Clathrin-mediated endocytosis is the major route of entry of cargos into cells and thus underpins many physiological processes. During endocytosis, an area of flat membrane is remodeled by proteins ...to create a spherical vesicle against intracellular forces. The protein machinery which mediates this membrane bending in plants is unknown. However, it is known that plant endocytosis is actin independent, thus indicating that plants utilize a unique mechanism to mediate membrane bending against high-turgor pressure compared to other model systems. Here, we investigate the TPLATE complex, a plant-specific endocytosis protein complex. It has been thought to function as a classical adaptor functioning underneath the clathrin coat. However, by using biochemical and advanced live microscopy approaches, we found that TPLATE is peripherally associated with clathrin-coated vesicles and localizes at the rim of endocytosis events. As this localization is more fitting to the protein machinery involved in membrane bending during endocytosis, we examined cells in which the TPLATE complex was disrupted and found that the clathrin structures present as flat patches. This suggests a requirement of the TPLATE complex for membrane bending during plant clathrin-mediated endocytosis. Next, we used in vitro biophysical assays to confirm that the TPLATE complex possesses protein domains with intrinsic membrane remodeling activity. These results redefine the role of the TPLATE complex and implicate it as a key component of the evolutionarily distinct plant endocytosis mechanism, which mediates endocytic membrane bending against the high-turgor pressure in plant cells.
This paper presents a system architecture for load management in smart buildings which enables autonomous demand side load management in the smart grid. Being of a layered structure composed of three ...main modules for admission control, load balancing, and demand response management, this architecture can encapsulate the system functionality, assure the interoperability between various components, allow the integration of different energy sources, and ease maintenance and upgrading. Hence it is capable of handling autonomous energy consumption management for systems with heterogeneous dynamics in multiple time-scales and allows seamless integration of diverse techniques for online operation control, optimal scheduling, and dynamic pricing. The design of a home energy manager based on this architecture is illustrated and the simulation results with Matlab/Simulink confirm the viability and efficiency of the proposed framework.
The broad implementation of thermoelectricity requires high‐performance and low‐cost materials. One possibility is employing surfactant‐free solution synthesis to produce nanopowders. We propose the ...strategy of functionalizing “naked” particles’ surface by inorganic molecules to control the nanostructure and, consequently, thermoelectric performance. In particular, we use bismuth thiolates to functionalize surfactant‐free SnTe particles’ surfaces. Upon thermal processing, bismuth thiolates decomposition renders SnTe‐Bi2S3 nanocomposites with synergistic functions: 1) carrier concentration optimization by Bi doping; 2) Seebeck coefficient enhancement and bipolar effect suppression by energy filtering; and 3) lattice thermal conductivity reduction by small grain domains, grain boundaries and nanostructuration. Overall, the SnTe‐Bi2S3 nanocomposites exhibit peak z T up to 1.3 at 873 K and an average z T of ≈0.6 at 300–873 K, which is among the highest reported for solution‐processed SnTe.
A novel strategy of functionalizing the surface of “naked” particles by using inorganic molecules is proposed. In particular, bismuth thiolate were used to functionalize surfactant‐free SnTe particles’ surfaces. Upon thermal processing, bismuth thiolates decomposition renders SnTe‐Bi2S3 nanocomposites with synergistic functions to enhance thermoelectric performance.
Solution synthesis of particles emerges as an alternative to prepare thermoelectric materials with less demanding processing conditions than conventional solid‐state synthetic methods. However, ...solution synthesis generally involves the presence of additional molecules or ions belonging to the precursors or added to enable solubility and/or regulate nucleation and growth. These molecules or ions can end up in the particles as surface adsorbates and interfere in the material properties. This work demonstrates that ionic adsorbates, in particular Na+ ions, are electrostatically adsorbed in SnSe particles synthesized in water and play a crucial role not only in directing the material nano/microstructure but also in determining the transport properties of the consolidated material. In dense pellets prepared by sintering SnSe particles, Na remains within the crystal lattice as dopant, in dislocations, precipitates, and forming grain boundary complexions. These results highlight the importance of considering all the possible unintentional impurities to establish proper structure–property relationships and control material properties in solution‐processed thermoelectric materials.
Polycrystalline SnSe is prepared from surfactant‐free particles prepared in solution. Ionic species adsorbed on the surface compensate for the particles′ charge and remain during processing. The adsorbates affect the nano/microstructure of the final material and its transport properties. In the case of sodium, it remains as a dopant and forms secondary phases that induce energy‐filtering effects.
This paper introduces a simple method for the measurement of the relative permittivity and the Pockels coefficient of electro-optic (EO) materials in a waveguide up to sub-THz frequencies. By ...miniaturizing the device and making use of plasmonics, the complexities of traditional methods are mitigated. This work elaborates the fabrication tolerance and simplicity of the method, and highlights its applicability to various materials, substrates and configurations. The method is showcased using drop-casted perovskite barium titanate (BaTiO3, BTO) nano-particle thin-films and it has previously been used to measure epitaxial thin film BTO. In this work we show the effective relative permittivity of drop casted BTO to be ε
∼ 30 at 200 MHz, dropping to ∼ 18 at 67 GHz and similarly, the effective Pockels coefficient was found to be r
∼ 16 at 350 MHz and ∼ 8 at 70 GHz. These values are a factor > 50 below the values found for thin film BTO. Yet, the fact that the method can be applied to such different samples and Pockels strengths gives testimony to its versatility and sensitivity.
We report the fabrication of BaTiO3-Ni magnetoelectric nanocomposites comprising of BaTiO3 nanotubes surrounded by Ni matrix. BaTiO3 nanotubes obtained from the hydrothermal transformation of TiO2 ...have both inner and outer surfaces, which facilitates greater magnetoelectric coupling with the surrounding Ni matrix. The magnetoelectric coupling was studied by measuring the piezoelectric behavior in the presence of an in-plane direct magnetic field. A higher magnetoelectric voltage coefficient of 110 mV/cm·Oe was obtained, because of better coupling between Ni and BaTiO3 through the walls of the nanotubes. Such nanocomposite developed directly on Ti substrate may lead to efficient fabrication of magnetoelectric devices.
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The recent demand of multifunctional materials and devices for advanced applications in energy conversion and data storage resulted into a revival of multiferroics, that is, materials characterized ...by the coexistence of ferromagnetism and ferroelectricity. Despite intense efforts made in the past decade, single-phase room temperature multiferroics are yet to be discovered/fabricated. Nanostructured ferroic materials could potentially exhibit multiferroism since a high fraction of their atoms/ions are superficial, thereby altering significantly the properties of the bulk phase. Alternately, a magnetic order can be induced into ferroelectric materials upon aliovalent doping with magnetic ions. Here, we report on the synthesis of aggregate-free single-phase transition-metal-doped BaTiO3 quasi-monodisperse cuboidal nanocrystals (NC) which exhibit multiferroic properties at room temperature and can be suitable for applications in data storage. The proposed synthetic route allows the inclusion of a high concentration of magnetic ions such as M n+ (M = Cr, Mn, Fe, Co) up to a nominal concentration of 4% without the formation of any secondary phase. The size of the nanocrystals was controlled in a wide range from ∼15 up to ∼70 nm by varying the reaction time from 48 to 144 h. The presence of unpaired electrons and their magnetic ordering have been probed by electron paramagnetic resonance spectroscopy (EPR), and a vibrating sample magnetometer (VSM). Likewise, an acentric structure, associated with the existence of a dielectric polarization, was observed by lattice dynamics analysis and piezoresponse force microscopy (PFM). These results show that high-quality titanium-containing perovskite nanocrystals which display multiferroic properties at room temperature can be fabricated via soft solution-based synthetic routes, and the properties of these materials can be modulated by changing the size of the nanocrystals and the concentration of the dopant thereby opening the door to the design and study of single-phase multiferroic materials.
Biological systems are the sum of their dynamic three-dimensional (3D) parts. Therefore, it is critical to study biological structures in 3D and at high resolution to gain insights into their ...physiological functions. Electron microscopy of metal replicas of unroofed cells and isolated organelles has been a key technique to visualize intracellular structures at nanometer resolution. However, many of these methods require specialized equipment and personnel to complete them. Here, we present novel accessible methods to analyze biological structures in unroofed cells and biochemically isolated organelles in 3D and at nanometer resolution, focusing on Arabidopsis clathrin-coated vesicles (CCVs). While CCVs are essential trafficking organelles, their detailed structural information is lacking due to their poor preservation when observed via classical electron microscopy protocols experiments. First, we establish a method to visualize CCVs in unroofed cells using scanning transmission electron microscopy tomography, providing sufficient resolution to define the clathrin coat arrangements. Critically, the samples are prepared directly on electron microscopy grids, removing the requirement to use extremely corrosive acids, thereby enabling the use of this method in any electron microscopy lab. Secondly, we demonstrate that this standardized sample preparation allows the direct comparison of isolated CCV samples with those visualized in cells. Finally, to facilitate the high-throughput and robust screening of metal replicated samples, we provide a deep learning analysis method to screen the “pseudo 3D” morphologies of CCVs imaged with 2D modalities. Collectively, our work establishes accessible ways to examine the 3D structure of biological samples and provide novel insights into the structure of plant CCVs.
Planta clathrin-coated vesicles are essential trafficking organelles but have not undergone detailed characterization. Here the authors present accessible methods to visualize them in three dimensions with nanometer resolution in cells or biochemically isolated preparations. The presented methods focus on creating 3D representations of single vesicles at high resolution, or, by utilizing deep learning, provide a high-throughput robust screening approach to analyze the 3D morphology of vesicles from lower resolution images..
A new organic-inorganic ferroelectric hybrid capacitor designed by uniformly incorporating surface modified monodisperse 15 nm ferroelectric BaTiO
3
nanocubes into non-polar polymer blends of ...poly(methyl methacrylate) (PMMA) polymer and acrylonitrile-butadiene-styrene (ABS) terpolymer is described. The investigation of spatial distribution of nanofillers
via
a non-distractive thermal pulse method illustrates that the surface functionalization of nanocubes plays a key role in the uniform distribution of charge polarization within the polymer matrix. The discharged energy density of the nanocomposite with 30 vol% BaTiO
3
nanocubes is ∼44 × 10
−3
J cm
−3
, which is almost six times higher than that of the neat polymer. The facile processing, along with the superior mechanical and electrical properties of the BaTiO
3
/PMMA-ABS nanocomposites make them suitable for implementation into capacitive electrical energy storage devices.
A new organic-inorganic ferroelectric hybrid capacitor designed by uniformly incorporating monodisperse 15 nm ferroelectric BaTiO
3
nanocubes into non-polar polymer blends of poly(methyl methacrylate) (PMMA) and acrylonitrile-butadiene-styrene (ABS) terpolymer is described.
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