• 제목/요약/키워드: Biomedical Engineering

검색결과 7,011건 처리시간 0.042초

In vitro Estimation of Cardiac Output for the TAH using an Adaptive Fuzzy Identifier

  • Choi, W.W.;Jo, Y.H.;Ahn, J.M.;Park, S.K.;Choi, J.S.;Om, K.S.;Lee, J.J.;Choi, J.H.;Kim, H.C.;Min, B.G.
    • 대한의용생체공학회:학술대회논문집
    • /
    • 대한의용생체공학회 1996년도 추계학술대회
    • /
    • pp.263-267
    • /
    • 1996
  • An estimation algorithm based on training of fuzzy logic system using back-propagation is proposed, in this paper, for determining cardiac output in the TAH. The proposed estimation utilizes only a motor current waveform generated from the moving actuator of the electromechanical TAH without using any extra transducers as an information source for estimation. In in vitro tests, the resultant estimation performance was acceptable to alppy the proposed algorithm to animal experiments and further clinical applications.

  • PDF

Cordycepin inhibits chondrocyte hypertrophy of mesenchymal stem cells through PI3K/Bapx1 and Notch signaling pathway

  • Cao, Zhen;Dou, Ce;Li, Jianmei;Tang, Xiangyu;Xiang, Junyu;Zhao, Chunrong;Zhu, Lingyu;Bai, Yun;Xiang, Qiang;Dong, Shiwu
    • BMB Reports
    • /
    • 제49권10호
    • /
    • pp.548-553
    • /
    • 2016
  • Mesenchymal stem cells (MSCs) are widely used in cartilage tissue engineering to repair articular cartilage defects. However, hypertrophy of chondrocytes derived from MSCs might hinder the stabilization of hyaline cartilage. Thus, it is very important to find a suitable way to maintain the chondrogenic phenotype of chondrocytes. It has been reported that cordycepin has anti-inflammatory and anti-tumor functions. However, the role of cordycepin in chondrocyte hypertrophy remains unclear. Therefore, the objective of this study was to determine the effect of cordycepin on chondrogenesis and chondrocyte hypertrophy in MSCs and ATDC5 cells. Cordycepin upregulated chondrogenic markers including Sox9 and collagen type II while down-regulated hypertrophic markers including Runx2 and collagen type X. Further exploration showed that cordycepin promoted chondrogenesis through inhibiting Nrf2 while activating BMP signaling. Besides, cordycepin suppressed chondrocyte hypertrophy through PI3K/Bapx1 pathway and Notch signaling. Our results indicated cordycepin had the potential to maintain chondrocyte phenotype and reconstruct engineered cartilage.

뉴트럴레드가 고정화된 다공성 졸-겔 필름을 이용한 고감도 광섬유 pH 센서의 특성 (High-Sensitive Fiber-Optic pH Sensor Using Neutral Red Immobilized in Porous Sol-Gel Film)

  • 전다영;유욱재;신상훈;한기택;박장연;박병기;조승현;이봉수
    • 센서학회지
    • /
    • 제21권3호
    • /
    • pp.223-228
    • /
    • 2012
  • In this study, a fiber-optic pH sensor based on a pH sol-gel film is fabricated. The sol-gel film is made by co-polymerizing tetramethoxysilane, trimethoxymethylsilane, ethanol and distilled water. As a pH indicator, a neutral red is immobilized in a thin porous film formed by the sol-gel process. The pH change in a sensing probe gives rise to a change in the color of the pH sol-gel film, and the absorbance of reflected light through the pH sol-gel film is also changed. By using a spectrometer, therefore, the spectra of reflected lights in the sensing probe with different pH values are measured. Also, the relationships between the pH values and the absorbance are analyzed on the basis of the color variations of the pH sol-gel films. In repeated experiments, the fiber-optic pH sensor shows that it has reversibility, a high reproducibility and a wide absorbance change in a pH range from pH 5 to 9. Also, we confirmed that the fabricated pH sol-gel film exhibits a fast response time, little or no pH indicator leaching and a dynamic range of 2.04 dB from pH 5 to 9. Based on the results of this study, a fiber-optic pH sensor can be developed for the pH monitoring in the harsh environments.

컬러 영상 분석을 통한 치아 영상 분할 (Color Image Segmentation of Tooth Image)

  • 이성택;신승원;이선주;김경섭;윤태호
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2008년도 제39회 하계학술대회
    • /
    • pp.1987-1988
    • /
    • 2008
  • In this study, we try to implement an image segmentation algorithm to extract only the tooth regions from the tooth color image so that we can assess the color features to estimate the status of denticulus progression.

  • PDF

Present Status of High Field 3.0T MRI System

  • Choe, Bo-Young;Kim, Euy-Neyung;Suh, Tae-Suk;Lee, Hyoung-Koo;Lee, Heung-Kyu;Chun, Heung-Jae;Shinn, Kyung-Sub
    • 대한자기공명의과학회:학술대회논문집
    • /
    • 대한자기공명의과학회 2000년도 제5차 추계학술대회
    • /
    • pp.45-46
    • /
    • 2000
  • PDF