Recent lbnl_es items

Entropy-Driven Stabilization of Highly Charged Peptoid Nanosheets

Wed, 4 Nov 2026 00:00:00 +0000

Abstract Free-standing two-dimensional (2D) peptoid nanosheets are promising for many aqueous applications, yet how the ionic environment governs their structure and thermal stability remains poorly understood. Here we design an ultrathin (∼2 nm) crystalline peptoid nanosheet with an extremely small ionizable (ethylammonium) polar domain as a structurally well-defined, highly charged model system, whose molecular packing is directly resolved by cryogenic electron microscopy. Solution-state differential scanning calorimetry reveals that salt-induced stabilization is dominated by entropy rather than enthalpy. Our Molecular Dynamics (MD) simulations attribute this to the release of surface-condensed counterions upon melting, which is set by both the surface’s counterion-condensing capacity and the bulk ion concentration, with our computed release entropies tracking the measured melting entropies. With sodium halide salts, the melting temperatures follow a Hofmeister-like ordering...

Dynamics and Energy Relaxation of Formic Acid Dimers Following Inner Valence Ionization

Tue, 3 Nov 2026 00:00:00 +0000

Abstract We study gas-phase dissociation of the formic acid dimer dication as a model for DNA base-pair interactions after inner-valence 56 eV extreme ultraviolet (EUV) ionization. Employing reaction microscopy, we measure the 3D momenta of electrons and fragment-ions in coincidence to reconstruct channel-resolved electron kinetic energies, fragment kinetic energy release, and angular distributions. This work focuses on the symmetric 2-body (HCOOH+ + HCOOH+) and asymmetric 3-body (HCOOH+ + HCOO+ + H) breakup channels, reporting their relative yields and dynamics. Electron-energy signatures and angular correlations distinguish direct double ionization (DDI) from sequential ionization (SI) with a ratio of ∼9:5. In SI, low-energy electrons and their near-isotropic angular distributions indicate a competition between local intramolecular autoionization (AI) and nonlocal intermolecular Coulombic decay (ICD). Real-time simulations of the electron dynamics support AI/ICD-driven secondary...

Text-mined dataset of sol-gel synthesis protocols with phase purity outcomes using large language models

Wed, 28 Oct 2026 00:00:00 +0000

Sol-gel synthesis is a versatile method for producing inorganic materials that offers advantages such as atomic-level mixing and lower processing temperatures over traditional solid-state methods. Despite these benefits, achieving phase purity remains a challenge due to the process’s sensitivity to synthesis parameters such as precursor choice, solvent selection, and heating conditions. Phase-impure outcomes are essential for understanding sol-gel reaction pathways, but are largely absent from existing curated datasets. This work leverages Gemini 3.0 Flash to construct a text-mined inorganic sol-gel database with phase purity information. The dataset contains ~148,000 synthesis records, including ~28,000 phase-impure entries. All extracted entities achieved F1 scores greater than 0.89. At the record level, 68% of extracted records match human annotation on all evaluated fields. Furthermore, to validate the scientific utility of our dataset, we demonstrate that the aggregated data...

Structural Basis for Recognition of a Gonococcal Lipooligosaccharide Epitope by Monoclonal Antibody 2C7 Informs Vaccine and Immunotherapeutic Design

Tue, 27 Oct 2026 00:00:00 +0000

Abstract Neisseria gonorrhoeae, the causative agent of gonorrhea, represents an escalating global health concern because of the rapid spread of antimicrobial resistance and the continued lack of an effective vaccine. The lipooligosaccharide (LOS) epitope targeted by monoclonal antibody 2C7 is highly conserved and expressed by the majority of clinical isolates, highlighting its potential as an attractive target for therapeutic and vaccine-based interventions. To define the molecular basis for 2C7 recognition, we structurally characterized mAb 2C7 bound to an LOS-derived octasaccharide. NMR and a 1.6 Å crystal structure of the Fab 2C7–octasaccharide complex showed that mAb 2C7 recognizes the β- and γ-glycan chains through an extensive network of hydrogen-bonding and hydrophobic interactions within the Fab binding cleft. MD simulations indicated that β and γ chains form stable, specific interactions with 2C7, whereas α-chain contacts are transient. Guided by structure, we synthesized...

Taking the heat off tantalum

Tue, 27 Oct 2026 00:00:00 +0000

Krypton-assisted growth of low-loss α-phase tantalum on silicon stays within back-end-of-line semiconductor thermal budgets while delivering state-of-the-art qubit coherence.

Gonococcal Peptide Mimetic Vaccine Antigen Forms a Beta-hairpin Structure and Binds to a Chimeric Antibody Primarily through Hydrophobic Interactions

Tue, 27 Oct 2026 00:00:00 +0000

Gonococcal Peptide Mimetic Vaccine Antigen Forms a Beta-hairpin Structure and Binds to a Chimeric Antibody Primarily through Hydrophobic Interactions

Modification of Cysteine-Substituted Antibodies Using Enzymatic Oxidative Coupling Reactions

Fri, 23 Oct 2026 00:00:00 +0000

Cysteines are routinely used as site-specific handles to synthesize antibody-drug conjugates for targeted immunotherapy applications. Michael additions between thiols and maleimides are some of the most common methods for modifying cysteines, but these functional groups can be difficult to prepare on scale, and the resulting linkages have been shown to be reversible under some physiological conditions. Here, we show that the enzyme tyrosinase, which oxidizes conveniently accessed phenols to afford reactive ortho-quinone intermediates, can be used to attach phenolic cargo to cysteines engineered on antibody surfaces. The resulting linkages between the thiols and ortho-quinones are shown to be more resistant than maleimides to reversion under physiological conditions. Using this approach, we construct antibody conjugates bearing cytotoxic payloads, which exhibit targeted cell killing, and further demonstrate this method for the attachment of a variety of cargo to antibodies,...

Gold catalysis for organic synthesis II

Fri, 23 Oct 2026 00:00:00 +0000

Gold catalysis for organic synthesis II

Development of Second-Generation Acyl Silane Photoaffinity Probes for Cellular Chemoproteomic Profiling

Fri, 23 Oct 2026 00:00:00 +0000

Deconvolution of the protein targets of hit compounds from phenotypic screens, often conducted in live cells, is critical for understanding mechanism of action and identifying potentially hazardous off-target interactions. While photoaffinity labeling and chemoproteomics are long-established approaches for discovering small-molecule-protein interactions in live cells, there are a relatively small number of photoaffinity labeling strategies that can be applied for chemoproteomic target identification studies. Recently, we reported a novel chemical framework for photoaffinity labeling based on the photo-Brook rearrangement of acyl silanes and demonstrated its ability, when appended to protein-targeting ligands, to label recombinant proteins. Here, we report the application of these probes to live cell photoaffinity workflows, demonstrate their complementarity to current state-of-the-art minimalist diazirine-based photoaffinity probes, and introduce a modular synthetic route to access...

Assessment of Complementary Catalysts in an Uncharted Enantioselective Reaction of Sulfondiimines

Fri, 23 Oct 2026 00:00:00 +0000

Traditionally, many chemists turn to "privileged" catalyst scaffolds, which often demonstrate appreciable performance for a broad range of transformations. However, these structures can be challenging to modify, so complementary catalysts, such as peptides, are of interest. We simultaneously explored both peptidic and privileged cinchona catalysts for the asymmetric trifluoroacetylation of sulfondiimines (SDIs), an unexplored enantioselective reaction. The resultant acylated SDIs can enable access to a broad range of enantioenriched sulfur(VI) products for potential applications as bioisosteres. A significant challenge facing the establishment of an enantioselective variant of this reaction is that the background reaction has a high rate of reactivity, achieving 70% conversion in just 1 h at -78 °C. Nonetheless, we identified both a peptide and a cinchona alkaloid featuring kinetic profiles that outcompete this extremely fast background reactivity by an order of magnitude. Substrate...

Conformational Dynamics for Catalysis beyond the Sabatier Limit

Fri, 23 Oct 2026 00:00:00 +0000

Abstract Conformational changes occur throughout biology and are implicated in numerous phenomena, including enzyme catalysis where their role remains controversial. Conformational dynamics have also been observed in small-molecule catalysis, yet a lack of systematic study means that their influence is poorly understood. Here, we highlight how advances in chemical reaction network mathematics, alongside the translation of the Sabatier principle from heterogeneous to homogeneous catalysis, now enable the behavior of conformationally dynamic catalysts to be understood from first principles. We demonstrate that for common classes of reaction mechanisms, catalyst conformational dynamics can, in principle, cause large rate enhancements relative to each of the catalyst’s individual conformations, as well as rate enhancements of orders of magnitude above the Sabatier limit. This quantitative understanding reveals how particular features of a catalyst or reaction mechanism govern catalytic...

Abstracting Complementarity for the Design of Stereoselective Acid Catalysts

Fri, 23 Oct 2026 00:00:00 +0000

Abstract Complementarity is invoked to holistically characterize interactions between a catalyst and its substrate. Although the paradigm maintains utility across many fields of chemistry, it is challenging to proactively deploy, requiring post hoc analyses to demonstrate. Here, we report active site-based buried volume furnishes a quantitative and generalizable representation for complementarity by Brønsted acid organocatalysts. The low-dimensional, geometric abstraction helps construct analytical Gaussian models encoding complementarity. From these footholds, experimental validation realizes new stereoselective solutions across diverse structural motifs and functional modes. Unlike other heuristics for stereoinduction, active site-based buried volume guides the design of stereoselective solutions without requiring detailed attention to the mechanisms of stereoinduction. We anticipate the successful abstraction of high-dimensional, stereoselective interactions by complementarity...

Reactions of Difluorocarbene with Organogold(I) Complexes: Synthesis of Gem‐Difluoromethylene Organometallics via Difluorocarbene Insertion and Cycloaddition Reactions

Fri, 23 Oct 2026 00:00:00 +0000

The gem-difluoromethylene functional group is an important motif in medicinal chemistry, and development of new fluoroalkyl-metal systems has been crucial to enable new syntheses of gem-difluoromethylenes. However, well-defined and isolable examples of either nucleophilic RCF₂M or difluorocyclopropenyl transition metal complexes are rare. The Au(I) platform has been useful for the synthesis of isolable transition-metal complexes bearing reactive ligands. Herein we utilize reactions of difluorocarbene with organogold(I) complexes, analogous to reactions of difluorocarbene with organic substrates, to access novel examples of gem-difluoromethylene organometallics. First, difluorocarbene insertion into the R─Au(I) bond of organogold(I) species with free difluorocarbene was demonstrated for the first time, forming alkyl-CF₂-Au(I) and aryl-CF₂-Au(I) species. Second, via a difluorocarbene cycloaddition reaction we isolate for the first time a κ¹-difluorocyclopropenyl-transition...

Singlet Photoredox Catalysis via Supramolecular Host–Guest Interactions

Fri, 23 Oct 2026 00:00:00 +0000

Abstract Photocatalysts most often leverage long-lived triplet excited states to promote valuable reactivity in organic synthesis. Consequently, many potential photosensitizers remain unviable for catalytic applications because of the kinetic constraints of diffusion-controlled intermolecular electron transfer. Supramolecular mechanisms can obviate this constraint through ground-state association with a reactant, enabling species with short-lived excited-state lifetimes to engage in synthetically relevant transformations. Thus far, the instability of host architectures toward open-shell intermediates has limited their use as photoredox catalysts. Through the synthesis of an oxidatively robust GeIV catecholate cage (Ep/2 = 0.357 V vs Fc/Fc+), we have enabled the (4 + 2) synthesis of isoquinolones via singlet photoredox catalysis. These results establish supramolecular preorganization as a generalizable platform for harnessing the unique redox potentials of singlet excited states...

Selective Deposition of N‐Heterocyclic Carbene Monolayers on Designated Au Microelectrodes within an Electrode Array

Fri, 23 Oct 2026 00:00:00 +0000

The incorporation of organic self-assembled monolayers (SAMs) in microelectronic devices requires precise spatial control over the self-assembly process. In this work, selective deposition of N-heterocyclic carbenes (NHCs) on specific electrodes within a two-microelectrode array is achieved by using pulsed electrodeposition. Spectroscopic analysis of the NHC-coated electrode arrays reveals that each electrode is selectively coated with a designated NHC. The impact of NHC monolayers on the electrodes' work function is quantified using Kelvin probe force microscopy. These measurements demonstrate that the work function values of each electrode can be independently tuned by the adsorption of a specific NHC. The presented deposition method enables to selectively coat designated microelectrodes in an electrode array with chosen NHC monolayers for tuning their chemical and electronic functionality.

Discovery of Potent Pyrazoline‐Based Covalent SARS‐CoV‐2 Main Protease Inhibitors**

Fri, 23 Oct 2026 00:00:00 +0000

While vaccines and antivirals are now being deployed for the current SARS-CoV-2 pandemic, we require additional antiviral therapeutics to not only effectively combat SARS-CoV-2 and its variants, but also future coronaviruses. All coronaviruses have relatively similar genomes that provide a potential exploitable opening to develop antiviral therapies that will be effective against all coronaviruses. Among the various genes and proteins encoded by all coronaviruses, one particularly "druggable" or relatively easy-to-drug target is the coronavirus Main Protease (3CL^pro or Mpro), an enzyme that is involved in cleaving a long peptide translated by the viral genome into its individual protein components that are then assembled into the virus to enable viral replication in the cell. Inhibiting Mpro with a small-molecule antiviral would effectively stop the ability of the virus to replicate, providing therapeutic benefit. In this study, we have utilized activity-based protein...

Stereoselective Generalizations over Diverse Sets of Chiral Acids Enabled by Buried Volume

Fri, 23 Oct 2026 00:00:00 +0000

Stereoselective catalysis is a paradigm of complexity, navigating arrays of specific, yet weak, noncovalent interactions to achieve asymmetric induction. Accordingly, structure-activity relationships modeling stereoselectivity have required bespoke representations, high dimensionality, and/or large data sets to furnish productive trends, hampering their subsequent interpretability and utility. Here, we report that active site-based buried volume is a uniquely advantageous descriptor for the construction of models to stereoselectivity by Brønsted acid organocatalysts. Through statistical analyses of 50+ data sets across nearly 200 distinct catalysts, we realize active site-based buried volume is an exceptional representation, accommodating both extensive structural diversity (within data sets) and functional diversity (across data sets). We show that the descriptor's value likely relates to its surprising capacity to generalize beyond simple steric interactions and account for...

A Porous Crystalline Nitrone‐Linked Covalent Organic Framework**

Fri, 23 Oct 2026 00:00:00 +0000

Herein, we report the synthesis of a nitrone-linked covalent organic framework, COF-115, by combining N, N', N', N'''-(ethene-1, 1, 2, 2-tetrayltetrakis(benzene-4, 1-diyl))tetrakis(hydroxylamine) and terephthaladehyde via a polycondensation reaction. The formation of the nitrone functionality was confirmed by solid-state ¹³ C multi cross-polarization magic angle spinning NMR spectroscopy of the ¹³ C-isotope-labeled COF-115 and Fourier-transform infrared spectroscopy. The permanent porosity of COF-115 was evaluated through low-pressure N₂ , CO₂ , and H₂ sorption experiments. Water vapor and carbon dioxide sorption analysis of COF-115 and the isoreticular imine-linked COF indicated a superior potential of N-oxide-based porous materials for atmospheric water harvesting and CO₂ capture applications. Density functional theory calculations provided valuable insights into the difference between the adsorption properties...

Data Science-Enabled Palladium-Catalyzed Enantioselective Aryl-Carbonylation of Sulfonimidamides

Fri, 23 Oct 2026 00:00:00 +0000

New methods for the general asymmetric synthesis of sulfonimidamides are of great interest due to their applications in medicinal chemistry, agrochemical discovery, and academic research. We report a palladium-catalyzed cross-coupling method for the enantioselective aryl-carbonylation of sulfonimidamides. Using data science techniques, a virtual library of calculated bisphosphine ligand descriptors was used to guide reaction optimization by effectively sampling the catalyst chemical space. The optimized conditions identified using this approach provided the desired product in excellent yield and enantioselectivity. As the next step, a data science-driven strategy was also used to explore a diverse set of aryl and heteroaryl iodides, providing key information about the scope and limitations of the method. Furthermore, we tested a range of racemic sulfonimidamides for compatibility of this coupling partner. The developed method offers a general and efficient strategy for accessing...

Near‐Micron Single‐Crystalline Mn‐Rich Cathodes With Exceptional Cycling Stability

Wed, 21 Oct 2026 00:00:00 +0000

ABSTRACT Achieving high‐energy‐density and long‐term cycling stability in Mn‐redox‐based cathodes is a critical step toward advancing Ni‐ and Co‐free Li‐ion chemistries to diversify supply chains and lower battery costs. Here, we demonstrate an unusually high performance benchmark for Mn‐redox cathodes using near‐micron single‐crystalline δ‐phase cation‐disordered rocksalt (δ‐DRX), derived from Mn‐rich DRX, delivering ≈640 Wh kg −1 with ≈97% capacity retention over 400 cycles. The very high energy density and cycle life were achieved by using a high Mn content, to suppress oxygen redox activity, and careful control of the synthesis parameters to tune single crystal particle size. Using high‐throughput automated electron microscopy, we identify interparticle compositional heterogeneity present in the early stage of phase‐pure DRX formation as the origin of orthorhombic LiMnO 2 impurity formation during cooling, a finding that rationalizes the long high‐temperature dwell times...

Accurate SEM-EDS quantification, automation, and machine learning enable high-throughput compositional characterization of powders

Tue, 20 Oct 2026 00:00:00 +0000

Compositional characterization is essential for understanding and optimizing material performance. For powder-based materials underpinning many modern technologies, however, accurately and rapidly resolving the composition of individual constituent phases remains an unsolved challenge, slowing materials research and limiting autonomous laboratory platforms. Scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) offers a time- and cost-effective route, but artifacts generated by irregular particle morphologies fundamentally limit its reliability for quantitative compositional analysis. Here, we introduce a scalable particle-based SEM-EDS quantification scheme that overcomes these artifacts requiring only one experimental standard per element, including light elements conventionally difficult to quantify. To deploy this capability at scale, we then integrate this core quantification scheme with automated measurements and unsupervised machine-learning analysis...

Broad Stability and pH-Mediated Reversible Disassembly of In Vitro Assembled Bacterial Microcompartment Shells

Tue, 20 Oct 2026 00:00:00 +0000

Abstract Bacterial microcompartments (BMCs) are self-assembling organelles that colocalize enzymes and metabolites of various biochemical pathways. Their selectively permeable shell is made entirely of protein, and the inherent properties of these systems make them attractive templates for bioengineering synthetic nanoreactors. Understanding the extent of shell stability in an extended range of conditions broadens the scope of chemistries that can be confined in these nanocompartments. Here we analyze the stability of in vitro assembled BMC shells and find that they retain their structure at high concentrations of various solvents and detergents, at temperatures up to 75 °C, and across a pH range from 3.9 to 11. Shell disassembly is observed below pH 3.9, but shells can be reassembled upon increasing the pH back to 8. These results expand the range of reactions that can be performed inside protein-based nanoreactors and underscore the potential of modular BMC shell proteins as...

Artifact segmentation using the U-Net architecture for powder X-ray diffraction images

Tue, 20 Oct 2026 00:00:00 +0000

Modern synchrotron X-ray facilities generate X-ray diffraction (XRD) image data at rates that far exceed the capacity of manual analysis, yet critical processing steps such as artifact removal rely on human intervention. Rule-based algorithms in standard beamline software cannot reliably distinguish harmful artifacts like single-crystal diffraction spots from desirable features like preferred orientation, which leads to incorrectly processed data. We demonstrate that a U-Net convolutional neural network trained on expert-labeled experimental data can help automate artifact segmentation in time-resolved XRD measurements of battery materials. To address overfitting from redundant time-series frames, we introduce a mutual information-based pruning algorithm that selects maximally diverse training images. Our optimized model achieves an 85.1% true positive rate on a fully held-out battery dataset while reducing false positives by 34% compared with GSAS-II. Critically, the model preserves...

Prediction and Experimental Verification of Electrolyte Solvation Structure from an OMol25-Trained Interatomic Potential

Tue, 13 Oct 2026 00:00:00 +0000

A molecular-level understanding of electrolyte solvation structure and ion-ion correlations is critical to developing next-generation battery chemistries. Atomistic simulation capabilities with sufficient accuracy, speed, and transferability to deliver reliable structural insights while avoiding arduous system-specific reparameterization are thus highly desirable. Machine learning interatomic potentials (MLIPs) trained on large, chemically diverse data sets are revolutionizing computational chemistry, enabling molecular dynamics simulations of battery electrolytes with near-DFT accuracy over 10,000× faster than DFT. While previous MLIP training data sets with suitable elemental coverage for electrolytes have been based on inorganic materials, the Open Molecules 2025 (OMol25) data set provides large-scale molecular DFT MLIP training data with broad elemental coverage and specifically samples tens of millions of electrolyte configurations. Here, we integrate computational modeling...

Automating Chemical Reasoning in High‐Throughput Phase Identification With a Probabilistic, LLM‐Guided Framework

Tue, 13 Oct 2026 00:00:00 +0000

Autonomous laboratories increasingly enable materials synthesis at scale, but traditional high-throughput characterization workflows remain limited by the need for expert chemical intuition to distinguish plausible interpretations from formally good but chemically incorrect fits. We present an automated interpretation framework that combines probabilistic inference with automated chemical reasoning for phase identification from powder x-ray diffraction (PXRD). The framework evaluates multiple candidate interpretations using diffraction pattern-based metrics. It then refines these likelihoods using chemically-informed priors derived from composition balance and a large language model (LLM)-based plausibility estimate with human-readable justification and also produces a trustworthiness score. In a blinded multi-project benchmark, the framework's top-ranked interpretation was selected over the lowest- baseline in 93% of cases where evaluators expressed a clear preference (95% CI:...

Diiron µ2-N2 complexes in bimetallic, four-fold bond activations of SiH4 to produce µ2-silicide complexes

Tue, 13 Oct 2026 00:00:00 +0000

Fe(0) dinitrogen complexes [SiP₃ ^R]Fe-N[triple bond, length as m-dash]N-Fe[SiP₃ ^R] (1-R; [SiP₃ ^R] = PhSi(CH₂PR₂)₃; R = ⁱ Pr, Ph) are accessed by one- or two-electron reduction of Fe(i) and Fe(ii) chloride complexes [SiP₃ ^{ⁱ Pr}]FeCl or κ²-[SiP₃ ^R]FeCl₂ (R = ⁱ Pr, Ph), respectively, and fully characterized by means of multinuclear NMR spectroscopy, single-crystal X-ray diffraction (SC-XRD), and Mössbauer spectroscopy. Complexes 1-R represent rare examples of bimetallic Fe(0) compounds with dinitrogen as a bridging ligand and have an overall spin of S = 0. Heating 1-R in the presence of SiH₄ gas resulted in four-fold Si-H activation to furnish diiron complexes [SiP₃ ^R](H)₂Fe[double bond, length as m-dash]Si[double bond,...

TEM Agent: enhancing transmission electron microscopy with modern AI tools

Tue, 13 Oct 2026 00:00:00 +0000

Recent improvements in large language models (LLMs) have had a dramatic effect on capabilities and productivity across many disciplines involving critical thinking and writing. The development of the model context protocol (MCP) provides a way to extend the power of LLMs to a specific set of tasks or scientific equipment with help from curated tools and resources. Here, we describe a framework called TEM Agent designed for transmission electron microscopy (TEM) that leverages the benefits of LLMs through a MCP approach. We simultaneously access and control several subsystems of the TEM, a data management platform, and high-performance computing resources through text-based instructions. We demonstrate the abilities of the TEM Agent to set up and complete intricate workflows using a simplified set of MCP tools and resources accompanying a commercial LLM without any additional training. The use of a framework such as the TEM Agent simplifies access to complex microscope ecosystems...

HDX–MS finds that partial unfolding with sequential domain activation controls condensation of a cellular stress marker

Mon, 5 Oct 2026 00:00:00 +0000

Eukaryotic cells form condensates to sense and adapt to their environment [S. F. Banani, H. O. Lee, A. A. Hyman, M. K. Rosen, Nat. Rev. Mol. Cell Biol. 18, 285-298 (2017), H. Yoo, C. Triandafillou, D. A. Drummond, J. Biol. Chem. 294, 7151-7159 (2019)]. Poly(A)-binding protein (Pab1), a canonical stress granule marker, condenses upon heat shock or starvation, promoting adaptation [J. A. Riback et al., Cell 168, 1028-1040.e19 (2017)]. The molecular basis of condensation has remained elusive due to a dearth of techniques to probe structure directly in condensates. We apply hydrogen-deuterium exchange/mass spectrometry to investigate the mechanism of Pab1's condensation. Pab1's four RNA recognition motifs (RRMs) undergo different levels of partial unfolding upon condensation, and the changes are similar for thermal and pH stresses. Although structural heterogeneity is observed, the ability of MS to describe populations allows us to...

X-ray footprinting/mass spectrometry provides a new, detailed view of intrinsically disordered protein structural ensembles

Mon, 5 Oct 2026 00:00:00 +0000

X-ray footprinting/mass spectrometry provides a new, detailed view of intrinsically disordered protein structural ensembles

X-ray footprinting/mass spectrometry offers a new, detailed view of intrinsically disordered protein structural ensembles

Mon, 5 Oct 2026 00:00:00 +0000

X-ray footprinting/mass spectrometry offers a new, detailed view of intrinsically disordered protein structural ensembles

Investigating disorder-containing complexes using hydrogen-deuterium exchange with mass spectrometry

Mon, 5 Oct 2026 00:00:00 +0000

Investigating disorder-containing complexes using hydrogen-deuterium exchange with mass spectrometry

Quantitative X‐ray scattering and reflectivity measurements of polymer thin films with 2D detectors

Thu, 1 Oct 2026 00:00:00 +0000

Abstract We describe a fully open‐sourced Python package to process raw X‐ray scattering data using a GANESHA SAXSLAB facility, and review in this manuscript the connection of X‐ray scattering theories with the open‐sourced package. This package affords researchers more flexibility in analyzing and visualizing X‐ray scattering and reflectivity data from what is now a commonplace facility at many universities and research laboratories engaged in polymer research. We briefly review the applications of X‐ray scattering and diffraction, followed by the scattering theories. A pedagogical introduction to processing X‐ray scattering data is provided using the modules in the Python package. We compare conventions to visualize and interpret transmission and grazing‐incidence scattering data using self‐assembled lamellar morphology of bottlebrush copolymers as an example, then describe how area detectors measure specular and off‐specular reflectivity. Examples of in‐house reflectivity and...

CO2 Conversion to Butene via a Tandem Photovoltaic–Electrochemical/Photothermocatalytic Process: A Co-design Approach to Coupled Microenvironments

Thu, 1 Oct 2026 00:00:00 +0000

We developed a tandem, unassisted, solar-driven electrochemical and photothermocatalytic process for the single-pass conversion of CO2 to butene using only simulated solar irradiation as the energetic input. The two-step process involves electrochemical CO2 reduction (CO2R) to ethylene followed by ethylene dimerization to butene. We assessed two unassisted electrochemical setups to concentrate ethylene in the CO2R reactor, achieving concentrations up to 5.4 vol% with 1.8% average solar-to-ethylene conversion and 5.6% average CO2-to-ethylene single-pass conversion under 1-sun illumination. When the effluent electrochemical gas stream was passed through the photothermocatalytic ethylene oligomerization reactor, we generated 600 ppm of butene under 3-sun illumination. Through analysis of this process, we identified that the presence of H2, CO, and H2O leads to rapid deactivation of the Ni-based ethylene oligomerization catalyst.

AI@ALS Workshop Report: Machine Learning Needs at the Advanced Light Source

Thu, 1 Oct 2026 00:00:00 +0000

AI@ALS Workshop Report: Machine Learning Needs at the Advanced Light Source

Assessing Thermodynamic Selectivity of Solid-State Reactions for the Predictive Synthesis of Inorganic Materials

Thu, 1 Oct 2026 00:00:00 +0000

Synthesis is a major challenge in the discovery of new inorganic materials. Currently, there is limited theoretical guidance for identifying optimal solid-state synthesis procedures. We introduce two selectivity metrics, primary and secondary competition, to assess the favorability of target/impurity phase formation in solid-state reactions. We used these metrics to analyze 3520 solid-state reactions in the literature, ranking existing approaches to popular target materials. Additionally, we implemented these metrics in a data-driven synthesis planning workflow and demonstrated its application in the synthesis of barium titanate (BaTiO₃). Using an 18-element chemical reaction network with first-principles thermodynamic data from the Materials Project, we identified 82985 possible BaTiO₃ synthesis reactions and selected 9 for experimental testing. Characterization of reaction pathways via synchrotron powder X-ray diffraction reveals that our selectivity metrics...

Automated synthesis of InSb quantum dots with improved batch-to-batch reproducibility via kinetically matched co-reduction

Wed, 30 Sep 2026 00:00:00 +0000

Indium antimonide (InSb) colloidal quantum dots (CQDs) are attractive heavy-metal-free absorbers for infrared photodetection, yet their synthesis remains challenging because precursor reduction overlaps with nucleation and growth, hindering kinetic control and yielding broad size distributions. Here we employ an automated workflow to achieve precise control over InSb CQD synthesis, leading to improved batch-to-batch reproducibility and narrow size distributions without laborious post-synthetic size-selective precipitation. We find that InSb CQD formation proceeds through a kinetically matched precursor co-reduction pathway, which requires an In-rich environment to compensate for the faster reduction of Sb3+ precursor. Within this framework, we tune CQD size by modulating precursor conversion kinetics through In/Sb precursor molar ratio and reducing agent availability. This kinetically guided size control tunes the first excitonic absorption peak of CQDs across 1120-1650 nm in...

3D, Structure-Based, Deep Learning Approach to Predict the Regioselectivity of Olefin Hydroformylations

Wed, 30 Sep 2026 00:00:00 +0000

The rational development of transition-metal catalysts, even when guided by theory and mechanistic knowledge, involves significant trial and error. Although machine learning offers the potential to accelerate catalyst discovery and optimization, accurately modeling the complex structures of catalysts and the multistep mechanisms by which they react remains challenging, given the limited sets of data available. Olefin hydroformylation is a quintessential example of this challenge: its catalytic cycle involves many, often reversible, steps, and decades of study have not yielded reliable structure-selectivity relationships. We report Libra-ML, a 3D structure-based deep learning approach for predicting experimental outcomes of transition-metal-catalyzed reactions. To demonstrate the ability of Libra-ML to model the outcomes of complex catalytic reactions, we predicted the regioselectivity of hydroformylation with terminal olefins catalyzed by rhodium complexes. Comparisons to existing...

Resonant electron attachment to N-ethylacetamide: Reduced signature of an intermediate resonant state

Wed, 30 Sep 2026 00:00:00 +0000

Dissociative electron attachment to N-ethylacetamide is investigated using velocity map imaging with a tunable electron beam. Previously reported ion-yield spectra reveal two prominent resonant features near 5.5 and 8.8 eV across all observed anion channels. Surprisingly, no distinct structure is observed in the intermediate 6–7-eV energy region, where smaller amides typically exhibit an additional resonance associated with amide-bond cleavage. For N-ethylacetamide, the absence of a clear feature in this energy region indicates that any corresponding transient negative-ion state does not contribute significantly to dissociation. The momentum distributions obtained in the present work reveal distinct dissociation dynamics for different channels. The CH3− fragment at 5.5 eV exhibits an anisotropic distribution, indicating a direct dissociation process with finite kinetic-energy release. In contrast, the NH− fragment at 8.8 eV shows an isotropic distribution with near-zero kinetic...

Automated and High-Throughput Phase Separation Control for Supramolecular Polymer Blends Enabled by Machine Learning

Wed, 30 Sep 2026 00:00:00 +0000

Supramolecular polymer blends (SPBs) offer tunable morphologies that dictate their macroscopic properties, yet their rational design is limited by the absence of predictive structure-morphology models. Here, we introduce a data-driven high-throughput workflow that integrates modular polymer synthesis, robotic formulation, automated morphology characterization, and machine learning (ML) for accelerated SPB discovery. Using a plug-and-play synthetic strategy, 33 hydrogen-bonding end-functional homopolymers were prepared and orthogonally combined to generate 260 SPBs in 1 day. A fully automated atomic force microscopy (AFM) pipeline enabled systematic imaging, producing 2340 morphology data sets with minimal human intervention. Domain spacings were extracted through complementary image-processing methods and used to train ML models. A support vector regression (SVR) model accurately predicted target phase-separation sizes (50, 100, and 150 nm), which were experimentally validated....

Predicting Enantioselectivity of Ruthenium-Catalyzed Ketone Hydrogenation with 3D Structure-Based Deep Learning

Wed, 30 Sep 2026 00:00:00 +0000

We report machine-learning (ML) models that predict with high accuracy the enantioselectivity of ketone hydrogenation with Noyori-type diphosphine-diamine catalysts. To mitigate bias in published data, we combined a data set curated from the literature with >1,000 examples from our own high-throughput experimentation. We demonstrate that 3D graph neural networks, trained on 3D representations derived from the enantiodetermining transition state, outperform models based on 2D graphs, molecular fingerprints, and descriptors derived from semiempirical quantum calculations. These results indicate that models trained on 3D structural representations that reflect catalyst-substrate interactions relevant to enantioselectivity can accurately extrapolate to structures distinct from those in the training set.

Amplification of Lanthanide f‑Orbital Differences by Redox Noninnocent Semiquinone Binding

Wed, 30 Sep 2026 00:00:00 +0000

A deeper understanding of the electronic structure of the lanthanides (Ln) is essential to harness their technological applications and enable responsible recovery/separation. Here, an isostructural series of tris(3,5-dimethyl-1-pyrazolyl)borate (Tp*)-supported LnIII adducts of a redox noninnocent 3,5-di-tert-butyl-o-semiquinone (DTBSQ) ligand, (Tp*)2Ln(DTBSQ), is characterized experimentally and computationally for all the early lanthanides La-Gd, except Pm. Computational simulations, together with spectroscopic measurements on selected systems, show the metals retain the trivalent oxidation state despite semiquinone binding with weak metal-radical coupling. While LnIII-DTBSQ bond distances decrease with decreasing LnIII ionic radii, theory suggests increased 4f-orbital mixing driven by the energetic accessibility of the f-shell, with significant radical contributions to the bonding, occurs for Sm/Eu. Orbital analyses and multireference calculations confirm these effects originate...

Erratum: Charge order induced Dirac pockets in the nonsymmorphic crystal TaTe4 [Phys. Rev. B 108, 155121 (2023)]

Tue, 29 Sep 2026 00:00:00 +0000

Erratum: Charge order induced Dirac pockets in the nonsymmorphic crystal TaTe4 [Phys. Rev. B 108, 155121 (2023)]

Observation of mirror-odd and mirror-even spin texture in ultrathin epitaxially strained RuO2 films

Tue, 29 Sep 2026 00:00:00 +0000

Recently, rutile ruthenium dioxide (RuO₂) has attracted renewed interest due to expectations of prominent altermagnetic spin splitting. However, accumulating experimental evidence suggests that, in its bulk and thick-film forms, RuO₂ does not display any form of magnetic ordering. Despite this, the spin structure of RuO₂ remains largely unexplored in the ultrathin limit, where substrate-imposed epitaxial strain can be substantial. Here, we use spin-resolved angle-resolved photoemission spectroscopy, supported by ab initio calculations, to reveal the electronic structure of 2-nanometer-thick epitaxial RuO₂ heterostructures. We observe an unconventional spin texture characterized by the coexistence of mirror-even and mirror-odd momentum-dependent components. A comprehensive symmetry analysis rules out nonmagnetic origins of this spin texture. These findings suggest an emergent nonrelativistic spin structure enabled by epitaxial strain...

Author Correction: Integrated rocksalt–polyanion cathodes with excess lithium and stabilized cycling

Tue, 29 Sep 2026 00:00:00 +0000

Correction to: Nature Energyhttps://doi.org/10.1038/s41560-024-01615-6, published online 23 August 2024. In the version of this article initially published, there were errors in the legends to Fig. 2h, i, where for the scale bars sizes now reading “2 nm,” the size was originally given in both places as “1 nm.” In the x-axis units for Fig. 3f, now reading “(mAh),” the units were originally listed as “(mAh g⁻¹).” In the Methods “Electrochemical measurements” section, in the sentences now reading “The loading of the electrode films was 2–3 mg cm⁻²” and “For pouch cells, cathode film with active material loading of 2.5 mg cm⁻²,” in both sentences, cm⁻² appeared originally as “cm⁻¹.” The text and figure have been updated in the HTML and PDF versions of the article.

Multiscale Characterization of Lignocellulosic Biomass Variability and Its Implications to Preprocessing and Conversion: a Case Study for Corn Stover

Tue, 29 Sep 2026 00:00:00 +0000

Abstract Feedstock variability that originates from biomass production and field conditions propagates through the value chain, posing a significant challenge to the emerging biorefinery industry. Variability in feedstock properties impacts feeding, handling, equipment operations, and conversion performance. Feedstock quality attributes, and their variations, are often overlooked in assessing feedstock value and utilization for conversion to fuels, chemicals, and products. This study developed and employed a multiscale analytical characterization approach coupled with data analytic methods to better understand the sources and distribution of feedstock quality variability through evaluation of 24 corn stover bales collected in 4 counties of Iowa. In total, 216 core samples were generated by sampling nine positions on each bale using a reliable bale coring process. The samples were characterized for a broad suite of physicochemical properties ranging across field and bale, macro,...

Tautomerism induces bending and twisting of biogenic crystals

Mon, 28 Sep 2026 00:00:00 +0000

Understanding and exploiting material flexibility through phenomena such as the bending and twisting of molecular crystals has been a subject of increased interest owing to the number of applications that benefit from these properties, such as optoelectronics, mechanophotonics, soft robotics, and smart sensors. Here, we report the growth of spontaneously bent and twisted ammonium urate crystals induced by the keto-enol tautomerism of the urate molecule. The major tautomer is native to biogenic crystals, whereas the minor tautomer functions as an effective crystal growth modifier to induce naturally bent and twisted ammonium urate crystals. We show that the degree of curvature can be tailored based on the judicious selection of growth conditions. A combination of state-of-the-art microscopy and spectroscopy techniques are used to characterize the origin of bending. Spatially resolved nano-electron diffraction and high-resolution electron microscopy of naturally bent crystals show...

Degradation Mechanisms of Fluorinated Disordered Rocksalt Cathodes: Effects of Electrolyte Chemistry and Discharge Voltage

Fri, 25 Sep 2026 00:00:00 +0000

Cation-disordered rock-salt (DRX) oxides have emerged as a promising class of high energy density cathodes for next-generation lithium-ion batteries. Fluorination has been widely employed to tune the redox chemistry and structural stability of these materials, leading to enhanced electrochemical performance. However, the degradation mechanisms of fluorinated DRX (F-DRX) cathodes during electrochemical cycling remain poorly understood. Here, we investigate the degradation behavior of an F-DRX cathode cycled in a conventional carbonate-based electrolyte and a localized high-concentration electrolyte (LHCE). By correlating electrochemical performance with interfacial and bulk structural evolution, we elucidate the role of electrolyte chemistry and deep discharge voltage in governing structural transformation and degradation. The results reveal more pronounced surface and bulk structural changes in the conventional LiPF6-carbonate electrolyte relative to LiFSI-LHCE, indicating accelerated...

Colloquium: Quantum properties and functionalities of magnetic skyrmions

Thu, 24 Sep 2026 00:00:00 +0000

Competing magnetic interactions may stabilize smooth magnetization textures that can be characterized by a topological winding number. Such textures, which are spatially localized within a two-dimensional plane, are commonly known as skyrmions. On the classical level, their significance for fundamental science and their potential for applications, ranging from spintronic devices to unconventional computation platforms, have been intensively investigated in recent years. This Colloquium considers quantum effects associated with skyrmion textures: their theoretical origins, the experimental and material challenges associated with their detection, and the promise of exploiting them for quantum operations. Starting with classical skyrmions, this Colloquium discusses their magnon and electron excitations and shows how hybrid architectures offer new platforms for engineering quantum orders, including topological superconductivity. The focus then moves to the quantization of the skyrmion...

An adenoviral-vectored vaccine confers seroprotection against capsular group B meningococcal disease

Tue, 22 Sep 2026 00:00:00 +0000

Adenoviral-vectored vaccines are licensed for prevention of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Ebola virus, but, for bacterial proteins, expression in a eukaryotic cell may affect the antigen's localization and conformation or lead to unwanted glycosylation. Here, we investigated the potential use of an adenoviral-vectored vaccine platform for capsular group B meningococcus (MenB). Vector-based candidate vaccines expressing MenB antigen factor H binding protein (fHbp) were generated, and immunogenicity was assessed in mouse models, including the functional antibody response by serum bactericidal assay (SBA) using human complement. All adenovirus-based vaccine candidates induced high antigen-specific antibody and T cell responses. A single dose induced functional serum bactericidal responses with titers superior or equal to those induced by two doses of protein-based comparators, as well as longer persistence and a similar breadth. The fHbp transgene...

Structure of a MenB de-N-acetyl polysialic acid antibody and mechanism of immune cell inhibition

Tue, 22 Sep 2026 00:00:00 +0000

The Neisseria meningitidis serogroup B (MenB) polysaccharide, α(2-8) polysialic acid (polySia), is essential for resistance to complement-mediated bacteriolysis and inhibition of opsonophagocytosis. The monoclonal antibody SEAM 3 binds de-N-acetyl polySia (dPSA) but not polySia, yet still recognizes encapsulated MenB, indicating the capsule contains dPSA derivatives. Since SEAM 3 also recognizes other pathogens as well as human cancers, we have explored its biological role and mapped the SEAM 3 epitope. We compared binding of N-acetylated and de-N-acetylated polySia and ganglioside GD3 derivatives to sialic-acid-binding immunoglobulin-like lectins (Siglecs) on leukocytes. Siglec-9 showed higher affinity for dPSA and de-N-acetyl GD3 (K_D ∼2.6-3.1 nM) than for their acetylated counterparts, while Siglec-5 bound polySia and GD3 derivatives with similar and moderate (K_D∼40-60 nM and 7.9 nM, respectively) affinity. Siglecs-2, -3, -7, -10, and -11 showed negligible...

Fast-Response Operando Mass Spectrometry Demystifies C₂ Product Formation in Cu-Catalyzed CO and CO₂ Reduction: Burst of Ethylene Isotopologues

Sat, 19 Sep 2026 00:00:00 +0000

It has been a long-standing challenge in electrocatalysis to measure product formation with kinetically relevant time resolution. Here, we couple a real-time gas analyzer mass spectrometer with a modified sampling inlet to a gas diffusion electrode cell, achieving sub-second time resolution for both reactant consumption and product formation. We focus on CO 2 /CO reduction on oxide-derived Cu, motivated by the continuing interest in its reaction mechanism and its high selectivity to ethylene (C 2 H 4 ) formation. Potential step experiments for CO reduction reveal that the initial consumption of CO is fast (< 1 s), but the appearance of C 2 H 4 products can be 10 times slower, which we attribute to the time required for CO storage on the Cu surface and subsequent reconstruction into the active, C 2+ -forming, configuration. Previous studies have reported that the co-feed of 12 CO 2 / 13 CO results in the enhancement of 13 C-containing ethylene isotopologues, but the mechanism...

Ionic gel-mediated synthesis of nanostructured chiral 2D halide perovskites with amplified chiroptical response