Browse Articles

Monolithic Porous Polymer Architectures for Visible‐to‐UV Upconversion‐Driven Photochemical Reactions

ABSTRACT Triplet–triplet annihilation‐based photon upconversion (TTA‐UC) expands the accessible spectral window for photochemical transformations by generating high‐energy photons from low‐energy excitation. Although TTA‐UC has been widely demonstrated in solution and in various solid‐state formats, examples of polymer materials capable of efficient visible‐to‐ultraviolet (vis‐to‐UV) upconversion under low excitation intensities remain scarce. Achieving vis‐to‐UV TTA‐UC in a porous solid is particularly challenging because it requires balancing chromophore proximity for TTA with the suppression of aggregation‐induced quenching, while simultaneously preserving substrate accessibility. Here, we introduce porous polymer monoliths that enable solid‐state TTA‐UC specifically designed for heterogeneous photochemistry. By embedding sensitizer‐annihilator dye pairs into polymer matrices with controlled co‐continuous porosity, we create monolithic architectures that display upconverted UV emission from blue light at excitation intensities below a few mW cm − 2 , with the operational wavelength further extended to green light excitation. The porous architecture enhances energy transfer to reaction substrates, providing a versatile platform for heterogeneous photochemical processes. Owing to their robustness and tunability, these monoliths are promising candidates as heterogeneous photoreactors, opening new opportunities for scalable and sustainable photochemistry.

Time-of-flight neutron radiography for differentiating ice and water during phase transitions in natural porous media

Abstract Measurement of coexistent liquid water and ice distributions is useful for many materials and systems such as fuel cells, concrete, snow, and soil. Energy-resolved neutron imaging is a promising technique for these measurements by exploiting differences in neutron cross-section between ice and water at cold neutron energies. Until now, energy-resolved neutron imaging techniques have only been used with relatively thin and non-natural samples. Given the importance of liquid water and ice distributions in many natural porous materials, we investigated the feasibility of using time-of-flight neutron radiography for two natural porous materials. Two exploratory experiments were performed with a model system of glass beads (simple soil analogue) and a natural snow sample with sample thicknesses of 5 mm. The experiments demonstrated that the relative attenuation could be used to distinguish between liquid and solid water phases as well as to dynamically track the phase transition within these porous materials. The results also demonstrated that significant challenges with respect to the scattering in thick samples, inconsistent thicknesses associated with spatial variations of the porosity, and time-variant structures of the porous matrix remain.

Narrowband Hydrocarbon Emitters Enabled by Stereo‐Locked Through‐Space Interactions

ABSTRACT High‐purity emitters with a narrowband emission are a critical requirement for next‐generation displays and lighting, yet it remains a formidable challenge for purely organic materials, particularly in the pure‐violet region. Herein, a general molecular design strategy based on the “stereo‐lock” concept, represented by diarylbenzene derivatives solely from carbon and hydrogen, is presented. This strategy effectively suppresses intramolecular C─C/C─H stretching and attenuates vibronic coupling via intramolecular through‐space interactions between two aryl groups, yielding a record full width at half maximum (FWHM) of merely 6 nm at 80 K from a single molecule. In the solid state, their aggregates with intermolecular positive exciton coupling induce quantum interference that selectively quenches the v 0‐0 transition, resulting in an FWHM of 17 nm at room temperature. Leveraging this synergy, diarylbenzene‐based OLED devices with pure‐violet electroluminescence with an 18 nm FWHM and a CIE coordinate of (0.165, 0.022) are achieved. This stereo‐lock architecture circumvents the fundamental limitation of vibronic coupling in pure hydrocarbons and addresses the absence of high‐color‐purity violet OLEDs, establishing a powerful and versatile design paradigm for narrowband emitters.

Artificial intelligence-based adaptive gain tuning for robust data-driven cardiac rhythm control under uncertainty

Unprotected <i>C</i> ‐Aryl Glycosides From Native Sugars via Glycosyl Sulfonyl Hydrazides: A Thermal Cap‐and‐Glycosylate Strategy

ABSTRACT We report a thermal cap‐and‐glycosylate strategy for the direct, protecting‐group‐free synthesis of unprotected aryl C‐glycosides from native sugars, employing glycosyl sulfonyl hydrazides as glycosyl radical precursors under redox‐neutral nickel catalysis. This two‐step process avoids photoirradiation, chromatography, and external redox agents. 11 Unprotected monosaccharides react with high 1,2‐ trans selectivity, tolerating diverse functional groups and heteroarenes. The utility is showcased by two‐step assembly of gliflozin drugs, their analogues and Neopetrosin C. This platform positions glycosyl sulfonyl hydrazides as a versatile radical source and a scalable alternative to photoinduced C‐glycosylation.

Spatially customized demand estimation for demand responsive transit

Abstract Demand-responsive transit (DRT) has emerged as a flexible mobility solution for addressing service blind spots in areas underserved by conventional public transportation. However, empirical research on DRT demand estimation remains limited, especially in the context of regional heterogeneity and zero-inflated demand. This study proposes a data-driven DRT demand estimation framework using operational records from two contrasting regions in Incheon, South Korea. Yeongjongdo is a tourism- and airport-oriented area with a high floating population and strong temporal variability, while Geomdan New Town is a residential district with relatively stable travel patterns. A grid-based origin–destination (O–D) modeling structure was employed, incorporating spatial variables such as land use, population dynamics, facility distribution, and public transport accessibility. Multiple region-specific machine learning models were developed and evaluated to estimate planning-oriented mean daily demand for each O–D-hour. A comparative analysis of alternative model configurations showed that the appropriate model structure varied according to regional demand conditions. In Yeongjongdo, the proposed two-stage model, which combines demand-occurrence classification and conditional regression, achieved the best overall performance, with a test MAE of 0.0022 and RMSE of 0.0105. These values represented reductions of 37.1% and 42.0%, respectively, relative to the strongest direct regression benchmarks. In contrast, direct regression was more effective in Geomdan New Town, achieving a test MAE of 0.0071 and RMSE of 0.0190. These results indicate that the relative performance of direct regression and two-stage prediction may vary across regional demand contexts.

Allegra Franchino

Design, synthesis, and characterization of glyoxime-functionalized hydroxypropyl methylcellulose/acrylic acid hydrogel for efficient removal of lead (II) ions from aqueous media

Proton‐Switching Regulates Interfacial Iodine Chemistry for Long‐Life Zinc–Iodine Batteries

ABSTRACT Aqueous zinc–iodine (Zn–I 2 ) batteries are promising candidates for safe and cost‐effective energy storage, yet their practical application is limited by uncontrolled iodine speciation at electrified interfaces, driving severe polyiodide shuttling and parasitic reactions that cause rapid capacity fading. Existing strategies predominantly rely on static confinement or adsorption, which cannot adapt to evolving iodine speciation during charge–discharge, causing a trade‐off between shuttle suppression and redox kinetics. In this study, we report a proton‐switching strategy that regulates interfacial iodine chemistry via electrochemically driven protonation–deprotonation within an imine‐linked two‐dimensional polymer framework, thereby dynamically rewiring interfacial electrostatics during cycling. During discharge, protonation of imine generates positively polarized C═NH + sites that stabilize I − through electrostatic interactions, enabling controlled reduction of polyiodides without accumulation. Upon charging, deprotonation restores the neutral framework, favoring polyiodide stabilization and efficient iodine oxidation. As a result, the constructed Zn–I 2 battery delivers 51 000 cycles at 20 A g −1 at 25°C and sustains over 70 000 cycles at −20°C. This durability is retained at a high iodine loading of 35.7 mg cm −2 , delivering an areal capacity of 5 mAh cm −2 over 2000 cycles with negligible decay, placing this system among the most durable Zn–I 2 batteries.

A low-temperature spray-cyclone system for zero-liquid discharge treatment of RO brine using extended two-phase CFD modeling and experimental validation

Chromium‐Catalyzed Stereodivergent Carbonyl Addition Dictated by Non‐Covalent Interactions

ABSTRACT Catalytic stereodivergent synthesis, which accesses the full complement of stereoisomers from a common precursor set, is a paramount objective in drug discovery. However, achieving this control via radical‐involved pathways remains a formidable frontier due to the transient nature of open‐shell intermediates. Here, we report a unified chromium‐catalyzed platform that harnesses a radical–polar crossover mechanism to achieve the fully ligand‐controlled stereodivergent synthesis of chiral β ‐fluoro alcohols. We demonstrate that the stereochemical outcome is not inherent to the substrate but is dictated by the ancillary ligand through distinct non‐covalent interactions: a chiral bisoxazoline ligand enforces a rigid transition state via fluorine‐mediated hydrogen bonding to selectively deliver syn ‐diastereomers, whereas a chemically distinct pyridine–imidazoline ligand exploits electronic desymmetrization via π–π stacking to invert selectivity toward anti ‐isomers. Notably, this protocol enables the programmable assembly of all four stereoisomers of fluorosugar derivatives.

Design of a novel reliable 9-level switched capacitor-based inverter with low voltage stress on the devices for renewable energy applications

Generalizable Strategies for the Synthesis of Cereblon‐Recruiting PROTAC Prodrugs

ABSTRACT Cereblon (CRBN)‐recruiting PROTACs (proteolysis‐targeting chimeras) are among the most clinically advanced degraders but remain challenging to chemically modify for translation to prodrug‐based delivery strategies. Here, we report three orthogonal approaches—triazole quaternization, tertiary‐amine alkylation, and installation of a hydroxyl linker—that enable chemoselective, high‐yielding syntheses of CRBN‐recruiting PROTAC prodrugs. These strategies allow incorporation of self‐immolative linkers whose cleavage kinetics can be predictably tuned to release the parent PROTAC, which is demonstrated in the context of PEGylated macromonomer and bottlebrush prodrug macromolecular scaffolds. In multiple myeloma models, representative PROTAC‐bottlebrush prodrugs (PROTAC‐BPDs) induce cellular potency profiles that follow the designed PROTAC release rates, confirming that the observed protein degradation and cytotoxicity arise from effective prodrug linker cleavage. Collectively, this work establishes generalizable approaches for constructing prodrugs of CRBN‐based PROTACs, expanding the synthetic space for targeted protein degradation and providing new design principles for controlling degrader activation, selectivity, and in vivo delivery.

Electro-thermal surface evolution in EDM of dissimilar stainless-carbon steel welds: parametric effects and micro-texture correlations

Organic Molecules in Zeolites for Long‐Lifetime Afterglow

ABSTRACT Organic afterglow materials based on host–guest assembly have recently attracted extensive attention for their promising applications in photobiology and optoelectronics, as well as their simple and versatile preparation. However, the poor stability of the host matrix limits their actual applications. In this study, a new class of long afterglow materials with AlPO 4 ‐5 zeolite as the host matrix and various aromatic acids (terephthalic acid, 2‐naphthoic acid, and 1‐pyrenecarboxylic acid) as guest molecules has been developed. The prepared composites exhibit tunable afterglow emissions across the visible spectrum from blue to green to red, with lifetimes of 919, 1540, and 74 ms and intensities approximately 42, 579, and 29 times higher than those of the corresponding pure organic molecular solid powders. Studies reveal that the efficient afterglow emission primarily stems from the effective dispersion and strong adsorption of organic molecules by the zeolite matrix, as well as the host–guest coordination interactions. Remarkably, the zeolite matrix endows the composites with excellent stability against radiation, solvents, acids, alkalis, and heat, together with potential for multimodal applications. Such a combination of properties is challenging to achieve with other matrix materials. This work establishes a novel strategy for developing long afterglow materials that integrate efficient emission, robustness, and multifunctionality.

Revisiting the inorganic component of bone: beyond the accepted concept of “mineral”

Abstract Bone is widely believed to be constructed of apatite with a composition close to that of hydroxyapatite. The mineral of bone is a made up of polycrystalline 5 nm-thick plates of a monoclinic crystal with a composition like that of apatite but differing from that mineral in most significant respects. Although it is a well-defined crystalline species with diagnostic shape, size, composition range and symmetry, it is not a new mineral because it is not known to grow in any known geological environment. It appears to be a different crystalline phase from apatite .

High‐Efficiency and Carbon‐Lean Electrochemical Desalination Enabled by Nucleophilic Engineering of Organic Molecular Electrode

ABSTRACT The worsening global freshwater crisis positions seawater desalination as a critical solution. However, conventional desalination technologies remain constrained by a persistent sustainability trilemma involving high energy consumption, chemical reliance, and substantial carbon emissions. Here, we present an electrochemical strategy that overcomes these constraints by delivering high‐performance desalination behaviors while generating substantial environmental and energy benefits. Our approach utilizes a molecularly nucleophilic‐engineered dinitro‐functionalized pyrenephenazine (PPZ‐2NO 2 ) organic electrode integrated in a capacitive deionization (CDI) cell, enabling real seawater desalination. The electron‐withdrawing nitro groups precisely modulate the electronic structure and electrochemical activity of the PPZ‐2NO 2 electrode, unlocking the full utilization of redox‐active sites. The resulting organic‐based CDI configuration possesses high salt ion adsorption capacity and ultrafast rate under low‐voltage operation without chemical additives. The validation at module scale demonstrates practical viability, producing industrial‐grade freshwater at a 97.2% yield ratio in compliance with World Health Organization (WHO) criteria, while achieving an exceptional seawater desalination capacity of 349.91 mg g −1 . Furthermore, the process operates with low energy consumption and a carbon footprint of only 0.147 t CO 2 eq per ton of salt removed, which is ∼61.18% lower than state‐of‐the‐art technologies. This work offers a molecular‐level design for carbon‐lean electrochemical desalination toward sustainable water‐energy integration.

A resilient and efficient authentication and key agreement protocol for medical IoT: the PSU-MAKA framework

Beyond PXRD Pattern Matching: Toward Rigorous Structure Determination in Covalent Organic Frameworks

ABSTRACT Widespread reliance on qualitative powder x‐ray diffraction (PXRD) pattern matching has led to systematic overinterpretation of covalent organic framework (COF) structures. As a result, structure–property relationships are often obscured, mechanistic conclusions can be misleading, and reported performance is not always reproducible. In this Perspective, we take a closer look at common weaknesses in current practice, focusing on mismatches between proposed structural models and the characterization data used to support them. Through representative case studies, we show how these inconsistencies arise and why they matter. We argue that more rigorous, evidence‐based approaches, achieved via complementary characterization techniques, are needed for reliable structure determination. We also emphasize the importance of transparent data reporting and deposition, and introduce a practical checklist to help authors, reviewers, and editors assess the strength of structural claims in COFs.

Task geometry alignment enables parameter independent and accurate genomic search

Abstract Standard sequence alignment models biological homology through the metric space of edit distance. While effective for global orthology, this rigid geometric assumption struggles with discrete biological realities–such as insertions/deletions (indels) and fragment-to-reference asymmetry–forcing a reliance on heuristic gap penalties. To address this, we propose Task-Geometry Alignment (TGA), a design principle that structurally aligns algorithmic representation with the intrinsic geometry of the biological task. We implement TGA in TGAlign , an expert-parameter-independent tool that tiles reference databases to match query lengths, encodes sequences into gap-robust syncmer profiles, and indexes them for high-speed Approximate Nearest Neighbor (ANN) search. Benchmarking against leading aligners (USEARCH, VSEARCH, MMseqs2) demonstrates performance strictly bounded by biological architecture. On standard substitution-heavy markers (COI), TGAlign achieves statistical parity with the state-of-the-art. Conversely, on sequence fragments and indel-heavy markers, TGAlign yields statistically significant accuracy improvements (up to 10% on 16S) while matching the peak performance of MMseqs2 on highly variable ITS datasets. By translating sequence comparison into dense matrix operations via ANN indexing, the current implementation maintains sub-millisecond query latency–an order-of-magnitude reduction over traditional aligners–providing a robust and scalable framework for post-alignment genomic search. Source code is available at https://github.com/JustinBooneLab/TGAlign and datasets are archived at Zenodo (DOI: 10.5281/zenodo.17973054).