• Journal of Korean Society for Atmospheric Environment
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• v.34 no.1
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• pp.56-75
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• 2018

Korean Photochemical Assessment Monitoring Stations (PAMS) have been established since the late 2001 to monitor ambient air concentrations of VOC species, which would enhance understanding photo-chemical formation of ozone and subsequently contribute to developing efficient ozone control strategies. The present study aims at identifying major VOC species and examining their trends by analyzing PAMS monitoring data collected from the year 2006 to 2016. All the 18 PAMS sites operated by the Ministry of Environment were included in the study. PAMS monitored the 56 target VOC species, which are classified into four groups, alkenes, lower alkanes ($C{\leq}3$), higher alkanes ($C{\geq}4$), aromatics. The higher alkanes and aromatics dominated over the lower alkanes and alkenes in the type 2 and 3 PAMS sites except Joongheung site. N-butane was a major alkane species, toluene was a major aromatic species and most of VOCs showed decreasing trends in these sites. On the other hand, only the alkenes showed decreasing trends at the Joongheung site in Yeosu. Major sources of abundant species such as ethane, propane, n-butane, toluene were estimated by analyzing seasonal variations, correlation with other VOC species, and emission profiles. A major source of n-butane was identified as LPG cars, while major sources of toluene varied considerably from one site to another. The lower alkanes were composed of ethane and propane, both of which showed a strong seasonal variation, low in the summer and high in the winter, indicating that a major source might be the heating by gaseous fuels. Ozone formation potentials of VOC species were evaluated by applying MIR and POCP to the measured VOC species concentrations. Toluene contributed the most to total ozone forming potentials followed by m,p-xylene for all the type 2 and 3 PAMS sites except for two sites in Yeosu-Gwangyang. Ethylene and propylene were the first and second contributors to total ozone forming potentials at Joongheung site in Yeosu.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.3
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• pp.286-296
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• 2007

Ozone creation potentials suited for Seoul metropolitan area was derived by utilizing the PAMS monitoring data and the source inventory. A simple box model with variable height was developed to calculate the incremental reactivity for all the ozone episode days in the year 2003 and 2004. RIR (Relative Incremental Reactivity) was introduced as a measure of contribution to ozone generation in the Seoul metropolitan area. RIR was defined as a function of ratio of VOC to $NO_x$ and therefore it addresses both VOC and $NO_x$ limited regime. For the days that more than 10 monitoring stations out of 27 monitoring station in Seoul recorded the daily maximum ozone concentrations higher than 70 ppb, toluene had the highest RIR value in all the type II and type III PAMS site and m/p-xylene followed with the second highest RIR value. Analyses using MIR (Maximum Incremental Reactivity) and POCP (Photochemical Ozone Creation Potential) instead of RIR also yields dominance of toluene and m/p-xylene in generating ozone concentrations to demonstrate the validity of RIR.

• Elastomers and Composites
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• v.51 no.2
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• pp.99-105
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• 2016

Alkoxy modified silicone (PAMS) was synthesized from hydroxyl-terminated polydimethylsiloxane (OH-PDMS) and vinyltrimethoxysilane (VTMO) under alkali catalyst (NaOH and KOH) at room temperature ($25^{\circ}C$) via condensation polymerization. Then, the structural verification of the synthesized PAMS was confirmed using $^1H$-NMR and FT-IR spectroscopy. The reaction rate of PAMSs was studied in terms of the concentration variation of alkali catalyst. The reaction rate increased with the concentration of alkali catalyst, but no correlation between conversion and concentration of alkali catalyst was observed.

• Journal of Korean Neurosurgical Society
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• v.62 no.5
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• pp.610-617
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• 2019

Objective : This study aimed to assess the surgical results of the intradural transpetrosectomy for petrous apex meningiomas (PAMs). In addition, we describe the methods and techniques used to expose and manage superior petrous vein and greater superficial petrosal nerve. Methods : The authors conducted a retrospective study of 16 patients with PAMs operated by the senior author via the intradural transpetrosectomy between February 2012 to May 2017. We reviewed patient data regarding the general characteristics, surgical technique and surgery-related outcomes and adopted a combined follow-up strategy of clinic and telephone contacts to evaluate postoperative complications. Results : Simpson grade I and II resection was performed in 10 out of 16 cases (62.5%), and grade III resection were reported in the remaining six cases (37.5%) with no resultant mortality. The mean Karnofsky Performance Status score was 85.6 preoperatively and improved to 91.9 postoperatively, with a mean follow-up period of 34.4 months (range, 6-66 months). Tumor recurrence was found in two patients and they underwent the second surgical operation. Conclusion : PAMs could be completely resected by the intradural transpetrosectomy with an improved survival rate and postoperative life quality. Superior petrous vein and greater superficial petrosal nerve should be managed properly in avoidance of postoperative complications. Finally, most meningioma inside cavernous sinus or adhered to brainstem could be totally removed without postoperative complications.

• Polymer(Korea)
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• v.31 no.4
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• pp.356-367
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• 2007

Three kinds of amylose derivatives such as: cholesteryloxycarbonated amyloses(CAMs) with degree of esterification(DE) ranging from 1.8 to 3, (6-cholesteryloxycarbonyl)pentanoated amyloses(PAMs) with DE ranging from 0.3 to 3, and fully cholesteryloxycarbonated PAMs(CPAMs) were synthesized, and their thermotropic liquid crystalline properties were investigated. CAMs with $DE{\geq}2.6$, PAM with DE=1.6 and all the CPAMs formed enantiotropic cholesteric phases, whereas PAM with $DE{\geq}2.2$ exhibited monotropic cholesteric phases. PAM with $DE{\geq}2.2$ and CPAMs with (6-cholesteryloxycarbonyl)pentanoyl DE (DS) more than 1.0 formed cholesteric phases with left-handed helical structures whose optical pitches (${\lambda}_{m'}s$) decrease with increasing temperature. However, the ${\lambda}_{m'}s$ of these samples decreased with increasing DS at the same temperature. On the other hand, CAMs, PAM with DE=1.6, and CPAM with DS=0.3 did not display reflection colors over the full cholesteric range, suggesting that the helicoidal twisting power of the cholesteryl group highly depends on the length of the spacer joining the cholesteryl group to the main chain and DS. The thermal stability and degree of order in the mesophase observed for the amylose derivatives highly depended on DE or DS. The results were discussed in terms of the difference ul the hydrogen bond, the internal plasticization, and the decoupling of the motion of side group with the main chain.

• Journal of Veterinary Science
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• v.22 no.3
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• pp.39.18-39.18
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• 2021

Background: Interferon lambda receptor 1 (IFNLR1) is a type II cytokine receptor that clings to interleukins IL-28A, IL29B, and IL-29 referred to as type III IFNs (IFN-λs). IFN-λs act through the JAK-STAT signaling pathway to exert antiviral effects related to preventing and curing an infection. Although the immune function of IFN-λs in virus invasion has been described, the molecular mechanism of IFNLR1 in that process is unclear. Objectives: The purpose of this study was to elucidate the role of IFNLR1 in the pathogenesis and treatment of porcine reproductive and respiratory syndrome virus (PRRSV). Methods: The effects of IFNLR1 on the proliferation of porcine alveolar macrophages (PAMs) during PRRSV infection were investigated using interference and overexpression methods. Results: In this study, the expressions of the IFNLR1 gene in the liver, large intestine, small intestine, kidney, and lung tissues of Dapulian pigs were significantly higher than those in Landrace pigs. It was determined that porcine IFNLR1 overexpression suppresses PRRSV replication. The qRT-PCR results revealed that overexpression of IFNLR1 upregulated antiviral and IFN-stimulated genes. IFNLR1 overexpression inhibits the proliferation of PAMs and upregulation of p-STAT1. By contrast, knockdown of IFNLR1 expression promotes PAMs proliferation. The G0/G1 phase proportion in IFNLR1-overexpressing cells increased, and the opposite change was observed in IFNLR1-underexpressing cells. After inhibition of the JAK/STAT signaling pathway, the G2/M phase proportion in the IFNLR1-overexpressing cells showed a significant increasing trend. In conclusion, overexpression of IFNLR1 induces activation of the JAK/STAT pathway, thereby inhibiting the proliferation of PAMs infected with PRRSV. Conclusion: Expression of the IFNLR1 gene has an important regulatory role in PRRSV-infected PAMs, indicating it has potential as a molecular target in developing a new strategy for the treatment of PRRSV.

• Journal of Environmental Science International
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• v.12 no.3
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• pp.337-344
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• 2003

The photodegradation of pyrene, chrysene and benzo［a］pyrene, that were similar in structure among poly-cyclic aromatic hydrocarbons (PAMs), were investigated in water irradiated with a low-pressure mercury lamp (wavelength of 253.7 nm and UV output of 1.35 ${\times}$ 10$\^$-3/J/s). The effects of several factors (t-BuOH, HCO$_3$$\^$-/ and pH) on photodegradation of above three PAHs were also examined. The photodegradation rates of PAHs decreased with increasing the concentration of t-BuOH, but decreased little with increasing the concentration of HCO$_3$$\^$-/ under the concentrations used in this study. The photodegradation rates of PAHs decreased with increasing pH, but their change were greater in case of pH increase from acid to neutral and were little in case of pH increase from neutral to base. The photodegradation rates of PAMs fitted a first-order kinetic model and their photodegradation rates decreased in the following sequences: pyrene>chrysene>benzo[a]pyrene among the PAHs used.

• Journal of Korean Society of Transportation
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• v.30 no.1
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• pp.31-43
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• 2012

Domestic road type-and period-specific driving pattern measurement was required as Korea's participation in developing "Worldwide harmonized light-duty vehicle emission test procedure (WLTP/DHC)" studied by UN WP29. This study measured road driving data reflecting road and traffic conditions of Korea, and analyzed seven types of representative road type-and period-specific driving patterns with driving pattern standardization methodology proposed by WP29. PAMS (Portable Activity Monitoring Systems) equipment was used to collect enormous (35,410km) road driving data. There are significant difference among seven derived driving patterns.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2007.10a
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• pp.351-353
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• 2007

• Journal of Pharmaceutical Investigation
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• v.36 no.2
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• pp.115-121
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• 2006

The aim of this study was to develop new protein/peptide depot system instead of poly(DL-lactic acid-coglycolic acid) (PLGA) microspheres. Pullulan was chemically modified by the addition of acetic anhydride (pullulan acetate; PA) and then investigated as new depot system for protein/peptide delivery. PA microspheres (PAM) with lysozyme as a model protein were prepared by w/o/w double emulsion method. The microspheres had a mean size of 10-50 mm with a spherical shape. The size distributions reduced with increasing the degree of acetylation. The loading efficiency of lysozyme was also increased. Lysozyme aggregation behavior in the microsphere was monitored to estimate the change of protein stability during preparation step. The ratios of protein aggregation in PAMs are lower than that of PLGA microsphere, in particular, PA 5 showed lowest as about 16%. The result indicated that the increase of acetylation suppressed the aggregation of protein. The release profiles of lysozyme from PAMs were significantly different. High acetylation effectively improved lysozyme release kinetics by reducing initial burst release and extending continuous release over a period of time. To check the effect of preservation for structural stability of lysozyme, the activity of lysozyme released from PA 5 was also observed. The activity of lysozyme was maintained almost 100% for 25 day. Therefore, PAM may become to a useful carrier for delivery of protein/peptide drugs, if it will be supported by biocompatibility and biodegradability results.