• Title/Summary/Keyword: Reaction monitoring

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Simultaneous Determination of Baicalein, Baicalin, Wogonin, and Wogonoside in Rat Plasma by LC-MS/MS for Studying the Pharmacokinetics of the Standardized Extract of Scutellariae Radix

  • Chung, Hye-Jin;Lim, Sun-Young;Kim, In-Sook;Bu, Young-Min;Kim, Ho-Cheol;Kim, Dong-Hyun;Yoo, Hye-Hyun
    • Bulletin of the Korean Chemical Society
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    • v.33 no.1
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    • pp.177-182
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    • 2012
  • A new composition of standardized Scutellariae Radix extract (HPO12) was developed for treatment of Alzheimer's disease. For the preclinical pharmacokinetic study of HPO12, a rapid, sensitive, and selective LCMS/MS method was developed and validated for the simultaneous determination of 4 bioactive compounds, baicalein, baicalin, wogonin, and wogonoside. After extraction with ethylacetate, chromatographic analysis was performed on a Thermo $C_{18}$ column ($150mm{\times}2.1mm$, $3{\mu}m$) with a mobile phase consisting of 0.1% formic acid (A) and 0.1% formic acid in 95% acetonitrile (B) by using gradient elution at a flow rate of $250{\mu}L/min$. Analytes introduced to a mass spectrometer were monitored by multiple reaction monitoring (MRM) in positive ion mode. Using $25{\mu}L$ of plasma sample, the method was validated over the following concentration ranges: 25-5000 ng/mL for baicalein, 20-40000 ng/mL for baicalin, 1-1000 ng/mL for wogonin, and 5-10000 ng/mL for wogonoside. The intra- and inter-day precision and accuracy of the quality control samples at the 4 concentrations showed $\leq$ 13.7% relative standard deviation (RSD) and 86.6-105.5% accuracy. The method was successfully applied to determine the concentrations of baicalein, baicalin, wogonin, and wogonoside in rat plasma after intraperitoneal and oral administrations of HPO12.

Pentafluorophenylprophyl Ligand-based Liquid Chromatography-Tandem Mass Spectrometric Method for Rapid and Reproducible Determination of Metformin in Human Plasma

  • Yang, Jeong Soo;Oh, Hyeon Ju;Jung, Jin Ah;Kim, Jung-Ryul;Kim, Tae-Eun;Ko, Jae-Wook;Lee, Soo-Youn;Huh, Wooseong
    • Bulletin of the Korean Chemical Society
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    • v.34 no.11
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    • pp.3284-3288
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    • 2013
  • This paper describes first development and validation of pentafluorophenylprophyl ligand-based liquid chromatography coupled to tandem mass spectrometry (PFPLC-MS/MS) method to determine metformin, a highly polar compound, in human plasma. Metformin and Phenformin (internal standard) were extracted from human plasma 50 ${\mu}L$ with a single-step protein precipitation. The chromatographic separation was performed using a linear gradient elution of mobile phase involving 5.0 mM ammonium formate solution with 0.1% formic acid (A) and acetonitrile (B) over 3.0 min of run time on a Phenomenex Luna PFP column. The detection was performed using a triple-quadrupole tandem mass spectrometer (Waters Quattro micro) with electrospray ionization in the mode of positive ionization and multiple-reaction monitoring (MRM). The developed method was validated with 5.0 ng/mL of lower limit of quantification (LLOQ). The calibration curve was linear over 5-3000 ng/mL of the concentration range ($R^2$ > 0.99). The specificity, selectivity, carry-over effect, precision, accuracy and stability of the method met the acceptance criteria. The method developed in this study had had rapidness, simplicity and ruggedness. The reliable method was successfully applied to high throughput analysis of real samples for a practical purpose of a pharmacokinetic study.

Genetic defects in the nef gene are associated with Korean Red Ginseng intake: monitoring of nef sequence polymorphisms over 20 years

  • Cho, Young-Keol;Kim, Jung-Eun;Woo, Jun-Hee
    • Journal of Ginseng Research
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    • v.41 no.2
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    • pp.144-150
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    • 2017
  • Background: The presence of gross deletions in the human immunodeficiency virus nef gene ($g{\Delta}nef$) is associated with long-term nonprogression of infected patients. Here, we investigated how quickly genetic defects in the nef gene are associated with Korean Red Ginseng (KRG) intakein 10 long-term slow progressors. Methods: This study was divided into three phases over a 20-yr period; baseline, KRG intake alone, and KRG plus highly active antiretroviral therapy (ART). nef gene amplicons were obtained using reverse transcription polymerase chain reaction (PCR) and nested PCR from 10 long-term slow progressors (n = 1,396), and nested PCR from 36 control patients (n = 198), and 28 ART patients (n = 157), and these were then sequenced. The proportion of $g{\Delta}nef$, premature stop codons, and not in-frame insertion or deletion of a nucleotide was compared between three phases, control, and ART patients. Results: The proportion of defective nef genes was significantly higher in on-KRG patients (15.6%) than in baseline (5.7%), control (5.6%), on-KRG plus ART phase (7.8%), and on-ART patients (6.6%; p < 0.01). Small in-frame deletions or insertions were significantly more frequent among patients treated with KRG alone compared with controls (p < 0.01). Significantly fewer instances of genetic defects were detected in samples taken during the KRG plus ART phase (7.8%; p < 0.01). The earliest defects detected were $g{\Delta}nef$ and small in-frame deletions after 7 mo and 67 mo of KRG intake, respectively. Conclusion: KRG treatment might induce genetic defects in the nef gene. This report provides new insight into the importance of genetic defects in the pathogenesis of AIDS.

Polyclonal Antibody against Paenibacillus larvae and its Application (Paenibacillus larvae에 대한 다클론 항체 및 그 응용)

  • 백경찬;양옥순;정규회;윤병수
    • Korean journal of applied entomology
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    • v.41 no.1
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    • pp.49-53
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    • 2002
  • Paenibacillus larvae is a gram-positive, spore-forming bacterium that is etiological agent for american foulbrood disease (AFB), which is the most severe disease in honey bee. To detect P. larvae from infected honeybee-comb or larvae, polyclonal antibody against whole bacterium was produced from guineapig and its specificity was evaluated. After optimization of ELISA-based detection system using these antibodies, a number of different P. larvae strains were analysed. Polyclonal antibody against P. larvae ATCC 25747 showed high affinity to most strains of P. larvae including P. larvae. strain ATCC 9545 (type strain), ATCC 25747 and other korean strain, SJl5 but exhibited no cross-reaction with other bacterial species. Additionally, this type of ELISA system was used for the detection of AFB in field-application The results have shown that this antibody could be useful for the rapid identification and monitoring of P. larvae in honeybee-comb.

High Speed Separation of PFCs in Human Serum by C18-Monolithic Column Liquid Chromatography-Tandem Mass Spectrometry

  • Lee, Won-Woong;Lee, Sun-Young;Yu, Se Mi;Hong, Jongki
    • Bulletin of the Korean Chemical Society
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    • v.33 no.11
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    • pp.3727-3734
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    • 2012
  • An analytical method has been developed for the rapid determination of perfluorinated compounds (PFCs) in human serum samples. The extraction and purification of PFCs from human serum were performed by the modified method of previous report. Ten PFCs were rapidly separated within 3.3 min by C18-monolithic column liquid chromatography (LC) and detected by electrospray ionization (ESI) tandem mass spectrometry (MS/MS) in negative ion mode. The runtime of PFCs on monolithic column LC was up to 4-fold faster than that on conventional column LC. The effect of triethylamine (TEA) to the mobile phase has investigated on the overall MS detection sensitivity of PFCs in ESI ionization. Quantification was performed by LC-MS/MS in multiple-ion reaction monitoring (MRM) mode, using $^{13}C$-labeled internal standards. Method validation was performed to determine recovery, linearity, precision, and limits of quantification, followed by, the analysis of a standard reference material (SRM 1957 from NIST). The overall recoveries ranged between 81.5 and 106.3% with RSDs of 3.4 to 16.2% for the entire procedure. The calibration range extended from 0.33 to 50 $ng\;mL^{-1}$, with a correlation coefficient ($R^2$) greater than 0.995 and the limits of quantification with 0.08 to 0.46 $ng\;mL^{-1}$. This approach can be used for rapid and sensitive quantitative analysis of 10 PFCs in human serum with high performance and accuracy.

Quality Monitoring of Specification of Crataegi Fructus in the Korean Pharmacopoeia and Studies HPLC Standard Chromatogram (산사(山楂)의 규격 기준 모니터링 및 HPLC 표준크로마토그램 연구)

  • Kim, Kyoung Hee;Kim, Sun Mi;Lee, Young Jong;Baek, Wan Sook
    • The Korea Journal of Herbology
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    • v.32 no.1
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    • pp.55-62
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    • 2017
  • Objectives : Crataegi Fructus has been used as traditional medicines for more digestion action, amenorrhea due to blood stasis, and hyperlipemia. The aim of this study was to compare of Crataegi Fructus in South Korea collected during three years according to the standards in monographs of the Korean Pharmacopoeia Eleventh edition (KP 11). Methods : Crataegi Fructus was carried out identification test (Qualitative reaction, Thin layer chromatography), heavy metal test, and total ash registered at KP. Add to we tested loss on dry, contents of ethanol-soluble extracts, and HPLC profiling. Results : Identification test (TLC) was on comparing with ursolic acid standard solution in $R_f$ value, all samples showed red purple spot ($R_f$ value 0.9). Ursolic acid spot in $R_f$ value 0.35 showed by changing mobile phase condition. Heavy metals showed contents for Pb, Cd, As, and Hg range of 0.0 ~ 0.5 ppm, 0.0 ~ 0.2 ppm, 0.0 ~ 0.3 ppm, and 0.0 ~ 0.1 ppm. Loss on drying was ranged from 5.5 to 11.9 %, total ash was between the range 2.7 ~ 4.0 %. Contents of ethanol-soluble extracts was ranged from 17.8 to 44.9 %. The content of chlorogenic acid was ranged from 0.0 to 0.1 % based on the chlorogenic acid standard curve. Conclusion : We have verified the current specification standard of Crataegi Fructus and standard that is not set. We hope that it will help the standardization of Crataegi Fructus.

COMPARATIVE STUDY OF SEVERAL TYPE PULSE OXIMETER AND OXYGEN SATURATION EXTRACTED FROM THEM (다종의 Pulse Oximeter에서 측정된 산소 분압도의 차이와 상호 비교 결과에 대한 보고)

  • Yoo, Seung-Hoon;Kim, Eung-Hak;Kwon, Soon-Won;Kim, Jong-Soo
    • Journal of the korean academy of Pediatric Dentistry
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    • v.27 no.4
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    • pp.494-498
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    • 2000
  • A major concern in pediatric dentistry is maximizing risk management through optimal monitoring of respiratory function during sedation techniques, and Pulse Oximeter is one of the most popular devices for these purpose. Pulse Oximeter is non-invasive device for detecting the sensitive fraction between the saturated & desaturated hemoglobin. Several Studies proved that there is no significant difference between the $SpO_2$ and $SaO_2$. In this article, We examined three Pulse Oximeter $(3300MX^{(R)},\;OX90^{(R)},\;BPM200^{(R)})$. The Pulse Oximeter using shorter pulse beat averaging showed more sensitive reaction to the statue of the patient and lower saturation data. We compared pair of Pulse Oximeter applied to one patient at one time. and $BPM200^{(R)}$(using shorter pulse beat averaging) showed statistically low saturation.

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Design of I-123 Nuclide Production System (I-123 핵종생산장치 시스템 설계)

  • Jung, Hyun-Woo;You, Jae-Jun;Kim, Byung-Il;Lee, Dong-Hoon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.6
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    • pp.1462-1468
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    • 2014
  • Xe gas is moved to target from GPM. It is used to feasible nuclear reaction from proton of 30MeV cyclotron being investigated by the Xe-124 gas target system. This system is divided into four parts. The hardware system was constructed by solidworks 3-D CAD and Helium supply is to cool the Havor foil. The Cooling water has the job of cooling down the temperature when Xe gas is being investigated in the target. Temperature and pressure gauges are attached to be checked easily. GPM has the part that prepares to transport Xe gas. There are storage vessel that stores Xe gas, the cold trap that filters humidity and impurity and lastly storage vessel that temporarily stores Xe gas. HCS using the helium is to clean and cool for each part. These parts are configured with SIEMENS PLC and PcVue monitoring program for more comfortable and easy maintenance.

WEC-Sim: A Simulator for Optimum Management of Wastewater Treatment Plant (WEC-Sim : 하수처리장 최적 운영을 위한 시뮬레이터)

  • Lee, Sung-Koo;Ahn, Sae-Young
    • Journal of Digital Contents Society
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    • v.11 no.4
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    • pp.463-471
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    • 2010
  • In the management of a wastewater treatment plant which is a combination system of physical, chemical, and biological processes, computer simulator is an indispensable part for analysis of the operation status and evaluation of the treatment performance due to its fast computing speed. As an application software carrying out the data input-output operations and the mathematical calculations of the models, simulator is to be a powerful tool for estimating the treatment reaction and calculating mass balance of substrates, microorganisms, and chemicals within the treatment system in a given condition. Qualitative and quantitative prediction of treatment performance provides the plant manager with validity of decision-making through implementing modeling and simulation as a role of knowledge-based expert system in charge of automation and control. This paper shows the proceeding of design and development of the "WEC-Sim" software which is owned the various functions of data acquisition, monitoring, simulation, and control.

A Study on the Measurement System Design for the Resin Flow and Curing in the Vacuum Assisted Resin Transfer Molding(VARTM) Process Using the Long Period Fiber Bragg Grating (삽입된 장주기 광섬유 격자를 이용한 VARTM 공정에서의 수지이동 및 변형 과정 예측 시스템 설계에 관한 연구)

  • Yoon, Young-Ki;Chung, Seung-Hwan;Lee, Woo-Il;Lee, Byoung-Ho;Byun, Joon-Hyung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.5
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    • pp.489-494
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    • 2004
  • Long Period Gratings (LPG) is currently receiving considerable attention because of their consistent measuring results fur pressure, temperature, strain and flow. LPG is easier to prepare and has a high sensitivity compared with Fiber Bragg Gratings (FBG). In addition, this kind of optical fiber sensors could be used for implementations in various structures. In this paper, LPG was used to monitor in situ the resin flow and the curing process in VARTM (Vacuum Assisted Resin Transfer. Molding). In order to demonstrate the effectiveness of the method, FBG is inserted into the glass mat to monitor the resin flow using optical spectrum analyzer (OSA). The curing reactions in VARTM are also observed using the same method. From the results, the attenuation wavelength shift and the loss change of attenuation band can be obtained from the status of the RTM (Resin Transfer Molding) sample owing to the internal variations of the .effective index, temperature, and pressure. It is shown that the proposed LPG is more effective in monitoring the curing reaction than FBG.