• 대한화학회지
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• 제43권6호
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• pp.670-675
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• 1999

Methanopterin의 pteridine부분과 관련있는 구조를 가지는 6-[1-(4-ribityl-anilino)ethyl]-1,3,7-trimethyllumazine (2)를 합성하였다. 4-Ribitylaniline 유도체는 D-ribose와 N-benzoyl-4-bromoaniIine (7)을출발 물질로 하여 여러 단계를 거쳐 합성되었다. 6-Acetyl-1,3,7-trimethyllumazine (4)는 Timmis 반응을 이용하여 4-amino-1,3-dimethyl-5-nitrosouracil (3)과 2,4-pentanedione을 반응시켜 얻을 수 있었다. 화합물 4는 $NaBH_4$에 의한 환원반응과 뒤이은 $SOCl_2$에 의한 염소화반응으로 6-(1-chloroethyl)-1,3,7-trimethyllumazine (6)으로 변환되었다. 화합물 6과 4-(2,3:4,5-di-O-isopropylidene-D-ribityl)aniline (13)의 친핵성 치환반응으로 6-[1-{4-(2,3:4,5-di-O-isopropylidene-D-ribityl)anilino}ethyl]-1,3,7-trimethyllumazine (14)가 합성되었다 목표 화합물 2는 산 촉매하에서 화합물 14를 가수분해하여 얻어졌다.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2002년도 춘계 국제 학술대회
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• pp.40.1-43
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• 2002

The purpose of this study was to evaluate a new sampling and analytical method for the determination of hexavalent chromium, Cr(VI) in mist from field plating operation. The Procedures of this new method (Shin & Paik's Method) are as the following: Airborne hexavalent chromium is collected on polyvinyl chloride (PVC) filter according to the National Institute for Occupational Safety and Health (NIOSH) Method 7600, and the filter sample is placed in a screw-capped vial and soaked with 2％ NaOH/3％ Na₂CO₃ solution immediately after sampling. The Cr(VI) sample is analyzed by ion chromatography/visible spectrophotometry (IC/VS) according to the U.S. Environmental Protection Agency (EPA) Method 218.6. The airborne Cr(VI) concentrations measured by this method were compared with those determined by three reference methods: One (NIOSH/EPA Method) consisted of sampling airborne Cr(VI) on PVC filters and storing the sample filters in screw-capped vials according to the NIOSH method, and analyzing Cr(VI) in samples using IC/VS according to the EPA method. The second method (Impinger Method/NaHCO₃) consisted of absorbing airborne Cr(VI) into 0.02 MN/sub a/Hco₃ solution in midget impinger, and analyzing the Cr(VI) in samples using IC/VS. The third method was the OSHA Method Id-215. Using these four different methods, four replicates of air samples were collected at an electroplating process and analyzed simultaneously. Two-way ANOVA and Paired t-test were used to test difference among values determined by the methods. There was no significant difference and a strong correlation (r/sup 2/=0.99) between Cr(VI) concentrations measured by the shin & Paik's Method and an impinger method (p＞0.05). However, Cr(VI) concentrations determined by Shin & Paik's Method were Significantly different form those by the NIOSH/EPA Method (p＜0.05) or the OSHA method (p＜0.05). The Cr(VI) concentrations of Shin & Paik's Method were Significantly higher than those of the NIOSH/EPA Method or the OSHA method. We concluded that the Shin & Paik's Method could prevent Cr(VI) losses caused by reduction and give more reliable results of airborne Cr(VI) concentrations in work environments.

• Advances in concrete construction
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• 제9권2호
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• pp.217-225
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• 2020

The recovery of waste proves a solution with two impacts: the environmental impact by the reduction of pollution and the gain of the occupied space by this waste, and the economic impact by the use of these lasts in the building and in the area of public works. The present research consists in recovering a waste marble (thrown powder exposed to the different meteorological phenomena) generated by the quarry marble of Fil-fila, located at the east side of Skikda in the north-east of Algeria, and add it, as sand in the composition of sand concrete. To carry out this research, we analyzed the evolution brought by the substitution of ordinary sand by marble waste sand, with 25%, 50%, 75% and 100% on the properties in the fresh state (density, workability and air content) and in the cured state (compressive strength, tensile strength, surface hardness and sound velocity). For durability we tested water absorption by immersion and chloride penetration. The results obtained are compared with control samples of 0% of substitution rate. In order to have a good filling of the voids in the granular skeleton; we added a quantity of limestone recycled fines from the quarries and for a good workability a super-plasticizing additive. The results showed that the partial substitution modified both the fresh and the hardened characteristics of the tested concretes, the durability parameters also improved.

• 환경생물
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• 제22권1호
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• pp.133-140
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• 2004

유기주석화합물이 넙치의 기관계 구조에 미치는 독성을 알아보기 위하여 넙치를 대조구와 TBTO를 첨가한 6개 농도구(0.17, 0.36, 0.60, 3.20, 6.30, 12.50 ${\mu}g \;L^{-1}$)에서 42일 동안 노출 실험을 하였다. 조직상의 변화 정도는 노출 시간과 TBTO농도의 증가에 따라 심하게 나타났다. 저농도의 TBTO 노출구에서 관찰된 초기 조직학적 변화로는 아가미에서는 점액세포와 염세포의 활성, 새판 모세혈관의 충혈, 상피층의 비후, 간췌장에서는 간세포의 활성화와 췌장 효소원과립의 감소, 담관의 변성이 확인되었으며, 신장에서는 모세혈관의 충혈, 호산성세포와 혹색 대식세포군의 출현이 관찰되었다. 고농도의 TBTO 노출구에서 관찰된 조직학적 변화로는 아가미에서는 새판 상피층의 박리와 새판의 붕괴, 간췌장에서는 간세포의 핵응축, 세포질의 혼탁 및 과립변성, 신장에서는 조혈세포의 핵응축, 사구체와 세뇨관의 붕괴 등 정상적인 기능 수행이 어려울 것으로 판단되는 조직상들이 관찰되었다. 이와 같은 결과는 TBTO는 다른 수중오염원과 마찬가지로 어류 기관계의 조직병리학적 변화를 유도한다는 것을 나타낸다.

• 한국축산식품학회지
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• 제40권2호
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• pp.231-241
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• 2020

The current study investigated the effects of timing of NaCl (2%) and sodium tripolyphosphate (STPP, 0.5%) addition and cooking rates on color and pigment properties of ground chicken breasts. Four treatments were tested as follows: treatment 1, no NaCl and STPP added and stored for 7 d; treatment 2, NaCl+STPP added on 0 d and stored for 7 d; treatment 3, NaCl added on 0 d and STPP added on 7 d; and treatment 4, stored for 7 d and NaCl+STPP added. All samples were cooked at a fast (5.67℃/min) or slow cooking rate (2.16℃/min). Regardless of the timing of NaCl and STPP addition, reflectance ratios of nitrosyl hemochrome, cooking yield, pH values, oxidation-reduction potential, and percent myoglobin denaturation were similar (p>0.05) across treatments 2, 3, and 4. The highest CIE a^⁎ values were observed in treatment 4 (p<0.05), while treatment 2 was effective in reducing the redness in cooked chicken products. The fast cooking rate resulted in lower CIE a^⁎ values and higher CIE L^⁎ values and cooking yield in cooked chicken breasts compared to the slow cooking rate. Our results indicate that adding NaCl and STPP to meat, followed by storing and cooking at a fast rate, may result in inhibiting the pink color defect sporadically occurred in cooked ground chicken breasts.

• 콘크리트학회논문집
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• 제20권6호
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• pp.741-746
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• 2008

RC 구조물에서 매립된 철근의 부식을 억제하기 위하여 많은 방법들이 소개되어 왔다. 철근의 부식을 억제하는 방법 중 하나가 부식억제제이다. 최근 탄닌산을 이용하여 활성태의 녹을 부동태의 녹으로 전환시킴으로써 부식의 진행을 지연시키는 기술이 개발되었다. 그러나 이 부식억제제가 일반적인 금속 제품에 대한 방식을 위하여 개발되었기 때문에 콘크리트구조물에 대한 성능이 검토되지 않았다. 따라서 본 연구에서는 탄닌산을 이용한 부식억제제의 적용성을 콘크리트 시험체에 대하여 조사하였다. 연구 결과에 따르면, 탄닌산 부식억제제는 콘크리트에 있어 시공성 및 압축강도의 저하를 발생시키지 않았다. 부식억제제가 시멘트 중량당 4% 이상 첨가될 경우, 염화물 침투깊이가 10% 정도 감소하였다. 또한, 탄닌산 부식억제제는 녹을 안정한 상태로 변환시키는 효과를 가지고 있어, 부식 저항성이 향상된다. 특히, 6% 이상의 첨가가 부식 저항성에 효과적인 것으로 나타났다.

• Nutrition Research and Practice
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• 제8권4호
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• pp.391-397
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• 2014

BACKGROUND/OBJECTIVE: Myocardial cell death due to occlusion of the coronary arteries leads to myocardial infarction, a subset of coronary heart disease (CHD). Dietary fiber is known to be associated with a reduced risk of CHD, the underlying mechanisms of which were suggested to delay the onset of occlusion by ameliorating risk factors. In this study, we tested a hypothesis that a beneficial role of dietary fiber could arise from protection of myocardial cells against ischemic injury, manifested after occlusion of the arteries. MATERIALS/METHODS: Three days after rats were fed apple pectin (AP) (with 10, 40, 100, and 400 mg/kg/day), myocardial ischemic injury was induced by 30 min-ligation of the left anterior descending coronary artery, followed by 3 hr-reperfusion. The area at risk and infarct area were evaluated using Evans blue dye and 2,3,5-triphenyltetrazolium chloride (TTC) staining, respectively. DNA nicks reflecting the extent of myocardial apoptosis were assessed by TUNEL assay. Levels of cleaved caspase-3, Bcl-2, and Bax were assessed by immunohistochemistry. RESULTS: Supplementation of AP (with 100 and 400 mg/kg/day) resulted in significantly attenuated infarct size (IS) (ratio of infarct area to area at risk) by 21.9 and 22.4%, respectively, in the AP-treated group, compared with that in the control group. This attenuation in IS showed correlation with improvement in biomarkers involved in the apoptotic cascades: reduction of apoptotic cells, inhibition of conversion of procaspase-3 to caspase-3, and increase of Bcl-2/Bax ratio, a determinant of cell fate. CONCLUSIONS: The findings indicate that supplementation of AP results in amelioration of myocardial infarction by inhibition of apoptosis. Thus, the current study suggests that intake of dietary fiber reduces the risk of CHD, not only by blocking steps leading to occlusion, but also by protecting against ischemic injury caused by occlusion of the arteries.

• 한국축산식품학회지
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• 제26권1호
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• pp.15-19
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• 2006

The aim of this study was to determine the best processing conditions for producing of dried lean pork as a ready-to-serve product without using large-scale machines. Lean pork sausage was produced using 1.27% sodium chloride, 0.075% sodium polyphosphate, 0.06% sodium ascorbate, 0.075% sodium pyrophosphate, 0.009% sodium nitrite, 0.009% dextrin, 0.11% sodium glutamate and 1.4% spice mixture. The most appropriate slice thickness for drying was examined by slicing the sausage at a 0.5, 1 and 2 cm thickness. The drying temperatures were determined by drying the sausage slices at 35, 48 and $68^{\circ}$. The total drying period was for 12 hr, In order to examine the ability of this process to sterilize the pork, the raw meat materials were inoculated with Escherichia coli (E. coli). The optimal conditions for producing lean pork sausages were a 2 cm slice thickness and drying temperature of $68^{\circ}C$ for 12 hr, The moisture content water activity, color, hardness and pH were measured in the dried product. The product had a moisture content of 47.5% and a water activity of 0.93. There was a 47.7% percentage reduction in moisture. The dried product tested negative for E. coli even though the raw meat materials been inoculated with E. coli.

• 한국작물학회지
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• 제42권3호
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• pp.275-280
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• 1997

본 실험은 벼 종자에 Al을 0, 300, 600 및 900ppm으로 처리하여 발아중 Al에 대한 벼의 초장, 근장, 발아율 등의 생육특성, 엽록소 함량, 전분, 당 및 유리 proline함량 등의 변화를 일품벼와 향미벼 001를 공시하여 검시한 결과를 요약하면 다음과 같다. 1. 초장과 근장은 Al의 농도가 증가할수록 신장이 감소하였는데 뿌리의 신장억제가 보다 현저하였다. 발아율은 일품벼와 향미벼 001 모두 Al의 농도가 증가함에 따라 발아율의 급격한 감소를 보였다. 2. 엽록소 함량은 품종간 뚜렷한 차이를 보였고 두 품종 모두 Al의 농도가 증가할수록 함량이 감소하는 경향을 보였다. 3. 식물체의 전분과 당함량은 Al 처리시 대조구에 비해 함량이 감소하였다. 4. 식물체의 중금속과 무기성분의 함량은 일품벼에 있어 무처리보다 Al의 농도가 증가함에 따라 Al 600ppm까지는 식물체내의 중금속 축적이 증가하다가 Al 900ppm에서는 오히려 감소하는 경향을 보였고, Ca, Mg, Fe 및 Mn의 식물체내의 함량은 두 품종 모두 Al 처리시 무처리에 비해 Al 처리시 급격한 증가를 보였다. 5. 무처리에 있어서는 발아일수별로 proline함량이 차이가 없었으나 Al 처리의 경우 발아후 1일째는 Al의 농도가 증가함에 따라 유리 proline의 함량도 증가하였고 특히 처리 후 3일째에는 급격한 함량의 증가를 보였다.

• 상하수도학회지
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• 제25권4호
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• pp.479-488
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• 2011

Nanofiltration was performed with polyaluminium chloride solutions at different pH conditions to understand effects of inorganic compounds on aluminum hydrolysis products, i.e., three distinctive groups of aluminum species: polymeric Al at low pH; $Al(OH)_3$ at neutral pH; and ${Al(OH)_4}^-$ at high pH. The PACl solution was prepared to be approximately 4.0mM and adjusted to the designated pH. The influence of inorganic compounds on Al species fouling was investigated with 4.9mM $CaCl_2$ and 3.5mM $MgSO_4$ because $Ca^{2+}$, $Mg^{2+}$, $Cl^-$, ${SO_4}^{2-}$ are the most common inorganics in the drinking water. NF membrane fouling was measured by flux decline rate. The impact of $CaCl_2$ was not significant on the individual Al hydrolysis products fouling. However, the flux decline rate was drastically changed in the presence of $MgSO_4$. The concentration of particulate matters was considerably increased possibly due to interaction between Al species and ${SO_4}^{2-}$ where $MgSO_4$ was introduced. The particulates were accumulated on the membrane and enhanced the hydraulic resistance of the cake layer. In addition, conductivity removal of the membrane was decreased when Al-hydroxide was dominant due to reduction of membrane surface charge. The rejection of $Ca^{2+}$and $Mg^{2+}$ were considerably different, which implys that composition of inorganics paly a role on conductivity removal.