• Journal of the Korean Geographical Society
• /
• v.46 no.1
• /
• pp.1-19
• /
• 2011

The physical and chemical characteristics of loess-paleosol sequence in Jeongjang-ri, Geochang basin are examined using the magnetic susceptibility measurement, grain size analysis, OSL age dating, major, rare earth and trace elements analysis. The grain size characteristics of the loess-palesol sequence are obviously different from those of river sediment forming river terrace deposits and the Chinese Loess Plateau. The loess-paleosol sequence consisting of L1, L1LL1, L1S1, L1L2, S1 and L2 from top to bottom is estimated to MIS 2~MIS 6 and the river terrace to MIS 7. The compositions of major, rare earth and trace elements indicate that the sequence show more weathered characteristics than the Chinese Loess Plateau and originated from the Chinese Loess Plateau. These features are in harmony with the previous studies in Korea.

• Korean journal of applied entomology
• /
• v.35 no.3
• /
• pp.249-253
• /
• 1996

In the laboratory study, the toxicities of chlorpyrifos-methyl, chlorpyrifos, etofenprox, etofenprox+PAF' and deltamethrin for different larval instars of S. litura decreased significantly as larvae aged. LCso values for chlorpyrifos- methyl and chlorpyrifos increased significantly from 3rd instar larvae, while those for etofenprox+PAP and deltamethrin-increased from 2nd instar larvae. In pot study, no significant differences in control efficacy were observed among each treated plots and over 90% control efficacy at 5 d after treatment was obtained in all of the treated plots, except treatment with deltamethrin. Therefore four insecticides excluding deltamethrin will be effective for controlling S. litura. However, it will be probably important to select appropriate insecticides and decide a proper time of treatment because the developmental stage is a significant factor in deciding insecticide efficacy because various developmental stages of the tobacco cutworm inhibit in fields.

• Horticultural Science & Technology
• /
• v.30 no.2
• /
• pp.137-143
• /
• 2012

Chinese cabbage plant was grown hydroponically for 4 weeks in order to examine the temporal relationship of calcium concentration of the nutrient solution with calcium content in the leaf tissue and susceptibility of the tissue to soft rot disease by $Pectobacterium$ $carotovorum$ ssp. $carotovorum$ (Pcc). Calcium concentration from 0.5 to 32.0 mM was maintained for 1 week using Hoagland & Arnon solution. The calcium content of the leaf was proportionally increased to the concentration of the nutrient in the solution (r = 0.912). In contrast, the severity of soft rot symptom in the young leaves was inversely related with the amount of calcium supplied to the nutrient solution (r = 0.899). Water-soluble chitosan, prepared by hollow fiber filtration (> 100 kDa) was applied into the nutrient solution from 0.0 to 5,000 ppm. The chitosan of 10 ppm was the most effective to promote calcium uptake of the leaf, showing 155% of the control. The same chitosan solution prohibited most soft rot development of the leaf by Pcc, exhibiting only 53% of the control. Among different molecular weight fractions, chitosan fraction obtained from 30-100 kDa molecular weight cut-off promoted calcium uptake the most up to 163% of the control, and reduced the development of soft rot disease recording merely 36% of the control of the leaf tissue. The results obtained in the present study suggest that large scale production of water-soluble chitosan with an optimum molecular weight and its commercial application to Chinese cabbage production will be important to improve yield and quality of the crop.

• The Korean Journal of Food And Nutrition
• /
• v.27 no.2
• /
• pp.213-218
• /
• 2014

The enterotoxin production and antimicrobial susceptibility on hemolytic strains from stools of diarrheal pigs was investigated in this study. Through morphological observation, gyrB nucleotide sequence, and API kit analysis, the selected potential pathogenic strain BY06 was identified as Bacillus cereus. Because the characteristic of enterotoxin symptoms were widely caused by Bacillus cereus strains, a PCR test was carried out in order to check the enterotoxin genes (hblA) in this strain. According to the results, this strain was an enterotoxin positive strain containing the hblA gene. The minimum inhibitory concentrations of 10 different antimicrobial agents were screened by the agar dilution test, indicating that this strain was resistant to penicillin G and intermediate to erythromycin; however, it susceptible to cephalothin, vancomycin, clindamycin, fusidic acid, gentamicin, ciprofloxacin, tetracycline and rifampin. These results suggest that the B. cereus BY06 isolated from pig feces has a potential risk of producing enterotoxin and is resistant to penicillin G, but susceptible to various antimicrobial agents.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.sup3
• /
• pp.23-26
• /
• 2016

Breast cancer (BC) is the most common cancer and the second cause of mortality in women all around the world. It is caused by several factors including genetic determinants, so that both genetic susceptibility factors and environmental factors are involved in the etiology. Significance of genes functioning in steroid hormone synthesis and metabolism are well established in breast cancer susceptibility. In this study, 134 women with BC and 135 normal controls were analyzed for their genotypes for the polymorphisms, rs743572, rs10046 and rs4646903, resided in CYP17, CYP19 and CYP1A1 genes, respectively. Significant differences in distributions of allele and genotype frequencies were found for the rs10046 polymorphism in CYP19 (p-value=0.01, OR (CI 95%) =1.59 (1.1-2.3), p-value=0.04, OR (CI 95%) =1.7 (1.1-2.5) respectively). For rs743,572 and rs 4646903 polymorphisms, no significant associations were observed. A significant association was observed between the rs10046 polymorphism of the CYP19gene and breast cancer in Iranian patients. Due to inconsistent previous results, more studies in different populations with larger sample sizes are indicated.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.49 no.5
• /
• pp.582-588
• /
• 2016

Seventy-nine Vibrio parahaemolyticus isolates from surface seawater from Gomso Bay, west coast of Korea, were analyzed for the presence of virulence genes and their susceptibility to 30 different antimicrobials. All 79 isolates were examined for the presence of two virulence genes (tdh or trh) using polymerase chain reaction (PCR); however, no isolates possessed either the tdh or trh gene. According to a disk diffusion susceptibility test, all of the strains studied were resistant to oxacillin, penicillin, and vancomycin, followed by ticarcillin (97.5%), ampicillin (96.2%), clindamycin (86.1%), erythromycin (10.1%), streptomycin (7.6%), cefoxitin (6.3%), amikacin (2.5%), and cephalothin (2.5%). However, all of the strains were susceptible to 19 other antimicrobials including cefepime, cefotaxime, chloramphenicol, gentamycin, nalidixic acid, sulfamethoxazole/trimethoprim, and trimethoprim. All 79 isolates (100%) were resistant to four or more classes of antimicrobials, and two strains exhibited resistance to eight antimicrobial agents. The average minimum inhibitory concentrations (MICs) for V. parahaemolyticus for ampicillin, penicillin, ticarcillin, and vacomycin were 946.5, 1,305.9, 1,032.3, and 45.0 µg/mL, respectively.

• Mycobiology
• /
• v.36 no.4
• /
• pp.249-254
• /
• 2008

Minimal growth inhibitory concentrations (MICs) of chitosan acetate (M.W. 60 kDa) on heterotrophic bacteria (strains MK1, S, and R) isolated from the soft-rotten tissues of Neungee mushroom (Sarcodon aspratus) were measured. The slimy substance produced by the MK1 strain was responsible for the diseased mushroom’s appearance. The S and R strains were members of the Burkholderia cepacia complex. These strains showed different levels of susceptibility toward chitosan acetate. The MIC of chitosan acetate against the MK1 and S strains was 0.06%. The MIC against the R strain was greater than 0.10%. Survival fractions of the MK1 and S strains at the MIC were $3\;{\times}\;10^{-4}$ and $1.4\;{\times}\;10^{-3}$ after 24 h, and $2\;{\times}\;10^{-4}$ and $7\;{\times}\;10^{-4}$ after 48 h, respectively. Survival fractions of the R strain after 24 and 48 hr at 0.1% chitosan acetate were $1\;{\times}\;10^{-2}$ and $6.9\;{\times}\;10^{-3}$, respectively. Compared to the MK1 and S strains, the low susceptibility of the R stain towards chitosan acetate could be due to the ability of the R strain to utilize chitosan as a carbon source. Thirty-eight percent of Neungee pieces treated in a 0.06% chitosan acetate solution for $2{\sim}3$ second did not show any bacterial growth at 4 days, whereas bacterial growth around untreated mushroom pieces occurred within 2 days. These data suggest that chitosan acetate is highly effective in controlling growth of indigenous microorganisms on Neungee. The scanning electron micrographs of the MK1 strain treated with chitosan revealed a higher degree of disintegrated and distorted cellular structures.

• Advances in Traditional Medicine
• /
• v.6 no.1
• /
• pp.27-33
• /
• 2006

The Sasang constitutional medicine classifies the mankind into four constitutional types according to the individual psychological and physical traits. Differences in the Sasang constitutional medicine may be explained by the genetic factors. In order to determine the association of Sasang constitutional classification and interleukin-1 receptor antagonist (IL-1Ra) in genetic susceptibility to ischemic stroke, we classified the four constitutional types in ischemic stroke patients (n = 125) and the healthy control subjects (n = 107), and genotyped for IL-1Ra polymorphism by polymerase chain reaction (PCR) methods. The distribution of the $IL1RN^*1/IL1RN^*2$ genotype in the ischemic stroke patients was significantly different from the healthy controls (OR = 6.09; P =0.0134). And the prevalence of $IL1RN^*1/IL1RN^*2$ genotype was increased in Taeum-in ischemic stroke patients, as compared to Taeum-in healthy controls (OR = 14.71; P = 0.0144). These results suggest that $IL1RN^*1/IL1RN^*2$ genotype in Taeum-in might be associated with the increasing risk for ischemic stroke. Furthermore, this relationship could provide the basis for a new approach in the investigation of the etiology of ischemic stroke.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.52 no.6
• /
• pp.587-595
• /
• 2019

Eighty-three Vibrio parahaemolyticus isolates from surface seawater in Gomso Bay on the west coast of Korea, and commercial fisheries from Gunsan fisheries center were analyzed for the presence of virulence genes and susceptibility to 30 different antimicrobials. All 83 isolates were examined for the presence of two virulence genes (tdh or trh) using polymerase chain reaction; however, neither gene was found in any of the isolates. A disk diffusion susceptibility test, showed that all of the strains studied were resistant to clindamycin, oxacillin, ticarcillin, and vancomycin, and also revealed varying levels of resistance to ampicillin (98.8%), penicillin G (95.2%), streptomycin (20.5%), cefoxitin (14.5%), amikacin (6.0%), cephalothin (4.8%), and erythromycin (3.6%). However, all of the strains were susceptible to 19 other antimicrobial agents, including cefepime, cefotaxime, chloramphenicol, gentamycin, nalidixic acid, sulfamethoxazole/trimethoprim, and trimethoprim. All 83 isolates (100%) were resistant to five or more classes of antimicrobials, and two strains exhibited resistance to ten antimicrobial agents. The average minimum inhibitory concentrations against V. parahaemolyticus of clindamycin, oxacillin, ticarcillin, and vancomycin were 55.9, 98.3, 499.3, and 44.3 ㎍/mL, respectively. These results provide new insight into the necessity for seawater sanitation in Gomso Bay and commercial fisheries, and provide evidence to help reduce the risk of contamination by antimicrobial-resistant bacteria.

• Journal of the Korean Magnetics Society
• /
• v.5 no.3
• /
• pp.185-190
• /
• 1995

Rare earth-aluminum intermetallic compounds $RAI_{2}$ (R ; Lu, Ce, Gd) are prepared by the arc-melt method and the magnetic properties and electronic structures are investigated by magnetic susceptiptibiliy measurements using SQUID magnetometer. The magnetic suceptibiliyof $LuAl_{2}$ is weakly temperature dependent and shows a Pauli susceptibility of $10.1{\times}10^{-5}$ emu/mol, which means 3.2 states/eV/formula unit. On the other hand, the susceptibility data of $CeAl_{2}$ and $GdAl_{2}$ show a Curie-Weiss behavior for paramagnets. The magnetization data at low temperatures confirm that $CeAl_{2}$ undergoes an antiferromagnetic phase transition near 4 K whereas $GdAl_{2}$ a ferromagnetic transition at 170 K. The distinctive magnetic behaviors of $RAI_{2}$ originate from the different 4f band filling.