• Journal of Food Hygiene and Safety
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• v.36 no.5
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• pp.392-399
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• 2021

This study was conducted to research the status of pesticide residues in a total of 114 herbs and spices obtained from January to October 2020. 341 pesticide residues were analyzed by the multi class pesticide multiresidue methods using GC-MSMS, GC-ECD, GC-NPD, LC-MSMS, LC-PDA, and LC-CAS. As a result of analysis, 36 pesticide residues were found, and detection rate was 31.6%. Of them, seven samples were detected over Maximum Residue Limits (MRLs) and the unsuitable level in pesticide was 6.1%. The herbs and spices exceeding MRLs include coriander (2 times), mint (2 times), basil (once), rosemary (once), and boraye (once). According to an analysis of 341 pesticide residues, 22 pesticides were detected 52 times and 8 pesticides were found to exceed the MRLs. The pesticides exceeding MRLs were ingredients such as etofenprox, flufenoxuron, fluquinconazole, iprodione, lufenuron, paclobutrazol, phenthoate, and spiromesifen.

• Applied Biological Chemistry
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• v.17 no.1
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• pp.63-80
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• 1974

The chemical components of Citrus junos produced in Korea were divided into two parts; common and special components respectively. In the former the relation between the physiological effects of the plant and its ripening process was observed periodically while the latter was analyzed the ripening fruits for their effective utilization as food. The results are summarized as follows: 1. The analytical result of seasonal change showed that the rind ratio was higher than the flesh ratio and on a regional basis, the rind ratio was higher in the islands than on land areas. 2. In the experiment the moisture was increased until the third period, but afterwards it was made constant. While the content of crude fat, cellulose, ash, total acid and soluble non-nitrogen material were decreased until the third period and the cotent of cellulose and total acid were continuousely redused until the last period. In con trast with the above the content of reducing sugars was increased but the content of crude fat, cellulose, ash, crude protein and soluble non-nitrogen material were increased until last period. 3. The content of vitamin C was richer in the rind than in the flesh, in the Korean species than in the Japanese. 4. Free sugars; xylose, fructose, glucose were richer in the rind than in the flesh. 5. The content of volatile organic acids was richer in the rind than in the flesh. Among them, volatile acids, acetic acid, formic and n-valeric acid were found in the rind and formic acid, acetic acid and propionic acid were deteceed in the flesh. 6. The total content of non-volatile acids was richer in the flesh than in the rind. In the kind of non-volatile acids, citric acid,glutaric acid, malic acid, tartaric acid, oxalic acid, malonic acid, succinic acid and an unknown acid were found in the rind and citric acid, malic acid, succinic acid, oxalic acid, glutaric acid and malonic acid in the flesh. 7. Three kinds of aromatic components: D-limonene, ${\alpha}-pinene$, p-cymene and seven other kinds of unknown aromatic components were detected in neutral essential oils. Among them, D-limonene seemed to be main aromatic component in the fruits. 8. From the above results it is confirmed that both rind and flesh of the ripened fruit could be utilized for food effectively, and unripened fruits are suitable for producing citric acid, ripened fruits are also useful for producing juice.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.2
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• pp.108-125
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• 2015

The agro-climatic index is one of the ways to assess the climate resources of particular agricultural areas on the prospect of agricultural production; it can be a key indicator of agricultural productivity by providing the basic information required for the implementation of different and various farming techniques and practicalities to estimate the growth and yield of crops from the climate resources such as air temperature, solar radiation, and precipitation. However, the agro-climate index can always be changed since the index is not the absolute. Recently, many studies which consider uncertainty of future climate change have been actively conducted using multi-model ensemble (MME) approach by developing and improving dynamic and statistical downscaling of Global Climate Model (GCM) output. In this study, the agro-climatic index of Korean Peninsula, such as growing degree day based on $5^{\circ}C$, plant period based on $5^{\circ}C$, crop period based on $10^{\circ}C$, and frost free day were calculated for assessment of the spatio-temporal variations and uncertainties of the indices according to climate change; the downscaled historical (1976-2005) and near future (2011-2040) RCP climate sceneries of AR5 were applied to the calculation of the index. The result showed four agro-climatic indices calculated by nine individual GCMs as well as MME agreed with agro-climatic indices which were calculated by the observed data. It was confirmed that MME, as well as each individual GCM emulated well on past climate in the four major Rivers of South Korea (Han, Nakdong, Geum, and Seumjin and Yeoungsan). However, spatial downscaling still needs further improvement since the agro-climatic indices of some individual GCMs showed different variations with the observed indices at the change of spatial distribution of the four Rivers. The four agro-climatic indices of the Korean Peninsula were expected to increase in nine individual GCMs and MME in future climate scenarios. The differences and uncertainties of the agro-climatic indices have not been reduced on the unlimited coupling of multi-model ensembles. Further research is still required although the differences started to improve when combining of three or four individual GCMs in the study. The agro-climatic indices which were derived and evaluated in the study will be the baseline for the assessment of agro-climatic abnormal indices and agro-productivity indices of the next research work.

• Journal of Oral Medicine and Pain
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• v.33 no.2
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• pp.159-166
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• 2008

An ideal anti-bacterial medication for oral infection requires selective effect on pathogens causing dental caries and periodontal disease but not on normal flora. In addition, it should be less toxic for human and even for environment. This study was to seek such a natural anti-bacterial medication and thus anti-bacterial effect of Hamamelis virginiana was evaluated. Many recent researches on the anti-bacterial effect of natural plant extract and essential oil have reported that natural products can be used as medication for prevention and restrainment of dental caries, halitosis and periodontitis. It has been also reported that Hamamelis virginiana has anti-bacterial effect on Porphyromonas gingivalis, Fusobacterium nucleatum, Capnocytophaga gingivalis, Veilonella parvula, Eikenella corrodens, Peprostreptococcus micros, and Actinomyces odontolyticus. This study evaluated anti-bacterial effect of Hamamelis virginiana on Streptoccoccus mutans, Haemophylus actinomycetemcomitans, and Klebsiella pneumoniae to expand its anti-bacterial effect on other important oral pathogens and eventually to develop its oral care products or apply to clinical purpose. In this study, anti-bacterial tests for antibiotic disk susceptibility, minimal inhibitory concentration and minimal bactericidal concentration were performed to evaluate anti-bacterial effect of Hamamelis virginiana against Streptoccoccus mutans, Haemophylus actinomycetemcomitans, and Klebsiella pneumoniae. The results showed that Hamamelis virginiana has anti-bacterial effect on all pathogen strains tested in this study and furthermore Hamamelis virginiana possesses bactericidal effect other than bacteriostatic effect on Streptoccoccus mutans, Haemophylus actinomycetemcomitans, Klebsiella pneumoniae. This study indicates that a natural anti-bacterial medication for oral diseases can be developed using Hamamelis virginiana.

• Korean Journal of Microbiology
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• v.45 no.2
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• pp.119-125
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• 2009

To understand the ecological function of heterotrophic bacterial community in water column of large freshwater lakes in the permafrost zone, we investigated the structure and function of bacterial community in Lake Khuvsgul, Mongolia. Species composition of overall bacterial community was analyzed by denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene fragments, and bacteria that can be cultured at 10oC were isolated and characterized. Based on the depth profile of environmental parameters, thermocline and chemocline were recognized at the 5~10 m zone of the water column. The stratified DGGE profile indicated that the discontinuity of water properties might influence the structure of bacterial community: band profiles in the 0~5 m zone were diverse with large change by depth, but the profile was relatively stable at the $\geq$10 m zone, with predominance of the band identified as Acidovorax facilis. Bacterial cultures were screened for protease, cellulase, amylase and lipase activity, and 23 isolates were selected for high activity of the hydrolytic enzymes. The isolates were identified based on their 16S rRNA gene sequences. In the surface water (zero meter depth), Acidovorax defluvii and Sphingobacterium faecium with high cellulase activity were present. Flavobacterium succinicans, Mycoplana bullata and A. facilis were stably predominant isolates at 2 m, 5 m, and $\geq$10 m depths, respectively. F. succinicans isolates showed high protease activity while M. bullata isolates showed moderate levels of protease and celluase activity. A. facilis isolates showed either cellulase or lipase activity, exclusively to each other. According to the profile of growth rates of the isolates in the temperature range of $0\sim42^{\circ}C$, the surface-zone (0~5 m) isolates were facultative psychrophiles while isolates from $\geq$10 m depth were typical mesophiles. This stratification is believed to be due to stratified availability of organic materials to the bacterial decomposers. In the water column below the chemoline, the environment is extremely oligotrophic so that the trait of rapid growth in low temperature might not be demanded by deep-lake decomposers. The stratified distribution of community composition and decomposer activity in Lake Khuvsgul implies that ecological functions of bacterial community in lakes of cold region are sharply divided by water column stratification.

• Journal of Practical Agriculture & Fisheries Research
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• v.24 no.3
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• pp.15-24
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• 2022

In 2000, a total of 23,794ha of forest was lost due to the East Coast forest fire, and about 70% of the damaged area was concentrated in Samcheok. In 2001, artificial restoration and natural restoration were implemented in the damaged area. This study was conducted to understand the current vegetation structure 21 years after the restoration of forest fire damage in the Samcheok, Gumbong Mountain area. As a result of classifying the vegetation community, it was divided into three communities: Quercus variabilis-Pinus densiflora community, Pinus densiflora-Quercus mongolica community, and Pinus thunbergii community. Quercus variabilis, Pinus densiflora, and Pinus thunbergii planted in the artificial restoration site were found to continue to grow as dominant species in the local vegetation after restoration. As for the species diversity index of the community, the Quercus variabilis-Pinus densiflora community dominated by deciduous broad-leaf trees showed the highest, and the coniferous forest Pinus thunbergii community showed the lowest. Vegetation in areas affected by forest fires is greatly affected by reforestation tree species, and 21 years later, it has shown a tendency to recover to the forest type before forest fire. In order to establish DataBase for effective restoration and to prepare monitoring data, it is necessary to construct data through continuous vegetation survey on the areas affected by forest fires.