• Journal of Microbiology and Biotechnology
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• 제28권1호
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• pp.12-21
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• 2018

Photorhabdus temperata (PT), a gram-negative bacterium, lives symbiotically within entomopathogenic nematodes. The insecticidal compounds derived from Photorhabdus are used as biopesticides in agriculture. However, the physiological properties are not well characterized. In the course of our screening for neuroprotective and anti-neuroinflammatory substances from natural products, the culture broth of PT showed considerable activities. By activity-guided purification, five anthraquinones, namely, 3-methoxychrysazine (1), 1,3-dimethoxy-8-hydroxy-9,10-anthraquinone (2), 1,3,8-trihydroxy-9,10-anthraquinone (3), 3,8-dihydroxy-1-methoxy-9,10-anthraquinone (4), and 1,3,4-trimethoxy-8-hydroxy-9,10-anthraquinone (5), were isolated from the ethyl acetate fraction of the PT culture broth. Among the isolated compounds, $75{\mu}M$ 3 significantly protected mouse hippocampal neuronal cells (HT22) against 5 mM glutamate-induced cell death via the inhibition of reactive oxygen species production, $Ca^{2+}$ influx, and lipid peroxidation. Additionally, 3 and 4 effectively suppressed the interferon-${\gamma}$-induced neuroinflammation of mouse-derived microglial cells (BV2) at 10 ng/ml, via the reduction of nitric oxide, interleukin-6, and tumor necrosis factor-${\alpha}$. Anthraquinones 3 and 4 derived from the PT culture broth are a potential starting point to discover neuroprotective and anti-neuroinflammatory drug leads. The novel compound 5 is reported for the first time in this study.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.150-150
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• 2016

Mankind is enjoying a great convenience of their life by the rapid growth of secondary industry since the Industrial Revolution and it is possible due to the invention of huge power such as engine. The automobile which plays the important role of industrial development and human movement is powered by the Engine Module, and especially Diesel engine is widely used because of mechanical durability and energy efficiency. The main work mechanism of the Diesel engine is composed of inhalation of the organic material (coal, oil, etc.), combustion, explosion and exhaust Cycle process then the carbon compound emissions during the last exhaust process are essential which is known as the major causes of air pollution issues in recent years. In particular, COx, called carbon oxide compound which is composed of a very small size of the particles from several ten to hundred nano meter and they exist as a suspension in the atmosphere. These Diesel particles can be accumulated at the respiratory organs and cause many serious diseases. In order to compensate for the weak point of such a Diesel Engine, the DPF(Diesel Particulate Filter) post-cleaning equipment has been used and it mainly consists of ceramic materials(SiC, Cordierite etc) because of the necessity for the engine system durability on the exposure of high temperature, high pressure and chemical harsh environmental. Ceramic Material filter, but it remains a lot of problems yet, such as limitations of collecting very small particles below micro size, high cost due to difficulties of manufacturing process and low fuel consumption efficiency due to back pressure increase by the small pore structure. This study is to test the possibility of new structure by direct infiltration of SiC Whisker on Carbon felt as the next generation filter and this new filter is expected to improve the above various problems of the Ceramic DPF currently in use and reduction of the cost simultaneously. In this experiment, non-catalytic VS CVD (Vapor-Solid Chemical Vaporized Deposition) system was adopted to keep high mechanical properties of SiC and MTS (Methyl-Trichloro-Silane) gas used as source and H2 gas used as dilute gas. From this, the suitable whisker growth for high performance filter was observed depending on each deposition conditions change (input gas ratio, temperature, mass flow rate etc.).

• The Korean Journal of Physiology and Pharmacology
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• 제19권2호
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• pp.183-189
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• 2015

Foeniculum vulgare Mill. (fennel) is used to flavor food, in cosmetics, as an antioxidant, and to treat microbial, diabetic and common inflammation. No study to date, however, has assessed the anti-inflammatory effects of fennel in experimental models of inflammation. The aims of this study were to investigate the anti-inflammatory effects of fennel in model of lipopolysaccharide (LPS)-induced acute lung injury. Mice were randomly assigned to seven groups (n=7~10). In five groups, the mice were intraperitoneally injected with 1% Tween 80-saline (vehicle), fennel (125, 250, $500{\mu}l/kg$), or dexamethasone (1 mg/kg), followed 1 h later by intratracheal instillation of LPS (1.5 mg/kg). In two groups, the mice were intraperitoneally injected with vehicle or fennel ($250{\mu}l/kg$), followed 1 h later by intratracheal instillation of sterile saline. Mice were sacrificed 4 h later, and bronchoalveolar lavage fluid (BALF) and lung tissues were obtained. Fennel significantly and dose-dependently reduced LDH activity and immune cell numbers in LPS treated mice. In addition fennel effectively suppressed the LPS-induced increases in the production of the inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha, with $500{\mu}l/kg$ fennel showing maximal reduction. Fennel also significantly and dose-dependently reduced the activity of the proinflammatory mediator matrix metalloproteinase 9 and the immune modulator nitric oxide (NO). Assessments of the involvement of the MAPK signaling pathway showed that fennel significantly decreased the LPS-induced phosphorylation of ERK. Fennel effectively blocked the inflammatory processes induced by LPS, by regulating pro-inflammatory cytokine production, transcription factors, and NO.

• 한국식품저장유통학회지
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• 제12권6호
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• pp.613-616
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• 2005

배추김치의 발효숙성을 $4^{\circ}C$에서 29일간 실시하면서 pH 및 적정산도 측정과 전자코를 활용한 향기성분 패턴 분석을 실행하였다. $4^{\circ}C$에서 숙성한 배추김치의 pH는 저장 초기에는 큰 변화를 보이지 않다가 숙성 후 14일째부터 낮아졌고, 적정산도는 초기 $0.26\%$에서 16일째에 $0.43\%$까지 일정하다가 이후부터 급증하여 29일에는 $1.15\%$에 도달하였다. 전자코 분석 결과, 배추김치의 향기성분 패턴은 숙성기간이 늘어나면서 제1주성분 값이 negative에서 Positive로 이동하는 경향을 보였다. 29일간숙성 중의 모든 배추김치 향은 전자코의 제1주성분과 제2주성분 값으로 나타낸 그림 상에 크게 5 그룹으로 나타낼 수 있었다. 즉, 4일, 6-14일, 16일, 21-25일과 29일로 구분할 수 있고, 이를 pH와 적정산도의 결과와 함께 고려하여,4일, 6-14일(이상 산도에 따라 구분한 1기), 16일(산도에 따라 구분한 2기), 21-25일과 29일(이상 산도에 따라 구분한 3기)로 구분할 수 있었다. 따라서 배추김치의 이화학적 성질분석과 향기성분 패턴 분석을 위한 전자코 실험결과 숙성온도와 숙성기간에 따른 배추김치의 숙성도를 예측할 수 있었다.

• 대한의용생체공학회:의공학회지
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• 제28권6호
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• pp.756-767
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• 2007

For the combination of phosphor screens having various thicknesses and a photodiode array manufactured by complementary metal-oxide-semiconductor (CMOS) process, we report the observation of image-quality degradation under the irradiation of 45-kVp spectrum x rays. The image quality was assessed in terms of dark pixel signal, dynamic range, modulation-transfer function (MTF), noise-power spectrum (NPS), and detective quantum efficiency (DQE). For the accumulation of the absorbed dose, the radiation-induced increase both in dark signal and noise resulted in the gradual reduction in dynamic range. While the MTF was only slightly affected by the total ionizing dose, the noise power in the case of $Min-R^{TM}$ screen, which is the thinnest one among the considered screens in this study, became larger as the total dose was increased. This is caused by incomplete correction of the dark current fixed-pattern noise. In addition, the increase tendency in NPS was independent of the spatial frequency. For the cascaded model analysis, the additional noise source is from direct absorption of x-ray photons. The change in NPS with respect to the total dose degrades the DQE. However, with carefully updated and applied correction, we can overcome the detrimental effects of increased dark current on NPS and DQE. This study gives an initial motivation that the periodic monitoring of the image-quality degradation is an important issue for the long-term and healthy use of digital x-ray imaging detectors.

• 한국결정성장학회지
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• 제19권2호
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• pp.75-78
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• 2009

PBN 도가니를 이용하여 Si이 도핑된 GaAs 단결정을 수직경사 응고법으로 성장시켰다. PBN 도가니에 산화막인 $B_{2}O_{3}$의 양을 $0{\sim}0.2wt%$ 범위에서 변화시키면서, 성장 후 캐리어 농도를 측정하였다. $B_{2}O_{3}$ 첨가량이 증가함에 따라, 초기 0.1 정도의 Si 도판트의 편석계수는 0.01 부근까지 급격히 감소하고, 동시에 캐리어 농도도 감소하는 것을 알 수 있었다. 이는 성장도중 도판트인 Si이 $B_{2}O_{3}$과 반응하며 도너인 Si 양을 감소시키며, 동시에 억셉터인 B 양을 증가시키기 때문으로 보인다. 한편 PBN 도가니 내면에 얇은 유리질의 $B_{2}O_{3}$층 형성이 용이한 고온 산화막 처리가 결함감소에 효과적임을 확인하였다.

• 한국전자통신학회논문지
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• 제12권5호
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• pp.791-796
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• 2017

본 연구에서는 DRAM 커패시터의 유전막 박막화를 위한 Load Lock(L/L) LPCVD 시스템을 이용한 적층형 커패시터의 제조 공정이 셀 커패시턴스에 미치는 영향을 조사하였다. 그 결과 기존의 non-L/L 장치에 비하여 약 $6{\AA}$의 산화막 유효두께를 낮춤으로 커패시턴스로 환산 시 약 3-4 fF의 차이가 나타남을 확인할 수 있었다. 또한 절연막으로써 질화막 두께의 측정 범위가 정상적인 관리 범위의 분포임에도 불구하고 Cs는 계산치보다 약 3~6 fF 정도 낮은 것으로 확인되었다. 이는 node poly FI CD가 spec 상한치로 관리되어 셀 표면적의 감소를 초래하였고 이는 약 2fF의 Cs 저하를 나타내었다. 따라서 안정적인 Cs의 확보를 위해서는 절연막의 두께 및 CD 관리를 spec 중심값의 10 % 이내로 관리할 필요가 있음을 확인하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제33권5호
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• pp.825-835
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• 2020

Objective: The aim of the present study was to investigate the effect of dietary zinc supplementation of Friesian cows on chemical-nutritional and aromatic properties of Caciocavallo cheese after 7 days (C₇) and 120 days (C₁₂₀) of ripening. Methods: Twenty eight Friesian cows, balanced for parity, milk production and days in milk, were randomly assigned to 2 groups. The control group (CG) was fed with a conventional complete diet, while the experimental group (zinc group, ZG) received a daily zinc supplementation of 60 mg for kg of dry complete feed. During the experimental period, the milk yield was monitored and samples of milk and caciocavallo cheese were collected and analyzed for chemical-nutritional composition and aromatic profile. Results: The enrichment of dairy cows diet with zinc, did not influence milk yield and composition, however a marked reduction of somatic cell count was evidenced. Both in milk and cheese the ZG samples were characterized by a lower concentration of satured fatty acids and an increase in oleic, vaccenic and rumenic acids. The aromatic profile of dairy products was also positively affected by dietary zinc intake, with an increase in concentration of carboxylic acids, esters and lactones. Conclusion: The present results suggest a positive role of dietary zinc intake in improving the quality of bovine milk and related cheese, in particular for the increase in concentration of bioactive fatty acids such as rumenic acid. The changes evidenced in cheese through the analysis of the volatile profile, would be consistent with the development of interesting organoleptic properties, although further evaluations should be performed to confirm the consumer acceptability of these changes.

• 전자공학회논문지
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• 제50권6호
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• pp.131-137
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• 2013

광각 카메라는 단 초점 렌즈를 장착하여 넓은 시야의 이미지를 처리하는데, 렌즈의 광학 문제로 인해 이미지에 베럴 왜곡(barrel distortion)이 발생한다. 본 논문에서는 베럴 왜곡을 실시간 디지털 신호처리를 통해 보정하기 위한 낮은 복잡도의 프로세서 구조를 제시하고 이를 실제 구현하여 유효성을 검증하였다. 제안하는 왜곡 보정 프로세서는 하드웨어 복잡도를 낮추기 위해서, 좌표 위치 보정에 필요한 계산을 점증적(incremental)으로 수행한다. 또한, 높은 보정 속도를 달성하기 위해 파이프 라인 구조로 설계하였다. 설계된 보정 프로세서는 $0.11{\mu}m$ complementary metal-oxide semiconductor(CMOS) 공정을 사용하여 14.3K의 논리 게이트로 구현되었다. $2048{\times}2048$ 픽셀 영상에 대하여, 최대 314MHz의 동작 주파수로 초당 74.86번의 속도로 보정이 가능하다.

• Korean Chemical Engineering Research
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• 제44권3호
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• pp.259-264
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• 2006

염화반응에 의한 $TaCl_5$의 제조에서 반응생성물 중 $NbCl_5$, $TiCl_4$, $FeCl_2$ 등이 주요 불순물로 존재하게 된다. $TaCl_5$와 $NbCl_5$는 증류나 수소 환원법에 의해 쉽게 분리가 되므로, 반응생성물에서 $TaCl_5/NbCl_5$ 혼합물을 99.9％ 이상 순도로 분리하기 위해 2기의 연속식 증류공정을 사용하여 light한 성분과 heavy한 성분을 제거하는 공정을 구성하였다. 본고에서는 순차배열(direct sequence)과 비 순차배열(indirect sequence)으로서의 두 분리공정에 대한 비교연구를 상용성 화학공정모사기인 Aspen Plus 13.1을 이용해서 전산모사를 수행하였다. 비교결과 순차배열이 비 순차배열에 비하여 초기 장치투자비용이나 운전비용에서 좀 더 우수한 것으로 나타났다.