• The Korean Journal of Physiology and Pharmacology
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• 제5권2호
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• pp.189-197
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• 2001

To investigate propofol's effects on ionic currents induced by ${\gamma}-aminobutyric$ acid (GABA) and glycine as well as on those produced by the nicotinic acetylcholine- and glutamate-responsive channels, rat dorsal raphe neurons were acutely dissociated and the nystatin-perforated patch-clamp technique under voltage-clamp conditions was used to observe their responses to the administration of propofol. Propofol evoked ion currents in a dose-dependent manner, and propofol $(10^{-4}\;M)$ was used to elicit ion currents through the activation of $GABA_A,$ glycine, nicotinic acetylcholine and glutamate receptors. Propofol at a clinically relevant concentration $(10^{-5}\;M)$ potentiated $GABA_A-,$ glycine- and NMDA receptor-mediated currents. The potentiating action of propofol on $GABA_A-,$ glycine- and NMDA receptor-mediated responses involved neither opioid receptors nor G-proteins. Apparently, propofol modulates inhibitory and excitatory neurotransmitter-activated ion channels either by acting directly on the receptors or by potentiating the effects of the neurotransmitters, and this modulation appears to be responsible for the majority of the anaesthetic and/or adverse effects.

• 한국대기환경학회지
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• 제14권5호
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• pp.491-498
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• 1998

Fog water samples were collected at Chunchon, Korea, by using active fog sampler during foggy Period in fall of 1996 and 1997. The average annual foggy days at Chunchon increased from 37 days, for the yearn 1963 ∼ 1973, to 63 days , for the year 1974∼1993 that followed the construction of Lake Soyang. Volume weighted mean pH of fog water was 5.5 with a range of 4.8 to 7.0 in 1996, and 5.0 with a range of 4.1 to 6.6 in 1997. These pH values were higher than those of rain water sampled in corresponding years. However the concentration of ionic species in fog water were 26 times higher than those of rain water. The major anions in fog water were in order of SO42-, NO3- and Cl-, and their average concentrations were 1770.6meq/ml, 346.2 meq/ml, 216 meq/ml in 1996, and 901.8meq/ml, 269.6meq/ml, 141.0meq/ml in 1997, respectively. The major cations were Ca2+, NH4+, Mg2+ and K+, and their average concentrations frere 408.5meq/ml, 280.0meq/ml, 43.8meq/ml, 45.2meq/ml in 1996, and 400.4 meq/ml, 299.0meq/ml, 73.1meq/ml, 44.5meq/ml in 1997, respectively. The fraction acidity of fog water was 0.006 and that of rain water was 0.2, which means fog water was much more neutralized than rain water.

• 한국대기환경학회지
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• 제29권6호
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• pp.701-712
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• 2013

The purpose of this study is to determine concentrations and compositions of $PM_{2.5}$ and their characteristic variations at Ieodo Ocean Research Station in the East China Sea and to examine the influence of air pollutants transported from Asia continents. $O_3$ and meteorological parameters were measured since June 2003 and $PM_{2.5}$ filter samples were collected from June 2004 to June 2008. In total, 244 samples were analyzed for water soluble ions and carbonaceous compounds. The mean mass concentration of $PM_{2.5}$ and $O_3$ were $21.8{\pm}14.9{\mu}g/m^3$ and $51.6{\pm}16.1$ ppb, respectively. The average concentrations (mass fractions) of sulfate and ammonium were $6.26{\mu}g/m^3$ (28.74%) and $1.59{\mu}g/m^3$ (7.31%), respectively. Nitrate was considered to be lost through evaporation due to long stay at the station. The mean concentrations of EC and OC were $1.01{\mu}g/m^3$ and $2.34{\mu}g/m^3$, respectively, from June 2006 to June 2008. The average OC/EC ratio was 2.31. The organic matter converted from OC by multiplying 2.1 and elemental carbon constituted 22.60% and 4.66% of $PM_{2.5}$ mass, respectively.

• Journal of Pharmaceutical Investigation
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• 제41권2호
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• pp.95-102
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• 2011

An amphiphilic cationic branched methoxy poly (ethylene glycol)-branched polyethylenimine - poly(L-phenylalanine) (mPEG-bPEI-pPhe) block copolymer was successfully synthesized by ring-opening polymerization (ROP) of N-carboxyanhydride of L-phenylalanine (Phe-NCA) with mPEG-bPEI for the preparation of more stable polyelectrolyte complex (PEC) included a hydrophobic interaction. mPEG-bPEI was firstly prepared by the coupling of mPEG and bPEI using hexamethylene diisocyanate (HMDI). The structural properties of mPEG-bPEI-pPhe copolymers were confirmed by $^1H$ NMR. The copolymers exhibited a self-assemble behavior in water above critical aggregate concentration (CAC) in the range of 0.01-0.14 g/L. The CAC of copolymers obviously depended on the hydrophobic block content in the copolymers (the value decreased with the increase of the pPhe block content). The cationic copolymers have the ability to form multi-interaction complex (MIC) with bovine serum albumin (BSA) and plasmid DNA through multi-interaction (electrostatic and hydrophobic interaction). The physicochemical characterization of the complex was carried out by the measurement of zeta potential and particle size. Their zeta-potentials were positive (approximately +10 mV) and their sizes decreased with increasing pPhe contents in the copolymers (PPF/BSA wt% ratio = 2). The complex showed good stability at high ionic strength. Therefore, mPEG-bPEI-pPhe block copolymer was considered as a potential material to enhance the stability of complex including biotherapuetic drugs.

• Asian Journal of Atmospheric Environment
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• 제7권3호
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• pp.129-138
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• 2013

The water uptake by fine aerosol in the atmosphere has been investigated at Gosan, Korea during ABC-EAREX 2005. The concentration of inorganic ion and carbon components, size distribution, and light scattering coefficients in normal and dry conditions were simultaneously measured for $PM_{2.5}$ by using a parallel integrated monitoring system. The result of this study shows that ambient fine particles collected at Gosan were dominated by water-soluble ionic species (35%) and carbonaceous materials (18%). In addition, it shows the large growth of aerosol in the droplet mode when RH is higher than 70%. Size distribution of the particulate surface area in a wider size range ($0.07-17{\mu}m$) shows that the elevation of RH make ambient aerosol grow to be the droplet mode one around $0.6{\mu}m$ or the coarse mode one, larger than $2.5{\mu}m$. Hygroscopic factor data calculated from the ratio of aerosol scattering coefficients at a given ambient RH and a reference RH (25%) show that water uptake began at the intermediate RH range, from 40% to 60%, with the average hygroscopic factor of 1.10 for 40% RH, 1.11 for 50% RH, and 1.17 for 60% RH, respectively. Finally, average chemical composition and the corresponding growth curves were analyzed in order to investigate the relationship between carbonaceous material fraction and hygroscopicity. As a result, the aerosol growth curve shows that inorganic salts such as sulphate and nitrate as well as carbonaceous materials including OC largely contribute to the aerosol water uptake.

• 한국대기환경학회지
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• 제25권1호
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• pp.75-89
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• 2009

The purpose of this study was to identify $PM_{2.5}$ sources and to estimate their contributions to the border of Yongin-Suwon area, based on the analysis of the $PM_{2.5}$ mass concentration and the associated inorganic elements, ions and carbon components. The contribution of $PM_{2.5}$ sources were estimated by using a positive matrix factorization (PMF) model to identify air emission sources. For this study, $PM_{2.5}$ samples were collected from May, 2007 to April, 2008. The inorganic elements were analyzed by an ICP-AES. The ionic components in $PM_{2.5}$ were analyzed by an Ie. The carbon components were also analyzed by DRI/OGC analyzer. After performing PMF modeling, a total of 12 sources were identified and their contributions were quantitatively estimated. The contributions from each emission source were as follows: 11.3% from oil combustion source, 3.4% from bus/highway source, 5.8% from diesel vehicle source, 4.7% from gasoline vehicle source, 8.8% from biomass burning source, 15.1 % from secondary sulfate, 5.2% from secondary nitrate source, 13.4% from industrial related source, 4.1% from Cl-rich source, 19.6% from soil related source, 1.0% from aged sea salt, and 7.4% from coal combustion source, respectively. This study provides basic information on the major sources affecting air quality, and then it will help to effectively control $PM_{2.5}$ in this study area.

• 약학회지
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• 제49권4호
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• pp.323-329
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• 2005

Antimicrobial peptides are evolutionary ancient weapons for animal and plant species to depend themselves against infectious microbes. In the present study, we investigated if an antimicrobial peptide was produced from Coptidis Rhizoma. For the determination, protein substance from the medicinal plant was isolated by various preparations. Among the preparations, the protein portion dissolved in phosphate-buffered saline solution (CRP-DS) that contained the most amount of protein $(90\%)$ resulted in maximal inhibition of Candida albicans which causes local and systemic infections. Analyses by gel-electrophoresis and gel-permeation chromatography showed the CRP-DS formed a single band of approximately 11.8 KDa as molecular size. Antifungal activity of the CRP-DS was almost equivalent to antifungal activity by fluconazole, resulting in MIC (minimal inhibitory concentration) of approximately $50{\mu}g/ml$. The antifungal activity was a dose-dependent. The antifungal activity appeared to be inactivated by heat-treatment and ionic strength, respectively. In a murine model, the CRP-DS enhanced resistance of mice against disseminated candidiasis. The HPLC analysis demonstrated maximum $4\%$ of berberine as residual content in the CRP-DS preparation resulted in no influence on the antifungal activity. In addition, protein portion isolated from Phellodendri Cortex producing the alkaloid component like Coptidis Rhizoma had no such anticandidal effect. These results indicate that the protein substance from Coptidis Rhizoma was responsible for the antifungal activity.

• 유기물자원화
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• 제14권1호
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• pp.169-177
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• 2006

본 연구에서는 휘발성 유기 화합물의 촉매연소에 의한 제거 반응에 대하여 조사 하였다. 촉매와 VOC의 접촉형태(공간속도 및 촉매층의 높이)에 따라 완전연소온도가 조금씩 달라지며 공간속도(SV)는 처리가스의 유량(Q, $m^3/hr$)을 촉매 층의 부피(V,$m^3$)로 나눈 값(SV=Q/V)을 나타내는 값으로, 촉매연소 장치에서는 보통 $10,000{\sim}50,000hr^{-1}$을 유지한다 열교환기를 통한 VOC는 수소염 이온화 검출기를 통하여 농도를 측정하였으며 반응온도는 373K-423K에서 촉매를 활성화 시켜 VOC 농도의 제거효율을 측정하였다. 농도측정은 100회 이상하여 제거효율을 조사 하였다. 자동차 도장시설에서 VOC 배출농도는 63.37 ppm 이며 373K 촉매 활성시 제거율은 평균 70% 이며 423K 촉매 활성시 제거효율은 78.92% 이었다. 반응농도가 증가할수록 제거효율은 증가하는 경향이었다.

• 한국환경과학회지
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• 제17권7호
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• pp.817-826
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• 2008

Using high voltage electric fields induced by high voltage AC (10-12 kV/cm, 20 kHz) and pulsed (20-30 kV/cm, 40 Hz) electric field generator as a semipermanent and environment-friendly disinfecting apparatus, the disinfection effect of coliform group in the effluent of sewage plant was investigated. The effects of electric field strength, treatment time, discharge area of a discharge tube, water quality factors (electric conductivity, pH and SS) on its death rate were examined. The death rate of coliform group was increased with increasing electric field strength and treatment time. For AC and pulsed electric field generator, the critical electric field strength was 6 kV/cm and 2 kV/cm, respectively, and the critical treatment time was 5 min and 2 min, respectively, regardless of electric field strength. Comparing the death rate of coliform group by AC and pulsed electric fields used in this study, its death rate was higher for the latter than the former, but did not increase linearly with increasing electric field strength. The results obtained for the effects of discharge area, electric conductivity, pH and SS on the death rate of coliform group using AC electric field (12 kV/cm, 20 kHz) were as follows: its death rate showed the trend to increase linearly with increasing discharge area; for the effect of electric conductivity, its death rate was increased with increasing electric conductivity, regardless of ionic species, increased with increasing cationic valency, but was similar between the same cationic valency; the pH $5{\sim}9$ used in this study did not affect its death rate; its death rate was decreased with increasing SS concentration.

• KSBB Journal
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• 제18권2호
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• pp.100-106
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• 2003

의학, 약학적으로 작용이 뛰어난 약리성분이 인체 내에서 상처 부위에 얼마나 빨리 도달하여 치료를 하는지를 알기 위하여 혈장 단백질과 약리성분의 결합력을 연구하는 새로운 연구 분야가 HPFA이다. 본 연구는 인체 내에 존재하는 혈장단백질과 항암제로서 알려져 있는 (S)-perillyl alcohol의 결합력과 결합 매개변수를 구하기 위하여 on-line frontal analysis HPLC system을 적용하였다. Develosil 100 Diol 5 (10 cm $\times$ 4.6 mm I.D.)의 HPFA 컬럼을 이용하였고, 이동상은 인산완충용액(pH = 7.4, I = 0.17)을 이용하였다. UV wavelength 205 nm에서 실험을 수행하였고, 주입 부피는 본 실험 조건인 혈장 단백질이 350 rM일 경우에 최대의 혈장 단백질과 결합되지 않은 약리성분의 농도를 갖게 되는 600 ${\mu}\ell$으로 정하였다. Scatchard analysis를 통한 연구 결과로 혈장 단백질인 HSA와 (S)-perillyl alcohol의 결합 매개변수(K)와 단위 HSA에 대한 S-POH의 결합 위치의 수(n)는 각각 K : 2.05 $\times$ $10^{6}$ [M$^{-1}$], n : 0.00428로 실험적으로 구하였다