• Title/Summary/Keyword: L $D_{50}$

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Dechlorination of Atrazine in Sediment Using Zero Valent Iron (영가철($Fe^0$)을 이용한 퇴적물내 Atrazine의 탈염소화)

  • Kim, Geon-Ha;Jeong, Woo-Hyeok;Choe, Seung-Hee
    • Journal of Soil and Groundwater Environment
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    • v.11 no.4
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    • pp.33-40
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    • 2006
  • Residual pesticides discharged from diffuse sources at agricultural area in association with suspended solid will be settled at downstream, and may degrade surface water quality. This research studied dechlorination kinetic of atrazine, one of triazine-category herbicide, using zero-valent iron (ZVI) in sediment. It can be observed from the experiments that buffer capacity of sediment helped pH maintained beutral, resulted in continuous dechlorination. Sediments were spiked with atrazine at 10, 30, and 50 mg atrazine/L of total sediment for batch experiments. Dechlorination constants were $1.38x10^{-1}/d$ for the initial concentration of 10 mg/L, $1.29x10^{-l}/d$ for 30 mg/L, and $7.43x10^{-2}/d$ for 50 mg/L while dechlorination constants of initial concentration of 50 mg/L without ZVI adding were estimated as $3.05x10^{-2}/d. Half lifes atrazine by ZVI were estimated as 5.03 d fur 10 mg/L, 5.38 d for 30 mg/L, and 9.33 d for 50 mg/L, respectively.

Correlation between Serum D-Dimer Level and Volume in Acute Ischemic Stroke

  • Park, Young-Woo;Koh, Eun-Jeong;Choi, Ha-Young
    • Journal of Korean Neurosurgical Society
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    • v.50 no.2
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    • pp.89-94
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    • 2011
  • Objective : D-dimer is a breakdown product of fibrin mesh after factor XIII stabilization. Previously, many authors have demonstrated a relationship between D-dimer level and stroke progression or type. This study aimed to investigate the relationship between D-dimer level and stroke volume. Methods : Between January 2008 and December 2009, we analyzed the D-dimer levels of 59 acute ischemic stroke patients in our neurosurgical department both upon admission and after seven days of initial treatment. Each patient's National Institute of Health Stroke Scale score, modified Rankin Scales score, Glasgow outcome score, and infarction volume were also evaluated. Results : Mean D-dimer level at admission was 626.6 ${\mu}g/L$ (range, 77-4,752 ${\mu}g/L$) and the mean level measured after seven days of treatment was 238.3 ${\mu}g/L$ (range, 50-924 ${\mu}g/L$). Mean D-dimer level at admission was 215.3 ${\mu}g/L$ in patients with focal infarctions, 385.7 ${\mu}g/L$ in patients with multiple embolic infarctions, 566.2 ${\mu}g/L$ in those with 1-19 cc infarctions, 668.8 ${\mu}g/L$ in 20-49 cc infarctions, 702.5 ${\mu}g/L$ in 50-199 cc infarctions, and 844.0 ${\mu}g/L$ in >200 cc infarctions (p=0.044). On the 7th day of treatment, the D-dimer levels had fallen to 201.0 ${\mu}g/L$, 293.2 ${\mu}g/L$, 272.0 ${\mu}g/L$, 232.8 ${\mu}g/L$, 336.6 ${\mu}g/L$, and 180.0 ${\mu}g/L$, respectively (p=0.530). Conclusion : Our study shows that D-dimer level has the positive correlation with infarction volume and can be use to predict infarction-volume.

Characterization of Exolytic GH50A β-Agarase and GH117A α-NABH Involved in Agarose Saccharification of Cellvibrio sp. KY-GH-1 and Possible Application to Mass Production of NA2 and L-AHG (Cellvibrio sp. KY-GH-1의 아가로오스 당화 관련 엑소형 GH50A β-아가레이즈와 GH117A α-NABH의 특성 및 NA2와 L-AHG 양산에의 적용 가능성)

  • Jang, Won Young;Lee, Hee Kyoung;Kim, Young Ho
    • Journal of Life Science
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    • v.31 no.3
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    • pp.356-365
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    • 2021
  • Recently, we sequenced the entire genome of a freshwater agar-degrading bacterium Cellvibrio sp. KY-GH-1 (KCTC13629BP) to explore genetic information encoding agarases that hydrolyze agarose into monomers 3,6-anhydro-L-galactose (L-AHG) and D-galactose. The KY-GH-1 strain appeared to possess nine β-agarase genes and two α-neoagarobiose hydrolase (α-NABH) genes in a 77-kb agarase gene cluster. Based on these genetic information, the KY-GH-1 strain-caused agarose degradation into L-AHG and D-galactose was predicted to be initiated by both endolytic GH16 and GH86 β-agarases to generate NAOS (NA4/NA6/NA8), and further processed by exolytic GH50 β-agarases to generate NA2, and then terminated by GH117 α-NABHs which degrade NA2 into L-AHG and D-galactose. More recently, by employing E. coli expression system with pET-30a vector we obtained three recombinant His-tagged GH50 family β-agarases (GH50A, GH50B, and GH50C) derived from Cellvibrio sp. KY-GH-1 to compare their enzymatic properties. GH50A β-agarase turned out to have the highest exolytic β-agarase activity among the three GH50 isozymes, catalyzing efficient NA2 production from the substrate (agarose, NAOS or AOS). Additionally, we determined that GH117A α-NABH, but not GH117B α-NABH, could potently degrade NA2 into L-AHG and D-galactose. Sequentially, we examined the enzymatic characteristics of GH50A β-agarase and GH117A α-NABH, and assessed their efficiency for NA2 production from agarose and for production of L-AHG and D-galactose from NA2, respectively. In this review, we describe the benefits of recombinant GH50A β-agarase and GH117A α-NABH originated from Cellvibrio sp. KY-GH-1, which may be useful for the enzymatic hydrolysis of agarose for mass production of L-AHG and D-galactose.

Effect of Plant Growth Regulator on Antioxidant Activity of Rosmarinus officinalis L. and Lavandula spica L. (로즈마리(Rosmarinus officinalis L.)와 라벤더(Lavandula spica L.)의 항산화 활성에 미치는 식물생장물질의 영향)

  • Yoon Jae-Ho;Lee Jong-Il;Oh Chi-Kun;Zhi, Chen;Yang Seung-Yul;Song Won-Seob
    • Korean Journal of Plant Resources
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    • v.19 no.2
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    • pp.315-322
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    • 2006
  • This experiment was conducted to investigate the induction rate of callus and antioxidative activity of rosemary and lavender. Callus induction rate of rosemary was 92% and 94% at 0.5mg/L and 1.0mg/L of 2,4-D in the media, respectively. The antioxidative activities of rosemary appeared differently according to the callus cultured under various concentrations of plant growth regulators. The strongest effect was observed at 0.1mg/L of 2,4-D extract, with $43{\pm}1.5{\mu}g/mL$ of an RC50 value. Callus induction rate of lavender was 98% and 99% at 1.0mg/L of 2,4-D and 1.0mg/L of NAA in the media, respectively. The regeneration rate of roots lavender was 85% at 1.0mg/L of NAA in the media. Antioxidative activities of lavender appeared diffently according to the callus cultured under plant growth regulators. The strongest effect was observed in 0.1mg/L of 2,4-D extract, with $37.6{\pm}0.9{\mu}g/mL$ of an RC50 value, which could be compared with value of leaf.

Antioxidative Activities of Whole Plant Extracts of Solanum nigrum L. (까마중(Solanum nigrum L.) 전초 추출물의 항산화 활성)

  • Seong, Joon Seob;Kim, Kyoung Mi;Suh, Ji Young;Ha, Ji Hoon;Park, Soo Nam
    • Journal of the Korean Applied Science and Technology
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    • v.32 no.4
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    • pp.781-788
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    • 2015
  • In this study, the antioxidative effects of 50% ethanol extract, ethylacetate fraction and aglycone fraction obtained from dried whole plant of Solanum nigrum L. were investigated. The free radical scavenging activities ($FSC_{50}$) were $215.46{\mu}g/mL$, $42.43{\mu}g/mL$ and $52.28{\mu}g/mL$, respectively. Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) in $Fe^{3+}-EDTA/H_2O_2$ system were $25.25{\mu}g/mL$, $7.05{\mu}g/mL$ and $6.25{\mu}g/mL$, respectively. 50% ethanol extract and aglycone fraction showed the cellular protective effect against $^1O_2$ induced cellular damage of rabbit erythrocytes at $5{\sim}25{\mu}g/mL$, but not at high concentrations. These results indicated that S. nigrum extract/fractions could be used as an antioxidative agent. However, it could induce cellular damage at high concentrations. In conclusion, a special caution is required to use S. nigrum extracts as a cosmetic ingredient.

Antioxidative Activity and Component Analysis of Prunella vulgaris L. Extract/Fractions (하고초 추출물의 항산화 활성 및 성분 분석)

  • Suh, Ji Young;Seong, Joon Seob;Yun, Mid Eum;Lee, Ye Seul;Ha, Ji Hoon;Park, Dong Soon;Park, Soo Nam
    • Journal of the Korean Applied Science and Technology
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    • v.33 no.4
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    • pp.647-657
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    • 2016
  • In this study, the antioxidative effects and active component analysis of 50% ethanol extract, ethyl acetate fraction and aglycone fraction obtained from Prunella vulgaris L. were investigated. The free radical scavenging activities ($FSC_{50}$) was investigated at 50% ethanol extract ($15.25{\mu}g/mL$), ethyl acetate fraction ($8.68{\mu}g/mL$), and aglycone fraction ($8.25{\mu}g/mL$) respectively. Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) in $Fe^{3+}-EDTA/H_2O_2$ system using the luminol-dependent chemiluminescence assay was investigated at 50% ethanol extract ($4.68{\mu}g/mL$), ethyl acetate fraction ($1.00{\mu}g/mL$), and aglycone fraction($1.02{\mu}g/mL$) respectively. In the cellular protective effect against $^1O_2$ induced cellular damage of human erythrocytes, extract/fractions of P. vulgaris L. were increased in a concentration dependent manner($1{\sim}25{\mu}g/mL$). Especially, ${\tau}_{50}$ of aglycone fraction at concentrations of $25{\mu}g/mL$ showed the most protective effects at 337.9 min. It's showed nine times higher (+)-${\alpha}$-tocopherol (${\tau}_{50}=38.7min$) as typical antioxidant in the $^1O_2$-induced photohemolysis of human erythrocytes. TLC and HPLC were used to analyse active components in the ethyl acetate fraction and aglycone fraction of P. vulgaris L. In ethyl acetate fraction, caffeic acid, rosmarinic acid, quercetin 3-${\beta}$-D-glucoside, rutin, kaempferol-3-O-rutinoside, astragalin (kaempferol-3-O-glucoside) were identified. In aglycone fraction, caffeic acid, rosmarinic acid, quercetin, kaempferol were identified. These results indicated that extract/fraction of P. vulgaris L. is may be used in cosmetics industry as natural antioxidants by quenching and/or scavenging $^1O_2$ and other ROS, and protecting cellular membranes.

Evaluation of electrical characterization and critical length of interconnect for high-speed MCM (고속 MCM 배선의 전기적 특성 및 임계길이 평가)

  • 이영민;박성수;주철원;이상복;백종태;김보우
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.35D no.10
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    • pp.67-75
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    • 1998
  • This paper examined the geometrical variables of microstrip to control the characteristic impedance of MCM interconnect and also with respect to the practical requirements, evaluated the critical lengths for attenuation, propagation delay, and crosstalk at 500 MHz frequency compared to at 50 MHz frequency. With the illustration of each MCM-L and MCM-D interconnect having 50 characteristic impedance, it was revealed that the most important geometrical variables to control the characteristic impedance of microstrip are eventually dielectric thickness and line width. In particular, the dielectric thickness of MCM-D interconnect must be controlled with tolerance below 2 m. It is clear that the attenuation does not give rise to signal distortion in the range of up to 500MHz frequency for both MCM-L and MCM-D interconnects. However, the propagation delay is so significant that both MCM-L and MCM-D interconnects should be matched with load at the 500 MHz frequency. For the MCM-D interconnect, the crosstalk voltage would not be high to generate the wrong signal on the neighboring line at 500 MHz frequency, but the MCM-L interconnect could not be used due to severe crosstalk. Eventually, it is clear that the transmission line behavior must be studied for the design of MCM substrate at the 500 MHz frequency.

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Determining the Required Vitamin D Level for Bone Health Based on Bone Turnover Markers

  • Ismail, Tuan Salwani Tuan;Muda, Bayani Che;Rosdi, Roznie Aida Mohd;Zainuddin, Azalina;Isa, Salbiah;Mustapaha, Zulkarnain
    • Korean Journal of Clinical Laboratory Science
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    • v.49 no.4
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    • pp.337-344
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    • 2017
  • To date, no clear threshold that has been established for defining an adequate store of vitamin D for bone health. Therefore, this study aims to determine the required level of vitamin D to maintain a healthy skeleton based on bone remodelling process among healthy adult population. This was a cross sectional study, involving a healthy adult population in Kota Bharu, Malaysia, aged 18~50 years. We measured serum 25(OH)D (vitamin D), serum parathyroid hormone (PTH), serum C-terminal telopeptide of type 1 collagen (CTX), and Procollagen 1 Intact N-Terminal (P1NP) in 120 healthy adults selected via multi stage sampling (64 males, 56 females) from 6 subdistricts in Kota Bharu. The mean level of 25(OH)D was 23.50 (${\pm}8.74$) nmol/L. There was a significant difference of the vitamin D level between genders ($26.81{\pm}8.3nmol/L$ vs $19.72{\pm}7.68nmol/L$ in males and females respectively) (p value<0.001). More than 50% of female subjects had 25(OH)D less than 20 nmol/L, while only 20.3% of male subjects had 25(OH)D below 20 nmol/L. Based on the LOESS plot, the bone turnover markers showed a plateauing result, at the 25(OH)D level of 35 nmol/L for CTX and 20 nmol/L for P1NP. Contrastingly, PTH showed a step rise in the 25(OH)D level of 20 nmol/L. Based on the LOESS plot for CTX, P1NP and PTH versus 25(OH)D, level of vitamin D between 20 to 35 nmol/L is recommended to maintain healthy skeleton.

Effect of Irrigation Methods for Reducing Drainage on Growth and Yield of Paprika (Capsicum annuum 'Coletti') in Rockwool and Cocopeat Culture (배액절감형 양액공급 방법이 파프리카(Capsicum annuum 'Coletti') 생육과 수량에 미치는 영향)

  • An, Chul Geon;Hwang, Yeon Hyeon;An, Jae Uk;Yoon, Hae Suk;Chang, Young Ho;Shon, Gil Man;Hwang, Seung Jae;Kim, Kang Soo;Rhee, Han Cheol
    • Journal of Bio-Environment Control
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    • v.21 no.3
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    • pp.228-235
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    • 2012
  • This study was carried out to investigate the effect of irrigation methods for reducing a drainage on the growth and yield in rockwool (Grodan co.) and cocopeat (chip : dust = 50 : 50 included fiber) culture. The nutrient solution was irrigated by $100J{\cdot}cm^{-2}$-100 mL, $50J{\cdot}cm^{-2}$-45 mL, $50J{\cdot}cm^{-2}$-40 mL, $50J{\cdot}cm^{-2}$-35 mL ($100{\sim}50J{\cdot}cm^{-2}$-100~35 mL, Nutrient solution 100~35 mL was irrigated per plant when the accumulated radiation was $100{\sim}50J{\cdot}cm^{-2}$). The drain rates per plant of 100-100, 50-45, 50-40, 50-35 were 26.3%, 8.8%, 6% 4.4% and 23.1%, 7.5%, 5% 3.4% in rockwool and cocopeat slabs. The water contents and EC of 100-100 and 50-45 were managed by the 55~70%, $3.0{\sim}5.0dS{\cdot}m^{-1}$ which were good condition for paprika culture in rockwool and cocopeat slabs, while those of 50-40 and 50-35 were managed by beyond 50%, $4.5{\sim}9.5dS{\cdot}m^{-1}$. The plant height, number of branches and leaf size of 100-100 and 50-45 were similarly increased while those of 50-40 and 50-35 were decreased. The fruit size and weight of 50-40 and 50-35 were small and light, while those of 100-100 and 50-45 were similarly big and heavy. The marketable fruits of 100-100 and 50-45 treatments were similarly more by 9.7~9.8 in rockwool and 8.8~8.9 in cocopeat, while the unmarketable fruits, the small and blossom end rot fruits were increased in 50-40 and 50-35 treatments. The yield of 100-100 and 50-45 treatments were similarly high.

A Study on Serum Lipid Levels of Elderly People in Wando Area -Based on Dietary Behaviors- (완도지역 중·장년층의 혈중지질 수준에 관한 연구 -식행동을 중심으로-)

  • Kim, Eun-Ju;Cha, Bok-Kyeong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.9
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    • pp.1148-1160
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    • 2007
  • This study was performed to document the association between eating behaviors and major risk factors for cardiovascular diseases. Those who stated that they ate a daily breakfast for male and female were 88.6% and 96.0%, $1{\sim}2$ times a week were 9.1% and 2.0%, $3{\sim}4$ times a week were 2.3% and 2.0%, respectively. Those who stated that they were overeating of $0{\sim}1$ time a week for man and female were 80.7% and 89.9%, overeating of $2{\sim}3$ times a week were 19.3% and 10.1%, respectively. Those who said that they were regular of meal time for man and female were 38.6%, and 37.4%, sometimes irregular of meal time were 14.8% and 19.2%, irregular of meal time were 46.6% and 43.4%, respectively. Those who said that they were light of eating volume for man and female were 20.5% and 25.3%, moderate of eating volume were 69.3% and 61.6%, heavy of eating volume were 10.2% and 13.1%, respectively. Those who said that they were very fast of eating speed for man and female were 15.9% and 8.1%, fast of eating speed were 51.1% and 34.3%, moderate of eating speed were 4.5% and 20.2%, slow of eating speed were 17.0% and 14.1%, and very slow of eating speed were 11.4% and 23.2%, respectively. Higher frequency of breakfast a week resulted in higher serum total cholesterol and blood sugar for the daily eating group for both genders with women having high LDL-cholesterol and HDL-cholesterol. Both group had high HDL-cholesterol and low blood sugar with less number of overeating, with men having low triglyceride and LDL-cholesterol. With regular meal, both group had low triglyceride, total-cholesterol, atherogenic index, and blood sugar with women having low LDL-cholesterol. For both groups, the triglyceride, total-cholesterol, LDL-cholesterol, atherogenic index, and blood sugar had higher figures for overeating, with men having low HDL-cholesterol and women having high HDL-cholesterol. This study revealed that less number of overeating, regular mealtime, and less volume of food intake are effective in preventing and treating for the cardiovascular diseases.