• Title/Summary/Keyword: Nuclear integrity

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Deterministic Fracture Mechanics Analysis of Pressurized Thermal Shock

  • M. J. Jhung;Park, Y. W.
    • Nuclear Engineering and Technology
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    • v.30 no.5
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    • pp.470-484
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    • 1998

  • An analysis program for the evaluation of pressure vessel integrity under pressurized thermal shock (PTS) is developed. For given material properties and transient history such as temperature and pressure, the stress distribution is calculated and then stress intensity factors are obtained for a wide range of crack sizes. The stress intensity factors are compared with the fracture toughness to check if cracking is expected to occur during the transient. Using this program a round robin problem of PTS during a small break loss of coolant transient has been analyzed as a part of the international comparative assessment study. The allowable maximum reference nil-ductility transition temperatures are determined for various crack sizes.

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Nuclear structures and their emerging roles in cell differentiation and development

  • Hye Ji Cha
    • BMB Reports
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    • v.57 no.9
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    • pp.381-387
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    • 2024

  • The nucleus, a highly organized and dynamic organelle, plays a crucial role in regulating cellular processes. During cell differentiation, profound changes occur in gene expression, chromatin organization, and nuclear morphology. This review explores the intricate relationship between nuclear architecture and cellular function, focusing on the roles of the nuclear lamina, nuclear pore complexes (NPCs), sub-nuclear bodies, and the nuclear scaffold. These components collectively maintain nuclear integrity, organize chromatin, and interact with key regulatory factors. The dynamic remodeling of chromatin, its interactions with nuclear structures, and epigenetic modifications work in concert to modulate gene accessibility and ensure precise spatiotemporal control of gene expression. The nuclear lamina stabilizes nuclear shape and is associated with inactive chromatin regions, while NPCs facilitate selective transport. Sub-nuclear bodies contribute to genome organization and gene regulation, often by influencing RNA processing. The nuclear scaffold provides structural support, impacting 3D genome organization, which is crucial for proper gene expression during differentiation. This review underscores the significance of nuclear architecture in regulating gene expression and guiding cell differentiation. Further investigation into nuclear structure and 3D genome organization will deepen our understanding of the mechanisms governing cell fate determination.

  • https://doi.org/10.5483/BMBRep.2024-0101 인용 PDF