• 제목/요약/키워드: Crossover study

검색결과 512건 처리시간 0.022초

Establishment of Injection Protocol of Test Bolus for Precise Scan Timing in Canine Abdominal Multi-Phase Computed Tomography

  • Choi, Sooyoung;Lee, In;Choi, Hojung;Lee, Kija;Park, Inchul;Lee, Youngwon
    • 한국임상수의학회지
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    • 제35권3호
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    • pp.93-96
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    • 2018
  • This study aimed to establish an injection protocol to determine the precise CT scan timing in canine abdominal multi-phase CT using the test bolus method. Three dynamic scans with different contrast injection parameters were performed using a crossover design in eight normal beagle dogs. A contrast material was administered at a fixed dose of 200 mg iodine/kg as a test bolus for dynamic scans 1 and 2, and 600 mg iodine/kg as a main bolus for dynamic scan 3. The contrast materials were administered with 1 ml/s in dynamic scan 1, and 3 ml/s in dynamic scan 2 and 3. The mean arrival time to the appearance of aortic enhancement in dynamic scan 3 was similar to that in dynamic scan 2, and different significantly to that in dynamic scan 1. The mean arrival time to the peak aortic and pancreatic parenchymal enhancement in dynamic scan 3 was similar to that in dynamic scan 1, and different significantly to that in dynamic scan 2. In multi-phase CT scan, a test bolus should be injected with the same injection duration of a main bolus, to obtain the precise arrival times to peak of arterial or pancreatic parenchymal enhancement.

플루옥세틴 캅셀제의 지원자에 대한 생체이용율 및 대사율 비교 (Comparative Bioavailability and Metabolism of Two Capsule Formulations of Fluoxetine in Human Volunteers)

  • 강원구;박용순;조규행;최준식;권광일
    • 약학회지
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    • 제42권5호
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    • pp.513-518
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    • 1998
  • Fluoxetine is a nontricyclic antidepressant which blocks serotonin reuptake selectively. Its N-demethyl metabolite, norfluoxetine is also selective inhibitor of serotonin uptake . This study was carried out to compare the bioavailability of Myung-in fluoxetine (20mg/cap.) with that of Prozac$^{\circde{R}}$. The bioavailability was conducted on 24 healthy volunteers who received a single dose (80mg) of each drug in the fasting state, in a randomized balanced 2-way crossover design. After closing, serial blood samples were collected for a period of 48 hours, Plasma was analyzed for fluoxetine and norfluoxetine by a sensitive and validated HPLC assay. The major pharmacokinetic parameters ($AUC_{0-48\;hr}$, Cmax, Tmax , $AUC_{inf.}$, MRT. $T_{1/2}$, Vd and Cl) were, calculated from the plasma fluoxetine concentration-time data of each volunteer. The microcomputer program, 'WinNonlin' was used for compartmental analysis. A two-compartment model with first-order input, first-order output and no lag time was chosen as the most appropriate pharmacokinetic model. The data were best described by using a weighting factor of $1/y^2$. Though the plasma fluoxetine concentrations of Myung-in fluoxetine were higher than those of Prozac$^{\circde{R}}$ at all observed time from 7.9% to 16.9% (P<0.05 at 6.7 and 10 hr), the bioavailability of Myung-in fluoxetine appeared to be bioequivalent with that of Prozac$^{\circde{R}}$. There were no statistical significant differences between the two drugs in all pharmacokinetic parameters including $AUC_{0-48\;hr}$ of norfluoxetine.

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무인항공기용 200W 급 직접메탄올연료전지 경량화 스택 제작 및 작동 특성 연구 (II) (Development of a Lightweight 200W Direct Methanol Fuel Cell Stack for UAV Applications and Study of its Operating Characteristics (II))

  • 강경문;박성현;곽건희;지현진;주현철
    • 한국수소및신에너지학회논문집
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    • 제23권3호
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    • pp.243-249
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    • 2012
  • A lightweight 200W direct methanol fuel cell (DMFC) stack is designed and fabricated to power a small scale Unmanned Aerial Vehicle (UAV). The DMFC stack consists of 33-cells in which membrane-electrode assemblies (MEAs) having an active area of 88 $cm^2$ are sandwiched with lightweight composite bipolar plates. The total stack weight is around 3.485 kg and stack performance is tested under various methanol feed concentrations. The DMFC stack delivers a maximum power of 248 W at 13.2 V and $71.3^{\circ}C$ under methanol feed concentration of 1.2 M. In addition, the voltage of individual cell in the 33-cell stack is measured at various current levels to ensure the stability of DMFC stack operations. The cell voltage distribution data exhibit the maximum cell voltage deviation of 28 mV at 15 A and hence the uniformity of cell voltages is acceptable. These results clearly demonstrate that DMFC technology becomes a potential candidate for small-scale UAV applications.

고분자전해질 연료전지용 Poly(arylene ether sulfone) 막의 특성 (Characteristics of Poly(arylene ether sulfone) Membrane for Proton Exchange Membrane Fuel Cells)

  • 정재진;신용철;이무석;이동훈;나일채;이호;박권필
    • Korean Chemical Engineering Research
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    • 제51권5호
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    • pp.556-560
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    • 2013
  • 최근에 저가의 고분자전해질 연료전지(Proton Exchange Membrane Fuel Cells, PEMFC)용 비불소계 전해질 막 연구개발이 활발히 진행되고 있다. 본 연구에서는 PEMFC 운전 조건에서 Poly(arylene ether sulfone)(PAES) 막과 불소계막의 특성을 비교하였다. I-V 분극곡선, 수소투과도, 전기화학적 표면적, 막저항 및 부하 전달 저항 등을 측정 분석했다. PAES 막은 상대습도 100%에서는 불소계 막과 비슷한 성능을 보였으나 낮은 상대습도에서 이온전도도가 낮아 성능감소가 컸다.

Development of succinate producing Cellulomonas flavigena mutants with deleted succinate dehydrogenase gene

  • Lee, Heon-Hak;Jeon, Min-Ki;Yoon, Min-Ho
    • 농업과학연구
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    • 제44권1호
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    • pp.30-39
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    • 2017
  • This study was performed to produce succinic acid from biomass by developing mutants of Cellulomonas flavigena in which the succinate dehydrogenase gene (sdh) is deleted. For development of succinate producing mutants, the upstream and downstream regions of sdh gene from C. flavigena and antibiotic resistance gene (neo, bla) were inserted into pKC1139, and the recombinant plasmids were transformed into Escherichia coli ET12567/pUZ8002 which is a donor strain for conjugation. C. flavigena was conjugated with the transformed E. coli ET12567/pUZ8002 to induce the deletion of sdh in chromosome of this bacteria by double-crossover recombination. Two mutants (C. flavigena H-1 and H-2), in which sdh gene was deleted in the chromosome, were constructed and confirmed by PCR. To estimate the production of succinic acid by the two mutants when the culture broth was fermented with biomass such as CMC, xylan, locust gum, and rapeseed straw; the culture broth was analyzed by HPLC analysis. The succinic acid in the culture broth was not detected as a fermentation products of all biomass. One of the reasons for this may be the conversion of succinic acid to fumaric acid by sdh genes (Cfla_1014 - Cfla_1017 or Cfla_1916 - Cfla_1918) which remained in the chromosomal DNA of C. flavigena H-1 and H-2. The other reason could be the conversion of succinyl-CoA to other metabolites by enzymes related to the bypass pathway of TCA cycle.

Pharmacokinetics and Bioequivalence of Haloperidol Tablet by Liquid Chromatographic Mass Spectrometry with Electrospray Ionization

  • Yun Min-Hyuk;Kwon Jun-Tack;Kwon Kwang-il
    • Archives of Pharmacal Research
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    • 제28권4호
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    • pp.488-492
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    • 2005
  • The purpose of this study is to investigate the bioequivalence of two haloperidol 5 mg tablets, Myung In haloperidol (Myung In Pharm. Co., Ltd., test drug) and $Peridol^{R}$(Whanin Pharm. Co., Ltd., reference drug), and also to estimate the pharmacokinetic parameters of haloperidol in Korean volunteers. The bioavailability and pharmacokinetics of haloperidol tablets were examined on 24 healthy volunteers who received a single oral dose of each preparation in the fasting state in a randomized balanced 2 way crossover design. After an oral dosing, blood samples were collected for a period of 60 h. Plasma concentrations of haloperidol were determined using a liquid chromatographic electrospray mass spectrometric (LC-MS) method. The pharmacokinetic parameters were calculated with noncompartmental pharmacokinetic analysis. The geometric means of $AUC_{0-60h} and C_{max}$ between test and reference formulations were $17.21\pm8.26 ng\cdot/mL vs 17.31\pm13.24 ng\cdot/mL and 0.87\pm0.74 ng/mL vs 0.85\pm0.62 ng/mL$. respectively. The $90\%$ confidence intervals of mean difference of logarithmic transformed $AUC_{0-60h} and C_{max} were log0.9677{\sim}log1.1201 and log0.8208{\sim}log1.1981$, respectively. It shows that the bioavailability of test drug is equivalent with that of reference drug. The geometric means of other pharmacokinetic parameters ($AUC_{inf}. t_{1/2}, V_{d}/F, and CL/F$) between test drug and reference drug were $21.75\pm8.50 ng{\cdot}h/mL vs 21.77\pm15.63 ng{\cdot}h/mL, 29.87\pm8.25 h vs 29.60\pm7.56 h, 11.51\pm5.45 L vs 12.90\pm6.12 L and 0.26\pm0.09 L/h vs 0.31\pm0.17 L/h$, respectively. These observations indicate that the two formulation for haloperidol was bioequivalent and, thus, may be clinically interchangeable.

지원자의 Cefixime캅셀제 생체이용율에 대한 생물학적동등성 연구 (Bioequivalency on the Comparative Bioavailability of Two Capsule Formulations of Cefixime in Human Volunteers)

  • 강원구;우종수;권광일
    • 한국임상약학회지
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    • 제8권1호
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    • pp.19-22
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    • 1998
  • Cefixime is an orally absorbed 3rd generation cephalosporin with a broad spectrum of activity against Gram-positive and Gram-negative bacteria and is highly resistant to $\beta-lactamase$ degradation. This study was carried out to evaluate the bioavailability of a new test drug of cefixime (100 mg/capsule) relative to the reference drug. The bioavailability was conducted on 20 healthy volunteers who received a single dose (400 mg) of the test and the reference drugs in the fasting state, in a randomized balanced 2-way crossover design. After dosing, serial blood samples were collected for a period of 12 hours. Plasma was analyzed for cefixime by a sensitive and validated HPLC assay. The major pharmacokinetic parameters $(AUC_{0-12hr},\;C_{max},\;T_{max})$ were calculated from the plasma concentration-time data of each volunteer. The $AUC_{0-12hr},\;C_{max}\;and\;T_{max}$ of the test drug were $36.91\pm11.85\;{\mu}g{\cdot}hr/ml,\;5.47\pm1.61\;{\mu}g/ml,\;and\;4.00\pm0.65\;hr,$ respectively, and those of the reference drug were $34.08\pm8.81\;{\mu}g{\cdot}hr/ml,\;5.25\pm1.40\;{\mu}g/ml,\;and\;4.20\pm0.62\;hr$, respectively. Mean differences of those parameters were 8.32, 4.29, and $4.76\%$, respectively, and the least significant differences at $\alpha$=0.05 for $AUC_{0-12hr},\;C_{max},\;T_{max}$ were 16.02, 13.78, and $11.76\%$, respectively. In conclusion, the test drug was bioequivalent with the reference drug.

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sPEEK 막으로 제조한 고분자전해질 연료전지(PEMFC) 막전극합체(MEA)의 특성 (Characteristics of Proton Exchange Membrane Fuel Cells(PEMFC) Membrane and Electrode Assembly(MEA) Using Sulfonated Poly(ether ether ketone) Membrane)

  • 이혜리;이세훈;황병찬;나일채;이정훈;오성준;박권필
    • Korean Chemical Engineering Research
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    • 제54권2호
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    • pp.181-186
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    • 2016
  • 최근에 저가의 고분자 전해질 연료전지(Proton Exchange Membrane Fuel Cells, PEMFC)용 비불소계 전해질 막 연구개발이 활발히 진행되고 있다. 본 연구에서는 sulfonated Poly(ether ether ketone)(sPEEK)막의 특성을 술폰화도, 상대습도, 단위 전지 온도에 따라 PEMFC 운전 조건에서 비교하였다. I-V 분극곡선, 수소투과도, 전기화학적 표면적, 막 저항 및 부하 전달 저항 등을 측정 분석했다. 술폰화도와 온도, 상대습도가 높을수록 성능이 높았으며, 특히 낮은 슬폰화도와 낮은 상대습도에서 이온 전도도 감소 때문에 성능이 큰 폭으로 감소함을 확인하였다.

Open Channel Block of Kv3.1 Currents by Genistein, a Tyrosine Kinase Inhibitor

  • Choi, Bok-Hee;Park, Ji-Hyun;Hahn, Sang-June
    • The Korean Journal of Physiology and Pharmacology
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    • 제10권2호
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    • pp.71-77
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    • 2006
  • The goal of this study was to analyze the effects of genistein, a widely used tyrosine kinase inhibitor, on cloned Shaw-type $K^+$ currents, Kv3.1 which were stably expressed in Chinese hamster ovary (CHO) cells, using the whole-cell configuration of patch-clamp techniques. In whole-cell recordings, genistein at external concentrations from 10 to $100{\mu}M$ accelerated the rate of inactivation of Kv3.1 currents, thereby concentration-dependently reducing the current at the end of depolarizing pulse with an $IC_{50}$ value of $15.71{\pm}0.67{\mu}M$ and a Hill coefficient of $3.28{\pm}0.35$ (n=5). The time constant of activation at a 300 ms depolarizing test pulses from -80 mV to +40 mV was $1.01{\pm}0.04$ ms and $0.90{\pm}0.05$ ms (n=9) under control conditions and in the presence of $20{\mu}M$ genistein, respectively, indicating that the activation kinetics was not significantly modified by genistein. Genistein $(20{\mu}M)$ slowed the deactivation of the tail current elicited upon repolarization to -40 mV, thus inducing a crossover phenomenon. These results suggest that drug unbinding is required before Kv3.1 channels can close. Genistein-induced block was voltage-dependent, increasing in the voltage range $(-20\'mV{\sim}0\'mV)$ for channel opening, suggesting an open channel interaction. Genistein $(20{\mu}M)$ produced use-dependent block of Kv3.1 at a stimulation frequency of 1 Hz. The voltage dependence of steady-state inactivation of Kv3.1 was not changed by $20{\mu}M$ genistein. Our results indicate that genistein blocks directly Kv3.1 currents in concentration-, voltage-, time-dependent manners and the action of genistein on Kv3.1 is independent of tyrosine kinase inhibition.

미취학 아동 어머니의 양육특성과 건강 특성이 경제활동 참가에 미치는 융합적 요인 분석 (Analysis of Convergence Factors of Preschool children's Parenting and Health Characteristics on Economic Participation)

  • 김성민;송혜영
    • 한국융합학회논문지
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    • 제12권9호
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    • pp.285-293
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    • 2021
  • 본 연구는 제7차 여성 가족 패널 조사자료를 2차 분석하여, 직장군과 비직장군의 양육 특성과 건강 특성을 비교하기 위한 서술적 조사 연구이다. 만19세 이상 64세 이하의 여성 중에서 미취학 아동 어머니를 대상 총 697명을 대상으로 교차분석과 로지스틱 회귀분석을 실시하였다. 아이돌보미가 있는 경우, 이용하는 보육 시설개수가 많을수록, 시부모나 친정부모 돌봄을 받는 경우, 신체활동을 주 3회 미만으로 하는 경우가 경제활동을 많이 하였다. 반면, 미취학 자녀 수가 많을수록 경제활동을 안 하는 것으로 나타났다. 미취학 아동 어머니의 신체활동 확보와 일과 가정 양립을 뒷받침할 수 있는 양육 친화적 가족 및 직장문화 조성이 필요하다.