Speed of complex network synchronization

Synchrony is one of the most common dynamical states emerging on networks. The speed of convergence towards synchrony provides a fundamental collective time scale for synchronizing systems. Here we study the asymptotic synchronization times for directed networks with topologies ranging from completely ordered, grid-like, to completely disordered, random, including intermediate, partially disordered topologies. We extend the approach of master stability functions to quantify synchronization times. We find that the synchronization times strongly and systematically depend on the network topology. In particular, at fixed in-degree, stronger topological randomness induces faster synchronization, whereas at fixed path length, synchronization is slowest for intermediate randomness in the small-world regime. Randomly rewiring real-world neural, social and transport networks confirms this picture.     

Rotational Spectra and Molecular Structures of Ethylanilines

The molecular structures of three ethylanilines, ortho-, meta- and para-ethylaniline, have been obtained by means of Fourier-transform microwave spectroscopy. Rotational spectra of all three molecules display the nuclear quadrupole hyperfine structures arising from the \begin{document}$ ^{14} $\end{document}N nucleus. Comparison of the determined structures allows a direct study of the influence of the position of the ethyl substituent on the structure of the amino group communicated through the phenyl ring.     

Stacked but not Stuck: Unveiling the Role of π→π* Interactions with the Help of the Benzofuran–Formaldehyde Complex

The 1:1 benzofuran–formaldehyde complex has been chosen as model system for analyzing π→π* interactions in supramolecular organizations involving heteroaromatic rings and carbonyl groups. A joint “rotational spectroscopy–quantum chemistry” strategy unveiled the dominant role of π→π* interactions in tuning the intermolecular interactions of such adduct. The exploration of the intermolecular potential energy surface led to the identification of 14 low-energy minima, with 4 stacked isomers being more stable than those linked by hydrogen bond or lone-pair→π interactions. All energy minima are separated by loose transition states, thus suggesting an effective relaxation to the global minimum under the experimental conditions. This expectation has been confirmed by the experimental detection of only one species, which was unambiguously assigned owing to the computation of accurate spectroscopic parameters and the characterization of 11 isotopologues. The large number of isotopic species opened the way to the determination of the first semi-experimental equilibrium structure for a molecular complex of such a dimension.     

Spectroscopic Characterization of 3-Aminoisoxazole,a Prebiotic Precursor of Ribonucleotides

The processes and reactions that led to the formation of the first biomolecules on Earth play a key role in the highly debated theme of the origin of life. Whether the first chemical building blocks were generated on Earth (endogenous synthesis) or brought from space (exogenous delivery) is still unanswered. The detection of complex organic molecules in the interstellar medium provides valuable support to the latter hypothesis. To gather more insight, here we provide the astronomers with accurate rotational frequencies to guide the interstellar search of 3-aminoisoxazole, which has been recently envisaged as a key reactive species in the scenario of the so-called RNA-world hypothesis. Relying on an accurate computational characterization, we were able to register and analyze the rotational spectrum of 3-aminoisoxazole in the 6–24 GHz and 80–320 GHz frequency ranges for the first time, exploiting a Fourier-transform microwave spectrometer and a frequency-modulated millimeter/sub-millimeter spectrometer, respectively. Due to the inversion motion of the −NH₂ group, two states arise, and both of them were characterized, with more than 1300 lines being assigned. Although the fit statistics were affected by an evident Coriolis interaction, we were able to produce accurate line catalogs for astronomical observations of 3-aminoisoxazole.     

CO-induced embedding of Pt adatoms in a partially reduced FeO(x) film on Pt(111)

The reduction of a single-layer FeO film grown on Pt(111) by CO at elevated pressures and temperatures has been studied through an interplay of scanning tunneling microscopy, ambient-pressure X-ray photoelectron spectroscopy, and density functional theory calculations. Exposure of the FeO thin film to CO at pressures between 1 and 30 Torr and temperatures between 500 and 530 K leads to formation of a honeycomb-structured Fe(3)O(2) film with hollow sites occupied by single Pt atoms extracted from the substrate surface. The formation of these adatoms is driven by an increase in CO adsorption energy. In addition, the structure incorporates undercoordinated Fe centers, which are proposed to have substantial effects on the catalytic properties of the surface.     

Ion Exchange Controlled Drug Release from Polymerized Ionic Liquids

In this work ion functionalized hydrogels as potent drug delivery systems are presented. The ion functionalization of the hydrogel enables the retention of ionic drug molecules and thus a reduction of burst release effects. Timolol maleate in combination with polymerized anionic 3‐sulfopropylmethacrylate potassium and ibuprofen combined with cationic poly‐[2‐(methacryloyloxy)ethyl] trimethylammonium chloride are investigated in respect to their drug release profile. The results are showing an ion exchange depending release behavior instead of a diffusion‐controlled drug release as it is known from common drug delivery systems. Furthermore, the suitability of such hydrogels for standard methods for sterilization is investigated.