• Korea-Australia Rheology Journal
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• 제14권3호
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• pp.129-138
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• 2002

A cationic surfactant, cetyltrimethylammonium $\rho$-toluenesufonate (CTA$\rho$TS), forms long threadlike micelles in aqueous solution. The threadlike micelles make concentrated entanglement networks, so that the solution shows pronounced viscoelastic behavior as concentrated polymer systems do. However, a mechanism for a process responsible for the longest relaxation time of the threadlike micellar system is different from that of semi-dilute to concentrated polymer systems. The threadlike micellar system exhibits unique viscoelasticity described by a Maxwell model. The longest relaxation time of the threadlike micellar system is not a function of the concentration of CTA$\rho$TS, but changes with that of $\rho$-toluenesufonate ($\rho$$TS^{-}$) ions in the bulk aqueous phase supplied by adding sodium $\rho$-toluenesulfonate (NapTS). The rates of molecular motions in the threadlike micelles are not influenced by the concentration of $\rho$$TS^{-}$ anions, therefore, molecular motions in the threadlike micelles (micro-dynamics) are independent of the longest relaxation mechanism (macro-dynamics). A nonionic surfactant, oleyldimethylamineoxide (ODAO), forms long threadlike micelles in aqueous solution without any additives. The aqueous threadlike micellar system of ODAO also shows Maxwell type viscoelastic behavior. However, the relaxation mechanism for the longest relaxation process in the system should be different from that in the threadlike micellar systems of CTA$\rho$TS, since the system of ODAO does not contain additive anions. Because increase in the average degree of protonation of head groups of ODAO molecules in micelles due to adding hydrogen bromide causes the relaxation time remarkably longer, changes in micro-structure and micro-dynamics in the threadlike micelle are closely related to macro-dynamics in contrast with the threadlike micellar system of CTA$\rho$TS.

• 한국재료학회지
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• 제24권2호
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• pp.73-80
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• 2014

Ink-jet printing technology has been widely attractive due to its facility for direct and fine printing on various substrates. Recent studies have focused on expanding the application of ink-jet printing technology from general consumer use and design companies to the prototype production of precision parts and parts manufacturing. The use of ink-jet printing technology in decorated tableware, tiles, and other ceramic products also has many advantages. The printing process is fast and can be adaptable to various kinds of objects because there is no direct contact point between the printer and the substrates to be printed. For application to ceramic product decoration, inks containing highly dispersed inorganic nano-pigments are required. Here we report the synthesis and characterization of blue $CoAl_2O_4$ nanopigment for ink-jet printing. Blue ceramic ink based on the obtained $CoAl_2O_4$ pigment was prepared by dissolving $CoAl_2O_4$ pigment in a mixed solution of ethylene glycol and ethanol with volume ratios of 7:3 and 8:2, respectively, to obtain the appropriate viscosity for ink-jet printing. The ink solution contained 15 wt% of $CoAl_2O_4$ pigment and Cetyltrimethyl ammonium bromide(CTAB) and Sodium dodecyl sulfate(SDS) as dispersive agents. The prepared blue ceramic ink was stably jetted and formed a sphere-shaped droplet from an ink-jet printer.

• 대한한의학회지
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• 제28권1호통권69호
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• pp.198-210
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• 2007

Objectives : Nitric oxide(NO) is a reactive free radical and a messenger molecule in many physiological functions. However, excessive release NO of induces neurotoxicity. We investigated whether a mixture of red ginseng and paeonia radix prossesses a protective effect against sodium nitroprusside(SNP)-induced apoptosis in the human neuroblastoma cell line SK-N-MC. Methods : We performed 3- (4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay, 4,6-diamidino-2-phenylindole(DAPD) staining, terminal deoxynucleotidyl transferase(TdT)-mediated dUTP nick end labeling(TUNEL)assay, DNA fragmentation assay, reverse transcription-polymerase chain reaction(RT-PCR), Western blot analysis, and caspase-3 enzyme activity assay in SK-N-HFC cells. Result : MTT assay showed that SNP treatment significantly reduced the viabilities of cells and that pre-treatment with the red ginseng and paeonia radix mixture alleviated SNP-induced cytotoxicity. The cells treated with SNP exhibited several apoptotic features, while those pre-treated fir 1 h with the mixture of red ginseng and paeonia radix 1 h prior to SNP expose showed reduced apoptotic features. In addition, the cells pre-treated with the red ginseng and paeonia radix mixture for 1 h prior to SNP expose increased bel-2 expressions, decreased Bax expressions, and decreased caspase-3 enzyme activity. Conclusions : These results show that the red ginseng and paeonia radix mixture exerts a protective effect against SNP-induced apoptosis in SK-N-MC cells.

• 대한한의학회지
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• 제31권3호
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• pp.55-65
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• 2010

Background: Nitric oxide (NO) is a reactive free radical gas and a messenger molecule. NO has many physiological functions, but excessive NO production induces neurotoxicity. Objective: The present study investigated whether the aqueous extract of Polygala tenuifolia Willdenow possesses a protective effect on NO-induced apoptosis in human neuroblastoma cell line SK-N-MC. Method: For this study, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, 4,6-diamidino-2-phenylindole (DAPI) staining, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) assay, DNA fragmentation assay, reverse transcription-polymerase chain reaction (RT-PCR), Western blot, and caspase-3 enzyme assay were performed. Result: Sodium nitroprusside (SNP) exposure significantly decreased the viability of cells. The cells treated with SNP exhibited several apoptotic features such as increasing of Bax expression, caspase-3 enzyme activity and inhibiting of Bcl-2 expression. On the other hand, the viability of cells pre-treated with the aqueous extract of Polygala tenuifolia Willdenow was increased dose-dependently. The cells pre-treated for 1 h with the aqueous extract of Polygala tenuifolia Willdenow followed by treatment with SNP showed a decreased occurrence of apoptotic features like decreasing Bax expressions, caspase-3 enzyme activity and increasing Bcl-2 expressions. The aqueous extract of Polygala tenuifolia Willdenow reduced apoptotic cell death in neuroblastoma cell line SK-N-MC through the inhibition of Bax-dependent caspase-3 activation and the increasing of Bcl-2 expression. Conclusion: Based on the present results, it is possible that Polygala tenuifolia Willdenow has therapeutic value for the treatment of a variety of NO-induced brain diseases.

• Journal of Microbiology and Biotechnology
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• 제22권3호
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• pp.283-291
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• 2012

Bioremediation efforts often rely on the application of surfactants to enhance hydrocarbon bioavailability. However, synthetic surfactants can sometimes be toxic to degrading microorganisms, thus reducing the clearance rate of the pollutant. Therefore, surfactant-resistant bacteria can be an important tool for bioremediation efforts of hydrophobic pollutants, circumventing the toxicity of synthetic surfactants that often delay microbial bioremediation of these contaminants. In this study, we screened a natural surfactant-rich compartment, the estuarine surface microlayer (SML), for cultivable surfactant-resistant bacteria using selective cultures of sodium dodecyl sulfate (SDS) and cetyl trimethylammonium bromide (CTAB). Resistance to surfactants was evaluated by colony counts in solid media amended with critical micelle concentrations (CMC) of either surfactants, in comparison with non-amended controls. Selective cultures for surfactant-resistant bacteria were prepared in mineral medium also containing CMC concentrations of either CTAB or SDS. The surfactantresistant isolates obtained were tested by PCR for the Pseudomonas genus marker gacA gene and for the naphthalene-dioxygenase-encoding gene ndo. Isolates were also screened for biosurfactant production by the atomized oil assay. A high proportion of culturable bacterioneuston was tolerant to CMC concentrations of SDS or CTAB. The gacA-targeted PCR revealed that 64% of the isolates were Pseudomonads. Biosurfactant production in solid medium was detected in 9.4% of tested isolates, all affiliated with genus Pseudomonas. This study shows that the SML is a potential source of surfactant-resistant and biosurfactant-producing bacteria in which Pseudomonads emerge as a relevant group.

• 한국응용과학기술학회지
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• 제31권1호
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• pp.7-13
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• 2014

양이온 에스테르형 계면활성제인 N-2-hydroxy-3-(2-hydroxyacetoxy)proply-N,N-dimethyl dodecylaminium chloride (HPDA)를 합성하였고, FT-IR 과 $^1H$-NMR 분석으로 확인하였다. 합성화합물의 묽은 수용액에 대하여 표면장력을 측정하고, 임계미셀농도를 산정하였다. 표면장력은 $10^{-3}{\sim}10^{-2}mol/L$ 농도 범위에서 33~34 dyne/cm 이었고, 표면장력법에 의해 산정한 임계미셀농도는 $8.5{\times}10^{-3}mol/L$ 이었다. 합성 계면활성제인 HPDA와 SLS, TTAB의 유화특성을 시험하였다. 그 결과 HPDA가 우수한 유화제로 확인되었다. 그리고 Ross-Miles 방법으로 기포력과 기포안정성도 측정하였다.

• Horticulture, Environment, and Biotechnology : HEB
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• 제59권6호
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• pp.827-833
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• 2018

Plasma lighting systems have been engineered to simulate sunlight. The objective of this study was to determine the effects of plasma lighting on tomato plant growth, photosynthetic characteristics, flowering rate, and physiological disorders. Tomato plants were grown in growth chambers at air temperatures of $25/23^{\circ}C$ (light/dark period), in a $16h\;day^{-1}$ light period provided by four different light sources: 1 kW and 700 W sulfur plasma lights (1 SPL and 0.7 SPL), 1 kW indium bromide plasma light, and 700 W high pressure sodium lamp (0.7 HPS) as a control. The totaldry weight and leaf area at 0.7 SPL were approximately 1.2 and 1.3 times greater, respectively, than that of 0.7 HPS at the 62 days after sowing (DAS). The maximum light assimilation rate was observed at 1 SPL at the 73 DAS. In addition, the light compensation and saturation points of the plants treated with plasma lighting were 98.5% higher compared with HPS. Those differences appeared to be related to more efficient light interception, provided by the SPL spectrum. The percentage of flowering at 0.7 SPL was 30.5%, which was higher than that at 0.7 HPS; however, there were some instances of severe blossom end rot. Results indicate that plasma lighting promotes tomato growth, flowering, and photosynthesis. Therefore, a plasma lighting system may be a valuable supplemental light source in a greenhouse or plant factory.

• 한국응용과학기술학회지
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• 제34권1호
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• pp.50-57
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• 2017

금속산화물 반도체 중 하나인 산화아연은 인체에 무해하고 친환경적이며, 우수한 화학적, 열적 안정성의 특성을 지니며 3.37 eV의 넓은 밴드갭 에너지와 60 meV의 높은 엑시톤 바인딩 에너지로 인해 태양전지, 염료페기물의 분해, 가스센서 등 다양한 분야에 응용이 가능한 물질이다. 산화아연은 입자 형상 및 결정성의 변화에 따라 광촉매 활성이 변하게 된다. 따라서, 다양한 실험변수와 첨가제를 사용하여 입자를 합성하는 것이 매우 중요하다. 본 논문에서는 마이크로파 수열합성법을 사용하여 산화아연을 합성하였다. 전구체로는 질산아연을 사용하였고, 수산화나트륨을 사용하여 용액의 pH를 11로 조정하였다. 첨가제로는 계면활성제인 에탄올아민, 세틸트리메틸암모늄브로마이드, 소듐도데실설페이트, 솔비탄모노올레이트를 첨가하였다. 합성된 입자는 별모양, 원추형, 씨드형태, 박막형태의 구형의 형상을 보였다. 합성된 산화아연의 물리 화학적 특성은 XRD, SEM, TGA을 통하여 확인하였고, 광학적 특성은 UV-vis spectroscopy, PL spectroscopy, Raman spectroscopy으로 확인하였다.

• 식물병연구
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• 제20권2호
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• pp.79-86
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• 2014

화훼 수출 검역에서 기존 메틸브로마이드 훈증보다 경제적이고 친환경적이며 안전한 대안으로서 감마선 융복합 처리 기술을 백합 잎마름병 방제에 적용하였다. 감마선 융복합 처리는 200 Gy 감마선과 이염화이소시안산나트륨(NaDCC) 은나노 입자(NSS)의 화학대체제를 시베리아, 르네부, 소르본느 품종의 절화 백합이 담긴 수출포장용 종이상자에 총 6회로 실시하였다. 감마선 조사 8일 후 백합 잎과 꽃잎에서 측정한 발병율(disease incidence)과 발병도(disease severity)로 분석 결과, 감마선은 소르본느 잎에서 발병도를 약 13-25% 감소시킨 반면, 르네부 잎에서는 발병도를 2-5% 증가시켰다. 화학대체제 처리와 무처리를 비교한 결과 절화 백합 수출현장에서 화학대체제의 잎마름병 발병 억제 효과를 기대할 수 없었다. 한편, 조사 12일 후 감마선 처리 유무에 따른 백합 잎의 엽록소 함량 비교 결과 감마선에 의해 통계적으로 유의하게 감소하였고, 시베리아와 소르본느 꽃의 만개 기간을 0.4-1.2일 연장시켰다. 또한 감마선이 조사된 절화는 화병에서 무처리에 비해 마름이 발생하여 생중량 감소가 뚜렷하였다. 한편, 1과 2 kGy 고선량 감마선은 백합 꽃봉오리 끝 부분을 짙은 갈색으로 변색시키거나 꽃봉오리 목 부분의 꺽임, 봉오리가 개화하지 못하게 하는 등 마름 이외에도 감마선 과도에 의한 품질저해 피해가 나타났다.

• 사상체질의학회지
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• 제15권1호
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• pp.72-89
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• 2003

To elucidate the neuroprotective effect of Yeoldahanso-tang(YHT) on nerve cells damaged by hypoxia, the cytotoxic effects of exposure to hypoxia were determined by XTT(SODIUM3,3'-{I-[(PHENYLAMINO) CARBONYL]-3,4-TETRAZOLIUM}- BIS (4-METHOXY-6-NITRO) BENZENE SULFONIC ACID HYDRATE), NR(Neutral red), MTT(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and SRB(Sulforhodamin B) asssay. The activity of catalase and SOD(Superoxide dismutase) was measured by spectrophometry, and $TNF-{\alpha}$(Tumor cell necrosis $fector-{\alpha}$) and PKC(Protein kinase C) activity was measured after exposure to hypoxia and treatment of YHTWE. Also the neuroprotective effect of YHTWE was researched for the elucidatioion of neuroprotective mechanism. The results were as follows; 1. Hypoxia decreased cell viability measured by XTT, NR assay when cultured cerebral neurons were exposed to 95% N2/5% CO2 for $2{\sim}26$ minutes in these cultures and YHTWE inhibited the decrease of cell viability. 2. H2O2 treatment decreased cell viability measured by MTT, and SRB assay when cultured cerebral neurons were exposed to 1-80 ${\mu}M$ for 6 hours, but YHTWE inhibited the decrease of cell viability. 3. Hypoxia decreased catalase and SOD activity, and also $TNF-{\alpha}$ and PKC activity in these cultured cerebral neurons, but YHTWE inhibited the decrease of the catalase and SOD activity in these cultures. 4. Hypoxia triggered the apoptosis via caspase activation and internucleosomal DNA fragmentation. Also hypoxia stimulate the release of cytochrome c forom mitochondria. YHTWE inhibited the apoptosis via caspase activation induced by hypoxia. From these results, it can be suggested that brain ischemia model induced hypoxia showed neurotoxicity on cultured mouse cerebral neurons, and the YHTWE has the neuroprotective effect in blocking the neurotoxicity induced by hypoxia in cultured mouse cerebral neurons.