• Title, Summary, Keyword: cell

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A 3-cell CCI(Cell-to-Cell Interference) model and error correction algorithm for Multi-level cell NAND Flash Memories (다중셀 낸드 플래시 메모리의 3셀 CCI 모델과 이를 이용한 에러 정정 알고리듬)

  • Jung, Jin-Ho;Kim, Shi-Ho
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.48 no.10
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    • pp.25-32
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    • 2011
  • We have analyzed adjacent cell dependency of threshold voltage shift caused by the cell to cell interference, and we proposed a 3-adjacent-cell model to model the pattern dependency of the threshold voltage shift. The proposed algorithm is verified by using MATLAB simulation and measurement results. In the experimental results, we found that accuracy of the proposed simple 3-adjacient-cell model is comparable to the widely used conventional 8-adjacient-cell model. The Bit Error Rate (BER) of LSB and of MSB is improved by 28.9% and 19.8%, respectively, by applying the proposed algorithm based on 3-adjacent-cell model to 20nm-class 2-bit MLC NAND flash memories.

Regulatory Role of CD29 $({\beta}1-integrins)$ in Monocytic Cell Functions (단핵구 기능 수행에서의 $CD29({\beta}1-integrins)$ 조절 역할)

  • Kim, Byung-Hun;Cho, Jae-Youl
    • YAKHAK HOEJI
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    • v.52 no.1
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    • pp.48-55
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    • 2008
  • CD29 $({\beta}1-integrins)$ is one of major adhesion molecules involved in regulating cell adhesion, migration and morphological changes. In this study, we investigated the regulatory role of CD29 in monocytic functions using monocytic cell line U937 cells. CD29 was found to be one of highly expressed membrane proteins in U937 cells, according to flow cytometric analysis. The activation of CD29 by agonistic antibody MEM101A and extracellular matrix protein (ECM) fibronectin strongly induced cell-cell and cell-fibronectin adhesions. However, blocking antibodies to CD98 and CD147 showed different inhibitory features in these two adhesion events. Furthermore, U0126, an ERK inhibitor, only blocked cell-cell adhesion but not cell-fibronectin adhesion, indicating that cell-cell or cell-fibronectin adhesion events may be regulated by different molecular mechanisms. Meanwhile, CD29 activation also enhanced ROS generation but not phagocytic ability, and similarly radical scavenger N-acetyl-L-cysteine strongly blocked CD29-mediated cell-cell adhesion, implying that ROS may play a critical role in up-regulating cell-cell adhesion. Therefore, our data suggest that the activation of CD29 may be critically involved in regulating monocytic cell-mediated cell-cell adhesion and ROS generation.

Development of a 2-Chamber Culture System for Impedimetric Monitoring of Cell-cell Interaction

  • Lei, Kin Fong;Tsai, Meng-Tsan;Zhong, Ming-Hong;Huang, Chia-Hao;Tsang, Ngan-Ming;Lee, Ming-Yih
    • BioChip Journal
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    • v.11 no.2
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    • pp.139-145
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    • 2017
  • In cancer research, study of cell-cell interaction is important to understand tumor initiation, progression, metastasis, and therapeutic resistance. Conventionally, transwell system was adopted and cell proliferation was quantified by end-point bio-assays. The operations are labor-intensive and time-consuming while studying of the dynamic cellular responses of cell-cell interaction. Although impedance measurement was suggested to be a promising technique to monitor cellular responses, electrodes cannot be integrated into the transwell for the measurement purpose. In this work, a 2-chamber culture system incorporated with impedance measurement technique was developed to quantitatively study cell-cell interaction. The chamber was composed of 2 sub-chambers separated with a barrier. By this design, two types of cells could be independently cultured and concurrently monitored under common medium supplied. Cell-cell interaction was demonstrated by aberrant cell proliferation induced by the EGF secreted from the transfected cells cultured on another sub-chamber. Real-time and non-invasive monitoring of cell-cell interaction was successfully demonstrated. This work provides a practical solution for monitoring the dynamic cellular responses of cell-cell interaction during the culture course. It is a reliable and convenient platform and facilitate more quantitative assessments in cancer research.

Every Single Cell Clones from Cancer Cell Lines Growing Tumors In Vivo May Not Invalidate the Cancer Stem Cell Concept

  • Li, Fengzhi
    • Molecules and Cells
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    • v.27 no.4
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    • pp.491-492
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    • 2009
  • We present the result of our research on the tumorigenic ability of single cell clones isolated from an aggressive murine breast cancer cell line in a matched allografting mouse model. Tumor formation is basically dependent on the cell numbers injected per location. We argue that in vivo tumor formation from single cell clones, isolated in vitro from cancer cell lines, may not provide conclusive evidence to disprove the cancer stem cell (CSC) theory without additional data.

Differentiation of Chromophobe Renal Cell Carcinoma and Clear Cell Renal Cell Carcinoma by Using Helical CT (나선식 CT를 이용한 혐색소형 신세포암과 투명세포형 신세포암의 감별)

  • Kim, Hong-Chul;Cho, Jae-Ho
    • Yeungnam University Journal of Medicine
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    • v.29 no.1
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    • pp.14-18
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    • 2012
  • Background: The purpose of this study was to differentiate chromophobe renal cell carcinoma and clear cell renal cell carcinoma on helical CT. Methods: The CT images of 9 patients histopathologically proven to have chromophobe renal cell carcinoma and 20 patients with clear cell renal cell carcinoma were reviewed. The tumor sizes, margins, enhancement degrees and patterns, presence or absence of calcification, and tumor spread patterns (including perinephric changes, venous invasion, lymphadenopathy, and distant metastasis) were compared. Results: All the chromophobe renal cell carcinomas showed well-demarcated margins. Thechromophobe renal cell carcinomas showed milder enhancements than the clear cell renal cell carcinomas. The sensitivity and specificity for differentiating the chromophobe renal cell carcinoma from the clear cell renal cell carcinoma were 100 and 88%, respectively, when 101 Hounsfield units was used as the cut-off value in the corticomedullary phase, and 95 and 100% when a less-than-three-time enhancement change was used as a cut-off value in the corticomedullary phase (p<0.05). The chromophobe renal cell carcinomas (67%) tended to show a homogeneous enhancement whereas the clear cell renal cell carcinomas (85%) usually showed a heterogeneous enhancement (p<0.05). Statistical analysis revealed that the frequencies of the tumor spread pattern and calcification in the two subtypes didnot differ significantly (p>0.05). Conclusion: The CT findings of the chromophobe renal cell carcinomascompared to those of the clear cell renal cell carcinomas showed that there were mild enhancements in the corticomedullary phase, homogeneous enhancements, and well-demarcated margins.

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Aircraft Engine Performance Test Technologies by 150K lbf Thrust Test Cell (15만 파운드급 테스트 셀을 이용한 엔진성능 시험기술)

  • Kim, Woocheol;Kim, Chul;Kim, Sangbaek
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • pp.180-187
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    • 2017
  • Major design targets such as test cell type, cell flow, cell bypass ratio, approach velocity, cell depression, front cell distortion, noise level and vibration level to construct a new 150,000 lbf thrust aircraft engine test facility were established. Based on the final aerodynamic and acoustic performance tests conducted at the newly constructed test facility, it was found that the new test facility is judged to be excellent and meets design targets.

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CELL MORPHOLOGY CHANGE BY THE ULTRAVIOLET RAY IRRADIATION

  • Park, Myoung-Joo;Matuo, Yoichirou;Akiyama, Yoko;Izumi, Yoshinobu;Nishijima, Shigehiro
    • Journal of Radiation Protection and Research
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    • v.34 no.1
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    • pp.15-24
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    • 2009
  • The effect of low doses of ultraviolet (UV) irradiation on morphology changes of cell has been studied based on the observation of the cell length. It was shown that UV-irradiated cell has different behavior in comparison with non-irradiated cell. From the histogram of cell-length distribution, it was confirmed that cell cycle of non irradiated cell was 28 hours, and that cell cycle of irradiated cell with dose of $20\;Jm^{-2}$ was delayed (39 hours), while irradiated cell with $40\;Jm^{-2}$ and $60\;Jm^{-2}$ did not divide and kept growing continuously. It was supposed that in case of $20\;Jm^{-2}$ of irradiation dose, the cell cycle was delayed because the checkpoint worked in order to repair DNA damage induced by generation of pyrimidine dimer, reactive oxygen species and so on. It was also supposed that in case of $40\;Jm^{-2}$ and $60\;Jm^{-2}$ of irradiation dose, overgrowth was induced because the checkpoint was not worked well. The morphology of overgrown cell was similar to that of normally senescent cell. Therefore, it was considered that cell senescence was accelerated by UV irradiation with irradiation doses of $40\;Jm^{-2}$ and $60\;Jm^{-2}$.

Effects of Acanthopanacis Cortex Radicis on the Apoptosis in HeLa cell and MCF-7 cell (HeLa cell과 MCF-7 cell에 대한 오가피(五加皮)의 apoptosis 효과)

  • Kim, Kyung-Sook;Lee, Jin-Moo;Lee, Chang-Hoon;Jang, Jun-Bock;Lee, Kyung-Sub
    • The Journal of Korean Obstetrics and Gynecology
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    • v.24 no.3
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    • pp.14-27
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    • 2011
  • Objectives: This study was designed to investigate the effects of Acanthopanacis Cortex Radicis extract(ACRE) on the apoptosis in HeLa cell and MCF-7 cell. Methods: After treatment with various concentration of ACRE, cell growth was evaluated in HeLa cell and MCF-7 cell. Hoechst 33342 staining was performed to estimate DNA fragment effect of ACRE on the apoptosis in HeLa cell and MCF-7 cell. Annexin V/PI apoptosis assay was used to estimate the effects of ACRE on the early apoptosis in HeLa cell and MCF-7 cell. RT-PCR was used to estimate the apoptosis gene expression effect of ACRE on Hela cell MCF-7 cell. Results: Under $0.1mg/m\ell$ of ACRE, cytotoxic effect was not found per NIH3T3 cell. The viability of HeLa cell and MCF-7 cells was significantly decreased ACRE ($100{\mu}g/m\ell$) in HeLa cell and MCF-7 cell, ACRE ($50{\mu}g/m\ell$) in HeLa cell 3 days after treatment, in MCF-7 cell 1&3 days after treatment (p<0.01). DNA fragmentation was observed 3 days after treatment of cl of ACRE on HeLa cell and MCF-7 cell. In Annexin V/PI apoptosis assay, after treatment of $100{\mu}g/m\ell$ of ACRE, the early apoptotic cell increased both in HeLa cell and MCF-7 cell. In RT-PCR analysis, after treatment of $100{\mu}g/m\ell$ of ACRE, bcl-2 were decreased and bax, caspase-3 were increased both in HeLa cell and MCF-7 cell. Conclusions: ACRE appears to have considerable activity on the apoptosis in HeLa cell and MCF-7 cell.

Study of Apoptosis by Scirpi Tuber in Hela Cell and MCF-7 Cell (자궁경부암(子宮頸部癌)과 유방암(乳房癌)에 대한 삼릉(三稜)의 세포자멸사 연구)

  • Yoo, Gap-Soon;Lee, Jin-Moo;Lee, Chang-Hoon;Jang, Jun-Bock;Lee, Kyung-Sub
    • The Journal of Korean Obstetrics and Gynecology
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    • v.24 no.3
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    • pp.1-13
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    • 2011
  • Objectives: This study was designed to investigate the analysis of apoptosis by Scirpi Tuber in Hela cell and MCF-7 cell. Methods: For cytotoxic effect of Scirpi Tuber extract, Scirpi Tuber extract were cultured on NIH3T3 cell in vitro. After treatment with various concentration of Scirpi Tuber, cell growth was evaluated in Hela cell and MCF-7 cell. Hoechst 33342 staining was performed to estimate DNA fragment effect of Scirpi Tuber on the apoptosis in Hela cell and MCF-7 cell. Annexin V/PI apoptosis assay was used to estimate the effects of Scirpi Tuber on the early apoptosis in Hela cell MCF-7 cell. All the stained cells were analyzed by a FACS. RT-PCR was used to estimate the apoptosis gene expression effect of Scirpi Tuber extract on Hela cell and MCF-7 cell. Results: Cytotoxic effect of Scirpi Tuber extract was not found on per NIH3T3 cell. The viability of Hela cell was significantly decreased Scirpi Tuber (500, $1000{\mu}g/m\ell$) in Hela cell 1day, 3day and 5days after treatment (p<0.01). The viability of MCF-7 cell was significantly decresed Scirpi Tuber ($1000{\mu}g/m\ell$) in MCF-7 cell (p<0.01), Scirpi Tuber ($500{\mu}g/m\ell$) in MCF-7 cell only 3days after treatment (p<0.01). In RT-PCR analysis, after treatment of $100{\mu}g/m\ell$ of ACR extract, BCL-2 were decreased and BAX, caspase-3 were increased both in Hela cell and MCF-7 cell. DNA fragmentation was observed the Scirpi Tuber on Hela cell and MCF-7 cell. As time goes on DNA fragmentation incresed. In Annexin V/PI apoptosis assay, after treatment of $1mg/m\ell$ of Scirpi Tuber, the early apoptotic cell increased both in Hela cell and MCF-7 cell. As time goes on apoptotic cell increased. Conclusion: Scirpi Tuber appears to have considerable activity on the apoptosis in Hela cell and MCF-7 cell.

Study of hydrogenated a-SiGe cell for middle cell of Triple junction solar cell (Triple junction 태양전지의 a-SiGe middle cell에 관한 연구)

  • Park, Taejin;Baek, Seungjo;Kim, Beomjoon
    • 한국신재생에너지학회:학술대회논문집
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    • pp.83.1-83.1
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    • 2010
  • Hydrogenated a-SiGe middle cell for triple junction solar cell was investigated with various process parameters. a-SiGe I-layer was deposited at substrate temperature $245^{\circ}C$ and hydrogen content(R) was up to 26.7. Low optical bandgap(1.45eV) of a-SiGe cell was applied for middle cell although a-SiGe single cell efficiency with low Ge content was higher. And this cell was applied to the middle cell of a glass superstrate type a-Si/a-SiGe/uc-Si triple junction solar cell. The triple junction solar cell was resulted in the initial efficiency of about 9%, area $0.25cm^2$, under global AM 1.5 illumination.

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