Flavonol glycosides from whole cottonseed by-product

Cottonseeds are fed to high-producing dairy cows as a source of fat and highly-digestible fibre. Seven flavonol glycosides have been identified from whole cottonseed by-product. Their structures were established as quercetin 3-O-{β-d-apiofuranosyl-(1 → 2)-[α-l-rhamnopyranosyl-(1 → 6)]-β-d-glucopyranoside} (1), kaempferol 3-O-{β-d-apiofuranosyl-(1 → 2)-[α-l-rhamnopyranosyl-(1 → 6)]-β-d-glucopyranoside} (2), quercetin 3-O-[β-d-apiofuranosyl-(1 → 2)-β-d-glucopyranoside] (3), quercetin 3-O-β-d-glucopyranoside (4), kaempferol 3-O-[α-l-rhamnopyranosyl-(1 → 6)-β-d-glucopyranoside] (5), quercetin 3-O-[α-l-rhamnopyranosyl-(1 → 6)-β-d-glucopyranoside] (6), and kaempferol 3-O-α-l-rhamnopyranoside (7). Gallic acid (8) and 3,4-dihydroxybenzoic acid (9) were also found. All structures were elucidated by ESI-MS and NMR spectroscopic methods. Total polyphenols were assayed by the Folin–Ciocalteu method.     

Innovative Caciocavallo cheeses made from a mixture of cow milk with ewe or goat milk

This study assessed and compared the physicochemical, microbiological, and sensorial characteristics of Caciocavallo cheeses, made from cow milk and a mixture of cow with ewe or goat milk, during ripening. Different cheese-making trials were carried out on an industrial scale following the standard procedure of pasta filata cheeses, with some modifications. The percentage of the different added milk to cow milk influenced compositional and nutritional characteristics of the innovative products, leading to a satisfactory microbiological and sensorial quality.     

Cycloolefin copolymer/fumed silica nanocomposites

We prepared cycloolefin copolymer (COC)/fumed silica nanocomposites by melt compounding to study the effect of the filler dimensions (filler surface area) on the physical properties, with particular attention to their thermal, mechanical, and optical behaviors. Thermogravimetric analysis revealed a positive contribution of silica nanoparticles to the thermal degradation resistance of COC, as the decomposition temperature of the nanofilled samples increased by 40°C with respect to that of the unfilled matrix. Dynamic mechanical thermal analysis and quasi‐static tensile tests of the nanocomposites evidenced a slight stiffening effect, proportional to the nanofiller surface area, without any reduction in the fracture toughness. Creep resistance of the nanocomposites was increased by the addition of silica nanoparticles, especially when high‐surface‐area nanoparticles were used. The positive effect of the nanoparticles on the viscoelastic and fracture behavior was related to the uniform dispersion of silica aggregates in the matrix. Ultraviolet–visible spectrometry measurements evidenced that the original transparency of neat COC was practically maintained after the addition of silica nanoparticles. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Surface electrostatic potentials in carbon nanotubes and graphene membranes investigated with electron holography

We used low-voltage transmission electron holography to probe surface electrostatic potentials in graphene membranes and carbon nanotubes, as the number of graphenes varies. Further, we measured the phase shift induced by an individual graphene, and mapped the phase shift variation throughout a whole few-graphene-crystal as a function of the local number of layers. We found a size/surface effect as the ratio between the surface and the total number of atoms increases for an individual nanotube or graphene membrane. This surface phase term can be related to a fine electrostatic potentials redistributions occurring at the outer layers in carbon nanotubes and graphene membranes.     

The Role of Adaptivity in MIMO Line-of-Sight Systems for High Capacity Backhauling

Spectrally efficient backhaul networks are one of the key-factors for the deployment of next generation wireless cellular systems. The ambitious capacity requirements for future broadband wireless networks and the high infrastructure costs for new cell sites pose new challenges in the design of high capacity point-to-point (PtP) wireless microwave links. In this paper we present a study on PtP links that utilize a peculiar form of multiple-input multiple-output configuration, in which a capacity doubling is obtained by exploiting the geometric characteristics of the Line-of-Sight link. The impact of adaptivity on the maximum achievable transmission distance in presence of the main electronic impairments, for typical physical parameters, is discussed in order to reveal the feasibility and the advantages of this class of solutions.     

The citer-success-index: a citer-based indicator to select a subset of elite papers

The goal of this paper is introducing the citer-success-index (cs-index), i.e. an indicator that uses the number of different citers as a proxy for the impact of a generic set of papers. For each of the articles of interest, it is defined a comparison term—which represents the number of citers that, on average, an article published in a certain period and scientific field is expected to “infect”—to be compared with the actual number of citers of the article. Similarly to the recently proposed success-index (Franceschini et al. Scientometrics 92(3):621–6415, 2011), the cs-index allows to select a subset of “elite” papers. The cs-index is analyzed from a conceptual and empirical perspective. Special attention is devoted to the study of the link between the number of citers and cited authors relating to articles from different fields, and the possible correlation between the cs- and the success-index. Some advantages of the cs-index are that (i) it can be applied to multidisciplinary groups of papers, thanks to the field-normalization that it achieves at the level of individual paper and (ii) it is not significantly affected by self citers and recurrent citers. The main drawback is its computational complexity.     

A Spaceborne Gravity Gradiometer Concept Based on Cold Atom Interferometers for Measuring Earth’s Gravity Field

We propose a concept for future space gravity missions using cold atom interferometers for measuring the diagonal elements of the gravity gradient tensor and the spacecraft angular velocity. The aim is to achieve better performance than previous space gravity missions due to a very low white noise spectral behavior and a very high common mode rejection, with the ultimate goals of determining the fine structures of the gravity field with higher accuracy than GOCE and detecting time-variable signals in the gravity field better than GRACE.     

Growth on poly(l-lactic acid) porous scaffold preserves CD73 and CD90 immunophenotype markers of rat bone marrow mesenchymal stromal cells

Few data are available on the effect of biomaterials on surface antigens of mammalian bone marrow-derived, adult mesenchymal stromal cells (MSCs). Since poly(l-lactic acid) or PLLA is largely used in tissue engineering of human bones, and we are developing a reverse engineering program to prototype with biomaterials the vascular architecture of bones for their bioartificial reconstruction, both in humans and animal models, we have studied the effect of porous, flat and smooth PLLA scaffolds on the immunophenotype of in vitro grown, rat MSCs in the absence of any coating, co-polymeric enrichment, and differentiation stimuli. Similar to controls on plastic, we show that our PLLA scaffold does not modify the distribution of some surface markers in rat MSCs. In particular, the maintained expression of CD73 and CD90 on two different subpopulations (small and large cells) is consistent with their adhesion to the PLLA scaffold through specialized appendages, and to their prominent content in actin. In addition, our PLLA scaffold favours retention of the intermediate filament desmin, believed a putative marker of undifferentiated state. Finally, it preserves all rat MSCs morphotypes, and allows for their survival, adhesion to the substrate, and replication. Remarkably, a subpopulation of rat MSCs grown on our PLLA scaffold exhibited formation of membrane protrusions of uncertain significance, although in a size range and morphology compatible with either motility blebs or shedding vesicles. In summary, our PLLA scaffold has no detrimental effect on a number of features of rat MSCs, primarily the expression of CD73 and CD90.     

Giant Magnetoresistance in a Molecular Thin Film as an Intrinsic Property

The magnetic, thin‐film structural, conductivity, and magnetoresistance properties of [Ni(quinoline‐8‐thiolate)₂] ([Ni(qt)₂]) are studied. The conducting and magnetoresistance properties are studied in single crystals and in evaporated thin films through deposition on an interdigitated electrode array. Non‐linear conductivity interpreted through a space‐charge limited conduction mechanism with charges injected from the electrodes is observed. Under applied magnetic field, the material displays giant negative magnetoresistance above 50% at 2 K in both single crystals and in evaporated thin films. The effect can still be observed at 200 K and is interpreted in terms of a double exchange mechanism with the shape of the curve determined by the magnetic anisotropy. The unique observation of giant magnetoresistance (GMR) as an intrinsic effect in an evaporated thin film of paramagnetic molecules opens up new possibilities in organic spintronics.     

Interface Functionalities in Multilayer Stack Organic Light Emitting Transistors (OLETs)

Herein is described a multidisciplinary approach to understand the performance limitations of small molecule organic light emitting transistors (OLETs) based on a layered architecture, an innovative architecture potentially competitive with the state of the art and more flexible for spectral emission control. The processes of charge injection and field‐effect transport at metal/organic and organic/organic interfaces are analysed using microscopic and spectroscopic techniques in coordination. Atomic force microscopy and ultrasonic force microscopy are employed to characterize the interface morphology and the initial growth stages of organic films where charge transport actually occurs. X‐ray diffraction and near edge X‐ray dichroic absorption with linearly polarised light allow to determine the unit cell packing and the molecular orientation at the active organic interfaces, as well as the amount of non‐ordered domains. Moreover, chemical reactivity at the interfaces is measured by X‐ray photoelectron spectroscopy. It is found that a strong reaction occurs at the metal‐organic interfaces, with molecular fragmentation. Additionally, the transport properties strongly depend on the nature of the materials forming the organic stack. Specifically, amorphous conjugated films as bottom layers can promote an increased molecular disorder in the upper active layer, with a concomitant deterioration of the conduction properties.