• Biomolecules & Therapeutics
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• 제15권1호
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• pp.52-57
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• 2007

Lysolipids such as lysophosphatidylcholine (LPC), sphingosylphosphorylcholine (S PC), galactosylsphingosine (psychosine) have been matched as ligands for OGR1-subfamily G-protein-coupled receptors (GPCR), consisted of OGR1, GPR4, G2A, and TDAG8. Recently, those members of GPCRS have been reported as proton-sensing GPCRs. We used Jurkat T cells, which express four members of OGR1 subfamily GPCRs endogenously to investigate effects of proton on lysolipid-induced several cellular events. We found no significant effect of proton on the lysolipid-induced $Ca^{2+}$ increase and ROS production in Jurkat T cells. Further investigation is necessary to clarify the relationship of lysolipid and proton on the OGR1-subfamily GPCRs.

• Journal of Microbiology and Biotechnology
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• 제16권5호
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• pp.673-677
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• 2006

A perfusion culture of transgenic Nicotiana tabacum cell suspensions, transformed to express recombinant glucuronidase (GUS), was successfully performed in a 5-1 stirred tank bioreactor. With 0.1 $day^{-1}$ of perfusion rate, the maximum dry cell weight (DCW) reached to 29.5 g/l in 16 days, which was 2.1-fold higher than the obtained in batch culture (14.3 g/l). In terms of the production of GUS, the volumetric activity could be increased up to 12.8 U/ml by using perfusion, compared with 4.9 U/ml in batch culture. The specific GUS activities in both perfusion and batch cultures were maintained at similar levels, 200-400 U/g DCW. Consequently, a perfusion culture could be a good strategy for the enhanced production of recombinant proteins in a plant cell culture system.

• 대한수학회지
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• 제37권3호
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• pp.491-502
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• 2000

The disjoint union of mapping class groups g,1 gives us a braided monoidal category so that it gives rise to a double loop space structure. We show that there exists a natural twist in this category, so it gives us a ribbon category. We show that there exists a natural twist in this category, so it gives us a ribbon category. We explicitly express this structure by showing how the twist acts on the fundamental group of the surface Sg,l. We also make an explicit description of this structure in terms of the standard Dehn twists, as well as in terms of Wajnryb's Dehn twists. We show that the inverse of the twist g for the genus g equals the Dehn twist along the fixed boundary of the surface Sg,l.

• 한국전자파학회논문지
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• 제27권5호
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• pp.445-453
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• 2016

본 논문은 3GPP LTE(Long Term Evolution)-TDD(Time Division Duplexing) 표준을 기반으로 NI(National Instruments)의 USRP RIO SDR(Software Defined Radio) 플랫폼을 이용해 28 GHz 밀리미터파 대역에서 HD 비디오를 무선으로 송수신하는 1T-1R(1 Transmitter-1 Receiver) 시스템을 설계 및 구현하였다. 해당 시스템은 Verilog로 설계한 LTE-TDD 송수신 모뎀을 USRP RIO에 내장된 Xilinx Kintex-7칩에 구현하여 USRP RIO를 베이스밴드로 사용하였으며, USRP RIO에서 송수신되는 신호는 자체 설계한 28 GHz RF 송수신 모듈로 업 다운 변환을 수행한 후 자체 설계한 $4{\times}8$ 서브 배열 안테나를 통해 최종적으로 HD 비디오 데이터를 통신하게 된다. USRP RIO와 Host PC의 통신 방식은 데이터 송수신시 발생되는 지연을 최소화하기 위해 PCI express(Peripheral Component Interconnect express)${\times}4$를 사용하였다. 구현한 시스템은 25.85 dBc 이상의 높은 EVM(Error Vector Magnitude) 성능을 보였으며, 실험환경 내 어디서든 HD 비디오를 성공적으로 송수신 하였다.

• 호남수학학술지
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• 제43권2호
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• pp.183-197
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• 2021

Recently several authors have extended the Beta function by using its integral representation. However, in many cases no expression of these extended functions in terms of classic special functions is known. In the present paper, we introduce a further extension by defining a family of functions G_r,s : ℝ^*₊ → ℂ, with r, s ∈ ℂ and ℜ(r) > 0. For given r, s, we prove that this function satisfies a second-order linear differential equation with rational coefficients. Solving this ODE, we express G_r,s as a combination of confluent hypergeometric functions. From this we deduce a new integral relation satisfied by Tricomi's function. We then investigate additional specific properties of G_r,1 which take the form of new non trivial integral relations involving exponential and error functions. We discuss the connection between G_r,1 and Stokes' first problem (or Rayleigh problem) in fluid mechanics which consists in determining the flow created by the movement of an infinitely long plate. For $r{\in}{\frac{1}{2}}{\mathbb{N}}^*$, we find additional relations between G_r,1 and Hermite polynomials. In view of these results, we believe the family of extended beta functions G_r,s will find further applications in two directions: (i) for improving our knowledge of confluent hypergeometric functions and Tricomi's function, (ii) and for engineering and physics problems.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1744-1746
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• 2004

This paper focuses on the problem of asymptotic stabilization for time-delay systems. To this end, a memoryless state feedback controller is proposed. Then, based on the Lyapunov method, a delay-dependent stabilization criterion is devised by taking the relationship between the terms in the Leibniz-Newton formula into account. Certain free weighting matrices are used to express this relationship and linear matrix inequalities (LMIs)-based algorithm to design the controller stabilizing the system.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.318-320
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• 2011

Numerical study was conducted to simulate the heat transfer on the real launch vehicle base. Three different base temperatures were chosen, to simulate the heat accumulation on the base. Moreover, six different pressure ratio conditions were used to express the different air conditions. As a result, the table that can used to estimate the base heat fox along the base temperature and pressure condition was made.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.274-277
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• 2000

SHS is recognized as an attractive process for producing high-temperature, hard materials that difficult and/or expensive to produce by conventional fabrication methods. The goal of this work is to investigate new express technology of doped Fe alloys materials. The high density, homogeneity of the components, and the low processing temperatures achieved and minimum synthesis time are all of paramount importance in fabricating Fe alloys as functional materials.

• IMMUNE NETWORK
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• 제12권3호
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• pp.89-95
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• 2012

Immune cells express toll-like receptors (TLRs) and respond to molecular patterns of various pathogens. CpG motif in bacterial DNA activates innate and acquired immune systems through binding to TLR9 of immune cells. Several studies reported that CpG can directly regulate B cell activation, differentiation, and Ig production. However, the role of CpG in B cell growth and Ig production is not fully understood. In this study, we analyzed the effect of CpG on the kinetics of mouse B cell viability, proliferation, and Igs production. Overall, CpG enhanced mouse B cell growth and production of Igs in a dose-dependent manner. Unlike LPS, 100 nM CpG (high dose) did not support TGF-${\beta}1$-induced IgA and IgG2b production. Moreover, 100 nM CpG treatment abrogated either LPS-induced IgM or LPS/TGF-${\beta}1$-induced IgA and IgG2b production, although B cell growth was enhanced by CpG under the same culture conditions. We subsequently found that 10 nM CpG (low dose) is sufficient for B cell growth. Again, 10 nM CpG did not support TGF-${\beta}1$-induced IgA production but, interestingly enough, supported RA-induced IgA production. Further, 10 nM CpG, unlike 100 nM, neither abrogated the LPS/TGF-${\beta}1$- nor the LPS/RA-induced IgA production. Taken together, these results suggest that dose of CpG is critical in B cell growth and Igs production and the optimal dose of CpG cooperates with LPS in B cell activation and differentiation toward Igs production.

• 한국식품위생안전성학회지
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• 제34권3호
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• pp.309-315
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• 2019

본 연구는 식품으로부터 S. aureus를 분리하는 데 사용되는 선택배지들의 성능을 평가하였다. 먼저 BPA와 MSEY agar의 민감도 비교를 통해 BPA를 선택하였고, 이 배지의 회수율을 $3M^{TM}$ $Petrifilm^{TM}$ Staph Express Count Plate(STX petrifilm)의 회수율과 비교하였다. 축산식품 중 돼지고기 주물럭과 육회용 꾸릿살, 수산식품 중 쥐포와 반건조 오징어, 전통식품 중 떡과 잡채를 선정하여 S. aureus를 접종한 후 BPA와 STX Petrifilm 배지를 사용하여 회수율 분석 실험을 실시하였다. 6가지 식품에 대해 인위적으로 S. aureus를 저농도에서부터 고농도까지 접종한 후 0시간과 24시간 후의 검출률을 측정하였다. 두 배지 간의 유의 수준을 분석한 결과 식품의 종류, 접종 농도에 관계없이 두 선택배지 간에 통계적 유의차는 없는 것으로 확인되었다(P>0.05). 따라서 STX Petrifilm은 BPA를 대체할 수 있을 뿐만 아니라 배지의 준비 및 도말에 소요되는 분석시간을 절감하고 배양에도 최소한의 공간이 필요하게 되어 신속, 정확한 분석에 크게 기여할 수 있을 것으로 판단된다.