• Title/Summary/Keyword: stress resistance

Search Result 2,288, Processing Time 0.03 seconds

Stress granules dynamics: benefits in cancer

  • Jeong In, Lee;Sim, Namkoong
    • BMB Reports
    • /
    • v.55 no.12
    • /
    • pp.577-586
    • /
    • 2022
  • Stress granules (SGs) are stress-induced subcellular compartments, which carry out a particular function to cope with stress. These granules protect cells from stress-related damage and cell death through dynamic sequestration of numerous ribonucleoproteins (RNPs) and signaling proteins, thereby promoting cell survival under both physiological and pathological condition. During tumorigenesis, cancer cells are repeatedly exposed to diverse stress stimuli from the tumor microenvironment, and the dynamics of SGs is often modulated due to the alteration of gene expression patterns in cancer cells, leading to tumor progression as well as resistance to anticancer treatment. In this mini review, we provide a brief discussion about our current understanding of the fundamental roles of SGs during physiological stress and the effect of dysregulated SGs on cancer cell fitness and cancer therapy.

Liquefaction Strength of Shelly Sand in Cyclic Simple Shear Test (반복단순전단 시험에 의한 패각질 모래의 액상화 강도)

  • Yoon, Yeowon;Yoon, Gillim;Choi, Jaekwon
    • Journal of the Korean GEO-environmental Society
    • /
    • v.8 no.6
    • /
    • pp.69-76
    • /
    • 2007
  • The sands which use for soil improvement of soft ground at coastal area contain more or less amount of shells. In this research the effects of shell contents on the liquefaction resistance of the shelly sand were studied. NGI cyclic simple shear tests were performed for the shell-sands with shell contents of 0%, 5%, 10%, 20%, 30% under the effective vertical stress of 50kPa, 100kPa and 150kPa for 40% and 55% of relative density, respectively. Cyclic simple shear test results showed that for the low effective vertical stress, the liquefaction resistance increased rapidly with increase of shell contents in both 40% and 55% relative density. On the other hand, for the high effective vertical stress, the liquefaction resistance increased slightly in 40% relative density and was almost same in 55% relative density. Liquefaction resistance decreased with increasing effective vertical stress for both 40% and 55% relative density. In the same effective vertical stress and shell contents, liquefaction resistance increased with the increase of relative density.

  • PDF

The Crack Resistance for PSG and Pe-Sin Films in the Semiconductor Device (반도체소자의 표면보호용 PSG, PE-SIN박막의 항균열특성에 대한 연구)

  • Ha, Jung-Min;Shin, Hong-Jae;Lee, Soo-Woong;Kim, Young-Wug;Lee, Jung-Kyu
    • Korean Journal of Materials Research
    • /
    • v.3 no.2
    • /
    • pp.166-174
    • /
    • 1993
  • Abstract The crack resistance of PSG(Phosphosilicate Glass) and PE-SiN(Plasma Enhanced CVD S${i_2}{N_4}$)films deposited on aluminium thin films on Si substrate was analyzed in this study. PSG was deposited by AP-CVD and PE- SiN by PE-CVD. All the films underwent repeated heat cycles at 45$0^{\circ}C$for 30 min. Crack formation and development were examined between each heat cycle. The crack behavior was found to be closely related to the stresses in the films. The stress induced by the difference in thermal expansion behavior between the passivation layers and underlying aluminum film may cause the crack. Crack resistance decreases as the thickness of PSG films increases due to the high tensile stress of the films. Phosphorus in the PSG films releases tensile stress and consequently the stress of the films tends to show compressive stress. As a result, crack resistance increased as the concentratin of P in the PSG films increased. Crack resistance in the PE-SiN films also increased with compressive stress. An experimental model to predict crack generation in the PSG and PE-SiN films during heat cycle was suggested.

  • PDF

Transient Temperature Drstributions in a Adiabatic Plate Due to Resistance Spot Welding (저항점용접(抵抗點熔接)에 따른 과도적(過渡的) 냉각(冷却) 온도이력(溫度履歷))

  • Hyo-Chul,Kim
    • Bulletin of the Society of Naval Architects of Korea
    • /
    • v.9 no.1
    • /
    • pp.15-20
    • /
    • 1972
  • As the technique of resistance spot welding became more and more advanced the factors hitherto considered secondary become more and more important. Among these factors the distribution of heat and temperature during resistance spot welding is particularly important in conjunction with thermal stress, strain and residual stress, strain problems. The analytical investigations upon the transient temperature due to resistance spot welding were made for the carbon steel plate and aluminum alloy plate. The numerical values obtained by the analytical investigation are nearly identical with the temperature distribution which obtained by D.J. Sullivan and some other experimental data. It was thought therefore useful to estimate the heat effect upon the material such as a residual stress and strain, metalurgical change, change in physical properties and etc.

  • PDF

Low streee Abrasive Wer mechanism of the Iron/Chromium Hardfacing Alloy (저응력하의 철/크롬 올버레이합금의 긁힘마모기구)

  • 백응률
    • Journal of Welding and Joining
    • /
    • v.16 no.2
    • /
    • pp.73-83
    • /
    • 1998
  • This study investigated the relationships between the microstructure and the wear resistance of hardfaced iron/chromium alloys to examine the low stress abrasive wear mechanism. The effects of volume fraction of reinforcing phases(chromium carbide and eutectic phase) were studied. The alloys were deposited once or twice on a mild steel plate using a self-shielding flux cored arc welding process. The low stress abrasion resistance of he alloys against dry sands was measured by the Dry Sand/Ruber Wheel Abrasion Tester (RWAT). The wear resistance of hypoeutectic alloys, below 0.36 volume fraction of chromium-carbide phase (VFC), behaved as Equal Pressure Mode (EPM) for the inverse rule of mixture whereas the wear resistance of hypereutectic alloys, above 0.36 VFC, represented Equal Wear Mode (EWM) for the linear rule of mixture.

  • PDF

The Influence on the Information Security Techno-stress on Security Policy Resistance Through Strain: Focusing on the Moderation of Task Technology Fit (정보보안 기술스트레스가 스트레인을 통한 보안정책 저항에 미치는 영향: 업무기술 적합성의 조절 효과 중심)

  • Hwang, In-Ho
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.16 no.5
    • /
    • pp.931-940
    • /
    • 2021
  • As information security(IS) is recognized as a critical success factor for organizational growth, organizations are increasing their investment in adopting and operating strict IS policies and technologies. However, when strict IS technology is adopted, IS-related techno-stress may occur in the employees who apply IS technology to their tasks. This study proposes the effect of IS-related techno-stress formed in individuals on IS policy resistance through IS strain and proves that task-technology fit mitigates the negative effect of techno-stress. Research models and hypotheses were presented through previous studies, and the secured samples were used, and structural equation modeling was applied to verify hypothesis. As a result of the study, it was confirmed that IS-related techno-stress (overload, complexity) affected IS policy resistance through IS strain (anxiety, fatigue), and that task-technology fit moderated the relationship between techno-stress and strain. This study suggests a strategic direction for improving the level of internal IS from the viewpoint of suggesting ways to mitigate the stress of employees that may occur when IS policies and technologies are adopted.

Oxidative Stress, Nrf2, and Epigenetic Modification Contribute to Anticancer Drug Resistance

  • Kang, Kyoung Ah;Hyun, Jin Won
    • Toxicological Research
    • /
    • v.33 no.1
    • /
    • pp.1-5
    • /
    • 2017
  • Nuclear factor E2-related factor 2 (Nrf2), a transcription factor, controls the expression of genes encoding cytoprotective proteins, including antioxidant enzymes that combat oxidative and electrophilic stress to maintain redox homeostasis. However, recent studies demonstrated that, in cancer, aberrant activation of Nrf2 by epigenetic alterations promotes high expression of cytoprotective proteins, which can decrease the efficacy of anticancer drugs used for chemotherapy. In this review, we summarize recent findings regarding the relationship between oxidative stress, Nrf2, epigenetic modification, and anticancer drug resistance, which should aid in development of new strategies to improve chemotherapeutic efficacy.

The Variation of Electrical Characteristics of PV Module due to Mechanical Stress (기계적 스트레스에 의한 태양전지모듈의 전기적 특성변화)

  • Kong, Ji-Hyun;Ji, Yang-Geun;Kang, Gi-Hwan;Kim, Kyung-Su;Yu, Gwon-Jong;Ahn, Hyung-Kuen;Han, Deuk-Young
    • New & Renewable Energy
    • /
    • v.6 no.1
    • /
    • pp.38-45
    • /
    • 2010
  • Abstract Under the physical stress on photovoltaic (PV) module, it will be warped according to elongation of the front glass and then micro-crack will be occurred in the thermally sealed solar cell. This micro-crack leads to drop of short circuit current of the PV module. This is because of increase of resistance component by micro-crack. Micro-crack at specific solar cell in the module lessens the durability of PV module with reduced output, hot-spot caused by solar cell output mismatch and increased resistance component. This study shows the relation between electrical characteristics and micro- cracks due to mechanical stress on PV module.

The Evaluation of Crack Propagation in Functionally Graded Materials with Coatings (코팅 경사기능 재료의 균열전파에 관한 평가)

  • Kwon, Oh-Heon
    • Journal of the Korean Society of Safety
    • /
    • v.23 no.4
    • /
    • pp.25-29
    • /
    • 2008
  • Recently, new functionally graded material(FGM) that has a spatial variation in composition and properties is developed because of its good quality. This material yields the demands for resistance to corrosion and high temperature in turbine blade, wear resistance as in gears and high strength machine parts. Especially coating treatment in FGM surface brings forth a mechanical weak at the interface due to discontinuous stress resulting from a steep material change. It often, leads cracks or spallation in a coating area around an interface. The behavior of propagation cracks in FGMs was here investigated. The interface stresses were reduced because of graded material properties. Also graded material parameter with exponential equation was founded to influence the stress intensity factor. And the resistance curve with FGM coating was slightly increased.

Contact Resistance and Thermal Cycling Reliability of the Flip-Chip Joints Processed with Cu-Sn Mushroom Bumps (Cu-Sn 머쉬룸 범프를 이용한 플립칩 접속부의 접속저항과 열 싸이클링 신뢰성)

  • Lim, Su-Kyum;Choi, Jin-Won;Kim, Young-Ho;Oh, Tae-Sung
    • Korean Journal of Metals and Materials
    • /
    • v.46 no.9
    • /
    • pp.585-592
    • /
    • 2008
  • Flip-chip bonding using Cu-Sn mushroom bumps composed of Cu pillar and Sn cap was accomplished, and the contact resistance and the thermal cycling reliability of the Cu-Sn mushroom bump joints were compared with those of the Sn planar bump joints. With flip-chip process at a same bonding stress, both the Cu-Sn mushroom bump joints and the Sn planar bump joints exhibited an almost identical average contact resistance. With increasing a bonding stress from 32 MPa to 44MPa, the average contact resistances of the Cu-Sn mushroom bump joints and the Sn planar bump joints became reduced from $30m{\Omega}/bump$ to $25m{\Omega}/bump$ due to heavier plastic deformation of the bumps. The Cu-Sn mushroom bump joints exhibited a superior thermal cycling reliability to that of the Sn planar bump joints at a bonding stress of 32 MPa. While the contact resistance characteristics of the Cu-Sn mushroom bump joints were not deteriorated even after 1000 thermal cycles ranging between $-40^{\circ}C$ and $80^{\circ}C$, the contact resistance of the Sn planar bump joints substantially increased with thermal cycling.