• BMB Reports
• /
• 제49권10호
• /
• pp.529-535
• /
• 2016

The NLRP3 inflammasome is activated by a variety of external or host-derived stimuli and its activation initiates an inflammatory response through caspase-1 activation, resulting in inflammatory cytokine IL-1β maturation and secretion. The NLRP3 inflammasome activation is a kind of innate immune response, most likely mediated by myeloid cells acting as a host defense mechanism. However, if this activation is not properly regulated, excessive inflammation induced by overactivated NLRP3 inflammasome can be detrimental to the host, causing tissue damage and organ dysfunction, eventually causing several diseases. Previous studies have suggested that mitochondrial damage may be a cause of NLRP3 inflammasome activation and autophagy, which is a conserved self-degradation process that negatively regulates NLRP3 inflammasome activation. Recently, mitochondria-selective autophagy, termed mitophagy, has emerged as a central player for maintaining mitochondrial homeostasis through the elimination of damaged mitochondria, leading to the prevention of hyperinflammation triggered by NLRP3 inflammasome activation. In this review, we will first focus on the molecular mechanisms of NLRP3 inflammasome activation and NLRP3 inflammasome-related diseases. We will then discuss autophagy, especially mitophagy, as a negative regulator of NLPP3 inflammasome activation by examining recent advances in research.

• 전자공학회논문지D
• /
• 제34D권5호
• /
• pp.45-51
• /
• 1997

Low temperature activation of dopants which were doped using ion mass doping system in amorphous silicon(a-Si) thin films was investigated. With a 20.angs.-thick Ni film on top of the a-Si thin film, the activation temperature of dopants lowered to 500.deg. C. When the doping was performaed after the deposition of Ni thin film on the a-Si thin films (post-doping), the activation time was shorter than that of dopants mass, the activation time of the dopants doped by pre-doping method increased. It turned NiSi2 formation, while the decrease of activation time was mainly due to the enhancement of the NiSi2 formation by mixing of Ni and a-Si at the interface of Ni and a -Si thin during the ion doping process.

• 한국재료학회지
• /
• 제30권7호
• /
• pp.327-332
• /
• 2020

Laser induced surface activation (LISA) technology requires refined selection of process variables to fabricate conductive microcircuits on a general polymer material. Among the process variables, laser mode is one of the crucial factors to make a reliable conductor pattern. Here we compare the continuous wave (CW) laser mode with the pulse wave (PW) laser mode through determination of the surface roughness and circuit accuracy. In the CW laser mode, the surface roughness is pronounced during the implementation of the conductive circuit, which results in uneven plating. In the PW laser mode, the surface is relatively smooth and uniform, and the formed conductive circuit layer has few defects with excellent adhesion to the polymer material. As a result of a change of laser mode from CW to PW, the value of Ra of the polymer material decreases from 0.6 ㎛ to 0.2 ㎛; the value of Ra after the plating process decreases from 0.8 ㎛ to 0.4 ㎛, and a tight bonding force between the polymer source material and the conductive copper plating layer is achieved. In conclusion, this study shows that the PW laser process yields an excellent conductive circuit on a polymeric material.

• 한국환경과학회지
• /
• 제29권12호
• /
• pp.1205-1211
• /
• 2020

In this study, the applicability of reduction-oxidation-linked treatment was evaluated for nitrobenzene and a by-product by analyzing the reaction kinetics. Nitrobenzene showed very low reactivity to persulfate that was activated using various methods. Nitrobenzene effectively reacted through the reduction process using Zero-Valent Iron (ZVI). However, aniline, a toxic substance, was produced as a by-product. Reduction-oxidation-linked treatment is a method that can allow the oxidative degradation of aniline after reducing nitrobenzene to aniline. The experimental results show improved reactivity and complete decomposition of the by-product. Improved reactivity and decomposition of the by-product were observed even under conditions in which the reduction-oxidation reaction was induced simultaneously. No activator was injected for persulfate activation in the process of reducing oxidant linkage, and the activation reaction was induced by ferrous iron eluted from the ZVI. This indicates that this method can be implemented relatively simply.

• 한국콘텐츠학회논문지
• /
• 제21권3호
• /
• pp.616-625
• /
• 2021

심층신경망은 임의의 함수를 근사화하는 방법으로 선형모델로 근사화한 후에 비선형 활성함수를 이용하여 추가적 근사화를 반복하는 근사화 방법이다. 이 과정에서 근사화의 성능 평가 방법은 손실함수를 이용한다. 기존 심층학습방법에서는 선형근사화 과정에서 손실함수를 고려한 근사화를 실행하고 있지만 활성함수를 사용하는 비선형 근사화 단계에서는 손실함수의 감소와 관계가 없는 비선형변환을 사용하고 있다. 본 연구에서는 기존의 활성함수에 활성함수의 크기를 변화시킬 수 있는 크기 파라메터와 활성함수의 위치를 변화시킬 수 있는 위치 파라미터를 도입한 파라메트릭 활성함수를 제안한다. 파라메트릭 활성함수를 도입함으로써 활성함수를 이용한 비선형 근사화의 성능을 개선시킬 수 있다. 각 은닉층에서 크기와 위치 파라미터들은 역전파 과정에서 파라미터들에 대한 손실함수의 1차 미분계수를 이용한 학습과정을 통해 손실함수 값을 최소화시키는 파라미터를 결정함으로써 심층신경망의 성능을 향상시킬 수 있다. MNIST 분류 문제와 XOR 문제를 통하여 파라메트릭 활성함수가 기존의 활성함수에 비해 우월한 성능을 가짐을 확인하였다.

• 경영과학
• /
• 제34권3호
• /
• pp.43-60
• /
• 2017

This study empirically examined the differences in degrees of product or process innovations according to the activation forms of all knowledge management (KM) processes (i.e., socialization, internalization, externalization, and combination), which are influenced by the usage patterns of management control systems (MCS)(i.e., interactive and diagnostic usage patterns). We empirically investigated and identified the links among usage patterns of MCS, the activation forms of KM processes, and the kinds of innovation promoted. Under high competitive conditions, it was found that the interactive usage of MCS is relatively more preferred and enhanced. However, when environmental uncertainty is high, it was shown that the diagnostic use of MCS is more emphasized. Thus, it is evident that the use patterns of MCS are determined by environmental conditions. From the results of this study, it was suggested that under high interactive use of MCS, the activation of socialization and internalization is more enhanced than the facilitation of externalization. It was also observed that when both interactive and diagnostic usage of MCS are high, KM processes are more activated and strengthened. The results indicated that under high activation of KM processes, product innovation as well as process innovation are more frequently occurred. Finally, the results of this study suggested that according to the levels of innovation openness, major innovations are more frequently occurred and promoted than minor innovations.

• 과학교육연구지
• /
• 제46권1호
• /
• pp.30-39
• /
• 2022

이 연구의 목적은 중등학생의 자기조절 과정에서 동화, 갈등, 조절의 세부 과정에 대한 뇌 활성을 비교하고 분석하는 것이다. 자기조절 과제는 생물학적 계통발생 과제로 제시되었고, 뇌활성은 fNIRS로 측정 및 분석되었다. 그 결과 동화 과정과 비교하여 갈등 과정에서 좌측 DLPFC, OFC, FP 영역에서 유의미한 활성이 발견되었고, 조절 과정에서는 DLPFC, VLPFC에서 유의미한 활성화가 발견되었다. 중등학생의 학년이 높아질수록 갈등 과정에서도 DLPFC가 증가하고 동화 과정에서도 VLPFC가 증가한다. 또한, 갈등과 조절 과정을 비교한 결과, 7학년 학생들은 오른쪽 VLPFC에서 유의미한 뇌 활동을 보였고, 9학년 학생들은 조절 과정에서 왼쪽 FP와 DLPFC 영역에서 유의미한 뇌 활동을 보였지만, 11학년 학생들은 이 과정에서 유의미한 뇌 활동을 보이지 않았다. 이러한 결과는 신경학적 연구 방법이 인지 활동과 강의실 교육 상황과 관련된 교육 연구에 적용될 수 있음을 보여준다.

• Bulletin of the Korean Chemical Society
• /
• 제35권1호
• /
• pp.103-110
• /
• 2014

Sisal fiber, an agricultural resource abundantly available in china, has been used as raw material to prepare activated carbon with high surface area and huge pore volume by chemical activation with zinc chloride. The orthogonal test was designed to investigate the influence of zinc chloride concentration, impregnation ratio, activation temperature and activation time on preparation of activated carbon. Scanning electron micrograph, Thermo-gravimetric, $N_2$-adsorption isotherm, mathematical models such as t-plot, H-K equation, D-R equation and BJH methods were used to characterize the properties of the prepared carbons and the activation mechanism was discussed. The results showed that $ZnCl_2$ changed the pyrolysis process of sisal fiber. Characteristics of activated carbon are: BET surface area was $1628m^2/g$, total pore volume was $1.316m^3/g$ and ratio of mesopore volume to total pore volume up to 94.3%. These results suggest that sisal fiber is an attractive source to prepare mesoporous high-capacity activated carbon by chemical activation with zinc chloride.

• Korean Chemical Engineering Research
• /
• 제61권1호
• /
• pp.58-61
• /
• 2023

PEMFC(Proton Exchange Membrane Fuel Cells)는 초기 성능향상을 위해 활성화(Activation) 과정이 필수적이다. 제일 많이 사용되는 활성화 방법은 전압변화(부하변화) 방법으로 과잉으로 진행될 경우 전극 촉매 열화를 동반할 수 있다. 많은 활성화 과정에서 전압변화 범위를 0.4 V에서 OCV 까지 넓은 범위에서 활성화를 진행시키는데 전극 촉매 열화 방지와 활성화 시간을 단축시키기 위해 전압변화 범위를 감소시키는 연구가 필요하다. 그래서 본 연구에서는 활성화 전압범위를 0.4~0.6 V, 0.4~0.8 V, 0.4~OCV로 했을 때 성능과 전극, 고분자막의 특성 변화를 분석해 효과적인 활성화 방법을 연구개발하고자 하였다. 0.4 V에서 제일 높은 OCV 까지 전압 범위를 넓힌 활성화에서 성능 향상도 제일 낮고 56 사이클 활성화 했을 때 활성화 전보다 오히려 성능이 10% 감소했다. 0.4~0.6 V 활성화 사이클에 의해 성능이 최고 20%까지 제일 높게 향상되고 과잉 활성화에 의한 성능 감소도 제일 작아서 최적 임을 보였다.

• Carbon letters
• /
• 제20권
• /
• pp.32-38
• /
• 2016

In this study, cellulose nanoplates (CNPs) were fabricated using cellulose nanocrystals obtained from commercial microcrystalline cellulose (MCC). Their pyrolysis behavior and the characteristics of the product carbonaceous materials were investigated. CNPs showed a relatively high char yield when compared with MCC due to sulfate functional groups introduced during the manufacturing process. In addition, pyrolyzed CNPs (CCNPs) showed more effective chemical activation behavior compared with MCC-induced carbonaceous materials. The activated CCNPs exhibited a microporous carbon structure with a high surface area of 1310.6 m²/g and numerous oxygen heteroatoms. The results of this study show the effects of morphology and the surface properties of cellulose-based nanomaterials on pyrolysis and the activation process.