Publications by authors named "Robert Anton"

We compute ionic free energy adsorption profiles at an aqueous graphene interface by developing a self-consistent approach. To do so, we design a microscopic model for water and put the liquid on an equal footing with the graphene described by its electronic band structure. By evaluating progressively the electronic and dipolar coupled electrostatic interactions, we show that the coupling level including mutual graphene and water screening permits one to recover remarkably the precision of extensive quantum simulations.

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To date, the scalable synthesis of elemental two-dimensional materials beyond graphene still remains elusive. Here, we introduce a versatile chemical vapor deposition (CVD) method to grow borophenes, as well as borophene heterostructures, by selectively using diborane originating from traceable byproducts of borazine. Specifically, metallic borophene polymorphs were successfully synthesized on Ir(111) and Cu(111) single-crystal substrates and conjointly with insulating hexagonal boron nitride (BN) to form atomically precise lateral borophene-BN interfaces or vertical van der Waals heterostructures.

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Liquid state theories such as integral equations and classical density functional theory often overestimate the bulk pressure of fluids because they require closure relations or truncations of functionals. Consequently, the cost to create a molecular cavity in the fluid is no longer negligible, and those theories predict incorrect solvation free energies. We show how to correct them simply by computing an optimized Van der Walls volume of the solute and removing the undue free energy to create such volume in the fluid.

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Two-dimensional materials such as graphene (G) and hexagonal boron nitride (BN) have demonstrated potential applications in membrane science and in particular for the harvesting of blue energy. Although pure G and BN atomic layers are known to remain inert towards neutral water, one may wonder about the aqueous reactivity of hybridized monolayers formed by joining BN and G sheets in a planar fashion. Here, we perform ab initio molecular dynamics calculations of liquid water in contact with all possible planar heterostructures.

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We report the on-surface synthesis of a nonmetal porphyrin, namely, silicon tetraphenylporphyrin (Si-TPP), by the deposition of atomic silicon onto a free-base TPP layer on a Ag(100) surface under ultrahigh vacuum (UHV) conditions. Scanning tunneling microscopy provides insights into the self-assembly of the TPP molecules before and after Si insertion. Silicon coordinates with all four nitrogen atoms of the TPP macrocycle and interacts with a silver atom of the substrate as confirmed by scanning tunneling spectroscopy, X-ray photoelectron spectroscopy, and complementary density functional theory calculations.

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Herbs are used in Europe as medicinal products, food, food supplements, and related products. This paper will discuss the concepts of Traditional Herbal Medicines and Traditional Plant Food Supplements, defined in European legislation under differing legal frameworks, regarding Traditional Plant Food Supplements (including Claims Regulation) and the role of the European Food Safety Authority in health claims.

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Objective: The objective was to define the term evidence based nutrition on the basis of expert discussions and scientific evidence.

Methods And Procedures: The method used is the established Hohenheim Consensus Conference. The term "Hohenheim Consensus Conference" defines conferences dealing with nutrition-related topics.

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Several species of the genus Vochysia (Vochysiaceae) are used by traditional communities in South America to relieve ailments linked to inflammation, such as skin sores, asthma and pulmonary congestion. As the cAMP phosphodiesterase 4 isozyme (PDE4) is currently considered as an intracellular target for new antiinflammatory drugs, several constituents of Vochysia pacifica Cuatrec., an endemic tree from the Western coast of Colombia, were tested for their ability to inhibit PDE4.

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Twenty extracts from nine Benin medicinal plants, traditionally used to treat malaria, were screened for in vitro antiplasmodial activity towards Plasmodium falciparum K1 chloroquine resistant and 3D7 chloroquine sensitive strains. All plants showed antiplasmodial activity below 10 microg/ml. Nine extracts exhibited IC50 values below 5 microg/ml towards one or both of the two strains.

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Two new coumarins, 7-methoxy-5-prenylcoumarin (isocedrelopsin) (1) and 3',4'-dihydrobraylin (2), were isolated from the trunk bark of Cedrelopsis grevei, along with five known coumarins, microfolicoumarin (6,7-dimethoxy-5-prenylcoumarin, (3), obliquin (4), 8-methoxyobliquin (5), aesculetin (6), cedrelopsin (7) and scoparone (8).

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Eight extracts from four Ivorian medicinal plants, traditionally used to treat malaria, were tested for their antiplasmodial activity in vitro by assessing their ability to inhibit the uptake of [3H]hypoxanthine into the Plasmodium falciparum K1 chloroquine-resistant strain. The most active extract was the methylene chloride extract of Anogeissus leiocarpus which exhibited an IC(50) value of 3.8 micro g/ml.

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The activity-guided fractionation of the hydroalcoholic extract of trunk bark of Cedrelopsis grevei led to the isolation of five coumarins, norbraylin (1), methyl-O-cedrelopsin (2), cedrecoumarin A (3), scoparone (4) and braylin (5) as a part of the constituents responsible for the vasorelaxing activity observed for the crude extract.

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Studies characterizing the types of GABA receptors present on cells isolated from the skate retina have allowed us to develop a working model of possible GABA interactions at the level of the outer plexiform layer (OPL). Earlier studies have shown an electrogenic GABA transport mechanism in horizontal cells presents a source of GABA in the OPL which could modulate feedback onto photoreceptors. GABA(A) receptors on Müller cells, or GABA(A) and/or GABA(C) receptors on bipolar cells.

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A new 4,5-di-O-caffeoylquinic acid butyl ester (1) was isolated from an ethyl acetate soluble fraction of Isertia pittieri stems, along with three known compounds, 1,5-di-O-caffeoylquinic acid (2), 3,4-di-O-caffeoylquinic acid (3) and 4,5-di-O-caffeoylquinic acid (4).

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