Browse Articles

Minute‐Scale Repeated Metabolic Probing of Living Cells Enabled by Rapid Parahydrogen‐Based Hyperpolarization

ABSTRACT Hyperpolarized (HP) 13 C nuclear magnetic resonance (NMR) spectroscopy enables real‐time observation of metabolic fluxes but is typically limited to single‐shot measurements due to complex preparation procedures and low experimental throughput. Here, we established a rapid and experimentally accessible workflow for temporally controlled HP measurements in living cells. Using SABRE‐SHEATH at 0.4 µT, we achieved 7.7% ± 0.2% 13 C polarization of 50 mM [1‐ 13 C]pyruvate within 60 s. Simple 1:50 dilution with phosphate‐buffered D 2 O yielded cell‐compatible solutions that retained 5.3% ± 0.4% polarization of 1.3 mM pyruvate without multi‐step purification. Combined with a simplified agarose bead immobilization approach, this enabled four injections of HP pyruvate into the same HeLa cell population within 7 min. Under rapid (≈2 min) reinjection intervals, the pyruvate‐to‐lactate conversion progressively declined, whereas stable metabolic conversion was maintained at 20 min intervals with intermittent cell medium perfusion. These findings demonstrate that rapid repeated substrate delivery can transiently exhaust cellular metabolic conversion capacity. This experimentally accessible operating mode enables the study of short‐term metabolic dynamics that remain obscured in conventional single‐shot HP‐NMR or long timescale thermally polarized NMR measurements.

Deep Learning Enables Identification of Antimicrobial Peptides Through Mechanochromic Fingerprints

ABSTRACT Antimicrobial peptides (AMPs) are promising antibiotic alternatives, but their diverse modes of action make functional classification slow and labor‐intensive. Here we introduce a rapid and scalable strategy for AMP identification that integrates low‐cost, self‐assembled polydiacetylene (PDA) sensors with hyperspectral imaging and deep learning. AMP–PDA interactions generate mechanochromic spectral fingerprints that capture subtle differences in affinity, conformation, and penetration depth in membranes. Convolutional neural networks (CNNs) trained on full spectral datasets accurately distinguished seven AMPs at two concentrations with 96.79% accuracy, whereas conventional two‐wavelength colorimetric response failed entirely. The rich chemical information embedded across the entire visible wavelength spectral region reveals that mechanochromic polymers encode far more detail than previously recognized. These findings establish PDA mechanochromism, when paired with high‐throughput spectral imaging and deep learning, as a powerful and accessible platform for rapid AMP screening and, more broadly, as a foundation for scalable, information‐dense biosensing technologies.

Selective Electrosynthesis of High‐Concentration Mn ^IV ═O in Oxidant‐Free Systems for Sustainable Water Remediation

ABSTRACT High‐valent metal‐oxo (HVMO) exhibit selective oxidation properties, but their selective synthesis and high‐concentration aggregation remain challenging in oxidant‐free systems. This work employs sinusoidal alternating current (AC) to efficiently synthesize Mn IV ═O with water as an oxygen source. The positive half‐cycle continuously transforms H 2 O adsorbed on ≡Mn II site into high‐concentration HVMO through a multi‐step electron transfer and deprotonation process (≡Mn II −OH 2 →≡Mn II −OH→≡Mn III −OH→≡Mn IV ═O). The negative half‐cycle reduces the inactive Mn III generated during the consumption of Mn IV ═O back to the initial Mn II state and simultaneously alleviates proton accumulation. This AC strategy achieves stable cycling of the Mn oxidation state and effectively suppresses the overoxidation of ≡Mn III −OH to ≡Mn IV −OOH, thereby realizing the efficient preparation of HVMO with 99.3% selectivity and a steady‐state concentration of 2.8 × 10 −6  mM. Employing the selective removal of bisphenol A (BPA) as a model, Mn IV ═O can selectively oxidize target pollutants in the presence of interferents, achieving removal rates approaching 99% within 1 h. Stable operation in a continuous flow reactor scaled up by 40 times for over 100 h highlights the application potential of this strategy. This work reveals a novel green strategy to generate HVMO without rectification or additional oxidants for water purification.

Anchoring‐Induced Interphase via Dual Mortise‐Tenon Interactions for Synergistic Stabilization of Surface Co and O in High‐Voltage LiCoO ₂ Cathodes

ABSTRACT Interfacial instability of LiCoO 2 (LCO) above 4.6 V remains a bottleneck for high‐energy‐density batteries due to the coupled Co dissolution and O release. Here, inspired by mortise‐tenon structures, we propose a dual‐site cooperative anchoring strategy targeting Co and O lattice sites via atomic orbital‐level interactions. Through screening based on electronic structure and geometric compatibility, phenylmethylsulfonyl fluoride (PMSF) was identified as an optimal additive. Owing to its high HOMO level and precise spatial matching, PMSF undergoes site‐specific sacrificial oxidation prioritized at the LCO surface lattice. This dual‐site docking achieves directional orbital overlap with the surface Co and O sites, effectively lowering the activation energy for the formation of a uniform, ion‐conductive, and thin (∼5 nm) cathode electrolyte interphase. The resulting interphase acts as a robust chemical shield that suppresses Co dissolution and O loss simultaneously. As a result, LCO half‐cells with 0.3 wt% PMSF retained 61.9% capacity after 200 cycles at 4.8 V. Moreover, 1 Ah graphite||LCO pouch cells maintained 99.5% and 79.6% capacity after 300 and 600 cycles at 4.6 V, respectively. These findings demonstrate that dual‐site anchoring provides a pivotal guiding principle for transitioning from disordered decomposition to controlled, site‐specific interfacial assembly for next‐generation high‐voltage cathodes.

Underexplored Catalysts as General Structures: Application of Machine Learning Techniques for Reaction‐Specific Datasets

ABSTRACT General catalysts are usually identified through broad experimental screening to find structures that perform reliably across many substrates and reaction classes. In secondary amine organocatalysis, historical reporting is strongly skewed toward a small set of standard catalysts, leaving many plausible scaffolds underexplored and difficult to evaluate objectively. Here, we apply a bias‐aware machine learning workflow designed for small, uneven datasets to prioritize candidate general catalysts from limited historical data. Within the iminium‐based reaction space used to construct the curated and virtually balanced dataset, this analysis surfaced several high‐performing candidates, including a rarely studied imidazolidinone bearing a benzyl‐protected indole substituent. Despite minimal precedent, this scaffold performed competitively in experimental benchmarking and external transferability tests. In a retrospective analysis restricted to pre‐2005 examples, the same workflow prioritized catalyst families that later became widely adopted (e.g., diarylprolinol silyl ethers and imidazolidinones) among its top candidates, consistent with earlier prioritization from the literature available at the time. Together, these results show how bias‐aware modeling can highlight overlooked scaffolds and reduce the experimental burden required to identify broadly useful catalysts. Pairing targeted experiments with data‐driven prioritization provides a practical route to expanding the set of reliable secondary‐amine catalysts beyond the structures that dominate current practice.

Dual‐Boron Multi‐Resonance Thermally Activated Delayed Fluorescence Emitters Based on Spirofluorene‐Rigidified Indolocarbazole for Ultra‐Narrowband Luminescence

ABSTRACT Multi‐resonance thermally activated delayed fluorescence (MR‐TADF) emitters are a research focus for organic light‐emitting diodes (OLEDs) targeting ultra‐high‐definition displays. Expanding the multi‐resonance plane through multi‐boron structures enables emission color tuning and spectral narrowing, which rigid indolocarbazole moieties could further reinforce. However, excessive expansion of conjugated aromatic planes leads to severe aggregation‐caused quenching (ACQ). Herein, we combined the spirofluorene‐based multi‐resonance skeleton with indolocarbazoles as the bridging unit to construct a double‐boron architecture, aiming to utilize the three‐dimensional spatial rigidity of spirofluorene while suppressing intermolecular interactions in aggregated states. Three isomeric emitters were thereby obtained, with emission maxima at 524–565 nm. All emitters exhibit full widths at half‐maximum below 20 nm, with the narrowest being 17 nm, and these emitters maintain narrow‐band emission even at a high doping concentration of 6 wt%, where film spectral broadening is limited to within 3 nm. OLEDs based on these emitters display narrow bandwidths of 22–26 nm, the highest maximum EQE of 36.2%, and low efficiency roll‐off, corresponding to a high EQE of up to 30.2% even under ultra‐high luminance of 5 × 10 4  cd m −2 . This work confirms the feasibility of spirofluorene‐modified multi‐boron large‐plane multi‐resonance emitters and provides a reliable molecular design strategy for narrowband OLEDs.

Conversion of Alkenes Into Simple or Functionalized Aldehydes by Reaction With an Ambiphilic Masked Formyl Radical

ABSTRACT The synthetic application of formyl radicals and other masked formyl radicals is constrained by their weak electrophilicity ( ω = 1.17 eV for the formyl radical, ω = 0.58 eV for the •CH(OEt) 2 radical), which often results in a mismatched reactivity with unactivated alkenes. Herein, we develop two novel formylating reagents that overcome this limitation by generating an ambiphilic masked formyl radical, enabling the masked formylation of both activated and unactivated alkenes. The reaction initiates from the N─O bond homolysis of (benzoyloxy)‐(methylsulfonyl)methyl oxime ester reagents under the photocatalytic energy‐transfer strategy, releasing CO 2 to form a persistent iminyl radical and a transient ambiphilic (benzoyloxy)‐(methylsulfonyl)methyl radical as the masked formyl radical. Consequently, the aminoformylation, heteroarylformylation, and hydroformylation of alkenes can be achieved by adding the masked formyl radicals to olefins, followed by quenching of the formed carbon‐radicals by iminyl radicals, heteroarenes, and solvents, respectively. The resulting masked aldehydes are readily deprotected under mild basic or acidic conditions, affording simple or functionalized free aldehydes. Density functional theory (DFT) calculations confirm that the (benzoyloxy)‐(methylsulfonyl)methyl radical has superior electrophilicity ( ω = 1.82 eV) compared to conventional formyl radical equivalents.

Photochemical Cascade Nitrile Activation via a Carbene‐Nitrene Relay

ABSTRACT The deliberate integration of reactive intermediates into programmed bond‐forming sequences represents a powerful approach for advancing organic synthesis and enabling novel transformations. Among these intermediates, transient nitrene species are particularly attractive due to their capacity to generate two new X─N covalent bonds. However, the development of nitrene‐mediated reactions has been hindered by difficulties in controlling their high reactivity and the limited availability of efficient precursors. We hypothesized that a catalytic strategy enabling the sequential generation of carbene and nitrene intermediates could facilitate the cascade activation of common nitriles, thereby unveiling their latent potential as nitrene sources. In this work, we report a methodology for the catalytic generation of a sulfoxonium (S VI )‐substituted metal‐carbenoid, which undergoes reaction with nitriles to afford S VI ‐azirine species. Under photochemical and metal‐mediated activation conditions, these three‐membered strained rings rearrange to form vinyl metal‐nitrenoid intermediates. Subsequent B‐H insertion of the nitrenoid with boranes delivers tetra‐ substituted enamine products. The described approach proceeds with high efficiency and selectivity, traverses two highly reactive intermediates, and establishes an unprecedented activation mechanism for conventional nitrile substrates.

Construction of a Glutathione‐Gated Intelligent Nanoclassifier for Spatioselective Visualization of Dual CircRNAs and Synergistic Photodynamic Therapy

ABSTRACT Circular RNAs (circRNAs) are key endogenous regulators of tumorigenesis and progression, and their high interspecies diversity and strong sequence homology pose a great challenge for simultaneous, live‐cell differentiation of multiple circRNA variants. Herein, we construct an intelligent nanoclassifier (DB‐CHA@PAN) by assembling disulfide bond (DB)‐modified catalytic hairpin assembly (CHA) probes onto programmable cruciform framework‐based nanoparticles (PAN) for spatioselective visualization of dual circRNAs and synergistic photodynamic therapy. Upon entering cancer cells, GSH cleaves disulfide bonds to initiate multiple rounds of circRNAs‐fueled cyclic CHA cascades, inducing spatial separation of photosensitizer (PS)/BHQ3 and Cy3/BHQ2 pairs and consequently recovery of PS photodynamic activity and Cy3 fluorescence signal. Released PS can generate abundant singlet oxygen ( 1 O 2 ) upon light irradiation, inducing oxidative damage and apoptosis. This intelligent nanoclassifier enables attomolar‐level detection of circCDYL and circHIPK3 in vitro and simultaneous imaging of circCDYL and circHIPK3 in living cells. It can quantify circRNA levels at single‐cell sensitivity, discriminate circRNAs from mismatched variants with single‐base resolution, and even diagnose breast/lung cancer across entire clinical spectrum with 100% accuracy. Moreover, it can real‐time track circRNAs dynamics in living cells and MCF‐7 tumor‐bearing nude mice, and significantly enhance therapeutic efficacy via synergistic photodynamic activation, with promising applications in clinical diagnostics and therapeutics.

Central Core Engineering of Aromatic Carbonyl Molecules Enables Highly Efficient and Stable Perovskite Solar Cells

ABSTRACT Aromatic carbonyl molecules have emerged as highly effective passivation additives for fabricating efficient and stable perovskite solar cells. However, the influence of variations in the central core structure of aromatic carbonyl molecules on the passivation capability of their carbonyl groups remains insufficiently explored, thereby hindering the rational design of aromatic carbonyl‐based passivation additives. To address this limitation, we employed a central‐core engineering strategy to design three structurally similar molecules with different core groups. Through systematic investigation, we found that enhancing the electron‐donating ability of the molecular core increases the electron density on the carbonyl groups, thereby improving their defect‐passivation effectiveness. Consequently, perovskite solar cells incorporating TBPAA with the most electron‐rich core delivered power conversion efficiencies of 26.12% (0.09 cm 2 ) and 22.41% (14.0 cm 2 ), while retaining 95% of their initial efficiency after 1200 h of continuous maximum power point tracking at a temperature of 65°C under 1‐sun illumination (ISOS‐L‐2). This work highlights the critical role of the molecular central core in defect passivation and offers new molecular design guidelines for the development of highly efficient and long‐term stable perovskite photovoltaics.

Tunable Synthesis of Multi‐Responsive NH‐Containing Helical Nanographenes With a Chiroptical Switching Function

ABSTRACT Helical nanographenes (HNGs) have attracted much attention owing to their red‐region chiroptical properties. These HNGs, typically based on hexa‐peri‐hexabenzocoronene (HBC), are commonly synthesized via the Diels–Alder reaction followed by the Scholl reaction; however, the former generally requires harsh conditions (> 200°C), thereby limiting modular tuning and structural diversity. Here, we report the tunable synthesis of NH‐containing HNGs based on carbazole frameworks that enable π‐extension without protecting the NH group. Multifold Scholl reactions of 1,3,6,8‐tetrakis(oligophenyl)‐appended carbazoles, derived from a common 1,3,6,8‐tetrabromocarbazole platform, enabling uniform installation of arene units for π‐extension, afford HNGs through the formation of up to 12 C─C bonds at defined positions. The use of identical arenes suppresses regioisomer formation, while the symmetric framework enforces a single reaction pathway, avoiding regioisomeric scrambling. The resulting HNGs were successfully resolved into their enantiopure forms by chiral HPLC and exhibit distinct chiroptical properties. Notably, the unprotected NH groups enable a pronounced redshift and reversible on/off switching of circularly polarized luminescence (CPL) upon treatment with base and acid, respectively, indicating pH‐driven chiroptical switching. Furthermore, excited‐state proton transfer in dimethyl sulfoxide generates anionic species showing redshifted fluorescence and CPL even under neutral conditions.

Metabolic Labeling and Visualization of Isoprenoids Using Alkyne‐Modified DMAPP Analogs in <i>Bacillus subtilis</i>

ABSTRACT Isoprenoids are a chemically and functionally diverse class of metabolites that underlie essential bacterial physiology including respiration and cell envelope biogenesis. Chemical interrogation of isoprenoid metabolism remains limited because the two central five‐carbon (C 5 ) precursors, isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP) are highly polar and cell‐impermeant, rendering exogenous addition of them or functional analogs intractable. Here, we report the development of cell‐permeant alkynylated DMAPP precursors ( 1‐3 ) that enable DMAPP‐specific bioorthogonal labeling of isoprenoids in Bacillus subtilis . Growth rescue, toxicity profiling, and downstream incorporation analyses showed that alkyne geometry and substitution pattern strongly influence the metabolic suitability of DMAPP surrogates. We found that a directly substituted Z ‐alkynyl DMAPP analog was the only biosynthetically productive surrogate tested. Metabolic incorporation of this probe resulted in regiospecific labeling of membrane‐embedded isoprenoids, including menaquinone‐7 (MK‐7), bactoprenol, and tetraprenyl‐β‐curcumene. Pathway inhibition and supplementation assays demonstrate that the labeling efficiency of DMAPP surrogates is governed by competition with endogenous DMAPP and IPP. Lastly, post‐incorporation CuAAC derivatization enabled direct visualization of isoprenoid localization and targeted mass‐spectrometric profiling of labeled prenyl metabolites. These results establish a general chemical platform for bioorthogonal tagging of C 5 metabolism in B. subtilis .

Interstellar Ice Chemistry Yields Elusive Sulfinothioic Acid (HS(O)SH)

ABSTRACT Low‐oxidation‐state sulfur oxyacids are key yet experimentally elusive intermediates in interstellar sulfur chemistry; even the simplest member, sulfinothioic acid (HS(O)SH), has neither been detected in space nor isolated terrestrially. The S–S(O) motif, also present in biological systems, can be reduced to form disulfide bridges (RSSR’), suggesting potential astrobiological relevance. Here, we report the first formation of sulfinothioic acid in astrophysically relevant sulfur dioxide (SO 2 )–water (H 2 O) ices and its identification via isomer‐selective photoionization reflectron time‐of‐flight mass spectrometry combined with isotopic labeling. Irradiation of these ices at 5 K under ultrahigh vacuum with galactic cosmic‐ray proxies yields sulfinothioic acid. These results establish a missing link in interstellar sulfur chemistry and reveal a previously unrecognized class of astrochemically accessible sulfur oxyacids formed via radical‐mediated, non‐equilibrium processes driven by energetic particles in cold interstellar environments.

Number comparison in bilinguals is not affected by their second language

Abstract Language background can show subtle effects on number comparison even with Arabic digits. Number pairs can be decade-unit compatible, i.e. the decision about number size is the same for unit and decade (e.g. 24 and 57, 2 &lt; 5 and 4 &lt; 7), or decade-unit incompatible (e.g. 29 and 57, 2 &lt; 5 but 9 &gt; 7). Incompatible pairs often lead to longer response times. This compatibility effect is larger in languages with number word inversion (e.g. German). We aimed to investigate the influence of language on the compatibility effect in bilinguals. In Experiment 1, we compared the compatibility effect in German monolinguals and German-English bilinguals. We found a significant compatibility effect, but no significant differences between the mono- and bilinguals. In Experiment 2, we manipulated language activation within participants by asking German-English bilinguals to describe scenes either in English or German before completing number comparison trials. There was a significant cost of switching languages, showing that participants did activate German and English. However, the size of the compatibility effect was not significantly influenced by participants activating German or English. Overall, we did not find an influence of a bilingual’s language on number comparison with Arabic digits.

An NHC‐Coordinated Silicon/Sulfur Analogue of an Acyl Carbene

ABSTRACT Despite great advances in the chemistry of low‐valent silicon species, a silicon/sulfur analogue of an acyl carbene, namely a silathioacyl silylene, has remained elusive. Herein, we report that the reaction of dialkyldisilyne 1 with cyclic thiourea 2a affords 3 , an N ‐heterocyclic carbene (NHC) complex of a silathioacyl silylene. The solid‐state structure of 3 reveals a three‐membered ring with a markedly elongated Si─S bond and an Si–Si single bond, consistent with hitherto unknown intramolecular coordination of the silanethione sulfur to the silylene center, while computational studies indicate negligible disilathiirene character. Compound 3 exhibits silylene‐like reactivity toward xylyl isocyanide to give an NHC complex of an imino‐substituted silanethione.

Assessment of thermomechanical properties of CFRP laminates reinforced with nano-graphene, with and without phenol addition

Nitrogen‐Mediated Orbital‐Compatible π‐Extension: Balancing Excited‐State Components and Suppressing Vibrational Broadening Toward Redshifted Narrowband MR‐TADF Emitters

ABSTRACT BN‐based multi‐resonance thermally activated delayed fluorescence (MR‐TADF) emitters face a critical bottleneck in achieving redshifted narrowband emission complying with the BT.2020 standard. The widely used π‐extension strategy typically induces severe spectral broadening due to imbalanced, short‐range charge transfer (SRCT) and long‐range charge transfer (LRCT) components arising from non‐MR aromatic units. Herein, we establish a nitrogen‐mediated orbital‐compatible π‐extension strategy by incorporating sp 2 ‐hybridized nitrogen atoms at specific sites to construct BN‐core‐compatible MR π‐segments, thereby preserving the persistent MR character across the entire skeleton. Starting from BN‐TP, three derivatives ( BNCz‐BQ , BNCz‐PQ , BNCz‐PMQ ) were synthesized and theoretically screened. Notably, BNCz‐PQ exhibits balanced HOMO/LUMO contributions of 9.00%/8.20% on its π‐extended fused segment, the lowest LRCT fraction of 17.34%, and a reorganization energy of 408.6 cm − 1 , markedly outperforming BNCz‐BQ and BNCz‐PMQ . Such site‐specific N‐doping effectively suppresses low‐frequency vibrations and out‐of‐plane torsions that dominate broadening in BN‐TP. Consequently, BNCz‐PQ emits intense green light with an ultranarrow FWHM of 24 nm, 10 nm narrower than that of BN‐TP. The corresponding OLEDs achieve a maximum EQE of 27.7% with greatly suppressed roll‐off, retaining 27.1% and 23.6% at 1000 and 10 000 cd m − 2 . This work establishes a general orbital‐guided principle for designing high‐performance long‐wavelength narrowband MR‐TADF emitters.

Improving wind power prediction performance using the SKB-FA-XGB method based on hybrid feature selection

Reprogramming Ion‐Transport Dimensionality via Crystal‐Channel Engineering to Stabilize Zinc Anodes

ABSTRACT Unstable zinc (Zn) deposition in aqueous zinc‐ion batteries is intrinsically linked to the interfacial confinement of Zn 2+ transport, where ion migration is dominated by lateral diffusion along the electrode surface. This quasi‐two‐dimensional transport amplifies local electric‐field and concentration heterogeneities, leading to uneven nucleation and dendritic growth. Here, we demonstrate that Zn deposition can be fundamentally regulated by reprogramming the dimensionality of ion transport. A three‐dimensionally interpenetrated covalent organic framework (COF) incorporating crown‐ether moieties is embedded into a hydrogel electrolyte. The confined macrocyclic sites selectively coordinate Zn 2+ and partially displace solvating water molecules, while the interconnected crystalline channels enable continuous, isotropic bulk ion migration. This architecture converts Zn 2+ transport from interface‐limited diffusion to bulk‐governed three‐dimensional flux, resulting in intrinsically uniform Zn deposition. Consequently, symmetric Zn cells exhibit stable cycling for over 2000 h at 1 mA cm −2 , and Zn||NH 4 V 4 O 10 full cells retain 81.6% of their capacity after 3000 cycles. These findings identify ion‐transport dimensionality as a key descriptor for metal‐deposition stability and establish a general electrolyte‐engineering strategy that transcends conventional regulation.

Adverse and positive childhood experiences and dental pain in adulthood: a cross-sectional study