Elemental and isotopic profiling: a tool for distinguishing the botanical origin of oenological tannins

Much contemporary evidence underscores the pathophysiological importance of Ca2+ handling by acidic organelles such as lysosomes. Whereas our knowledge of how Ca2+ is released from these acidic Ca2+ stores (the ‘outs’) is advancing, we know relatively little about how Ca2+ uptake is effected (the ‘ins’). Here I highlight new work identifying animal Ca2+/H+ (CAX) exchangers that localize to acidic organelles, mediate Ca2+ uptake and regulate cell migration in vivo. Continued molecular definition of the acidic Ca2+ store toolkit provides new insight into Ca2+-dependent function

Analysis of Bonding between Conjugated Organic Molecules and Noble Metal Surfaces Using Orbital Overlap Populations

The electronic structure of metal−organic interfaces is of paramount importance for the properties of organic electronic and single-molecule devices. Here, we use so-called orbital overlap populations derived from slab-type band-structure calculations to analyze the covalent contribution to the bonding between an adsorbate layer and a metal. Using two prototypical molecules, the strong acceptor 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) on Ag(111) and the strong donor 1H,1′H-[4,4′]bipyridinylidene (HV0) on Au(111), we present overlap populations as particularly versatile tools for describing the metal−organic interaction. Going beyond traditional approaches, in which overlap populations are represented in an atomic orbital basis, we also explore the use of a molecular orbital basis to gain significant additional insight. On the basis of the derived quantities, it is possible to identify the parts of the molecules responsible for the bonding and to analyze which of the molecular orbitals and metal bands most strongly contribute to the interaction and where on the energy scale they interact in bonding or antibonding fashion

Synthesis of Novel Double-Layer Nanostructures of SiC–WOxby a Two Step Thermal Evaporation Process

A novel double-layer nanostructure of silicon carbide and tungsten oxide is synthesized by a two-step thermal evaporation process using NiO as the catalyst. First, SiC nanowires are grown on Si substrate and then high density W18O49nanorods are grown on these SiC nanowires to form a double-layer nanostructure. XRD and TEM analysis revealed that the synthesized nanostructures are well crystalline. The growth of W18O49nanorods on SiC nanowires is explained on the basis of vapor–solid (VS) mechanism. The reasonably better turn-on field (5.4 V/μm) measured from the field emission measurements suggest that the synthesized nanostructures could be used as potential field emitters

Arsenic present in the soil-vine-wine chain in vineyards situated in an old mining area in Trentino, Italy

The present study follows arsenic (As) transfer through the chain of soil-vine-leaves-grapes-wine to assess the possible risk of arsenic intake related to consuming grapes and wines produced in 10 vineyards located in a mining area rich in this element. The results are compared with date from 18 uncontaminated areas. In the soil, the content of As extracted with acqua regia and that available, extracted with ammonium acetate, was analyzed. Leaves and berries were analyzed after washing with acidified aqueous solution and acid mineralization in a closed vessel, whereas wines were simply diluted before analysis. All analyses were performed using an inductively coupled plasma mass-spectrometer. The aqua regia extractable As concentration in soil ranged from 3.7 to 283 mg/kg, whereas available As varied from 18 to 639 µg/kg, and As total concentration ranged from 16.3 to 579 µg/kg dry weight in leaves and from <0.1 to 36.8 µg/kg dry weight in grapes. Arsenic levels in wines were always below 1.62 µg/L, with higher concentration in red wines than in white wines. Significant and positive correlations between the As concentrations in soils, leaves and berries are highlighted, with the samples collected near the mining area having significantly higher values. Nevertheless, As levels in wines were always well below the limit (200 µg/L) suggested by the International Organization of Vine and Win