• 천문학회보
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• 제45권1호
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• pp.67.1-67.1
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• 2020

Adaptive Optics (AO) is the technology for ground-based telescopes to overcome the interference caused by atmospheric turbulence. We are developing an AO system for the 1-m telescope at Seoul National University Observatory (SNUO). The seeing size of the SNUO is 2 arcseconds on average, and 0.85 arcseconds at best condition. Our system is based on MEMS deformable mirror and Shack-Hartmann wavefront sensor. We developed the wavefront sensor using a cheap CMOS camera, and measured phase disturbance at SNUO. To verify the performance of the AO system, we designed an artificial phase disturber that produces similar scale phase error, measured at SNUO. We carried out laboratory tests in which the AO system measures and corrects the wavefront using the phase disturber and an F/6 light source, the same as that of SNUO telescope. The control system was developed in C++. The system performs closed-loop PI correction up to 100 Hz at a consumer-grade PC.

• 한국가금학회지
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• 제32권4호
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• pp.291-300
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• 2005

남은 음식물에서 Aspergillus oryzae(AO)의 유용한 배양조건(시간, 수분함량, 접종균수)을 구하기 위하여 2가지 실험과 닭에서 그 배양물의 영양소 이용율을 구명하기 위하여 본 시험을 수행하였다. <시험 1> 적정 배양시간과 접종균수의 측정을 위하여 수분함량을 30, 40, 50, $60\%$로 정하였다. 잔반 사료에 접종하는 seed로서 1mL Aspergillus oryzae(AO) $(1.33\times10^5\;CFU/mL)$를 이용하였다. 배양을 위한 적정 수분함량은 $40\~50\%$였으며 배양시간은 72시간 이상이었다. 계속하여 AO 균수에 의한 효과를 결정하기 위해 AO seed 0.25, 0.50, 0.75, 1.00mL를 남은음식물 사료에 접종하였다. AFW의 AO균수를 비교하기 위하여 72시간과 96시간 배양하였으나, 접종량에 따른 유의차는 없었다. 다시 수준을 낮추어 0.01, 0.05, 0.10mL를 접종하고 72시간과 96시간동안 배양한 결과, 72시간 배양 AO colony 수는 0.1 mL 접종 처리 구에서 가장 많았다. <시험 2> FW의 배양조건을 결정한 후에, 20수의 5주령 Hubbard종을 공시하여 소화율 시험을 수행하였다. 처리구는 T1-대조구, T2-기초사료 $60\%$+건조잔반 $40\%$, T3-기초사료 $60\%$+건조잔반 $20\%$+AO균 접종 건조잔반 $20\%$, T-4-기초사료 $60\%$+AO균 접종 건조잔반 $40\%$ 처리구 등 총 4처리구, 처리구당 5반복씩 20수를 인공항문 장착하여 소화율을 조사하였다. 영양소 소화율에 있어 일반성분과 아미노산은 대조구에 비해 T2 처리구가 전성분에서 낮았고(p<0.05), AFW(T3, T4)처리구에 비해 조지방과 인의 소화율에서 차이를 보였다(p<0.05). T3와 T4는 T2에 비해 조섬유 및 조회분의 소화율이 증가하였다(p<0.05). 대조구는 T3와 T4에 비해 필수아미노산인 arginine, leucine, phenylalanine의 소화율이 높았으나(p<0.05), T3와 T4 처리구는 T2 처리구에 비해 필수아미노산 arginine, lysine 및 thereonine과 비필수아미노산 alanine의 소화율이 개선되었다(p<0.05). 이러한 결과들로부터 건조 잔반의 AO 배양조건 구명과 영양소 이용율 시험을 통해 FW사료의 품질이 기초사료에 비해 영양소 이용율이 낮고, AFW 사료가 AO에 의해 개선될 수 있음을 시사한다

• The Korean Journal of Physiology and Pharmacology
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• 제1권6호
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• pp.775-781
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• 1997

Although reoxygenation is the best way to salvage hypoxic tissues, reduced oxygen species (ROS) generated during reoxygenation are blown to cause further tissue injuries and the induction of heat shock proteins (HSPs). The present study was undertaken to determine any causal relationship between the severity of hypoxia and the opposite outcomes, either beneficial or detrimental, of the subsequent reoxygenation by measuring the HSP72. To this aim, one group (6 male cats, $2.5{\sim}3.5\;kg$) was subjected to a 5-min episode of hypoventilation (H, ventilation rate: 5/min) for the induction of slight hypoxia and the other group (6 male cats, $2.4{\sim}3.7\;kg$) was subjected to a 5-min episode of apnea (A) for severe hypoxia. Each 3 animals from both groups received a 10-min episode of ventilation with $(95%\;O_2\;(0)$, whereas the remainder did not. After these procedures, all animals were allowed to be ventilated within physiological range for 1, 4, or 8 hours (1H, 1HO, 4H, 4HO, 8H, 8HO, 1A, 1AO, 4A, 4AO, 8A and 8AO groups). Control animals did not receive any manipulation. The arterial blood $pCO_2$ was significantly higher just after apnea than hypoventilation, while $pCO_2$ and pH were significantly lower just after apnea than hypoventilation. Western blot analysis revealed that the magnitude of HSP72 synthesis is larger in 1H, 4H and 8H groups than in 1HO, 4H and 8HO groups, respectively. In contrast, 1AO, 4AO and 8AO groups more induced HSP72 than 1A, 4A and 8A groups, respectively. These results suggest that the reoxygenation is beneficial after slight hypoxia but detrimental after severe hypoxia.

• 대기
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• 제24권1호
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• pp.29-38
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• 2014

A characteristic of snowfall and minimum temperature variability in South Korea with respect to the variability of Arctic Oscillation (AO) was investigated. The climatic snowfall regions of South Korea based on daily new fresh snowfall data of 59 Korea Meteorological Administration (KMA) stations data corresponding to the sign of AO index during December to February 1979~2011 were classified. Especially, the differences between snowfalls of eastern regions and that of western regions in South Korea were seen by each mean 1000hPa geopotential height fields, which is one of physical structure, for the selected cases over the East Asia including the Korean Peninsula. Daily minimum temperature variability of 59 KMA station data and daily AO index during the same period were investigated using Cyclo-stationary empirical orthogonal function (CSEOF) analysis. The first CSEOF of wintertime daily AO index and that of minimum temperature of 59 KMA stations explain 33% and 66% of total variability, respectively. Correlation between principal component time series corresponding to the first CSEOF of AO index and that of temperature at the period of 1990s is over about -0.7 when that of AO index leads about 40 days.

• 대한임상독성학회지
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• 제18권1호
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• pp.26-33
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• 2020

Purpose: Agent Orange (AO) is a herbicide and defoliant used by the United States and its military allies during the Vietnam War. Pneumonia is a common cause of death among Vietnam veterans in our hospital. There have been no previous studies researching any association between AO exposure and the prognosis for pneumonia. The primary objective of this study was to investigate associations between AO exposure and 30-day mortality due to pneumonia. The secondary objective was to examine the clinical factors associated with therapeutic outcomes in veterans with pneumonia, and to assess the prevalence of combined diseases in AO-exposed veterans. Methods: This study retrospectively included veteran patients diagnosed with pneumonia in the emergency department and hospitalized between February 2014 and March 2018. The enrolled patients were grouped according to their defoliant exposure history, and the clinical information of defoliant-exposed and non-defoliant-exposed groups were compared. Patients were divided according to 30-day mortality, and significant factors influencing mortality were evaluated by using univariate analysis and multivariate analysis. The final multivariate model revealed the effect of AO exposure on therapeutic outcomes of pneumonia. Results: A total of 1006 patients were analyzed. Of these, 276 patients had a history of AO exposure, whereas 730 patients had not been exposed. Factors positively associated with 30-day mortality were malignancy, respiratory rate, blood urea nitrogen, and albumin which was negatively associated with mortality. Conclusion: Exposure to defoliant is not associated with 30-day mortality in patients with pneumonia. However, veterans with defoliant exposure are associated with a high prevalence of diabetes mellitus, hypertension, cerebrovascular accident, malignancy, and chronic kidney disease.

• 대한족부족관절학회지
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• 제13권1호
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• pp.75-79
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• 2009

Purpose: To evaluate the outcomes of intra-articular calcaneal fractures treated using AO calcaneal plate surgically. Materails and Methods: Total 15 cases of intra-articular calcaneal fracture that treated with open reduction and internal fixation using AO calcaneal plate were evaluated. The patients were followed over a mean period of 19.8 months. The mean age was 41.6 years. By Sanders classification, there were 2 cases of type II, 10 cases of type III, and 3 cases of type IV. We evaluated radiological outcomes by Bohler angle, Gissane angle, calcaneal hight, calcaneal width and clinical outcomes by Creighton-Nebraska health foundation score. Results: All fractures united at a mean duration of 13.3 weeks. Radiologically, the mean preoperative Bohler angle was $8.5^{\circ}$ and restored to $23.3^{\circ}$. The mean preoperative Gissane angle was $118.7^{\circ}$ and restored to $124.2^{\circ}$. The mean preoperative calcaneal hight was 30.8 mm and restored to 38.9 mm. The mean preoperative calcaneal width was 41.3 mm and restored to 35.3 mm. 10 cases had excellent and good clinical outcomes and 5 cases having fair outcome. Conculsion: In our study, open reduction and internal fixation using AO calcaneal plate showed good results with anatomical restoration of articular surface and stable fixation without late collapse.

• Journal of Microbiology and Biotechnology
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• 제22권6호
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• pp.742-753
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• 2012

Copper-containing compounds are introduced into the environment through agricultural chemicals, mining, and metal industries and cause severe detrimental effects on ecosystems. Certain microorganisms exposed to these stressors exhibit molecular mechanisms to maintain intracellular copper homeostasis and avoid toxicity. We have previously reported that the soil bacterial isolate Achromobacter sp. AO22 is multi-heavy metal tolerant and exhibits a mer operon associated with a Tn21 type transposon. The present study reports that AO22 also hosts a unique cop locus encoding copper homeostasis determinants. The putative cop genes were amplified from the strain AO22 using degenerate primers based on reported cop and pco sequences, and a constructed 10,552 base pair contig (GenBank Accession No. GU929214). BLAST analyses of the sequence revealed a unique cop locus of 10 complete open reading frames, designated copSRABGOFCDK, with unusual separation of copCD from copAB. The promoter areas exhibit two putative cop boxes, and copRS appear to be transcribed divergently from other genes. The putative protein CopA may be a copper oxidase involved in export to the periplasm, CopB is likely extracytoplasmic, CopC may be periplasmic, CopD is cytoplasmic/inner membrane, CopF is a P-type ATPase, and CopG, CopO, and CopK are likely copper chaperones. CopA, B, C, and D exhibit several potential copper ligands and CopS and CopR exhibit features of two-component regulatory systems. Sequences flanking indicate the AO22 cop locus may be present within a genomic island. Achromobacter sp. strain AO22 is thus an ideal candidate for understanding copper homeostasis mechanisms and exploiting them for copper biosensor or biosorption systems.

• 한국환경보건학회지
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• 제31권4호
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• pp.340-348
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• 2005

Laboratory scale experiments were conducted to compare the performance of two types of sequencing batch reactor(SBR) systems, anoxic-oxic-anoxic-oxic $((AO)_2)$ SBR and anoxic-oxic-anoxic $(A_2O)$ SBR on the biological nitrogen and phosphorus removal. Also, the profiles of DO and pH in reactors were used to monitor the biological nutrient removal in two SBRs. The break point in the pH and DO curves at the oxic period coincided with the end of nitrifying activity at about 1 h 30 min in oxic phase, and the change in pH appears to be related to nitrate concentration. The TOC removal efficiency in $A_2O$ SBR was higher than that in $(AO)_2$ SBR. The denitrification was completed at the influent period. The 2nd non-aeration and aeration periods were not necessary for the nitrogen and phosphorus removal because of the low influent TOC concentration in this study. The release and uptake of phosphorus in $AO_2$ SBR was much higher than that in $(AO)_2SBR.$ In order to uptake more phosphorus, the 1st aeration period in $A_2O$ SBR should be prolonged.

• 미생물학회지
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• 제37권1호
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• pp.61-65
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• 2001

식물잎권의 잎표면세균에 대한 직접관찰과 이들을 분리시킨 용액 내 세균에 대한 간접관찰을 위하여 형광염료인 4', 6-diamidino-2-phenylindole(DAPI)와 acridine orange(AO)로 염색한 후 형광현미경을 사용하였다. AO로 염색한 잎표면은 배경형광이 진한 주홍색 이나 적색을 띠어 잎표면세균의 관잘 및 계수가 극히 힘들었으나 DAPI로 염색된 잎권세균은 뚜렷한 형광 영상을 나타내었다. 반면 잎표면세균 분리용액의 여과지에 대한 형광염색 결과는 DAPI와 AO 모두가 관찰이 가능하였다. 다만 DAPI가 AO에 비하여 형광 영상이 좀 더 뚜렷하였고 AO 염색과정에서는 염색된 여과지에 대한 세척과정이 필수적이었다. 최적의 DAPI 염색법은 잎과 여과지 모두가 5 $\mu$g/ml의 농도에서 5분 동안 염색하는 것이었다. 잎권의 형광현미경 관찰에 있어서 핵심적인 요소는 잎에서 나오는 수분을 최소화하는 것으로서 염색된 잎 시료를 거름종이 위에 올려놓고 공기 중에서 말리는 대신 $70^{\circ}C$를 유지한 건조기에서 2분 동안 말린 다음 바로 현미경으로 관찰하는 것이 가장 종은 방법인 것으로 확인되었다. 이렇게 확립된 형광현미경 관찰법을 떡갈나무의 잎권세균을 성공적으로 관찰하고 계수할 수 있었다.

• Korean Chemical Engineering Research
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• 제50권3호
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• pp.455-463
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• 2012

본 연구에서는 에틸렌 옥사이드와 프로필렌 옥사이드가 부가된 DEP-OSA82-AO 양쪽성 계면활성제에 대하여 계면활성제의 기본적인 물성(임계 마이셀 농도, 표면장력, 계면장력, 접촉각, 점도, 기포 안정성 등)을 측정하였다. 또한 계면활성제 수용액에 대한 제타전위 측정과 QCM (quartz crystal microbalance) 실험을 통하여 양쪽성 계면활성제가 양이온 계면활성제에서 비이온 계면활성제로 작용이 전환되는 등전점을 결정하였다. 제타전위 측정을 통하여 결정한 양쪽성 계면활성제의 등전점은 QCM 실험을 통하여 결정한 등전점 결과가 거의 일치하였으며, 표면 마찰 시험기를 사용하여 측정한 유연력 측정 결과와도 일치하는 경향을 나타내었다. 특히 DEP32-OSA82-AO와 DEP34-OSA82-AO 계면활성제의 경우, 산성 조건 혹은 중성 조건일 경우가 알칼리성 조건에 비하여 섬유 유연 효과가 큰 것을 확인하였는데, 이러한 결과는 등전점 보다 낮은 pH 산성 혹은 중성 조건에서 DEP32-OSA82-AO와 DEP34-OSA82-AO 계면활성제가 모두 양이온 계면활성제로 작용함으로써 세탁 후 린스 과정에서 유연제로서 효과적으로 작용할 수 있음을 의미한다.