• Archives of Reconstructive Microsurgery
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• 제16권2호
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• pp.86-92
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• 2007

Failure of reattachment of finger is inevitable in replantation surgery and that failure rate is about 10 % are reported in many authors. Management of the failed finger replantation is challenge to microsurgeons. We report 7 cases of thumb reconstruction after failure of replantation. The reconstructive surgery composed with early debridement of soft tissue that are under gangrenous processing, extract the phalangeal bone without any soft tissues. Osteosynthesis of the extracted phalangeal bone with host phalangeal bone. The exposed bony portion covered with vascularized flaps such as reverse radial forearm pedicled flap, free radial forearm flap and neurovascular island finger flap. This procedure underwent within a week after vascular insufficiency developed. All of the flaps are survived, bone union achieved within 3 months. The function and external appearance of the reconstructed thumb were encouraging; pinch power was average 1.2 pounds. Early removal of necrotizing soft tissue followed by covering none vascular phalangeal bone which extracted from the dead phalanx with vascularized flap is one of the useful alterative solutions in failed replantation surgery in hand.

• 융합신호처리학회논문지
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• 제1권1호
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• pp.49-57
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• 2000

In this study, a new algorithm for canceling a MRI artifact due to the translational motion In the image plane is described. Unlike the conventional iterative phase retrieval algorithm, in which there is no guarantee for the convergence, a direct method for estimating the motion is presented. In previous approaches, the motions in the x(read out) direction and the y(phase encoding) direction were estimated simultaneously. However, the feature of x and y directional motions are different from each other. By analyzing their features, each x and y directional motion is canceled by the different algorithms in two steps. First, it is noticed that the x directional motion corresponds to a shift of the x directional spectrum of the MRI signal, and the non-zero area of the spectrum just corresponds to the projected area of the density function on the x axis. So the motion is estimated by tracing the edges between non-zero area and zero area of the spectrum, and the x directional motion is canceled by shifting the spectrum in an reverse direction. Next, the y directional motion is canceled by using a new constraint condition, with which the motion component and the true image component can be separated. This algorithm is shown to be effective by using a phantom image with simulated motion.

• Animal cells and systems
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• 제13권4호
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• pp.381-389
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• 2009

Using the DDRT-PCR, a series of differentially expressed genes in human primary cervical cancer was isolated. Among the 250 PCR amplimers, 88 gene fragments were confirmed by reverse Northern hybridization. Homology searches indicated that 26 out of 88 were previously known genes including calmodulin, human BBC1, histone H3.3, a series of ribosomal proteins (RPL19, RPS19, and RPS12), translation initiation factor (eIF-4AI), lactoferrin, integrin ${\alpha}6$, cell-surface antigens (CD9 and CD59), transcription factor (mbp-1), and mitochondrial proteins. Several unknown clones showed sequence homology with known genes. Furthermore, six of the unknown genes showed identical sequence with expressed sequence tags (EST) of unknown function. Differential expression patterns of identified genes were further examined and confirmed with multiple pairs of cervical cancer samples using Northern hybridization. Our profiling of differentially expressed genes may provide useful information about the underlying genetic alterations in human cervical carcinoma and diagnostic markers for this disease. The precise roles of these genes in cancer development remain to be elucidated.

• The Journal of the Acoustical Society of Korea
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• 제24권3E호
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• pp.87-89
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• 2005

The acoustical sources of intake and exhaust systems in fluid machines are often characterized by the source impedance and strength using linear frequency-domain modeling. In the case of the sources which are nonlinear and time-variant, however, the source parameters were sometimes incorrectly obtained. In this paper, the source model and direct measurement technique are modified in order to evaluate the effect due to nonlinear and periodically time-varying source character as well as the linear property of the reflectivity of in-duct fluid machine source. With a priori known kinematical information of the source, the types of nonlinear time-variant terms can be presumed by a simple physical model, in which there is practically no restriction on the form of the model. The concept of source impedance can be extendable by introducing the linear frequency response function for each nonlinear or time-variant input. Extending the conventional method and adapting the reverse MISO technique, it is possible to develop a direct method that can deal with the nonlinear time-variant source parameters. The proposed direct method has a novel feature that there is no restriction on the probability or spectral natures of the excited sound pressure data. The present method is verified by the simulated measurements for simplified fluid machines. It is thought that the proposed method would be useful in predicting the insertion loss or the radiated sound level from intake or exhaust systems.

• Molecules and Cells
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• 제38권11호
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• pp.959-965
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• 2015

Inducible and reversible gene silencing in desired types of cells is instrumental for deciphering gene functions using cultured cells or in vivo models. However, efficient conditional gene knockdown systems remain to be established. Here, we report the generation of an inducible expression system for short hairpin RNA (shRNA) targeted to PTEN, a well-documented dual-specificity phosphatase involved in tumor suppression and ontogenesis. Upon induction by doxycycline (DOX), the reverse tetracycline transcriptional activator (rtTA) switched on the concomitant expression of GFP and a miR-30 precursor, the subsequent processing of which released the embedded PTEN-targeted shRNA. The efficacy and reversibility of PTEN knockdown by this construct was validated in normal and neoplastic cells, in which PTEN deficiency resulted in accelerated cell proliferation, suppressed apoptosis, and increased invasiveness. Transgenic mice harboring the conditional shRNA-expression cassette were obtained; GFP expression and concurrent PTEN silencing were observed upon ectopic expression of rtTA and induction with Dox. Therefore, this study provides novel tools for the precise dissection of PTEN functions and the generation of PTEN loss of function models in specific subsets of cells during carcinogenesis and ontogenesis.

• 한국연소학회:학술대회논문집
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• 한국연소학회 1998년도 제17회 KOSCI SYMPOSIUM 논문집
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• pp.9-21
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• 1998

The optimization of frontal device including fuel nozzle and swirler is required to secure the mixing of fuel and air, and the combustion stability in the gas turbine combustor design for the reduction of pollutant emissions and the increase of combustion efficiency. The effects of injection nozzle and swirler on the flow field, spray characteristics and consequently the combustion stability, were experimentally investigated by measuring the velocity field, droplet sizes of fuel spray, lean combustion limit and the temperature field in the main combustion region. The effect of fuel injection nozzle was tested by adopting three different nozzles; a dual orifice fuel nozzle, a hollow cone nozzle and a solid cone nozzle. These tests were combined with the three different swirler geometries; a dual-stage swirler with 40$^{\circ}$ /-4 5$^{\circ}$ vanes and two single-stage swirlers with 40$^{\circ}$ vane angle having 12 and 16vanes, respectively. Flow fields and spray characteristics were measured with APV(Adaptive Phase Doppler Velocimetry) under atmospheric condition using kerosine fuel. Temperatures were measured by Pt-PtI3%Rh, R-type thermocouple which was 0.2mm thick. It was found that the dual swirler resulted in the biggest recirculation zone with the highest reverse flow velocity at the central region, which lead the most stable combustion. The various combustion characteristics were observed as a function of the combination between the injector and swirler, that gave a tip for the better design of gas turbine combustor.

• 전자공학회논문지S
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• 제36S권9호
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• pp.18-26
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• 1999

여러쓰는이 검파는 간섭과 근원 효과 문제를 해결할 수 있기 때문에 널리 연구되고 있다. 이 논문에서는 유사동기 채널에서 안테나 배열을 쓰는 역방향 연결 시스템에서의 유사최대비슷함 검파기를 생각하였다. 제안한 시스템은 다른 쓰는이들의 정보를 모두 알지 않더라고 쓰는이 사이 간섭을 줄일 수 있음과 이제까지의 정합 여파기보다 성능이 더 뛰어남을 보였다.

• 한국전자파학회논문지
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• 제8권6호
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• pp.645-655
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• 1997

본 논문에서는 CDMA 시스댐에 적용하기 위해 기저 대역에서 설계된 비동기식 동기 추적 회로의 성능을 이론적으로 분석하고 컴퓨터 시뮬레이션을 통해 검증한다. AWGN 채널 환경에서 지터 분산을 펼스 성형 필터, 타이밍 오프셋, 신호 대 잡음 비, 루우프 필터 계수의 함수로 이론적으로 유도하고 2차 동기 추적 회로를 중심으로 루우프 필터의 설계에 판해 고찰한다. 끝으로, 설계된 동기 추적 회로를 ETRI에서 IMT-2000을 위해 설계한 동기식 CDMA 시스템의 역방향 링크에 적용하여 AWGN과 레일라이 페이딩 환경에서의 성능을 시율레이션을 통해 검증한다.

• International Journal of Oral Biology
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• 제31권4호
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• pp.135-140
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• 2006

Temperature signaling can be initiated by members of transient receptor potential (thermo-TRP) channels. Hot and cold substances applied to teeth usually elicit pain sensation. Since odontoblasts constitute a well-defined layer between the pulp and the mineralized dentin, being first to encounter thermal stimulation from oral cavity, they may be involved in sensory transduction process, in addition to their primary function as formation of dentin. We investigated whether thermo-TRP channels are expressed in a odontoblast cell line, MDPC-23. The expressions of thermo-TRP channels were examined using reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry, fluorometric calcium imaging. Analysis of RT-PCR revealed mRNA expression of TRPV1, TRPV2, TRPV4 and TRPM8, but no TRPV3, TRPA1. Immunohistochemical approach failed to detect TRPV1 expression. Whereas the application of 4-phorbol-12,13-didecanoate($10\;{\mu}M$, a TRPV4 agonist), menthol(1 mM, a TRPM8 agonist) and icilin($10\;{\mu}M$, a TRPM8 agonist) produced the enhancement of intracellular calcium concentration, capsaicin($1\;{\mu}M$, a TRPV1 agonist) did not. Our results suggest that subfamily of thermo-TRP channels expressed in odontoblasts may serve as thermal or mechanical transducer in teeth.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.7-12
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• 2004

Desalination system of revers osmosis(RO) membrane has been proven to be the most economical not only for the desalination of water containing salts, but also for the concentration of solute. RO membranes were traditionally made of inorganic polymers such. as cellulose acetate(CA), Polyamide(PA). To retain more minerals in deep ocean water, a new hybrid membrane composed of tourmaline film as organic material onto inorganic layer of CA polymer in asymmetric structure was developed for RO membrane process. The performance tests were carried out in the permeability of pure water and the rejection of NaCl solution to evaluate the adaptability for DOW desalination. The results of these basic tests show possibility to apply the new hybrid RO membrane for the desalination with function control.