• The Korean Journal of Pharmacology
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• v.26 no.1
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• pp.1-6
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• 1990

We established an in vitro system of central serotonergic neurons by culturing dissociated rat embryonic (El4) brainstem cells to 14 days in vitro and monitored the serotonergic neuronal growth by measuring 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) contents in the cells with hish performance liquid chromatography with electrochemical detection (HPLC-EC). We studied also tile effects of various drugs on the contents of 5-HT and 5-HIAA, confirming in vivo reports. The 5-HT content (13 ng/mg protein) and 5-HT turnover rate (17 pmol/mg protein/h) at 14 days in vitro were in good agreement with those reported in the adult rat brain. The 5-HT content was more easily depleted with p-chlorophenylalanine, a tryptophan hydroxylase inhibitor than with NSD 1015 (3-hydroxybenzylhydrazine), an aromatic L-amino acid decarboxylase (AADC) inhibitor. Incubation of the cultures with tryptophan or 5-hydroxytryptophan increased the rate of serotonin formation implying that neither tryptophan hydroxylase nor AADC is saturated with its amino acid substrate in this in vitro system . The 5-HT content was depleted by reserpine. The 5-HT and 5-HIAA contents were increased and decreased, respectively, by monoamine oxidase inhibitors. All the above results indicate that the biochemical properties of the central serotonergic neurons in this culture system reflect reliably those of central serotonergic neurons in vivo. We suggest that measuring 5-HT and 5-HIAA contents in the primary cultured dissociated brainstem-cells with HPLC-EC is useful in the study of pharmacology as well as toxicolgy of the central serotonergic neurons.

• The Korean Journal of Pharmacology
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• v.22 no.1 s.38
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• pp.34-44
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• 1986

In our previous studies, we had clarified many pharmacological effects of majarine: the bacteriostatic effect in vitro; the potentiation of hypnotic action of alcohol; hypotensive effect in rats and hypothermic effect in mice. This study was undertaken to search for a new antihypertensive drug. Red crystalline was obtained from majarine (which was extracted from Berberis koreana Palibin) by chemical methods. And this crystalline was identified as $C_{19}H＿{16}NO＿4$ contained one hydroxy group instead of methoxy group of majarine in isoquinoline ring and named 'Majarol' (5,6-Dihydro-9-hydroxy, 10-methoxybenzo-[g]-1,3-benzodioxolo [5,6-a] quinolizinium). We examined the effects of majarol on blood pressure and heart rate in urethane ancsthetized rats and the rate and amplitude of contraction of isolated frog heart. Several drugs: atropine sulfate, diphenhydramine chloride, hexamethonium bromide, phentolamine, epinephrine, propranolol and isoproterenol were used to clarify the mechanism of the hypotensive action of majarol. The results of experimints were as follows; 1. In low dose (0.5-2mg/kg, i.v.), majarol showed a typical transient hypotensive effect and slight decrease in heart rate. In high dose (5-10 mg/kg, i.v.), majarol showed a typical transient and a subsequent prolonged hypotensive effect and a significant prolonged decrease in heart rate was followed. 2. The hypotensive effects of majarol was not abolished by the pretreatments with atropine sulfate, hexamethonium bromide and diphenhydramine. The pretreatment with phentolamine inhibited significantly the hypotensive effects of majarol and the pretreatment wtih majarol blocked markedly the hypertensive effect of epinephrine. The positive chronotropic effect of isoproterenol was not blocked by the pretreatment with majarol. 3. In low dose, majarol increased the amplitude and decreased rate of contraction, but in high dose, majarol inhibited the amplitude and rate of contraction of isolated frog heart.

• Journal of Nutrition and Health
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• v.49 no.5
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• pp.335-346
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• 2016

Purpose: This study was conducted to conduct dietary assessment of Korean adults according to intake of Korean soup and stew. Methods: To accomplish this study, 20,926 adults aged 19 yr or higher who participated in the dietary intake survey (24 h recall method) were analyzed from the data of the 2011~2014 Korea National Health and Nutrition Examination Survey (KNHANES). The items included in the soup and stew were guk, tang, jjigae, jijimi, and jeongol. Results: Intakes of soup and stew of subjects were divided into quartiles; intake range by quartile was Q1: < 22.96 g, Q2: 22.96~98.75 g, Q3: 98.75~212.23 g, and Q4: $${\geq_-}212.24g$$. In the case of the Q4 group, male, married, employed, higher educated, and high income subjects showed increased intakes of soup and stew. In addition, sodium intake among nutrient intakes increased from 3,849.04 mg in Q1 group to 5,363.57 mg in Q4 group. Intakes of cereals/grains, potatoes/starches, legumes, seeds/nuts, vegetables, mushrooms, fruits, meat, fishes/shell fishes, milks/dairy products, oils/fats, and seasonings among all foods significantly increased from Q1 group to Q4 group. Lastly, in the multivariable regression analysis, male, higher age, married, eating breakfast, consumption of snacks, prepared meals from home/institution, average eating-out frequency per week, energy consumption, and sodium intake related parameters increased intake of Korean soup and stew. Conclusion: Excessive intake of sodium was related to high blood pressure and metabolic syndrome. Thus, there are needs to improve dietary guidelines and nutrition education for balanced intake of soup and stew.

• The Korean Journal of Pharmacology
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• v.27 no.2
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• pp.155-166
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• 1991

In order to evaluate a potential role of mitochondria in the mediation of toxicity of paraquat (PQ), submitochondrial particle and microsome of mouse liver were compared by oxygen radical generation and lipid peroxidation. With NADH in submitochondrial particle and NADPH in microsome as electron donors, PQ stimulated production of superoxide anion and $H_2O_2$ in both fractions. Under the same conditions, PQ enhanced the generation of ethylene from methional suggestiong stimulation of OH production by PQ. But these effects by PQ were somewhat lower in submitochondrial particle than in microsome. In addition, lipid peroxidation(measured as MDA production) was stimulated by PQ in both fractions. The stimulation of lipid peroxidation in both fractions seemed to occur by the same mechanism probably through perferryl ion. This was supported by the following findings: i) The lipid peroxidation in both fractions was partially inhibited by SOD and completely inhibited by DETAPAC(an iron chelator) but not by catalase or OH scavenger. ii) Addition of $ADP-Fe^{3+}$ further increased PQ-induced lipid peroxidation but decreased ethylene production from methional suggesting no correlation between OH production and lipid peroxidation. The redox-cycling of PQ in mitochondria appeared to be linked to NADH dehydrogenase, not to CoQ since all of the observed stimulations by PQ in submitochondrial particle were inhibited by p-hydroxymercuribenzoate(a NADH dehydrogenase inhibitor) but not affected by other respiratory chain blockers. The above results demonstrate that redox-cycling properties of PQ leading to oxygen radical generation and lipid peroxidation can also occur in mitochondria in the same manner as in microsome. Therefore, the observed actions of PQ in mitochondria suggest that mitochondria may also contribute to toxicity of this drug in vivo.

• The Korean Journal of Pesticide Science
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• v.7 no.1
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• pp.38-44
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• 2003

In vitro inhibitory activity of 34 insecticides and 31 fungicides to glutathione-S-transferase and esterases extracted from rats was determined. Of tested pesticides, the pesticides with high activity on both detoxifying enzymes were mixed with pesticides that are known to be detoxified by detoxifying enzymes. Glutathione-S-transferase was inhibited by thiodicarb $(I_{50}:1.87\times10^{-4}M)$, thiocyclam $(7.40\times10^{-4}M)$, dithianon $(7.55\times10^{-5}M)$, and tolylfluanide $(8.66\times10^{-5}M)$, while esterases by dichlorvos $(8.95\times10^{-8}M)$, pirimicarb $(2.74\times10^{-6}M)$, pyrazophos $(3.31\times10^{-5}M)$, and benomyl $(4.96\times10^{-5}M)$. After acephate known to be detoxified by glutathione-S-transferase was mixed with glutathione-S-transferase-inhibiting pesticides and phenthoate known to be detoxified by esterases was mixed with esterases-inhibiting pesticides, insecticidal activities of such mixtures were determined against diamondback moth (PlutelLa xylostella L.). Synergistic action was observed in all pesticide combinations. The highest synergistic action was obtained when phenthoate was combined with dichlorvos, showing that co-toxicity coefficients were 1512 and 1877 after 24 and 48 hours of treatment, respectively. Several other combinations of pesticides, such as phenthoate with benomyl, and acephate with dithianon, also showed synergism, showing that their co-toxicity coefficients were about 1,000 and 500, after 24 hours of treatment, respectively. Our results showed that combinations of pesticides inhibited by detoxifying enzymes and ones detoxified by detoxifying enzymes resulted in increased toxicities of pesticides, suggesting that such combinations could be used to develop pesticide mixtures with more broad spectrum and high effectiveness.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.2
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• pp.120-132
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• 1993

A continuous hollow fiber membrane reactor(CHFMR) was developed and optimized for the production of yellowfin sole(Limanda aspera) skin gelatin hydrolysates using trypsin. The results were summerized as follows: The $K_m$ value of the CHFMR was 2.4 times higher than that of the batch reactor, indicating reduced enzyme affinity for the substrate. The $K_2$ value of the CHFMR was 8.5 times lower than that of the batch process, showing a significant reduction in trypsin activity in the CHFMR. The optimum operating conditions for the CHFMR process were $55^{\circ}C$, pH 9.0, flux 7.79 ml/min, residence time 77min, and trypsin to substrate ratio, 0.01(w/w) After operating for 60min under the above conditions, $79\%$ of the total amount of initial gelatin was hydrolysed. Enzyme leakage was observed through the 10,000 MWCO membrane after the 20min of reactor operation, while none occurred after 5hr. Total enzyme leakage was about $12.95\%$ at $55^{\circ}C$ for 5hrs. However, there was no apparent correlation between enzyme leakage and substrate hydrolysis. The membrane has a significant effect on trypsin activity loss for 60min of the CHFMR operation. The CHFMR operating with the membrane lost $34\%$ of the initial activity versus a $23\%$ loss of activity after 3hr in the continuous reactor lacking the hollow fiber membrane. The measurement of fouling property showed that relative flux reduction was $91\%$ and flux recover rate was $92\%$ at $10\%$ substrate solution. The productivity(378.85mg product/mg enzyme) of the CHFMR was more than 4 times higher than that of the batch reactor at $55^{\circ}C$.

• Journal of Intelligence and Information Systems
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• v.17 no.4
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• pp.305-316
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• 2011

Recommender system is the system which, by using automated information filtering technology, recommends products or services to the customers who are likely to be interested in. Those systems are widely used in many different Web retailers such as Amazon.com, Netfix.com, and CDNow.com. Various recommender systems have been developed. Among them, Collaborative Filtering (CF) has been known as the most successful and commonly used approach. CF identifies customers whose tastes are similar to those of a given customer, and recommends items those customers have liked in the past. Numerous CF algorithms have been developed to increase the performance of recommender systems. However, the relative performances of CF algorithms are known to be domain and data dependent. It is very time-consuming and expensive to implement and launce a CF recommender system, and also the system unsuited for the given domain provides customers with poor quality recommendations that make them easily annoyed. Therefore, predicting in advance whether the performance of CF recommender system is acceptable or not is practically important and needed. In this study, we propose a decision making guideline which helps decide whether CF is adoptable for a given application with certain transaction data characteristics. Several previous studies reported that sparsity, gray sheep, cold-start, coverage, and serendipity could affect the performance of CF, but the theoretical and empirical justification of such factors is lacking. Recently there are many studies paying attention to Social Network Analysis (SNA) as a method to analyze social relationships among people. SNA is a method to measure and visualize the linkage structure and status focusing on interaction among objects within communication group. CF analyzes the similarity among previous ratings or purchases of each customer, finds the relationships among the customers who have similarities, and then uses the relationships for recommendations. Thus CF can be modeled as a social network in which customers are nodes and purchase relationships between customers are links. Under the assumption that SNA could facilitate an exploration of the topological properties of the network structure that are implicit in transaction data for CF recommendations, we focus on density, clustering coefficient, and centralization which are ones of the most commonly used measures to capture topological properties of the social network structure. While network density, expressed as a proportion of the maximum possible number of links, captures the density of the whole network, the clustering coefficient captures the degree to which the overall network contains localized pockets of dense connectivity. Centralization reflects the extent to which connections are concentrated in a small number of nodes rather than distributed equally among all nodes. We explore how these SNA measures affect the performance of CF performance and how they interact to each other. Our experiments used sales transaction data from H department store, one of the well?known department stores in Korea. Total 396 data set were sampled to construct various types of social networks. The dependant variable measuring process consists of three steps; analysis of customer similarities, construction of a social network, and analysis of social network patterns. We used UCINET 6.0 for SNA. The experiments conducted the 3-way ANOVA which employs three SNA measures as dependant variables, and the recommendation accuracy measured by F1-measure as an independent variable. The experiments report that 1) each of three SNA measures affects the recommendation accuracy, 2) the density's effect to the performance overrides those of clustering coefficient and centralization (i.e., CF adoption is not a good decision if the density is low), and 3) however though the density is low, the performance of CF is comparatively good when the clustering coefficient is low. We expect that these experiment results help firms decide whether CF recommender system is adoptable for their business domain with certain transaction data characteristics.

• The Korean Journal of Pesticide Science
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• v.20 no.2
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• pp.93-103
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• 2016

A simultaneous analytical method was developed for the determination of isoxaflutole and metabolite (diketonitrile) in agricultural commodities. Samples were extracted with 0.1% acetic acid in water/acetonitrile (2/8, v/v) and partitioned with dichloromethane to remove the interference obtained from sample extracts, adjusting pH to 2 by 1 N hydrochloric acid. The analytes were quantified and confirmed via liquid chromatograph-tandem mass spectrometer (LC-MS/MS) in positive-ion mode using multiple reaction monitoring (MRM). Matrix matched calibration curves were linear over the calibration ranges ($0.02-2.0{\mu}g/mL$) for all the analytes into blank extract with $r^2$ > 0.997. For validation purposes, recovery studies were carried out at three different concentration levels (LOQ, 10LOQ, and 50LOQ) performing five replicates at each level. The recoveries were ranged between 72.9 to 107.3%, with relative standard deviations (RSDs) less than 10% for all analytes. All values were consistent with the criteria ranges requested in the Codex guideline (CAC/GL40, 2003). Furthermore, inter-laboratory study was conducted to validate the method. The proposed analytical method was accurate, effective, and sensitive for isoxaflutole and diketonitrile determination in agricultural commodities.

• The Korean Journal of Mycology
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• v.2 no.1
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• pp.15-19
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• 1974

A severe ginseng root rot disease was occurred and became widespraed in 1973 affecting the ginseng cultivating plot around Kangwha and Gimpo-Gun of Kyunggi province. Soil samples were collected from the area of Wolgot-Myun, Gimpo-Gun, Kuunggi-Do, 1974. We examined general fungi and Fusarium sp. in soil layers and also in different kinds of soil of respective diseased, uncultivated and healthy areas, and found the following results. 1. In the diseased and uncultivated area, the content of moisture, organic matter and silt was greater than in the healthy area. 2. Contray to the above, the healthy area contained a greater amount of inorganic elements such as $P_2O_5$, K,Ca and of soil particle such as Cs and Fs. The degree of pH and content of Mg were even in the three types of soils. 3. General fungi were found in abundance in the diseased and uncultivated soils. It was observed that in all types of areas, general fungi reside in abundance in the rhizosphere, i.e., 10-15cm layers and that the closer the surface, the greater the numbers of fungi. 4. A great number of Fusarium sp. was found in the uncultivated area, and followed diseased and healthy areas. It was observed that in all types of areas, Fusarium sp. distributed in abundance in rhizosphere and that the closer the surface, the greater the numbers of Fusarium sp., with the numbers decreasing as the soil layers increase.

• Korean Journal of Weed Science
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• v.14 no.4
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• pp.258-264
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• 1994

The weed survey in lowland rice field in 1992 was conducted to identify weed population change as affected by different elevation, soil type and cultivation pattern at Gangweon province. There were more perennial weeds in plain and east coastal area while more annual weeds in mid alpine and alpine area. Meanwhile, perennial weed species was more dominant at ordinary and sandy soil but annual weed species was more dominant at poorly drained soil. In general, hand and machine(30 day old seedling) transplanting would result in higher dominant weed species of perennial while there was more annual weed species in machine (10 day old seedling) transplanting and dry seeding, respectively. Also, annual weed species was more predominant at spring plowing time compared to autumn plowing time. Particularly, there was change in dominant weed species with time. In 1971 annual weed species was more predominant but perennial weed species was highly dominant in 1981 and 1992.