lymphocytes(1 : 200, Dakopatt, Denmark), OPD4 for helper T lymphocytes(l : 200, Dakopatt, Denmark) and alpha-1-antichymotrypsin for macrophages(l : 2000, Dakopatt, Denmark). The following results were obtained : 1. All the periapical lesions studied were infiltrated by T lymphocytes, plasma cells, B lymphocytes, and macrophages. T lymphocytes were more infiltrated than B lymphocytes, and B lymphocytes and macrophages were less infiltrated than T lymphocytes and plasma cells(P<0.05 : Oneway ANOVA test). 2. In untreated group and canal irrigated and enlarged group of all the periapical lesions, helper T lymphocytes were predominently infiltrated(P>0.05 : Oneway ANOVA test). 3. In canal filled groups of all lesions except periapical cyst, plasma cells were predominently infiltrated. But, in canal filled group of periapical cyst, helper T lymphocytes were the predominent cells(P>0.05 : Oneway ANOVA test). The above results shows that the immunologic responses play important role in pathogenesis of periapical lesions and the immunologic response involved undergoes certain changes after endodontic therapy.

• Korean Journal of Crystallography
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• v.6 no.2
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• pp.80-87
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• 1995

The structure of Tetrapropionyloxycalix[4]arene(C40H40O8) has been studied by X-ray diffraction method. The crystal is monoclinic a=13.921(3), b=13.552(2), c=19.840(5)Å, β=110.38(2)°, Z=4 T=297K, Dc=1.23gcm-3, F(000)=1376, Systematic absences : hkl none, h0l : h+l=2n, 0k0: k=2n define space group P21/n. The structure was solved by direct method and refined by full-matrix least-squares methods to final R of 0.06 for 2514 observed reflections. The macrocycle exists in partial cone conformation. Three propionyl groups direct toward the exterior of the macrocycle cavity.

• Biodesign
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• v.5 no.4
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• pp.136-140
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• 2017

Lam6 is a member of sterol-specific ${\underline{l}ipid$ transfer proteins ${\underline{a}}nchored$ at ${\underline{m}ebrane$ contact sites (LAMs). Lam6 localizes to the ER-mitochondria contact sites by its PH-like domain and the C-terminal transmembrane helix. Here, we purified and crystallized the Lam6 PH-like domain from Saccharomyces cerevisiae. To aid crystallization of the Lam6 PH-like domain, T4 lysozyme was fused to the N-terminus of the Lam6 PH-like domain with a short dipeptide linker, GlySer. The fusion protein was crystallized under the condition of 0.1 M HEPES-HCl pH 7.0, 10% (w/v) PEG 8000, and 0.1 M $Na_3$ Citrate at 293K. X-ray diffraction data of the crystals were collected to $2.4{\AA}$ resolution using synchrotron radiation. The crystals belong to the orthorhombic space group $P2_12_12_1$ with unit cell parameters $a=59.5{\AA}$, $b=60.1{\AA}$, and $c=105.6{\AA}$. The asymmetric unit contains one T4L-Lam6 molecule with a solvent content of 58.7%. The initial attempt to solve the structure by molecular replacement using the T4 lysozyme structure was successful.