• Title/Summary/Keyword: Half Life Time

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Comparison of the Pavement Performance for Concrete Overlay and Asphalt Overlay on Aged Cement Concrete Pavement (노후화된 시멘트 콘크리트 포장에 대한 콘크리트 및 아스팔트 덧씌우기의 포장성능 비교)

  • Lee, Seung-Woo;Son, Hyeon-Jang
    • International Journal of Highway Engineering
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    • v.13 no.2
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    • pp.31-39
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    • 2011
  • More than sixty percentage of highway in South Korea were constructed by concrete pavements and more than half of the concrete pavements were twenty years or older. Maintenance and rehabilitation of aged cement concrete pavements required early transportation opening due to difficulty of preparing bypass roads, given South Korea's transportation condition and so far, mostly asphalt concrete overlay has been used. However, asphalt concrete pavement maintenance and rehabilitation is costly because of early damage and at the same time, it causes inconvenience to the road users. Recently, as an effective method of rehabilitation for aged cement concrete pavement, bonded concrete overlay is being attempted. Therefore, utilizing various data on year-by-year basis is needed to rationally analyze of the damage on asphalt concrete overlay and bonded concrete overlay is necessary. However, in South Korea database of Serviceability damage on asphalt concrete overlay and bonded concrete overlay does not exist. In this research, performance is evaluated by the LTPP (Long Term Pavement Performance) Data of U.S.A, which accumulated various damage data of asphalt concrete overlay and bonded concrete overlay. However, the pattern distress of asphalt concrete overlay and bonded concrete overlay are different. Therefore, the pavement distress data of each section is collected into database and distress are calculated PCI(Pavement Condition Index) in order to compare life of asphalt concrete overlay and bonded concrete overlay.

The Promotive Effects of Antioxidative Apigenin on the Bioavailability of Paclitaxel for Oral Delivery in Rats

  • Choi, Sang-Joon;Choi, Jun-Shik
    • Biomolecules & Therapeutics
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    • v.18 no.4
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    • pp.469-476
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    • 2010
  • This study was to investigate the effect of apigenin on the bioavailability of paclitaxel after oral and intravenous administration in rats. The effect of apigenin on P-glycoprotein (P-gp), cytochrome P450 (CYP)3A4 activity was evaluated. The pharmacokinetic parameters of paclitaxel were determined in rats after oral (40 mg/kg) or intravenous (5 mg/kg) administration of paclitaxel with apigenin (0.4, 2 and 8 mg/kg) to rats. Apigenin inhibited CYP3A4 activity with 50% inhibition concentration ($IC_{50}$) of 1.8 ${\mu}M$. In addition, apigenin significantly inhibited P-gp activity. Compared to the control group, apigenin significantly increased the area under the plasma concentration-time curve (AUC, p<0.05 by 2 mg/kg, 59.0% higher; p<0.01 by 8 mg/kg, 87% higher) of oral paclitaxel. Apigenin also significantly (p<0.05 by 2 mg/kg, 37.2% higher; p<0.01 by 8 mg/kg, 59.3% higher) increased the peak plasma concentration ($C_{max}$) of oral paclitaxel. Apigenin significantly increased the terminal half-life ($t_{1/2}$, p<0.05 by 8 mg/kg, 34.5%) of oral paclitaxel. Consequently, the absolute bioavailability (A.B.) of paclitaxel was significantly (p<0.05 by 2 mg/kg, p<0.01 by 8 mg/kg) increased by apigenin compared to that in the control group, and the relative bioavailability (R.B.) of oral paclitaxel was increased by 1.14- to 1.87-fold. The pharmacokinetics of intravenous paclitaxel were not affected by the concurrent use of apigenin in contrast to the oral administration of paclitaxel. Accordingly, the enhanced oral bioavailability by apigenin may be mainly due to increased intestinal absorption caused via P-gp inhibition by apigenin rather than to reduced renal and hepatic elimination of paclitaxel. The increase in the oral bioavailability might be mainly attributed to enhanced absorption in the gastrointestinal tract via the inhibition of P-gp and reduced first-pass metabolism of paclitaxel via the inhibition of the CYP3A subfamily in the small intestine and/or in the liver by apigenin. It appears that the development of oral paclitaxel preparations as a combination therapy is possible, which will be more convenient than the i.v. dosage form.

Analysis of Research for the Actual State and Management of Automated Horticultural Facilities (경북지역 현대화 원예시설의 관리실태 조사분석)

  • 정현교;이기명;박규식
    • Journal of Bio-Environment Control
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    • v.5 no.2
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    • pp.174-186
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    • 1996
  • This study was carried out in order to understand the plan, design, constructing and actual condition of management of modernized horticultural facilities in Kyungpook Province which had been constructed from 1992 to 1995 funded by Government support. The aim of this study is to provide reference data for success of the forth project. It was performed by making up a question about driving of project and management condition of equipment after constructing. The results obtained from this study are as follows: 1. 73.5% of facilities horticulture farmhouse recognized that the prospect of greenhouse is bright, but 92.5% of the farmhouse also recognised that they need technical consultation on protected horticulture farming. Therefore, technical educations would must be enhanced about foundation of greenhouse and cultivation technique. 2. The holding times of explanatory meetings, cause of understanding to farmhouse, were one or two times in greenhouse construction, and 62.5% of the farmhouse expressed the insufficiency at the explanation and educational data. For this reason, it was judged that the construction contract had been delayed more than 5 months in 49.3% of the farmhouse after the decision of project budget. 3. In constructing after a contract, the rates of construction delay is 53.4% and defect occurrence is 41.1%. The biggest reasons of construction delay was insufficiency of worker and materials supply. Each percentage is 29.1%. And the reason of defect occurrence is badness of machinery equipment(62.9% ). 4. In management of greenhouse, a pipe-constructed plastic film greenhouse changes plastic film every one and three years because of sticking dust on plastic film. It was needed to about in cleaning technique of coverings. Because that used 3-5 years only half of the expected life span. 5. The order of broken rating in the subsidiary equipment is like this lollop ventilator (42.8%), a general control system(33.3%) especially, in the case of a general control system, the rate of all family can control is 52.7%. so, it is time to develop easy control equipment which every one could use as soon as possible. 6. When choose heat generator as decide capacity, the most priority is the mount of heat generator the percent is 45.5% heat generator and as decide model, the private purchase's percent is 77.3%. It is higher than a public bidding heat generator the percent is 22.7% heat generator when it compare with a public bidding. In the case of $CO_2$ generator, using rate is only 19.0%. The using rate is very low, so it needs education how to use depends on the way of the subsidiary equipment. 7. In the case of seedlings, it is asked to use factory-processed seedling effectively. because it's difficult to get security of labors(58.8%), hoped crops (55.9%) access same crops(29.4%) much more and changing of crops depends on market situation. that is the main reason the lack of knowhow.

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Determination of Ethambutol n Human Plasma by a Validated HPLC Method and Its Application to Single-dose Pharmacokinetics (인체혈장 중 에탐부톨의 HPLC 분석법의 검증 및 단일용량 투여에 의한 약물동태 연구)

  • Gwak, Hey-Sun;Park, Kyung-Ho;Choi, Jun-Shik;Song, Gin-A;Sung, Min-Kyung;Jang, Jung-Ok;Lee, Hwa-Jeong
    • Journal of Pharmaceutical Investigation
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    • v.35 no.2
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    • pp.123-127
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    • 2005
  • An HPLC method was employed for the determination of ethambutol in human plasma. After addition of internal standard (IS, octylamine, $2\;{\mu}g/mL$) and alkalinization of the plasma with 5 M sodium hydroxide, the drug and IS were extracted into the mixture of chloroform and diethyl ether (40:60, v/v). Following a 15-min vortex-mixing and a 10min centrifugation, the organic phase was spiked with $100{\mu}L$ of phenylethylisocyanate $(2000{\mu}g/mL)$ for chemical derivatization, mixed for 5 min and evaporated to dryness under a stream of nitrogen. The residue was reconstituted with $100{\mu}L$ of mobile phase and $20{\mu}L$ was injected into C18 column with a mobile phase consisting of methanol:water (70:30, v/v). The samples were detected utilizing an ultraviolet detector at 200 nm. The method was specific and validated with a limit of $0.15\;{\mu}g/mL$. Intra- and inter-day precision and accuracy were acceptable for all quality control samples including the lower limit of quantification. The applicability of this method was demonstrated by analysis of human plasma after oral administration of a single 1200-mg dose to 20 healthy subjects. From the plasma ethambutol concentration vs. time curves, the mean AUC was $9.61{\pm}1.64\;{\mu}g{\cdot}hr/mL$ and Cmax of $2.68\;{\mu}g/mL$ reached 2.73 hr after administration. The mean biological half-life of ethambutol was $3.46{\pm}1.21$ hr. Based on the results, this simple and validated assay could readily be used in any pharmacokinetic studies using humans.

Criteria in ′Landscape and Memory′ as Sense of Place for the Sustainable Development of Korean Mountainous Landscape

  • Jino Kwon;Shin, Joon-Hwan;Park, Myoung-Sub
    • The Korean Journal of Quaternary Research
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    • v.17 no.2
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    • pp.85-99
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    • 2003
  • Since the experience of major landscape change during last half of the century due to war and rapid urbanization, the traditional character has been weakened, and it is necessary for a reconsideration to improve the landscape for the future. To review these relationships, the importance of a comprehensive understanding of nature has been suggested. Therefore identification of a new concept based on the 'socio-cultural influence of landscape' and 'sense of place' which are related to peoples' previous experience, is required. Furthermore more practical definitions and criteria to reveal the relationship are necessary. Among the terms suggested to describe sense of place such as 'home', 'place identity', 'place-based meaning' and 'settlement identity' etc., the 'home' is selected to represent our surrounding landscape. For more practical classification of home landscape, additional terms are suggested and defined based on both the relationships between human beings and nature, and between memory derived from previous experience and shared values with in the community. The additional terms which are the most important in the role of landscape character related to humans' are; ⅰ) Personal Landscape: Landscape of an individual human, which derives from previous personal experience; involves distinguishable character for a given person, and it is emotional and flexible depending on circumstances. ⅱ) Ordinary Landscape: Landscape of the 'common interest' between members of a community, which is acceptable as a surrounding for everyday daily life, it produces the richness and variety of landscape. ⅲ) Kernel Landscape: Landscape of the 'common ground' which is acceptable to the majority members of the community, and it provides variety and stability for periods of time, and it could strongly represent community attitudes toward nature. ⅳ) Prototype Landscape: Landscape as the 'common denominator' of overall community from past to present and towards the future, which encompasses all the kernel landscape throughout history. It provides a sense of place, balances the homogeneity of character throughout overall communities. Some part of this can be shared throughout history to shape an overall sense of place. It can also represent short terms fashions. For a prototype landscape to reveal sense of place, there are a couple of points which we should underline the commencing point. Firstly, understanding the relationship between humans and nature should be based on a given character of surroundings. Secondly, reoccurring landscape elements which have sustained in history can lead to sense of place, and should be reviewed the influences between nature and humans.

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Narrative and Music of Changgeuk Madame Ong (창극 <변강쇠 점 찍고 옹녀>의 서사와 음악)

  • Shin, Sa-Bin
    • The Journal of the Korea Contents Association
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    • v.14 no.12
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    • pp.639-654
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    • 2014
  • What is noticeable in Changgeuk Madame Ong is that for "narrativization," a main character is replaced with Madame Ong and her mother and a reinvented story as a result thereof is the female liberation from oppression. The director sought for the completeness of the narrative with a plot line created (i) by daringly deleting the latter half (episode relating to Gangsoe's death), which was a persistent problem unsolved both in the original and its derivative contents, (ii) by diluting Gangsoe's patriarchal authority and thereby creating the ending of endless love and the fruition of love, and (iii) by severing the link between Madame Ong's doomed fate of widowhood and Gangsoe's doomed fate of death by the violation of a taboo (the key factors of the original story) and at the same time, thereby inserting the doomed fate of death by Jowang (god of fire), declaring a war against jangseung (Korean traditional totem pole), the aesthetic structure representing "fictionization," and enabling a female character to gain love, fame and life through free will and spirit of resistance. The director achieved a remarkable success in terms of composition by (i) taping into a variety of genres of music, (ii) by maximizing the effect of Madame Ong's solo, (iii) by strengthening the "uniqueness of each part" through chorus, (iv) by creating a dramatic atmosphere for the change of scene, (v) by applying a dual variation of tension (resistance theme) and relaxation (freedom theme), etc.

Early Childhood Teachers' Perception for Fairy Tale Appearance Using Background Music (배경음악을 활용한 동화감상에 대한 유아교사의 인식)

  • Park, Seon-Young;Hong, Soon-Ock
    • The Journal of the Korea Contents Association
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    • v.18 no.3
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    • pp.342-353
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    • 2018
  • The purpose of this study was to investigate the awareness of early childhood teachers for the development of early childhood education programs using background music. The subjects of this study were 272 early childhood teachers of kindergartens in Busan and Kyungnam provinces. The data were collected through questionnaires on the awareness of children's appreciation of fairy tales using background music. The collected data were analyzed by frequency and percentage using SPSS 18.0 program. The results of this study are as follows: First, the number of early childhood teachers who had experience of performing fairy tales using background music were less than half of them. Secondly, the purpose of appreciation of fairy tales using background music was to develop rich emotions. In order to understand the systematic knowledge and concept of background music, it was necessary to supply background music in various life styles. Third, development of a fairy tale appreciation program using background music was generally required. Third, development of a fairy tale appreciation program using background music was generally required. Fourth, a fairy tale appreciation program using background music is appropriate for the large group activity time of 10~20 minutes one or two times a week and it was necessary to have a concatenated structure of pre-activities, introduction methods, questioning techniques in development, finishing methods, evaluation methods, and extension activity methods.

Pharmacokinetics of Recombinant Human Epidermal Growth Factor (DWP401) in Rats (재조합 인간 상피세포성장인자(DWP401)의 흰쥐에서의 약물동태)

  • Chung, Joo-Young;Koh, Yeo-Wook;Nam, Kwon-Ho;Cho, Jae-Youl;Park, Seung-Kook;Yu, Young-Ho;Kim, Jae-Hwan;Han, Kun;Park, Myung-Hwan;Shim, Chang-Koo
    • YAKHAK HOEJI
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    • v.41 no.3
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    • pp.328-334
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    • 1997
  • Pharmacokinetics of DWP401, a recombinant human epidermal growth factor (rhEGF), was studied using radioimmunoassay (RIA) and $^{125}I$-DWP401 in rats. When DWP401 was adm inistered i.v. at doses of 50 and 500 mcg/kg, the plasma DWP401 disappeared biiexponentially with terminal half life of 4.7 and 92.8 min. The $C_{max}$ and $T_{max}$ after s.c. administration of ti at doses of 50 and 500 ${\mu}g$/kg were determined to be 23.6 and 17.5 ng/ml at 50 ${\mu}g$/kg, and 261.4 ng/ml and 36.8 min, respectively. Both the total urinary and biliary recoveries of intact DWP401 2343 very low (<0.4%), probably due to its extensive degradation in the body. the concentration ratio of DWP401 between the organ and plasma decreased especially in the liver and kidney as the dose and time after the dose increased. For example, the liver/plasma and kidney/plasma concentration ratio of DWP401 at 2.5 min after i.v. doses of 50 ${\mu}g$/kg were comparable and much larger than unity. But, the ratio at 2.5 min after i.v. doses of 500${\mu}g$/kg was much larger in the kidney that in than in the liver. These results suggest that the systemic administration of DWP401 might be subject to rapid and extensive clearance from circulation within several hour after main distrbution to liver and kidney.

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Pharmacokinetic Study of YH1885 (I): Absorption, Distribution and Excretion of $^{14)C-YH1885$ in Rats (YH1885의 체내동태(제1보):흰쥐에서 $^{14)C-YH1885$의 단회투여시 흡수, 조직분포 및 배설)

  • Ahn, Byung-Nak;Fujio, Naoki;Kusumoto, Naotoshi;Abe, Yoshifumi;Odomi, Masaaki;Lee, Jong-Wook
    • YAKHAK HOEJI
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    • v.41 no.3
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    • pp.335-344
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    • 1997
  • The absorption, distribution and excretion of $^{14}C$ labeled YH1885 {5,6-Dimethyl-2(4-fluorophenylamino)-4-(1-methyl-1,2,3,4-tetrahydroisoquinolin-2-yl)pyrimidine hydroc hloride), a new proton pumpinhibitor, were investigated in rats after a single administration of $^{14}C$-YH1885. 1. After intravenous administration of 5mg/kg, the blood level of radioactivity declined in a biphasic fashion with the mean terminal elimination half-life of 12.4hr. 2. After oral administration of 20mg/kg, the maximum blood level of radioactirity was reached at 4.0hr in female rats. The blood level of radioactivity-time profiles in male and female rats were similar, and the absorptionof $^{14}C$-YH1885 was not affected by food. 3. Appproximately 89% and 1% of radioactivity of the total dose were excreted in feces and urine, respectively. 4. Biliary excretion of radioactivity was 47.9% of the dose. Enterohepatic circulation of radioactivity was 49.6%. 5. Radioactivity was excreted maily into feces via bile. 6. The concentration of radioactivity in most tissues reached the peak level at 4.0hr after dosing, and then declined. Autoradiograms of male rats showed that the radioactivity levlels in the fat, harder's gland, liver and G-Itract were higher than those in the other tissues and the elimination of radioactivity from fat and liver was slow. 7. Autoradiograms of a pregnant rat showed that radioactivity was transferred to mammary gland, placenta and fetus. The radioactivity level in the mammary gland was higher than that in the blood.

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Consecutive automated production of carbon-11 labeled radiopharmaceuticals by sharing 11C-methylation reagent from one 11C-synthetic module

  • Park, Hyun Sik;Lee, Hong Jin;An, Hyun Ho;Moon, Byung Seok;Lee, Byung Chul;Kim, Sang Eun
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.2 no.2
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    • pp.123-131
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    • 2016
  • Increasing clinical demand for carbon-11 labeled radiopharmaceuticals has triggered technological advances in fields of radiochemistry and automated modules. Even though carbon-11 has a short half-life ($t_{1/2}=20.4min$), the consecutive second production of carbon-11 labeled radiopharmaceutical in one $^{11}C$-synthetic module should be delayed at least over 4 h to avoid the high radiation exposure. We herein aimed to produce two different carbon-11 labeled radiopharmaceuticals ([$^{11}C$]PIB and [$^{11}C$]methionine) by sharing of [$^{11}C$]methylation source in one $^{11}C$-synthetic module. The synthesis of $^{11}C$-labeling reagents ($[^{11}C]CH_3I$ or $[^{11}C]CH_3OTf$) is fully automated using the commercial TRACERlab $FX_{C-pro}$ module and is readily adaptable to $^{11}C$-labeling reactor for [$^{11}C$]PIB as well as another $^{11}C$-labeling apparatus for [$^{11}C$]methionine via the three-way valve. After completing the [$^{11}C$]PIB production, the re-synthesized $[^{11}C]CH_3I$ was passed through the three-way valve connected the polyetheretherketone (PEEK) line and loaded into the C18 Sep-Pak cartridge including the methionine precursor. The labeled product [^${11}C$]methionine was purified by a simple cartridge separation and reformulated into saline. The radiochemical yield of [$^{11}C$]PIB and [$^{11}C$]methionine were $5.3{\pm}0.6%$ and $18.7{\pm}0.8%$ (n.d.c.), respectively, with over 97% of radiochemical purity. The specific activity of [$^{11}C$]PIB was over $110GBq/{\mu}mol$. Total production time of two radiopharmaceuticals needs about 2 h from $1^{st}$ beam irradiation including quality control tests. Final [$^{11}C$]PIB and [$^{11}C$]methionine were satisfied all quality control test standards.