Dispersion Of Layers Research Articles

The effect of the synthesis conditions on the crystal structure of palladium(II) oxide nanofilms

Nanocrystalline films of palladium(II) oxide obtained by oxidation of the initial metallic Pd layers with a thickness of 35 nm on Si (100) substrates in atmospheric air were studied using XRD analysis, TEM, and RHEED. PdO/SiO2/Si (100) heterostructures were synthesised in two stages. First, we obtained finely dispersed layers of metallic Pd on SiO2/Si (100) substrates with an ~ 300 nm SiO2 buffer layer using thermal sublimation in a high vacuum. The Pd layers were then oxidised in the temperature range Tox = 620 – 1100 K in atmospheric air (with the partial pressure of oxygen of about 21 kPa). The study determined that the deformation of the tetragonal crystal structure of homogeneous nanocrystalline PdO films is explained by an increase in the values of lattice parameters with the oxidation temperature. The deformation reaches its maximum values at Tox ~ 970 K. Comparison of the obtained results with the earlier data regarding PdO/SiO2/Si (100) heterostructures synthesised in a dry oxygen atmosphere (with the partial pressure of oxygen of about 101.3 kPa) demonstrated that PdO films synthesized in an oxygen atmosphere are characterized by a higher degree of deformation of the crystal structure. The effect of the oxidation temperature and O2 partial pressure on the increase in the tetragonal lattice parameters of the PdO films can be explained by the formation of interstitial oxygen atoms in the octahedral void in the centre of the palladium(II) oxide unit cell.

The effect of compaction of the dispersed wood biomass layer on its drying efficiency

The article presents the results of experimental studies of the process of drying a layer of relatively large thickness (up to 100 mm) of woody biomass under conditions of radiation-convective heating. Based on the temperature values recorded in the experiments at the characteristic points of the biomass layer during the drying period, an analysis was made of the influence of the density of the filling of finely dispersed wood (pine shavings, sawdust) on the drying times. It has been established that the compaction of biomass leads to a significant acceleration (by 1.5–2 times, depending on the ambient temperature) of the drying process. A physical model is formulated that describes a complex of heat and mass transfer processes that occur during heating of woody biomass under compaction conditions. It is shown that a 1.7-fold increase in the density of a layer of finely dispersed wood (with an initial thickness of 100 mm) leads to an increase in the layer temperature during the entire drying period by an average of 23%. In order to substantiate the established regularities, an analysis was made of the change in the thermal conductivity of biomass during its compaction using a group of mathematical models of the thermal conductivity of heterogeneous media. The results of the theoretical analysis showed that the increase in the efficiency of biomass drying during its compaction occurs as a result of an increase in the effective thermal conductivity of the layer of crushed woody biomass. The results of the experiments clearly illustrate the possibility of increasing the efficiency of drying dispersed woody biomass without additional costs for optimizing heat and mass transfer processes.

Near-field enhancement of optical second harmonic generation in hybrid gold–lithium niobate nanostructures

Nanophotonics research has focused recently on the ability of nonlinear optical processes to mediate and transform optical signals in a myriad of novel devices, including optical modulators, transducers, color filters, photodetectors, photon sources, and ultrafast optical switches. The inherent weakness of optical nonlinearities at smaller scales has, however, hindered the realization of efficient miniaturized devices, and strategies for enhancing both device efficiencies and synthesis throughput via nanoengineering remain limited. Here, we demonstrate a novel mechanism by which second harmonic generation, a prototypical nonlinear optical phenomenon, from individual lithium niobate particles can be significantly enhanced through nonradiative coupling to the localized surface plasmon resonances of embedded gold nanoparticles. A joint experimental and theoretical investigation of single mesoporous lithium niobate particles coated with a dispersed layer of ~10 nm diameter gold nanoparticles shows that a ~32-fold enhancement of second harmonic generation can be achieved without introducing finely tailored radiative nanoantennas to mediate photon transfer to or from the nonlinear material. This work highlights the limitations of current strategies for enhancing nonlinear optical phenomena and proposes a route through which a new class of subwavelength nonlinear optical platforms can be designed to maximize nonlinear efficiencies through near-field energy exchange.

Hydrogen Sulphide Sequestration with Metallic Ions in Acidic Media Based on Chitosan/sEPDM/Polypropylene Composites Hollow Fiber Membranes System.

This paper presents the preparation and characterization of composite membranes based on chitosan (Chi), sulfonated ethylene-propylene-diene terpolymer (sEPDM), and polypropylene (PPy), and designed to capture hydrogen sulfide. The Chi/sEPDM/PPy composite membranes were prepared through controlled evaporation of a toluene dispersion layer of Chi:sEPDM 1;1, w/w, deposited by immersion and under a slight vacuum (100 mmHg) on a PPy hollow fiber support. The composite membranes were characterized morphologically, structurally, and thermally, but also from the point of view of their performance in the process of hydrogen sulfide sequestration in an acidic media solution with metallic ion content (Cu2+, Cd2+, Pb2+, and/or Zn2+). The operational parameters of the pertraction were the pH, pM, matrix gas flow rate, and composition. The results of pertraction from synthetic gases mixture (nitrogen, methane, carbon dioxide) indicated an efficient removal of hydrogen sulfide through the prepared composite membranes, as well as its immobilization as sulfides. The sequestration and the recuperative separation, as sulfides from an acid medium, of the hydrogen sulfide reached up to 96%, decreasing in the order: CuS > PbS > CdS > ZnS.

Metal-metal oxide synergistic catalysis: Pt nanoparticles anchored on mono-layer dispersed ZrO2 in SBA-15 for high efficiency selective hydrogenation

It is generally believed that noble metal catalysts exhibited higher activity for selective hydrogenation, while metal oxides were almost inactive. Here, we report metal-metal oxide synergistic catalysis for high efficiency selective hydrogenation by a hybrid nano-structure Pt/@-ZrO2/SBA-15 catalyst, which was fabricated by anchored Pt nanoparticles on the mono-layer dispersed ZrO2 film layer coated in SBA-15 support via a photochemical route. This Pt/@-ZrO2/SBA-15 catalyst exhibited remarkable catalytic activity in the selective hydrogenation of CO bond, NO2, and CC bond. For the selective hydrogenation of benzaldehyde, conversion >99.9% was achieved with >99% selectivity, and the turnover frequency (TOF) can be achieved up to 4822 h−1, which was much higher than that of the atomically dispersed Pd1/TiO2-EG catalyst (1002 h−1) reported in the literature, no decay in the activity was observed by several cycles. Combined the experimental and characterization results, proved that the ZrO2 was dispersed in a mono-layer in the channel of SBA-15, and the results showed that an appropriate loading of ZrO2 in this catalyst could maximize the advantage of this hybrid nano-structure to achieve the best catalytic activity. The superior activity of Pt/@-ZrO2/SBA-15 was attributed to the synergistic catalysis, strong interface electronic effect, and the unique properties of the special hybrid nano-structure. This work demonstrated synergistic catalysis of metal Pt nanoparticles and monolayer dispersion ZrO2 for high efficiency selective hydrogenation.

Micro-foaming of plant protein based meat analogues for tailored textural properties

Meat-like foods based on plant protein sources are supposed to be a solution for a more sustainable sustenance of the world population while also having a great potential to reduce the impact on climate change. However, the transition from animal-based products to more climate-friendly alternatives can only be accomplished when consumers' acceptance of plant-based alternatives is high. This article introduces a novel micro-foaming process for texturized High-Moisture Meat Analogues (HMMA) conferring enhanced structural properties and a new way to tailor the mechanical, appearance and textural characteristics of such products. First, the impact of nitrogen injection and subsequent foaming on processing pressures, temperatures and mechanical energy were assessed using soy protein concentrate and injecting nitrogen fractions in a controlled manner in the range of 0 wt% to 0.3 wt% into the hot protein melt. Direct relationships between related extrusion parameters and properties of extruded HMMAs were established. Furthermore, optimized processing parameters for stable manufacturing conditions were identified. Secondly, so produced HMMA foams were systematically analyzed using colourimetry, texture analysis, X-ray micro-tomography (XRT) and by performing water and Preprint submitted to Innovative Food Science and Emerging Technologies June 17, 2023 oil absorption tests. These measurements revealed that perceived lightness, textural hardness, cohesiveness and overrun can be tailored by adapting the injected N2 concentrations provided that the gas holding capacity of the protein matrix is high enough. Moreover, the liquid absorption properties of the foamed HMMA were greatly optimized. XRT measurements showed that the porosity at the center of the extrudate strands was the highest. The largest porosity of 53% was achieved with 0.2 wt% N2 injection, whilst 0.3 wt% N2 lead to destructuration of the HMMA foam structure through limited gas dispersion and wall slip layer formation. The latter can, nonetheless, be improved by adapting the processing parameters. All in all, this novel extrusion microfoaming process opens new possibilities to enhance the structural properties of plant-based HMMA and ultimately, consumers’ acceptance.

Heat transport and magnetohydrodynamic hybrid micropolar ferrofluid flow over a non-linearly stretching sheet

<abstract> <p>A stable colloid called ferrofluid is made up of tiny magnetic particles, often magnetite (Fe<sub>3</sub>O<sub>4</sub>), that have been bonded with an amphiphilic dispersion layer and are then suspended in a suitable liquid solvent carrier. Current industrial uses for ferrofluid include dynamic sealing, inertial and viscous damping, magnetic drug targeting, liquid microrobots, etc. In this article, we studied the heat transfer and MHD micropolar ferrofluid flow caused by non-linearly stretching surface. The results are presented for hybrid alumina- copper/ethylene glycol (${Al}_2 {O}_3$-Cu/EG) nanofluid. The governing non-linear equations describing flow are transformed into a system of ordinary differential equations using similarity transformations. Using the BVp4c method, the microstructure and inertial properties of a magnetite ferrofluid across a non-linear stretched sheet are studied. The influence of relevant parameters on stream function, velocity, micro-rotation velocity, and temperature are obtained and represented graphically. The computed results are original, and it has been observed that if we increase the magnetic parameter, the stream function and the velocity decrease, while the temperature and micro-rotation velocity increase. As the Prandtl number increases, the temperature profile decreases. It has been observed that the Nusselt number or heat transfer rate of hybrid nanofluid is better as compared to nanofluid flow.</p> </abstract>

Bi-functional role of high charge mobility with 2D/2D interactions for effective PEC and visible photocatalysis in NiO/MoS2 nanocomposites

Bi-functional 2D–2D NiO/MoS2 exhibits superior photoactivity and hydrogen production due to homogenously dispersed layers, electronic conductivity, and interfacial charge coupling.

Well-dispersed graphene toward robust lubrication via reorganization of sliding interface

Excellent lubrication performance of graphene lubricant is mostly attributed to the dispersion of graphene and forming of tribo-film. Herein, diethylene glycol dodecyl ether (E2C12) functionalized graphene oxide (E2C12-GO) was successfully prepared by simple esterification. The physicochemical properties of as-prepared samples were characterized by a series of characterization methods. E2C12-GO with flat edge and high-level spacing possesses high dispersion stability in PAO 20 base oil. Compared with base oil, 0.08 wt% E2C12-GO could achieve the reduction of average friction coefficient and wear rate by 30 % and 57 % at 150 N, respectively. Even with each long-term friction, E2C12-GO could still maintain the state of robust low friction coefficient. Meanwhile, the addition of E2C12-GO can significantly improve the load-bearing capacity (PB value and PD value) of base oil. The excellent tribological properties of E2C12-GO were attributed to high dispersion and high layer spacing, as well as the reorganization of sliding interface. Prospectively, the E2C12-GO shows promising potential as a multi-functional oil-based lubricating additive in industrial applications.

2D/3D- C3N4/CeO2 S-scheme heterojunctions with enhanced photocatalytic performance

• Successfully developed a novel method to obtain g-C 3 N 4 /CeO 2 composite photo-catalysts via simple, ball milled thermal spreading technique. • Facile control of surface morphology of carbon nitride on ceria. The optical absorption is tuned by morphology control. • The optimum loading was found to be 7.5 wt. %. • Morphology with an intermediate thickness between very thin and bulk carbon nitride on ceria surface is important to achieve maximum efficiency. • High efficiency of methylene blue degradation and good recycling performance. A facile, green and easily scalable method has been developed to facilitate the construction of 2D-C 3 N 4 /3D-CeO 2 heterojunction materials. It uses only cheap urea and ceria in a thermal spreading technique that allows the controlled growth of carbon nitride layers on cerium oxide surface. The exfoliation of bulk carbon nitride and subsequent stabilization of layers on ceria takes place during thermal spreading technique in a single step. Simple variation of carbon nitride allowed to control the morphology of carbon nitride from highly dispersed thin layer up to bulk-like structures over ceria surface. The optical absorption was enhanced with 2D-C 3 N 4 /3D-CeO 2 materials. The variation of structure and consequent differences in the solar powered decomposition of methylene blue has been analyzed. Results reveal that, the optimum loading of 7.5 wt.% carbon nitride can lead to the formation of intermediate structure in between very thin layers and bulk-like structure, that achieves best contact between the two phases making effective heterojuctions. This best catalyst exhibits 98% conversion at a timing of 100 minutes. The radical scavenging studies showed that •O 2− and h+ performed an imperative role. In addition, a plausible mechanism of photo catalytic decomposition is also proposed for 2D-C 3 N 4 /3D-CeO 2 materials.

Towards retrieving dispersion profiles using quantum-mimic optical coherence tomography and machine learning.

Artefacts in quantum-mimic optical coherence tomography are considered detrimental because they scramble the images even for the simplest objects. They are a side effect of autocorrelation, which is used in the quantum entanglement mimicking algorithm behind this method. Interestingly, the autocorrelation imprints certain characteristics onto an artefact - it makes its shape and characteristics depend on the amount of dispersion exhibited by the layer that artefact corresponds to. In our method, a neural network learns the unique relationship between the artefacts' shape and GVD, and consequently, it is able to provide a good qualitative representation of object's dispersion profile for never-seen-before data: computer-generated single dispersive layers and experimental pieces of glass. We show that the autocorrelation peaks - additional peaks in the A-scan appearing due to the interference of light reflected from the object - affect the GVD profiles. Through relevant calculations, simulations and experimental testing, the mechanism leading to the observed GVD changes is identified and explained. Finally, the network performance is tested in the presence of noise in the data and with the experimental data representing single layers of quartz, sapphire and BK7.

Corrosion Properties of Ni-P-B Dispersion Coating for Industrial Knives and Blades

Industrial blades, particularly the one used in food processing, requires not only a high hardness and a good wear protection but also an adequate corrosion protection. Currently, there is a wide variety of materials being used for this purpose that satisfy the above requirements. However, they come at a cost. Typically, steel with a high number of alloyed elements is chosen because the alloyed elements improved the steel quality. For example, incorporation of nickel, chromium, phosphorus and molybdenum in the steel improves amongst others the corrosion protection. However, the thermal processing of such steel, that is quenching, repeated tempering and followed by nitriding or boriding, is lengthy and complicated which drive the cost to produce knives using such steel up.Besides steel cutting tools, there is also cutting tools made from ceramic and carbide. Compared to steel knives, carbide knives have a longer lifespan and provide a higher temperature tolerance, which results in the application of the carbide cutting tools at higher speed and for longer periods without experiencing tool failure. Admittedly, due to carbides high hardness and thus the increase in difficulty to machine carbide, the production cost of carbide cutting tools is much higher compared to their steel counterparts. For ceramics, while the material is corrosion free and can maintain hardness and wear properties at a very high temperature, it is also more brittle than steel and carbide cutting tools. This results in premature chipping of the cutting edge and a shorter lifespan of the blade.To further reducing the production cost of industrial knives, the alternative of using a low alloyed steel which is coated with a hard coating and adjacently thermally treated for 1 h is investigated. This method is chosen because the tempering process of the low alloyed steel is not as lengthy as for high alloyed steel. The homogenously incorporated boron particles in the nickel phosphorus coating reduce the subsequent thermal treatment duration due to a shorter diffusion path compared to the conventional boriding. Previous study by the author [1] shows this approach to produce a high hardness at approx. 900 HV. Electroless nickel phosphorus coating is applied due to its good anti-corrosive properties. The presence of boron as particles in the coating or as boride after thermal treatment could change the corrosion behaviour of the coating. To date, no studies have yet been done to determine its corrosion properties and benchmarking this Ni-P-B dispersion coating with the other coating systems.In this study, the corrosion behaviour of the dispersion layer as coated and after thermal treatments at different temperatures is investigated. The corrosion resistance in NaCl 3.5 % is characterized though potentiodynamic polarisation and electrochemical impedance spectrometry. The results will be evaluated and compared to the other established coating systems.[1] The previous study will be presented at 241st ECS Meeting in Vancouver, Canada and has not yet been published at the time this abstract is submitted for the 242nd ECS Meeting in Atlanta.

Multi-field driven thermochromic films with phase change energy storage properties

Phase change energy storage microcapsules (PCESM) are commonly used for energy storage and energy conservation management. The device has the function to absorb and store external energy by doping PCESM. In the field of optoelectronic displays, the multi-field driven thermochromic film (TCF) was driven through continuous action of electric field and temperature field to realize the special display function of TCF. The study presents a multi-field driven thermochromic films with phase change energy storage properties (PCES-TCF). PCES-TCF is constructed by thermochromic liquid crystal layer and polymer dispersed liquid crystal layer. In the performance experiments, the effects of diluent, liquid crystal and PCESM contents on the electro-optical properties of PCES-TCF were mainly investigated. In the film formation experiments, PCES-TCF is driven by the electric and temperature fields for transmittance and color change, while preparing multi-color patterns. The film formation on either rigid or flexible substrates possesses stable phase change energy storage as determined by infrared thermography and differential scanning calorimetry (DSC). PCES-TCF has a strong potential for application by reducing external energy consumption based on enhanced color change time controllability.

Quantitative Evaluation of the Phase Function Effects on Light Scattering and Radiative Transfer in Dispersed Systems

The light scattering properties of particles play important roles in radiative transfer in many dispersed systems, such as turbid atmosphere, ocean water, nanofluids, composite coatings and so on. As one of the scattering property parameters, the scattering phase functions of particles are strongly dependent on the particle size, size distribution, and morphology, as well as on the complex refractive indices of the particles and surrounding media. For the sake of simplicity, the empirical phase function models are widely used in many practical applications. In this work, we focus on the radiative transfer problem in dispersed systems composed of spherical particles, and give quantitative analyses of the impact of scattering phase functions on the radiative transfer process. We fit the scattering phase functions of four different types of practical dispersed systems using four previously proposed empirical phase function models, including the Henyey–Greenstein (HG) model, Cornette Shanks (CS) model, Reynold and McCormick (RM) model and two-term Reynolds–McCormick (TTRM) model. By comparing the radiative transfer characteristics (i.e., hemispherical reflectance, hemispherical transmittance and total absorptance) of dispersed layers calculated using the Monte Carlo method, the relative errors caused by using the empirical phase functions are systematically investigated. The results demonstrate that the HG, CS and RM models cause obvious errors in the calculation of hemispherical reflectance in many cases. Meanwhile, the induced errors show no obvious regularity, but are related to the particle size and layer optical thickness. Due to the good fitting effect in both forward and backward directions, the TTRM model provides significantly higher performances in fitting the phase functions of all considered cases than the widely used single-term parametrizations. Moreover, for different particle sizes and layer optical thicknesses, the induced errors of the TTRM model in radiative transfer characteristics are very small, especially for the case of polydisperse particles. Our results can be used to guide the design, analysis and optimization of dispersed systems in practical optics and photonics applications.

3D Disease Modelling of Hard and Soft Cancer Using PHA-Based Scaffolds.

Simple SummaryTumour progression in vivo was able to be well mimicked in 3D culture by utilizing biodegradable 10 mm × 10 mm × 8 mm P(3HO-co-3HD) and P(3HB)-based 3D scaffolds with a pore size of 30 to 300 µm. Both hard (MCF7 and MDA-MB-231) and soft (HCT116) tumour-related cells were successfully grown on the scaffolds, and their growth patterns were studied for 5 days. MDA-MB-231 tend to grow in clusters, and MCF7 cells form an evenly dispersed layer, which covered most of the 3D PHA scaffolds, while HCT116 formed large colonies within the pockets of the 3D PHA scaffold. Epithelial mesenchymal transition (EMT) marker genes, including Wnt-11, E-cadherin, Vim and Snail expression profiles, were like those seen in real tumour samples, which confirmed that the cancer models were exhibiting real tumour-like characteristics with high fidelity. These models are important in mimicking hypoxic tumours and in studying gene expression, cellular signalling, angiogenesis and drug response for translational research.Tumour cells are shown to change shape and lose polarity when they are cultured in 3D, a feature typically associated with tumour progression in vivo, thus making it significant to study cancer cells in an environment that mimics the in vivo milieu. In this study we established hard (MCF7 and MDA-MB-231, breast cancer) and soft (HCT116, colon cancer) 3D cancer tumour models utilizing a blend of P(3HO-co-3HD) and P(3HB). P(3HO-co-3HD) and P(3HB) belong to a group of natural biodegradable polyesters, PHAs, that are synthesised by microorganisms. The 3D PHA scaffolds produced, with a pore size of 30 to 300 µm, allow for nutrients to diffuse within the scaffold and provide the cells with the flexibility to distribute evenly within the scaffold and grow within the pores. Interestingly, by Day 5, MDA-MB-231 showed dispersed growth in clusters, and MCF7 cells formed an evenly dispersed dense layer, while HCT116 formed large colonies within the pockets of the 3D PHA scaffolds. Our results show Epithelial Mesenchymal Transition (EMT) marker gene expression profiles in the hard tumour cancer models. In the 3D-based PHA scaffolds, MDA-MB-231 cells expressed higher levels of Wnt-11 and mesenchymal markers, such as Snail and its downstream gene Vim mRNAs, while MCF7 cells exhibited no change in their expression. On the other hand, MCF7 cells exhibited a significantly increased E-Cadherin expression as compared to MDA-MB-231 cells. The expression levels of EMT markers were comparative to their expression reported in the tumour samples, making them good representative of cancer models. In future these models will be helpful in mimicking hypoxic tumours, in studying gene expression, cellular signalling, angiogenesis and drug response more accurately than 2D and perhaps other 3D models.

Fabrication of Highly Conductive Silver-Coated Aluminum Microspheres Based on Poly(catechol/polyamine) Surface Modification.

A novel and cost-effective method for the fabrication of highly conductive Al/Ag core-shell structured microspheres was proposed and investigated. The oxidative co-deposition of catechol and polyamine was firstly performed to modify the surface of the aluminum microsphere. Then, a two-step electroless plating was conducted to fabricate the Al/Ag microspheres. During the first step of the electroless plating process, the surface of the aluminum microsphere was deposited with silver nanoparticle seeds using n-octylamine and ethylene glycol. Then, during the second step of the electroless plating process, silver particles grew evenly to form a compact silver shell on the surface of aluminum via a silver mirror reaction. According to the scanning electron microscope and energy dispersive X-ray results, a compact and continuous silver layer was successfully generated on the surface of the aluminum. The valence of the sliver on the surface of the aluminum was confirmed to be zero, based on the X-ray photoelectron spectrometer and X-ray diffractometer analyses. As a result, the as-prepared Al/Ag microspheres exhibited a high conductivity of 10,000 S/cm. The Al/Ag/MVQ composite demonstrated low electrical resistivity of 0.0039 Ω·cm and great electromagnetic interference shielding effectiveness at more than 70 dB against the X-band, and this result suggests that the as-prepared composite is a promising conductive and electromagnetic shielding material.

Impact properties of carbon fiber/cellulose nanofiber reinforced epoxy composite using asymmetric stacking sequence of non-hydrophobic cellulose nanofiber dispersion layer

Cellulose nanofibers (CNFs) are sustainable materials with high specific strengths. To enhance the impact properties of carbon fiber reinforced plastics (CFRPs), the authors have developed an efficient process for incorporating a non-hydrophobized CNF dispersion layer into CFRPs. In this study, the impact properties of CFRP with asymmetrically stacked CNF dispersion layer was investigated by conducting the instrumented Charpy impact tests. Two types of CNFs were used for comparison. Consequently, by inserting the CNF dispersion layer into the opposite side of the striking surface, the Charpy impact value increased by 26% compared to CFRP without CNF dispersion layer.

Granule cell dispersion in two mouse models of temporal lobe epilepsy and reeler mice is associated with changes in dendritic orientation and spine distribution.

Temporal lobe epilepsy is characterized by hippocampal neuronal death in CA1 and hilus. Dentate gyrus granule cells survive but show dispersion of the compact granule cell layer. This is associated with decrease of the glycoprotein Reelin, which regulates neuron migration and dendrite outgrow. Reelin-deficient (reeler) mice show no layering, their granule cells are dispersed throughout the dentate gyrus. We studied granule cell dendritic orientation and distribution of postsynaptic spines in reeler mice and two mouse models of temporal lobe epilepsy, namely the p35 knockout mice, which show Reelin-independent neuronal migration defects, and mice with unilateral intrahippocampal kainate injection. Granule cells were Golgi-stained and analyzed, using a computerized camera lucida system. Granule cells in naive controls exhibited a vertically oriented dendritic arbor with a small bifurcation angle if positioned proximal to the hilus and a wider dendritic bifurcation angle, if positioned distally. P35 knockout- and kainate-injected mice showed a dispersed granule cell layer, granule cells showed basal dendrites with wider bifurcation angles, which lost position-specific differences. Reeler mice lacked dendritic orientation. P35 knockout- and kainate-injected mice showed increased dendritic spine density in the granule cell layer. Molecular layer dendrites showed a reduced spine density in kainate-injected mice only, whereas in p35 knockouts no reduced spine density was seen. Reeler mice showed a homogenous high spine density. We hypothesize that granule cells migrate in temporal lobe epilepsy, develop new dendrites which show a spread of the dendritic tree, create new spines in areas proximal to mossy fiber sprouting, which is present in p35 knockout- and kainate-injected mice and loose spines on distal dendrites if mossy cell death is present, as it was in kainate-injected mice only. These results are in accordance with findings in epilepsy patients.

Ultralow loss visible light metamaterials assembled by metaclusters

Abstract Optical metamaterials give birth to the control and regulation of light. However, because of strong energy dissipation and fabrication difficulty in meta-atoms, low-loss isotropic three dimensional negative index metamaterials (NIMs) in the visible spectrum has long been regarded as an extremely challenging. Here, we report an ultralow loss isotropic metamaterials for visible light and its inverse Doppler effect. The ball-thorn-shaped metaclusters with symmetrical structure consisting of the dielectric and its surface dispersed super-thin silver layer was proposed, the surface plasma resonance is formed by discrete silver layer with a thickness of two or three atomic layers. We invented a unique technique for preparing ultralow loss isotropic clusters and three-dimensional large block samples. The negative refractive index and the inverse Doppler effect of green and red light is measured by the prism method for the first time. The discrete super-thin silver layer produced by the photoreduction method greatly reduces the generation of loss and break through noble metal high energy losses of traditional optical frequency metamaterial, the metaclusters unfold bottleneck of the nano-assemble visible light metamaterials, opening a door for disorder assembling ultralow loss isotropic three-dimensional large block NIMs devices of arbitrary shape.

Interfaces Based on Laser-Structured Arrays of Carbon Nanotubes with Albumin for Electrical Stimulation of Heart Cell Growth.

Successful formation of electronic interfaces between living cells and electronic components requires both good cell viability and performance level. This paper presents a technology for the formation of nanostructured arrays of multi-walled carbon nanotubes (MWCNT) in biopolymer (albumin) layer for higher biocompatibility. The layer of liquid albumin dispersion was sprayed on synthesized MWCNT arrays by deposition system. These nanostructures were engineered using the nanosecond pulsed laser radiation mapping in the near-IR spectral range (λ = 1064 nm). It was determined that the energy density of 0.015 J/cm2 provided a sufficient structuring of MWCNT. The structuring effect occurred during the formation of C–C bonds simultaneously with the formation of a cellular structure of nanotubes in the albumin matrix. It led to a decrease in the nanotube defectiveness, which was observed during the Raman spectroscopy. In addition, laser structuring led to a more than twofold increase in the electrical conductivity of MWCNT arrays with albumin (215.8 ± 10 S/m). Successful electric stimulation of cells on the interfaces with the system based on a culture plate was performed, resulting in the enhanced cell proliferation. Overall, the MWCNT laser-structured arrays with biopolymers might be a promising material for extended biomedical applications.