• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.293-299
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• 2022

Recently, various stakeholder are interested in microplastic to cause pollution of the marine's ecosystem and effort to conduct study of product's life cycle to reduce pollution of marine's ecosystem. The micorplastic refer to materials of the nano- to micro- sized units and it can be classified into primary and secondary. The primary microplastic mean the manufactured for use in the specific field such as the microbead of the cosmetic or cleanser. also, secondary mean the unintentionally generated during use of the product such as the textile crumb by the doing the laundry. Tire and Road Wear Particles(TRWPs) are also defined as secondary microplastic. Typically, TRWPs are created by friction between the tread compound's rubber of the tire and the surface of the road du ring the driving cars. Most of the generated TRWPs exist on the roadside and some of them were carried to marine by the rainwater. In this study, we perform the quantitative analysis of the TRWPs existed in fine dust at the roadside. So, we collected the dust from the roadside in Chungcheongnam-do's C site with a movement of 1,300 cars per the hour. The collected samples were separated according to size and density. And shape analysis was performed using the Scanning Electron Microscope(SEM). We were possible to discover a lot of TRWPs at the fine dust of the 100 ± 20 ㎛. And we analysis it u sing the Thermo Gravimetric Analysis(TGA) and Gas Chromatography/Mass Spectrometer(GC/MS) for the quantitative components from the tire. As a result, it was confirmed that TRWPs generated from the roadside fine dust were included the 0.21 %, and the tire and road components in the generated TRWPs consisted of the 3:7 ratio.

• Korean Journal of Veterinary Service
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• v.31 no.3
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• pp.385-395
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• 2008

This study was carried out to investigate the residue level of fluoroquinolones in hen's general eggs and specific eggs by microbiological assay method and high performance liquid chromatography (HPLC) method. HPLC separation was carried out by reversed phase chromatography on a Symmetry $C_{18}$ (250${\times}$4.6 mm, $5{\mu}m$ particle size) with a phase composed of distilled water (containing 0.4% triethylamine and phosphoric acid) : Methanol (780 : 220, v/v), pumped isocratically at a flow rate of 1.0ml/min. A fluorescence detector was utilized with an excitation wavelength of 278nm and an emission wavelength of 456nm. The calibration curves were linear $({\gamma}^2{\geq}0.999)$ over a concentration range of $0.025{\sim}0.4{\mu}g/ml$. Average recoveries of the five fluoroquinolones in whole eggs at fortified levels of $0.05{\sim}0.2{\mu}g/g$ were ranged mean $78.1{\sim}91.7%$ and low coefficient of variation was less than 10% for all analysed samples. The limits of detection and limits of quantification for whole eggs were $1.2{\sim}6.0ng/g$ and $2.3{\sim}9.1ng/g$, respectively. Only one hen's general eggfrom chicken farm in Incheon was detected with the residual fluoroquinolones (Microbiological assay method; 1 of 47 general eggs) ; the range of residual concentration enrofloxacin was 0.12ppm. Those in food stores were detected with the residual fluoroquinolones (Microbiological assay method; 4 of 88 general eggs) ; the ranges of residual concentration enrofloxacin were $0.15{\sim}2.2 ppm$, ciprofloxacin $0.01{\sim}0.06ppm$, and hen's specific eggs (40) in food stores were not detected. For the microbiological assay method of fluoroquinolones in hen's eggs, as the results of comparative analysis, the disc diffusion method with E coli may be a little highly detected for the residual fluoroquinolones.

• Journal of Veterinary Clinics
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• v.21 no.4
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• pp.329-335
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• 2004

Dog spermatozoa were recovered from the caudae epididymides of 23 domestic dogs which were 11 pure breed and 12 mix-breed dogs ranging in age from 0.6 to 3 years. The experimental designs were as follows: 1) the effect of chilling to 0. 10 or 37$^{\circ}C$. 2) the kinetics of chilling injury at 0 or 4$^{\circ}C$, and 3) the effect of sugars at $0^{\circ}C$. Viable spermatozoa were recovered by percoll gradient separation and adjusted to 5${\times}$10$^{7}$ spermatozoa/ml. In experiment 1, spermatozoa were diluted with 0.33 M glucose supplemented with 3% BSA (G-BSA) at 1:2 dilution. Spermatozoa were loaded into straws and exposed at 0, 10 or 37$^{\circ}C$ for 30 min. In experiment 2, spermatozoa were prepared as the experiment 1 and exposed for 0.5, 5, 15, or 30 min at 0 or 4$^{\circ}C$. In experiment 3, spermatozoa were diluted with different sugars (0.33 M galactose, glucose, fructose, mannitol, lactose, sucrose, raffinose) and cooled to $0^{\circ}C$ for 30 min. Sperm membrane integrity, motility and acrosome integrity were assayed after rewarming at 37$^{\circ}C$ for 5 min. Sperm motility and membrane integrity abruptly decreased with decreasing temperature but acrosome integrity gradually decreased (P<0.05). Sperm motility was more sensitive to cold shock than membrane integrity and acrosome integrity. Spermatozoa cooled to $0^{\circ}C$ were more damaged than those at 4$^{\circ}C$. Sperm motility was not different among exposed times at both. 0 and 4$^{\circ}C$. However, membrane integrity of spermatozoa exposed for 30 min at both 0 and 4$^{\circ}C$ was significantly lower (P<0.05). Spermatozoa diluted in 0.33 M fructose or galactose showed lower motility and higher morphological abnormality with coiled tail at $0^{\circ}C$. These sperm characteristics were strongly related. These results indicate that dog epididymal spermatozoa are relatively sensitive to rapid cooling and higher morphological abnormality at $0^{\circ}C$ was shown in spermatozoa diluted in fructose and galactose.

• Journal of Information Display
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• v.2 no.3
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• pp.48-53
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• 2001

Carbon nanotube emitters, prepared by screen printing, have demonstrated a great potential towards low-cost, largearea field emission displays. Carbon nanotube paste, essential to the screen printing technology, was formulated to exhibit low threshold electric fields as well as an emission uniformity over a large area. Two different types of triode structures, normal gate and undergate, have been investigated, leading us to the optimal structure designing. These carbon nanotube FEDs demonstrated color separation and high brightness over 300 $cd/m^2$ at a video-speed operation of moving images. Our recent developments are discussed in details.

• Korean Journal of Pharmacognosy
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• v.47 no.4
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• pp.381-388
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• 2016

Hyangso-san is a traditional herbal medicine that consists of the seven herbal medicines, Cyperi Rhizoma, Perillae Folium, Atractylodis Rhizoma, Citri Unshius Pericarpium, Glycyrrhizae Radix et Rhizoma, Zingiberis Rhizoma Crudus, and Allii Fistulosi Bulbus. Hyangso-san has long been clinically used to treat the influenza, including headache, ferver, chills, and pantalgia. In this study, we were performed the simultaneous analysis of the 15 marker compounds (liquiritin apioside, liquiritin, ferulic acid, naringin, hesperidin, rosmarinic acid, liquiritigenin, kaempferol, glycyrrhizin, nobiletin, 6-gingerol, elemicin, atractylenolide III, nootkatone, and atractylenolide I) in Hyangso-san using liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS/MS). Column for the separation of the 15 ingredients was used a Waters Acquity UPLC BEH $C_{18}$ analytical column ($2.1{\times}100mm$, $1.7{\mu}m$) at $45^{\circ}C$ by using a mobile phase of 0.1% (v/v) formic acid in water and acetonitrile with gradient condition. Identifications of all analytes were performed using a Waters ACQUITY TQD LC-MS/MS system. The flow rate and injection volume were 0.3 mL/min and $2.0{\mu}L$, respectively. Correlation coefficient of the calibration curve was ${\geq}0.9958$. The values of limits of detection and quantification of the 15 components were 0.002-4.29 and 0.01-12.88 ng/mL, respectively. The result of an analysis using the established LC-MS/MS method, kaempferol and atractylenolide I were not detected, while other 13 compounds were 0.08-56.87 mg/g in lyophilized Hyangso-san sample.

• Applied Chemistry for Engineering
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• v.9 no.2
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• pp.306-310
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• 1998

The soluble polyimides(PMDA/diamine/dianhydride) were prepared and investigated. After coating the prepared PMDA/diamine/dianhydride solution into the commercial tubular alumina ceramic membranes, gas permeation characteristics was investigated. $T_g{\prime}s$ of the polyimides were in the range of $337{\sim}358^{\circ}C$ and thermal stability was good. The polymer was soluble in NMP, DMAc, DMSO, THF, and m-cresol. The adhesion between the alumina membrane and the soluble polyimide was excellent. The soluble polyimide/alumina membranes containing 6FDA showed the highest permeability among others. The permeability of nitrogen of PMDA/1,3PDA/6FDA-alumina membrane was about $7.6{\times}10^{-7}(mol/m^2{\cdot}Pa{\cdot}s)$ in the gas permeation experiments. The ideal separation factor of $O_2/N_2$ and $H_2/N_2$ in PMDA/1,3PDA/6FDA-alumina membrane were 6.19, and 70.0, respectively.

• Journal of Ginseng Research
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• v.40 no.2
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• pp.105-112
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• 2016

Background: Minor saponins or human intestinal bacterial metabolites, such as ginsenosides Rg3, F2, Rh2, and compound K, are more pharmacologically active than major saponins, such as ginsenosides Rb1, Rb2, and Rc. In this work, enzymatic hydrolysis of ginsenoside Rb1 was studied using enzyme preparations from cultured mycelia of mushrooms. Methods: Mycelia of Armillaria mellea, Ganoderma lucidum, Phellinus linteus, Elfvingia applanata, and Pleurotus ostreatus were cultivated in liquid media at $25^{\circ}C$ for 2 wk. Enzyme preparations from cultured mycelia of five mushrooms were obtained by mycelia separation from cultured broth, enzyme extraction, ammonium sulfate (30-80%) precipitation, dialysis, and freeze drying, respectively. The enzyme preparations were used for enzymatic hydrolysis of ginsenoside Rb1. Results: Among the mushrooms used in this study, the enzyme preparation from cultured mycelia of A. mellea (AMMEP) was found to convert ginsenoside Rb1 into compound K with a high yield, while those from G. lucidum, P. linteus, E. applanata, and P. ostreatus produced remarkable amounts of ginsenoside Rd from ginsenoside Rb1. The enzymatic hydrolysis pathway of ginsenoside Rb1 by AMMEP was $Rb1{\rightarrow}Rd{\rightarrow}F2{\rightarrow}$ compound K. The optimum reaction conditions for compound K formation from ginsenoside Rb1 were as follows: reaction time 72-96 h, pH 4.0-4.5, and temperature $45-55^{\circ}C$. Conclusion: AMMEP can be used to produce the human intestinal bacterial metabolite, compound K, from ginsenoside Rb1 with a high yield and without food safety issues.

• Herbal Formula Science
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• v.20 no.2
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• pp.37-46
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• 2012

Objectives : Oyaksungi-san(Wuyaoshunqisan) has been used for treatment of stroke and rheumatoid arthritis in Korea. In this study, a simple and accurate high-performance liquid chromatography(HPLC) method was established for simultaneous determination of six main components, liquiritin, ferulic acid, naringin, hesperidin, neohesperidin, and glycyrrhizin in Oyaksungi-san, a traditional Korean herbal prescription. Methods : The analytical column for separation of six constituents was used a Gemini $C_{18}$ column maintained at $40^{\circ}C$. The mobile phase consisted of two solvent systems, 1.0% (v/v) acetic acid in $H_2O$ (A) and 1.0% (v/v) acetic acid in acetonitrile (B) by gradient flow. The flow rate was 1.0 mL/min and the detector was a photodiode array (PDA) set at 254 nm for glycyrrhizin, 280 nm for liquiritin, naringin, hesperidin, and neohesperidin, and 320 nm for ferulic acid. Results : Calibration curves were acquired with $r^2$ values ${\geq}0.9998$. The results of recovery test were 91.58%-105.90% with a relative standard deviations (RSDs, %) value less than 2.0%. The values of RSD for intra- and inter-day precision were 0.03%-1.72% and 0.03%-1.63%, respectively. The contents of the six compounds in Oyaksungi-san were 0.33-9.30 mg/g. Conclusions : The newly established HPLC method will be helpful to improve quality control of Oyaksungi-san.

• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.742-753
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• 2012

Copper-containing compounds are introduced into the environment through agricultural chemicals, mining, and metal industries and cause severe detrimental effects on ecosystems. Certain microorganisms exposed to these stressors exhibit molecular mechanisms to maintain intracellular copper homeostasis and avoid toxicity. We have previously reported that the soil bacterial isolate Achromobacter sp. AO22 is multi-heavy metal tolerant and exhibits a mer operon associated with a Tn21 type transposon. The present study reports that AO22 also hosts a unique cop locus encoding copper homeostasis determinants. The putative cop genes were amplified from the strain AO22 using degenerate primers based on reported cop and pco sequences, and a constructed 10,552 base pair contig (GenBank Accession No. GU929214). BLAST analyses of the sequence revealed a unique cop locus of 10 complete open reading frames, designated copSRABGOFCDK, with unusual separation of copCD from copAB. The promoter areas exhibit two putative cop boxes, and copRS appear to be transcribed divergently from other genes. The putative protein CopA may be a copper oxidase involved in export to the periplasm, CopB is likely extracytoplasmic, CopC may be periplasmic, CopD is cytoplasmic/inner membrane, CopF is a P-type ATPase, and CopG, CopO, and CopK are likely copper chaperones. CopA, B, C, and D exhibit several potential copper ligands and CopS and CopR exhibit features of two-component regulatory systems. Sequences flanking indicate the AO22 cop locus may be present within a genomic island. Achromobacter sp. strain AO22 is thus an ideal candidate for understanding copper homeostasis mechanisms and exploiting them for copper biosensor or biosorption systems.

• Journal of Radiation Protection and Research
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• v.41 no.3
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• pp.253-259
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• 2016

Background: This study investigated the effects of zoledronic acid (ZA) on radiation-induced bone loss in C3H/HeN mice. Materials and Methods: C3H/HeN mice were divided into sham control and three irradiated groups (3 Gy, gamma ray). The irradiated mice were treated for 12 weeks with vehicle, amifostine (intraperitoneal injection), or ZA (subcutaneous injection). Grip strength, uterus weight, and serum alkaline phosphatase (ALP), and tartrate-resistant acid phosphatase (TRAP) levels were measured. Tibiae were analyzed using micro-computed tomography. Results and Discussion: Treatment of ZA ($100{\mu}g{\cdot}kg^{-1}{\cdot}week^{-1}$) significantly preserved trabecular bone volume, trabecular thickness, trabecular number, trabecular separation, bone mineral density of proximal tibia metaphysic, and cortical bone volume, but did not alter the uterus weight of the mice. The administration of ZA for 12 weeks lowered serum ALP and TRAP levels in irradiated mice, suggesting that ZA can reduce the bone turnover rate in mice. No differences were apparent between the amifostine-treated group and the irradiation control group. Conclusion: The results indicate that ZA can prevent radiation-induced bone loss in mice.