• Analytical Science and Technology
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• v.23 no.3
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• pp.278-283
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• 2010

This study was performed to compare the analytical results among L2000DX and two GC/ECD methods (rapid and conventional). 15 samples of transformer oils were collected to compare the analytical results. In the analytical results of PCBs-containing transformer oil, the PCBs concentrations were in the range of 4.4 mg/L to 182.8 mg/L with L2000DX, N.D. to 14.63 mg/L with conventional GC/ECD, and N.D. to 13.03 mg/L using rapid GC/ECD. The PCB concentrations detected with the L2000DX showed a large difference to those detected with GC/ECD methods. Otherwise, little difference was shown between the two GC/ECD methods at a concentration range lower than 4 mg/L, although the rapid GC/ECD method tended to detect a slightly lower concentration near the regulation criteria of Korea for 2 mg/L.

• The Korea Journal of Herbology
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• v.27 no.5
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• pp.15-20
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• 2012

Objectives : The purpose of this study was to estimate the antioxidant activity of water extract of Nelumbinis stamen (WNS) in GC-2 spd (ts) cells. Methods : we investigated the effect of WNS in mouse GC-2 spd (ts) cells by MTT assay. The protective effects of WNS against hydrogen peroxide-induced oxidative stress in GC-2 spd (ts) cells were examined by measuring cell viability. Lipid peroxidation levels and catalase were measured. Results : WNS showed cell viability as 101.9, 108.9, 111.8, 125.8, 134.5% in 2.5, 5, 10, 25, 50 ${\mu}g/ml$ concentrations, respectively. The protective effect of WNS concentration was 2.5 ${\mu}g/ml$ against hydrogen peroxide-induced oxidative stress in GC-2 spd (ts) cells. LPO were decreased significantly at 2.5, 5, 25 ${\mu}g/ml$ of WNS concentrations. Catalase activity was significantly increased at 2.5, 5 and 10 ${\mu}g/ml$ of WNS concentrations, respectively. Conclusions : In conclusion, WNS has antioxidant activities in GC-2 spd(ts) cells against oxidative stress.

• Biomolecules & Therapeutics
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• v.8 no.2
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• pp.171-178
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• 2000

To evaluate the pharmacokinetic properties and tissue distribution of a newly developed recombinant human erythropoietin (GC-rhEPO), we analyzed the plasma and tissue levels of erythropoietin by an ELISA after intravenous (IV) and subcutaneous (SC) adminstration to the male rats at the doses of 20, 100, 500 or 2,500 unit/kg. After single IV bolus injection of GC-rhEPO, the plasma concentration was rapidly increased and decreased with two phases with half-lives of 13.4 min and 2.94 hours. AUC was increased dose- dependently but plasma half-lives remained constant regardless of GC-rhEPO doses. Following SC administration, the plasma concentration increased slowly with half-life of 9.2 hours and reached peak at 8 hours. Mean residence time and bioavailability were 18.2 hours and 44%, respectively. After single IV dose of 100 unit/kg, tissue GC-rhEPO level was higher in bone marrow and spleen, while the depletion rate was slower in liver and bone marrow, indicating the higher affinity of GC-rhEPO to bone marrow. Taken together, the experimental results indicate that GC-rhEPO contained the typical pharmacokinetic properties and the tissue distribution patterns inherent to human erythropoietin.

• Korean Journal of Animal Reproduction
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• v.17 no.3
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• pp.233-242
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• 1993

The effects of in vitro maturation and sperm treatment condition on the in vitro fertilization (IVF) and developmental capacity of bovine oocytes were investigated and the development of embryos was compared under the 2 different co-culture system, with GC or BOEC. The cultured embryo to 16 cell or morula wre transferred into recipients or frozen by 2 different freezing method. The results obtained were summarized as follows; 1. In vitro maturation rates of vovine follicular oocytes cultrued in TCM199 with 10% FCS or ECS were 64.0% and 72.7%, but the case of addition of 10% FCS or ECS to TCM199 co-cultured with granulosa cells were 81.3% and 84.0%, respectively. IVM rate of three TCM199 added to granulosa cells was higher than that of media without granulosa cells. 2. When bovine follicular oocytes were matured in TCM199 with 10% FCS and GC and then fertilized in vitro by sperm treated with caffeine, embryo developments of bovine oocytes co-cultured with BOEC were 38.4% and 51.4%, respectively. But those of bovine oocytes co-cultured with GC were 52.2% by sperm treated with caffeine-heparin. 3. Cleavage rates of bovine oocytes cultured with 10% FCS alone and fertilized in vitro by sperm treated with caffeine-heparin was 33.0%. 4. When bovine follicular oocytes were matured in TCM199 with 10% FCS and GC, embryo developments of bovine ooctyes co-cultured with BOEC of GC were 46.0% and 50.2%, respectively. 5. When bovine follicular oocytes were matured in TCM199 with 10% ECS and GC, embryo developments co-cultured with BOEC or GC were 45.2% and 51.4%, respectively. 6. When Korean Native cow's follicular oocytes matured in TCM199 with 10% FCS and GC, embryo developed co-cultured with BOEC or GC were 45.2% and 51.4%, respectively. 6. When Korean Native cow's follicular oocytes matured in TCM199 with 10% FCS and GC, embryo developments of the bovine oocyte co-cultured with BOEC and GC were 41.8% and 60.1%. But with FCS 10% those of the bovine oocytes co-cultured with BOEC and GC were 42.0% and 48.4%, respectively. 7. When Holstein's follicular oocytes were matured in TCM199 with 10% ECS and GC, embryo developments fo the bovine oocytes co-cultured with BOEC and GC were 50.0% and 57.7%, but with ECS 10% those of the bovine oocytes co-cultured with BOEC and GC were 52.2% and 56.5%, respectively. 8. The viability of frozen-thawed embryos ranged from 60~80% and those of frozen-thawed embryos from vitrification was lower than that from conventional metiod. 9. The selected fresh embryos were transferred nonsurgically to 7 recipients but did not result in pregnancy.

• Journal of Gastric Cancer
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• v.22 no.4
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• pp.348-368
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• 2022

Purpose: Chromosomal instability is a hallmark of gastric cancer (GC). It can be driven by single nucleotide variants (SNVs) in cell cycle genes. We investigated the associations between SNVs in candidate genes, PLK2, PLK3, and ATM, and GC risk and clinicopathological features. Materials and Methods: The genotyping study included 542 patients with GC and healthy controls. Generalized linear models were used for the risk and clinicopathological association analyses. Survival analysis was performed using the Kaplan-Meier method. The binding of candidate miRs was analyzed using a luciferase reporter assay. Results: The PLK2 C_rs15009-C_rs963615 haplotype was under-represented in the GC group compared to that in the control group (P_corr=0.050). Male patients with the PLK2 rs963615 CT genotype had a lower risk of GC, whereas female patients had a higher risk (P=0.023; P=0.026). The PLK2 rs963615 CT genotype was associated with the absence of vascular invasion (P=0.012). The PLK3 rs12404160 AA genotype was associated with a higher risk of GC in the male population (P=0.015). The ATM T_rs228589-A_rs189037-G_rs4585 haplotype was associated with a higher risk of GC (P<0.001). The ATM rs228589, rs189037, and rs4585 genotypes TA+AA, AG+GG, and TG+GG were associated with the absence of perineural invasion (P=0.034). In vitro analysis showed that the cancer-associated miR-23b-5p mimic specifically bound to the PLK2 rs15009 G allele (P=0.0097). Moreover, low miR-23b expression predicted longer 10-year survival (P=0.0066) in patients with GC. Conclusions: PLK2, PLK3, and ATM SNVs could potentially be helpful for the prediction of GC risk and clinicopathological features. PLK2 rs15009 affects the binding of miR-23b-5p. MiR-23b-5p expression status could serve as a prognostic marker for survival in patients with GC.

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3123-3127
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• 2010

A highly sensitive electrochemical detection method for dopamine (DA) has been developed by relying on a multiwalled carbon nanotube (CNT)-sol-gel titania-Nafion composite film modified glassy carbon (GC) electrode. The CNT-titania-Nafion/GC electrode exhibited excellent electrocatalytic activity towards DA. Therefore, the CNT-titania-Nafion/GC electrode showed improved voltammetric and amperometric responses for DA compared to those obtained with both titania-Nafion/GC and Nafion/GC electrodes. The CNT-titania-Nafion/GC electrode gave a linear response ($R^2$ = 0.999) for DA from $0.5\;{\mu}M$ to 0.5 mM with a detection limit (S/N = 3) of $0.1\;{\mu}M$ and a good sensitivity of 150 mA/M while other electrodes such as CNT-Nafion/GC, titania-Nafion/GC, and a bare GC gave a sensitivity of 89, 39, and 36 mA/M, respectively. Besides, the CNT-titania-Nafion/GC electrode displayed very fast response time within 2 s. The modified electrode showed good selectivity against ascorbic acid. The modified electrode showed good stability and reproducibility. The CNT-titania-Nafion/GC electrode was applied to the determination of DA in urine and serum samples.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.10 no.1
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• pp.126-146
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• 2000

To develop and evaluate formaldehyde measurement method using 2,4-dinitro-phenylhydrazine (2,4-DNPH) coated sampler and gas chromatography, laboratory test and field test were conducted. Results of this study are as follows. Limit of detection(LOD) of measurement methods, HPLC-UVD, GC-NPD and GC-FID, is $0.008{\mu}g/m{\ell}$ $0.060{\mu}g/m{\ell}$, $0.472{\mu}g/m{\ell}$ respectively. Coefficiency of measurement methods, HPLC-UVD, GC-NPD and GC-FID, is 0.008, 0.009, 0.020 respectively. Desorption efficiency of sep-pak xposure aldehyde sampler and sorbent sample tube is 1.05(range : 0.99 - 1.12), 1.02(range : 0.99 - 1.06) respectively. Samples of sorbent sample tube and sep-pak xposure aldehyde sampler turned out to be stored at refrigerator, according to storage test results. Measurement methods of HPLC-UVD, GC-NPD, GC-FID, according to results of precision for the combined sampling and analytical procedure, became acceptable to OSHA evaluation standard. Field test using exposure chamber met the NIOSH overall uncertainty recommendation(less than 25%). Overall uncertainty of Sepak-HPLC(UVD), Tube-GC(NPD), Tube-GC(FID) is 11.0% - 17.0%. Consequently gas chromatography(GC-NPD, GC-FID) and high performance liquid chromatography(EPA TO-11) using 2,4-DNPH coated sampler for formaldehyde measurement turned out to be suitable to measure personal formaldehyde exposure at workplaces.

• Journal of Environmental Science International
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• v.6 no.2
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• pp.183-187
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• 1997

Organophosphate pesticides were extracted with 70% acetone and then transferred to dichloromethane. Extracts were applied to open-column chromatography with florisil. The florial extract was analyzed by gas chromatography with nitrogen-phosphorus detector(GC/NPD). Recoveries of the 18 organophosphate pesticides were ranged from 88.7% to 100. 0% for the narrow-bore capillary GC(Ultra-21. The minimum detectable level of this analytical method was 0.019 - 0.035 mg/kg. Sample throughput(extraction, open-column chro- matography, and GC analysts) was decreased considerably (8h per sample).

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.68.2-68.2
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• 2012

We present a discovery of two new globular clusters in the Hubble Space Telescope archive images of the M81 group. They are located much farther from both M81 and M82 in the sky, compared with previously known star clusters in these galaxies. Both clusters show that higher luminosity and larger effective radius than typical globular clusters in Milky Way and M81. Using the available spectroscopic data provided by the Sloan Digital Sky Survey, we derive a low metallicity with [Fe/H] ${\approx}$ -2.3 and an old age ~14 Gyr for GC-2. The I-band magnitude of the tip of the RGB for GC-1 is consistent with that of the halo stars in the GC-1 and GC-2 field. However, that of GC-2 is 0.26 mag fainter than its field. It shows that GC-2 is about 400 kpc behind the M81 halo along our line of sight. The deprojected distance to GC-2 from M81 is much larger than any other known globular clusters in the local universe. We discuss the possible scenarios to explain the existence of globular cluster in such an extremely isolated environment.

• Bulletin of Food Technology
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• v.22 no.2
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• pp.255-264
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• 2009