• Applied Biological Chemistry
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• v.42 no.2
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• pp.99-104
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• 1999

Soil actinomycetes of 703 strains were isolated from 25 sampling points in Cheju Island using 4 different media. Arginine glycerol salts agar containing soil extract was found to be the best medium for the isolation of soil actinomycetes. Soil samples from pasture land showed higher population and diversity of the actinomycetes than those from citrus field, forest, island, hill or valley. When the antibacterial activity of the 526 isolates was tested against three bacterial strains, Escherichia coli, Staphylococcus aureus and Pseudomonas solanacearum the frequency of the isolates with antibacterial activity varied much depending upon the media used for isolation and cultivation. BL106Ba, one of the 10 isolates that showed antibacterial activity against all the above 3 test strains, was chosen based upon the pH and heat stability of its antibacterial metabolites, and was identified as Streptomyces sp. based upon its cultural, morphological and physiological characteristics. The partially purified white crystalline substance obtained from the culture supematant of BL1063a through cation exchange chromatography(AG MP-50) and three times consecutive gel filtration(Sephadex G-10) showed high antimicrobial activity against gram positive and negative bacteria, but low activity against yeasts. The partially purified substance was found to contain at least four different compounds with antibacterial activity by both thin layer chromatography and high performance liquid chromatography.

• Applied Chemistry for Engineering
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• v.21 no.3
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• pp.265-271
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• 2010

Desalination effects of capacitive deionization (CDI) process was studied using $TiO_2$/activated carbon electrode. In order to enhance the wettability of electrode and decrease a electrode resistance, $TiO_2$ was coated on activated carbon. By means of $TiO_2$ coating on activated carbon, electric double layer to adsorption content in CDI process was increased. It was identified from TEM, XRD, and XPS that the activated carbon based on $TiO_2$ composite was fabricated successfully by means of sol-gel method. As a results of cyclic voltammetry and impedance, it was identified that $TiO_2$/activated carbon electrode has more electric double later capacitance and less diffusion resistance than activated carbon. Also charge-discharge and ion conductivity profiles showed that the ion removal ratios of $TiO_2$/activated carbon electrode in NaCl electrolyte of $1000\;{\mu}S/cm$ more increased about 39% than that of activated carbon. In conclusion it was possible to identify that the carbon electrode coated $TiO_2$ as electrode material was more effective than raw carbon electrode.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.274-282
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• 2002

The ethanol extract and n-hexane fraction from Hypericum ascyron L. showed strong growth inhibition at 25 ppm on 5 strains of Listeria monocytogenes for 72 hr at $32^{\circ}C$. The purified substance, H2-5-2 fraction, was isolated by silica gel column and preparative thin layer chromatography from n-hexane fraction of Hypericum ascyron L. The H2-5-2 fraction showed a strong bacteriostatic activity on 5 strains of L. monocytogenes at 10 ppm in tryptic soy broth, and the viable cell was reduced 1 log cycle compared to initial cell number. The n-hexane fraction of Hypericum ascyron L. showed strong growth inhibition at 25 ppm on Bacillus cereus and Staphylococcus aureus, and at 50 ppm on Vibrio parahaemolyticus for 72 hr. The purified antimicrobial substance, the H2-5-2 fraction, was assumed as high unsaturated sterol by $^1H-NMR$ and $^{13}C-NMR$. On application test using minced Alaska pollack and ground beef, the n-hexane fraction of Hypericum ascyron L. at the level of 250 ppm was applied at $32^{\circ}C$ and $5^{\circ}C$. At $32^{\circ}C$ storage condition, the antimicrobial substances did not reduced L. monocytogenes ATCC 19113, meanwhile at $5^{\circ}C$ storage condition, L. monocytogenes ATCC 19113 was reduced in viable number.

• The Korean Journal of Nuclear Medicine
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• v.29 no.3
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• pp.328-331
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• 1995

$^{99m}Tc$ labeled PnAO(propylene amine oxime) derivatives have been widely studied as brain perfusion agents. We synthesized and characterized a PnAO derivative, (RR/SS/ meso)-4,8-diaza-3,9-dimethylundecane-2, 10-dione bisoxime(PRODD). Proton-NMR spectroscopy and thin layer chromatography(silica gel) were performed for its characterization. PRODD was labeled with $^{99m}Tc$ using stannous chloride as reducing agent. The labeling efficiency was determined to be about 85%. Brain uptakes of $4.16{\pm}0.42$ %ID/g and $3.24{\pm}0.13$ %ID/g were found after 10min and 30min after intravenous injection. Brain-to-blood ratios were 1.17 and 0.75 at 10 and 30 minutes, which were lower than 1.3 and 1.9 of the ratios with commercial ${\pm}$-HMPAO. Autoradiographs of rat brain sections showed the gray matter to white matter ratios of $1.13{\pm}0.10$ at 30 min after intravenous injection, which was lower than $1.94{\pm}0.19$ of commercial $^{99m}Tc$-HMPAO. With the above findings, we concluded that the lipophilic $^{99m}Tc$-PRODD complex was able to cross the blood-brain barrier, however the complex showed lower uptake than $^{99m}Tc$-HMPAO in mouse or rat brains. We could suggest possibility that PRODD could be used as another $^{99m}Tc$ chelator.

• Clean Technology
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• v.8 no.3
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• pp.119-128
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• 2002

In the present study the membrane filtration characteristics of a commercially available synthetic water-based cutting oil through two kinds of ultrafiltration membranes (HF1-45-CM50 and HF1-43-CM100) with molecular weight cut-offs of 50,000 and 100,000, respectively, have been investigated in detail. Among these membranes, the hydrophilic one (HF1-45-CM50) was found to show a satisfactory result for both the permeate flux and the permeability of oil components, whereas the permeate flux obtained with the hydrophobic membrane (HF1-43-CM100) appears to be significantly low, indicating that synthetic cutting oil was easily wetted on the hydrophobic membrane surface and induced more membrane fouling. The effect of material characteristics of the membrane on the filtration characteristics was found to be much more significant compared with the mean pore size of the membrane. Backflushing by nitrogen gas was applied to reduce the formation of a gel layer and membrane fouling. With the hydrophilic membrane, the backflushing was found to increase the permeate flux, whereas the backflushing resulted in a decrease in flux for the hydrophobic membrane. The flux recovery was observed to be highest when the membranes fouled with waste synthetic cutting oil were immersed into a cleaning solution for more than 72 hours and then backflushed by nitrogen gas.

• Restorative Dentistry and Endodontics
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• v.15 no.1
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• pp.107-119
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• 1990

The purpose of this study was to evaluate the marginal adaptability of the amalgam restorations in applying the cavity varnish (Copalite$^{(R)}$) and dentin bonding agent (Scotchbond 2$^{(R)}$) under the scanning electron microscope. For this study, eighteen sound extracted human molars were selected. Class I cavities in 12 teeth and class V cavities in 6 teeth were prepared using an air turbine with No. 701 tungsten carbide bur and finished using a low speed handpiece with No. 557 fissure bur. The prepared specimens were then divided into three groups including 4 class I cavities and 2 class V cavities in each group and restored as follows ; Group I. All the prepared cavities were restored with amalgam only (Control). Group II. Two layers of Copalite$^{(R)}$ cavity varnish were applied to the cavities with a gentle stream of air after each application and cavities were restored with amalgam. Group III. The enamel cavity margins were etched with 37% phosphoric acid gel for 60 sec., rinsed for 30 sec. and dried. One layer of visible lightcured Scotchbond Dental Adhesive$^{(R)}$ was applied and immediately cured for 20 seconds with visible light-cure unit and cavities were restored with amalgam. All the specimens were cut at the neck of the teeth and the occlusal halves of specimens were sectioned buccolingually in the longitudinal axis centering the amalgam restorations, using the disk. The cut specimens were ground with sandpapers (400, 600, 800, 1000 grit), and cleaned for 5 minutes in the ultrasonic cleaner (Brason Co. U.S.A.). In the cut surfaces, the amalgam - tooth interfaces were examined under the scanning electron microscope (JSM, 35C type, JEOL). The obtained results were as follows ; 1. The amalgam-tooth interfaces were reduced more significantly in the Copalite$^{(R)}$ and Scotchbond 2$^{(R)}$ application group than in the control group. 2. In the class I cavities, the Scotchbond 2$^{(R)}$ application group showed the findings similar to the Copalite$^{(R)}$ application group in the cavity floor, and the marginal adaptability was better in the side wall than in the cavity floor. 3. In the class I cavities, the Scotchbond 2$^{(R)}$ application group showed better marginal adaptability in the occlusal margin than in the gingival margin. 4. The marginal adaptability was in the order of the Scothbond 2$^{(R)}$ application group, the Copalite$^{(R)}$ application group and the control group.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.9
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• pp.1321-1327
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• 2011

The microorganism producing an invertase (E.C. 3.2.1.26) was isolated from wine and tentatively identified as Saccharomyces cerevisiae by cellular fatty acid analysis. The invertase was purified to homogeneity by ammonium sulfate precipitant, dialysis, ion-exchange chromatography on DEAE-Sephadex A-50, and gel chromatography on Sephadex G-200 from the culture supernatant of Saccharomyces cerevisiae JS59. The specific activity and the purification fold of the purified invertase were 7620.9 unit/mg protein and 13.9, respectively. The molecular weight of the purified invertase was estimated to be 38.5 kDa by SDS-PAGE. The optimum pH and temperature for the invertase activity were pH 5 and $55^{\circ}C$, respectively. The invertase activity was relatively stable at pH 4~6 and temperature $55^{\circ}C$. The activity of invertase was inhibited by $Ag^{2+}$ and $Hg^{2+}$, but on the contrary, activated by $Co^{2+}$ and $Mn^{2+}$. Michaelis constant ($K_m$) for invertase reaction in sucrose solution was 11.5 mM. TLC analysis of the products produced in sucrose solution during invertase reaction showed the progressive presence of glucose and fructose in accordance with sucrose hydrolysis.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.1
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• pp.11-17
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• 2009

Betamethasone propionate, an anti-inflammatory glucocorticosteroid, was detected in cosmetics with no indication on the label of this compound as an ingredient. The product was formulated as a topical spray or shampoo and labeled to contain zinc pyrithione as the active ingredient. A thin-layer chromatographic analysis was carried out on silica gel plates to provide a first indication about the presence of a compound with steroid structure and reactivity; then high-performance liquid chromatography (HPLC) separation allowed the identification of the corticosteroid agent and its quantification. To identify the corticosteroid agent from these commercial samples we collected the fractions suspected to have ketol steroids by prep HPLC and identified the compound as betamethasone propionate by NMR and MS spectrometry. Then we synthesized the standard for the betamethasone 17-propionate and 21-propionate and quantitate the corticosteroids from the sample by HPLC with that standards. By this method we identified the corticosteroid compounds from some commercial cosmetics such as zinc pyrithione sprays. The finding of betamethasone propionate in the products was shown by comparison to an authenticated standard of betamethasone propionate by retention time on reverse-phase HPLC. Two of the tested products contained betamethasone propionate at the levels of 0.005 ${\sim}$ 0.02% and the others were free of betamethasone propionate.

• Journal of Ginseng Research
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• v.17 no.1
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• pp.52-60
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• 1993

Panax ginseng has been extensively used in the traditional oriental medicine as a restorative, tonic and Prophylactic agent. Recently, several reports regarding to anticancer effects of Panax ginseng has accumulated. These studies emphasized the fact that the anticancer activities might be due to a glycoside group called ginsenoside or pan.u saponin which has a water soluble characteristic. However, the authors and collaborates demonstrated that a highly lipid soluble component in extract of Panax ginseng roots contains a considerable cytotoxic activities against marine leukemic cells (L1210, P388) and human censer cells (HRT-18, HT-29, HCT48). This study was devised to observe the cytotoxic activities of Petroleum-ether extract of Panax giuseng roots (crude GBD and its Partially Purified fraction from silicic acid column chromatography (7 : 3 GX) against sarcoma-180 (5-180) and Walker carcinosar- coma 256 (Walker 256) in vivo, and murine leukemic Lymphocytes (L1210) and human rectal cancer cells (HRT-18) and human colon cancer cells (HT-29 and HCT48) in vitro. Each cell-line was cultured in medium containing serial concentration of the crude GX or 7 : 3 GX in vitro. A highly lipid soluble compound in the extract of Panax ginseng root was cytocidal to murine leukemic cells and human colon and rectal cancer cells in vitro. In the meantime, ginseng saponin derivatives did not have cytotoxic effects at its corresponding concentration. The growth rates of the cancer cells in medium containing ginseng extracts were inhibited gradually to a significant degree roughly in proportion to the increase of the extract concentration. The cytotoxic activity of 7 : 3 GX was about 3 times more potent than that of crude GX, one unit of cytotoxic activity against L1210 cells being equivalent to 2.54 Ug and 058 Ug for the crude GX and 7 : 3 GX, respectively. The Ri value of the active compound on silica- gel thin layer chromatography with petroleum-ether/ethyl ether/acetic acid mixture (90 : 10 : 1, v/v/v) as a developing so lvent was 053. While, the Panaxydol and Panaxynol as active compounds were purified from Petroleum-ether extract of Panax ginseng root by Drs. Ahn and Kim, and author found out that the one unit of cytotoxic activity of the Panaxydol and Panaxynol against L1210 cells being equivalent to 056 Ug and 0.3918 respectively. The survival times of mice inoculated with S-180 cells were extended about 1.5 to 2 times by the 7 : 3 GX treatment compared with their control group. The significantly decreased hemoglobin values of rats after inoculation with Walker 256 were recovered to normal range by oral administration of the crude Gt The synthetic levels of protein, DNA and RNA in human colon and rectal cancer cells were significantly diminished by treatment with the crude GX, which can explain a part of the origin of its anticancer activity.

• Journal of the Microelectronics and Packaging Society
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• v.16 no.2
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• pp.33-42
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• 2009

A polymer-based flexible neural probe was fabricated for monitoring of neural activities from a brain. To improve the insertion stiffness, a 5 ${\mu}m$ thick biocompatible Au layer was electroplated between the top and bottom polymer layers. The developed neural probe penetrated a gel whose elastic modulus is similar to that of a live brain tissue without any fracture, To minimize mechanical residual stress and bending from the probe, two new methods were employed: (1) use of a thermal annealing process after completing the device and (2) incorporation of multiple different layers to compensate the residual stress between top and bottom layers. Mechanical bending around the probe tip was clearly removed after employing the two processes. In electrical test, the developed probe showed a proper impedance value to record neural signals from a brain and the result remained the same for 72 hours. In simple in-vitro probe characterization, the probe showed a great removal of residual stress and an excellent recording performance. The in-vitro recording results did not change even after 1 week, suggesting that this electrode has the potential for great recording from neuron firing and long-term implant performance.