• Title/Summary/Keyword: Reaction monitoring

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Quantification of Momilactones A and B in Rice Straw

  • Lee, Choon-Woo;Koichi Yoneyama;Yasutomo Takeuchi;Ryu, Su-Noh
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.47 no.4
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    • pp.283-285
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    • 2002
  • Momilactones A and B, the major phytotoxins and phytoalexins in rice plants, were quantified by a HPLC-APCI-MS-MS (APCI-MS-MS) system under multiple reaction monitoring conditions. Since MA and MB were found to be easily extracted with water, these phytotoxic compounds may affect germination and growth of other plant species when the rice straws were left in the fields.

Ignition Delay Times in $C_2H_2-O_2$-Ar Mixture behind a Reflected Shock Wave

  • 류지철;서희;강준길;오규형
    • Bulletin of the Korean Chemical Society
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    • v.18 no.10
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    • pp.1071-1075
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    • 1997
  • Detonation characteristics of acetylene were studied behind reflected shock waves in the temperature range 800-1350 K by monitoring OH emission and pressure profiles. For a comprehensive measurement of ignition delay time, the mixture composition was varied in a wide range of Ar mole % was varied from 0.625 to 2.5 in stoichiometric ratio of C2H2-O2-Ar. A computer simulation study was also performed to elucidate the important elementary steps determining ignition behavior. The 33-reaction mechanism provides a good agreement in delay time between the observed and the calculated ones.

Necrotizing Sialometaplasia: A Diagnostic Puzzle for Clinicians

  • Jeong, Bo-Young;Park, Hee-Kyung
    • Journal of Oral Medicine and Pain
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    • v.47 no.2
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    • pp.102-106
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    • 2022
  • Necrotizing sialometaplasia is a rare, benign, self-limiting inflammatory process, with most cases occurring in the palatal region. Although the pathophysiology of this condition remains unknown, it has generally been considered an ischemic reaction involving the minor salivary glands. Due to its clinical and histologic similarities to malignant salivary gland tumor, diagnostic biopsy is required. Careful monitoring is also recommended, and clinicians should provide sufficient information for pathologists to ensure the histologic diagnosis.

Treatment of Pharmaceutical Wastewaters by Hydrogen Peroxide and Zerovalent Iron

  • Jeon, Byeong-Cheol;Nam, Se-Yong;Kim, Young-Kwon
    • Environmental Engineering Research
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    • v.19 no.1
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    • pp.9-14
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    • 2014
  • Fenton reaction with zerovalent iron (ZVI) and $Fe^{2+}$ ions was studied to treat pharmaceutical wastewaters (PhWW) including antibiotics and non-biodegradable organics. Incremental biodegradability was assessed by monitoring biochemical oxygen demand (BOD) changes during Fenton reaction. Original undiluted wastewater samples were used as collected from the pharmaceutical factory. Experiments were carried out to obtain optimal conditions for Fenton reaction under different $H_2O_2$ and ion salts (ZVI and $Fe^{2+}$) concentrations. The optimal ratio and dosage of $H_2O_2$/ZVI were 5 and 25/5 g/L (mass basis), respectively. Also, the optimal ratio and dosage of $H_2O_2/Fe^{2+}$ ions were 5 and 35/7 g/L (mass basis), respectively. Under optimized conditions, the chemical oxygen demand (COD) removal efficiency by ZVI was 23% better than the treatment with $Fe^{2+}$ ion. The reaction time was 45 min for ZVI and shorter than 60 min for $Fe^{2+}$ ion. The COD and total organic carbon (TOC) were decreased, but BOD was increased under the optimal conditions of $H_2O_2$/ZVI = 25/5 g/L, because organic compounds were converted into biodegradable intermediates in the early steps of the reaction. The BOD/TOC ratio was increased, but reverse-wise, the COD/TOC was decreased because of generated intermediates. The biodegradability was increased about 9.8 times (BOD/TOC basis), after treatment with ZVI. The combination of chemical and biological processes seems an interesting combination for treating PhWW.

Catalytic Reduction of Oxidized Mercury to Elemental Form by Transition Metals for Hg CEMS (수은 연속측정시스템에서 전이금속에 의한 산화수은의 원소수은으로의 촉매환원)

  • Ham, Sung-Won
    • Clean Technology
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    • v.20 no.3
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    • pp.269-276
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    • 2014
  • This study was aimed to develop catalytic system for the dry-based reduction of oxidized mercury ($Hg^{2+}$) to elemental mercury ($Hg^0$) which is one of the most important components comprising mercury continuous emission monitoring system (Hg-CEMS). Based on the standard potential in oxidation-reduction reaction, transition metals including Fe, Cu, Ni and Co were selected as possible candidates for catalyst proceeding spontaneous reduction of $Hg^{2+}$ into $Hg^0$. These transition metal catalysts revealed high activity for reduction of $Hg^{2+}$ into $Hg^0$ in the absence of oxygen in reactant gases. However, their activities were greatly decreased in the presence of oxygen, which was attributed to the transformation of transition metals by oxygen to the corresponding transition metal oxides with less catalytic activity for the reduction of oxidized mercury. Hydrogen supplied to the reactant gases significantly enhanced $Hg^{2+}$ reduction activity even in the presence of oxygen. It might be due to occurrence of combustion reaction between $H_2$ and $O_2$ causing the consumption of $O_2$ at such high reaction temperature at which oxidized mercury reduction reaction took place. Because the system showed high activity for $Hg^{2+}$ reduction to $Hg^0$, which was compatible to that of wet-chemistry technology using $SnCl_2$ solution, the catalytic reduction system of Fe catalyst with the supply of $H_2$ could be employed as a commercial system for the reduction of oxidized mercury to elemental mercury.

Transcriptome profiling identifies immune response genes against porcine reproductive and respiratory syndrome virus and Haemophilus parasuis co-infection in the lungs of piglets

  • Zhang, Jing;Wang, Jing;Zhang, Xiong;Zhao, Chunping;Zhou, Sixuan;Du, Chunlin;Tan, Ya;Zhang, Yu;Shi, Kaizhi
    • Journal of Veterinary Science
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    • v.23 no.1
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    • pp.2.1-2.18
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    • 2022
  • Background: Co-infections of the porcine reproductive and respiratory syndrome virus (PRRSV) and the Haemophilus parasuis (HPS) are severe in Chinese pigs, but the immune response genes against co-infected with 2 pathogens in the lungs have not been reported. Objectives: To understand the effect of PRRSV and/or HPS infection on the genes expression associated with lung immune function. Methods: The expression of the immune-related genes was analyzed using RNA-sequencing and bioinformatics. Differentially expressed genes (DEGs) were detected and identified by quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemistry (IHC) and western blotting assays. Results: All experimental pigs showed clinical symptoms and lung lesions. RNA-seq analysis showed that 922 DEGs in co-challenged pigs were more than in the HPS group (709 DEGs) and the PRRSV group (676 DEGs). Eleven DEGs validated by qRT-PCR were consistent with the RNA sequencing results. Eleven common Kyoto Encyclopedia of Genes and Genomes pathways related to infection and immune were found in single-infected and co-challenged pigs, including autophagy, cytokine-cytokine receptor interaction, and antigen processing and presentation, involving different DEGs. A model of immune response to infection with PRRSV and HPS was predicted among the DEGs in the co-challenged pigs. Dual oxidase 1 (DUOX1) and interleukin-21 (IL21) were detected by IHC and western blot and showed significant differences between the co-challenged pigs and the controls. Conclusions: These findings elucidated the transcriptome changes in the lungs after PRRSV and/or HPS infections, providing ideas for further study to inhibit ROS production and promote pulmonary fibrosis caused by co-challenging with PRRSV and HPS.

Real Time Alarm System of Enormous Structure Using RTK GPS (RTK GPS를 이용한 대형구조물의 실시간 경보 시스템)

  • 박운용;송연경;이현우
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.22 no.1
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    • pp.11-19
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    • 2004
  • Such social structures as bridges,, buildings, dams and towers have been transformed by their own load or fundamental ground. They have been behaved by other external causes. These regular or irregular behaviors threaten to do their users safety. Therefore, to monitor the load of the structures or reaction shown by them could help to verify their behaviors. RTK GPS allows the use of a static base station and remote rover unit to allow f3r data collection within several seconds and in real time. It is useful for monitoring the behaviors of massive structures like bridges. In this Study, Among GPS methods, we used RTK GPS to analyze the precision of monitoring and then on the basis of it, we developed a monitoring system using RTK GPS when measured the behavior of main tower of a suspension bridge by using RTK GPS. Comparing a deviation between observation values, X axis was Imm, Y axis was 1mm and Z axis 2.2mm. It turned out that it was possible to monitor and measure structures by RTK GPS.

Factors Affecting the Adverse Drug Reactions of Mycophenolate Mofetil (Mycophenolate Mofetil 부작용 발생에 미치는 요인 분석)

  • Kim, Keum-Hi;Lee, Ju-Yeun;Park, Kyung-Ho;Son, In-Ja;Lee, Hye-Suk
    • Korean Journal of Clinical Pharmacy
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    • v.20 no.2
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    • pp.151-158
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    • 2010
  • Therapeutic drug monitoring of Mycophenolate mofetil(MMF) has been suggested in some clinical trials, but has not been widely adopted in Korea. The purpose of this study was to analyze the withdrawal rates of MMF and determine the characteristics of the patients who experienced adverse reactions with MMF therapy and to suggest the criteria for selecting patients who need monitoring of MMF levels. We retrospectively collected data of patients who started MMF between July 2007 and June 2008. A total of 154 adult patients were included in our study. Among them, ninety seven patients discontinued MMF with 59 cases being due to adverse drug reactions. Thirty one patients required dosage reduction of MMF with twenty three cases being due to adverse reactions. Twenty six patients continued the MMF without or with mild adverse reactions. Of the 82 adverse reaction cases, hematologic adverse reactions accounted for 38 cases (46%) and gastrointestinal (GI) adverse reactions accounted for 28 cases (34%). Older age and lower serum albumin levels were significantly different characteristics between the patients who withdraw MMF due to hematological adverse reactions and those who were able to continue therapy. The group who experienced GI adverse reactions had higher MMF dosages based on body weight and lower serum albumin levels. In conclusion, the factors affecting the adverse reactions of MMF were age, serum albumin level and higher dosage, therefore therapeutic drug monitoring of MMF should be considered in these patients.

Applications of Cure Monitoring Techniques by Using Fiber Optic Strain Sensors to Autoclave, FW and Rm Molding Methods

  • Fukuda, Takehito;Kosaka, Tatsuro;Osaka, Katsuhiko
    • Composites Research
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    • v.14 no.6
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    • pp.47-58
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    • 2001
  • This paper describes applications of cure monitoring techniques by using embedded fiber optic strain sensors, which are extrinsic Fabry-Perot interoferometric (EFPI) and/or fiber Bra99 grating (FBG) sensors, to three kinds of molding methods of autoclave, FW and RTM molding methods. In these applications, internal strain of high-temperature curing resin was monitored by EFPI sensors. From theme experimental results, it was shown that strain caused by thermal shrink at cooling stage could be measured well. In addition, several specific matters to these molding methods were considered. As thor an autoclave molding of unidirectional FRP laminates, it was confirmed that off-axis strain of unidirectional FRP could be monitored by EFPI sensors. As for FW molding using room-temperature (RT) cured resin, it was found that the strain outputs from EFPI sensors represented curing shrinkage as well as thermal strain and the convergence meant finish of cure reaction. It was also shown that this curing shrinkage should be evaluated with consideration on logarithmic change in stiffness of matrix resin. As for a RTM melding, both EFPI and FBC sensors were employed to measure strain. The results showed that FBG sensors hale also good potential for strain monitoring at cooling stage, while the non-uniform thermal residual strain of textile affected the FBG spectrum after molding. This study has proven that embedded fiber optic strain sensors hale practical ability of cure monitoring of FRP. However, development of automatic installation methods of sensors remains as a problem to be solved for applications to practical products.

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