Results 51 to 60 of about 28,343 (263)
پژوهشهای ریاضی, 2021 In this paper, in the first part, the affine geometry is assumed as the main framework. Then we have a spacious explanation of necessary introduction in rather different subjects.
Azam Etemad Dehkordy
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On sectional curvatures of a Weyl manifold
Proceedings of the Japan Academy, Series A, Mathematical Sciences, 2006 In [\textit{H. Pedersen} and \textit{K. P. Tod}, Adv. Math. 97, No. 1, 74--109 (1993; Zbl 0778.53041)], it is proved that if \(M\) is a compact positive-definite Einstein-Weyl manifold whose scalar curvature is everywhere strictly negative, then \(M\) is conformal to an Einstein manifold. In this paper, the author shows that if \(M\) is a Weyl manifold,
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An estimate of sectional curvatures of hypersurfaces with positive Ricci curvatures [PDF]
Proceedings of the Edinburgh Mathematical Society, 1995 Let M be a hypersurface in Euclidean space and let the Ricci curvature of M be bounded below by some nonnegative constant. In this paper, we estimate the sectional curvature of M in terms of the lower bound of Ricci curvature and the upper bound of mean curvature.
Kim, Ju Seon, Kim, Sang Og
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Molecular Oncology, EarlyView.Glioma cells mainly express the endothelin receptor EDNRB, while EDNRA is restricted to a perivascular tumor subpopulation. Endothelin signaling reduces glioma cell proliferation while promoting migration and a proneural‐to‐mesenchymal transition associated with poor prognosis. This pathway activates Ca2+, K+, ERK, and STAT3 signalings and is regulated
Donovan Pineau +36 more
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The Cross Curvature Flow of 3-manifolds with Negative Sectional Curvature
, 2003 We introduce a geometric evolution equation for 3-manifolds with sectional curvature of one sign which is in some sense dual to the Ricci flow. On a closed 3-manifold with negative sectional curvature, we establish short time existence and a pair of monotonicity formulas for solutions to the flow. One of these formulas shows that, provided the solution
Chow, Bennett, Hamilton, Richard S.
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On Einstein Manifolds of Positive Sectional Curvature
Annals of Global Analysis and Geometry, 1999 Let (M,g) be a compact oriented Einstein 4-manifold. If M has positive intersection form and g has non-negative sectional curvature, we show that, up to rescaling and isometry, (M,g) is CP2, equipped with its standard Fubini-Study metric.
Gursky, Matthew J., LeBrun, Claude
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Molecular Oncology, EarlyView.Loss of the miR‐214/199a cluster is associated with recurrence in ovarian cancer. Engineered small extracellular vesicles (m214‐sEVs) elevate miR‐214‐3p/miR‐199a‐5p in tumor cells, suppress β‐catenin, TLR4, and YKT6 signaling, reprogram tumor‐derived sEV cargo, reduce chemoresistance and migration, and enhance carboplatin efficacy and survival in ...
Weida Wang +12 more
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Molecular Oncology, EarlyView.Cytarabine is a key therapy for acute myeloid leukaemia (AML), but its efficacy is limited by the dNTPase SAMHD1, which hydrolyses its active metabolite. Screening nucleotide biosynthesis inhibitors revealed that IMPDH inhibitors selectively sensitise SAMHD1‐proficient AML cells to cytarabine.
Miriam Yagüe‐Capilla +9 more
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Nasal and temporal curvatures of lamina CRIBROSA in myopic eyes
Scientific Reports, 2022 Little is known about the myopic characteristics of lamina cribrosa (LC) curvature. As such, we investigated nasal and temporal LC curvatures in myopia.
Sooyeon Choe +6 more
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Molecular Oncology, EarlyView.Beyond its role in immune evasion, this study identified that CD47 drives tumor‐intrinsic signaling in non‐small cell lung cancer (NSCLC). Transcriptomic profiling and functional studies revealed that CD47 regulates cell adhesion, migration, and metastasis through an ERK–EMT signaling axis.
Asa P.Y. Lau +8 more
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