The study demonstrates that the introduction of the electrochemically inactive dielectric additive Li2TiO3 to LTO results in a strong decrease in the grain boundary resistance of LTO-Li2TiO3 (LTC) ...composites at a low concentration of Li2TiO3. With the increase in the concentration of Li2TiO3 in LTC composites, the grain boundary resistance goes through a minimum and increases again due to the growth of the insulation layer of small Li2TiO3 particles around LTO grains. For LTO-TiO2 (LTT) composites, a similar effect was observed, albeit not as strong. It was found that LTC composites at low concentration of Li2TiO3 have unusually high charge–discharge capacity exceeding the theoretical value for pure LTO. This effect is likely to be caused by the occurrence of the electrochemical activity of Li2TiO3 in the vicinity of the interfaces between LTO and Li2TiO3. The increase in the capacity may be qualitatively described in terms of the model of two-phase composite in which there is the interface layer with a high capacity. Contrasting with LTC composites, in LTT composites, no capacity enhancement was observed, which was likely due to a noticeable difference in crystal structures of LTO and TiO2 preventing the formation of coherent interfaces.
Cerium doped Gd3Ga3Al2O12 (GGAG) single crystals as well as GGAG:Ce single crystals co-doped by divalent (Mg2+, Ca2+) and tetravalent (Zr4+, Ti4+) ions have been studied by means of time-resolved ...luminescence as well as the excitation luminescence spectroscopy in vacuum ultraviolet (VUV) and soft X-ray (XUV) spectral range. Tunable laser excitation was applied for time-resolved experiments in order to obtain luminescence decay curves under excitations in Ce3+, Gd3+ and excitonic absorption bands. The influence of the co-dopant ions on the Ce3+ luminescence decay kinetics is elucidated. The fastest luminescence decay was observed for the Mg2+ co-doped crystals under any excitation below bandgap energy indicating the perturbation of the 5d states of Ce3+ by Mg2+ ions. Synchrotron radiation was utilized for the luminescence excitation in the energy range from 4.5 to 800 eV. Special attention was paid to the analysis of Ce3+ excitation spectra in VUV and XUV spectral range where multiplication of electronic excitation (MEE) processes occur. Our results demonstrated that GGAG:Ce single crystals co-doped by Mg2+ ions as well as the GGAG:Ce crystal annealed in vacuum reveal the most efficient excitation of Ce3+ emission in VUV-XUV excitation range. The role of intrinsic defects in MEE processes in the co-doped as well as in the annealed GGAG:Ce single crystals is discussed.
У даній статті розкрито основні положення щодо організації та проведення судово-психологічної експертизи неповнолітніх жертв насильства. Розглянуто поняття фізичного, сексуального та психологічного ...насильства над дитиною. Теоретично проаналізовано місце судово-психологічної експертизи неповнолітніх жертв насильства та її значення в кримінальному процесі. Визначено предмет, об’єкт та завдання судово-психологічної експертизи. Розглянуто особливості прояву психотравматизації дитини як наслідка насильства. Розроблено алгоритм психодіагностичного інструментарію відповідно до вікових періодів неповнолітніх жертв насильства.
Sm2+ and Sm3+ co-doped SrB4O7 could be utilized in several high-level optical devices and fundamental knowledge about the optical behavior of these materials benefits the development of luminescent ...applications. Herein, we report luminescence and its vacuum ultraviolet (VUV) excitation spectra in samarium doped SrB4O7. Both, Sm2+ and Sm3+ luminescence centers have been examined and distinguished in the emission and the excitation spectra investigated under synchrotron radiation. The contribution of either Sm2+ or Sm3+ emission lines into the emission spectra heavily depended on the excitation energy, and strong f-f transitions of both Sm2+ and Sm3+ were detected. At 10 K, a broad intrinsic luminescence in the UV range was detected and attributed to the radiative transition of either bound or self-trapped exciton in SrB4O7. The optical behavior, including e.g. inter-configurational f-d transitions of Sm(n+) were elucidated with first-principles calculations. Partial density of states well represents the changes of the electronic states that are related to the samarium doping, which in turn explains the emerging features in excitation spectra. In summary, the obtained results clarify the excitation and emission behavior of samarium doped SrB4O7.
•Luminescence and VUV excitation spectra of Sm(n+) ions in SrB4O7 are demonstrated.•First principle calculations of Sm2+ and Sm3+ ions in SrB4O7 are performed.•Energy transfer process from SrB4O7 host lattice to Sm(n+) centers are suggested.•Multiplications of electronic excitations region in SrB4O7 is identified.•The excitation spectrum of self-trapped exciton emission in SrB4O7 is obtained.
Cytokinins, classical phytohormones, affect all stages of plant ontogenesis, but their application in agriculture is limited because of the lack of appropriate ligands, including those specific for ...individual cytokinin receptors. In this work, a series of chiral N6-benzyladenine derivatives were studied as potential cytokinins or anticytokinins. All compounds contained a methyl group at the α-carbon atom of the benzyl moiety, making them R- or S-enantiomers. Four pairs of chiral nucleobases and corresponding ribonucleosides containing various substituents at the C2 position of adenine heterocycle were synthesized. A nucleophilic substitution reaction by secondary optically active amines was used. A strong influence of the chirality of studied compounds on their interaction with individual cytokinin receptors of Arabidopsis thaliana was uncovered in in vivo and in vitro assays. The AHK2 and CRE1/AHK4 receptors were shown to have low affinity for the studied S-nucleobases while the AHK3 receptor exhibited significant affinity for most of them. Thereby, three synthetic AHK3-specific cytokinins were discovered: N6-((S)-α-methylbenzyl)adenine (S-MBA), 2-fluoro,N6-((S)-α-methylbenzyl)adenine (S-FMBA) and 2-chloro,N6-((S)-α-methylbenzyl)adenine (S-CMBA). Interaction patterns between individual receptors and specific enantiomers were rationalized by structure analysis and molecular docking. Two other S-enantiomers (N6-((S)-α-methylbenzyl)adenosine, 2-amino,N6-((S)-α-methylbenzyl)adenosine) were found to exhibit receptor-specific and chirality-dependent anticytokinin properties.
This work demonstrates the use of a modified mica to concentrate proteins, which is required for proteomic profiling of blood plasma by mass spectrometry (MS). The surface of mica substrates, which ...are routinely used in atomic force microscopy (AFM), was modified with a photocrosslinker to allow "irreversible" binding of proteins via covalent bond formation. This modified substrate was called the AFM chip. This study aimed to determine the role of the surface and crosslinker in the efficient concentration of various types of proteins in plasma over a wide concentration range. The substrate surface was modified with a 4-benzoylbenzoic acid N-succinimidyl ester (SuccBB) photocrosslinker, activated by UV irradiation. AFM chips were incubated with plasma samples from a healthy volunteer at various dilution ratios (10
X, 10
X, and 10
X). Control experiments were performed without UV irradiation to evaluate the contribution of physical protein adsorption to the concentration efficiency. AFM imaging confirmed the presence of protein layers on the chip surface after incubation with the samples. MS analysis of different samples indicated that the proteomic profile of the AFM-visualized layers contained common and unique proteins. In the working series of experiments, 228 proteins were identified on the chip surface for all samples, and 21 proteins were not identified in the control series. In the control series, a total of 220 proteins were identified on the chip surface, seven of which were not found in the working series. In plasma samples at various dilution ratios, a total of 146 proteins were identified without the concentration step, while 17 proteins were not detected in the series using AFM chips. The introduction of a concentration step using AFM chips allowed us to identify more proteins than in plasma samples without this step. We found that AFM chips with a modified surface facilitate the efficient concentration of proteins owing to the adsorption factor and the formation of covalent bonds between the proteins and the chip surface. The results of our study can be applied in the development of highly sensitive analytical systems for determining the complete composition of the plasma proteome.
The paper presents theoretical and experimental studies on the reducing drag of a circular cylinder. The reduction drag is achieved by installing near a circular cylinder four flat plates. Flat ...plates installed under the meridional angle relative to the cylinder and at an angle of attack. Flat plates are symmetrically relative to the cylinder. There is a flat injection channel of constant width between the plates and the cylinder. We examine this situation of flat plates due to which the drag coefficient of the total combination reaches the smallest value. The study of reducing the drag of the cylinder was carried out in the package hydrodynamic analysis of Flow Simulation, as well as in the wind tunnel of Samara University. It has been shown that that the location of plates near the cylinder at certain angles, allows us to achieve reduction drag approximately before 40% compared with an isolated cylinder.
The long-read RNA sequencing developed by Oxford Nanopore Technology provides a direct quantification of transcript isoforms. That makes the number of transcript isoforms per gene an intrinsically ...suitable metric for alternative splicing (AS) profiling in the application to this particular type of RNA sequencing. By using this simple metric and recruiting principal component analysis (PCA) as a tool to visualize the high-dimensional transcriptomic data, we were able to group biospecimens of normal human liver tissue and hepatocyte-derived malignant HepG2 and Huh7 cells into clear clusters in a 2D space. For the transcriptome-wide analysis, the clustering was observed regardless whether all genes were included in analysis or only those expressed in all biospecimens tested. However, in the application to a particular set of genes known as pharmacogenes, which are involved in drug metabolism, the clustering worsened dramatically in the latter case. Based on PCA data, the subsets of genes most contributing to biospecimens’ grouping into clusters were selected and subjected to gene ontology analysis that allowed us to determine the top 20 biological processes among which translation and processes related to its regulation dominate. The suggested metrics can be a useful addition to the existing metrics for describing AS profiles, especially in application to transcriptome studies with long-read sequencing.
The comparative study of solid state synthesis of Li4Ti5O12 from rutile and anatase as initial reagents was carried out using the method of in situ synchrotron radiation dynamic diffractometry. ...Initial samples were obtained by mechanical treatment of Li2CO3 and TiO2 (anatase or rutile modifications). It was found that on the first stage an intermediate β-Li2TiO3 phase forms in the reaction system. On further heating the process of formation of the Li4Ti5O12 phase from β-Li2TiO3 and TiO2 is limited by lithium cation diffusion through the β-Li2TiO3 phase. Reaction strongly accelerates at temperatures above 800 oC. Using nano-sized anatase precursor, well-crystallized LTO with smaller grain size may be obtained at lower temperatures.
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