Individual Constituents Research Articles

Evaluation of the Phenolic Content and the Nutraceutical Potential of Ancestor and Cultivated Artichokes.

Wild cardoon (Cynara cardunculus var. sylvestris) is the ancestor of many cultivated forms, including globe artichoke (C. cardunculus var. scolymus). Four organs (receptacles, bracts, leaves and stems) of wild and cultivated artichokes (organic and conventional) were assessed considering their individual phenolic constituents (HPLC-DAD), total phenol-flavonoid content, and pharmaceutical potentials (antibacterial and antioxidant). All three sources of artichokes had the highest concentration of 1,3-dicaffeoylquinic acid (cynarin) in their receptacles and cultivated artichoke receptacles had more cynarin than wild one. On the other hand, receptacles of wild cardoon had the highest 1,5-dicaffeoylquinic acid and caffeic acid than the cultivated ones. Generally, receptacles, stems and leaves of wild cardoon were superior to both cultivated artichokes on antioxidant potential, and total phenol-flavonoid content. The rise in total phenolic content can be attributed to an increase in antioxidant capacity in all artichoke organs. Only the leaves of all different artichokes showed antibacterial activity against Gram-positive bacteria. The investigated wild cardoon was believed to be a true ancestor since a comparison of wild and cultivated varieties revealed similar trends in terms of phenolic profile and biological properties. The nutraceutical industry can profit from this invasive wild cardoon due to their strong antioxidant potential and phenolic content.

Does the Processing Advantage of Formulaic Language Persist in Its Nonadjacent Forms? Evidence from Eye Movements of Chinese Collocations.

It has been well documented that formulaic language (such as collocations; e.g., provide information) enjoys a processing advantage over novel language (e.g., compare information). In natural language use, however, many formulaic sequences are often inserted with words intervening in between the individual constituents (e.g., provided information → provide some of the information). Whether or not the processing advantage persists in nonadjacent forms remains largely unknown. The present study thus sought to address this gap by recording the eye movements of Chinese native speakers when they were reading sentences embedded with formulaic sequences (high frequency collocations) versus novel phrases (low frequency controls), in their adjacent (e.g., 'resolve difficulties' vs. 'experience difficulties'), short-insertion (e.g., 'resolve these difficulties' vs. 'experience these difficulties'), and long-insertion forms (e.g., 'resolved so many difficulties' vs. 'experienced so many difficulties'). Results suggested that the processing advantage for formulaic language over novel language existed not only in their adjacent form, but also in their short-insertion form, albeit the magnitude of the processing advantage diminished with the increase of insertion length. The persistence of FL processing advantage is in line with usage-based approach to language learning, processing, and use.

Site-specific electronic structure of covalently linked bimetallic dyads from nitrogen K-edge x-ray absorption spectroscopy.

A nitrogen K-edge x-ray absorption near-edge structure (XANES) survey is presented for tetrapyrido[3,2-a:2',3'-c:3″,2″-h:2‴,3‴-j]phenazine (tpphz)-bridged bimetallic assemblies that couple chromophore and catalyst transition metal complexes for light driven catalysis, as well as their individual molecular constituents. We demonstrate the high N site sensitivity of the N pre-edge XANES features, which are energetically well-separated for the phenazine bridge N atoms and for the individual metal-bound N atoms of the inner coordination sphere ligands. By comparison with the time-dependent density functional theory calculated spectra, we determine the origins of these distinguishable spectral features. We find that metal coordination generates large shifts toward higher energy for the metal-bound N atoms, with increasing shift for 3d < 4d < 5d metal bonding. This is attributed to increasing ligand-to-metal σ donation that increases the effective charge of the bound N atoms and stabilizes the N 1s core electrons. In contrast, the phenazine bridge N pre-edge peak is found at a lower energy due to stabilization of the low energy electron accepting orbital localized on the phenazine motif. While no sensitivity to ground state electronic coupling between the individual molecular subunits was observed, the spectra are sensitive to structural distortions of the tpphz bridge. These results demonstrate N K-edge XANES as a local probe of electronic structure in large bridging ligand motifs, able to distinctly investigate the ligand-centered orbitals involved in metal-to-ligand and ligand-to-ligand electron transfer following light absorption.

Exploring the hierarchical structure of lamellar bone and its impact on fracture behaviour: A computational study using a phase field damage model

Bone is a naturally occurring composite material composed of a stiff mineral phase and a compliant organic matrix of collagen and non-collagenous proteins (NCP). While diverse mineral morphologies such as platelets and grains have been documented, the precise role of individual constituents, and their morphology, remains poorly understood. To understand the role of constituent morphology on the fracture behaviour of lamellar bone, a damage based representative volume element (RVE) was developed, which considered various mineral morphologies and mineralised collagen fibril (MCF) configurations. This model framework incorporated a novel phase-field damage model to predict the onset and evolution of damage at mineral-mineral and mineral-MCF interfaces. It was found that platelet-based mineral morphologies had superior mechanical performance over their granular counterparts, owing to their higher load-bearing capacity, resulting from a higher aspect ratio. It was also found that MCFs had a remarkable capacity for energy dissipation under axial loading, with these fibrillar structures acting as barriers to crack propagation, thereby enhancing overall elongation and toughness. Interestingly, the presence of extrafibrillar platelet-based minerals also provided an additional toughening through a similar mechanism, whereby these structures also inhibited crack propagation. These findings demonstrate that the two primary constituent materials of lamellar bone play a key role in its toughening behaviour, with combined effect by both mineral and MCFs to inhibit crack propagation at this scale. These results have provided novel insight into the fracture behaviour of lamellar bone, enhancing our understanding of microstructure-property relationships at the sub-tissue level.

Direct Z-scheme GeH/InSe heterostructure with high solar-to-hydrogen efficiency for photocatalytic water splitting

The stability, electronic structures and photocatalytic applications of GeH/InSe heterostructure are studied through first-principles calculations. The GeH/InSe heterostructure can be used as a direct Z-scheme photocatalyst for overall water splitting due to the influence of the built-in electric field and the interface band bending. The heterostructure exhibits a lower exciton binding energy than their individual constituents, indicating the effective separation of electron-hole pairs. Electron mobilities along transport directions are two orders of magnitude greater than hole mobilities, which further prompts the carriers separation rate. The heterostructure’s solar-to-hydrogen efficiency is 24.72 % at pH = 0, indicating great application prospects in photocatalysis.

Comparison of water-soluble organic matter (WSOM)-containing and WSOM-free biochars for simultaneous sorption of lead and cadmium

The effects of individual biochar constituents and natural environmental media on the immobilization behaviors and chemical activities of toxic heavy metals are still poorly understood. In this work, the physicochemical properties of raw corn straw (CS) and CS-derived biochar materials as well as their sorption abilities and retention mechanisms for lead (Pb) and cadmium (Cd) were evaluated by combining batch experiments and spectral approaches. According to the spectral analysis results and single variable principle, the setting of biochars after soaking in solution as the control group was suggested when evaluating their retention mechanisms for Pb and Cd. The rising of ionic strength did not apparently affect the immobilization of Pb by biochar prepared at 500 °C (i.e., CB500) and Pb/Cd by water-soluble organic matter (WSOM)-free CB500 (i.e., DCB500), while slightly inhibited the sorption of Cd by CB500. Pb and Cd exhibited a mutual inhibition effect on their sorption trends with a higher sorption preference of Pb. The dominant fixation mechanism of Pb by CB500 and DCB500 was identified to be mineral precipitation. In contrast, the main sorption mechanism of Cd changed from mineral precipitation in the single-metal system to surface complexation in the binary-metal system. The sorption ratios of Pb and Cd on CB500 were comparable to those on DCB500 with the coexistence of mixed natural organic matters (NOM) and ferrihydrite. The current experimental findings suggested that DCB500 was a suitable remediation agent for regulating the migration behaviors of toxic Pb and Cd in acidic and NOM-rich soil and water systems.

If speed is of the essence: rapid analysis of ambergris by APCI compact mass spectrometry

The use of atmospheric pressure chemical ionisation (APCI) compact mass spectrometry (CMS) was investigated for the analysis of jetsam and museum-archived ambergris and of ambergris components in perfumes. The data were compared with those from existing methods. Authentic samples of some individual ambergris constituents (ambrein, coprostanol, epicoprostanol and coprostanone), were also examined. Rapid APCI CMS was achieved using either a solids probe or a probe with solutions held in capillary melting point tubes. Interpretation is made of the spectra of the principal natural product components, the relative ion responses were measured and the elemental composition of key ions in the spectra confirmed using high resolution accurate mass APCI MS. Rapid analysis of ambergris by APCI CMS may prove to be a further convenient method of identifying ambrein, of measuring the relative ratios of ambrein and steroids in ambergris and even of quantifying the latter, with minimal sample preparation.

Effect of microwave and oven roasting on chemical composition, bioactive properties, phenolic compounds and fatty acid compositions of sunflower seed and oils

AbstractIn this study, the effects of microwave (540, 720 and 900 W) and oven (120, 150 and 230°C) roasting techniques on the total phenolics, flavonoids, antioxidant capacity, polyphenolic and fatty acid results of sunflower seed and oils were investigated. Total phenol (except oven 150°C), flavonoid (except oven 120°C) contents and antioxidant activity values of sunflower seeds and oils subjected to oven and microwave heat treatment decreased compared to the control. Total phenolic, total flavonoids and antioxidant activities were higher in MRS oil than ORS oil. Individual phenolic constituent in both seed and oil samples from ORS and MRS showed significant (p &lt; 0.05) changes to the control (non‐roasted seed and its oil). A general increase in the phenolic components of seeds and oils was observed with oven and microwave roasting compared to the control. Oleic acid values (%) of the oil extracted from seeds roasted in oven and microwave systems were recorded to be between 23.76 (120°C) and 29.41% (150°C) to 24.32 (540 W) and 26.10% (720 W), respectively. Linoleic acid values of the oils obtained from seeds roasted in oven and microwave systems varied to be between 57.01 (150°C) and 65.89% (120°C) to 60.70 (720 W) and 65.26% (540 W), respectively. As a result of the applied heat treatment, while the linoleic acid values of the oil samples decreased, an increase was observed in the palmitic, stearic and oleic acid values of the oil.

Antifungal activity of Carya illinoinensis extracts against Alternaria alternata pathogen and their cytotoxicity effects on HEK-293T cells: HPLC analysis of bioactive compounds

Derivatives of Carya illinoinensis (pecan) are used as dietary supplements and their leaf and nuts-in-shuck extracts are used in the treatment of various pathologies due to their significant composition in phenolic compounds that act as natural antifungal and anticancer agents. This study aimed to evaluate the antifungal activity of acetone extracts (AEs) from leaves (L) and nuts-in-shucks (S) of cultivars (cv.) Wichita (Wic) and Ukulinga (Uku) of South African C. illinoinensis against A. alternata pathogen. The AEs of Wic-L and Uku-L showed higher antifungal efficacy against all tested A. alternata isolates, with inhibition zones ranging from 11 to 39 mm. Acetone crude extracts of cv. Wichita and cv. Ukulinga showed efficacy against the isolates and were significantly different (p < 0.001). Scanning electron microscopy (SEM) showed major morphological damages on the conidia from assayed cultures, which resulted in inhibition. We further evaluated the in vitro cytotoxic effects of Carya illinoinensis on human embryonic kidney 293 (HEK-293T) cell lines with methanolic extracts (MEs). HEK-293T cell lines (10 × 103 cells/well) were treated with each sample of the extracts at various concentration (1.56, 6.25, 12.5, 25, 50, and 100 µg/mL) and cell viability was quantitated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay after 48 h. The HEK-293 cell viabilities when exposed to MEs of Wic-L, Wic-S, and Uku-L were 88.2%, 75.2%, and 86.3% respectively, confirming non-toxic properties in accordance with International Organisation for Standardization (ISO) norms. However, the viability of cell culture after the treatment with MEs of Uku-S was 37% and was as toxic. We further used High-performance liquid chromatography (HPLC) to investigate individual phenolic constituents and total phenolic content in the leaves and shucks of both cultivars. Twelve individual phenols were detected through HPLC analysis in the respective extracts. The total phenolic content was higher in the extracts of Wic-L (102.19 mg GAE/g) and Uku-L (110.13 mg GAE/g) relative to the Wic-S (62.03 mg GAE/g) and Uku-S (85.07 mg GAE/g) extracts. Finally, these findings highlighted the possibility of pecan leaf extracts as a potential natural bioactive antifungal agent against black spot disease on pecans in South Africa.

Registration of melting temperature at phase boundaries in melting powder mixtures

An integral constituent of the induction surfacing process for parts hardening pertains to the thermal treatment of rigid alloy particulates and the flux contained within the surfacing amalgam. This scholarly exposition delineates the outcomes of a comprehensive investigation, oriented towards the quantification and simulation of thermal gradients at interphase boundaries within intricate amalgamations of melting and thermosetting powdery substrates. In order to monitor the thermal dynamics during induction surfacing, the application of the CA-microthermocouple methodology and the thermal indication technique utilizing self-propagating SHS-process compositions is posited. The study encompasses both computational simulations and the resolution of the unsteady-state heat conduction problem within the chosen model of composite contacting materials. The devised methodologies for the intricate tracking of thermal profiles during induction surfacing offer the capability to ascertain the temperatures at which the surfacing amalgam and its individual constituents undergo liquefaction, in conjunction with the temperature gradient exhibited by the surface of the targeted component. This facet holds marked significance in the context of optimizing the hardening regimen and ensuring the requisite attributes of the amalgamated materials post-fusion. The outcomes of this research bear practical relevance in industrial applications, wherein enhancements to the caliber and dependability of hardened components are sought, simultaneously facilitating the curtailment of production overheads.

The Effects of Indium Additions on Tribological Behavior of Spark Plasma Sintering-Produced Graphene-Doped Alumina Matrix Composites for Self-Lubricating Applications

Alumina (Al2O3) ceramics are interesting for low-weight and mid-high temperature applications. The addition of indium (In) and graphene nanoplatelets (GNPs) can be used to reduce the density and modify the functional properties and mechanical performance of the ceramic matrix. GNP and In-reinforced Al2O3 matrix composites were prepared by the spark plasma sintering (SPS) technique. Monolithic Al2O3 and Al2O3 matrix composites with either 5 or 10 wt.% of In and 2 wt.% of GNPs (Al2O3-5In-2GNPs and Al2O3-10In-2GNPs) were compacted into disc-shaped samples. The microstructure was studied and characterized with light-optical microscopy (LOM) and scanning electron microscopy (SEM). Hardness was determined using the Vickers technique and tribological properties were studied by the ball-on-disk method. The coefficient of friction (COF) and specific wear rates were evaluated from tribological tests. Worn surfaces were studied by SEM and confocal microscopy. Interdiffusion transition regions were formed among individual microstructural constituents (Al2O3, In, GNPs) under high sintering temperatures, which were responsible for the balanced hardness and low porosity of the produced composites. The addition of In and graphene nanoplatelets resulted in smaller COF and wear rates indicating good improvement in the tribological behavior. The prepared Al2O3-5In-2GNP and Al2O3-10In-2GNP composites represent promising nanocomposites for self-lubricating applications.

Electronic transparency of internal interfaces in metallic nanostructures comprising light, heavy and ferromagnetic metals measured by terahertz spectroscopy

Abstract We investigate the electronic transport at the internal interface within a selection of metallic bilayer nanostructures using the contact-free, all-optical method of THz time-domain spectroscopy. The Ru/Co, Ru/Pt, and Ru/Al bilayer nanostructures and their individual constituent metals are studied, with Ru representing an archetypal d-band metal, Co an archetypal ferromagnet, and Pt and Al archetypal heavy and light metals, respectively. The THz conductivity data were analyzed in terms of Drude and Bloch–Grüneisen models, and the interface current coefficient of the internal nanointerface was determined. Strong temperature dependency of the interface current coefficient in the Ru/Co nanostructure is revealed.

A breakthrough in periodontitis treatment: Revealing the pharmacodynamic substances and mechanisms of Kouqiangjie formula

Ethnopharmacology relevancePeriodontitis, a complex inflammatory disease, significantly affects people's lives. Traditional Chinese multi-herbal formulas, composed of various herbs, exhibit their therapeutic efficacy holistically. Kouqiangjie Formula (KQJF), comprising 12 herbs including Rhizoma smilacis glabrae, Polygonatum sibiricum Delar. ex Redoute, Taraxacum mongolicum Hand.-Mazz, etc., has been clinically proven to effectively treat periodontitis. However, the potential active substances conferring these effects and their mechanisms of action remain unclear. Aim of the studyThe current investigation endeavours to utilize Ultra Performance Liquid Chromatography Quadrupole Time of Flight Mass Spectrometry (UPLC-Q-TOF-MS), network pharmacology, and in vivo animal experiment confirmation to explore the plausible bioactive compounds and operational mechanisms underpinning KQJF's therapeutic impact on periodontitis. Materials and methodsUsing the UPLC-Q-TOF-MS technique, we deciphered the chemical constituents of KQJF. Network pharmacology was employed to earmark key bioactive elements, forecast principal targets, and operational pathways which were later substantiated through molecular docking. Experimental validations were carried out in a periodontitis animal model using a range of techniques, including micro-CT, H&E staining, qRT-PCR, and protein blotting procedures, providing comprehensive verification of our initial assumptions. ResultsUtilizing UPLC-Q-TOF-MS, we characterized 87 individual chemical constituents in KQJF. Network pharmacology revealed that 14 components, including senkyunolide A, glycycoumarin, licoflavonol, glycyrin, senkyunolide I, and senkyunolide H, form the key therapeutic basis of KQJF in targeting periodontitis. Significant targets and pathways were discerned as AKT1, MMP9, JUN, PTGS2, CASP3, TLR4, IL1β, BCL2, PPARG, and pathways such as the TNF signaling pathway, NF-κB signaling pathway, osteoclast differentiation, and Wnt signaling pathway. Molecular docking demonstrated robust binding activity between these crucial targets and the key active ingredients. In vivo experimentation corroborated that, compared with the model group, KQJF significantly ameliorated symptoms and micro-CT imaging parameters of periodontitis in the rat model, down-regulating the expression of AKT1, MMP9, JUN, PTGS2, CASP3, TLR4, and IL1β, while up-regulating the expression of BCL2 and PPARG. ConclusionIn summary, this study has pioneered a comprehensive exploration of the potential therapeutic constituents, targets, and mechanisms of KQJF for periodontitis treatment, adopting a synergistic strategy of “chemical component analysis-network pharmacology screening-in vivo animal experiment validation”. This provides experimental evidence for the clinical application of KQJF and further in-depth research. Additionally, it presents an effective strategy for the research of other Chinese herbal formulations.

Ordered hierarchical superlattice amplifies coated-CeO2 nanoparticles luminescence

Achieving a controlled preparation of nanoparticle superstructures with spatially periodic arrangement, also called superlattices, is one of the most intriguing and open questions in soft matter science. The interest in such regular superlattices originates from the potentialities in tailoring the physicochemical properties of the individual constituent nanoparticles, eventually leading to emerging behaviors and/or functionalities that are not exhibited by the initial building blocks. Despite progress, it is currently difficult to obtain such ordered structures; the influence of parameters, such as size, softness, interaction potentials, and entropy, are neither fully understood yet and not sufficiently studied for 3D systems. In this work, we describe the synthesis and characterization of spatially ordered hierarchical structures of coated cerium oxide nanoparticles in water suspension prepared by a bottom-up approach. Covering the CeO2 surface with amphiphilic molecules having chains of appropriate length makes it possible to form ordered structures in which the particles occupy well-defined positions. In the present case superlattice arrangement is accompanied by an improvement in photoluminescence (PL) efficiency, as an increase in PL intensity of the superlattice structure of up to 400 % compared with that of randomly dispersed nanoparticles was observed. To the best of our knowledge, this is one of the first works in the literature in which the coexistence of 3D structures in solution, such as face-centered cubic (FCC) and Frank-Kasper (FK) phases, of semiconductor nanoparticles have been related to their optical properties.

Programming structural and magnetic anisotropy for tailored interaction and control of soft microrobots

Swarms of soft microrobots controlled by minimally invasive magnetic fields show promise as biomedical agents. The collective behaviour of such swarms, governed by magnetic and hydrodynamic interactions, emerges from the properties of their individual constituents. The introduction of both magnetic and structural anisotropy into microrobots expands the possibilities for tailoring and predetermining interactions and collective behaviours that result. Unfortunately, current methods for large-scale production of soft microrobots, typically result in isotropic properties. Herein, by combining simulation-guided design and droplet-based microfluidics, we present a versatile, high-throughput technique for fabricating soft microrobots with programmable structural and magnetic anisotropy. Such microrobots consist of iron oxide nanoparticles organized into supra-domain structures and entrapped in a hydrogel matrix that can be elongated independently of its magnetic properties. By applying rotating magnetic fields to resulting swarms, distinct collective behaviours are produced, including gas-like formations, variable crystals, and heterogeneous motions.

Note on super-critical charged boson stars

We study the transition of charged boson stars from sub- to super-criticality. This transition is defined as that choice of coupling constants for which the Coulomb repulsion of two individual bosons (that make up the star) exactly cancels their gravitational attraction. It was recently shown that without self-interaction super-critical boson stars are unstable to decay into their individual constituents. Here we show that this is no longer true for the self-interacting case and that boson stars can possess spatial oscillations in the scalar field. We also discuss the corresponding black hole solutions that carry charged scalar hair.

Elucidating the role of diverse mineralisation paradigms on bone biomechanics - a coarse-grained molecular dynamics investigation.

Bone as a hierarchical composite structure plays a myriad of roles in vertebrate skeletons including providing the structural stability of the body. Despite this critical role, the mechanical behaviour at the sub-micron levels of bone's hierarchy remains poorly understood. At this scale, bone is composed of Mineralised Collagen Fibrils (MCF) embedded within an extra-fibrillar matrix that consists of hydroxyapatite minerals and non-collagenous proteins. Recent experimental studies hint at the significance of the extra-fibrillar matrix in providing the bone with the stiffness and ductility needed to serve its structural roles. However, due to limited resolution of experimental tools, it is not clear how the arrangement of minerals, and in particular their relative distribution between the intra- and extra-fibrillar space contribute to bone's remarkable mechanical properties. In this study, a Coarse Grained Molecular Dynamics (CGMD) framework was developed to study the mechanical properties of MCFs embedded within an extra-fibrillar mineral matrix and the precise roles extra- and intra-fibrillar mineralisation on the load-deformation response was investigated. It was found that the presence of extra-fibrillar mineral resulted in the development of substantial residual stress in the system, by limiting MCF shortening that took place during intra-fibrillar mineralisation, resulting in substantial compressive residual stresses in the extra-fibrillar mineral phase. The simulation results also revealed the crucial role of extra-fibrillar mineralisation in determining the elastic response of the Extrafibrillar mineralised MCF (EFM-MCF) system up to the yield point, while the fibrillar collagen affected the post-yield behaviour. When physiological levels of mineralisation were considered, the mechanical response of the EFM-MCF systems was characterised by high ductility and toughness, with micro-cracks being distributed across the extra-fibrillar matrix, and MCFs effectively bridging these cracks leading to an excellent combination of strength and toughness. Together, these results provide novel insight into the deformation mechanisms of an EFM-MCF system and highlight that this universal building block, which forms the basis for lamellar bone, can provide an excellent balance of stiffness, strength and toughness, achieving mechanical properties that are far beyond the capabilities of the individual constituents acting alone.

Graikiškosios filosofijos sampratos aktualumas: ko galėtume pasimokyti iš senovės graikų

The article is dedicated to the problem of relevance of the Classical Greek understanding of philosophy to contemporary philosophy. A distinction is made between the relevance of the Greek philosophy that has already been realized, or made actual, in the sphere of contemporary philosophy and culture, and the relevance of the Greek philosophy which is yet in need of realization, that is, which has a potential of being realized in the future. The author, mainly focusing on this latter kind of relevance, for it is more interesting from the philosophical point of view and suggests new ways to reinvigorate the contemporary field of philosophical thought, discusses the original Greek understanding of philosophy that can be discerned from the ancient Greek philosophical texts and the original Greek term for philosophy, philosophia. The author presents an analysis of the Greek word philosophia from the etymological and conceptual points of view, disclosing its several layers of meaning. It is argued that the Greek philosophical thinking employs a productive combination of pre-methodical and methodical thought, deriving from this combination a specific synergy that might also be useful to contemporary philosophy. A point is made that the original Greek notion of philosophy, understood as the love of divine wisdom, presupposes both modesty, stemming from the acknowledgment of one’s absolute ignorance of the most important philosophical answers, and intellectual passion. The author makes a claim that the original close and deep relation between the Greek philosophy and astronomy was instrumental in the original Greek understanding of the philosopher as a theōros of a special kind, that is, as a theoretic viewer of the entire cosmos who focuses on the whole of the cosmos (or reality in general), not on its individual constituents and details. What was expected of the Greek philosopher was the ability to deeply appreciate the beauty, unity, and underlying divine order of the cosmos, not the capacity to acquire the knowledge of concrete information related to it. The attention is drawn to the circumstance that the Greek philosopher’s aesthetic appreciation of the cosmos that took place at the moments of its theoretical contemplation had also a specific ethical aspect to it – an aspect that cannot be simply explained in terms of the Classical Greek virtue ethics and can be rather viewed in terms of the modern approaches to ethics. The relation between the ability to acknowledge one’s ignorance of the most important matters and the capacity to theoretically contemplate and aesthetically appreciate the cosmos in holistic terms is viewed by the author as potentially relevant to those contemporary thinkers who seek to reassert the unique status of philosophy, its special place among other disciplines, and to rethink the radical difference between philosophy and science. After discussing some other aspects of potential relevance of the Greek understanding of philosophy to contemporary philosophy, the author makes a conclusion that the Classical Greek understanding of the nature of philosophy should be viewed not as having to replace, but as being able to complement the current understanding of the nature and mission of philosophy.

ОБОСНОВАНИЕ НАПРАВЛЕНИЙ РАЗВИТИЯ ТОПЛИВНОГО РЫНКА В РЕГИОНАХ СИБИРИ И ДАЛЬНЕГО ВОСТОКА

The article is devoted to the study of the fuel market of the regions of the Siberian and Far Eastern Federal Districts based on cluster analysis. It is shown that the spatial structure of oil refining capacities in Russia is heterogeneous. Significant refining capacities are located in the Volga, Southern, and Central federal districts, while throughout the entire territory of Siberia and the Far East, which is significantly larger in area than the European part of Russia, there are only 7 large refineries. And the economy of these regions does not largely depend on the reliability of the only channels for the supply of petroleum products. Diversification of the regional fuel market can increase the region’s resilience to interruptions in the supply of traditional automobile fuel. The purpose of the work is to study the fuel market of individual constituent entities of the Russian Federation to justify the choice of promising areas of development, among which the authors highlight: the development of gas motor fuel, the development of electric transport, or maintaining the leading role of traditional automobile fuel. The analysis was carried out on a sample of 18 regions (Siberian and Far Eastern federal districts), for each of which the most important indicators were selected that characterize the socio-economic, infrastructural, environmental and climatic state of the regions. For the task at hand, the k-means method was chosen. As a result of cluster analysis, three groups of regions were identified with similar parameters within the groups and the maximum difference between the groups. For the regions of the first group, the optimal scenario would be to stimulate the development of the gas motor fuel market and support the population in converting engines to run on gas motor fuel. For the regions of the second group, increasing the use of alternative fuels, including the development of electric motor transport, has high potential. For the regions of the third group, it is advisable to focus on developing the market for traditional and natural gas motor fuel. It is recommended for some regions to develop programs to stimulate the development of the fuel market in relevant areas to reduce the operating costs of vehicles and ensure the reliability of meeting the demand for automobile fuel.

Pt-surface stabilization by high-entropy alloys for enhancing oxygen reduction reaction property: Single-crystal model catalyst study

In this work, we study the oxygen reduction reaction (ORR) properties of Pt-containing 3d transition-metal high-entropy alloy (Pt-HEA) surfaces, focusing on the constituent alloying elements. The surface Pt and underlying Cr-Mn-Co-Ni(111) (Pt/Cr-Mn-Co-Ni(111)) stacked lattice layers, which are synthesized through the vacuum deposition of the underlying alloy and surface Pt stacking layers on Pt(111) substrate, exhibit high pristine ORR activity and structural stability under potential-cycle loading, compared to Pt/Cr-Co-Ni, Pt/Mn-Co-Ni, and Pt/Co-Ni(111) surfaces. The outperformed ORR properties are attributed to the effective suppression of the surface segregation of Cr. This study demonstrates that not only the “high-entropy” effect induced by increasing the numbers of constituent elements but also the “chemical affinity” of Pt and the individual HEA constituent elements determine the ORR performances of Pt-HEA.