• Korean Journal of Materials Research
• /
• v.25 no.1
• /
• pp.32-36
• /
• 2015

Hot rolling of Mg-6Zn-0.6Zr-0.4Ag-0.2Ca-(0, 8 wt%)Li powder was conducted at the temperature of $300^{\circ}C$ by putting the powder into the Cu pipe. The microstructure and mechanical properties of the samples were observed. Mg-6Zn-0.6Zr-0.4Ag-0.2Ca without Li element was consisted of ${\alpha}$ phase and precipitates. The microstructure of the 8 wt%Li containing alloy consisted of two phases (${\alpha}$-Mg phase and ${\beta}$-Li phase). In addition, $Mg_2Zn_3Li$ was formed in 8%Li added Mg-6Zn-0.6Zr-0.4Ag-0.2Ca alloy. By addition of the Li element, the non-basal planes were expanded to the rolling direction, which was different from the based Mg alloy without Li. The tensile strength was gradually decreased from 357.1 MPa to 264 MPa with increasing Li addition from 0% to 8%Li. However, the elongation of the alloys was remarkably increased from 10 % to 21% by addition of the Li element to 8%. It is clearly considered that the non-basal texture and ${\beta}$ phase contribute to the increase of elongation and formability.

• Journal of the Korean Chemical Society
• /
• v.15 no.5
• /
• pp.241-245
• /
• 1971

Endothermic peak of transformation of ${\gamma}-MnO_2$ was obviously shown by differential heating curve in the present study, and the transformation temperature was different from other modification. ${\gamma}-MnO_2$ carried out to analyze exclusively, by means of the half area method in corresponding endothermic peak of differential heating curve. ${\alpha}-\;and\;{$beta}-MnO_2$ (Pyrolusite) containing in sample about 75% is interfered about ${\pm}$10% of the relative error, and while those of below 50% is interfered about ${\pm}$5%.

• Korean Journal of Food Science and Technology
• /
• v.44 no.1
• /
• pp.41-47
• /
• 2012

Steeping and germination conditions were investigated in order to produce barley containing a high ${\gamma}$-aminobutyric acid (GABA) content, and the changes in GABA and nutritional components before and after germination were also evaluated in this study. Water absorption rates of three barleys increased alongside both steeping time and steeping temperature. The highest GABA contents of the three barleys, 10.4-14.1 mg/100 g, were obtained from the steeping condition of $25^{\circ}C$ for 24 hr. The GABA contents of germinated barleys ranged from 14.3 to 20.9 mg/100 g, increasing by 3.9 to 14.6 times compared with raw barley. The crude lipid, crude ash and total mineral contents were slightly decreased after germination. The major fatty acids of the three barleys before and after germination were linoleic and palmitic acids. ${\beta}$-glucan contents of three barleys were slightly decreased after germination.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.8 no.2
• /
• pp.233-239
• /
• 1998

SiC thin films were deposited by chemical vapor deposition method using tetramethylsilane (TMS) and hexamethyldisilane (HMDS). The chamber pressure during the deposition was kept at about 1 torr. Precursor was transported to the reaction chamber by $H_2$gas and SiC deposition was carried out at the reaction temperature of $1200^{\circ}C$. Si-wafer masked with tantalum and MgO single crystal covered with platinum and molybdenum were used as substrates. The selectivity of SiC deposition was observed by comparing the microstructure between metal (Ta, Pt, and Mo) surfaces and substrate surfaces (Si and MgO). The deposited films were identified as the $\beta-SiC$ phase by X-ray diffraction pattern. Also, the deposition -behavior of SiC on each surface was investigated by the scanning electron microscope analysis.

• Microbiology and Biotechnology Letters
• /
• v.33 no.4
• /
• pp.241-247
• /
• 2005

A new lactococcal shuttle/expression vector for lactococci, pWgal13T, was constructed using a $\beta$-galactosi-dase gene (lacZ) from Lacfococcus lactis ssp. lactis ATCC 7962 as a screening marker. The pWgal 13T was introduced into Escherichia coli DH5a and L. lactis MG1363, and was easily detected by the formation of blue colonies on a medium containing X-gal without any false transformants. Also, the quantitatively lacZ activity of pWgal13T was measured in L. lactis ssp. cremoris MG1363, and was found to be four times higher than that of L. lactis ssp. lactis ATCC7962 grown on a medium containing glucose, which shows that the lacZ gene of pWgal13T can be used for the efficient screening of L. lactis on general media. The pWgal13T was equipped with a lactococcal replicon of pWV01 from L. lactis Wg2, the new promoter P13C from L. lactis ssp. cremoris LM0230, multiple cloning sites, and a terminator for the expression of a relevant gene. The vee-tor pWgal13T was used for the expression of the EGFP gene in E. coli and L. lactis. These results show that the lactococcal expression/shuttle vector constructed in the present study can be used for the production of foreign proteins in E. coli and L. lactis.

• Journal of Pharmaceutical Investigation
• /
• v.31 no.3
• /
• pp.151-160
• /
• 2001

The purpose of this study is to investigate the interaction of progesterone with various cyclodextrins (CDs) in the aqueous solution and in solid state, and finally to formulate a parenteral aqueous formulation. CDs used were ${\alpha}-$, ${\beta}-$, and ${\gamma}-CD$, $2-hydroxypropyl-{\beta}-CD$ (HPCD), sulfobutyl $ether-{\beta}-CD$ (SBCD), $dimethyl-{\beta}-CD$ (DMCD) and $trimethyl-{\beta}-CD$ (TMCD). The solubility studies of progesterone were performed in the presence of various CDs as a function of concentration or temperature. The solubility of progesterone increased in the rank order of ${\alpha}-CD$ < ${\beta}-CD$ < ${\gamma}-CD$ < TMCD$ < HPCD < DMCD < SBCD. Addition of SBCD (200 mg/ml) in water increased the aqueous solubility $(9.36\;{\mu}g/ml)$ about 3,200 times, and lowering the temperature facilitated the solubilization of progesterone. However, the addition of HPCD and SBCD in 20:80 (v/v) polyethylene glycol 300-water and propylene glycol-water cosolvents markedly decreased the solubility of progesterone, compared with solubilizing effects in water. Physical mixtures and solid dispersions of progesterone with HPCD or SBCD were prepared, and evaluated by differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR), near IR spectroscopy and dissolution studies. By DSC and IR studies, it was found that progesterone was dispersed in HPCD in monotectic state and dissolved rapidly from both solid dispersions. Based on solubility studies, new aqueous progesterone fonnulations (5 mg/ml) containing SBCD (200 mg/ml) could be prepared and did not form precipitates even after 2 months at $4^{\circ}C$. The solution was transparent when mixed with normal saline and 5% dextrose injection at 1: 1, 1:10 and 1:20 (v/v) even after 7 days. Permeation rates of progesterone through a cellulose membrane from 20% PEG 300 solution $(50\;{\mu}g/ml)$ containing HPCD or SBCD were compared with oily formulation. Permeation of progesterone from oily formulation did not occur up to 8 hr, but aqueous formulations showed fast permeation rates from early stage of permeation study. The addition of HPCD or SBCD retarded the permeation rates of progesterone with the increase of CD concentrations, suggesting the possibility of a controlled absorption from the site administered intramuscularly. These results demonstrate that it is feasible to develop a new progesterone parenteral aqueous injection (5 mg/ml) using SBCD.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.19 no.4
• /
• pp.342-348
• /
• 1990

Effects of various monosodium glutamate(MSG_ concentration (0-400mg%) on the quality of Korean cabbage kimchi during fermentation at 2$0^{\circ}C$ were investigated. The growth of lactic acid bacteria titratable acidity pH content of thiamine ascorbic acid $\beta$-carotene and sensory evaluation were observed in the presencve of MSG. Titratable acidity was increased in the kimchi contained MSG during the fermentation.l Wheeas the changes of pH in the kimchi contained MSG were similar to those in control, Maximum growth of lactic acid bacteria was observed after 49 hour of fermentation in kimchi contained with 200mg MSG. The might be due to the fact that MSG was given optimum pH for acid bacteria growth because of its buffering action. Therefore the periods of kimchi fermentation were reduced by addition of MSG, MSG also affected on the stability of ascorbic acid thiamine and $\beta$-carotene. According of MSG. MSG also affected on the stability of ascorbic acid thiamine and $\beta$-carotene. According to sensory evaluation MSG reduced sour taste in kimchi which increased edible periods.

• Journal of Microbiology and Biotechnology
• /
• v.16 no.2
• /
• pp.200-204
• /
• 2006

The enzymology of an activated sludge system for a petroleum wastewater purification process was investigated. Leucine-aminopeptidase (L-AMP), ${\beta}$-glucosidase (${\beta}-GLC$), and lipase (LIP) were selected for the study. It was found that more than 81.7% of enzymatic activity was associated with microbial cells in the activated sludge floc. The metabolic response of a mixed microbial population to increased phenol concentration showed that L-AMP activity increased in the activated sludge, whereas activities of ${\beta}-GLC$ and LIP decreased, due to the inhibitory effect of the phenol which varied from 100 mg/l to 500 mg/l.

• YAKHAK HOEJI
• /
• v.41 no.5
• /
• pp.658-665
• /
• 1997

Identification of a soil microorganism strain X-8, producer of ${\beta}$-lactamase inhibitor, based on its morphological, physiological, biochemical and chemotaxonomical characteristics was performed. The strain X-8 was identified as Pseudomonas sp. The beta-lactamase inhibitor produced by this strain was highly achieved in fermentation medium contained glucose 0.5%, urea 0.25%, $K_2HPO_4{\cdot}3H_2O\;0.5%,\;MgSO_4{\cdot}7H_2O\;0.5%,\;FeSO_4{\cdot}7H_2O\;0.01%,\;CuSO_4,\;ZnSO_4,\;MnSO_4\;0.02%$. The beta-lactamase inhibitor was not extracted by organic solvent such as n-butanol and ethyl acetate but remained in aqueous layer. The n-butanol extract showed antimicrobial activity against M. smegmatis. The ${\beta}$-lactamase inhibitor was stable at pH 7.0~8.0 and 4$^{\circ}C$ for 24h. The ${\beta}$-lactamase inhibitor was bound on ion exchanger Diaion WA-30 and HP-20 and eluted with 2N-$NH_4OH$ and acetone, respectively.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.23 no.2
• /
• pp.397-404
• /
• 2009

For standardization of LMK02 quality, Ginsenoside Rg3 of Red Ginseng and Decursin of Angelica gigas Nakai in the constituents of LMK02 were estimated as indicative components. From LMK02 water extract, has been used in vitro test for its beneficial effects on neuronal survival and neuroprotective functions, particularly in connection with APP-related dementias and Alzheimer's disease (AD). $A{\beta}$ oligomer derived from proteolytic processing of the ${\beta}$-amyloid precursor protein (APP), including the amyloid-${\beta}$ peptide ($A{\beta}$), play a critical role in the pathogenesis of Alzheimer's dementia. We determined that oligomer amyloid-${\beta}$ ($A{\beta}$) have a profound attenuation in the increase in rat hippocampus H19-7 cells from. Experimental evidence indicates that LMK02 protects against neuronal damage from cells, but its cellular and molecular mechanisms remain unknown. Using a hippocampus cell line on $A{\beta}$ oligomer-induced neuronal cytotoxicity, we demonstrated that LMK02 inhibits formation of $A{\beta}$ oligomer, which are the behavior, and possibly causative, feature of AD. In the Red Ginseng, the average amounts of Ginsenoside Rg3 were $47.04{\mu}g/g$ and $42.3{\mu}g/g$, 90 % of its weight were set as a standard value. And, in the Angelica gigas Nakai, the average amounts of Decursin were 2.71 mg/g and 2.44mg/g, 90 % of its weight were also set as a standard value. The attenuated $A{\beta}$ oligomer in the presence of LMK02 was observed in the conditioned medium of this $A{\beta}$ oligomer-induced cells under in vitro. In the cells, LMK02 significantly activated antiapoptosis and decreased the production of ROS. These results suggest that neuronal damage in AD might be due to two factors: a direct $A{\beta}$ oligomer toxicity and multiple cellular and molecular neuroprotective mechanisms, including attenuation of apoptosis and direct inhibition of $A{\beta}$ oligomer, underlie the neuroprotective effects of LMK02 treatment.