Orthophosphate and Alkaline Phosphatase Induced the Formation of Apatite with Different Multilayered Structures and Mineralization Balance

Mineralized collagen is a natural organic-inorganic composite. The combination of organic collagen and inorganic apatite to form different nanostructures is the key to produce bone- substitutes with biomechanical properties that...

First-Principles Density Functional Theory Study of Modified Germanene-Based Electrode Materials

Germanene, with a wrinkled atomic layer structure and high specific surface area, showed high potential as an electrode material for supercapacitors. According to the first-principles calculation based on Density Functional Theory, the quantum capacitance of germanene could be significantly improved by introducing doping/co-doping, vacancy defects and multilayered structures. The quantum capacitance obtained enhancement as a result of the generation of localized states near the Dirac point and/or the movement of the Fermi level induced by doping and/or defects. In addition, it was found that the quantum capacitance enhanced monotonically with the increase of the defect concentration.

Cell polarity determinant Dlg1 facilitates epithelial invagination by promoting tissue-scale mechanical coordination

Epithelial folding mediated by apical constriction serves as a fundamental mechanism to convert flat epithelial sheets into multilayered structures. It remains elusive whether additional mechanical inputs are required for folding mediated by apical constriction. Using Drosophila mesoderm invagination as a model, we identified an important role for the non-constricting, lateral mesodermal cells adjacent to the constriction domain ("flanking cells") in facilitating epithelial folding. We found that depletion of the basolateral determinant, Dlg1, disrupts the transition between apical constriction and invagination without affecting the rate of apical constriction. Strikingly, the observed delay in invagination is associated with ineffective apical myosin contractions in the flanking cells that lead to overstretching of their apical domain. The defects in the flanking cells impede ventral-directed movement of the lateral ectoderm, suggesting reduced mechanical coupling between tissues. Specifically disrupting the flanking cells in wildtype embryos by laser ablation or optogenetic depletion of cortical actin is sufficient to delay the apical constriction-to-invagination transition. Our findings indicate that effective mesoderm invagination requires intact flanking cells and suggest a role for tissue-scale mechanical coupling during epithelial folding.

Spatiotemporally Orchestrated Interactions between Viral and Cellular Proteins Involved in the Entry of African Swine Fever Virus

African swine fever (ASF) is a highly contagious hemorrhagic disease in domestic pigs and wild boars with a mortality of up to 100%. The causative agent, African swine fever virus (ASFV), is a member of the Asfarviridae family of the nucleocytoplasmic large DNA viruses. The genome size of ASFV ranges from 170 to 194 kb, encoding more than 50 structural and 100 nonstructural proteins. ASFV virions are 260–300 nm in diameter and composed of complex multilayered structures, leading to an intricate internalization pathway to enter host cells. Currently, no commercial vaccines or antivirals are available, due to the insufficient knowledge of the viral receptor(s), the molecular events of ASFV entry into host cells, and the functions of virulence-associated genes. During the early stage of ASFV infection, the fundamental aspects of virus-host interactions, including virus internalization, intracellular transport through the endolysosomal system, and membrane fusion with endosome, are precisely regulated and orchestrated via a series of molecular events. In this review, we summarize the currently available knowledge on the pathways of ASFV entry into host cells and the functions of viral proteins involved in virus entry. Furthermore, we conclude with future perspectives and highlight areas that require further investigation. This review is expected to provide unique insights for further understanding ASFV entry and facilitate the development of vaccines and antivirals.

Towards an Understanding of the Effect of Adding a Foam Core on the Blast Performance of Glass Fibre Reinforced Epoxy Laminate Panels

This paper presents insights into the blast response of sandwich panels with lightweight foam cores and asymmetric (different thicknesses) glass fibre epoxy face sheets. Viscously damped elastic vibrations were observed in the laminates (no core), while the transient response of the sandwich panels was more complex, especially after the peak displacement was observed. The post-peak residual oscillations in the sandwich panels were larger and did not decay as significantly with time when compared to the equivalent mass laminate panel test. Delamination was the predominant mode of failure on the thinner facesheet side of the sandwich panel, whereas cracking and matrix failure were more prominent on the thicker side (which was exposed to the blast). The type of constituent materials used and testing conditions, including the clamping method, influenced the resulting failure modes observed. A probable sequence of damage in the sandwich panels was proposed, based on the transient displacement measurements, a post-test failure analysis, and consideration of the stress wave propagation through the multilayered, multimaterial structure. This work demonstrates the need for detailed understanding of the transient behaviour of multilayered structures with significant elastic energy capacity and a wide range of possible damage mechanisms. The work should prove valuable to structural engineers and designers considering the deployment of foam-core sandwich panels or fibre reinforced polymer laminates in applications when air-blast loading may pose a credible threat.

A Novel Technique for Controllable Fabrication of Multilayer Copper/Brass Block

Fabricating a dissimilar-metal block with micro/nano-multilayered structures is usually used by engineers and scientists because of their excellent mechanical properties. In the current work, multilayered copper/brass blocks were effectively fabricated by a synthetical DWFR technique, which includes the processes of diffusion welding, forging and rolling. Diffusion welding was used as the first operation to metallurgically bond the copper and brass sheets, with a Zn diffusion transition layer (thickness of ~100 μm), which can guarantee the bonding strength of copper/brass interfaces during the subsequent forging and rolling processes. After diffusion welding, the original copper/brass blocks were required to be forged, with its total thickness reduced to ~10 mm. This can further restrain the delamination of copper and brass layers during the final rolling process. Rolling was utilized as the ideal operation that can precisely tune the thickness of copper/brass laminate. This novel DWFR technique can easily tune the multilayered copper/brass blocks with controllable layer thickness (from ~250 to ~800 nm). The copper/brass interfaces were well-bonded, and the utilization efficiency of raw materials was very high (>95%).

International Conference PhysicA.SPb/2021

The International Conference PhysicA. SPb was held 18-22 October 2021 in Saint Petersburg, Russia. The Conference continues the tradition of St.Petersburg Seminars on Physics and Astronomy originating from mid-90s. Since then PhysicA.SPb maintains both scientific and educational quality of contributions delivered to the audience. This is the main feature of the Conference that makes it possible to combine the whole spectrum of modern Physics and Astronomy within one event. PhysicA. SPb/2021 has brought together over 400 academics from many universities and research institutes across whole Russia as well as from USA, UK, South Africa, Poland, Ukraine, Kazakhstan, Belarus, Azerbaijan, and Australia. Oral and poster presentations were combined into well-defined sections among which one should name Astronomy and Astrophysics, Optics and spectroscopy, Physics of ferroics, Nanostructured and thin-film materials, Mathematical physics and numerical methods, Devices and materials for the THz and microwave ranges, Biophysics, Optoelectronic devices, Surface phenomena, Physics and technology of energy conversion, Plasma physics, hydrodynamics and aerodynamics, Nuclear and elementary particle physics, Impurities and defects in solids, Multilayered structures, Spectroscopy of atoms and molecules and Physics of quantum structures. This issue of the Journal of Physics: Conference Series presents the extended contributions from participants of PhysicA.SPb/2021 that were peer-reviewed by expert referees through processes administered by the Presiders of the Organising and Program Committees to the best professional and scientific standards. This was made possible by the efforts of the Sectional and Technical Editors of this Issue: Prof. Petr Arseev (Lebedev Physical Institute), Prof. Alexander Ivanchik (Ioffe Institute), Prof. Polina Ryabochkina (Ogarev Mordova State University), Prof. Yuri Kusraev (Ioffe Institute), Dr. Sergey Nekrasov (Ioffe Institute), Dr. Nikolay Bert (Ioffe Institute), Dr. Nikita Gordeev (Ioffe Institute), Dr. Alexey Popov (Ioffe Institute), Dr. Prokhor Alekseev (Ioffe Institute), Dr. Mikhail Dunaevskii (Ioffe Institute), Prof. Mikhail Nestoklon (Ioffe Institute), Dr. Andrey Dunaev (Orel State University), Prof. Anton Vershovskii (Ioffe Institute), Dr. Vadim Evtikhiev (Ioffe Institute), Prof. Alexey Ustinov (St.Petersburg Electrotechnical University “LETI”), Dr. Alexandra Kalashnikova (Ioffe Institute), Prof. Ivan Mitropolsky (NRC Kurchatov Institute - PNPI), Dr. Evgenia Cherotchenko (Ioffe Institute) and Prof. Dmitry Khokhlov (Moscow State University). The Editors: Nikita S. Averkiev, Sergey A. Poniaev and Grigorii S. Sokolovskii

Propagation and scattering effects in temporal metastructures

Electromagnetic scattering typically occurs when a change in the material properties is perceived by the propagating wave, that inevitably splits into a reflected and refracted wave to maintain the continuity of the field components at the interface between the two media. However, such a scattering phenomenon occurs also when the entire media suddenly switches its properties to other values at a certain instant of time, realizing the so-called temporal interface. After a temporal interface, a couple of waves, one reflected and one transmitted, starts to propagate in the new media with the same wavelength but at a different frequency. Exploiting the analogies and differences between spatial and temporal interfaces, in this contribution we present the temporal counterparts of conventional electromagnetic devices based on dielectric slabs and a cascade of them, i.e., the multilayered structures. We discuss about the analysis and design strategies for synthetizing the desired scattering response in both transmission and reflection and present the possible families of devices based on multi-switched temporal metamaterials that can be conceived.