34 research outputs found

    An Internet-Based Real-Time Audiovisual Link for Dual MEG Recordings

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    Hyperscanning Most neuroimaging studies of human social cognition have focused on brain activity of single subjects. More recently, "two-person neuroimaging" has been introduced, with simultaneous recordings of brain signals from two subjects involved in social interaction. These simultaneous "hyperscanning" recordings have already been carried out with a spectrum of neuroimaging modalities, such as functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and functional near-infrared spectroscopy (fNIRS). Dual MEG Setup We have recently developed a setup for simultaneous magnetoencephalographic (MEG) recordings of two subjects that communicate in real time over an audio link between two geographically separated MEG laboratories. Here we present an extended version of the setup, where we have added a video connection and replaced the telephone-landline-based link with an Internet connection. Our setup enabled transmission of video and audio streams between the sites with a one-way communication latency of about 130 ms. Our software that allows reproducing the setup is publicly available. Validation We demonstrate that the audiovisual Internet-based link can mediate real-time interaction between two subjects who try to mirror each others' hand movements that they can see via the video link. All the nine pairs were able to synchronize their behavior. In addition to the video, we captured the subjects' movements with accelerometers attached to their index fingers; we determined from these signals that the average synchronization accuracy was 215 ms. In one subject pair we demonstrate inter-subject coherence patterns of the MEG signals that peak over the sensorimotor areas contralateral to the hand used in the task.Peer reviewe

    Never Resting Brain: Simultaneous Representation of Two Alpha Related Processes in Humans

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    Brain activity is continuously modulated, even at “rest”. The alpha rhythm (8–12 Hz) has been known as the hallmark of the brain's idle-state. However, it is still debated if the alpha rhythm reflects synchronization in a distributed network or focal generator and whether it occurs spontaneously or is driven by a stimulus. This EEG/fMRI study aimed to explore the source of alpha modulations and their distribution in the resting brain. By serendipity, while computing the individually defined power modulations of the alpha-band, two simultaneously occurring components of these modulations were found. An ‘induced alpha’ that was correlated with the paradigm (eyes open/ eyes closed), and a ‘spontaneous alpha’ that was on-going and unrelated to the paradigm. These alpha components when used as regressors for BOLD activation revealed two segregated activation maps: the ‘induced map’ included left lateral temporal cortical regions and the hippocampus; the ‘spontaneous map’ included prefrontal cortical regions and the thalamus. Our combined fMRI/EEG approach allowed to computationally untangle two parallel patterns of alpha modulations and underpin their anatomical basis in the human brain. These findings suggest that the human alpha rhythm represents at least two simultaneously occurring processes which characterize the ‘resting brain’; one is related to expected change in sensory information, while the other is endogenous and independent of stimulus change

    Comparative Analysis of Mobile Learning Trends of Physical Education Teaching Students: Republic of Kosovo and Russia Example

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    The aim of this research is to conduct a comparative analysis of the mobile learning trends of students of the physical education teaching department studying in The Republic of Kosovo and Russia. In this research, causal comparative research method was used. The study group consists of 40 students studying physical education teaching at various universities in Kosovo and Russia in the 2020-2021 academic year. A total of 80 students participated in the study. The research data were collected by the semi-structured interview form developed by the researcher and the data was analyzed by content analysis method. The research results reveal that students studying in both countries have a high mobile learning tendency. In addition, students from both countries have similarly defined the advantages and disadvantages of mobile device use in education

    Theoretical Insight into B–C Chemical Bonding in <i>Closo</i>-Borate [B<sub>n</sub>H<sub>n−1</sub>CH<sub>3</sub>]<sup>2−</sup> (n = 6, 10, 12) and Monocarborane [CB<sub>n</sub>H<sub>n</sub>CH<sub>3</sub>]<sup>−</sup> (n = 5, 9, 11) Anions

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    A theoretical investigation of mono-methyl derivatives of closo-borate anions of the general form [BnHnCH3]2– (n = 6, 10, 12) and monocarboranes [HCBnHnCH3]− (n = 5, 9, 11) was carried out. An analysis of the main bonding descriptors of exo-polyhedral B–C bonds was performed using the QTAIM (quantum theory of “Atoms in Molecules”), ELF (electron localisation function), NBOs (natural bond orbitals) analyses and several other approaches for the estimation of B–C bond orders (viz. Laplacian bond order (LBO), fuzzy bond order (FBO) and Mayer and Wiberg formalisms). Based on the data obtained on electron density descriptors, it can be concluded that orbital interaction increases with increasing boron cluster size. The present investigation provides a better understanding of exo-polyhedral B–C bond phenomena in boron cluster systems. The data obtained can be used to estimate B–C bond strength, which can be useful for studies devoted to the synthesis and properties of boron cluster systems

    Non-Covalent Interactions in the Crystal Structures of Perbrominated Sulfonium Derivatives of the closo-Decaborate Anion

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    A new series of compounds based on perbrominated disubstituted sulfonium derivatives of the closo-decaborate anion (n-Bu4N)[2-B10Br9SR2] (R = n-Pr, i-Pr, n-Bu, n-C8H17, n-C12H25, n-C18H37) was obtained, characterised by modern physicochemical methods of analysis. According to the results of an X-ray diffraction study, some of the anions and solvate molecules were disordered. The cations (n-Bu4N)+ and anions [2-B10Br9SR2]&minus; were associated via C-H&hellip;Br and H&hellip;H contacts. In addition, Br&hellip;Br interactions between anions were revealed. The role of these contacts was analysed in terms of Hirshfeld surface analysis, QTAIM theory and the NCI method using quantum chemical calculations. An increase in the size of the alkyl R moiety led to significant strengthening of the total energy of H&hellip;H interactions. In the case of R = -n-C18H37, a parallel mutual orientation of alkyl moieties was established that was similar to the packing of salts of fatty acids. The nature of C-H&hellip;Br and Br&hellip;Br interionic interactions was found to be attractive, in contrast to the repulsive nature of intermolecular Br&hellip;Br interactions

    Nucleophilic Substitution Reactions in the [B3H8]&minus; Anion in the Presence of Lewis Acids

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    As a result of our study on the interaction between the octahydrotriborate anion with nucleophiles (Nu = THF, Ph3P, Ph2P-(CH2)2-PPh2 (dppe), Ph3As, Et3N, PhNH2, C5H5N, CH3CN, Ph2CHCN)) in the presence of a wide range of Lewis acids (Ti(IV), Hf(IV), Zr(IV), Al, Cu(I), Zn, Mn(II), Co(II) halides and iodine), a number of substituted derivatives of the octahydrotriborate anion [B3H7Nu] are obtained. It is found that the use of TiCl4, AlCl3, ZrCl4, HfCl4, CuCl and iodine leads to the highest product yields. In this case, it is most likely that the reaction proceeds through the formation of an intermediate [B3H7-HMXnx], which was detected by NMR spectroscopy. The structures of [Ph3P&middot;B3H7] and [PhNH2&middot;B3H7] were determined by X-ray diffraction

    New Aspects of the Synthesis of <i>closo</i>-Dodecaborate Nitrilium Derivatives [B<sub>12</sub>H<sub>11</sub>NCR]<sup>−</sup> (R = <i>n</i>-C<sub>3</sub>H<sub>7</sub>, <i>i</i>-C<sub>3</sub>H<sub>7</sub>, 4-C<sub>6</sub>H<sub>4</sub>CH<sub>3</sub>, 1-C<sub>10</sub>H<sub>7</sub>): Experimental and Theoretical Studies

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    The preparation of novel nitrilium derivatives of closo-dodecaborate anion [B12H11NCR]−, R = n-C3H7, i-C3H7, 4-C6H4CH3, 1-C10H7 is described. Target compounds were obtained in good yields (up to 73%). The synthesis of target borylated nitrilium derivatives was characterised by the simplicity of the chemical apparatus and the absence of the necessity for the purification of desired compounds. The crystal structures of previously obtained [B12H11NCCH3]− and novel [B12H11NCC3H7]− were established with the help of X-ray structure analysis. DFT-analysis of several nitrilium derivatives [B12H11NCR]−, R = CH3, C3H7, 4-CH3C6H4 was carried out. The main peculiarities of the C≡N bond of the exo-polyhedral substituent were revealed in terms of bond lengths, bond orders and atomic charges. The LUMO orbitals of the systems considered were examined for understanding of the electrophilic nature of the nitrilium derivatives of the closo-dodecaborate anion

    Primary Amine Nucleophilic Addition to Nitrilium <i>Closo</i>-Dodecaborate [B<sub>12</sub>H<sub>11</sub>NCCH<sub>3</sub>]<sup>−</sup>: A Simple and Effective Route to the New BNCT Drug Design

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    In the present work, a convenient and straightforward approach to the preparation of borylated amidines based on the closo-dodecaborate anion [B12H11NCCH3NHR]−, R=H, Alk, Ar was developed. This method has two stages. A nitrile derivative of the general form [B12H11NCCH3]− was obtained, using a modified technique, in the first stage. On the second stage the resulting molecular system interacted with primary amines to form the target amidine products. This approach is characterised by a simple chemical apparatus, mild conditions and high yields of the final products. The mechanism of the addition of amine to the nitrile derivative of the closo-dodecaborate anion was studied, using quantum-chemical methods. The interaction between NH3 and [B12H11NCCH3]− ammonia was chosen as an example. It was found that the structure of the transition state determines the stereo-selectivity of the process. A study of the biological properties of borylated amidine sodium salts indicated that the substances had low toxicity and could accumulate in cancer cells in significant amounts

    Synthesis of Disubstituted Carboxonium Derivatives of <i>Closo</i>-Decaborate Anion [2,6-B<sub>10</sub>H<sub>8</sub>O<sub>2</sub>CC<sub>6</sub>H<sub>5</sub>]<sup>−</sup>: Theoretical and Experimental Study

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    A comprehensive study focused on the preparation of disubstituted carboxonium derivatives of closo-decaborate anion [2,6-B10H8O2CC6H5]− was carried out. The proposed synthesis of the target product was based on the interaction between the anion [B10H11]− and benzoic acid C6H5COOH. It was shown that the formation of this product proceeds stepwise through the formation of a mono-substituted product [B10H9OC(OH)C6H5]−. In addition, an alternative one-step approach for obtaining the target derivative is postulated. The structure of tetrabutylammonium salts of carboxonium derivative ((C4H9)4N)[2,6-B10H8O2CC6H5] was established with the help of X-ray structure analysis. The reaction pathway for the formation of [2,6-B10H8O2CC6H5]− was investigated with the help of density functional theory (DFT) calculations. This process has an electrophile induced nucleophilic substitution (EINS) mechanism, and intermediate anionic species play a key role. Such intermediates have a structure in which one boron atom coordinates two hydrogen atoms. The regioselectivity for the process of formation for the 2,6-isomer was also proved by theoretical calculations. Generally, in the experimental part, the simple and available approach for producing disubstituted carboxonium derivative was introduced, and the mechanism of this process was investigated with the help of theoretical calculations. The proposed approach can be applicable for the preparation of a wide range of disubstituted derivatives of closo-borate anions

    Protonation of Borylated Carboxonium Derivative [2,6-B10H8O2CCH3]&minus;: Theoretical and Experimental Investigation

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    The process of protonation of [2,6-B10H8O2CCH3]&minus; was investigated both theoretically and experimentally. The most suitable conditions for protonation of the derivative [2,6-B10H8O2CCH3]&minus; were found. The process of protonation was carried out in the presence of an excess of trifluoromethanesulfonic acid CF3SO3H at room temperature in dichloromethane solution. The structure of the resulting complex [2,6-B10H8O2CCH3*Hfac]0 was established using NMR data and the results of DFT calculations. An additional proton atom Hfac was found to be localized on one of the facets that was opposite the boron atom in a substituted position, and which bonded mainly with one apical boron atom. The main descriptors of the B-Hfac bond were established theoretically using QTAIM and NBO approaches. In addition, the mechanism of [2,6-B10H8O2CCH3]&minus; protonation was investigated
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