Hailey-Hailey disease successfully treated with photodynamic therapy: Case report.

Hailey-Hailey disease (HHD) is a rare genetic benign condition resulting in blisters predominantly on the skin folds. The inheritance is autosomal dominant with complete penetrance, but a variable expressivity in affected family members. It can be triggered by a vast variety of factors such as sweating, weight gain, infection, trauma, pregnancy, and ultraviolet radiation, but the major cause of the disease is a mutation in the ATP2C1 gene. The lesions are typically distributed symmetrically within intertriginous regions such as the retroarticular folds, axillae, inguinal, and perianal regions and presents as flaccid vesicles and blisters on erythematous skin, giving rise to erosions, fissures, and vegetations. There is no specific therapy for HHD. The therapeutic approach to HHD involves the control of exacerbating factors, secondary infections, and cutaneous inflammation. Because of the rarity of the disease, evidence of efficacy for topical or systemic therapies is mainly based on small observational studies, case reports, and clinical experience. We present a case of HHD successfully treated by photodynamic therapy (PDT) with a topical liposomal chlorin photosensitizer.

A molecular dynamics study of the nonlinear spectra and structure of charged (101) quartz/water interfaces.

The relationship between the nonlinear spectra and the structure of charged (101) α-quartz/water interfaces was investigated by classical molecular dynamics simulations. The results of the simulations show that the layered organization of interfacial water is only slightly perturbed by the surface charge and the ionic strength of the aqueous phase. Molecules next to the surface, in a bonded interfacial layer (BIL), tend to direct one of their OH bonds towards the surface, while the water orientation further from the surface, in a diffuse layer (DL), is essentially isotropic. A Stern layer of solvated cations is built up already on a neutral surface and the deprotonation of silanols leads to the formation of an inner Helmholtz plane of cations directly interacting with the SiO- surface sites. A flip of the molecular orientation in the DL could be inferred from the analysis of the structural characteristics of concentrated NaCl solution in contact with a highly charged surface. The computed spectra of χ(2) susceptibility show a double band structure typical of the spectra of silica/water interfaces and the calculations reproduce the experimentally observed variation of the spectral intensity with the pH of the liquid phase. The analysis of results suggests that the behaviour stems from the interplay between the orientational and induced components of the χ(2) susceptibility of the BIL and DL. The dependence of the Im[χ(2)] spectra of the BIL on the surface charge yields the spectrum of H2O molecules directly interacting with SiO- sites. The spectrum is in excellent agreement with the experimental spectrum of the topmost water of a silica/water interface [Urashima et al., J. Phys. Chem. Lett., 2018, 9, 4109].

Hypercapnic hypoxia improves cognitive and motor functions of children with cerebral palsy.

A randomized, triple-blind, placebo-controlled trial involving 42 patients between 3 and 7 years of age with spastic cerebral palsy was performed. For the treatment test group (n=22), daily respiratory exercises with hypercapnic hypoxia were performed using a Carbonic training apparatus for 20 minutes per day; a total of 14 to 16 sessions were performed. Before the start of the study and the day after training was completed, the patients underwent neurological and neurophysiological examinations (electroencephalography, magnetic stimulation of the pyramidal tract, and cognitive potentials Р300).The evoked potentials showed a decrease in the peak latency of the P3 component of the test group after treatment (302 ms) that was more pronounced than that of the placebo group (305 ms; p<0.05). Magnetic stimulation showed that hypercapnic hypoxic training resulted in reductions in central motor conduction time by 2.2 to 2.5 ms (p<0.05) and in the excitation threshold of the motor cortex by 12% to 16% (р<0.01) depending on the lateralization; The strategy of adjusting to hypercapnic hypoxia, either unfavorable (hyperventilation and avoidance) or favorable (homeostatic with the achievement of preset values for hypercapnia and hypoxia), did not change during the process of training in the placebo group; however, it shifted considerably toward favorable (from 33% to 57%; р<0.05) in the test group.Respiratory training with hypercapnic hypoxia can have a positive impact on the functional state of the nervous system of children with cerebral palsy and can be considered a method of improving the efficiency of standard therapy.

Structure and sum-frequency generation spectra of water on neutral hydroxylated silica surfaces.

Structural organization and vibrational sum-frequency generation (VSFG) spectra of water on crystalline and amorphous neutral silica surfaces were investigated by classical molecular dynamics simulations. The liquid phase represented with neat water and 1 M NaCl solution was analysed in terms of bonded interfacial layer (BIL), diffuse layer (DL) and bulk region. The simulations show that the structure of BIL depends on the surface morphology and density of surface OH groups. The water-silanol H-bond network and BIL structure are mainly insensitive to the presence of ions in the liquid phase. Molecules in DL of SiO2/neat water interfaces preferentially orient their OH bonds towards the surfaces. This effect is directly related to an effective negative charge of formally neutral surfaces. Ions of the electrolyte solution affect the intermolecular structure in DL by screening the surface electric field and by the chaotropic effect. Calculated phase-sensitive VSFG (Im[χ(2)]) spectrum of BIL features low-frequency negative and high-frequency positive bands. Characteristics of the positive band reflect the strength of water-surface interactions and surface crystallinity, while the position and shape of the negative band are common to all interfaces. The Im[χ(2)] spectrum of DL is dominated by a contribution from the third-order χ(3) susceptibility with the sign of the contribution directly related to the sign of electrostatic potential in the interfacial region. The DL spectrum is strongly affected by the presence of solvated ions. The computed intensity and Im[χ(2)] spectra of the amorphous silica/NaCl solution interface are in a good agreement with the conventional and phase-sensitive experimental VSFG spectra of fused SiO2/water system at low pH, in contrast to the spectra of the amorphous silica/neat water interface. Origins of the discrepancy are discussed.

Hot electron energy relaxation time in vanadium nitride superconducting film structures under THz and IR radiation.

The paper presents the experimental results of studying the dynamics of electron energy relaxation in structures made of thin (d ≈ 6 nm) disordered superconducting vanadium nitride (VN) films converted to a resistive state by high-frequency radiation and transport current. Under conditions of quasi-equilibrium superconductivity and temperature range close to critical (~ Tc), a direct measurement of the energy relaxation time of electrons by the beats method arising from two monochromatic sources with close frequencies radiation in sub-THz region (ω ≈ 0.140 THz) and sources in the IR region (ω ≈ 193 THz) was conducted. The measured time of energy relaxation of electrons in the studied VN structures upon heating of THz and IR radiation completely coincided and amounted to (2.6-2.7) ns. The studied response of VN structures to IR (ω ≈ 193 THz) picosecond laser pulses also allowed us to estimate the energy relaxation time in VN structures, which was ~ 2.8 ns and is in good agreement with the result obtained by the mixing method. Also, we present the experimentally measured volt-watt responsivity (S~) within the frequency range ω ≈ (0.3-6) THz VN HEB detector. The estimated values of noise equivalent power (NEP) for VN HEB and its minimum energy level (δE) reached NEP@1MHz ≈ 6.3 × 10-14 W/√Hz and δE ≈ 8.1 × 10-18 J, respectively.

Structure and sum-frequency generation spectra of water on uncharged Q4 silica surfaces: a molecular dynamics study.

The structural characteristics and sum-frequency generation (SFG) spectra of water near neutral Q4 silica surfaces were investigated by molecular dynamics simulations. The interactions of water molecules with atoms of the solid were described by different potential models, in particular by the CLAYFF [Cygan et al., J. Phys. Chem. B, 2004, 108, 1255] and INTERFACE [Heinz et al. Langmuir, 2013, 29, 1754] force fields. The calculations of the contact angle of water have shown that the silica surface modeled with CLAYFF behaves as macroscopically hydrophilic, in contrast to the surface described with the INTERFACE model. The hydrophilicity of CLAYFF stems from too attractive electrostatic surface-water interactions. Regardless of the surface's affinity for water, the aqueous phase has a layered structure in the direction perpendicular to the surface with density fluctuations decaying within a distance of 10 Å from the surface. The orientational ordering of H2O molecules was found to be more short-range than the density fluctuations, especially for the hydrophobic surfaces. Modeling the SFG spectra has shown that the spectra of all studied hydrophobic silica-water interfaces are similar and have features in common with the spectrum of the water-vapor interface. The spectra fairly agree with experimental results obtained for the silica-water interface at low pH conditions [Myalitsin et al., J. Phys. Chem. C, 2016, 120, 9357]. The spectral response for the hydrophobic interface was computed to primarily arise from the topmost molecules of the first layer of interfacial water. In contrast, the SFG signal from the hydrophilic silica-water interface is accumulated over a greater distance extending for several water layers due to more long-range perturbation of the structure by the surface.

A Spectroscopic Study of Tautomeric Equilibrium of Salicylideneaniline in ZSM-5 Zeolites.

Salicylideneaniline (SA) sorbed in cation-exchanged M-ZSM-5 (M = H⁺, Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺ and Zn2+) zeolites was studied by spectroscopic techniques assisted by quantum-chemical calculations. The nature of extra-framework cations present in the zeolite void was found to affect the spectral signature of the sorbed SA molecule that points to the shift of tautomeric equilibrium between the enol and keto forms. Small size cations, such as H⁺ and Li⁺, stabilize a cis-keto SA tautomer along with a enol one in the zeolite structure. The calculations indicate that the sorbed cis-keto tautomer may have the dipole large enough to be considered as a zwitterion. New features appearing in the spectra with the increase of the cation size were attributed to the presence of trans-keto SA tautomer, which up to now has been observed only in time-resolved spectroscopic experiments. A strong interaction of the molecule with cations in Zn-ZSM-5 zeolite results in the chelation of enol SA with the divalent Zn2+ ions. The results of the study suggest that the tautomeric equilibrium of molecules belonging to the Schiff base family can be tuned by the confinement in the nanoporous materials via a choice of topology of zeolite framework and the nature of extra-framework cations.

Single photon detection system for visible and infrared spectrum range.

We demonstrate niobium nitride based superconducting single-photon detectors sensitive in the spectral range 452-2300 nm. The system performance was tested in a real-life experiment with correlated photons generated by means of spontaneous parametric downconversion, where one photon was in the visible range and the other was in the infrared range. We measured a signal to noise ratio as high as 4×104 in our detection setting. A photon detection efficiency as high as 64% at 1550 nm and 15% at 2300 nm was observed.

Unraveling the Structure-Raman Spectra Relationships in V2O5 Polymorphs via a Comprehensive Experimental and DFT Study.

Vanadium pentoxide polymorphs (α-, ß-, γ'-, and ε'-V2O5) have been studied using the Raman spectroscopy and quantum-chemical calculations based on density functional theory. All crystal structures have been optimized by minimizing the total energy with respect to the lattice parameters and the positions of atoms in the unit cell. The structural optimization has been followed by the analysis of the phonon states in the Γ-point of the Brillouin zone, and the analysis has been completed by the computation of the Raman scattering intensities of the vibrational modes of the structures. The optimized structural characteristics compare well with the experimental data, and the calculated Raman spectra match the experimental ones remarkably well. With the good agreement between the spectra, a reliable assignment of the observed Raman peaks to the vibrations of specific structurals units in the V2O5 lattices is proposed. The obtained results support the viewpoint on the layered structure of vanadium pentoxide polymorphs as an ensemble of V2O5 chains held together by weaker interchain and interlayer interactions. Similarities and distinctions in the Raman spectra of the polymorphs have been highlighted, and the analysis of the experimental and computational data allows us, for the first time, to put forward spectrum-structure correlations for the four V2O5 structures. These findings are of the utmost importance for an efficient use of Raman spectroscopy to probe the changes at the atomic scale in the V2O5-based materials under electrochemical operation.

A modeling study of methane hydrate decomposition in contact with the external surface of zeolites.

The behavior of methane hydrate (MH) enclosed between the (010) surfaces of the silicalite-1 zeolite was studied by means of molecular dynamics simulations at temperatures of 150 and 250 K. Calculations reveal that the interaction with the hydrophilic surface OH groups destabilizes the clathrate structure of hydrate. While MH mostly conserves the structure in the simulation at the low temperature, thermal motion at the high temperature breaks the fragilized cages of H-bonded water molecules, thus leading to the release of methane. The dissociation proceeds in a layer-by-layer manner starting from the outer parts of the MH slab until complete hydrate decomposition. The released CH4 molecules are absorbed by the microporous solid, whereas water is retained at the surfaces of hydrophobic silicalite and forms a meniscus in the interlayer space. Methane uptake reaches 70% of the silicalite sorption capacity. The energy necessary for the endothermic MH dissociation is supplied by the exothermic methane absorption by the zeolite.

Anion exchangers with negatively charged functionalities in hyperbranched ion-exchange layers for ion chromatography.

Novel pellicular poly(styrene-divinylbenzene)-based (PS-DVB) anion exchangers with covalently-bonded hyperbranched functional ion-exchange layers containing negatively charged functionalities are obtained and examined. The hyperbranched coating is created on the surface of aminated PS-DVB substrate by repeating the modification cycles including alkylation with 1,4-butanediol diglycidyl ether (1,4-BDDGE), and amination of the terminal epoxide rings with methylamine (MA) or glycine (Gly). The influence of the position and the number of the layers with glycine, as well as of the total number of the layers of amine in the coating on the chromatographic properties of the obtained stationary phases is investigated. Chromatographic performance of the obtained stationary phases is evaluated using the model mixtures of inorganic and organic anions with hydroxide eluent. It is shown that the best selectivity toward weakly retained organic acids and oxyhalides is possessed by the anion exchanger obtained after 5 modification cycles, with glycine being used in the first one. Such anion exchanger packed in 25-cm long column is capable of separating 22 anions in 58min including 7 standard anions, mono-, di- and trivalent organic acids, oxyhalides, and some other double- and triple-charged anions.

A molecular dynamics study of the interaction of water with the external surface of silicalite-1.

The interaction of water with the hydroxylated (010) surface of silicalite-1 was studied by classical molecular dynamics simulations. Interatomic interactions in the system were described using a set of effective potentials combining well-tested BKS and SPC models. The extended force field is shown to correctly reproduce the structural, energy, and dynamical characteristics of the silica surface OH groups. The interaction of water with the hydrophilic silanols leads to an ordering of H2O molecules in the vicinity of the surface. The ordering is found to be limited to two molecular layers extending to 7 Å above the surface. Despite the hydrophobic nature of the silicalite structure and the presence of hydrophilic surface sites, water molecules are capable of penetrating the porous silicalite system, where they form an H-bonded network blocking further access to the bulk. Water uptake by the zeolite was computed to be small in the time-scale of the simulations. The vibrational dynamics of the surface OH groups and adsorbed water molecules is discussed in detail. In agreement with the results of spectroscopic experiments, water molecules in the ordered surface layer have a spectral signature different from that of molecules more distant from the surface.

An improved back-flush-to-vent gas chromatographic method for determination of trace permanent gases and carbon dioxide in ultra-high purity ammonia.

A novel method for rapid, quantitative determination of trace permanent gases and carbon dioxide in ultra-high purity ammonia by dual-channel two-dimensional GC-PDHID is presented. An improved matrix back-flush-to-vent approach combining back-flush column switching technique with auxiliary NaHSO4 ammonia trap is described. The NaHSO4 trap prevents traces of ammonia from entering the analytical column and is shown not to affect the impurity content of the sample. The approach allows shortening the analysis time and increasing the amount of measurements without extensive maintenance of the GC-system. The performance of the configuration has been evaluated utilizing ammonia- and helium-based calibration standards. The method has been applied for the analysis of 99.9999+% ammonia purified by high-pressure distillation at the production site.

Effect of resonance dipole-dipole interaction on spectra of adsorbed SF6 molecules.

Adsorption of SF6 on zinc oxide and on silicalite-1 was investigated by a combination of IR spectroscopy with the calculations of spectra by means of a modernized model, developed previously for liquids. Comparison of the experimental spectra and the results of modeling shows that the complex band shapes in spectra of adsorbed molecules with extremely high absorbance are due to the strong resonance dipole-dipole interaction (RDDI) rather that the surface heterogeneity or the presence of specific surface sites. Perfect agreement between calculated and observed spectra was found for ZnO, while some dissimilarity in band intensities for silicalite-1 was attributed to complicated geometry of molecular arrangement in the channels.

Transverse dispersion in ordered pillar arrays as a Markov chain: extension of the Galton-board model.

An extension of the Galton-board model of the transverse solute dispersion in laminar flow through ordered arrays of non-porous cylindrical pillars was proposed. In contrast to the original model, which describes the dispersion process as a one-dimensional random walk with independent, equally probable steps, the extended model treats the process as a Markov chain, namely as a random walk with such correlated steps that the velocity-dependent probability to make a step in the same direction as the preceding step is smaller than the probability to reverse the direction of motion. The relationship between the average squared transverse displacement of the solute and the number of steps in the chain was used to find the expression for the velocity dependence of the transverse dispersion coefficient. The obtained equation differs from the one in the Galton-board model by the multiplier that accounts for the leveling-off of the experimental dependences at high reduced velocities. Although this modified Galton-board model cannot be directly applied to low velocities, a few additional assumptions lead to the expression that fits the whole range of the recent simulated dispersion data well.

Vibrational dynamics of the salicylideneaniline molecule in the solid phase and the confined state.

The salicylideneaniline (SA) molecule, both in the solid phase and sorbed in silicalite-1 zeolite, was studied by a large palette of vibrational spectroscopic methods (INS, Raman, and infrared) and by computational techniques. The comparison of the experimental and calculated spectra unambiguously indicates that the molecule is present in the cis-enol form in both phases. The results of the study allowed the proposal of a complete assignment of the vibrational spectrum of the SA molecule. The analysis of peak positions in the Raman and INS spectra of the molecule in the solid and sorbed states, and of the corresponding vibrational modes, shows that the confinement by the zeolite mostly affects those modes whose vibrational amplitude is localized on atoms of the phenol ring. This finding suggests that the molecule sits in the zeolite void such that the phenol ring is affected by the sorption to a greater extent than the benzene one. This assumption is corroborated by results of molecular modeling that shows the most energetically preferred position of the molecule in the straight channel of the zeolite framework with the phenol ring lying between two channel intersections, whereas the benzene ring is situated in the intersection.

Structure-dependent interatomic dispersion coefficients in oxides with maximally localized Wannier functions.

The interatomic C(6) dispersion coefficients in crystalline and amorphous SiO(2) and ZrO(2) structures were obtained with the approach proposed by Silvestrelli (2008 Phys. Rev. Lett. 100 053002) and based on the use of maximally localized Wannier functions (MLWFs) for partitioning the electron density. Localization of Wannier functions close to the nuclei in oxide systems makes it possible to assign the MLWFs to the atoms in an unambiguous way and then to compute the C(6) coefficients in an atom pairwise manner. A modification of the method is suggested in which the MLWFs are condensed to effective orbitals centred on the atoms and parameters of these effective orbitals are used for computing the interatomic dispersion coefficients. The obtained values of the dispersion coefficients were found to vary not only from one oxide to another, but also between different modifications of the same compound. The oxygen-oxygen coefficient C6(OO) reveals the largest variation and its value in ZrO(2) structures is twice as large as that in SiO(2) ones. Atomic characteristics obtained in the frame of the effective orbital method, such as the self-atom dispersion coefficient, and the oxide ion polarizability were found to correlate with the metal-oxygen bond length and the oxygen coordination number in the systems. This behaviour is attributed to the confinement of electrons by the electrostatic potential. The values of the coefficient and of the polarizability were related to charges of the oxygen atoms. In all studied systems the oxygen atoms having larger absolute values of charge were found to be less polarizable because of a stronger confinement effect. The obtained results can be used in the development of polarizable force fields for the atomistic modelling of oxide materials.

Effect of monomer mixture composition on structure and chromatographic properties of poly(divinylbenzene-co-ethylvinylbenzene-co-2-hydroxyethyl methacrylate) monolithic rod columns for separation of small molecules.

Porous poly(divinylbenzene-co-ethylvinylbenzene-co-2-hydroxyethyl methacrylate) monoliths were synthesized via thermally initiated free-radical polymerization in confines of surface-vinylized glass columns (150 mm × 3 mm i.d.) and applied to the reversed-phase separation of low-molecular-weight aromatic compounds. In order to compensate for the polymer shrinkage during the synthesis and prevent the monolith from detachment from the column wall, polymerization was conducted under nitrogen pressure. The reaction proceeded at 60°C for 22 h. 2,2'-Azo-bis-isobutironitrile was used as the initiator and 1-dodecanol was used as the porogen. A series of monoliths with different monomer ratios were obtained. All the monoliths had high specific surface areas ranging from 370 to 490 m(2)/g. In the studied range of monomer mixture compositions, the mechanical stability of the stationary phase in water/acetonitrile eluents was found to be high enough and practically insensitive to the fraction of 2-hydroxyethyl methacrylate (HEMA). Increasing the molar fraction of HEMA from 10.5% to 14.7% resulted in the decrease of column permeability by two orders of magnitude (from 1.1×10(-12) to 1.8×10(-14) m(2)) and led to weaker retention of alkylbenzenes. The higher HEMA content was shown to reduce the plate height of the columns in the separation of small molecules from 160-490 µm to 40-76 µm. This was attributed mainly to the decrease of the domain size of the monoliths leading to lower eddy dispersion and mass transfer resistance in the column.

Water behaviour in nanoporous aluminosilicates.

This paper briefly reviews results of molecular dynamics simulation studies of water confined in nanoporous aluminosilicates. The behaviour of confined molecules is shown to be influenced by the nature of the host structure, and the size and the topology of the voids. For some of the systems discussed the ambiguity in results of different modelling studies call for the use of extended potential and structural models. Thus, the use of polarizable force fields was shown to be necessary to take into account the variation of the molecular dipole of confined molecules in different environments.

Electro-Optical Parameters for Computation of Nonresonance Raman Scattering Intensities of Peptides.

A set of electro-optical parameters (EOPs) of cylindrical zero-order bond polarizability model (BPM) for chemical bonds found in peptides was obtained from the results of quantum-chemical computations. The calculation of the polarizability tensors and the Raman scattering activities of four test molecules (N-methylacetamide, N,N-dimethylacetamide, dialanine, and diglycine) has shown that the BPM calculated quantities are in good agreement with the reference data obtained in experiments or derived by quantum-chemical calculations. The mean molecular polarizabilities are reproduced with the maximum relative error of 1.6%. A good agreement was obtained for the Raman activity of stretching vibrations, whereas a limited performance of the EOPs was found for the vibrational modes with a significant contribution of the bending internal coordinates involving H atoms. The origins of the discrepancies are analyzed, and the ways of improvement of the model performance are discussed.