• Title/Summary/Keyword: Reaction monitoring

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Monitoring of VHS and RSIVD in Cultured Paralichthys olivaceus of Jeju in 2015 (2015년 제주도 양식 넙치(Paralichthys olivaceus)를 대상으로 한 VHS 및 RSIVD 모니터링)

  • Park, Hyun Kyung;Jun, Lyu Jin;Kim, Seung Min;Park, Myoung Ae;Cho, Mi Young;Hwang, Seong Don;Park, Shin Hoo;Jeong, Hyun Do;Jeong, Joon Bum
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.49 no.2
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    • pp.176-183
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    • 2016
  • In this study, disease surveillance was performed to monitor the prevalence of viral haemorrhagic septicaemia virus (VHSV) and red seabream iridovirus (RSIV) in olive flounder, Paralichthys olivaceus in 2015. The fish samples were collected in March (60 farms), May (55 farms) and July (52 farms) from different farms in Jeju. Reverse transcription polymerase chain reaction (RT-PCR) (VHSV) or PCR (RSIV) results showed that VHSV detected in 2 farms, but RSIV has not been detected in any farms. The sequences of the nucleocapsid protein (N) and glycoprotein (G) gene of the 2 VHSV isolates were successfully sequenced. Phylogenetic analysis was included VHSV isolates reported here together with a representative VHSV isolates available in GenBank. Phylogenetic analysis indicated that most of Korea VHSV isolates were closely related to the Japan and China genotype IVa which is clearly distinct from the North American genotype IVb.

Automated assessment of cracks on concrete surfaces using adaptive digital image processing

  • Liu, Yufei;Cho, Soojin;Spencer, Billie F. Jr;Fan, Jiansheng
    • Smart Structures and Systems
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    • v.14 no.4
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    • pp.719-741
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    • 2014
  • Monitoring surface cracks is important to ensure the health of concrete structures. However, traditional visual inspection to monitor the concrete cracks has disadvantages such as subjective inspection nature, associated time and cost, and possible danger to inspectors. To alter the visual inspection, a complete procedure for automated crack assessment based on adaptive digital image processing has been proposed in this study. Crack objects are extracted from the images using the subtraction with median filter and the local binarization using the Niblack's method. To adaptively. determine the optimal window sizes for the median filter and the Niblack's method without distortion of crack object an optimal filter size index (OFSI) is proposed. From the extracted crack objects using the optimal size of window, the crack objects are decomposed to the crack skeletons and edges, and the crack width is calculated using 4-connected normal line according to the orientation of the local skeleton line. For an image, a crack width nephogram is obtained to have an intuitive view of the crack distribution. The proposed procedure is verified from a test on a concrete reaction wall with various types of cracks. From the crack images with different crack widths and patterns, the widths of cracks in the order of submillimeters are calculated with high accuracy.

Composition Effect of the Outer Layer on the Vesicle Fusion Catalyzed by Phospholipase D

  • Park, Jin-Won
    • Bulletin of the Korean Chemical Society
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    • v.35 no.12
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    • pp.3509-3513
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    • 2014
  • Phospholipase D (PLD) catalyzed the generation of phosphatidic acid (PA) from phosphatidylcholine (PC) at the outer layer of the vesicles prepared through layer by layer via a double emulsion technique. The generation induced a curvature change in the vesicles, which eventually led them to fuse each other. The ratio of two-fatty-acid-tail ethanolamine (PE) to one-fatty-acid-tail ethanolamine (PE) was found to acquire the condition where the mixed-phospholipid vesicles were stable identically with pure two-fatty-acid-tail PC. The effect of the outer-layer mixture on the PLD-induced vesicle fusion was investigated using the fluorescence intensity change. 8-Aminonaph-thalene-1,3,6-trisulfonic acid disodium salt (ANTS) and p-Xylene-bis(N-pyridinium bromide) (DPX) were encapsulated in the vesicles, respectively, for the quantification of the fusion. The fluorescence scale was calibrated with the fluorescence of a 1/1 mixture of ANTS and DPX vesicles in NaCl buffer taken as 100% fluorescence (0% fusion) and the vesicles containing both ANTS and DPX as 0% fluorescence (100% fusion), considering the leakage into the medium studied directly in a separate experiment using vesicles containing both ANTS and DPX. The fusion data for each composition were acquired with the subtraction of the leakage from the quenching. From the monitoring, the vesicle fusion caused by the PLD reaction seems dominantly to occur rather than the vesicle lysis, because the composition effect on the fusion was observed identically with that on the change in the vesicle structure. Furthermore, the diameter measurements also support the fusion dominancy.

SOx Sensor Using NASICON Solid Electrolyte (NASICON 고체 전해질을 사용한 SOx 가스 감지센서)

  • Choi, Soon-Don;Lee, Kwang-Beum
    • Journal of Sensor Science and Technology
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    • v.5 no.4
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    • pp.25-34
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    • 1996
  • A SOx sensor using NASICON electrolyte was developed for monitoring of air pollution. The following galvanic cell with $Na_{2}SiO_{3}(Pt)$ reference electrode was assembled : Pt | $Na_{2}SiO_{3}$ | NASICON | $Na_{2}SO_{4}$ | Pt, $SO_{2}$, air $Na_{2}SO_{4}$ was used as an indicator electrode to protect NASICON electrolytes from chemical reaction with $SO_{2}$. The EMFs were measured after injecting $SO_{2}$ in the initial concentrations range of $5{\sim}95ppm$ at $400{\sim}550^{\circ}C$. The measured and calculated potentials were in good agreement above $500^{\circ}C$. However, the cells were unstable below $500^{\circ}C$, most likely due to incomplete attainment of chemical equilibrium. Response time was within 10 min. Based on the stability and response time of this cell, the NASICON solid electrolyte with $Na_{2}SiO_{3}(Pt)$ as the reference electrode and $Na_{2}SO_{4}$ (Pt)as the indicator electrode showed the possibility of a reliable, inexpensive commercial solid-state SOx sensor.

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Development of the Large-Scale Oligonucleotide Chip for the Diagnosis of Plant Viruses and its Practical Use

  • Nam, Moon;Kim, Jeong-Seon;Lim, Seungmo;Park, Chung Youl;Kim, Jeong-Gyu;Choi, Hong-Soo;Lim, Hyoun-Sub;Moon, Jae Sun;Lee, Su-Heon
    • The Plant Pathology Journal
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    • v.30 no.1
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    • pp.51-57
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    • 2014
  • A large-scale oligonucleotide (LSON) chip was developed for the detection of the plant viruses with known genetic information. The LSON chip contains two sets of 3,978 probes for 538 species of targets including plant viruses, satellite RNAs and viroids. A hundred forty thousand probes, consisting of isolate-, species- and genus-specific probes respectively, are designed from 20,000 of independent nucleotide sequence of plant viruses. Based on the economic importance, the amount of genome information, and the number of strains and/or isolates, one to fifty-one probes for each target virus are selected and spotted on the chip. The standard and field samples for the analysis of the LSON chip have been prepared and tested by RT-PCR. The probe's specific and/or nonspecific reaction patterns by LSON chip allow us to diagnose the unidentified viruses. Thus, the LSON chip in this study could be highly useful for the detection of unexpected plant viruses, the monitoring of emerging viruses and the fluctuation of the population of major viruses in each plant.

Study on analytical method of fluoroquinolone residues in eggs by LC/MS/MS (LC/MS/MS를 이용한 식용란 중 fluoroquinolone계 항균물질의 분석법에 관한 연구)

  • Choi, You-Jeong;Yun, I-Ran;Nam, Sang-Yun;Park, Young-Ho;Kim, Byeong-Hun;Son, Seong-Gi
    • Korean Journal of Veterinary Service
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    • v.30 no.1
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    • pp.13-21
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    • 2007
  • An atmospheric pressure chemical ionization (APcI) LC/MS/MS method was developed for the simultaneous analysis of fluoroquinolones (norfloxacin, ciprofloxacin, enrofloxacin, danofloxacin) residues in eggs. The spiked and blank samples were extracted from whole eggs using 50mM phosphate buffer (pH 7.4). The extract was cleaned up by passage though $Oasis^{(R)}$ MAX extraction cartridge for solid-phase extraction followed by elution with 4% formic acid in methanol. The extract of sample was separated on a Waters $Atlantis^{TM}$ $dC_{18}$ reversed-phase column ($4.6{\times}150mm,\;5{\mu}m$) and analyzed by APcI positive mode mass spectrometry. The mobile phase consists of aqueous 0.2% nonafluoropentanoic acid (NFPA) and methanol. Multiple reaction monitoring (MRM) using the precursor to product ion combinations of m/z $320\;{\dashrightarrow}\;302,\;332\;{\dashrightarrow}\;314,\;360\;{\dashrightarrow}\;342$ and m/z $358\;{\dashrightarrow}\;340$ were used to quantify norfloxacin (NOR), ciprofloxacin (CIP), enrofloxacin (ENR) and danofloxacin (DAN), respectively. The limits of quantification (LOQ) were 7.8ppb for NOR, 8.5ppb for CIP, 8.9ppb for ENR, and 4.8ppb for DAN. Average recoveries of fortified sample at levels of 0.025 to 0.1 ppm were estimated 71.29% for NOR, 75.27% for CIP, 85.51% for ENR and 81.22% for DAN. These results could be applied for the confirmation and quantification in eggs.

Determination of Veterinary Antibiotic Residues: III. Analytical Methods_A Review (시료 중 잔류 항생제 분석 방법: III. 기기 분석 방법)

  • Kim, Chansik;Ryu, Hong-Duck;Chung, Eu Gene;Kim, Yongseok;Rhew, Doug Hee
    • Journal of Korean Society on Water Environment
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    • v.32 no.6
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    • pp.649-669
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    • 2016
  • This study explored the analytical conditions for 21 veterinary antibiotics which have been popularly sold in South Korea in 2014 but have not yet been targeted in EPA method 1694. Most of the selected antibiotics were separated by a reverse-phase C18 column with a combination of (buffered) water and organic polar solvent, which was commonly methanol and acetonitrile in the gradient elution mode. Volatile additives such as formic acid, ammonium acetate and ammonium formate were usually added to the mobile phases to minimize asymmetrical and tailing of antibiotics' peaks and to increase their ionization in mass spectrometry. The analytical methods of aminoglycoside antibiotics were distinct from those of the other antibiotics in terms of adoption of ion-pair chromatography (IPC) and hydrophilic interaction liquid chromatography (HILIC) capable of retaining and separating extremely polar compounds due to their hydrophilicity. Trifluoroacetic acid or heptafluorobutyric acid was frequently added to the mobile phase as an ion-pair reagent for the IPC. Tandem mass spectrometry was numerously applied to the detection of antibiotics using positive electrospray ionization (ESI) and the selected reaction monitoring (SRM) mode. All reviewed analytical methods had been/were validated by evaluating recovery, limits of detection and quantification, decision limit or detection capability of the methods.

Inhibitory Effects of 12 Ginsenosides on the Activities of Seven Cytochromes P450 in Human Liver Microsomes

  • Jo, Jung Jae;Shrestha, Riya;Lee, Sangkyu
    • Mass Spectrometry Letters
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    • v.7 no.4
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    • pp.106-110
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    • 2016
  • Ginseng, a traditional herbal drug, has been used in Eastern Asia for more than 2000 years. Various ginsenosides, which are the major bioactive components of ginseng products, have been shown to exert numerous beneficial effects on the human body when co-administered with drugs. However, this may give rise to ginsenoside-drug interactions, which is an important research consideration. In this study, acassette assay was performed the inhibitory effects of 12 ginsenosides on seven cytochrome P450 (CYP) isoforms in human liver microsomes (HLMs) using LC-MS/MS to predict the herb-drug interaction. After incubation of the 12 ginsenosides with seven cocktail CYP probes, the generated specific metabolites were quantified by LC-MS/MS to determine their activities. Ginsenoside Rb1 and F2 showed strong selective inhibitory effect on CYP2C9-catalyzed diclofenac 4'-hydroxylation and CYP2B6-catalyzed bupropion hydroxylation, respectively. Ginsenosides Rd showed weak inhibitory effect on the activities of CYP2B6, 2C9, 2C19, 2D6, 3A4, and compound K, while ginsenoside Rg3 showed weak inhibitory effects on CYP2B6. Other ginsenosides, Rc, Rf, Rg1, Rh1, Rf, and Re did not show significant inhibitory effects on the activities of the seven CYPs in HLM. Owing to the poor absorption of ginsenosides after oral administration in vivo, ginsenosides may not have significant side effects caused by interaction with other drugs.

The Clinical Characteristics of Adverse Drug Reactions Reported from the Community Pharmacy (지역약국에서 보고된 약물유해반응의 분석)

  • Yu, Yun Mi;Choi, Soo An;Lee, Mo Se;Youn, So Jung;Kim, Mi Hye;Choi, Kwang Hoon;Shin, Wan Gyoon
    • Korean Journal of Clinical Pharmacy
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    • v.24 no.1
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    • pp.45-52
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    • 2014
  • Objective: To evaluate the clinical manifestations and causative drugs of the outpatient adverse drug reactions (ADRs) reported by community pharmacy. Methods: From April 2013 to September 2013, all outpatient ADRs reported by community pharmacy to Regional Pharmacovigilance Center of Korean Pharmaceutical Association were included. The causality of ADRs was assessed by the criteria of WHO-Uppsala Monitoring Centre. The clinical features and the offending drugs were analyzed using the WHO-Adverse Reaction Terminology and the classification of American Hospital Formulary Service Drug Information, respectively. Results: 2,826 (97.0%) of the total 2,912 ADRs had causal relationship. The 1,923 patients with mean age of 55.1 years and female fraction of 66.5% were included in the ADRs. Gastrointestinal (33.6%), nervous system (14.9%), and skin (13.5%) symptoms were common in ADRs. Analgesic drugs (19.7%), gastrointestinal drugs (17.7%), and central nervous system drugs (11.0%) were prevalent offending drugs. The leading causative generic drug was the complex of acetaminophen and tramadol. Among 203 ADRs by the nonprescription drugs, the most common clinical features were skin (37.4%) and gastrointestinal (23.6%) symptoms and the most prevalent offending drugs were analgesic drugs (40.0%) and mucocutaneous system drugs (16.3%). The combination of acetaminophen and chlorzoxazone was the leading causative generic in nonprescription drugs. Conclusion: In this study, gastrointestinal symptom was the most common manifestation and analgesic drug was the most common causative drug in outpatient ADRs reported by community pharmacy.

Free-standing Three Dimensional Graphene Incorporated with Gold Nanoparticles as Novel Binder-free Electrochemical Sensor for Enhanced Glucose Detection

  • Bui, Quoc Bao;Nguyen, Dang Mao;Nguyen, Thi Mai Loan;Lee, Ku Kwac;Kim, Hong Gun;Ko, Sang Cheol;Jeong, Hun
    • Journal of Electrochemical Science and Technology
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    • v.9 no.3
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    • pp.229-237
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    • 2018
  • The electrochemical sensing performance of metal-graphene hybrid based sensor may be significantly decreased due to the dissolution and aggregation of metal catalyst during operation. For the first time, we developed a novel large-area high quality three dimensional graphene foam-incorporated gold nanoparticles (3D-GF@Au) via chemical vapor deposition method and employed as free-standing electrocatalysis for non-enzymatic electrochemical glucose detection. 3D-GF@Au based sensor is capable to detect glucose with a wide linear detection range of $2.5{\mu}M$ to 11.6 mM, remarkable low detection limit of $1{\mu}M$, high selectivity, and good stability. This was resulted from enhanced electrochemical active sites and charge transfer possibility due to the stable and uniform distribution of Au NPs along with the enhanced interactions between Au and GF. The obtained results indicated that 3D-GF@Au hybrid can be expected as a high quality candidate for non-enzymatic glucose sensor application.