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Topic Review
Carbon-Burning Process
The carbon-burning process or carbon fusion is a set of nuclear fusion reactions that take place in the cores of massive stars (at least 8 [math]\displaystyle{ \begin{smallmatrix}M \odot\end{smallmatrix} }[/math] at birth) that combines carbon into other elements. It requires high temperatures (> 5×108 K or 50 keV) and densities (> 3×109 kg/m3). These figures for temperature and density are only a guide. More massive stars burn their nuclear fuel more quickly, since they have to offset greater gravitational forces to stay in (approximate) hydrostatic equilibrium. That generally means higher temperatures, although lower densities, than for less massive stars. To get the right figures for a particular mass, and a particular stage of evolution, it is necessary to use a numerical stellar model computed with computer algorithms. Such models are continually being refined based on nuclear physics experiments (which measure nuclear reaction rates) and astronomical observations (which include direct observation of mass loss, detection of nuclear products from spectrum observations after convection zones develop from the surface to fusion-burning regions – known as dredge-up events – and so bring nuclear products to the surface, and many other observations relevant to models).
  • 1.9K
  • 17 Nov 2022
Topic Review
Cardiovascular Disease after Chronic Kidney Disease
Cardiovascular diseases remain the most common cause of morbidity and mortality in chronic kidney disease patients undergoing hemodialysis. Epicardial adipose tissue (EAT), visceral fat depot of the heart, was found to be associated with coronary artery disease in cardiac and non-cardiac patients. Additionally, EAT has been proposed as a novel cardiovascular risk in the general population and in end-stage renal disease patients. It has also been shown that EAT, more than other subcutaneous adipose tissue deposits, acts as a highly active organ producing several bioactive adipokines, and proinflammatory and proatherogenic cytokines. 
  • 438
  • 01 Mar 2022
Topic Review
Carina
Carina, Latin for "the keel" or "the hull," is a constellation in the southern celestial hemisphere. Representing the keel of the mythical ship Argo Navis, Carina is home to several notable celestial objects, including the second-brightest star in the night sky, Canopus. It is rich in nebulae, star clusters, and other deep-sky wonders.
  • 304
  • 29 Feb 2024
Biography
Carl Eckart
Carl Henry Eckart (May 4, 1902 in St. Louis, Missouri – October 23, 1973 in La Jolla, California ) was an United States physicist, physical oceanographer, geophysicist, and administrator. He co-developed the Wigner–Eckart theorem and is also known for the Eckart conditions in quantum mechanics,[1] and the Eckart–Young theorem in linear algebra.[2] Eckart began college in 1919 at Washing
  • 434
  • 14 Dec 2022
Biography
Carl H. Brans
Carl Henry Brans (/brænz/; born December 13, 1935) is an American mathematical physicist best known for his research into the theoretical underpinnings of gravitation elucidated in his most widely publicized work, the Brans–Dicke theory. A Texas , born in Dallas, Carl Brans spent his academic career in neighboring Louisiana, graduating in 1957 from Loyola University New Orleans. Having obt
  • 372
  • 01 Dec 2022
Topic Review
Cassiopeia
Cassiopeia, named after the queen in Greek mythology, is a prominent constellation in the northern celestial hemisphere. Known for its distinctive "W" or "M" shape, depending on its orientation in the sky, Cassiopeia is easily recognizable and has been a subject of fascination for astronomers and stargazers throughout history.
  • 237
  • 29 Feb 2024
Topic Review
Cathodoluminescence of Diamond
Cathodoluminescence (CL) microscopy revealed heterogeneities in diamonds in a very detailed manner with high spatial resolution.
  • 524
  • 21 Jan 2022
Topic Review
Causal Fermion System
The theory of causal fermion systems is an approach to describe fundamental physics. It provides a unification of the weak, the strong and the electromagnetic forces with gravity at the level of classical field theory. Moreover, it gives quantum mechanics as a limiting case and has revealed close connections to quantum field theory. Therefore, it is a candidate for a unified physical theory. Instead of introducing physical objects on a preexisting spacetime manifold, the general concept is to derive spacetime as well as all the objects therein as secondary objects from the structures of an underlying causal fermion system. This concept also makes it possible to generalize notions of differential geometry to the non-smooth setting. In particular, one can describe situations when spacetime no longer has a manifold structure on the microscopic scale (like a spacetime lattice or other discrete or continuous structures on the Planck scale). As a result, the theory of causal fermion systems is a proposal for quantum geometry and an approach to quantum gravity. Causal fermion systems were introduced by Felix Finster and collaborators.
  • 411
  • 28 Oct 2022
Topic Review
Cell-to-Cell Communication and Information Transfer
Crucial events are generated by criticality, namely by the processes of phase transition from disorder to correlated disorder, affecting key organismal network functions. There is, as suggested by, “a subtle connection between informational exchange within and between networks and the complexity (non-simplicity) of those networks”. West and Grigolini replaced the term complexity with non-simplicity and explain their reasoning by stating that in physics it is easier to understand how phenomena function by the properties or characteristics that are missing, rather than those that are present.
  • 634
  • 22 Sep 2021
Topic Review
Cells Respond to Mechanical Cues of Extracellular Matrix
Extracellular biophysical properties have particular implications for a wide spectrum of cellular behaviors and functions, including growth, motility, differentiation, apoptosis, gene expression, cell–matrix and cell–cell adhesion, and signal transduction including mechanotransduction. Cells not only react to unambiguously mechanical cues from the extracellular matrix (ECM), but can occasionally manipulate the mechanical features of the matrix in parallel with biological characteristics, thus interfering with downstream matrix-based cues in both physiological and pathological processes. Bidirectional interactions between cells and (bio)materials in vitro can alter cell phenotype and mechanotransduction, as well as ECM structure, intentionally or unintentionally. Interactions between cell and matrix mechanics in vivo are of particular importance in a variety of diseases, including primarily cancer. 
  • 115
  • 31 Jan 2024
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