• Parasites, Hosts and Diseases
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• v.21 no.2
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• pp.116-186
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• 1983

An epidemiological study on Clonorchis sinensis infection along the Nam-river (total length ; 186km) flowing in Gyeongsang-nam-do, southern part of Korea, was carried out. Formalin-ether concentration technique and Stoll's egg counting method were employed to figure out the prevalence of C. sinensis infection. For the detection of cercariae from Parafossarulus sp., the snail host of C. sinensis, each snail was placed in aerated tap water, and examined for expelled cercariae. For observing the metacercariae the fresh water fish favorably eaten in raw conditions wore prepared by means of pressing the muscles between two slide glasses and/or by digesting them with artificial gastric juice. The fresh water fish were fed to the rabbits to get the worms and to identify the morphology of adult C. sinensis. The results are summarized as follows: 1. Overall Prevalence of C. sinensis infection was 38.75 from 5,291 examinees; 44.15 (1,408 out of 3,196) in male and 30.4% (637 out of 2,095) in female. 2. The prevalence rates were 42.0% at the upper stream, 41.2% around the vicinity of Jinyanglake, 34.2% at Jinju city, 34.2% at middle stream and 40.3% at down stream regions, respectively. 3. By age, the highest positive rate (53.4∼54.3%) was observed in 30 to 59 years of age. In this age group, the rate in males was 59.7∼62.2%, and in females 42.2∼44.4%, In the age group of less than 19 years it was 7.5∼20.9%. 4. By social strata, the positive rate was 16.5% in the primary school children, 22.6% in school students, 46.2% in teachers and local officers and 49.6% in the general inhabitants. 5. The quantitative examinations with the stool collected from clonorchiasis cases revealed that the light infection (less than 4,000/EPG) was 53.6%, moderate infection (4,001∼10,000 /EPG) 30.3% and heavy infection (more than 10,001/EPG) 16.1%, respectively. More than half of total cases examined were light infection, and 73.2% of female examinees were lightly infected with this cuke. 6. The average value of EPG was 4,963 (male, 6,057; female, 2,557 and the highest value was obtained from the age group of 30 to 59 years (5,240∼6,454). 7. The prevalence of Metagonimus yokogawai infection in humans was 5.5%, and 89.8% of metagonimiasis cases wore double-infected arith C. sinensis. The highest prevalence rate was observed in Jinju city (11.2%). 8. Total of 5,005 Parafossarulus sp., the snail intermediate host of C. sinensis, were examined for the detection of cercariae. The cercarial expulsion rate was 0.34%, and the snails collected in Jin-yang-lake side and in the down stream expelled mainly the cercariae of C, sinensis. 9. About 788 cercariaejday (range: 127∼1,503) were expelled daily from a snail naturally infected with C. sinensis. The snails which released more than 1,000 cercariae/day were 30.8% out of total collected. A snail uniquely released 5,840 cercariae/day in this study. 10. The other trematode cercariae besides C. sinensis were also detected, and the rates out of total snails were the cercariae of Losogenes liberum 6.71%, Cyathocotyle orientalis 0.26%, Notocotylus attenuatus 2.52% and Mucobucaris 0.54%, 11. Ten out of 18 species of fresh water fish caught along the river harbored the metacercariae of C, sinensis. The highest rate of metacercarial infection in fish was detected in Pseudorasbora larva (85.9%). The fish mainly eaten by the inhabitants along the Nam-river, and the metacercarial infection rates were: Zacco platypus 8.0%, Hemibarbus sp. 18.2∼26.7%, Gnathepcgcn sp. 37.5%, Ischikauia steenackeri 42.9% and Pseudogobio esocinus 16.7%. 12. Out of 36 P. larva, the number of metacercariae were about 109 (ranEe; 18∼446) per fish and 27 per gram of flesh. The fish caught in spring harbored the highest number of metacercariae. As indicated above, the prevalence of C. sinensis infection in the inhabitants residing around the Nam-river was relatively high. The farther toward the upper stream areas, the higher was the positive rate of C. sinensis infection, and most of clonorchiasis cases were lightly infected. The snail hosts of C. sinensis distributed all around the Nam-river. Several species of freshwater fish were infected with the metacercariae of C. sinensis and the infection rates were relatively high. To prevent C. sinensis infection in the endemic areas, the effective health education system is suggested as a control measure, although mass treatment is also expected to be useful, using chemotherapeutic agents such as "praziquantel", a recently developed anthelminthic for C. sinensis inftraction.

• Research in Community and Public Health Nursing
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• v.32 no.3
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• pp.292-302
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• 2021

Purpose: Suicide among adolescents is a serious problem worldwide, and especially, the suicide rate of teenagers is increasing rapidly in South Korea. This study was conducted to investigate the factors affecting the respective suicidal behavior in terms of home-environment characteristics, health behavior characteristics, and psychological health characteristics in Korean adolescents. Methods: The data of the Web-based Survey of the Youth Risk Behavior from 2015 to 2017 collected by the Korea Centers for Disease Control and Prevention (KCDC) was analyzed using multivariable logistic regression analysis. Results: The influential factors by depression and suicidal behavior (suicidal ideation (SI), suicidal plan (SP), and suicidal attempt (SA)) were female(adjusted odds ratios [aOR], 1.45, 1.69, 1.30, 2.19), age (aOR 1.03, 0.98, 0.97, 0.90), no family members (aOR 1.21, 1.36, 2.11, 2.32), living with only the father (aOR 1.05, 1.06, 1.07, 1.11), high economic status (aOR 1.15, 1.22, 1.34, 1.46), residence in relatives' home (aOR 1.6, 1.36, 2.34, 1.97), drinking experience (aOR 1.35, 1.47, 1.57, 1.76), smoking experience (aOR 1.28, 1.30, 1.31, 1.94), hospital treatment experience due to violence (aOR 2.18, 3.33, 6.24, 8.40), bad health status (aOR 1.23, 1.48, 2.00, 2.15), unhappiness (aOR 2.49, 6.14, 6.72, 8.89), and a lot of stress (aOR 6.05, 10.40, 4.86, 5.52). Conclusion: The suicidal behavior risk screening and prevention program for adolescents should be developed considering the subjective happiness and hospital treatment experience status due to violence that affects suicidal behavior.

• The Journal of the Korean Society for Microbiology
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• v.35 no.1
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• pp.31-40
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• 2000

Bacillus anthracis, the etiological agent of anthrax has been classified into the Bacillus subgroup I with B. cereus, B. mycoides and B. thuringiensis based on morphological and DNA similarity. DNA studies have further indicated that these species have very AT-rich genomes and high homology, indeed it has been proposed that these four sub-species be recognized as members of the one species. Several methods have been developed to obtain good differentiation between these species. However, none of these methods provides the means for an absolutely correct differntiation. The analysis of fatty acid methyl esters (FAMEs) was employed as a quick, simple and reliable method for the identification of 21 B. anthracis strains and closley related strains. The most significant differences were found between B. anthracis and B. anthracis closely related strains in FAMEs profiles. All tested strains of B. anthracis had a branched fatty acid C17:1 Anteiso A, whereas the fraction of unsaturated fatty acid Iso C17:1 w10c was found in B. anthracis closely related strains. By UPGMA clustering analysis of FAMEs profiles, all of the tested strains were classified into two clusters defined at Euclidian distance value of 24.5. The tested strains of B. anthracis were clustered together including Bacillus sp. Kyungjoo 3. However, the isolates of B. anthracis closely related spp. Rho, S10A, 11R1, CAU9910, CAU9911, CAU9912 and CAU9913 were clustered with the other group. On the basis of these results, isolates of B. anthracis Bongchon, Kyungjoo 1, 2 and Bacillus sp. Kyungjoo 3 were reclassified as a B. anthracis. It is concluded that FAMEs analysis provides a sensitive and reliable method for the identification of B. anthracis from closely related taxa.

• Journal of Aquaculture
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• v.15 no.3
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• pp.123-129
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• 2002

In Nam-myeon coastal area of southern sea, Korea, the following hydrobiological conditions prevailed during 1997: water temperature: 12.6 ~24.5 $^{\circ}C$ ; Salinity: 27.32 ~33.$10 \textperthousand$, Dissolved oxygen: 7.05 $ml/L$ and Chlorophyll a: 1.69 ~ 7.40 $\mu $/L. Phytoplankton, dominated by Ceratium sp, peaked during June-July. Mean growth rates of the bay scallop of selected and non-selected groups cultured for 185 days in this area from July to December, 1997 were 0.17 and 0.19 mm/day for shell height, and 0.17 and 0.16 g/day for total weight, respectively. Maximum predicted values of shell height, calculated by von Bertalanffy growth model, were 54.98 mm for the selected and 52.62 mm for the non-selected groups. Survival of the selected and non-selected groups was 80.0 and 87.0%, respectively.

• Biomolecules & Therapeutics
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• v.21 no.1
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• pp.42-48
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• 2013

Nystatin, a polyene antifungal antibiotic, is a cholesterol sequestering agent. The antifungal agent alters composition of the plasma membrane of eukaryotic cells, whereas its effects on cells are poorly investigated. In the current study, we investigated the question of whether nystatin was able to induce expression of macrophage inflammatory protein-1 (MIP-1). THP-1 cells rarely express MIP-$1{\alpha}$ and MIP-$1{\beta}$, however, upon exposure to nystatin, significantly elevated expression of MIP-$1{\alpha}$ and MIP-$1{\beta}$ was observed in a dose-dependent fashion at the messenger and protein levels. Cellular factors activated by nystatin as well as involved in nystatin-induced expression of MIP-1 proteins were identified in order to understand the molecular mechanisms of action of the anti-fungal agent. Treatment with nystatin resulted in enhanced phosphorylation of Akt, ERK, p38 MAPK, and JNK. Abrogation or significant attenuation of nystatin-induced expression of MIP-$1{\alpha}$ and MIP-$1{\beta}$ was observed by treatment with Akt inhibitor IV, LY294002, and SP6001250. Inhibition of ERK or p38MAPK using U0126 and SB202190 did not lead to attenuation of MIP-1 expression. In addition, inhibitors of protein kinase C, such as GF109203X and Ro-318220, also attenuated expression of MIP-1. These results indicate that nystatin is able to activate multiple cellular kinases and, among them, Akt and JNK play primary roles in nystatin-induced expression of MIP-1 proteins.

• Molecules and Cells
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• v.39 no.3
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• pp.266-279
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• 2016

The mechanism by which 12-O-tetradecanoylphorbol-13-acetate (TPA) bypasses cellular senescence was investigated using human diploid fibroblast (HDF) cell replicative senescence as a model. Upon TPA treatment, protein kinase C (PKC) ${\alpha}$ and $PKC{\beta}1$ exerted differential effects on the nuclear translocation of cytoplasmic pErk1/2, a protein which maintains senescence. $PKC{\alpha}$ accompanied pErk1/2 to the nucleus after freeing it from $PEA-15pS^{104}$ via $PKC{\beta}1$ and then was rapidly ubiquitinated and degraded within the nucleus. Mitogen-activated protein kinase docking motif and kinase activity of $PKC{\alpha}$ were both required for pErk1/2 transport to the nucleus. Repetitive exposure of mouse skin to TPA downregulated $PKC{\alpha}$ expression and increased epidermal and hair follicle cell proliferation. Thus, $PKC{\alpha}$ downregulation is accompanied by in vivo cell proliferation, as evidenced in 7, 12-dimethylbenz(a)anthracene (DMBA)-TPA-mediated carcinogenesis. The ability of TPA to reverse senescence was further demonstrated in old HDF cells using RNA-sequencing analyses in which TPA-induced nuclear $PKC{\alpha}$ degradation freed nuclear pErk1/2 to induce cell proliferation and facilitated the recovery of mitochondrial energy metabolism. Our data indicate that TPA-induced senescence reversal and carcinogenesis promotion share the same molecular pathway. Loss of $PKC{\alpha}$ expression following TPA treatment reduces pErk1/2-activated SP1 biding to the $p21^{WAF1}$ gene promoter, thus preventing senescence onset and overcoming G1/S cell cycle arrest in senescent cells.

• Korean Journal of Agricultural Science
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• v.21 no.1
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• pp.60-66
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• 1994

Among the various bacterial isolates from municipal sewages which utilized linear alkylbenzene sulfonate (LAS) as a sole source of carbon. 3 potent strains - KL-3, SH-2 and EN-1 - were selected. The strains were classified: KL-3 as a strain belong to the genus Klebsiella; SH-2 Shigella; and EN-1 Enterobacter, respectively. They were grown in a broth containing 200 ppm of LAS, using a laboratory scale fermentor: the bacterial growth reached stationary phase after 2 days with a maximum viability of $10^8cfu/mL$ of the culture; initial rates of LAS degradation were high during the first 24 hours of cultivation (KL-3 and SH-2, approx. 50%; EN-1, 20%); after 1 day a lag period of about 24 hours was observed for all the strains, and thereafter break-down proceeded rapidly; final rates after 7 days were approximately 85% by KL-3, 82% by SH-2 and 75% by EN-1. Adsorption of LAS by the bacterial cell mass was high for the strain SH-2, as Freundlich equation: Y= 0.030X + 0.95 was calculated.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.3
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• pp.225-237
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• 2001

The community structure of macrobenthos was investigated around Sorido Island, southern coast of Korea between August 1996 and April 1997. Triplicate macrobenthic samples were taken seasonally at twelve stations in August and November 1996 and fourteen stations in February and April 19n by van Veen grab ($0.1m^2$). A total of 217 macrobenthic species were identified during study Period: 80 species were from polychaetes, 60 species from crustaceans, and 46 species from mollusks. The mean density of macrobenthos estimated $1,068 ind/m^2$, and polychaetes comprised $85\%$ of total density. The mean biomass was $110.2 g/m^2$, and echinoderms contributed to more than a half of the biomass. Major dominant species based on abundance were three polychaetes Tharyx sp., Lumbrineris longifolia, and Magelona japonica, which frequently occur in the coastal area enriched by organic pollution. The densities of the species were $582 ind/m^2$, $72 ind/m^2$, and $41 ind/m^2$, respectively. These species showed very low density in the offshore area. The study area was classified into four regions each sustaining specific macrofaunal assemblages by Bray-Curtis cluster analysis: a station group adjacent to the Kwangyang Bay and Yosu harbour and three station groups around Sorido Island. There were negative correlations between the concentration of PAHs in sediments and the abundance of Ampeliscidae spp. and Amphipoda. These results were discussed in terms of both environmental factors and distribution of benthic community.

• Korean journal of applied entomology
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• v.21 no.2 s.51
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• pp.78-86
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• 1982

The ecological studies were conducted to identify some bark-beetles on apricot and plum trees in Jeonnam province. Harmful bark-beetles caught from apricot and plum trees were identified as Scolytus seulensis. Xyleborus atratus., X. germanus, X. rubricollis and X. saxeseni. The seoul barkbeetle emerged during the period from early May to late October $1980\~1981$, it happens twice in a year, with the peak July 10 and August 25 in 1950, July 15 and August 20 in 1981. A daily peak emerged for adults was at 11 AM to 1 PM. Distribution of holes on the apricot stems varied; more than 100 holes per meter in Henderson (Apricot) and Y-49057 (Apricot), 12 holes per meter in Derbyroyal (Apricot). Comparatively more holes were found in the European variety, and the cardinal distribution was in the order of east, south, west and north. The longer the longth of the mother-gallery, the greater number of egg-gallery found. Optimum temperature for mating was $27^{\circ}C$. The time for mating was longer during May-June than July-August. The fruit weight of damaged plum tree reached 12.25g around four weeks after flowering; where as that of normal tree increased up to 63.5g at harvest time. The natural enemy of the seoul bark beetle was Eurytoma sp. They were found as mature larva or pupa and they emerged from early May to the middle of June. Adult longevity was about a week.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.1
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• pp.16-21
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• 2019

This study has its aim to judge both applicability and suitability of recycling of waste soil for the use of farmland amelioration and low-lying farmland reclamation through growth and development experiment and component analysis. As results of physical characteristic evaluation on recycling of waste soil, the classification based on unified soil classification system has investigated as SW and SP affiliation and soil classification has appeared to be a loamy sand. As results of chemical component analysis, pH has appeared to be 7.0~8.4 which is relatively higher than general soil, however, heavy metal has investigated within the 1 region's standard value of soil pollution standards. As results of germination experiment, when using it by mixing recycling soil less than 75%, there is no significant influence on germination, and in the growth and development experiment, when using horticultural bed soil which is mixed with less than 40% of recycling of waste soil, it has confirmed that there is no significance difference with general soil. In case of farmland, the growth disorder of recycling of waste soil rate no more than 40% has shown that it has relatively small influences, and in case of using it by mixing with agricultural soil, it has evaluated to require concrete review of factors which may restrict growth condition including nutrition and pH.