New complexes of liquid crystal discotic triphenylenes: induction of the double gyroid phase.

Electron donor-acceptor liquid crystals have been attracting considerable attention due to possible applications in optoelectronics and photonics. The creation of such charge transfer complexes is a powerful and flexible instrument for modifying the structures and properties compared to those of the initial components. In the present work, such an approach is exemplified on new complexes formed via non-covalent interactions of triphenylene discotics, namely, 2,3,6,7,10,11-hexakis(pentyloxy) triphenylene (H5T) and 2-(acryloyloxypropyloxy)-3,6,7,10,11-pentapentylox-triphenylene (TPh-3A), with an electron acceptor, ß-(2,4,7-trinitro-9-fluorenylideneaminooxy) propionic acid (TNF-carb). The structure of thin supported films of H5T, TPh-3A and their blends with TNF-carb was investigated by grazing-incidence wide-angle X-ray scattering using a synchrotron source. At room temperature, the pristine discotics crystallize in orthorhombic unit cells whereas the self-assembly of H5T and TPh-3A with TNF-carb results in a double gyroid and hexagonal phases, respectively. Formation of the double gyroid phase with the lattice parameter of 36.5 Å is driven by phase separation between the aromatic and alkyl regions of the system. It is supposed that the TNF-carb molecules of the complex are positioned in the nodes of the structure while the H5T molecules are located in the struts adjoining the nodes via triple junctions. For the hexagonal crystal of the TPh-3A/TNF-carb complex, the acceptor molecules are likely located in the interstices between the neighboring supramolecular columns of TPh-3A. The molecular structures of the blends were also explored by means of FTIR spectroscopy. A detailed FTIR spectra analysis illustrates fine changes in inter-molecular bonds. For example, the initially dimerized acceptor molecules totally disappear in the complex structures whereas in TPh-3A/TNF-carb additional H-bonds between the carboxylate group in TNF-carb and the ester group of TPh-3A form. The experimental data allows putting forward possible molecular models of the complex structures.

Feedback-Induced Quantum Phase Transitions Using Weak Measurements.

We show that applying feedback and weak measurements to a quantum system induces phase transitions beyond the dissipative ones. Feedback enables controlling essentially quantum properties of the transition, i.e., its critical exponent, as it is driven by the fundamental quantum fluctuations due to measurement. Feedback provides the non-Markovianity and nonlinearity to the hybrid quantum-classical system, and enables simulating effects similar to spin-bath problems and Floquet time crystals with tunable long-range (long-memory) interactions.

[Clinical and economic comparison of utilization of reslizumab, mepolizumab and benralizumab in the treatment of severe eosinophilic asthma].

During last few years, the approaches to the management of patients with severe asthma have been revised. Monoclonal antibodies (MABs), inhibitors of interleukin-5 (reslizumab, mepolizumab, benralizumab) have been recently introduced for the treatment of severe eosinophilic asthma. The mentioned drugs were approved in Russia and included into the list of Vitally Essential Drugs. AIM: The aim of this study was to compare the clinical and economic consequences of the use of biological agents that antagonize IL-5 in the treatment of severe eosinophilic asthma in adults. MATERIALS AND METHODS: Two methods of clinical and economic research were used: assessment of the cost-effectiveness ratio and analysis of the budget impact. The effectiveness of the drugs was assessed using indirect comparison; special attention was paid to comparability of the patient groups in the studies chosen for such an assessment. Two approaches were used for calculation of the cost of therapy for severe asthma: using DRGs (applicable to most regions of Russia), and without the use of DRGs, which is relevant only for few Russian regions. RESULTS: Basing on the data obtained from a budget impact study without the use of DRG, it was shown that reslizumab was dominating for patients with body mass of up to 70 kg, while for the patients with body mass of 70 to 110 kg, mepolizumab was dominating, while utilization of reslizumab appeared to be somewhat more expensive. In the group of patients with body mass over 110 kg, mepolizumab also was dominating. The calculation of the cost-effectiveness ratio (CER) showed that reslizumab appeared to be dominating over two other MABs, The results of the study using the DRG demonstrated that the cost of an annual course of benralizumab in most cases in Russia would exceed the amount that can be compensated by Territorial Funds for Mandatory Medical Insurance to a healthcare institution for therapy of bronchial asthma in one adult patient with genetically engineered drugs. Therefore, further comparisons were made for reslizumab and mepolizumab only. Analysis of the impact on the budget demonstrated that treatment with reslizumab and mepolizumab would represent a similar burden for the budget. When applying cost-effectiveness analysis, reslizumab was more cost-effective than mepolizumab (regardless of patient body mass). CONCLUSION: Thus, the results of the clinical and economic study suggested that, basing on the cost-effectiveness analysis, reslizumab appeared to be the dominant IL-5 antagonist (regardless of body mass if DRG approach was used and in patients with body mass up to 110 kg, if such an approach was not used). Basing on budget impact analysis, calculations without use of DRG approach showed superiority of reslizumab over mepolizumab and benralizumab for the patients with body mass up to 70 kg and the DRG-based approach showed equal burden for the budget for reslizumab and mepolizumab for the patients with any body mass.

The Time-Resolved Fluorescence Stokes Shift of Cucurbit[6]Uril Complexes with a Pyridinium Styryl Dye.

The time-resolved Stokes shift of fluorescence of styryl dye, trans-4-[4-(dimethylamino)-styryl]-1-methylpyridinium iodide (DASPI), and its host-guest complexes with cucurbit[6]uril (CB[6]) was studied by up-conversion technique on a 5 ps time scale. In all cases, the solvation time correlation function - that describes relaxation of the fluorescent state - contains two components. The time constant of the first component, which is related to the vibrational relaxation of the dye cation, increases from 118 fs without CB[6] to 224 fs in the presence CB[6]. It suggests the production of CB[6] complexes to disturb the hydrogen-bond net in the vicinity of DASPI cation. The time constant of the second component, which is associated with solvation, changes from 0.81 ps without CB[6] to 1.15 ps in the presence of the cavitand. The observed increase can be related to the displacement of the dye cation deeper into CB[6] that allows considering DASPI-CB[6] complexes as a light-controlled molecular machine with a response time on the picosecond scale.

Impact of the solubility of organic semiconductors for solution-processable electronics on the structure formation: a real-time study of morphology and electrical properties.

The control of structure formation in the active layers of organic solar cells allows for improvement in their processability and enhancement of the efficiency of the final devices. In the present work, in situ studies of film formation from binary toluene solutions of an electron donor, poly(3-hexylthiophene) (P3HT), and an electron acceptor such as [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM) or indene-C60 bisadduct (ICBA) have been conducted. These experiments were carried out using GIWAXS with simultaneous electric current measurements. The comparative analysis of the intensity of the amorphous halo, and the 100 and 020 peaks of P3HT reveals the development of the semicrystalline morphology of the donor through a partly-ordered phase. The experiments show the impact of the chemical structure of the acceptor, as well as that of the donor : acceptor ratio on the kinetics of drying and crystallization. The optimal bulk heterojunction morphology was achieved for P3HT : ICBA 1 : 1, which exhibited the highest value of current. A more efficient phase separation in non-annealed P3HT:ICBA films as compared to P3HT:PCBM was accounted for by the differences in solubility of the components in toluene. The structure formation during solvent evaporation can be subdivided into three stages, including the ordering of the polymer in solution, phase separation during precipitation, and the perfectioning of P3HT crystals in the dry film.

An "on-off" switchable cubic phase with exceptional thermal stability and water sorption capacity.

We report on the phase behaviour of a wedge-shaped mesogen, which can exist in two different states at room temperature, a stable columnar and a metastable cubic gyroid phase. The latter reveals exceptional stability and remarkable water sorption capacity accounted for by the locally-ordered peripheral alkyl chains.

N-methyl serotonin analogues from the Bufo bufo toad venom interact efficiently with the α7 nicotinic acetylcholine receptors.

Two low-molecular-weight compounds were isolated from the parotid gland secret of the toad Bufo bufo, which by absorption spectra and HPLC-MS/MS chromatography data correspond to di- and trimethyl derivatives of serotonin (5-hydorxytryptamine): bufotenine (confirmed by counter synthesis) and bufotenidine (5-HTQ). In experiments on competitive radioligand binding, these compounds showed a higher affinity and selectivity for neuronal α7 nicotinic acetylcholine receptors compared with the muscular cholinergic receptors. The most efficient compound in terms of binding value was bufotenine, the efficiency of 5-HTQ was an order of magnitude lower, and the minimal activity was exhibited by serotonin.

Humidity-induced formation of water channels in supramolecular assemblies of wedge-shaped amphiphiles: the effect of the molecular architecture on the channel topology.

In supramolecular assemblies, absorption of water can assist the channel formation, similarly to biological systems and Nafion-like commercial ion-selective membranes. In this work, we investigate humidity-induced formation of water channels in wedge-shaped amphiphilic molecules, namely sodium 4'-[3'',4'',5''-tris(alkyloxy)benzoyloxy]azobenzene-4-sulfonates. The studied molecules contain a polar sulfonate group at the tip and a hydrophobic periphery composed of alkyl chains of two different lengths. Upon increasing the relative humidity (RH) the amount of absorbed water significantly increases for the mesogen with dodecyl chains as compared to the one with octyl groups. In the former case, water sorption is accompanied by a considerable enhancement of ionic conductivity and a phase transition. In particular, an increase of RH induces a transition from a lamellar to a columnar phase resulting in the formation of 1D water channels running along the axis of the supramolecular columns. For the compound with shorter alkyl chains the lamellar phase exists in the entire RH-range exhibiting pronounced swelling at high RH-values and thereby forming a 2D water channel structure. NMR diffusometry was used to address the different molecular motions in the lyotropic mesophases of the studied amphiphiles.

Designing the topology of ion nano-channels in the mesophases of amphiphilic wedge-shaped molecules.

The wedge-shaped amphiphiles bearing sulfonate groups at the tip of the wedge are prone to form ion nano-channels upon exposure to a humid atmosphere. During swelling, water molecules preferentially accumulate in polar regions of the system resulting in the formation of a lyotropic phase. In this work, the details of the structure formation processes occurring upon swelling in water vapour, including determination of the size and topology of the ion nano-channels, are explored. The electron density profiles across the channel are obtained from the fits of the X-ray scattering data with two- and three-phase structural models the applicability of which is critically analysed. The results show that the ion channel size correlates not only with water uptake but also with the molecular architecture such as the structure of the rigid molecular fragment bearing a polar group. These findings can help optimising the ion transport for development of ion-selective membranes.

Fractional excitations in the square lattice quantum antiferromagnet.

Quantum magnets have occupied the fertile ground between many-body theory and low-temperature experiments on real materials since the early days of quantum mechanics. However, our understanding of even deceptively simple systems of interacting spins-1/2 is far from complete. The quantum square-lattice Heisenberg antiferromagnet (QSLHAF), for example, exhibits a striking anomaly of hitherto unknown origin in its magnetic excitation spectrum. This quantum effect manifests itself for excitations propagating with the specific wave vector (π, 0). We use polarized neutron spectroscopy to fully characterize the magnetic fluctuations in the metal-organic compound CFTD, a known realization of the QSLHAF model. Our experiments reveal an isotropic excitation continuum at the anomaly, which we analyse theoretically using Gutzwiller-projected trial wavefunctions. The excitation continuum is accounted for by the existence of spatially-extended pairs of fractional S=1/2 quasiparticles, 2D analogues of 1D spinons. Away from the anomalous wave vector, these fractional excitations are bound and form conventional magnons. Our results establish the existence of fractional quasiparticles in the high-energy spectrum of a quasi-two-dimensional antiferromagnet, even in the absence of frustration.

Structure formation and hydrogen bonding in all-aliphatic segmented copolymers with uniform hard segments.

Fully aliphatic segmented poly(ether ester amide) copolymers with uniform hard segments prepared by melt polycondensation of α,ω-hydroxyl end-functionalized polytetrahydrofuran and short glycine or ß-alanine bisester-bisoxalamide units hold promise for biomedical applications. For polymers with the hard block contents varying from 10% to 27%, differential scanning calorimetry and atomic force microscopy reveal a highly phase-separated morphology, with ribbon-like nanocrystals dispersed in the soft segment matrix. To relate the polymer properties to the structure of the hard segment, the monomers were prepared and studied by optical and X-ray diffraction measurements. It was shown that the glycine and ß-alanine carbonyl ester groups are tilted away from the oxalamide plane, which can affect the degradation rate via hydrolysis of the ester bond.

Superhydrophobic surfaces from various polypropylenes.

Superhydrophobic surfaces were prepared from solutions of isotactic polypropylenes of various molecular weights using soft chemistry. Varying the conditions of the experiments (polymer concentration and initial amount of the coated solution) allowed us to optimize the superhydrophobic behavior of the polymer film. Results show that decreasing the concentration and/or film thicknesses decreases the probability to get superhydrophobicity for all polypropylenes tested. Measurement and analysis of advancing and receding contact angles as well as estimation of surface homogeneity were performed. Similar results were obtained with syndio- as well as atactic polypropylenes.

Allowed charge transfers between coherent conductors driven by a time-dependent scatterer.

We derive constraints on the statistics of the charge transfer between two conductors in the model of arbitrary time-dependent instant scattering of noninteracting fermions at zero temperature. The constraints are formulated in terms of analytic properties of the generating function: its zeros must lie on the negative real axis. This result generalizes existing studies for scattering by a time-independent scatterer under time-dependent bias voltage.

[Estimation of the sweat composition of fatty acids].

Changes in the fatty acid composition of sweat lipid were studied in persons whose activity was associated with military service. There were significant changes in essential fatty acids of sweat lipids, which made it possible to use this noninvasive biological object as a criterion for rating dysadaptive processes in armed forces personnel.

Contact-line friction of liquid drops on self-assembled monolayers: chain-length effects.

The static and dynamic wetting properties of self-assembled alkanethiol monolayers of increasing chain length were studied. The molecular-kinetic theory of wetting was used to interpret the dynamic contact angle data and evaluate the contact-line friction on the microscopic scale. Although the surfaces had a similar static wettability, the coefficient of contact-line friction zeta0 increased linearly with alkyl chain length. This result supports the hypothesis of energy dissipation due to a local deformation of the nanometer-thick layer at the contact line.

Multiexponential decay autocorrelation function in dynamic light scattering in near-critical ternary liquid mixture.

The dynamic structure factor of a ternary liquid mixture is calculated from the theory of thermodynamic fluctuations with the help of linearized hydrodynamic equations. The theoretical model allows evaluating and classifying the transport properties near a critical solution point of a ternary mixture. In the vicinity of the critical solution point, experimental dynamic light scattering measurements reveal two hydrodynamic relaxation modes with well-separated characteristic relaxation times. From the autocorrelation functions, we can determine two effective diffusivities D(1) and D(2). As theoretically predicted by a model developed in this work, one of these two modes can be associated with thermal diffusion and the other with mass diffusion. In the special case of an incompressible liquid mixture limit, D(1) and D(2) are decoupled, becoming thermodiffusion coefficient D(T) and mutual mass diffusion coefficient D(ij). A possible physical meaning of D(1) and D(2) for a ternary mixture is discussed.

Exploring the melting of a semirigid-chain polymer with temperature-resolved small-angle X-ray scattering.

The thermal behavior of semirigid semicrystalline polymers differs significantly from that of flexible-chain polymers. The origin of the differences is believed to lie in the higher energy expenditure associated with the formation of adjacent re-entry folds at the crystalline surface in the case of semirigid chains. The effect of constraints imposed by the interlamellar amorphous regions on the neighboring crystals was studied with temperature-resolved synchrotron radiation small-angle X-ray scattering (SAXS). The analysis of SAXS patterns with a generalized paracrystalline lamellar stack model indicates that melting of a semirigid-chain polymer is not a random process but that the crystals grown in the smallest amorphous gaps melt first. This suggests that the hitherto largely neglected geometrical confinement effects may play an important role in determining the thermodynamic stability of semirigid-chain polymer crystals.

Non-Abelian statistics of half-quantum vortices in p-wave superconductors.

Excitation spectrum of a half-quantum vortex in a p-wave superconductor contains a zero-energy Majorana fermion. This results in a degeneracy of the ground state of the system of several vortices. From the properties of the solutions to Bogoliubov-de Gennes equations in the vortex core we derive the non-Abelian statistics of vortices identical to that for the Moore-Read (Pfaffian) quantum Hall state.

Discotic mesogens with potential electron carrier properties.

A new family of discotic liquid crystals, potentially electron carriers, has been synthesised, some members of which exhibit a particularly rich thermotropic behaviour.