Eigenvalues of rank one perturbations of unstructured matrices

Let A be a fixed complex matrix and let $u\text{,}v$ be two vectors. The eigenvalues of matrices $A+\tau {\mathit{uv}}^{?}$ $(\tau \in \mathbb{R})$ form a system of intersecting curves. The dependence of the intersections on the vectors $u\text{,}v$ is studied.     

On the Comparison of Cryptographical Properties of Two Different Families of Graphs with Large Cycle Indicator

The paper is devoted to the implementations of the public key algorithms based on simple algebraic graphs A(n, K) and D(n, K) defined over the same finite commutative ring K. If K is a finite field both families are families of graphs with large cycle indicator. In fact, the family D(n, F _q ) is a family of graphs of large girth (f.g.l.g.) with c =?1, their connected components CD(n, F _q ) form the f.g.l.g. with the speed of growth 4/3. Family A(n, q), char F _q ?? 2 is a family of connected graphs with large cycle indicator with the largest possible speed of growth. The computer simulation demonstrates the advantage (better density which is the number of monomial expressions) of public rules derived from A(n, q) in comparison with symbolic algorithm based on graphs D(n, q).     

Solar hydrogen production with semiconductor metal oxides: new directions in experiment and theory

An overview of a collaborative experimental and theoretical effort toward efficient hydrogen production via photoelectrochemical splitting of water into di-hydrogen and di-oxygen is presented here. We present state-of-the-art experimental studies using hematite and TiO(2) functionalized with gold nanoparticles as photoanode materials, and theoretical studies on electro and photo-catalysis of water on a range of metal oxide semiconductor materials, including recently developed implementation of self-interaction corrected energy functionals.     

Cellular delivery of pyrenyl-arene ruthenium complexes by a water-soluble arene ruthenium metalla-cage

Three pyrenyl-arene ruthenium complexes (M(1)-M(3)) of the general formula [Ru(η(6)-arene-pyrenyl)Cl(2)(pta)] (pta = 1,3,5-triaza-7-phosphaadamantane) have been synthesised and characterised. Prior to the coordination to ruthenium, pyrene was connected to the arene ligand via an alkane chain containing different functional groups: ester (L(1)), ether (L(2)) and amide (L(3)), respectively. Furthermore, the pyrenyl moieties of the M(n) complexes were encapsulated within the hydrophobic cavity of the water soluble metalla-cage, [Ru(6)(η(6)-p-cymene)(6)(tpt)(2)(donq)(3)](6+) (tpt = 2,4,6-tri-(pyridin-4-yl)-1,3,5-triazine; donq = 5,8-dioxydo-1,4-naphthoquinonato), while the arene ruthenium end was pointing out of the cage, thus giving rise to the corresponding host-guest systems [M(n)?Ru(6)(η(6)-p-cymene)(6)(tpt)(2)(donq)(3)](6+) ([M(n)?cage](6+)). The antitumor activity of the pyrenyl-arene ruthenium complexes (M(n)) and the corresponding host-guest systems [M(n)?cage][CF(3)SO(3)](6) were evaluated in vitro in different types of human cancer cell lines (A549, A2780, A2780cisR, Me300 and HeLa). Complex M(2), which contains an ether group within the alkane chain, demonstrated at least a 10 times higher cytotoxicity than the reference compound [Ru(η(6)-p-cymene)Cl(2)(pta)] (RAPTA-C). All host-guest systems [M(n)?cage](6+) showed good anticancer activity with IC(50) values ranging from 2 to 8 μM after 72 h exposure. The fluorescence of the pyrenyl moiety allowed the monitoring of the cellular uptake and revealed an increase of uptake by a factor two of the M(2) complex when encapsulated in the metalla-cage [Ru(6)(η(6)-p-cymene)(6)(tpt)(2)(donq)(3)](6+).     

Membrane Affinity and Antibacterial Properties of Cationic Polyelectrolytes With Different Hydrophobicity

The antibacterial behavior of cationic polyelectrolytes is studied using model membrane experiments and in vitro bacterial investigations. The molecular interaction with lipid films is evaluated by the degree of penetration of the polymers into Langmuir monolayers of neutral or negatively charged lipids. The polymer/lipid interaction results in structural changes of the penetrated lipid layer visualized using AFM. The polymers are found to be effective in inhibiting the proliferation of E. coli, B. subtilis and S. aureus. The influence of the chemical structure on the functional behavior is related to the conformational properties. An optimum structure is identified on the basis of antibacterial and hemolytic tests as well as membrane‐destroying efficacy of the antimicrobial polymers.

     

Phytotherapy of alcoholism

Alcoholism is a medical, social, and economic problem where treatment methods mostly include difficult and long-lasting psychotherapy and, in some cases, quite controversial pharmacological approaches. A number of medicinal plants and pure natural compounds are reported to have preventive and therapeutic effects on alcoholism and alcohol dependency, but their constituents, efficacy and mechanism of action are mostly unknown so far. Recently, kudzu [Pueraria lobata (Willd.) Ohwi], St. John's wort (Hypericum perforatum L.), danshen (Salvia miltiorrhiza Bge.), ginseng (Panax ginseng C.A. Mey.), Japanese raisin tree (Hovenia dulcis Thunb.), ibogaine (Tabernanthe iboga H. Bn.), evening primrose (Oenothera biennis L.), prickly pear fruit (Opuntia ficus indica (L.) Mill.), purple passionflower (Passiflora incarnata L.), thyme (Thymus vulgaris L.), fenugreek seed (Trigonella foenum-graecum L.), ginger (Zingiber officinale Roscoe) and many others drew the attention of researchers. Can, therefore, drugs of natural origin be helpful in the treatment of alcoholism or in decreasing alcohol consumption?     

Optimum correction conditions for aberration-corrected HRTEM SiC dumbbells chemical imaging

Over the last decade, the spatial resolution of transmission electron microscopes has been considerably improved thanks to the development of aberration correctors. At the same time, image interpretation has become easier as the influence of instrument aberrations on image intensity has been reduced for phase contrast imaging. New aberration-corrected microscopes now offer the possibility to extract both the structural and the chemical information from a quantitative analysis of the image's contrast, which is promising in many fields of materials science where knowledge of the chemical content at the atomic scale is crucial. However, appropriate imaging conditions must be used for a quantitative analysis of the image at the sub-angström scale. In this paper, we focus on the impact of chromatic and geometric aberrations on phase contrast and we compare the advantages offered by the few optimum imaging conditions proposed in the literature. Effects of residual aberrations are also considered while the influence of chromatic aberration correction in future C_s/C_c-corrected instruments is emphasized. A critical value of C_c is given depending on the instrumental parameters. Silicon carbide imaging using a C_s-corrected microscope is presented and illustrates the assessments derived from the theoretical study of residual aberration influence on phase contrast imaging.     

LaTiO2N/In2O3 photoanodes with improved performance for solar water splitting

LaTiO(2)N photoanodes for solar water splitting were prepared by electrophoretic deposition and demonstrated the best photocurrents ever reported for this material. Further important enhancement of the performance was obtained by the use of a sputtered In(2)O(3) overlayer.