• 동의생리병리학회지
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• 제37권2호
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• pp.25-29
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• 2023

This study was designed to establish an atopic dermatitis (AD) model using MC903 and was conducted to find out the optimal challenge concentration that can cause dermatitis symptoms enough to be experimentally verified while reducing adverse effects such as weight loss. MC903 was treated at concentrations of 2, 3, and 4 nmol/day, and evaluation of skin surface symptoms, water contents, histopathological changes, body weight changes, and spleen/body weight ratio was conducted. In addition, the expression level of thymic stromal lymphopoietin (TSLP) was also observed. In our results, MC903 induced AD skin lesions such as erythema, scab and fissure and lowered skin moisture level significantly. In addition, water holding capacities in the 3 or 4 nmol groups were diminished significantly compared to that in the control group. On the other hand, 4 nmol treatment induced a weight loss of up to 20% compared to control group. Finally, a higher level of TSLP expression was observed in the 3 nmol group than in the 2 nmol group or the 4 nmol group. Taken together, we propose a total 14-day protocol consisting of 3 days of sensitization (2 nmol/day) and 6 days of challenge (3 nmol/day).

• 한국식품조리과학회지
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• 제28권3호
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• pp.311-318
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• 2012

The correlation between osteoporosis and reactive oxygen species (ROS)-induced oxidative stress was investigated. Thus, interest in food and plants with antioxidant effects that can reduce damage caused by ROS during bone metabolism is heightening. In this study, the antioxidant effect of Taraxacum mongolicum on proliferation and differentiation of MC3T3-E1 cells under H2O2-induced oxidative stress was studied to investigate its protective effect against oxidative stress and its availability as an antioxidant material related to bone diseases. As a result, total polyphenol and total flavonoid contents of T. mongolicum were 33.65 mg/g and 4.45 mg/g, respectively. The T. mongolicum extract increased proliferation of both MC3T3-E1 cells and differentiated osteoblasts under $H_2O_2$-induced oxidative stress conditions. In addition, two differentiation markers, alkaline phosphatase activity and mineralization level in the T. mongolicum extract, tended to increase. These results indicate that T. mongolicum extract suppressed the damage to osteoblasts under oxidative stress and that it is potential antioxidant materials for preventing bone diseases.

• 한국위성정보통신학회논문지
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• 제3권1호
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• pp.8-14
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• 2008

본 논문에서는 DVB-RCS시스템에서 향후 그 사용 빈도가 높아질 Ka 대역과 비행기, 고속철도와 같은 고속으로 이동하는 단말 환경을 위하여 적합한 다중접속 방식을 제안한다. 이를 위하여 단말의 고속 이동에 의한 큰 도플러 천이가 존재하는 환경에서 기존 MF-TDMA다중접속 방식과 스크램블된 WH부호, PPGC부호를 사용하는 QS MC-DS/CDMA다중접속 방식의 처리성능을 비교 하였다. 30.458GHz 주파수를 사용하고 단말의 최대속도가 1000Km/h인 DVB-RCS시스템에서 스크램블된 WH부호를 사용하는QS MC-DS/CDMA방식이 MF-TDMA 방식에 비해 약5.7%, PPGC부호를 사용하는 QS MC-DS/CDMA방식에 비해 약8% 높은 처리성능을 보였다. 최종적으로 Ka대역을 사용하는 고속 이동체 환경의 DVB-RCS시스템을 위한 다중접속 방식으로는 처리성능 측면에서 스크램블된 WH부호를 사용하는QS MC-DS/CDMA방식이 기존의 MF-TDMA방식에 비해 효율적이다.

• 디지털콘텐츠학회 논문지
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• 제6권3호
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• pp.137-142
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• 2005

CDMA 방식은 미래의 모바일 네트워크를 위한 다중접속 방식으로 많은 주목을 받고 있으며 높은 무선 용량과 유연한 데이터 전송에 대한장점을 가지고 있다. 그리고 CDMA방식은 실시간 음성 및 비실시간 데이터 서비스를 제공하는 차세대 멀티미디어 시스템 분야에서 ITU에 제안된 주요 기술이다. 본 논문에서는 무선 채널에서 다중 접속 간섭 및 부분 대역 간섭의 제거와 시스템 채널 용량의 증가를 위해 MIMO-MC/CDMA 시스템의 용량을 평가하였다. 최근에 스펙트럼 효율과 링크의 신뢰도를 증가하기 위하여 다중경로를 이용하는 MIMO 방식이 제안되고 있다. 특히, 본 논문에서는 MIMO-MC/CDMA시스템의 채널 용량을 Eb/No, Mc, p, B에 따라서 평가하였다. 얻어진 결과로부터 채널용량을 개선하기 위해서는 신호의 요소들은 서로 무상관이어야하며 만약 부적당한 공간에 의한 상관과 부분 대역 간섭에 의한 주파수 간섭이 발생하만 MIMO-MC/CDMA 시스템의 채널 용량은 상당히 감소하게 됨을 알 수 있었다.

• Restorative Dentistry and Endodontics
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• 제39권3호
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• pp.187-194
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• 2014

Objectives: The effects of bone morphogenetic protein-2 (BMP-2) and enamel matrix derivative (EMD) respectively with mineral trioxide aggregate (MTA) on hard tissue regeneration have been investigated in previous studies. This study aimed to compare the osteogenic effects of MTA/BMP-2 and MTA/EMD treatment in MC3T3-E1 cells. Materials and Methods: MC3T3-E1 cells were treated with MTA (ProRoot, Dentsply), BMP-2 (R&D Systems), EMD (Emdogain, Straumann) separately and MTA/BMP-2 or MTA/EMD combination. Mineralization was evaluated by staining the calcium deposits with alkaline phosphatase (ALP, Sigma-Aldrich) and Alizarin red (Sigma-Aldrich). The effects on the osteoblast differentiation were evaluated by the expressions of osteogenic markers, including ALP, bone sialoprotein (BSP), osteocalcin (OCN), osteopontin (OPN) and osteonectin (OSN), as determined by reverse-transcription polymerase chain reaction analysis (RT-PCR, AccuPower PCR, Bioneer). Results: Mineralization increased in the BMP-2 and MTA/BMP-2 groups and increased to a lesser extent in the MTA/EMD group but appeared to decrease in the MTA-only group based on Alizarin red staining. ALP expression largely decreased in the EMD and MTA/EMD groups based on ALP staining. In the MTA/BMP-2 group, mRNA expression of OPN on day 3 and BSP and OCN on day 7 significantly increased. In the MTA/EMD group, OSN and OCN gene expression significantly increased on day 7, whereas ALP expression decreased on days 3 and 7 (p < 0.05). Conclusions: These results suggest the MTA/BMP-2 combination promoted more rapid differentiation in MC3T3-E1 cells than did MTA/EMD during the early mineralization period.

• 한국재료학회지
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• 제12권5호
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• pp.414-422
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• 2002

Three different multi-component white cast irons alloyed with Cr, V, Mo and W were prepared in order to study their as-cast and solidification structures. Three combinations of the alloying elements were selected so as to obtain the different types of carbides and matrix structures : 3%C-10%Cr-5%Mo-5%W(alloy No.1), 3%C-10%V-5% Mo-5%W(alloy No. 2) and 3%C-17%Cr-3% V(alloy No.3). The as-cast microstructures were investigated with optical and scanning electron microscopes. There existed two different types of carbides, $M_7C_3$ carbide with rod-like morphology and $M_6C$ carbide with fishbone-like one, and matrix in the alloy No. 1. The alloy No. 2 consisted of MC carbide with chunky and flaky type and needle-like $M_2C$ carbide, and matrix. The chunky type referred to primary MC carbide and the flaky one to eutectic MC carbide. The morphology of the alloy No. 3 represented a typical hypo-eutectic high chromium white cast iron composed of rod-like $M_7C_3$ carbide which is very sensitive to heat flow direction and matrix. To clarify the solidification sequence, each iron(50g) was remelted at 1723K in an alumina crucible using a silicon carbide resistance furnace under argon atmosphere. The molten iron was cooled at the rate of 10K/min and quenched into water at several temperatures during thermal analysis. The solidification structures of the specimen were found to consist of austenite dendrite(${\gamma}$), $ ({\gamma}+ M_7C_3)$ eutectic and $({\gamma}+ M_6C)$ eutectic in the alloy No. 1, proeutectic MC, austenite dendrite(${\gamma}$), (${\gamma}$+MC) eutectic and $({\gamma}+ M_2C)$ eutectic in the alloy No. 2, and proeutectic $M_7C_3$ and $ ({\gamma}+ M_7C_3)$ eutectic in the alloy No 3. respectively.

• 한국축산식품학회지
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• 제20권3호
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• pp.199-206
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• 2000

축육 생산시 주요 부산물인 돼지 심장근으로부터 항산화제(0.02% propyl gallate, 0.2% asxorbic acid, 0.2% sodium tripolyphosphate) 첨가 세척액(25 mM phosphate buffer, pH 6.0)에 의해 제조된 surimi(5% protein 0.6 M NaCl, 25 mM phosphate buffer, pH 6.0)를 alginate(0.4%), calcium carbonate(0.075%) 및 lactate(0.6%) 등의 첨가에 의해 AC surimi 로 조제한 다음, CMC 또는 MC를 일정수준 (0.5%, 1.0%) 첨가하여 surimi 의 pH, 겔의 보수력과 조리 손실을 비롯하여 겔읨 루성을 비교 검톻였다. CMC 첨가시 pH는 0.2 단위씩 감소하는 경향을 보인데 비해 MC 첨가시에는 뚜렷한 변화를 보이지는 않았다. 조리 손실에 대한 영향을 살펴 본 결과 CMC와 MC 첨가구에서 0.5% CMC 첨가구를 제외하고서는 나머지 세 처리구에서 감소하는 경향이었고, 특히 MC 첨가시에는 대조구에 비해 뚜렷한 감소 경향을 나타내었으나(p<0.05) 첨가수준에 따른 차이는 나타나지 않았다 CMC나 MC의 첨가는 보수력에 대해서는 거의 영향을 미치지 않은 것으로 나타났고, 물성에 대한 측정 결과에서 CMC 첨가시에는 겔의 강도. 경도 및 탄성등은 약간 증가하였으나 유의적인 차이를 나타내지는 않았고 (P<0.05), MC 첨가시에는 뚜렷한 차이를 나타내지 않았으며, 겔 응집성에 대해서는 CMC와 MC 첨가에 의해 서로 다른 경향을 나타내었다.

• 대한수의학회지
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• 제45권3호
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• pp.335-339
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• 2005

The melanocortin 1 receptor (MC1R) plays an important role in regulation of melanin pigment synthesis within mammalian melanocytes. Mutations within the gene encoding MC1R have been shown to explain coat color variations within several mammalian species including cattle. To develope a rapid and accurate method for the identification of Hanwoo, we performed a modified PCR-RFLP analysis of MC1R gene using single nucleotide polymorphism (SNP) within MC1R as a target. A size of 538 bp (537 bp for Hanwoo) was amplified by PCR, digested with Hpa II, and electrophoresed on a 1.5% agarose gel. A PCR product from Hanwoo showed a single band of 537 bp, whereas two fragments of 328 bp and 210 bp were detected in both Holstein and Black angus. The current result suggests that the PCR-RFLP using our primers and enzyme digestion system would be very accurate, easy and reproducible method to discriminate between Hanwoo and Holstein/Black angus meat.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.70-71
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• 2007

Multicrystalline silicon(mc-Si) solar cells are steadily increasing their share of the PV market due to the lower material costs. However, commercial mc-Si solar cells have lower efficiency than singlecrystalline silicon solar cells. To improve efficiency of mc-Si solar cells, it is important to reduce optical losses from front surface reflection. Isotropic etching with acid solution based on hydrofluoric acid(HF) and nitric acid$(HNO_3)$ is one of the promising methods that can reduce surface reflectance for mc-Si solar cells. Anisotropic etching is not suitable for mc-Si because of its various grain orientations. In this paper, we isotropically etched mc-Si using acid solution. After that, etched surface was observed by Scanning Electron Microscope(SEM) and surface reflectance was measured. We obtained 29.29% surface reflectance by isotropic etching with acid solution in wavelength from 400nm to 1000nm for fabrication of mc-Si solar cells.

• Nuclear Engineering and Technology
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• 제55권4호
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• pp.1428-1438
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• 2023

A novel Fission Diffusion Synthetic Acceleration (FDSA) method is developed and implemented as a part of a hybrid neutronics method for source convergence acceleration and variance reduction in Monte Carlo (MC) criticality calculations. The acceleration of the MC calculation stems from constructing a synthetic operator and solving a low-order problem using information obtained from previous MC calculations. By applying the P₁ approximation, two correction terms, one for the scalar flux and the other for the current, can be solved in the low-order problem and applied to the transport solution. A variety of one-dimensional (1-D) and two-dimensional (2-D) numerical tests are constructed to demonstrate the performance of FDSA in comparison with the standalone MC method and the coupled MC and Coarse Mesh Finite Difference (MC-CMFD) method on both intended purposes. The comparison results show that the acceleration by a factor of 3-10 can be expected for source convergence and the reduction in MC variance is comparable to CMFD in both slab and full core geometries, although the effectiveness of such hybrid methods is limited to systems with small dominance ratios.