• Title/Summary/Keyword: Half-Life

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The Change of Half Value Breadth and Residual Stress during Fatigue Process in S45C Steel (S45C강의 피로과정에 대한 반가폭 및 잔류응력의 변화)

  • Boo, Myung-Hwan;Koo, Hoo-Taek;Jeong, Jong-Hyun;Park, Young-Chul;Kim, Byeong-Soo;Kim, Young-Suk
    • Proceedings of the KSME Conference
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    • 2001.06a
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    • pp.591-596
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    • 2001
  • The purpose of this study is to examine the change of half value breadth and residual stress during fatigue process in S45C Steel by X-ray diffraction. For S45C Steel, the relationship between the change in fatigue damage of the specimen and the half value breadth, and residual stress of X-ray diffraction profiles during the fatigue processes has been investigated. The half value breadth(HVB) decreases in he early period of fatigue cycle. The change of HVB is relation to cyclic work hardening. In $10{\sim}20%$ of ratio of fatigue life, the change in the half value breadth is not marked. During fatigue process, the residual stress is changed with fatigue cycle increasing.

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Fusion Peptide Improves Stability and Bioactivity of Single Chain Antibody against Rabies Virus

  • Xi, Hualong;Zhang, Kaixin;Yin, Yanchun;Gu, Tiejun;Sun, Qing;Shi, Linqing;Zhang, Renxia;Jiang, Chunlai;Kong, Wei;Wu, Yongge
    • Journal of Microbiology and Biotechnology
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    • v.27 no.4
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    • pp.718-724
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    • 2017
  • The combination of rabies immunoglobulin (RIG) with a vaccine is currently effective against rabies infections, but improvements are needed. Genetic engineering antibody technology is an attractive approach for developing novel antibodies to replace RIG. In our previous study, a single-chain variable fragment, scFv57R, against rabies virus glycoprotein was constructed. However, its inherent weak stability and short half-life compared with the parent RIG may limit its diagnostic and therapeutic application. Therefore, an acidic tail of synuclein (ATS) derived from the C-terminal acidic tail of human alpha-synuclein protein was fused to the C-terminus of scFv57R in order to help it resist adverse stress and improve the stability and half-life. The tail showed no apparent effect on the preparation procedure and affinity of the protein, nor did it change the neutralizing potency in vitro. In the ELISA test of molecular stability, the ATS fusion form of the protein, scFv57R-ATS, showed an increase in thermal stability and longer half-life in serum than scFv57R. The protection against fatal rabies virus challenge improved after fusing the tail to the scFv, which may be attributed to the improved stability. Thus, the ATS fusion approach presented here is easily implemented and can be used as a new strategy to improve the stability and half-life of engineered antibody proteins for practical applications.

Pharmacokinetics of $[^{14}C]$DA-5018 after Subcutaneous Injection and Topical Application (피하주사 및 국소도포시 $[^{14}C]$DA-5018의 약동력학)

  • 이응두;이종진;심현주;이상득;기원배;양중익;이명걸
    • Biomolecules & Therapeutics
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    • v.5 no.1
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    • pp.82-86
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    • 1997
  • Pharmacokinetics of a new capsaicin analog, DA-5018 were evaluated after a subcutaneous injection or topical application of $[^{14}C]$--labelled or unlabelled DA-5018 to rats and rabbits. After subcutaneous injection of $_{14}$c-labelled or unlabelled DA-5018, 0.5 mg/kg (equivalent to DA-5018) to rats, the plasma total activity peaked at 2 hr with the terminal half life of 5.34 hr, however, unlabelled-DA-5018 peaked at 1 hr with the terminal half life of 1.26 hr. Moreover, the AUC (0.726 versus 0.2337g hr/ml) and MRT (7.82 versus 3.55 hr) increased significantly based on total radioactivity compared with intact DA-5018. Above data indicated that DA-5018 is extensively metabolized in rats and the terminal half- life of the metabolite(5) had a longer half-life than that of DA-5018. The cumulative percentages of biliary excretion of dose after subcutaneous injection of $[^{14}C]$DA-5018 was 40.2%, however, the value was only 2.14% when unlabelled DA-5018 was injected. After topical application of 0.1% or 0.3% $_{14}$C-labelled or unlabelled DA-5018 cream, 500 mg/kg to rats, the plasma and tissue concentrations except applied skin were under the detection limit. After consecutive 7 days topical application of unlabelled DA-5018, 0.1% and 0.3% cream to rats, the plasma concentrations were also under the detection limit. But the urinary excretion of DA-5018 was significantly increased by repeated topical administration. After topical application of unlabelled DA-5018, 0.1% and 0.3% cream to rabbits, the plasma and urine concentrations were under the detection limit. Above data indicated that the skin permeation of DA-5018 was lower and the metabolism of DA-5018 was higher in rabbits than that in rats.

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Research on the Holding Value of Academic Journals Based on the Half-Life Index-Number in Science and Technology (과학기술분야 학술잡지의 반감기 측정에 의한 소장 가치 연구)

  • So, Min-Ho;Ko, Seong-Soon
    • Journal of Korean Library and Information Science Society
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    • v.39 no.4
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    • pp.377-395
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    • 2008
  • This article aims to help decide until when a library has to hold journal volumes for user efficiency by measuring the value of academic journals to find the frequency of journal use over the elapsed time based on the half-life index-number of literature obsolescence by Burton & Kebler. Four general subjects categories in science was analyzed. (4 detailed subjects in mathematics, 12 in physics, 12 in chemistry, 14 in technology was selected.) As a result, citation ages are $20{\sim}29$ years in mathematics, $8{\sim}11$ in physics, chemistry, and technology. Average half-life indexes are 11.22 year in mathematics, 7.5 in physics, 8.4 in chemistry, and 8.88 in technology.

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A Study on the Meanings of Half-Life: Alyx and the Success Factors of VR Games (하프라이프 알릭사의 의미와 VR게임 성공 요소 고찰)

  • Kwon, Dong-Hyun
    • The Journal of the Korea Contents Association
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    • v.20 no.9
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    • pp.271-284
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    • 2020
  • Good reviews that Half-Life: Alyx received created a turning point for the vitalization of the VR market with an uncertain future due to the absence of a revenue model together with the increased sales of VR equipment. Based on previous studies, this study categorized the characteristics of VR games according to graphs, first-person system, interface, controller, interaction technology, sound and stories. The analysis results show that the seven elements corresponded with "interactions" and "virtual images," which represent the completion level of games as part of VR components, and were connected to one another, which led to the proposal of an upper-rank concept "presence" to put them together. "Immersiveness," which represents users' emotions as part of VR components, was analyzed with the immersion theory to assign tasks of proper difficulty level for users' abilities. In the research process, the Delphi technique and FGI were administered to a panel of 15 experts to ensure objectivity. Finally, "presence" and "immersiveness" are characteristics in proportion to each other and can be valid concepts in future analysis of VR games as well as Half-Life: Alyx, which led to the proposal a new concept framework called 'presence effects' by combining the two words.

A Study on the Citation Analysis of Scholarly Journal in the Field of Life Science (생명과학 학술지의 인용 분석 연구)

  • Kim, Hong-Ryul
    • Journal of the Korean Society for information Management
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    • v.22 no.3 s.57
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    • pp.85-102
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    • 2005
  • The purpose of this study is to analysis the type of cited materials, dependence ratio of foreign information of domestic researchers, and to predicts half-life of life science for the collection development of libraries and user friendly information services. The journal articles was extracted from five subjects-medical science, pharmacy, food science, agricultural science, microbiology. In result, it was found that it citing the scholarly journal most plentifully, and dependence ratio of foreign information of domestic researchers was high most the microbiology. And then, half-life of life science was found 8.98 in agricultural science, and 7.11 in food science, and 6.96 in pharmacy, and so on.

Development of an electronic starter using a half-wave rectifier for fluorescent lamps (반파정류를 이용한 형광램프용 전자식 스타터의 개발)

  • Lee, Dong-Ho;Song, Song-Bin;Yeo, In-Seon
    • Proceedings of the KIEE Conference
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    • 1998.07f
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    • pp.2088-2090
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    • 1998
  • A low-cost electronic starter is developed to decrease ignition failure significantly through successive starting trial and to prevent overheating at the end of fluorescent lamp life. Moreover, it has an additional feature of being capable of ignition at the recovered lamp voltage without any circuit correction. The developed electronic starter is consisted of four parts - a half wave rectifier circuit, a timer circuit, a switching circuit and a protection circuit. The protection circuit made up of a transistor and capacitors utilizing capacitive characteristics, carries out successive starting trial and end-of-life protection. Lamp ignition is completed within 0.5 seconds with taking advantage of a high preheating current from the half-wave rectifier circuit. Nevertheless, its performance is proved to be very excellent through a standard switching endurance test.

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Establishment of Pre-Harvest Residue Limit of Fungicides Pyrimethanil and Trifloxystrobin during Cultivation of Persimmon (단감 재배기간 중 살균제 pyrimethanil과 trifloxystrobin의 생산단계 잔류허용기준 설정)

  • Lee, Dong-Yeol;Kim, Yeong-Jin;Lee, So-Jung;Cho, Kyu-Song;Kim, Sang-Gon;Park, Min-Ho;Kang, Kyu-Young
    • Korean Journal of Environmental Agriculture
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    • v.31 no.1
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    • pp.45-51
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    • 2012
  • BACKGROUND: This study was carried out to establish pre-harvest residue limit of fungicides pyrimethanil and trifloxystrobin in persimmon, based on dissipation and biological half-lives of two fungicides residue. METHODS AND RESULTS: Both pyrimethanil and trifloxystrobin were extracted with acetonitrile, clean-up with $NH_2$ SPE cartridge and residue were analyzed by HPLC/DAD. Limit of Detection was 0.01 mg/kg. Average recovery were $81{\pm}1.62%$, $98{\pm}1.58%$ of pyrimethanil, and $91{\pm}2.94%$, $98{\pm}1.25%$ of trifloxystrobin at fortification levels at 0.1 and 0.5 mg/kg, respectively. CONCLUSION: The biological half-lives of pyrimethanil were 15.6 and 11.6 days at sprayed with recommended and double dosage, respectively. The biological half-lives of trifloxystrobin were 10.4 and 10.3 days at sprayed with recommended and double dosage, respectively. The pre-harvest residue limit of pyrimethanil and trifloxystrobin were recommended as 2.69 and 0.83 mg/kg for 10 days before harvest, respectively.

Future Opportunities for life Science Programs in Space

  • Hiroki Yokota;Sun, Hui-Bin;George M. Malacinski
    • Animal cells and systems
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    • v.4 no.3
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    • pp.239-243
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    • 2000
  • Most space-related life science programs are expensive and time-consuming, requiring international cooperation and resources with trans-disciplinary expertise. A comprehensive future program in "life sciences in space" needs, therefore, well-defined research goals and strategies as well as a sound ground-based program. The first half of this review will describe four key aspects such as the environment in space, previous accomplishments in space (primarily focusing on amphibian embryogenesis), available resources, and recent advances in bioinformatics and biotechnology, whose clear understanding is imperative for defining future directions. The second half of this review will focus on a broad range of interdisciplinary research opportunities currently supported by the National Aeronautics and Space Administration (NASA), National Institute of Health (NIH), and National Science Foundation (NSF). By listing numerous research topics such as alterations in a diffusion-limited metabolic process, bone loss and skeletal) muscle weakness of astronauts, behavioral and cognitive ability in space, life in extreme environment, etc., we will attempt to suggest future opportunities.

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Dissipation and Processing Factor of Etofenprox and Fenitrothion Residue in Chinese Matrimony Vine by drying (건조에 따른 구기자 중 etofenprox와 fenitrothion의 잔류량 변화 및 가공계수)

  • Noh, Hyun Ho;Lee, Jae Yun;Park, Hyo Kyoung;Jeong, Hye Rim;Lee, Jung Woo;Jo, Seung Hyeon;Kwon, Hyeyoung;Kyung, Kee Sung
    • Korean Journal of Environmental Agriculture
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    • v.37 no.3
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    • pp.213-220
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    • 2018
  • BACKGROUND: This study was carried out to determine characteristics of residual pesticides in time-dependent manner and calculate half-lives of the residual pesticides in fresh and dried Chinese matrimony vine. In addition, processing factors were calculated based on the residual concentrations in them. METHODS AND RESULTS: The test pesticides, etofenprox and fenitrothion, were sprayed onto the Chinese matrimony vine plants at once or twice (at seven-day interval) and then samples were collected at 0 (after 3 hours), 1, 3, 5 and 7 days after the last spraying. Dried samples were prepared in hot-air drying oven at $60^{\circ}C$ for 48 hours until water content of less than 20%. Residual concentrations of etofenprox in fresh and dried samples decreased by 54.0-60.9% after 7 days of the last pesticide-application. In case of fenitrothion, the concentrations were found to have decreased by 69.2-76.5%. Processing factors of etofenprox were 2.6-3.0 for the one-time spraying and 2.5-3.0 for the two-time spraying and those of fenitrothion were found to be 1.5-22 for the one-time spraying and 1.6-2.0 for the two-time spraying. First half-lives of etofenprox and fenitrothion in fresh and dried samples ranged from 5.0 to 6.3 and from 3.4 to 4.0 days, respectively. The third half-lives were found to be 15.0-18.9 and 10.2-12.1 days, respectively. CONCLUSION: Residual concentrations of the tested pesticides in the studied crop decreased, but those in the dried samples appeared to have increased. In addition, processing factor and half life were constant regardless of spraying times.