• Bulletin of the Korean Chemical Society
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• v.17 no.11
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• pp.995-999
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• 1996

A method for the determination of cobalt(Ⅱ) by differential pulse voltammetry using a carbon paste electrode constructed by incorporating 1-(2-pyridylazo)-2-naphthol(PAN) into a conventional carbon paste mixture composed of graphite powder and Nujol oil has been developed. Several influencing factors for the determination of cobalt(Ⅱ) were studied in detail and the optimum analytical conditions were found to be as follows: pH, 4.6; composition of electrode, 20%; temperature of deposition, 43 ℃; time of preconcentration, 15 min. Regeneration of the electrode surface for the continuous uses of the electrode was achieved by exposing the carbon paste electrode to an acidic solution. Response of the electrode was reproducible for the uses of five times and the relative standard deviations were 6.7 and 4.6% for 2.0×10-5 M and 4.0×10-6 M cobalt(Ⅱ), respectively. The calibration curve for cobalt(Ⅱ) obtained by differential pulse voltammetry was divided into two linear ranges of 1.7× 10-6-1.3×10-4 M and 2.0×10-7-8.0×10-7 M. The detection limit was estimated to be 1.3×10-7 M. The effects of coexisting ions were also investigated to test the applicability of the proposed method to the determination of cobalt(Ⅱ) in real samples.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.3
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• pp.207-217
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• 1995

Extracting efficiencies of seven extracting solutions currently employed in extracting heavy metals from soils were compared and the functional relationships among them were calculated by regression analysis for Cd, Zn, Cu, and Pb. Extracting solutions employed were 0.1M HCl, 0.1M $HNO_3$, 0.05M EDTA, 0.001M DTPA(pH 7.3), 1M $NH_4OAc$ (pH 7.0), 0.1M $NH_4Ox$, and 4M $HNO_3$ respectively. Soil samples were collected from rice paddy fields near old zinc mining sites and from rice paddy fields near agro-industry complexes. Soils sampled from old zinc mining sites were also extracted using a sequential extraction method. Extraction by 4M $HNO_3$ and sequential extraction were performed on the samples collected both in 1979 and in 1991 to investigate the change in content and in chemical form of heavy metals. Functional relationships among the extracting solutions were highly correlated for Cd and Zn, whereas those for Cu and Pb were not. The predominant chemical form of Cd. Zn, Cu, and Pb in soils from old zinc mining sites was found to be of sulfide/residue form. The exchangeable form of Cd, the organically bound form of Cu, and the carbonate form of Pb were relatively high, while the sulfide/residue form of Zn was very high(> 79%). Although transformation among the extracted forms was not clear during those 12 years, a decrease in total content of Cd, Zn, Cu, and Pb was clearly observed.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.5281-5286
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• 2012

Purpose: Receptor 7 (CXCR7) has recently been characterized as a novel receptor for CXCL12/SDF-1 (stromal cell derived factor-1). Given the demonstrated importance of CXCL12/SDF-1 in angiogenesis and tumour metastasis, we hypothesized that CXCR7 may also play a role in tumour pathogenesis. Located in the limited space of the intracranial cavity, any brain tumours can be inherently serious and life-threatening. However, the expression of CXCR7 in pituitary adenoma, neurilemmoma or hemangioblastoma remains to be elucidated. Therefore, we aimed to determine the potential contribution of CXCR7 in the development of brain tumours. Methods: In this study we examined and quantified the mRNA expression of CXCR7 in four different human brain tumours - 27 patients with neurilemmoma (8 patients), pituitary adenoma (7 patients), hemangioblastoma (6 patients), or meningioma (6 patients) undergoing surgical resection in the West China Hospital of Sichuan University. There were 15 females and 12 males aged from 28 to 70 years old. Total RNA was isolated and mRNA was measured by quantitative real-time RT-PCR. One-way analysis of variance (ANOVA) was performed using SPSS 11.0 statistical software to compare the mRNA levels of CXCR7 among four groups. Results: We found that CXCR7 mRNA was detected in all tumour samples. Quantitative results showed that the levels of CXCR7 mRNA in brain tissues from patients with neurilemmoma or meningioma were significantly higher than those with pituitary adenoma or hemangioblastoma. Conclusions: The results suggest that the CXCR7 may play a role in progression, metastasis and angiogenesis of brain tumours.

• Analytical Science and Technology
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• v.23 no.5
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• pp.457-464
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• 2010

The analytical method of four pharmaceuticals (virginiamycin, erythromycin, tylosin and cimetidine) in drinking water was developed. Effective simultaneous sample clean-up and extraction by solid-phase extraction (SPE) using HLB cartridge prior to LC/ESI-MS/MS analysis were performed. A linear correlation observed in the calibration curves for drinking water in the range of 0.01~2.0 ng/mL showed above $r^2$=0.995. Absolute recovery was in the range of 64.7~118.1% (except cimetidine (37.7~48.1%)). Limit of detection (LOD) and limit of quantitation (LOQ) in spiked drinking water matrix were in the range of 1.6~74.8 pg/mL and 5.5~249.7 pg/mL, respectively. The established method can be used to determine low pg/mL levels of pharmaceuticals in the drinking water.

• The Korean Journal of Mycology
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• v.15 no.3
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• pp.149-157
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• 1987

This study was undertaken to investigate the differentiation, from spore germination to hyphae growth and phialide formation, of Aspergillus niger through the method of synchronous and submerged culture. Through continuous experiments by shake culture with potassium acetate medium, we observed the formation of spores at appropriate concentration and pH. Potassium acetate medium was set pH 5.5, 6.0, 6.5 and 7.0 on each scale, and control, 20 mM, and 40 mM, 80 mM and 160 mM concentrations on the other scale. Aspergillus niger was cultured in the defined media at $28^{\circ}C$, and mycelial dry weight, changes of pH and the onset of sporulation were checked. The mycelial dry weight, increased in potassium acetate medium, and pH increased during mycelial growth and gradually decreased after the spore formation. When pH increased excessively in Potassium acetate medium with pH 7.0, the mycelia could not adapt and mycelial dry weight decreased gradually. At pH 5.5, the onset of sporulation was done within one day at 20 mM it took, at 80 mM three days and at 160 mM concentration. in two days, at 40 mM one to four days were taken, 80 mM concentration respectively. At pH 6.5, the onset of sporulation was done in three days and four days at 80 mM concentrations respectively. Spore formation was not shown at pH 7.0. In controlled medium with all levels of pH, spore formation was not shown.

• Microbiology and Biotechnology Letters
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• v.17 no.3
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• pp.198-201
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• 1989

Steptomyces sp. GI 32 with high production of glucose isomerase was isolated from soil. The maximum enzyme production was observed in the culture medium containing 1% sorbitol, 0.6% tryptone, 0.4% yeast extract, 1mM Fe$_2$(SO$_4$)$_3$ with initial pH 7.0 when the cell was cultured at 35$^{\circ}C$ about 18 hours with shaking. The enzyme was partially purified by ammonium sulfate fractionation and DEAE cellulose chromatography. The enzyme was also appeared to be relatively thermostable, and no apopreciable inactivation was observed after incubation at 7$0^{\circ}C$ for 1 hour. The optimal pH and temperature of the enzyme were pH 8.0 and 7$0^{\circ}C$, respectively.

• Korean Journal of Plant Taxonomy
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• v.39 no.1
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• pp.24-28
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• 2009

The chromosome morphology of two Korean Lactuca (L. indica, L. triangulata) is reported herein. The chromosome number and karyotype of a naturalized plant, L. scariola are reported for the first time. The basic chromosome number was x = 9. Polyploid forms were not recorded. The karyotypes of L. indica, L. scariola, and L. triangulata were 2 n = 18 = 2 m+ 7 sm, 2 n = 18 = 1 m + 6 sm+ 2 st, 2 n = 18 = 2 m + 5 sm+ 2 st, respectively. Both L. indica and L. triangulata had satellites at the ends of their short arms. The haploid genome lengths of L. indica, L.scariola, and L. triangulata were $56.3{\mu}m$, $35.3{\mu}m$, and $72.5{\mu}m$ respectively. Each chromosome length of naturalized L. scariola was $2.7-5.2{\mu}m$; the smallest among Korean Lactuca. The chromosome lengths of L. indica and L. triangulata were $4.7-7.6{\mu}m$ and $2.9-7.9{\mu}m$, respectively. The karyotype of L. scariola differed from that of L.indica and L.triangulata both of which belong to sect. Tuberosae. Therefore, L. scariola is thought to belong to sect. Lactuca subsect. Lactuca.

• Bulletin of the Korean Chemical Society
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• v.20 no.12
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• pp.1409-1412
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• 1999

The spectrophotometric determination method of scandium with eriochrome cyanine R (ECR) and the composition ratio of the complex were investigated in the presence of surfactants. A volume of 5 mL of 1.0×$10^{-3}$ M ECR and 10 mL of 2.0×$10^{-4}$ M CTMAB are necessary for the determination of 1.0×$10 ^{-7}$ ~ 3.0×$10^{-6}$ M Sc(III) at pH 6.5. The apparent molar absorption coefficient of the Sc(III)-ECR-CTMAB, ternary complex at 610 nm is 5.6×$10^5$ $mol^{-1}cm{-1}$L and its detection limit is 1.0×$10^{-7}$ M. Separation studies were conducted by the column method. The effect of pH, elution solution and the influence of rare earth elements as interferents was discussed. Their separation was carried out in 0.1 M HCl-50% methanol solution and 1.0 M HCl media. The method was applied for the determination of Sc(III) in monazite.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.435-443
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• 2007

Antimicrobial susceptibility test of the 116 strains of Mycoplasma pneumoniae isolates were performed by a broth micro-dilution method against to moxifloxacin, levofloxacin, sparfloxacin, ofloxacin, ciprofloxacin, clarithromycin minocycline, erythromycin, josamycin, and tetracycline. The initial-minimum inhibitory concentration (I-MIC) was evaluated as the lowest concentration of antimicrobial agents that prevented a color change in the medium at that time when the drug-free growth control, about 7 days after incubation, and the final-minimum inhibitory concentration (F-MIC) was defined a color change about 14 days after incubation. The evaluation to the drug-resistant M. pneumoniae isolates were determined the $MIC{\pm}1.0$ ${\mu}g/ml$ of each antimicrobial agent. According to the I-MIC, single drug-resistant M. pneumoniae strains to ciprofloxacin, ofloxacin, clarithromycin and erythromycin were 79.3, 53.5, 10.3, and 7.8%, respectively. Two kinds of drug-resistant M. pneumoniae strains to ofloxacin and ciprofloxacin, or ciprofloxacin and clarithromycin were 42.2 and 9.5%. Three kinds of drug-resistant M. pneumoniae strains to erythromycin, ofloxacin, and ciprofloxacin, or ofloxacin, ciprofloxacin and clarithromycin were 6.9 and 6.0% . According to the F-MIC, single drug-resistant M. pneumoniae strains to tetracycline, ciprofloxacin, ofloxacin, minocycline,erythromycin, josamycin, clarithromycin and sparfloxacin were 91.4, 91.4, 91.4, 89.7, 68.1, 52.6, 28.5, and 11.2%, respectively. The incidence of two kinds of drug-resistant M. pneumoniae strains were from 20.7% to 91.4%, three kinds of drug-resistant M. pneumoniae strains were from 28.5% to 89.7%, four kinds of drug-resistant M. pneumoniae strains were 2.6%, five kinds of drug-resistant M. pneumoniae were from 2.6% to 21.6%, six kinds of drug-resistant M. pneumoniae strains were from 0.9% to 24.1%, seven kinds of drug-resistant M. pneumoniae strains were from 0.9% to 2.6%, and eight kinds of drug-resistant M. pneumoniae strains were 1.7%. These results suggest that sparfloxacin, moxifloxacin and levofloxacin might be promising antimicrobial agents for the treatment of M. pneumoniae infection in Korea. However, most strains of M. pneumoniae isolates were single or multi-resistance pattern to the other tested antimicrobial agents. Therefore, tetracycline, minocycline, erythromycin, clarithromycin, and second-generation quinolones are more carefully used to patients with M. pneumoniae infection in Korea.

• Journal of Aquaculture
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• v.19 no.1
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• pp.25-32
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• 2006

An experiment was carried out to investigate changing of water quality during the seed production of dark-banded rockfish Sebastes inermis in large scale tanks. Ten broodstock of dark-banded rockfish were held in three circular tanks (diameter 6.5 m; depth 2 m; water volume 50 ton) each (stocking density $0.061kg/m^3$). During the experiment the temperature ranged from 14.2 to $16.1^{\circ}C$. The fingerlings were 134 with rotifers only during 1 to 9 days after parturition, rotifers with Artemia nauplii during 10 to 20 days after parturition, Artemia nauplii only during 21 to 35 days after parturition, Artemia nauplii with commercial diet during 36 to 80 days after parturition and commercial diet only during 81 to 85 days after parturition. Water quality (dissolved oxygen, pH, $NH_4^+-N,\;NO_2^--N,\;NO_3^--N\;and\;PO_4^{3-}-P$) in rearing tanks measured every 5 days in long term monitoring investigation or every 2 hours in diurnal monitoring investigation. In 85 days after parturition, the body weight of fish grew up to 0.88 f and specific growth rate was 8.0%/day in body weight. In long term monitoring investigation, with the increase of the amount of supplied commercial diet, the concentration of dissolved oxygen (DO) and pH decreased, but the concentration of $NH_4^+-N\;(4.5\;to\;76.3{\mu}M),\;NO_2^--N\;(0.02\;to\;0.06{\mu}M),\;NO_3^--N\;(3.0\;to\;5.9{\mu}M)$, and $PO_4^{3-}-P\;(0.41\;to\;0.59{\mu}M)$ increased. In the diurnal monitoring investigation, the concentration of $NH_4^+-N$ showed great fluctuation and ranged from 3.0 to $9.1{\mu}M$ when fed rotifers, 16.3 to $45.8{\mu}M$ when fed Artemia nauplii and 36.5 to $120.1{\mu}M$ when fed commercial diet. After daily feeding with each of feed, the amount of dissolved inorganic nitrogen (DIN) and phosphorus (P) wastage were 7.0 g and 0.7 g when fed rotifers, 24.7 g and 0.7 g when fed Artemia nauplii and 140.9 g and 2.2 g when 134 commercial diet. The amount of DIN and phosphorous wastage during 134 commercial diet was significantly higher than that of fed rotifer and Artemia nauplii (P<0.05). Results will provide valuable information far water quality management and culture of dark-banded rockfish in commercial seed production systems.