Local study of lithiation and degradation paths in LiMn2O4 battery cathodes via scanning probe microscopy and confocal raman microscopy

The work was financially supported by Russian Science Foundation (Grant 17-72-10144). The equipment of Ural Center for Shared Use “Modern Nanotechnology” Ural Federal University was used

Quantitative characterization of the ionic mobility and concentration in Li-battery cathodes via low frequency electrochemical strain microscopy

The work was financially supported by Russian Science Foundation (Grant 17-72-10144). The equipment of the Ural Center for Shared Use “Modern nanotechnol-ogy” UrFU was used

A Comparative Study of Three Different Types of Stem Cells for Treatment of Rat Spinal Cord Injury

Three different sources of human stem cells-bone marrow-derived mesenchymal stem cells (BM-MSCs), neural progenitors (NPs) derived from immortalized spinal fetal cell line (SPC-01), and induced pluripotent stem cells (iPSCs)-were compared in the treatment of a balloon-induced spinal cord compression lesion in rats. One week after lesioning, the rats received either BM-MSCs (intrathecally) or NPs (SPC-01 cells or iPSC-NPs, both intraspinally), or saline. The rats were assessed for their locomotor skills (BBB, flat beam test, and rotarod). Morphometric analyses of spared white and gray matter, axonal sprouting, and glial scar formation, as well as qPCR and Luminex assay, were conducted to detect endogenous gene expression, while inflammatory cytokine levels were performed to evaluate the host tissue response to stem cell therapy. The highest locomotor recovery was observed in iPSC-NP-grafted animals, which also displayed the highest amount of preserved white and gray matter. Grafted iPSC-NPs and SPC-01 cells significantly increased the number of growth-associated protein 43 (GAP43+) axons, reduced astrogliosis, downregulated Casp3 expression, and increased IL-6 and IL-12 levels. hMSCs transiently decreased levels of inflammatory IL-2 and TNF-alpha. These findings correlate with the short survival of hMSCs, while NPs survived for 2 months and matured slowly into glia- and tissue-specific neuronal precursors. SPC-01 cells differentiated more in astroglial phenotypes with a dense structure of the implant, whereas iPSC-NPs displayed a more neuronal phenotype with a loose structure of the graft. We concluded that the BBB scores of iPSC-NP- and hMSC-injected rats were superior to the SPC-01-treated group. The iPSC-NP treatment of spinal cord injury (SCI) provided the highest recovery of locomotor function due to robust graft survival and its effect on tissue sparing, reduction of glial scarring, and increased axonal sprouting

Нова формула для розрахунку дистрибутивної функції відбивної здатності поверхні

На сучасному етапі розвитку комп'ютерної графіки особливу увагу приділяють формуванню реалістичних зображень, які найбільш точно відтворюють об'єкти реального світу. Важливим при цьому є достовірна передача кольору, що передбачає використання при зафарбовуванні тривимірних графічних об'єктів спеціальних методів, серед яких найбільш поширеним є метод Фонга [1,2]. У методі Фонга розраховуються значення векторів нормалей у вершинах полігону, які потім у процесі растеризації лінійно інтерполюються вздовж ребер і рядків сканування. Нормалізовані вектори нормалей використовуються у функції тонування для обчислення інтенсивності кольору кожного елемента зображення. Метод Фонга враховує кривизну поверхонь, і, як наслідок, забезпечує формування реалістичних зображень. Враховуючи, що зафарбовування за методом Фонга є достатньо трудомістким, то актуальними є питанням розробки нових підходів до підвищення його продуктивності

Local electronic transport across probe/ionic conductor interface in scanning probe microscopy

Charge carrier transport through the probe-sample junction can have substantial consequences for outcomes of electrical and electromechanical atomic-force-microscopy (AFM) measurements. For understanding physical processes under the probe, we carried out conductive-AFM (C-AFM) measurements of local current-voltage (I-V) curves as well as their derivatives on samples of a mixed ionic-electronic conductor Li1-xMn2O4 and developed an analytical framework for the data analysis. The implemented approach discriminates between contributions the highly resistive sample surface layer and the bulk with the account of ion redistribution in the field of the probe. It was found that, with increasing probe voltage, the conductance mechanism in the surface layer transforms from Pool-Frenkel to space-charge-limited current. The surface layer significantly alters the ion dynamics in the sample bulk under the probe, which leads, in particular, to a decrease of the effective electromechanical AFM signal associated with the ionic motion in the sample. The framework can be applied for the analysis of electronic transport mechanisms across the probe/sample interface as well as to uncover the role of the charge transport in the electric field distribution, mechanical, and other responses in AFM measurements of a broad spectrum of conducting materials. © 2020 Elsevier B.V.This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 and UIDP/50011/2020, financed by national funds through the Portuguese Foundation for Science and Technology/MCTES. The work was financially supported by the Portuguese Foundation for Science and Technology (FCT) within the project PTDC/CTM-ENE/6341/2014. It is also funded by national funds (OE), through FCT ? Funda??o para a Ci?ncia e a Tecnologia, I.P. in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19. The authors thank Daniele Rosato (Robert Bosch, GmbH) for providing samples of Li-battery cathodes and useful discussions. Equipment of the Ural Center for Shared Use ?Modern nanotechnology? of the Ural Federal University was used in the experiments. The work has been supported in part by the Ministry of Science and Higher Education of the Russian Federation under the project #FEUZ-2020-0054

Electrochemical Strain Microscopy of Li-ion battery cathodes

The work was financially supported by the Portuguese Foundation for Science and Technology (FCT) within the project PTDC/CTM-ENE/6341/2014. The equipment of the Ural Center for Shared Use “Modern nanotechnology” UrFU was used

A spectroscopic analysis of the chemically peculiar star HD207561

In this paper we present a high-resolution spectroscopic analysis of the chemically peculiar star HD207561. During a survey programme to search for new roAp stars in the Northern hemisphere, Joshi et al. (2006) observed significant photometric variability on two consecutive nights in the year 2000. The amplitude spectra of the light curves obtained on these two nights showed oscillations with a frequency of 2.79 mHz [P~6-min]. However, subsequent follow-up observations could not confirm any rapid variability. In order to determine the spectroscopic nature of HD207561, high-resolution spectroscopic and spectro-polarimetric observations were carried out. A reasonable fit of the calculated Hbeta line profile to the observed one yields the effective temperature (Teff) and surface gravity (log g) as 7300 K and 3.7 dex, respectively. The derived projected rotational velocity (vsin i) for HD207561 is 74 km/sec indicative of a relatively fast rotator. The position of HD207561 in the H-R diagram implies that this is slightly evolved from the main-sequence and located well within the delta-Scuti instability strip. The abundance analysis indicates the star has slight under-abundances of Ca and Sc and mild over-abundances of iron-peak elements. The spectro-polarimetric study of HD207561 shows that the effective magnetic field is within the observational error of 100 gauss (G). The spectroscopic analysis revealed that the star has most of the characteristics similar to an Am star, rather than an Ap star, and that it lies in the delta-Scuti instability strip; hence roAp pulsations are not expected in HD207561, but low-overtone modes might be excited.Comment: 8 pages, 7 figures, 3 tables. Accepted for pubblication in MNRA