• 한국진공학회지
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• 제15권1호
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• pp.50-56
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• 2006

[ $Si(5\;5\;12)-2{\times}1$ ] 표면에 벤젠과 피리딘의 흡착구조를 80K 온도에서 주사 터널링 현미경과 density functional theory 계산 방법으로 연구했다. 벤젠 분자는 기울어진 butterfly 형태로 $Si(5\;5\;12)-2\times1$의 D2, D3 유닛에 두 개의 adatom과 강하게 결합된다. 흡착 벤젠 분자에 두 개의 C=C 이중 결합이 있으며 탄소와 Si adatom 사이에 $di-\sigma$ 결합이 있다. 피리딘 분자는 Si-N dative 결합 또는 $di-\sigma$ 형태로 D2와 D3 유닛의 adatom과 결합을 한다 질소 원자의 홀전자쌍에 의해 결합된 dative 결합은 수직 형태의 구조를 띠며 $di-\sigma$ 결합보다 더 안정한 것으로 나타났다. $Di-\sigma$ 결합은 Si-C2와 Si-C5 또는 Si-Nl와 Si-C4으로 형성된다.

• Molecules and Cells
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• 제21권2호
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• pp.284-293
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• 2006

Even though Ac/Ds gene-tagging systems have been established in many higher plants, maize is the only major plant in which short-distance transposition of Ac/Ds has been utilized to probe gene function. This study was performed to evaluate the efficiency of obtaining new alleles and functional revertants from Ds insertion loci in rice. By analyzing 1,580 plants and the progeny of selected lines, the insertion sites and orientations of Ds elements within 16 new heritable alleles of three rice loci were identified and characterized. Intragenic transposition was detected in both directions from the original insertion sites. The closest interval was 35 bp. Three of the alleles had two Ds elements in cis configuration in the same transcription units. We also analyzed the excision footprints of intragenic and extragenic transpositions in Ds-inserted alleles at 5 loci. The 134 footprints obtained from different plants revealed predominant patterns. Ds excision at each locus left a predominant footprint at frequencies of 30-75%. Overall, 66% of the footprints were 7-bp additions. In addition, 16% of the excisions left 0-, 3-, 6-, and 9-bp additions with the potential of conserving reading frame.

• 한국식품과학회지
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• 제23권1호
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• pp.81-87
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• 1991

15% 비율로 가수한 corn grit 원료를 reverse element 수를 달리한 스크류 조합을 사용한 실험실용 동방향 회전 이축 압출성형기로 extrusion cooking할 때, 각 스크류 조합에서 원료 투입량($30{\sim}60\;kg/hr$), 스크류 회전속도($200{\sim}400\;rpm$) 및 die hole 수($2{\sim}4$개) 등의 process parameters 변화에 대한 system parameters(압출온도 및 압력, 기계적 에너지 소모율 및 평균체류시간)의 변화 양상을 다중회기분산 분석을 통하여 분석하였다. 원료 투입량이 증가할 수록, 압출온도, 기계적 에너지 소모율 및 평균체류시간이 감소하는 경향을 보인 반면에 알출압력은 증가하였다. 그리고, 스크류 회전속도가 증가할 수록, 압출온도, 기계적 에너지 소모율 및 압출압력이 증가하는 경향을 보였으나, 평균체류시간은 감소하였다. 그러나 die hole 수가 증가할 수록, 측정한 4가지 system parameters는 모두 감소하는 경향을 나타내었다. 이러한 경향은 reverse element의 수를 증가시킨 스크류 조합을 사용한 경우에 더욱 뚜렸이 나타나는 결과를 보여 주었다. 이상의 결과를 각 스크류 조합에서 각각의 system parameters와 process parameters를 독립변수로 하는 함수식으로 나타낼 수 있었고, 이 때 각 함수식의 상관관계는 0.90 이상 이었다.

• 해양환경안전학회지
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• 제21권2호
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• pp.207-214
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• 2015

본 연구에서는 공리적 설계 방법론에서 중요한 2가지 공리 중 독립공리를 시스템 개발에서 설계 기준으로 적용하였다. 기능 요구사항과 대응하는 설계 파라메터는 설계행렬을 구성하고 이를 이용하여 독립공리에 부합하는 설계 파라메터의 순서를 정한 후 블록 레벨링 시스템에서의 독립적 구성요소를 판별하였다. 이러한 공리적 설계의 결과로서 설계 순서에 맞는 블록 레벨링 시스템 구성을 도출하였다. 도출된 블록 레벨링 시스템 구성의 검증과 확인을 위해 블록 조립 현장에서 사용하고 있는 3차원 좌표 측정기인 토털 스테이션을 사용하여 실제 조립이 완료된 블록에 대하여 구현된 블록 레벨링 시스템을 적용하여 데이터를 비교하는 시험을 수행하였다. 토털 스테이션의 측정 데이터와 블록 레벨링 시스템의 수신 데이터를 비교하여 1 mm 이내의 정밀도로 블록 레벨링 시스템이 동작함을 검증하고 확인하였다.

• 한국연소학회지
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• 제22권3호
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• pp.17-22
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• 2017

An experimental study has been conducted to elucidate the effect of AC electric field on behaviors of laminar lifted flame in nitrogen-diluted methane coflow-jets. Our concerns are focued on the regime to show a decrease in liftoff height, $H_L$ with increasing nozzle exit velocity, $U_O$ (hereafter, $decreasing-H_L$). The $H_L$ with $U_O$ near flame extinction were measured by varying the applied AC voltage, $V_{AC}$ and frequency, $f_{AC}$ in a single electrode configuration. The behavior of $H_L$ with a functional dependency of $V_{AC}$ and $f_{AC}$ was categorized into two regime : (I) $H_L$ decreased for nozzle diameter, D = 1.0 mm, and (II) $H_L$ increased in the increase of $f_{AC}$ for a fixed $V_{AC}$ in a D = 4.0, 8.4 mm. The lifted flames in $decreasing-H_L$ region was unstable in high voltage regimes while the $H_L$ showed a decreasing tendency with $U_O$ except them. Such behaviors in $H_L$ were also characterized by functional dependencies of related physical parameters such as $V_{AC}$, $f_{AC}$, $U_O$, fuel mole fraction ($X_{F.O}$) and D.

• Archives of Reconstructive Microsurgery
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• 제18권1호
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• pp.27-30
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• 2009

Purpose: Recently, replantation of fingertip amputation, Zone I by Yamano classification, is still difficult because digital arteries branch into small arteries and also digital veins are hard to separate from the immobile soft tissue. However the replantation of fingertip in adults is a well-established procedure, but the replantation in infant or child is still uncommon. Therefore we present one case of replantation of the fingertip of the small finger in 12-months-old patient. Methods: We experienced a 12-months-old male amputation of small finger. It had been amputated completely at the level of Zone I by Yamano classification. Replantation was performed using the arteryonly technique with neither vein nor nerve repair. Because the artery has been damaged, it is still possible to make a direct suture by transposing the arterial arch in an inverted Y to I arterial configuration. Venous drainage was provided by an external bleeding method with partial nail excision and repaired margin for approximately 7 days. Results: We were performed replantation in infant with only-arterial anastomosis successfully, result in good recovery of aesthetic and functional outcome. Conclusion: In conclusion, although fingertip injury was difficult to replantation in infant and child, we must try it. Because of its functional and cosmetic advantage.

• 한국자기학회지
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• 제25권4호
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• pp.106-110
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• 2015

Fe 원자 2개를 포함한 2종류의 이중 철 효소의 전기구조 및 자기적 성질을 제1원리의 범밀도함수법을 이용하여 계산하였다. 계산 된 결과, 전자구조는 주위 6개의 배위 원자로 인해 비슷한 모습을 보이고 있었다. 총 에너지 계산에서는 두 종류 모두 반강자성적 상호작용이 낮은 에너지를 가지고 있었다. 계산 된 $Fe^{+3}$ 원자 사이의 교환상호작용 크기는 diiron-4가 diiron-2보다 한 단위 큰 값을 얻었고, 실험과 잘 일치하였다. 이 원인은 diiron-4가 더 가까운 Fe-O 원자거리를 가지고 있었고, Fe 사이 산소 매개 원자의 2p 준위가 높아 강한 초교환상호작용을 일으켰다. 또한, 직각에 가까운 diiron-2 Fe-O-Fe 각도보다 커서 Fe-O의 강한 ${\sigma}$ 결합으로 인한 초교환상호작용의 결과이다.

• Archives of Plastic Surgery
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• 제49권3호
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• pp.378-396
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• 2022

Several reconstructive methods have been reported to restore the continuity of the aerodigestive tract following resection of pharyngeal and hypopharyngeal cancers. However, high complication rates have been reported after voice prosthesis insertion. In this setting, the ileocolon free flap (ICFF) offers a tubularized flap for reconstruction of the hypopharynx while providing a natural phonation tube. Herein, we systematically reviewed the current evidence on the use of the ICFF for reconstruction of the aerodigestive tract. A systematic literature search was conducted across PubMed MEDLINE, Web of Science, ScienceDirect, Scopus, and Ovid MEDLINE(R). Data on the technical considerations and surgical and functional outcomes were extracted. Twenty-one studies were included. The mean age and follow-up were 54.65 years and 24.72 months, respectively. An isoperistaltic or antiperistaltic standard ICFF, patch flap, or chimeric seromuscular-ICFF can be used depending on the patients' needs. The seromuscular chimeric flap is useful to augment the closure of the distal anastomotic site. The maximum phonation time, frequency, and sound pressure level (dB) were higher with ileal segments of 7 to 15 cm. The incidence of postoperative leakage ranged from 0 to 13.3%, and the majority was occurring at the coloesophageal junction. The revision rate of the microanastomosis ranged from 0 to 16.6%. The ICFF provides a reliable and versatile alternative for reconstruction of middle-size defects of the aerodigestive tract. Its three-dimensional configuration and functional anatomy encourage early speech and deglutition without a prosthetic valve and minimal donor-site morbidity.

• Biomolecules & Therapeutics
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• 제31권1호
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• pp.108-115
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• 2023

Numerous psychotropic and addictive substances possess structural features similar to those of β-phenethylamine (β-PEA). In this study, we selected 29 β-PEA derivatives and determined their structure-activity relationship (SAR) to their ability to inhibit dopamine (DA) reuptake; conducted docking simulation for two selected compounds; and identified their potential functionals. The compounds were subdivided into arylethylamines, 2-(alkyl amino)-1-arylalkan-1-one derivatives and alkyl 2-phenyl-2-(piperidin-2-yl)acetate derivatives. An aromatic group, alkyl group, and alkylamine derivative were attached to the arylethylamine and 2-(alkyl amino)-1-arylalkan-1-one derivatives. The inhibitory effect of the compounds on dopamine reuptake increased in the order of the compounds substituted with phenyl, thiophenyl, and substituted phenyl groups in the aromatic position; compounds with longer alkyl groups and smaller ring-sized compounds at the alkylamine position showed stronger inhibitory activities. Docking simulation conducted for two compounds, 9 and 28, showed that the (S)-form of compound 9 was more stable than the (R)-form, with a good fit into the binding site covered by helices 1, 3, and 6 of human dopamine transporter (hDAT). In contrast, the (R, S)-configuration of compound 28 was more stable than that of other isomers and was firmly placed in the binding pocket of DAT bound to DA. DA-induced endocytosis of dopamine D₂ receptors was inhibited when they were co-expressed with DAT, which lowered extracellular DA levels, and uninhibited when they were pretreated with compound 9 or 28. In summary, this study revealed critical structural features responsible for the inhibition of DA reuptake and the functional role of DA reuptake inhibitors in regulating D₂ receptor function.

• 대한의용생체공학회:의공학회지
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• 제44권6호
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• pp.392-403
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• 2023

This study presents a new hybrid fNIRS-EEG system to meet the demand for a lightweight and low-cost sleep pattern monitoring device. For multiple-channel configuration, a six-channel electroencephalogram (EEG) and a functional near-infrared spectroscopy (fNIRS) system with eight photodiodes (PD) and four dual-wavelength LEDs are designed. To enhance the convenience of signal measurement, the device is miniaturized into a patch-like form, enabling simultaneous measurement on the forehead. Due to its fully integrated functionality, the developed system is advantageous for performing sleep stage classification with high-temporal and spatial resolution data. This can be realized by utilizing a two-dimensional (2D) brain activation map based on the concentration changes in oxyhemoglobin and deoxyhemoglobin during sleep stage transitions. For the system verification, the phantom model with known optical properties was tested at first, and then the sleep experiment for a human subject was conducted. The experimental results show that the developed system qualifies as a portable hybrid fNIRS-EEG sleep pattern monitoring device.