• 한국식품저장유통학회지
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• 제3권1호
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• pp.7-13
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• 1996

Total carbohydrates of Kumquats was 14.69% Kumquats, Citrus natsudaidai, and C. platgmama contained 18.3, 11.1 and 13.0%, of soluble solids, and 42.39, 32.09 and 20.13mg/100g, of vitamin C, respectively. Acid contents of C. natsudaidai and C. plafmama harvested on March 1995 in south Cheju were 2.52% and 0.89% . In preparing of Kumquats-tea, combination of 50% honey and sugar, 5% oligo-sugar, 32% Kumquats slice, 13% juice of C. natsudaidai were the best recipe for sensory evaluation. In C. natsudaidai-tea, combination of 5∼10% peel slice treated at 90$^{\circ}C$ for 1min, 50∼60% concentration of sugar and 35∼40% of flesh of C. natsudaidai were good. for sensory evaluation. Microbial growth was not observed in the sterilized products for more than one month at 30$^{\circ}C$.

• 한국광학회지
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• 제13권2호
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• pp.123-127
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• 2002

본 연구에서는 1550nm 영역에서 $^{13}$C$_2$H$_2$분자의 회전-진동 모드에 대한 분광을 수행하고, 각 전이선들에 대한 파장을 측정하였다. 파장 측정을 위해서 각 흡수선의 피크에서 레이저주파수 변조를 시켜, 변조신호의 1차 하모닉 록킹법으로 레이저의 주파수를 안정화시키고, 광주파수 표준기로 사용되고 있는 요오드 안정화 헬륨-네온 레이저(KRISS-R70l)로 교정한 파장계를 사용하여 3$\times$$10^{-7}$ 의 정확도로 $^{13}$C$_2$H$_2$의 전이선들의 파장을 측정하였다. 그리고, 아세틸렌 분자 흡수선의 옆선에 주파수 안정화하는 방법을 이용하여 ITU-T 그리드의 절대 파장에 일치하는 표준광원 개발은 제안하였다.

• Investigative Magnetic Resonance Imaging
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• 제26권2호
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• pp.125-134
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• 2022

Purpose: The aim of this study was to investigate the change in signal sensitivity over different acquisition start times and optimize the scanning window to provide the maximal signal sensitivity of [1-¹³C]pyruvate and its metabolic products, lactate and alanine, using spatially localized hyperpolarized 3D ¹³C magnetic resonance spectroscopic imaging (MRSI). Materials and Methods: We acquired 3D ¹³C MRSI data from the brain (n = 3), kidney (n = 3), and liver (n = 3) of rats using a 3T clinical scanner and a custom RF coil after the injection of hyperpolarized [1-¹³C]pyruvate. For each organ, we obtained three consecutive 3D ¹³C MRSI datasets with different acquisition start times per animal from a total of three animals. The mean signal-to-noise ratios (SNRs) of pyruvate, lactate, and alanine were calculated and compared between different acquisition start times. Based on the SNRs of lactate and alanine, we identified the optimal acquisition start timing for each organ. Results: For the brain, the acquisition start time of 18 s provided the highest mean SNR of lactate. At 18 s, however, the lactate signal predominantly originated from not the brain, but the blood vessels; therefore, the acquisition start time of 22 s was recommended for 3D ¹³C MRSI of the rat brain. For the kidney, all three metabolites demonstrated the highest mean SNR at the acquisition start time of 32 s. Similarly, the acquisition start time of 22 s provided the highest SNRs for all three metabolites in the liver. Conclusion: In this study, the acquisition start timing was optimized in an attempt to maximize metabolic signals in hyperpolarized 3D ¹³C MRSI examination with [1-¹³C] pyruvate as a substrate. We investigated the changes in metabolic signal sensitivity in the brain, kidney, and liver of rats to establish the optimal acquisition start time for each organ. We expect the results from this study to be of help in future studies.

• 생약학회지
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• 제18권3호
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• pp.151-167
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• 1987

The $^{13}C-NMR$ chemical shifts of amyrins and their derivatives published up to an early spring of 1987 are listed and a number of methods for signal assignment are explained. A list of 214 amyrins, the $^{13}C-NMR$ chemical shifts of which have been assigned, is included.

• 약학회지
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• 제33권3호
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• pp.203-205
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• 1989

A method is presented for calculating the $^{13}C$ chemical shifts produced in liquid solution by referenced relative to RF frequency. The method is useful to get the real variations of chemical shifts in magnetic field by eliminating the affects of the variation of a reference substance.

• Bulletin of the Korean Chemical Society
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• 제19권3호
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• pp.295-299
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• 1998

HSP104 protein in Saccharomyces cerevisiae is known to provide thermotolerance when induced by various kinds of stresses, such as a mild heat shock, ethanol, and hypoxia. It helps cells survive at an otherwise lethal temperature. Mechanisms by which HSP104 protein works are yet to be elucidated. In order to understand a molecular basis of thermotolerance due to HSP104 protein induced by a mild heat shock, studies on respiratory pathways were carried out in the wild type as well as in the hsp104 deleted mutant. Especially the degree of 13C-acetate incorporation into glutamate-C4 was examined for both strains using 13C-13C homonuclear spin coupling measurements, since glutamate is in a rapid equilibrium with α-ketoglutarate in the TCA cycle. In addition, the temperature effects on the rate of 13C incorporation are compared with or without HSP104 protein expressed. Finally, the inhibitory effect of HSP104 on the respiration pathway was confirmed by the measurements of oxygen consumption rates for both strains.

• Journal of the Korean Wood Science and Technology
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• 제9권2호
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• pp.1-30
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• 1981

알칼리 펄프화중(化中)에 생성(生成)되는 리그닌의 착색구조(着色構造)를 구명(究明)하기 위(爲)하여 바닐린알코올[${\alpha}-^{13}C$] 과이아실 글리세롤-${\beta}$-아릴에테르[${\alpha}-^{13}C$] 혹은 [${\gamma}-^{13}C$] 페닐쿠마란[${\alpha}-^{13}C$] 구조(構造)를 각각(各各) 165$^{\circ}C$에서 1.5~3시간(時間) 알칼리용액을 처리한 후(後) 반응생성물(反應生成物)을 단리(單離) 또는 반응혼합물(反應混合物)을 $^{13}C$-NMR로 조사(調査)한 결과(結果), 바닐린아코올의 알칼리 처리(處理)는 Ca-$C_1$ 및 Ca-$C_5$의 결합(結合)을 갖는 축합체(縮合體)(II-1~5)로 되며, 이들은 공기산화(空氣酸化)에 의(依)해 퀴노이드 공역형구조(共役型構造)(Fig 3-7)로 산화(酸化)되며, 과이아실글리세롤 -${\beta}$- 아릴에테르의 알칼리 처리(處理)는 ${\alpha}$-아릴-${\beta}$-아록시퀴논구조(構造)(IV-15, IV-16) 디과이아실-1, 4-펜탄디엔 ${\beta}$, ${\beta}$' -디아록시스티렌메탄(V-4) ${\beta}$-아록시스티렌메탄(V-6)이 생성(生成)되며 스티렌메탄 구조(構造)는 공기산화(空氣酸化)에 의(依)해 O-퀴논메티드구조(V-8, V-9)로 된다. 페닐쿠마란은 알칼리처리(處理)에 의(依)해 다량(多量)의 스틸벤유도체(誘導體)를 생성(生成)하지만 이스틸벤구조가 퀴논구조로 산화되기 보다는 2량체(量體)(IV-11)로 안정화(安定化)되는 경향(傾向)이 있다. 이상(以上)과 같은 착색구조(着色構造)는 반응기구의 견지에서 알칼리 펄프화중(化中)에 생산되는 중요한 착색구조(着色構造)라고 생각된다.

• 한국결정학회지
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• 제6권1호
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• pp.43-48
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• 1995

X-ray 회절법을 이용하여 P-toluenesulfonanilide, C13H13NO2S의 결정 및 분자구조를 규명하였다. Methanol 용액으로부터 얻은 무색 단결정은 단사정계, 공간군은 P21/c이며, a=8.777(1)Å, b=9.784(2)Å, c=15.139(2)Å, β=99.00(1)°, Z=4, V=1284.0(6)Å3, Dc=1.28g/cm3, λ(Mo-Kα)=0.71069Å, μ=2.3cm-1, F(000)=520, Temperature : 293±3K, 직접법으로 개략적인 분자모델을 설정하고 3.0σ이상인 711개의 독립 회절반점에 대하여 완전행렬 최소자승법으로 정밀화하여 최종신뢰도값 R=0.038인 최종적인 분자모형을 구하였다. 두 벤젠고리의 이면각이 68.4°이며 분자들은 c축 방향 2회선 나선형으로 이상적으로 충진되어 있으며 분자간은 van der Walls 결합력으로 이루어져있다.

• 한국환경농학회지
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• 제29권4호
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• pp.362-366
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• 2010

Carbon isotope ratio ($^{13}C/^{12}C$, expressed as ${\delta}^{13}C$) of tree ring can be proxy of atmospheric $CO_2$ concentration ([$CO_2$]) due to the inter-correlation between atmospheric [$CO_2$], ${\delta}^{13}C$ of atmospheric $CO_2$, and ${\delta}^{13}C$ of plant tissue that assimilates atmospheric $CO_2$. This study was conducted to investigate if ${\delta}^{13}C$ of tree ring of Pinus densiflora in polluted area may show a lower value than that in unpolluted area and to explore the possibility of reconstructing atmospheric [$CO_2$] using its relationship with ${\delta}^{13}C$ of tree ring. During the period between 1999 and 2005, ${\delta}^{13}C$ of tree annual ring tended to decrease over time, and the ${\delta}^{13}C$ in polluted area (-27.2‰ in 2009 to -28.3‰ in 2005) was significantly (P<0.001) lower than that (-26.0‰ in 1999 to -27.1‰ in 2005) in unpolluted area. This reflects a greater emission of $CO_2$ depleted in $^{13}C$ in the polluted area. Atmospheric [$CO_2$] was significantly (P<0.01) correlated with ${\delta}^{13}C$ of tree ring in a linear fashion. Using the linear regression equation, atmospheric [$CO_2$] in the polluted area was estimated to range from 392.3 ppm in 1999 to 410.9 ppm in 2005, and these values were consistently higher than the national atmospheric [$CO_2$] monitored at the Anmyoundo meteorological station (from 370.7 ppm in 1999 to 387.2 ppm in 2005). Our study suggested that it is possible to reconstruct atmospheric [$CO_2$] in a certain area using the relationship between tree ring ${\delta}^{13}C$ and atmospheric [$CO_2$].

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.402-404
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• 2005

2004년 7월부터 2005년 2월까지 8개월 동안 강원도 정선지역 탄산염지대 지하수 및 하천수의 ${\delta}^{13}C$의 조사 결과, 탄산염 지대 지하수의 13C는 $-12.07{\sim}-8.63$ (평균 -10.34 ), 탄사염지대 하천수의 ${\delta}^{13}C$는 $-10.32{\sim}-6.80$ (평균 -7.944 ) 이었다. 하천수와 지하수 ${\delta}^{13}C$는 수온(T)과 음의 상관관계를 보이고 물의 전기전도도(EC)와 양의 상관관계를 보이며, 여름보다 겨울에 높은 값을 보이는 반면 산화환원 전위(Eh), 용존산소(DO), pH와는 상관관계가 미약함을 보이고 있다. 탄산염지대 지하수 및 하천수의 ${\delta}^{13}C$는 연구지역의 지하수와 하천수가 탄산염암의 용해, 대기 $CO_2$와 용존 $CO_2$의 교환, 유입된 대기 $CO_2$가 물 분자와 반응하여 ${HCO_3}^-$ 이온으로 전환될 때 있는 분별작용의 효과에 의해 주로 영향을 받았으며 수중생물의 신진대사에 의한 변화는 미미한 것으로 나타났다.