• Journal of Ginseng Research
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• v.20 no.1
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• pp.111-112
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• 1996

The chemical shifts of C-21 and C-23 in the $^{13}C$-NMR for (20R)-protopanaxatriol, (20R)-ginsenoside $Rh_1$ and (20R)-ginsenoside $Rg_3$ were revised by employing some extensive 2D-NMR techniques.

• Journal of Photoscience
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• v.9 no.2
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• pp.110-113
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• 2002

We demonstrate here a dynamic structure of bacteriorhodopsin (bR) as revealed by $^{13}$ C NMR studies on [3_$^{13}$ C]_,[1-$^{13}$ C]Ala- and/or Val-labeled wild type and a variety of site-directed mutants at ambient temperature. For this purpose, well-resolved (up to twelve) I$^{13}$ C NMR peaks were assigned with reference to the displacement of peaks due to the conformation-dependent I$^{13}$ C chemical shifts and reduced peak-intensities due to site-directed mutations. Revealed bR structure was not rigid as anticipated from 2D crystals of hexagonal array but a dynamically heterogeneous, undergoing a variety of local fluctuations depending upon specific site with frequency range of 10$^2$ -10$^{8}$ Hz. In particular, dynamics- dependent suppression of peaks turned out to be very sensitive to the motion of 10$^{-4}$ s and 10$^{-5}$ s interfered with frequency of magic angle spinning and proton decoupling, respectively. It is also noteworthy that such dynamic feature is strongly dependent upon the manner of 2D crystalline packing: $^{13}$ C NMR peaks of monomeric bR yielded either highly broadened or completely suppressed signals, depending upon the type of $^{13}$ C-labeled amino-acid residues.

• 한국지구과학회:학술대회논문집
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• 2005.02a
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• pp.115-125
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• 2005

Carbon isotopic composition of a stream (Odaecheon Stream) monitored over 7 months from July 2004 to January 2005 in Gangweon Province ranges from -9.24 to -4.69‰. Strong negative correlation between ${\delta}^{13}C_{DIC}$ and water temperature suggests that temperature is a dominant factor controlling ${\delta}^{13}C_{DIC}$ in the Odaecheon Stream. The variation pattern of ${\delta}^{13}C_{DIC}$ was thought to be caused by fractionation of C isotope between stream water and atmosphere and more fractionation at reduced temperature. More fractionation of C isotope between stream water and atmosphere at reduced temperature resulted in increase of ${\delta}^{13}C_{DIC}$ of stream water in winter compared to summer. Photosynthesis and respiration of aqueous biota seem to affect little in ${\delta}^{13}C_{DIC}$ as indicated by little variation of dissolved oxygen and reverse variation pattern of Eh in the stream and scarce aqueous biota in stream water. pH seems to be controlled by $CO_2{2}$ exchange between stream water and atmosphere. During summer more $CO_2{2}$ exchange between stream water and atmosphere resulted in decrease in pH value.

• Clinical and Experimental Pediatrics
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• v.49 no.3
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• pp.268-272
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• 2006

Purpose : The reinfection rate of H. pylori reported before $^{13}C$-urea breath test($^{13}C$-UBT) era was higher than that of the post $^{13}C$-UBT era. Children are usually reluctant to receive invasive endoscopic evaluation for the reinfection of H. pylori, particularly when they are asymptomatic. The aim of the study is to discover the reinfection rate by different diagnostic tests, and to find out what causes the difference. Methods : Children confirmed to be eradicated from H. pylori were included in the study. Reinfection was evaluated by endoscopic biopsy based tests(n=34, mean age $11.5{\pm}3.7$ years) and/or a $^{13}C$-UBT(n=38, mean age $10.0{\pm}3.6$ years) at the time of 18 months after eradication. At first visit, H. pylori infection had been diagnosed by positive results from a rapid urease test, Giemsa stain and Warthin-Starry stain and/or a positive culture. Eradication was defined as negative results from all above tests 1-3 months after eradication therapy. Results : Reinfection rate by endoscopic biopsy based tests was 35.3 percent(12/34). All patients had abdominal symptoms(P=0.000). Reinfection rate was 13.2 percent(5/38) by a $^{13}C$-UBT. Reinfection rate was higher in children with abdominal symptoms(P=0.008). There was no evidence that reinfection rate depended on the sex(P=0.694), age(P=0.827), diseases(peptic ulcers vs gastritis, P=0.730) and eradication regimen(P=0.087). Conclusion : Helocibacter pylori reinfection rate in Korean children was 13.2 percent per 18 months by a non-invasive test or $^{13}C$-UBT. Accurate determinations of the reinfection rate in children is affected by the compliance of the diagnostic tests. Non-invasive tests should be considered to investigate the reinfection rate in children.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.440-445
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• 1996

An attempt was made to study the relative composition of Monohydroperoxide isomers of methyl linoleate oxidized to different peroxide values at 60, 90, 120 and $150^{\circ}C$, respectively. HPLC was used to analyze and isolate the monohydroperoxide isomers fractionated by silica gel column after reduction with NaBH.. GC-MS was used to identify four monnhydroperoxide isomers as trimethylsilyl (TMS) in mixtures of oxidized methyl linoleate In the geometrical isomers, the proportions of 9/13-OOH-trans, trant-diene were higher than those of 9/13-OOH-cis, trans-diene at $60^{\circ}C$ and $90^{\circ}C$. However in the initial stage at $150^{\circ}C$, the proportions of 9/13-OOH-cis, trans-diene were slightly higher than those of 9/13-OOH-trans, trans-diene. In case of positional isomers, equal proportions of 9-OOH-10, 12-diene and 13-OOH-9, 11-diene were found in all samples of methyl linoleate oxidized at different temperatures and peroxide levels.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.220-225
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• 2010

Soybean sprouts produced at optimal temperature are placed or displayed for several days in market shelf of relatively cool temperature (ca. $13^{\circ}C$). During this period a number of changes occur including changes in color, smell, taste, nutritional quality, etc. In order to investigate the changes of these factors, soybean sprouts packed in plastic film bag (OPP+PE) were stored at the two different temperature ($3^{\circ}C$ and $13^{\circ}C$). Morphological characters, physicochemical changes and enzymes activity related to visible quality (color) of soybean sprouts were examined. The numbers of fine roots were greater and hypocotyls were longer in soybean sprouts stored at $13^{\circ}C$, although there was no significant difference in diameter, fresh weight and dry weight of hypocotyls between the two storage temperatures. Browning of hypocotyl, as an indicator of a typical deterioration in sprout quality, was highly dependent on the activity of polyphenol oxidase (PPO). Considering the low level of soluble protein in hypocotyls, the relatively higher activity of PPO suggested a critical role of PPO in stored soybean sprouts. PPO activity of sprouts stored at $13^{\circ}C$ was 2-fold higher than that of sprouts stored at $3^{\circ}C$ after 4 days. In sprouts stored at $13^{\circ}C$, the PPO activity was increased from day 0 until 6 days and since then, it was not detected. Crude protein content was increased to 30.9~35.4% based on dry weight with extended storage period. The change in crude protein was greater in sprouts stored at high temperature ($13^{\circ}C$). Total free amino acid content was increased in both temperatures. However, the changing rate of free amino acid was greater in sprouts stored at $13^{\circ}C$.

• Journal of Sericultural and Entomological Science
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• v.14 no.2
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• pp.61-65
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• 1972

The main purpose of this experiment is to select the best combining ability among KC${\times}$N13, and C20${\times}$N13 in view of the cocoon shell weight in Bombyx mori. In the spring of 1972, the author raised silkworms which were born from the crossing of the Chinese strain KC, C14, C20(female) with japanese strain N13 (male). Among each combining of crosses, the heritability of the cocoon shell weight was estimated by the method of variance analysis. The result of the experiment may he summarized as fellow; 1. For KC${\times}$N13 The cocoon shell was heavier than other combining crosses, but its heritability was lower than the others. The heritability of male moth was higher than that of female. 3. For C14${\times}$N13 The cocoon shell and the heritability was in medium value among the combining crosses, and the heritability of female moth was higher than that of male. 3. For C20${\times}$N13 The cocoon shell weigt was lower than the others, but its heritability was higher than that of others. In these combining crosses, C20${\times}$N13 is selected as a new race, which is much better than the commercial one, 103${\times}$104.

• Journal of Korean Society of Forest Science
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• v.99 no.3
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• pp.353-358
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• 2010

In this study, we investigated the relationship of tree-ring growth with total nitrogen content, and stable carbon and nitrogen isotopes from the core samples of Pinus koraiensis (35-year-old). Annual ring width showed significant positive correlations with the ${\delta}^{13}C$ (P=0.003). The total nitrogen content (P=0.024), and the ${\delta}^{13}C$ content was also correlated with total nitrogen content (P=0.038), indicating that the growth of P. koraiensis was stimulated as the contents of both ${\delta}^{13}C$ and total nitrogen were increased. On the other hand, the less the ${\delta}^{15}N$ content and the C/N ratio were, the larger the annual ring width was. Moreover the families with relatively better growth performance contained the higher levels of ${\delta}^{13}C$ in the xylem compared to other families. These results suggest that the ${\delta}^{13}C$ and total nitrogen contents are the important determinants in the growth performance of P. koraiensis.

• Journal of the Korean Chemical Society
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• v.39 no.4
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• pp.301-305
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• 1995

The cytotoxic metabolites, against the KB cell line, halenaquinone, epispongiatriol and aldisin were isolated from the sponge Spongia sp. collected in September 1992, Manado Bay, Sulawesi in Indonesia. Their structures were elucidated by 1H, 13C NMR, 1H 13C(1 bond) Heteronuclear Multiple Quantum Coherence Spectroscopy (HMQC), 1H 13C(2 and 3 bond) Heteronuclear Multiple Bond Correlation Spectroscopy (HMBC), Electron Impact Mass Spectroscopy (EI ms) and Infrared Spectroscopy (IR).

• Journal of Aquaculture
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• v.20 no.4
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• pp.265-269
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• 2007

We studied the effects of temperature on the egg development and larvae of Takifugu pardalis. The larvae hatched 135-480 hr after fertilization in $13^{\circ}C-24^{\circ}C$ and 32 ppt. The higher the temperature the earlier the larvae hatch within $13^{\circ}C-24^{\circ}C$. The maximum hatching rate was made in $15^{\circ}C$ and 32 ppt. The higher the temperature the larger the newly hatched larvae. The larvae hatched in $24^{\circ}C$ were ca. 3.35 mm in total length. Occurrence of the deformed larvae was lower in $13^{\circ}C-18^{\circ}C$ regime and higher over $21^{\circ}C$ regime.