• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.43 no.3
• /
• pp.231-238
• /
• 2010

The Induction of regeneration and maturation in the free-living gametophytes of Ecklonia stolonifera Okamura was studied at four temperatures (5, 10, 15, and $20^{\circ}C$), four levels of irradiance (5, 10, 20, and 40 ${\mu}mol\;m^{-2}s^{-1}$) and three photoperiods (14:10, 12:12, and 10:14 h L:D). Female gametophyte fragments were maintained in active regeneration without reaching sexual maturity under $5{\sim}10^{\circ}C$, 10 ${\mu}mol\;m^{-2}s^{-1}$, 10:14 h (L:D), whereas the conditions for male gametophytes were slightly different at $20^{\circ}C$, 40 ${\mu}mol\;m^{-2}s^{-1}$, 10:14 h (L:D). The sexual maturation of female and male gametophytes was facilitated at $15^{\circ}C$, 20 ${\mu}mol\;m^{-2}s^{-1}$, 14:10 h (L:D). These results provide basic information for controlling the regeneration and maturation of the free-living gametophytes for artificial seed production of E. stolonifera.

• The Journal of the Korea Contents Association
• /
• v.6 no.10
• /
• pp.34-40
• /
• 2006

In this study, the treatment of organic matters and nutrients like Nitrogen and Phosphorus with sequencing batch reactors (SBR) was conducted. The following conclusions can be summarized from the study. The influent BOD concentration was varied 19.6 to 40.0mg/L and the effluent was 3.0 to 14.8mg/L. The variations of BOD removal efficiency during the experimental period was $47.9{\sim}88.4%$ and the average was 80.8%. The average removal efficiency was stabilized with the passage of time. Also the COD concentration was flowed into as $12.2{\sim}32.0mg/L$ and the effluent concentration was varied 3.3 to 18.6 mg/L, and then the average COD removal efficiency was 57.3%(minimun 19.2% and maximum 78.6%). But fortunately, the COD removal efficiency was also stabilized as 70.2% after 79days. In the case of T-N, the influent concentration range was $7.53{\sim}14.99mg/L$ and the effluent concentration was 6.59mg/L(the average removal efficiency was 40.3%) until the first experiment time 79days. But after normalizing the system, it was 4.44mg/L (the average removal efficiency was 56.4%). Also the influent T-P concentration was varied from 0.77 to 1.91mg/L and the effluent concentration was $0.26{\sim}1.53mg/L$. The removal efficiency was varied from 5.3 to 71.7%. considerably, therefore the average removal efficiency was 42.6%. The reason was concluded that the sludge wasn't discharged for increasing MLSS concentration.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.4
• /
• pp.586-590
• /
• 2003

The pharmacological effect of Korean-Chinese traditional herbal medicine, Hawangyeonhaedoktang (HT) on experimentally induced-triglyceride accumulation in cultured human hepatocyte HepG2 cells was studied. HePG2 cells were cultured in the Dulbecco's modified Eagle's (DME) medium without (Control medium) or with HT (0.5 mg/mL and 5.0 mg/mL) containing 1 mM oleate, 0.2% bovine serum albumin (BSA), and glucose 4.5 mg/mL for 6 and 24 hours in experiment I and 2 mM oleate, 0.5% BSA, and glucose 4.5 mg/mL for 6, 24 and in hours in Experiment II or 1 and 3 hours in Experiment III. Oleate ［$^{14}$ C］(0.5 $\mu$Ci/mL medium) added as a radioactive lipid precursor in the experiment I. In the experiment I, the intracellular triglyceride concentration was decreased remarkably during incubation for 6 and 24 hours, in a dose-dependent manner. At the same time, HT caused a decrease in the incorporation of ［$^{14}$ C］ oleate into intracellular triglyceride fraction and the secretion of triglyceride labeled with ［$^{14}$ C］ oleate into medium. In the experiment II and III compared to experiment I, the triglyceride accumulation in HepG2 cells was occurred, and HT prevented the accumulation of triglyceride during incubation for 24 and 48 hours. This result suggest that HT prevent the triglyceride accumulation in human hepatocytes by its inhibiting action on the intercellular triglyceride biosynthesis.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.41 no.5
• /
• pp.381-388
• /
• 2008

Induction of regeneration and maturation for the free-living gametophytes of Ecklonia cava Kjellman was conducted under various temperature, irradiance and photoperiod conditions. Culture conditions for female or male gametophyte fragments were 4 temperature (5, 10, 15 and $20^{\circ}C$), 4 irradiance (5, 10, 20 and $40{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and 3 photoperiod (14:10, 12:12 and 10:14 h L:D). Female and male gametophyte fragments were maintained in active regeneration without reaching sexual maturity under $5{\sim}10^{\circ}C$, $5{\sim}10{\mu}mol{\cdot}m-2{\cdot}s-1$, 12:12h or 10:14h (L:D) and $15-20^{\circ}C$, $20-40{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 14:10h (L:D), respectively. Sexual maturation of female and male gametophytes facilitated under $15^{\circ}C$, $20-40{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 14:10h (L:D) and $5-10^{\circ}C$, $5-10{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 10:14h (L:D), respectively. These results provide basic informations to control the regeneration or maturation of the free-living gametophytes for artificial seed production of E. cava.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.44 no.2
• /
• pp.155-161
• /
• 2011

Induction of regeneration and maturation of the free-living gametophytes of Undariopsis peterseniana (Kjellman) Miyabe et Okamura was studied at four temperatures (5, 10, 15, and $20^{\circ}C$), four levels of irradiance (5, 10, 20, and 40 ${\mu}mol$ $m^{-2}\;s^{-1}$) and three photoperiods (14:10, 12:12, and 10:14 h L:D). Female gametophyte fragments were maintained in active regeneration without reaching sexual maturity under conditions of $15^{\circ}C$, 20 ${\mu}mol\;m^{-2}\;s^{-1}$, 10:14 h (L:D), whereas the conditions for male gametophytes were slightly different at $15^{\circ}C$, 20 ${\mu}mol\;m^{-2}\;s^{-1}$, 14:10 h (L:D). The sexual maturation of female and male gametophytes took place under $15^{\circ}C$, 20 ${\mu}mol\;m^{-2}\;s^{-1}$, 14:10 h (L:D) and $10^{\circ}C$, 10 ${\mu}mol\;m^{-2}\;s^{-1}$, 10:14 h (L:D), respectively. These results provide basic information for controlling the regeneration and maturation of free-living gametophytes for artificial seed production of U. peterseniana.

• The Korean Journal of Mycology
• /
• v.39 no.3
• /
• pp.249-253
• /
• 2011

Cetecol has been known as a component of melanin in teliospores of the corn smut fungus Ustilago maydis. Its metabolic precursor has been assumed to be benzoic acid but it has not been proven yet. This study was carried out to verify the synthesis of benzoic acid and to chase its metabolic origin in U. maydis. For this aim, the catabolic process of phenylalanine was investigated by culturing the fungus in the complete medium containing L-$^{14}C$-phenylalanine and $^{14}C$-trans-cinnamic acid. We detected trans-cinnamic acid, benzoic acid, 4-hydroxybenzoic acid and hydroxybenzoic acid derivatives from the extracts of the fungus cells and cultural filtrates by thin layered chromatography analysis. We also observed that the fungus could completely catabolize L-$^{14}C$-phenylalanine and produce $^{14}CO_2$ in the air. Conclusively, this study provided an evidence that U. maydis could produce benzoic acid through catabolic process of phenylalanine.

• Phonetics and Speech Sciences
• /
• v.14 no.4
• /
• pp.19-24
• /
• 2022

This study examined which acoustic cue(s) that Korean learners of English give weight to in perceiving English lexical stress. We manipulated segmental and suprasegmental cues in 5 steps in the first and second syllables of an English stress minimal pair "object". A total of 27 subjects (14 native speakers of English and 13 Korean L2 learners) participated in the English stress judgment task. The results revealed that native Korean listeners used the F0 and intensity cues in identifying English stress and weighted vowel quality most strongly, as native English listeners did. These results indicate that Korean learners' experience with these cues in L1 prosody can help them attend to these cues in their L2 perception. However, L2 learners' perceptual attention is not entirely predicted by their linguistic experience with specific acoustic cues in their native language.

• Korean Journal of Clinical Laboratory Science
• /
• v.46 no.4
• /
• pp.117-123
• /
• 2014

Creatinine is a general marker as a screening test for renal disease. This study was conducted to provide basic data about pediatric concentration for serum and urine creatinine. The data from the 2011 Korean National Health and Nutrition Examination Survey was used. Analysis was done on 488 Children and Adolescents (boys 278, girls 210) aged 10 to 19, the Jaffe reaction method was used to gather the data. The highest serum creatinine levels were found in boys aged 19 to 20 years, the mean being 0.97 mg/dL (min 0.81 mg/dL, max 1.14 mg/dL). The levels showed increase over those in the 10 year old group. The highest urine creatinine levels were found aged 19 to 20 years, and the mean was 222.68 mg/dL (min 133 mg/dL, max 324 mg/dL). In the case of girls, the highest serum creatinine levels were found with those aged between 18 and 19, the mean being 0.71 mg/dL (min 0.49 mg/dL, max 0.84 mg/dL). The levels showed increase over the 11 to 18 year old group. The highest urine creatinine levels were found aged 14 to 15 years, and the mean was 218.44 mg/dL (min 131 mg/dL, max 321 mg/dL). The mean difference in serum creatinine in all age groups was statistically significant except for those aged 10 to 14, that of urine creatinine in all age groups was not significant statistically except for those aged 12 to 13, 17 to 18. Therefore, it is suggested that reference values for children and adolescents should be divided into different groups according to gender, further studies are needed using complementing data of the pediatrics.

• Biomolecules & Therapeutics
• /
• v.32 no.1
• /
• pp.154-161
• /
• 2024

Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disorder that causes progressive paralysis. L-Citrulline is a nonessential neutral amino acid produced by L-arginine via nitric oxide synthase (NOS). According to previous studies, the pathogenesis of ALS entails glutamate toxicity, oxidative stress, protein misfolding, and neurofilament disruption. In addition, L-citrulline prevents neuronal cell death in brain ischemia; therefore, we investigated the change in the transport of L-citrulline under various pathological conditions in a cell line model of ALS. We examined the uptake of [¹⁴C]L-citrulline in wild-type (hSOD1wt/WT) and mutant NSC-34/ SOD1^G93A (MT) cell lines. The cell viability was determined via MTT assay. A transport study was performed to determine the uptake of [¹⁴C]L-citrulline. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis was performed to determine the expression levels of rat large neutral amino acid transported 1 (rLAT1) in ALS cell lines. Nitric oxide (NO) assay was performed using Griess reagent. L-Citrulline had a restorative effect on glutamate induced cell death, and increased [¹⁴C]L-citrulline uptake and mRNA levels of the large neutral amino acid transporter (LAT1) in the glutamate-treated ALS disease model (MT). NO levels increased significantly when MT cells were pretreated with glutamate for 24 h and restored by co-treatment with L-citrulline. Co-treatment of MT cells with L-arginine, an NO donor, increased NO levels. NSC-34 cells exposed to high glucose conditions showed a significant increase in [¹⁴C]L-citrulline uptake and LAT1 mRNA expression levels, which were restored to normal levels upon co-treatment with unlabeled L-citrulline. In contrast, exposure of the MT cell line to tumor necrosis factor alpha, lipopolysaccharides, and hypertonic condition decreased the uptake significantly which was restored to the normal level by co-treating with unlabeled L-citrulline. L-Citrulline can restore NO levels and cellular uptake in ALS-affected cells with glutamate cytotoxicity, pro-inflammatory cytokines, or other pathological states, suggesting that L-citrulline supplementation in ALS may play a key role in providing neuroprotection.

• Bulletin of the Korean Chemical Society
• /
• v.14 no.2
• /
• pp.191-195
• /
• 1993

Molecular orbital calculations at the extended Huckel level have been carried out for an electron deficient cluster, $Tl_3(FeL_3)_2{(FeL_4)_3}^{-3}$, where L=CO or $H^-$. The LUMO, $2a_2$", is destabilized by the secondary interaction of the LUMO with $1a_2$" on $(FeL_3)_2$ fragment. This is one of six skeletal bonding orbitals which are associated with $Tl-FeL_3$ bonds. Overlap population analysis has been applied to account for two kinds of Tl-Fe bonds. Replacement of the terminal $C_{3v}$, $FeL_4$, by the $C_{2v}$, $FeL_4$ units in cluster results in slight energy stabilization of the cluster.