• Progress in Medical Physics
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• v.25 no.3
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• pp.123-127
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• 2014

The Cs-137 irradiator is widely used to irradiate biological samples for radiobiological research. To obtain the accurate outcomes, correct measurements of the delivered absorbed dose to a sample is important. The IAEA protocols such as TRS-277 and TRS-398 were recommended for the Cs-137 reference dosimetry. However in TRS-398 protocol, currently known as the most practical dosimetry protocol, the quality factor ($k_{Q,Q_0}$) for Cs-137 gamma rays is not suggested. Therefore, the use of TRS-398 protocol is currently unavailable for the Cs-137 dosimetry directly. The calculation method previously introduced for high energy photon beams in radiotherapy was used for deriving the Cs-137 beam qualities ($k_{Q,Q_0}$) for the 15 commercially available farmer type ionization chambers in this study. In conclusion, $k_{Q,Q_0}$ values were ranged from 0.998 to 1.002 for Cs-137 gamma rays. These results can be used as the reference and dosimeter calibrations for Cs-137 gamma rays in the future radiobiological researches.

• Journal of Life Science
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• v.22 no.7
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• pp.950-957
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• 2012

Development of garlic processing products by thermal treatment and researched biological activity of a new product, red garlic. Red garlic MeOH extract was graduated by solvents, such as hexane, chloroform, ethyl acetate, butanol, and water, in order. Each solvent fraction was dried by a rotary evaporator and then resolved in water for analysis of its antioxidant and antiobesity activity. Browning compounds of red garlic fractions were the highest in the chloroform fraction. Total phenolic compounds and flavonoid content were highest in the hexane fraction. The chloroform fraction showed significantly higher activity in DPPH, ABTS radical scavenging activity, and antioxidant activity by FRAP. We propose that the antioxidant activity of the solvent fractions from red garlic was revealed interaction of browning compounds, total phenolic compounds, and flavonoids. Due to the higher activity of the shown fraction, the hexane and the chloroform fractions were have high contents of these compounds. Below $500{\mu}g/ml$, pancreatic lipase inhibition activity was significantly increased by sample concentration. And chloroform fraction, have the highest inhibition activity was shown over the 40%. In 3T3-L1 cells, the lipid accumulation inhibition activity was lower in the hexane and in the chloroform fraction than in the other fractions.

• Journal of the Korean Geosynthetics Society
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• v.16 no.3
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• pp.21-30
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• 2017

Cement grouting method is generally applied for the purpose of reinforcement of deteriorated reservior. Problems have been raised due to the limit of the injection material. In order to solve these problems, various grout materials have been developed. However, there are many cases in which the grounds are disturbed in actual field. In this study, the physical properties of hybrid grout with high fineness and high viscosity characteristics were analyzed to enable penetration into the ground. Optimum inflation agent was selected and mixed with the grout. The pressure and compaction effect on expansion was examined and its effectiveness was verified. From the result of confirming expansion ratio, uniaxial compressive strength, expansion pressure and compaction effect, the HI-E (2%) sample was analyzed to be excellent in improvement effect by the inflation agent. Hence, hybrid grout can be effectively applied for the impermeable and reinforcement method of deterioration reservoir and tide embankment.

• Korean Journal of Environment and Ecology
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• v.30 no.3
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• pp.308-319
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• 2016

The purpose of this study is to identify distribution patterns of hydrophytes in the Mokpo wetland in relation to the depth of water. Sample surveys were conducted based on plant species distribution status and water depths at 274 spots. This study also developed a detailed depth distribution map for Mokpo wetland, which was never done in any previous studies. Through this study, it was found that the average depth of the wetland was 77cm (${\pm}29cm$) and the maximal depth was 157cm. The outer edge was no deeper than 60cm and the center approximately 120~130cm in depth, forming a concave bowl-like shape. This research confirmed inhabitation of 6 types of submerged plants (Verticillate hydrilla, Vallisneria natans, Najas graminea, Potamogeton cripus, Ceratophyllum demersum, and Potamogeton brechtoldi), and three types of floating leaved plants (Euryale ferox, Hydrocharis dubia and Trapa japonica) in the surveyed areas of the wetland. The distribution of these hydrophytes showed a statistically significant difference (${\chi}^2=982.2$, df = 8, p < 0.01), which confirms the fact that distribution varies based on environmental conditions. The most frequently observed species was Trapa japonicas at 244 times, and it showed a distribution pattern by which coverage increased with greater depth, as was also seen in the case of Potamogeton cripus. Five species-Euryale ferox, Hydrocharis dubid, Verticillate hydrilla, Najas graminea, and Ceratophyllum demersum-showed a negative correlation to depth, by which coverage decreased with increasing depth. It has been shown that fundamentally, the distribution of hydrophytes based on depth is affected by ecological factors, but also reflects the environmental properties of Mokpo wetland.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.2
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• pp.80-87
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• 2017

Purpose: The aim of this study was to assess the physical properties of a novel resin-based endodontic sealer, Any-Seal, in comparison with AH Plus Jet. Materials and Methods: Flow, radiopacity and compressive strength were examined according to ISO 6876/2001. For flow test, 0.05 mL of sealer was placed between glass plate and 100 g weight were applied. Ten minutes after mixing the sealers, the load was removed and the diameters of the compressed sealer discs were measured. For radiopacity, 10 mm diameter and 1 mm thickness sample were fabricated and took radiograph with an aluminum step-wedge and analyzed using imaging program. For compressive strength test, $4mm{\times}6mm$ cylindrical specimen was fabricated and tested after 24 hours and 1 week using Universal testing machine. Results: Both tested sealers were consistent with ISO 6876/2001 in the flow and radiopacity test. The flow values of both sealers were not significantly different (P > 0.05). AH Plus Jet had significantly higher radiopacity (P < 0.05). AH Plus Jet showed higher compressive strength at both time intervals (P < 0.05). Conclusion: Any-Seal showed low compressive strength until after 1 week, so its physical and biological aspect should be evaluated more before clinical use.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.12
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• pp.1893-1898
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• 2013

Seaweeds, laver, sea mustard, kelp, and fusiformis, were prepared and investigated for its antioxidant and tyrosinase inhibition activities. The extracts yield, color, total phenolic contents, antioxidative activity, and tyrosinase inhibition activity of the extract samples were measured. Hunter Lightness values of laver, sea mustard, kelp, and fusiformis extracts were 82.88, 78.53, 83.04, and 78.11, respectively. The contents of total phenolic compounds of the seaweed extracts powder, laver, sea mustard, kelp, and fusiformis were 43.23, 11.59, 10.09, and 46.59 mg/g of sample, respectively. 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of the fusiformis extract was shown to be the highest value compared with other seaweed extracts. 2,2'-azino-bis-3-ethylbenzo-thiazoline-6-sulfonic acid (ABTS) radical scavenging activities of laver, sea mustard, kelp, and fusiformis extracts were 258.00, 219.26, 95.77, and $1186.62{\mu}mol$ trolox equivalence per gram, respectively, at the 1,000 ppm level. TBARS value of oil emulsion, samples without extracts was higher than those of the samples prepared with laver and sea mustard extracts. The inhibition rates (%) of the mushroom tyrosinase of laver, sea mustard, kelp, and fusiformis extracts powder were 25.93, 26.32, 24.76 and 20.24% at 1,000 ppm, respectively. The results indicated that laver, sea mustard, kelp and fusiformis extracts possess biological activities such as antioxidant activity and tyrosinase inhibition effect.

• Journal of Life Science
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• v.26 no.5
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• pp.503-508
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• 2016

Biosensors have been used as first-step monitoring tools to detect on-site samples in a simple and cost-effective manner. Numerous recombinant microbial biosensors have been exploited for monitoring on-site toxic chemicals and biological signals. Herein, a recombinant microbial biosensor was constructed for monitoring cadmium. The cadmium responding cadC regulatory gene and it’s promoter from Staphylococcus aureus was amplified through PCR, fused with the lacZ gene, and transformed into Escherichia coli BL21 (DE3) cells. In the presence of cadmium, the biosensor cells express β-galactosidase showing red color development with chlorophenol red β-galactopyranoside (CPRG) as the enzymatic substrate. The biosensor cells showed the best β-galactosidase activity after 3 hr induction with cadmium at pH 5 and a detection range from 0.01 μM to 10 mM cadmium with a linearity from 0.01 to 0.1 μM cadmium (y = 0.98 x + 0.142, R² = 0.98). Among the heavy metals, cadmium and lead showed good responses, tin and cobalt showed medium responses, and mercury and copper showed no responses. The biosensor cells showed good responses to several waste waters similar to buffer solution, all spiked with cadmium. The biosensor described herein could be applied for on-site cadmium monitoring in a simple and cost-effective manner without sample pretreatments.

• Korean Journal of Food Science and Technology
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• v.39 no.2
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• pp.200-208
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• 2007

Fifty-four natural plants from Jeju Island, Korea were extracted by 70% methanol. The extracts containing the highest total phenolic contents (TPC) (>250 mg gallic acid equivalents/g dry sample) were obtained from Ostrya japonica, Geranium thunbergii, Malus sieboldii, Ardisia japonica, and Agrimonia pilosa. DPPH inhibition activity was greatest in Ardisia crenata at 94.1%. A high correlation was observed between DPPH inhibition activity and TPC ($R^2=0.87$). Tyrosinase inhibition activities of more than 85% were obtained from the extracts of Persicaria filiformis, Rhus javanica, Alnus firma, and Myrica rubra. On the other hand, the P. filiformis and M. rubra extracts each showed more than 90% XOD inhibition activity. The five natural plants with the highest biological activities were also extracted by pressurized liquid (PLE, 100% methanol, 13.6 MPa, $40^{\circ}C$). The DPPH and tyrosinase inhibition activities were almost the same in both the 70% methanol and PLE extracts. The $IC_{50}$ for tyrosinase and elastase inhibition activities in PLE were 802 and 88 ppm in A. japonica, and 959 and 66 ppm in M. rubra, respectively.

• Parasites, Hosts and Diseases
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• v.51 no.6
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• pp.689-694
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• 2013

Opisthorchis viverrini and Clonorchis sinensis are parasites known to be carcinogenic and causative agents of cholangiocarcinoma in Asia. The standard method for diagnosis for those parasite infections is stool examination to detect parasite eggs. However, the method has low sensitivity, and eggs of O. viverrini and C. sinensis are difficult to distinguish from each other and from those of some other trematodes. Here, we report a multiplex real-time PCR coupled with high resolution melting (HRM) analysis for the differentiation of O. viverrini and C. sinensis eggs in fecal samples. Using 2 pairs of species-specific primers, DNA sequences from a portion of the mitochondrial NADH dehydrogenase subunit 2 (nad 2) gene, were amplified to generate 209 and 165 bp products for O. viverrini and C. sinensis, respectively. The distinct characteristics of HRM patterns were analyzed, and the melting temperatures peaked at $82.4{\pm}0.09^{\circ}C$ and $85.9{\pm}0.08^{\circ}C$ for O. viverrini and C. sinensis, respectively. This technique was able to detect as few as 1 egg of O. viverrini and 2 eggs of C. sinensis in a 150 mg fecal sample, which is equivalent to 7 and 14 eggs per gram of feces, respectively. The method is species-specific, rapid, simple, and does not require fluorescent probes or post-PCR processing for discrimination of eggs of the 2 species. It offers a new tool for differentiation and detection of Asian liver fluke infections in stool specimens.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.2
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• pp.77-86
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• 2002

Soil color characteristics were measured by a optical instrument, colorimeter, comparing with the conventional Munsell color chart and related to the chemical properties of soils. Total of the 67 experimental soils were taken from tobacco fields that located at Cheongwon, Enmseong, Boeun, Goesan, Jincheon, and Chungju countries in Chungbuk Province having the 29 soil series including Samgag. The values of L, a, and b measured by colorimeter were closely related with hue, value, and chroma of Munsell color chart, respectively, indicating the quantitative measurement of soil color characteristics. The standard deviations in measurement for L, a, and b values was smaller in soil sample passed by 0.5 mm sieve than 2 mm sieve, suggesting that soil particle size less than 0.5 mm was better condition for colorimeter measurement. The values of L and b measured by colorimeter showed a tendency to decrease as increase of soil moisture content but nearly on difference with moisture condition for the value of a. However, correlation coefficient between air dry samples and wet soil samples(soil moisture retension of -10 hPa) for measurements of L, a and b value were more than 0.9 showing the same tendency in measurement. Consequently, air dry soil passed by 0.5 mm sieve was recommended to desirable conditions for stable measurement by colorimeter. The measured values by colorimeter were significantly correlated with organic matter, CEC, exchangeable Ca and Mg, showing the highest correlation coefficient between L value and organic matter.