• 제목/요약/키워드: Half-life(t1/2)

검색결과 249건 처리시간 0.041초

A Study for Establishment of High Dose Radioiodine Therapy Patients' Release Standard

  • Park, Hoon-Hee;Kim, Hyun-Soo;Dong, Kyung-Rae
    • 대한디지털의료영상학회논문지
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    • 제13권4호
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    • pp.153-156
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    • 2011
  • This study, which is proceeded in the department of nuclear medicine, aims at preventing unnecessary radiation exposure to the patients and the people near the patients by understanding and presenting the realities about the isolating period for the high dose radioiodine patients after total thyroidectomy in the 7 general hospitals in metropolitan area. Theoretically, the physical half-life of the high dose radioiodine is 8 days. Radioiodine lower than 100 mCi usually is eliminated all in 2 days 1 night considering the biological half-life and the amount of excreting radioiodine The hospitalization standard of the patients treated with high-dose radioiodine therapy has been established according to the fact above. Investigation of the data and questionnaire from the hospital have proven that some hospitals didn't even measure the acceptable dose because of the faith in the vague data. Besides, the some of those inevitably let the readmitting patients exceeding the acceptable dose be in the general ward, not in the isolation ward, because the number of the isolation rooms is relatively smaller than the patients. Thus, we want to contribute that patients understand the realities and the hospitals consider the relevant problem actively so that the problem will be settled by this journal.

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돼지와 랫트에서 sulfamethazine의 약물동태학 및 조직분포 (Pharmacokinetic profile and tissue distribution of sulfamethazine in pigs and rats)

  • 윤효인;박승춘;오태광;조준형;박종명
    • 대한수의학회지
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    • 제37권2호
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    • pp.291-299
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    • 1997
  • In order to establish optimal dosage schedules and withdrawal times for sulfamethazine(SMZ) in pigs, pharmacokinetic and tissue distribution experiments were conducted in pigs. For comparative purposes, tissue depletion kinetics are also studied in rats. From three pigs administered with SMZ i.v., the pharmacokinetic profile of SMZ in two pigs was adequately described by a one-compartment open model whereas that in one pig was patterned after a two-compartment open model. Volume of distribution(Vd) was 0.48~0.57 L/kg and biological half-life($t_{1/2}$) was 11.8-16.8 h. From three pigs dosed with SMZ p.o., pharmacokinetic profile was explainable with a one-compartment open model. Time to reach maximum SMZ concentration in serum (Tmax) was 2.8 h, 3.2 h and 7.5 h. Elimination half-life was 2.8-7.5 h. The descending order in concentration of SMZ was plsama > kidney > liver > lung > heart > pancreas > spleen > duodenum > ileum > brain > adipsoe tissue from three pigs sacrificed at 5h, 29h and 54h after the administration of SMZ, p.o.. The protein binding of SMZ in pigs was 55.2%($2.5{\mu}g/ml$), 71.5% ($5{\mu}g/kg$) and 71.5%($10{\mu}g/ml$). The mean systemic bioavailability (F) of SMZ p.o. was 49.1 %. Meanwhile the pharmacokinetic profile of SMZ in rats was adequately described by a one-compartment open model. Absorption of SMZ p.o. in the rat was very rapid. In conclusion, the oral optimal dosage regimen of SMZ for pigs was the initial dose of 45.7 mg/kg followed by the maintenance dose of 30.2 mg/kg for high specific pathogens to SMZ. The time to reach below the stipulated residual allowable concentration (0.1 ppm) was calculated 93 h after oral administration of 200 mg/kg recommended by manufactureres.

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Isolation and Characterization of Nonylphenol-degrading Bacteria

  • Yu, Dae-Ung;Kim, Dong-Myung;Chung, Yong-Hyun;Lee, Yang-Bong;Kim, Young-Mog
    • Fisheries and Aquatic Sciences
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    • 제15권2호
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    • pp.91-97
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    • 2012
  • To isolate a nonylphenol (NP)-degrading bacterium, we isolated a single colony from the NP-degrading microbial consortium SW-3, which was previously isolated from an aqueous environment. Ten colonies that exhibited different cell morphologies were isolated and the strains were named SW-3-A, -B, -C, -D, -E, -F1, -F2, -G, -H, and -I. The ability of isolates to degrade NP was evaluated by kinetic analysis by the constant of NP degradation rate ($k_1$) and the half-life time of NP degradation ($t_{1/2}$). SW-3-F1, -F2, -G, and -I strains were superior at degrading NP. The $k_1$ and $t_{1/2}$ values of the four strains were sixfold higher and one-sixth lower, respectively, than those of the consortium strain. Additionally, SW-3-F1, -G, and -I strains were tested for their ability to degrade NP during coculture. NP degradation by coculture with a combination of all three strains was inferior to that of culture conducted with single isolates, suggesting that the three strains are antagonistic toward each other during NP degradation.

한국 흑염소에 있어서 Indocyanine Green 배설시험 (Indocyanine Green Excretion Test in Korean Black Goats)

  • 이성엽;이창우
    • 한국임상수의학회지
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    • 제4권2호
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    • pp.473-481
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    • 1987
  • This experiment was performed in order to establish a proper method to determine the half life of indocyanine green(ICG T$\frac{1}{2}$) and its fractional clearance rate(KICG) and investigate the applicability of indocyanine green ( ICG ) excretion test in hepatotoxicity experiment in Korean black goats. The results were as follows : 1. Maximum absorbance of ICG in plasma was at 810 nm in this experiment. 2. The coefficient of correlation between the results obtained by standard method and potassium cyanide method was 0.99 and the regression equation between two methods was y=0.9996 x+0.0065. 3. As the disappearance curve of ICG plotted in semi-log graph revealed linear pattern at least for 6 minutes after injection, the postinjection blood samples were decided to collect at 2 and 6 minutes after ICG injection. 4. ICG T$\frac{1}{2}$ and KICG values were not affected by dose level of ICG. 5. When 0.25 mg of ICG per kg body weight was administered the normal data of ICG T$\frac{1}{2}$ and KICG in Korean black goa were 1.468${\pm}$0.197 minutes(mean${\pm}$SD) and 0.482${\pm}$0.076/minutes respectively. 6. After administration of carbon tetracholride. the ICG T$\frac{1}{2}$ started to increase acutely from day 1, revealed the peak at day 3, and then returned almostly but not completely to preinjection level at day 14. The ICG T$\frac{1}{2}$ value was suggested to be a sensitive indicator of hepatic injury in Korean black goats.

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Removal characteristics of chromium by activated carbon/CoFe2O4 magnetic composite and Phoenix dactylifera stone carbon

  • Foroutan, Rauf;Mohammadi, Reza;Ramavandi, Bahman;Bastanian, Maryam
    • Korean Journal of Chemical Engineering
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    • 제35권11호
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    • pp.2207-2219
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    • 2018
  • Activated carbon (AC) was synthesized from Phoenix dactylifera stones and then modified by $CoFe_2O_4$ magnetic nanocomposite for use as a Cr(VI) adsorbent. Both $AC/CoFe_2O_4$ composite and AC were fully characterized by FTIR, SEM, XRD, TEM, TGA, and VSM techniques. Based on the surface analyses, the addition of $CoFe_2O_4$ nanoparticles had a significant effect on the thermal stability and crystalline structure of AC. Factors affecting chromium removal efficiency like pH, dosage, contact time, temperature, and initial Cr(VI) concentration were investigated. The best pH was found 2 and 3 for Cr adsorption by AC and $AC/CoFe_2O_4$ composite, respectively. The presence of ion sulfate had a greater effect on the chromium sorption efficiency than nitrate and chlorine ions. The results illustrated that both adsorbents can be used up to seven times to adsorb chromium. The adsorption process was examined by three isothermal models, and Freundlich was chosen as the best one. The experimental data were well fitted by pseudo-second-order kinetic model. The half-life ($t_{1/2}$) of hexavalent chromium using AC and $AC/CoFe_2O_4$ magnetic composite was obtained as 5.18 min and 1.52 min, respectively. Cr(VI) adsorption by AC and $AC/CoFe_2O_4$ magnetic composite was spontaneous and exothermic. In general, our study showed that the composition of $CoFe_2O_4$ magnetic nanoparticles with AC can increase the adsorption capacity of AC from 36 mg/L to 70 mg/L.

OLED소자의 수명에 미치는 다층 보호막의 영향 (The Effect of Multilayer Passivation Film on Life Time Characteristics of OLED Device)

  • 주성후;양재웅
    • 한국표면공학회지
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    • 제45권1호
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    • pp.20-24
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    • 2012
  • Multilayer passivation film on OLED with organic/inorganic hybrid structure as to diminish the thermal stress and expansion was researched to protect device from the direct damage of $O_2$ and $H_2O$ and improve life time characteristics. Red OLED doped with 1 vol.% Rubrene in $Alq_3$ was used as a basic device. The films consist of ITO(150 nm)/ELM200_HIL(50 nm)/ELM002_HTL(30 nm)/$Alq_3$: 1 vol.% Rubrene(30 nm)/$Alq_3$(30 nm) and LiF(0.7 nm)/Al(100 nm) which were formed in that order. Using LiF/$SiN_x$ as a buffer layer was determined because it significantly improved life time characteristics without suffering damage in the process of forming passivation film. Multilayer passivation film on buffer layer didn't produce much change in current efficiency, while the half life time at 1,000 $cd/m^2$ of OLED/LiF/$SiN_x$/E1/$SiN_x$ was 710 hours which showed about 1.5 times longer than OLED/LiF/$SiN_x$/E1 with 498 hours. futhermore, OLED/LiF/$SiN_x$/E1/$SiN_x$/E1/$SiN_x$ with 1301 hours showed about twice than OLED/LiF/$SiN_x$/E1/$SiN_x$ which demonstrated that superior characteristics of life time was obtained in multilayer passivation film. Through the above result, it was suggested using LiF/$SiN_x$ as a buffer layer could reduce the damage from the difference of thermal expansion coefficient in OLED with protective films, and epoxy layer in multilayer passivation film could function like a buffer between $SiN_x$ inorganic layers with relatively large thermal stress.

Nonactivated Arylazoindolinobenzospiropyran Derivatives. Part $2^1$ : Preparation and Kinetic Measurements of the Spiro-ring Formation from the Merocyanine Form

  • 금삼록;이명진
    • Bulletin of the Korean Chemical Society
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    • 제20권12호
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    • pp.1464-1468
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    • 1999
  • Non-activated indolinobenzospiropyrans, 6-(p-substituted phenylazo)-1',3',3'-trimethylspiroindolinobenzopyrans(1-4) have been synthesized by the reaction of commercially available Fischer's base with 2-hydroxy-5-arylazobenzaldehyde (S1-S4). The arylazosalicylaldehydes were obtained from the diazocoupling reaction of substituted anilines with salicylaldehyde. The rate of spiro-ring formation from the open form of these nonactivated spiropyran derivatives at room temperature has been investigated utilizing the stopped-flow method de-veloped earlier. Half life times $(t_{1/2})$ of the ring-closure reaction in ethanol are about 0.3-14 seconds for the nonactivated spiropyrans examined. UV-Visible absorption spectral data of the open merocyanine form of nonactivated spiropyrans, which showed no chromotropism at room temperature, have also been obtained.

가토에서 생체리듬이 겐타마이신의 약물동태에 미치는 영향 (The Effect of Circadian Rhythm on the Gentamicin Pharmacokinetics in Rabbits)

  • 고재원;백채선;최준식
    • 한국임상약학회지
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    • 제10권3호
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    • pp.125-129
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    • 2000
  • The effect of circadian rhythm on gentamicin pharmacokinetics was studied in rabbits who took a single intravenous 2 mg/kg dose of gentamicin at 09:00 in the morning (a.m.) and 22:00 in the evening (p.m.). A significant circadian rhythm of pharmacokinetic parameters as a function of time of day was noted in rabbits, showing lower total body clearance $CL_t$ and higher serum area under the curve (AUC) when given in the evening. The half-life $t_{1/2}$ was shorter in the morning $(3.88\pm0.62h)$ when compared to the evening $(4.76\pm0.75\;h)$. The AUC was greater in the evening $(25.92\pm3.49\;{\mu}g/ml{\cdot}hr)$ than that in the morning $(22.42\pm3.42\;{\mu}g/ml{\cdot}hr)$, most likely because the CLt was significantly higher when gentamicin was given in the morning $(0.18\pm0.28\;ml/hr)$ versus in the evening $(0.15\pm0.26\;ml/hr)$. The $t_{1/2}$ of gentamicin in the evening was increased significantly(p<0.05) compared to those of gentamicin in the morning. It is reasonable to consider individual circadian rhythm for effective dosage regimen of gentamicin in clinical chronotherapeutics.

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테놀민 정(아테놀올 50 mg)에 대한 신일아테놀올 정의 생물학적 동등성 (Bioequivalence of Sinil Atenolol Tablets to Tenormin Tablets (Atenolol 50 mg))

  • 곽혜선;강성하;전인구
    • Journal of Pharmaceutical Investigation
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    • 제33권1호
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    • pp.51-53
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    • 2003
  • This study was conducted to compare the bioavailability of a generic product of Sinil Atenolol Tablets (Sinil Pharmaceutical Co., Ltd., Korea) with the innovator product, $Tenormin^{\circledR}$ Tablets in 20 healthy Korean volunteers. The volunteers received a single 50 mg dose of each atenolol formulation according to a randomized, two-way crossover design. Plasma samples were obtained over a 24-hour interval, and atenolol concentrations were determined by HPLC with a fluorescence detector. From the plasma atenolol concentration vs time curves, the following parameters were compared: area under the plasma concentration-time curve (AUC), peak plasma concentration $(C_{max})$, time to reach peak plasma concentration $(T_{max})$, and terminal first order elimination half-life $(t_{1/2})$. No statistically significant difference was obtained between the $T_{max}$ values, and the logarithmic transformed AUC and $C_{max}$ values of the two products. The 90% confidence for the ratio of the logarithmically transformed AUC and $C_{max}$ values of Sinil Atenolol Tablets over those of $Tenormin^{\circledR}$ Tablets were calculated to be between 0.99 and 1.07, and 1.04 and 1.16, respectively; both were within the bioequivalence limit of 0.80-1.25. The mean of $T_{max}$ in $Tenormin^{\circledR}$ Tablet group was 3.68 hour, and that in Sinil Atenolol Tablet group was 3.65 hour. The values of $t_{1/2}$ between the two products were found comparable, and the mean $t_{1/2}$ values of $Tenormin^{\circledR}$ Tablets and Sinil Atenolol Tablets were 5.9 and 6.0 hour, respectively. Based on these results, it was concluded that Sinil Atenolol Tablets were comparable to $Tenormin^{\circledR}$ Tablets in both the rate and extent of absorption, indicating that Sinil Atenolol Tablets were bioequivalent to the reference product, $Tenormin^{\circledR}$ Tablets

자아실현성과 공동의사결정에 관한 연구 - 남편과 부인을 중심으로 (A Study on the Relation between Husband and Wife's Self-Actualization and Joint Decision-Making)

  • 김성희;문숙재
    • 가정과삶의질연구
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    • 제7권2호
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    • pp.163-178
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    • 1989
  • This study was mainly concerned providing a basic of data for the more reasonable home management. The purpose study was to investigate the relationship of husbands and wives self-actualization and degree of joint decision-making. For the purpose of this study 500 questionaire were distributed to the marital in seoul. The 412 data were analized by Frequency, Percentage, T-test, ANOVA, Scheffe-test. The major findings of this study were as follows: 1) Over one and half of husbands and wives are try to be self-actualized. 2) The tendency of the husbands and wives decision-making was joint decision-making. 3) The important influential variables on the husbands and wives self-actualization husbands were age, life-cycle, job employment motivation. And wives were life-cycle, education, income, job, employment motivation. 4) The important influential variables on the joint decision-making were age, number of child, life-cycle. 5) A marital joint decision-making level differs significantly, according to the degree of husbands and wives self-actualization. The higher level of husbands and wives self-actualization, the higher degree of marital joint decision-making. The result of this study implies that a marital joint-making necessary in order to carry on happy home management and the reasonable home administration.

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