• 제목/요약/키워드: Acidic treatment

검색결과 574건 처리시간 0.027초

Modeling the Chemical Kinetics of Atmospheric Plasma

  • 김호영;이현우;김규천;이재구
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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    • pp.270-270
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    • 2012
  • Low temperature atmospheric pressure plasmas (APPs) have been known to be effective for living cell inactivation in the water [1]. Many earlier research found that pH level of the solution was changed from neutral to acidic after plasma treatment. The importance of the effect of acidity of the solution for cell treatments has already been reported by many experiments. In addition, several studies have demonstrated that the addition of a small amount of oxygen to pure helium results in higher sterilization efficiency of APPs [2]. However, it is not clear yet which species are key factors for the cell treatment. To find key factors, we used GMoo simulation. We elucidate the processes through which pH level in the solution is changed from neutral to acidic after plasma exposure and key components with pH and air variation with using GMoo simulation. First, pH level in a liquid solution is changed by He+ and He(21S) radicals. Second, O3 density decreases as pH level in the solution decreases and air concentration decreases. It can be a method of removing O3 that cause chest pain and damage lung tissue when the density is very high. H2O2, HO2 and NO radicals are found to be key factors for cell inactivation in the solution with pH and air variation.

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원수 탁도와 pH 변화가 혼화응집침전 과정에서 원생동물과 탁질 제거에 미치는 영향 (The Effects of Turbidity and pH on the Removal of Cryptosporidium and Giardia by Coagulation Process)

  • 정현미;박상정
    • 상하수도학회지
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    • 제20권1호
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    • pp.71-78
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    • 2006
  • The removal of protozoa in the coagulation process was evaluated under the different pH and turbidity using the jar test after the addition of polyaluminium chloride (PAC) as a coagulant. Two well-known protozoa of Cryptosporidium parvum and Giardia lamblia were tested at the same time with turbidity, the critical water quality parameter of the water treatment process. Both protozoa were removed about 1log (and up to 2log) at the optimum injection of PAC. The source water turbidity and pH affected the removal of protozoa and turbidity. At neutral and alkaline pH, 1.3-1.7log removal of protozoa for low turbid water with 5NTU, and 1.6-2.3log removal for high turbid water with 30NTU were achieved. However, at acidic pH, maximum 0.8-1.0log and 1.1-1.2log were removed for low and high turbid water, respectively, at the optimum PAC injection of 15mg/L. The relation of protozoa and turbidity removals were expressed as the 1st order equation (significantly positive relation) in the most of the tested conditions. In addition, the relation of protozoan removals with residual turbidity were also expressed the 1st order equation (significantly negative relation), although the significance of the equations were reduced at acidic pH. Therefore, residual turbidity could be a good index of efficient protozoan removal in the coagulation process, probably except at the low pH condition.

Photonic 재로로서 페닐실리카 코팅막의 특성 (Phenyl modified silica sol-gel films for photonics)

  • Ahn, Bok-Yeop;Seok, Sang-Il;Kim, Joo-Hyeun;Lim, Mi-Ae
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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    • pp.131-131
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    • 2003
  • The advent of photonic technologies in the field of communications and data transmission has been heavily increasing the demand in integrated optical (IO) circuits capable of accomplishing not only simple tasks like signal, but also more sophisticated functions like all-optical signal routing or active multiplexing/demultiplexing. In the last decade, sol-gel technology has been widely used to prepare optical materials. Sol-gel processes show many promises for the development of low-loss, high-performance glass integrated optical circuits. However, crack formation is likely to occur during heat treatment in thick gel films. In order to overcome the critical thickness limitation, the organic-modified silicate has been widely used. In this case coating matrices have been prepared from the organo-silanes of T structures, acidic catalyst and the as-prepared gel films have been heat-treated below 200$^{\circ}C$ to avoid the crack formation and the degradation of organic components. However, the films prepared in the acidic condition and the low heat temperature make the films contain high OH groups which is the major optical loss function. In this work, C$\sub$6/H$\sub$5/SiO$\sub$1.5/ films were prepared on silicon substrate by sol-gel method using base catalyst in a PTMS/NH$_4$OH/H$_2$O/C$_2$H$\sub$5/OH system. The sol showed spinable viscosity at 50 wt% of solid content, and neglectable viscosity change with time. The films were crack-free and transparent after curing at 450 $^{\circ}C$, and highly condensed to minimize OH content in C$\sub$6/H$\sub$5/SiO$\sub$1.5/ networks. The effects of heat treatment of the films are characterized on the critical thickness, the chemical composition and the refractive indices by means of SEM, FT-IR, TGA, prism coupler, respectively.

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시료 중 잔류 항생제 분석 방법: II. 액상 시료 전처리 방법 (Determination of Antibiotic Residues: II. Extraction and Clean-up Methods for Liquid Samples_A Review)

  • 김찬식;류홍덕;정유진;김용석;류덕희
    • 한국물환경학회지
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    • 제32권6호
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    • pp.628-648
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    • 2016
  • Increased attention has been paid to the presence of veterinary antibiotics in various environmental matrices due to their toxicological behavior in the ecosystem and development of antibiotic-resistant strains of pathogenic bacteria. In the this review, 37 target antimicrobials were selected based on annual sales of antibiotics for livestock in South Korea 2014. Also, extraction and clean-up methods for the determination of the antibiotic residues in liquid samples including water, milk, and honey were comprehensively reviewed in the literature. Solid-phase extraction (SPE) was commonly used as a pre-treatment method for the samples. Most of the analytes were extracted in acidic conditions (2.5~4.0) except for aminoglycosides, which were extracted in neutral conditions (7.0~8.0). ${\beta}-Lactams$ showed the highest recoveries in neutral pH due to their degradation characteristics in acidic media. Starta-X, Oasis HLB, and Oasis MCX were frequently applied as an SPE cartridge and Oasis HLB showed the highest recoveries for the majority of antibiotic classes. The homogenized honey and milk were extracted by mixing with acids for deproteinization. Solids and other interfering substances in the extract were eliminated by centrifugation followed by membrane filtration or SPE before injection into HPLC.

도홍사물탕(挑紅四物湯)이 C6 신경교세포의 2-DG에 의한 오토파지성 세포사멸에 미치는 영향 (Protective Effects of Dohongsamul-tang on 2-deoxy-D-glucose Induced Autophagic Cell Death in C6 Glial Cells)

  • 신학수;이성근;문병순
    • 동의생리병리학회지
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    • 제23권3호
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    • pp.581-589
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    • 2009
  • The water extract of Dohongsamul-tang(DHSMT) has been traditionally used in treatment of ischemic heart and brain diseases in Oriental Medicine. However, little is known about the mechanism by which DHSMT protects C6 glial cells from glucose deprevation induced damages. Therefore, this study was designed to evaluate the protective effects of DHSMT on 2-deoxy-D-glucose induced autophagy of C6 glial cells. Autophagic phenotype is evaluated by fluorescence microscopy and flow cytometry with specific biological staining dyes, including monodansylcadaverine and acridine orange, as well as Western blot analysis with microtubule-associated protein 1 light chain 3(LC3) and Beclin-1. Treatment with 2-deoxy-D-glucose significantly resulted in a decrease of the viability of C6 glial cells and increase of the extracellular LDH release in a dose and time-dependent manner. However, pretreatment with DHSMT protected C6 glial cells from glucose deprivation with 2-deoxy-D-glucose. The author also observed the fact that autophagy phenotype occurred by 2-deoxy-D-glucose in C6 glial cells. Pretreatment with 3-MA, a pharmacological inhibitior of autophagy, abolished the formation of acidic vesicle organelle in C6 glial cells treated with 2-deoxy-D-glucose. However, pretreatment with DHSMT inhibited the formation of autophagic phenotypes, including formation of acidic vesicle organelle, and increase of the expression of LC-3 II Beclin-1 proteins in C6 glial cells treated with 2-deoxy-D-glucose. Taken together, these data suggest that DHSMT is able to protect C6 glial cells from glucose deprivation with marked inhibition of autophagy formation.

난소화성 획분이 높은 난소화성 덱스트린의 제조 방법 (Methods for Preparing Indigestible Dextrin with High Indigestible Fraction)

  • 우동호;문태화
    • 한국식품과학회지
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    • 제32권3호
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    • pp.610-617
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    • 2000
  • 높은 난소화성 획분을 갖는 난소화성 덱스트린은 열처리 덱스트린의 효소 가수분해액을 에탄올 또는 강산성 양이온 교환수지(UBK 530)로 처리함으로써 제조하였다. 난소화성 획분, 식이섬유 및 수출을 고려하여 ${\alpha}-amylase$와 amyloglucosidase를 반응시킨 가수분해액으로부터 난소화성 덱스트린을 제조하기 위한 에탄올 처리의 최적 조건은 에탄올을 30%(w/w) 효소 반응액에 고형분 대비 5배로 첨가하여 상온에서 3시간 동안 방치시키는 공정이었다. 포도당을 포함하는 저분자 당류와 고분자 당류를 강산성 양이온 교환수지에 의해 분리한 결과 내열성 ${\alpha}-amylase$와 amyloglucosidase에 의한 초기 효소 반응액은 43.6%의 DPI(glucose)과 51.5%의 DP4+(maltotetaos이상)를 나타낸 반면, 양이온 교환수지에 의해 초기 효소 반응액의 50%까지 분취한 난소화성 덱스트린은 7.1%의 DPI(glucose)과 91.2%의 DP4+(maltoteoaose이상)를 나타내었다. 따라서, 초기 효소 반응액의 난소화성 획분 44.5%는 저분자 당류의 분리 후 78.9%까지 증가하였다.

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Enhancement of Murine NK cell Activity in vitro by Red Ginseng Acidic Polysaccharide

  • Choi, Hye-Sook;Sohn, Eun-Wha;Rhee, Dong-Kwon;Pyo, Suh-Kneung
    • Journal of Ginseng Research
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    • 제33권4호
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    • pp.278-282
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    • 2009
  • 본 논문은 홍삼 산성 다당류 (RGAP)의 생체외 쥣과 NK 세포 활성 향상에 대한 내용으로 주요 내용은 다음과 같다. RGAP는 Yac-1 종양 세포에서 NK 세포 활성을 향상시켰다. 비장 세포에 16시간 동안 RGAP 10 및 $100{\mu}g$/ml을 처리한 결과, NK 활성이 239와 250% 증가 하였다. 인터페론 (IFN)-$\gamma$ 생성은 17-125% 증가하였고, 종양 괴사 인자 (TNF)-${\alpha}$ 생성도 15-100% 증가 하였다. NK 세포의 세포 독성 증가는 NK 세포가 생성하는 이 두 시토카인 증가가 원인이다. 따라서 RGAP는 NK 세포에 미치는 면역증진 효과가 있다는 내용이다.

Glial Fibrillary Acidic Protein Splice Variants in Hepatic Stellate Cells - Expression and Regulation

  • Lim, Michelle Chin Chia;Maubach, Gunter;Zhuo, Lang
    • Molecules and Cells
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    • 제25권3호
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    • pp.376-384
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    • 2008
  • The glial fibrillary acidic protein (GFAP) is traditionally used as a marker for astrocytes of the brain, and more recently for the hepatic stellate cells (HSCs) of the liver. Several GFAP splice variants have been previously reported in the astrocytes of the CNS and in the non-myelinating Schwann cells of the PNS. In this study, we investigate whether GFAP splice variants are present in the HSCs and their expression as a function of HSCs activation. Furthermore, the regulation of these transcripts upon treatment with interferon gamma ($IFN-{\gamma}$) will be explored. Using semi-quan-titative RT-PCR and real-time PCR, we examine the expression and regulation of GFAP splice variants in HSCs as well as their respective half-life. We discover that most of the GFAP splice variants ($GFAP{\alpha}$, ${\beta}$, ${\delta}$, ${\varepsilon}$ and $\kappa$) found in the neural system are also expressed in quiescent and culture-activated primary HSCs. Interestingly, $GFAP{\alpha}$ is the predominant form in quiescent and culture-activated primary HSCs, while $GFAP{\beta}$, predominates in the SV40-immortalized activated HSC-T6. $GFAP{\delta}$, ${\varepsilon}$ and ${\kappa}$ have similar half-lives of 10 hours, while $GFAP{\beta}$ has a half-life of 17 hours. Treatment of HSC-T6 with $IFN-{\gamma}$ results in a significant 1.29-fold up-regulation of $GFAP{\alpha}$ whereas the level of the other transcripts remains unchanged. In summary, $GFAP{\alpha}$, ${\beta}$, ${\delta}$, ${\varepsilon}$ and $\kappa$ are present in HSCs. They are differentially regulated on the transcription level, implying a role of the 5' and 3' untranslated regions.

분리 땅콩 단백질의 기포 특성에 관한 연구 (A Study of the Foaming Properties of Peanut Protein Isolate)

  • 박현경;손경희;김현정
    • 한국식품조리과학회지
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    • 제6권3호통권12호
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    • pp.9-15
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    • 1990
  • Peanut prptein isolate was tested for the purpose of finding out the effect of pH, Sodium Chloride concentration and heat treatment on the solubility, surface hydrophobicity, foam expansion and foam stability. The solubility of peanut protein isolate was affected by pH and showed the lowest value at pH 4.5. When the peanut protein isolate was heated, the solubility decreased at pH 3 and pH 7 but at pH 9 solubility increased. At all pH range, solubility decreased as NaCl was added. The surface hydrophobicity of peanut protein isolate showed the highest value at pH 1.5. Generally, at acidic pH range the surface hydrophobicity was high, but at alkaline region, the surface hydrophobicity increased as the temperature increased. And when NaCl was added, the surface hydrophobicity was also increased. Foam expansion of peanut protein isolate was no significant difference among the values about pH. When the peanut protein was heated and NaCl was added, foam expansion was increased at pH 7. Foam stability was significantly low at pH 4.5 and foam stability was increased at acidic pH region below pH 4.5. At pH 7 and pH 9, heat treatment above $60^{\circ}C$ increased foam stability. When NaCl was added, foam stability was significantly increased at pH 3 and pH 7.

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전해수 및 유기산처리에 의한 양상치에 오염된 Listeria monocytogenes의 생육저해 (Effect of Electrolyzed Water and Organic Acids on the Growth Inhibition of Listeria monocytogenes on Lettuce)

  • 박부길;오민희;오덕환
    • 한국식품저장유통학회지
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    • 제11권4호
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    • pp.530-537
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    • 2004
  • 본 연구는 신선편이 양상치를 대상으로 전해수와 유기산의 단독 또는 병용처리에 의한 위해미생물의 살균효과를 조사하였다. 산성전해수는 액상배지에서 L. monocytogenes를 60초 내에 완전히 사멸하였으나, 알칼리전해수는 약 1.7 log CFU/g 정도 감소하였다. 그러나 L. monocytogenes를 접종한 양상치에서 산성전해수는 현저하게 살균력이 감소하여 3분 침지시 약 2.5 CFU/g의 감소를 나타내었으나 알칼리전해수는 산성전해수와 거의 살균력의 차이가 없었다. 한편, L. monocytogenes에 오염된 양상치를 전해수와 유기산 단독 또는 병용처리 하였을 때 무처리구에 비하여 산성전해수와 알칼리전해수는 약 2 log CFU/g 정도의 감소를 나타냈으며, $1\%$ acetic acid, lactic acid, citric acid 및 ascorbic acid를 처리하였을 경우 각각 1.52.5 log CFU/g의 감소를 나타냈으나, 산성전해수와 알칼리전해수에 $1\%$ 유기산을 병용처리 하였을 경우 약 2.63.7 log CFU/g의 현저한 감소를 나타내었다. 특히 산성전해수와 알칼리전해수 모두 $1\%$ citric acid와 병용처리 하였을 때 가장 강한 살균력을 나타내었다. 양상치에 오염된 총균수, 효모 및 곰팡이의 경우도 L. monocytogenes에 오염된 양상치의 살균력과 비슷한 경향을 나타내었다. 또한, L. monocytogenes를 접종한 양상치를 전해수 처리한 후 온도별로 저장하면서 생육변화를 측정한 결과, 병용처리구에서 현저하게 생육이 저해되는 것으로 나타나 양상치를 세척시 알칼리전해수와 $1\%$ citric acid를 병용처리하면 총균수는 물론 L. monocytogenes에 의한 오염방지에 매우 효과적이었다. 한편, SEM 결과, 양상치에 오염된 L. monocytogenes 는 알칼리수와 $1\%$ citric acid의 병용처리구에서는 현저하게 세포막이 파괴되어 세포가 사멸하는 것으로 나타났다.