• Bulletin of the Korean Chemical Society
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• v.25 no.7
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• pp.1036-1040
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• 2004

$Mn_{12}O_{12}(O_2CCH_2CH_2CH_2Cl)_{16}(H_2O)_4]$ (noted as $Mn_{12}$-BuCl), a new polynuclear complex of manganese chlorobutyrate has been successfully prepared by substitution of acetate with 4-chlorobutyric acid. The $Mn_{12}-BuCl$ crystallizes into triclinic space group P-1 with a = 14.5560(11) ${\AA}$, b = 14.5819(11) TEX>${\AA}$, c = 27.265(2) ${\AA}$, ${\alpha}\;=\;84.1140(10)^{\circ}\;,\;{\beta}\;=\;88.805(2)^{\circ},\;{\gamma}\;=\;89.8820(10)^{\circ}$, and Z = 2. The local environments of manganese 3+ and 4+ ions of the title compound are close to those of other $Mn_{12}$ compounds. The electrochemical data for $Mn_{12}-BuCl$ involve reversible reactions of two-electron reductions. The $Mn_{12}-BuCl$ also presents magnetic relaxation below 10 K implying that each molecule behaves as a single molecule magnet.

• Journal of Microbiology and Biotechnology
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• v.10 no.5
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• pp.580-586
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• 2000

A soluble Cr(VI) reductase was purified from the Cr(VI) reducing strain Escherichia coli ATCC33456 by ammonium sulfate fractionation, and chromatographies on Q-Sepharose FF, Cibacron blue 3GA dye affinity, Mono-Q 5/5, and Superdex 200 HR 10/30 columns. The estimated molecular mass of the purified enzyme was 27 kDa on SDS-polyacrylamide gel electrophoresis and 54 kDa on gel filtration, thus indicating a dimeric structure. The isoelectric point of the enzyme was pH 4.85. The optimum reaction pH and storage pH were both 7.0, the optimum reaction temperature was $37^{\circ}C$, and the storage temperature was $4^{\circ}C$. NADH and NADPH both served as electron donors for the reductase, with $V_{max}$ of 68.3 ${\mu}M$ Cr(VI)/min/mg protein and Km of 7.6 $\mu$M using HADH, and Vmax of 42.3 ${\mu}M$ Cr(VI)/min/mg protein and Km of 14.6 $\muM$ using NADPH. When 1 mM EDTA was added, the Cr(VI) reducing activity increased 4-fold.

• BMB Reports
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• v.45 no.7
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• pp.419-424
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• 2012

High-fat diets (HFD) and high-carbohydrate diets (HCD)-induced obesity through different pathways, but the metabolic differences between these diets are not fully understood. Therefore, we applied proton nuclear magnetic resonance ($^1H$ NMR)-based metabolomics to compare the metabolic patterns between C57BL/6 mice fed HCD and those fed HFD. Principal component analysis derived from $^1H$ NMR spectra of urine showed a clear separation between the HCD and HFD groups. Based on the changes in urinary metabolites, the slow rate of weight gain in mice fed the HCD related to activation of the tricarboxylic acid cycle (resulting in increased levels of citrate and succinate in HCD mice), while the HFD affected nicotinamide metabolism (increased levels of 1-methylnicotineamide, nicotinamide-N-oxide in HFD mice), which leads to systemic oxidative stress. In addition, perturbation of gut microflora metabolism was also related to different metabolic patterns of those two diets. These findings demonstrate that $^1H$ NMR-based metabolomics can identify diet-dependent perturbations in biological pathways.

• Journal of The Korean Society of Grassland and Forage Science
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• v.27 no.4
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• pp.241-248
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• 2007

Cytokinins are essential plant hormones that play crucial roles in various aspects of plant growth and development. By using mRNA differential display, we isolated a cytokinine-inducible cDNA encoding pathogenesis-related (PR) 4 from Arabidopsis amp1 mutant. The full-length PR4 cDNA, designated AtPR4, contains an open reading frame of 212 amino acids with calculated molecular mass of 22,900 Da and isoelectric point (pI) of 7.89. Genomic DNA blotting showed that the Arabidopsis genome has one copy of AtPR4. AtPR4 mRNA was induced by cytokinin and NaCl, but decreased by SA or JA treatment. PR proteins are induced in response to pathogen attack. Thus the AtPR4 gene isolated in this study may be a useful candidate for genetic engineering of forage crops for increased tolerance against pathogen.

• Mass Spectrometry Letters
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• v.7 no.3
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• pp.69-73
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• 2016

High-resolution quadrupole-Orbitrap mass spectrometry (HRMS), with high-resolution (> 10,000 at full-width at half-maximum) and accurate mass (< 5 ppm deviation) capabilities, plays an important role in the structural elucidation of drug metabolites in the pharmaceutical industry. ML106, a derivative of imidazobenzimidazole, decreased melanin content and tyrosinase activity in a dose-dependent manner. Here, we investigated the phase 1 metabolic pathway of ML106 using HRMS in human liver microsomes (HLMs) and recombinant cDNA-expressed cytochrome P450 (CYP). After the incubation of ML106 with pooled HLMs and recombinant cDNA-expressed CYP in the presence of NADPH, five phase 1 metabolites, including three mono-hydroxylated metabolites (M1-3) and two di-hydroxylated metabolites (M4 and M5), were investigated. The metabolite structures were postulated by the elucidation of protonated mass spectra using HRMS. The CYP isoforms related to the hydroxylation of ML106 were studied after incubation with recombinant cDNA-expressed CYP. Here, we identified the phase 1 metabolic pathway of ML106 induced by CYP in HLMs.

• Journal of Veterinary Clinics
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• v.34 no.2
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• pp.135-139
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• 2017

This study was performed to evaluate the clinical efficacy of alfaxalone for induction of inhalation anesthesia in small animal practice. Patient data were collected according to anesthetic records (136 dogs and 14 cats) presented to the Veterinary Medical Teaching Hospital of Seoul National University for surgeries and diagnostic imaging from July 2013 to March 2014. Anesthetic results included signalment, American Society of Anesthesiologists (ASA) grade, premedicated drugs, procedures, induction quality, and recovery after anesthesia. One hundred fifty anesthetic events were classified according to the ASA grade. Three patients were ASA grade I, 52 patients grade II, 86 patients grade III, and 9 patients grade IV, respectively. The most common premedication was midazolam and hydromorphone combination (n = 59, 39.3%) follow by acepromazine and hydromorphone combination (n = 22, 14.7%). The majority of anesthesia procedures were diagnostic imaging (n = 33, 22.0%) and ophthalmic surgeries (n = 31, 20.7%), followed by soft tissue surgeries (n = 27, 18.0%), and orthopedic surgeries (n = 20, 13.3%). Intravenous alfaxalone provided smooth induction for inhalation anesthesia in almost cases, but transient apnea and twitching/paddling were observed after induction and during recovery, respectively. In addition, alfaxalone did not show pain response during intravenous administration. Alfaxalone showed smooth induction of inhalation anesthesia in dogs and cats with mild to severe systemic disease (ASA 2-4). Alfaxalone was considered as an acceptable induction agent for patients with higher risk in small animal practice.

• Korean Journal of Remote Sensing
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• v.25 no.2
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• pp.193-203
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• 2009

Snow cover is one of the important parameters since it determines surface energy balance and its variation. To classify snow and cloud from satellite data is very important process when inferring land surface information. Generally, misclassified cloud and snow pixel can lead directly to error factor for retrieval of surface products from satellite data. Therefore, in this study, we perform algorithm for detecting snow cover area with remote sensing data. We just utilize visible reflectance, and infrared channels rather than using NDSI (Normalized Difference Snow Index) which is one of optimized methods to detect snow cover. Because COMS MI (Meteorological Imager) channels doesn't include near infra-red, which is used to produce NDSI. Detecting snow cover with visible channel is well performed over clear sky area, but it is difficult to discriminate snow cover from mixed cloudy pixels. To improve those detecting abilities, brightness temperature difference (BTD) between 11 and 3.7 is used for snow detection. BTD method shows improved results than using only visible channel.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.1
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• pp.19-27
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• 2022

A series of QPAE/TiO₂-x (x = 1, 4, 7 and 10 wt%) organic/inorganic composite membranes were prepared as electrolyte membranes for alkaline anion exchange membrane fuel cells by controlling the content of inorganic filler with quaternized poly(arylene ether) (QPAE) random copolymer. Among the prepared QPAE/TiO₂-x organic/inorganic composite membranes, the highest ionic conductivity was 26.6 mS cm^-1 at 30℃ in QPAE/TiO₂-7 composite membrane, which was improvement over the ionic conductivity value of 6.4 mS cm^-1 (at 30℃) of the pristine QPAE membrane. Furthermore, the water uptake, swelling ratio, ionic exchange capacity, and thermal property of QPAE/TiO₂-x composite membranes were improved compared to the pristine QPAE membrane. The results of these studies suggest that the fabricated QPAE/TiO₂-x composite membranes have good prospects for alkaline anion exchange membrane fuel cell applications.

• Journal of agriculture & life science
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• v.45 no.6
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• pp.163-173
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• 2011

The objective of this study was to determine microbiological risk factors in hot pepper farms for the application of good agricultural practices (GAP). Samples were collected from cultivation environments and utensils, plants, workers, and air at 3 hot pepper farms located in Cheongsong, Korea and were tested to detect sanitary indications [aerobic plate bacteria (APC), coliform, and Escherichia coli], foodborne pathogens, and fungi. APC, coliform, and fungi were detected at the levels of 0.7~6.2, 0.2~4.7, and 0.4~4.3 log CFU, respectively, in the three farms. Four (4.4%; l leaf, l irrigation water, and 2 soil) of 90 samples collected were revealed to be E. coli positives. For foodborne pathogens, Staphylococcus aureus was only detected at $1.0log\;CFU/100cm^2$ in the worker's cloth of B farm, and Bacillus cereus was detected at the levels 1.0~2.5 log CFU in the cultivation environments and utensils and worker of B and C farms. However, other pathogens were not detected. The results demonstrated potential microbiological risks for hot pepper cultivated in the farms. Therefore, a management system to minimize the microbial risk such as GAP is required to ensure the safety of hot pepper.

• Journal of Embryo Transfer
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• v.28 no.2
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• pp.141-147
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• 2013

The purpose of this study was attempted to new methods in mammalian embryos vitrification. This method was affected to increase of the embryo vitrification efficiency and it would be applied to the field of embryo transfer to recipient by modified loading method of embryo into 0.25 ml plastic straw. The frozen mouse embryos were carried out warmed from two different cell stages (8-cell and blastocyst, respectively) by attachment of an embryo in the vitrification straw (aV) method. All groups were cultured in M-16 medium to determine the development and survivability for 24 h, respectively. Results shown that, the survivability of two different groups were significantly different (94.8% vs. 70.9%). Total cell number was not significantly different the non-frozen blastocyst ($99.7{\pm}12.4$) compared to the post-thaw blastocyst ($94.8{\pm}15.1$). From the 8-cell embryo, total cell number of frozen blastocysts were significantly lower than others groups ($74.7{\pm}14.6$, p<0.05). In the case of cell death analysis, the blastocysts from non-frozen and frozen-thawed 8-cell group were not different ($0.0{\pm}0.0$ vs. $1.9{\pm}3.1$, p>0.05). However, the apoptotic nuclei of blastocyst were significantly observed the frozen-thawed group ($5.4{\pm}4.4$) compared to non-frozen group (p<0.05). Therefore, this new method of embryos using in-straw dilution and direct transfer into other species would be more simple procedure of embryo transfer rather than step-wise dilution method and cryopreservation vessels, so we can be applied in animal as well as human embryo cryopreservation in further.