• Applied Biological Chemistry
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• v.49 no.3
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• pp.180-185
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• 2006

${\alpha}$-Galactosidase was partially purified from the culture filtrate of Debaryomyces sp. by Mannobiose-Sepharose affinity column chromatography. The galactosidase exhibited maximum activity at pH 4.0 and $60^{\circ}C$, and was stable in the pH and temperature ranges of 3 to 4.5 and 30 to $50^{\circ}C$, respectively. The enzyme was inhibited by $Hg^{2+}\;and\;Ag^{2+}$. The enzyme activity was not affected considerably by treatment with other metal compounds. The enzyme hydrolyzed melibiose to galactose and glucose, raffinose to galactose and sucrose, and $Gal^3Man_3$ ($6^3-{\alpha}$-galactosyl-1,4-mannotriose) to galactose and mannotriose. On the contrary, it could not hydrolyze $Gal^3Man_4$ ($6^3-{\alpha}$-galactosyl-1,4-mannotetraose).

• Bulletin of the Korean Chemical Society
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• v.25 no.7
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• pp.1012-1019
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• 2004

The synthesis of novel group 9 metal complexes containing the S,S'-chelate ligands, $Li_2S_2C_2B_{10}H_{10}$ (2a) and $LiS(S=PMe_2)C_2B_{10}H_{10$} (2b), is described. Two new dinuclear complexes of the type $[{(cod)M}_2(S,S'-S_2C_2B_{10}H_{10})]$ (cod = 1,5-cyclooctadiene; M = Rh (3a), or Ir (3b)) were synthesized by the reaction of chloridebridged dimers $[M({\mu}-Cl)(cod)]_2$ with one molar equivalent of the corresponding dilithium dithiolato ligand $Li_2S_2C_2B_{10}H_{10}$ (2a). X-ray crystal structure analysis of 3a revealed a dinuclear structure in which each (cod)Rh unit is attached to a distinct sulfur atom of a 1,2-dithio-o-carboranyl ligand (2a). Additionally, the electrochemical properties of 3a and 3b were investigated by cyclic voltammetry. In an analogous manner, reaction of the lithium dithiolato ligand $LiS(S=PMe_2)C_2B_{10}H_{10}$ (2b) with $Cp^{\ast}CoI_2(CO)$ produced a mononuclear dithiolato complex, $[Cp^{\ast}CoI{(S,S'-S(S=PMe_2)C_2B_{10}H_{10})}]$ (4), which was characterized by single-crystal X-ray analysis.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.4
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• pp.309-315
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• 2012

Catalytic combustion is generally accepted as one of the environmentally preferred alternatives for heat and power from fossil fuels, as it has the advantage of stable combustion under very lean conditions with such low emissions as UHC, CO, and NOx. In this work, therefore, comparative numerical studies on the catalytic combustion behaviors over Pd-based catalysts have been conducted with the gaseous $CH_4$, $C_2H_6$, and $C_3H_8$. In the following, after introducing the governing equations with 1D channel and Langmuir-Hinshelwood models, numerical investigations on the catalyst performance are conducted by changing such various parameters as inlet temperature, excess air ratio, and space velocity. The numerical results show that outlet temperature and conversion of $C_3H_8$ are highest among others because of its chemical structure and reactivity.

• Journal of the Korean Magnetics Society
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• v.4 no.1
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• pp.7-11
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• 1994

Ferromagnetic resonance experiment was performed to study the variations of micromagnetic structure with heat treatment of melt spun $Fe_{76}Cu_{1}Nb_{3}Si_{14}B_{6}$ alloy for 1h at every $50^{\circ}C$ in the temperature range of $400^{\circ}C-700^{\circ}C$. The variations of micromagnetic structure was discussed qualitatively in terms of the variations of line width ${\Delta}H_{p-p}$ and resonance magnetic field $H_{res}$. With increasing armealing temperature to $400^{\circ}C$, ${\Delta}H_{p-p}$ decreases and $H_{res}$ increases due to the decrease in magnetic anisotropy resulting from structural relaxation during heat treatment. With increasing annealing temperature from 400 to $500^{\circ}C$, ${\Delta}H_{p-p}$ increases and $H_{res}$ decreases due to the increase in magnetic anisotropy resulting from the formation of nanocrystalline particles embedded in an amorphous matrix. With increasing armealing temperature from 500 to $550^{\circ}C$, ${\Delta}H_{p-p}$ decreases and $H_{res}$ increases due to the decrease in magnetic anisotropy resulting from the formation of homogeneous nanocrystalline structure with a minor amorphous phase. Further increase in armealing temperature above $550^{\circ}C$ C causes ${\Delta}H_{p-p}$ to increase and $H_{res}$ to decrease due to the increase in magnetic anisotropy due to the formation of inhomogeneous grain structure and intermetallic compounds.

• Korean Journal of Crystallography
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• v.8 no.2
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• pp.144-148
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• 1997

the molecular and crystal 3-dimensional structure of bentazone, C10H12N2O3S, has been determined from single crystal x-ray diffraction study. Crystal system is monoclinic: a=8.7817(9)Å, b=9.6059(9) Å, c=13.574(9) Å, β=97.269(1)', V=1136.1(6)Å, space group : P21/c, z=4. The molecular structure model was solved by direct method and refined by full matrix least squares. The final reliable factor, R, is 0.045 for 1396 independent reflections(Fo2>4σFo2). A molecule has a staggered conformation with thiocarbazin ring and isopropyl functional group and the molecules by hydrogen bonds are cross stacked along the c-axis.

• Korean Journal of Crystallography
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• v.11 no.1
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• pp.10-15
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• 2000

Compound trans-[FeH(NCS(i-Pr)-S)(dppe)₂](1) reacted with isopropyl iodide (i-PrI) to give an Fe(II)-organic isothiocyanide complex, trans-[FeH(NCS(i-Pr)-S)(dppe)₂]I (2). Compound 2 was structurally characterized, in which the hydride ligand appears to be involved in the "dihydrogen" bonding, M-H…H-C. Crystallographic data for 2: monoclinic space group P2₁/n, a=13.490(2)Å, b=17.269(3)Å, c=21.384(3)Å, β=90.682(7)°, Z=4, R(wR₂)=0.0348(0.0894).

• Journal of the Korean Ceramic Society
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• v.30 no.1
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• pp.46-54
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• 1993

$\beta$-SiC was chemically vapor deposited by pyrolysis of MTS＋H2 gas mixture. The experiments were conducted in the temperature range of 1100~150$0^{\circ}C$ with a r.f. induction furnace under atmospheric pressure. The IR, XRD, EDS and AES analysis revealed that the free Si was always codeposited with SiC below 140$0^{\circ}C$, regardless of the total flow rate and MTS concentration, whereas $\beta$-SiC single phase was deposited at 150$0^{\circ}C$. C3H8 or CH2Cl2 as an excess C sources, was supplied with MTS in order to obtain stoichiometric SiC at low temperature. With the addition of C3H8 or CH2Cl2, the deposition rate was increased and $\beta$-SiC single phase could be deposited even at temperature as low as 110$0^{\circ}C$. In the absence of C3H8 or CH2Cl2, the microhardness of the layer was quite low (

• Korean Journal of Microbiology
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• v.29 no.6
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• pp.408-415
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• 1991

TOL plsmid size of Flavobacterium odoratum SUB53 was estimated as 83 Md and the optimum concentration of m-toluate degradation by TOL plasmid was 5 mM. $H_{2}$ production by Rhodopseudomonas sphaeroides KCTC1425 was largely dependent on nitrogenase activity and showed the highest at 30 mM malate with 7 mM glutamate as nitrogen source. Nitrogenase activities were inhibited by 0.3 mM $NH_{4}^{+}$ions, to be appeared the decrease of $H_{2}$ production. Conjugation of TOL plasmids from F. odoratum SUB53 and Pseudomonas putida mt-2 to R. sphaeroides showed the optimum at the exponential stage of recipient cells in presence of helper plasmid pRK2013. According to the investigation of catechol-1,2-oxygenase (C-1, 2-O) and catechol-2,3-oxygenase (C-2,3-O) activities of R. sphaeroides C1 (TOL SUB53) and C2 (TOL mt-2), the gene for C-2,3-O is located on TOL plasmid and gene for C-1, 2-O on the chromosome of R. sphaeroides. m-Toluate was biodegraded by TOL plasmid in R. sphaeroides C1 and C2, presumably to be produced $H_{2}$ gas from the secondary metabolites of m-toluate.e.

• Transactions on Electrical and Electronic Materials
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• v.10 no.4
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• pp.131-134
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• 2009

The electrical properties and the microstructure of nitrogen-doped poly 3C-SiC films used for micro thermal sensors were studied according to different thicknesses. Poly 3C-SiC films were deposited by LPCVD (low pressure chemical vapor deposition) at $900^{\circ}C$ with a pressure of 4 torr using $SiH_2Cl_2$ (100%, 35 sccm) and $C_2H_2$ (5% in $H_2$, 180 sccm) as the Si and C precursors, and $NH_3$ (5% in $H_2$, 64 sccm) as the dopant source gas. The resistivity of the poly SiC films with a 1,530 ${\AA}$ thickness was 32.7 ${\Omega}-cm$ and decreased to 0.0129 ${\Omega}-cm$ at 16,963 ${\AA}$. The measurement of the resistance variations at different thicknesses were carried out within the $25^{\circ}C$ to $350^{\circ}C$ temperature range. While the size of the resistance variation decreased when the films thickness increased, the linearity of the resistance variation improved. Micro heaters and RTD sensors were fabricated on a $Si_3N_4$ membrane by using poly 3C-SiC with a 1um thickness using a surface MEMS process. The heating temperature of the SiC micro heater, fabricated on 250 ${\mu}m$${\times}$250 ${\mu}m$ $Si_3N_4$ membrane was $410^{\circ}C$ at an 80 mW input power. These 3C-SiC heaters and RTD sensors, fabricated by surface MEMS, have a low power consumption and deliver a good long term stability for the various thermal sensors requiring thermal stability.

• Molecules and Cells
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• v.43 no.10
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• pp.841-847
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• 2020

Histone acetylation and deacetylation play central roles in the regulation of chromatin structure and transcription by RNA polymerase II (RNA Pol II). Although Hda1 histone deacetylase complex (Hda1C) is known to selectively deacetylate histone H3 and H2B to repress transcription, previous studies have suggested its potential roles in histone H4 deacetylation. Recently, we have shown that Hda1C has two distinct functions in histone deacetylation and transcription. Histone H4-specific deacetylation at highly transcribed genes negatively regulates RNA Pol II elongation and H3 deacetylation at inactive genes fine-tunes the kinetics of gene induction upon environmental changes. Here, we review the recent understandings of transcriptional regulation via histone deacetylation by Hda1C. In addition, we discuss the potential mechanisms for histone substrate switching by Hda1C, depending on transcriptional frequency and activity.