Otolith abnormalities and bilateral asymmetry are analyzed in five reproductively isolated forms and natural F1 hybrids between the forms in Arctic charr Salvelinus alpinus complex from lakes Lama and Kapchuk (Norilo-Pyasinskaya water system, Taimyr). Otolith abnormalities are associated with the partial replacement of aragonite (the usual otolithic polymorph of CaCO 3 ) by vaterite (another less stable crystalline modification of CaCO 3 ) and their unusual shape. The abnormalities are observed in 11.9% of the specimens and may be induced by technogenic pollution from Nornickel, the world’s largest manufacturer of palladium, nickel, and platinum. The assessment of bilateral asymmetry based on otolith measurements and shape indices does not indicate notable differences in this parameter between the charr forms. However, the shapes of the left and right otoliths described by wavelet analysis are significantly different in two groups: a form of Lake Kapchuk designated as the main form and F1 hybrids. The differentiation of the forms is evaluated using wavelet and linear discriminant analyses of otolith shape. The difference in the topologies of two dendrograms constructed based on the shapes of the left and right otoliths obtained from the same specimens can be explained by the occurrence of bilateral asymmetry.

The size composition of the fish, gonadal condition, and oocyte and spermatozoon ultrastructure are studied in Parupeneus heptacanthus from the coastal zone of Nha Trang (southern Central Vietnam). The males are larger than the females, and the body length—body weight relationship is significantly different in the representatives of both sexes. Based on ovarian condition, oogenesis is continuous. Average batch fecundity is 11 056 oocytes. The egg envelope in the end of vitellogenesis ( 300 µm in diameter) includes zona radiata 5.0 µm in width and chorion (0.5 µm). Based on spermatozoon head ultrastructure, the species is similar to other species of the genus Parupeneus, but the flagellum is substantially longer reaching on average 63 µm.

The inner ear position and structure, related parts of the brain and neurocranium, as well as the morphology of the lapillus, sagitta, and asteriscus, are described in climbing perch, an obligate air-breathing fish capable of terrestrial movements. The olfactory bulbs and telencephalon are well developed. The dorsal protrusion with two symmetrical lobes is observed on the dorsal posterior surface of the telencephalon. The almost triangular rear part of the brain capsule and a narrow posterior region of the neurocranium represent the border of the suprabranchial chamber. The pars superior of the inner ear is located along the internal triangular part of the brain capsule, and both crus communis and ductus semicircularis posterior are located close to each other in the narrow extreme rear region of the brain capsule. The sacculus is enclosed in the large oval bony capsule (saccular swelling), and the sagitta is large with the average otolith length–total body length (TL) ratio equal to 0.06. Linear growth of the lapillus and sagitta is characterized by negative allometry in relation to body length. Despite the slow growth rate of the lapillus, its shape substantially changes during the growth of the fish 36–205 mm TL that, most likely, reflects increasing locomotion complexity. Possible adaptations of climbing perch inner ear to terrestrial movements are discussed.

Currently, alpha-emitting radionuclide 225Ac is one of the most promising isotopes in alpha therapy due to its high linear energy transfer during four sequential alpha decays. However, the main obstacle preventing the full introduction of 225Ac into clinical practice is the lack of stable retention of radionuclides, leading to free circulation of toxic isotopes in the body. In this work, the surface of silica nanoparticles (SiO2 NPs) has been modified with metallic shells composed of titanium dioxide (TiO2) and gold (Au) nanostructures to improve the retention of 225Ac and its decay products within the developed nanocarriers. In vitro and in vivo studies in healthy mice show that the metallic surface coating of SiO2 NPs promotes an enhanced sequestering of radionuclides (225Ac and its daughter isotopes) compared to non-modified SiO2 NPs for a prolonged period of time. Histological analysis reveals that for the period of 3–10 d after the injections, the developed nanocarriers have no significant toxic effects in mice. At the same time, almost no accumulation of leaked radionuclides can be detected in non-target organs (e.g., in the kidneys). In contrast, non-modified carriers (SiO2 NPs) demonstrate the release of free radionuclides, which are distributed over the whole animal body with the consequent morphological changes in the lung, liver and kidney tissues. These results highlight the potential of the developed nanocarriers to be utilized as radionuclide delivery systems and offer an insight into design rules for the fabrication of new nanotherapeutic agents.

Annealing of amorphous TiOx films obtained by electron-beam evaporation under atmospheric conditions at temperatures from 300 to 400°C is found to lead to the formation of an anatase crystalline phase. According to Raman spectroscopy data, the increase in the fraction of the the crystalline phase stops at an annealing temperature above 350°C. According to the results of X-ray phase analysis, the average crystallite diameter is about 23 nm. Electron microscopy studies have shown that, upon annealing, the near-surface layer (15 nm thick) crystallizes in the films, and TiO2 nanocrystals with sizes from 4 to 10 nm are formed in the bulk. As the depth increases, the number of nanocrystals decreases.

The annealing of amorphous TiO x films obtained by electron-beam evaporation under atmospheric conditions at temperatures from 300 to 400°C is found to lead to the formation of an anatase crystalline phase. According to Raman spectroscopy data, the increase in the fraction of the crystalline phase stops at an annealing temperature above 350°C. According to the results of X-ray diffraction analysis, the average crystallite diameter is about 23 nm. Electron-microscopy studies show that, upon annealing, the surface layer (15 nm thick) crystallizes in the films, and TiO 2 nanocrystals with sizes from 4 to 10 nm are formed in the bulk. As the depth increases, the number of nanocrystals decreases.

The properties of semiconductors are highly dependent on their crystalline structure. The formation of metastable polytypes under the action of external mechanical stresses leads to a change in the properties of the initial materials. In particular, for hexagonal silicon polytypes, an improvement in light-emitting properties can be observed compared to diamond-like silicon. In this work, the photoluminescent properties of silicon samples with the 9R-Si hexagonal phase synthesized by implanting Kr+ ions into the SiO2/Si system have been studied. The effect of post-implantation annealing conditions on the evolution of PL peaks in the spectral range around 1240 nm is analyzed. The contribution to the observed PL peaks of the light-emitting 9R-Si phase and W, S1, S2 defects associated with radiation damage in silicon substrates is discussed. It is shown that the formation of the 9R-Si phase and associated PL are affected by mechanical stresses formed in the SiO2 film upon irradiation.

The feeding-related skull structures are described and occluding elements of the upper and lower regions of the buccopharyngeal cavity are analyzed in climbing perch. At each side of the neurocranium, the transverse process of the parasphenoid with four or five large conical teeth oppose the hypobranchial 3, and the medial teeth of the parasphenoid oppose the medial joints between paired hypobranchials 3 and ceratobranchials 4. As in the majority of other advanced Teleostei, the pharyngeal bite is carried out by the lower pharyngeal jaw (fused ceratobranchials 5) and upper pharyngeal jaws (left and right plates of pharyngobranchials 3–4). The latter jaws are articulated with paired pharyngeal processes of the basioccipital. At both sides of the skull, the strong elongated Baudelot’s ligament joins the basioccipital and supracleithrum. The hypothesis on the occurrence of the unique lower pharyngeal jaw–parasphenoid bite in climbing perch is rejected.

Hexagonal silicon polytypes have attracted significant attention within the scientific community due to their potential applications in next-generation electronics and photonics. However, obtaining stable heterostructures based on cubic and hexagonal polytypes is a challenging task. This study demonstrates the synthesis of thin layers of the hexagonal phase of silicon, specifically 9R-Si, using a conventional microelectronics technique—ion implantation. Implantation of Kr ^+ ions was performed through a SiO _2 layer, with thickness approximately twice the projected range of Kr ^+ ions, followed by high-temperature annealing. High-resolution transmission electron microscopy revealed that damage to Si substrate at the SiO _2 interface resulted in the formation of a thin amorphous layer, which recrystallized during annealing, leading to the formation of the 9R-Si polytype. It is presumed that mechanical stresses induced by implantation through the oxide layer promote hexagonalization during subsequent high-temperature annealing. The effectiveness of hexagonalization was found to depend on the substrate orientation. In addition to the formation of the 9R-Si phase, under the utilized implantation and annealing parameters, silicon exhibited light-emitting defects, with photoluminescence observed at a wavelength of approximately ∼ 1240 nm up to temperatures of about ∼ 120 K. The obtained results may find applications in silicon micro-, nano-, and optoelectronics.

The morphology of asteriscus, lapillus, and (partly) sagitta is described in gibel and crucian carps from a small natural pond located in Nizhny Novgorod oblast, Russia. The otolith shape analysis was conducted to assess the interspecific differences. A comparison of otolith structure shows that the lapillus is more rounded in the latter species, and the asteriscus length (in anteroposterior direction) is larger than its width (in dorsoventral direction) in gibel carp vs. smaller than its width in crucian carp. Bilateral directional asymmetry is registered for some otolith measurements. The two species are significantly different by six shape indices of the asteriscus and lapillus. A distinct separation between three groups (mainly immature C. gibelio < 70 mm FL, mainly adult C. gibelio > 100 mm FL, and C. carassius 37–86 mm FL) is observed based on Fourier and wavelet analyses of asteriscus and lapillus shapes. Otolith morphology can be used as an additional diagnostic character for the identification of Carassius species and possible hybrid individuals.

Arctic charr Salvelinus alpinus (L.) complex has two or more sympatric forms in many lakes representing a subject for discussions on the mechanisms of their origin and taxonomic status. To determine the number of sympatric forms in three large lakes of the Norilo-Pyasinskaya water system (Taimyr) and their reproductive and phylogenetic relationships, 17 microsatellite loci, sequences of the mtDNA control region, and several morphological characteristics were analyzed. Our data indicate that eight reproductively isolated forms inhabit lakes Lama and Kapchuk, and at least three forms are distributed in Lake Sobach'e. The origin of the forms is associated with the secondary contact and hybridization of the European and Siberian phylogenetic lineages. The same names of the forms from different lakes of Taimyr and Chukotka, for example, Boganida charr and Dryagin's charr, may reflect their certain morphological similarity, but rarely close relationships. Our data indirectly indicate that introgressive hybridization and biogeographical changes of the lakes within the region in the last glacial and post-glacial periods played a significant role in the formation of a high Arctic charr biodiversity. The problem associated with systematics, taxonomy, and conservation of the forms in Taimyr lakes is complex and should be solved gradually.

Oocyte morphology and spermatozoa ultrastructure are studied in the representatives of the genera Parascorpaena and Scorpaenopsis. Oocytes of P. aurita and S. cirrosa are attached to peduncles originated from ovigerous stroma located in the central part of the ovary. Oocyte diameter at the final phases of vitellogenesis is 450 and 500 µm, respectively. The oogenesis is asynchronous and continuous. Spermatozoa of four species (P. aurita, P. mossambica, S. cirrosa, and S. diabolus) possess similar morphology: spermatozoon head width is slightly larger than its length. The genera Parascorpaena (three species) and Scorpaenopsis (four species) differ in three from four indices designating spermatozoon head and midpiece shapes, size of nuclear fossa in the spermatozoon nucleus base (20–25 vs. 0–12% of head length), and relative location of proximal and distal centrioles (coaxial and orthogonal, respectively). The irregular shape of the nuclear fossa in the spermatozoon nucleus base of P. aurita can be interpreted as apomorphy.

The analysis of 17 microsatellite loci reveals five general forms of Arctic charr Salvelinus alpinus in large lakes Lama and Kapchuk (Norilo-Pyasinskaya water system, Taimyr) connected by the river. Three of them are represented by sister pairs, and, thus, eight reproductively isolated forms are defined. The immature individuals of different forms are hardly identified by external morphology. For the morphological differentiation of the five general forms, multivariate analyses of morphometric parameters of the body, otolith shape indices, and wavelet coefficients describing otolith contours are applied. All analyses show that goggle-eyed charr (“pucheglazka”) substantially differs from the other forms. The relationships between the four other general forms are variable depending on the method of analysis. Besides, a certain difference is observed in the data evaluating the left and right otolith shapes. The total correct jack-knifed classification of the forms in the linear discriminant analyses is 55.9% for morphometric indices and reaches 56.1 and 61.4% for the left and right otolith shapes assessed by wavelet transform. The overall morphological similarity of the forms can be explained by their parallel evolution in a restricted number of available trophic niches.

— The mutual arrangement of the inner ear structures (membranous labyrinth) and their localization in the neurocranium are studied in gibel carp Carassius gibelio . The upper anterior part of the labyrinth (pars superior) is located at a substantial distance from its lower posterior part (pars inferior). The ventral region of the pars superior is freely located in the depression of the upper part of the prootic. The pars inferior including the sacculus and lagena is enclosed in a bone capsule of the basioccipital and bounded from above by a thin bony membrane (tectum basioccipital). The pars inferior structures that participated into the reception of vibrations of the swim bladder wall are located at the same level as the elements of the Weberian apparatus. The crus communis of the pars superior transits into the elongated ductus utriculus-sacculus, which enters the bony capsule through the medial opening in the tectum basioccipital. An updated scheme of the gibel carp inner ear is illustrated. The morphological and functional properties of the membranous labyrinth of the representatives of the group Otophysi are discussed.

Memristors attract the considerable interest of researchers and engineers due to the prospects for creating new information and computing systems on their basis. First of all, this refers to memristive devices based on the resistive switching (RS) effect, which, in most cases, are fabricated in the form of metal–insulator–metal structures. At the same time, the requirement for compatibility with the basic technological process of manufacturing complementary metal-oxide-semiconductor (CMOS) structures makes it very attractive to fabricate memristive devices directly on a silicon substrate or a silicon-on-insulator (SOI) substrate using standard insulator layers such as silicon oxide. The electrical characteristics and RS of memristors based on SiOx thin films formed on SOI substrates are studied. The memristors under study do not require electroforming. For the first time, the possibility of improving the parameters of the resistive switching of SiOx-based memristors on SOI substrates using laser and heat treatments is shown.

The population structure and features of sexual maturity of gibel carp Carassius gibelio and crucian carp C. carassius are studied in a small (588 m2) natural pond. The abundance of the former species is 2.4 times larger than that of the latter species. The sex ratio (females : males) is 80 : 1 (n = 674) and 0.8 : 1 (n = 128), respectively. The gibel carp is represented by gynogenetic form. The populations of both species are characterized by similar age structure, reach sexual maturity at the age of 2–3 years, but the growth rate of the gibel carp is notably higher in comparison with that of the crucian carp; the latter species is represented by a small (on average, 55 mm FL) pedomorphic form. In the pond, individuals of both species inhabit mainly different ecological niches leading to a weak interspecific competition.

We report on the investigation of the growth defect formation in the GeSn/Ge/Si(001) epitaxial layers grown by hot wire chemical vapor deposition of Ge with simultaneous co-evaporation of Sn from an effusion cell. The nucleation of alpha-Sn nanoinclusions in the course of the growth process was found to be the main mechanism of elastic strain relaxation in the Ge1_xSnx epitaxial layers at x > 2.5% as opposed to the misfit dislocation formation at the GeSn/Ge interfaces. Also, beta-Sn nanoislands nucleating on the surface of the GeSn epitaxial layers with increased Sn concentration due to Sn segregation were identified by confocal Raman microscopy.

The memristor is a simple two-terminal device that can be realized as a capacitor-like thin film stack demonstrating the effect of resistive switching (resistive memory) due to atomic (defect) reconstruction, when a voltage of a certain polarity and magnitude is applied. The main physicochemical phenomena associated with the diffusion and drift of oxygen ions (vacancies), local processes of formation and reduction-oxidation of conducting channels (filaments) in different metal-oxide materials are considered in this chapter. The conclusions about the filamentary nature of resistive switching are supported by the local electrical characterization of thin oxide films with scanning probe microscopy techniques and multiscale simulation of electroforming and switching by using phenomenological approaches, ab initio, molecular dynamics and kinetic Monte Carlo methods.

III–V/Ge/Si(001), III–V/Ge/SOI(001), and III–V/GaAs(001) heterostructures are fabricated and investigated. The Ge buffer layer for the III–V/Ge/Si structure is grown by vapor deposition onto a Si(001) substrate via the decomposition of monogermane on a “hot wire”. In the case of III–V/Ge/SOI, the Ge buffer layer is obtained on a SOI(001) substrate by molecular-beam epitaxy via two-stage growth. The III–V layers are grown by metalorganic chemical-vapor deposition. It is shown that Ge/SOI formed by molecular-beam epitaxy using two-stage growth allows the fabrication of III–V layers that are highly competitive with those formed on Ge/Si in terms of crystalline and optical quality.