BINA

Background: There are compelling evidence from animal models and retrospective clinical studies that early exposure to clinically relevant general anesthetic medications interferes with brain development and may lead to permanent cognitive impairments. 1 2 At least in immature rodents, exposure to either NMDA-type glutamate receptor antagonists or positive modulators of GABAA receptors can lead to increased apoptosis. Blockade of NMDA receptors by ketamine in the developing rodent brain causes excessive apoptosis. 2 Additionally, ketamine inhibits proliferation of neural stem cells and disturbs normal neurogenesis. 3 However, it is currently not clear whether similar exposures can similarly affect children and what are the mechanisms that mediate these effects. Neurosteroids such as allopregnanolone (ALLO) have anesthetic properties and have been shown to be neuroprotective. 4 Understanding their neuroprotective role in anesthetic induced injury may have major implications in decreasing anesthetic-induced brain damage or designing potentially less toxic anesthetic agents. 5Methods: In this project we studied the effects of ketamine on human neural stem cells, and neurons. We have generated immortalized human neural stem cells (NSCs), and neurons that maintain the phenotypes and functions of the original cells.Results: Using human neural cells in culture, we demonstrated that ketamine induced a dose-dependent decrease in the proliferation of NSCs and an increase in cell death of neurons (Figure). We also demonstrate that ALLO (1 μM) protected NSCs from the inhibitory effect of ketamine on cell proliferation. Moreover …

Many catalyst materials have been tried to synthesize ultra-long carbon nanotubes (CNTs) by extending catalyst lifetime and delaying growth termination. We propose a time-controlled, variable composition iron–molybdenum catalyst system, where the diffusion of molybdenum (as a thin layer reservoir) is mediated by the alumina underlayer, to reach and to slowly alloy with the Fe catalyst on the surface during the thermal process. This technique enhanced both the catalytic activity and the catalytic lifetime to grow CNT carpets with heights up 5 mm, compared to a maximum of approximately 1.5 mm for a regular sample (without Mo reservoir). Moreover, the CNT height increased with the thickness of the Mo thin layer reservoir for thicknesses from 10 nm to 30 nm. We discuss this new growth mechanism using high resolution transmission microscopy (HRTEM) images of cross-section lamellas and Rutherford Back …

The papers in this volume were part of the technical conference cited on the cover and title page. Papers were selected and subject to review by the editors and conference program committee. Some conference presentations may not be available for publication. Additional papers and presentation recordings may be available online in the SPIE Digital Library at SPIEDigitalLibrary. org.

We consider stochastic processes, piecewise constant in time, which can be viewed as a gapless sequences of statistically independent box functions of duration τ i and height v i. Lengths and heights of the boxes are deterministically coupled, whereas the areas τ i v i are iid random variables. These processes are closely related to the velocity process of space-time coupled Levy walks, but can more generally be viewed as a renewal processes, where the life times τ i are not simply drawn from one given distribution, but are determined via a deterministic law by the values v i of a relevant stochastic variable. Despite its simplicity, these processes can show anomalous diffusion, or, more general, anomalous behavior of its moments. The latter can be related either to invariant densities, which are non-normalizable, or, for other parameters, to certain scaling densities. We obtained exact results for these quantities …

We propose an experimentally realizable method to demonstrate Lyapunov instability and to estimate ergodization time in chaotic many-particle systems by monitoring equilibrium noise of virtually any observable quantity before and after time reversal of dynamics (Loschmidt echo). In the quantum regime, the quantity of interest for the method is a counterpart of out-of-time-order correlators (OTOCs). The ergodization time is defined as the characteristic time required to extract the largest Lyapunov exponent from a system's dynamics. The proposal focuses specifically on a lattice of coupled Bose-Einstein condensates in the classical regime describable by the discrete Gross-Pitaevskii equation. We support our theoretical analysis by direct numerical simulations demonstrating that the largest Lyapunov exponent and the ergodization time can indeed be extracted from the Loschmidt echo routine.

Pancreatic β-cell membranes and presynaptic areas of neurons contain analogous protein complexes that control the secretion of bioactive molecules. These complexes include the neuroligins (NLs) and their binding partners, the neurexins (NXs). It has been recently reported that both insulin secretion and the proliferation rates of β-cells increase when cells are co-cultured with full-length NL-2 clusters. The pharmacological use of full-length protein is always problematic due to its unfavorable pharmacokinetic properties. Thus, NL-2-derived short peptide was conjugated to the surface of polyamidoamine-based (PAMAM) dendrimers. This nanoscale composite improved β-cell functions in terms of the rate of proliferation, glucose-stimulated insulin secretion (GSIS), and functional maturation. This functionalized dendrimer also protected β-cells under cellular stress conditions. In addition, various novel peptidomimetic …

The construction of low cost, printable compatible, solution processed, of high performance, stable solar cells is one of the scientific milestones of the next ten years. The discovery of graphene launched a new era in the materials science, and the research implemented in the exceptional properties of the two-dimensional (2D) materials. The chemical, physical, electrical and mechanical properties of 2D materials match with the requirements that the various building blocks of the third-generation photovoltaics should have in order for these devices to deliver exceptional performance and become attractive alternatives to silicon-based solar cells. The 2D library of materials expands in a very high pace and nowadays includes 150 exotic layered materials. Among them are the transition metal dichalcogenides (2D-TMDs). Recent advances in atomically thin 2D-TMDs (e.g., MoS2, WS2, MoSe2 and WSe2) have …

Background: There are compelling evidence from animal models and retrospective clinical studies that early exposure to clinically relevant general anesthetic medications interferes with brain development and may lead to permanent cognitive impairments. 1 2 At least in immature rodents, exposure to either NMDA-type glutamate receptor antagonists or positive modulators of GABAA receptors can lead to increased apoptosis. Blockade of NMDA receptors by ketamine in the developing rodent brain causes excessive apoptosis. 2 Additionally, ketamine inhibits proliferation of neural stem cells and disturbs normal neurogenesis. 3 However, it is currently not clear whether similar exposures can similarly affect children and what are the mechanisms that mediate these effects. Neurosteroids such as allopregnanolone (ALLO) have anesthetic properties and have been shown to be neuroprotective. 4 Understanding their neuroprotective role in anesthetic induced injury may have major implications in decreasing anesthetic-induced brain damage or designing potentially less toxic anesthetic agents. 5Methods: In this project we studied the effects of ketamine on human neural stem cells, and neurons. We have generated immortalized human neural stem cells (NSCs), and neurons that maintain the phenotypes and functions of the original cells.Results: Using human neural cells in culture, we demonstrated that ketamine induced a dose-dependent decrease in the proliferation of NSCs and an increase in cell death of neurons (Figure). We also demonstrate that ALLO (1 μM) protected NSCs from the inhibitory effect of ketamine on cell proliferation. Moreover …

Epitaxially grown films of VO 2 are one of the most promising materials for oxide electronics due to a very convenient temperature and remarkable controllability of the insulator-to-metal phase transition (IMT) by doping, strain, photo excitations or applying an electric field. Scaling the IMT-based devices down to submicron size is a technological challenge because of the high variability of the resulted functional characteristics from device to device. Our work focuses on the structural and morphological origins of such variations. We used X-ray nano diffraction mapping to study the evolution of mosaicity, strain and phase coexistence in 70 nm thick VO 2 film (r-cut Al 2O 3) during thermal cycling and annealing. We found high anisotropy in the grain and crack network structure which remarkably resonates with anisotropy of transport properties. We were able to distinguish a persistent morphological pattern due to the film …

Coverage is a canonical task where a robot or a group of robots are required to visit every point in a given work area, typically within the shortest possible time. Previous work on offline coverage highlighted the benefits of determining a circular coverage path, divided into segments for different robots (if more than one). This paper contributes a number of significant improvements to the planning and utilization of circular coverage paths with single and multiple robots. We focus on circular paths that exactly decompose the environment into cells, where each obstacle-free cell is covered in a back-and-forth movement. We show that locally changing the coverage direction (alignment) in each cell can improve coverage time, and that this allows for merging bordering cells into larger cells, significantly reducing the number of turns taken by the robots. We additionally present a novel data structure to compactly …

SYNTHESIS OF ARGENTUM VANADATE'S OBTAINED BY ION-EXCHANGING WAY ON THE BASE OF SYNTHESIZED ELECTROCHEMICALLY V 2 O 5-X· YH 2 O, AND THEIR BEHAVIOR IN THE ELECTRODES FOR LITHIUM ACCUMULATOR

Adenosine to inosine (A-to-I) RNA editing is a co/post-transcriptional modification of double stranded RNA, catalysed by the adenosine deaminase acting on RNA (ADAR) family of enzymes, which results in recognition of inosine as guanosine by translational and splicing machinery causing potential recoding events in amino acid sequences. A-to-I editing is prominent within brain-specific transcripts and dysregulation of editing at several well-studied loci (e.g., Gria2, Htr2c) has been implicated in acute and chronic stress in rodents as well as neurological (e.g., Alzheimer’s) and psychopathological disorders such as schizophrenia and major depressive disorder. However, only a small fraction of recoding sites has been investigated within the brain following stress and our understanding of the role of RNA editing in transcriptome regulation following environmental stimuli remains poorly understood. Thus, we aimed …

The ability of our immune system to recognize ever-evolving threats is critical to survival. Initial recognition of pathogens depends on generating a diverse repertoire of antibodies (a.k.a. immunoglobulins, Igs) through recombination of gene segments, followed by dynamic modifications as activated B cells undergo cycles of division, somatic hypermutation and affinity-dependent selection. This affinity maturation produces expanded memory B cell clones expressing mutated Igs with high-affinity for the pathogen. Recent developments in high-throughput sequencing bring exciting possibilities, allowing for large-scale characterization of Ig repertoires. Analyzing Ig repertoires offers insights into the infection history of individuals, teaches us about fundamental immune processes and reveals dysregulations. Ig repertoire sequencing and analysis (REP-seq) require dedicated experimental protocols and computational …

Oil emulsion droplets in water have been observed to spontaneously deform into polyhedral shapes at temperatures where the surfactant interface freezes while the bulk oil and water remain liquid. The interface monolayer crystalizes into a hexagonal lattice, which is topologically constrained to accomodate a certain number of defects, namely disclinations. Additional defects, called dislocations, are also expected to be found in crystals with large number of particles. Dislocations are not only thermally induced but, more importantly, they are known to screen the large stresses around disclinations by forming chain-like structures at their vicinity. We address the problem of faceting droplets by studying the interplay between the interface geometry and the arragement of dislocations. We have found that the coupling between the distribution of crystal defects, surface curvature and entropy is key to understand the …

Particles at disordered droplet interfaces were extensively investigated, aiming both at their fundamental physics and at their applications in particle-stabilized pharmaceuticals and aerosols. Yet, particles residing at the ubiquitous ordered interfaces have never been studied. We study the dynamics of tracer colloids, incorporated into a curved 2nm-thick crystal, forming at T= T s 26 o C at the interface of liquid oil-in-water emulsion droplets. We demonstrate the particles to be spontaneously dragged to particular surface locations, identified with topological defects within the crystalline structure. At T= T d< T s, the droplets undergo an unprecedented sphere-to-icosahedron shape transformation, with their bulk remaining liquid. At T d, the attractors self-position onto the vertices of the icosahedra and fix there the colloids' positions. At an even lower temperature, the particles are spontaneously expelled from the droplets …