812 results match your criteria: "Frumkin Institute of Physical chemistry and Electrochemistry[Affiliation]"

This study delves into the thermodynamics of liquid-phase adsorption on hypercrosslinked polystyrene networks (HPSNs), widely recognized for their distinct structure and properties. Despite the considerable progress in HPSN synthesis and characterization, gaps persist regarding the chromatographic retention mechanism, thermodynamics of adsorption, and their impact on the adsorption selectivity, especially in the case of networks with ultra-high crosslinking densities (up to 500%). Utilizing high-performance liquid chromatography (HPLC), we have explored, for the first time, the thermodynamic intricacies of liquid-phase adsorption onto HPSNs crosslinked in the entire range of the crosslinking degree from 100 to 500%.

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A method is proposed for the theoretical assessment of potential membrane properties in materials based on microphase-separated block copolymer films subjected to the etching of one of the components. The concepts of topological permeability and connectivity contrast introduced by the authors are used to compare the percolation characteristics of simple cubic, diamond, and diamond-like morphologies compatible with the slit geometry and specified by a given distribution of the order parameter. The diamond-like morphology, which has the most promising transport characteristics, can be formed in a thin film of diblock copolymer AB placed on a chemically structured substrate.

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In the title compound, CHNOS·CDOS, the central six-membered ring has a slightly distorted boat conformation, while the fused pyrrolidine ring adopts an envelope conformation. These conformations are stabilized by O-H⋯O hydrogen bonds between the main compound and solvent mol-ecules. In addition, intra-molecular C-H⋯O hydrogen bonds in the main mol-ecule form two (6) rings.

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The title compound, [RuCl(CHNO)], is an example of a new generation of ,-dialkyl ruthenium catalysts with an N-Ru coordination bond as part of a six-membered chelate ring. The Ru atom has an Addison τ parameter of 0.244, which indicates a geometry inter-mediate between square-based pyramidal and trigonal-bipyramidal.

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Article Synopsis
  • New two-dimensional (2D) models for heating, cooling, and evaporation of sessile droplets are introduced, improving upon previous one-dimensional (1D) models by considering the spatial distribution of heat.
  • The advanced 2D model uses COMSOL Multiphysics to numerically solve equations related to mass, momentum, vapor mass fraction, and energy, while the simpler models retain assumptions about droplet shape and do not account for factors like droplet deformation or the Marangoni effect.
  • Validation of the models against experimental data from distilled water droplets indicates that the simplest 1D model effectively predicts droplet radius changes, while the advanced 2D model aligns closely with observed temperature changes during evaporation.
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H-NMR spectroscopy of lanthanide complexes is a powerful tool for deriving spectral-structural correlations, which provide a clear link between the symmetry of the coordination environment of paramagnetic metal centers and their magnetic properties. In this work, we have first synthesized a series of homo- (M = M* = Dy) and heteronuclear (M ≠ M* = Dy/Y and Dy/Tb) triple-decker complexes , where BuO- and 15C5- are, respectively, butoxy and 15-crown-5 substituents on phthalocyanine (Pc) ligands. We provide an algorithmic approach to assigning the H-NMR spectra of these complexes and extracting the axial component of the magnetic susceptibility tensor, χax.

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Ionizing radiation-induced damage in cancer and normal cells leads to apoptosis and cell death, through the intracellular oxidative stress, DNA damage and disorders of their metabolism. Irradiation doses that do not lead to the death of tumor cells can result in the emergence of radioresistant clones of these cells due to the rearrangement of metabolism and the emergence of new mutations, including those in the genes responsible for DNA repair. The search for the substances capable of modulating the functioning of the tumor cell repair system is an urgent task.

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The nuclear export protein of the influenza A virus (NEP) is involved in many important processes of the virus life cycle. This makes it an attractive target for the treatment of a disease caused by a virus. Previously it has been shown, that recombinant variants of NEP are highly prone to aggregation in solution under various conditions with the formation of amyloid-like aggregates.

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Rapamycin functionalized carbon Dots: Target-oriented synthesis and suppression of vascular cell senescence.

J Colloid Interface Sci

April 2024

Institute for Advanced Ceramics, State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150001, PR China; Laboratory of Dynamics and Extreme Characteristics of Promising Nanostructured Materials, Saint Petersburg State University, St. Petersburg, 199034, Russia. Electronic address:

Suppression of vascular cell senescence is of great significance in preventing cardiovascular diseases such as hypertension and atherosclerosis. The oxidative stress damage caused by reactive oxygen species (ROS) can lead to cellular senescence. Rapamycin (Rapa) is well known to suppress cell senescence via mammalian target of rapamycin (mTOR) pathway.

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This paper presents data on the macroscopic polarization of copolymer films of vinylidene fluoride with tetrafluoroethylene obtained with a modified apparatus assembled according to the Sawyer-Tower Circuit. The kinetics of the polarization process were analyzed taking into consideration the contributions of both bound and quasi-free (impurity) charges. It was shown that an "abnormal" decrease in conductivity was observed in fields near the coercive fields.

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The global spread of multidrug-resistant (MDR) hospital-acquired pathogens is a serious problem for healthcare units. The challenge of the spreading of nosocomial infections, also known as hospital-acquired pathogens, including Pseudomonas aeruginosa, must be addressed not only by developing effective drugs, but also by improving preventive measures in hospitals, such as passive bactericidal coatings deposited onto the touch surfaces. In this paper, we studied the antibacterial activity of superhydrophilic and superhydrophobic copper surfaces against the strain PA103 and its four different polyresistant clinical isolates with MDR.

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LnCl(THF) (Ln = Y, La ÷ Nd, Sm ÷ Lu) readily react with the tridentate 1,3,5-trimethyl-1,3,5-triazacyclohexane (Metach) ligand to form mono- or binuclear lanthanide trichloride complexes, depending on the stoichiometry of the reaction and the ionic radius of the metal: mononuclear pseudosandwich [LnCl(Metach)], (Ln = Y, La ÷ Ho) or binuclear complexes [LnCl(Metach)], or [LnCl(Metach)(THF)] (Ln = Sm, Tb). Detailed analysis of the NMR data of [LnCl(Metach)] complexes with paramagnetic lanthanide ions showed that their structures remained unchanged in the toluene solution. A series of isomorphous complexes [LnCl(Metach)(Py)] (Ln = La, Sm, Tb, Er, Lu; Py = pyridine) have been obtained by the recrystallization of either mononuclear or binuclear complexes from pyridine.

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Fungi and plants are not only capable of synthesizing the entire spectrum of lipids de novo but also possess a well-developed system that allows them to assimilate exogenous lipids. However, the role of structure in the ability of lipids to be absorbed and metabolized has not yet been characterized in detail. In the present work, targeted lipidomics of phosphatidylcholines (PCs) and phosphatidylethanolamines (PEs), in parallel with morphological phenotyping, allowed for the identification of differences in the effects of PC molecular species introduced into the growth medium, in particular, typical bacterial saturated (14:0/14:0, 16:0/16:0), monounsaturated (16:0/18:1), and typical for fungi and plants polyunsaturated (16:0/18:2, 18:2/18:2) species, on .

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Phase equilibria, interdiffusion and structure in the initial uncured mixtures of epoxy oligomer-polysulfone-alkyl glycidyl ether were studied. Binodal curves were constructed on isothermal sections of the ternary phase diagram. Thermodynamic mixing parameters were calculated and spinodal curves were plotted.

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From the examples of three and four-component polymer-polymer systems characterized by amorphous separation, an original technique for determining the pair parameters of interaction between components based on the sorption isotherms of common solvent vapor, particularly water vapor, has been developed. The possibility of calculating thermodynamic characteristics of multicomponent polymer compositions with specific interactions of functional groups from experimentally obtained sorption isotherms is shown. An algorithm for calculating pair interaction parameters, estimating concentration dependences of chemical potential and Gibbs free energy of mixing, and predicting the phase state of polymer mixtures was presented for the first time for such systems.

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Biomolecular corona is the major obstacle to the clinical translation of nanomedicines. Since corona formation is governed by molecular interactions at the nano-bio interface, nanoparticle surface properties such as topography, charge and surface chemistry can be tuned to manipulate biomolecular corona formation. To this end, as the first step towards a deep understanding of the processes of corona formation, it is necessary to develop nanoparticles employing various biocompatible materials and characterize their surface structure and dynamics at the molecular level.

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The absorption of water by slippery coatings is a ubiquitous phenomenon that arises due to small but finite water dissolution during the contact of aqueous media with lubricants. In this study, using the concept of surface forces, we have analyzed the influence of trace amounts of water in lubricants on the stability of slippery coatings for both coatings with hydrophilic porous bases, prone to form hydrogen bonds with water, and those with hydrophobic porous bases. To perform such analysis, we have considered for the first time the electrostatic problem of the distribution of the electric potential and electric field strength in stratified films that contain two thin dielectric layers imitating the lubricant and a hydrophobic layer sandwiched between the porous substrate and air or water.

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The paper presents the results of the synthesis, a detailed kinetics study, and an investigation of the biological activity of silver nanoparticles (AgNPs) in aqueous solutions of N-reacetylated oligochitosan hydrochloride. UV-visible spectrophotometry and dynamic light scattering were employed to control silver ion reduction. The process was observed to follow a pseudo-first-order law.

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The creation of antibacterial nanocomposites that provide prolonged release of encapsulated drugs is of great interest for various fields of medicine (dentistry, tissue regeneration, etc.). This article demonstrates the possibility of creating such nanocomposites based on sodium alginate and drug-templated mesoporous silica nanocontainers (MSNs) loaded with two bioactive substances.

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Thickness of lipid bilayer membranes is a key physical parameter determining membrane permeability and stability with respect to formation of through pores. Most membrane inclusions or impurities like amphipathic peptides, transmembrane peptides, lipid inclusions of a different molecular shape, lipid domains, and protein-lipid domains, locally deform the membrane. The detailed structure of the locally deformed region of the membrane is a kind of "fingerprint" for the inclusion type.

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Textiles and nonwovens (including those used in ventilation systems as filters) are currently one of the main sources of patient cross-infection. Healthcare-associated infections (HAIs) affect 5-10% of patients and stand as the tenth leading cause of death. Therefore, the development of new methods for creating functional nanostructured coatings with antibacterial and antiviral properties on the surfaces of textiles and nonwoven materials is crucial for modern medicine.

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Cyclic trinuclear Ag(I) pyrazolate interacts with phenylacetylene forming a mix-ligand complex in which one pyrazolate ligand is changed to phenylethynide. The CC fragment coordinates only to two silver(I) atoms one carbon atom demonstrating unique μ-η σ-coordination with close Ag-C bond lengths and Ag-C-C angles. The complex exhibits blue emission under UV irradiation.

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A series of easy-to-prepare and modular chiral ,-bidentate phosphoramidites were synthesized. With respect to Pd(II), these ligands showed the ability to form stable ,-chelate allylic complexes. The structures of the ligands and their complexes were confirmed by 2D NMR spectroscopy and single-crystal X-ray diffraction.

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Herein, neptunium(V) carbonates containing sodium or potassium cations were synthesized via chemical precipitation. Various techniques such as scanning electron microscopy, energy-dispersive X-ray spectroscopy, thermogravimetry combined with differential scanning calorimetry, X-ray diffraction, and X-ray absorption spectroscopy were used to analyze the microstructures and elemental compositions of these samples. The crystal structures of hydrated NaNpOCO·3HO (1, = 4.

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Dispersion forces start to play role in modern micro/nanoelectromechanical devices, but the methods to measure these forces at distances close to contact (<50 nm) suffer from pull-in instability. The method of adhered cantilever proposed recently has no instability and is able to make measurements at short separations. To measure the force at the average distance between surfaces in contact, one has to know the shape of an elastic beam with one end fixed at a height of 1-10 μm and the other end adhered to the substrate.

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