Understanding physical mechanisms underlying morphogenesis requires the knowledge of the mechanical properties of embryonic tissue. Despite a long-standing interest in this subject, very few in vivo measurements are currently available. Here, using the early fly embryo as a model, we describe a novel cantilever-based technique for measuring material properties of embryonic tissues. A major advantage of our approach is the ability to exert large (nanonewton-range) forces with subcellular spatial precision: our technique improves signal to noise by approximately an order of magnitude compared to previous methods. This advance allowed us to demonstrate that deformation caused by force applied to a single cell edge spreads across the whole embryo on a time scale of seconds and that the mechanical response is dominated by system-size effects, and not friction between the tissue and its environment. Based on these measurements, we estimate the Young's modulus of the cellular edges in the early embryo.
Double-perovskite PrBaCo2O5.5+δ thin films were grown on (001) LaAlO3 substrates for investigating the processing dynamic-tuned epitaxial nature and physical properties under different oxygen contents. Microstructural studies reveal that the as-grown films are c-axis oriented with good single crystallinity and epitaxial quality. It is interesting to find that a strained layer (SL) can be formed at the interface between the substrate and the film under a short-time annealing processing for partially releasing the interface compressive strain energy. The electrical and magnetic transport property studies demonstrate that the resistivity, the ferromagnetic states, and the magnetic moment of the films are sensitive to the oxygen content and nature of interface SL. These findings suggest that the microstructure and thus the physical properties of perovskite complex oxides can be manipulated not only by different annealing environments but also by annealing oxygen kinetics, which provides new information for investigating multifunctional complex oxide systems.
We demonstrate a two-step electrosynthesis approach for the preparation of silver pyrovanadate, Ag4V2O7 in thin-film form. In the first, cathodic step, polycrystalline Ag was deposited on fluorine doped tin oxide substrate from a non-aqueous bath. Aqueous pyrovanadate species were then generated by aging of a CO2-infused sodium orthovanadate (Na3VO4) solution for three weeks. Silver ions were subsequently generated in situ in this medium using anodic stripping of the Ag/indium tin oxide films from the first step. Interfacial precipitation of the Ag+ ions with the pyrovanadate species afforded the targeted product in phase pure form. The various stages of the electrosynthesis were monitored in situ via the combined use of voltammetry, electrochemical quartz crystal nanogravimetry, and coulometry. The Ag4V2O7 thin films were characterized by a variety of experimental techniques, including X-ray diffraction, laser Raman spectroscopy, diffuse reflectance spectroscopy, scanning electron microscopy, and high-resolution transmission electron microscopy. Surface photovoltage spectroscopy, ambient-pressure photoemission spectroscopy, and Kelvin probe contact potential difference (work function) measurements afforded information on the energy band structure of the p-type Ag4V2O7 semiconductor. Finally, the electrochemical and photoelectrochemical properties of the electrosynthesized Ag4V2O7 thin films were studied in both aqueous and non-aqueous electrolytes.
Magnesium vanadate (MgV2O6) and its alloys with copper vanadate were synthesized via the solution combustion technique. Phase purity and solid solution formation were confirmed by a variety of experimental techniques, supported by electronic structure simulations based on density functional theory (DFT). Powder X-ray diffraction combined with Rietveld refinement, laser Raman spectroscopy, diffuse reflectance spectroscopy, and high-resolution transmission electron microscopy showed single-phase alloy formation despite the MgV2O6 and CuV2O6 end members exhibiting monoclinic and triclinic crystal systems, respectively. DFT-calculated optical band gaps showed close agreement in the computed optical bandgaps with experimentally derived values. Surface photovoltage spectroscopy, ambient-pressure photoemission spectroscopy, and Kelvin probe contact potential difference (work function) measurements confirmed a systematic variation in the optical bandgap modification and band alignment as a function of stoichiometry in the alloy composition. These data indicated n-type semiconductor behavior for all the samples which was confirmed by photoelectrochemical measurements.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.