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In order to create new biodegradable nanocomposites for biomedicine, packaging, and environmentally effective adsorbents, ultra-thin composite fibers consisting of poly(3-hydroxybutyrate) (PHB) and graphene oxide (GO) were obtained by electrospinning. Comprehensive studies of ultrathin fibers combining thermal characteristics, dynamic electron paramagnetic resonance (ESR) probe measurements, and scanning electron microscopy (SEM) were carried out. It is shown that at the addition of 0.05, 0.1, 0.3, and 1% OG, the morphology and geometry of the fibers and their thermal and dynamic characteristics depend on the composite content. The features of the crystalline and amorphous structure of the PHB fibers were investigated by the ESR and DSC methods. For all compositions of PHB/GO, a nonlinear dependence of the correlation time of molecular mobility TEMPO probe (τ) and enthalpy of biopolyether melting (ΔH) is observed. The influence of external factors on the structural-dynamic properties of the composite fiber, such as hydrothermal exposure of samples in aqueous medium at 70 °C and ozonolysis, leads to extreme dependencies of τ and ΔH, which reflect two processes affecting the structure in opposite ways. The plasticizing effect of water leads to thermal destruction of the orientation of the pass-through chains in the amorphous regions of PHB and a subsequent decrease in the crystalline phase, and the aggregation of GO nanoplates into associates, reducing the number of GO-macromolecule contacts, thus increasing segmental mobility, as confirmed by decreasing τ values. The obtained PHB/GO fibrillar composites should find application in the future for the creation of new therapeutic and packaging systems with improved biocompatibility and high-barrier properties.

The article examines the regularities of structure formation of ultrafine fibers based on poly-3-hydroxybutyrat under the influence of technological (electrical conductivity, viscosity), molecular (molecular weight), and external factors (low-molecular and nanodispersed substances of different chemical natures). Systems with polar substances are characterized by the presence of intermolecular interactions and the formation of a more perfect crystalline fiber structure. Changes in technological and molecular characteristics affect the fiber formation process, resulting in alterations in the morphology of the nonwoven fabric, fiber geometry, and supramolecular fiber structure. Polymer molecular weight, electrical conductivity, and solution viscosity influence fiber formation and fiber diameter. The fiber structure is heterogeneous, consisting of both crystalline and non-equilibrium amorphous phases. This article shows that with an increase in the molecular weight and concentration of the polymer, the diameter of the fiber increases. At the same time, the increase in the productivity of the electrospinning process does not affect the fiber geometry. The chemical structure of the solvent and the concentration of polar substances play a decisive role in the formation of fibers of even geometry. As the polarity of the solvent increases, the intermolecular interaction with the polar groups of poly-3-hydroxybutyrate increases. As a result of this interaction, the crystallites are improved, and the amorphous phase of the polymer is compacted. The action of polar molecules on the polymer is similar to the action of polar nanoparticles. They increase crystallinity via a nucleation mechanism. This is significant in the development of matrix-fibrillar systems for drug delivery, bioactive substances, antiseptics, tissue engineering constructs, tissue engineering scaffolds, artificial biodegradable implants, sorbents, and other applications.

Abstract Tumor inflammation is prognostically significant in high-grade muscle-invasive bladder cancer (MIBC). However, the underlying mechanisms remain elusive. To identify inflammation-associated immune gene expression patterns, we performed transcriptomic profiling of 40 MIBC archival tumors using the NanoString nCounter Human v.1.1 PanCancer Panel. Findings were validated using the TCGA MIBC dataset. Unsupervised and supervised clustering identified a distinctive immune-related gene expression profile for inflammation, characterized by significant upregulation of 149 genes, particularly chemokines, a subset of which also had potential prognostic utility. Some of the most enriched biological processes were lymphocyte activation and proliferation, leukocyte adhesion and migration, antigen processing and presentation and cellular response to IFN-γ. Upregulation of numerous IFN-γ-inducible chemokines, class II MHC molecules and immune checkpoint genes was detected as part of the complex immune response to MIBC. Further, B-cell markers linked to tertiary lymphoid structures were upregulated, which in turn is predictive of tumor response to immunotherapy and favorable outcome. Our findings of both an overall activated immune profıle and immunosuppressive microenvironment provide novel insights into the complex immune milieu of MIBC with inflammation and supports its clinical significance for predicting prognosis and immunotherapeutic responsiveness, which warrants further investigation. This may open novel opportunities to identify mechanisms for developing new immunotherapeutic strategies.

We introduce the new price probability measure, which entirely depends on the probability measures of the value and the volume of the market trades. We define the nth statistical moment of the price as the ratio of the nth statistical moment of the value to the nth statistical moment of the volume of all trades performed during an averaging time interval Δ. The set of the price statistical moments determines the price characteristic function and its Fourier transform defines the price probability measure. The price volatility depends on the 1st and the 2nd statistical moments of the value and the volume of the trades. The prediction of the price volatility requires a description of the sums of squares of the value and the volume of the market trades during the interval Δ and we call it the second-order economic theory. To develop that theory, we introduce numerical continuous risk ratings and distribute the agents by the risk ratings as coordinates. Based on distributions of the agents by the risk coordinates, we introduce a continuous economic media approximation that describes the collective trades. The agents perform the trades under the action of their expectations. We model the mutual impact of the expectations and the trades and derive equations that describe their evolution. To illustrate the benefits of our approach, in a linear approximation we describe perturbations of the mean price, the mean square price and the price volatility as functions of the first and the second-degree trades’ disturbances.

α-tricalcium (α-TCP) phosphate is widely used as an osteoinductive biocompatible material, serving as an alternative to synthetic porous bone materials. The objective of this study is to obtain a highly filled fibrous nonwoven material composed of poly-3-hydroxybutyrate (PHB) and α-TCP and to investigate the morphology, structure, and properties of the composite obtained by the electrospinning method (ES). The addition of α-TCP had a significant effect on the supramolecular structure of the material, allowing it to control the crystallinity of the material, which was accompanied by changes in mechanical properties, FTIR spectra, and XRD curves. The obtained results open the way to the creation of new osteoconductive materials with a controlled release of the source of calcium into the living organism.

In this work, film materials based on binary compositions of poly-(3-hydroxybutyrate) (PHB) and chitosan with different ratios of polymer components in the range from 0/100 to 100/0 wt. % were studied. Using a combination of thermal (DSC) and relaxation (EPR) measurements, the influence of the encapsulation temperature of the drug substance (DS) of dipyridamole (DPD) and moderately hot water (at 70 °C) on the characteristics of the PHB crystal structure and the diffusion rotational mobility of the stable TEMPO radical in the amorphous regions of the PHB/chitosan compositions is shown. The low-temperature extended maximum on the DSC endotherms made it possible to obtain additional information about the state of the chitosan hydrogen bond network. This allowed us to determine the enthalpies of thermal destruction of these bonds. In addition, it is shown that when PHB and chitosan are mixed, significant changes are observed in the degree of crystallinity of PHB, degree of destruction of hydrogen bonds in chitosan, segmental mobility, sorption capacity of the radical, and the activation energy of rotational diffusion in the amorphous regions of the PHB/chitosan composition. The characteristic point of polymer compositions was found to correspond to the ratio of the components of the mixture 50/50%, for which the inversion transition of PHB from dispersed material to dispersion medium is assumed. Encapsulation of DPD in the composition leads to higher crystallinity and to a decrease in the enthalpy of hydrogen bond breaking, and it also slows down segmental mobility. Exposure to an aqueous medium at 70 °C is also accompanied by sharp changes in the concentration of hydrogen bonds in chitosan, the degree of PHB crystallinity, and molecular dynamics. The conducted research made it possible for the first time to conduct a comprehensive analysis of the mechanism of action of a number of aggressive external factors (such as temperature, water, and the introduced additive in the form of a drug) on the structural and dynamic characteristics of the PHB/chitosan film material at the molecular level. These film materials have the potential to serve as a therapeutic system for controlled drug delivery.

This work addresses the challenges concerning the development of “all-green” high-performance biodegradable membrane materials based on poly-3-hydroxybutyrate (PHB) and a natural biocompatible functional additive, iron-containing porphyrin, Hemin (Hmi) via modification and surface functionalization. A new facile and versatile approach based on electrospinning (ES) is advanced when modification of the PHB membranes is performed by the addition of low concentrations of Hmi (from 1 to 5 wt.%). Structure and performance of the resultant {HB/Hmi membranes were studied by diverse physicochemical methods, including differential scanning calorimetry, X-ray analysis, scanning electron microscopy, etc. Modification of the PHB fibrous membranes with Hmi allows control over their quality, supramolecular structure, morphology, and surface wettability. As a result of this modification, air and liquid permeability of the modified electrospun materials markedly increases. The proposed approach provides preparation of high-performance all-green membranes with tailored structure and performance for diverse practical applications, including wound healing, comfort textiles, facial protective masks, tissue engineering, water and air purification, etc.

Developing biodegradable materials based on polymer blends with a programmable self-destruction period in the environmental conditions of living systems is a promising direction in polymer chemistry. In this work, novel non-woven fibrous materials obtained by electrospinning based on the blends of poly(lactic acid) (PLA) and poly(3-hydroxybutyrate) (PHB) were developed. The kinetics of biodegradation was studied in the aquatic environment of the inoculum of soil microorganisms. Oxidative degradation was studied under the ozone gaseous medium. The changes in chemical composition and structure of the materials were studied by optical microscopy, DSC, TGA, and FTIR-spectroscopy. The disappearance of the structural bands of PHB in the IR-spectra of the blends and a significant decrease in the enthalpy of melting after 90 days of exposure in the inoculum indicated the biodegradation of PHB while PLA remained stable. It was shown that the rate of ozonation was higher for PLA and the blends with a high content of PLA. The lower density of the amorphous regions of the blends determined an increased rate of their oxidation by ozone compared to homopolymers. The optimal composition in terms of degradation kinetics is a fibrous material based on the blend of 30PLA/70PHB that can be used as an effective ecosorbent, for biopackaging, and as a highly porous covering material for agricultural purposes.

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A composite material based on electrospinning printed polyhydroxybutyrate fibers impregnated with brushite cement containing Zn substitution was developed for bone implant applications. Powder X-ray Diffraction (PXRD), Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy were applied for materials characterization. Soaking the composite in Ringer’s solution led to the transformation of brushite into apatite phase, accompanied by the morphology changes of the material. The bending strength of the composite material was measured to be 3.1 ± 0.5 MPa. NCTC mouse fibroblast cells were used to demonstrate by means of the MTT test that the developed material was not cytotoxic. The behavior of the human dental pulp stem cells on the surface of the composite material investigated by the direct contact method was similar to the control. It was found that the developed Zn containing composite material possessed antibacterial properties, as testified by microbiology investigations against bacteria strains of Escherichia coli and Staphylococcus aureus. Thus, the developed composite material is promising for the treatment of damaged tissues with bacterial infection complications.

Aliphatic and aromatic polyesters of hydroxycarboxylic acids are characterized not only by biodegradability, but also by biocompatibility and inertness, which makes them suitable for use in different applications. Polyesters with high enzymatic hydrolysis capacity include poly(lactic acid), poly(ε-caprolactone), poly(butylene succinate) and poly(butylene adipate-co-terephthalate), poly(butylene succinate-co-adipate). At the same time, poly(lactic acid) is the most durable, widespread, and cheap polyester from this series. However, it has a number of drawbacks, such as high brittleness, narrow temperature-viscosity processing range, and limited biodegradability. Three main approaches are known for poly(lactic acid) modification: incorporation of dispersed particles or low molecular weight and oligomeric substances, copolymerization with other polymers, and blending with other polymers. The review includes an analysis of experimental works devoted to developing mixtures based on poly(lactic acid) and other polymers. Regularities in the formation of the structure of such systems and the possibility of controlling the properties of poly(lactic acid) are considered.

Simple Summary: In this study, scientists investigated how pathologists test for a protein called HER2 in a type of cancer called endometrial cancer (EC). They checked samples from 180 patients tested over the first two years following approval of the test in the clinic. They found that 28% of the samples had HER2 overexpression, which makes them eligible for HER2-targeted therapies. They also noticed that in some cases, the test results were different depending on the method used. This study shows that there are challenges in testing for HER2 in endometrial cancer and suggests that we need standardized guidelines to help doctors make better decisions about endometrial cancer treatment. HER2-targeted therapies have transformed the management of advanced or recurrent serous endometrial cancer (EC), leading to an increased clinical demand for HER2 testing. Despite its adoption in select academic centers, the global extent of such tumor testing is unclear. In this study, we report on the initial two-year experience of HER2 testing at a major academic center with a reference gynecologic oncology service and biomarker reference laboratory. All patients who underwent HER2 testing based on physician discretion, reflex HER2 testing, and reference laboratory requests were included. From February 2021 to October 2023, HER2 testing was performed on 192 tumor tissue samples from 180 EC patients. Serous carcinoma constituted 52% of samples, reflecting diagnostic challenges and limited therapeutic options for advanced EC. HER2 positivity was found in 28% of all cases and 30% of p53-aberrant cases. An immunohistochemistry (IHC) score of 3+ was found in 15% of samples, while IHC 2+ was found in 45% (13% IHC 2+/ISH+ and 32% IHC 2+/ISH−). The newly identified 'HER2-low' category comprised 46% of the samples. Heterogeneity was noted in 42% of HER2-positive cases, with complex patterns in 3%. NGS and HER2 IHC-FISH showed a 24% discordance, attributed to intratumoral heterogeneity, tumor cellularity, a small number of amplified cells, and the HER2/CEP17 ratio near the cut-off. This study offers real-world insights into HER2 testing in EC, highlighting the challenges and underscoring the need for standardized guidelines in specimen handling, proficiency testing, and scoring criteria to enhance patient management and therapeutic decision-making. [ABSTRACT FROM AUTHOR]

Criegee intermediates, which are the result of ozonolysis of alkenes, play a key role in many chemical and physical processes in the Earth's atmosphere. Their reactions with various atmospheric compounds are responsible for formation of hydroxyl radicals, atomic oxygen and hydrogen, sulfuric and nitric acids, and other chemically active radicals and molecules. In this work we have considered collisional-induced chemical reactions between three simple Criegee intermediate molecules: CH2OO, CH3CHOO, and (CH3)2COO with methane, which is a well-known active greenhouse gas. Methane concentration rapidly growths last decades that causes serious concern to the global scientific community. It was established that reactions between methane and Criegee Intermediates can follow through two main routes. One of them occurs over exchange of oxygen and hydrogen atoms upon collision and leads to the formation of methanol. Another one pass through the formation of an intermediate complex with a deep energy minimum, and produces OH radicals and a variety of other products, among which are acetone, acetaldehyde, formaldehyde, propaldehyde, methanol, water molecules, and others. In this work, the both kinds of the reactions have been studied, and the relative reaction rates of both pathways have been compared. [ABSTRACT FROM AUTHOR]

The importance of promising composites in modern materials science is constantly increasing. The use of various fillers or additives is associated with their influence not only on the defining properties of the composite, but also on physical and mechanical characteristics of the material. In this case, the distribution of the additive and its wetting with a polymer play an important role. The problem highlighted in this article is the influence of different copper-containing fillers (copper (II) sulphate powder, micro-sized copper (II) oxide powder, and nano-structured copper (II) oxide-based hollow microspheres) on the technological and physical–mechanical properties of the composites based on polylactic acid (PLA). The hollow microspheres of copper (II) oxide have been obtained by ultrasonic spray atomization via pyrolysis of copper (II) nitrate. The structure of the copper-based additives has been studied using X-ray diffraction, scanning electron microscopy, and static light scattering. For the PLA-composites, scanning electron microscopy, differential scanning calorimetry, stress-strain properties testing, and density analysis have been performed. The plasticizing effect of polycaprolactone and polyethylene glycol has been studied for the highly filled PLA/CuSO4 composite. The samples of PLA with over 2 wt.% of CuO microspheres have a full volume-filling and percolation structure of the additive’s particles. Due to the regular spherical shape of the particles and a lower specific volume, CuO hollow microspheres are uniformly distributed in the PLA matrix acting as a structuring and reinforcing modifier. Differential scanning analysis showed heterogeneous crystallization on CuO particles with an increase in the degree of crystallinity and the melting point of the polymer. It has been shown that the pre-masterbatching technology and adding plasticizers to obtain PLA composites contribute minimizing defects and enhance mechanical properties.

The development of innovative fibrous materials with valuable multifunctional properties based on biodegradable polymers and modifying additives presents a challenging direction for modern materials science and environmental safety. In this work, high-performance composite fibrous materials based on semicrystalline biodegradable poly-3-hydroxybutyrate (PHB) and natural iron-containing porphyrin, hemin (Hmi) were prepared by electrospinning. The addition of Hmi to the feed PHB mixture (at concentrations above 3 wt.%) is shown to facilitate the electrospinning process and improve the quality of the electrospun PHB/Hmi materials: the fibers become uniform, their average diameter decreases down to 1.77 µm, and porosity increases to 94%. Structural morphology, phase composition, and physicochemical properties of the Hmi/PHB fibrous materials were studied by diverse physicochemical methods, including electronic paramagnetic resonance, optical microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy, elemental analysis, differential scanning calorimetry, Fourier-transformed infrared spectroscopy, mechanical analysis, etc. The proposed nonwoven Hmi/PHB composites with high porosity, good mechanical properties, and retarded biodegradation due to high antibacterial potential can be used as high-performance and robust materials for biomedical applications, including breathable materials for wound disinfection and accelerated healing, scaffolds for regenerative medicine and tissue engineering.

Comprehensive studies combining X-ray diffraction analysis, thermophysical, dynamic measurements by probe method and scanning electron microscopy have been carried out. The peculiarity of the crystalline and amorphous structure of ultra-thin fibers based on poly(3-hydroxybutyrate) (PHB) containing minor concentrations (0–5%) of a gene and a tetraphenylporphyrin (TFP) complex with iron (in the form of FeCl) are considered. When these complexes are added to the PHB fibers, the morphology of the fibers change: a sharp change in the crystallinity and molecular mobility in the amorphous regions of PHB is observed. When adding a gel to the fibers of PHB, a significant decrease in the degree of crystallinity, melting enthalpy, and correlation time can be observed. The reverse pattern is observed in a system with the addition of FeCl-TFP—there is a significant increase in the degree of crystallinity, melting enthalpy and correlation time. Exposure of PHB fibers with gemin in an aqueous medium at 70 °C leads to a decrease in the enthalpy of melting in modified fibers—to an increase in this parameter. The molecular mobility of chains in amorphous regions of PHB/gemin fibers increases at the same time, a nonlinear dependence of changes in molecular dynamics is observed in PHB/FeCl-TFP fibers. Ozonolysis has a complex effect on the amorphous structure of the studied systems. The obtained fibrous materials have bactericidal properties and should be used in the creation of new therapeutic systems of antibacterial and antitumor action.

Glycero-(9,10-trioxolane)-trioleate (ozonide of oleic acid triglyceride, OTOA) was introduced into polylactic acid (PLA) films in amounts of 5, 10, 30, 50, and 70% w/w. The morphological, mechanical, thermal, and water absorption properties of PLA films after the OTOA addition were studied. The morphological analysis of the films showed that the addition of OTOA increased the diameter of PLA spherulites and, as a consequence, increased the proportion of amorphous regions in PLA films. A study of the thermodynamic properties of PLA films by differential scanning calorimetry (DSC) demonstrated a decrease in the glass transition temperature of the films with an increase in the OTOA content. According to DSC and XRD data, the degree of crystallinity of the PLA films showed a tendency to decrease with an increase in the OTOA content in the films, which could be accounted for the plasticizing effect of OTOA. The PLA film with 10% OTOA content was characterized by good smoothness, hydrophobicity, and optimal mechanical properties. Thus, while maintaining high tensile strength of 21 MPa, PLA film with 10% OTOA showed increased elasticity with 26% relative elongation at break, as compared to the 2.7% relative elongation for pristine PLA material. In addition, DMA method showed that PLA film with 10% OTOA exhibits increased strength characteristics in the dynamic load mode. The resulting film materials based on optimized PLA/OTOA compositions could be used in various packaging and biomedical applications.

Problem/Relevance - This paper presents new description of the business cycles that for decades remain as relevant and important economic problem. Research Objective/Questions - We propose that econometrics can provide sufficient data for assessments of risk ratings for almost all economic agents. We use risk ratings as coordinates of agents and show that the business cycles are consequences of collective change of risk coordinates of agents and their financial variables. Methodology - We aggregate similar financial variables of agents and define macro variables as functions on economic space. Economic and financial transactions between agents are the only tools that change their extensive variables. We aggregate similar transactions between agents with risk coordinates x and y and define macro transactions as functions of x and y. We derive economic equations that describe evolution of macro transactions and hence describe evolution of macro variables. Major Findings - As example we study simple model that describes interactions between Credits transactions from Creditors at x to Borrowers at y and Loan-Repayment transactions that describe refunds from Borrowers at y to Creditors at x. We show that collective motions of Creditors and Borrowers from safer to risky area and back on economic space induce frequencies of macroeconomic Credit cycles. Implications – Our model can improve forecasting of the business cycles and help increase economic sustainability and financial policy-making. That requires development of risk ratings methodologies and corporate accounting procedures that should correspond each other to enable risk assessments of economic agents.