• International Journal of Industrial Entomology and Biomaterials
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• 제31권2호
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• pp.95-102
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• 2015

Insects are heterotherms that exhibit a close relationship between their ecology (especially temperature changes) and physiology. In the present study, selected genes associated with cell death and temperature were examined to determine gene expression in Bombyx mori in high and low temperature environments. We determined the amount of dsRNA, different concentrations of dsRNA, and different type of cells to set the conditions most efficient for RNAi. We then prepared dsRNA transcripts of the genes associated with cell death and temperature response. We analyzed cell damage via Trypan blue staining and found that cell viability was reduced after knockdown of these genes. The special transduced cell lines produced in the present study can be applied in various research fields. We also expect that these cell lines can be used as a research tool for the precise functional analysis of various genes.

• 한국잠사곤충학회지
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• 제38권1호
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• pp.42-47
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• 1996

AcNPV와 BmNPV를 배양세포주에서 동시감염시켜 선발한 숙주범위가 넓어진 재조합 바이러스인 RecB-727과 RecS-A6의 분자생물학적인 특성들을 조사하였다. 재조합 바이러스의 LT50 값을 조사한 결과, RecS-A6는 모바이러스인 BmNPV 보다 비교적 낮은 병원성을 보았으나 RecB-727은 거의 비슷한 수준의 높은 병원성을 나타내었다. 재조합 바이러스 DNA를 분리하여 모바이러스 DNA와 함께 제한효소 패턴을 비교한 결과 DNA 수준에서 재조합이 일어났음을 확인할 수 있었으며, 일부 유전자의 재조합을 예측할 수 있었다. 또한 p10 유전자에 대한 Southern blot 분석 결과 RecB-727의 p10 유전자는 AcNPV에서 유래되었으며, RecS-A6는 BmNPV의 p10 유전자를 갖고 있는 것으로 추정된다. 재조합 바이러스의 숙주범위 확장에 중요한 역할을 하는 것으로 알려진 DNA helicase 유전자 내의 HindIII-SacI 0.6kb 부위에 대하여 약 250 bp의 염기서열을 조사한 결과, 이 부위의 염기서열은 BmNPV helicase의 염기서열과 동일하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.277-277
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• 2012

PCDTBT (Poly[N-9''-hepta-decanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)]) is an attractive material as a semiconducting polymer for organic thin film transistor (OTFT) and organic solar cell (OSC). High power conversion efficiency (~6%) under simulated AM 1.5G solar illumination of bulk-heterojunction solar cell with PCDTBT and [6,6]-phenyl C60 butyric acid methyl ester (PC61BM) blend was reported. In OSC, it is known that the band alignment at the interface between donor and acceptor is critical. Therefore, we studied the interfacial electronic structures of PCDTBT and PC61BM. The polymers are deposited by electro-spray on gold and In-situ x-ray and ultraviolet photoelectron spectroscopy measurements revealed the interfacial electronic structures. We obtained the energy level alignment between two materials and the different interface formation was observed with different deposition order.

• International Journal of Industrial Entomology and Biomaterials
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• 제4권1호
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• pp.57-62
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• 2002

Cationic liposomes complexed with DNA have been extensively utilized for the delivery of reporter or therapeutic genes both in culture and in vivo. We investigated and determined the optimum conditions of a cationic liposome, composed of dimethyldioctadecy-lammonium bromide (DDAB) and dioleoyl phosphati-dylethanolamine UOPE), mediated a reporter plasmid expressing luciferase into insect cell lines (Sf-21 and Bm-N) and silkworm larvae. Together the data demonstrated that Bombyx mori nuclear polyhedrosis virus (BmNPV) genomic DNA (128 kb) was successfully transfected into Bm-5 cells using this liposome. These results suggest that DDAB/DOPE liposome will be useful as delivery agents for gene transfer to insect cells both in vitro and in vivo.

• Clinical and Experimental Pediatrics
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• 제52권1호
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• pp.28-35
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• 2009

목 적 : 액상 대두기반 영아식이 개발되어 시판되고 있으나 이에 대한 영양학적 연구는 미흡한 상태이다. 액상 대두영아식을 섭취하는 경우 영유아의 성장 및 발달을 모유 및 우유기반 영유아식을 먹이는 경우와 비교하였다. 방 법 : 2001년 6월부터 203년 8월까지 충북대학교병원에서 만기 정상분만으로 출생한 신생아를 대상으로 모유군(n=20)과 대두 영유아식(n=19) 및 우유 영유아식군(n=12)으로 나누어, 생후 첫 3개월간은 모유 및 인공 영유아식을 각 군에 해당하는 식이를 먹이고 생후 4개월부터는 이유식을 자유롭게 하도록 했다. 신체계측으로는 출생 시, 1, 2, 4, 5, 12개월, 그리고 36개월에 신장, 체중, 두위, 삼두박근 피부두께, 그리고 상완둘레를 측정하였다. 일반혈액 및 혈청의 화학검사는 생후 5, 12 그리고 36개월에 시행하였다. 결 과 : 생후 5개월까지는 대두 영유아식군의 체중이 가장 낮았으나 신장은 차이가 없었고, 이후 체중과 신장은 36개월까지 모든 영유아식군 간에 차이가 없었다. 혈중 헤모글로빈은 5개월과 12개월에 모유군이 가장 낮았다(P<0.05). 혈청화학 검사에서는 대두 영유아식군에서 생후 5개월에 BUN은 가장 높았고, cholesterol, 인, 포타슘은 가장 낮았으나, 그 이후는 모든 화학검사 수치의 차이가 없었다. 결 론 : 대두기반 영유아식을 준 경우에 생후 3년간 우유 영유아식군이나 모유군에 비하여 신체의 성장에는 차이가 없었다. 대두기반 영유아식이 우유기반 영유아식이나 모유에 비하여 무기질 함량이 높은데도 불구하고 생후 5개월에 혈청 인 및 포타슘이 낮아 무기물의 흡수율을 높이는 방법을 개발해야 할 것으로 보인다.

• 한국잠사곤충학회지
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• 제38권1호
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• pp.36-41
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• 1996

AcNPV 와 BmNPV의 배양세포주에서의 동시감염에 의해 선발된 재조합 바이러스 RecS-A6는 그 다각체 외부 형태가 모바이러스와 다를뿐만 아니라 배양 세포주에 따라서도 그 형태에 차이가 있었다. 이러한 다각체의 특징적인 형태가 나타나는 요인을 다각체 단백질 유전자를 중심으로 조사한 결과 RecS-A6는 AcNPV 와 BmNPV의 다각체 단백질 유전자를 모두 갖고 있는 것이 확인되었으며, 또한 RecS-A6의 다각체를 단백질 전기영동하여 분석한 결과 RecS-A6의 다각체를 단백질 전기영동하여 분석한 결과 AcNPV와 BmNPV의 다각체 단백질이 모두 다각체 형성에 이용되었음을 확인할 수 있었다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권3호
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• pp.339-345
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• 2016

This paper presents a two-stage power amplifier MMIC using a $0.4{\mu}m$ GaN-HEMT process. The two-stage structure provides high gain and compact circuit size using an integrated inter-stage matching network. The size and loss of the inter-stage matching network can be reduced by including bond wires as part of the matching network. The two-stage power amplifier MMIC was fabricated with a chip size of $2.0{\times}1.9mm^2$ and was mounted on a $4{\times}4$ QFN carrier for evaluation. Using a downlink LTE signal with a PAPR of 6.5 dB and a channel bandwidth of 10 MHz for the 2.6 GHz band, the power amplifier MMIC exhibited a gain of 30 dB, a drain efficiency of 32%, and an ACLR of -31.4 dBc at an average output power of 36 dBm. Using two power amplifier MMICs for the carrier and peaking amplifiers, a Doherty power amplifier was designed and implemented. At a 6 dB back-off output power level of 39 dBm, a gain of 24.7 dB and a drain efficiency of 43.5% were achieved.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제47권6호
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• pp.454-464
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• 2021

Objectives: This study aimed to investigate the in vitro osteoinductivity of the combination of bone morphogenetic protein-2 (BMP-2) and nanohydroxyapatite (nHAp) and the in vivo effects of implants coated with nHAp/BMP-2. Materials and Methods: To evaluate the in vitro efficacy of nHAp/BMP-2 on bone formation, bone marrow-derived mesenchymal stem cells (BM-MSCs) were seeded onto titanium disks coated with collagen (Col), Col/nHAp, or Col/nHAp/BMP-2. Protein levels were determined by a biochemical assay and reverse transcriptase-polymerase chain reaction. Stem cell differentiation was analyzed by flow cytometry. For in vivo studies with mice, Col, Col/nHAp, and Col/nHAp/BMP-2 were injected in subcutaneous pockets. Titanium implants or implants coated with Col/nHAp/BMP-2 were placed bilaterally on rabbit tibias and evaluated for 4 weeks. Results: In the in vitro study, BM-MSCs on Col/nHAp/BMP-2 showed reduced levels of CD73, CD90, and CD105 and increased levels of glycosaminoglycan, osteopontin, and alkaline phosphatase activity. After 4 weeks, the Col/nHAp/BMP-2 implant showed greater bone formation than the control (P=0.07), while no differences were observed in bone implant contact and removal torque. Conclusion: These results suggest that a combination of BMP-2 and an nHAp carrier would activate osseointegration on dental implant surfaces.

• Journal of electromagnetic engineering and science
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• 제17권4호
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• pp.178-180
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• 2017

This study presents a 2-20 GHz monolithic distributed power amplifier (DPA) using a $0.25{\mu}m$ AlGaN/GaN on SiC high electron mobility transistor (HEMT) technology. The gate width of the HEMT was selected after considering the input capacitance of the unit cell that guarantees decade bandwidth. To achieve high output power using small transistors, a 12-stage DPA was designed with a non-uniform drain line impedance to provide optimal output power matching. The maximum operating frequency of the proposed DPA is above 20 GHz, which is higher than those of other DPAs manufactured with the same gate-length process. The measured output power and power-added efficiency of the DPA monolithic microwave integrated circuit (MMIC) are 35.3-38.6 dBm and 11.4%-31%, respectively, for 2-20 GHz.

• Journal of electromagnetic engineering and science
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• 제14권4호
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• pp.399-404
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• 2014

A power amplifier (PA) for a femto-cell base station should be highly efficient, linear and small. The efficiency for amplification of a high peak-to-average power ratio (PAPR) signal was improved by designing an asymmetric Doherty PA (DPA). The linearity was improved by applying third-order inter-modulation (IM3) cancellation method. A small size is achieved by designing the DPA using GaN MMIC process. The implemented 2-stage DPA delivers a power-added efficiency (PAE) of 38.6% and a gain of 33.4 dB with an average power of 34.2 dBm for a 7.2 dB PAPR 10 MHz bandwidth LTE signal at 2.14 GHz.