Abstract

Turner syndrome (TS) is a genetic condition characterized by partial or complete monosomy X. Alterations in hormonal function, height, and peer relationships, among other features and correlates of TS, appear to be risks for depressive illness. In order to summarize what is known about depression in Turner syndrome, with the aim of determining if individuals with TS are at increased risk for depression, a literature search and analysis was conducted. In total, 69 studies were identified and 35 met criteria of being peer-reviewed English language articles that collected original data on the experience of depression in individuals with TS. Most studies used patient or parent questionnaires to evaluate depressive symptoms. These studies, a majority of which examined adults and half that examined adolescents, found that individuals with TS experienced more frequent and severe depressive symptoms than individuals without TS diagnoses. Articles studying children with TS did not demonstrate a difference in their depressive experience compared to individuals without TS. Three articles used clinician administered scales, such as the Structured Clinical Interview for DSM-IV; all diagnosed depression in those with TS at higher rates than others. Five studies relied on expert opinion to evaluate depression. The remaining eight articles were case reports or case series that relied on expert opinion. From these data, we conclude that adolescents and adults with TS are at risk for depression and adulthood appears to be the period of highest risk. Studies in the last 12 years show consistently more severe depressive symptoms in individuals with TS than in previous years. Implications, risk factors, and recommendations for future research are discussed.

Some of the most effective visible obscurants for military applications are toxic or incendiary or present serious logistical complications. Sustainable alternatives are needed to mitigate the risks of human exposure and environmental contamination. The FactSage 6.4 software package was used to model the thermodynamics of pyrotechnic smoke compositions based on boron carbide, hexachloroethane, and phosphorus. The computational results are shown to be relevant in light of prior experimental observations. Boron phosphide is proposed as a benign source of phosphorus for next-generation pyrotechnic smoke compositions. The thermodynamics of the BP–KNO3 system have been studied computationally. The results indicate that certain stoichiometries should produce elemental phosphorus upon combustion. The properties of the BP–KNO3 system are examined considering the functional requirements of smoke munitions.

Noble metal aerogels offer a wide range of catalytic applications due to their high surface area and tunable porosity. Control over monolith shape, pore size, and nanofiber diameter is desired in order to optimize electronic conductivity and mechanical integrity for device applications. However, common aerogel synthesis techniques such as solvent mediated aggregation, linker molecules, sol–gel, hydrothermal, and carbothermal reduction are limited when using noble metal salts. Here, we present the synthesis of palladium aerogels using carboxymethyl cellulose nanofiber (CNF) biotemplates that provide control over aerogel shape, pore size, and conductivity. Biotemplate hydrogels were formed via covalent cross linking using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) with a diamine linker between carboxymethylated cellulose nanofibers. Biotemplate CNF hydrogels were equilibrated in precursor palladium salt solutions, reduced with sodium borohydride, and rinsed with water followed by ethanol dehydration, and supercritical drying to produce freestanding aerogels. Scanning electron microscopy indicated three-dimensional nanowire structures, and X-ray diffractometry confirmed palladium and palladium hydride phases. Gas adsorption, impedance spectroscopy, and cyclic voltammetry were correlated to determine aerogel surface area. These self-supporting CNF-palladium aerogels demonstrate a simple synthesis scheme to control porosity, electrical conductivity, and mechanical robustness for catalytic, sensing, and energy applications.

For the U.S. Department of Defense, high-performance power sources are a critical technology for current and future gun-fired munitions. Molten salt thermal batteries are the reserve power source of choice for many weapon systems due to their high power density, proven long shelf life, and capability to function across a wide range of operating environments. The incorporation of nanomaterials into thermal battery components offers the potential to produce batteries with performance improvements, such as higher voltages at increased current densities. In this study, nanoscale iron disulfide (FeS2) was synthesized using a fully scalable, high energy milling method, and characterized utilizing SEM, XRD, ICP-OES, BET surface area analysis, TGA-DSC, and other techniques. Nanostructured cathode mixtures containing the nanoscale FeS2 and LiCl-KCl eutectic salt electrolyte were pressed into electrode pellets. Their electrochemical performance was then characterized as compared to standard FeS2 cathode electrode pellets currently used in industry. Single cell thermal battery discharge testing, polarization type scans, and pulse load capability were used to compare cell performance for better understanding of best-use applications for these materials. Compared to control cells, the cells utilizing nanostructured cathodes provided higher power response, with respect to both voltage and runtime.

Here, a method to synthesize gold, palladium, and platinum aerogels via a rapid, direct solution-based reduction is presented. The combination of various precursor noble metal ions with reducing agents in a 1:1 (v/v) ratio results in the formation of metal gels within seconds to minutes compared to much longer synthesis times for other techniques such as sol-gel. Conducting the reduction step in a microcentrifuge tube or small volume conical tube facilitates a proposed nucleation, growth, densification, fusion, equilibration model for gel formation, with final gel geometry smaller than the initial reaction volume. This method takes advantage of the vigorous hydrogen gas evolution as a by-product of the reduction step, and as a consequence of reagent concentrations. The solvent accessible specific surface area is determined with both electrochemical impedance spectroscopy and cyclic voltammetry. After rinsing and freeze drying, the resulting aerogel structure is examined with scanning electron microscopy, X-ray diffractometry, and nitrogen gas adsorption. The synthesis method and characterization techniques result in a close correspondence of aerogel ligament sizes. This synthesis method for noble metal aerogels demonstrates that high specific surface area monoliths may be achieved with a rapid and direct reduction approach.

Multi-metallic and alloy nanomaterials enable a broad range of catalytic applications with high surface area and tuning reaction specificity through the variation of metal composition. The ability to synthesize these materials as three-dimensional nanostructures enables control of surface area, pore size and mass transfer properties, electronic conductivity, and ultimately device integration. Au-Cu nanomaterials offer tunable optical and catalytic properties at reduced material cost. The synthesis methods for Au-Cu nanostructures, especially three-dimensional materials, has been limited. Here, we present Au-Cu nanofoams and Au-Cu-Pd macrobeams synthesized from salt precursors. Salt precursors formed from the precipitation of square planar ions resulted in short- and long-range ordered crystals that, when reduced in solution, form nanofoams or macrobeams that can be dried or pressed into freestanding monoliths or films. Metal composition was determined with X-ray diffraction and energy dispersive X-ray spectroscopy. Nitrogen gas adsorption indicated an Au-Cu nanofoam specific surface area of 19.4 m2/g. Specific capacitance determined with electrochemical impedance spectroscopy was 46.0 F/g and 52.5 F/g for Au-Cu nanofoams and Au-Cu-Pd macrobeams, respectively. The use of salt precursors is envisioned as a synthesis route to numerous metal and multi-metallic nanostructures for catalytic, energy storage, and sensing applications.

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