• Analytical Science and Technology
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• v.19 no.4
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• pp.290-300
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• 2006

Disinfection by-products(DBPs), such as volatile trihalomethanes and the nonvolatile organochlorine acids, created by chlorination have been extensively studied. However MX which contributes 20-50% of the mutagenic activity in drinking water began to people's attention since 1990. Its chemical name is 3-chloro-4-dichloromethyl-5-hydroxy-2(5H)-furanone. According to WHO guidelines its concentration should be controlled, but its value has not been set up. Due to analytical difficulties in measuring this compound at such a low concentrations and lack of information on toxicity to human. Because concentration (ng/L) of MX in drinking water is low traditional testing methods are ineffective. Therefore this study compared LLE and SPE and have chosen SPE to improve preconcentration. MX has been identified in chlorinated drinking water samples in several countries but not in korea Therefore this study analyzed concentration of MX in different water sources and in spring water. This study examined the causes of changing MX content. Chlorine dosage, seasons, water temperature and distance from the source was all discoverd to be relavant. MX was analyzed in various treatment to find optimum disinfection methods. The outcome was that the concentration of MX was minimized when using biological activated carbon-O3 and granular activated carbon.

• Natural Product Sciences
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• v.29 no.2
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• pp.74-82
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• 2023

Nepeta sibirica L. or Siberian catmint is a medicinal plant species used in Mongolian traditional medicine for curing human different disorders and veterinary practices. The previous study of the whole plant concentrated on the determination of its essential oil composition and reported that the major ones are sesquiterpenes, including nepetalactone. The aim of this study was to reveal a new biological activity of the above-ground parts of N. sibirica L. and compare the activity of different extracts correlating with the content of biologically active compounds and evaluate their toxicity. For this purpose, anti-oxidative and acetylcholinesterase inhibitory activities of the above-ground parts of N. sibirica L. aqueous and ethanol (EtOH) (40%, 70%) extracts were assayed spectrophotometrically. The aqueous extract showed positive anti-oxidative activity by both tested DPPH and FRAP assays with IC₅₀ 134.24 ± 1.42 mg/mL and FRAP value 1385.15 ± 8.12 µmol/L at 200 ㎍/mL, in contrast to 40% and 70% EtOH extracts. The 70% EtOH extract presented the highest acetylcholinesterase inhibitory activity (IC₅₀ 77.29 ± 0.38 mg/mL) followed by 40% EtOH extract (176.72 ± 0.35 mg/mL) and aqueous extract (275.41 ± 0.23 mg/mL). Total phenolics were found to be gallic acid equivalent, % 3.74 ± 0.05 (70% EtOH), 3.94 ± 0.04 (40% EtOH), and 3.79 ± 0.16 (aqueous), whereas the total flavonoids as a rutin equivalent, % as 2.01 ± 0.12, 1.44 ± 0.17 and 1.99 ± 0.02, each. The aqueous extract showed the best anti-oxidative and lowest activity against the acetylcholinesterase; however, the 70% EtOH extract showed the opposite effects than that of the aqueous. No mortality incidence was visible at various doses, indicating that the oral median lethal dose of aqueous and 70% EtOH extracts were considered greater than 5000 mg/kg. N. sibirica L. belongs to the non-toxic category of the OECD 423 classification.

• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.339-347
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• 2023

Dissolved organic matter (DOM) is a key component in the biogeochemical cycling in freshwater ecosystem. However, it has been rarely explored, particularly complex river watershed dominated by natural and anthropogenic sources, such as various effluent facility and livestock. The current research developed a new analytical method for TOC/TN (Total Organic Carbon/Total Nitrogen) stable isotope ratio, and distinguish DOM source using stable isotope value (δ¹³C-DOC) and spectroscopic indices (fluorescence index [FI] and biological index [BIX]). The TOC/TN-IR/MS analytical system was optimized and precision and accuracy were secured using two international standards (IAEA-600 Caffein, IAEA-CH-6 Sucrose). As a result of controlling the instrumental conditions to enable TOC stable isotope analysis even in low-concentration environmental samples (<1 mgC L^-1), the minimum detection limit was improved. The 12 potential DOM source were collected from watershed, which includes top-soils, groundwater, plant group (fallen leaves, riparian plants, suspended algae) and effluent group (pig and cow livestock, agricultural land, urban, industry facility, swine facility and wastewater treatment facilities). As a result of comparing characteristics between 12 sources using spectroscopic indices and δ¹³C-DOC values, it were divided into four groups according to their characteristics as a respective DOM sources. The current study established the TOC/TN stable isotope analyses system for the first time in Korea, and found that spectroscopic indices and δ¹³C-DOC are very useful tool to trace the origin of organic matter in the aquatic environments through library database.

• Journal of fish pathology
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• v.36 no.2
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• pp.337-348
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• 2023

This study was undertaken to evaluate the effect of amprolium hydrochloride on detoxification process of olive flounder Paralichthys olivaceus. A series of two experiment was performed based on the LD₅₀ value obtained for amprolium. First, thirty flounder (average weight 230.27 g; average length 27.99 cm) was randomly allocated into five groups. Treatment was carried out using intra-muscular injection of amprolium at the dose levels of 4, 8, 16, and 32 mg/kg body weight. At 8, 24 and 48 h post injection, liver and kidney were collected for expression assay of drug metabolizing enzymes and pro-inflammatory cytokine genes. We found that the interleukin-1β (IL-1β) mRNA level were induced at 32 mg/kg and CYP1A genes showed the opposite pattern, while UDP-glucuronosyl-transferase (UGT1A7) and GST were significantly reduced in the liver. Moreover, the suppression of drug metabolizing enzymes and cytokine gene in the kidney was observed after treatment. Another treatment was carried out using intramuscular injection with 4, 8, 16, and 32 mg/kg and 60, 80, 100, 120 mg/kg body weight. At 6 days post injection, liver was collected. The IL-1β expression was markedly induced in the experimental group treated with 4 mg/kg. In addition, glutathione S-transferase (GST) mRNA level was higher in the group with 4 mg/kg. In conclusion, our data suggests that amprolium seem to cause direct or indirect physical, or biological toxicity of flounders, although this drug is considered one of the safest synthetic anticoccidial drugs of the livestock industry.

• Animal Bioscience
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• v.37 no.5
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• pp.896-907
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• 2024

Objective: The potential of aqueous extract of Christ's thorn jujube (Ziziphus spina-christi) leaves (SLAE) to reduce the negative impacts of heat stress on production performance and physiological traits was investigated in dual-purpose layers under subtropical farming. Methods: A total of 200, 25-week-old laying hens (Inshas strain) were randomly assigned to four dietary treatments including SLAE at 0, 2.5, 5.0, and 7.5 mL/kg, respectively. The average temperature-humidity index value was 26.69 during the experimental period. The SLAE contained saponin (0.045%), total flavonoid content of 17.9 mg of quercetin equivalent/100 g and overall antioxidant capacity concentration of 17.9 mg of ascorbic acid equivalent/100 g. Results: The maximum final body weight (BW), BW gain, egg weight, number, and mass occurred at the level of SLAE7.5 inclusion. The egg quality was significantly higher in SLAE groups than in control, and overall, SLAE7.5 had the most favorable influence at 28 and 32 weeks. Liver and kidney function, as well as lipids profile, improved significantly by SLAE inclusion; the lowest concentrations of these parameters were in SLAE7.5 hens. Treatment with SLAE7.5 increased total antioxidant capacity and endogenous antioxidant enzymes compared to control, whereas no effect on superoxide dismutase was noticed. Conclusion: The addition of SLAE at 7.5 mL/kg diet improved egg laying performance and quality, metabolic profiles, and antioxidant status during hyperthermia conditions.

• Korean journal of applied entomology
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• v.63 no.1
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• pp.25-32
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• 2024

Frankliniella occidentalis and Thrips palmi are economically important pests of cucumber. The chemicals used to control them can be effective; however, they should not be used frequently on cucumbers that are consumed raw. Banker plants were selected to increase the control efficiency of Orius laevigatus, a natural enemy that can replace the chemicals. The hatching rate, emergence rate, nymph developmental period, survival rate, and reproductive capacity (fecundity and oviposition period) of O. laevigatus for four plants (moss rose, basil, broad bean, and cucumber) were investigated. The density of O. laevigatus on two selected banker plants was investigated in a cucumber greenhouse. The hatching rate of O. laevigatus eggs was highest at 92% in moss rose; however, there was no significant difference in survival rates between moss rose and basil. The fecundity and oviposition period of O. laevigatus were better in moss rose than in basil, with no significant difference between them. The flowering period of basil was longer than that of moss rose, from April to September. Therefore, basil has potential value as a banker plant for O. laevigatus and is expected to increase the biological control effect of O. laevigatus.

• Journal of Korean Society of Forest Science
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• v.113 no.3
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• pp.327-338
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• 2024

Forest road construction can degrade the physical and biological environments of forest ecosystems. Although this degradation may be temporary, some research has shown the potential for the long-term recovery of the original ecosystem. This study investigated changes in communities' structures over time to understand the process of ecosystem change following road construction. Data were collected from 63 plots, each measuring 25m², in Buyeo-gun, Chungcheongnam-do, including plots from roads constructed in 1998 (25 years elapsed), 2021 (two years elapsed), and 2022 (one year elapsed), using phytosociological methods. The results showed that the importance of the values of Pinus densiflora an d Quercus variabilis in the tree and subtree layers of the 25-year-old cut slopes were similar to those of the control plots, indicating the significant recovery of the original ecosystem's structure and function after 25 years. Species diversity analysis revealed the higher evenness and lower dominance of the cut slopes and road surfaces attributed to the high dominance of species such as Arundinella hirta and Miscanthus sinensis. The community similarity index and detrended correspondence analysis (DCA) indicated that the control plots, all the edge plots, and the 25-year-old cut slopes could be considered part of the same community. In conclusion, forest roads in place for 25 years appear to have been restored to the level of the original ecosystem. These findings can serve as valuable ecological data for understanding the vegetation recovery process at future forest road construction sites.

• Clinical and Experimental Vaccine Research
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• v.13 no.3
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• pp.242-252
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• 2024

Purpose: In this study, an in-house enzyme-linked immunosorbent assay (ELISA) was developed and validated. The titer of ELISA was calculated using the reference line (RFL) method based on the standard curve drawn using the international reference anti-mouse serum NIBSC (National Institute for Biological Standards and Control) 97/642. Materials and Methods: In the development step, signal to noise was depicted to select the buffers that showed the most appropriate ratio. In the validation step, standard range, precision, dilution linearity, and specificity were confirmed, and RFL and parallel line (PLL) methods were compared in precision and dilution linearity. Results: Coating concentration for plate was achieved at 0.1 ㎍/mL for pertussis toxin (PT), 0.15 ㎍/mL for filamentous hemagglutinin antigen (FHA), and 0.25 ㎍/mL for pertactin (PRN). The signal to noise ratio was 22.02 for PT, 14.93 for FHA, and 8.02 for PRN with 0.25% goat serum in phosphate-buffered saline (PBS) as a dilution buffer, and 2% skim milk in PBS as a blocking buffer. Based on the precision results, we assessed the lower limit of quantification by 1, 0.2, and 1.5 EU/mL concentration for PT, FHA, and PRN which met the ICH (International Council for Harmonization) M10 criteria of a 25% accuracy and total error of 40%. In specificity, homologous serum was spiked into heterologous serum and the accuracy met the criteria. There was no difference in the results between RFL and PLL calculations (p-value=0.3207 for PT, 0.7394 for FHA, 0.2109 for PRN). Conclusion: ELISA validated with RFL calculation method in this study is a relatively accurate assay for mouse humoral immunogenicity test.

• Applied Biological Chemistry
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• v.9
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• pp.9-27
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• 1968

Studies were carried out in order to elucidate chemical components and microflora in three types of soy-sauce, 12-year aged soy-sauce prepared by improved method. 7-year aged and 20-year aged soy-sauce prepared by ordinary method. They results are summarized as follows: 1. The followings are found to be the important factors affecting the quality of soy sauce. a. Organic acids, reducing sugars and free amino acids were increased in the course of storage. b. In the aged soy-sauces under study non-volatile organic acid increased while volatile organic acid decreased and the total acidity was dependent only upon tie latter. c. It was found that suit concentration decreased during the storage. 2. The results of investigation of microflora in the stored soy-sauce are shown as follows. Soy-sauce Improved Ordinary Microbe 12-Y. 20-Y. 7-Y. Aerobic bacteria colony/1ml. 6 123 2 Halophilic lactic acid bacteria colony/1ml. 4 6 10 Osmophilic yeast colony/1ml. $828{\times}10^4$ 248 - b. In the stored soy-sauces, aerobic bacteria are incapable of growing due to drop in pH value and the influence of salt concentration. c. Halophilic lactic acid bacteria are incapable of growing due to drop in pH value, even the salt concentrations decreased during the storage. d. Osmophilic yeast are still growing in low pH value and in the decreasing salt concentration during the strage. 3. The results of amino acid analysis by paper partition chromatographic and calorimetric methods are shown as follows. a. Fourteen kinds of amino acid and thirteen amino acids were detected in the soy-sauce of 12-year aged improved soy-sauce and 7-year aged and 20-year aged ordinary one, respectively. b. The contents of aspartic acid, glutamic acid, serine, valine, leucine, lysine, histidine and methionine increased in the 20-year aged ordinary soy-sauce compared to the 7-year aged one. On the other hand those of alanine, tyrosine, phenylalanine and cystine decreased. 4. The results of sugar analysis by paper chromatography are as follows. a. In the 12-year aged improved soy-sauce, galactose, glucose, arabinose, xylose, rhamnose, maltose and an unknown were detected, and their amounts were in the above order except maltose and an unknown. b. Both in the 7 and 12-year aged ordinary soy-sauces, galactose, arabinose, xylose, glucose and rhamnose were detected and the amounts of the sugars were in the above order. c. In the non-aged ordinary soy-sauce, glucose was not detected but detected from 7-year and 20-year aged ordinary soy-sauce. 5. The results of organic acid analysis by paper chromatography were as follows. a. As volatile acids, acetic, propionic and butyric acids were detected in the 7-year aged ordinary soy-sauce. On the other hand in both the 20-year aged ordinary soy-sauce and the 12-year aged improved ones, only acetic acid was abundant while propionic and butyric acids were round in trace. It was found that propionic and butyric acids, as the unpleasant flavor components, decreased during the storage. b. In the ordinary soy-sauce, citric acid were produced during the storage and lack, malic and tartaric acids increased in the course of aging while succinic, glycolic, fumaric and malonic acids were shown to decrease. Glutaric and oxalic acids disappeared. Citric acid was produced also in the improved soy-sauce, but lactic, tartaric, succinic, malic, and glycolic acids decreased, while both malonic and glutaric acids disappeared. From the above results the citric acid production was considered to be a favorable factor for the taste. c. In the aged soy-sauces, pyruvic, α-ketoglutaric and probably acetoacetic and oxaloacetic acids (both in trace) were present and their amounts were in the above order. All of the α-keto acid abruptly decreased during the storage.

• Journal of Korean Society of Forest Science
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• v.86 no.2
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• pp.135-145
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• 1997

This study aimed at evaluating one curvilinear equation and nine non-linear equations for estimating stand growth characteristics(mean dbh, mean height and volume per ha) for the plantations of Pinus koraiensis and the natural stands of Quercus mongolica. The data were collected from 92 plots in Pines koraiensis stands and 83 plots in Quercus mongolica stands, and the site index of all the stands is 14. The curvilinear equation, $Y=at^be^{-c/t}$, used in preparing the yield tables was well fitted within the range of data, but was likely to give overestimates when extrapolating in old stage due to the tendency of linear increase. Among the non-linear equations, logistic equation and Sloboda equation gave overestimates in young stands and reached the asymptotic status early which means underestimates in old stage. Extrapolating in old stage, Hossfeld equation generally gave larger values than others due to its large estimates of parameter a, the maximum value. On the other hand, Bertalanffy equation gave underestimates in young and old stands and overestimates in middle-aged stands. The estimates with Korf equation was relatively low for Pinus koraiensis stands, and this tendency was more obvious in dbh growth of Quercus mongolica stands. Ueno-Ohzaki equation was liable to give over or underestimates depending on the value of parameter b when extrapolating in old stands. Considering the accuracy of estimates and the biological base of the growth equations, Gompertz equation, Chapman-Richards equation and Weibull equation were generally applicable for estimating the stand growth characteristics of both species in the whole range of stand ages including extrapolated range. To get more accurate and precise parameter estimates, more data, especially in old stands, should be required in further study.