2,358 research outputs found
Single--peaks for a magnetic Schr\"{o}dinger equation with critic al growth
We prove existence results of complex-valued solutions for a semilinear
Schr\"odinger equation with critical growth under the perturbation of an
external electromagnetic field. Solutions are found via an abstract
perturbation result in critical point theory.Comment: To appea
Semiclassical limit for Schr\"odinger equations with magnetic field and Hartree-type nonlinearities
The semi-classical regime of standing wave solutions of a Schr\"odinger
equation in presence of non-constant electric and magnetic potentials is
studied in the case of non-local nonlinearities of Hartree type. It is show
that there exists a family of solutions having multiple concentration regions
which are located around the minimum points of the electric potential.Comment: 34 page
Architecture of viral genome-delivery molecular machines.
From the abyss of the ocean to the human gut, bacterial viruses (or bacteriophages) have colonized all ecosystems of the planet earth and evolved in sync with their bacterial hosts. Over 95% of bacteriophages have a tail that varies greatly in length and complexity. The tail complex interrupts the icosahedral capsid symmetry and provides both an entry for viral genome-packaging during replication and an exit for genome-ejection during infection. Here, we review recent progress in deciphering the structure, assembly and conformational dynamics of viral genome-delivery tail machines. We focus on the bacteriophages P22 and T7, two well-studied members of the Podoviridae family that use short, non-contractile tails to infect Gram-negative bacteria. The structure of specialized tail fibers and their putative role in host anchoring, cell-surface penetration and genome-ejection is discussed
Cleavage of DFNA5 by caspase-3 during apoptosis mediates progression to secondary necrotic/pyroptotic cell death.
Apoptosis is a genetically regulated cell suicide programme mediated by activation of the effector caspases 3, 6 and 7. If apoptotic cells are not scavenged, they progress to a lytic and inflammatory phase called secondary necrosis. The mechanism by which this occurs is unknown. Here we show that caspase-3 cleaves the GSDMD-related protein DFNA5 after Asp270 to generate a necrotic DFNA5-N fragment that targets the plasma membrane to induce secondary necrosis/pyroptosis. Cells that express DFNA5 progress to secondary necrosis, when stimulated with apoptotic triggers such as etoposide or vesicular stomatitis virus infection, but disassemble into small apoptotic bodies when DFNA5 is deleted. Our findings identify DFNA5 as a central molecule that regulates apoptotic cell disassembly and progression to secondary necrosis, and provide a molecular mechanism for secondary necrosis. Because DFNA5-induced secondary necrosis and GSDMD-induced pyroptosis are dependent on caspase activation, we propose that they are forms of programmed necrosis
Band gap renormalization in photoexcited semiconductor quantum wire structures in the GW approximation
We investigate the dynamical self-energy corrections of the electron-hole
plasma due to electron-electron and electron-phonon interactions at the band
edges of a quasi-one dimensional (1D) photoexcited electron-hole plasma. The
leading-order dynamical screening approximation is used in the calculation
by treating electron-electron Coulomb interaction and electron-optical phonon
Fr\"{o}hlich interaction on an equal footing. We calculate the
exchange-correlation induced band gap renormalization (BGR) as a function of
the electron-hole plasma density and the quantum wire width. The calculated BGR
shows good agreement with existing experimental results, and the BGR normalized
by the effective quasi-1D excitonic Rydberg exhibits an approximate
one-parameter universality.Comment: 11 pages, 3 figure
On fractional Schrodinger equations with Hartree type nonlinearities
Goal of this paper is to study the following doubly nonlocal equation
in the case of general nonlinearities of Berestycki-Lions type.
We prove existence of ground states and we obtain regularity and asymptotic decay of general solutions, extending some results by Moroz and Van Schaftingen
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