• 펄프종이기술
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• 제30권4호
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• pp.28-34
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• 1998

Polyvinyl acetate emulsion has been widely used as adhesives for wood and paper, paint additives and binders for fiber, leather, and other materials because it is an excellent adhesive with many advantages including low in toxicity risks and manufacturing cost. It is expected the consumption of polyvinyl acetate emulsion as adhesives will increase in cigarette industry as well as in paperboard coating industry. Recently the operation speed of the cigarette tip wrapper increased so substantially that improvement of the emulsion properties is required including good wet tack development, narrow and controlled particle size distribution, low viscosity, etc. In this study the effects of such polymerization conditions as the type and amount of emulsifier, internal or external plasticizing, and emulsification methods on the viscosity and particle size of polyvinyl acetate emulsions were examined. Results showed that polyvinyl alcohol with a high degree of hydrolysis and low molecular weight and nonionic surfactants are superior to anionic surfactant in improving adhesion and emulsion stability. They also tend to produce emulsions with smaller particle size. External plasticization with dipropylene glycol dibenzoate was more effective in improving flexibility than internal plasticization with butyl acrylate. Monomer emulsification under high shear was more effective in decreasing the particle size.

• Journal of Electrochemical Science and Technology
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• 제11권3호
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• pp.220-237
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• 2020

Modern electrochemical energy devices involve generation and reduction of fuel gases through electrochemical reactions of water splitting, alcohol oxidation, oxygen reduction, etc. Initially, these processes were executed in the presence of noble metal-based catalyst that showed low overpotential and high current density. However, its high cost, unavailability, corrosion and related toxicity limited its application. The search for alternative with high stability, durability, and efficiency led scientists towards carbon nanoparticles supported catalysts which has high surface area, good electrical conductivity, tunable morphology, low cost, ease of synthesis and stability. Carbon nanoparticles are classified into two groups based on morphology, one and zero dimensional particles. Carbon nanoparticles at zero dimension, denoted as carbon dots, are less used carbon support compared to other forms. However, recently carbon dots with improved electronic properties have become popular as catalyst as well as catalyst support. This review focused on the recent advances in electrocatalytic activities of carbon dots. The mechanisms of common electrocatalytic reactions and the role of the catalysts are also discussed. The review also proposed future developments and other research directions to overcome current limitations.

• Natural Product Sciences
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• 제5권3호
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• pp.127-133
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• 1999

'Gunja' is attributable to the plant Abrus precatorius L. (Leguminosae). Three forms with red, brown and another with white seeds are known to occur in this species and are employed for different therapeutic uses viz. as purgative, emetic, aphrodisiac, tonic and also as an abortifacient. According to some Ayurvedic literature the seeds are poisonous and should be given to the patients after proper processing ('Shodhan'). A comparative study of various phytochemical parameters, namely, percentage of successive extractives, total proteins, tannins, total ash and acid insoluble ash of these three forms of the processed (with cow's milk and Kanji) and unprocessed seeds was done. TLC and densitometric scanning of successive extractives was also carried out to serve as markers for processed and unprocessed seeds. The percentage of proteins, tannins, alcohol and water soluble extractives decreased in the processed material. Besides, their acute toxicity, CNS activity were also studied in albino mice and it was found that white seeds are more toxic as compared to the red and brown. The toxic effect was reduced with the processing. Further, the 'Kanji' processed seeds are less toxic than the milk processed one.

• 한국응용과학기술학회지
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• 제21권4호
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• pp.313-319
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• 2004

Ethanol washing with distillation as a cleanup process of polycyclic aromatic hydrocarbon(PAH)-contaminated soil was investigated in this study. A multistage ethanol washing with distillation process was applied to three different types of soil, i.e., sandy soil, alluvial soil, and clay with the initial concentration of benzo(a)pyrene 10 mg/kg, benz(a)anthracene 250 mg/kg, and pyrene 100 mg/kg soil. Ethanol was selected as washing solvent because of its high PAH removal efficiency, low cost, and non-toxicity comparing to the other solvent such as isopropyl alcohol and sodium dodecyl sulfate. The satisfactory results (i.e. lower than benzo(a)pyrene 1 mg/kg, pyrene 10 mg/kg, benz(a)anthracene 25 mg/kg, which are the Canada or the Netherlands soil standard) for three types of soils were obtained by at most five-six times washing. It was suggested that organic content in soil decreased the removal efficiency by ethanol washing.

• 한국태양에너지학회 논문집
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• 제31권6호
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• pp.66-71
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• 2011

Various single solvents were tested to find the effective solvent for the extraction of algae oil from wet-form Chlorella minutissima. In the case of single solvents, their extractabilities for algae oil were increased with their polarity because the water in wet algae cell is to form a solvent shell around the lipids. Based on these results, the wet-form algae samples were treated with a polar alcohol solvent and then a nonpolar solvent was added in algae residue. In the algae oil extraction by ethanol/n-hexane, total lipid contents were 40-50% and composition of triglyceride in extracted oil was 46.50%. Considering solvent toxicity of conventional solvent mixture such as chloroform and methanol for algae oil extraction, the ethanol/n-hexane system was identified as the effective one for the oil extraction from wet-form Chlorella minutissima.

• Archives of Pharmacal Research
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• 제23권4호
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• pp.267-282
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• 2000

Cytochrome P45O (CYP) 2E1 catalyzes the metabolism of a wide variety of therapeutic agents, procarcinogens, and low molecular weight solvents. CYP2E1-catalyzed metabolism may cause toxicity or DNA damage through the production of toxic metabolites, oxygen radicals, and lipid peroxidation. CYP2E1 also plays a role in the metabolism of endogenous compounds including fatty acids and ketone bodies. The regulation of CYP2E1 expression is complex, and involves transcriptional, post-transcriptional, translational, and post-translational mechanisms. CYP2E1 is transcriptionally activated in the first few hours after birth. Xenobiotic inducers elevate CYP2E1 protein levels through both increased translational efficiency and stabilization of the protein from degradation, which appears to occur primarily through ubiquitination and proteasomal degradation. CYP2E1 mRNA and protein levels are altered in response to pathophysiologic conditions by hormones including insulin, glucagon, growth hormone, and leptin, and growth factors including epidermal growth factor and hepatocyte growth factor, providing evidence that CYP2E1 expression is under tight homeostatic control.

• 한국균학회지
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• 제34권1호
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• pp.7-14
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• 2006

수집, 동정된 새로운 동충하초의 간에 관한 기전연구 및 기능향상을 확인하고자 본 연구를 수행하였다. 번데기 동충하초를 버섯채집회 등을 통해서 수집하고, 염기서열 분석을 실시하였다. 분석된 염기서열을 유전자은행에 등록된 번데기 동충하초와 계통발생학적인 비교를 통해 동일종으로 확인하였다. 추출조건 및 방법을 다양화시켜 열수 및 유기용매 추출법으로부터 얻어진 분획중에서 간관련 효소활성 시험을 통해 효능이 있는 추출물 분획을 찾아내고, 이 추출물을 이용하여 간의 대사효소인 ADH, ALDH의 활성증가가 시판되고 있는 의약품, 천연차, 혼합음료, 드링크 등의 6종류의 제품과 비교 실험하여 $500\;{\mu}g/m{\ell}$의 동충하초 추출물이 월등한 활성증가를 확인하였다. 또한 생체에 투여하여 동충하초 추출물에 의해 혈중 알코올과 아세트알데히드의 분해 및 대사가 촉진되고 정상상태로 빠르게 회복됨을 관찰하였다. 그리고 설치류 단회독성시험 및 유전독성시험을 통하여 시험물질의 무독성을 확인하였고, 간을 손상물질인 사염화탄소를 투여하여 급성손상에 대한 혈액생화학변화(GOT, GPT) 및 조직에서 동충하초 추출물에 의한 보호 및 회복작용을 확인하였다. 본 연구에서는 번데기 동충하초의 추출물이 독성물질에 대한 급성적인 반응을 보였지만, 저독성의 오랜기간 노출로 인한 만성간장해와 이로 인해 발생하는 지방간 등에 대한 효과에 대해서는 앞으로 추가적인 연구가 필요할 것으로 사료된다.

• 한국토양비료학회지
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• 제40권4호
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• pp.274-279
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• 2007

4 종류의 폐기물(생활하수오니, 공단하수오니, 피혁오니, 주정오니)과 대조구로서 돈분퇴비가 지렁이에게 미치는 독성을 평가하기 위하여 대표적인 유해성 평가 biomarker 3종류 (acetylcholinesterase, cytochrome $P_{450}$, heat shock protein 70)를 사용하였다. 유기성 폐기물에 대한 acetylcholinesterase의 활성은 돈분퇴비의 경우 활성이 약간 촉진된 반면 생활하수오니, 공단하수오니, 피혁오니, 주정오니는 영향을 미치지 않았다. Cytochrome $P_{450}$의 활성은 공단하수오니와 피혁오니는 활성을 억제하였고 생활하수오니, 주정오니, 돈분퇴비는 영향을 미치지 않았다. 또한 Hsp70의 발현량은 증류수보다 돈분퇴비는 1.9배, 주정오니는 3.0배, 생활하수오니는 3.3배, 공단오니는 4.4배, 피혁오니는 4.7배 순으로 지렁이 (Eisenia fetida)에게 스트레스를 많이 주었다. 이상의 결과로부터, 4 종류의 폐기물(생활하수오니, 공단하수오니, 피혁오니, 주정오니)은 돈분퇴비보다 독성이 강한 것으로 판단하였다. 또한 AChE, Cytochrome $P_{450}$과 Hsp70은 추후 유기성 폐기물의 유해성을 모니터링하기에 적합한 biomarker로서 가치가 있다고 생각한다.

• 한국응용곤충학회지
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• 제4권
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• pp.47-50
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• 1965

Chlorophenol 유도체들이 농약으로 많이 사용되고 있으므로 저자들은 Trichlorophenol과 Dibromoethane으로 Bis(2,4,5-trichlorophenoxy) ethane 과 Bis(2,4,6-trichlorophenoxy) ethane을 합성하고 mice에 대한 독성 및 Bis(2,4,5-trichlorophenoxy) ethane의 귤응애, 누에 및 무우잎별레에 대한 살충작용을 Phenkapton, Tedion V-18. BHC 및 DBT 등과 비교관찰하여 다음과 같은 결과를 얻었다. (1) Bis(2,4,5-trichlorophenory) ethane의 yield 는 8.0g $(50.06\%)\;(m.p. 157-159^{\circ}C)$이며 Bis(2,4,6-trichlorophenoxy) ethane 의 yield는 5.2g $(32.60\%)\;(m.p. 162-163^{\circ}C}$였다. (2) Bis(2,4,6-trichlophenoxy) ethane의 귤응애(Citrusred mite)에 대한 살충작용은 Tedion V-18 보다 강하고 Phenkapton에 비해서는 약하다. (3) 누에 (Bombix mori)에 대한 살충작용은 BHC 및 DDT보다 약하다. (4) 무잎별레(Daikon leaf beetle)에 대해서는 살충력이 없였다. (5) 2,4,5-BTPE 및 2,4,6-BTPE는 체중 k9당 5g씩 mice에 경구투여한 바 72시간동안 한 마리도 죽지 않아 독성은 적은 것으로 본다.

• Journal of Applied Biological Chemistry
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• 제59권3호
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• pp.265-271
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• 2016

해마는 아시아 등지에서 이미 약재로 사용이 되어지고 있지만 그와 관련된 연구는 부족한 실정이다. 이에 본 연구는 해양생물인 해마의 간 보호 효능을 확인하고자 하였다. 해마를 단백질 가수분해효소인 alcalase를 이용하여 가수분해 후 얻은 가수분해물(ALC)을 얻은 후 실험을 수행하였다. Chang 세포에 ALC를 1시간 전처리 후 에탄올 800 mM을 가하여 24시간 후 세포생존율을 확인했을 때, 세포가 알코올 독성으로부터 보호되는 것을 확인할 수 있었다. 그리고 Chang 세포에 ALC를 2시간 전처리 후 TGF-${\beta}$ 10 ng/mL을 처리하였을 때도, TGF-${\beta}$에 의해 증가된 vimentin, ${\alpha}$-SMA, slug의 발현이 억제되는 것을 확인하였다. 또한 에탄올을 이용한 급성과 만성 In vivo 조건에서도 ALC에 의한 간 보호 효과를 확인할 수 있었다. 알코올 투여에 의한 간 무게 감소와 혈청 GOT 및 GPT 활성 증가가 해마 가수분해물 처리에 의해 억제되었으며, 만성 알코올 독성 실험의 경우에는 실험동물의 무게와 식이섭취량도 해마 가수분해물 처리에 의해 정상군과 유사한 수준으로 회복되는 것을 확인할 수 있었다. 따라서 추가적인 연구를 통해 해마가 간 보호 효능의 기능성 식품소재로 활용 가능할 수 있을 것이라 사료된다.