• BMB Reports
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• 제56권12호
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• pp.663-668
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• 2023

C-reactive protein (CRP) is an inflammatory marker and risk factor for atherosclerosis and cardiovascular diseases. However, the mechanism through which CRP induces myocardial damage remains unclear. This study aimed to determine how CRP damages cardiomyocytes via the change of mitochondrial dynamics and whether survivin, an anti-apoptotic protein, exerts a cardioprotective effect in this process. We treated H9c2 cardiomyocytes with CRP and found increased intracellular ROS production and shortened mitochondrial length. CRP treatment phosphorylated ERK1/2 and promoted increased expression, phosphorylation, and translocation of DRP1, a mitochondrial fission-related protein, from the cytoplasm to the mitochondria. The expression of mitophagy proteins PINK1 and PARK2 was also increased by CRP. YAP, a transcriptional regulator of PINK1 and PARK2, was also increased by CRP. Knockdown of YAP prevented CRP-induced increases in DRP1, PINK1, and PARK2. Furthermore, CRP-induced changes in the expression of DRP1 and increases in YAP, PINK1, and PARK2 were inhibited by ERK1/2 inhibition, suggesting that ERK1/2 signaling is involved in CRP-induced mitochondrial fission. We treated H9c2 cardiomyocytes with a recombinant TAT-survivin protein before CRP treatment, which reduced CRP-induced ROS accumulation and reduced mitochondrial fission. CRP-induced activation of ERK1/2 and increases in the expression and activity of YAP and its downstream mitochondrial proteins were inhibited by TAT-survivin. This study shows that mitochondrial fission occurs during CRP-induced cardiomyocyte damage and that the ERK1/2-YAP axis is involved in this process, and identifies that survivin alters these mechanisms to prevent CRP-induced mitochondrial damage.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 유기절연재료 방전 플라즈마연구회
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• pp.108-111
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• 2003

The main objective of this paper is to module design and pressure relief test a new type of polymer gapless surge arrester for power distribution line. Metal oxide surge arrester for most electric power system applications, power distribution line and electric train are now being used extensively to protect overvoltage due to lightning. Surge arresters with porcelain housing must not have explosive breakage of the housing to minimize damage to other equipment when subjected to internal high short circuit current. When breakdown of gapless elements in a surge arrester occurs due to flashover, fault short current flows through the arrester and internal pressure of the arrester rises. The pressure rise can usually be limited by fitting a pressure relief diaphragm and transferring the arc from the inside to the outside of the housing. However, there is possibility of porcelain fragmentation caused by the thermal shock, pressure rise, etc. Non-fragmenting of the housing is the most desired way to prevent damage to other equipment. The pressure change which is occurred by flashover become discharge energy. This discharge energy raises to damage arrester housing and arrester housing is dispersed as small fragment. Therefore, the pressure relief design is requested to obstruct housing dispersion.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 춘계학술대회 논문집
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• pp.175-179
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• 2005

The main objective of this paper is to module design and pressure relief test a new type of polymer gapless surge arrester for power distribution line. Metal oxide surge arrester for most electric power system applications, power distribution line and electric train are now being used extensively to protect overvoltage due to lightning. Surge arresters with porcelain housing must not have explosive breakage of the housing to minimize damage to other equipment when subjected to internal high short circuit current. When breakdown of gapless elements in a surge arrester occurs due to flashover, fault short current flows through the arrester and internal pressure of the arrester rises. The pressure rise can usually be limited by fitting a pressure relief diaphragm and transferring the arc from the inside to the outside of the housing. However, there is possibility of porcelain fragmentation caused by the thermal shock, pressure rise, etc. Non-fragmenting of the housing is the most desired way to prevent damage to other equipment. The pressure change which is occurred by flashover become discharge energy. This discharge energy raises to damage arrester housing and arrester housing is dispersed as small fragment. Therefore, the pressure relief design is requested to obstruct housing dispersion.

• 대한한의학회지
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• 제24권3호
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• pp.72-83
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• 2003

Objective : The goal of the present study was to investigate the protective effect of Gamiheechum-tang (Jiaweixiqian-tang; GHCT) on brain tissue damage from chemical or ischemic insults. Methods : Levels of cultured cortical neuron death caused by toxic chemicals were measured by LDH release assay. Neuroprotective effects of GHCT on brain tissues were examined in vivo by ischemic model of middle cerebral artery (MCA) occlusion. Results : Animal groups treated with GBCT showed significantly decreased hypertension, and reduced levels of aldosterone, dopamine, and epinephrine in the plasma. GHCT treatments ($l0-200\mu\textrm{g}/ml$) significantly decreased cultured cortical neuron death mediated by AMPA, kainate, BSO, or Fe2+ when measured by LDH release assay. Yet, cell death mediated by NMDA was effectively protected by GHCT at the highest concentration examined ($200\mu\textrm{g}/ml$). In the in vivo experiment examining brain damage by MCA occlusion, affected brain areas by ischemic damage and edema were significantly less in animal groups administered with GHCT compared to the non-treated control group. Neurological examinations of forelimbs and hindlimbs showed that GHCT treatment improved animals' recovery from ischemic injury. Moreover, the extent of injury in cortical and hippocampal pyramidal neurons in ischemic rats was much reduced by GHCT, whose morphological features were similarly observed in non-ischemic animals. Conclusion : The present data suggest that GBCT may play an important role in protecting brain tissues from chemical or ischemic injuries.

• 한방비만학회지
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• 제19권1호
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• pp.1-11
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• 2019

Objectives: The purpose of the present study was to evaluate the preventive effects of ethanol extract of Polygalae radix (EEPR) against oxidative stress (hydrogen peroxide, $H_2O_2$)-induced DNA damage and apoptosis in Chang liver cells. Methods: Chang liver cells were pretreated with various concentrations of EEPR and then challenged with 0.5 mM $H_2O_2$. The cell viability and apoptosis were assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and flow cytometry analysis, respectively. The levels of reactive oxygen species (ROS), mitochondrial membrane potentials (MMPs) and adenosine tri-phosphate (ATP) contents were measured. Expression levels of Bcl-2 and Bax were also determined using Western blot analysis. Results: The results showed that the decreased survival rate induced by $H_2O_2$ could be attributed to the induction of DNA damage and apoptosis accompanied by the increased production of ROS, which was remarkably protected by EEPR. In addition, the loss of $H_2O_2$-induced MMPs and ATP contents was significantly attenuated in the presence of EEPR. The inhibitory effect of EEPR on $H_2O_2$-induced apoptosis was associated with up-regulation of Bcl-2 and down-regulation of Bax, thus reducing the Bax/Bcl-2 ratio. Conclusions: Our data prove that EEPR protects Chang liver cells against $H_2O_2$-induced DNA damage and apoptosis by scavenging ROS and thus suppressing the mitochondrial-dependent apoptosis pathway.

• 한국압력기기공학회 논문집
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• 제8권2호
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• pp.33-41
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• 2012

The component cooling water heat exchangers are critical components in a nuclear power plant. As the operation years of the heat exchanger go by, the maintenance costs required for continuous operation also increase. Most heat exchangers have carbon steel shells, tube support plates and flow baffles. The titanium tube is susceptible to flow induced vibration. The damage on carbon steel tube support rod and titanium tube around cooling water entrance area is inevitable. Therefore, analysis of internal flow around the component cooling water entrance and tube channel is a good opportunity to seek for failure prevention practice and maintenance method. The numerical study was carried out by FLUENT code to find out the causes of tube failure and its location.

• 한국항만학회지
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• 제15권1호
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• pp.107-119
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• 2001

Disaster mitigation, especially as a concept similar to damage mitigation caused by heavy rainfalls and flood is closely related to long-term development plan. This plan of an harbor area where is located in lower region is established and carried under consideration of disaster mitigation concept such as internal drainage and so on. Flood damage is somewhat predictable in accordance with height, stream and rainfall characteristics of the region. Therefore it is necessary to establish national and urban plan under consideration of this fact. But this consideration of existing regulation and institution is insufficient and improvement of regulation and institution is needed. This consideration of disaster mitigation fields is regulated declaratively and inclusively in national plan which is established in broad region, and specifically and detailedly in urban plan which is established in narrow region. The program to improve regulation and institution is proposed in order to consider disaster mitigation fields as a level of this plan.

• 대한한방내과학회지
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• 제12권1호
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• pp.56-67
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• 1991

According to the results of the studies on 23 references, the orders in the cause of Liver-Exhaustion (肺勞) were as follows ; 1) Liver-damage (肺傷) was the most abundant by occuping 26.09% (6/23) 2) Trouble-resources-prudence (勞力謀慮) and Liver-deficiency (肝虛) were the second by occuping each 21.74% (5/23). 3) Spirit-damage (神損) was 13.04% (3/23) and Anger-counter-up (怒氣逆上) was 8.70% (2/23). The Orders in the cases of Liver-exhaustion (肝勞) were as follows ; 1) Dry-dark-countenance (面目乾黑) was the most abundant by occuping 34.79% (8/23). 2) Spirit-unstableness (精神不守) was the second by occuping 30.43% (7/23) 3) Sight-unclearness (目視不明) was 20.09% (6/23) 4) Muscle relaxation not maintained by oneself (緩不能自收指) was 21.74% (5/23) Other various cases were excepted because of low frequence.

• 비파괴검사학회지
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• 제30권3호
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• pp.271-281
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• 2010

Brazing fitting which is one of the aircraft hydraulic power system components is widely used for saving weight and achieving higher reliability. Any inherent defects or damage of fitting can cause system failure and/or physical damage of human body due to highly pressurized fluid. Radiographic testing(RT) technique and additional micro-structure investigation on cut-away surfaces have been accomplished to find out some defect-like-inhomogeneity in the fittings. The radiography results showed that some defect-like-inhomogeneity existed inside body. Additional micro-structure investigation on cut-away surface reveals that the inhomogeneity is due to internal voids. In this study, it can be is said that RT technique can be a useful tool for field acceptance test of hydraulic brazing fitting in short time.

• 한국산학기술학회논문지
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• 제18권10호
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• pp.688-695
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• 2017

CFRP는 금속에 비해 가벼우면서 강도 및 강성과 내열성 등 기계적 특성이 매우 뛰어나 다양한 분야에서 사용되어지고 있으며 최근 우주항공 분야에 까지 사용되어지고 있지만 외부 충격하중으로 인하여 내부에 발생되는 손상에 대해서는 매우 취약한 단점을 보이고 있다. 본 연구는 외부 충격을 받은 CFRP 적층판의 내부 충격손상에 대해 반복적인 사용에 따른 파괴에 이르기까지의 강도를 고찰함으로써 우주항공 분야에 사용되는 항공기 외판의 설계를 위한 설계 데이터를 확보하기 위한 실험적 연구이다. 실험 빙법으로는 적층구성을 달라하여 제작된 의사등방형 CFRP 시험편과 직교이방성 CFRP 시험편에 대해 직경 5mm의 강구를 충돌시킴으로써 발생하는 충격손상을 관찰한 후 3점 굽힘피로실힘을 통하여 내부 층간분리 및 충격손상의 진전을 관찰하였다. 시험편 내부의 파괴가 발생하기 까지 굽힘피로실험에 따른 굽힘피로강도를 고찰한 결과 강구에 의해 충격을 받은 면이 인장을 받는 경우와 충격을 받는 경우 모두 의사등방성 적층구성의 강도가 높게 나타남을 알 수 있었다.