• 공업화학
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• 제22권5호
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• pp.479-485
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• 2011

다양한 비율의 Pt와 Bi를 carbon black (Vulcan XC-72R)에 담지시킨 Pt-Bi/C 촉매를 환원법을 이용하여 합성하였다. Pt와 Bi의 전구체로는 염화백금산($H_2PtCl_6{\cdot}xH_2O$)과 비스무스트리질산($Bi(NO_3)_3{\cdot}5H_2O$) 수용액을 각각 사용하였으며, 금속을 carbon에 담지하기 전, 금속물질의 분산도를 높여주기 위해 열처리와 산처리를 수행한 carbon black을 사용하였다. XRD (X-ray Diffraction) 분석과 XPS (X-ray Photoelectron Spectroscopy) 분석을 통하여 Pt-Bi/C 촉매 내에 Pt와 Bi가 소성시키기 전에는 BiPt 혹은 $Bi_2Pt$로 존재하지만 $500^{\circ}C}$에서 소성을 한 후에는 Pt 격자구조 안으로 Bi가 침투하여 alloy을 형성하는 것을 확인하였다. 합성한 전극의 메탄올 산화반응은 전기화학분석장치(Potentiostat; Princeton applied research, VSP)를 사용하여 0.5 M $CH_3OH$와 0.5 M $H_2SO_4$의 혼합수용액에서 순환전압법(cyclic voltammetry, CV)을 이용해 측정하였다. 메탄올 산화에 대한 전기화학적 촉매 활성을 평가한 결과 적절한 양의 Bi를 첨가한 경우, 메탄올 산화반응에 대한 높은 촉매활성을 나타냄을 확인하였다. 메탄올 산화에 대한 활성은 전극과 전해질 사이의 안정성과 밀접한 관련이 있다. 정전압법(Chronoamperometry, CA)을 이용하여 전극의 안정성을 평가한 결과 메탄올 산화반응에 높은 활성을 나타내는 촉매일수록 전극의 안정성도 높은 것을 확인하였다.

• International Journal of Oral Biology
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• 제37권1호
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• pp.1-7
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• 2012

Opioid receptors have been pharmacologically classified as ${\mu}$, ${\delta}$, ${\kappa}$ and ${\varepsilon}$. We have recently reported that the antinociceptive effect of morphine (a ${\mu}$-opioid receptor agonist), but not that of ${\beta}$-endorphin (a novel ${\mu}/{\varepsilon}$-opioid receptor agonist), is attenuated by whole body irradiation (WBI). It is unclear at present whether WBI has differential effects on the antinociceptive effects of ${\mu}-$, ${\delta}-$, ${\kappa}-$ and ${\varepsilon}$-opioid receptor agonists. In our current experiments, male ICR mice were exposed to WBI (5Gy) from a $^{60}Co$ gamma-source and the antinociceptive effects of opioid receptor agonists were assessed two hours later using the hot water ($52^{\circ}C$) tail-immersion test. Morphine and $D-Ala^2$, $N-Me-Phe^4$, Gly-olenkephalin (DAMGO), [$D-Pen^2-D-Pen^5$] enkephalin (DPDPE), trans-3,4-Dichloro-N-methyl-N-[2-(1-pyrrolidinyl)-cyclohexyl]-benzeneacetamide (U50,488H), and ${\beta}$-endorphin were tested as agonists for ${\mu}$, ${\delta}$, ${\kappa}$, and ${\varepsilon}$-opioid receptors, respectively. WBI significantly attenuated the antinociceptive effects of morphine and DAMGO, but increased those of ${\beta}$-endorphin. The antinociceptive effects of DPDPE and U50,488H were not affected by WBI. In addition, to more preciously understand the differential effects of WBI on ${\mu}-$ and ${\varepsilon}$-opioid receptor agonists, we assessed pretreatment effects of ${\beta}$-funaltrexamine (${\beta}$-FNA, a ${\mu}$-opioid receptor antagonist) or ${\beta}$-$endorphin_{1-27}$ (${\beta}$-$EP_{1-27}$, an ${\varepsilon}$-opioid receptor antagonist), and found that pretreatment with ${\beta}$-FNA significantly attenuated the antinociceptive effects of morphine and ${\beta}$-endorphin by WBI. ${\beta}$-$EP_{1-27}$ significantly reversed the attenuation of morphine by WBI and significantly attenuated the increased effects of ${\beta}$-endorphin by WBI. The results demonstrate differential sensitivities of opioid receptors to WBI, especially for ${\mu}-$ and ${\varepsilon}$-opioid receptors.

• 한국식품과학회지
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• 제43권1호
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• pp.98-104
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• 2011

효율적인 메밀 새싹채소의 수확 후 관리방법을 구축하기 위하여, 적정 염소수세와 헹굼, 예냉, 포장 처리를 새싹 재배공장에서 각기 구분하여 실시하고 관행적으로 출고하던 메밀 새싹과 비교하여 이들 처리구의 저장 중 품질특성 변화를 측정하였다. 수확 후 염소수세 및 헹굼 과정을 거친 모든 처리구의 호기성 중온균과 대장균군은 무처리 대조구에 비해 약 1 log cycle 정도 감소하였으나 저장 중 증가하여 처리구간의 차이를 구분할 수 없었다. 무처리 대조구를 포함하여 염소수세, 냉수예냉, PP 용기 밀봉포장 처리구의 생체중량 감소율은 저장기간 중 4% 이하의 낮은 수준을 유지하였다. 저장 중 새싹시료의 수분함량, 가용성 고형분함량, 표면색 등은 유의적인 차이를 확인할 수 없었고, 관능평가 측면에서도 처리구별로 유의차를 구분할 수 없었다. 결과적으로 메밀 새싹의 수확 후 관리공정에서 염소수 소독처리를 통해 오염미생물을 저감시키고, 적절한 헹굼과 예냉과정을 거쳐 기체투과성이 높은 포장재로 밀봉하는 방법을 적용한다면 새싹채소 상품의 유통 중 신선도 유지에 긍정적 효과를 기대할 수 있을 것으로 판단되었다.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1247-1247
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• 2001

Constituents of animal biofluids such as milk, blood and urine contain information specifically related to metabolic and health status of the ruminant animals. Some changes in composition of biofluids can be attributed to disease response of the animals. Mastitis is a major problem for the global dairy industry and causes substantial economic losses from decreasing milk production and reducing milk quality. The purpose of this study was to investigate potential of NIRS combined with multivariate analysis for cow's mastitis diagnosis based on NIR spectra of milk, blood and urine. A total of 112 bulk milk, urine and blood samples from 4 Holstein cows were analyzed. The milk samples were collected from morning milking. The urine samples were collected before morning milking and stored at -35$^{\circ}C$ until spectral analysis. The blood samples were collected before morning milking using a catheter inserted into the carotid vein. Heparin was added to blood samples to prevent coagulation. All milk samples were analyzed for somatic cell count (SCC). The SCC content in milk was used as indicator of mastitis and as quantitative parameter for respective urine and blood samples collected at same time. NIR spectra of blood and milk samples were obtained by InfraAlyzer 500 spectrophotometer, using a transflectance mode. NIR spectra of urine samples were obtained by NIR System 6500 spectrophotometer, using 1 mm sample thickness. All samples were divided into calibration set and test set. Class variable was assigned for each sample as follow: healthy (class 1) and mastitic (class 2), based on milk SCC content. SIMCA was implemented to create models of the respective classes based on NIR spectra of milk, blood or urine. For the calibration set of samples, SIMCA models (model for samples from healthy cows and model for samples from mastitic cows), correctly classified from 97.33 to 98.67% of milk samples, from 97.33 to 98.61% of urine samples and from 96.00 to 94.67% of blood samples. From samples in the test set, the percent of correctly classified samples varied from 70.27 to 89.19, depending mainly on spectral data pretreatment. The best results for all data sets were obtained when first derivative spectral data pretreatment was used. The incorrect classified samples were 5 from milk samples,5 and 4 from urine and blood samples, respectively. The analysis of changes in the loading of first PC factor for group of samples from healthy cows and group of samples from mastitic cows showed, that separation between classes was indirect and based on influence of mastitis on the milk, blood and urine components. Results from the present investigation showed that the changes that occur when a cow gets mastitis influence her milk, urine and blood spectra in a specific way. SIMCA allowed extraction of available spectral information from the milk, urine and blood spectra connected with mastitis. The obtained results could be used for development of a new method for mastitis detection.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.4105-4105
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• 2001

Near infrared spectroscopy (NIRS) was employed to qualify and quantify on survival, the injury rate and apoptosis of the human breast cancer cell line MCF-7 cells. MCF-7 cells were cultured in RPMI medium supplemented with 10% FCS in a 95% air and 5% CO2 atmosphere at 37$^{\circ}C$. For the viable cells preparation, cells were de-touched by 0.1% of trypsin treatment and washed with RPMI supplemented with 10% FCS medium by centrifugation at 1000 rpm for 3min. For the dead cells preparation, cells were de-touched by a cell scraper. The cells were counted by a hemacytometer, and the viability was estimated by the exclusion method with frypan blue dye. Each viable and dead cells were suspended in PBS (phosphate bufferred saline) or milk at the cell density desired. For the quantitative determination of cell death by measuring the LDH (lactate dehydrogenase) activity liberated from cells with cell membrane injuries, LDH-Cytotoxic Test Wako (Wako, Pure Pharmaceutical Co. Ltd., Japan) was used. We found that NIRS measurement of MCF-7 cells at the density range could evaluate and monitor the different characteristics of living cells and dead cells. The spectral analysis was performed in two wavelength ranges and with 1,4, 10 mm pathlength. Different spectral data pretreatment and chemometrics methods were used. We applied SIMCA classificator on spectral data of living and dead cells and obtained good accuracy when identifying each class. Bigger variation in the spectra of living cells with different concentrations was observed when compared to the same concentrations of dead cells. PLS was used to measure the number of cells in PBS. The best model for measurement of dead cells, as well as living cells, was developed when raw spectra in the 600-1098 nm region and 4 mm pathlength were used. Smoothing and second derivative spectral data pretreatment gave worst results. The analysis of PLS loading explained this result with the scatter effect found in the raw spectra and increased with the number of cells. Calibration for cell count in the 1100-2500 nm region showed to be very inaccurate.

• 청정기술
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• 제25권2호
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• pp.129-139
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• 2019

대나무는 지구상에 존재하는 식물 중 적절한 기후와 토양조건에서 생산성이 가장 높고, 성장속도가 가장 빠른 다년생 식물로 알려져 있다. 전통적으로 아시아에서 대나무는 음식, 건축 및 다양한 재료로 활용되고 있다. 바이오매스 자원으로 대나무는 열분해과정을 거쳐 활성탄으로 제조될 수 있다. 본 연구에서는 탄화온도, 활성화 온도, 시간, 수증기의 양, 그리고 인산의 양 등을 변화에 따른 최적의 대나무 활성탄 제조 연구를 수행하였다. 대나무 탄화 후 수증기 활성화를 위해 $700{\sim}900^{\circ}C$의 온도, $0.8{\sim}1.8mL-H_2O\;g-char^{-1}\;h^{-1}$ 수증기 유량 범위에서 1 ~ 3 h 동안 활성화를 진행하였다. 수증기 유량을 $1.4mL-H_2O\;g-char^{-1}\;h^{-1}$으로 2 h 동안 실험한 결과 활성탄 수율과 비표면적은 각각 2.04 ~ 20.59 wt%, $499.17{\sim}1074.04m^2\;g^{-1}$의 값이 나왔다. 대나무와 인산의 질량비를 1:1로 혼합한 후 $700^{\circ}C$에서 유량 $1.4mL-H_2O\;g-char^{-1}\;h^{-1}$ 속도로 2 h 동안 활성화를 진행한 결과 활성탄 수율과 비표면적은 각각 24.67 wt%, $1389.59m^2\;g^{-1}$의 값이 나타냈다. 제조된 대나무 활성탄을 대상으로 메틸렌블루 흡착 실험을 통해 유사 1차, 2차 속도식 모델을 적용하였으며, 화학적 흡착을 의미하는 유사 2차 속도식에 따랐다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권1호
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• pp.92-97
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• 2012

The trial was conducted to evaluate the effects of sea buckthorn leaves (SBL) on meat flavor in broilers during heat stress. A total 360 one-day-old Arbor Acre (AA) broilers (male) were randomly allotted to 4 treatments with 6 replicates pens pretreatment and 15 birds per pen. The control group was fed a basal diet, the experimental group I, II and III were fed the basal diet supplemented with 0.25%, 0.5%, 1% SBL, respectively. During the 4th week, broilers were exposed to heat stress conditions ($36{\pm}2^{\circ}C$), after which, muscle and liver samples were collected. High performance liquid chromatography (HPLC) was performed to measure the content of inosine monophosphate (IMP); Real-Time PCR was performed to determine the expression of the ADSL gene. The results showed that the content of breast muscle IMP of group I, II and III was significantly increased 68%, 102% and 103% (p<0.01) compared with the control, respectively; the content of thigh muscle IMP of group II and III was significantly increased 56% and 58% (p<0.01), respectively. Additionally, ADSL mRNA expression in group I, II and III was increased significantly 80%, 65% and 49% (p<0.01) compared with the control, respectively. The content of IMP and expression of ADSL mRNA were increased by basal diet supplemented with SBL, therefore, the decrease of meat flavor caused by heat stress was relieved.

• 상하수도학회지
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• 제29권2호
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• pp.183-192
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• 2015

Response surface methodology (RSM) based on a Box-Behnken Design (BBD) was applied to optimize the thermal-alkaline pre-treatment operating conditions for anaerobic digestion of flotation scum in food waste leachate. Three independent variables such as thermal temperature, NaOH concentration and reaction time were evaluated. The maximum methane production of 369.2 mL $CH_4/g$ VS was estimated under the optimum conditions at $62.0^{\circ}C$, 10.1% NaOH and 35.4 min reaction time. A confirmation test of the predicted optimum conditions verified the validity of the BBD with RSM. The analysis of variance indicated that methane production was more sensitive to both NaOH concentration and thermal temperature than reaction time. Thermal-alkaline pretreatment enhanced the improvement of 40% in methane production compared to the control experiment due to the effective hydrolysis and/or solubilization of organic matters. The fractions with molecular weight cut-off of scum in food waste leachate were conducted before and after pre-treatment to estimate the behaviors of organic matters. The experiment results found that thermal-alkaline pre-treatment could reduce the organic matters more than 10kD with increase the organic matters less than 1kD.

• 한국식품과학회지
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• 제27권2호
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• pp.225-229
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• 1995

저칼로리 감미료로서 장내 미생물 균총을 개선한다고 알려진 대두 올리고당을 전처리 및 Steffen법을 이용하여 대두 침지액으로부터 분리, 회수하였다. 전처리로서 pH를 $3.5{\sim}4.0$으로 조절하거나, 염화칼슘을 당 대비 8%(w/w)를 첨가하여 대두 침지액 중에 함유된 단백질을 약 $25{\sim}30%$가량 제거할 수 있었다. 또한 대두 침지액에 염화칼슘과 산화칼슘 분말을 각각 당 대비 약 20%, $100{\sim}120%$씩 첨가한 후 $5^{\circ}C$에서 20분 동안 반응시키는 Steffen법을 이용하면 대두 침지액 중에 존재하는 대두 올리고당의 약 85%를 saccharate 형태로 분리, 회수할 수가 있었다. 이산화탄소로 당을 탈착시켜 회수한 결과 최종적으로 약 80%의 수율로 당을 회수할 수가 있었으며 단백질은 약 80% 정도 제거할 수가 있었다. 회수된 당액의 당조성은 대두 침지액과 유사하였다.

• 한국작물학회지
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• 제37권2호
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• pp.134-140
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• 1992

당근종자의 발아율의 낮음과 발아지정의 문제점을 해결하기 위해서 Danver 126품종을 공시하여 여러가지 prime처리와 density separation 방법을 이용한 결과 다음과 같은 효과를 얻었다. 1. 여러가지 prime처리중 SMP처리(수분함량 90%, 6일간처리)에서 배의 생장이 아주 양호하였고 발아속도 및 발아율이 가장 좋았으며 종자에 피해도 없었다. 2. 무기염처리(0.2M KNO$_3$＋0.1M $K_2$HPO$_4$)에 서는 배의 생장은 좋았으나 염에 의해 종자가 피해를 입었다. 3. SMP처리(수분함량 90%, 6일간)된 종자를 density separation한 결과 종자의 비중이 낮을수록 배의 생장이 컸으며 발아율 및 발아속도가 빨랐다.