• Plant Resources
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• 제8권3호
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• pp.293-299
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• 2005

This study used RAPD markers to assume genetic diversity and variation in selected populations of Hovenia dulcis var. koreana. Ratio of polymorphic RAPD markers were 93.4% in selected populations of Hovenia dulcis Thunb., difference of genetic structure among populations and within populations showed 16.45%, 83.55%, respectively in amount of total genetic variation of 4 populations. Total gene diversity($H_T$) that show genetic diversity appeared 0.313 and coefficient of gene differentiation($G_{ST}$) that compare genetic differentiation of populations appeared 0.1645, analysis of AMOVA for variation among populations and within populations was significantly different (P<0.001). Genetic diversity of whole populations showed that 12.44% difference among population and 87.56% difference within populations. As a result, difference within populations was larger than difference among populations in genetic diversity. Nei's genetic distance and cluster analysis appeared that mean genetic distance among populations was 0.076, thus dividing two main groups and geographic relationship did not show in populations.

• 한국수산과학회지
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• 제47권6호
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• pp.713-718
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• 2014

The seasonal variation in the proximate composition, pH, and glycogen contents of oysters Crassostrea gigas collected in Geoje and Jaran Bays on the southern coast of Korea was studied between March 2012 and February 2013. In the Geoje Bay oysters, the moisture content was 77.49-81.50 g/100 g, lipids ranged between 1.22 and 2.47 g/100 g, proteins between 9.46 and 13.11 g/100 g, and ash between 1.88 and 2.58 g/100 g. In the Jaran Bay oysters, the moisture content was 74.22-82.05 g/100 g, lipids comprised 1.32-2.37 g/100 g, proteins 9.19-13.35 g/100 g, and ash 1.96-2.45 g/100 g. The moisture content was highest in October and January in Geoje and Jaran Bay, respectively, and tended to increase from July until September. The highest protein levels occurred in August in both bays, which coincided with the timing of oocyte maturation, and then decreased at the beginning of total spawning. The highest lipid levels occurred in April in Geoje Bay, and February in Jaran Bay. The glycogen content was 0.40-2.28 g/100 g in Geoje Bay, and 0.61-3.53 g/100 g in Jaran Bay, and was highest in February and decreased from March onwards. The lowest glycogen content occurred in September and then increased from October onwards. The pH ranged between 6.29 and 6.48, and 6.32 and 6.59, for Geoje and Jaran Bay, respectively, and was highest in February.

• Asian-Australasian Journal of Animal Sciences
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• 제13권7호
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• pp.962-966
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• 2000

Effects of the pattern of energy supply on the efficiency of nitrogen utilization for microbial protein synthesis (MPS) were examined in cows consuming grass silage (7.1 kg DM/d) and supplement of 1 kg sucrose per day given as an intraruminal infusion. Three non-lactating cows received three experimental treatments in a $3{\times}3$ Latin square design with each period lasting 14 days. The treatments were (1) the basal diets of silage alone given in one meal each day at 09:30 h (BASAL), supplemented with (2) 1.0 kg sucrose given a 4-h infusion starting at 09:30 h (SYNC), (3) 1.0 kg sucrose given a continuous infusion for 24 h (CONT). Compared with BASAL, sucrose infusions altered (p<0.05) the pattern of variation in ruminal pH and the concentration of ammonia at 4 h after feeding but none of the sucrose treatments resulted in any changes in the ruminal concentration of VFA. All sucrose treatments increased (p<0.05) MPS relative to BASAL by 14% and 33% for SYNC and CONT, respectively, and that for CONT was greater (p<0.05) than for SYNC. It is concluded that synchronization of energy and nitrogen over the shorter term has no further advantage of the efficiency for MPS relative to CONT.

• 치위생과학회지
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• 제20권1호
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• pp.9-15
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• 2020

Background: Although the consumption of vitamin beverages has increased because of the recent interest in health and beauty, guidelines addressing appropriate consumption habits are lacking. Thus, the aim of this study was to investigate the erosive potential of several vitamin beverages and to propose guidelines for the appropriate intake of these drinks. Methods: Five vitamin beverages were selected after a pre-investigation of the current beverage market. Coca-Cola and mineral water were selected as the control beverages. The pH of the beverages was measured with a calibrated pH meter, and the titratable acidity (TA) was determined by using 1 M sodium hydroxide to reach pH 5.5 (TA5.5) and 7.0 (TA7.0). The screening method suggested by the International Organization for Standardization was used to measure pH variation (ΔpH) by using an under-saturated hydroxyapatite solution to determine the difference between the initial and final pH of the screening solution. All measurements were performed in triplicate. Results: All vitamin beverages tested in this study exhibited a low pH (2.53~2.99), similar to Coca-Cola, which is known to be a highly acidic beverage. The highest TA5.5 and TA7.0 values of the vitamin beverages were 7.03 ml and 8.81 ml, respectively. The largest change in pH determined by using the screening solution was found in Bacchus D (ΔpH 1.44±0.05). The mean ΔpH of the vitamin beverages was 1.12±0.29, which was higher than that of Coca-Cola (positive control, ΔpH 0.58±0.05). Conclusion: Vitamin beverages exhibited an erosive potential capable of damaging enamel surfaces. Therefore, the frequency of vitamin beverage intake should be limited, and individuals consuming these drinks should try to restore normal oral pH as quickly as possible.

• BMB Reports
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• 제44권1호
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• pp.64-69
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• 2011

A peroxidase (PD-cP; 0.47 mg/100 g leaves) was purified from autumn leaves of Phytolacca dioica L. and characterized. PD-cP was obtained by acid precipitation followed by gel-filtration and cation exchange chromatography. Amino acid composition and N-terminal sequence of PD-cP up to residue 15 were similar to that of Spinacia oleracea (N-terminal pairwise comparison showing four amino acid differences). PD-cP showed a molecular mass of approx. 36 kDa by SDS-PAGE, pH and temperature optima at 3.0 and $50.0^{\circ}C$, respectively and seasonal variation. The Michaelis-Menten constant ($K_M$) for $H_2O_2$ was 5.27 mM, and the velocity maximum ($V_{max}$) $1.31\;nmol\;min^{-1}$, while the enzyme turnover was $0.148\;s^{-1}$. Finally, the presence of $Ca^{2+}$ and $Mg^{2+}$ enhanced the PD-cP activity, with $Mg^{2+}$ 1.4-fold more effective than $Ca^{2+}$.

• 대한화학회지
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• 제9권2호
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• pp.101-105
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• 1965

7-Nitroso-8-hydroxyquinoline-5-sulfonate(NHQS)는 pH 4.5에서 Co(Ⅱ)와 安定한 赤色 complex를 形成하므로 이것을 利用하여 NHQS에 依한 Co(Ⅱ)의 吸光光度定量方法을 檢討하였다. 吸光度는 528$m{\mu}$, $25^{\circ}C$에서 測定하였다. Co(Ⅱ)의 濃度 0.3∼6p.p.m에서 Beer의 法則은 成立하며 complex의 分子吸光係數는 $1.1{\times}10^4$이었다. 共存이온中 Fe(Ⅱ), Fe(Ⅲ), Cu(Ⅱ), Mn(Ⅱ), Hg(Ⅰ), CN-, EDTA 等은 本定量에서 妨害가 된다. Complex의 組成을 몰比法과 連續變化法으로 檢討한 結果 NHQS와 Co(Ⅱ)의 몰比는 3:1이었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2410-2412
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• 2005

In this study, two types of PS substrate were fabricated for sensing of chemical and biological substances. For sensing of the humidity and chemical analyzes such as $CH_3OH$ or $C_2H_5OH$, PS layers are prepared by photoelectrochemical etching of silicon wafer in aqueous hydrofluoric acid solution. To evaluate their sensitivity, we measured the resistance variation of the PS diaphragm. As the amplitude of applied voltage increases from 2 to 6Vpp at constant frequency of 5kHz, the resistance variation for humidity sensor rises from 376.3 to $784.8{\Omega}$/%RH. And the sensitivities for $CH_3OH$ and $C_2H_5OH$ were 0.068 uA/% and 0.212 uA/%, respectively. For biological sensing application, amperometric urea sensors were fabricated based on porous silicon(PS), and planar silicon(PLS) electrode substrates by the electrochemical methods. Pt thin film was sputtered on these substrates which were previously formed by electrochemical anodization. Poly (3-methylthiophene) (P3MT) were used for electron transfer matrix between urease(Urs) and the electrode phase, and Urs also was by electrochemically immobilized. Effective working area of these electrodes was determined for the first time by using $Fe(CN)_6^{3-}/Fe(CN)_6^{4-}$ redox couple in which nearly reversible cyclic voltammograms were obtained. The $i_p$ vs $v^{1/2}$ plots show that effective working electrode area of the PS-based Pt thin film electrode was 1.6 times larger than the PLS-based one and we can readily expect the enlarged surface area of PS electrode would result in increased sensitivity by ca. 1.6 times. Actually, amperometric sensitivity of the Urs/P3MT/Pt/PS electrode was ca 0.91uA/$mM{\cdot}cm^2$, and that of the Urs/P3MT/Pt/PLS electrode was ca. 0.91uA/$mM{\cdot}cm^2$ in a linear range of 1mmol/L to 100mmol/L urea concentrations

• 생명과학회지
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• 제22권4호
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• pp.466-471
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• 2012

참가리비($Patinopecten$ $yessoensis$) 60개체를 채집하여 유전적 다양성과 집단구조를 조사하였다. 임의 유전 다형성 DNA (RAPD)로 109개 유전자형과 79개 다형성 좌위(72.8%)를 발견하였다. 전체 유전적 다양도($H_T$)와 집단내 변이($H_S$)는 각각 0.254와 0.178였다. 유전자 좌위에 근거하여 집단 간 분화 정도($G_{ST}$)는 0.299였다. 이는 전체변이의 약 70.1%가 집단 내에 존재하고 있음을 시사한다. 참가리비 세 나라 집단에서 한 집단에 국한되는 대립유전자 좌위와 한 개체에만 발현된 밴드가 발견되었다. RAPD 마커는 한국, 중국, 일본에 분포하는 참가리비를 구분하는데 매우 효과적이었다. 또한 참가리비의 집단 내, 집단 간 유전적 다양성에 대한 통찰은 동물 유전자원의 수진 전략과 양식에 유익할 것으로 사료된다.

• 폴리머
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• 제32권4호
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• pp.377-384
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• 2008

본 연구에서는 UV 조사와 alkoxy 가수분해 법을 이용하여 구형 마이크로 실리콘 고분자 비드를 합성하였다. 구형 실리콘 고분자 비드의 입자들의 coefficient of variation(CV)은 UV 조사량의 세기와 조사시간, 반응온도가 증가함에 따라 감소하였다. 합성된 비드의 평균 입경, 굴절률, pH는 각각 $4.1{\mu}m$, 1.43, 7.5이었으며 진비중, 겉보기 비중은 1.30, 0.40이었으며, 수분함량은 2%이하였다. Hexamethyldisilazane(HMDS) 농도가 0.1 wt%일 때 입자크기와 CV는 가장 작았고, 진원도는 $0.95{\sim}0.98{\mu}m$이었다. UV 조사량과 조사시간이 450 W, 90 min일 때 CV는 4.92%이었다. Methyltrimethoxysilane(MTMS)의 농도가 20 wt%일 때 수율은 총 충전량 대비 11.3%까지 증가하였으며 입자의 평균직경은 교반속도와 온도가 증가함에 따라 작아졌다.

• 대한환경공학회지
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• 제33권9호
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• pp.630-635
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• 2011

본 연구는 급속 OUR (Oxygen Uptake Rate)방법의 영향인자 평가로서 최적의 미생물 활성도에 미치는 영향인자를 평가하는 실험을 진행하였으며, 실폐수를 이용하여 OUR변화에 따른 SCOD의 변화를 비교 평가하였다. 그 결과 최적의 F/M비는 0.03~0.05이었고, pH는 6.0~8.5, 온도는 $20{\sim}30^{\circ}C$에서 OUR 값이 가장 높았으며, 질산화에 대한 산소소모는 미비했다. OUR 변화에 따른 SCOD (Soluble COD)의 변화는 OUR 변곡점 시간 전후로 SCOD의 분해속도에 차이가 있음을 알 수 있었다. 본 연구의 실험방법을 이용하여 하수처리장의 유입수 실시간 예측을 통해 최적의 운영을 할 수 있을 것이라 기대한다.