• Korean Journal of Weed Science
• /
• v.3 no.1
• /
• pp.75-99
• /
• 1983

The herbicidal properties of perfluidone [1,1,1-trifluoro-N-2-methyl-4-(phenylsulponyl) phenyl methanesulfonamide] were investigated in pots and paddy fields. At the rate of 2.0kg prod./10a, perfluidone did not cause any injury to the 4 leaf stage (LS) rice seedlings. Although the crop injury increased with increasing the application rate, the injury caused by 16kg prod. perfluidone/10a gave rise to only 30% yield reduction. The crop injury was greatest when perfluidone was applied 2 days before transplanting and decreased as the application time delayed. Perfluidone showed greater crop injury to the 3 LS seedlings, at more than 7cm water depth, and at high temperature than to the 4 LS seedlings, at 3-5cm water depth, and at low temperature. Indica and indica ${\times}$ japonica rice varieties were generally more sensitive to perfluidone than japonica rice variety. Perfluidone effectively controlled most of annual weeds and such perennial weeds as Sagittaria pygmaea MIQ., Potamogeton distinctus A. BENN, Cyperus serotinus ROTTB, Scirpus maritimus L., Eleocharis kuroguwai OHWL, and Scirpus hotarui OHWL, whereas Sagittaria trifolia L. and Polygonum hydropiper SPACH. were tolerent to perfluidone. The weeding effect decreased with increasing the leaching amount of water and the overflowing of irrigated water within 24 hours after the herbicide application. When the application time was done later than 8 days after transplanting, the perennial weeds were shown at deeper soil layers, and the standing water was deeper than 7cm, the effect tended to decrease. However, there was no difference in the weeding effect between soil types. Downward movement of perfluidone in flooded soil ranged from 2 to 8cm deep. The movement increased with increasing the leaching amount of water and the application rate and at a sandy loam soil which possessed less adsorptive capacity. Residual effect of perfluidone was found at 35 to 80 days after application, which varied such factors as Soil types. Increase in the leaching amount of water resulted in decrease in the period of the residual effect. The period was shorter at non-sterilized soil than at sterilized soil. The 0.75kg ai perfluidone + 1.5kg ai SL-49 (1,3-dimethyl-6-(2,4-dichlor-benzoyl)-5-phenacyloxy-pyrazole)/ha and 1.5kg ai perfluidone + 1.05kg ai bifenox (2,4-dichlorophenyl-3-methoxy carbonyl-4-nitro phenyl ether)/ha showed less crop injury than 1.5kg ai/ha perfluidone alone. However, the weeding effect of the former was similar to that of the later.

• Korean Journal of Food Science and Technology
• /
• v.41 no.5
• /
• pp.578-586
• /
• 2009

This study was conducted to determine the effects of alkaline electrolyzed water (AIEW), acidic electrolyzed water (AcEW), 1% citric acid, and 100 ppm sodium hypochlorite, either alone or in combination with citric acid, in reducing the populations of spoilage bacteria and foodborne pathogens (Listeria monocytogenes and Escherichia coli O157:H7) on lettuce at various exposure times (3, 5, and 10 min) with different dipping temperatures (1, 20, 40, and $50^{\circ}C$). In addition, the inhibitory effect of alkaline electrolyzed water combined with citric acid on the browning reaction during storage at $4^{\circ}C$ for 15 days was investigated. Compared to the untreated control, electrolyzed water more effectively reduced the number of total bacteria, mold, and yeast than 100 ppm sodium hypochlorite under the same treatment conditions. All treatments exposed for 5 min significantly reduced the numbers of total bacteria, yeast, and mold on head lettuce. The inactivation effect of each treatment on head lettuce was enhanced as the dipping temperature increased from 1 to $50^{\circ}C$, but there was no significantly difference at temperatures greater than $40^{\circ}C$ (p<0.05). The total counts of yeast and mold in head lettuce were completely eliminated when a combination of 1% citric acid and AlEW treatment was used at temperatures greater than $40^{\circ}C$. However, decreased reduction in L. monocytogenes (2.81 log CFU/g), and E. coli O157:H7 (2.93 log CFU/g) on head lettuce was observed under these treatment conditions. In addition, enhanced anti-browning effect was observed when the samples were subjected to both 1% citric acid and AlEW treatment at temperatures greater than $40^{\circ}C$ compared to when single treatments alone were used. Thus, this combined treatment might be considered a potentially beneficial sanitizing method for improving the quality and safety of head lettuce.

• The Journal of the Petrological Society of Korea
• /
• v.16 no.3
• /
• pp.144-161
• /
• 2007

The studied Nangsan area is widely covered by the Jurassic biotite granodiorite, which is mainly light grey in color and medium-grained in texture. Results of the regional fracture pattern analysis for the granodiorite body are as follows. Strike directions of fractures show three dominant sets in terms of frequency order. The sets are in an order of a (1) $N80^{\circ}{\sim}90^{\circ}E$ (1st-order)>(2) $N70^{\circ}{\sim}80^{\circ}E$ (2nd-order)>(3) $NS{\sim}N10^{\circ}E$ (3rd-order). Spacings of the fractures are mostly predominant in less than 200 cm. Therefore, the granodiorite of the area has more potential for non-dimensional stones than dimension ones. And orientations of vertical quarrying planes can be also divided into two groups in terms of frequency $N14^{\circ}W{\sim}N16^{\circ}E$ (1st-order) and (2) $N78^{\circ}E{\sim}N88^{\circ}E$ (2nd-order). The orientations of the two groups are more or less different from those of the regional fracture patterns. These can be mainly attributed to the preferred orientations of microcrack developed in the quarries. Of physical properties, specific gravity, absorption ratio, porosity, compressive strength, tensile strength and abrasive hardness are 2.65, 0.28%, 0.73%, $1,628kg/cm^2,\;100kg/cm^2$ and 31, respectively. Contrary to the porosity, both granites of the Nangsan and Sogrisan areas show almost similar values of the abrasive hardness. These can be explained by the differences of Qz+Af modes, which can be regarded as an index for abrasive resistance. Meanwhile, it is anticipated that comprehensive understanding of the orientations of vertical quarrying planes and characteristics of various physical properties will be utilized as an important information for stone resources.

• Tuberculosis and Respiratory Diseases
• /
• v.39 no.1
• /
• pp.42-54
• /
• 1992

Background:It has been suggested that the cyclooxygenase metabolites play an important role in changes of early hemodynamic parameters in the endotoxin-induced acute lung injury. But there have been many debates about their role in the late increase of alveolar-capillary permeability, and it is not known whether they act directly or indirectly through oxygen free radicals which have been known to be produced during the metabolic process of cyclooxygenase pathway. So we performed this study to identify the pathogenetic role of cyclooxygenase metabolites in the endotoxin-induced acute lung injury in domestic pigs. Method: We infused endotoxin into 8 domestic pigs; endotoxin only (n=3), and pretreatment with indomethacin (n=5). We observed the sequential changes in hemodynamic parameters, the concentration of plasma oxidized glutathione (GSSG) in pulmonary arterial and venous blood, and albumin content in bronchoalveolar lavage fluid (BALF). Results: 1) While cardiac output decreased, mean pulmonary arterial pressure, pulmonary vascular resistance, and alveolar-arterial oxygen difference increased over phase 1 (0-2hr) and phase 2 (2-4.5hr) by endotoxin, indomethacin attenuated the decrease in cardiac output during phase 1 and increase in mean pulmonary arterial pressure, pulmonary vascular resistance, and alveolar-arterial oxygen difference during both phases. 2) The increase in plasma GSSG content during phase 2 was not attenuated by indomethacin. 3) The content of BALF albumin was significantly lower in indomethacin groups than that of endotoxin group. Conclusion: These results suggest that it is likely that cyclooxygenase metabolites have an effect on endotoxin-induced acute lung injury during both phases probably through direct action.

• Korean Journal of Poultry Science
• /
• v.44 no.1
• /
• pp.1-9
• /
• 2017

The objective of the present study was to determine the expression of genes associated with lipopolysaccharide (LPS)-induced stressor in two breeds of chickens: the Korean native chicken (KNC) and the White Leghorn chicken (WLH). Forty chickens per breed, aged 40 weeks, were randomly allotted to the control (CON, administered the saline vehicle) and LPS-injected stress groups. Samples were collected at 0 and 48 h post-LPS injection, and total RNA was extracted from the chicken livers for RNA microarray and quantitative real-time polymerase chain reaction (qRT-PCR) analyses. In response to LPS, 1,044 and 1,193 genes were upregulated, and 1,000 and 1,072 genes were downregulated in the KNC and WLH, respectively, using a ${\geq}2$-fold cutoff change. A functional network analysis revealed that stress-related genes were downregulated in both KNC and WLH after LPS infection. The results obtained from the qRT-PCR analysis of mRNA expression of heat shock 90 (HSP90), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), activating transcription factor 4 (ATF4), sterol regulatory element-binding protein 1 (SREBP1), and X-box binding protein 1 (XBP1) were confirmed by the results of the microarray analysis. There was a significant difference in the expression of stress-associated genes between the control and LPS-injected KNC and WLH groups. The qRT-PCR analysis revealed that the stress-related $HSP90{\alpha}$ and HMGCR genes were downregulated in both LPS-injected KNC and WLH groups. However, the HSP70 and $HSP90{\beta}$ genes were upregulated only in the LPS-injected KNC group. The results suggest that the mRNA expression of stress-related genes is differentially affected by LPS stimulation, and some of the responses varied with the chicken breed. A better understanding of the LPS-induced infective stressors in chicken using the qRT-PCR and RNA microarray analyses may contribute to improving animal welfare and husbandry practices.

• Journal of the Korean earth science society
• /
• v.28 no.2
• /
• pp.169-178
• /
• 2007

In this research we diagnosed the actual status of the 7th National science elective curriculum and suggested a way to select and organize the content of the new science elective curriculum. The first science education reform was grounded in the structuralism where the structure of discipline was valued above everything else. On the other hand, the second science education reform suggested alternative interpretations of students' opportunity to learn, putting a brake on the structuralist thinking. According to the survey result, the majority of the science elective courses are in need for revision because the contents are overcrowded, too difficult in light of students' learning readiness, failed to draw students' interest in science, and are overlapped and repeated among the 10th grade science, high school science I and II. In particular, Earth Science II and physics II are the most unfavorable courses among students. Thus, we recommended a fundamental change be made in the new curriculum in addition to the optimization of the content. In this paper, we suggested 'topic-centered content organization' for the science elective course I, i.e., Physics I, Chemistry I, Biology I and Earth Science I that is designed for both science track and non-science track students. Since curriculum provides students with an 'opportunity to learn', a curriculum study should focus on what the 'opportunity to learn' is that students ought to be offered. Based on the result of this study, we recommended one way to select and organize the content of high school elective curriculum.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.15 no.1
• /
• pp.3-9
• /
• 2011

Purpose: Generally dual energy X-ray absorptiometry has been used for the purpose of evaluation of osteoporosis and treatment. Recently the interest of obesity came to be high and body percent fat test is increasing. Existing measure of body fat have to scan the whole body can be evaluated, but only lumbar spine and hip measurements was assumed to be whole body fat as well as improving the software. It tries to check whether the part measured value not being whole body measurement has the validity or not compared with the value calculated with the method that it is different, it forgives through a correlation with a (BIA) and (BMI). Materials and Methods: In 2010, the body percent fat was measured among the examinee coming to the Asan Medical Center public health care center from March till August against 90 females more than 40 years old through (DXA) and BIA. BMI utilized the value which wrote an hight and weight measured through the body measuring instrument in the examinee information and is automatically calculated. In addition, it classified as the low weight ($13-18.5kg/m^2$), normal ($18.5-25kg/m^2$), and corpulence ($25-30kg/m^2$) based on BMI and so that it could check whether there was the difference according to the weight or not BMI and BIA and correlation between DXA were analyzed in each group. The statistical program for the analysis used SPSS 12.0. Results: The comparison of DXA at 3 which it divides into the low weight and normal and corpulence groups and BIA did not show the difference noted statistically in all groups and the between group comparison was exposed to do not have a meaning. The body percent fat measured by the correlation analysis result DXA at the state that it doesn't divide into the group showed the high correlation (r=0.908, p0.01) noted statistically compared with BMI and showed the high correlation noted statistically in a comparison with BIA (r=0.927, p0.01). Conclusion: It confirmed that the whole body percent fat presumed from the part bone density measurement showed the excel correlation compared with BIA and BMI and information is high. There is still no clear standard about the presumed whole body percent fat and it is difficult to evaluate the fat evaluation by the bone mineral density measurement. However, it is determined that the information offering which is more objective through the comparative study with the body percent fat which is very efficient and in that it can obtain till the information about a fat as well as diagnosis of the osteoporosis through the bone density checkup is measured by the afterward telegraph bone density checkup and is clinically useful is possible.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.32 no.2
• /
• pp.321-331
• /
• 2005

The purpose of this study was to compare the effectiveness of mechanical and acid treatment on enamel surfaces for the retention of pit and fissure sealants and evaluate the presence of a prismless layer. The etch pattern produced on enamel from immature and mature premolar teeth extracted with varying period of acid etching using 37% phosphoric acid was examined using a scanning electron microscope(SEM). The composition of each groups was evaluated using an energy dispersive x-ray(EDX) spectroscopy. The result of present study can be summarized as follows: 1. Prismless layer was commonly observed on the fissure enamel in young and mature premolar. 2. There were no differences in micro-structure and etching pattern on fissure enamel between the young and the mature premolar. 3. The most effective etching pattern for retention of pit and fissure sealant was observed in 60 seconds of etching time and no apparent difference of etching pattern was found among 15, 30, and 45 seconds of etching time which showed non-retentive etching patterns. 4. The etching pattern obtained by grinding enamel surface with bur followed by 60 seconds of etching was similar to that of 60 seconds of etching without any pretreatment of fissure surface. 5. Type 2 etching pattern was commonly found on fissure enamel in both young and mature premolar. 6. The calcium content and P/Ca ratio in fissure enamel between the young and the mature premolar were significantly different(P<0.05). But content of calcium, phosphate and P/Ca ratio on various regions of fissure enamel in both young and mature premolar did not showed any difference. Based on these results, prismless layer may negatively influence the retention of pit and fissure sealants. Therefore, the mechanical removal of the prismless layer by grinding prior to etching or by prolonged etching time of enamel within the fissure system should result in an improved bonding of a pit and fissure sealant.

• Korean Journal of Food Science and Technology
• /
• v.30 no.3
• /
• pp.630-637
• /
• 1998

Enzymatic properties of immobilized transglucosidase (TG) from Aspergillus niger was characterized and compared with soluble TG. Michaelis-Menten constant $(K_m)$ and maximum velocity $(V_{max})$ of immobilized TG were $122\;mM,\;3.9{\times}10^{-2}\;mM/min$ and in case of soluble TG, 21 mM, 0.4 mM/min. The optimum pH of immobilized TG was pH 5.0 like soluble TG but immobilized TG showed 16% and 45% higher activity than soluble TG at pH 5.0 and pH 6.0. Both of immobilized TG and soluble TG were stable from pH 2.0 to pH 9.0, and therefore their activities in these pH ranges were remained more than 90%. The temperature was optimal at $60{\sim}70^{\circ}C\;and\;70{\sim}80^{\circ}C$ for soluble TG and immobilized TG, respectively. The thermal stability of immobilized TG was significantly improved than that of soluble TG, and immobilized TG retained $32{\sim}40%$ higher activity than soluble TG. D-values from thermal inactivation of immobilized TG were 7690 sec at $65^{\circ}C$, 83 sec at $75^{\circ}C$, 7.2 sec at $80^{\circ}C$. Z-values of soluble and immobilized TG were $6.4^{\circ}C\;and\;5.3^{\circ}C$, respectively. The little difference of activation energies of soluble TG and immobilized TG supposed that there was little difference in mass transfer limitation during the reaction of soluble TG and immobilized TG.

• Food Science and Preservation
• /
• v.15 no.1
• /
• pp.49-57
• /
• 2008

This study was conducted to develop an optimal composite recipe for a cookie including yam powder that would be attractive to all age groups. Wheat flour was partially substituted by yam powder to reduce the content of wheat flour. This study has produced the sensory optimal composite recipe by making cookies, respectively with each 5 level of yam powder $(X_1)$, Sugar$(X_2)$, butter$(X_3)$, by C.C.D (Central Composite Design) and conducting sensory evaluation and instrumental analysis by means of RSM (Response Surface Methodology). Sensory items showed very significant values in color, softness, overall quality (p<0.01), flavor (p<0.05) and those of instrumental analysis showed significant values in lightness, redness (p<0.05), spread ratio, hardness (p<0.01). Also sensory optimal ratio of yam cookie was calculated at yam powder 37.35 g, sugar 50.75 g, butter 78.40 g and it was revealed that the factors of influencing yam cookie aptitude were in older of yam powder, butter, sugar.