• 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.

• Korean Journal of Human Ecology
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• v.23 no.1
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• pp.149-161
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• 2014

The purpose of this study was to investigate the nutrition teachers' operation and demand of dietary life education in Jeonbuk Province. The study was carried out using a self administered questionnaire and the subjects were 190 nutrition teachers. The questions were general characteristics of the subjects, operating status as frequency, place, the main use time, and training demand on dietary life education by elementary school and middle & high school, teaching career, and training hours. The results are as follows. Most of the subjects were female(98.9%), more than half were 40's(52.1%) in their age, school work career was 13.2 years. Frequency of the dietary life education operation was once per month(56.8%), 2~3 times per month(27.9%), and place of education were dinning room (49.7%), classroom(25.9%). Almost of the subjects(90.4%) recognized the facilities for education was lack, 89.3% of them did the education materials was lack, also. The desirable frequency of dietary life education was once per month(48.9%), and once per week(35.3%.) The half of the subjects recognized the objects of the dietary life education was not only students but also their parents and teachers. The proper education time was dietary life education tim (34.2%), discretion activity time(31.1%). Most of the subjects(95.7%) had willing to get training, the proper training program was 30 hours, and they prefer summer vacation(61.0%) than winter vacation(30.5%) and semester(8.6%). Proper experimental practice ratio of environment : health : thanks were 30% : 43% : 27%. It is concluded that the demand of nutrition teachers is necessary for their education program in elementary and middle & high school.

• Applied Chemistry for Engineering
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• v.31 no.5
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• pp.475-480
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• 2020

Chelates synthesized with Cu(II) ion and lactic acid or chitosan were applied to the hydrolysis of organophosphate simulant, DFP (diisopropyl fluorophosphate). Under the homogeneous reaction condition, Cu(II)-lactic acid chelate hydrolyzed DFP with the half life time of 37.1 min. Cu(II)-LMWS chitosan chelate was synthesized with 1 kDa molecular weight of chitosan, which showed low solubility, and then crystallized. The half life time for hydrolyzing DFP using Cu(II)-LMWS chitosan was 32.9 h indicating that the reaction rate is enhanced as much as 16 times more than that of using 18 kDa chitosan-Cu(II) complex. Under the homogeneous reaction condition, the half life time of Cu(II)-LMWS chitosan was 8.75 h. Therefore, we found out that the solubility of Cu(II)-LMWS chitosan makes the difference in the reaction rate as much as 4 times.

• Analytical Science and Technology
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• v.13 no.1
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• pp.34-40
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• 2000

The optimum conditions for the half-life time and residual analysis of the iminoactadine triacetate fungicide on soils were investigated by using the gas chromatography. Iminoctadine triacetate(IOTA) was extracted from soils with 2.0 M-NaOH/methanol and chloroform. The extracted IOTA was derivatized to pyrimidine hexafluroacetylacetone by the acetylation and analyzed with GC/ECD after elimination of moisture and impurities on the Sep-Pak column. From the standard addition experiments with 0.1 and 1.0 ppm, the average recoveries were ranged from 83.8 to 93.2 % and the detection limit was 0.005 ppm. The half-life time of iminoctadine triacetate in the silty clay was 30 days in the laboratory and 19.5 days in the field test whereas it was 27 days and 17.5 days for each in case of silty loam.

• Biomolecules & Therapeutics
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• v.6 no.4
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• pp.400-405
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• 1998

The pharmacokinetics of CJ-50001 (recombinant human granulocyte-colony stimulating factor, developed by R&D center of Cheil Jedang Corp.) were investigated in rats and dogs. The serum concentrations of CJ-50001 were measured by a sandwich enzyme immunoassay. After single intravenous (iv) administration of Cf-50001 to rats at a dose of 5 $\mu$g/kg, the mean terminal half-life and area under the concentration-time curve (AUC) were 0.96 h and 124.497g . h/ml, respectively. After single subcutaneous (sc) administration at the same dose, maximum serum concentration was observed at about 2 hours after administration, and the mean terminal half-life, AUC and the bioavailability were 1.11 h,63.58$\mu$g . h/ml and 51.07%, respectively. In repeated dosing studies, CJ-50001 was administered iv and sc to rats at a daily dose of 5$\mu$g/kg for 7 days. The pharmacokinetic parameters, such as mean AUC and terminal half-life, were no significantly different from those of single administration. Following single iv and sc administration of CJ-50001 to dogs at a dose of 5 $\mu$g/kg, mean AUCs were much higher than those of rats, due to the decreased clearence (CL). After sc administration to dogs, maximum serum concentration was observed at 2~4 hours after administration and the bioavailability was 54.60%.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.181-186
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• 2023

With the development of VR technology, the visual immersion of VR games has been greatly enhanced nowadays. There has been an issue that has been troubling players in previous VR games, which is motion sickness. Therefore, VR games have been limited in terms of game mechanics, game duration, and game scale, greatly reducing the immersive experience of visual immersion. However, <Half-Life: Alyx> is different from previous VR games in that players can actually perform spatial displacement in the game scene, rather than being fixed in one place for 360-degree observation and interaction. At the same time, compared to traditional games, VR games no longer need to rely on screens, and the complete visual immersion enhances the fun and playability of the game. This research focuses on the VR game <Half-Life: Alyx> to explore its immersive factors in terms of visual perception. Through in-depth analysis of elements such as color, texture mapping, lighting, etc. in VR games, it was found that the game creates a strong sense of visual immersion in these aspects. Through analysis, it is helpful to gain a deeper understanding of the factors that contribute to visual immersion in VR games, which has certain reference value for game developers and related professionals.

• Archives of Pharmacal Research
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• v.26 no.6
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• pp.499-503
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• 2003

Because physiological changes that potentially alter pharmacokinetics occurs in diabetes mellitus patients, pharamacokinetics of drugs used in the treatment of hypertension was studied using acebutolol as a model anti-hypertensive drug. Thus, the pharmacokinetics of acebutolol was investigated after oral administration of acebutolol (15 mg/kg) to control rabbits and rabbits with acute or chronic diabetes mellitus induced by alloxan. Kidney and liver functions were documented for acute and chronic diabetes mellitus groups based on plasma chemistry data. After oral administration of acebutolol to acute and chronic groups, the plasma concentrations appeared higher; As a result, area under the plasma concentration-time curve from time zero to time infinity10575 and 8668 $\mu g\cdot$ h/mL for acute and chronic group, respectively. In comparison, the area was apparently smaller in the control group (i.e., 7132 $\mu g\cdot$ h/mL). The half-life in acute groups was significantly prolonged 8.45 h compared with the half-life in the control group (i.e., 6.30 h). Alteration in acebutolol pharmacokinetics was more pronounced in the acute group as evidenced by the significantly higher values the area under the plasma concentration time curve, absorption rate constant and maximum plasma concentration compared with chronic or control group. Therefore, these observations indicate that acebutolol pharmacokinetics may be affected in patients with diabetes mellitus, especially in the early stage of the disease.

• Nuclear Engineering and Technology
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• v.54 no.12
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• pp.4644-4651
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• 2022

Due to its short half-life, thoron gas has been assumed to have negligible health hazards on humans compared to radon. But, one of the decay products with a long half-life can make it to be transported to a long distance and to cause a severe internal dose through respiration. Since most commercial radon detectors can not discriminate thoron signals from radon signals, it is very common to overestimate radon doses which in turn result in biased estimation of lung cancer risk in epidemiological studies. Though some methods had been suggested to measure thoron and radon separately, they could not be used for real-time measurement because of CR-39 or LR-115. In this study, an effective method was suggested to measure radon and thoron separately from the free air. It was observed that the activity of thoron decreases exponentially due to delay time caused by a long pipe between two chambers. Therefore from two ion chambers apart in time, it was demonstrated that thoron and radon could be measured separately and simultaneously. We also developed a collimated alpha source and with this source and an SBD, we could convert the ion chamber reading to count rate in cps.

• Analytical Science and Technology
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• v.13 no.6
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• pp.722-730
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• 2000

The residual concentration and half-life time of synthetic pyrethroid insecticide cyfluthrin in potato and soil were investigated by gas chromatography (GC). The pesticide in potato was extracted with n-hexane, filtered and concentrated. The concentrated phase was transferred to the Sep-Pak silica gel column and purified with acetonitrile and acetone for the analysis by gas chromatography equipped with electron capture detector (GC-ECD). From the standard additional experiments with 0.01 and $0.1{\mu}g$, the recoveries were 85-87% and the detection limit was 0.005 ng. The soil sample was extracted with acetone and dichloromethane. The organic phase was concentrated and redissolved with n-hexane and analyzed with GC-ECD after cleaned with Sep-Pak column. From the standard additional experiments with 0.01 and 0.1 ng, the recoveries were 84-88% and the detection limit was 0.005ng. The half-life time of cyfluthrin in the silty clay was 25 days in the room laboratory and 0.6 days in the fieJd test whereas it was 38 days and 0.5 days for each in case of silty loam.

• 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.