• Title/Summary/Keyword: Half Life

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Travel Times of Radionuclides Released from Hypothetical Multiple Source Positions in the KURT Site (KURT 환경 자료를 이용한 가상의 다중 발생원에서의 누출 핵종의 이동 시간 평가)

  • Ko, Nak-Youl;Jeong, Jongtae;Kim, Kyung Su;Hwang, Youngtaek
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.11 no.4
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    • pp.281-291
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    • 2013
  • A hypothetical repository was assumed to be located at the KURT (KAERI Underground Research Tunnel) site, and the travel times of radionuclides released from three source positions were calculated. The groundwater flow around the KURT site was simulated and the groundwater pathways from the hypothetical source positions to the shallow groundwater were identified. Of the pathways, three pathways were selected because they had highly water-conductive features. The transport travel times of the radionuclides were calculated by a TDRW (Time-Domain Random Walk) method. Diffusion and sorption mechanisms in a host rock matrix as well as advection-dispersion mechanisms under the KURT field condition were considered. To reflect the radioactive decay, four decay chains with the radionuclides included in the high-level radioactive wastes were selected. From the simulation results, the half-life and distribution coefficient in the rock matrix, as well as multiple pathways, had an influence on the mass flux of the radionuclides. For enhancing the reliability of safety assessment, this reveals that identifying the history of the radionuclides contained in the high-level wastes and investigating the sorption processes between the radionuclides and the rock matrix in the field condition are preferentially necessary.

Comparison of Effects of Different Activation Treatments on Development of Rabbit Embryos Reconstituted with Fetal Fibroblast

  • Lee, H.J.;Yoo, J.G.;Cho, S.R.;Lee, S.L.;Chong, J.R.;Yeo, H.J.;Hwang, J.M.;Park, J.S.;Yea, E.H.;Rho, G.J.;Choe, S.Y.
    • Proceedings of the KSAR Conference
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    • 2001.03a
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    • pp.22-22
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    • 2001
  • To produce reconstituted rabbit embryos with fetal fibroblasts, the present study was evaluated the efficiencies of the different fusion and activation conditions as assessments of subsequent development and chromosome in the embryos. New Zealand White rabbits were used throughout the study. Fetal fibroblasts collected from 22-d of fetuses were cultured in DMEM + 10% FBS in 5% $CO_2$ in air. The culture was maintained for 10 passages. In every passage half of cell suspension were kept In frozen. From rabbits treated with FSH in 30% PVP solution and hCG, oocytes were surgically collected from oviducts at 14 h post-hCG injection and stripped off their cumulus cells by re-pipetting in a 300 IU hyaluronidase solution. Oocytes with an extruded first polar body and dense cytoplasm were enucleated by micromanipulation in Ham's F-10 medium+7.5 g/$m\ell$ cytochalasin B. Euncleation was confirmed under a fluorescence microscope after staining with 5 g/$m\ell$ bisbenzimide for 2 min. Each enucleated oocyte was injected with a fetal fibroblast into a perivitelline space. Reconstructed eggs were compared fusion rates either at 2.0 ㎸/cm or 1.6 ㎸/cm(60 sec, double pulses). After fusion, all eggs were activated with the combination of 5 M ionomycin (5 min) and 10 g/$m\ell$ cycloheximide (CHX, 3h), and cultured in CRlaa medium and transferred into TCM199+10% FBS on day 3. Although there was not significantly differ in fusion rate between treatments (60%, 2.0 ㎸/cm vs. 79.4%, 1.6 ㎸/cm), none of them in the eggs fused with 2.0 ㎸/cm developed to blastocyst. In comparison of development and chromosome status between different activation treatments (Group 1; 5 M ionomycin/10 g/$m\ell$ CHX, Group 2; 5 M ionomycin/5 g/$m\ell$ CHX + 2 mM DMAP after fusion with 1.6 ㎸/cm), there were not differ in cleavage and development rates (67.3% and 28.9% in Group 1; 67% and 33% in Group 2). All out of 8 embryos evaluated in Group 1 appeared a normal diploid chromosome sets and mean number of cells (Mean SEM) on day 4.5 of culture was 141.5 23.15 (n=8). It can be concluded that the use of cycloheximide has not happened in chromosome abnormalities, and fetal fibroblasts can be used for cloning in rabbit.

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Biological Activity of Recombinant Human Erythropoietin (EPO) In Vivo and In Vitro

  • Park Jong-Ju;Lee Hyen-Gi;Nam In-Suk;Park Hee-Ja;Kim Min-Su;Chung Yun-Hi;Naidansuren Purevjargal;Kang Hye-Young;Lee Poong-Yun;Park Jin-Gi;Seong Hwan-Hoo;Chang Won-Kyong;Kang Myung-Hwa
    • Reproductive and Developmental Biology
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    • v.29 no.2
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    • pp.69-73
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    • 2005
  • The hematopoietic growth factor erythropoietin (EPO) is required for the maintenance, proliferation, and differentiation of the stem cells that produce erythrocytes. To analyse the biological activity of the recombinant human EPO (rec-hEPO), we have cloned the EPO cDNA and genomic DNA and produced rec-hEPO in the CHO cell lines. The growth and differentiation of EPO-dependent human leukemic cell line (F36E) were used to measure cytokine dependency and in vitro bioactivity of rec-hEPO. MIT assay values were increased by survival of F36E cells at 24h or 72h. The hematocrit and RBC values were increased by subcutaneous injection of 20 IU (in mice) and 100IU(in rats) rec-hEPO. Hematocrit values remarkably increased at $13.2\%$ (in mice) and $12.2\%$ (in rats). The pharmacokinetic behavior with injection of 6 IU of rec-hEPO remained detectable after 24 h in all mice tested. The highest peat appeared at 2h after injection. The long half-life of rec-hEPO is likely to confer clinical advantages by allowing less frequent dosing in patients treated for anemia. These data demonstratethat ree-hEPO produced in this study has a potent activity in vivo and in vitro. The results also suggest that biological activity of ree-hEPO could be remarkably enhanced by genetic engineering that affects the potential activity, including mutants with added oligosaccharide chain and designed to produce EPO-EPO fusion protein.

QA/QC for 222Rn analysis in groundwater (지하수 중 222Rn 분석을 위한 정도관리)

  • Jeong, Do Hwan;Kim, Moon Su;Kim, Hyun Koo;Kim, Hye Jin;Park, Sun Hwa;Han, Jin Seok;Ju, Byoung Kyu;Jeon, Sang Ho;Kim, Tae Seung
    • Analytical Science and Technology
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    • v.26 no.1
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    • pp.86-90
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    • 2013
  • $^{222}Rn$ concentrations in the groundwater samples without standard material due to the short half-life (3.82 day) were measured through the establishment of the counting efficiency of LSC (Liquid Scintillation Counter) using a standard source of $^{226}Ra$. This study for Quality Assurance/Quality Control (QA/QC) of $^{222}Rn$ analysis was performed to analyze blank samples, duplicate samples, samples of groundwater sampling before and after. In-situ blank samples collected were in the range of 0.44~6.28 pCi/L and laboratory samples were in the range of 1.66~4.95 pCi/L. Their correlation coefficient was 0.9691 and the source contamination from sampling, migration and keeping of samples were not identified. The correlation coefficient between original and duplicate samples from 65 areas was 0.9987. Because radon is an inert gas, in case of groundwater sampling, it is considered to affect the radon concentration. We analyzed samples separately by groundwater sampling before and after using distilled water, but there is no significant difference for $^{222}Rn$ concentrations in distilled waters of two types.

Genetic Studies on Grain Shape and Quality in Rice - II. Genetic Analysis of Chalkiness and Alkali Digestibility Value (벼 입형(粒型)과 미질(米質)에 관련(關聯)된 형질(形質)의 유전연구(遺傳硏究) - II. 미립(米粒)의 심복백(心腹白)과 Alkali 붕괴도(崩壞度)의 유전분석(遺傳分析))

  • Kim, Hyun Tae;Park, Gyu Hwan;Kim, Dal Ung
    • Current Research on Agriculture and Life Sciences
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    • v.6
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    • pp.31-36
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    • 1988
  • A seven-parent half-diallel cross was analyzed for white center, white belly and alkali digestibility value(ADV). The analysis of variences were significant for all characters at 1% level. Both general and specific combining ability were significant for all characters. Non-additive genetic varience predominated for ADV(12hr. treatment) and additive effects were more important than non-additive effects for other characters. With the exception of ADV(12hr. treatment), which showed complete dominance, partial dominance in a negative direction was observed for the other characters. Heritability values were high in all characters. White belly was high positively correlated with white center and ADV.

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Leaching potential of butachlor, ethoprophos, iprobenfos, isoprothiolane and procymidone in soils as affected by adsorption characteristics (Butachlor, ethoprophos, iprobenfos, isoprothiolane 및 procymidone의 토양흡착성에 따른 용탈 잠재성 평가)

  • Kim, Chan-Sub;Lee, Byung-Moo;Ihm, Yang-Bin;Choi, Ju-Hyeon
    • The Korean Journal of Pesticide Science
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    • v.6 no.4
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    • pp.309-319
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    • 2002
  • Soil adsorption study was carried out to define the mobility of pesticides or to evaluate leaching potential in soils. Five pesticides including ethoprophos, procymidone, iprobenfos, isoprothiolane, and butachlor were subjected to optimized adsorption experiment protocol for three types of cultivation soils. Freundlich adsorption coefficients (K) were ranged $0.35{\sim}0.95$ for ethoprophos, $0.98{\sim}2.2$ for iprobenfos, $1.2{\sim}4.3$ for procymidone, $1.5{\sim}3.5$ for isoprothiolane and $7.9{\sim}19$ for butachlor in three soils. Based on Koc values, ethoprophos was classified as mobile, iprobenfos, isoprothiolane and procymidone as moderately mobile and butachlor as slightly mobile. Two evaluation methods, Groundwater Ubiquity Score (GUS) index and standard indices of soil-chemical adsorption and biodegradation, were used for the estimation of pesticide leaching potential. Leachability of isoprothiolane and iprobenfos were evaluated as moderate, ethoprophos as a little potential, while butachlor and procymidone showed very low leaching potential. The leaching potential of pesticides was essentially determined on the basis of intrinsic properties of the pesticides and environmental properties. Among the soil properties, organic matter gave a great influence on the leachability of soils. Therefore, leachabilities of pesticides were expected less in loam with relatively higher organic matter than clay loam with lower organic matter.

Pharmacokinetic Evaluation and Gastric Ulcer Symptoms comparison of Ketorolac Tromethamine Sustained-Release Pellets after Oral Administration in Beagle Dogs (비글견을 이용한 케토롤락트로메타민 서방형 펠렛 제제의 위궤양 증상 비교와 약물속도론적 평가)

  • Yoon, Yang-No;Kim, Su-Ji;Jung, Suk-Hyun;Kim, Hyo-Jeong;Park, Eun-Seok;Hwang, Sung-Joo;Lee, Yong-Won;Seong, Ha-Soo;Shin, Byung-Cheol;Cho, Sun-Hang
    • Journal of Pharmaceutical Investigation
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    • v.39 no.6
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    • pp.401-409
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    • 2009
  • Ketrorolac tromethamine (KT), a nonsteroidal anti-inflammatory drug (NSAID) is required repeated administration due to its short blood half-life. To avoid dose-dependent side effects of KT, sustained-release pellets containing KT were prepared by coating with Eudragit$^{(R)}$ RS 100 and Eudragit$^{(R)}$ NE 30D. The in vitro and in vivo drug release behavior of KT from Eudragit$^{(R)}$ RS 100 and NE 30D coated pellet (SR-A), Eudragit$^{(R)}$ RS 100 coated pellet (SR-B) and conventional commercial immediate-release tablet (IR) was investigated. KT from SR-A and SR-B was slowly released over several hours, whereas IR showed rapid initial release in vitro. The pharmacokinetic study in vivo was performed by oral administration in beagle dogs. 5 mg IR was administered 3 times at intervals 5 hr. Five milligrams of IR was administered 3 times at intervals of 5 hr and 15 mg of SR-A and SR-B did once. After administering IR, KT concentration in blood showed high peak- trough fluctuation and stomach ulcer were discovered. On the other hand, SR-A and SR-B sustainedly released KT and reduced the occurrence of stomach ulcer. There sustained-release pellets will be effective system to minimize dosedependent of side effect and improve patient compliance.

Study on Pesticide Runoff from Soil Surface-II - Runoff of Phorate by Simulated Rainfall in Field - (농약의 토양 표면 유출에 관한 연구-II - 포장에서 인공강우에 의한 phorate의 유출특성 -)

  • Yeom, Dong-Hyuk;Kim, Jeong-Han;Lee, Sung-Kyu;Kim, Yong-Hwa;Park, Chang-Kyu;Kim, Kyun
    • Applied Biological Chemistry
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    • v.40 no.4
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    • pp.323-328
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    • 1997
  • Runoff of phorate, soil insecticide, were measured under simulated rainfall conditions in field using small test plot$(120\;cm{\times}120\;cm)$ at the loam area and loamy sand area. Fish acute toxicity tests were performed with runoff water to elucidate its toxicological effect on organisms in ecosystem. The average concentrations of phorate in runoff water from loam and loamy sand soil were 11.3 ppb and 4.8 ppb, respectively. However, there was no significant concentration difference between the heavy and the light rain. With loam soil, average runoff rates were 1.31 and 0.18%, while with loamy sand soil those were 0.48 and 0.012% under the heavy and the light rain conditions, respectively. Total average runoff rate was 0.50%. With killifish, no mortality was observed in runoff water from loamy sand soil, whereas half of the population was dead in runoff water from loam soil when it was diluted to 54.4% content.

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Studies on Microbial Penicillin Amidase (Part 6) Immobilization of Penicillin Amidase from Bacillus megaterium by Adsorption and Acrylamide Gel Entrappment (미생물 페니실린 아미다제에 관한 연구 (제 6 보) 흡착효소의 아크릴아마이드젤 포괄방법에 의한 Bacillus megaterium의 변이주가 생산하는 페니실린 아미다제의 고정화에 관한 연구)

  • Seong, Baik-Lin;Son, Hyeung-Jin;Mheen, Tae-Ick;Moon H. Han
    • Microbiology and Biotechnology Letters
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    • v.9 no.4
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    • pp.197-205
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    • 1981
  • Penicillin amidase of Bacillus megaterium was recovered from the fermentation broth by adsorption on celite and immobilized by entrapping the adsorbed enzyme in acrylamide gel. The operational stability in column reactor was greatly increased by entrappment as compared with that of without entrappment. The optimum pH of the immobilized enzyme was 8.7 with broader activity profile than that of the free enzyme, while the most stable pH range appeared to be between pH 7.5 and 8.0. The optimum temperature was shifted to 5$0^{\circ}C$ from 45$^{\circ}C$ for the soluble enzyme. The values of Km and the inhibition constants for 6-APA( $K_{ia}$ ) and phenylacetic acid ( $K_{ip}$ ), were 4.55 mM, 36.5mM, and 10.5mM, respectively. No significant internal pore diffusion limitation was found since the value of effectiveness factor was 0.95. The operational half life in a column reactor at pH 8.0 was 6.8 days at 4$0^{\circ}C$ and 47 days at 3$0^{\circ}C$, whereas that of without entrappment was only 1 day and 4 days, respectively. The performance of a batch and a column reactor was also discussed with respect to the productivity. The results demonstrated that the entrappment of an adsorbed enzyme for the enhancement of the operational stability of the immobilized enzyme was useful especially when an extracellular enzyme was used.

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Overexpression and Characterization of Bovine Pancreatic Deoxyribonuclease I in Saccharomyces cerevisiae and Pichia pastoris (Saccharomyces cerevisiae와 Pichia pastoris에서 Bovine Pancreatic Deoxyribonuclease I의 과발현과 특성)

  • Cho, Eun-Soo;Kim, Jeong-Hwan;Yoon, Ki-Hong;Kim, Yeon-Hee;Nam, Soo-Wan
    • Microbiology and Biotechnology Letters
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    • v.40 no.4
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    • pp.348-355
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    • 2012
  • In the present study, we investigated the overexpression and characterization of bovine pancreatic (bp)- DNase I in Saccharomyces cerevisiae and Pichia pastoris. The bp-DNase I gene was fused in frame with the GAL10 promoter, $MF{\alpha}$, and GAL7 terminator sequences, resulting in the plasmid, pGAL-$MF{\alpha}$-DNaseI (6.4 kb). Also, the bp-DNase I gene was fused in frame with the AOX1 promoter, $MF{\alpha}$, and AOX1 terminator sequences, resulting in the plasmid, pPEXI (8.8 kb). The recombinant plasmids, pGAL-$MF{\alpha}$-DNaseI and pPEXI were introduced into S. cerevisiae and P. pastoris host cells, respectively. When the transformed yeast cells were cultured at $30^{\circ}C$ for 48 h in galactose or methanol medium, bp-DNase I was overexpressed and the most of activity was found in the extracellular fraction. P. pastoris transformant activity showed 45.5 unit/mL in the culture medium at 48 h cultivation, whereas S. cerevisiae transformant revealed 37.7 unit/mL in the extracellular fraction at 48 h cultivation. The enzymatic characteristics, such as DNA cleavage and half life were investigated. Treatment of the recombinant DNase I from P. pastoris induced degradation of the calf thymus DNA within 1 minute, and this DNA degradation rate was higher than that of commercial bp-DNase I (SIGMA) and the recombinant DNase I from S. cerevisiae.