• Journal of Korean Society of Forest Science
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• v.109 no.4
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• pp.512-520
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• 2020

We assessed the nectar source potential of a prospective honey plant, Idesia polycarpa, by analyzing nectar volume, free sugar content, and free amino acid content. Idesia polycarpa is a dioecious tree; the males bloom approximately four days earlier than females, and the blooming period is approximately 17 days-from March 14th to March 30th. Upon investigating the patterns of nectar secretion, it was found that male flowers peak on the third day of blooming at 5.0 ± 2.5 μL, and female flowers peak on the second day of blooming, at 1.1 ± 0.4 μL. There was a significant difference between males and females in the total nectar volume (9.7 ± 2.9 μL for males and 1.7 ± 0.5 μL for females) and the dried nectar volume (2.2 ± 0.6 μL for males, 0.8 ± 0.3 μL for females) during the blooming period. The free sugar content of floral nectar was 54.6 ± 15.4 ㎍/μL for males and 20.5 ± 4.9 ㎍/μL for females, and the sugar content per flower was higher in males (170.7 ± 15.4 ㎍) than in females (24.9 ± 5.5 ㎍). Our analysis of the amino acid content showed that 20.4 ± 3.9 mg/L (comprised of 19 amino acids) is produced in male flowers and 3.2 ± 0.1 mg/L (11 amino acids) in female flowers. In the male flower, the main amino acid was glutamine, followed by asparagine and proline, whereas in the female nectar, asparagine was the main amino acid, followed by glutamic acid and glutamine. Idesia polycarpa blooms after the blooming period of a major honey plant, Robinia pseudoacacia, and its nectar volume and nectar characteristics, such as free sugar content and amino acid content, make it a viable honey plant.

• Korean Journal of Veterinary Research
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• v.41 no.3
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• pp.299-304
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• 2001

The effect of the nitric oxide synthase(NOS) inhibitor, $N^{G}$-nitro-L-arginine methyl ester (L-NAME), and the prostanoid synthesis inhibitor, indomethacin, on the vasodilatation produced in response to acetylcholine(Ach) on the isolated rabbit renal artery was examined. The vasodilatory reponses to Ach($10^{-8}-3{\times}10^{-5}M$) were completely absent in thevessel which the endothelium had previous been removed. L-NAME($10^{-4}M$) significantly reduced the vasodilatory reponse to the Ach($10^{-8}-3{\times}10^{-5}M$). When L-arginine ($10^{-3}M$) was also present in the organ bath along with L-NAME($10^{-4}M$), this inhibitory effect of L-NAME ($10^{-4}M$) on the vasodilatory response to Ach ($10^{-8}-3{\times}10^{-5}M$) was significantly attenuated, Indomethacin ($10^{-6}M$) did not significantly affect the vasodilatory responses to Ach ($10^{-8}-3{\times}10^{-5}M$). The inhibition by L-NAME ($10^{-4}M$) and indomethacin ($10^{-6}M$) on vasodilatory response to Ach was significantly greater than the inhibition due to L-NAME ($10^{-4}M$) alone. The present study has established that Ach induce relaxation via and endothelium-dependent mechanism, this relaxation to Ach involves both nitric oxide(NO) and prostanoid in the isolated rabbit renal artery.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.2
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• pp.173-180
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• 2017

In this study, air sampling locations in the stack of the Advanced Fuel Science Building (AFSB) at the Korea Atomic Energy Research Institute (KAERI) were assessed according to the ANSI/HPS N13.1-1999 specification. The velocity profile, flow angle and $10{\mu}m$ aerosol particle profile at the cross-section as functions of stack height L and stack diameter D (L/D) were assessed according to the sampling location criteria using COMSOL. The criteria for the velocity profile were found to be met at 5 L/D or more for the height, and the criteria for the average flow angle were met at all locations through this assessment. The criteria for the particle profile were met at 5 L/D and 9 L/D. However, the particle profile at the cross-section of each sampling location was found to be non-uniform. In order to establish uniformity of the particle profile, a static mixer and a perimeter ring were modeled, after which the degrees of effectiveness of these components were compared. Modeling using the static mixer indicated that the sampling locations that met the criteria for the particle profile were 5-10 L/D. When modeling using the perimeter ring, the sampling locations that met the criteria for particle profile were 5 L/D and 7-10 L/D. The criteria for the velocity profile and the average flow angle were also met at the sampling locations that met the criteria for the particle profile. The methodologies used in this study can also be applied during assessments of air sampling locations when monitoring stacks at new nuclear facilities as well as existing nuclear facilities.

• Korean Journal of Plant Tissue Culture
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• v.28 no.3
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• pp.135-140
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• 2001

A series of studies were carried out to establish micropropagation system, using airlift bioreactors (ebb $\varepsilon$ flood type, 5 L), of Lilium oriental hybrid 'Casa Blanca'. The bulblets with swollen basal plate were formed from bulb scales, then proliferated to bulblet clusters with swollen basal plate. Finally normal bulblets were formed from the sections. Bulblet formation and proliferation with swollen basal plate were not accomplished entirely in liquid culture of 5 L airlift bioreactors, but leafy bulb scales grew vigorously. Bulblet clusters with swollen basal plate were proliferated by periodic immersion culture. Bulblet proliferation was not affected by light, but scale leaves grew under light. MS medium containing 2.0 mg/L benzyl adenine (BA) and 0.3 mg/L indole acetic acid (IAA) was favorable to the bulblet proliferation with swollen basal plate. In liquid culture of 5 L bioreactors, bulblets from bulblet sections with swollen basal plate grew vigorously on MS medium with 70 g/L sucrose. It was effective for bulblet growth to replace the new medium after 8 weeks in culture during 16 weeks of cultural period. 15 g injection of bulblet sections as a cultural material was suitable for bulblet growth in 5 L bioreactors.

• Korean Journal of Food Science and Technology
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• v.35 no.4
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• pp.690-695
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• 2003

Physiological activities of 40% ethanol extracts of Phellinus ribis were studied by employing several biological and biochemical assays. The extracts of Phellinus ribis displayed nitrate-scavenging activities (NSA) at pH 1.2 as with 64% NSA with 1.0 mg/mL of the extracts. They also had 91% 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities at the concentration of 1.0 mg/mL. Antioxidant activities of the extracts (at 0.5 mg/mL) on the autoxidation of linoleic acid (p<0.001) were also observed.. The inhibitory effect of the extracts on angiotensin converting enzyme was 11%. Cytotoxic effects of Phellinus ribis extracts against human cancer cell tines were also examined using MTT assay. The extracts (at 50 mg/mL) had severe growth inhibitory effects on A549, Hela, AGS, and SK-Hep-1, which were 8, 44, 76 and 42%, respectively. Ames test indicated that the extracts had no mutating effects on Salmonella typhimurium TA98 and TA100.

• Horticultural Science & Technology
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• v.34 no.2
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• pp.249-256
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• 2016

This study was performed to investigate the effect of various concentrations of Diniconazole (DC) on the growth and quality of grafted tomato (Solanum lycopersicum) seedlings cultivated during the summer season. Concentrations of DC were set to 0 (non-treatment), 5, 10 and $20mg{\cdot}L^{-1}$, were treated once 3 days after grafting. Rootstock of the seedlings was shorter in the DC $5mg{\cdot}L^{-1}$ and $10mg{\cdot}L^{-1}$ treatment compared to the non-treatment, and the scions were significantly shorter in the DC $20mg{\cdot}L^{-1}$ treatment. Seedlings were significantly shorter in the DC $20mg{\cdot}L^{-1}$ treatment compared with the non-treatment. Leaf area was lower for seedlings subjected to all treatments than for seedlings in non-treatment group, and reduction was dose dependent. In particular, the DC $20mg{\cdot}L^{-1}$ treatment inhibited both leaf and stem growth. The fresh weighs of leaves and stems of the seedlings treated with DC $5mg{\cdot}L^{-1}$ and the fresh weights of roots subjected to all treatments were significantly greater than those of the non-treatment seedlings. Dry weight per organs of the seedlings treated with DC $5mg{\cdot}L^{-1}$ was significantly greater that of the non-treatment seedlings, but the dry weight of leaves of seedling treated with DC $20mg{\cdot}L^{-1}$ was much less than that of the non-treatment seedlings. The T/R ratio of the seedlings was lower for all treatments than for the non-treatment. The relative growth rate of the seedlings was significantly lower in the DC $20mg{\cdot}L^{-1}$ treatment and, the leaf area rate of seedlings was lower in the DC $5mg{\cdot}L^{-1}$ and $10mg{\cdot}L^{-1}$ treatment than in the non-treatment. Therefore, the optimal concentration of Dinoconazole used to produce a suitable grafted tomato seedling in the summer season is $10mg{\cdot}L^{-1}$ or less.

• Journal of Bio-Environment Control
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• v.26 no.2
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• pp.115-122
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• 2017

Objective of this research was to investigate the influence of lowered substrate pH on the reduction of bicarbonate injury in the vegetative growth of 'Ssanta' strawberry. The acid substrate was formulated by mixing sphagnum peat moss with pine bark (5:5, v/v) and the pH, EC, and CEC of the substrate were 4.07, $0.46dS{\cdot}m^{-1}$, and $91.3cmol^+{\cdot}kg^{-1}$, respectively. To adjust the pH of acid substrate, various amount of dolomitic lime [$CaMg(CO_3)_2$] were incorporated with the rate of 0 (untreated), 1, 2, 3, and $4g{\cdot}L^{-1}$. Then, mother plants were transplanted and grown with fertilizer solution containing $240mg{\cdot}L^{-1}$ of the $HCO_3{^-}$ and equal concentrations of essential nutrients to Hoagland solution. In growth of 'Ssanta' strawberry, fresh weight of mother plants were the highest in the treatment of $2g{\cdot}L^{-1}$ dolomitic lime such as 102.1 g followed by 94.7 g in $1g{\cdot}L^{-1}$, 91.2 g in $3g{\cdot}L^{-1}$, 75.7 g in $0g{\cdot}L^{-1}$ and 72.3 g in $4g{\cdot}L^{-1}$ treatments. The dry weight showed a similar tendency to fresh weight. At 140 days after transplanting, 5.8, 9.8, 11.8, 8.8, and 5.0 daughter plants were derived from each of the mother plants in the treatments of 0, 1, 2, 3, and $4g{\cdot}L^{-1}$ dolomitic lime, respectively. The highest occurrence of daughter plants were observed in the treatments $2g{\cdot}L^{-1}$ dolomitic lime. The substrate pH and bicarbonate concentration of 'Ssanta' strawberry seedlings in the 1 and $2g{\cdot}L^{-1}$ dolomitic lime treatments were maintained at a proper range such as 5.6 to 6.2. The micro-nutrient contents of above ground tissue in mother plants were the highest in $2g{\cdot}L^{-1}$ and the lowest in $4g{\cdot}L^{-1}$ dolomitic lime treatment. The above results indicate that incorporation rate of dolomitic lime in acid substrate with the pH of around 4 is $2g{\cdot}L^{-1}$ to raise the 'Ssanta' strawberry in propagation.

• Korean Journal of Ecology and Environment
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• v.44 no.1
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• pp.9-21
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• 2011

This study is conducted to know the change in water environment of Lake Hwajinpo from 2000 to 2008 with physico-chemical parameters; salinity, dissolved oxygen, total phosphorus and total nitrogen and others. And zooplanktons and phytoplanktons were studied from 2007 to 2008. From the water quality data of Lake Hwajinpo from 2000 to 200S; water temperature, salinity, transparency, chemical oxygen demand and dissolved oxygen ranges are $2.8{\sim}29.4^{\circ}C$, 0.23~33.2‰, $0.2{\sim}1.8\;m$, $0.2{\sim}20.2\;mg\;L^{-1}$ and $0.1{\sim}17.4\;mg\;L^{-1}$ and the average values are $18.0^{\circ}C$, 15.7‰, 0.7 m, $5.7\;mg\;L^{-1}$ and $8.0\;mg\;L^{-1}$, respectively. Total phosphorus (TP) and total nitrogen (TN) ranges are $0.024{\sim}0.869\;mg\;L^{-1}$ (average 0.091) and $0.240{\sim}5.310\;mg\;L^{-1}$ (average 1.235). Average TN/TP ratio is 16.4. The annual variations in COD, TP, TN and Chl.${\alpha}$ are compared. COD in 2000 is $4.83\;mg\;L^{-1}$ and 2008 is $1.80\;mg\;L^{-1}$ which is reduced by $0.34\;mg\;L^{-1}$ every year. TP in 2000 is $0.07\;mg\;L^{-1}$ and 2008 is $0.05\;mg\;L^{-1}$ reduced gradually. Yearly reduction in TN is $0.09\;mg\;L^{-1}$, in 2000 and 2008 the values are $1.54\;mg\;L^{-1}$ and $0.77\;mg\;L^{-1}$ respectivly. Chl.${\alpha}$ in 2000 is $46.30\;{\mu}g\;L^{-1}$ and $5.78\;{\mu}g\;L^{-1}$ in 2008; yearly reduction is $4.50\;{\mu}g\;L^{-1}$. The tropic state index (TSI) in south and north parts of Lake Hwajinpo in 2000 are 67 and 63 which are reduced to 63 and 59 in 2008 respectively. North and south part of Lake Hwajinpo have 67 species of phytoplankton under 47 families in 2007 and 2008. Dominant species in south part in 2007 are; Asterococcus superbus in May, Lyngbya sp. in September and Trachelomonas spp. in November and in 2008 Anabaena spiroides in August are abundant and varies with time. Zooplankton species in Lake Hwajinpo are 25 of 25 families. Dominant species in south part in May and August 2007 and May and November in 2008 Copepoda larvae and in September 2007 Protozoa spp. of Protozoan and Brachionus plicatilis and Brachionus urceolaris of Cladocera in August 2008. Dominant species in north part Asplanchna sp. of Cladecera in August and November 2007 and rest of the time are larvae of Copepoda. In this way, the water quality of Lake Hwajinpo is changing with slow rate in the long period specially nutrients concentration (TP, TN etc) is decreasing.

• BMB Reports
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• v.32 no.5
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• pp.480-485
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• 1999

Tyrosine phenol-lyase of thermophilic Symbiobacterium sp. SC-1, which is obligately and symbiotically dependent on thermophilic Bacillus sp. SK-1, was purified and characterized. The enzyme is composed of four identical subunits and contains approximately 1 mol of pyridoxal 5'-phosphate (PLP) per mol subunit as a cofactor. The enzyme showed absorption maxima at 330 and 420 nm, and lost this absorption profile by treatment with phenylhydrazine. The apparent dissociation constsnt, $K'_D$, for PLP was determined with the apoenzyme to be about $1.2\;{\mu}M$. The isoelectric point was 4.9. The optimal temperature and pH for the $\alpha,\beta$-elimination of L-tyrosine were found to be $80^{\circ}C$ and pH 8.0, respectively. The substrate specificity of the enzyme was very broad: L-amino acids including L-tyrosine, 3,4-dihydroxyphenyl-L-alanine (L-DOPA), L-cysteine, L-serine, S-methyl-L-cysteine, $\beta$-chloro-L-alanine, and S-(o-nitrophenyl)-L-cysteine all served as substrates. D-Tyrosine and D-serine were also decomposed into pyruvic acid and ammonia at rates of 7% and 31% relative to their corresponding L-enantiomers, respectively. D-Alanine, which was inert as a substrate in a, $\beta$-elimination, was the only D-amino acid racemized by the enzyme. The $K_m$ values for L-tyrosine, L-DOPA, S-(o-nitrophenyl)-L-cysteine, $\beta$-chloro-L-alanine, and S-methyl-L-cysteine were 0.19, 9.9, 0.36, 12, and 5.5 mM, respectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.1
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• pp.131-138
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• 2006

In this study, the optimum condition of pH was investigated on the hydrogen gas production under anaerobic fermentation process. The results of the experiment showed that the optimum condition was observed at pH 6, resulting in 1175.87 mL/L of hydrogen gas production rate and 22.51% theoretical hydrogen conversion ratio. Hydrogen gas production rate and theoretical hydrogen conversion ratio were 901.77 mL/L and 17.48 % respectively at pH 5. At pH 7 and 8, the production rate of hydrogen gas was little low as 82.15 mL/L. Among the organic acids from the sucrose fermentation, propionate was observed as the dominant acid at pH 7 and 8 but butyrate was the dominant at pH 5 and 6.