Results 71 to 80 of about 4,903 (262)
Periodic orbits, superintegrability, and Bertrand’s theorem
AIP Advances, 2020 Periodic orbits are the key for understanding classical Hamiltonian systems. As we show here, they are the clue for understanding Bertrand’s result relating the boundedness, flatness, and periodicity of orbits with the functional form of the potentials ...
R. P. Martínez-y-Romero +2 more
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Level spacings and periodic orbits [PDF]
Physical Review E, 2001 Starting from a semiclassical quantization condition based on the trace formula, we derive a periodic-orbit formula for the distribution of spacings of eigenvalues with k intermediate levels. Numerical tests verify the validity of this representation for the nearest-neighbor level spacing (k=0). In a second part, we present an asymptotic evaluation for
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CEACAM1 participation in breast cancer progression
Molecular Oncology, EarlyView.In invasive breast cancer (BC), CEACAM1 shifts from an apical to a uniform membranous/cytoplasmic pattern, or is lost, as tumors dedifferentiate, inversely tracking the Ki‐67 proliferative index. In MCF‐7 cells, only CEACAM1‐4L suppresses proliferation, repressing cell cycle and growth factor genes.
Mykola Lyndin +3 more
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Periodic orbits for an autonomous version of the Duffing–Holmes oscillator
Nonlinear AnalysisIn the autonomous Duffing–Holmes oscillator, the existence of periodic orbits was detected numerically. Using the Hopf bifurcation theory, we prove analytically that such periodic orbits exist.
Guangfeng Dong, Jaume Llibre
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Periodic orbits, breaktime and localization [PDF]
Journal of Physics A: Mathematical and General, 1998 The main goal of the present paper is to convince that it is feasible to construct a `periodic orbit theory' of localization by extending the idea of classical action correlations. This possibility had been questioned by many researchers in the field of `Quantum Chaos'.
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Molecular Oncology, EarlyView.This study identifies somatostatin receptor 4 (Sstr4) as a critical tumor suppressor against skin and head/neck cancers (HNSCC, cSCC, and BCC). The loss of Sstr4 removes a check on cell growth, causing hyperactivation of the MAPK‐ERK signaling pathway (↑).
Ali Taqvi +6 more
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Periodic Orbits Close to That of the Moon in Hill's Problem
Frontiers in Astronomy and Space Sciences, 2018 In the framework of the restricted, circular, 3-dimensional 3-body problem Sun-Earth-Moon, Valsecchi et al. (1993) found a set of 8 periodic orbits, with duration equal to that of the Saros cycle, and differing only for the initial phases, in which the ...
Giovanni B. Valsecchi +1 more
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The VHL tumor suppressor at the crossroad of protein folding, aggregation, and cancer
Molecular Oncology, EarlyView.Mutations, environmental stress, and chaperone dysfunction can destabilize pVHL, promoting its conversion from the native folded state into amyloid‐like assemblies. This transition may contribute to protein storage, cell dormancy, survival, and drug resistance.
Lara Abad +2 more
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Molecular Oncology, EarlyView.Extracellular vesicle (EV) lipidomic profiling of plasma and ascites from patients with high‐grade serous ovarian cancer and of ovarian cancer cell lines reveals enrichment of triglycerides (TGs), diacylglycerols (DGs), phosphatidylcholine (PCs), sphingomyelins (SMs), reflecting tumor metabolic reprogramming.
Shikha Rani +9 more
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Benjamini-Schramm convergence of periodic orbits. [PDF]
Geom Dedic, 2022 Mohammadi A, Rafi K.
europepmc +1 more source