• Horticultural Science & Technology
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• v.30 no.2
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• pp.152-157
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• 2012

We investigated the effect of 1-methylcyclopropene (1-MCP) on ethylene production induced by simulated transport stress in $Begonia$ ${\times}$ $hiemalis$ 'Blitz' and 'Carnival' to improve the display life in potted plants. The simulated transportation conditions were imposed for 4 days in simulated export containers with darkness, vibration with continuous shaking ($150{\pm}20$ rpm) on a rotary lab shaker, and low temperature ($12^{\circ}C$). Plants were treated with 1-MCP at three concentrations (5, 25, or 125 $nL{\cdot}L^{-1}$) and for three different periods (0, 6, or 12 hours) before undergoing the simulated transport stress treatments. Treatment with 25 or 125 $nL{\cdot}L^{-1}$ 1-MCP inhibited the abscission of open flowers by more than 40% as compared to the untreated plants. One week after the treatments, the ethylene production decreased in the plants treated with 125 $nL{\cdot}L^{-1}$ 1-MCP for 'Blitz' and 25 $nL{\cdot}L^{-1}$ for 'Carnival'. Ethylene production was correlated with concentration and duration of 1-MCP treatment in 'Blitz', but not in 'Carnival'. To reduce flower abscission and ethylene production, thus improve the display life when plants are exposed to transportation stress, we recommend pre-treatment with 1-MCP before packaging, using concentrations and durations specific to each cultivar, 125 $nL{\cdot}L^{-1}$ for 6 h and 25 $nL{\cdot}L^{-1}$ for 12 hours for 'Blitz' and 'Carnival', respectively.

• Journal of the Korean Wood Science and Technology
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• v.35 no.4
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• pp.61-66
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• 2007

The study was performed to purify and characterize laccase in culture of Trametes versicolor. The fungus was grown in liquid culture media of PDB and added 2,5-xylidine (0.2 mM) after 5 days to enhance the production of laccase. The fungal culture was incubated at $25^{\circ}C$ on a rotary shaker (120 rpm) for 7days, and the culture broth was clarified through Glass filter (GF/C). The aqueous solution was concentrated by ultramicrofiltration (Viva flow 50, GE Healthcare Bioscience, USA) and loaded onto a Hitrap Q FF column. Laccase activity could be detected at one peak, and this enzyme has a molecular mass of approximately 53kDa as determined by SDS-PAGE The optimum pH and temperature for syringaldazine were 5.0 and $60^{\circ}C$, respectively. The specific activity of crude, concentrated and purified laccase were 32, 409, and 1,243 U/mg, respectively.

• KEPCO Journal on Electric Power and Energy
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• v.3 no.2
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• pp.107-111
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• 2017

The reliability on high cycle fatigue damage mechanism for new blades manufactured by reverse-engineering is demonstrated by success-run test. Turbine blades always experience various dynamic loads in turbine operation, as well as being in resonance condition and forced by fluid-induced vibrations mostly during run-up/down, which may accumulate high cycle damage to the blades. The accidents caused by blade failure especially incur not only a lot of troubles to the machinery but also huge financial losses. Therefore it is necessary to verify the reliability of blades in advance for the safe use. The success run test for the reliability demonstration is designed and performed for the new blades using the technique known as resonant high cycle fatigue testing.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.10 no.S_2
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• pp.79-88
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• 2001

Humic acids react with chlorine to produce Trihalomethanes(THMs), known as carcinogens, during disinfection, the last stage in water purification. Currently, the removal of organic humic acids is considered the best approach to solve the problem of THM formation. Accordingly, the current study examined the adsorption of organic compounds of humic acids onto an inorganic carrier prepared from oyster shell waste. The adsorbent used was activated oyster shell powder(HAP) and silver ion-exchanged oyster shell powder(HAP-Ag), with CaCO$_3$ as the control. The adsorbates were phthalic acid, chelidamic acid, catechol, dodecylpyridinium chloride(DP), and 2-ethyl phenol(2-EP). The adsorption experiments were carried out in a batch shaker at $25^{\circ}C$ for 15 hours. The equilibrium concentration of the adsorbate solution was analyzed using a UV spectrophotometer and the data fitted to the Langmuir isotherm model. Since the solution pH values were found to be greater than the pKa values of the organic compounds used as adsorbates, the compounds apparently existed in ionic form. The adsorptive affinities of the organic acid and phenolic compounds varied depending on the interaction of electrostatic forces, ion exchange, and chelation. More carboxylic acids and catechol, rather than DP and 2-EP, were adsorbed onto HAP and HAP-Ag. HAP and HAP-Ag exhibited a greater adsorptive affinity for the organic compounds than CaCO$_3$, used as the control.

• Advances in concrete construction
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• v.8 no.4
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• pp.285-294
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• 2019

In the present paper, the fiber theory has been employed to model the reinforced concrete (RC) deep beams (DBs) considering the reinforcing steel bar-concrete interaction. To simulate numerically the behavior of materials, the uniaxial materials' constitutive laws have been employed for reinforcements and concrete and the bond stress-slip between the reinforcing steel bars and surrounding concrete are taken into account. Because of the high sensitivity of DBs to shear deformations, the Timoshenko beam theory has been applied. The shear stress-strain (S-SS) relationship has been defined by the modified compression field theory (MCFT) model. By modeling about 300 RC panels and employing a produced numerical database, a study has been carried out to show the sensitivity of the MCFT model. This is performed based on the multiple linear regression (MLR) models. The results of this research also illustrate how different parameters such as characteristic compressive strength of concrete, yield strength of reinforcements and the percentages of reinforcements in different directions get involved in the shear behavior of RC panels without applying complex theories. Based on the results obtained from the analysis of the MCFT S-SS model, a relatively simplified numerical S-SS model has been proposed. Application of the proposed S-SS model in modeling and analyzing the considered samples indicates that there is a good agreement between the simulated and the experimental test results. The comparison between the proposed S-SS model and the MCFT model indicates that in addition to the advantage of better accuracy, the main advantage of the proposed method is simplicity in application.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3285-3291
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• 2015

Background: Non-synonymous polymorphisms in XRCC1 hase been shown to reduce effectiveness of DNA repair and be associated with risk of certain cancers. In this study we aimed to clarify any association between XRCC1 Arg399Gln and colorectal cancer (CRC) risk by performing a meta-analysis of published case-control studies. Materials and Methods: PubMed and Google Scholar were searched to explore the association between XRCC1 and CRC. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the association strength. Publication bias was assessed by Egger's and Begg's tests. Results: Up to January 2015, 35 case control studies involving 9,114 CRC cases and 13,948 controls were included in the present meta-analysis. The results showed that the Arg399Gln polymorphism only under an allele genetic model was associated with CRC risk (A vs. G: OR 0.128, 95% CI 0.119-0.138, p<0.001). Also, this meta-analysis suggested that the XRCC1 Arg399Gln polymorphism might associated with susceptibility to CRC in Asians (A vs G: OR 0.124, 95% CI 0.112-0.138, p<0.001) and Caucasian (A vs G: OR 0.132, 95% CI 0.119-0.146, p<0.001) only under an allele genetic model. Conclusions: This meta-analysis confirms the association between XRCC1 Arg399Gln polymorphism and CRC risk and suggests that the heterogeneity is not strongly modified by ethnicity and deviation from the Hardy-Weinberg equilibrium.

• Journal of Microbiology and Biotechnology
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• v.23 no.6
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• pp.864-871
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• 2013

The recombinant strain P. pastoris GS115-lccC was used to produce laccase with high activity. Factors influencing laccase expression, such as pH, methanol concentration, copper concentration, peptone concentration, shaker rotate speed, and medium volume were investigated. Under the optimal conditions, laccase activity reached 12,344 U/L on day 15. The recombinant enzyme was purified by precipitating and dialyzing to electrophoretic homogeneity, and was estimated to have a molecular mass of about 58 kDa. When guaiacol was the substrate, the laccase showed the highest activity at pH 5.0 and was stable when the pH was 4.5~6.0. The optimal temperature for the laccase to oxidize guaiacol was $60^{\circ}C$, but it was not stable at high temperature. The enzyme could remain stable at $30^{\circ}C$ for 5 days. The recombinant laccase was used to degrade chlorpyrifos in several laccase/mediator systems. Among three synthetic mediators (ABTS, HBT, VA) and three natural mediators (vanillin, 2,6-DMP, and guaiacol), vanillin showed the most enhancement on degradation of chlorpyrifos. Both laccase and vanillin were responsible for the degradation of chlorpyrifos. A higher dosage of vanillin may promote a higher level of degradation of chlorpyrifos, and the 2-step addition of vanillin led to 98% chlorpyrifos degradation. The degradation of chlorpyrifos was faster in the L/V system ($k_{obs}$ = 0.151) than that in the buffer solution ($k_{obs}$ = 0.028).

• Microbiology and Biotechnology Letters
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• v.15 no.6
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• pp.381-387
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• 1987

Distribution of superoxide dismutase (SOD) which catalyzes the dismutation of superoxide radicals to hydrogen peroxide and oxygen has been examined in various genera of bacteria. SOD was produced by various bacteria independent of genus and species with variation in superoxide dismutase activity of each bacteria. Bacillus circulans which produced relatively large amount of SOD was selected and used to investigate the optimum culture conditions and further studies. The compositions of optimum culture medium for the enzyme production were 1% glucose, 2% polypeptone, 0.l% NaCl, and 0.2mM of methyl viologen and initial pH was 6.0. The highest enzyme production was observed after 20 hours of cultivation at 3$0^{\circ}C$ on a reciprocal shaker. The enzyme activity was maintained stably for a relatively long period by the addition of 5% ethanol in pH 5.0, 0.01M acetate buffer.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.1
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• pp.75-82
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• 2016

Paroxetine, a selective serotonin reuptake inhibitor (SSRI), has been reported to have an effect on several ion channels including human ether-a-go-go-related gene in a SSRI-independent manner. These results suggest that paroxetine may cause side effects on cardiac system. In this study, we investigated the effect of paroxetine on Kv1.5, which is one of cardiac ion channels. The action of paroxetine on the cloned neuronal rat Kv1.5 channels stably expressed in Chinese hamster ovary cells was investigated using the whole-cell patch-clamp technique. Paroxetine reduced Kv1.5 whole-cell currents in a reversible concentration-dependent manner, with an $IC_{50}$ value and a Hill coefficient of $4.11{\mu}M$ and 0.98, respectively. Paroxetine accelerated the decay rate of inactivation of Kv1.5 currents without modifying the kinetics of current activation. The inhibition increased steeply between -30 and 0 mV, which corresponded with the voltage range for channel opening. In the voltage range positive to 0 mV, inhibition displayed a weak voltage dependence, consistent with an electrical distance ${\delta}$ of 0.32. The binding ($k_{+1}$) and unbinding ($k_{-1}$) rate constants for paroxetine-induced block of Kv1.5 were $4.9{\mu}M^{-1}s^{-1}$ and $16.1s^{-1}$, respectively. The theoretical $K_D$ value derived by $k_{-1}/k_{+1}$ yielded $3.3{\mu}M$. Paroxetine slowed the deactivation time course, resulting in a tail crossover phenomenon when the tail currents, recorded in the presence and absence of paroxetine, were superimposed. Inhibition of Kv1.5 by paroxetine was use-dependent. The present results suggest that paroxetine acts on Kv1.5 currents as an open-channel blocker.

• The Plant Pathology Journal
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• v.19 no.2
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• pp.92-96
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• 2003

The study was conducted to determine the cultural conditions and the effect of inert fillers for melanization and sporulation abilities of sodium alginate pellets, and the weeding efficacy of the formula in the field. Melanin production of E. nematosporus was affected by striking frequency. Percentage of melanized beads was increased to 80.6% at higher rpm up to 180. The melanized pellets produced more conidia with abundant mucilage than unmelanized pellets. Shaker culture of Epicoccosorus nematosporus with sodium alginate yielded a total of 55 mg per 100 pellets. Percentage of melanized pellets was highest with 81.0% and 83.3% of melanization, when wheat bran and rice polish were amended and produced the conidia with 65.4 and 68.4 mg per 100 pellets, respectively. When 1 L of conidial suspension of 6.0$\times$$10^5$ conidia per ml was applied on 30-day-old plants in a plot, 74.5% of the plants were killed within 20 days, whereas, its melanized sodium alginate pellets killed 57.8% of the plants in the same period. The number of tuber formation of Eleocharis kuroguwai in the untreated control plots was 128.5 per plot, but those of the plots treated with conidial suspension and melanized pellets were 22.1 and 39.7, respectively, at the end of the season. Results of this study showed that melanization of mycelia-mixed sodium alginate are an important sporulation factor in E. namatosporus as a mycoherbicide.