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1. Examining the Summertime Ozone Formation Regime in Southeast Michigan Using MOOSE Ground‐Based HCHO/NO2 Measurements and F0AM Box Model

   https://doi.org/10.1029/2023JD038943  

   Xiong, Ying; Chai, Jiajue; Mao, Huiting; Mariscal, Noribeth; Yacovitch, Tara; Lerner, Brian; Majluf, Francesca; Canagaratna, Manjula; Olaguer, Eduardo P; Huang, Yaoxian (October 2023, Journal of geophysical research Atmospheres)

   Abstract Ambient ozone (O₃) concentrations in Southeast Michigan (SEMI) can exceed the U.S. National Ambient Air Quality Standard. Despite past efforts to measure O₃precursors and elucidate reaction mechanisms, changing emission patterns and atmospheric composition in SEMI warrant new measurements and updated mechanisms to understand the causes of observed O₃exceedances. In this study, we examine the chemical drivers of O₃exceedances in SEMI, based on the Phase I MOOSE (Michigan‐Ontario Ozone Source Experiment) field study performed during May to June 2021. A zero‐dimensional (0‐D) box model is constrained with measurement data of meteorology and trace gas concentrations. Box model sensitivity simulations suggest that the formaldehyde to nitrogen dioxide ratio (HCHO/NO₂) for the transition between the volatile organic compounds (VOCs)‐ and nitrogen oxides (NO_x)‐limited O₃production regimes is 3.0 ± 0.3 in SEMI. The midday (12:00–16:00) averaged HCHO/NO₂ratio during the MOOSE Phase I study is 1.62 ± 1.03, suggesting that O₃production in SEMI is limited by VOC emissions. This finding implies that imposing stricter regulations on VOC emissions should be prioritized for the SEMI O₃nonattainment area. This study, through its use of ground‐based HCHO/NO₂ratios and box modeling to assess O₃‐VOC‐NO_xsensitivities, has significant implications for air quality policy and the design of effective O₃pollution control strategies, especially in O₃nonattainment areas. 

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2. Frogs Uncouple Neural Activity From Oxygen Consumption After Hibernation

   https://doi.org/10.1111/apha.70247  

   Yaseen, Hafsa; Santin, Joseph M (June 2026, Acta Physiologica)

   ABSTRACT AimAerobic metabolism supplies ~90% of the ATP for neural activity. In frogs, activity has large aerobic needs typical of an average vertebrate, but surprisingly, can shift to using only glycolysis upon emergence from hibernation. We hypothesized that hibernation triggers a global reduction in the aerobic cost of neural function. MethodsWe simultaneously measured activity of the brainstem respiratory network via motor nerves and tissue O₂partial pressure (pO₂) in vitro from control and hibernated bullfrogs (4 weeks cold submergence; 4°C). To identify which functions differentially consume O₂, we sequentially blocked activity and various cellular processes requiring activity‐independent ion regulation and used the resulting tissue pO₂change (ΔpO₂) as an index of O₂consumed. We further assessed how activity varies as a function of tissue pO₂and how O₂consumption varies across network activity levels. ResultsDespite similar network activity levels, we provide three lines of evidence that hibernation reduces its aerobic requirement. First, hibernators consume less O₂for baseline activity. Second, network output remains stable from baseline to anoxia, whereas moderate hypoxia disrupts controls. Finally, accelerating activity does not enhance O₂consumption as in controls, but aerobic metabolism ultimately increases during seizure‐like activity. ConclusionHibernating frogs reduce aerobic needs for sustaining physiological levels of neural activity, revealing how they overcome the challenge of restarting motor circuits on the background of hypoxia during emergence from hibernation. More broadly, vertebrate neural circuits seemingly constrained by aerobic metabolism can exhibit substantial plasticity in the aerobic requirements for function. 

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3. A General Approach for Metal Nanoparticle Encapsulation Within Porous Oxides

   https://doi.org/10.1002/adma.202409710  

   Zhou, Chengshuang; Oh, Jinwon; Stone, Michael L; Richardson, Sydney; Chung, Pin‐Hung; Osio‐Norgaard, Jorge; Nhan, Bang T; Kumar, Abinash; Chi, Miaofang; Cargnello, Matteo (November 2024, Advanced Materials)

   Abstract Encapsulation of metal nanoparticles within oxide materials has been shown as an effective strategy to improve activity, selectivity, and stability in several catalytic applications. Several approaches have been proposed to encapsulate nanoparticles, such as forming core‐shell structures, growing ordered structures (zeolites or metal‐organic frameworks) on nanoparticles, or directly depositing support materials on nanoparticles. Here, a general nanocasting method is demonstrated that can produce diverse encapsulated metal@oxide structures with different compositions (Pt, Pd, Rh) and multiple types of oxides (Al₂O₃, Al₂O₃‐CeO₂, ZrO₂, ZnZrO_x, In₂O₃, Mn₂O₃, TiO₂) while controlling the size and dispersion of nanoparticles and the porous structure of the oxide. Metal@polymer structures are first prepared, and then the oxide precursor is infiltrated into such structures and the resulting material is calcined to form the metal@oxide structures. Most Pt@oxides catalysts show similar catalytic activity, demonstrating the availability of surface Pt sites in the encapsulated structures. However, the Pt@Mn₂O₃sample showed much higher CO oxidation activity, while also being stable under aging conditions. This work demonstrated a robust nanocasting method to synthesize metal@oxide structures, which can be utilized in catalysis to finely tune metal‐oxide interfaces. 

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4. Viscosity of Dry and Hydrous Diopside Melts at High Pressures: Implications for Upper Mantle Magma Dynamics

   https://doi.org/10.1029/2025JB032842  

   Chen, Qi; Zhao, Bin; Yu, Tony; Ashley, Aaron Wolfgang; Wang, Yanbin (December 2025, Journal of Geophysical Research: Solid Earth)

   Abstract Viscosity of silicate melts governs magma transport and influences mantle dynamics, yet effects of pressure and water on melt viscosity remain poorly understood. Here, we report in situ falling‐sphere viscosity measurements on diopside (Di) melts with 0–3 wt.% H₂O along the liquidus up to 7 GPa and 2103 K using synchrotron X‐ray radiography. By incorporating our hydrous melt data into a previously validated model for the dry system, the effects of pressure, temperature, and H₂O contents on Di melt viscosity can be satisfactorily captured by the function: whereT*is the homologous temperature,x_H2Ois the molar % H₂O,η₀ = 8.90 (1.50) × 10⁻⁸ Pa s,b₀ = 3.02 (0.10), andH*(P) = 15.72 (0.03)−0.35 (0.01)·P + 1.07 (0.07) × 10⁻²·P²−1.19 (0.14) × 10⁻⁴ P³, ×10⁻³ GPa⁻¹. Adding 3 wt.% H₂O systematically reduces viscosity by ∼0.7 log units. For both dry and hydrous melts, viscosity along the liquidus decreases monotonically with increasing pressure, suggesting that moderate hydration may not significantly alter the compressional behavior of Di melts. Combining the Di viscosity model with models for feldspar and olivine, we simulated the viscosity of analog basaltic magmas under mantle conditions. Increasing H₂O content from 0 to 3wt.% raises mobility of basaltic magma increases by >1 order of magnitude. In hot plume settings, the mobility further increases by a factor of 30 relative to typical ambient mantle. Assuming a simple percolation model, the increased mobility corresponds to faster melt ascent in mantle plumes that could, in part, explain the voluminous magmatism of large igneous provinces. 

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5. Momentum-independent magnetic excitation continuum in the honeycomb iridate H3LiIr2O6

   https://doi.org/10.1038/s41467-023-40769-x  

   de_la_Torre, A; Zager, B; Bahrami, F; Upton, M H; Kim, J; Fabbris, G; Lee, G-H; Yang, W; Haskel, D; Tafti, F; et al (December 2023, Nature Communications)

   Abstract Understanding the interplay between the inherent disorder and the correlated fluctuating-spin ground state is a key element in the search for quantum spin liquids. H₃LiIr₂O₆is considered to be a spin liquid that is proximate to the Kitaev-limit quantum spin liquid. Its ground state shows no magnetic order or spin freezing as expected for the spin liquid state. However, hydrogen zero-point motion and stacking faults are known to be present. The resulting bond disorder has been invoked to explain the existence of unexpected low-energy spin excitations, although data interpretation remains challenging. Here, we use resonant X-ray spectroscopies to map the collective excitations in H₃LiIr₂O₆and characterize its magnetic state. In the low-temperature correlated state, we reveal a broad bandwidth of magnetic excitations. The central energy and the high-energy tail of the continuum are consistent with expectations for dominant ferromagnetic Kitaev interactions between dynamically fluctuating spins. Furthermore, the absence of a momentum dependence to these excitations are consistent with disorder-induced broken translational invariance. Our low-energy data and the energy and width of the crystal field excitations support an interpretation of H₃LiIr₂O₆as a disordered topological spin liquid in close proximity to bond-disordered versions of the Kitaev quantum spin liquid. 

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