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Christopher A. Sims (1942–2026): Paradigm-shifting macroeconomist and econometrician

Christopher A. Sims, who died on March 14, 2026, left behind an indelible mark on macroeconomics and econometrics. His Nobel Prize winning research reshaped the paradigm for empirical macroeconomics, creating a rigorous and flexible framework for inferring the effects of macroeconomic policies. He also made important contributions to time series forecasting, Bayesian econometrics, factor modeling, approximation theory, and models of monetary and fiscal policy. Few academics have had as direct an impact on the work of central banks throughout the world. A frank and generous mentor with numerous students, Chris’s impact extends well beyond his published papers.

Aluminum phosphate-modified red clay as a stable nanocomposite catalyst for the selective conversion of methanol to dimethyl ether

Abstract Aluminum phosphate-modified Egyptian red clay (AlPO 4 /ERC) nanocomposites were developed as low-cost solid acid catalysts for methanol dehydration to dimethyl ether (DME). Structural and physicochemical analyses (XRD, FTIR, N₂ adsorption–desorption, TEM, SEM, and acid-probe reactions) show that AlPO 4 incorporation preserves the aluminosilicate framework while tuning surface acidity, porosity, and active-site accessibility. XRF and XRD confirm that ERC consists mainly of quartz, kaolinite, and iron oxides, whereas AlPO 4 introduces additional phosphate phases that interact with the clay matrix. Catalytic testing reveals a strong dependence on AlPO 4 loadings, with 5 wt.% AlPO 4 /ERC exhibiting optimal performance and achieving 90% methanol conversion with 100% DME selectivity at 200 °C. This enhancement correlates with an optimal balance of weak and intermediate acid sites (~ 2.5 mmol g −1 ) and a high specific surface area (52 m 2  g −1 ), which maximizes the number of accessible active centers. Higher loadings reduce activity because of pore blockage and decreased site accessibility. Mechanistically, methanol dehydration proceeds via acid-catalyzed surface methoxy intermediates, with activity governed by acid-site distribution rather than iron species. The catalyst shows excellent stability over 15 days without deactivation, confirming its strong structural robustness. Overall, controlled AlPO 4 incorporation optimizes the acidity-porosity synergy, enabling efficient and stable DME production.

Tissue‐Integrated Hydrogel Battery‐Enabled Electroceutical for Cardiac Arrhythmia Management

ABSTRACT Conventional implantable bioelectronic devices for cardiac arrhythmia management are bulky, invasive, prone to mechanical failure and immune rejection. Here, we introduce a standalone bioadhesive hydrogel battery‐enabled electroceutical device that seamlessly interfaces with cardiac tissue, enabling rapid electrochemical modulation of cardiac rhythm. Constructed from dynamic supermolecular hydrogels, the device achieves strong electrode–electrolyte adhesion and suture‐free integration with biological tissue (adhesion energy > 200 J m −2 ). It provides stable in vivo voltage outputs (0.90–1.17 V) for 14 days while suppressing immune response as indicated by downregulating inflammatory biomarkers. The battery discharge enhances cardiomyocyte contraction, promotes cell junction protein expression, and mediates cardiac arrhythmias in ex vivo rat hearts. Adhering directly to the myocardium without surgical fixation, the device generates sustained electrical stimulation for bradycardia correction and low‐energy defibrillation, restoring sinus rhythm within seconds (5–10 s) in a rat model. This tissue‐integrated electroceutical offers a promising alternative during cardiac surgery to treat arrhythmia by enhancing tissue integration and minimizing foreign‐body response.

Comparative assessment of hybrid AI models using metaheuristic algorithms for predicting shaft resistance of driven piles

Halogen‐Bonding‐Assisted Synthesis of CsPbI ₃ Perovskite Nanocrystal Emission Materials for Stable and Efficient Pure‐Red LEDs

ABSTRACT Perovskite nanocrystals (NCs) demonstrate exceptional potential as emitters to address Rec. 2020 standards for wide color gamut displays. However, the pure‐red‐targeted CsPbI 3 NCs generally suffer from imprecise synthetic control over emission wavelength and from structural instabilities that significantly diminish performance. We report a novel halogen engineering framework that addresses the otherwise unfavorable wavelength‐efficiency‐stability nexus. Our approach leverages surface I − ···I 2 interactions to simultaneously unlock exceptional optical characteristics and the elusive structural robustness needed for application. It achieves: (i) controlled quantum‐confinement‐tuned emission wavelength, (ii) near‐unity photoluminescence (PL) quantum yield through iodide vacancy defect management, and (iii) excellent environmental stability, even under harsh (85°C/85%) temperature and humidity conditions, through lattice‐distortion suppression. Rec. 2020 compliant, 638 nm peak light‐emitting diodes (LEDs) are then demonstrated with Commission Internationale de l'Éclairage coordinates (X, Y) = (0.703, 0.297), 22% external quantum efficiency, luminance ≥ 11,000 cd m −2 , and long lifetime, establishing a materials‐by‐design paradigm for advancing next‐generation perovskite display technologies.

Evaluation of the urinary bladder wall in healthy male dogs using B-mode ultrasonography and 2D shear wave elastography

Rapid glycolytic metabolism underpins mucosal-associated invariant T cell functional responses to innate cytokines

Abstract Mucosal-associated invariant T (MAIT) cells express a semi-invariant T cell receptor (TCR) that recognizes bacterial-derived antigens presented on MR1. Upon TCR triggering, MAIT cells respond rapidly, producing a range of effector molecules which facilitate host-protective responses in the context of microbial infections. In contrast, MAIT cell responses to viral infection are instead triggered by the recognition of cytokines, and occur independently of TCR engagement. The molecular and metabolic regulation of MAIT cell TCR responses is rapidly emerging, but there is a paucity of data on cytokine driven responses. Here, using high-resolution, quantitative proteomic analysis, we map the downstream proteome of innate cytokine (IL-18/IFNα)–activated MAIT cells, highlighting robust cytokine-driven remodeling and a signature that is distinct from the TCR-driven response. MAIT cells significantly increase protein biosynthesis in response to innate cytokine stimulation and rapidly upregulate the production of IFNγ, granzyme B, and IFN-stimulated gene 15. We demonstrate the metabolic kinetics of MAIT cell responses to cytokine stimulation and highlight a rapid but transient glycolytic burst that is uncoupled from mitochondrial remodeling and contrasts the robust metabolic profile elicited downstream of TCR engagement. Finally, we demonstrate differential contributions from both glycogen and glucose in supporting MAIT cell responses to innate cytokines and further highlight the importance of nutrient availability as a governing signal for MAIT cell fitness and effector functioning.

Lightweight All‐Solid‐State Pouch Cells Freed from High Stack Pressure

ABSTRACT Since 2011, ionic conductivity of some sulfide‐ and halide‐based solid‐state electrolytes (SSEs) have already reached a level comparable to that of liquid electrolytes. Numerous companies worldwide have proposed diverse technical pathways for commercializing electric vehicles with ultra‐long driving ranges. However, the practical vehicular application of all‐solid‐state batteries (ASSBs) remains highly challenging and uncertain. One of the major obstacles is the requirement for high stack pressure, which typically relies on heavy metallic plates and thereby reduces the overall energy density of the module battery. This perspective compares practical all‐solid‐state pouch cells (ASSPCs) with conventional liquid batteries to analyze the origins of stack pressure requirements. The analysis is conducted from material, interfacial, and structural viewpoints, revealing the critical factors underlying this limitation. Subsequently, strategies are proposed to mitigate stack pressure from the current 20 MPa to 5 MPa for the first stage and to 2 MPa as the final target. The effect of stack pressure on cell‐to‐module energy density efficiency is also calculated to quantitative analysis. These insights provide practical suggestion from ASSPCs design to module‐level pressure management.

Quality, reliability, and counseling content gaps in penile prosthesis implantation videos on Chinese short video platforms

Peptide exchange–competent class I MHC molecules produced in eukaryotic cells for rapid production of MHC multimers

Abstract Class I MHC peptide (MHC-Ip) multimers are well-established reagents that detect antigen-specific T cells. The classical method for production of MHC-Ip multimers begins with the expression of MHC heavy chains (HCs) and β2-microglobulin (β2m) subunits as inclusion bodies in Escherichia coli and is followed by denaturant solubilization, in vitro folding in the presence of a defined peptide ligand, and purification by size exclusion chromatography. This protocol is labor intensive, difficult to scale, and represents a significant bottleneck in application of the technology. Herein, we present a novel method for the expression in eukaryotic cells of secreted peptide exchange–competent class I MHC proteins in their native conformation. In this method, expression constructs are engineered as bimolecular complexes composed of an MHC HC and a β2m molecule covalently linked at its amino terminus to an MHC-binding peptide through a flexible peptide linker containing a defined protease site. Upon proteolysis, the original peptide occupant of the MHC binding site dissociates and is easily replaced with a synthetic peptide. When leucine zippers are added to the carboxyl terminus of each subunit, protease cleavage of the linker results in a stable HC/β2m complex that can be isolated and stored for subsequent peptide loading. Using this method, we have produced homogeneous MHC-Ip complexes for 25 class I MHC alleles and demonstrated that tetramers produced in this way are equivalent to conventionally produced tetramers for T-cell staining.

Vitamin B ₁₂ Precatalyst Enables Molecular Cobalamin(II) Catalysis for Organodisulfide Anolytes in Aqueous Redox Flow Batteries

ABSTRACT Affordable and stable organodisulfide anolytes are attractive for long‐duration aqueous redox flow batteries (ARFBs) for grid energy storage. However, the sluggish redox reactions involving the cleavage/formation of sulfur–sulfur (S─S) bonds cause severe polarization and limited capacity utilization, thus hindering the practical application of organodisulfide anolytes in ARFBs. Herein, we report a homogeneous catalysis strategy employing hydroxocobalamin (Vitamin B 12 , OHCbl) as an environmentally benign and biocompatible precatalyst which can enable molecular cobalamin(II) catalysis for organodisulfide anolytes. Cobalamin(II) generated in situ by electrochemical reduction of OHCbl bidirectionally accelerates the redox reactions of S─S bonds and significantly decreases the overpotential of the ARFB with SPS (bis(sodium sulfopropyl) disulfide) anolyte from 1.24 V to 0.36 V at 40 mA cm −2 , boosting the energy efficiency from 18% to 66%. The OHCbl‐catalyzed ARFB with 1.0 M SPS anolyte delivers a capacity of 51.45 Ah L −1 operated at 100% state of charge and remains stable for 850 cycles at 50 mA cm −2 with a low decay rate of 0.0189% per day. Moreover, a nearly saturated 1.3 M SPS‐based ARFB achieves 96.2% capacity utilization, corresponding to 67.05 Ah L −1 delivered capacity. This cobalamin(II) catalysis strategy addresses the kinetic bottlenecks inherent to organodisulfide‐based anolytes for ARFBs.

Non-rotational multi-channel endoscopic OCT for trajectory-resolved imaging in stereotactic brain biopsy

Identifying molecular signatures underpinning treatment responses to novel therapeutics influencing COVID-19 outcomes

Abstract COVID-19 continues to present ongoing global health challenges driven by diverse immune responses and heterogeneous clinical outcomes. The ACCORD trial evaluated 3 investigational treatments—bemcentinib, tozorakimab, and zilucoplan—in patients hospitalized with COVID-19, each of which has demonstrated clinical efficacy. To better understand their molecular mechanisms, we conducted a mechanistic follow-up study, integrating transcriptomic and clinical data from 65 patients and applying cellular deconvolution, differential expression, coexpression, and pathway enrichment analyses to uncover treatment-specific immune responses. Each therapy induced transcriptional shifts and modulated distinct immune pathways implicated in severe disease. Bemcentinib primarily modulated myeloid cell populations and inflammatory signalling; zilucoplan enhanced B-cell signalling and lymphocyte-associated pathways; and tozorakimab exerted broad immune and cellular responses across immune cell types. Co-expression analysis revealed gene networks associated with clinical improvement, each driven by distinct treatment-specific hub genes, indicating diverse regulatory mechanisms across treatments. Improved outcomes correlated with gene expression shifts in 4 key immunological pathways: B-cell signalling, antiviral defense, innate inflammation, and platelet/coagulation activity. In contrast, nonresponders had persistent dysregulation of 1 or more of these gene signatures. Our findings define molecular signatures of treatment response and failure in COVID-19, providing mechanistic insight into how distinct therapies modulate the immune system. These insights support the need for adaptive precision medicine approaches tailored to individual, evolving immune trajectories. Moreover, the immunological mechanisms targeted by these repurposed immunomodulatory therapies may inform treatment strategies across a broader spectrum of immune-mediated diseases beyond COVID-19.

Durable Seawater Electrolysis Enabled by Spherical Electrostatic Repulsion and Catalyst‐Support Interaction

ABSTRACT The electrolysis of seawater driven by renewable energy for hydrogen production represents a promising strategy toward net‐zero emissions. The high concentration of chloride ions (Cl − ) in seawater not only competes with the oxygen evolution reaction (OER) at the anode but also causes corrosion of the catalyst material. The construction of electrostatic shielding via anions on the catalyst surface can repel Cl − . However, studies on regulating anion distribution through designed geometries to maximize such repulsion remain limited. Herein, a sphere‐like catalyst, constructed with a heterojunction of carbonate‐intercalated nickel‐iron layered double hydroxides in situ grown on malachite microspheres (MM), exhibits enhanced catalytic durability and activity. The spherical electrostatic field induced by carbonate anions protects the catalyst, and the catalyst‐support interaction (CSI) tunes the electronic structure of active sites to boost OER. Finally, the assembled electrolyzer demonstrates outstanding durability over 1000 h and a voltage of 1.83 V at a current density of 1 A per cm 2 . This spherical geometrical design of electrostatic protection offers insights into catalyst optimization for seawater electrolysis.

Experimental and computational investigation of collagen modification in skin chromatic alterations

MiR-221-5p aggravates sepsis-induced myocardial injury by targeting neuropilin-1

Abstract Sepsis-induced cardiac dysfunction is a primary contributor to mortality, and microRNAs (miRNAs) are recognized as crucial mediators in sepsis pathogenesis. This study aims to identify the key regulatory miRNAs involved in cardiac dysfunction stemming from sepsis. We developed a rat model of sepsis using cecal ligation and puncture (CLP). Myocardial tissue from these rats underwent miRNA sequencing and transcriptome sequencing. Echocardiography was utilized to assess heart function, while cardiac damage was evaluated through HE staining, analysis of inflammatory factors, and detection of tissue injury biomarkers. To model inflammation-induced cardiomyocyte injury, rat cardiomyocyte H9C2 cells were treated with lipopolysaccharide (LPS). Cellular viability was determined using CCK8, and apoptosis was assessed via TUNEL staining and flow cytometry. Oxidative stress levels were analyzed by flow cytometry, and related marker levels were quantified by ELISA. Our results demonstrated that the CLP group displayed substantial cardiac dysfunction, myocardial injury, and elevated inflammatory factor levels. MiR-221-5p was found to be upregulated in both the in vivo and in vitro models. Overexpression of miR-221-5p reduced cardiomyocyte survival while increased apoptotic activity and oxidative stress in LPS-stimulated H9C2 cell. Mechanistically, Neuropilin-1 (NRP1) was identified as a target of miR-221-5p. The cardioprotective effect of miR-221-5p inhibition was reversed by NRP1 knockdown. Furthermore, in vivo administration of a miR-221-5p antagomir mitigated cardiac dysfunction and myocardial damage associated with septic conditions. In conclusion, our findings indicate that miR-221-5p exacerbates septic cardiomyopathy by negatively regulating NRP1, suggesting that the miR-221-5p/NRP1 pathway could represent a novel therapeutic strategy for sepsis-related heart complications.

A Self‐Strengthening Hydrogel Coating for Long‐Term Underwater Adhesion in Seawater Over 900 Days

ABSTRACT Reliable underwater adhesion is a prerequisite for the practical application of hydrogels as underwater coatings. Despite extensive efforts to enhance adhesion strength, strong initial adhesion does not ensure long‐term adhesion stability. Achieving durable underwater adhesion of hydrogels remains fundamentally challenging due to interfacial hydration and continuous water‐induced network degradation, particularly in complex aqueous environments such as seawater. To overcome these limitations, a hydrogel coating that achieves persistent underwater adhesion in natural seawater for over 900 days is developed. Strong initial adhesion is established across diverse substrates through synergistic interfacial interactions, while network integrity is maintained during prolonged immersion through multiple cooperative intermolecular interactions and continuous quinone‐mediated oxidative crosslinking. Consequently, the hydrogel exhibits persistently low water uptake (≈162 wt% after 900 days), suppresses swelling‐induced deterioration of interfacial adhesion, and maintains a shear adhesion strength of ≈110 kPa after 900 days of seawater immersion. The hydrogel coating also exhibits antibacterial and anti‐algal activity for marine antifouling, underwater superoleophobicity, and applicability as a gel electrolyte for flexible supercapacitors. This work establishes a design principle for achieving long‐term underwater functional hydrogels beyond previously reported time scales and provides a general strategy for developing continuously curing materials in underwater and marine environments.

Reversing vegetable biodiversity loss to diversify diets

Vegetables are a critical component of diets, with inadequate intake of this essential food group leading to poor dietary quality and malnutrition. Food system assessments identify insufficient production, comparatively high prices, and sociocultural barriers as key constraints to vegetable consumption. We argue that vegetable biodiversity, spanning vegetable species and their varieties, as well as their wild relative species, is a central yet underutilized lever for enhancing vegetable consumption. Vegetables span a wider phylogenetic range than any other plant-derived food group, offering options for different climatic, cultural, and market niches worldwide. However, vegetable biodiversity is declining due to market homogenization, land-use change, and other threats. Its current conservation is insufficient, restricting in turn access to this diversity for research, breeding, and innovation, and making it more difficult to bridge the gap between current and recommended vegetable intake. Reversing this trend globally requires aligning conservation with dietary goals through four complementary action areas: i) Securing vegetable biodiversity by collecting, regenerating, and conserving local crop varieties and wild relatives of key vegetable species in biodiversity hotspots; ii) Harnessing vegetable biodiversity to deliver new varieties through collaborative research, breeding, and variety testing; iii) Promoting vegetable biodiversity to diversify diets, particularly among children and other vulnerable groups, by including nutrient-dense, climate-resilient vegetables into home and school meals; and iv) Integrating vegetable biodiversity into policy frameworks for long-term impact. Implementing this integrated approach in hotspots where vegetable biodiversity and malnutrition overlap can transform an overlooked opportunity into a cornerstone strategy for healthier diets.

Hemispheric contributions to praxis: imitation of gestures and pantomime of tool use following left and right hemisphere damage

Correction to: p38 signaling enhances short-lived effector cell differentiation and weakens central memory CD8+ T-cell formation