Toward Efficient Electrocatalytic Oxygen Evolution: Emerging Opportunities with Metallic Pyrochlore Oxides for Electrocatalysts and Conductive Supports.

The design of active and stable electrocatalysts for oxygen evolution reaction is a key enabling step toward efficient utilization of renewable energy. Along with efforts to develop high-performance electrocatalysts for oxygen evolution reaction, pyrochlore oxides have emerged as highly active and stable materials that function as catalysts as well as conductive supports for hybrid catalysts. The compositional flexibility of pyrochlore oxide provides many opportunities to improve electrocatalytic performance by manipulating material structures and properties.

Dynamic Wettability on the Lubricant-Impregnated Surface: From Nucleation to Growth and Coalescence.

The surface dynamic wettability during droplet nucleation and growth involved with phase change is different from the static wettability formed from a sessile drop. Revealing this dynamic wettability of the lubricant-impregnated surfaces (LISs) and identification of the consistency between the wettability during condensation and the static wettability are of significant importance. In this study, we investigated condensation of water droplets on LISs using molecular dynamics simulations.

In situ TEM measurement of activation volume in ultrafine grained gold.

A micro-electromechanical system (MEMS) based technique is demonstrated for in situ transmission electron microscopy (TEM) measurements of stress relaxation with simultaneous observation of the underlying plastic deformation processes. True activation volumes are determined from repeated stress relaxation transients and thus provide a signature parameter of the governing mechanisms of plastic deformation. The technique is demonstrated with 100 nm-thick ultrafine-grained gold microspecimens under uniaxial tension.

Capillary-Based and Stokes-Based Trapping of Serial Sections for Scalable 3D-EM Connectomics.

Serial section electron microscopy (ssEM), a technique where volumes of tissue can be anatomically reconstructed by imaging consecutive tissue slices, has proven to be a powerful tool for the investigation of brain anatomy. Between the process of cutting the slices, or "sections," and imaging them, however, handling 10°-10 delicate sections remains a bottleneck in ssEM, especially for batches in the "mesoscale" regime, i.e.

Effect of the Side-Chain Length in Perfluorinated Sulfonic and Phosphoric Acid-Based Membranes on Nanophase Segregation and Transport: A Molecular Dynamics Simulation Approach.

The effect of side-chain length on the nanophase-segregated structure and transport in perfluorinated sulfonic acid (PFSA)-based and perfluorinated phosphoric acid (PFPA)-based membranes is investigated at 20 and 5 wt % water content conditions using a molecular dynamics simulation method. It is found using the pair correlation analysis that the longer side chain leads to more developed local water structures in the water phase at 20 wt % water content, observable in both membrane chemistries albeit more distinct in PFPA-based membranes. It is also confirmed from the structure factor analysis that large-scale nanophase segregation is enhanced with increasing side-chain length for PFPA membranes, whereas no significant change is observed at these scales for PFSA membranes.

Droplet Morphology and Mobility on Lubricant-Impregnated Surfaces: A Molecular Dynamics Study.

Slippery liquid-infused porous surfaces (SLIPS) are gaining remarkable attention and have advanced performance in many fields. Although all SLIPS are related to lubricant-impregnation within nano/microstructures on a surface, they differ in many aspects, such as the morphology of droplets, the state of cloaking, the wetting edge, and the lubricant thickness. Requirements of the droplet morphology on SLIPS might change according to a specific application.

Distinct Nanoscale Interphases and Morphology of Lithium Metal Electrodes Operating at Low Temperatures.

While Li-ion batteries are known to fail at temperatures below -20 °C, very little is known regarding the low-temperature behavior of next-generation high-capacity electrode materials. The lithium metal anode is of particular interest for high-energy battery chemistries, but improved understanding of and control over its electrochemical and nanoscale interfacial behavior in diverse conditions is necessary. Here, we investigate lithium deposition/stripping, morphology evolution, and solid-electrolyte interphase (SEI) structure and properties down to -80 °C using an ether-based electrolyte (DOL/DME).

Shear-induced platelet aggregation: 3D-grayscale microfluidics for repeatable and localized occlusive thrombosis.

Atherothrombosis leads to complications of myocardial infarction and stroke as a result of shear-induced platelet aggregation (SIPA). Clinicians and researchers may benefit from diagnostic and benchtop microfluidic assays that assess the thrombotic activity of an individual. Currently, there are several different proposed point-of-care diagnostics and microfluidic thrombosis assays with different design parameters and end points.

High-yield, automated intracellular electrophysiology in retinal pigment epithelia.

Background: Recent advancements with induced pluripotent stem cell-derived (iPSC) retinal pigment epithelium (RPE) have made disease modeling and cell therapy for macular degeneration feasible. However, current techniques for intracellular electrophysiology - used to validate epithelial function - are painstaking and require manual skill; limiting experimental throughput.

New Method: A five-stage algorithm, leveraging advances in automated patch clamping, systematically derived and optimized, improves yield and reduces skill when compared to conventional, manual techniques.

Low-dose material-specific radiography using monoenergetic photons.

Cargo containers constitute the most critical component of global trade: 108 million containers represent the movement of about 95% of the world's manufactured goods. The steady increase in cargo container shipments has had a profound effect on world security: the threat associated with smuggling of shielded special nuclear material is elevated every year. Containers reaching the borders of the U.

Prediction of Sub-Monomer A2 Domain Dynamics of the von Willebrand Factor by Machine Learning Algorithm and Coarse-Grained Molecular Dynamics Simulation.

We develop a machine learning tool useful for predicting the instantaneous dynamical state of sub-monomer features within long linear polymer chains, as well as extracting the dominant macromolecular motions associated with sub-monomer behaviors of interest. We employ the tool to better understand and predict sub-monomer A2 domain unfolding dynamics occurring amidst the dominant large-scale macromolecular motions of the biopolymer von Willebrand Factor (vWF) immersed in flow. Results of coarse-grained Molecular Dynamics (MD) simulations of non-grafted vWF multimers subject to a shearing flow were used as input variables to a Random Forest Algorithm (RFA).

The Effect of Nickel on MoS Growth Revealed with in Situ Transmission Electron Microscopy.

MoS has important applications in (electro)catalysis and as a semiconductor for electronic devices. Other chemical species are commonly added to MoS to increase catalytic activity or to alter electronic properties through substitutional or adsorption-based doping. While groundbreaking work has been devoted to determining the atomic-scale structure of MoS and other layered transition-metal dichalcogenides (TMDCs), there is a lack of understanding of the dynamic processes that govern the evolution of these materials during synthesis.

Enhancing cell seeding and osteogenesis of MSCs on 3D printed scaffolds through injectable BMP2 immobilized ECM-Mimetic gel.

Objective: Design of bioactive scaffolds with osteogenic capacity is a central challenge in cell-based patient-specific bone tissue engineering. Efficient and spatially uniform seeding of (stem) cells onto such constructs is vital to attain functional tissues. Herein we developed heparin functionalized collagen gels supported by 3D printed bioceramic scaffolds, as bone extracellular matrix (ECM)-mimetic matrices.

Spatial Mapping of Thermal Boundary Conductance at Metal-Molybdenum Diselenide Interfaces.

Improving the thermal transport across interfaces is a necessary consideration for micro- and nanoelectronic devices and necessitates accurate measurement of the thermal boundary conductance (TBC) and understanding of transport mechanisms. Two-dimensional transition-metal dichalcogenides (TMDs) have been studied extensively for their electrical properties, including the metal-TMD electrical contact resistance, but the thermal properties of these interfaces are significantly less explored irrespective of their high importance in their electronic devices. We isolate individual islands of MoSe grown by chemical vapor deposition using photolithography and correlate the 2D variation of TBC with optical microscope images of the MoSe islands.

Automation and Scale Up of Somatic Embryogenesis for Commercial Plant Production, With Emphasis on Conifers.

For large scale production of clonal plants, somatic embryogenesis (SE) has many advantages over other clonal propagation methods such as the rooting of cuttings. In particular, the SE process is more suited to scale up and automation, thereby reducing labor costs and increasing the reliability of the production process. Furthermore, the plants resulting from SE closely resemble those from seeds, as somatic embryos, like zygotic (seed) embryos, develop with good connection between root and shoot, and without the plagiotropism often associated with propagation by cuttings.

Geckos Race Across the Water's Surface Using Multiple Mechanisms.

Acrobatic geckos can sprint at high speeds over challenging terrain [1], scamper up the smoothest surfaces [2], rapidly swing underneath leaves [3], and right themselves in midair by swinging only their tails [4, 5]. From our field observations, we can add racing on the water's surface to the gecko's list of agile feats. Locomotion at the air-water interface evolved in over a thousand species, including insects, fish, reptiles, and mammals [6].

Phonon mode contributions to thermal conductivity of pristine and defective β-GaO.

β-Ga2O3 is emerging as a promising semiconductor for high-power high-frequency electronics. The low thermal conductivity of pristine β-Ga2O3 and the presence of defects, which can further suppress the thermal conductivity, will result in critical challenges for the performance and reliability of β-Ga2O3-based devices. We use first-principles density functional theory (DFT) along with the Boltzmann transport equation (BTE) to predict the phonon transport properties of pristine and defective β-Ga2O3.

Large-scale neuroanatomy using LASSO: Loop-based Automated Serial Sectioning Operation.

Serial section transmission electron microscopy (ssTEM) is the most promising tool for investigating the three-dimensional anatomy of the brain with nanometer resolution. Yet as the field progresses to larger volumes of brain tissue, new methods for high-yield, low-cost, and high-throughput serial sectioning are required. Here, we introduce LASSO (Loop-based Automated Serial Sectioning Operation), in which serial sections are processed in "batches.

In Situ Polymerization of Dopamine on Graphene Framework for Charge Storage Applications.

Polydopamine, a functional coating material, is redox active as cathode materials for both Li- and Na-ion batteries or hybrid capacitors. Here, a polydopamine coating onto 3D graphene framework is introduced through a simple hydrothermal process, during which graphene oxide serves not only as an oxidant for assisting the polymerization of dopamine, but also as a template for the conformal growth of polydopamine. High-density films are fabricated by compressing the polydopamine-coated graphene aerogels, which can be directly used as free-standing and flexible cathodes in both Li- and Na-cells.

Inhibition of high shear arterial thrombosis by charged nanoparticles.

Platelet accumulation under high shear rates at the site of atherosclerotic plaque rupture leads to myocardial infarction and stroke. Current antiplatelet therapies remain ineffective within a large percentage of the population, while presenting significant risks for bleeding. We explore a novel way to inhibit arterial thrombus formation by biophysical means without the use of platelet inactivating drugs.

Stabilization of Aliphatic Phosphines by Auxiliary Phosphine Sulfides Offers Zeptomolar Affinity and Unprecedented Selectivity for Probing Biological Cu.

Full elucidation of the functions and homeostatic pathways of biological copper requires tools that can selectively recognize and manipulate this trace nutrient within living cells and tissues, where it exists primarily as Cu . Buffered at attomolar concentrations, intracellular Cu is, however, not readily accessible to commonly employed amine and thioether-based chelators. Herein, we reveal a chelator design strategy in which phosphine sulfides aid in Cu coordination while simultaneously stabilizing aliphatic phosphine donors, producing a charge-neutral ligand with low-zeptomolar dissociation constant and 10 -fold selectivity for Cu over Zn , Fe , and Mn .

Low Temperature CMUT Fabrication Process with Dielectric Lift-off Membrane Support for Improved Reliability.

This paper reports an improved CMOS compatible low temperature sacrificial layer fabrication process for Capacitive Micromachined Ultrasonic Transducers (CMUTs). The process adds the fabrication step of silicon oxide evaporation which is followed by a lift-off step to define the membrane support area without a need for an extra mask. This simple addition improves reliability by reducing the electric field between the top and bottom electrodes everywhere except the moving membrane without affecting the vacuum gap thickness.

Mechanobiological Mimicry of Helper T Lymphocytes to Evaluate Cell-Biomaterials Crosstalk.

The unique properties of immune cells have inspired many efforts in engineering advanced biomaterials capable of mimicking their behaviors. However, an inclusive model capable of mimicking immune cells in different situations remains lacking. Such models can provide invaluable data for understanding immune-biomaterial crosstalk.