Superconducting Kondo phase in an orbitally-separated bilayer

The nature of superconductivity in heavy-fermion materials is a subject under intense debate, and controlling this many-body state is central for its eventual understanding. Here, we examine how proximity effects may change this phenomenon, by investigating the effects of an additional metallic layer on the top of a Kondo-lattice, and allowing for pairing in the former. We analyze a bilayer Kondo Lattice Model with an on-site Hubbard interaction, $-U$, on the additional layer, using a mean-field approach. For $U=0$, we notice a drastic change in the density-of-states due to multiple-orbital singlet resonating combinations. It destroys the well-known Kondo insulator at half filling, leading to a metallic ground state, which, in turn, enhances antiferromagnetism through the polarization of the conduction electrons. For $U\neq 0$, a superconducting Kondo state sets in at zero temperature, with the occurrence of unconventional pairing amplitudes involving $f$-electrons. We establish that this remarkable feature is only possible due to the proximity effects of the additional layer. At finite temperatures we find that the critical superconducting temperature, $T_c$, decreases with the interlayer hybridization. We have also established that a zero temperature superconducting amplitude tracks $T_c$, which reminisces the BCS proportionality between the superconducting gap and $T_c$.Comment: 11 pages, 10 figure

Impacto da introdução da vacina pneumocócica conjugada 10 valente nas hospitalizações por pneumonia em crianças de até 4 anos em Goiás após 2010: um estudo antes-depois

A pneumonia está entre as principais causas de morte em crianças em todo o mundo e está relacionada principalmente com o Streptococcus pneumoniae. Diante disso, a vacina pneumocócica conjugada 10-valente (PCV-10) foi criada para reduzir a morbimortalidade no Brasil ocasionado por 10 sorotipos deste patógeno. O objetivo deste trabalho será analisar o impacto da introdução da vacina PCV-10 nas hospitalizações por pneumonia em crianças de até quatro anos em Goiás, comparando os números de hospitalizações e custos do setor público de saúde do período pré-PCV-10 (2008 a 2010) com o período pós-PCV-10 (2011 a 2013). Será realizado um estudo retrospectivo analítico, tipo antes-depois, com base nos dados de hospitalizações de crianças com pneumonia fornecidos pelo banco de dados do Departamento de Informática do Sistema Único de Saúde (DATASUS). Será considerado para o período pré-PCV-10 os anos de 2008, 2009, 2010, pois a cobertura vacinal no ano de implementação da vacina (2010) foi baixa, e período pós-PCV-10 os anos de 2011, 2012 e 2013, pois as coberturas vacinais no período foram iguais ou maiores que 95%. O Teste x2 será usado para analisar as variáveis dicotômicas, enquanto teste t será utilizado para comparação das médias das variáveis dependentes nos períodos pré e pós PCV-10. Ao fim do estudo será possível determinar se o advento da PCV-10 a partir de 2010 em Goiás contribuiu de forma significativa para redução de hospitalizações e custos do setor público de saúde na faixa etária considerada

Collagen-based silver nanoparticles for biological applications: synthesis and characterization

Abstract\ud \ud Background\ud Type I collagen is an abundant natural polymer with several applications in medicine as matrix to regenerate tissues. Silver nanoparticles is an important nanotechnology material with many utilities in some areas such as medicine, biology and chemistry. The present study focused on the synthesis of silver nanoparticles (AgNPs) stabilized with type I collagen (AgNPcol) to build a nanomaterial with biological utility. Three formulations of AgNPcol were physicochemical characterized, antibacterial activity in vitro and cell viability assays were analyzed. AgNPcol was characterized by means of the following: ultraviolet–visible spectroscopy, dynamic light scattering analysis, Fourier transform infrared spectroscopy, atomic absorption analysis, transmission electron microscopy and of X-ray diffraction analysis.\ud \ud \ud Results\ud All AgNPcol showed spherical and positive zeta potential. The AgNPcol at a molar ratio of 1:6 showed better characteristics, smaller hydrodynamic diameter (64.34 ± 16.05) and polydispersity index (0.40 ± 0.05), and higher absorbance and silver reduction efficiency (0.645 mM), when compared with the particles prepared in other mixing ratios. Furthermore, these particles showed antimicrobial activity against both Staphylococcus aureus and Escherichia coli and no toxicity to the cells at the examined concentrations.\ud \ud \ud Conclusions\ud The resulted particles exhibited favorable characteristics, including the spherical shape, diameter between 64.34 nm and 81.76 nm, positive zeta potential, antibacterial activity, and non-toxicity to the tested cells (OSCC).FAPESP (14/02282-6)CAPES (AUX-PERM-705/2009)

Comparative descriptions of eggs from three species of Rhodnius (Hemiptera: Reduviidae: Triatominae)

The authors describe and compare the morphological and ultrastructural characteristics of eggs from the three most recent described species of the genus Rhodnius Stål, 1859, which have not previously been studied. These species are Rhodnius colombiensis (Mejia, Galvão & Jurberg 1999), Rhodnius milesi (Carcavallo, Rocha, Galvão & Jurberg 2001) and Rhodnius stali (Lent, Jurberg & Galvão 1993). The results revealed that there are similarities in the exochorial architecture of optical microscopy and scanning electron microscopy; these include the predominance of hexagonal cells that are common to all Rhodnius species and variable degrees of lateral flattening, which is common not only to species of this genus, but also to the Rhodniini tribe. Differences in overall colour, the presence of a collar in R. milesi, a longitudinal bevel in R. stali and the precise length of R. colombiensis can be useful distinguishing features. As a result of this study, the key for egg identification proposed by Barata in 1981 can be updated.European Community - Chagas Disease Intervention ActivitiesCNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES