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Nanoporous metals possess unique properties attributed to their high surface area and interconnected nanoscale ligaments. They are mostly fabricated by wet synthetic methods that are not universal to various metals and not free from impurities due to solution-based etching processes. Here, we demonstrate that the plasma treatment of metal nanoparticles formed by physical vapor deposition is a general route to form such films with many metals including the non-noble ones. The resultant nanoporous metallic films are free of impurities and possess highly curved ligaments and nanopores. The metal films are ultrathin, yet remarkably robust and very well connected, and thus are highly promising for various applications such as transparent conducting electrodes.

Cancer cells are in most instances characterized by rapid proliferation and uncontrolled cell division. Hence, they must adapt to proliferation-induced metabolic stress through intrinsic or acquired antimetabolic stress responses to maintain homeostasis and survival. One mechanism to achieve this is reprogramming gene expression in a metabolism-dependent manner. MondoA (also known as Myc-associated factor X–like protein X-interacting protein [MLXIP]), a member of the MYC interactome, has been described as an example of such a metabolic sensor. However, the role of MondoA in malignancy is not fully understood and the underlying mechanism in metabolic responses remains elusive. By assessing patient data sets, we found that MondoA overexpression is associated with worse survival in pediatric common acute lymphoblastic leukemia (ALL; B-precursor ALL [B-ALL]). Using clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) and RNA-interference approaches, we observed that MondoA depletion reduces the transformational capacity of B-ALL cells in vitro and dramatically inhibits malignant potential in an in vivo mouse model. Interestingly, reduced expression of MondoA in patient data sets correlated with enrichment in metabolic pathways. The loss of MondoA correlated with increased tricarboxylic acid cycle activity. Mechanistically, MondoA senses metabolic stress in B-ALL cells by restricting oxidative phosphorylation through reduced pyruvate dehydrogenase activity. Glutamine starvation conditions greatly enhance this effect and highlight the inability to mitigate metabolic stress upon loss of MondoA in B-ALL. Our findings give novel insight into the function of MondoA in pediatric B-ALL and support the notion that MondoA inhibition in this entity offers a therapeutic opportunity and should be further explored.

O processo de envolvimento do Brasil nas duas Guerras Mundiais — a Primeira Guerra ocorreu de 1914 a 1918 e a Segunda Guerra de 1939 a 1945 — se deu por meio de alguns fatores no âmbito da política interna com reflexos diretos sobre a postura internacional do país. Analisar as decisões tomadas, tanto por Wenceslau Braz (1868-1966) — que governou de 15 de novembro de 1914 a 15 de novembro de 1918 —, por meio da declaração de guerra de 1917, quanto por Getúlio Vargas (1882-1954) — que governou pela primeira vez entre 3 de novembro de 1930 e 29 de outubro de 1945 —, que declarou igualmente o estado de beligerância em 1942, com o conflito já bastante adiantado, é analisar o ápice de intensos acontecimentos no âmago da sociedade brasileira. Sociedade esta, percebida pela historiografia como tendo vivido dois distintos momentos de organização do Estado nacional, e que buscava ainda consolidar fatores identitários do Brasil. Entre as duas declarações de guerra transcorreu um período de vinte e cinco anos que compreende o centenário da Independência e algumas décadas de República.

Alloying a material and hence segregating solutes to grain boundaries is one way to tailor a material to the demands of its application. Direct observation of solute segregation is necessary to understand how the interfacial properties are altered. In this study, we investigate the atomic structure of a high angle grain boundary both in pure copper and upon silver segregation by aberration-corrected scanning transmission electron microscopy and spectroscopy. We further correlate the experiments to atomistic simulations to quantify the local solute excess and its impact on grain boundary properties. We observe that the grain boundary structure remains intact upon silver segregation and up to five different positions within a structural unit serve as segregation sites. By combining the atomic resolution observation with atomistic modelling, we are able to quantify the local silver concentration and elucidate the underlying segregation mechanism.

Modern devices based on modular designs require versatile and universal sensor components which provide an efficient, sensitive, and compact measurement unit. To improve the space capacity of devices, miniaturized building elements are needed, which implies a turning away from conventional microcantilevers toward nanoscale cantilevers. Nanowires can be seen as high-quality resonators and offer the opportunity to create sensing devices on small scales. To use such a one-dimensional nanostructure as a resonant cantilever, a precise characterization based on the fundamental properties is needed. We present a correlative electron and light microscopy approach to characterize the pressure and environment sensing capabilities of single nanowires by analyzing their resonance behavior

Abstract Size effects decisively influence the properties of materials at small length scales. In the context of mechanical properties, the trend of ‘smaller is stronger’ has been well established. This statement refers to an almost universal trend of increased strength with decreasing size. A strong influence of size on the elastic properties has also been widely reported, albeit without a clear trend. However, the influence of nanostructure shape on the mechanical properties has been critically neglected. Here, we demonstrate a profound influence of shape and size on the elastic properties of materials on the example of gold nanowires. The elastic properties are determined using in-situ mechanical testing in scanning and transmission electron microscopy by means of resonance excitation and uniaxial tension. The combination of bending and tensile load types allows for an independent and correlative calculation of the Young's modulus. We find both cases of softening as well as stiffening, depending critically on the interplay between size and shape of the wires. Graphic abstract

This article reports on energy-dispersive micro Laue (µLaue) diffraction of an individual gold nanowire that was mechanically deformed in three-point bending geometry using an atomic force microscope. The nanowire deformation was investigated by scanning the focused polychromatic X-ray beam along the nanowire and recording µLaue diffraction patterns using an energy-sensitive pnCCD detector that permits measurement of the angular positions of the Laue spots and the energies of the diffracted X-rays simultaneously., This article reports on energy-dispersive micro Laue (µLaue) diffraction of an individual gold nanowire that was mechanically deformed in three-point bending geometry using an atomic force microscope. The nanowire deformation was investigated by scanning the focused polychromatic X-ray beam along the nanowire and recording µLaue diffraction patterns using an energy-sensitive pnCCD detector that permits measurement of the angular positions of the Laue spots and the energies of the diffracted X-rays simultaneously. The plastic deformation of the nanowire was shown by a bending of up to 3.0 ± 0.1°, a torsion of up to 0.3 ± 0.1° and a maximum deformation depth of 80 ± 5 nm close to the position where the mechanical load was applied. In addition, extended Laue spots in the vicinity of one of the clamping points indicated the storage of geometrically necessary dislocations with a density of 7.5 × 1013 m−2. While µLaue diffraction with a non-energy-sensitive detector only gives access to the deviatoric strain, the energy sensitivity of the employed pnCCD offers absolute strain measurements with a resolution of 1%. Here, the residual strain after complete unloading of the nanowire amounted to maximum tensile and compressive strains of the order of +1.2 and −3%, which is comparable to the actual resolution limit. The combination of white-beam µLaue diffraction using an energy-sensitive pixel detector with nano-mechanical testing opens up new possibilities for the study of mechanical behavior at the nanoscale.

Nanoscale interdiffusion at the heterophase interfaces is the elementary process that controls solid-solid phase transformations and intermixing in multilayers. Here, we provide a direct experimental proof that the nanoscale multiphase interdiffusion is controlled by the interface mobility. We observed the anisotropic diffusion intermixing in Au–Fe bimetallic nanowhiskers, where the diffusion penetration depth of Fe into single crystalline Au nanowhisker across the incoherent Au–Fe interface was much greater than across its coherent counterpart. By applying a simple kinetic model to the results of diffusion measurements, we obtained the absolute values of mobilities of coherent and incoherent Fe-Au interfaces, and the Arrhenius parameters describing their temperature dependence. Atomic resolution scanning transmission electron microscopy confirmed that the lower mobility of the coherent interface is associated with the difficulties of the nucleation of interface disconnections. We proposed that the sluggish movement of the latter represents a kinetic “bottleneck” which determines the rate of intermixing. Our results indicate that the anisotropy of interface mobilities is a leading factor determining the anisotropic shape of precipitates formed in many heterogeneous solid-solid phase transformations.

Metallic nanowires (NWs) with twin boundaries (TBs) running parallel to the NW length direction exhibit unusual plastic strain recovery owing to the interaction of dislocations with TBs. Here, based on in-situ transmission electron microscopy nanomechanical testing and molecular dynamics simulations, we report observation and quantification of dislocation nucleation, interaction with TBs, and retraction in bi-twinned Ag NWs with a single TB along the NW length direction. Our results show that leading partial dislocations nucleated from the free surface can be hindered by the TB, and upon unloading all or part of the leading partials can retract due to the repulsive force from the TB, leading to full or partial plastic strain recovery (Bauschinger effect), respectively. The bi-twinned Ag NWs can undergo stress relaxation, even at a stress below the yield strength, where the plastic strain also recovers upon unloading. The relaxation and recovery behaviors are compared to those of penta-twinned Ag NWs. Our results illustrate that the internal TBs in NWs can interact with surface-nucleated dislocations, leading to time-dependent plastic strain recovery and Bauschinger effect. G.C. and Y.Z. acknowledge financial support from the National Science Foundation (NSF) under Award No. CMMI-1929646. S.Y. and H.G. acknowledge financial support from the NSF through Grant DMR-1709318 and computational support by the Extreme Science and Engineering Discovery Environment (XSEDE) through Grant MS090046. The authors acknowledge the use of the Analytical Instrumentation Facility (AIF) at North Carolina State University, which is supported by the State of North Carolina and the National Science Foundation (award number ECCS-1542015).

Gaseous nitriding of steel and iron can significantly improve their properties, for example corrosion resistance, fatigue endurance and tribological properties. In order to obtain a better understanding of the early stages of formation of the initial cubic primitive γ′-Fe4N, the mechanism and crystallography of the α–γ′ phase transformation was investigated under simplified conditions. Single-crystal α-Fe whiskers were nitrided at 823 K and a nitriding potential of 0.7 atm−1/2for 20 min. The resulting microstructure and phases, as well as the crystallographic orientation of crystallites belonging to a particular phase, were characterized by scanning electron microscopy coupled with electron backscatter diffraction. The habit planes were investigated by single- and two-surface trace analysis. The α-Fe whiskers partly transform into γ′-Fe4N, where γ′ grows mainly in a plate-like morphology. An orientation relationship close to the rational Pitsch orientation relationship and {0.0780.4320.898}αand {0.3910.3670.844}γ′as habit planes were predicted by the phenomenological theory of martensite crystallography (PTMC), adopting a {101}α〈101〉αshear system for lattice invariant strain, which corresponds to a {111}γ′〈112〉γ′shear system in γ′. The encountered orientation relationship and the habit planes exhibit excellent agreement with predictions from the PTMC, although the transformation definitely requires diffusion. The γ′ plates mainly exhibit one single internally untwinned variant. The formation of additional variants due to strain accommodation, as well as the formation of a complex microstructure, was suppressed to a considerable extent by the fewer mechanical constraints imposed on the transforming regions within the iron whiskers as compared to the situation at the surface of bulk samples.

Bubeck, C., et al. (2020). Correction: Bandgap-adjustment and enhanced surface photovoltage in Y-substituted LataivO2N. Journal of Materials Chemistry A, 8(26). https://doi.org/10.1039/D0TA90138E The authors regret that the affiliations for author Eduardo Salas Colera were not listed correctly on the original manuscript. The corrected list of affiliations for this paper is as shown here. The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers. Perovskite-type oxynitrides AB(O,N)3 are photocatalysts for overall water splitting under visible light illumination. In the past, structurally labile perovskite-type oxynitrides (e.g. YTaON2) were predicted to be highly suitable. In this work, we tackle the challenging YTa(O,N)3 synthesis by Y-substitution in LaTaIVO2N resulting in phase-pure La0.9Y0.1TaIVO2N, La0.75Y0.25TaIVO2N, and La0.7Y0.3TaIVO2N. By using microcrystalline YTaO4 together with an unconventional ammonolysis protocol we synthesized the highest reported weight fraction (82(2) wt%) of perovskite-type YTa(O,N)3. Ta4+ in La1−xYxTaIVO2N was verified by X-ray photoelectron spectroscopy (XPS) and X-ray near edge absorption structure (XANES) analysis. Density functional theory (DFT) calculations revealed a transparent conductor-like behavior explaining the unusual red/orange color of the Ta4+-containing perovskites. In combination with crystal structure analysis the DFT calculations identified orthorhombic strain as the main descriptor for the unexpected trend of the optical bandgap (EG,x=0.3 ≈ EG,x=0 < EG,x=0.1 < EG,x=0.25). Surface photovoltage spectroscopy (SPS) of particulate La1−xYxTaIVO2N (x = 0, 0.1, 0.25, 0.3) films revealed negative photovoltages at photon energies exceeding 1.75 eV, confirming that these materials are n-type semiconductors with effective bandgaps of ∼1.75 eV irrespective of the Y content. The photovoltage values increased with the Y content, suggesting an improved carrier generation and separation in the materials. However, increasing the Y content also slowed down the timescales for photovoltage generation/decay indicating trap states in the materials. Based on our results, we suggest a significantly weaker as classically assumed impact of reduced B-site metal cations such as Ta4+ on the photovoltage and charge carrier recombination rate. This work was supported by the Deutsche Forschungsgemeinschaft within the priority program SPP 1613 "Solar H2" (WE 2803/7-1). Support for surface photovoltage spectroscopy measurements was provided by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Grant DOE-SC0015329

The rational design of catalysts is crucial to make power-to-X technologies viable. Here the authors introduce the delafossite PdCoO2 as a highly active hydrogen evolution reaction catalyst due to the growth of a tensile-strained Pd-rich capping layer under reductive conditions. Image credit: Christop Hohmann., The rational design of hydrogen evolution reaction electrocatalysts that can compete with platinum is an outstanding challenge in the process of designing viable power-to-gas technologies. Here, we introduce delafossites as a family of hydrogen evolution reaction electrocatalysts in acidic media. We show that, in PdCoO2, the inherently strained Pd metal sublattice acts as a pseudomorphic template for the growth of a tensile-strained Pd-rich capping layer under reductive conditions. The surface modification ranges up to 400 nm and continuously improves the electrocatalytic activity by simultaneously increasing the exchange current density and by reducing the Tafel slope down to 38 mV dec(-1), leading to overpotentials eta(10) < 15 mV. The improved activity is attributed to the operando stabilization of a beta-PdHx phase with enhanced surface catalytic properties with respect to pure or nanostructured palladium. These findings illustrate how operando-induced electrodissolution can be used as a top-down design concept through the strain-stabilized formation of catalytically active phases.

The rational design of highly active electrocatalysts for ethanol electrooxidation reaction (EOR) is important for future commercial application of efficient direct ethanol fuel cells. Herein, we describe application of a solid-phase reaction for the creation of a well-defined, high-efficiency, nanoporous gold (NPG) electrocatalyst for EOR. The evaluation of the feature size and physical properties of the NPG electrocatalysts was undertaken using field-emission scanning electron microscopy and high-resolution transmission electron microscopy. Additionally, the catalytic performance of the prepared NPG electrocatalysts was determined using cyclic voltammetry (CV) and chronoamperometry (CA), with results indicating that their enhanced electrocatalytic activities and long-term durability were highly dependent upon morphology. The created NPG exhibited a mass activity of 308 mA mgAu−1 toward EOR in alkaline media, which is much higher than those of nanostructured Au catalysts. In particular, 800-cycle CV and ...

Recently, there has been growing attention and effort to search for new microbicidal drugs which present different mode of action from those already existing, as an alternative to the global threat of fungal and bacterial multi drug resistance (MDR). Here we propose biological synthesis of SnO₂ nanoparticles using mammalian cells as an economic and ecofriendly platform. This presents a novel biogenic method for SnO₂ synthesis using metal binding peptides extracted from MCF-7 human cancer cells, which induces the biomineralization of SnO₂ nanoparticles. A series of electron donor functional groups and metal binding sites in these peptides reacts with Sn2+ ions and directs the growth of SnO₂ nanoparticles without addition of toxic redox and capping agents in the reaction system. Since peptides present reactive sites in aqueous solution at room temperature, a facile reaction environment can be easily achieved. Furthermore, by tuning the reactants' concentration and pH, the size, shape and 3D-structures of SnO₂ nanoparticles can be controlled. Peptides also ensure biocompatibility, and SnO₂ nanoparticles provide antibacterial properties, which broadens their applications in biomedical fields.

Gold nanoparticle catalysts are important in many industrial production processes. Nevertheless, for traditional C sp2 -C sp2 cross-coupling reactions they have been rarely used and Pd catalysts usually give a superior performance. Herein we report that in situ formed gold metal nanoparticles are highly active catalysts for the cross coupling of allylstannanes and activated alkylbromides to form C sp3 -C sp3 bonds. Turnover numbers up to 29 000 could be achieved in the presence of active carbon as solid support, which allowed for convenient catalyst recovery and reuse. The present study is a rare case where a gold metal catalyst is superior to Pd catalysts in a cross-coupling reaction of an organic halide and an organometallic reagent.

Twinning and dislocation slip are two competitive deformation mechanisms in face-centered cubic (FCC) metals. For FCC metallic nanowires (NWs), the competition between these mechanisms was found to depend on loading direction and material properties. Here, using

Fe and Co nano-whiskers and Co platelets were synthesized via physical vapor deposition without any template and catalyst. Transmission electron microscopic analyses revealed that the Fe whiskers were all single crystal with whisker axis along [1 0 0] crystallographic direction. Both FCC and HCP crystal structures were found in the Co whiskers with stacking faults and micro-twins. Off-axis Electron holography results showed that all the whiskers synthesized were magnetic single domain structures. Vortex state was observed in a small platelet of high symmetry.

Controlled microrobotic navigation in the vascular system can revolutionize minimally invasive medical applications, such as targeted drug and gene delivery. Magnetically controlled surface microrollers have emerged as a promising microrobotic platform for controlled navigation in the circulatory system. Locomotion of micrororollers in strong flow velocities is a highly challenging task, which requires magnetic materials having strong magnetic actuation properties while being biocompatible. The L1(0)-FePt magnetic coating can achieve such requirements. Therefore, such coating has been integrated into 8 mu m-diameter surface microrollers and investigated the medical potential of the system from magnetic locomotion performance, biocompatibility, and medical imaging perspectives. The FePt coating significantly advanced the magnetic performance and biocompatibility of the microrollers compared to a previously used magnetic material, nickel. The FePt coating also allowed multimodal imaging of microrollers in magnetic resonance and photoacoustic imaging in ex vivo settings without additional contrast agents. Finally, FePt-coated microrollers showed upstream locomotion ability against 4.5 cm s(-1) average flow velocity with real-time photoacoustic imaging, demonstrating the navigation control potential of microrollers in the circulatory system for future in vivo applications. Overall, L1(0)-FePt is conceived as the key material for image-guided propulsion in the vascular system to perform future targeted medical interventions., Advanced Functional Materials, 32 (8), ISSN:1616-3028, ISSN:1616-301X

Cancer cells are in most instances characterized by rapid proliferation and uncontrolled cell division. Hence, they must adapt to proliferation-induced metabolic stress through intrinsic or acquired anti-metabolic stress responses to maintain homeostasis and survival. One mechanism to achieve this is to reprogram gene expression in a metabolism-dependent manner. MondoA (also known as MLXIP), a member of the MYC interactome, has been described as an example of such a metabolic sensor. However, the role of MondoA in malignancy is not fully understood and the underlying mechanism in metabolic responses remains elusive. By assessing patient data sets we found that MondoA overexpression is associated with a worse survival in pediatric common acute lymphoblastic leukemia (cALL). Using CRISPR/Cas9 and RNA interference approaches, we observed that MondoA depletion reduces transformational capacity of cALL cells in vitro and dramatically inhibits malignant potential in an in vivo mouse model. Interestingly, reduced expression of MondoA in patient data sets correlated with enrichment in metabolic pathways. The loss of MondoA correlated with increased tricarboxylic acid (TCA) cycle activity. Mechanistically, MondoA senses metabolic stress in cALL cells by restricting oxidative phosphorylation through reduced PDH activity. Glutamine starvation conditions greatly enhance this effect and highlight the inability to mitigate metabolic stress upon loss of MondoA in cALL. Our findings give a novel insight into the function of MondoA in pediatric cALL and support the notion that MondoA inhibition in this entity offers a therapeutic opportunity and should be further explored.Key PointsMondoA maintains aggressiveness and leukemic burden in common ALL, modulating metabolic stress response.

The first stages of plasticity in three-point bent Au nanowires are investigated by in situ three-point bending tests in combination with Laue micro-diffraction. To separate the elastic and plastic deformation, loading–unloading cycles were performed with increasing load in each consecutive cycle. The storage of the first four geometrically necessary dislocations of [011⎯⎯](111) slip system is observed in the vicinity of both clamping points, which might be attributed to the local rotations induced by the rigid Si support. At later stages of the deformation, additional slip systems are activated either by the torsion of the nanowire or by unintentional indentation from the AFM tip. The cyclic loading–unloading approach combined with Laue microdiffraction thus allows to study the onset of plasticity in defect-scarce nanostructures deformed by bending, offering additional possibilities in studying the dislocation nucleation process in bent nano-objects, which are essential for future applications, e.g., in flexible electronics and nano-electromechanical systems. The authors gratefully acknowledge the financial support from the French National Research Agency through Project No. ANR-11-BS10-0014 MecaniX. They further thank the French CRG program committee for the allocated beamtime at the BM32 beamline at ESRF and L. Belliard at INSP in Paris (France) for providing the Si micro-trenches.

The dynamics of solid state dewetting phenomena of a 50nm thick, mazed bicrystalline Al film on single crystalline α-Al2O3(sapphire) substrates was studied in-situ using an environmental scanning electron microscope (ESEM). The bicrystalline Al thin films served as a model system where the influence of grain boundaries and texture effects are well determined compared to polycrystalline films. The experiments were performed in controlled oxidizing and reducing atmospheres at 773K and 823K, respectively, to shed light on the differences in dewetting mechanisms and dynamics.While the reducing atmosphere led to spontaneous dewetting at 823K after an incubation time of a few minutes, a hierarchical dewetting process was observed for the sluggish dewetting under oxidizing conditions. Voids initiated at (substrate or surface) defects and expanded trying to maintain a hexagonal shape. Pinning and depinning processes led to a discontinuous void growth and irregular void shapes including finger instabilities. As a consequence, the void growth followed a variety of power law exponents between 0.10 and 0.55. A new microkink-flow mechanism was discovered at the terminating Al planes at the void.

Controlled plastic forming of nanoscale metallic objects by applying mechanical load is a challenge, since defect-free nanocrystals usually yield at near theoretical shear strength, followed by stochastic dislocation avalanches that lead to catastrophic failure or irregular, uncontrolled shapes. Herein, instead of mechanical load, we utilize chemical stress from imbalanced interdiffusion to manipulate the shape of nanowhiskers. Bimetallic Au-Fe nanowhiskers with an ultrahigh bending strength were synthesized employing the molecular beam epitaxy technique. The one-sided Fe coating on the defect-free, single-crystalline Au nanowhisker exhibited both single- and polycrystalline regions. Annealing the bimetallic nanowhiskers at elevated temperatures led to gradual change of curvature and irreversible bending. At low homological temperatures at which grain boundary diffusion is a dominant mode of mass transport this irreversible bending was attributed to the grain boundary Kirkendall effect during the diffusion of Au along the grain boundaries in the Fe layer. At higher temperatures and longer annealing times, the bending was dominated by intensive bulk diffusion of Fe into the Au nanowhisker, accompanied by a significant migration of the Au-Fe interphase boundary toward the Fe layers. The irreversible bending was caused by the concentration dependence of the lattice parameter of the Au(Fe) alloy and by the volume effect associated with the interphase boundary migration. The results of this study demonstrate a high potential of chemical interdiffusion in the controlled plastic forming of ultrastrong metal nanostructures. By design of the thickness, microstructure, and composition of the coating as well as the parameters of heat treatment, bimetallic nanowhiskers can be bent in a controlled manner.

Correction to: Communications Chemistry https://doi.org/10.1038/s42004-019-0237-x, published online 26 November 2019. The original version of this Article incorrectly omitted the received/accepted dates of Received: 28 March 2019; Accepted: 24 October 2019. This has now been corrected in the PDF and HTML versions of the Article.

Protein- and peptide-based manufacturing of self-assembled supramolecular functional materials has been a formidable challenge for biomedical applications, being complex in structure and immunogenic in nature. In this context, self-assembly of short amino acid sequences as simplified building blocks to design metal–biomolecule frameworks (MBioFs) is an emerging field of research. Here, we report a facile, bioinspired route of anisotropic nanostructure synthesis using gold binding peptides (10–15mers) secreted by cancer cells. The bioinformatics tool i-TASSER predicts the effect of amino acid sequences on metal binding sites and the secondary structures of the respective peptide sequence. Electron microscopy, X-ray, infrared, and Raman spectroscopy validated the versatile anisotropic gold nanostructures and the metal–bioorganic nature of this biomineralization. We studied the influence of precursor salt, pH, and peptide concentration on the evolution of nanoleaf, nanoflower, nanofiber, and dendrimer-like a...

The development of stable compounds for durable optics is crucial for the future of plasmonic applications. Even though niobium is mainly known as a superconducting material, it can qualify as an alternative material for high-temperature and active plasmonic applications. We utilize electron beam lithography combined with plasma etching techniques to fabricate nanoantenna arrays of niobium. Tailoring the niobium antenna geometry enables precise tuning of the plasmon resonances from the near- to the mid-infrared spectral range. Additionally, the hydrogen absorptivity as well as the high-temperature stability of the antennas have been investigated. Further advantages of niobium such as superconductivity make niobium highly attractive for a multitude of plasmonic devices ranging from active and refractory perfect absorbers/emitters to plasmon-based single photon detectors.

Survival rates of pediatric sarcoma patients stagnated during the last two decades, especially in adolescents and young adults (AYAs). Targeted therapies offer new options in refractory cases. Gene expression profiling provides a robust method to characterize the transcriptome of each patient's tumor and guide the choice of therapy. Twenty patients with refractory pediatric sarcomas (age 8-35 years) were assessed with array profiling: ten had Ewing sarcoma, five osteosarcoma, and five soft tissue sarcoma. Overexpressed genes and deregulated pathways were identified as actionable targets and an individualized combination of targeted therapies was recommended. Disease status, survival, adverse events (AEs), and quality of life (QOL) were assessed in patients receiving targeted therapy (TT) and compared to patients without targeted therapy (non TT). Actionable targets were identified in all analyzed biopsies. Targeted therapy was administered in nine patients, while eleven received no targeted therapy. No significant difference in risk factors between these two groups was detected. Overall survival (OS) and progression free survival (PFS) were significantly higher in the TT group (OS: P=0.0014, PFS: P=0.0011). Median OS was 8.83 versus 4.93 months and median PFS was 6.17 versus 1.6 months in TT versus non TT group, respectively. QOL did not differ at baseline as well as at four week intervals between the two groups. TT patients had less grade 1 AEs (P=0.009). The frequency of grade 2-4 AEs did not differ. Overall, expression based targeted therapy is a feasible and likely beneficial approach in patients with refractory pediatric sarcomas that warrants further study.

In situ micro-cantilever fracture testing is used to demonstrate changes in fracture behavior of nanostructured, heavily cold drawn pearlitic steel wires as a function of drawing strain and annealing conditions. It is shown that these steels exhibit a sharp transition in fracture behavior between a drawing strain of 320% and 520% with a drop in fracture toughness from 7.5 to 4 MPam(1/2). This is confirmed from the nature of fracture which is stable with some degree of plasticity at drawing strains below 320% and changes to catastrophic cleavage fracture at drawing strains of 420% and above. This transition and associated brittleness is attributed to structural (cementite decomposition and strain induced increase in tetragonality) and microstructural (increasing nanocrystallinity and dislocation density) evolution that these steels undergo at higher drawing strains. On heat treating, the 420% strained sample, brittle cleavage fracture continues for low temperature (200 degrees C) annealing with no visible changes in microstructure, while crack growth is suppressed and large-scale plasticity is recovered for high temperature (500 degrees C) annealing with accompanying grain coarsening, and re-precipitation of spherodized cementite at grain boundaries.

Ewing sarcomas (ES) are highly malignant, osteolytic bone or soft tissue tumors, which are characterized by EWS–ETS translocations and early metastasis to lung and bone. In this study, we investigated the role of the BRICHOS chaperone domain-containing endochondral bone protein chondromodulin I (CHM1) in ES pathogenesis. CHM1 is significantly overexpressed in ES, and chromosome immunoprecipitation (ChIP) data demonstrate CHM1 to be directly bound by an EWS–ETS translocation, EWS-FLI1. Using RNA interference, we observed that CHM1 promoted chondrogenic differentiation capacity of ES cells but decreased the expression of osteolytic genes such as HIF1A, IL6, JAG1, and VEGF. This was in line with the induction of the number of tartrate-resistant acid phosphatase (TRAP+)-stained osteoclasts in an orthotopic model of local tumor growth after CHM1 knockdown, indicating that CHM1-mediated inhibition of osteomimicry might play a role in homing, colonization, and invasion into bone tissues. We further demonstrate that CHM1 enhanced the invasive potential of ES cells in vitro. This invasiveness was in part mediated via CHM1-regulated matrix metallopeptidase 9 expression and correlated with the observation that, in an xenograft mouse model, CHM1 was essential for the establishment of lung metastases. This finding is in line with the observed increase in CHM1 expression in patient specimens with ES lung metastases. Our results suggest that CHM1 seems to have pleiotropic functions in ES, which need to be further investigated, but appears to be essential for the invasive and metastatic capacities of ES.

Nanomultilayers (NMLs) are envisaged for joining miniaturized and heat-sensitive components at ever-reduced temperatures. Investigation of the thermal stability of bulk-eutectic Al-Si12at.% nanolayers, confined between AlN barriers in a NML configuration, evidences the onset of phase separation of the supersaturated Al-Si solid solution into domains of pure Al and pure Si at around 200 °C. The phase-separated, but still nano-confined Al-Si nanolayers develop large in-plane compressive stresses upon further heating, which invoke extensive mass transport of both Si (by solid-state diffusion at T > 200 °C) and liquid Al (by heterogeneous contact melting at 300 < T < 400 °C) to the NML surface.

Nanoscale interdiffusion at the heterophase interfaces is the elementary process that controls solid-solid phase transformations and intermixing in multilayers. Here, we provide the first experimental proof that the nanoscale multiphase interdiffusion is controlled by the interface mobility. We observed the anisotropic diffusion intermixing in Au-Fe bimetallic nanowhiskers, where the diffusion penetration depth of Fe into single crystalline Au nanowhisker across the incoherent Au-Fe interface was much greater than across its coherent counterpart. By applying a simple kinetic model to the results of diffusion measurements, we obtained the absolute values of mobilities of coherent and incoherent Fe-Au interfaces, and the Arrhenius parameters describing their temperature dependence. Atomic resolution transmission electron microscopy confirmed that the lower mobility of the coherent interface is associated with the difficulties of the nucleation of interface disconnections. We proposed that the sluggish movement of the latter represents a kinetic "bottleneck" which determines the rate of intermixing. Our results indicate that the anisotropy of interface mobilities is a leading factor determining the anisotropic shape of precipitates formed in many heterogeneous solid-solid phase transformations.

The crystallography and mechanism of the early stages of the formation of cubic primitive γ′-Fe4N in single-crystal α-Fe whiskers during gaseous nitriding were investigated by electron microscopy and electron backscatter diffraction. The α–γ′ phase transformation could be observed under simplified conditions owing to the lack of geometric constraints for the transformation., Gaseous nitriding of steel and iron can significantly improve their properties, for example corrosion resistance, fatigue endurance and tribological properties. In order to obtain a better understanding of the early stages of formation of the initial cubic primitive γ′-Fe4N, the mechanism and crystallography of the α–γ′ phase transformation was investigated under simplified conditions. Single-crystal α-Fe whiskers were nitrided at 823 K and a nitriding potential of 0.7 atm−1/2 for 20 min. The resulting microstructure and phases, as well as the crystallographic orientation of crystallites belonging to a particular phase, were characterized by scanning electron microscopy coupled with electron backscatter diffraction. The habit planes were investigated by single- and two-surface trace analysis. The α-Fe whiskers partly transform into γ′-Fe4N, where γ′ grows mainly in a plate-like morphology. An orientation relationship close to the rational Pitsch orientation relationship and {0.078 0.432 0.898}α and {0.391 0.367 0.844}γ′ as habit planes were predicted by the phenomenological theory of martensite crystallography (PTMC), adopting a {101}α〈101〉α shear system for lattice invariant strain, which corresponds to a {1 1 1}γ′〈1 12〉γ′ shear system in γ′. The encountered orientation relationship and the habit planes exhibit excellent agreement with predictions from the PTMC, although the transformation definitely requires diffusion. The γ′ plates mainly exhibit one single internally untwinned variant. The formation of additional variants due to strain accommodation, as well as the formation of a complex microstructure, was suppressed to a considerable extent by the fewer mechanical constraints imposed on the transforming regions within the iron whiskers as compared to the situation at the surface of bulk samples.

Recent investigations of layered, rock salt and spinel-type manganese oxides in composite powder electrodes revealed the mutual stabilization of the Li-Mn-O compounds during electrochemical cycling. A novel approach of depositing such complex compounds as an active cathode material in thin-film battery electrodes is demonstrated in this work. It shows the maximum capacity of 226 mA h g