• Title/Summary/Keyword: Pretreat

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Pharmacokinetic Interaction between Diltiazem and Paclitaxel in Rats (딜티아젬과 파크리탁셀의 약물동태학적 상호작용)

  • Choi, Jun-Shik;Kim, Hyung-Joong
    • Journal of Pharmaceutical Investigation
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    • v.33 no.4
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    • pp.299-304
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    • 2003
  • The purpose of this study was to investigate the effect of coadministration (2.5, 10, 20 mg/kg) and 3 or 7 days-pretreatment (10 mg/kg) of diltiazem on the pharmacokinetic parameters of paclitaxel (50 mg/kg) given orally in rats. The plasma concentrations of paclitaxel coadministered or pretreated with diltiazem were significantly (p<0.05 at 20 mg/kg coadmin., p<0.05 at pretreat.) increased compared to that of control, from 0.5 hr to 24 hr. Area under the plasma concentration-time curve (AUC) of paclitaxel coadministered or pretreated with diltiazem was significantly (p<0.05 at 20 mg/kg coadmin., p<0.01 at pretreat.) higher than that of control. Peak concentrations $(C_{max})$ of paclitaxel with diltiazem were significantly (p<0.05 at 20 mg/kg coadmn. and pretreat.) increased compared to that of control. Elimination rate constants $(K_{el})$ of paclitaxel with diltiazem were significantly (p<0.05 at 20 mg/kg and 7 days-pretreat.) reduced compared to those of control. Half-life $(t_{1/2})$ and mean residence time (MRT) of paclitaxel with diltiazem was significantly (p<0.05 at 20 mg/kg ad 7 days-pretreat.) prolonged compared to those of control. Absolute bioavailability (AB%) of paclitaxel with diltiazem was significantly (p<0.05 at 20 mg/kg and 3 days-pretreat, p<0.01 at 7 days -pretreat.) increased compared to that of control. Based on these results, it might be considered that diltiazem may inhibit cytochrome $P_{450}$ and P-glycoprotein, which are respectively engaged in paclitaxel absorption and metabolism in liver and gastrointestinal mucosa.

Drug Interaction between Nifedipine and Paclitaxel in Rats

  • Kim, Hyung-Jung;Choi, Jun-Shik
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.240.1-240.1
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    • 2003
  • The purpose of this study was to investigate the effect of nifedipine (10 mg/kg) on the pharmacokinetic parameters and the bioavailability of paclitaxel (50 mg/kg) orally coadministered and pretreated in rats. The plasma concentration of paclitaxel in combination with nifedipine was significantly (p<0.05 at 10 mg/kg coadmin., p<0.01 at pretreat.) increased compared to that of control, from 2 hr to 24 hr. Area under the plasma concentration-time curve (AUC) of paclitaxel with nifedipine was significantly (p<0.05 at 10 mg/kg coadmin., p<0.01 at pretreat.) higher than that of control (omitted)

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Preliminary Experiments on Pozzonalic Activity of Dredged Sea Soil (소성 해양 준설토의 포졸란 반응성 시험)

  • Kim, Ji-Hyun;Moon, Hoon;Lee, Jae-Yong;Chung, Chul-Woo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.11a
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    • pp.49-50
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    • 2014
  • Dredged sea soil contains various contaminants. First priority to recycle dredged sea soil is to pretreat it to remove various contaminants because recycling dredge sea soil without any pre-treatment may cause a secondary contamination due to the leaching of hazardous chemicals. In this study, pretreated dredged sea soil was used to investigate pozzolanic activity. The properties of pretreated dredged sea soil were investigated, the method for heat treatment was determined, and the compressive strength of mortar using dredged sea soil was examined to evaluate pozzolanic activity. According to the results, pretreated dredged sea soil has some possibility to work as a pozzolanic material. When dredged sea soil was heat treated for 90min at 550℃, compressive strength was shown to be comparable to that of plain cement mortar.

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A Study on Applicability of Carbon Ceramic Disc using Pretreated Carbon Fiber (전처리된 탄소섬유를 이용한 카본 세라믹 디스크 적용 가능성에 대한 연구)

  • Yoo, Tae-Doo;Kim, Hong-Gun;Kwac, Lee-Ku
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.21 no.4
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    • pp.39-45
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    • 2022
  • In this study, it was verified that carbon-ceramic brake discs can replace existing cast-iron brake discs of the same size. In addition, a method of pretreating carbon fiber to secure heat dissipation characteristics while using a small amount of carbon fiber was established. The thermal conductivity and bending strength characteristics were analyzed according to the carbon content, and brake braking tests were conducted. Through pretreatment, the maximum temperature was lowered by 16 ℃ compared to the case using only carbon fiber, and the cooling rate was improved by approximately 10% compared to metal brake discs. However, the total heat capacity increased as the mass increased owing to the reaction. Thus, the measured temperature was higher than that of the metal brake disc; therefore, additional research is required.

Rapid Identification of Vibrio Species Isolated from the Southern Coastal Regions of Korea by MALDI-TOF Mass Spectrometry and Comparison of MALDI Sample Preparation Methods

  • Cho, Youngjae;Kim, Eiseul;Han, Sun-Kyung;Yang, Seung-Min;Kim, Mi-ju;Kim, Hyun-Joong;Kim, Chang-Gyeom;Choo, Dong-Won;Kim, Young-Rok;Kim, Hae-Yeong
    • Journal of Microbiology and Biotechnology
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    • v.27 no.9
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    • pp.1593-1601
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    • 2017
  • Vibrio species are generally recognized as pathogens predominant in seafood along coastal areas. The food industry has sought to develop efficient microbial detection methods. Owing to the limits of conventional methods, this study aimed to establish a rapid identification method for Vibrio isolated from Korea, based on matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Four different preparation procedures were compared to determine the appropriate means to pretreat Vibrio species, using 17 isolates and five reference strains. Extended direct transfer and full formic acid extraction methods using bacterial colonies on agar plates revealed very low identification rates. Formic acid and trifluoroacetic acid (TFA) extractions using bacterial broth cultures were also performed. All Vibrio isolates and reference strains prepared by TFA extraction were successfully identified to the species level (17/22, 77.3%) and to the genus level (5/22, 22.7%). Thus, TFA extraction was considered the most appropriate method to pretreat Vibrio species for MALDI-TOF MS. The remaining 33 isolates and two reference strains were prepared by TFA extraction and analyzed by MALDI-TOF MS. Overall, 50 isolates were identified to the species level (40/50, 80%) and to the genus level (10/50, 20%). All isolates were identified as 43 V. alginolyticus, six V. parahaemolyticus, and one V. vulnificus species. V. alginolyticus and V. parahaemolyticus were isolated from fish offal (87.5% and 12.5%, respectively), seawater (91.3%, 8.7%), and shellfish (62.5%, 37.5%), whereas V. alginolyticus and V. vulnificus were isolated from sediment (90.9% and 9.1%, respectively). This study established a reliable system of MALDI-TOF MS preparation and analysis for Vibrio identification.

TDS Removal using Bio-sorption with AGS and High Concentration Nitrogen Removal (AGS의 생물흡착을 이용한 TDS 제거 및 고농도 질소제거에 관한 연구)

  • Eom, Han Ki;Choi, Yoo Hyun;Joo, Hyun Jong
    • Journal of Korean Society on Water Environment
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    • v.32 no.3
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    • pp.303-309
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    • 2016
  • This study aimed to assay the biological removal of TDS (total dissolved solids) from RO (reverse osmosis) rejected water. Following bio-sorption of TDS with AGS (aerobic granular sludge), the effects of TDS on biological nitrogen removal were examined. The bio-sorption of TDS after AGS treatment was confirmed by checking for TDS removal efficiency and surface analysis of microorganisms with SEM and EDS. Then, the effects of TDS on biological nitrogen removal and the denitrification efficiency were evaluated using the MBR reactor. According to the results, the bio-sorption of TDS with AGS was 0.1 mg TDS/mg AGS, and we confirmed that the microorganism surfaces had adsorbed the TDS. Biological nitrogen removal efficiency was measured at inhibiting denitrification at 4,000 mg/L of TDS-injected material. Based on this study, it is necessary to pretreat TDS-containing RO rejected water and to maintain TDS concentration lower than a specific value (≤4,000 mg/L), when considering biological nitrogen removal.

Utilization of Saline Solutions in the Modification of Lignocellulose from Champaca Wood

  • Sangian, Hanny F.;Sehe, Muhammad Rifai;Tamuntuan, Gerald H.;Zulnazri, Zulnazri
    • Journal of the Korean Wood Science and Technology
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    • v.46 no.4
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    • pp.368-379
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    • 2018
  • Objective of this work is to study the effects of a saline solution used to pretreat lignocellulosic material derived from champak timber. The native lignocellulosic solids, in powder form, were mixed with saline water solutions of three different concentrations and maintained for 2 weeks without stirring. The treated solids were washed, recovered, and then dried under sunlight. The substrates were characterized using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). The crystallinity (CrI), lateral order index (LOI), total crystallinity index (TCI), and surface morphologies of all the samples were determined. The treated biomass structures were compared with controls. The data show that the structures of all the treated substrates changed, as indicated by CrI. CrI of the treated substrates decreased significantly compared with that of the original wood, as did LOI and TCI quantities, whereas the HBI parameter increased. The results indicate that the saline water pretreatment modified the wood samples.

Naloxone Reversal of He-Ne Laser Stimulation Induced Analgesia in Rat (헬륨 -네온 레이저자극으로 유발된 흰쥐 진통작용의 날록손 반전)

  • Lee Jae-Hyoung;Song In-Yong;Choi Eun-Yong
    • The Journal of Korean Physical Therapy
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    • v.8 no.1
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    • pp.15-20
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    • 1996
  • The purpose of this study were to 1) determine the analgesic effect of 632.8 nm of helium-neon (He-Ne) laser stimulation on acupuncture point in rat and 2) determine the reversal of analgesic effect by naloxone injection. Eighteen Sprague-Dawley rats were devided into three groups : control (n=6) : laser (n=6), laser stimulation at $3.58\;J/cm^2$ ; and naloxone (n=6), 1 mg/kg of naloxone chloride inject into peritoneum before laser stimulation at $3.63J/cm^2$. Tail-flick latency were measured pretreat and posttreat with hot plate $(55^{\circ}C)$. Data were analyzed using one-way ANOVA and paired t-teat for tail-flick latency. No significant change was noted in the tail-flick latency in either control or naloxone groups. But significant increased in tail-flick latency in taller group. The results suggest that He-Ne laser induced analgesic effect, and endogenous opioids may be involved in He-Ne laser induced analgesia.

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Liquid-phase Microextraction Pretreatment Techniques for Analysis of Chemical Warfare Agents and Their Degradation Byproducts in Environmental Aqueous Samples (환경샘플 내 화학작용제 및 분해물질 분석을 위한 Liquid Phase Microextraction (LPME) 전처리 기법)

  • Kim, Dongwook;Chung, Wooyoung;Kye, Youngsik
    • Applied Chemistry for Engineering
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    • v.26 no.1
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    • pp.17-22
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    • 2015
  • International interests in chemical warfare agents (CWAs) have been increased recently because of the use of sarin (GB) in Syrian civil war which caused around 1,300 casualties in 2013. After exposing to natural environments, CWAs undergo hydrolysis or photodegrade to non-toxic degradation byproducts. Generally, CWAs and their degradation byproducts are present at very low concentration (e.g. several ppb), thus pretreatment processes including separation, extraction and concentration are required prior to any analyses. Liquid-liquid extraction and solid-phase extraction (SPE) are common techniques to pretreat environmental samples. Recently, a novel pretreatment method, liquid phase miecoextraction (LPME), has been applied to CWAs analysis, which could reduce amounts of solvent used but promote analytical efficiencies. Fundamental backgrounds of LPME and its application to CWAs analysis were reviewed.

Studies on Physico-chemical Properties an d Pathogenicity of Porcine Enterovirus Isolated from Feces of Pigherds (돼지 분변 유래 PORCINE ENTEROVIRUS의 물리화학적 특성 및 병원성에 관한 연구)

  • 박정우;이종인;신용호;조우영;최윤식
    • Korean Journal of Veterinary Service
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    • v.14 no.2
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    • pp.110-120
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    • 1991
  • 28 porcine enteroviruses were isolated from 86 pig-feces of 9 swine farms located in south region, Chung-buk, from March to September 1990. Physico-chemical properties and pathogenicity of isolates were investigated. Results obtained throughout experiments are summarized as follows. According to the age, weanlings(40-90 days), sucklings(10-30 days) and adult pigs(6 months over) showed the isolation rate of 67%. 8% and 4%, respectively. By physico-chemical tests, YD-90/22, YD-90/43 and YD-90/64 strains were found to be ether, chloroform and PH stable. Nucleic acid test suggests the virus to have a DNA genome. Most of the Isolates were not evident of hemagglutinin using erythrocytes from various mammalian & avian. 22 strains among the isolates were shown CPE type I and the remainders were CPE type II. 3 strains among isolates of CPE type I strains were neutralized with high titers to serotype 2 antiserum. In the study on virus growth curve in PK-l5 cells, YD-90/22, YD-90/43 and YD-90/64 strains showed the maximum infectivity titers($10^{6.0}-l0^{6.5} TCID({50}ml$) at 4days post inoculation(PI). When 30 day-old commercial piglets were inoculated only intraoral route with the YD-90/22 strain at $10^{6.0} TCID_{50}ml,$ piglets not showed the symptoms. But piglets inoculated by intramuscle route, intraoral and intramuscle route after pretreat with dexamethasone(2.5mg /kg) for 5 days were shown the symptoms of anorexia, diarrhea, pyrexia and ataxia at 4th-6th days PI. The viral reisolation in the virus-inoculated piglets was examined from feces. The viruses were recovered intermittently from 2nd to 16th day PI and at 4th-6th day PI, all piglets excreted viruses.

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