Reactions of microcrystalline fullerene C60 with amino and aza macrocyclic ligands under solvent-free conditions

We evaluated the reactivity under solvent-free conditions of 2-aminomethyl-15-crown-5 (AM15C5), 2-aminomethyl-18-crown-6 (AM18C6), 1,4,8,12-tetraazacyclopentadecane (TACPD) and rac-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane (tet b) with microcrystalline fullerene C₆₀. The reactions of nucleophilic addition were carried out at temperatures of about 160°C for 5 h in the case of crown ethers and TACPD, and at 180–190°C for 24 h in the case of tet b. Characterization of the products obtained was performed by using Fourier-transform infrared (FTIR) and Raman spectroscopy, laser desorption/ionization time-of-flight (LDI-TOF) mass spectroscopy, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). To provide an additional insight into the reactivity of macrocyclic compounds with C₆₀ molecules, we employed theoretical calculations in the frame of density functional theory (DFT). According to the results of SEM imaging, macrocyclic reagents are generally unable to deeply penetrate into the bulk of fullerene microcrystals (with a possible exception of TACPD). According to TGA measurements, the reaction efficiency is very low for tet b, whereas the average content of organic fraction in C₆₀-AM15C5 and C₆₀-AM18C6 reaches about 29%, and in C₆₀-TACPD, almost 40%. According to LDI-TOF mass spectral analysis, the products of TACPD, tet b and AM15C5 reactions with fullerene have oligomeric or polymeric structure. By using DFT theoretical calculations, the latter observation was explained by enhanced reactivity of secondary amino groups toward nucleophilic addition onto fullerene cage.     

Style-Controllable Speech-Driven Gesture Synthesis Using Normalising Flows

Automatic synthesis of realistic gestures promises to transform the fields of animation, avatars and communicative agents. In off-line applications, novel tools can alter the role of an animator to that of a director, who provides only high-level input for the desired animation; a learned network then translates these instructions into an appropriate sequence of body poses. In interactive scenarios, systems for generating natural animations on the fly are key to achieving believable and relatable characters. In this paper we address some of the core issues towards these ends. By adapting a deep learning-based motion synthesis method called MoGlow, we propose a new generative model for generating state-of-the-art realistic speech-driven gesticulation. Owing to the probabilistic nature of the approach, our model can produce a battery of different, yet plausible, gestures given the same input speech signal. Just like humans, this gives a rich natural variation of motion. We additionally demonstrate the ability to exert directorial control over the output style, such as gesture level, speed, symmetry and spacial extent. Such control can be leveraged to convey a desired character personality or mood. We achieve all this without any manual annotation of the data. User studies evaluating upper-body gesticulation confirm that the generated motions are natural and well match the input speech. Our method scores above all prior systems and baselines on these measures, and comes close to the ratings of the original recorded motions. We furthermore find that we can accurately control gesticulation styles without unnecessarily compromising perceived naturalness. Finally, we also demonstrate an application of the same method to full-body gesticulation, including the synthesis of stepping motion and stance.     

Alkaline activation of coals and carbon-base materials

Data on the reactions and processes occurring under the conditions of the alkaline activation of carbon substances—the production of activated carbons by the thermolysis of carbon substances in the presence of alkali metal hydroxides MOH—are summarized. The following most important activation processes were recognized: (1) the interaction of functional groups with MOH and the formation of intermediate structures with the C-O-M group; (2) their conversion into metal-containing compounds (primarily, M₂CO₃ and M₂O) in reactions with carbon, especially, with terminal C atoms on the periphery of graphenes; and (3) the reduction of M₂CO₃ and M₂O to the metal M, which is intercalated into the interlayer spaces of crystallites. The mechanism of alkaline activation was studied in most detail for KOH as an activating agent. The thermally initiated reduction of potassium oxide with carbon and the intercalation of potassium metal are the two most important processes for the development of the microporosity of activated carbon.     

Solution of the problem of identifying structures of discrete stochastic objects based on the minimum posterior error criterion of distribution densities

The importance of studying methods for solving the problem of identifying structures of discrete stochastic objects has been shown. The general structure of an identification algorithm based on the use of generalized probabilistic criteria has been proposed. The structural identification algorithm is synthesized based on the minimum posterior error criterion of distribution densities. A numerical example that makes it possible to assess the effectiveness of the proposed approach has been considered.     

BaMg1/3Nb2/3O3–Mg4Nb2O9 composite microwave ceramics with high Q-factor and low sintering temperature

Revised thermodynamic equilibrium in the BaO–MgO–Nb₂O₅ pseudo-ternary system has lead to development of a novel composite dielectric material with dielectric constant, ?′ = 25.5, efficacy factor, Q × f = 160 THz, and temperature coefficient of the resonant frequency, τ_f = +0.5 ppm/K. The material shows one of the highest Q-factors among the Ta-free microwave dielectric resonators. It also does not contain volatile Zn and Co elements. Other important property of the title compound is low sintering temperature of 1320 °C which significantly reduces the processing cost.     

Tracking the Interplay between Bound Peptide and the Lid Domain of DnaK,Using Molecular Dynamics

Hsp70 chaperones consist of two functional domains: the 44 kDa Nucleotide Binding Domain (NBD), that binds and hydrolyses ATP, and the 26 kDa Substrate Binding Domain (SBD), which binds unfolded proteins and reactivates them, utilizing energy obtained from nucleotide hydrolysis. The structure of the SBD of the bacterial Hsp70, DnaK, consists of two sub-domains: A β-sandwich part containing the hydrophobic cavity to which the hepta-peptide NRLLLTG (NR) is bound, and a segment made of 5 α-helices, called the “lid” that caps the top of the β-sandwich domain. In the present study we used the Escherichia coli Hsp70, DnaK, as a model for Hsp70 proteins, focusing on its SBD domain, examining the changes in the lid conformation. We deliberately decoupled the NBD from the SBD, limiting the study to the structure of the SBD section, with an emphasis on the interaction between the charges of the peptide with the residues located in the lid. Molecular dynamics simulations of the complex revealed significant mobility within the lid structure; as the structure was released from the forces operating during the crystallization process, the two terminal helices established a contact with the positive charge at the tip of the peptide. This contact is manifested only in the presence of electrostatic attraction. The observed internal motions within the lid provide a molecular role for the function of this sub-domain during the reaction cycle of Hsp 70 chaperones.     

The effects of surface oxidation on luminescence of nano diamonds

In this work we quantify and characterise the effects of air-oxidation on nitrogen-vacancy defect luminescence in both high-temperature-high-pressure and detonation synthesized nanodiamonds using Raman and luminescence spectroscopies. We find that oxidation treatments result in an increased nitrogen-vacancy centre excited state lifetime from 13 ns to 25 ns and in 5-nm diamonds the intensity of this luminescence increases by at least 5-fold. At the same time, in 5-nm diamonds, short lived surface-defect related luminescence is reduced by 10-fold. Furthermore we find that air oxidation reduces the sp² and disordered carbon fraction of nanodiamonds by up to 5-fold in 5-nm nanodiamonds. Based on these results, the authors suggest that the disordered-carbon and graphite shell of 5-nm nanodiamonds quenches nitrogen-vacancy luminescence, and that this quenching can be partially reduced by surface oxidation. These findings provide useful insights into the role of the graphite and disordered carbon shell in quenching luminescence, and have implications for the applicability of 5-nm nanodiamonds to bio- and quantum physics applications.