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At least 865 records · Page 48

Suppressing Universal Cathode Crossover in High‐Energy Lithium Metal Batteries via a Versatile Interlayer Design**

Abstract The universal cathode crossover such as chemical and oxygen has been significantly overlooked in lithium metal batteries using high‐energy cathodes which leads to severe capacity degradation and raises serious safety concerns. Herein, a versatile and thin (≈25 μm) interlayer composed of multifunctional active sites was developed to simultaneously regulate the Li deposition process and suppress the cathode crossover. The as‐induced dual‐gradient solid‐electrolyte interphase combined with abundant lithiophilic sites enable stable Li stripping/plating process even under high current density of 10 mA cm −2 . Moreover, X‐ray photoelectron spectroscopy and synchrotron X‐ray experiments revealed that N‐rich framework and CoZn dual active sites can effectively mitigate the undesired cathode crossover, hence significantly minimizing Li corrosion. Therefore, assembled lithium metal cells using various high‐energy cathode materials including LiNi 0.7 Mn 0.2 Co 0.1 O 2 , Li 1.2 Co 0.1 Mn 0.55 Ni 0.15 O 2 , and sulfur demonstrate significantly improved cycling stability with high cathode loading.

25 ENERGY STORAGE↗

Engineering Active Sites of Metal/Metal Oxide Catalysts by Oxide Ligand Overlayers

Abstract Engineering sites of supported metal catalysts is essential to enhancing activity and selectivity. Such enhancement is typically achieved by particle size modification, surface alloying, or attaching molecular ligands. Yet, control strategies for complex, multifunctional molecules and catalysts, where selectivity is crucial, are lacking. Here, we demonstrate that submonolayer WO x with tunable coverage preferentially decorates well‐coordinated Pt terrace sites as a stable ligand. By combining experimental kinetics with probe molecules, in situ spectroscopies, and first‐principles modeling, we show that the WO x coverage on Pt modifies the metal‐to‐acid site balance while retaining the acid strength intact and results in optimal reactivity for metal‐acid catalyzed reactions at a specific metal, size, and support‐dependent WO x coverage. The oxide can also alter the reactant adsorption mode, reversing selectivity and pathways from terrace‐ to step‐dominated, as evidenced in furfural decarbonylation and hydrogenation. The insights open avenues for improving metal/metal oxide catalysts beyond the specific system.

Zhou, Jiahua↗

Cryogenic Carbon Monoxide Oxidation on Cuprous Oxide

Performing oxidation reactions at low temperatures using earth-abundant materials is crucial for advancing solutions for sustainable chemistry. CO oxidation serves as a benchmark reaction to characterize oxidation and to advance fundamental concepts in surface chemistry. While there are several examples of CO oxidation occurring on metal oxides at low temperatures, from 300 K to ∼200 K, reactivity in the cryogenic temperature regime typically requires a metal nanoparticle on a metal oxide. Here, we show oxygen atoms on the (111) facet of Cu 2 O react with CO to form CO 2 at temperatures below 100 K. Combining spectroscopic experimental evidence with calculations, we propose a low barrier path for CO oxidation at reconstructed surface sites on Cu 2 O(111). This finding is a rare example of an earth-abundant metal oxide, in this case copper, that can provide highly reactive multifunctional sites, enabling both adsorption and reaction fundamental steps toward the efficient heterogeneous oxidation of chemicals.

36 MATERIALS SCIENCE↗

Large Enhancements in Optical and Piezoelectric Properties in Ferroelectric Zn 1- x Mg x O Thin Films through Engineering Electronic and Ionic Anharmonicities

Multifunctionality as a paradigm requires materials exhibiting multiple superior properties. Integrating second-order optical nonlinearity and large bandgap with piezoelectricity can, for example, enable broadband, strain-tunable photonics. Though very different phenomena at distinct frequencies, both second-order optical nonlinearity and piezoelectricity are third-rank polar tensors present only in acentric crystal structures. However, simultaneously enhancing both phenomena is highly challenging since it involves competing effects with tradeoffs. Recently, a large switchable ferroelectric polarization of ≈80 μC cm –2 was reported in Zn 1-x Mg x O films. Here, ferroelectric Zn 1-x Mg x O is demonstrated to be a platform that hosts simultaneously a 30% increase in the electronic bandgap, a 50% enhancement in the second harmonic generation (SHG) coefficients, and a near 200% improvement in the piezoelectric coefficients over pure ZnO. These enhancements are shown to be due to a 400% increase in the electronic anharmonicity and a ≈200% decrease in the ionic anharmonicity with Mg substitution. Precisely controllable periodic ferroelectric domain gratings are demonstrated down to 800 nm domain width, enabling ultraviolet quasi-phase-matched optical harmonic generation as well as domain-engineered piezoelectric devices.

36 MATERIALS SCIENCE↗

Reduced type-A carbohydrate-binding module interactions to cellulose I leads to improved endocellulase activity

Dissociation of nonproductively bound cellulolytic enzymes from cellulose is hypothesized to be a key rate-limiting factor impeding cost-effective biomass conversion to fermentable sugars. However, the role of carbohydrate-binding modules (CBMs) in enabling nonproductive enzyme binding is not well understood. Here, we examine the subtle interplay of CBM binding and cellulose hydrolysis activity for three models type-A CBMs (Families 1, 3a, and 64) tethered to multifunctional endoglucanase (CelE) on two distinct cellulose allomorphs (i.e., cellulose I and III). We generated a small library of mutant CBMs with varying cellulose affinity, as determined by equilibrium binding assays, followed by monitoring cellulose hydrolysis activity of CelE–CBM fusion constructs. Finally, kinetic binding assays using quartz crystal microbalance with dissipation were employed to measure CBM adsorption and desorption rate constants kon and koff, respectively, towards nanocrystalline cellulose derived from both allomorphs. Overall, our results indicate that reduced CBM equilibrium binding affinity towards cellulose I alone, resulting from increased desorption rates (koff) and reduced effective adsorption rates (nkon), is correlated to overall improved endocellulase activity. Future studies could employ similar approaches to unravel the role of CBMs in nonproductive enzyme binding and develop improved cellulolytic enzymes for industrial applications.

59 BASIC BIOLOGICAL SCIENCES↗

Enhancing NO Reduction by CO Over NiO/CeO 2 Catalyst by Optimizing the Metal Oxide–Support Interaction

Noble metal catalysts are widely used in three-way catalysts (TWCs) due to their high efficiency, but their scarcity and high cost drive the need for effective, low-cost alternatives. Here, in this work, a series of NiO/CeO 2 catalysts were engineered by modulating the OH content and crystallite size of the CeO 2 support. This approach yielded Ni species ranging from isolated single atoms to small clusters and larger aggregates, with varied NiO/CeO 2 interaction strengths. Evaluation of their performance in NO reduction by CO, CO oxidation, and the water–gas shift reaction revealed that the NiO/CeO 2 -300 catalyst, featuring small CeO 2 crystallites and highly dispersed NiO clusters, delivered superior activity for NO reduction and CO oxidation. It was demonstrated that small NiO clusters, due to their efficient CO adsorption and activation, were more active than Ni single atoms. Furthermore, the presence of water was found to influence the catalyst stability, with NiO clusters less stable than single atoms likely due to the hydroxylation effect leading to the formation of Ni(OH) 2 . Oxygen storage capacity measurements revealed that performance was governed by a combination of CeO 2 crystallite size and the abundance of NiO/CeO 2 interfaces. These findings demonstrated that the catalytic performance of Ni/CeO 2 systems could be maximized by optimizing the Ni nanostructure and its interaction with CeO 2 support, positioning them as a promising, multifunctional nonprecious alternative for three-way catalysis application.

36 MATERIALS SCIENCE↗

Achieving Multimodal and Multicolor Luminescence in LaAlO 3 :Pr 3+ , Gd 3+ via Trap Engineering and Energy Transfer

Achieving multimodal luminescence within a single phosphor is vital for multifunctional applications but remains challenging due to complex color tuning and trap engineering. In this study, we report Pr 3+ and Gd 3+ co‐doped LaAlO 3 (LAO:PG) phosphors, designed through careful modulation of multilevel traps and Pr 3+ → Gd 3+ energy transfer dynamics. These materials exhibit diverse luminescence modes, including down‐conversion luminescence (DCL), up‐conversion luminescence (UCL), persistent luminescence (PersL), optically stimulated luminescence (OSL), and thermally stimulated luminescence (TSL) across a wide spectral range. Unlike previously studied Pr 3+ ‐doped LAO, the co‐doped LAO:PG shows DCL in both UV‐visible and NIR regions and displays ultraviolet‐C UCL under visible excitation. Notably, we observe, for the first time, PersL lasting several minutes in these phosphors—an improvement over the non‐PersL behavior of Pr 3+ ‐only doped LAO. Additionally, the LAO:PG phosphors exhibit strong OSL response. TSL analysis reveals five distinct trap levels linked to these properties. Density functional theory calculations further correlate intrinsic defects to these traps, supporting a proposed mechanism for the observed multimodal luminescence. These findings highlight LAO:PG as a promising platform for developing advanced phosphors with integrated luminescence modes, paving the way for future applications in data storage, phototherapy, and anti‐counterfeiting technologies.

Chemistry↗

One-Pot Process for Hydrodeoxygenation of Lignin to Alkanes Using Ru-Based Bimetallic and Bifunctional Catalysts Supported on Zeolite Y

The synthesis of high-efficiency and low-cost multifunctional catalysts for hydrodeoxygenation (HDO) of waste lignin into advanced biofuels is crucial for enhancing current biorefinery processes. Inexpensive transition metals, including Fe, Ni, Cu, Zn, were severally co-loaded with Ru on HY zeolite to form bimetallic and bifunctional catalysts. These catalysts were subsequently tested for HDO conversion of softwood lignin and several lignin model compounds. Results indicated that the inexpensive earth abundant metals could modulate the hydrogenolysis activity of Ru and decrease the yield of low molecular weight gaseous side-products. Among all the prepared catalysts, Ru-Cu/HY showed the best HDO performance, giving the highest selectivity to hydrocarbon products. The improved catalytic performance of Ru-Cu/HY was probably due to the following three factors: (1) high total and strong acid sites, (2) good dispersion of metal species and limited segregation, (3) high adsorption capacity for polar fractions, including hydroxyl groups and ether bonds. Moreover, all the bifunctional catalysts were proven to be superior over the combination catalysts of Ru/Al2O3 and HY zeolite, and this could be attributed to the “intimacy criterion”. The practical use of the designed catalysts would be promising in lignin valorization.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Binder-Free Graphite Anodes for Next-Generation High-Performance Lithium-Ion Batteries

High-energy density anodes are crucial for next-generation lithium-ion batteries (LIBs) particularly for electric vehicle (EV) applications. Sluggish lithium-diffusion kinetics coupled with conventional anode fabrication processes containing polymeric binders hinder fast-charging capabilities and high-energy density of graphite. Herein, we introduce a binder-free graphite anode fabrication strategy using the electrospinning technique that contains ~2.41% carbon nanotubes (CNTs). Our strategy relies on the formation of an interconnecting conductive CNT network coupled with an ultrathin N-doped carbon coating on graphite particles from sacrificial binders. This combination enhances both structural integrity and electrical conductivity and, in turn, improves fast-charging capabilities and high energy density of LIBs. The binder-free graphite anode achieves ~335.0 mAh g–1 capacity at C/3 rate over 400 cycles with capacity retention of >95% and average Coulombic efficiencies >99.95%. These promising results suggest that the binder-free anode fabrication with a multifunctional design approach could elevate the energy-density limits of the graphite anodes, solving high-energy density requirements of EVs, and potentially provides a path forward for the development of economically feasible energy storage systems for various applications.

Ozcan, Muca [ORNL] (ORCID:0000000320020474)↗

Production of Macrophage Inhibitory Factor (MIF) by Primary Sertoli Cells; Its Possible Involvement in Migration of Spermatogonial Cells

Macrophage migration inhibitory factor (MIF) is a multifunctional molecule. MIF was originally identified as a T‐cell‐derived factor responsible for the inhibition of macrophage migration. In testicular tissue of adult rats, MIF is constitutively expressed by Leydig cells under physiological conditions. The aim of this study was to examine MIF levels in testicular homogenates from different aged mice, and the capacity of Sertoli cells to produce it. We also examined MIF involvement in spermatogonial cell migration. Similar levels of MIF protein were detected in testicular homogenates of mice of different ages (1–8‐week‐old). However, the RNA expression levels of MIF were high in 1‐week‐old mice and significantly decreased with age compared to 1‐week‐old mice. MIF was stained in Sertoli, Leydig cells, and developed germ cells in the seminiferous tubules. Isolated Sertoli cells from 1‐week‐old mice stained to MIF. Cultures of Sertoli cells from 1‐week‐old mice produced and expressed high levels of MIF which significantly decreased with age. MIF was localized in the cytoplasm and nucleus of Sertoli cell cultures isolated from 1‐week‐old mice; however, it was localized only in the cytoplasm and branches of cultures isolated from 8‐week‐old mice. MIFR was detected in GFRα1 and Sertoli cells. MIF could induce migration of spermatogonial cells, and this effect was synergistic with glial cell‐line neurotrophic factor. Our results show, for the first time, the capacity of Sertoli cells to produce MIF under normal conditions and that MIFR expressed in GFRα1 and Sertoli cells. We also showed that MIF induced spermatogonial cell migration. J. Cell. Physiol. 232: 2869–2877, 2017. © 2016 Wiley Periodicals, Inc.

Huleihel, Mahmoud↗

Evolution of eggshell structure in relation to nesting ecology in non-avian reptiles

Amniotic eggs are multifunctional structures that enabled early tetrapods to colonize the land millions of years ago, and are now the reproductive mode of over 70% of all terrestrial amniotes. Eggshell morphology is at the core of animal survival, mediating the interactions between embryos and their environment, and has evolved into a massive diversity of forms and functions in modern reptiles. These functions are critical to embryonic survival and may serve as models for new antimicrobial and/or breathable membranes. However, we still lack critical data on the basic structural and functional properties of eggs, particularly of reptiles. Here, we first characterized egg shape, shell thickness, porosity, and mineralization of eggs from 91 reptile species using optical images, scanning electron microscopy, and micro computed tomography, and collected data on nesting ecology from the literature. We then used comparative analyses to test hypotheses on the selective pressures driving their evolution. We hypothesized that eggshell morphology has evolved to protect shells from physical damage and desiccation, and, in support, found a positive relationship between thickness and precipitation, and a negative relationship between porosity and temperature. Although mineralization varied extensively, it was not correlated with nesting ecology variables. Ancestral state reconstructions show thinning and increased porosity over evolutionary time in squamates, but the opposite in turtles and crocodilians. Egg shape, size, porosity and calcification were correlated, suggesting potential structural or developmental tradeoffs. This study provides new data and insights into the morphology and evolution of reptile eggs, and raises numerous questions for additional research.

59 BASIC BIOLOGICAL SCIENCES↗

Surface modification of bamboo fiber with sodium hydroxide and graphene oxide in epoxy composites

Bamboo fibers (BFs) have high mechanical properties and are candidate reinforcement for epoxy matrix composites. However, to improve performance, good fiber-matrix interaction is required. In this work, unidirectional long BF reinforced epoxy composites at fiber volume content of 22%, 40%, and 50% were made by compression molding. The 40 v% untreated BF reinforced composites exhibited 107% and 439% increase for flexural strength and modulus, respectively, compared to neat epoxy. Sodium hydroxide (NaOH) treatment was used to modify the surface of the BFs, and then the NaOH modified BFs were coated with graphene oxide (GO). The 40 v% NaOH modified BF composites showed an improvement from 259.9 to 327.5 MPa for flexural strength and from 16.7 to 21.5 GPa for flexural modulus, compared to 40 v% untreated BF composites. Slight improvement in properties up to 334.6 MPa for flexural strength and up to 23.8 GPa for flexural modulus was achieved for composites made of 40 v% NaOH/GO modified BF. Surface modification of BF after the NaOH and NaOH/GO treatment was confirmed by X-ray photoelectron spectroscopy and by scanning electron microscopy, which showed differences on the fiber surface morphology and on the composite fracture surface. This BF surface modification approach with GO has potential to impart other properties beyond mechanical to produce multifunctional composite and lead to the use of sustainable plant fibers as alternatives to synthetic fibers.

36 MATERIALS SCIENCE↗

Apo raver1 structure reveals distinct RRM domain orientations

Raver1 is a multifunctional protein that modulates both alternative splicing and focal adhesion assembly by binding to the nucleoplasmic splicing repressor polypyrimidine tract protein (PTB) or to the cytoskeletal proteins vinculin and {alpha}-actinin. The amino-terminal region of raver1 has three RNA recognition motif (RRM1, RRM2, and RRM3) domains, and RRM1 interacts with the vinculin tail (Vt) domain and vinculin mRNA. We previously determined the crystal structure of the raver1 RRM1-3 domains in complex with Vt at 2.75 {angstrom} resolution. Here, we report crystal structure of the unbound raver1 RRM1-3 domains at 2 {angstrom} resolution. The apo structure reveals that a bound sulfate ion disrupts an electrostatic interaction between the RRM1 and RRM2 domains, triggering a large relative domain movement of over 30{sup o}. Superposition with other RNA-bound RRM structures places the sulfate ion near the superposed RNA phosphate group suggesting that this is the raver1 RNA binding site. While several single and some tandem RRM domain structures have been described, to the best of our knowledge, this is the second report of a three-tandem RRM domain structure.

59 BASIC BIOLOGICAL SCIENCES↗

Molecular dynamics analysis of the binding of human interleukin-6 with interleukin-6 α-receptor

Human interleukin-6 (hIL-6) is a multifunctional cytokine that regulates immune and inflammatory responses in addition to metabolic and regenerative processes and cancer. hIL-6 binding to the IL-6 receptor (IL-6Rα) induces homodimerization and recruitment of the glycoprotein (gp130) to form a hexameric signaling complex. Anti-IL-6 and IL-6R antibodies are clinically approved inhibitors of IL-6 signaling pathway for treating rheumatoid arthritis and Castleman's disease, respectively. There is a potential to develop novel small molecule IL-6 antagonists derived from understanding the structural basis for IL-6/IL-6Rα interactions. In this work, we combine homology modeling with extensive molecular dynamics (MD) simulations to examine the association of hIL-6 with IL-6Rα. A comparison with MD of apo hIL-6 reveals that the binding of hIL-6 to IL-6Rα induces structural and dynamic rearrangements in the AB loop region of hIL-6, disrupting intraprotein contacts and increasing the flexibility of residues 48 to 58 of the AB loop. In contrast, due to the involvement of residues 59 to 78 in forming contacts with the receptor, these residues of the AB loop are observed to rigidify in the presence of the receptor. The binary complex is primarily stabilized by two pairs of salt bridges, Arg181 (hIL-6)- Glu182 (IL-6Rα) and Arg184 (hIL-6)- Glu183 (IL-6Rα) as well as hydrophobic and aromatic stacking interactions mediated essentially by Phe residues in both proteins. An interplay of electrostatic, hydrophobic, hydrogen bonding, and aromatic stacking interactions facilitates the formation of the hIL-6/IL-6Rα complex.

59 BASIC BIOLOGICAL SCIENCES↗

Synthesis, aphicidal activity and conformation of novel insect kinin analogues as potential eco‐friendly insecticides

Abstract BACKGROUND The discovery of ecofriendly insecticides through a new strategy for aphid control is important because of the substantial resistance and unexpected eco‐toxicity to honeybees caused by traditional insecticides. The insect kinins, a class of multifunctional insect neuropeptides, are considered for potential application in pest control. In our previous work we developed several series of insect kinin analogues and found a promising lead II‐1 with good aphicidal activity. To seek further eco‐friendly aphicides, the optimization of II‐1 is carried out in this study. RESULTS Fifteen novel Yaa 3 modified analogues based on the lead II‐1 were synthesized. The aphicidal tests indicated that IV‐3 , IV‐5 and IV‐10 exhibited significant activity against the soybean aphid Aphis glycines with LC 50 values of 0.0029, 0.0072 and 0.0086 mmol L –1 , respectively, higher than that of lead II‐1 and the commercial Pymetrozine. The molecular modeling results showed that analogues II‐1 , IV‐3 , IV‐5 , IV‐7 and IV‐10 formed a β‐turn‐like conformation, while the conformation of analogues IV‐1 , IV‐2 and IV‐9 seemed to be linear. Some structural elements favorable for the activity were proposed based on the conformation‐activity relationship of the analogues. CONCLUSION Insect kinin analogues derived from lead II‐1 by modifying the hydrolysis site Yaa 3 with natural, sterically hindered α‐ and β‐amino acids showed great potential as eco‐friendly insecticides. Inspiringly, the most active analogue IV‐3 can be a candidate for further development. The β‐turn‐like conformation and the orientation of the aromatic rings of the side chain of Phe 2 and Trp 4 may be critical factors beneficial to activity. © 2019 Society of Chemical Industry

Zhang, Chuanliang↗

In Situ MOF Pyrolysis Construction of Hierarchical Porous Co‐Nanoparticles/Carbon Cloth Composites for Enhanced Electromagnetic Wave Shielding and Absorption

The development of high-performance electromagnetic protection materials integrating broadband absorption and effective shielding capabilities is hindered by challenges in simultaneously optimizing multiple electromagnetic properties through conventional material designs. This study pioneers a hierarchical porous Co nanoparticle/carbon cloth (Co/CC) composite via controlled annealing of a Co-MOF precursor on carbon cloth. The Co-MOF served a dual role as both magnetic source and pore-forming agent, enabling in situ generation of uniformly dispersed Co nanoparticles and creation of abundant pores/interfaces on the CC fibers during pyrolysis. This unique architecture synergistically enhanced dielectric loss (via interfacial/dipolar polarization) and magnetic loss (via natural resonance, exchange interactions, and eddy currents), significantly improving impedance matching. The hierarchical pores further functioned as integrated “absorption–reflection” units for efficient electromagnetic energy attenuation. Consequently, the Co/CC composite annealed at 800°C (Co/CC-800) achieves minimum reflection loss (−40.69 dB) and 120% effective absorption bandwidth extension (6.16 GHz) as a filler, and exhibits superior electromagnetic interference shielding effectiveness (46.66 dB) as an integrated component. Significantly, Co/CC-800 demonstrated robust photothermal and electrothermal conversion capabilities, ensuring operational stability in ice-covered and humid harsh environments. This work pioneers a pore-structure-mediated strategy to harmonize dielectric–magnetic synergy, providing a new paradigm for designing advanced multifunctional electromagnetic protection materials.

dielectric‐magnetic synergy↗

P‐23: Enhancement in the Mobility and the Stability of Solution‐Processed Zinc‐Tin Oxide Thin‐Film Transistors Using Alkali Metal Superoxide

We have studied how to improve the mobility and stability of solution processed zinc‐tin oxide thin‐film transistors (ZTO TFTs) simultaneously using multifunctional potassium superoxide precursor. Potassium cations in the potassium superoxide precursor acts as a shallow donor in the ZTO thin film to improve the carrier concentration (electron), which allows the potassium‐doped ZTO TFT to exhibit high mobility. Then, the anion of the precursor exists as a superoxide radical, and it showed the effect of reducing the oxygen vacancy in the process of forming the oxide thin film Consequently, potassium‐doped ZTO TFT using potassium superoxide precursor exhibited improved mobility and stability, showing an increase in the mobility from 5.11 to 8.36 cm 2 /Vs and a decrease in the threshold voltage shift from 4.65 to 3.36 V under a negative bias temperature illumination stress test conducted over 5,000 sec..

Jung, Tae Soo↗