• Title/Summary/Keyword: R-Peak

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Pharmacokinetics of Verapamil and Its Major Metabolite, Norverapamil from Oral Administration of Verapamil in Rabbits with Hepatic Failure Induced by Carbon Tetrachloride

  • Choi Jun Shik;Burm Jin Pil
    • Archives of Pharmacal Research
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    • v.28 no.4
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    • pp.483-487
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    • 2005
  • The aim of this study was to investigate the pharmacokinetic changes of verapamil and its major metabolite, norverapamil, after oral administration of verapamil (10 mg/kg) in rabbits with slight, moderate and severe hepatic failure induced by carbon tetrachloride. The plasma verapamil concentrations in all groups of hepatic failure were significantly higher (p<0.01) than the control. However, the plasma norverapamil concentrations in severe hepatic failure were significantly higher (p<0.05) than the control. The peak concentrations ($C_{max}$) and the areas under the plasma concentration-time curve (AUC) of verapamil in the rabbits were significantly (p<0.01) higher than the control. The absolute bioavailability ($F_{A.B}$) and the relative bioavailability ($F_{R.B}$) of verapamil in the rabbits with hepatic failure were significantly higher ($13.6-22.2\% and 150-244\%$, respectively) than the control ($9.1\% and 100\%$, respectively). Although the AUC and $C_{max}$ of its major metabolite, norverapamil, in slight, moderate hepatic failure were not significantly lower than the control, the metabolite-parent AUC ratio in all groups of hepatic failure was decreased significantly (p<0.05, in slight group; p<0.01, in moderate and severe group) than the control. This could be due to decrease in metabolism of verapamil in the liver because of suppressed hepatic function in the hepatic failure groups because verapamil is mainly metabolized in the liver. From our data, it would seem appropriate that in patients with liver disease, doses of verapamil should be decreased by degree of hepatic failure.

Melting Characteristics of Cheese (치즈의 융해성질(融解性質)에 관한 연구)

  • Park, Ji-Yong;Rosenau, J.R.
    • Korean Journal of Food Science and Technology
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    • v.16 no.2
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    • pp.153-158
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    • 1984
  • The traditional methods of testing the meltability of cheese, the Schreiber and the Arnott test, were reviewed and compared. The limitations of such methods were examined. Different sensitivities were observed for these two tests. In the Schreiber test, sharp Cheddar showed highest meltability, followed by process American, mild Cheddar, and Mozzarella. In the Arnott test, however, the rank changed to Mozzarella, mild Cheddar, sharp Cheddar, and process American. Process cheese products showed very dispersed values. Meltability increased quickly until about 4 min and held constant after 5 min in the Schreiber test. In the Arnott test, it started to increase after 5 min and held constant after 15 min. The constant meltabilities shown after certain times were caused by scorching or case hardening which prevented further flow. The DSC-thermogram showed endothermal peaks at about 14 and $30^{\circ}C$. These peaks can be accounted for by the fusion of butter fat during heating.

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Relationship between Mixograph Properties and Bread Quality of Korean Wheat Cultivars and Breeding Lines (한국산(韓國産) 밀의 Mixograph특성(特性)과 제(製)빵적성(適性)과의 관계(關係))

  • Kim, Chang-Sik;Chang, Hak-Gil;Hah, Duk-Mo;Yoon, Joo-Ok;Shin, Hyo-Sun
    • Korean Journal of Food Science and Technology
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    • v.16 no.2
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    • pp.223-227
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    • 1984
  • Quality of flours of 166 different wheat varieties and breeding lines from the 1980-1982 year crop was evaluated with Mixograph. Protein content had a correlation coefficient of 0.68 with sedimentation value and of 0.67 with bread volume. Sedimentation value showed highly significant correlation (r = 0.74) with bread volume. Positive significant correlations were found between protein content and sedimentation value vs. Mixography water-absorption, however the protein content and sedimentation value were not consistently related with mixing time or height to peak. Mixograph curve of the flour in a cultivar showed the specific pattern regardless the environmental conditions.

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Outcomes and Use of Therapeutic Drug Monitoring in Multidrug-Resistant Tuberculosis Patients Treated in Virginia, 2009-2014

  • Heysell, Scott K.;Moore, Jane L.;Peloquin, Charles A.;Ashkin, David;Houpt, Eric R.
    • Tuberculosis and Respiratory Diseases
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    • v.78 no.2
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    • pp.78-84
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    • 2015
  • Background: Reports of therapeutic drug monitoring (TDM) for second-line medications to treat multidrug-resistant tuberculosis (MDR-TB) remain limited. Methods: A retrospective cohort from the Virginia state tuberculosis (TB) registry, 2009-2014, was analyzed for TDM usage in MDR-TB. Drug concentrations, measured at time of estimated peak ($C_{max}$), were compared to expected ranges. Results: Of 10 patients with MDR-TB, 8 (80%) had TDM for at least one drug (maximum 6 drugs). Second-line drugs tested were cycloserine in seven patients (mean $C_{2hr}$, $16.6{\pm}10.2{\mu}g/mL$; 4 [57%] below expected range); moxifloxacin in five (mean $C_{2hr}$, $3.2{\pm}1.5{\mu}g/mL$; 1 [20%] below); capreomycin in five (mean $C_{2hr}$, $21.5{\pm}14.0{\mu}g/mL$; 3 [60%] below); para-aminosalicylic acid in five (mean $C_{6hr}$, $65.0{\pm}29.1{\mu}g/mL$; all within or above); linezolid in three (mean $C_{2hr}$, $11.4{\pm}4.1{\mu}g/mL$, 1 [33%] below); amikacin in two (mean $C_{2hr}$, $35.3{\pm}3.7{\mu}g/mL$; 1 [50%] below); ethionamide in one ($C_{2hr}$, $1.49{\mu}g/mL$, within expected). Two patients died: a 38-year-old woman with human immunodeficiency virus/acquired immune deficiency syndrome and TB meningitis without TDM, and a 76-year-old man with fluoroquinolone-resistant (pre-extensively drug-resistant) pulmonary TB and low linezolid and capreomycin concentrations. Conclusion: Individual pharmacokinetic variability was common. A more standardized approach to TDM for MDR-TB may limit over-testing and maximize therapeutic gain.

Analysis and Distribution of Esculetin in Plasma and Tissues of Rats after Oral Administration

  • Kim, Ji-Sun;Ha, Tae-Youl;Ahn, Jiyun;Kim, Suna
    • Preventive Nutrition and Food Science
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    • v.19 no.4
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    • pp.321-326
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    • 2014
  • In this study, we developed a method to quantify esculetin (6,7-dihydroxycoumarin) in plasma and tissues using HPLC coupled with ultraviolet detection and measured the level of esculetin in rat plasma after oral administration. The calibration curve for esculetin was linear in the range of 4.8 ng/mL to 476.2 ng/mL, with a correlation coefficient ($r^2$) of 0.996, a limit of detection value of 33.2 ng/mL, and a limit of quantification value of 100.6 ng/mL. Recovery rates for the 95.2 ng/mL and 190.5 ng/mL samples were 95.2% and 100.3%, within-runs and 104.8% and 101.0% between-runs, respectively. The relative standard deviation was less than 7% for both runs. In the pharmacokinetic analysis, the peak plasma esculetin level was reached 5 min after administration ($C_{max}=173.3ng/mL$; $T_{1/2}=45min$; $AUC_{0{\sim}180min}=5,167.5ng{\cdot}min/mL$). At 180 min post-administration (i.e., after euthanasia), esculetin was only detectable in the liver ($30.87{\pm}11.33ng/g$) and the kidney ($20.29{\pm}7.02ng/g$).

Inhibition Effect of ACE (Angiotensin Converting Enzyme) and Kinetics of Aloe Acethylmannan (알로에 아세칠만난의 ACE (Angiotensin Converting Enzyme) 저해효과 및 동력학적 분석)

  • Ryu, Il-Whan;Shin, Yong-Seo
    • Korean Journal of Food Science and Technology
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    • v.29 no.6
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    • pp.1269-1274
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    • 1997
  • This study was researched to purify and characterize variety bioactive material acethylmannan from Aloe vera. Purified acethylmannan was mannose (67%), acetyl group (23%) and the rest glucose, galactose that consisting of long chain polydispered ${\beta}-1,4$ linked mannan polymers. The sugar and acetyl group in molecular were linked molar ration one third. $IC_{50}$ value (i.e that concentration which exhibits 50% more enzyme inhibition than control) on angiotensin converting enzyme were 0.58 mM. This compound were found to be a competitive inhibition of Angiotensin Converting Enzyme with apparent Ki values of 0.068 mM.

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Effects of Chitosan Addition on Physical Properties and Crystallization of Poly(3-hydroxybutyric acid) Film (Chitosan 첨가가 Poly(3-hydroxybutyric acid) 필름의 물리적 특성 및 결정구조에 미치는 영향)

  • 김미라;구진경
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.31 no.3
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    • pp.475-481
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    • 2002
  • Blend films of poly(3-hydroxybutyric acid) (PHB) with chitosan were prepared, and their Physical properties and crystallization were investigated. The degree of crystallinity of PHB/chitosan films by X-ray diffraction decreased with increasing chitosan concentration. In the fourier-transformed infrared spectra, carbonyl peak of PHB became lower with increasing the amount of chitosan. The addition of chitosan to PHB film decreased thermal stability and crystallinity of the blend films. The granular sizes of the films were reduced with the addition of chitosan to the film in the microstructural observation by a scanning electron microscope. Mechanical properties, including tensile strength and percent elongation, of the blend films increased with increasing chitosan ratio in the films. For color of the films, L and b values generally decreased with increasing chitosan ratio, but transparency of the films increased.

Analysis of Angular Velocity during Toe Tapping for the Quantification of the Lower Limb Bradykinesia in Patients with Idiopathic Parkinson's Disease (특발성 파킨슨병 환자의 하지 완서증 정량화를 위한 발 두드리기 동작의 각속도 분석)

  • Kim, Ji-Won;Kwon, Yu-Ri;Eom, Gwang-Moon;Kim, Hyung-Sik;Yi, Jeong-Han;Kwon, Do-Young;Koh, Seong-Beom;Park, Byung Kyu;Kwon, Tae-Kyu
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.11
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    • pp.2114-2118
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    • 2010
  • The purpose of this study was to analyze bradykinesia of toe tapping movement in patients with Parkinson's disease (PD) as compared to those of normal subjects. 39 PD patients (age: $65.5{\pm}11.2$ yrs, H&Y stage:$2.3{\pm}0.5$), 14 eldelry subjects with comparable mean age ($65.0{\pm}3.9$ yrs) and 17 healthy young subjects ($24.1{\pm}2.1$ yrs) participated in this study. Angular velocity during repetitive toe tapping movement was measured in both feet using a gyro sensor system. Suggested quantitative measures of bradykinesia were root-mean-squared (RMS) angular velocity, RMS angle, peak power and total power which were derived from the angular velocity signal. ANOVA showed that all measures were significantly different among three groups (p<0.001). Subsequent post-hoc test revealed that all measures in PD patients were significantly smaller than in healthy elderly and healthy young subjects (p<0.02). All measures were significantly correlated with UPDRS scores(r=-0.689~-0.825). These results suggest that the developed system can be used as quantitative measures of the lower limb bradykinesia in PD patients.

Fabrication of AlN Thin Film by Reactive RF Magnetron Sputtering and Sensing Characteristics of Oil Pressure (반응성 RF 마그네트론 스퍼터링에 의한 AlN 박막 제조 및 유압 감지 특성)

  • Seok, Hye-Won;Kim, Sei-Ki;Kang, Yang-Koo;Hong, Yeon-Woo;Lee, Young-Jin;Ju, Byeong-Kwon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.27 no.12
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    • pp.815-819
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    • 2014
  • Aluminum nitride (AlN) thin film and TiN film as a buffer layer were deposited on INCONEL 600 substrate by reactive RF magnetron sputtering at room temperature(R.T.) under 25~75% $N_2/Ar$ atmosphere. The as-deposited AlN films at 25~50% $N_2/Ar$ showed a polycrystalline phase of hexagonal AlN, and an amorphous phase. The peak of AlN (002) plane, which was determinant on a performance of piezoelectric transducer, became strong with increasing the $N_2/Ar$ ratio. Any change in the preferential orientation of the as-deposited AlN films was not observed within our $N_2$ concentration range. The piezoelectric sensing properties of AlN module were performed using pressure-voltage measurement system. The output signal voltage of AlN module showed a linear behavior between 20~80 mV in 1~10 MPa range, and the pressure-sensing sensitivity was calculated as 3.6 mV/MPa.

Real-Time XRD Analysis of Polystyrene/Clay Nanocomposites by In-Situ Polymerization (In-situ 중합법에 의한 폴리스티렌/점토 나노복합재료의 실시간 X선 분석)

  • Kim, Jang-Yup;Hwang, Seok-Ho;Hong, Yoo-Seok;Huh, Wan-Soo;Lee, Sang-Won
    • Polymer(Korea)
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    • v.29 no.1
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    • pp.87-90
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    • 2005
  • In this study, we have examined the exfoliation behavior of layered clay during in-situ polymeriztion with styrene by using real-time XRD analysis. The 4C1 beam line at the Pohang Accelerator Laboratory (PAL) was used for this study. Different exfoliation behaviors have been shown to depend on the cation exchange capacity (CEC) of clay and the chemical structure of organic modifiers. For 10A-MMT and 15A-MMT having high CEC, no peak shifts were observed on real-time XRD analysis during polymerization. However, 2$\theta$ for 25A-MMT and VDAC-MMT, each having low CEC’s as well as aromatic benzene moieties and vinyl groups, respectively, decreased as polymerization time increased.