• Journal of Microbiology
• /
• v.43 no.5
• /
• pp.417-423
• /
• 2005

In this study, the nematode-trapping fungus, Monacrosporium sphaeroides, was transformed with a plasmid harboring the hygromycin B phosphotransferase gene, via restriction enzyme-mediated integration (REMI). Frequencies of up to 94 transformants ${\mu}g^{-1}$ per linearized plasmid DNA were obtained by optimizing the PEG concentration, as well as the category and quantity of the added restriction enzyme. $90\%$ of the transformants were determined to be stable for drug resistance when 20 randomly selected transformants were tested. Southern analyses revealed that the transforming DNA was integrated into the M. sphaeroides genome either with or without rearrangement. Five mitotic stable mutant strains were obtained using this approach, all of which had been altered with regard to sporulation capacity and pathogenicity toward nematodes. Southern blot analyses of the five mutants revealed that foreign plasmid DNA had integrated into the genome. Three of the mutants, Tms2316, Tms3583 and Tms1536, exhibited integration at a single location, whereas the remaining two, Tms32 and Tms1913, manifested integration at double or multiple locations. Our results suggest that the transformation of M. sphaeroides via REMI will facilitate insertional mutagenesis, the functional analysis of a variety of genes, and the tagging or cloning of genes of interest.

• Journal of the Optical Society of Korea
• /
• v.18 no.3
• /
• pp.274-282
• /
• 2014

In this study, closely spaced Au nanoparticles which are arranged in nanocluster (heptamer) configurations have been employed to design efficient plasmonic subwavelength devices to function at the telecommunication spectrum (${\lambda}$~1550 nm). Utilizing two kinds of nanoparticles, the optical properties of heptamer clusters composed of Au rod and shell particles that are oriented in triphenylene molecular fashion have been investigated numerically, and the cross-sectional profiles of the scattering and absorption of the optical power have been calculated based on a finite-difference time-domain (FDTD) method. Plasmon hybridization theory has been utilized as a theoretical approach to characterize the features and properties of the adjacent and mutual heptamer clusters. Using these given nanostructures, we designed a complex four-branch ($1{\times}4$) Y-shape splitter that is able to work at the near infrared region (NIR). This splitter divides and transmits the magnetic plasmon mode along the mutual heptamers arrays. Besides, as an important and crucial parameter, we studied the impact of arm spacing (offset distance) on the guiding and dividing of the magnetic plasmon resonance propagation and by calculating the ratio of transported power in both nanorod and nanoshell-based structures. Finally, we have presented the optimal structure, that is the four-branch Y-splitter based on shell heptamers which yields the power ratio of 23.9% at each branch, 4.4 ${\mu}m$ decaying length, and 1450 nm offset distance. These results pave the way toward the use of nanoparticles clusters in molecular fashions in designing various efficient devices that are able to be efficient at NIR.

• Current Optics and Photonics
• /
• v.1 no.1
• /
• pp.23-28
• /
• 2017

The laser has been regarded as the potential illumination source for the next generation of projectors. However, currently the major issues in applying the laser as an illumination source for projectors are beam shaping and laser speckle. We present a compact solution for both issues by using a vibrating diffractive optical element (DOE). The DOE is designed and fabricated, and it successfully transforms the circular Gaussian laser beam to a low speckle contrast uniform rectangular pattern. Under a vibration frequency of 150 Hz and amplitude of $200{\mu}m$, the speckle contrast value is reduced from 67.67% to 13.78%, and the ANSI uniformity is improved from 24.36% to 85.54%. The experimental results demonstrate the feasibility and potential of the proposed scheme, and the proposed method is a feasible approach to the miniaturization of laser projection display illumination systems.

• Journal of Ocean Engineering and Technology
• /
• v.32 no.6
• /
• pp.502-510
• /
• 2018

In order to accumulate data to lower the friction coefficient of a press mold, tribological tests were performed before and after coating SM45C with a PVC/PO film and plasma coating (CrN, concept). The ultrasonic nanocrystal surface modification (UNSM)-treated material had a nano-size surface texture, high surface hardness, and large and deep compressive residual stress formation. Even when the load was doubled, the small amount of abrasion, small weight of the abrasion, and width and depth of the abrasion did not increase as much as those of untreated materials. A comparison of the weight change before and after the tribological test with the CrN and the concept coating material and that of the untreated material showed that the wear loss of the concept coating material and P-UNSM treated material (that is, the UNSM treated material treated with the concept coating) showed a tendency to decrease by approximately 55-75%. Concept 100N had a lower friction coefficient of about 0.6, and P-UNSM-30-100N showed almost the same curve as concept 100N and had a low coefficient of friction of about 0.6. The concept multilayer coating had a thickness of $5.32{\mu}m$. In the beginning, the coefficient of friction decreased because of the plasma coating, but it started to increase from about 250-300 s. After about 350 s, the coefficient of friction tended to approach the friction coefficient of the SM45C base metal. The SGV-280F film-attached test specimen was slightly pushed back and forth, but the SM45C base material was not exposed due to abrasion. The friction coefficient was 0.22, which was the lowest, and the tribological property was the best in this study.

• Journal of Environmental Science International
• /
• v.28 no.1
• /
• pp.107-123
• /
• 2019

The aerosol chemical components in $PM_{2.5}$ in several regions (Seoul, Busan, Daejeon, and Jeju Island) were investigated with regard to their concentration characteristics and optical properties. The optical properties of the various aerosol components (e.g., water-soluble, insoluble, Black Carbon (BC), and sea-salt) were estimated using hourly and daily aerosol sampling data from the study area via a modeling approach. Overall, the water-soluble component was predominant over all other components in terms of concentration and impact on optical properties (except for the absorption coefficient of BC). The annual mean concentration and Aerosol Optical Ddepth (AOD) of the water-soluble component were highest in Seoul (at the Gwangjin site) ($26{\mu}g/m^3$ and 0.29 in 2013, respectively). Further, despite relatively moderate BC concentrations, the annual mean absorption coefficient of BC ($21.7Mm^{-1}$) was highest in Busan (at the Yeonsan site) in 2013, due to the strong light absorbing ability of BC. In addition, high AODs for the water-soluble component were observed most frequently in spring and/or winter at most of the study sites, while low values were noted in summer and/or early fall. The diurnal variation in the AOD of each component in Seoul (at the Gwangjin site) was slightly high in the morning and low in the afternoon during the study period; however, such distinctions were not apparent in Jeju Island (at the Aweol site), except for a slightly high AOD of the water-soluble component in the morning (08:00 LST). The monthly and diurnal differences in the AOD values for each component could be attributed to the differences in their mass concentrations and Relative Humidities (RH). In a sensitivity test, the AODs estimated under RH conditions of 80 and 90% were factors of 1.2 and 1.7 higher, respectively, than the values estimated using the observed RH.

• Herbal Formula Science
• /
• v.27 no.1
• /
• pp.53-63
• /
• 2019

Objectives : In this study, we investigated the combination effects of Cinnamomi cortex Ethanol Extract (CcEE) and hyperthermia in the human AGS gastric cancer cell line. Methods : AGS cells were treated with the indicated concentrations of CcEE (0, 50 or $60{\mu}g/mL$) for 1h prior to hyperthermia. And then incubated for a further 30 min at the indicated temperatures (37, 42 or $43^{\circ}C$) in a humidified incubator containing 5% $CO_2$ or a thermostatically controlled water bath for hyperthermia. The cell viability was measured by MTT assay, Morphology assay and Trypan blue assay. To investigate the possible molecular signaling pathways, the activation of mitogen-activated protein kinase (MAPK) proteins (ERK, p38 and JNK) and expression of various anti-apoptotic proteins such as Caspase-3, Caspase-9, p53, Cyclin D1 and MMP-2 were assessed by Western blot analysis. In addition, Annexin V and 7-amino-actinomycin D (7-AAD) staining was performed to examine the apoptotic mechanism. Results : Combination of CcEE with hyperthermia effectively suppressed the cell viability and changed cellmorphology compared with CcEE or hyperthermia treatment alone. Combined treatment also abated the expression of Caspase-3, Caspase-9, Cyclin D1 and MMP-2. Whereas, the expression level of p53 was up-regulated by co-treatment. Moreover, combination treatment enhanced phosphorylation of ERK, p38 and JNK. In addition, this combination increased anti-cancer effect by inducing cell death through the apoptosis. Conclusions : Taken together, all these findings suggest that the combination treatment with CcEE and hyperthermia may have therapeutic potential as a promising approach to patients with stomach cancer.

• Natural Product Sciences
• /
• v.25 no.1
• /
• pp.28-33
• /
• 2019

A popular approach for the study of estrogen receptor ${\alpha}$ inhibition is to investigate the protein-protein interaction between the estrogen receptor (ER) and the coactivator surface. In our study, we investigated phytochemicals from Rubus coreanus that were able to disrupt $ER{\alpha}$ and coactivator interaction with an $ER{\alpha}$ antagonist. The E-screen assay and molecular docking analysis were performed to evaluate the effects of the estrogenic activity of R. coreanus extract and its constituents on the MCF-7 human breast cancer cell line. At $100{\mu}g/mL$, R. coreanus extract significantly stimulated cell proliferation ($574.57{\pm}8.56%$). Sanguiin H6, which was isolated from R. coreanus, demonstrated the strongest affinity for the $ER{\alpha}$ coactivator-binding site in molecular docking analysis, with a binding energy of -250.149. The initial results of the study indicated that sanguiin H6 contributed to the estrogenic activity of R. coreanus through the activation of the $ER{\alpha}$ coactivator-binding site.

• Journal of Industrial Convergence
• /
• v.16 no.1
• /
• pp.1-14
• /
• 2018

Online retail business has provided internet-based companies with the opportunities to be connected with online customers from all over the world. However, many online customers do not complete their transactions online even if they have already choose what they want because they perceive online payment service is risky or perceive difficulty of paying online. A large body of researchers have examined the important variables that influence online payment, however, these studies can hardly predict the future development tendency after five or ten years since the environment of online market changes so fast more than ever. Therefore, the purpose of this study is to examine the importance of factors affecting online payment and to provide long term dynamic decision making model for third-party payment companies and online service providers. To serve the purpose, this study used system dynamics approach to develop a model of online payment adoption and to simulate various development paths for ten years. The analysis results show that the number of online payment customers increase continuously in ten years, and service quality, system quality, and effort expectancy are key factors for customers to pay online.

• The Journal of Asian Finance, Economics and Business
• /
• v.8 no.8
• /
• pp.67-74
• /
• 2021

This study aims to examine and analyze the effect of Risk Profile, Good Corporate Governance (GCG), Earnings, Capital (RGEC), and Earnings per Share (EPS) on stock prices with financial distress as an intervening variable. The sampling technique used purposive sampling based on certain criteria and data used was secondary data, that is, annual reports of commercial banks in Indonesia for the period of 2012-2018 with a sample of 23 banks from a total population of 81 banks. This type of research is explanative with a quantitative descriptive approach to describe or explain quantitative data. The data obtained was analyzed using SEM (Structural Equation Model) with the AMOS Program. The results showed that RGEC, EPS, and financial distress affect stock prices. This is based on testing the direct effect as indicated by a p-value that is smaller than 0.05. Based on the mediation test, the results show that financial distress cannot mediate the effect of RGEC and EPS on stock prices as indicated by a p-value greater than 0.05. The implication of this research is very important for investors to analyze stock price changes based on RGEC, EPS, and financial distress to gain profits. In addition, there are various warning signs indicating that a company is experiencing financial distress or it is heading towards such a state. Being aware of these signs can help prevent failure.

• Smart Media Journal
• /
• v.12 no.6
• /
• pp.15-26
• /
• 2023

As face-to-face communication has become difficult due to the COVID-19 pandemic, studies have been conducted to understand the impact of non-face-to-face communication, but there is a lack of research that examines this through messenger application reviews. This study aims to identify the impact of the pandemic through Latent Dirichlet Allocation (LDA) topic modeling by collecting review data of 메신저 applications in the Google Play Store and suggest service strategies accordingly. The study categorized the data based on when the pandemic started and the ratings given by users. The analysis showed that messenger is mainly used by middle-aged and older people, and that family communication increased after the pandemic. Users expressed frustration with the application's updates and found it difficult to adapt to the changes. This calls for a development approach that adjusts the frequency of updates and actively listens to user feedback. Also, providing an intuitive and simple user interface (UI) is expected to improve user satisfaction.