• 한국수소및신에너지학회논문집
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• 제9권2호
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• pp.77-84
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• 1998

$H_2O/O_2$, $D_2O/H_2O$, $D_2O/H_$2 등의 반응계의 수소동위원소 교환반응용 전기방전을 이용하여 용이하게 일으킬 수 있다. 예를 들어, DC 코로나 방전을 위의 반응혼합물을 통하여 일으키면 여기된 상태의 반응물이 존재하는 플라즈마를 형성하게 된다. 이러한 플라즈마 내에서 반응물들은 양자에너지 준위의 여기, 이온화 그리고 라디칼 형성등을 통하여 매우 큰 반응성을 갖게되므로 실온에서도 용이하게 수소동위원소 교환반응을 일으킨다. 본 연구에서는 $H_2/D_2O$계의 기상에서의 교환반응에 대한 연구를 실시하였다. 위 반응계는 전기방전하에서 수소(H)와 중수소(D)간의 교환반응에 의하여 HDO와 HD를 생성하게 된다. 이러한 반응생성물을 FTIR 분광법을 이용하여 시간의 함수로 측정을 하였다.

• 한국미생물·생명공학회지
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• 제47권4호
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• pp.639-644
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• 2019

Diarrhea is one of the most common infectious diseases known worldwide. However, few studies have examined anaerobic diarrhea-causing bacteria (DB), which are difficult to culture. Recent advances in molecular biology have facilitated the detection and analysis of anaerobic DB. In this study, long-term trends in anaerobic DB were evaluated in Korea. From 2010 to 2018, symptoms of diarrhea reported were analyzed among patients hospitalized at the Dankook University Hospital in Korea. Results of multiplex polymerase chain reaction based on seasonality, age, overlapping infection, and other factors in patients were evaluated. DB were detected in 38.2% of 1716 stool specimens in the duration of the study. Of the pathogens detected using this method, 49.8% (n = 405/813) were anaerobic bacteria, including Clostridioides perfringens, Campylobacter spp., Clostridioides difficile toxin B, and Aeromonas spp. Among the four anaerobic bacteria, Clostridioides perfringens was the most commonly occurring (15.5%; n = 126/813). Detection rates of Clostridioides perfringens, Clostridioides difficile toxin B, and Aeromonas spp. were 34.1% (n = 22/55), 34.9% (n = 43/126), and 40.0% (n = 38/109), respectively. The detection rate of Campylobacter spp. (32.7%; n = 37/115) was the highest in patients between 10 and 20 years of age. The detection rate of anaerobic DB showed an increase in 2018 as compared with that in 2010, and the number of events of diarrhea caused by anaerobic DB also increased in this duration. Further studies are required to devise methods that might prevent the proliferation of anaerobic DB.

• 한국응용과학기술학회지
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• 제35권4호
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• pp.1472-1479
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• 2018

본 연구는 지속적인 곡예 운동이 여자 체조, 프리스타일 스키어 및 피겨 스케이터 선수의 동적자세 유지 능력에 미치는 영향을 분석하고자 하였다. 이 연구에 참여한 피험자는 운동경력이 4-6년 된 운동선수로서 체조선수 7명, 프리스타일 스키어 선수8명, 피겨 스케이터 7명과 일반 여학생 10명을 통제집단으로 분류하였다. 동적자세의 운동능력을 비교하고자 뉴로컴사의 동적자세측정기를 이용하여 6가지 각 조건에 맞는 이른바, 시각계, 전정계 및 체성감각계가 동원되는 상황을 연출하면서 실험에 임하였다. 자료처리는 일원변량분석을 실시하였고, 사후검증으로는 집단 간의 차이를 보고자 Scheffe로 하였고, 통계학적 유의수준은 .05로 하였다. 연구결과 운동집단 간에는 조건 5에서 프리스타일 선수와 체조선수 간의 유의한 차이가 있었으며, 운동선수 집단과 일반인 여학생 간에는 조건 2, 3, 4, 5, 6에서 유의한 차이가 나타났다. 결론적으로 지속적인 곡예 운동은 평형기관계를 자극하여 동적자세 조절의 향상에 효과가 있는 것으로 사료된다.

• Environmental Engineering Research
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• 제23권2호
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• pp.216-222
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• 2018

The growth characteristics of Spirulina platensis were investigated using four photo-bioreactors with $CO_2$-mixed air flows. Each reactor was operated under a specific condition: 3% $CO_2$ at 50 mL/min, 3% $CO_2$ at 150 mL/min, 6% $CO_2$ at 50 mL/min, and 6% CO2 at 150 mL/min. The 3% $CO_2$ at 150 mL/min condition produced the highest algal growth rate, while the 6% $CO_2$ at 150 mL/min conditioned produced the lowest. The algal growth performance was suitably assessed by the linear growth curve rather than the exponential growth. The medium pH decreased from 9.5 to 8.7-8.8 (3% $CO_2$) and 8.4-8.5 (6% $CO_2$), of which trends were predicted only by the pH-carbonate equilibrium and the reaction kinetics between dissolved $CO_2$ and $HCO_3{^-}$. Based on the stoichiometry between the nutrient amounts and cell elements, it was predicted that depleted nitrogen (N) at the early stage of the cultivation would reduce the algal growth rates due to nutrient starvation. In this study, use of the photobioreactors capable of good light energy distribution, proper ranges of $CO_2$ in bubbles and medium pH facilitated production of high amounts of algal biomass despite N limitation.

• 한국응용과학기술학회지
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• 제7권2호
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• pp.33-40
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• 1990

The Kinetics of the addition of benzalacetophenone derivatives was investigated by ultraviolet spectrophotometery in 5% dioxane $H_2O$ at $50^{\circ}C$. A rate equation was obtained in wide range of pH. The substituent effects on benzalacetophenone derivatives were studied, and addition were facilitated by electron attracting groups. The final product was benzalacetophenone-${\beta}$-thioglycolic acid synthesized by the addition of thioglycolic acid to benzalacetophenone. On the base of the rate equation, substituent effect, general base effect and final product, the plausible addition mechanism was proposed: Below pH 9.0, only neutral thioglycolic acid molecule was added to the carbon-carbon double bond, and in the range of pH $9.0{\sim}11.0$, neutral thioglycolic acid molecule and thioglycolic acid anion competitively attacted the double bond. By contrast, above pH 11.0, the reaction was dependent upon only the addition of thioglycolic acid anion.

• 한국응용과학기술학회지
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• 제6권2호
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• pp.59-65
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• 1989

The rate constants of the hydrolysis of cinnamanilide derivatives were determined UV spectrometry in $H_2SO_4\;(5{\sim}20N)$, NaOH($5{\sim}11N)\;at\;50{\sim}110^{\circ}C$ and rate equation could be applied over a strong acid and strong base were obtained. Final product of the hydrolysis was a cinnamic acid. The ${\rho}$ values obtained from the slope of linear plots of log $k_{abs}$ vs. Hammet $t{\sigma}$ constants were slightly negatives, Substituents on cinnamanilide showed a relatively small effect, with hydrolysis facilitated be electron donating group. Activation energy(Ea)was also calculated for the hydrolysis of the cinnamanilide. From this reaction rate equation, substituent effect and experimental of rate constants, that the hydrolysis of cinnamanillde was Initiated by the netural molecule of $H_2O$ which do not dissociate at strong acid, and proceeded by hydroxide ion at strong base.

• 한국광물학회지
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• 제9권1호
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• pp.7-16
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• 1996

Partially sericitized tourmaline from a pegmatite, Black Hills, South Dakota, U.S.A., was investigated using high-resolution transmission electron microscopy (HRTEM). Muscovite occurs as the only alteration product of tourmaline, and it is developed extensively as narrow veinlets along the {110} and {100} cleavage directions of tourmaline, indicating that a cleavage-controlled alteration mechanism was dominant. Muscovite was characterized mainly as two-layer polytypes with minor stacking disorder, but tourmaline is almost free of structural defects. HRTEM images of tourmaline-muscovite interfaces revealed that the interfaces between two minerals are composed of well-defined {110} and {100} boundaries of tourmaline. The (001) of muscovite is in general parallel to the c-axis of tourmaline, but tourmaline and replacing muscovite do not show specific crystallographic orientation relationship; muscovite consists of numerous 100-1000$\AA$ thick subparallel packets, and the angles between the (001) of muscovite and (110) of tourmaline is highly variable. Al/Si ratios of both minerals suggest that tourmaline to muscovite alteration by late magnetic fluids has been facilitated by their similar Al/Si ratio in the incipient alteration stage, in that the hydration reaction with preservation of Al and Si would require only addition of K+ and H2O. Aluminous minerals other than muscovite were not characterized as the alteration products of tourmaline, indicating that tourmaline reacted directly to muscovite; the tourmaline alteration apparently occurred by the presence of residual fluids in which K+ is available and silica was not undersaturated.

• BMB Reports
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• 제40권3호
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• pp.444-447
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• 2007

Polymerase chain reaction (PCR) is a powerful technique in molecular biology and is widely used in various fields. By amplifying DNA fragments, PCR has facilitated gene cloning procedures, as well as molecular genotyping. However, the extraction of DNA from samples often acts as a limiting step of these reactions. In particular, the extraction of PCR-compatible genomic DNA from higher plants requires complicated processes and tedious work because plant cells have rigid cell walls and contain various endogenous PCR inhibitors, including polyphenolic compounds. We recently developed a novel solution, referred to as AnyDirect, which can amplify target DNA fragments directly from whole blood without the need for DNA extraction. Here, we developed a simple lysis system that could produce an appropriate template for direct PCR with AnyDirect PCR buffer, making possible the direct amplification of DNA fragments from plant leaves. Thus, our experimental procedure provides a simple, convenient, non-hazardous, inexpensive, and rapid process for the amplification of DNA from plant tissue.

• BMB Reports
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• 제35권3호
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• pp.262-266
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• 2002

A non-isotopic neutravidin-based reverse transcriptase (RT) assay adapted for high throughput screening of HIV activity is described. Using a 96-well microtitre plate, HIV particles are lysed and the RT enzyme released into a reaction mixture containing poly(A) RNA, biotinylated oligo d(T) and fluorescein-labelled dUTP (FI-dUTP). With poly(A) as a template and oligo d(T) as primer, the viron RT incorporates FI-dUTP into an elongating DNA strand. The resulting product is captured on a neutravidin-coated 96-well plate and the unincorporated nucleotides removed by a series of washing steps. A simple ELISA is subsequently performed using a monoclonal antifluorescein antibody conjugated to alkaline phosphatase. Quantification of RT activity is facilitated by a colorimetric readout. The assay was validated in the context of a diagnostic HIV-1 phenotyping assay. Using supernatants from HIV-1 infected lymphocyte cultures the assay was shown to be as sensitive as a radioactive assay and the RT activity correlated well with levels of cell-asociated HIV-p24. Importantly, even minor reductions of RT activity by virus variants with reduced fitness could be distinguished.

• 한국산학기술학회논문지
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• 제3권3호
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• pp.194-197
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• 2002

이온교환은 액체상 이온과 고체상 이온간의 화학반응이며 연수 및 탈염공정, 특정물질의 제거 및 회수, 토양을 통한 이온성 물질의 이동에서 널리 이용되고 있다. 이온 선택도는 원자가가 높을수록, 수화반경이 작을수록 증가한다. 본 연구는 평형 이온교환에서 결정된 이온 선택도가 칼럼 이온교환에 적용되는 가를 조사하였다. 음이온 교환수지에 대한 이온 선택도 순서는 OH/sup -/ < F/sup -/ < HCO/sup -/ < Cl/sup -/ < Br/sup -/ ≤ NO₃/sup -/ < SO₄/sup 2-/ 이였으며, 음이온 칼럼교환에서도 동일하였다. 또한 바탕 양이온의 전하가 낮을수록 이온교환이 빠르게 진행됨을 알 수 있었다.