• 제목/요약/키워드: Effective precipitation

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나노입자수송시스템을 이용한 파클리탁셀 정맥주사제의 제조 및 평가 (Preparation and Evaluation of Paclitaxel Nano-particle Delivery System for Parenteral Formulations)

  • 전일순;김정수;이계원;지웅길
    • 약학회지
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    • 제49권4호
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    • pp.268-274
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    • 2005
  • Paclitaxel is an effective antineoplastic agent against ovarian, colon and breast tumors. But there have been many difficulties to formulate this drug due to the extremely low aqueous solubility. Paclitaxel is currently formulated in a vehicle composed of Cremophor EL and absolute ethanol mixture which is $5\~20$ fold diluted in normal saline or $5\%$ dextrose solution before I.V. injection. However, this formulation has many problems such as allergic reactions and drug precipitation on aqueous dilution. To overcome these problems, we prepared the micelle and microemulsion systems for parenteral administration of paclitaxel by using glycofurol, $Soluto^{(R)}lHS$ 15 and oleic acid. Phase diagram, pH-rate stability, particle size distributions and pharmacokinetics of the systems were studied. Micelles and microemulsions formulated as nano-particle delivery system were physically and chemically stable. Therefore, these formulations might be the promising alternative candidate for the parenteral delivery of paclitaxel.

CSOs를 고려한 도시유역의 수량 및 수질 분석을 위한 PCSWMM 모형의 적용 (Application of PCSWMM for the Analysis of Water Quantity and Quality Considering CSOs)

  • 홍원표;정은성;이준석;김경태;이길성
    • 한국물환경학회지
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    • 제25권1호
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    • pp.26-36
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    • 2009
  • Combined sewer system (CSS) has been built in the most urban areas across the nation. During dry weather conditions, CSS works fine. But during heavy rain storms, combined sewage frequently overflows into the stream. This study simulated the hydrologic cycle and pollutant loads (BOD, SS, TN and TP) in the Mokgamcheon watershed considering combined sewer overflows (CSOs). PC storm water management model (PCSWMM) was used for continuous simulation and CSOs are considered using the flow divider. Sensitivity analysis, calibration and verification for water quantity and quality are carried out. To verify CSOs, field measurements of CSOs are compared with simulated results. As a result, 41.3% of precipitation flows into the stream directly and 1.1% of water supply flows into stream as CSOs. 6.5% of BOD total loads, 12.0% of SS, 13.6% of TP, and 29.2% of TN are from CSOs. This result will be effective to the integrated watershed management for sustainability.

TOWARDS A SAFER ENVIRONMENT: 3) PHOSPHATIC CLAYS AS SOLUTION FOR REMOVING PB2+ FROM WASTEWATER

  • ABDALLAH SAMY MOHAMED
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2005년도 학술발표회(2)
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    • pp.1179-1180
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    • 2005
  • To immobilize the pollutants from wastewater in situ, two phosphatic clays collected from different areas in Egypt (eastern and western Sebaia, Aswan-Isna, Upper Egypt) used to remove contaminant ions from industrial wastewater. Obtained results confirmed the strong relationship between phosphatic clay and Pb elimination from wastewater. The sensitivity classification of phosphatic clay toward ions retained as described in three categories: highly sensitive to retain Pb , Al and Cr ; moderately sensitive for Mn; and weakly sensitive for Band Zn. Data suggested that large fraction of Pb removed by phosphatic clays stayed intact under a wide variation in extracting solution pH (3-11). In situ immobilization is considered a promising technique that has the potential to remove contaminant ions from wastewater. Two important factors need to be considered when applying this technique: The first, is the clay must be effective and selective under different composition of wastewater. The second, is the immobilized ions should be stable and non-leacheable under varying water conditions. Phosphatic clays with $Pb^{2+}$ were suitable to achieve these two factors. Possible mechanism for removal $Pb^{2+}$ by phosphatic clays is the formation of fluoropyromorphite through the dissolution of fluoro and hydroxyl apatite by its precipitation from solution, beside, Pb complexation at phosphatic clay surface at P-OH sites.

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Streptomyces fradiae에서 분리된 Aspartate Aminotransferase의 특성 (Characterization of Aspartate Aminotransferase Purified from Streptomyces fradiae)

  • Lee, Sang-Hee;Lee, Kye-Joon
    • 미생물학회지
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    • 제31권3호
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    • pp.237-244
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    • 1993
  • Aspartate aminotransferase (ASAT) (L-aspartate : 2-oxyoglutarate, EC 2.6. 1. 1.) from Streptomyces fradiae NRRL 2702 has been purified by acetone precipitation, DEAE-cellulose, hydroxyapatite, and preparative electrophoresis (Prep cell), of which the last was the most effective step in the purification of ASAT. The molecular mass was estimated to be 54,000 dalton by SDS-PAGE and 120,000 dalton by gel filtration chromatography. Preparative isoelectric focusing of purified ASAT resulted in one polypeptide band with a pI of 4.2, showing homogeneity and indicating that the enzyme is composed of two identical subunits. The enzyme was specific for L-aspartate as an amino donor ; the $K_{m}$ values were determined to be 2.7 mM for L-aspartate, 0.7 mM for 2-oxoglutarate, 12.8 mM for L-glutamate, and 0.15 mM for oxaloacetate. The enzyme was relatively heat-stable, having maximum activity at 55.deg.C, and it had a broad pH optimum ranging from 5.5 to 8.0. The activity of the purified enzyme was not inhibited by ammonium ions. This paper reports the first purification and characterization of the aspartate aminotransferase from a species of Streptomyces.s.

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초기농도와 pH 조건의 변화에 따른 제강슬래그의 카드뮴 제거능 평가 (Estimation of Cadmium Removal Capacity on Furnace Slag in the Change of Initial Concentration and pH)

  • 이광헌;김은협;박준범;오명학
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 춘계 학술발표회
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    • pp.1006-1011
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    • 2010
  • This study was focused on the reactivity of furnace slag against cadmium to design the vertical drain method with reactive column for improving contaminated sea shore sediment. The removal capacity of furnace slag was analyzed using pseudo-second-order model. And the effective parameters of removal test were initial concentration and initial pH. According to equilibrium removal amount and reactive constant calculated by pseudo-second-order model, the removal capacity was analyzed. Equilibrium removal amount of furnace slag was linearly increased as increasing intial cadmium concentration. Because the pH was around 11, the removal mechanism of furnace slag could be both sorption and precipitation. Therefore the removal amount was increased due to initial concentration. pH was increased to around 11 in the case of "No treat", but the pH were 3.8 in the case of "HAc added" and 0.7 in the case of "HCl added". The removal amount was different 4.8, 1.19 and 0.27 mg/g. This results show the pH was major factor to remove cadmium using furnace slag.

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산업폐수의 수처리를 위한 초전도 자기분리 장치 제작 (Superconducting Magnetic Separator for Purification of Industrial Wastewater)

  • 하동우;권준모;고락길;백승규;손명환;이유진;김태형
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.44-44
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    • 2010
  • Conventional water treatment facilities like precipitation process need large-scale equipment and wide space to purify the wastewater of paper factory. In case of massive waste water, high gradient magnetic separation (HGMS) parts are more effective to purify it rapidly and to occupy relatively small space, since large voids at filter with HGMS are adopted. Cryo-cooled Nb-Ti superconducting magnet with room temperature bore in diameter of 100 mm and 600 mm in height was used for magnetic separator. Magnetic filters were designed by the analysis of magnetic field distribution at superconducting magnets.

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비매개변수 핵밀도함수와 강우-유출모델의 합성곱(Convolution)을 이용한 수학적 해석 (Convolution Interpretation of Nonparametric Kernel Density Estimate and Rainfall-Runoff Modeling)

  • 이태삼
    • 한국방재안전학회논문집
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    • 제8권1호
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    • pp.15-19
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    • 2015
  • 수문학에서 사용되는 강우-유출 모델의 경우 선형적인 시스템을 기반으로 유효강수량으로부터 시간적 지연을 통해서 유출량이 결정되는데 그 양은 강우량의 선형적인 비로 표현되어서 결국 합성곱을 통해 해석되게 된다. 또한 자료에 대한 확률론적 분석에 많이 이용되는 비매개변수 핵밀도함수의 경우, 핵(Kernel)의 의미자체가 합성곱에서 나온 것으로서 개개의 자료를 바탕으로 핵을 통해 매끄러운 확률밀도함수를 구하게 된다. 본 연구에서는 합성곱을 바탕으로 강우-유출 모델과 비매개변수 확률밀도함수를 해석하는 방법에 대해서 되짚어 보고 그 공통적인 특성과 다른 점을 수학적으로 나타내 줌으로써 사용되는 합성곱 함수의 유용성에 대해서 논하였다.

A Simple Method for Preserving Underground Water Resources in Volcanic Island (Jeju)

  • Hwang, Junhyuk;Ban, Hoki
    • 한국지반환경공학회 논문집
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    • 제17권9호
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    • pp.29-35
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    • 2016
  • Being mostly made up of highly permeable basalt and volcanic ash soil, Jeju Island's lithosphere characterizes its streams to be dry, flowing only when precipitation is happening. Under this condition, this research was motivated to identify the need of conservation of underground water, which is taking up most of (84% of) Jeju's water usage, and made an attempt to reduce the permeability of stream beds so that it can replace underground water and be used instead. To this end, this study suggested a simple method to make dry streams to carry water all-year-round by reducing permeability of stream floor. The experiment of permeability was performed on the porous basalt and compared it with that of same basalt with volcanic ash soil and Jumunjin sand layer added on top. The results showed a dramatic decrease in permeability of water when both volcanic ash soil and Jumunjin sand is were layered on top of porous basalt. Despite being gained in a controlled environment with a simple test, this result may provide a realistic and effective method of preserving Jeju Island's underground water which ultimately is a method of resolving water related issues.

자연형 호안공법을 적용한 소하천의 수리특성 분석 (Analysis of Hydrodynamic Characteristics Apply to Nature-Friendly Stream Protection Method)

  • 이강석;박종화;연규방
    • 한국관개배수논문집
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    • 제17권2호
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    • pp.71-81
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    • 2010
  • Stream Pilot Project, which began in May 2003 and finished in December 2003, was selected to develop effective methods applicable to nature-like streams. Stream restoration projects aim to maintain or increase ecosystem goods and services while protecting downstream and coastal ecosystems. Fields environmental monitoring such as flow discharge and precipitation were conducted along the Idong stream for amount of channel zone change in 2007. This study selected three monitoring positions to measure the water level and discharge of flowing water. A stage-discharge relation is obtained from direct discharge measurements for three stations by fitting an empirical relationship to the data set. Since discharge measures are made only for low flow conditions, a curve of discharge against stage can then be built by fitting these data with a power curve. And this study used data obtained from floodmark checkup as well as HEC-RAS model to analyze the hydrodynamic characteristics of monitoring sites. Reach-averaged hydraulic parameters for the supply reach were calculated from the small area's HEC-RAS model for Idong stream, and a HEC-RAS model used to analyze hydraulics for a period in 2007, after the stream was considered bank stabilization.

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Cytoprotective effect of polysaccharide isolated from different mushrooms against 7-ketocholesterol induced damage in mouse liver cell line (BNL CL. 2)

  • Kim, Joo-Shin;Chung, Hau Yin;Na, Keun
    • Nutrition Research and Practice
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    • 제1권3호
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    • pp.180-183
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    • 2007
  • Cytoprotective ability of polysaccharides isolated from different edible mushrooms was investigated on the 7-ketocholesterol-induced damaged cell line. Polysaccharide extracts from six different edible mushrooms-Flammulina velutipes, Peurotus ostreatus, Lentinus edodes, Agrocybe aegerita, Agaricus blazei, and Cordyceps militaris- were prepared by hot water extraction and alcohol precipitation. Cytoprotective ability was evaluated by measuring the viable cells of the normal embryonic liver cell line (BNL CL. 2) in the presence of 7-ketocholesterol. At $80\;{\mu}g/mL$ of 7-ketocholesterol, cytotoxicity was very high with a loss of 98% of viable cells after 20 h of incubation. With the addition of $200\;{\mu}g/mL$ of each polysaccharide isolate to the cell line containing $80\;{\mu}g/mL$ of 7-ketocholesterol, polysaccharide isolates from both Flammulina velutipes and Peurotus ostreatus could significantly inhibit the 7-ketochoelsterol-induced cytotoxicity in the cells. But other polysaccharide isolates were not effective in inhibiting cell damage caused by the oxLDL-induced cytotoxicity.