BINA

Topological insulators, a class of materials possessing bulk bandgap and metallic surface states with a topological nontrivial symmetry, are considered promising candidates for emerging quantum and optoelectronic applications. However, achieving scalable growth and control over parameters including thickness, carrier density, bulk bandgap, and defect density remains a challenge in realizing such applications. In this work, we show the scalable growth of topological insulator alloys Bi2Se(3-x)Sx and demonstrate composition-tunable bandgap, using chemical vapor deposition (CVD). A bandgap increase of up to ~40% at a sulfur concentration of ~15% is demonstrated. Correspondingly, the real part (n) of the refractive index is reduced in the alloy by ~25% relative to that of Bi2Se3. Additionally, electronic transport measurements indicate a bulk p-type doping and field-effect tunable metallic surface states of the …

The innate immune sensor PKR for double-stranded RNA (dsRNA) is critical for antiviral defense, but its aberrant activation by cellular dsRNA is linked to various diseases. The dsRNA-binding protein PACT plays a critical yet controversial role in the PKR pathway. We demonstrate that PACT is a direct and specific suppressor of PKR against endogenous dsRNA ligands like inverted-repeat Alu RNAs, which robustly activate PKR in the absence of PACT. PACT-mediated inhibition does not involve competition for dsRNA binding. Instead, PACT impairs PKR ability to scan along dsRNA, a process necessary for PKR molecules to encounter and autophoshorylate each other for activation. By scanning along dsRNA and directly interacting with PKR, PACT restricts PKR movement on dsRNA, reducing the likelihood of PKR molecular collisions and subsequent autophosphorylation, effectively inhibiting PKR without sequestering dsRNA. Consequently, PKR inhibition is more robust with longer and less abundant dsRNA, and minimal with abundant or short dsRNA. Thus, PACT functions to adjust the PKR activation threshold for long endogenous dsRNA without altering its inherent activity, revealing new mechanisms for establishing self-tolerance.

Super-resolution optical imaging has become a prominent tool in life and material sciences, allowing one to decipher structures at increasingly greater spatial detail. Among the utilized techniques in this field, super-resolution optical fluctuation imaging (SOFI) has proved to be a valuable approach. A major advantage of SOFI is its less restrictive requirements for generating super-resolved images of neighboring nanostructures or molecules, as it only assumes that the detected fluctuating light from neighboring emitters is statistically uncorrelated, but not necessarily separated in time. While most optical super-resolution microscopies depend on signals obtained from fluorescence, they are limited by photobleaching and phototoxicity. An alternative source for optical signals can be acquired by detecting the light scattered from molecules or nanoparticles. However, the application of coherent scattering-based imaging modalities for super-resolution imaging has been considerably limited compared to fluorescence-based modalities. Here, we develop scattering-based super-resolution optical fluctuation imaging (sSOFI), where we utilize the rotation of anisotropic particles as a source of fluctuating optical signals. We discuss the differences in the application of SOFI algorithms for coherent and incoherent imaging modalities, and utilize interference microscopy to demonstrate super-resolution imaging of rotating nanoparticle dimers. We present a theoretical analysis of the relevant model systems, and discuss the possible effects of cusp artifacts and electrodynamic coupling between nearby nano-scatterers. Finally, we apply sSOFI as a label-free novelty …

Complete decarbonization of hard-to-abate industrial sectors is critical to reach the carbon neutrality goal set for 2050. The production of nitrogen-containing fertilizers (N-fertilizers) is responsible for 2.1% of the overall global carbon dioxide emissions. Urea is the most common N-fertilizer, and it is currently produced through the Bosch-Meiser process starting from ammonia (NH3) and carbon dioxide (CO2). Electrochemical production of urea can reduce drastically the emission of greenhouse gases and the energy required for the process. Promising results were recently reported using nitrate (NO3-) and CO2 as reagents with increasing production rate and Faradaic efficiency. In this mini-review, we summarize the most recent studies, including reaction mechanisms, electrocatalysts, and detection methods, highlighting the challenges in the field. A roadmap for future developments is envisioned with the scope of …

This study delves into the critical role of customized materials design and synthesis methods in influencing the performance of electrocatalysts for the oxygen reduction reaction (ORR) in anion exchange membrane fuel cells (AEMFCs). It introduces a novel approach to obtain platinum-free (PGM-free) electrocatalysts based on the controlled integration of iron active sites onto the surface of silica nanoparticles (NPs) by using nitrogen-based surface ligands. These NPs are used as hard templates to form tailored nanostructured electrocatalysts with an improved iron dispersion into the carbon matrix. By utilizing a wide array of analytical techniques including infrared and X-ray photoelectron spectroscopy techniques, X-ray diffraction and surface area measurements, this work provides insight into the physical parameters that are critical for ORR electrocatalysis with PGM-free electrocatalysts. The new catalysts showed a …

The testis is responsible for sperm production and androgen synthesis. Abnormalities in testis development and function lead to disorders of sex development and male infertility. Currently, no in vitro system exists for modelling the testis. Here, we generated testis organoids from neonatal mouse primary testicular cells using transwell inserts and show that these organoids generate tubule-like structures and cellular organization resembling that of the in vivo testis. Gene expression analysis of organoids demonstrates a profile that recapitulates that observed in in vivo testis. Embryonic testicular cells, but not adult testicular cells are also capable of forming organoids. These organoids can be maintained in culture for 8-9 weeks and shows signs of entry into meiosis. We further developed defined media compositions that promote the immature versus mature Sertoli cell and Leydig cell states, enabling organoid …

Magnesium batteries have attracted considerable attention as a promising technology for future energy storage because of their capability to undergo multiple charging reactions. However, most oxide materials utilized as hosts for magnesium batteries do not perform well at room temperature or in nonaqueous electrolytes. Herein, a host material, Na0.04MoO3·(H2O)0.49 is successfully developed through the chemical reduction of alpha‐MoO3, which enables magnesium storage reaction in a 0.5 m Mg(ClO4)2/acetonitrile electrolyte at 25 °C. Electrochemical analysis reveals that the cathode material possesses a discharge capacity of 157.4 mAh g−1 at a 0.2 C rate. The Na0.04MoO3·(H2O)0.49 cathode material also exhibits a capacity retention of 93.4% after 100 cycles compared to the first cycle at a 2 C rate, with an average discharge voltage of −0.474 V versus activated carbon (≈2.16 V estimated …

Non-alkaline Zn-air batteries (ZABs) attract great attention because they can potentially combine high energy density, safety, and low cost. However, cathodes for non-alkaline ZABs are underdeveloped and suffer from poor charge-discharge kinetics. Here we study N-doped hierarchically porous carbons, which are synthesized using a self-templating approach, as catalytic scaffolds for oxygen reduction and oxygen evolution reactions (ORR and OER) in near-neutral media. Interestingly, although nitrogen doping does not improve the OER performance or carbon corrosion rate during the OER, it leads to a significant boost of the ORR kinetics in non-alkaline ZABs. Specifically, the reported N-doped hierarchically porous carbons outperform their nitrogen-free hierarchically porous analog, as well as the best commercially available nitrogen-free carbons. These results show that N-doped carbons can serve as …

This study delves into the critical role of customized material design and synthesis methods in influencing the performance of electrocatalysts for oxygen reduction reaction (ORR) in anion exchange membrane fuel cells (AEMFCs). It introduces a novel approach to obtain platinum-free electrocatalysts (PGM-free), based on the controlled integration of iron active sites onto the surface of silica nanoparticles (NPs) by using nitrogen-based surface ligands. These NPs are used as hard templates to form tailored nanostructured electrocatalysts with an improved iron dispersion into the carbon matrix. Utilizing a wide array of analytical techniques including infrared and X-ray photoelectron spectroscopies, X-ray diffraction and surface area measurements, this work provides insight into the physical parameters that are critical for the ORR electrocatalysis with PGM-free electrocatalysts. These findings underscore the potential …

Nanocomposite materials, integrating nanoscale additives into a polymer matrix, hold immense promise for their exceptional property amalgamation. This study delves into the fabrication and characterization of polyetherimide (PEI) nanocomposite strings fortified with multiwall WS2 nanotubes. The manufacturing process capitalizes on the preferential alignment of WS2 nanotubes along the string axis, corroborated by scanning electron microscopy (SEM). Mechanical measurements unveil a remarkable acceleration of strain hardening in the nanocomposite strings, chiefly attributed to the WS2 nanotubes. Structural analyses via X-ray diffraction (XRD) and wide-angle X-ray scattering (WAXS) reveal intriguing structural alterations during tensile deformation. Notably a semi-crystalline framework ~100 nm in diameter surrounding the WS2 nanotubes emerges, which is stabilized by the π-π interactions between the PEI …

Currently, layered Ni-rich oxides cathodes of LiNi1-xMnyCozO2 (x ≥ 0.8) have gained a major attention for the high energy density Li-ion batteries (LIBs), due to their high specific capacity of ~200 mAh g-1 within the limited voltage. However, the large-scale use of these cathodes is severely limited by the poor structural stability, high surface reactivity, and severe capacity fade resulting from the intergranular micro cracks triggered by large volume changes and formation of rock salts at highly de-lithiated state. Knowing the demand for high specific capacity and high cycling stability, a core-shell oxide material 0.8LiNi0.85Mn0.10Co0.05O2-0.2Li1.2Ni0.16Mn0.56Co0.08O2 (NR-CS) with a core Ni-rich oxide, LiNi0.85Mn0.10Co0.05O2 (NMC85) and an outer shell of Mn-based Li-rich Li1.2Ni0.16Mn0.56Co0.08O2 oxide is synthesized, which delivers an initial discharge capacity of 212 mAh g-1 when cycled at 20 mA g -1 …

The performance of lithium–sulfur (Li–S) rechargeable batteries is strongly dependent on the entrapment of the higher‐order intermediate polysulfides at the sulfur cathode. An attracting way of preventing the polysulfide shuttle is by introducing a polar host which can form a Lewis acid–base complex with polysulfides. Herein, the Li–S battery by incorporating iron sulfides (FeS2) as a polar Lewis acid to entrap higher‐order polysulfides at the cathode center is investigated. FeS2/S cathode demonstrates largely improved retention of capacity compared to C/S cathode (capacity fading per cycle of 0.12% and 0.80% for FeS2/S and C/S respectively) and good rate performance in Li–S batteries compared to conventional carbon–sulfur (C/S) cathode. This is attributed to the decrease in polysulfide dissolution and better retention of active sulfur in the cathode during battery cycling which is due to the polar FeS2 additive …

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Cobalt toxicity is difficult to detect and therefore often underdiagnosed. The aim of this study was to explore the pathophysiology of cobalt-induced oxidative stress in the brain and its impact on structure and function. Thirty-five wild-type C57B16 mice received intraperitoneal cobalt chloride injections: a single high dose with evaluations at 24, 48, and 72 h (n= 5, each) or daily low doses for 28 (n= 5) or 56 days (n= 15). A part of the 56-day group also received minocycline (n= 5), while 10 mice served as controls. Behavioral changes were evaluated, and cobalt levels in tissues were measured with particle-induced X-ray emission. Brain sections underwent magnetic resonance imaging (MRI), electron microscopy, and histological, immunohistochemical, and molecular analyses. High-dose cobalt caused transient illness, whereas chronic daily low-dose administration led to longterm elevations in cobalt levels accompanied by brain inflammation. Significant neurodegeneration was evidenced by demyelination, increased blood–brain barrier permeability, and mitochondrial dysfunction. Treated mice exhibited extended latency periods in the Morris water maze test and heightened anxiety in the open field test. Minocycline partially mitigated brain injury. The observed signs of neurodegeneration were dose-and time-dependent. The neurotoxicity after acute exposure was reversible, but the neurological and functional changes following chronic cobalt administration were not.

Pharmaceutical waste and contaminants pose a significant global concern for water and food safety. The detection of piperidine, a common residue in drug and supplement synthesis, is critical due to its toxic nature to both humans and animals. In this study, we develop a plasmonic-based detector for surface enhanced Raman scattering (SERS) measurements. The plasmonic device is composed of triangular cavities, milled in silver thin film, and protected by a 5 nm SiO2 layer. Due to the confined and enhanced electromagnetic field, remarkable sensitivity to piperidine with a concentration of 10−8 M in water is achieved. Despite the relatively small polarizability of piperidine, high sensitivity is observed even when using a low numerical aperture of 0.3, attributed to the directional scattering from our plasmonic device. Thus, it offers a cost-effective alternative to traditional high numerical aperture used in SERS, and the …

Verena A. Neufeld opened a general discussion of the paper by Andreas Grüneis: In Table 6 of your article (https://doi. org/10.1039/d4fd00085d), EX top-fcc with CCSD (cT) is 0.41 eV which is similar in magnitude to the (cT)-corr. contribution (− 0.44 eV). How con dent can we be about the EX top and EX fcc comparison at the CCSD (cT) level since full con guration interaction could lower EX top-fcc further?Andreas Grüneis responded: Thank you for raising this important point. On the one hand, we agree that the large triples contribution indicate that higherorder correlation effects could be important. If possible, one should try to apply FCIQMC or other cost-effective and accurate approaches to this system and provide benchmark numbers for CC. On the other hand, the reasonable agreement with the experimentally measured adsorption energy suggests, that higherorder effects could potentially cancel out or are …

In recent years, there has been a lot of interest in biodegradable surface-engineered iron oxide nanoparticles (IONPs) because they could be used in drug delivery and other biomedical fields. This chapter gives an overview of the current state of research on how to make biodegradable IONPs, how to engineer their surfaces, and how to make them work for drug delivery and other biomedical applications. Because these nanoparticles are biodegradable, they will break down and leave the body in a safe way, reducing worries about toxicity. Also, the surface of IONPs can be changed to make them more stable, biocompatible, and able to target specific cells or tissues. This makes it easier for drugs to get to where they need to go. The review talks about how natural polymers, peptides, and targeting ligands are used to change the surface, as well as how these changes affect the physicochemical properties and …

Gold nanorods with reduced dimensions possess better cellular uptake and absorption efficiency. The ability to synthesize gold nanorods while maintaining tunability of the aspect ratio towards an increased value is challenging, as it requires careful control of the reaction conditions, often employing additional parameters such as pH modification or the use of polymeric additives. We demonstrate a seedless approach for the synthesis of mini (width<10 nm) gold nanorods with tunable longitudinal surface plasmon resonance from ~700 nm to >1000 nm with aspect ratios ranging from ~3 to ~7 without the use of any polymeric additives or pH modification. A single mild reduction agent, hydroquinone, allows for up to ~98% reaction yield from the gold precursor. A mechanism for the elongation is proposed based on partial silver decoupling from the reaction. Finally, the particles are coated with various capping agents to …

Photon‐number‐splitting (PNS) is a well‐known theoretical attack on quantum key distribution (QKD) protocols that employ weak coherent states produced by attenuated laser pulses. However, beyond the fact that it has not yet been demonstrated experimentally, its plausibility and effect on quantum bit error rate are questioned. In this work, an experimental scheme is presented for PNS attack employing demonstrated technological capabilities, specifically a single‐photon Raman interaction (SPRINT) in a cavity‐enhanced three‐level atomic system. Several aspects of the proposed implementation are addressed, analytically and simulatively, and the eavesdropper's information gain by the attack is calculated. Furthermore, it is analytically shown that the scheme results in a small (yet non‐zero) quantum bit error rate, and a comparison to purely theoretical analyses in the literature is presented. It is believed that the …

Tunnel type Na0.44MnO2 (tt-NMO) is a promising cathode for sodium-ion batteries having excellent structural stability, diffusion kinetics, and low cost. However, this cathode is reported to suffer from low initial charge capacity (e.g. ≤60 mA h g-1) due to limited accessibility of sodium ion extraction (0.22 ̶ 0.24 Na+ per formula unit) from the structure which hinders the practical viability of this material in a full battery cell. In this study, we report a tailored tt-NMO structure, synthesized using a two-step facile and scalable process, with >95% yield. Our tt-NMO demonstrated a 1st charge capacity of 110 A h g-1 followed by a 115 mA h g-1 discharge capacity within the potential window of 4 ̶ 1.7V versus Na/Na+. The long-term cycling performance at 0.5C rate and 1C rate (1C = 120 mA h g-1) shows excellent structural integrity for over 400 cycles with >75% capacity retention. We show experimentally and support it by …

Pharmaceutical waste and contaminants pose a significant global concern for water and food safety. The detection of piperidine, a common residue in drug and supplement synthesis, is critical due to its toxic nature to both humans and animals. In this study, we develop a plasmonic-based detector for surface enhanced Raman scattering (SERS) measurements. The plasmonic device is composed of triangular cavities, milled in silver thin film and protected by 5 nm of SiO2 layer. Due to the confined and enhanced electromagnetic field, remarkable sensitivity to piperidine with concentration of 10-8M in water is achieved. Despite the relative small polarizability of piperidine, high sensitivity is observed even when using a low numerical aperture of 0.3., attributing to the directional scattring from our plasmonic device. Thus, It offers a cost-effective alternative to traditional high numerical aperture used in SERS, and the …