Publications by authors named "Fonda E"

In the pursuit of enhancing cancer treatment efficacy while minimizing side effects, near-infrared (NIR) photothermal therapy (PTT) has emerged as a promising approach. By using photothermally active nanomaterials, PTT enables localized hyperthermia, effectively eliminating cancer cells with minimal invasiveness and toxicity. Among these nanomaterials, gold nanostars (AuNS) stand out due to their tunable plasmon resonance and efficient light absorption.

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Supported metal in the form of single atoms, clusters, and particles can individually or jointly affect the activity of supported heterogeneous catalysts. While the individual contribution of the supported metal to the overall activity of supported photocatalysts has been identified, the joint activity of mixed metal species is overlooked because of their different photoelectric properties. Here, atomically dispersed Pd (Pd) and Pd clusters are loaded onto CdS, serving as oxidation and reduction sites for methanol dehydrogenation.

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Importance: Infections due to multidrug-resistant organisms (MDROs) are associated with increased morbidity, mortality, length of hospitalization, and health care costs. Regional interventions may be advantageous in mitigating MDROs and associated infections.

Objective: To evaluate whether implementation of a decolonization collaborative is associated with reduced regional MDRO prevalence, incident clinical cultures, infection-related hospitalizations, costs, and deaths.

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We evaluated whether universal chlorhexidine bathing (decolonization) with or without COVID-19 intensive training impacted COVID-19 rates in 63 nursing homes (NHs) during the 2020-2021 Fall/Winter surge. Decolonization was associated with a 43% lesser rise in staff case-rates ( < .001) and a 52% lesser rise in resident case-rates ( < .

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A Surface OrganoMetallic Chemistry (SOMC) approach is used to prepare a novel hafnium-iridium catalyst immobilized on silica, HfIr/SiO, featuring well-defined [≡SiOHf(CH Bu)(μ-H)IrCp*] surface sites. Unlike the monometallic analogous materials Hf/SiO and Ir/SiO, which promote n-pentane deuterogenolysis through C-C bond scission, we demonstrate that under the same experimental conditions (1 bar D, 250 °C, 3 h, 0.5 mol %), the heterobimetallic catalyst HfIr/SiO is highly efficient and selective for the perdeuteration of alkanes with D, exemplified on n-pentane, without substantial deuterogenolysis (<2 % at 95 % conversion).

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Improvement of electrochemical technologies is one of the most popular topics in the field of renewable energy. However, this process requires a deep understanding of the electrode-electrolyte interface behavior under conditions. X-ray absorption spectroscopy (XAS) is widely employed to characterize electrode materials, providing element-selective oxidation state and local structure.

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A strategy for the synthesis of a gold-based single-atom catalyst (SAC) via a one-step room temperature reduction of Au(III) salt and stabilization of Au(I) ions on nitrile-functionalized graphene (cyanographene; G-CN) is described. The graphene-supported G(CN)-Au catalyst exhibits a unique linear structure of the Au(I) active sites promoting a multistep mode of action in dehydrogenative coupling of organosilanes with alcohols under mild reaction conditions as proven by advanced XPS, XAFS, XANES, and EPR techniques along with DFT calculations. The linear structure being perfectly accessible toward the reactant molecules and the cyanographene-induced charge transfer resulting in the exclusive Au(I) valence state contribute to the superior efficiency of the emerging two-dimensional SAC.

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Identifying the active site of catalysts for the oxygen evolution reaction (OER) is critical for the design of electrode materials that will outperform the current, expensive state-of-the-art catalyst, RuO. Previous work shows that mixed Mn/Ru oxides show comparable performances in the OER, while reducing reliance on this expensive and scarce Pt-group metal. Herein, X-ray photoelectron spectroscopy and X-ray absorption spectroscopy (XAS) are performed on mixed Mn/Ru oxide materials for the OER to understand structural and chemical changes at both metal sites during oxygen evolution.

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Controlling the deposition of spin-crossover (SCO) materials constitutes a crucial step for the integration of these bistable molecular systems in electronic devices. Moreover, the influence of functional surfaces, such as 2D materials, can be determinant on the properties of the deposited SCO film. In this work, ultrathin films of the SCO Hofmann-type coordination polymer [Fe(py) {Pt(CN) }] (py = pyridine) onto monolayers of 1T and 2H MoS polytypes are grown.

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The design of highly active and structurally well-defined catalysts has become a crucial issue for heterogeneous catalysed reactions while reducing the amount of catalyst employed. Beside conventional synthetic routes, the employment of polynuclear transition metal complexes as catalysts or catalyst precursors has progressively intercepted a growing interest. These well-defined species promise to deliver catalytic systems where a strict control on the nuclearity allows to improve the catalytic performance while reducing the active phase loading.

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Temperature plays a critical role in regulating body mechanisms and indicating inflammatory processes. Local temperature increments above 42 °C are shown to kill cancer cells in tumorous tissue, leading to the development of nanoparticle-mediated thermo-therapeutic strategies for fighting oncological diseases. Remarkably, these therapeutic effects can occur without macroscopic temperature rise, suggesting localized nanoparticle heating, and minimizing side effects on healthy tissues.

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Layered black phosphorus (BP) is endowed with peculiar chemico-physical properties that make it a highly promising candidate in the field of electronics. Nevertheless, as other 2D materials with atomic scale thickness, it suffers from easy degradation under ambient conditions. Herein, it is shown that the functionalization of BP with preformed and in situ grown Ni NPs, affects the electronic properties of the material.

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Iron-sulfur (Fe-S) clusters are prosthetic groups of proteins biosynthesized on scaffold proteins by highly conserved multi-protein machineries. Biosynthesis of Fe-S clusters into the ISCU scaffold protein is initiated by ferrous iron insertion, followed by sulfur acquisition, via a still elusive mechanism. Notably, whether iron initially binds to the ISCU cysteine-rich assembly site or to a cysteine-less auxiliary site via N/O ligands remains unclear.

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The use of high-pressure synthesis conditions to produce I-bearing aluminoborosilicate represents a promising issue for the immobilization of I radioisotope. Furthermore, iodine appears to be more solubilized in glasses under its iodate (I) form rather than its iodide (I) form. Currently, the local atomic environment for iodine is poorly constrained for I and virtually unknown for I or I.

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The production of carbon-neutral fuels from CO presents an avenue for causing an appreciable effect in terms of volume toward the mitigation of global carbon emissions. To that end, the production of isoparaffin-rich fuels is highly desirable. Here, we demonstrate the potential of a multifunctional catalyst combination, consisting of a methanol producer (InCo) and a Zn-modified zeolite beta, which produces a mostly isoparaffinic hydrocarbon mixture from CO (up to ∼85% isoparaffin selectivity among hydrocarbons) at a CO conversion of >15%.

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Metallization and dissociation are key transformations in diatomic molecules at high densities particularly significant for modeling giant planets. Using X-ray absorption spectroscopy and atomistic modeling, we demonstrate that in halogens, the formation of a connected molecular structure takes place at pressures well below metallization. Here we show that the iodine diatomic molecule first elongates by ∼0.

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Article Synopsis
  • The study investigates the amorphization process of SnI at high pressures (up to 26.8 GPa) using advanced techniques like x-ray absorption spectroscopy and powder x-ray diffraction.
  • Findings show that a key structural unit, the tetrahedral SnI, remains consistent through the transition from crystalline phase-I to phase-II, which occurs between 7 GPa and 10 GPa.
  • Iodine EXAFS data highlights the development of short iodine-iodine bonds and suggests that while the tetrahedral structure deforms under pressure, the angle between the iodine and tin atoms stays close to the ideal tetrahedral geometry.
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Tunnel boring muds, coming from underground works, are considered as specific materials due to their intrinsic characteristics (granularity, clay content, water content, presence of heavy metals). In order to determine if they can be valorized in road construction or civil engineering, a complete characterization, including their environmental behavior, is necessary. Thus, the aim of this study is to characterize a tunnel boring mud sample from chemical, mineralogical, and environmental point of view.

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The first colour photographs were created by a process introduced by Edmond Becquerel in 1848. The nature of these photochromatic images colours motivated a debate between scientists during the XIX century, which is still not settled. We present the results of chemical analysis (EDX, HAXPES and EXAFS) and morphology studies (SEM, STEM) aiming at explaining the optical properties of the photochromatic images (UV-visible spectroscopy and low loss EELS).

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Plasmonic core-shell-isolated nanoparticles are promising nanoplatforms for photocatalysis and for low detection analysis. This paper describes the characterization of a 2,2'-bipyridine phosphonate functionalized Ag@TiO nanocomposite which complexes copper ions by enhanced Raman spectroscopy and X-ray absorption (XANES and EXAFS). We distinguished Cu(i) from Cu(ii) complexes using shell-isolated nanoparticle enhanced Raman (SHINERS) combined with XAS spectroscopy.

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We explore heat transport properties of turbulent Rayleigh-Bénard convection in horizontally extended systems by using deep-learning algorithms that greatly reduce the number of degrees of freedom. Particular attention is paid to the slowly evolving turbulent superstructures-so called because they are larger in extent than the height of the convection layer-which appear as temporal patterns of ridges of hot upwelling and cold downwelling fluid, including defects where the ridges merge or end. The machine-learning algorithm trains a deep convolutional neural network (CNN) with U-shaped architecture, consisting of a contraction and a subsequent expansion branch, to reduce the complex 3D turbulent superstructure to a temporal planar network in the midplane of the layer.

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Fundamental to classical and quantum vortices, superconductors, magnetic flux tubes, liquid crystals, cosmic strings, and DNA is the phenomenon of reconnection of line-like singularities. We visualize reconnection of quantum vortices in superfluid He, using submicrometer frozen air tracers. Compared with previous work, the fluid was almost at rest, leading to fewer, straighter, and slower-moving vortices.

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We report on a comparative study of 5.5 nm (embedded in an ordered mesoporous silica matrix) and 100 nm (free) (photo)magnetic CoFe Prussian blue analogue (PBA) particles. Co and Fe K-edge X-ray absorption spectroscopy, X-ray diffraction, infrared spectroscopy, and magnetic measurements point out a core-shell structure of the particles in their ground states.

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The concept of self-regenerating or "smart" catalysts, developed to mitigate the problem of supported metal particle coarsening in high-temperature applications, involves redispersing large metal particles by incorporating them into a perovskite-structured support under oxidizing conditions and then exsolving them as small metal particles under reducing conditions. Unfortunately, the redispersion process does not appear to work in practice because the surface areas of the perovskite supports are too low and the diffusion lengths for the metal ions within the bulk perovskite too short. Here, we demonstrate reversible activation upon redox cycling for CH oxidation and CO oxidation on Pd supported on high-surface-area LaFeO, prepared as a thin conformal coating on a porous MgAlO support using atomic layer deposition.

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Single-atom catalysts with full utilization of metal centers can bridge the gap between molecular and solid-state catalysis. Metal-nitrogen-carbon materials prepared via pyrolysis are promising single-atom catalysts but often also comprise metallic particles. Here, we pyrolytically synthesize a Co-N-C material only comprising atomically dispersed cobalt ions and identify with X-ray absorption spectroscopy, magnetic susceptibility measurements and density functional theory the structure and electronic state of three porphyrinic moieties, CoNC, CoNC and CoNC.

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