Stability of self-gravitating magnetic monopoles

The stability of a spherically symmetric self-gravitating magnetic monopole is examined in the thin wall approximation: modeling the interior false vacuum as a region of de Sitter space; the exterior as an asymptotically flat region of the Reissner-Nordstr\"om geometry; and the boundary separating the two as a charged domain wall. There remains only to determine how the wall gets embedded in these two geometries. In this approximation, the ratio $k$ of the false vacuum to surface energy densities is a measure of the symmetry breaking scale $\eta$. Solutions are characterized by this ratio, the charge on the wall $Q$, and the value of the conserved total energy $M$. We find that for each fixed $k$ and $Q$ up to some critical value, there exists a unique globally static solution, with $M\simeq Q^{3/2}$; any stable radial excitation has $M$ bounded above by $Q$, the value assumed in an extremal Reissner-Nordstr\"om geometry and these are the only solutions with $M<Q$. As $M$ is raised above $Q$ a black hole forms in the exterior: (i) for low $Q$ or $k$, the wall is crushed; (ii) for higher values, it oscillates inside the black hole. If the mass is not too high these `collapsing' solutions co-exist with an inflating bounce; (iii) for $k$, $Q$ or $M$ outside the above regimes, there is a unique inflating solution. In case (i) the course of the bounce lies within a single asymptotically flat region (AFR) and it resembles closely the bounce exhibited by a false vacuum bubble (with Q=0). In cases (ii) and (iii) the course of the bounce spans two consecutive AFRs.Comment: 19 pages, RevTex two cols., 11 eps figs. Submitted to Phys. Rev.

Singularity-free model of electric charge in physical vacuum: Non-zero spatial extent and mass generation

We propose a model of a spinless electrical charge as a self-consistent field configuration of the electromagnetic (EM) field interacting with a physical vacuum effectively described by the logarithmic quantum Bose liquid. We show that, in contrast to the EM field propagating in a trivial vacuum, a regular solution does exist, and both its mass and spatial extent emerge naturally from dynamics. It is demonstrated that the charge and energy density distribution acquire Gaussian-like form. The solution in the logarithmic model is stable and energetically favourable, unlike that obtained in a model with a quartic (Higgs-like) potential.Comment: 10 pages, 9 figures, final/published versio

A G358S mutation in the Plasmodium falciparum Na⁺ pump PfATP4 confers clinically-relevant resistance to cipargamin

Diverse compounds target the Plasmodium falciparum Na(+) pump PfATP4, with cipargamin and (+)-SJ733 the most clinically-advanced. In a recent clinical trial for cipargamin, recrudescent parasites emerged, with most having a G358S mutation in PfATP4. Here, we show that PfATP4(G358S) parasites can withstand micromolar concentrations of cipargamin and (+)-SJ733, while remaining susceptible to antimalarials that do not target PfATP4. The G358S mutation in PfATP4, and the equivalent mutation in Toxoplasma gondii ATP4, decrease the sensitivity of ATP4 to inhibition by cipargamin and (+)-SJ733, thereby protecting parasites from disruption of Na(+) regulation. The G358S mutation reduces the affinity of PfATP4 for Na(+) and is associated with an increase in the parasite’s resting cytosolic [Na(+)]. However, no defect in parasite growth or transmissibility is observed. Our findings suggest that PfATP4 inhibitors in clinical development should be tested against PfATP4(G358S) parasites, and that their combination with unrelated antimalarials may mitigate against resistance development

Spin chemistry investigation of peculiarities of photoinduced electron transfer in donor-acceptor linked system

Photoinduced intramolecular electron transfer in linked systems, (R,S)- and (S,S)-naproxen-N-methylpyrrolidine dyads, has been studied by means of spin chemistry methods [magnetic field effect and chemically induced dynamic nuclear polarization (CIDNP)]. The relative yield of the triplet state of the dyads in different magnetic field has been measured, and dependences of the high-field CIDNP of the N-methylpyrrolidine fragment on solvent polarity have been investigated. However, both (S,S)- and (R,S)-enantiomers demonstrate almost identical CIDNP effects for the entire range of polarity. It has been demonstrated that the main peculiarities of photoprocesses in this linked system are connected with the participation of singlet exciplex alongside with photoinduced intramolecular electron transfer in chromophore excited state quenching.This work was supported by the grants 08-03-00372 and 11-03-01104 of the Russian Foundation for Basic Research, and the grant of Priority Programs of the Russian Academy of Sciences, nr. 5.1.5.Magin, I.; Polyakov, N.; Khramtsova, E.; Kruppa, A.; Stepanov, A.; Purtov, P.; Leshina, T.... (2011). Spin chemistry investigation of peculiarities of photoinduced electron transfer in donor-acceptor linked system. Applied Magnetic Resonance. 41(2-4):205-220. https://doi.org/10.1007/s00723-011-0288-3S205220412-4J.S. Park, E. Karnas, K. Ohkubo, P. Chen, K.M. Kadish, S. Fukuzumi, C.W. Bielawski, T.W. Hudnall, V.M. Lynch, J.L. Sessler, Science 329, 1324–1327 (2010)S.Y. Reece, D.G. Nocera, Annu. Rev. Biochem. 78, 673–699 (2009)M.S. Afanasyeva, M.B. Taraban, P.A. Purtov, T.V. Leshina, C.B. Grissom, J. Am. Chem. Soc. 128, 8651–8658 (2006)M.A. Fox, M. Chanon, in Photoinduced Electron Transfer. C: Photoinduced Electron Transfer Reactions: Organic Substrates (Elsevier, New York, 1988), p. 754P.J. Hayball, R.L. Nation, F. Bochner, Chirality 4, 484–487 (1992)N. Suesa, M.F. Fernandez, M. Gutierrez, M.J. Rufat, E. Rotllan, L. Calvo, D. Mauleon, G. Carganico, Chirality 5, 589–595 (1993)A.M. Evans, J. Clin. Pharmacol. 36, 7–15 (1996)Y. Inoue, T. Wada, S. Asaoka, H. Sato, J.-P. Pete, Chem Commun. 4, 251–259 (2000)T. Yorozu, K. Hayashi, M. Irie, J. Am. Chem. Soc. 103, 5480–5548 (1981)N.J. Turro, in Modern Molecular Photochemistry (Benjamin/Cummings, San Francisco, 1978)K.M. Salikhov, Y.N. Molin, R.Z. Sagdeev, A.L. Buchachenko, in Spin Polarization and Magnetic Field Effects in Radical Reactions (Akademiai Kiado, Budapest, 1984), p. 419E.A. Weiss, M.A. Ratner, M.R. Wasielewski, J. Phys. Chem. A 107, 3639–3647 (2003)A.S. Lukas, P.J. Bushard, E.A. Weiss, M.R. Wasielewski, J. Am. Chem. Soc. 125, 3921–3930 (2003)R. Nakagaki, K. Mutai, M. Hiramatsu, H. Tukada, S. Nakakura, Can. J. Chem. 66, 1989–1996 (1988)M.C. Jim′enez, U. Pischel, M.A. Miranda, J. Photochem. Photobiol. C Photochem. Rev. 8, 128–142 (2007)S. Abad, U. Pischel, M.A. Miranda, Photochem. Photobiol. Sci. 4, 69–74 (2005)U. Pischel, S. Abad, L.R. Domingo, F. Bosca, M.A. Miranda, Angew. Chem. Int. Ed. 42, 2531–2534 (2003)G.L. Closs, R.J. Miller, J. Am. Chem. Soc. 101, 1639–1641 (1979)G.L. Closs, R.J. Miller, J. Am. Chem. Soc. 103, 3586–3588 (1981)M. Goez, Chem. Phys. Lett. 188, 451–456 (1992)I.F. Molokov, Y.P. Tsentalovich, A.V. Yurkovskaya, R.Z. Sagdeev, J. Photochem. Photobiol. A 110, 159–165 (1997)U. Pischel, S. Abad, M.A. Miranda, Chem. Commun. 9, 1088–1089 (2003)H. Hayashi, S. Nagakura, Bull. Chem. Soc. Jpn. 57, 322–328 (1984)Y. Sakaguchi, H. Hayashi, S. Nagakura, Bull. Chem. Soc. Jpn. 53, 39–42 (1980)H. Yonemura, H. Nakamura, T. Matsuo, Chem. Phys. Lett. 155, 157–161 (1989)N. Hata, M. Hokawa, Chem. Lett. 10, 507–510 (1981)M. Shiotani, L. Sjoeqvist, A. Lund, S. Lunell, L. Eriksson, M.B. Huang, J. Phys. Chem. 94, 8081–8090 (1990)E. Schaffner, H. Fischer, J. Phys. Chem. 100, 1657–1665 (1996)Y. Mori, Y. Sakaguchi, H. Hayashi, Chem. Phys. Lett. 286, 446–451 (1998)I.M. Magin, A.I. Kruppa, P.A. Purtov, Chem. Phys. 365, 80–84 (2009)K.K. Barnes, Electrochemical Reactions in Nonaqueous Systems (M. Dekker, New York, 1970), p. 560J. Bargon, J. Am. Chem. Soc. 99, 8350–8351 (1977)M. Goez, I. Frisch, J. Phys. Chem. A 106, 8079–8084 (2002)A.K. Chibisov, Russ. Chem. Rev. 50, 615–629 (1981)J. Goodman, K. Peters, J. Am. Chem. Soc. 107, 1441–1442 (1985)H. Cao, Y. Fujiwara, T. Haino, Y. Fukazawa, C.-H. Tung, Y. Tanimoto, Bull. Chem. Soc. Jpn. 69, 2801–2813 (1996)P.A. Purtov, A.B. Doktorov, Chem. Phys. 178, 47–65 (1993)A.I. Kruppa, O.I. Mikhailovskaya, T.V. Leshina, Chem. Phys. Lett. 147, 65–71 (1988)M.E. Michel-Beyerle, R. Haberkorn, W. Bube, E. Steffens, H. Schröder, H.J. Neusser, E.W. Schlag, H. Seidlitz, Chem. Phys. 17, 139–145 (1976)K. Schulten, H. Staerk, A. Weller, H.-J. Werner, B. Nickel, Z. Phys. Chem. 101, 371–390 (1976)K. Gnadig, K.B. Eisenthal, Chem. Phys. Lett. 46, 339–342 (1977)T. Nishimura, N. Nakashima, N. Mataga, Chem. Phys. Lett. 46, 334–338 (1977)M.G. Kuzmin, I.V. Soboleva, E.V. Dolotova, D.N. Dogadkin, High Eng. Chem. 39, 86–96 (2005

Two hundred puzzling physics problems

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