• Food Science and Biotechnology
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• 제15권2호
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• pp.202-206
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• 2006

The oxidation stability of fish oil containing omega-3 polyunsaturated fatty acids (PUFAs), which is very susceptible to oxidative deterioration, needs to be improved before it can be successfully applied to functional foods. The antioxidant activities of 17 species of materials in anchovy oil (AO) were compared and a potent antioxidant was determined to improve the shelf-life of refined AO. Antioxidant activities of the 0.05% (w/w) materials in AO were compared against control during storage at $30^{\circ}C$ for 10 days. While no antioxidant effect was shown in alpha tocopherol against control, 3 species of grapefruit seed extracts (GSEs), astaxanthin (AX), soybean lecithin, and green tea extract showed good antioxidant activities. Especially, GSE B, GSE C, and AX showed significantly high peroxide inhibitory activities (PIAs) of $16.2{\pm}2.1$, $20.{\pm}3.5$, and $17.7{\pm}3.5%$, respectively, after the 4th day (p<0.01). Radical scavenging activities (RSAs) of GSE B, GSE C, and AX were $85.1{\pm}0.8$, $95.3{\pm}0.3$, and $85.9{\pm}0.8%$, respectively. Correlation between PIAs and RSAs was high ($R^2=0.926$) in GSE B, GSE C, and AX. Therefore, we concluded that one of the main antioxidative mechanisms of GSEs and AX must operate through an RSA pathway. The $RC_{50}$ (concentration required for 50% reduction of 1,1-diphenyl-2-picryl-hydrazyl, DPPH) of GSE C was $258\;{\mu}g/mL$.

• Clinical and Experimental Pediatrics
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• 제59권4호
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• pp.183-189
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• 2016

Purpose: This study aimed to evaluate the correlation, according to postnatal age, between plasma B-type natriuretic peptide (BNP) levels and echocardiographic parameters for the assessment of patent ductus arteriosus (PDA) in preterm infants with respiratory distress. Methods: We enrolled 42 preterm infants with respiratory distress who underwent serial echocardiographic evaluation with simultaneous plasma BNP measurements until ductal closure. The correlations between BNP levels and the following 4 representative echocardiographic parameters were studied: diameter of the ductus arteriosus (DA), ratio of the left atrial diameter to the aortic diameter (LA/Ao), ratio of the PDA diameter to the infant's left pulmonary artery diameter (PDA/LPA), and the antegrade diastolic flow of LPA (DFLPA). Results: BNP levels were significantly correlated to the magnitude of the ductal shunt, comprising the DA diameter, PDA/LPA ratio, LA/Ao ratio, and antegrade DFLPA for the overall study period. The earliest significant correlation, starting from postnatal day 2, was observed between the LA/Ao ratio and BNP levels. The PDA/LPA ratio and the antegrade DFLPA showed significant correlations with BNP levels postnatal day 3 onward, and with the DA diameter, postnatal day 5 onward. Conclusion: BNP levels and echocardiographic parameters showed a positive correlation, but the significance of the correlations differed according to the postnatal age, especially during the first few days of life.

• 멤브레인
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• 제33권2호
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• pp.61-69
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• 2023

최근 COVID-19로 인해 증가한 급성 폐부전 중증환자 치료를 위한 인공폐 기술의 필요성이 부각되었다. 또한, 빠르게 진행되고 있는 인구고령화는 인공장기(artificial organ, AO) 기술에 대한 높은 수요를 불가피하게 만들고 있다. 분리막은폐, 신장, 간 및 췌장을 포함한 많은 AO 기기의 핵심 부품이다. 특히 인공폐(artificial lung, AL) 기술은 지난 50년간 빠르게 발전해왔지만, 장기부전 환자의 생존율은 50% 내외로 여전히 낮은 편이다. 현재 대부분의 AL 관련문헌은 임상결과에 집중되어 있으며, AL 분리막의 개발연구는 매우 부족한 편이다. 이에 대한 원인 중 하나는 AL 기술이 생명공학을 포함하여 고분자 화학 및 분리공정 기술을 아우르는 융합적 기술개발을 요구하기 때문인 것으로 판단된다. 본 총설에서는 헬스케어산업에서 AL 분리막 기술의 역할과 기술개발이 필요한 난제들을 정리하였다. 특히, 분리막 소재의 혈액적합성, 분리성능, 모듈 디자인 및 공정 구성 측면에서 다양한 연구개발이 필요하다는 부분을 강조하고자 한다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제38권1호
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• pp.50-54
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• 2012

According to Luhr's classification, a fracture in the mandible with a width of less than 15-20 mm is considered to be an atrophic mandibular fracture and its incidence is very rare. Because of the reduced cross-sectional area and smaller contact area of the fractured ends as well as the poorly vascularized bony structure and delayed bone healing, an atrophic mandibular fracture is a great challenge for oral and maxillofacial surgeons. Surgeons tend to perform closed reduction, because open reduction is considered a non-life-saving surgery among elderly patients. Thus, most of them have limited experience in surgical management. According to recent reports, open reduction yields a good result, and the Association for Osteosynthesis (AO) group has recommended open reduction. This is a case report of our two experiences of open reduction and rigid fixation of atrophic mandibular fractures by the AO principle. Articles were also reviewed here.

• 천문학회보
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• 제36권2호
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• pp.132.2-132.2
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• 2011

We are developing Adaptive Optics (AO) system for astronomical use. The He-Ne laser works as an artificial light source. The tip-tilt correction servo is added to our AO system. The tip-tilt term, among the Zernike terms, is the biggest contributor of wavefront deformation caused by atmospheric turbulence at small telescopes. The tip-tilt correction servo consists of a Piezo tip-tilt platform with a mirror, a quadrant photodiode as a tip-tilt sensor, and controllers. The Shack-Hartmann wavefront sensor measures the residual wavefront errors and they are corrected by the MEMS (Micro Electro Mechanical System) deformable mirror. The MEMS deformable mirror allows the compact size at low cost compare to adaptive secondary mirror and other deformable mirrors. As the frame rates of the MEMS deformable mirror is about tens of kHz, the frame rates of the detector in wavefront sensor is the bottleneck of the wavefront correction speed. For faster performance, we replaced a CCD which provides frame rates only 70 Hz with a CMOS with frame rates up to 450 Hz.

• Journal of Biosystems Engineering
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• 제37권1호
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• pp.1-10
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• 2012

Purpose: The most important element of an agricultural helicopter is the rotor blade realizing lift force. In order to improve the performance of the rotor blades, two types (KA152313 and KB203611) of airfoils were designed and compared. Methods: The nose shape of the KB203611 airfoil was 'drooped' and 'sharp' compared to the leading edge of the KA152313 airfoil. The performance of the experimental airfoils was simulated using CFD-ACE program, and lifts were measured in situ using the 'AgroHeli-4G', a prototype helicopter. Results: Simulated lifts of the blade with the KA152313 airfoil showed proper values for a wide range of angles of attack between $14^{\circ}{\sim}18^{\circ}$, while the simulated lift of the KB203611 blade exhibited maximum values near $13^{\circ}{\sim}14^{\circ}$. In the lift measurements, the range of operable angles of attack was a collective pitch angle at the grip (GP) of $12^{\circ}{\sim}18^{\circ}$ for the KA152313 blade. On the other hand, the range of angles of attack for the KB203611 blade was a GP of $12^{\circ}{\sim}14^{\circ}$. Conclusions: The blade of KA152313 performed well over a wide range of AoAs and the blade of KB203611 performed better at low AoAs. In this study, a variative airfoil blade, gradually emerging from grip to tip using the two different airfoils, was suggested.

• 대한수의학회지
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• 제50권1호
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• pp.49-53
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• 2010

A 5-year-old female Cocker spaniel dog (body weight 7.0 kg) was presented with primary complaints of exercise intolerance and loud precordial thrill which was noticed since she was a puppy. Physical examination revealed a grade V/VI continuous murmur over the maximal point of the left basal area, bounding femoral pulse, but no differential cyanosis. Tall R waves were detected in electrocardiogram, suggesting left ventricular enlargement. Diagnostic imaging studies showed enlarged left ventricle, bulged descending aorta (dAo), markedly dilated right pulmonary artery, and continuous shunt flow between the dAo and main pulmonary artery. Based on these findings, the dog was diagnosed as left to right shunted patent ductus arteriosus (PDA). The patent ductus arteriosus was treated by lodging a PDA duct occluder via the transvenous approach. Clinical signs were markedly improved after the ductal occlusion, the shunt flow was mildly persistent. The case presented is the first case of PDA occluded by the PDA duct occluder via the transvenous approach in a small breed of dog. Although the residual shunt flow was mildly persisted, the dog was clinically normal without detectable murmurs.

• 한국가금학회지
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• 제32권4호
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• pp.275-279
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• 2005

본 시험은 시중에 유통되고 있는 일반 건조 잔반을 AO 배양물로서 산란계에 급여하여, 산란계의 생산성과 계란 품질에 미치는 영향을 구명하고자 실시하였다. 시험축은 평균 체중이 $1.5\pm0.5kg$인 50주령 산란계(ISA-Brown)를 공시하였고, 기초사료로 산란계 중기 사료를 급여하였으며, 시험사료는 대조구(Control), 잔반사료(FW)와 AO 배양물사료(AFW)를 각각 $25\%,\;50\%,\;75\%$씩 기초사료를 대체하여 총 7처리구, 3반복, 반복당 8수씩 168수를 공시하였다. 시험기간 중 사료섭취량에서 전처리구간 차이는 없었으나, FW구의 $50\%$ 처리구에서 대조구에 비해 유의적으로 감소했고, 산란률에 있어서는 대조구 $89.8\%$에 비해 AFW $25\%$ 처리구에서는 차이가 없었으나, 전 처리구에서 유의적으로 낮았다(p<0.05). 음수량은 잔반 사료의 대체 수준에 따라 증가하였다(p<0.05). 난중, 난각 두께 및 난각 강도는 전 처리구간 차이가 없었다. 호우유니트와 난황색에서는 남은 음식물 사료의 첨가에 따라 뚜렷한 차이를 보였으나(p<0.05) $50\%$ 이상의 첨가에서는 차이가 없었다. 남은 음식물사료의 첨가에 따른 난황내 콜레스테롤 함량에는 전 처리구간 차이가 없었다. 이러한 결과로부터, 잔반 사료는 산란율을 떨어뜨리지만, 난질 개선에 효과가 있고, 산란계 사료의 첨가제로서 AO 접종 잔반 사료의 사용이 가능할 수 있음을 시사한다.

• ETRI Journal
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• 제39권2호
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• pp.234-244
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• 2017

Research interest in three-dimensional multiple-input multiple-output (3D-MIMO) beamforming has rapidly increased on account of its potential to support high data rates through an array of strategies, including sector or user-specific elevation beamforming and cell-splitting. To evaluate the full performance benefits of 3D and full-dimensional (FD) MIMO beamforming, the 3D character of the real MIMO channel must be modeled with consideration of both the azimuth and elevation domain. Most existing works on the 2D spatial channel model (2D-SCM) assume a wide range for the distribution of elevation angles of departure (eAoDs), which is not practical according to field measurements. In this paper, an optimal FD-MIMO planar array configuration is presented for different practical channel conditions by restricting the eAoDs to a finite range. Using a dynamic network level simulator that employs a complete 3D SCM, we analyze the relationship between the angular spread and sum throughput. In addition, we present an analysis on the optimal antenna configurations for the channels under consideration.

• Current Optics and Photonics
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• 제2권6호
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• pp.612-622
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• 2018

In wave-front-sensor-less adaptive optics (WFS-less AO) systems, the Jacopo Antonello (JA) method belongs to the model-based class and requires few iterations to achieve acceptable distortion correction. However, this method needs a lot of measurements, especially when it deals with moderate or severe aberration, which is undesired in free-space optical communication (FSOC). On the contrary, the stochastic parallel gradient descent (SPGD) algorithm only requires three time measurements in each iteration, and is widely applied in WFS-less AO systems, even though plenty of iterations are necessary. For better and faster compensation, we propose a WFS-less hybrid approach, borrowing from the JA method to compensate for low-order wave front and from the SPGD algorithm to compensate for residual low-order wave front and high-order wave front. The correction results for this proposed method are provided by simulations to show its superior performance, through comparison of both the Strehl ratio and the convergence speed of the WFS-less hybrid approach to those of the JA method and SPGD algorithm.