• 접착 및 계면
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• 제6권3호
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• pp.10-18
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• 2005

자동차의 유리를 폴리카보네이트로 대체하기 위하여 폴리카보네이트 판 위에 하드 코팅을 시도하였다. 본 연구에서는 tetraethyl orthosilicate (TEOS), methyltriethoxysilane (MTES)으로부터 졸-겔 과정을 이용하여 코팅 막을 형성하였는데 이 때 가장 우수한 물성을 갖는 배합 조건을 찾아보았다. 폴리카보네이트 판의 전처리, TEOS와 MTES의 비율, 용매의 선택, aging 시간, 산 촉매의 양, 코팅의 횟수 등을 변화시켜가면서 형성된 코팅 막의 물성을 측정하였다. 측정 결과 폴리메칠메타크릴레이트를 이용한 전처리가 접착력 향상에 매우 효과적이었으며 이러한 졸-겔 과장으로부터 연필경도 2 H 정도의 아주 매끄러운 코팅 막이 형성되었다.

• 한국환경농학회지
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• 제16권4호
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• pp.311-319
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• 1997

광산폐수, 산업폐수등으로 부터 Cd, Pb, Zn 및 Cu등의 중금속에 강한 내성을 지니고 있을 뿐만 아니라 균체내 중금속 축적능력이 우수한 중금속 내성 미생물 균주 Pseudomonas putida(Cd), Pseudomonas aeruginosa(Pb), Pseudomonas chlororaphis(Zn) 및 Pseudomonas stutzeri(Cu)를 각각 분리하여, 여러가지 물리화학적인 방법으로 세포를 전처리하여 세포구성성분을 인위적으로 조절한 후 세포내 중금속이온의 흡수 거동 및 조단백질 함량과 중금속 축적관계를 조사한 결과는 다음과 같다. 세포를 알카리로 전처리하였을 경우 세포내 중금속 축적은 매우 감소되었으며, 메탄올과 클로포름으로 전처리하였을 경우에는 중금속 축적에 큰 영향을 미치지 않았으나, 메탄올과 클로로포름으로 전처리한 후 다시 알카리로 재차 처리하였을 경우에는 중금속 축적이 매우 감소되었다. 전처리된 세포내 중금속 축적은 용출되지 않고 남아있는 조단백질 함량이 감소됨에 따라 더 얼마나 크게 감소되었으므로 세포 구성물질중 단백질이 중금속 축적에 중요한 역할을 하는 물질인 것으로 판단되었다.

• 동의생리병리학회지
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• 제20권6호
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• pp.1612-1619
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• 2006

This Study was designed to investigate the mechanism of Mixture of Bambusae Caulis in Liquamen and Bamboo Extract on the change of regional cerebral blood flow (rCBF) and blood pressure (BP) in normal rats, and further to investigate cytokines production in serum of cerebral ischemic rats. Mixture were as follows ; Bamboo Extract extracted with distilled water at 98 $^{\circ}C$ for 3 hrs, Mixture of Bambusae Caulis in Liquamen and bamboo Extracts (MLE) mixed at the ratio 1 to 100 (MLE100), 1 to 50 (MLE50), 1 to 20 (MLE20), 1 to 10 (MLE10), 1 to 5 (MLE5). The results were as follows ; The MLE-induced increase in rCBF was significantly inhibited by pretreatment with indomethacin (1 mg/kg, I.p.), an inhibitor of cyclooxygenase as well as methylene blue (10 $^{\mu}g/kg$, I.p.), an inhibitor of guanylate cyclase. The MLE-induced increase in BP was significantly inhibited by pretreatment with methylene blue. In cytokines production in the serum drawn from femoral arterial 1 hr after middle cerebral artery occlusion, MLE5 significantly increased production of TGF-${\beta}$ and increased production of IL-10, but significantly decreased production of TGF-${\alpha}$ compared with control group. In cytokines production in the serum drawn from femoral arterial 1 hr after reperfusion, MLE5 significantly increased production of TGF-${\beta}$ and IL-10, but significantly decreased production of TGF-${\alpha}$ compared with control group. AS results above. And MLE5 had anti-ischemic effect by inhibiting TGF-${\alpha}$ production, and by accelerating IL-10 and TGF-${\beta}$ production.

• Journal of the Korean Wood Science and Technology
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• 제48권2호
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• pp.196-205
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• 2020

The purpose of this study was to investigate a method for improving the physical and mechanical properties of laminated board made from oil palm trunk (OPT). The effects of pretreating the lamina with heat-pressure and altering the lamina composition of the laminated board were investigated. The outer third of OPT in cross-section had high-density wood, while the underlying third had low to medium density. The hot press was applied to pretreat the lamina that had low to medium density. The lamina were 1.5 cm in thickness, 5 cm in width, and 65 cm in length. The hot press was applied at 2.94 MPa or 4.41 MPa at 150 ℃ for 60 minutes, and the target thickness of the lamina was 1 cm. The three layers of the laminated board samples were bonded with isocyanate adhesive at a glue spread of 300 g/㎡ and cold pressed at 0.98 MPa for 3 h. The laminated board samples were tested according to Japanese Agricultural Standard (JAS) 234-2003. The results showed that the densification of the inner lamina did not significantly affect the physical-mechanical properties of the laminated board produced. However, the laminated board made with high-density laminas for the outer layers fulfilled the JAS 234-2003 standard for the modulus of elasticity and the modulus of rupture.

• 한국수산과학회지
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• 제55권1호
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• pp.10-16
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• 2022

Interest in effluent treatment is currently increasing and the use of polymetric coagulants is considered as a pretreatment of physical filtration prior to effluent discharge to increase solids recovery. A jar test evaluated effluent treatment efficiency of polymeric coagulants for semi-recirculating aquaculture systems. The particle coagulation efficiency and distribution were evaluated at different polymer dosages in freshwater and seawater effluents. The polymer was added at 0.005-0.08 mL/g of total suspended solids (TSS) in the effluents. TSS in the supernatant after coagulation decreased with increasing polymer dose in the freshwater, while showing no corresponding changes with dose in the seawater. However, in all treatments for both effluents, the removal efficiency was above 90%, regardless of the dose in the tested range. Both the De Brouckere Mean Diameter (DBMD) and volumetric median diameter (VMD) were all above 100 ㎛ in the freshwater effluent. In the seawater effluent, the particle size appeared to be larger than that in freshwater, ranging from 400-1,000 ㎛ for both DBMD and VMD. Considering that the typical pore size of physical filtration in aquaculture is between 60 and 200 ㎛, the use of polymers is expected to improve the practicality of physical filtration for efficient treatment.

• 생명과학회지
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• 제26권8호
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• pp.976-982
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• 2016

해조류는 성장이 빠르고, 낮은 경작지 사용, 높은 이산화탄소 흡수 및 식량자원과 경쟁하지 않는 장점이 있다. 따라서 리그닌이 없는 해조류 사용은 바이오에탄올 생산을 위한 3세대 바이오매스로 주목받고 있다. 산 촉매 열가수분해 전처리법은 해조류로부터 높은 단당을 획득할 수 있는 경제적인 방법 중 하나이다. 고온 전처리 조건들에서 3,6-anhydrogalactoe는 저해물질인 HMF로 전환되는데, 이 저해물질은 세포 성장과 에탄올 생산을 저해한다. 따라서 바이오에탄올을 생산하기 위해 해조류의 탄수화물을 분해할 때는 높은 단당 수율과 낮은 저해물질 생성을 하는 효과적인 전처리 방법이 필요하다. 혼합 당을 이용한 에탄올 발효의 효율을 향상시키기 위해, 고농도 당에 순치한 효모는 혼합 당의 사용을 통해 해조류를 이용한 바이오 에탄올의 생산을 가능하게 한다.

• 한국융합학회논문지
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• 제13권1호
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• pp.149-160
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• 2022

본 연구에서는 스마트팜에서 생산된 새싹인삼의 저장성을 향상시키기 위해 전처리과정과 포장 용기에 따른 새싹인삼의 물리적 품질 및 미생물 변화를 10일 간 저장하면서 평가하였다. 전처리 방법(ascorbic acid, citric acid, peroxyacetic acid) 및 포장용기(expanded polystyrene (EP), polypropylene (PP), polyethylene (PE), polypropylene + polyethylene + cast polypropylene(PP+PE+CPP))에 따른 품질 변화를 물성(texture)검사, 일반세균수검사, 수분함량 및 색도 측정으로 평가하였다. 전처리 종류에 따라 비교한 결과, citric acid처리군에서 가장 낮은 텍스쳐 변화 및 세균 증식 억제에 효과를 확인하였다. 전처리 중 가장 효과가 높은 citric acid 처리군을 용기별로 저장 후 품질을 평가한 결과, PP용기에 10일 저장한 경우, 유의적인 텍스쳐 감소 및 색변화가 나타나지 않았고, 저장기간 증가에 따라 일반세균수가 가장 낮게 증가하였다. 따라서 본 연구는 citric acid 전처리군 및 PP용기에서 저장했을 때 새싹인삼의 품질 손상이 가장 적게 나타나 새싹인삼의 저장성 개선에 도움을 줄 수 있을 것으로 판단된다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권8호
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• pp.4025-4030
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• 2012

Background and Objective: Cardiotoxicity and oxidative stress is a life-threatening side effect of doxorubicin (DOX). We investigate the effects of short-term exercise as therapeutic tool for improvement of cardioprotection against DOX-induced cardiotoxicity in the rat. Methods: Wistar males (weighing $257{\pm}28g$) were divided into six groups: (1) control+placebo (2) control+DOX $10mg.kg^{-1}$ (3) control+DOX $20mg.kg^{-1}$ (4) training+placebo (5) training+ DOX$10mg.kg^{-1}$ (6) training+DOX $20mg.kg^{-1}$. Cardiotoxicity was induced by DOX (10 and $20mg.kg^{-1}$). The rats in groups 4, 5 and 6 experienced treadmill running of 25 to $39min.day^{-1}$ and 15 to $17m.min^{-1}$, 5 days/wk for 3 wk. At the end of the endurance training program, rats in the 1 and 4 groups, in the 2 and 5 groups and in the 3 and 6 groups received saline solution, DOX $10mg.kg^{-1}$ and DOX $20mg.kg^{-1}$, respectively. Result: DOX administration (10 and $20mg.kg^{-1}$) caused significant increase in MDA and Apelin, an insignificant increase in NO and a significant decrease in SOD, as compared to the C+P group. Three weeks of the pretreatment endurance exercise resulted in a significant increase of Apelin and SOD, an insignificant increase of NO and an insignificant decrease of MDA, as compared to the C+P group. Furthermore, after three weeks of endurance training and DOX treatment with $10mg.kg^{-1}$ and $20mg.kg^{-1}$, a significant increase in apelin and SOD, and a significant decrease in MDA were detected in comparison to C+DOX10 and/or C+DOX20 groups. There was a significant difference between DOX$10mg.kg^{-1}$ and DOX$20mg.kg^{-1}$ treatments in MDA levels only. Conclusion: Pretreatment exercise may improve myocardial tolerance to DOX-induced cardiotoxicity by inhibition of oxidative stress and up-regulation of antioxidants in heart tissue.

• 셀메드
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• 제6권2호
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• pp.13.1-13.7
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• 2016

Fatigue is a common complaint and affects the quality of life in modern people. Physical stress may induce activation of certain immune cells. Fermented porcine placenta (FPP) has been used to alleviate fatigue. Inflammatory cytokines are produced by physical stress and results in symptoms of fatigue. However, the role of FPP on fatigue-associated inflammatory cytokine production has not been elucidated yet. Thus, we estimated the anti-fatigue effect of FPP and its active components, leucine (Leu) and lysine (Lys) in activated RAW264.7 macrophages and forced swimming test (FST) fatigue animal model. Pretreatment with FPP, Leu, or Lys significantly inhibited the lipopolysaccharide (LPS)-induced tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 production without inducing cytotoxicity on LPS-stimulated RAW264.7 macrophages. FPP, Leu, or Lys inhibited the production of nitric oxide and downregulated the expression of inducible nitric oxide synthase on LPS-stimulated RAW264.7 macrophages. Furthermore, caspase-1 activities increased by LPS were significantly reduced by FPP, Leu, or Lys. In the FST, inflammatory cytokine levels of the mice administrated with FPP, Lys, and Leu were significantly reduced compared with the control group at 21 days. Collectively, these results show that anti-fatigue effect of FPP and its active components, Leu and Lys might be derived from the down-regulating of inflammatory mediators.

• Archives of Pharmacal Research
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• 제24권2호
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• pp.114-118
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• 2001

The present study was undertaken to investigate whether or not the hepatoprotective activity of acetylbergenin was superior to bergenin in carbon tetrachloride ($CCl_4$)-intoxicated rat. Acetylbergenin was synthesized by acetylating bergenin, which was isolated from Mallotus japonicus. The hepatoprotective effects of acetylbergenin were examined against $CCl_4$-induced liver damage in rats by means of serum and liver biochemical Indices. Acetylbergenin was administered orally once daily for 7 successive days, then a 0.5 ${m/kg}$ mixture of $CCl_4$in olive oil (1:1) was intraperitoneally injected at 12 h and 36 h after the final administration of acetylbergenin. Pretreatment with acetylbergenin reduced the elevated serum enzymatic activities of alanine/aspartate aminotransferase, sorbitol dehydrogenase and $\gamma$-glutamyltransferase in a dose dependent fashion. Acetylbergenin also prevented the elevation of hepatic malondialdehyde formation and depletion of glutathione content dose dependently in $CCl_4$-intoxicates rats. In addition, the decreased activities of glutathione S-transferase and glutathione reductase were restored to almost normal levels. The results of this study strongly suggest that acetylbergenin n has potent hepatoprotective activity against $CCl_4$-induced hepatic damage in rats by glutathione-mediated detoxification as well as having free radical scavenging activity. In addition, acetylbergenin doses of 50 ${mg/kg}$showed almost the same levels of hepatoprotection activity as 100 ${mg/kg}$ of bergenin, indicating that lipophilic acetylbergenin is more active against the antihepatotoxic effects of $CCl_4$ than those of the much less lipophilic bergenin.