• Title/Summary/Keyword: Tmax

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The Effects of Hydrochlorothiazide on the Pharmacokinetics of Carteolol in Rabbits (Hydrochlorthiazide가 Carteolol의 약동력학에 미치는 영향)

  • 정혜주;조윤성;김낙두;고광호
    • YAKHAK HOEJI
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    • v.27 no.2
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    • pp.149-154
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    • 1983
  • The effect of hydrochlorothiazide on the pharmacokinetics of carteolol in rabbits was studied. Animals were divided into two groups (group I and group II). Group I received carteolol (12mg/kg) and group II received carteolol (12mg/kg) with hydrochlorothiazide (20mg/kg) orally. The carteolol concentration in serum was measured by spectrofluorometric method and its pharmacokinetic parameter values were calculated. The serum concentration of carteolol in group II was significantly increased when compared with those in group I at 10min (p<0.01), and at 30min (p<0.05) after p. o. administration. In addition, the absorption rate constant of carteolol in group II was slightly increased and Tmax of carteolol in group II was significantly shortened (p<0.05) and Cmax of carteolol in group II was significantly increased (p<0.02) when compared with those in group I. But elimination rate constant and biological half-life of carteolol were similar in both groups.

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Efficient Time-Series Subsequence Matching Using Index Interpolation (인덱스 보간법을 이용한 효율적인 시계열 서브시퀀스 매칭)

  • Lim Seung-Hwan;Ko Hyun-Gil;Loh Woong-Kee;Kim Sang-Wook
    • Proceedings of the Korea Information Processing Society Conference
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    • 2004.11a
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    • pp.31-34
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    • 2004
  • 서브시퀀스 매칭은 시계열 데이터베이스에서 질의 시퀀스와 유사한 서브시퀀스틀 찾아내는 연산이다. 기존의 서브시퀀스 매칭 알고리즘들은 하나의 인덱스만을 사용하여 검색을 수행하기 때문에, 인덱스를 생성하기 위하여 데이터 시퀀스로부터 추출한 윈도우의 크기와 질의 시퀀스의 길이 간의 차이가 커질수록 검색 성능이 급격히 저하되는 문제점을 갖고 있다. 본 논문에서는 이러한 기존 알고리즘의 문제점을 해결하기 위하여 인덱스 보간법에 기반한 새로운 서브시퀀스 매칭 기법을 제안한다. 인덱스 보간법이란 하나 이상의 인덱스를 구축하고 주어진 질의 시퀀스의 길이에 따라 적절한 인덱스를 선택하여 검색을 수행하는 기법이다. 본 논문에서는 서브시퀀스 매칭 비용 공식을 산출하고, 이 비용 공식에 기반하여 제안된 기법의 성능을 최적화 하도록 다수의 인덱스를 구성하는 알고리즘을 제시한다. 마지막으로, 실제 데이터를 이용한 여러 가지 실험을 통하여 제안된 기법의 우수성을 정량적으로 검증한다.

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A Proposal for Education of Web-based Software Engineering (웹 기반 소프트웨어공학 교육을 위한 제안)

  • Choi, Young-Mee;Jang, Duk-Sung;Kwon, Ho-Yul;Oh, Chan-Joo;Kim, Sung-Ik
    • Proceedings of the Korea Information Processing Society Conference
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    • 2003.11c
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    • pp.1587-1590
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    • 2003
  • 웹 정보시스템 개발에 있어 사용자 요구사항이 복잡하고 다양해짐에 따라 웹 정보시스템 개발에 SE 기술을 접목하는 연구가 시도되고 있다. 그러나 아직 웹 기반 소프트웨어공학을 대학의 교육과정에 도입하는 경우는 없다. 본 논문에서는 웹 정보시스템의 개발 및 운영에 대한 핵심 소프트웨어공학 기법을 교육함에 있어서 중요하고 시급한 주제, 네 가지를 제안하려 한다. 첫 번째는 웹 기술과 컴포넌트 기술을 적용한 소프트웨어 아키텍처이고, 두 번째는 웹 효과적인 웹 응용 개발을 위한 디자인 패턴이며, 세 번째는 웹기반 SW 테스팅의 계획수립 및 테스트 수행 기법이고 마지막으로 웹서비스 기술과 적용 사례가 교육되어야 할 것으로 보인다.

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The Study on the drug pharmacokinetics according to the progression of liver disease

  • Sohn, Soo-Jung;Choi, Hong-Serck;Ahn, Mee-Ryung;Chung, Hye-Joo;Yoo, Tae-Moo;Lee, Min-Ho;Park, Moon-Seung;Shin, In-Chul;Kim, Ju-ll
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.308.1-308.1
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    • 2003
  • We underwent this study to know correlation between the amount of portosysternic shunt/hepatic fibrosis and bioavailability parameters such as AUC, Cmax, Tmax and t1 /2 of high extraction ratio drug, propranolol, in CCl4-induced liver cirrhosis model of rats. This study describes the bioavaility study of propranolol(5 mg/kg), Shunt Index using thallium-201 per rectum scintigraphy to to measure the amount of portosystemic shunt indirectly and intrahepatic hydroxyproline content performed in the CCl4-induced liver cirrhosis model of rats. (omitted)

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Pharmacokinetic Profiles of Isoniazid and Rifampicin in Korean Tuberculosis Patients (한국인 결핵환자에서 Isoniazid와 Rifampicin의 약동학)

  • Ahn, Seok-Jin;Park, Sang-Joon;Kang, Kyeong-Woo;Suh, Gee-Young;Chung, Man-Pyo;Kim, Ho-Joong;Kwon, O-Jung;Rhee, Chong-H.;Cha, Hee-Soo;Kim, Myoung-Min;Choi, Kyung-Eob
    • Tuberculosis and Respiratory Diseases
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    • v.47 no.4
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    • pp.442-450
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    • 1999
  • Background : Isoniazid(INH) and rifampicin(RFP) are the most effective anti-tuberculosis drugs which make the short-course chemotherapy possible. Although prescribed dosages of INH and RFP in Korea are different from those recommended by American Thoracic Society, there has been few study about pharmacokinetic profiles of INH and RFP in Korean patients who receive INH, RFP, ethambutol(EMB) and pyrazinamide(PZA) simultaneously. Methods : Among the patients with active tuberculosis from Dec. 1997 to July 1998, we selected 17 patients. After an overnight fast, patients were given INH 300mg, RFP 450mg, EMB 800mg and PZA 1500mg daily. Blood samples for the measurement of plasma INH(n=15) and RFP(n=17) level were drawn each at 0, 0.5, 1, 1.5, 2, 4, 6, 8 and 12hrs, and urine was also collected. INH and RFP level in the plasma and the urine were measured by high-performance liquid chromatography(HPLC). Pharmacokinetic parameters such as peak serum concentration(Cmax), time to reach to peak serum concentration(Tmax), half-life, elimination rate constant(Ke), total body clearance(CLtot), nonrenal clearance(CLnr), and renal clearance(CLr) were calculated. Results : 1) Pharmacokinetic parameters of INH were as follows: Cmax; $7.63{\pm}3.20{\mu}g/ml$, Tmax; $0.73{\pm}0.22hr$, half-life; $2.12{\pm}0.84hrs$, Ke; $0.83{\pm}0.15hrs^{-1}$, CLtot; $17.54{\pm}8.89L/hr$, CLnr; $14.74{\pm}8.35L/hr$, CLr; $2.79{\pm}1.31L/hr$. 2) Pharmacokinetic parameters of RFP were as follows: Cmax; $8.93{\pm}3.98{\mu}g/ml$, Tmax; $1.76{\pm}1.13hrs$, half-life; $2.27{\pm}0.54hrs$, Ke; $0.32{\pm}0.08hrs^{-1}$, CLtot; $14.63{\pm}6.60L/hr$, CLr; $1.04{\pm}0.55L/hr$, CLnr; $13.59{\pm}6.21L/hr$. 3) While the correlation between body weight and Cmax of INH was not statistically significant (r=-0.514, p value>0.05), Cmax of RFP was significantly affected by body weight of the patients(r=-0.662, p value<0.01). Conclusion : In Korean patients with tuberculosis, 300mg of INH will be sufficient to reach the ideal peak blood level even in the patients over 50kg of body weight However, 450mg of RFP will not be the adequate dose in the patients who weigh over 50~60kg.

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Comparison of Enalapril Maleate Tablets on Bioavailability and the Time Course of Inhibition of Plasma Angiotensin-Converting Enzyme (Enalapril Maleate 정제의 동등성에 관한 연구 ; 약동학적 성상 및 혈장 ACE 활성도 억제 효과)

  • Jang, In-Jin;Jang, Byung-Soo;Shin, Sang-Goo;Shin, Jae-Gook;Rho, Il-Kun;Lee, Kyeong-Hun;Park, Chan-Woong
    • The Korean Journal of Pharmacology
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    • v.26 no.2
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    • pp.219-226
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    • 1990
  • Enalapril maleate tablets of two different producers were tested for bioequivalence. Enalapril is rapidly metabolized to an active metabolite, enalaprilat which inhibits angiotensin-converting enzyme (ACE). The pharmacokinetics of enalapril maleate and the time course of inhibition of plasma ACE activity after administration of the drugs were studied. Two single doses of 10mg each of enalapril maleate were administered orally to twelve male volunteers in a balanced, randomized, two-way crossover investigation. Plasma enalaprilat concentrations were determined over a 23-hour after the dose by enzyme inhibition assay and enalapril by the same method following in vitro hydrolysis. Urinary recoveries of enalapril and enalaprilat were determined for the calculation of renal clearance. Plasma ACE activity was determined by an enzyme assay. Peak plasma levels of enalapril were observed about 1 hour after the doses, and practically all enalapril had disappeared from plasma within 6 hour. Peak enalapril concentrations of both formulations were almost identical ($Vasotec^{\circledR}$, 61.38 ng/ml; $Beartec^{\circledR}$, 64.27 ng/ml). The values of the pharmacokinetic parameters of enalaprilat computed for $Vasotec^{\circledR}$ and $Beartec^{\circledR}$ tablets are presented in that order; area under the curve=330.63:320.96 $ng{\cdot}hr/ml$; peak concentration=38.63:39.43 ng/ml; time to peak=3.83:4.08 hour; elimination half-life=3.95:3.92 hours. No statistically significant difference was detected when area under the curve and all other parameters were compared. Using criteria of 95% confidence interval for the comparison of these parameters, only the upper limits of area under the curve and time to peak of enalapril were over 120%. All the parameters of enalaprilat were acceptable. Percent inhibition of plasma ACE to plasma enalaprilat concentration showed the sigmoid concentration-inhibition relationship. Time courses of plasma ACE inhibition after the administration of both formulations were quite similar. The formulations were found to be equivalent when compared on the premise that no significant difference was detected when pharmacokientic parameters and inhibition of ACE activity were compared, based on the confidence limits analysis.

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Contrast Media in Abdominal Computed Tomography: Optimization of Delivery Methods

  • Joon Koo Han;Byung Ihn Choi;Ah Young Kim;Soo Jung Kim
    • Korean Journal of Radiology
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    • v.2 no.1
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    • pp.28-36
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    • 2001
  • Objective: To provide a systematic overview of the effects of various parameters on contrast enhancement within the same population, an animal experiment as well as a computer-aided simulation study was performed. Materials and Methods: In an animal experiment, single-level dynamic CT through the liver was performed at 5-second intervals just after the injection of contrast medium for 3 minutes. Combinations of three different amounts (1, 2, 3 mL/kg), concentrations (150, 200, 300 mgI/mL), and injection rates (0.5, 1, 2 mL/sec) were used. The CT number of the aorta (A), portal vein (P) and liver (L) was measured in each image, and time-attenuation curves for A, P and L were thus obtained. The degree of maximum enhancement (Imax) and time to reach peak enhancement (Tmax) of A, P and L were determined, and times to equilibrium (Teq) were analyzed. In the computed-aided simulation model, a program based on the amount, flow, and diffusion coefficient of body fluid in various compartments of the human body was designed. The input variables were the concentrations, volumes and injection rates of the contrast media used. The program generated the time-attenuation curves of A, P and L, as well as liver-to-hepatocellular carcinoma (HCC) contrast curves. On each curve, we calculated and plotted the optimal temporal window (time period above the lower threshold, which in this experiment was 10 Hounsfield units), the total area under the curve above the lower threshold, and the area within the optimal range. Results: A. Animal Experiment: At a given concentration and injection rate, an increased volume of contrast medium led to increases in Imax A, P and L. In addition, Tmax A, P, L and Teq were prolonged in parallel with increases in injection time The time-attenuation curve shifted upward and to the right. For a given volume and injection rate, an increased concentration of contrast medium increased the degree of aortic, portal and hepatic enhancement, though Tmax A, P and L remained the same. The time-attenuation curve shifted upward. For a given volume and concentration of contrast medium, changes in the injection rate had a prominent effect on aortic enhancement, and that of the portal vein and hepatic parenchyma also showed some increase, though the effect was less prominent. A increased in the rate of contrast injection led to shifting of the time enhancement curve to the left and upward. B. Computer Simulation: At a faster injection rate, there was minimal change in the degree of hepatic attenuation, though the duration of the optimal temporal window decreased. The area between 10 and 30 HU was greatest when contrast media was delivered at a rate of 2 3 mL/sec. Although the total area under the curve increased in proportion to the injection rate, most of this increase was above the upper threshould and thus the temporal window was narrow and the optimal area decreased. Conclusion: Increases in volume, concentration and injection rate all resulted in improved arterial enhancement. If cost was disregarded, increasing the injection volume was the most reliable way of obtaining good quality enhancement. The optimal way of delivering a given amount of contrast medium can be calculated using a computer-based mathematical model.

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Comparison of Rabbit Caecal Content and Rabbit Hard Faeces as Source of Inoculum for the In vitro Gas Production Technique

  • Bovera, Fulvia;D'Urso, Simona;Di Meo, Carmelo;Piccolo, Giovanni;Calabro, Serena;Nizza, Antonino
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.11
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    • pp.1649-1657
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    • 2006
  • In order to find an alternative source of inoculum to caecal content for studying the fermentation activity of rabbit hindgut, caecal content and faeces of 25 hybrid Hyla rabbits were used as inocula for an in vitro gas production trial. About 1 g of three substrates (dehydrated alfalfa meal, dehydrated beet pulp, barley) was weighed, in quadruplicate per inoculum, in 120 ml bottles; 75 ml of anaerobic medium and 4 ml of reducing solution were added and bottles were placed at $39^{\circ}C$. Caecal content and faeces were diluted respectively 1:2 (CI) and 1:8 (FI) with anaerobic medium and were introduced in the respective bottles (10 ml). Gas production was recorded 20 times at 2-24 h intervals throughout fermentation (96 h). The fermentation characteristics (i.e. degraded organic matter, OMd; potential gas production, A; fermentation rate, Rmax; time at which it is reached, Tmax; pH, volatile fatty acid, VFA) were studied by inoculum and feedstuffs. The feedstuffs, according to their chemical composition, showed very different fermentation characteristics. In particular, OMd, A and Rmax allowed feedstuff classification as follows: barley>beet pulp>alfalfa. The inocula differ (p<0.05) in Tmax, were higher for CI (15.53 vs. 11.96 h) and in VFA production. In particular, CI produced higher levels of acetate (38.9 vs. 33.4 mM/g OM incubated, p<0.01) and isobutyrate (0.72 vs. 0.42, p<0.01) but less propionate (7.1 vs. 10.3, p<0.01) and butyrate (11.3 vs. 14.0, p<0.01). However, the trend of gas production, similar for the inocula according to the fermented substrate, and the good regression equation to estimate some caecal fermentation parameters from faeces suggest that, after standardisation, the faeces could be used as an alternative inoculum for gas tests in rabbit.

Translocation of Polychlorinated Biphenyls in Carrot-Soil Systems (Polychlorinated Biphenyl의 작물-토양간 흡수 이행성)

  • Lim, Do-Hyung;Lim, Da-Som;Keum, Young-Soo
    • The Korean Journal of Pesticide Science
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    • v.20 no.3
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    • pp.203-210
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    • 2016
  • Polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants, found in the many environments. PCBs exerts various toxicological effects, including endocrine-disrupting activity. Most researches with these toxicants performed with soil matrix with mixtures of congeners, namely Aroclor, while the biological activities have been tested with animals. However, studies with pure congeners are limited. In this study, 5 congeners were synthesized and their fates (bioaccumulation, degradation, kinetics) were studied in carrot-soil system. The soil half-lives of biphenyl, PCB-1, PCB-3, PCB-77, and PCB-126 were 20.2, 16.0, 11.6, 46.5, 198.0 days, respectively. In general, the longer half-lives were observed with the higher hydrophoicity of PCBs. Times, required for maxium accumulation of PCBs in carrot (Tmax) were 10-20 days for most congeners and the concentrations were 0.4-2.6 mg/kg. The concentrations of PCBs in carrot were kept as constant after Tmax, except PCB-126. The concentration ratio between carrot and soil after 90 days of treatment were 1.7, 8.1, 1.9, 1.8, and 5.9 for biphenyl, PCB-1, PCB-3, PCB-77, and PCB-126. Because of the increase of biomass, the total residual amount of PCBs in carrots however, increased till the end of experiment. The portions of PCB-126 in carrot were 1.1% of the soil residues at 90 days after planting.

Test methodology of acceleration life test on feeder cable assembly (Feeder Cable Assembly의 가속수명시험법 개발)

  • Han, Hyun Kak
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.8
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    • pp.62-68
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    • 2016
  • The feeder cable assembly is an automotive part used for telecommunication. If it malfunctions, the control and safety of the automobile can be put at risk. ALT (Accelerated Life Testing) is a testing process for products in which they are subjected to conditions (stress, strain, temperatures, etc.) in excess of their normal service parameters in an attempt to uncover faults and potential modes of failure in a short amount of time. Failure is caused by defects in the design, process, quality, or application of the part, and these defects are the underlying causes of failure or which initiate a process leading to failure. Thermal shock occurs when a thermal gradient causes different parts of an object to expand by different amounts. Thermal shock testing is performed to determine the ability of parts and components to withstand sudden changes in temperature. In this research, the main causes of failure of the feeder cable assembly were snapping, shorting and electro-pressure resistance failure. Using the Coffin-Manson model for ALT, the normal conditions were from Tmax = $80^{\circ}C$ to Tmin = $-40^{\circ}C$, the accelerated testing conditions were from Tmax = $120^{\circ}C$ to Tmin = $-60^{\circ}C$, the AF (Acceleration Factor) was 2.25 and the testing time was reduced from 1,000 cycles to 444 cycles. Using the Bxlife test, the number of samples was 5, the required life was B0.04%.10years, in the acceleration condition, 747 cycles were obtained. After the thermal shock test under different conditions, the feeder cable assembly was examined by a network analyzer and compared with the Weibull distribution modulus parameter. The results obtained showed good results in acceleration life test mode. For the same reliability rate, the testing time was decreased by a quarter using ALT.