• The Journal of Advanced Prosthodontics
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• 제12권4호
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• pp.189-196
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• 2020

PURPOSE. The aim of the present study was to investigate the effects of surface treatments on the bond strengths between polymer-containing restorative materials and two dual-cure resin cements. MATERIALS AND METHODS. In the present study, rectangular samples prepared from Lava Ultimate (LU) and Vita Enamic (VE) blocks were used. The specimen surfaces were treated using CoJet sandblasting, 50 ㎛ Al₂O₃ sandblasting, % 9 HF (hydrofluoric) acid, ER,Cr:YSGG laser treatment, and Z-Prime. Dual-cure resin cements (TheraCem and 3M RelyX U 200) were applied on each specimen's treated surface. A micro-tensile device was used to evaluate shear bond strength. Statistical analysis was performed using the SAS 9.4v3. RESULTS. While the bond strength using TheraCem with LU or VE was not statistically significant (P=.164), the bond strength using U200 with VE was statistically significant (P=.006). In the TheraCem applied VE groups, Z-Prime and HF acid were statistically different from CoJet, Laser, and Sandblast groups. In comparison of TheraCem used LU group, there was a statistically significant difference between HF acid and other surface treatments. CONCLUSION. The bonding performance between the restorative materials and cements were material type-dependent and surface treatment had a large effect on the bond strength. Within the limitations of the study, the use of both U200 and TheraCem may be suggested if Z-prime was applied to intaglio surfaces of VE. The cementation of LU using TheraCem is suitable after HF acid conditioning of the restoration surfaces.

• Journal of Life Science
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• 제11권1호
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• pp.42-46
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• 2001

Subtilisin YaB, produced by alkalophilic Bacillus strain YaB, is an extracellular alkaline serine protease having 55% homology to subtilisin BPN'. It is synthesized as a 378-amino acid preproenzyme and secreted into the culture medium as a 265-amino acid mature protease. To examine the role of pro-sequence for the secretion of subtilisin YaB, we have studied the expression, in Bacillus subtilis, of a mutant preprosubtilisin YaB in which active site Ser214 is substituted with Cys. The use of a six protease-deficient strain, WB600, was required for its efficient production. The prosubtilisin YaB, thus produced, was indeed secreted into the culture medium and was processed to its mature form upon treatment with exogenously added active subtilisin YaB. From these results, we have concluded that the processing of pro-sequence is not essential for the secretion of the enzyme.

• Asian-Australasian Journal of Animal Sciences
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• 제29권3호
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• pp.378-383
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• 2016

The objective of this study was to determine the effects of chromium methionine (Cr-Met) chelate supplementation on blood metabolites and fatty acid profile of beef from Holstein steers during late fattening period. Fifteen Holstein steers were allotted randomly into two groups including the control (non Cr-Met feeding, NCM, ave. body weight [BW] = $483{\pm}25.7kg$) and the treatment (Cr-Met feeding for 4 months, 4CM, ave. $BW=486{\pm}27.5kg$) group. The feeding amount of Cr-Met to animals was limited to 400 ppb/cow/d and was supplemented to total mixed ration. No difference in blood albumin, alkaline phosphatase, urea-nitrogen, calcium, creatine, glucose, total protein, triglyceride, and cholesterol were observed between the treatment groups (p>0.05). The level of high density lipoprotein was higher in the 4CM group than the NCM group, whereas low density lipoprotein was lower in the 4CM group (p<0.05). The fatty acid composition (caprate, laurate, myristate, pentadecanoate, palmitate, palmitoleate, margarate, cis-11 heptadodecanoate, stearate, oleate, trans-vaccenate, linoleate, cis-11 eicosenoate, docosa hexaenoic acid, and docosa pentaenoic acid) of the beef showed no difference between the two groups (p>0.05). The arachidonic acid level tended to be higher in the 4CM than the NCM group (p = 0.07). Cr-Met had no influence (p>0.05) on the ratio of saturated, unsaturated, unsaturated/saturated, monounsaturated/saturated and polyunsaturated/saturated fatty acids whereas the ratio of polyunsaturated fatty acids (PUFA) in the 4CM group was comparatively higher than the NCM group (p<0.05). This study concluded that feeding Cr-Met supplementation in 400 ppb/d to Holstein steers for 4 months during late fattening period can improve some blood metabolites and beef quality by increasing PUFA and gamma-linoleate compositions of beef.

• 생명과학회지
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• 제25권8호
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• pp.917-924
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• 2015

와송과 유산균 발효 와송을 식이 중에 2.5% 및 5.0% 수준으로 첨가하여 10일간 흰쥐에 급여하고, orotic acid 유발 비알코올성 지방간을 일으켜 임상생화학적 특성 및 조직 내 항산화 활성 및 간 조직에 미치는 영향을 검토하였다. OA군은 간 기능 지표 효소인 혈중 AST, ALT, ALP, cholinesterase, LDH 활성에서 모두 높은 활성을 나타내었지만, OM군과 FOM군은 활성이 감소하여 N군과 유사한 수치를 나타내었다. 또한 유의적으로 큰 차이는 보이지 않았지만 OM군보다 FOM군이 더 낮은 수치를 보였으며, 농도의존적으로 감소하는 경향을 보였다. 특히 LDH에서 5FOM군은 N군보다 더 낮은 활성을 나타내었다. OA군은 간 조직의 분획물, 고환, 신장, 비장의 TBARS의 함량이 증가하였지만, OM군과 FOM군에서 감소하는 경향을 보였으며 특히 5FOM군에서 유의적으로 낮은 결과를 나타내었다. 장기 내 존재하는 glutathione의 함량 또한 OA군이 N에 비해 낮은 수치를 보였으나, OM군과 FOM군에서 농도의존적으로 증가하는 경향을 나타내었다. 특히, 5FOM군에서 N군에 상응하는 높은 수치를 보였으며, 비장과 심장에서는 N군보다 높은 수치를 나타내었다. 이상의 실험결과로 유산균 발효 와송은 orotic acid 유발 비알코올성 흰쥐 지방간에 대한 개선 효과를 보여 간 기능 개선에 효과적인 건강식품 소재로서 가능성을 보였다.

• 대한의생명과학회지
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• 제7권3호
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• pp.99-102
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• 2001

Toluene is mainly metabolized in liver by oxidative pathway. Oxigen free radicals occur through the process of toluene metabolism Therefore it causes tissue and cell min by the oxygen free radicals from the metabolism of toluene. Melatonin acts as a highly efficient free radical scavenger that protects cells from damage by oxygen free radicals. To test this hypothesis, toluene hepatotoxicity was induced by an abdominal injection of toluene. To see if the melatonin protects the rat's liver, melatonin was administrated orally, at the time of each toluene injection. Aspartate aminotransferase(AST), alanin aminotransferase(ALT), latic dehydrogenase(LDH) and alkaline phosphatase(ALP) levels in serum were measured to estimate hepatic function. Malondialdehyde(MDA), which gives an indirect index of oxidative injury was also measured. Hippuric acid is the last metabolic Production of toluene was measured by HPLC. There were significantly higher in AST, ALT, LDH, MDA and hippuric acid in toluene group, but there were no significant difference in melatonin group except ALT and hippuric acid. There was significantly lower in ALP level in toluene group, but there was no significant difference melatonin group, suggesting a significant hepatotoxicity due to oxygen free radicals through the process of toluene metabolism Melatonin treatment significantly protected hepatic function and free radical-mediated injury in the liver against toluene-induced changes. Accordingly, this study shows that melatonin is helpful in protecting liver injury by acute toluene intoxication.

• 상하수도학회지
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• 제7권1호
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• pp.20-28
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• 1993

The Wastewater from the weight reduction process of polyester is more difficult to be treated biologically than the general wastewater from dyeing and finishing processes in textile industries. Above wastewater shows high pH, high organic strength and wide variation of organic loading. These characteristics are due to TPA and EG resulting from alkaline weight-reduction process and make trouble in the operation of activated sludge process. Therefore, the objective of this study is to develop the pretreatment method for the successful operation of treatment process. For the successful pretreatment process, the wastewater from weight-reduction process should be segregated from other wastewater stream and then acidified with concentrated sulfuric acid to precipitate out TPA from DST solution. At the optimum pH of 2. 2, the initial $COD_{cr}$ 60,000mg/l is reduced to 11,500mg/l and the removal efficiency of $COD_{cr}$ is 81.1%. The required amount of sulfuric acid for pretreatment is not greater than the amount for the the existing neutralization process. Moreover, the supernatant of pretreatment process can be reused in acidification of wastewater.

• 한국의류학회지
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• 제20권5호
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• pp.728-737
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• 1996

The purpose of this study is to investigate the change of the chemical properties of wool treated with six kinds of alkali (NaOH, Naac03, NH40H, NH2CH3CH30H, TMAH and BTMAH) with or without CTAB. Content of bound fatty acid liberated from wool surface, elemental composition and allw6rden time were measured to compare the surface modification of untreated and alkali treated wool. Also, the chemical degradation of the fiber was investigated by measuring cystine contents and urea-hydrogensulfite solubility. The result were as follows: 1. By the alkali treatment of wool, the covalently bound fatty acid of the epicuticle was removed and the allworden time was shortened, and in the case of wool treated with TMAH, BTMAH, the allw6rden sacs were formed unevenly and rarely. Also, cystine contents and urea-hydrogensulfite solubility were decreased by alkali treatment on wool. 2. The modification of epicuticle and the chemical degradation of wool were occurred due to alkaline hydrolysis in the order of TMAH, BTMAH > NaOH, Na3c03> NH2CH3CHaOH, NH40H. 3. As a treating time increased, the modification of epicuticle and chemical degradation of wool were accelerated. By the addition of CTAB to the alkali solution, the modification of epicuticle was increase, and the cystine contents and urea-hydrogensulfite solubility were reduced than that of wool teated with alkli without CTAB due to reduction of negative charge on the wool surface by the adhesion of CTAB.

• 대한수의학회지
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• 제47권3호
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• pp.265-271
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• 2007

This study investigated the protective effects of ethylene glycol-bis(${\beta}$-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA), an extracellular calcium chelator, and ethylenediaminetetraacetic acid (EDTA), which chelates calcium and most metal ions, against carbon tetrachloride ($CCl_4$)-induced acute hepatotoxicity in mice. Mice were treated with EGTA or EDTA at a dose of 20 (low) or 100 mg/kg (high) subcutaneously 1h before $CCl_4$ administration. The mice were fasted and sacrificed 18h after $CCl_4$ treatment. Blood samples were collected from the carotid artery by decapitation under light ether anesthesia. Serum alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglyceride (TG), and cholesterol levels were measured. Malondialdehyde (MDA) production was determined as an index of lipid peroxidation in the liver. The liver, kidneys, and spleen were weighed. We also evaluated the histopathological changes in the liver in each group. The relative weights of the liver were significantly higher in the $CCl_4$-treatment group than in the normal group, except in the high-EDTA treatment group. EGTA and EDTA treatment caused a significant decrease in serum ALP, ALT, and AST levels. Of all of the doses of EGTA and EDTA tested, the high-EDTA dose resulted in the most remarkable inhibitory action. The protective effect in the high-EDTA-treatment group was confirmed histopathologically. The low-EGTA-treatment group showed a significant decrease in serum TG and cholesterol levels. Liver MDA levels were significantly decreased in the EGTA (20 mg/kg) and EDTA (20, 100 mg/kg) groups. These results suggest that EDTA, which chelates both calcium and metal ions, confers better protection in $CCl_4$-induced acute liver damage than does EGTA, a calcium chelator.

• 한국축산시설환경학회지
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• 제18권3호
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• pp.229-234
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• 2012

본 연구는 구제역 긴급행동 지침 (SOP)에서 제시한 화학적 처리가 양돈분뇨의 이화학적 성상에 미치는 영향을 알아보고 이에 따른 적절한 후처리 방법을 모색하기 위하여 수행한 것이다. 가축분뇨의 알칼리처리-산중화 및 산처리-알칼리 중화처리는 처리조건에 따라 다양한 이화학적 변화가 있었으며, 이에 대한 결과요약은 다음과 같다. 1. B4 처리구 (Citric Acid-Calcium Oxide)의 경우는 산처리 후 알칼리 중화처리 시에 응고현상이 발생하였다. 이는 구연산과 생석회의 투입으로 인한 물질 간 화학적 결합에 기인하는 것으로 사료된다. 2. 산처리-알칼리 중화 (B처리구)의 모든 처리구에서 EC가 약 50 mS/cm 전후까지 증가 하였으며, A4 처리구를 제외한 알칼리처리-산 중화 (A처리구)에서는 처리 후 원수의 EC 보다도 낮은 경향을 나타냈다. 3. $NH_4{^+}$-N의 농도는 산처리-알칼리 중화 (B처리구)에서 처리 후 거의 변화가 없는 반면, 알칼리처리-산 중화 (A처리구)에서는 급격히 감소하였다. 이는 암모니아의 탈기로 인한 기작으로 사료되며, 특히 CaO를 이용한 A1, A2 처리구에서 두드러지게 나타났다. 4. 알칼리처리-산 중화 및 산처리-알칼리 중화는 처리조건에 따라서 이화학적 변화의 양상이 다양하다. 적정 pH 수준을 위한 시약의 소요량 및 운영관리 면에서 볼 때, 병원성미생물 등으로 오염된 가축분뇨 화학적 전처리시에는 산처리-알칼리중화 (B처리구) 보다는 알칼리처리-산 중화 처리구 (A처리구) 적합 할 것으로 사료된다. 그러나 자원화, 정화처리 등 후처리방법의 선정은 각 농가 및 지역적 환경요소에 따라 다르므로 산 알칼리제제의 소요량에 따른 경제성 평가 및 처리목적 등에 대한 충분한 검토가 필요하다.

• 한국수산과학회지
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• 제37권1호
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• pp.1-6
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• 2004

In preparing sodium alginates from sea tangle (Laminaria japonica) powder using the Mexican process, alkaline extraction, conversion to alginic acid and reversion to sodium alginates were used to increase purity. The effect of hot water treatment and dialysis on measuring the average molecular weight of sodium alginates were investigated. Intrinsic viscosity and average molecular weight of sodium alginates after dialysis were higher than those before dialysis. Average molecular weight of sodium alginates treated with hot water was higher than that without. Hot treatment has little effect on the ash content of sodium alginates. Ash content of sodium alginates before dialysis were $27-30\%$ those after dialysis were $10\%.$ After dialysis, Na content was highest $(89-91\%),$ K was $11-12\%,$ Ca was $1.9\%,$ and Mg was $0.05\%.$ Ash content of alginates had little effect on average molecular weight. SAV (slope of apparent viscosity) of alginates solution after dialysis showed higher values than before. SAV of the alginates with hot water treatment were higher than without treatment.