• Title/Summary/Keyword: Regenerative cycle

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Mind Bomb-Binding Partner RanBP9 Plays a Contributory Role in Retinal Development

  • Yoo, Kyeong-Won;Thiruvarangan, Maivannan;Jeong, Yun-Mi;Lee, Mi-Sun;Maddirevula, Sateesh;Rhee, Myungchull;Bae, Young-Ki;Kim, Hyung-Goo;Kim, Cheol-Hee
    • Molecules and Cells
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    • v.40 no.4
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    • pp.271-279
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    • 2017
  • Ran-binding protein family member, RanBP9 has been reported in various basic cellular mechanisms and neuropathological conditions including schizophrenia. Previous studies have reported that RanBP9 is highly expressed in the mammalian brain and retina; however, the role of RanBP9 in retinal development is largely unknown. Here, we present the novel and regulatory roles of RanBP9 in retinal development of a vertebrate animal model, zebrafish. Zebrafish embryos exhibited abundant expression of ranbp9 in developing brain tissues as well as in the developing retina. Yeast two-hybrid screening demonstrated the interaction of RanBP9 with Mind bomb, a component of Notch signaling involved in both neurogenesis and neural disease autism. The interaction is further substantiated by co-localization studies in cultured cells. Knockdown of ranbp9 resulted in retinal dysplasia with defective proliferation of retinal cells, downregulation of neuronal differentiation marker huC, elevation of neural proliferation marker her4, and alteration of cell cycle marker p57kip2. Expression of the $M{\ddot{u}}ller$ glial cell marker glutamine synthase was also affected in knockdown morphants. Our results suggest that Mind bomb-binding partner RanBP9 plays a role during retinal cell development of zebrafish embryogenesis.

Combustion Performance of a Fullscale Liquid Rocket Thrust Chamber (실물형 액체로켓 연소기 지상 연소 성능 결과)

  • Seo Seong-Hyeon;Kim Jong-Gyu;Moon Il-Yoon;Han Yeoung-Min;Choi Hwan-Seok;Lee Soo-Yong;Cho Kwang-Rae
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2005.11a
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    • pp.235-239
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    • 2005
  • A 30-tonf-class fullscale thrust chamber for the application to a LEO SLV has been combustion tested over the wide ranges of a mixture ratio and a chamber pressure. The thrust chamber designed for an open cycle engine with a turbopump was tested with a ablative combustion chamber instead of a regenerative chamber to first evaluate its performance and function. The test results revealed stable combustion characteristics. The hardware survived the harsh environment and showed very sound functional characteristics. The estimated combustion efficiency of the chamber turned out to be 95% and a specific impulse at sea level was estimated as 254sec, which are comparable to or above the predicted design values.

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Combustion Experiments of a High Pressure Liquid Propellant Thrust Chamber (액체로켓 엔진용 고압 연소기의 연소시험)

  • Seo, Seong-Hyeon;Han, Yeoung-Min;Moon, Il-Yoon;Lee, Kwang-Jin;Kim, Jong-Kyu;Lim, Byung-Jik;Ahn, Kyu-Bok;Choi, Hwan-Seok
    • Journal of the Korean Society of Propulsion Engineers
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    • v.10 no.4
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    • pp.40-46
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    • 2006
  • A 30-tonf-class fullscale thrust chamber for the application to a Low-Earth-Orbit Space Launch Vehicle has been combustion tested over the wide ranges of a mixture ratio and a chamber pressure. The thrust chamber designed for a pump-fed open cycle engine was tested with an ablative chamber instead of a regenerative one for the initial evaluation of its performance and function. The test results revealed stable combustion characteristics. The hardware survived the harsh environment and showed very sound functional characteristics. The measured combustion efficiency turned out to be 95% and a specific impulse at sea level was estimated as 254sec, which are comparable to or above the predetermined design values.

Apoptotic Effects of psiRNA-STAT3 on 4T1 Breast Cancer Cells in Vitro

  • Zhou, Yue;Tian, Lin;Zhang, Ying-Chao;Guo, Bao-Feng;Zhou, Qing-Wei
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.16
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    • pp.6977-6982
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    • 2014
  • Background: The aim of this study was to investigate the effect of a Lipofectamine2000 (Life2000) Transfection Reagent transfected psiRNA-STAT3 plasmid on 4T1 breast cancer cells. Materials and Methods: MTT was used to detect the cell proliferation of breast cancer 4T1 cells at different periods (0h, 6h, 8h, 10h); the cell cycle was assessed by flow cytometry; variation of apoptosis and mitochondrial membrane potential was observed under a fluorescence microscope; immunohistochemical staining was used to determine the expression of caspase-3 and cyclin-D1 protein. Results: An obvious effect of inhibition to 4T1 cancer cells could be observed at 8h after the psiRNA-STAT3 was transfected. Typical alterations of apoptotic morphological features were visible in the psiRNA-STAT3 treatment group. Mitochondrial membrane potential decreased significantly, the number of cells was increased in G0/G1 phase, and the number of cells was decreased in S phase, and the data were statistically significant (p<0.05), compared with the Scramble and Mock groups. Expression of caspase-3 protein was increased significantly, while that of cyclin D1 was significantly decreased. Conclusions: Life2000 transfected psiRNA-STAT3 plasmid can inhibit 4T1 tumor cell proliferation and promote apoptosis of 4T1 tumor cells, which process depends on the regulation of expression of cyclin D1 and caspase-3 protein.

Design and Implementation of Modified Current Source Based Hybrid DC - DC Converters for Electric Vehicle Applications

  • Selvaganapathi, S.;Senthilkumar, A.
    • Transactions on Electrical and Electronic Materials
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    • v.17 no.2
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    • pp.57-68
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    • 2016
  • In this study, we present the modern hybrid system based power generation for electric vehicle applications. We describe the hybrid structure of modified current source based DC - DC converters used to extract the maximum power from Photovoltaic (PV) and Fuel Cell system. Due to reduced dc-link capacitor requirement and higher reliability, the current source inverters (CSI) better compared to the voltage source based inverter. The novel control strategy includes Distributed Maximum Power Point Tracking (DMPPT) for photovoltaic (PV) and fuel cell power generation system. The proposed DC - DC converters have been analyzed in both buck and boost mode of operation under duty cycle 0.5>d, 0.5<d<1 and 0.5<d for capable electric vehicle applications. The proposed topology benefits include one common DC-AC inverter that interposes the generated power to supply the charge for the sharing of load in a system of hybrid supply with photovoltaic panels and fuel cell PEM. An improved control of Direct Torque and Flux Control (DTFC) based induction motor fed by current source converters for electric vehicle.In order to achieve better performance in terms of speed, power and miles per gallon for the expert, to accepting high regenerative braking current as well as persistent high dynamics driving performance is required. A simulation model for the hybrid power generation system based electric vehicle has been developed by using MATLAB/Simulink. The Direct Torque and Flux Control (DTFC) is planned using Xilinx ISE software tool in addition to a Modelsim 6.3 software tool that is used for simulation purposes. The FPGA based pulse generation is used to control the induction motor for electric vehicle applications. FPGA has been implemented, in order to verify the minimal error between the simulation results of MATLAB/Simulink and experimental results.

Developmental Characteristics of SCNT Pig Embryos Knocked-out of Alpha-1,3-Galactosyltransferase Gene

  • Shim, Joo-Hyun;Park, Mi-Rung;Yang, Byoung-Chul;Ko, Yeoung-Gyu;Oh, Keon-Bong;Lee, Jeong-Woong;Woo, Jae-Seok;Park, Eung-Woo;Park, Soo-Bong;Hwang, Seong-Soo
    • Reproductive and Developmental Biology
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    • v.33 no.3
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    • pp.157-162
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    • 2009
  • This study was performed to comprehend the developmental characteristics of cloned embryos knocked out (KO) of $\alpha$-1,3-galactosyltransferase (GalT) gene. Immature oocytes were collected and cultured for 40 hrs (1-step) or 20hrs (with hormone) + 20hrs (without hormone) (2-step). The embryos transferred with miniature pig ear fibroblast cell were used as control. The reconstructed embryos were cultured in PZM-3 with 5% $CO_2$ in air at $38.5^{\circ}C$ for 6 days. To determine the quality of the blstocysts, TUNEL and quantitative realtime RT-PCR were performed. The embryos were transferred to a surrogate (Landrace) at an earlier stage of the estrus cycle. The maturation rate was significantly higher in 2-step method than that of 1-step (p<0.05). The blastocyst development of GalT KO embryos was significantly lower than that of normal cloned embryos (p<0.05). The total and apoptotic cell number of GalT KO blastocysts was not different statistically from control. The relative abundance of Bax-$\alpha$/Bcl-xl ratio was significantly higher in both cloned blastocysts than that of in vivo blastocysts (p<0.05). Taken together, it can be postulated that the lower developmental potential and higher expression of apoptosis related genes in GalT KO SCNT embryos might be a cause of a low efficiency of GalT KO cloned miniature pig production.

Primary Cilium by Polyinosinic:Polycytidylic Acid Regulates the Regenerative Migration of Beas-2B Bronchial Epithelial Cells

  • Gweon, Bomi;Jang, Tae-Kyu;Thuy, Pham Xuan;Moon, Eun-Yi
    • Biomolecules & Therapeutics
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    • v.30 no.2
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    • pp.170-178
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    • 2022
  • The airway epithelium is equipped with the ability to resist respiratory disease development and airway damage, including the migration of airway epithelial cells and the activation of TLR3, which recognizes double-stranded (ds) RNA. Primary cilia on airway epithelial cells are involved in the cell cycle and cell differentiation and repair. In this study, we used Beas-2B human bronchial epithelial cells to investigate the effects of the TLR3 agonist polyinosinic:polycytidylic acid [Poly(I:C)] on airway cell migration and primary cilia (PC) formation. PC formation increased in cells incubated under serum deprivation. Migration was faster in Beas-2B cells pretreated with Poly(I:C) than in control cells, as judged by a wound healing assay, single-cell path tracking, and a Transwell migration assay. No changes in cell migration were observed when the cells were incubated in conditioned medium from Poly(I:C)-treated cells. PC formation was enhanced by Poly(I:C) treatment, but was reduced when the cells were exposed to the ciliogenesis inhibitor ciliobrevin A (CilioA). The inhibition of Beas-2B cell migration by CilioA was also assessed and a slight decrease in ciliogenesis was detected in SARS-CoV-2 spike protein (SP)-treated Beas-2B cells overexpressing ACE2 compared to control cells. Cell migration was decreased by SP but restored by Poly(I:C) treatment. Taken together, our results demonstrate that impaired migration by SP-treated cells can be attenuated by Poly(I:C) treatment, thus increasing airway cell migration through the regulation of ciliogenesis.

Performance Analysis of Shell Coal Gasification Combined Cycle systems (Shell 석탄가스화 복합발전 시스템의 성능해석 연구)

  • Kim, Jong-Jin;Park, Moung-Ho;Song, Kyu-So;Cho, Sang-Ki;Seo, Seok-Bin;Kim, Chong-Young
    • Journal of Energy Engineering
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    • v.6 no.1
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    • pp.104-113
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    • 1997
  • This study aims to develop an analysis model using a commercial process simulator-ASPEN PLUS for an IGCC (Integrated Gasification Combined Cycle) system consisting a dry coal feeding, oxygen-blown entrained gasification process by Shell, a low temperature gas clean up process, a General Electric MS7001FA gas turbine, a three pressure, natural recirculation heat recovery steam generator, a regenerative, condensing steam turbine and a cryogenic air separation unit. The comparison between those results of this study and reference one done by other engineer at design conditions shows consistency which means the soundness of this model. The greater moisture contents in Illinois#6 coal causes decreasing gasifier temperature and the greater ash and sulfur content hurt system efficiency due to increased heat loss. As the results of sensitivity analysis using developed model for the parameters of gasifier operating pressure, steam/coal ratio and oxygen/coal ratio, the gasifier temperature increases while combustible gases (CO+H2) decreases throughout the pressure going up. In the steam/coal ratio analysis, when the feeding steam increases the maximum combustible gas generation point moves to lower oxygen/coal ratio feeding condition. Finally, for the oxygen/coal ratio analysis, it shows oxygen/coal ratio 0.77 as a optimum operating condition at steam/coal feeding ratio 0.2.

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Experimental Studies on the Mechanism of Reproductive Cycle in the Bluegill, Lepomis macrochirus (파랑볼우럭, Lepomis macrochirus의 생식기구에 관한 실험적 연구)

  • LEE Taek Yuil;Kim Sunng Yeon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.20 no.6
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    • pp.489-500
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    • 1987
  • Annual reproductive cycle of Bluegill, Lepomis macrochirus (RAFINESQUE) were studied in the natural population. Based on these informations, reproductive mechanism of the fish including activation, degeneration and remature were examined under the controlled conditions of temperature and photoperioe. In the natural populations, gonads began to grow with the temperature increase in March ana matured in June, and spawning occurred in July. With the onset of the shorter day-length and the maximum temperature condition in August, the gonads began to degenerate. Resting stage was continued during winter season. In the laboratory-reared population, activation of the gonads was initiated by the complex environmental factors including higher temperature$(>15^{\circ}C)$ and longer photoperiod $(>14L)$. For the maturation, photoperiod of more than 14 hours was critical. Under this condition higher temperature was the only compensative factor. Regeneration of the gonads was induced by higher temperature$(>25^{\circ}C)$ and the shorter photoperiod accelerated the regenerative processes. Even from the resting stage the gonads can be induced to matured stage by the longer photoperiod $(>15L)$. Based on these observations, the reproductive rhythm of this fish is supposed to be artificially controlled.

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Effects of Sophorae Radix Extracts on the Expression ofcell cycle regulatory porteins in Human Gingival Fibroblasts (고삼추출물이 치은섬유아세포의 세포주기 조절단백질 발현에 미치는 영향)

  • Kim, Heung-Sik;Kim, Hyun-A;Yu, Yong-Ouk;Kang, Tai-Hyun;Kim, Youn-Chul;Kim, Tak;Pee, Sung-Hee;You, Hyung-Keun;Shin, Hyung-Shik
    • Journal of Periodontal and Implant Science
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    • v.30 no.4
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    • pp.869-885
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    • 2000
  • Fibroblasts are major cellular components of gingiva and periodontal ligament. They regulate the healing process after surgery or injury. Recently, many natural medicines, whose advantages are less side effects and possibility of long-term use, have been studied for their capacity, their anti-bacterial and anti-inflammatory effects and regenerative potential of periodontal tissues. Sophorae radix have been traditionally used as an anti-bacterial and antiinflammatory drug in oriental medicine. The purpose of present study was to investigate the effects of Sophorae radix extract on cell cycle progression and its molecular mechanism in human gingival fibroblasts. Sophorae radix extracts($100{\mu}g/ml$) notably increased cell proliferation and cell activity in the human gingival fibroblasts as compared to non-supplemented controls. There was an increase in the S phase and a decrease in the G1 phase in $100{\mu}g/ml$ of Sophorae radix extracts group as compared to non-supplemented controls. The level of cyclin E and cdk 2 protein in test group was higher than that of control groups. But that of cyclin D, cdk 4, and cdk 6 was not distinguished from controls. The level of p53 protein in test group was lower than that of controls, whereas that of p21 was not different. The level of pRB protein in test group was higher than that of controls, whereas that of p16 was lower. These results indicate that the increase of cell proliferation by Sophorae radix extracts may be due to the increased expression of cyclin E and cdk 2, and the decreased expression of p53 and p16 in human gingival fibroblasts.

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