• Title/Summary/Keyword: Cell-chip

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Effects of 5-azacytidine, a DNA methylation inhibitor, on embryogenic callus formation and shoot regeneration from rice mature seeds (벼 성숙종자로부터 배상체 캘러스 형성 및 식물체 재분화에 DNA methylation 억제제인 5-azacytidine의 영향)

  • Lee, Yeon-Hee;Lee, Jung-Sook;Kim, Soo-Yun;Sohn, Seong-Han;Kim, Dool-Yi;Yoon, In-Sun;Kweon, Soon-Jong;Suh, Seok-Chul
    • Journal of Plant Biotechnology
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    • v.35 no.2
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    • pp.133-140
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    • 2008
  • The modification of DNA and histone plays an important role for gene expression in plant development. The objective of this research is to observe the effects of methylation on the gene expression during dedifferentiation from rice mature seeds to callus and differentiation from callus to shoots. The embryogenic callus with ability to shoot regeneration was not induced on the N6A medium supplemented with 5-azacytidine and abnormal callus with brown color was formed. When the normal rice callus was placed on the regeneration MSRA medium supplemented with 5-azacytidine, the shoot regeneration was inhibited. The results showed that 5-azacytidine, DNA demethylating agent, had negative effects on normal embryogenic callus formation and shoot regeneration. This suggested that DNA methylation of some genes was required for normal cell dedifferentiation and differentiation in tissue culture. The microarray and $GeneFishig^{TM}$ DEG screening were used to observe the gene transcript profile in callus induction and regeneration on N6A (N6 medium + 5-azaC) and MSRA (MS regeneration medium + 5-azaC). Subsets of genes were up-regulated or down-regulated in response to 5-azaC treatments. The genes related with epigenetic regulation, electron transport, nucleic acid metabolism and response to stress were up and down regulated. The different expression of some genes (germin like protein etc.) during callus induction and shoot regeneration was confirmed using RT-PCR and northern blot analysis.

Pre-Packing, Early Fixation, and Multi-Layer Density Analysis in Analytic Placement for FPGAs (FPGA를 위한 분석적 배치에서 사전 패킹, 조기 배치 고정 및 밀도 분석 다층화)

  • Kim, Kyosun
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.10
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    • pp.96-106
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    • 2014
  • Previous academic research on FPGA tools has relied on simple imaginary models for the targeting architecture. As the first step to overcome such restriction, the issues on analytic placement and legalization which are applied to commercial FPGAs have been brought up, and several techniques to remedy them are presented, and evaluated. First of all, the center of gravity of the placed cells may be far displaced from the center of the chip during analytic placement. A function is proposed to be added to the objective function for minimizing this displacement. And then, the density map is expanded into multiple layers to accurately calculate the density distribution for each of the cell types. Early fixation is also proposed for the memory blocks which can be placed at limited sites in small numbers. Since two flip-flops share control pins in a slice, a compatibility constraint is introduced during legalization. Pre-packing compatible flip-flops is proposed as a proactive step. The proposed techniques are implemented on the K-FPGA fabric evaluation framework in which commercial architectures can be precisely modeled, and modified for enhancement, and validated on twelve industrial strength examples. The placement results show that the proposed techniques have reduced the wire length by 22%, and the slice usage by 5% on average. This research is expected to be a development basis of the optimization CAD tools for new as well as the state-of-the-art FPGA architectures.

Effect of Compaction Method on Induced Earth Pressure Using Dynamic Compaction Roller (진동롤러에 의한 다짐방법이 인접구조물의 다짐토압에 미치는 영향)

  • Roh, Han-Sung
    • International Journal of Highway Engineering
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    • v.3 no.4 s.10
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    • pp.127-136
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    • 2001
  • To increase the structural integrity of concrete box culvert good compaction by the dynamic compaction roller with bi9 capacity is as effective as good backfill materials. It is needed for effective compaction that a compaction roller closes to concrete structure with high frequency. However structural distress of the culvert could be occur due to the excessive earth pressure by great dynamic compaction load. To investigate the characteristics of Induced stress by compaction, a box culvert was constructed with changing cushion materials and compaction methods. Two types of cushion material such as tire rubber chip and EPS(Expanded Polystyrene) were used as cushion panels and they are set on the culverts before backfill construction. Laboratory test result of cushion material says that the value of dynamic elastic modulus of rubber is lesser than that of EPS. On the other hand, material damping of rubber material is greater than that of EPS. In most case, dynamic compaction rollers with 10.5 ton weights were used and vibration frequency was applied 30Hz for the great compaction energy. This paper presents the main results on the characteristics of dynamic earth pressures during compaction. The amounts of induced dynamic pressures$(\Delta\sigma\;h)$ by compaction are affected with construction condition such as compaction frequency, depth of pressure cell, distance between roller and the wall of culvert and roller direction. Based on the measured values dynamic lateral pressure on the culverts, it could be said that orthogonal direction of roller to the length of culvert is more effective to compaction efficiency than parallel direction.

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A Low Power SRAM using Supply Voltage Charge Recycling (공급전압 전하재활용을 이용한 저전력 SRAM)

  • Yang, Byung-Do;Lee, Yong-Kyu
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.46 no.5
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    • pp.25-31
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    • 2009
  • A low power SRAM using supply voltage charge recycling (SVCR-SRAM) scheme is proposed. It divides into two SRAM cell blocks and supplies two different powers. A supplied power is $V_{DD}$ and $V_{DD}/2$. The other is $V_{DD}/2$ and GND. When N-bit cells are accessed, the charge used in N/2-bit cells with VDD and $V_{DD}/2$ is recycled in the other N/2-bit cells with $V_{DD}/2$ and GND. The SVCR scheme is used in the power consuming parts which bit line, data bus, word line, and SRAM cells to reduce dynamic power. The other parts of SRAM use $V_{DD}$ and GND to achieve high speed. Also, the SVCR-SRAM results in reducing leakage power of SRAM cells due to the body-effect. A 64K-bit SRAM ($8K{\times}8$bits) is implemented in a $0.18{\mu}m$ CMOS process. It saves 57.4% write power and 27.6% read power at $V_{DD}=1.8V$ and f=50MHz.

Design and Implementation of the Channel Adaptive Broadband MODEM (채널 적응형 광대역 모뎀 설계 및 구현)

  • Chang, Dae-Ig;Kim, Nae-Soo
    • The KIPS Transactions:PartC
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    • v.11C no.1
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    • pp.141-148
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    • 2004
  • Recently, the demand of broadband communications such as high-speed internet, HDTV, 3D-HDTV and ATM backbone network has been increased drastically. For transmitting the broad-bandwidth data using wireless network, it is needed to use ka-band frequency. However, the use of this ka-band frequency is seriously affected to the received data performance by rain fading and atmospheric propagation loss at the Ka-band satellite communication link. So, we need adaptive MODEM to endure the degraded performance by channel environment. In this paper, we will present the structure and design of the 155Mbps adaptive Modem adaptively compensated against channel environment. In order to compensate the rain attenuation over the ka-band wireless channel link, the adaptive coding schemes with variable coding rates and the multiple modulation schemes such as trellis coded 8-PSK, QPSK, and BPSK are adopted. And the blind demodulation scheme is proposed to demodulate without Information of modulation mode at the multi-mode demodulator, and the fast phase ambiguity resolving scheme is proposed. The design and simulation results of adaptive Modem by SPW model are provided. This 155Mbps adaptive MODEM was designed and implemented by single ASIC chip with the $0.25\mu{m}$ CMOS standard cell technology and 950 thousand gates.

In Silico Analysis of Gene Function and Transcriptional Regulators Associated with Endoplasmic Recticulum (ER) Stress (Endoplasmic recticulum stress와 관련된 유전자기능과 전사조절인자의 In silico 분석)

  • Kim, Tae-Min;Yeo, Ji-Young;Park, Chan-Sun;Rhee, Moon-Soo;Jung, Myeong-Ho
    • Journal of Life Science
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    • v.19 no.8
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    • pp.1159-1163
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    • 2009
  • It has been postulated that endoplasmic (ER) stress is involved in the development of several diseases. However, the detailed molecular mechanisms have not been fully understood. Therefore, we characterized a genetic network of genes induced by ER stress using cDNA microarray and gene set expression coherence analysis (GSECA), and identified gene function as well as several transcription regulators associated with ER stress. We analyzed time-dependent gene expression profiles in thapsigargin-treated Sk-Hep1 using an oligonucleotide expression chip, and then selected functional gene sets with significantly high expression coherence which was processed into functional clusters according to the expression similarities. The functions related to sugar binding, lysosome, ribosomal protein, ER lumen, and ER to golgi transport increased, whereas the functions with mRNA processing, DNA replication, DNA repair, cell cycle, electron transport chain and helicase activity decreased. Furthermore, functional clusters were investigated for the enrichment of regulatory motifs using GSECA, and several transcriptional regulators associated with regulation of ER-induced gene expression were found.

Microarray analysis of gene expression in raw cells treated with scolopendrae corpus herbal-acupuncture solution (蜈蚣(오공) 약침액(藥鍼液)이 LPS로 처리된 RAW 세포주(細胞柱)의 유전자(遺傳子) 발현(發顯)에 미치는 영향(影響))

  • Bae, Eun-Hee;Lee, Kyung-Min;Lee, Bong-Hyo;Lim, Seong-Chul;Jung, Tae-Young;Seo, Jung-Chul
    • Korean Journal of Acupuncture
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    • v.23 no.3
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    • pp.133-160
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    • 2006
  • Objectives : Scolopendrae Corpus has a broad array of clinical applications in Korean medicine, including treatment of inflammatory conditions such as arthritis. To explore the global gene expression profiles in human Raw cell lines treated with Scolopendrae Corpus herbal-acupuncture solution (SCHAS), cDNA microarray analysis was performed. Methods : The Raw 264.7 cells were treated with lipopolysaccharide (LPS), SCHAS, or both. The primary data was normalized by the total spots of intensity between two groups, and then normalized by the intensity ratio of reference genes such as housekeeping genes in both groups. The expression ratio was converted to log2 ratio. Normalized spot intensities were calculated into gene expression ratios between the control and treatment groups. Greater than 2 fold changes between two groups were considered to be of significance. Results : Of the 8 K genes profiled in this study, with a cut-off level of two-fold change in the expression, 20 genes (BCL2-related protein A1, MARCKS-like 1, etc.) were upregulated and 5 genes (activated RNA polymerase II transcription cofactor 4, calcium binding atopy-related autoantigen 1, etc.) downregulated following LPS treatment. 139 genes (kell blood group precursor (McLeod phenotype), ribosomal protein S7, etc.) were upregulated and 42 genes (anterior gradient 2 homolog (xenopus laevis), phosphodiesterase 8B, etc.) were downregulated following SCHAS treatment. And 10 genes (yeast saccharomyces cerevisiae intergeneic sequence 4-1, mitogen-activated protein kinase 1, etc.) were upregulated and 8 genes (spermatid perinuclear RNA binding protein, nuclear receptor binding protein 2, etc.) were downregulated following co-stimulation of SCHAS and LPS. Discussions : It is thought that microarrays will play an ever-growing role in the advance of our understanding of the pharmacological actions of SCHAS in the treatment of arthritis. But further studies are required to concretely prove the effectiveness of SCHAS.

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