Synthesis and physical properties of (Pb0.5M0.5)(Sr,La)2CuOz (z~5; M = Fe, Co, Cu, and Zn)

(Pb0.5Cu0.5)(Sr0.5La0.5)2CuOz (abbreviated as (Pb,Cu)-"1-2-0-1") with superconducting transition temperature (Tc) of 25 K is a member (n = 1) of one of the homologous series of cuprate superconductors, (Pb4+,Cu2+)(Sr2+,Ln3+)2(Y3+,Ca2+)n-1Cu2+nO2-2n+3 (n = 1-4; Ln: lanthanoid elements). For the (Pb,Cu)-"1-2-0-1", substitution effects of 3d transition metal elements M (M = Fe, Co, and Zn) for the Cu site in the (Pb,Cu)-O charge-reservoir layer (labelled as Cu(1)) are systematically investigated. Because Fe, Co and Ni ions exist as divalent or trivalent in ionic crystals, the Sr2+/La3+ ratio in the (Sr,Ln) site is adjusted to satisfy charge neutrality, assuming that they are in a trivalent state. This results in the successful synthesis of new materials with nominal compositions of (Pb0.5M0.5)(Sr0.75La0.25)2CuOz (M = Fe and Co). This observation suggests that Fe and Co are trivalent in "1-2-0-1". For M = Zn, the nominal composition of (Pb0.5Zn0.5)(Sr0.5La0.5)2CuOz was found to yield a nearly single "1-2-0-1" phase. Temperature dependence of electrical resistivity and magnetization were measured, and superconductivity was confirmed only for the case of M = Zn with a Tc of 19.7 K. For these three materials, the distribution of Fe, Co and Zn between Cu(1) and another Cu site in the Cu-O2 plane labelled as Cu(2) was investigated employing transmission electron microscopy, which showed that Fe, Co, and Zn occupy both the Cu(1) and Cu(2) sites.Comment: 26 pages, 10 figure

Optimal Trade Mechanism with Adverse Selection and Inferential Mistakes

We study an adverse selection environment, where a rational seller can trade a good of which she privately knows its value to a buyer, and there are gains from trade. The buyer’s types differ in their degree of inferential abilities: A rational type correctly infers the value of the good from the seller’s offer, whereas a naive type under-appreciates the correlation between the seller’s private information and offer. We characterize the optimal menu mechanism that maximizes the social surplus. Notably, no matter how severe the adverse selection is (in particular, even when no trade is the unique possible outcome if all agents are rational), all types of buyers trade in the optimal mecha- nism. The rational buyer’s trade occurs at the expense of the naive buyer’s losses. We also investigate a consumer-protection policy of limiting the losses and discuss its implications

Constraints on two-neutron separation energy in the Borromean C-22 nucleus

The recently extracted matter radius of carbon isotope C-22 allows us to estimate the mean-square distance of a halo neutron with respect to the center-of-mass of this nucleus. By considering this information, we suggest an energy region for an experimental investigation of the unbound C-21 virtual state. Our analysis, in a renormalized zero-ranged three-body model, also indicates that the two-neutron separation energy in C-22 is expected to be found below similar to 0.4 MeV, where the C-22 is approximated by a Borromean configuration with a pointlike C-20 and two s-wave halo neutrons. A virtual-state energy of C-21 close to zero, would make the C-22, within Borromean nuclei configurations, the most promising candidate to present an excited bound Efimov state or a continuum three-body resonance. (C) 2011 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)UNESP Univ Estadual Paulista, Inst Fis Teor, BR-01156970 São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, BR-04039002 São Paulo, BrazilCTA, Inst Tecnol Aeronaut, Dept Fis, BR-12228900 Sao Jose Dos Campos, BrazilUniv Fed Fluminense, Inst Fis, BR-24210346 Niteroi, RJ, BrazilUniversidade Federal de São Paulo UNIFESP, BR-04039002 São Paulo, BrazilWeb of Scienc

Effect of Ethanol Vapor Inhalation Treatment on Lethal Respiratory Viral Infection With Influenza A

Ethanol (EtOH) effectively inactivates enveloped viruses in vitro, including influenza and severe acute respiratory syndrome coronavirus 2. Inhaled EtOH vapor may inhibit viral infection in mammalian respiratory tracts, but this has not yet been demonstrated. Here we report that unexpectedly low EtOH concentrations in solution, approximately 20% (vol/vol), rapidly inactivate influenza A virus (IAV) at mammalian body temperature and are not toxic to lung epithelial cells on apical exposure. Furthermore, brief exposure to 20% (vol/vol) EtOH decreases progeny virus production in IAV-infected cells. Using an EtOH vapor exposure system that is expected to expose murine respiratory tracts to 20% (vol/vol) EtOH solution by gas-liquid equilibrium, we demonstrate that brief EtOH vapor inhalation twice a day protects mice from lethal IAV respiratory infection by reducing viruses in the lungs without harmful side effects. Our data suggest that EtOH vapor inhalation may provide a versatile therapy against various respiratory viral infectious diseases.journal articl