• Journal of Microbiology and Biotechnology
• /
• 제32권1호
• /
• pp.126-140
• /
• 2022

Stem cells can be applied usefully in basic research and clinical field due to their differentiation and self-renewal capacity. The aim of this study was to establish an effective novel therapeutic cellular source and create its molecular expression profile map to elucidate the possible therapeutic mechanism and signaling pathway. We successfully obtained a mesenchymal stem cell population from human embryonic stem cells (hESCs) cultured on chemically defined feeder-free conditions and treated with connective tissue growth factor (CTGF) and performed the expressive proteomic approach to elucidate the molecular basis. We further selected 12 differentially expressed proteins in CTGF-induced hESC-derived mesenchymal stem cells (C-hESC-MSCs), which were found to be involved in the metabolic process, immune response, cell signaling, and cell proliferation, as compared to bone marrow derived-MSCs(BM-MSCs). Moreover, these up-regulated proteins were potentially related to the Wnt/β-catenin pathway. These results suggest that C-hESC-MSCs are a highly proliferative cell population, which can interact with the Wnt/β-catenin signaling pathway; thus, due to the upregulated cell survival ability or downregulated apoptosis effects of C-hESC-MSCs, these can be used as an unlimited cellular source in the cell therapy field for a higher therapeutic potential. Overall, the study provided valuable insights into the molecular functioning of hESC derivatives as a valuable cellular source.

• 한국대기환경학회지
• /
• 제22권3호
• /
• pp.287-295
• /
• 2006

PAHs (Polycyclic Aromatic Hydrocarbons), one of the carcinogenic materials in environment, were investigated in this study. The standardized analysis conditions were tested, and then various factors which affect to the ambient PAHs concentration in Seoul were estimated. Moreover, the emissions of PAHs from major stationary sources were investigated to determine the quantitative relationships between ambient PAHs concentrations and emission sources. From the factor analysis, three factors relevant to the ambient PAHs in Seoul were found. Factor 1 was related to the concentrations of chrysene, pyrene, indeno (1, 2, 3-cd)pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo prerylene which were mainly emitted from gasoline and diesel fueled cars. Factor 2 showed higher loadings in phenanthrene and anthracene which were due to LNG and BC oil combustion in industry and home. And factor 3 included dibenz(a, h)anthracene and acenaphthene which were emitted from open burning and municipal solid waste incineration. Conclusively, all of three factors were consisted in 82% of total variance. The contribution of mobile sources in ambient air in Seoul was estimated at 64%, that of industrial and home sources at 17%, and that of open burning and municipal incineration at 1%.

• 전기학회논문지
• /
• 제61권10호
• /
• pp.1442-1447
• /
• 2012

In this paper, direct power control system for three-phase PWM AC/DC converter without the source voltage sensors is proposed. The sinusoidal input current and unity effective power factor are realised based on the estimated flux in the observer. Both active and reactive power calculated using estimated flux. The estimation of flux is performed based on the Reduced-order flux observer using the actual currents and the command control voltage. The source voltage sensors are replaced by a flux estimator. The active and reactive powers estimation are performed based on the estimated flux and Phase anble. The proposed algorithm is verified through simulation and experiment.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
• /
• pp.71-74
• /
• 2002

We have development the dimming controller using the ac chopper technique. The ac chopper change the amplitude of the input source voltage with the unchanged its frequency. The conventional dimming controller is operated by controlling voltage phase and is consist of the triac. It has a bad characteristic about a current THD and a power factor. But the dimming controller using the at chopper technique has a low current THD and a good power factor. The developed dimming controller is consist of the MOSFET and the low pass filter. The system is operated by the variation circuit of the input source voltage and the microprocessor.

• 한국지열·수열에너지학회논문집
• /
• 제9권2호
• /
• pp.8-15
• /
• 2013

Recently, an interest in the use of renewable energy has been growing up due to the rise of raw material price, international oil price and depletion of fossil energy. Ground source heat pump system has a high efficiency by using the constant temperature of underground and various types of the systems have been installed and utilized in the building. there are few studies on the system performance factors in the SCW system. Furthermore, even though the performance of the system depends on the temperature of heat source, the research on their relationship is rare. In this research, in order to analyze the performance factor for the open-loop system the monitoring of the real building with the standing column well systems and the simulation with building model were conducted.

• 한국미생물·생명공학회지
• /
• 제23권3호
• /
• pp.311-315
• /
• 1995

Assay conditions for screening of $\beta$-1,3-glucan synthase inhibitor were evaluated. Cells in the beginning of mid-log phase showed the highest activity of the $\beta$-1,3-glucan synthase. Cells permeabilized with 1% digitonin treatment could be used as a good crude enzyme source for convenient screening of the $\beta$-1,3-glucan synthase inhibitors. Calcofluor white (0.125% in final) and papulacandin B (25 $\mu$g/ml) inhibit 90% and more than 50% of the $\beta$-1,3-glucan synthase activity, respectively. Cells grown at 37$\circ$C showed higher enzyme activity than those of 25$\circ$C. Catalytic factor of the $\beta$-1,3-glucan synthase was solubilized from particulated membrane preparations, holoenzyme, by extracting with 0.00938% CHAPS.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
• /
• pp.395-397
• /
• 1999

This paper presents a method of improving the power factor and the waveform of A.C line currents and the out waveforms of AC to DC fully bridge converter systems which is achieved by connecting converters in series and parallel. The results of simulation show that the power factor and the source voltage and current waveforms are improved by the method of connecting converter in series, and the controlled input voltage and current waveform using a current limit controller.

• 한국가구학회지
• /
• 제22권2호
• /
• pp.118-125
• /
• 2011

These days global warming is the most important problem and the most important factor is high emission of carbon dioxide. The 23% of carbon dioxide emission for building construction must be reduced. Thermal conductivity is the most basic factor that can decrease the energy consumption especially insulation. Therefore, an accurate and continuous thermal conductivity measurement can be a way to save energy. In this paper, there are methods about how to investigate thermal conductivity measurements and comparing two methods which are the Heat Flow Meter 436 and TCi.

• Applied Microscopy
• /
• 제33권4호
• /
• pp.251-259
• /
• 2003

물질의 구조 특성파악에 많이 사용되는 X-선과 전자선에 대한 소스 원을 살펴보고 물질과의 반응을 atomic scattering factor의 항으로 설명하였다. 물질과의 회절을 역 격자 공간에서의 Ewald sphere로 설명하고 유한 크기의 소스 파장과 검출기의 효과도 함께 고려하였다.

• 보건행정학회지
• /
• 제4권1호
• /
• pp.123-137
• /
• 1994

The objectives of this research is to find the factors which determined hospital profitability. The unit of analysis is hospital, and the data is collected from two sources. One source is derived from Ministry of Health and Social Affairs(4 years' data from 134 hospitals), and another source is derived from Sam-II Accounting Co.(1 year's data from 37 hospitals). Hospital profitability, which is dependent variable in our research, is measured with financial ration, such as ROI(reture on investment). The major findings are as follows; 1) The hospital profitability is determined with not hospital type itself but management-incentives associated with hospital type. 2) The maximum profitability is obtained in 775 bed-size. 3) The hospital location isn't a factor to determine profitability 4) The internal control and management, such as account receivables, inventory, fixed assert investment, is major factor to hospital profitability.