Non-Stoichiometric Amorphous Calcium Carbonate Forms in Macromolecular Condensates via Interphase Diffusion.

Transient amorphous phases are known as functional precursors in the formation of crystalline materials, both in vivo and in vitro. A common route to regulate amorphous calcium carbonate (ACC) crystallization is via direct interactions with negatively charged macromolecules. However, a less explored phenomenon that can influence such systems is the electrostatically driven formation of Ca-macromolecule dense phases.

Morphological Evolution of Metal-Organic Frameworks into Hedrite, Sheaf and Spherulite Superstructures with Localized Different Coloration.

The branched metal-organic frameworks (MOFs) are the first superstructures of this kind, and the growth mechanism may explain crystal shapes of other materials. The mechanism of the formation of fascinating structures having a hedrite, sheaf or spherulite appearance are detailed. The branching can be controlled, resulting in crystals that either exhibit multiple generations of branching or a single generation.

Metal ions guide the production of silkworm silk fibers.

Silk fibers' unique mechanical properties have made them desirable materials, yet their formation mechanism remains poorly understood. While ions are known to support silk fiber production, their exact role has thus far eluded discovery. Here, we use cryo-electron microscopy coupled with elemental analysis to elucidate the changes in the composition and spatial localization of metal ions during silk evolution inside the silk gland.

Harnessing precursor-directed biosynthesis with glucose derivatives to access cotton fibers with enhanced physical properties.

Cotton ovule cultures are a promising platform for exploring biofabrication of fibers with tailored properties. When the ovules' growth medium is supplemented with chemically synthesized cellulose precursors, it results in their integration into the developing fibers, thereby tailoring their end properties. Here, we report the feeding of synthetic glucosyl phosphate derivative, 6-deoxy-6-fluoro-glucose-1-phosphate (6F-Glc-1P) to cotton ovules growing , demonstrating the metabolic incorporation of 6F-Glc into the fibers with enhanced mechanical properties and moisture-retention capacity while emphasizing the role of molecular hierarchical architecture in defining functional characteristics and mechanical properties.

Local Environment of Sc and Y Dopant Ions in Aluminum Nitride Thin Films.

The local environments of Sc and Y in predominantly ⟨002⟩ textured, AlDoN (Do = Sc, = 0.25, 0.30 or Y, = 0.

Elemental compositions of sea urchin larval cell vesicles evaluated by cryo-STEM-EDS and cryo-SEM-EDS.

During spicule formation in sea urchin larvae, calcium ions translocate within the primary mesenchymal cells (PMCs) from endocytosed seawater vacuoles to various organelles and vesicles where they accumulate, and subsequently precipitate. During this process, calcium ions are concentrated by more than three orders of magnitude, while other abundant ions (Na, Mg) must be removed. To obtain information about the overall ion composition in the vesicles, we used quantitative cryo-SEM-EDS and cryo-STEM-EDS analyzes.

Real-Time Study of Surface-Guided Nanowire Growth by Scanning Electron Microscopy.

Surface-guided growth has proven to be an efficient approach for the production of nanowire arrays with controlled orientations and their large-scale integration into electronic and optoelectronic devices. Much has been learned about the different mechanisms of guided nanowire growth by epitaxy, graphoepitaxy, and artificial epitaxy. A model describing the kinetics of surface-guided nanowire growth has been recently reported.

-Axis Textured, 2-3 μm Thick AlScN Films Grown on Chemically Formed TiN/Ti Seeding Layers for MEMS Applications.

A protocol for successfully depositing [001] textured, 2−3 µm thick films of Al0.75Sc0.25N, is proposed.

Examining atherosclerotic lesions in three dimensions at the nanometer scale with cryo-FIB-SEM.

We employed in a correlative manner an unconventional combination of methods, comprising cathodoluminescence, cryo-scanning electron microscopy (SEM), and cryo-focused ion beam (FIB)-SEM, to examine the volumes of thousands of cubed micrometers from rabbit atherosclerotic tissues, maintained in close-to-native conditions, with a resolution of tens of nanometers. Data from three different intralesional regions, at the media-lesion interface, in the core, and toward the lumen, were analyzed following segmentation and volume or surface representation. The media-lesion interface region is rich in cells and lipid droplets, whereas the core region is markedly richer in crystals and has lower cell density.

Directing the Morphology, Packing, and Properties of Chiral Metal-Organic Frameworks by Cation Exchange.

We show that metal-organic frameworks, based on tetrahedral pyridyl ligands, can be used as a morphological and structural template to form a series of isostructural crystals having different metal ions and properties. An iterative crystal-to-crystal conversion has been demonstrated by consecutive cation exchanges. The primary manganese-based crystals are characterized by an uncommon space group (P622).

Nanotubes from the Misfit Layered Compound (SmS)TaS: Atomic Structure, Charge Transfer, and Electrical Properties.

Misfit layered compounds (MLCs) MX-TX, where M, T = metal atoms and X = S, Se, or Te, and their nanotubes are of significant interest due to their rich chemistry and unique quasi-1D structure. In particular, LnX-TX (Ln = rare-earth atom) constitute a relatively large family of MLCs, from which nanotubes have been synthesized. The properties of MLCs can be tuned by the chemical and structural interplay between LnX and TX sublayers and alloying of each of the Ln, T, and X elements.

Poly(L-lactic acid) Reinforced with Hydroxyapatite and Tungsten Disulfide Nanotubes.

Poly(L-lactic acid) (PLLA) is a biocompatible, biodegradable, and semi-crystalline polymer with numerous applications including food packaging, medical implants, stents, tissue engineering scaffolds, etc. Hydroxyapatite (HA) is the major component of natural bone. Conceptually, combining PLLA and HA could produce a bioceramic suitable for implants and bone repair.

Three-dimensional sensing of arbitrarily shaped nanoparticles by whispering gallery mode resonators.

Whispering-gallery-mode (WGM) microresonators are a promising platform for highly sensitive, label-free detection and probing of individual nano-objects. Our work expands these capabilities by providing the analysis tools required for three-dimensional (3D) characterization of arbitrarily shaped nanoparticles. Specifically, we introduce a theoretical model that describes interactions between nanoparticles and WGM resonators, taking into account effects that were often not considered, such as the elliptical polarization of the transverse-magnetic (TM) mode, the possible non-spherical shape of the nanoparticle, its finite size, and the open-system nature of the modes.

Imaging and quantifying homeostatic levels of intracellular silicon in diatoms.

Diatoms are an abundant group of microalgae, known for their ability to form an intricate cell wall made of silica. Silicon levels in seawater are in the micromolar range, making it a challenge for diatoms to supply the rapid intracellular silicification process with the needed flux of soluble silicon. Here, we use three-dimensional cryo-electron microscopy and spectroscopy to quantitatively analyze, at submicrometer spatial resolution and sensitivity in the millimolar range, intracellular silicon in diatom cells.

Large lattice distortions and size-dependent bandgap modulation in epitaxial halide perovskite nanowires.

Metal-halide perovskites have been shown to be remarkable and promising optoelectronic materials. However, despite ongoing research from multiple perspectives, some fundamental questions regarding their optoelectronic properties remain controversial. One reason is the high-variance of data collected from, often unstable, polycrystalline thin films.

Luminescence reveals variations in local structural order of calcium carbonate polymorphs formed by different mechanisms.

In nature, calcium carbonate (CaCO) in the form of calcite and aragonite nucleates through different pathways including geogenic and biogenic processes. It may also occur as pyrogenic lime plaster and laboratory-precipitated crystals. All of these formation processes are conducive to different degrees of local structural order in CaCO crystals, with the pyrogenic and precipitated forms being the least ordered.

Chemical Composition and Toxicity of Particles Emitted from a Consumer-Level 3D Printer Using Various Materials.

Consumer-level 3D printers emit ultrafine and fine particles, though little is known about their chemical composition or potential toxicity. We report chemical characteristics of the particles in comparison to raw filaments and assessments of particle toxicity. Particles emitted from polylactic acid (PLA) appeared to be largely composed of the bulk filament material with mass spectra similar to the PLA monomer spectra.

Modular Molecular Nanoplastics.

In view of their facile fabrication and recycling, functional materials that are built from small molecules ("molecular plastics") may represent a cost-efficient and sustainable alternative to conventional covalent materials. We show how molecular plastics can be made robust and how their (nano)structure can be tuned modular construction. For this purpose, we employed binary composites of organic nanocrystals based on a perylene diimide derivative, with graphene oxide (GO), bentonite nanoclay (NC), or hydroxyethyl cellulose (HEC), that both reinforce and enable tailoring the properties of the membranes.

Crystallization of Small Organic Molecules in a Polymer Matrix: Multistep Mechanism Enables Structural Control.

The widely employed crystallization of organic molecules in solution is not well understood and is difficult to control. Employing polymers as crystallization media may allow enhanced control via temperature-induced regulation of polymer dynamics. Crystallization of a small organic molecule (perylene diimide) is investigated in polymer matrices (polystyrene) that enable the mechanistic study and control over order evolution.

In-Plane Nanowires with Arbitrary Shapes on Amorphous Substrates by Artificial Epitaxy.

The challenge of nanowire assembly is still one of the major obstacles toward their efficient integration into functional systems. One strategy to overcome this obstacle is the guided growth approach, in which the growth of in-plane nanowires is guided by epitaxial and graphoepitaxial relations with the substrate to yield dense arrays of aligned nanowires. This method relies on crystalline substrates which are generally expensive and incompatible with silicon-based technologies.

Opacification of hydrophilic intraocular lenses associated with vitrectomy and injection of intraocular gas.

Objective: To report 11 cases of intraocular lens (IOL) opacification after pars plana vitrectomy (PPV) involving intravitreal gas injection.

Methods And Analysis: Eleven cases of hydrophilic IOLs that opacified following PPV with intravitreal gas injection are described. Eight IOLs were explanted and analysed by light microscopy and scanning electron microscopy.

Synthesis and characterization of isotopically-labeled silver, copper and zinc oxide nanoparticles for tracing studies in plants.

In parallel to technological advances and ever-increasing use of nanoparticles in industry, agriculture and consumer products, the potential ecotoxicity of nanoparticles and their potential accumulation in ecosystems is of increasing concern. Because scientific reports raise a concern regarding nanoparticle toxicity to plants, understanding of their bioaccumulation has become critical and demands more research. Here, the synthesis of isotopically-labeled nanoparticles of silver, copper and zinc oxide is reported; it is demonstrated that while maintaining the basic properties of the same unlabeled ("regular") nanoparticles, labeled nanoparticles enable more sensitive tracing of nanoparticles within plants that have background elemental levels.

Characterization of unusual MgCa particles involved in the formation of foraminifera shells using a novel quantitative cryo SEM/EDS protocol.

Unlabelled: Quantifying ion concentrations and mapping their intracellular distributions at high resolution can provide much insight into the formation of biomaterials. The key to achieving this goal is cryo-fixation, where the biological materials, tissues and associated solutions are rapidly frozen and preserved in a vitreous state. We developed a correlative cryo-Scanning Electron Microscopy (SEM)/Energy Dispersive Spectroscopy (EDS) protocol that provides quantitative elemental analysis correlated with spatial imaging of cryo-immobilized specimens.

Metallic Nanocrystal Ripening on Inorganic Surfaces.

In this paper, we demonstrate the formation of hybrid nanostructures consisting of two distinctive components mainly in a one-to-one ratio. Thermolysis of inorganic nanotubes (INT) and closed-cage, inorganic fullerene-like (IF) nanoparticles decorated with a dense coating of metallic nanoparticles (M = Au, Ag, Pd) results in migration of relatively small NPs or surface-enhanced diffusion of atoms or clusters, generating larger particles (ripening). AuNP growth on the surface of INTs has been captured in real time using in situ electron microscopy measurements.