• Title/Summary/Keyword: light utilization

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Mesenchymal stem cells for restoration of ovarian function

  • Yoon, Sook Young
    • Clinical and Experimental Reproductive Medicine
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    • v.46 no.1
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    • pp.1-7
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    • 2019
  • With the progress of regenerative medicine, mesenchymal stem cells (MSCs) have received attention as a way to restore ovarian function. It has been reported that MSCs derived from bone marrow, adipose, umbilical cord blood, menstrual blood, and amniotic fluid improved ovarian function. In light of previous studies and advances in this field, there are increased expectations regarding the utilization of MSCs to restore ovarian function. This review summarizes recent research into potential applications of MSCs in women with infertility or primary ovarian insufficiency, including cases where these conditions are induced by anticancer therapy.

Improvement of Photo Current Density in Dye-sensitized Solar Cell by Glass Texturing

  • Nam, Sang-Hun;Suk, Won;Yang, Hee-Su;Hwang, Ki-Hwan;Jin, Hyun;Seop, Kyu;Hong, Byungyou;Boo, Jin-Hyo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.423-423
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    • 2012
  • Recently, many researchers made progress in various studies improving the efficiency of dye-sensitized solar cell. In this paper, we used glass textured by wet-chemical etching process for improvement of photocurrent density in dye-sensitized solar cells. This is owing to increase coefficient of light utilization. Consequently, DSSC using the textured glass exhibit a Jsc of 9.49 mA/$cm^2$, a Voc of 0.73 V and a fill factor (FF) of 0.67 with an overall conversion efficiency of 4.64. This result showed increasing of 20% current density and 16% conversion efficiency using the textured glass. These results suggested that glass texturing was very effective in controlling the light-scattering properties into the photovoltaic cell.

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Light-weight Design of Automotive Spring Link Based on Computer Aided Engineering (컴퓨터 시뮬레이션을 이용한 자동차용 스프링 링크의 경량화 설계)

  • Park, Jun-Hyub;Kim, Kee Joo;Yoon, Jun-Gyu
    • Transactions of the Korean Society of Automotive Engineers
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    • v.21 no.5
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    • pp.157-161
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    • 2013
  • It is well known that the targeted fuel efficiency could only be achieved by more than 40% reduction of the vehicle weight through improved design and extensive utilization of lightweight materials. In order to obtain the goal of the weight reduction of automobiles, the researches about lighter and stronger spring link have been studied without sacrificing the safety of automotive components. In this study, the weight reduction design process of spring link could be proposed based on the variation of von-Mises stress contour by substituting an aluminum alloys (A356) having tensile strength of 245 MPa grade instead of SAPH440 steels. In addition, the effect of the stress and stiffness on shape variations of the spring link were examined and compared carefully. It could be reached that this approach could be well established and be contributed for light-weight design guide and the safe design conditions of the automotive spring link development.

The Stability of Carotenoid Pigments in Astringent Persimmon(Diospyros kaki) Consumed in Korea (떫은감 Carotenoid의 색소 안정성)

  • 강미정;윤경영;성종환;이광희;김광수
    • Journal of the East Asian Society of Dietary Life
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    • v.14 no.4
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    • pp.355-362
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    • 2004
  • Studies on extraction and color stability of carotenoids from astringent persimmon(Diospyros kaki) were performed to provide the basic information for the utilization of persimmon pigment as a new source of natural food colorant. The major carotenoids in astringent persimmon were beta-cryptoxanthin, lycopene and beta-carotene. Beta-cryptoxanthin was the first major pigment and lycopene the next. Total carotenoid content in persimmon calculated as beta-carotene equivalent was 107.4 $\mu\textrm{g}$/g. The data indicated that the astringent persimmon was a good source of carotenoid pigment. The physical and chemical stabilities of carotenoid from astringent persimmon were investigated at various conditions of temperature, pH and antioxidant. The effects of oxygen and light on the stability of carotenoid pigment has been investigated. The factors that cause the discoloration were visible light, temperature above 60, pH below 5 and oxygen. Especially, the carotenoid pigment was very sensitive to light and oxygen. Carotenoid stability was much improved with increasing nitrogen concentration in the atmosphere. Persimmon pigments have been found to be most stable at 5∼10. And tocopherol was the most effective inhibitor of the pigment discoloration.

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Subcellular partitioning-dependent functional switching of Arabidopsis photoreceptor phytochrome B in response to brassinosteroids

  • Ryu, Jong-Sang;Choi, Hyun-Mo;Hong, Sung-Hyun;Matsushita, Tomonao;Nagatani, Akira;Nam, Hong-Gil
    • Interdisciplinary Bio Central
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    • v.1 no.1
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    • pp.1.1-1.5
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    • 2009
  • Many organisms control their physiology and behavior in response to the local light environment, which is first perceived by photoreceptors that undergo light-dependent conformational changes. Phytochromes are one of the major photoreceptors in plants, controlling wide aspects of plant physiology by recognizing the light in red (R) and far-red (FR) spectra. Higher plants have two types of phytochromes; the photo-labile type I (phyA in Arabidopsis) and photo-stable type II (phyB-E in Arabidopsis). Phytochrome B (phyB), a member of the type II phytochromes in Arabidopsis, shows classical R and FR reversibility between the inter-convertible photoisomers, Pr and Pfr. Interestingly, the Pr and Pfr isomers show partitioning in the cytosol and nucleus, respectively. In the over 50 years since its discovery, it has been thought that the type II phytochromes only function to mediate R light. As described in the text, we have now discovered phyB has an active function in FR light. Even striking is that the R and FR light exert an opposite effect. Thus, FR light is not simply nullifying the R effect but has an opposing effect to R light. What is more interesting is that the phyB-mediated actions of FR and R light occur at different cellular compartment of the plant cell, cytosol and nucleus, respectively, which was proven through utilization of the cytosolic and nuclear-localized mutant versions of phyB. Our observations thus shoot down a major dogma in plant physiology and will be considered highly provocative in phytochrome function. We argue that it would make much more sense that plants utilize the two isoforms rather than only one form, to effectively monitor the changing environmental light information and to incorporate the information into their developmental programs.

Shear Performance of Hybrid Post and Beam Wall System Infilled with Structural Insulation Panel (SIP)

  • Shim, Kug-Bo;Hwang, Kweon-Hwan;Park, Joo-Saeng;Park, Moon-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.38 no.5
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    • pp.405-413
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    • 2010
  • A hybrid post and beam shear wall system with structural insulation panel (SIP) infill was developed as a part of a green home 'Han-green' project through post and beam construction for contemporary life style. This project is on-going at the Korea Forest Research Institute to develop a new building system which improves Korean traditional wet-type building system and stimulates industrialized wood construction practice with pre-cut system. Compared to the traditional wet-type infill wall components, the hybrid wall system has benefits, such as, higher structural capacity, better thermal insulation performance, and shorter construction term due to the dry-type construction. To build up the hybrid wall system, in previous, SIP infill wall components can be manufactured at factory, and then inserted and nailed with helically threaded nails into the post and beam members at site. Shear performance of the hybrid wall system was evaluated through horizontal shear tests. The SIP hybrid wall system showed higher maximum shear strength, initial stiffness, ductility, yield strength, specified strength, and the specified allowable strength than those of post and beam with light-frame wall system. In addition to this, the hybrid wall system can provide speedy construction and structural and functional advantages including energy efficiency in the building system.

Influence of the Educational Planning Model(ADDIE) Utilization and Self-Leadership on Work Performance among Occupational Health Managers (보건관리자의 ADDIE 모형 활용정도와 셀프 리더십이 직무성과에 미치는 영향)

  • Kim, Young-Im;Jung, Hye-Sun;Lee, Da-Ye
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.29 no.3
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    • pp.394-403
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    • 2019
  • Objectives: This study was conducted to examine the effect of the utilization of the educational planning model (ADDIE) and self-leadership of occupational health managers (OHM) on work performance. Methods: The sample of this study was 180 OHM with over six months of experience, who attended continuing education by the Korean Academic Society of Occupational Health Nursing. Data were collected from April to June 2019 and analyzed using frequency analysis, t-test, F-test, Pearson's correlation analysis, and multiple regression analysis through SPSS Program Ver. 23. Results: According to the results of multiple regression analysis of the factors influencing the work performance of OHM, the model was significant and the explanatory power was 40%. Self-leadership (${\beta}=.45$, p=.001), utilization of the educational planning model (${\beta}=.20$, p<.005), and position (${\beta}=.16$, p=.024) were significant influence factors on work performance. Conclusions: To improve the work performance of OHM, a customized program needs to be developed that promotes the utilization ability of the educational planning model and a strategy of benchmarking high performers in the light of their positions. The improvement of the work performance of OHM will eventually make a contribution to the reduction of industrial disaster and occupational diseases.

Effects of Light Intensity on Photosynthetic Activity of Shade Tolerant and Intolerant Tree Species (광도(光度)가 내음성(耐陰性)이 서로 다른 3수종(樹種)의 광합성(光合成) 생리(生理)에 미치는 영향(影響))

  • Kim, Pan-Gi;Yi, Yong-Sub;Chung, Dong-Jun;Woo, Su-Young;Sung, Joo Han;Lee, Eun Ju
    • Journal of Korean Society of Forest Science
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    • v.90 no.4
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    • pp.476-487
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    • 2001
  • In this study, three tree species (Populus euramericana, Kalopanax pictus and Quercus serrata) exhibiting different levels of shade tolerance were employed to investigate photosynthetic responses to the lower light condition on forest floors. Chlorophyll contents, spectral properties and photosynthetic characteristics were examined by using the tree species grown under high light intensity (PPFD $920{\mu}mol\;m^{-2}s^{-1}$) or low light intensity (PPFD $80{\mu}mol\;m^{-2}s^{-1}$). Plants grown under the low light intensity tended to have reduced leaf area, chlorophyll content per unit leaf area, light absorption and respiration in the shade intolerant tree species of P. euramericana. However, the shade tolerant species K. pictus and Q. serrata showed increased leaf area, chlorophyll content and net apparent quantum yield. Therefore, light absorption and light utilization efficiency were improved under the low light intensity. Also shade tolerant species maintained activities of photosystems and $CO_2$ fixation systems with little changes in low light intensity condition.

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Isolation of Mouse Ig Heavy and Light Chain Genomic DNA Clones, and Construction of Gene Knockout Vector for the Generation of Humanized Xenomouse (인간 단클론 항체 생산용 Humanized Xenomouse 제작의 기초 소재인 생쥐 Ig 중사슬 및 경사슬 Genomic DNA 클론의 확보 및 유전자 적중 벡터의 제작)

  • Lee, Hee-kyung;Cha, Sang-hoon
    • IMMUNE NETWORK
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    • v.2 no.4
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    • pp.233-241
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    • 2002
  • Background: Monoclonal antibodies (mAb) of rodent origin are produced with ease by hybridoma fusion technique, and have been successfully used as therapeutic reagents for humans after humanization by genetic engineering. However, utilization of these antibodies for therapeutic purpose has been limited by the fact that they act as immunogens in human body causing undesired side effects. So far, there have been several attempts to produce human mAbs for effective in vivo diagnostic or therapeutic reagents including the use of humanized xenomouse that is generated by mating knockout mice which lost Ig heavy and light chain genes by homologous recombination and transgenic mice having both human Ig heavy and light gene loci in their genome. Methods: Genomic DNA fragments of mouse Ig heavy and light chain were obtained from a mouse brain ${\lambda}$ genomic library by PCR screening and cloned into a targeting vector with ultimate goal of generating Ig knockout mouse. Results: Through PCR screening of the genomic library, three heavy chain and three light chain Ig gene fragments were identified, and restriction map of one of the heavy chain gene fragments was determined. Then heavy chain Ig gene fragments were subcloned into a targeting vector. The resulting construct was introduced into embryonic stem cells. Antibiotic selection of transfected cells is under the progress. Conclusion: Generation of xenomouse is particularly important in medical biotechnology. However, this goal is not easily achieved due to the technical difficulties as well as huge financial expenses. Although we are in the early stage of a long-term project, our results, at least, partially contribute the successful generation of humanized xenomouse in Korea.

Optimal Temperature and Light Intensity for Improved Mixotrophic Metabolism of Chlorella sorokiniana Treating Livestock Wastewater

  • Lee, Tae-Hun;Jang, Jae Kyung;Kim, Hyun-Woo
    • Journal of Microbiology and Biotechnology
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    • v.27 no.11
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    • pp.2010-2018
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    • 2017
  • Mixotrophic microalgal growth gives a great premise for wastewater treatment based on photoautotrophic nutrient utilization and heterotrophic organic removal while producing renewable biomass. There remains a need for a control strategy to enrich them in a photobioreactor. This study performed a series of batch experiments using a mixotroph, Chlorella sorokiniana, to characterize optimal guidelines of mixotrophic growth based on a statistical design of the experiment. Using a central composite design, this study evaluated how temperature and light irradiance are associated with $CO_2$ capture and organic carbon respiration through biomass production and ammonia removal kinetics. By conducting regressions on the experimental data, response surfaces were created to suggest proper ranges of temperature and light irradiance that mixotrophs can beneficially use as two types of energy sources. The results identified that efficient mixotrophic metabolism of Chlorella sorokiniana for organics and inorganics occurs at the temperature of $30-40^{\circ}C$ and diurnal light condition of $150-200{\mu}mol\;E{\cdot}m^{-2}{\cdot}s^{-1}$. The optimal specific growth rate and ammonia removal rate were recorded as 0.51/d and 0.56/h on average, respectively, and the confirmation test verified that the organic removal rate was $105mg\;COD{\cdot}l^{-1}{\cdot}d^{-1}$. These results support the development of a viable option for sustainable treatment and effluent quality management of problematic livestock wastewater.