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Knockdown of Archvillin by siRNA Inhibits Myofibril Assembly in Cultured Skeletal Myoblast

  • Lee, Yeong-Mi;Kim, Hyun-Suk;Choi, Jun-Hyuk;Choi, Jae-Kyoung;Joo, Young-Mi;Ahn, Seung-Ju;Min, Byung-In;Kim, Chong-Rak
    • Biomedical Science Letters
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    • v.13 no.4
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    • pp.251-261
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    • 2007
  • A myofiber of skeletal muscle is composed of myofibrils, sarcolemma (plasma membrane), and constameres, which anchor the myofibrils to the sarcolemma. Achvillin is a recently identified F-actin binding muscle protein, co-isolates with dystrophin and caveolin-3 in low-density sarcolemma of striated muscle, and colocalizes with dystrophin at costameres, the specialized adhesion sites in muscle. Archvillin also binds to nebulin and localizes at myofibrillar Z-discs, the lateral boundaries of the sarcomere in muscle. However other roles of archvillin on the dynamics of myofibrillogenesis remain to be defined. The goal of this study is, by using siRNA-mediated gene silencing technique, to investigate the effect of archvillin on the dynamics of myofibrillogenesis in cell culture of a mouse skeletal myogenic cell line (C2C12), where presumptive myoblasts withdraw from the cell cycle, fuse, undergo de novo myofibrillogenesis, and differentiate into mature myotubes. The roles of archvillin in the assembly and maintenance of myofibril and during the progression of myofibrillogenesis induced in skeletal myoblast following gene silencing in the cell culture were investigated. Fluorescence microscopy demonstrated that the distribution of archvillin was changed along the course of myofibril assembly with nebulin, vinculin and F-actin and then located at Z-lines with nebulin. Fluorescence microscopy demonstrated that knockdown of mouse archvillin expression led to an impaired assembly of new myofibrillar clusters and delayed fusion and myofibrillogenesis although the mouse archvillin siRNA did not affect those expressions of archvillin binding proteins, such as nebulin and F-actin. This result is corresponded with that of RT-PCR and western blots. When the perturbed archvillin was rescued by co-transfection with GFP or Red tagged human archvillin construct, the inhibited cell fusion and myotube formation was recovered. By using siRNA technique, archvillin was found to be involved in early stage of myofibrillogenesis. Therefore, the current data suggest the idea that archvillin plays critical roles on cell fusion and dynamic myofibril assembly.

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A Study on the Improvement the Start-up Support Policy: Focused on the ICT Start-up (창업기업 지원 정책 개선 방안 연구: ICT 창업기업을 중심으로)

  • Gil, Wungyu;Bae, Hongbeom;Sim, Yongho;Kim, Seokyun
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.13 no.4
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    • pp.117-128
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    • 2018
  • Various government support policies are being promoted in order to stimulate growth of SMEs. The government is striving to provide effective support through direct methods of tax, finance and indirect methods through support programs. However, the view on the government's startup policy is still tense. We are sympathetic with the need for support, but discussions continue to be made on the effectiveness of support projects and support projects. Therefore, this study evaluates the importance and satisfaction of the government start-up support project. For this purpose, we conducted questionnaires on ICT start-ups who have experienced government start-up support projects. Of these, 128 were analyzed for GAP analysis and ISA. As a result of the GAP analysis of the government start - up support project, the degree of satisfaction (4.408) was lower than the degree of importance (5.221), confirming that the beneficiary's evaluation on the start-up support project was negative. As a result of the importance-satisfaction analysis, 'R&D' and 'commercialization' are located in the maintenance area, and 'government funding', 'marketing, overseas advancement' projects are included in the concentrated area. In the low-ranking areas, there are 'entrepreneur events and networks' items. Finally, there are 'facilities and spaces', 'mentoring and consulting', and 'entrepreneurship education' in the surplus areas. As a result of multiple regression analysis, it was found that 'R&D', 'entrepreneurial education', and 'government funding' influenced satisfaction. Based on the results of this study, it is expected that it will contribute to improving the quality level of the government start-up support project by establishing the support policy for the ICT start-up enterprises and improving the system.

Effects of Insects on Pollination in Angelica gigas Nakai and Angelica acutiloba Kitagawa (방화 곤충에 의한 당귀의 화분매개 효과)

  • Kim, Dong-Hwi;Park, Hee-Woon;Park, Chun-Geun;Sung, Jung-Sook;Seong, Nak-Sul
    • Korean Journal of Medicinal Crop Science
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    • v.14 no.4
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    • pp.217-220
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    • 2006
  • It is known that the process of variety development and maintenance of original plant is difficult in Angelica gigas and Angelica acutiloba because they are allogamous plants. The contents like this are stand in the way of theirs breeding. This study was conducted to investigate the foraging activity and pollinational efficacy by insects to flowers of A. gigas and A. acutiloba. Foraging activity by pollinators was observed every day from 10:00 to 10:30 during 3 days after September 21. Honey bee and fly were major pollinators. The rate of hymenoptera and diptera to total numbers of insects was the 56.5% and 40.6% in A. gigas, respectively. It was also 46.3% and 51.8% in A. acutiloba, respectively. The other insects were lepidoptera, coleoptera and hemiptera. The numbers of hymenoptera and diptera were more in flowers of A. gigas was 49.2% with bee, 36.0% with fly, 15.3% with human, 0.9% without anything in the nethouse and 76.6% in the open field. That of A. acutiloba was 43.6% with bee, 27.9% with fly, 20.3% with human, 0.6% without anything in the nethouse and 46.9% in the open field. Excepting open field, seed setting rate of with bee in the nethouse was the highest of all the others. However, we concluded that the use of fly was the most effective method for pollination of A. gigas and A. acutiloba considering low cost and convenient handling.

Optimal Flow Rate Evaluation for Low Energy, High Efficiency Cleaning of Forward Osmosis (FO) (정삼투 공정의 저에너지 고효율 세정을 위한 최적 유속 평가)

  • Kim, Yihyang;Kim, Jungbin;Zhan, Min;Min, Dahae;Hong, Seungkwan
    • Membrane Journal
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    • v.29 no.6
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    • pp.339-347
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    • 2019
  • Forward osmosis (FO) is operated at a lower pressure than reverse osmosis (RO), which has great advantages in terms of fouling control, maintenance, membrane cleaning, and potential energy reduction. In particular, since the membrane fouling layer of the forward osmosis process has a relatively loose and dispersed property, it is possible to control the membrane fouling by physical cleaning, unlike the reverse osmosis process. However, existing studies do not apply the proper cleaning flow rate for forward osmosis physical cleaning, and thus there is a limit that the optimal operation can not be performed. Therefore, this study aims to evaluate the justification of proper flow rate that can show high efficiency cleaning with economical energy amount. The membrane fouling experiments of the forward osmosis process were maintained at a circulating flow rate of 8.54 cm/s and the recovery rates were compared with the three cleaning flow rates. As a result of this experiment, it was confirmed that the 2 × speed cleaning showed the same efficiency as the water permeability recovery rate of the 3 × speed cleaning, and it was confirmed that the 2 × speed cleaning was an appropriate flow rate with high cleaning efficiency and economical SEC.

A Model of Time Dependent Design Value Engineering and Life Cycle Cost Analysis for Apartment Buildings (공동주택의 시간의존적 설계VE 및 LCC분석 모델)

  • Seo, Kwang-Jun;Choi, Mi-Ra;Shin, Nam-Soo
    • Korean Journal of Construction Engineering and Management
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    • v.6 no.6 s.28
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    • pp.133-141
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    • 2005
  • In the resent years, the importance of VE (value engineering) and LCC (life cycle cost) analysis for apartment building construction projects has been fully recognized. Accordingly theoretical models, guidelines, and supporting software systems were developed for the value engineering and life cycle cost analysis for construction management including large building systems. However, the level of consensus on VE and LCC analysis results is still low due to the lack of reliable data on maintenance. This paper presents time dependent LCC model based value analysis method for rational investment decision making and design alternative selection for construction of apartment building. The proposed method incorporates a time dependent LCC model and a performance evaluation technique by fuzzy logic theory to properly handle the uncertainties associated with statistics data and to analyze the value of alternatives more rationally. The presented time dependent VE and LCC analysis procedure were applied to a real world project, and this case study is discussed in the paper. The model and the procedure presented in this study can greatly contribute to design value engineering alternative selection, the estimation of the life cycle cost, and the allocation of budget for apartment building construction projects.

Influence of Water Depth on Climate Change Impacts on Caisson Sliding of Vertical Breakwater (직립방파제의 케이슨 활동에 미치는 기후변화영향에 대한 수심의 효과)

  • Kim, Seung-Woo;Kim, So-Yeon;Suh, Kyung-Duck
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.24 no.3
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    • pp.179-188
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    • 2012
  • Performance analyses of vertical breakwaters were conducted for fictitiously designed breakwaters for various water depths to analyze the influence of climate change on the structures. The performance-based design method considering sea level rise and wave height increase due to climate change was used for the performance analysis. One of the problems of the performance-based design method is the large calculation time of wave transformation. To overcome this problem, the SWAN model combined with artificial neural network was used. The significant wave height and principal wave direction at the breakwater site are quickly calculated by using a trained neural network with inputs of deepwater significant wave height and principal wave direction, and tidal level. In general, structural stability becomes low due to climate change impacts, but the trend of stability is different depending on water depth. Outside surf zone, the influence of wave height increase becomes more significant, while that of sea level rise becomes negligible, as water depth increases. Inside surf zone, the influence of both wave height increase and sea level rise diminishes as water depth decreases, but the influence of wave height increase is greater than that of sea level rise. Reinforcement and maintenance policies for vertical breakwaters should be established with consideration of these results.

A Classification of Car-related Mobile Apps: For App Development from a Convergence Perspective (차량용 모바일 앱의 분류: 융복합 관점의 앱 개발을 위해)

  • Zhang, Chao;Wan, Lili;Min, Daihwan
    • Journal of Digital Convergence
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    • v.15 no.3
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    • pp.77-86
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    • 2017
  • This study selected car-related mobile apps for app developers suffering from low revenue and classified car apps assisting users in driving or managing a car. A total of 697 car apps were classified into eight categories. Most apps are in four categories: car news & information (28%), locating service (23%), car rental service (15%), safe/efficient driving service (12%). The remaining categories are buying & selling, driver's communication, maintenance management, and expenses monitoring. Many apps are simple and too similar in their main functions. Only a few apps are designed to be more comprehensive and have functions in two or more categories. For the practicality of the categorization scheme, this study checked the inter-rater reliability in two tests and got 0.886 and 0.828. The result from this study suggests functions that are not implemented yet or need to be combined. Future research will focus on identifying promising car apps or designing multi-functional car apps.

Studies on Steroid Hormone Concentration during the Estrous Cycle in the MediKinetics Micropig®

  • Seong, Hun-Ki;Seo, Kyeong-Seok;Kim, Jeong-Su;Her, Chang-Gi;Kang, Myung-Hwa;Sim, Bo-Woong;Yoon, Jong-Taek;Min, Kwan-Sik
    • Reproductive and Developmental Biology
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    • v.41 no.1
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    • pp.1-6
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    • 2017
  • In all mammalian species, progesterone is essential to both the preparation for, and maintenance of, pregnancy. The $20{\alpha}$-hydroxysteroid dehydrogenase ($20{\alpha}$-HSD) enzyme predominantly converts progesterone into its biologically inactive form $20{\alpha}$-hydroxyprogesterone, thereby regulating its activity. Thus, to directly assess sexual maturation in the MediKinetics $micropig^{(R)}$, we analyzed the concentration of the steroid hormones progesterone and estradiol during the estrous cycle. Our results show that the progesterone level exhibited by the analyzed $micorpig^{(R)}$ was low at the beginning of the estrous cycle, and then abruptly increased to $30.32{\pm}10.0ng/mL$ and $46.37{\pm}11.0ng/mL$ by days 9 and 11 of the cycle, respectively. It reached the highest level $55.87{\pm}3.5ng/mL$ on day 13 of the estrous cycle, before decreasing to $46.58{\pm}13.1ng/mL$ and $10.0{\pm}7.6ng/mL$ by days 15 and 17 of the cycle, respectively. In contrast, the estradiol level was shown to be highest ($27.13{\pm}11.2ng/mL$) at the initiation of the estrous cycle, after which point it decreased to $13.29{\pm}6.5ng/mL$ and $10.94{\pm}5.9ng/mL$ by days 4 and 5 of the estrous cycle, respectively. By day 17 of the estrous cycle, the estradiol level decreased to $4.13{\pm}7.6ng/mL$. We anticipate that these results will provide useful information to enable the study of human ovulation and reproductive physiology using the MediKinetics $micoripig^{(R)}$ as a model system. We recommend further investigation to elucidate the functional mechanisms underlying the regulation of sexual maturation in the MediKinetics $micropig^{(R)}$.

Diamond-Blackfan anemia: long-term follow-up of six cases (Diamond-Blackfan 빈혈: 6예 장기간 추적관찰보고)

  • Son, Young Jun;Baek, Hee Jo;Kook, Hoon
    • Clinical and Experimental Pediatrics
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    • v.51 no.11
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    • pp.1211-1216
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    • 2008
  • Purpose : Diamond-Blackfan anemia (DBA) is a rare heterogeneous genetic disorder of infancy and early childhood. It is characterized by red cell aplasia, congenital anomalies, and a predisposition to cancer. Corticosteroids and red cell transfusions are the mainstays of therapy. We describe our experience of 6 cases of DBA that were encountered over a period of 16 years. Methods : Medical records of 6 patients diagnosed to have DBA and admitted to the Chonnam National University Hospital between 1992 and 2008 were retrospectively reviewed. Results : Three patients were males. The age at diagnosis ranged from 3 to 18 months (median, 5.5 months). Heart defects were observed in 4, polydactyly in 2, and strabismus in 1 patient. The median number of transfusions was 3 (range, 2-8). All patients responded to initial treatment with steroids and had a hemoglobin level ${\geq}9g/dL$ with a median of 12.5 days (range, 7-22 days). Three patients are currently not receiving steroid therapy. A minimum dose of oral prednisolone (<5 mg per day) was required to maintain hemoglobin ${\geq}9mg/dL$ in 3 cases. Red cell transfusion was infrequently required in 1 patient. In the median follow-up of 14 years, there was no development of malignancy. No significant side effects of steroids were found, except for short stature in 2. Conclusion : The majority of DBA patients achieved complete response and under maintenance therapy with low dose of steroids. Close observation is needed to monitor steroid side effects, cardiac function, and development of malignancy. A nation-wide survey is necessary to further characterize this rare disease in Korean children.

A Study on the Experiment of Represtressed Preflexional Composite Beams (RPF 합성보의 실험 연구)

  • Chang, Dong Il;Hwang, Yoon Kook;Kim, Jung Ho;Cho, Tae Jun
    • Journal of Korean Society of Steel Construction
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    • v.9 no.4 s.33
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    • pp.697-705
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    • 1997
  • The conventional preflex beams are designed by the method of paritial prestressing and allow the tensile stresses at the lower concrete of beams. As a consequence, most of preflex beams experience the tensile cracks under the service loads. This study was conducted to develop the most effective preflex beams, which do not allow tensile stress under the service load, by introducing additional prestressing called 'represtressing' at the lower concrete of beams. The objective of the study was accomplished by developing a computer analysis and design program and conducting experiments. Using the developed computer program, standard sections of the represtressed preflex beams were determined by computer modeling. In the experiment, two actual size of represtressed beams were tested under the imitated service loads. The results of test have shown that the performance of the represtressed preflex beams is generally excellent. A remarkable improvement was made in the design of preflex composite beams. Since the represtressed preflex beams(RPF) do not experience the tensile cracks under the service loads, the use of this beam for the bridge structures will lead to easy bridge maintenance and management. Furthermore, due to the low beam depth, high clearance and economical design can be realized in the bridge design using RPF.

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