• 제목/요약/키워드: Cell Block

검색결과 785건 처리시간 0.026초

유전자 재조합 대장균을 사용한 Alpha-interferon의 생산과 분비: 제2부. 재조합 균주의 생장특성 (Extracellular Production of Alpha-Interferon by Recombinant Escherichia coli: Part II. The Growth Behavior of the Recombinant Cells)

  • 노갑수;최차용
    • KSBB Journal
    • /
    • 제5권3호
    • /
    • pp.195-200
    • /
    • 1990
  • 대장균의 lipoprotein promoter, lactose promotor 및 operator 와 lipoprotein의 signal sequence 를 가지는 vector에alpha-IFN 유전자가 cloning된 plasmid pIF-Ill-B를 여러종류의 대장균 숙주 세포에 형칠전환하여 alpha-IFN 의 생산성, 생장특성을 조사하였다. 또한 plasmid 자체와 cloning된 alpha-IFN 유전자의 발현유도가 세포생장에 미치는 영 향을 조사하였다.

  • PDF

수관부를 제거한 이태리 포플러에서 유관속 형성층과 그 유도조직의 비교해부 (Comparative Anatomy of Vascular Cambium and Its Derivative Tissues in Decapitated Populus euramericana)

  • 한경식
    • Journal of Plant Biology
    • /
    • 제36권3호
    • /
    • pp.251-257
    • /
    • 1993
  • The size variation of the cambial initials and their derivatives, in relation to the increase of girth, in the intact and decapitated stem of Populus euramericana was anatomically studied. In the typical nonstoried cambium of P. euramericana, the cell size of fusiform initials, vessel member, and sieve tube member were gradually increased and thus it reached a maximal state. In the intact plants, the size of the cambial initials and their derivatives was larger then in the decapitated ones. On the other hand, the frequency of anticlinal division of the cambial cells, the rate of the elongation and loss of the daughter initials in the intact plants was higher than in the decapitated ones. The cambium of the intact plants had higher ray compared with that of the decapitated ones. It was interpreted that these results were caused by the decapitation, which could block the supply of certain substances for cell growth such as hormones and metabolites.

  • PDF

선박용 블라스팅 셀 내에서의 실시간 위치 추적 기술을 이용한 작업자 안전 시스템에 대한 연구 (A Study on Safety System for Blasting Workers using Real Time Location System in the Shipyard)

  • 윤원준;노영식;조상복
    • 대한조선학회논문집
    • /
    • 제47권6호
    • /
    • pp.836-842
    • /
    • 2010
  • Safety system including location monitoring system for blasting workers was studied. Positioning performance of the location monitoring system was highly dependent on communication protocol and the number of access points in the blasting cell. RTLS(Real Time Location System) is an important technology to develop the location information of workers and variously used to enhance workers safety. Location monitoring system with Cell-ID and RSSI wireless communication technology was verified to have a proper positioning performance for the steel block application.

Chondrogenic Properties of Human Periosteum-derived Progenitor Cells (PDPCs) Embedded in a Thermoreversible Gelation Polymer (TGP)

  • Choi, Yang-Soo;Lim, Sang-Min;Shin, Hyun-Chong;Lee, Chang-Woo;Kim, Dong-Il
    • Biotechnology and Bioprocess Engineering:BBE
    • /
    • 제11권6호
    • /
    • pp.550-552
    • /
    • 2006
  • Periosteum-derived progenitor cells (PDPCs) were isolated using a fluorescence-activated cell sorter and their chondrogenic potential in biomaterials was investigated for the treatment of defective articular cartilage as a cell therapy. The chondrogenesis of PDPCs was conducted in a thermoreversible gelation polymer (TGP), which is a block copolymer composed of temperature-responsive polymer blocks such as poly(N-isopropylacrylamide) and of hydrophilic polymer blocks such as polyethylene oxide, and a defined medium that contained transforming growth $factor-{\beta}3\;(TGF-{\beta}3)$. The PDPCs exhibited chondrogenic potential when cultured in TGP. As the PDPCs-TGP is an acceptable biocompatible complex appropriate for injection into humans, this product might be readily applied to minimize invasion in a defected knee.

Flexural Behaviors of 4D Carbon/carbon Composites with the Preform Architectures

  • Lee, Ki-Woong;Park, Jong-Min;Joo, Hyeok-Jong
    • Carbon letters
    • /
    • 제9권1호
    • /
    • pp.28-34
    • /
    • 2008
  • Multidirectional reinforcement is aimed primarily at overcoming interlaminar weakness, hence a major interest lies in the mechanical properties of multidirectional carbon/carbon composites. Mechanical properties depend on the type of carbon fiber, the size of the fiber bundle, the spacing of the bundles, the angles of the bundles relative to the axes of the block, and matrix formation. In the present studies, PAN based carbon fiber preforms manufactured different size of unit cell have been prepared. Densification of these used high pressure infiltration and carbonization technique with coal tar pitch as matrix precursor was carried out. Scanning electron microscopy has been used to study the fracture behavior of composites. The size of unit cell of the preforms has considerably affected on the flexural properties as well as microstructure of the carbon/carbon composites.

전자현미경 In Situ Hybridization에 의한 Viral RNA의 진단에 관한 연구 (Studies on In Situ Hybridization of Electron Microscopy for Detection of Viral RNA)

  • 최원기;주경웅;김석홍
    • 대한의생명과학회지
    • /
    • 제2권2호
    • /
    • pp.257-265
    • /
    • 1996
  • 토끼 바이러스성 출혈증의 원인체를 실험 토끼에 접종하여 증식을 유도하고 간장에서 hematoxylin & eosin 염 색 에서 조직학적 진단과 세포내 viral RNA의 소재를 결정하기 위해 post-unicryl 포매한 block의 절편을 사용하여 단 염색과 전자현미경적 in situ hybridization을 시도하였다. 토끼 출혈증 viral RNA의 보합 결합에 이용하는 probe는 4717에서 4800(84bases)까지 oligonucleotide를 5'말단에 biotin-CE phosphoramidite로 표지하여 사용하였다. 보합결합물의 증명은 신호 표지로서 antibiotin antibody-l0nm gold를 사용하였으며, hybridization이나 증명은 기존 protocol에서 약간의 변법을 사용하였다. 0.02% glutaraldehyde에서 고정하고 unicryl resin 포매한 표본, biotinylated oligonucleotide probe, antibiotin antibody-l0nm gold로 실험한 결과 증강된 신호를 얻을 수 있었다. 특히 전처리를 생략하므로써 실험 과정을 간단하게 하여 신속한 결과를 얻을 수가 있었다. 전자현미경 in situ hybridization을 통하여 토끼 출혈증 바이러스의 주요 표적은 간세포로 감염 세포의 세포질 내 미토콘드리아와 핵 사이에서 immune gold입자가 뚜렷하게 표지 됨으로서 viral RNA를 증명할 수 있었다.

  • PDF

Blockade of Kv1.5 by paroxetine, an antidepressant drug

  • Lee, Hyang Mi;Hahn, Sang June;Choi, Bok Hee
    • The Korean Journal of Physiology and Pharmacology
    • /
    • 제20권1호
    • /
    • pp.75-82
    • /
    • 2016
  • Paroxetine, a selective serotonin reuptake inhibitor (SSRI), has been reported to have an effect on several ion channels including human ether-a-go-go-related gene in a SSRI-independent manner. These results suggest that paroxetine may cause side effects on cardiac system. In this study, we investigated the effect of paroxetine on Kv1.5, which is one of cardiac ion channels. The action of paroxetine on the cloned neuronal rat Kv1.5 channels stably expressed in Chinese hamster ovary cells was investigated using the whole-cell patch-clamp technique. Paroxetine reduced Kv1.5 whole-cell currents in a reversible concentration-dependent manner, with an $IC_{50}$ value and a Hill coefficient of $4.11{\mu}M$ and 0.98, respectively. Paroxetine accelerated the decay rate of inactivation of Kv1.5 currents without modifying the kinetics of current activation. The inhibition increased steeply between -30 and 0 mV, which corresponded with the voltage range for channel opening. In the voltage range positive to 0 mV, inhibition displayed a weak voltage dependence, consistent with an electrical distance ${\delta}$ of 0.32. The binding ($k_{+1}$) and unbinding ($k_{-1}$) rate constants for paroxetine-induced block of Kv1.5 were $4.9{\mu}M^{-1}s^{-1}$ and $16.1s^{-1}$, respectively. The theoretical $K_D$ value derived by $k_{-1}/k_{+1}$ yielded $3.3{\mu}M$. Paroxetine slowed the deactivation time course, resulting in a tail crossover phenomenon when the tail currents, recorded in the presence and absence of paroxetine, were superimposed. Inhibition of Kv1.5 by paroxetine was use-dependent. The present results suggest that paroxetine acts on Kv1.5 currents as an open-channel blocker.

MPPT 제어 기능을 갖는 이중 입력 에너지 하베스팅 충전기 (A Dual-Input Energy Harvesting Charger with MPPT Control)

  • 정찬호;김용승;정효범;양민재;윤은정;유종근
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국정보통신학회 2015년도 추계학술대회
    • /
    • pp.484-487
    • /
    • 2015
  • 본 논문에서는 진동에너지와 빛에너지를 이용한 MPPT 기능을 갖는 이중 입력 충전기 회로를 제안한다. 빛에너지는 photovoltaic cell로부터 수확하고, 진동에너지는 piezoelectric cell로부터 수확하여 각각 커패시터에 저장된다. Charger 블록에 의해 배터리 전압이 승압되며 이때 두 가지 에너지원이 모두 입력으로 사용되어 충전하게 된다. 승압하는 방법은 DC-DC boost converter를 사용하였으며 시간 구간에 따라 하나의 인덕터를 공유하는 방법을 적용하였고, 진동에너지와 빛에너지를 입력으로 사용하는 비율은 8:1로 설계하였다. 제안된 회로는 0.35um CMOS 공정으로 설계하였고 배터리 관리블록에 의해 배터리 커패시터의 충전 상태가 제어되며 최대 3V의 전압까지 충전할 수 있다. 설계된 회로의 최대 효율은 88.56%이며, 칩 면적은 패드를 포함하여 $1230um{\times}1330um$이다.

  • PDF

저장 장치를 위한 다양한 부호화 기법의 성능 분석 (Performance Analysis of Various Coding Schemes for Storage Systems)

  • 김형준;김성래;신동준
    • 한국통신학회논문지
    • /
    • 제33권12C호
    • /
    • pp.1014-1020
    • /
    • 2008
  • 메모리 등의 저장 장치는 다양한 전자제품에 널리 이용되면서 높은 메모리 집적도가 요구되고 있으며 멀티 레벨로 데이터를 저장하는 단계에 이르렀다. 그 결과 데이터의 오류율은 더 높아지게 되었다. 본 논문에서 우리는 저장장치의 낮은 오류율을 만족시키기 위하여 통신시스템에서 널리 사용되고 있는 오류정정부호 기법을 적용하였다. 평균 오류율 (BER)이 $10^{-5}$ 또는 $5{\times}10^{-6}$인 AWGN 채널에서 4-level cell을 이용한 저장장치에 대하여 목표 부호율 0.99과 목표 오류율 (BER) $10^{-11}$$10^{-13}$를 만족시킬 수 있는 방법을 알아본다. 높은 부호율에서는 연접부호의 성능이 블록 부호만 사용한 경우보다 좋지 않은 경우도 많으며, 이때 천공을 많이 한 경우에도 성능 열화가 덜한 안쪽 부호를 선정하는 것이 중요함을 확인하였다. 일반적인 feedfoward systematic 길쌈 부호를 이용한 연접부호는 복잡도를 고려하지 않더라도 블록 부호를 단독으로 사용한 경우보다 성능이 좋지 않음을 확인하였고, 높은부호율 에서도 성능이 우수한 천공 길쌈 부호를 만들기 위해서는 RSC 부호를 사용해야 한다는 것을 모의실험 결과를 통해 보여준다.

Prospective Assessment of the Performance of a New Fine Needle Biopsy Device for EUS-Guided Sampling of Solid Lesions

  • El Hajj, Ihab I.;Wu, Howard;Reuss, Sarah;Randolph, Melissa;Harris, Akeem;Gromski, Mark A.;Al-Haddad, Mohammad
    • Clinical Endoscopy
    • /
    • 제51권6호
    • /
    • pp.576-583
    • /
    • 2018
  • Background/Aims: Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) remains the most common EUS-guided tissue acquisition technique. This study aimed to evaluate the performance of a new Franseen tip fine needle biopsy (FNB) device for EUSguided sampling of solid lesions and compare it with the historical FNA technique. Methods: $Acquire^{(R)}$ 22 G FNB needle (Boston Scientific Co., Natick, MA, USA) was used for solid tumor sampling (Study group). Tissue was collected for rapid on-site evaluation, and touch and crush preparations were made. Historical EUS-FNA samples obtained using $Expect^{(R)}$ 22 G FNA needle (Boston Scientific Co.) were used as controls (Control group). All specimens were independently evaluated by two cytopathologists blinded to the formal cytopathological diagnosis. Results: Mean cell block histology scores were significantly higher (p=0.046) in the FNB group (51 samples) despite a significantly lower (p<0.001) mean number of passes compared to the FNA group (50 specimens). The overall diagnostic yields for the FNB vs. FNA groups were 96% vs. 88%. The degree of tumor differentiation was adequately assessed in all cell block qualifying lesions in the FNB group. Two patients developed post-FNB abdominal pain. Conclusions: The new Franseen tip FNB device provides histologically superior and cytologically comparable specimens to those obtained by FNA, but with fewer passes.