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Abstract: Microstructure engineering provides an effective way to improve the vortex pinning via addition of nano precipitates in a superconducting matrix. Precise control of these nano precipitates, including their dimensions and alignment, is critical to obtain optimal pinning. DyBa2Cu3O7-x (DyBCO) films with BaZrO3 nano precipitates (BZO-NPs) were grown on biaxially-textured MgO buffer layers deposited by Inclined Substrate Deposition (ISD) on Hastelloy substrates. A critical current density (Jc) of 0.9 MA cm-2 was obtained at 77K in self-field. Orientation and size of the BZO-NPs were investigated using Transmission Electron Microscopy (TEM). The BZO-NPs were aligned along the (a,b)-plane of DyBCO and thus was greatly affected by the faceted geometry of the ISD MgO buffer layer. [Copyright &y& Elsevier]

Abstract: DyBa2Cu3O7-δ (DyBCO) films were grown on biaxially-textured MgO buffer layers deposited on Hastelloy substrates, typical critical current densities (Jc) were 2.1 MA cm-2 at 77K in self-field. Biaxial texturing and the orientation relationship of DyBCO films with respect to the Inclined Substrate Deposition MgO buffer layer were investigated using plan-view and cross-section Transmission Electron Microscopy (TEM). A detailed analysis of the microstructural parameters will be summarized. Despite the large lattice mismatch (8.5%) the DyBCO grows epitaxially on the MgO buffer layer and the biaxial texture of the MgO is well transferred to the DyBCO. A growth model for the DyBCO is presented. [Copyright &y& Elsevier]

DyBa2Cu3O7-x (DyBCO) films with MgO buffer layers were grown on Hastelloy substrates by inclined substrate deposition (ISD). An almost linear increase of the critical current with the DyBCO film thickness was observed. A maximum critical current of 1018 A cm-1 was measured for a DyBCO film with 5.9 μm thickness, yielding a critical current density of 1.7 MA cm-2 at 77 K and self-field. Transmission electron microscopy (TEM) yielded highly biaxially textured DyBCO films at all thicknesses and, thus, no significant decrease of the critical current density occurs with the film thickness. ISD yields a non-zero component of the growth direction parallel to the DyBCO (a, b)-plane since the DyBCO grows on a faceted MgO surface and avoids a-axis growth. Therefore, the ISD technology offers a unique possibility to overcome thickness limitations in coated conductor technology. [ABSTRACT FROM AUTHOR]

DyBa2Cu3O7-x (DyBCO) films with MgO buffer layers were grown on Hastelloy substrates by inclined substrate deposition (ISD). An almost linear increase of the critical current with the DyBCO film thickness was observed. A maximum critical current of 1018 A cm-1 was measured for a DyBCO film with 5.9 μm thickness, yielding a critical current density of 1.7 MA cm-2 at 77 K and self-field. Transmission electron microscopy (TEM) yielded highly biaxially textured DyBCO films at all thicknesses and, thus, no significant decrease of the critical current density occurs with the film thickness. ISD yields a non-zero component of the growth direction parallel to the DyBCO (a, b)-plane since the DyBCO grows on a faceted MgO surface and avoids a-axis growth. Therefore, the ISD technology offers a unique possibility to overcome thickness limitations in coated conductor technology. [ABSTRACT FROM AUTHOR]

Abstract: Sb2Te3 and Bi2Te3 thin films were grown at room temperature on SiO2 and BaF2 substrates using molecular beam epitaxy. A layer-by-layer growth was achieved such that metallic layers of the elements with 0.2nm thickness were deposited. The layer structure in the as-deposited films was confirmed by X-ray diffraction and was seen more clearly in Sb2Te3 thin films. Subsequent annealing was done at 250°C for 2h and produced the Sb2Te3 and Bi2Te3 crystal structure as confirmed by high-energy X-ray diffraction. This preparation process is referred to as nano-alloying and it was demonstrated to yield single-phase thin films of these compounds. In the thin films a significant texture could be identified with the crystal c axis being almost parallel to the growth direction for Sb2Te3 and tilted by about 30° for Bi2Te3 thin films. In-plane transport properties were measured for the annealed films at room temperature. Both films yielded a charge carrier density of about 2.6×1019 cm−3. The Sb2Te3 films were p-type, had a thermopower of +130μVK−1, and surprisingly high mobilities of 402cm2 V−1 s−1. The Bi2Te3 films were n-type, showed a thermopower of −153μVK−1, and yielded significantly smaller mobilities of 80cm2 V−1 s−1. The chemical composition and microstructure of the films were investigated by transmission electron microscopy (TEM) on cross sections of the thin films. The grain sizes were about 500nm for the Sb2Te3 and 250nm for the Bi2Te3 films. In the Bi2Te3 thin film, energy-filtered TEM allowed to image a Bi-rich grain boundary phase, several nanometers thick. This secondary phase explains the poor mobilities of the Bi2Te3 thin film. With these results the high potential of the nano-alloying deposition technique for growing films with a more complex layer architecture is demonstrated. [Copyright &y& Elsevier]

Electrochemical CO 2 reduction (CO 2 R) in acidic media provides a pathway to curtail CO 2 losses by suppressing the formation of (bi)carbonates. In such systems, a high concentration of alkali metal cations is necessary for mitigating the proton-rich environment and suppressing the competing hydrogen evolution reaction. However, a high cation concentration also promotes salt precipitation within the gas diffusion layer, resulting in poor system durability. Here, we resolve this conundrum by replacing the liquid catholyte with a solid-state proton conductor to regulate H + transport. This is postulated to allow for a locally alkaline environment at the cathode, enabling selective CO 2 R even without alkali metal cations. We show that this strategy is effective over a broad range of catalyst systems. For instance, we achieve an 87% CO faradaic efficiency (FE) at 300 mA/cm 2 using a composite nanoporous Au and single-atom Ni catalyst, with 0.25 M H 2 SO 4 as the anolyte. Stable operation over 110 h and a high single-pass carbon efficiency of 82.8% were also successfully demonstrated. Importantly, we find that this solid-state system is also particularly effective at converting dilute feedstock (5% CO 2 ) with a CO FE of 47.7%, a factor of 16.4 times higher than a conventional system. Our results introduce a simple yet effective design approach for developing efficient acidic CO 2 R electrolyzers.

The pursuit of high-performance thermoelectric materials is of paramount importance in addressing energy sustainability and environmental concerns. Here, we explore the multifaceted impact of sulfur passivation in the matrix of tellurium nanowires (TeNWs), encompassing environmental control, thermoelectric properties, and charge carrier mobility. In this study, we present the facile production of TeNWs using an aqueous solution synthesis approach. The synthesized TeNWs were subsequently subjected to surface modification involving sulfur moieties. Our findings demonstrate that sulfur passivation not only effectively safeguards the nanowires from environmental degradation but also significantly augments their thermoelectric properties. Notably, the highest recorded values were achieved at 560 K for passivated tellurium nanowires, exhibiting a Seebeck coefficient of 246 μV/K, an electrical conductivity of 14.2 S/cm, and power factors of 86.7 μW/m-K 2 . This strategy presents a promising avenue for the development of advanced thermoelectric materials for applications in energy harvesting, waste heat recovery, and sustainable energy conversion technologies.

Organic-inorganic hybrid thermoelectric (TE) materials have attracted tremendous interest for harvesting waste heat energy. Due to their mechanical flexibility, inorganic-organic hybrid TE materials are considered to be promising candidates for flexible energy harvesting devices. In this work, enhanced TE properties of Tellurium (Te) nanowires (NWs)- poly (3-hexylthiophene-2, 5-diyl) (P3HT) hybrid materials are reported by improving the charge transport at interfacial layer mediated via controlled oxidation. A power factor of ≈9.8 µW (mK 2 ) -1 is obtained at room temperature for oxidized P3HT-TeNWs hybrid materials, which increases to ≈64.8 µW (mK 2 ) -1 upon control of TeNWs oxidation. This value is sevenfold higher compared to P3HT-TeNWs-based hybrid materials reported in the literature. MD simulation reveals that oxidation-free TeNWs demonstrate better templating for P3HT polymer compared to oxidized TeNWs. The Kang-Snyder model is used to study the charge transport in these hybrid materials. A large σ E0 value is obtained which is related to better templating of P3HT on oxygen-free TeNWs. This work provides evidence that oxidation control of TeNWs is critical for better interface-driven charge transport, which enhances the thermoelectric properties of TeNWs-P3HT hybrid materials. This work provides a new avenue to improve the thermoelectric properties of a new class of hybrid thermoelectric materials., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Total bacterial count is a routine parameter in microbial safety assessment used in many fields, such as drinking water and industrial water testing. The current gold standard method for counting bacteria is the plate culture method (or heterotrophic plate count) that requires a microbiology laboratory and a long turnover time of at least 24 hours. To tackle these shortcomings, we developed a rapid total bacterial count method that relies on gold nanoparticles (AuNPs) conjugated with affinity ligands to stain bacterial cells captured on a syringe filter. Two affinity ligands were exploited, i.e. a DNA aptamer (AB2) and a lectin Griffonia simplicifolia II (GSII) that recognize bacterial cell wall commonalities, i.e. peptidoglycan and its amino sugars. Upon proper formulation with addition of a surfactant, the AB2 conjugated AuNPs (AB2-AuNPs) can selectively stain bacterial cells captured on the filter membrane with a higher sensitivity than GSII-AuNPs. Measuring the staining intensity using an in-house-built handheld detector allowed us to correlate its intensity reading with the total number of bacterial units present. This bacteria quantification method, referred to as "Filter-and-Stain", had an efficient turnover time of 20 min suggesting its potential usage for rapid on-site applications. Additionally, the detection sensitivity provided by the AB2-AuNP nanoreagent offered a limit of detection as low as 100 CFU mL -1 . We have demonstrated the use of the AB2-AuNPs for detection of bacteria from environmental water samples.

In this study, magnetic Fe 3 O 4 nanoparticles (NPs) were dispersed uniformly by varying the thickness of the SiO 2 coating, and their electronic and magnetic properties were investigated. X-ray diffraction confirmed the structural configuration of monophase inverse-spinel Fe 3 O 4 NPs in nanometer size. Scanning electron microscopy revealed the formation of proper nonporous crystallite particles with a clear core-shell structure with silica on the surface of Fe 3 O 4 NPs. The absorption mechanism studied through the zeta potential indicates that SiO 2 -coated Fe 3 O 4 nanocomposites (SiO 2 @Fe 3 O 4 NCs) possess electrostatic interactions to control their agglomeration in stabilizing suspensions by providing a protective shield of amorphous SiO 2 on the oxide surface. High-resolution transmission electron microscopy images demonstrate a spherical morphology having an average grain diameter of ∼11-17 nm with increasing thickness of SiO 2 coating with the addition of a quantitative presence and proportion of elements determined through elemental mapping and electron energy loss spectroscopy studies. Synchrotron-based element-specific soft X-ray absorption spectroscopy and X-ray magnetic circular dichroism (XMCD) techniques have been involved in the bulk-sensitive total fluorescence yield mode to understand the origin of magnetization in SiO 2 @Fe 3 O 4 NCs. The magnetization hysteresis of Fe 3 O 4 was determined by XMCD. At room temperature, the magnetic coercivity ( H c ) is as high as 1 T, which is about 2 times more than the value of the thin film and about 5 times more pronounced than that of NPs. For noninteracting single-domain NPs with the H c spread from 1 to 3 T, the Stoner-Wohlfarth model provided an intriguing explanation for the hysteresis curve. These curves determine the different components of Fe oxides present in the samples that derive the remnant magnetization involved in each oxidation state of Fe and clarify which Fe component is responsible for the resultant magnetism and magnetocrystalline anisotropy based on noninteracting single-domain particles.

Platinum-based metal catalysts are considered excellent converters in various catalytic reactions, particularly in fuel cell applications. The atomic structure at the nanocrystal surface and the metal interface both influence the catalytic performance, controlling the efficiency of the electrochemical reactions. Here we report the synthesis of Ag/Pt and Ag/Pd core/shell nanocrystals and insight into the formation mechanism of these bimetallic core/shell nanocrystals when undergoing oxygen plasma treatment. We carefully designed the oxidation treatment that determines the structural and compositional evolution. The accelerated oxidation-triggered diffusion of Ag toward the outer metal shell leads to the Kirkendall effect. After prolonged oxygen plasma treatment, most core/shell nanocrystals evolve into hollow spheres. At the same time, a minor fraction of the metal remains unchanged with a well-protected Ag core and a monocrystalline Pt or Pd shell. We hypothesize that the O 2 plasma disturbs the Pt or Pd shell surface and introduces active O species that react with the diffused Ag from the inside out. Based on EDX elemental mapping, combined with several electron microscopic techniques, we deduced the formation mechanism of the hollow structures to be as follows: (I) the oxidation of Ag within the Pt or Pd lattice causes a disrupted crystal lattice of Pt or Pd; (II) nanochannels arise at the defect locations on the Pt or Pd shell; (III) the remaining Ag atoms pass through these nanochannels and leave a hollow crystal behind. Our findings deepen the understanding of interface dynamics of bimetallic nanostructured catalysts under an oxidative environment and unveil an alternative approach for catalyst pretreatment.

It has been long known that low molecular weight resists can achieve a very high resolution, theoretically close to the probe diameter of the electron beam lithography (EBL) system. Despite technological improvements in EBL systems, the advances in resists have lagged behind. Here we demonstrate that a low-molecular-mass single-source precursor resist (based on cadmium(II) ethylxanthate complexed with pyridine) is capable of a achieving resolution (4 nm) that closely matches the measured probe diameter (∼3.8 nm). Energetic electrons enable the top-down radiolysis of the resist, while they provide the energy to construct the functional material from the bottom-up─unit cell by unit cell. Since this occurs only within the volume of resist exposed to primary electrons, the minimum size of the patterned features is close to the beam diameter. We speculate that angstrom-scale patterning of functional materials is possible with single-source precursor resists using an aberration-corrected electron beam writer with a spot size of ∼1 Å.

The spreading of a liquid droplet on flat surfaces is a well-understood phenomenon, but little is known about how liquids spread on a rough surface. When the surface roughness is of the nanoscopic length scale, the capillary forces dominate and the liquid droplet spreads by wetting the nanoscale textures that act as capillaries. Here, using a combination of advanced nanofabrication and liquid-phase transmission electron microscopy, we image the wetting of a surface patterned with a dense array of nanopillars of varying heights. Our real-time, high-speed observations reveal that water wets the surface in two stages: 1) an ultrathin precursor water film forms on the surface, and then 2) the capillary action by nanopillars pulls the water, increasing the overall thickness of water film. These direct nanoscale observations capture the previously elusive precursor film, which is a critical intermediate step in wetting of rough surfaces., Competing Interests: The authors declare no competing interest.

Dense arrays of high-aspect-ratio (HAR) vertical nanostructures are essential elements of microelectronic components, photovoltaics, nanoelectromechanical, and energy storage devices. One of the critical challenges in manufacturing the HAR nanostructures is to prevent their capillary-induced aggregation during solution-based nanofabrication processes. Despite the importance of controlling capillary effects, the detailed mechanisms of how a solution interacts with nanostructures are not well understood. Using in situ liquid cell transmission electron microscopy (TEM), we track the dynamics of nanoscale drying process of HAR silicon (Si) nanopillars in real-time and identify a new mechanism responsible for pattern collapse and nanostructure aggregation. During drying, deflection and aggregation of nanopillars are driven by thin-liquid-film instability, which results in much stronger capillary interactions between the nanopillars than the commonly proposed lateral meniscus interaction forces. The importance of thin-film instability in dewetting has been overlooked in prevalent theories on elastocapillary aggregation. The new dynamic mechanism revealed by in situ visualization is essential for the development of robust nanofabrication processes.

(1) Background: The effects of a high-concentrate (HC) diet in inducing mammary epithelial cell apoptosis in dairy cows via the NOD1/Caspase-8 pathway have never been investigated before the current study. (2) Methods: Twelve Holstein Frisian cows at mid-lactation were selected to conduct this research. The animals were randomly allocated to two groups (n = 6), and both groups received one of two diets: a low-concentrate (LC) (forage: concentrate 6:4) or a high-concentrate (HC) (forage: concentrate 4:6) diet. Furthermore, an enzyme activity assay, tunnel cell assay, RT-qPCR, western blotting, and an immunofluorescence antibody (IFA) assay were performed to elucidate the effect of an HC diet in the mammary gland of dairy cows. (3) Results: The tunnel cell assay revealed a significant number of apoptotic cells in HC group, and the concentration of Caspase-3, and Caspase-8 was higher in the HC group than in the LC group. NOD1, Rip-2, Caspase-3, Caspase-8, Caspase-9, and Bax mRNA expressions, and NOD1, Caspase-3, Caspase-8, and Bax protein expressions, in the HC group were markedly higher than those in the LC group. Furthermore, Bcl-2 mRNA and protein expressions were markedly decreased in the HC compared to those in the LC group. (4) Conclusions: A HC diet fed to dairy cows incites subacute ruminal acidosis (SARA), which increases the iE-DAP concentration and induces apoptosis in the mammary gland via the NOD1/Caspase-8 pathway.

This study aimed to develop nanostructured lipid carriers (NLCs) for improved oral absorption of tilmicosin (TMS) in broilers. Thus, palmitic acid, lauric acid, and stearic acid were selected as solid lipids to formulate TMS-pNLCs, TMS-lNLCs, and TMS-sNLCs, respectively. They showed similar physicochemical properties and meanwhile possessed excellent storage and gastrointestinal stability. The TMS interacted with the lipid matrix and was encapsulated efficiently in NLCs in an amorphous structure. NLCs could enhance oral absorption of TMS compared to 10% tilmicosin phosphate solution in broilers, among which the TMS-sNLCs were the most efficient drug delivery carriers, with a relative oral bioavailability of 203.55%. NLCs could inhibit the efflux of P-glycoprotein (P-pg) toward TMS, which may be involved with improved oral absorption. Taken together, these types of solid lipids influenced the enhanced level of NLCs toward oral bioavailability of TMS, and the sNLCs proved to be the most promising oral delivery carriers of TMS.