FeCoCp3 Molecular Magnets as Spin Filters

Metallorganic molecules have been proposed as excellent spin filters in molecular spintronics because of the large spin-polarization of their electronic structure. However, most of the studies involving spin transport, have disregarded fundamental aspects such as the magnetic anisotropy of the molecule and the excitation of spin-flip processes during electron transport. Here, we study a molecule containing a Co and an Fe atoms stacked between three cyclopentadienyl rings that presents a large magnetic anisotropy and a S=1. These figures are superior to other molecules with the same transition metal, and improves the spin-filtering capacities of the molecule. Non-equilibrium Green's functions calculations based on density functional theory predict excellent spin-filtering properties both in tunnel and contact transport regimes. However, exciting the first magnetic state drastically reduces the current's spin polarization. Furthermore, a difference of temperature between electrodes leads to strong thermoelectric effects that also suppress spin polarization. Our study shows that in-principle good molecular candidates for spintronics need to be confronted with inelastic and thermoelectric effects

Sound-driven single-electron transfer in a circuit of coupled quantum rails

Abstract: Surface acoustic waves (SAWs) strongly modulate the shallow electric potential in piezoelectric materials. In semiconductor heterostructures such as GaAs/AlGaAs, SAWs can thus be employed to transfer individual electrons between distant quantum dots. This transfer mechanism makes SAW technologies a promising candidate to convey quantum information through a circuit of quantum logic gates. Here we present two essential building blocks of such a SAW-driven quantum circuit. First, we implement a directional coupler allowing to partition a flying electron arbitrarily into two paths of transportation. Second, we demonstrate a triggered single-electron source enabling synchronisation of the SAW-driven sending process. Exceeding a single-shot transfer efficiency of 99%, we show that a SAW-driven integrated circuit is feasible with single electrons on a large scale. Our results pave the way to perform quantum logic operations with flying electron qubits

Biochemical, physiological, and performance response of a functional watermelon juice enriched in L-citrulline during a half-marathon race

Background: Watermelon is a rich natural source of l-citrulline. This non-essential amino acid increases exercise performance. Objective: Evaluate the effect of Fashion watermelon juice enriched in l-citrulline (CWJ) (3.45 g per 500 mL) in physical performance and biochemical markers after a half-marathon race. Design: A randomised, double blind, crossover design where 2 h after drinking 500 mL of CWJ or placebo (PLA, beverage without l-citrulline) amateur male runners performed two half-marathon races. Jump height, heart rate and rating of perceived exertion were evaluated before and after the races. Moreover, muscle soreness and plasma markers of muscle damage and metabolism were evaluated for 72 h after the races. Results: Muscle soreness perception was significantly lower from 24 to 72 h after the race with CWJ beverage. Immediately after the races, runners under CWJ condition showed plasma lactate and glucose concentrations significantly lower and higher lactate dehydrogenase and l-arginine concentration than runners under PLA. A maintenance of jump heights after the races under CWJ supplementation was found, decreasing significantly with PLA. Conclusion: A single Fashion watermelon juice enriched in l-citrulline dose diminished muscle soreness perception from 24 to 72 h after the race and maintained lower concentrations of plasma lactate after an exhausting exercise.Actividad Física y Deport

Tetrapterys crispa

Angiosperm

Tetrapterys crispa

Angiosperm

Biosystematic and chemosystematic studies in five South American species of Conyza (Asteraceae) Estudios biosistemáticos en cinco especies sudamericanas de Conyza (Asteraceae)

The composition of the essentials oils of five species of Conyza Less from Argentina was determined by Gas Chromatography-Mass Spectrometer. This composition is associated to morphological and cytogenetic characters. The monoterpenes constitute more than 60% of the essential oils in C. blakei, C glandulitecta, C. sumatrensis var. sumatrensis and C. sumatrensis var. floribunda, in which limonene is the predominant compound. In C. bonariensis and C. primulaefolia the monoterpene content constitute less than the 40%. C. bonariensis presents only 13% limonene, while in C. primulaefolia it is absent. The similarity analysis of monoterpenes showed a relationship between the morphological and cytogenetic analysis, and the monoterpene content character seems to be important in biosystematic studies of the group studied. In general, C. sumatrensis var. sumatrensis is the species with more ancestral characters, while C. bonariensis and C. primulaefolia show more derived ones.<br>Fueron determinados mediante Cromatografía Gaseosa - Espectrómetro de Masa los componentes de los aceites esenciales de seis especies de Conyza Less. de Argentina. Esta composición es asociada a caracteres morfológicos y citogenéticos. Los monoterpenos constituyen mas de 60% de aceites esenciales en C. blakei, C glandulitecta, C. sumatrensis var. sumatrensis, C. sumatrensis var. floribunda, en las cuales limoneno es el componente predominante. En C. bonariensis y C. primulaefolia el contenido de monoterpenos constituye menos de 40%. C. bonariensis presenta solo 13% limoneno, mientras que en C. primulaefolia este compuesto esta ausente. El análisis de similitud utilizando monoterpenos muestra relación con el análisis dado por caracteres morfológicos y citogenéticos, por lo que el carácter contenido de monoterpeno resulta importante en estudios biosistemáticos en el grupo estudiado. En general, C. sumatrensis var. sumatrensis es la especie que presenta un mayor numero de caracteres ancestrales, mientras que C. bonariensis y C. primulaefolia revelarían caracteres derivados

Karyotype relationships among four South American species of Urvillea (Sapindaceae: Paullinieae)

A cytogenetic study was conducted on four species of the genus Urvillea (Sapindaceae, Paullinieae): U. chacoensis Hunz., U. filipes Radlk. and U. ulmacea Kunth of the Urvillea section and U. laevis Radlk. of the Stenelytron section. The chromosome numbers in U. chacoensis (2n = 22) and U. laevis (2n = 24) were confirmed, and new chromosome numbers are reported for U. filipes with 2n = 22 and U. ulmacea with 2n = 88. Additionally, data on interphase nuclear structure, chromosome banding patterns (C-Giemsa and C-CMA3/DAPI) and FISH with rDNA probes are also presented. The distribution of AT- and GC-rich regions and the physical mapping of ribosomal genes (45S and 5S rDNA sites) were established for the first time in these Urvillea species. Sections of Urvillea are cytogenetically differentiated according to basic chromosome number, where x = 11 in the section Urvillea and x = 12 in the section Stenelytron. This first section displayed an important karyotypic feature, the occurrence of large AT- and GC-rich bands at terminal chromosomal regions. The Urvillea section showed polyploidy and its species were differentiated by their banding patterns. Urvillea chacoensis showed several terminal AT-rich bands, while terminal AT- and GC-rich bands were both found in U. ulmacea. However, the section Stenelytron did not exhibit this banding pattern. The 45S rDNA sites appeared always associated with GC-rich regions and they were numerically variable among species, being located or not the same chromosome 5S rDNA sites. Variation in the repetitive DNA distribution and their role in karyotype differentiation among these Urvillea species are discussed.Fil: Urdampilleta, Juan Domingo. Universidade Estadual de Londrina; BrasilFil: Ferrucci, María Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Torezan, J. M. D.. Universidade Estadual de Londrina; BrasilFil: Vanzela, A. L. L.. Universidade Estadual de Londrina; Brasi