1,721,058 research outputs found
Bifunctional viscous nanovesicles co-loaded with resveratrol and gallic acid for skin protection against microbial and oxidative injuries
No full textThis work was partially supported by grants B102014-52872-R (Ministerio de Economia y Competitividad, Spain), which included FEDER funds, and 2014-SGR-938 (Generalitat de Catalunya, Spain).Vitonyte, J., Manca, M.L., Caddeo, C., Valenti, D., Peris, J.E., Usach, I., Nacher, A., Matos, M., Gutiérrez, G., Orrù, G., Fernàndez-Busquets, X., Fadda, A.M., Manconi, M
Encapsulation of bioactive fermented wheat (Lisosan G) in Eudragit-liposomes
Full text linkLiposomes are one of the most studied and most promising nanocarriers to date, representing a biocompatible, safe, and efficient delivery system for both hydrophilic and lipophilic compounds. This work aimed to evaluate the efficacy in encapsulating an aqueous extract of Lisosan G (LG), a Triticum aestivum whole grains fermented powder with strong antioxidant activity, into Eudragit-liposomes designed for oral delivery. The total phenolics and the antioxidant activity of LG extract and LG extract encapsulated in Eudragit-liposomes were evaluated by the Folin-Ciocalteu, DPPH, and FRAP colorimetric assays. Finally, the biological activity of both LG formulations was assessed as human erythrocytes protection from oxidative stress through the cellular antioxidant activity (CAA) assay. Our results demonstrate that the encapsulation into Eudragit-liposomes preserved the phenolics content of LG extract and retained its antioxidant properties both in vitro and ex vivo. Furthermore, LG Eudragit-liposomes exhibited increased ferric reducing capacity and protection of human erythrocytes from oxidative insult, probably due to the antioxidant properties of liposome constituents. Therefore, the encapsulation into Eudragit-liposomes represents an excellent strategy to prevent possible reduction and loss of activity of LG bioactive compounds, and to deliver them via oral administration
Oral delivery of natural compounds by phospholipid vesicles
No full textThe purpose of this report is to summarize and critically analyze emerging trends in phospholipid vesicles for the oral delivery of natural compounds. Liposomes have long been used as delivery systems, thanks to their ability to incorporate diverse bioactives, their biocompatibility and safety. However, the efficacy of oral liposomes is hampered by their low stability under the harsh conditions of the gastrointestinal tract. Different approaches have been utilized with the aim of improving the stability of liposomes and the payload after oral administration. This report provides an overview on the phospholipid vesicles used for oral delivery of natural compounds, exploring the current strategies to improve their performance by modifying the lipid bilayer composition and assembly or the physical state
Donuts and Spin Vortices at the Fermi Surfaces of Hybrid LeadIodide CH3NH3PbI3 Perovskites
No full textWe show that spin-orbit coupling in methylammonium lead-iodide perovskite generates Fermi surfaces of peculiar topology: for the low charge-injection regime of interest for photovoltaic applications, the Fermi surfaces are donuts (ring tori), which evolve into apples (spindle tori) as the band population is raised, with a vortex spin texture that indicates the dominance of the Rashba effect. This material is a significant example of a bulk system, where despite the lack of any macroscopic field, a strong Rashba effect shows up, originated by a local dipole field on Pb and I orbitals, with the field direction locked to the vortex point loci in k-space. Remarkably, the same Fermi surface topology and spin helicity characterize both electrons and holes: this makes the presence of Rashba compatible with the direct band gap behavior described by photoluminescence experiment
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Fermi Surface Topology and Rashba‐Edelstein Charge‐Spin Conversion in Lead‐Halide Perovskites
Full text linkThe conversion of charge current into spin current by the Rashba-Edelstein effect enables the reciprocal control of electron charge and magnetization in magnetoelectric and magneto-optical devices. The fundamentals of this effect are described in 3D lead-halide perovskites: due to spin-momentum locking, a strong charge-spin conversion, widely tunable by the injected charge density, is envisaged. The analysis highlights the close relationship between charge-spin conversion and the topological transition occurring from the low-density, torus-shaped Fermi surface (genus 1) to the high-density, simply connected Fermi surfaces (genus 0). At room temperature, spin-polarizations as large as approximate to 10% are obtained for input charge currents in the approximate to 102 to 106 Acm(-2) range; at low temperature, almost full spin-polarization can be achieved, owed to the large, impurity scattering-limited mobilities. The results qualify lead-halide perovskites as suitable materials for spin-orbitronic applications
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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