• Journal of the Korean Society for Heat Treatment
• /
• v.15 no.2
• /
• pp.76-81
• /
• 2002

The melt-spun amorphous $Fe_{77-X}P_{13}C_4B_4Al_2Mo_X$(x=4~10) and $Fe_{82-X}P_XC_4B_4Al_2Mo_8$(x=9~15) alloys were found to exhibit a large supercooled liquid region(${\Delta}T_x$) exceeding 40 K before crystallization. The largest ${\Delta}T_x$ for the glassy alloys containing Mo reaches as large as 65 K for the $Fe_{69}P_{13}C_4B_4Al_2Mo_8$ alloy. The corrosion behavior of the amorphous $Fe_{77-X}P_{13}C_4B_4Al_2Mo_X$(x=4~15) and $Fe_(82-X)P_XC_4B_4Al_2Mo_8$ (x=9~17) alloys were examined by electrochemical measurements in 9M $H_2SO_4$ solution at 303 K. The addition of Mo(or P) for replacing some portion of Fe is effective in improving the corrosion resistance of the investigated Fe-based glassy alloys. They are spontaneously passivated and have a wide passive region with low passive current density.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.12 no.3
• /
• pp.161-172
• /
• 1992

The agronomic performance of four introduced corn(Zea mays L.) hybrids and a domestic hybrid Suwon 19(control) was compared for silage production in the Middle Northwestern Coast(MNWC). Middle Southwestern Coast(MSWC) and Middle Northern Inland(MN1) regions of Korea, 1988 to 19 90. In the MNWC region, DK713 and P3144W were recorded as more resistant corn hybrids to rice black streaked dwarf virus(RBSDV) than other hybrids. P3144W, P3352 and DK689 hybrids produced higher dry matter(DM) and total digestible nutrient(TDN) than the control hybrid Suwon 19 and DK 713. In the MSWC region, P3144W and DK689 tended to yield more DM and TDN than other hybrids and a severe infection of RBSDV was observed during 3 years of experiment. In the MNI region, P3144W and P3352 corn hybrids showed higher ear and dry matter percentage and gave the highest DM and TDN yield compared with other hybrids. The RBSDV infection of the hybrids in the MNI region was moderate level compared with the two regions, but rate of stay green was the lowest. In the three regions, the control hybrid Suwon 19 gave the highest RBSDV infection, followed by P 3352, DK689, and P3144W, while DK713 was the lowest. P3144W and P3352 hybrids gave higher DM and ear percentages than all other hybrids at harvest. During 3 years of experiment, it was found that there were regional and year differences in RBSDV infection, forage DM yield, DM percentage and ear ratio to total DM yield of the corn hybrids.

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.8
• /
• pp.1022-1027
• /
• 2010

Effects of increasing dietary rice straw on chewing activity, ruminal fermentation, and fibrolytic enzyme activity in growing goats were investigated in a $4{\times}4$ Latin Square experiment. The goats were offered four diets with an increasing proportion of rice straw (i.e. 0.05, 0.10, 0.15 and 0.20, respectively, on dry matter basis). Increasing level of rice straw increased ($P_{linear\;effect}$ <0.05) the time spent on eating, ruminating, and chewing. The ruminal pH and acetate: propionate ratio were increased ($P_{linear\;effect}$ <0.05), while the $NH_3$-N concentration was decreased ($P_{linear\;effect}$ <0.01). Increasing level of rice straw in the diet increased ($P_{linear\;effect}{\leq}0.01$) molar proportion of acetate and isovalerate, and decreased ($P_{linear\;effect}$ <0.01) molar proportion of propionate. The CMCase, xylanase and cellobiase activities in the rumen were decreased ($P_{linear\;effect}$ <0.05) with increasing level of dietary rice straw, whereas the avicelase activity was increased ($P_{linear\;effect}$ <0.01). In summary, increased level of rice straw elevated the dietary neutral detergent fibre (NDF) content in the diet and had a great impact on chewing activity and ruminal fermentation.

• Journal of Environmental Health Sciences
• /
• v.42 no.3
• /
• pp.213-223
• /
• 2016

Objectives: This study was designed to assess the level of physical exposure to heavy metals among residents who live around a Chungcheongnam-do Province industrial complex and to provide baseline data on the effects and harms of heavy metals on the human body by comparing their exposure levels to those of people from control regions. Methods: We measured blood lead and cadmium levels and urine mercury and chromium levels and conducted a survey among 559 residents from the affected area and 347 residents of other areas. Results: Blood lead and cadmium levels and urine mercury levels were significantly higher in the case region than among those in the control region (p=0.013, p<0.001, p<0.001, respectively). In the thermoelectric power plant area, blood cadmium and urine mercury levels were significantly higher than in the control region (p<0.001, p<0.001, respectively). In the steel mill and petrochemical industry areas, blood cadmium level was significantly higher than that in the control region (p<0.001). Dividing groups by the reference level of blood cadmium ($2{\mu}g/L$), the odds ratios between the case and control regions were 2.56 (95% CI=1.83-3.58), 3.11 (95% CI=2.06-4.71) for the thermoelectric power plant area, 1.78 (95% CI=1.19-2.65) for the steel mill area and 4.07 (95% CI=2.40-6.89) for petrochemical industry area. Conclusion: This study showed that the levels of exposure to heavy metals among residents living near a Chungcheongnam-do Province industrial complex were significantly higher than those in the control region. This seems to be attributable to exposure to heavy metals emissions from the industrial complex. Further research and safety measures are required to protect residents' health.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.5
• /
• pp.1993-1999
• /
• 2014

Background: This study aimed to explore the role of XRCC1 (Arg399Gln) and XPD (Lys751Gln) gene polymorphisms, lifestyle and environmental factors as well as their possible interactions in propensity to develop lung cancer in a population with high incidence from North East India. Materials and Methods: A total of 272 lung cancer cases and 544 controls were collected and XRCC1 (Arg399Gln) and XPD (Lys751Gln) genotypes were analyzed using a polymerase chain reaction based restriction fragment length polymorphism assay. Conditional multiple logistic regression analysis was used to calculate adjusted odds ratios and 95% confidence intervals after adjusting for confounding factors. Results: The combined Gln/Gln genotype of XRCC1 and XPD genes (OR=2.78, CI=1.05-7.38; p=0.040) was significantly associated with increased risk for lung cancer. Interaction of XRCC1Gln/Gln genotype with exposure of wood combustion (OR=2.56, CI=1.16-5.66; p=0.020), exposure of cooking oil fumes (OR=3.45, CI=1.39-8.58; p=0.008) and tobacco smoking (OR=2.54, CI=1.21-5.32; p=0.014) and interaction of XPD with betel quid chewing (OR=2.31, CI=1.23-4.32; p=0.009) and tobacco smoking (OR=2.13, CI=1.12-4.05; p=0.022) were found to be significantly associated with increased risk for lung cancer. Conclusions: Gln/Gln alleles of both XRCC1 and XPD genes appear to amplify the effects of household exposure, smoking and betel quid chewing on lung cancer risk in the study population.

• Journal of Animal Science and Technology
• /
• v.51 no.6
• /
• pp.537-542
• /
• 2009

For a period of over 6 years, more than 160,000 milk samples were collected and analyzed to determine the influence of different seasonal temperatures and geographic regional location on milk composition in South Korea. Fat, protein, lactose, non fat milk solids (NFMS) and total solids (TS) contents were significantly higher among dairy cows milked in winter season than other seasons (p<0.05). In contrast, freezing point (FP), milk urea nitrogen (MUN) and somatic cell count (SCC) were significantly higher in summer season than other seasons (p<0.05). The average SCC in the autumn season was $358{\times}10^3$/ml, which was lower than any other seasons (p<0.05). These results may be due to the changes in temperature during different seasons. Meanwhile, milk produced by dairy cows in central region had higher fat, protein, lactose, NFMS, TS and MUN and had lower SCC compared to other regions (p<0.05). Fat, TS, FP, MUN and citric acid in northeast region were lower than other regions (p<0.05). The SCC was significantly higher in southeast region than those of other regions (p<0.05). As a result, it might be possible that the differences in feeding management in each different region may affect the milk composition. In conclusion, present results indicated that milk composition is clearly influenced by both season and regional location. Therefore, based on these results, development of different feeding systems, according to season and region is needed to produce high quality and satiable milk production.

• Journal of Mushroom
• /
• v.10 no.1
• /
• pp.37-43
• /
• 2012

This study was carried to identify a correct species and asses genetic diversity within the same species of Polyporus spp. preserved in Division of applied Microbiology. Contaminated isolates showed different growth rates, morphology and color of hyphae. We have reconstructed the phylogenetic tree of a select group of Polyporus spp. using nucleotide sequences of the internal transcribed spacer region(ITS) region. The phylogenetic tree was constructed by using the neighbor-joining method. PELF primers of 20-mer were used to assess genetic diversity of preserved isolates. Sequence analysis showed that three strains were different species and four strains were identified completely different nomenclature. According to the analysis of ITS sequences, the genus Polyporus clustered into five distinct group, most of which correlated with species-groups identified by RAPD method. Four isolates included strain PM02 showed high similarity with P. arcularius, four isolates included strain PM03 high similarity with P. alveolaris, three isolates included strain PM01 high similarity with P. tuberaster, and PM 06 and PM04 high similarity with P. brumalis and P. squamossus. Isolates were collected in the United States(PM10, PM11) was identified as P. alveolarius and P. arcularius. RAPD analysis of genetic polymorphisms of genus Polyporus showed a very different band patterns. As the result of RAPD and ITS region sequences analysis for preserved isolates, it seems likely that 6 isolates of Polyporus spp. may be need to reclassify or eliminate from preserved catalogue.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.6
• /
• pp.788-795
• /
• 2009

Vascular endothelial growth factor (VEGF) is a key regulator of angiogenesis under various physiological and pathological conditions. We found that the VEGF isoforms VEGF120, VEGF164, and VEGF188 were expressed in the bovine mammary gland and bovine mammary epithelial cells (bMECs). Expression of VEGF in the mammary gland was significantly higher during the lactation period than during the dry period. Although dexamethasone or prolactin alone had little effect on the expression of VEGF, that in dexamethasone-treated cells was significantly induced after additional treatment with prolactin. Furthermore, the VEGF expression induced by the combination of dexamethasone and prolactin was reduced by PD98059 in a dose-dependent manner. This combination also stimulated the phosphorylation of p44/p42 MAP kinase in these cells. These results strongly suggest that the combination of dexamethasone and prolactin stimulates VEGF expression in bMECs via p44/p42 MAP kinase.

• Journal of Microbiology and Biotechnology
• /
• v.3 no.3
• /
• pp.146-155
• /
• 1993

A DNA fragment from an alkali-tolerent Bacillus sp., conferring strong promoter activity, was subcloned into the promoter probe plasmid pPL703 and the nucleotide sequence of this promoter region was determined. The sequence analysis suggested that this highly efficient promoter region containing the complex clustered promoters comprised three kinds of promoters (P1, P2 and P3), which are transcribed by $\sigma^B (formerly \sigma^{37}), \sigma^E(formerly \sigma^{29}) and \sigma^A (formerly \sigma^{43})$ RNA polymerase holoenzymes which play major rules at the onset of endospore formation, during sporulation and at the vegetative phase of growth, respectively. S1 nuclease mapping experiments showed that all three promoters had staggered transcription initiation points. The results of chloramphenicol acetyltransferase assay after the subcloning experiments also indicated that the expression of these clustered promoters was correlated with the programs of growth and endospore development. Promoter P1, P2 and P3 were preceded by 75% AT, 79% AT and 81% AT regions, respectively, and a partial deletion of AT-rich region prevented transcription from promoter P1 in vivo. Two sets of 5 -AGTGTT-3 sequences and inverted repeat sequences located around the promoter P1 were speculated as the possible cis acting sites for the catabolite repression in B. subtilis. In vivo transcripts from these sequence regions may be able to form a secondary structure, however, the possibility that a regulatory protein induced by the excess amount of glucose could be bound to such a domain for crucial action remains to be determined.

• Korean Journal of Microbiology
• /
• v.31 no.1
• /
• pp.44-47
• /
• 1993

A replication initiation gene was identified and its nucleotide sequence has been determined from a 3.8 kb, chloramphenicol acethyltransferase conferring R-plasmid pSBK203 of Staphylococcus aures. Location of the replication related region of pSBK 203 was determined by interuption with pUC 119 at XBaI and MspI sites which resulted in inactivation of replication in Bacilius subtilis. Base sequence of this region revealed on open reading frame of 942 base pairs, which encoded a 314 amino acid protein. Base sequence homology with other rep of pT181 family plasmids such as pT181, pC221, pC223, pS194, pU112, and pCW7 was ranged from 78% to 97% and the predicted amino acid sequence homology was from 72% to 95%.