Phase Transformations in MOFs Induced by Adsorbate Exchange.

Deformation of nanoporous materials induced by gas adsorption is a ubiquitous phenomenon that plays an important role in adsorption separations, gas and energy storage, nanosensors, actuators, secondary gas recovery, and carbon dioxide sequestration in coal and shale reservoirs. One of the most prominent examples is the breathing phase transformation in metal-organic frameworks (MOF) associated with significant volume variations upon adsorption and desorption of guest molecules. Here, we present a theoretical framework for the quantitative description of the breathing transitions upon adsorption of binary mixtures, drawing on the practically important example of the displacement of methane by carbon dioxide in the MIL-53 MOF.

Unveiling non-monotonic deformation of flexible MOFs during gas adsorption: From contraction and softening to expansion and hardening.

Flexibility of metal-organic frameworks (MOFs) plays an important role in their applications, particularly in adsorption separations, energy and gas storage, and drug delivery. As an important practical example, we study adsorption of CH, and CO on isoreticular MOF-1 (IRMOF-1) crystal at different temperatures using an original computational scheme of iterative grand canonical Monte Carlo (GCMC) and isothermal-isobaric ensemble molecular dynamics (NPT-MD) simulations. Our findings reveal that thermal fluctuations and flexibility of the host framework affect adsorption of guest molecules, which in turn exert a significant adsorption stress, up to 0.

Development and Application of an Advanced Percolation Model for Pore Network Characterization by Physical Adsorption.

Physical adsorption is one of the most widely used techniques to characterize porous materials because it is reliable and able to assess micro- and mesopores within one approach. Challenges and open questions persist in characterizing disordered and hierarchically structured porous materials. This study introduces a pore network model aimed at enhancing the textural characterization of nanoporous materials.

Understanding the origins of reversible and hysteretic pathways of adsorption phase transitions in metal-organic frameworks.

Phase behavior of nanoconfined fluids adsorbed in metal-organic frameworks is of paramount importance for the design of advanced materials for energy and gas storage, separations, electrochemical devices, sensors, and drug delivery, as well as for the pore structure characterization. Phase transformations in adsorbed fluids often involve long-lasting metastable states and hysteresis that has been well-documented in gas adsorption-desorption and nonwetting fluid intrusion-extrusion experiments. However, theoretical prediction of the observed nanophase behavior remains a challenging problem.

[Results of the first All-Russian consensus conference on bariatric surgery].

Until now, there has not been organized consensus for standardization in bariatric surgery In Russia. We present the results of the first Bariatric Surgery Consensus Conference conducted in Barnaul (March, 2023). A list of questions was proposed within 6 blocks: 1) general issues of bariatric surgery, 2) sleeve gastrectomy, 3) one-anastomosis gastric bypass («mini-gastric bypass»), 4) Roux-en-Y Gastric Bypass, 5) Single Anastomosis Duodenal Switch and other options for biliopancreatic bypass, 6) rare procedures.

Surface-Constrained Metropolis Monte Carlo: Simulation of Reactions on Triply Periodic Minimal Surfaces.

Triply periodic minimal surfaces (TPMS) inspired by nature serve as a foundation for developing novel nanomaterials, such as templated silicas, graphene sponges, and schwarzites, with customizable optical, poroelastic, adsorptive, catalytic, and other properties. Computer simulations of reactions on TPMS using reactive intermolecular potentials hold great promise for constructing and screening potential TPMS with the desired properties. Here, we developed an off-lattice, surface-constrained Metropolis Monte Carlo (SC-MMC) algorithm that utilized a temperature quench process.

Pore Structure Compartmentalization for Advanced Characterization of Metal-Organic Framework Materials.

Metal-organic frameworks (MOFs) are nanoporous crystals which are widely used as selective adsorbents, separation membranes, catalysts, gas and energy storage media, and drug delivery vehicles. The unique adsorption and transport properties of MOFs are determined by their complex three-dimensional (3D) networks of pores, cages, and channels that differ in size, shape, and chemical composition. While the morphological structure of MOF crystals is known, practical MOF materials are rarely ideal crystals.

[Onto-phylogenetic prerequisites for development of chronic cystitis in women].

Introduction: Urinary tract infections (UTIs) are among the most common bacterial infections. At the request "cystitis", there are 12,067 publications in the RSCI system (e.library) as of 10/08/2023 and 16,332 articles were screened in the Pubmed.

Young-IFSO Bariatric/Metabolic Surgery Training and Education Survey.

Background: This international Young-IFSO survey aims to address variations, trends, and obstacles in bariatric/metabolic surgery (BMS) training globally, since expectations and resources differ among young surgeons.

Methods: The Young-IFSO scientific team designed an online confidential questionnaire with 50 questions analyzing the individual BMS training. The survey link was sent to all IFSO/ASMBS members and was shared in social media.

[Chronic cystitis: how to prolong the relapse-free period?].

Introduction: Chronic cystitis predominates in the structure of urinary tract infections (UTIs). International guidelines are mainly focused on the treatment of acute uncomplicated cystitis; the approaches for managing patients with chronic cystitis has not been sufficiently developed.

Material And Methods: A total of 91 patients were included in prospective multicenter randomized comparative controlled study.

Adsorption of pulmonary and exogeneous surfactants on SARS-CoV-2 spike protein.

COVID-19 is transmitted by airborne particles containing virions of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Coronavirus virions represent nanoparticles enveloped by a lipid bilayer decorated by a "crown" of Spike protein protrusions. Virus transmission into the cells is induced by binding of Spike proteins with ACE2 receptors of alveolar epithelial cells.

Quasicontinuous Cooperative Adsorption Mechanism in Crystalline Nanoporous Materials.

The hase behavior of confined fluids adsorbed in nanopores differs significantly from their bulk counterparts and depends on the chemical and structural properties of the confining structures. In general, phase transitions in nanoconfined fluids are reflected in stepwise adsorption isotherms with a pronounced hysteresis. Here, we show experimental evidence and an interpretation of the reversible stepwise adsorption isotherm which is observed when methane is adsorbed in the rigid, crystalline metal-organic framework IRMOF-1 (MOF-5).

Adsorption of Pulmonary and Exogeneous Surfactants on SARS-CoV-2 Spike Protein.

COVID-19 is transmitted by inhaling SARS-CoV-2 virions, which are enveloped by a lipid bilayer decorated by a "crown" of Spike protein protrusions. In the respiratory tract, virions interact with surfactant films composed of phospholipids and cholesterol that coat lung airways. Here, we explore by using coarse-grained molecular dynamics simulations the physico-chemical mechanisms of surfactant adsorption on Spike proteins.

Interactions of Crosslinked Polyacrylic Acid Polyelectrolyte Gels with Nonionic and Ionic Surfactants.

The morphology and stability of surfactant-loaded polyelectrolyte gels are of great interest for a variety of personal care, cosmetic, and pharmaceutical products. However, the mechanisms of surfactant interactions with gel-forming polymers are poorly understood and experimentally challenging. The aim of this work is to explore the specifics of surfactant absorption within polyelectrolyte gels drawing on the examples of typical non-ionic octaethylene glycol monooctyl ether (CE) and anionic sodium dodecyl sulfate (SDS) surfactants and polyacrylic acid modified with hydrophobic sidechains mimicking the practically important Carbopol polymer.

Effect of sleeve gastrectomy, Roux-en-Y gastric bypass, and ileal transposition on myocardial ischaemia-reperfusion injury in non-obese non-diabetic rats.

Bariatric surgery (BS) improves outcomes in patients with myocardial infarction (MI). Here we tested the hypothesis that BS-mediated reduction in fatal MI could be attributed to its infarct-limiting effect. Wistar rats were randomized into five groups: control (CON), sham (SHAM), Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), and ileotransposition (IT).

Dissipative particle dynamics simulations in colloid and Interface science: a review.

Dissipative particle dynamics (DPD) is one of the most efficient mesoscale coarse-grained methodologies for modeling soft matter systems. Here, we comprehensively review the progress in theoretical formulations, parametrization strategies, and applications of DPD over the last two decades. DPD bridges the gap between the microscopic atomistic and macroscopic continuum length and time scales.

Effects of metal-polymer complexation on structure and transport properties of metal-substituted polyelectrolyte membranes.

Morphological and transport properties of hydrated metal-substituted Nafion membranes doped with metal ions of different valency and coordination strength are explored using coarse-grained dissipative particle dynamics simulations. To incorporate the effects of metal-polymer complexation, we introduce a novel metal ion complexation model, in which the charged central metal ion is surrounded by dummy sites that coordinate with ligands. The model parameters are determined by matching the metal-ligand running coordination numbers and the diffusion coefficients obtained from atomistic simulations and/or experiments.

Effects of three types of bariatric interventions on myocardial infarct size and vascular function in rats with type 2 diabetes mellitus.

Aims: The effects of three types of bariatric interventions on myocardial infarct size were tested in the rat model of type 2 diabetes mellitus (T2DM). We also evaluated the effects of bariatric surgery on no-reflow phenomenon and vascular dysfunction caused by T2DM.

Main Methods: Rats with T2DM were assigned into groups: without surgery, sham-operated, ileal transposition, Roux-en-Y gastric bypass, and sleeve gastrectomy.

Regulatory Action of Plasma from Patients with Obesity and Diabetes towards Muscle Cells Differentiation and Bioenergetics Revealed by the C2C12 Cell Model and MicroRNA Analysis.

Obesity and type 2 diabetes mellitus (T2DM) are often combined and pathologically affect many tissues due to changes in circulating bioactive molecules. In this work, we evaluated the effect of blood plasma from obese (OB) patients or from obese patients comorbid with diabetes (OBD) on skeletal muscle function and metabolic state. We employed the mouse myoblasts C2C12 differentiation model to test the regulatory effect of plasma exposure at several levels: (1) cell morphology; (2) functional activity of mitochondria; (3) expression levels of several mitochondria regulators, i.

Suspensions of lyophobic nanoporous particles as smart materials for energy absorption.

Hypothesis: Suspensions of nanoporous particles in non-wetting fluids (lyophobic nanoporous suspensions, LPNPS) are explored as energy absorbing materials for shock absorbers, bumpers, and energy storage. Upon application of pressure, the non-wetting fluid invades the pores transforming the impact energy into the interfacial energy that can be stored and released on demand.

Experiments: Here, we present a comprehensive experimental study of the dynamics of LPNPS compression within a wide range of shock impact energy for three types of mesoporous materials (Libersorb 23, Polysorb-1, and Silochrome-1.

Stability of Lipid Coatings on Nanoparticle-Decorated Surfaces.

Lipid membranes supported on solid surfaces and nanoparticles find multiple applications in industrial and biomedical technologies. Here, we explore the mechanisms of the interactions of lipid membranes with nanostructured surfaces with deposited nanoparticles and explain the characteristic particle size dependence of the uniformity and stability of lipid coatings observed . Simulations are performed to demonstrate the specifics of 1,2-dimyristoyl--glycero-3-phosphocholine (DMPC) lipid membrane adhesion to hydrophilic and hydrophobic nanoparticles ranging in size from 1.