Browse Articles

Construction induced responses of the high speed railway subgrade to undercrossing by a large section mined metro tunnel

Spinterface-like Mechanism of the Chirality-Induced Spin Selectivity in Donor–Chiral Bridge–Acceptor Complexes

Abstract The chirality-induced spin selectivity (CISS) effect has been invoked to explain recent reports of differences in the time-resolved EPR signals between chiral and achiral molecules. However, the microscopic origin of these differences and their connection to CISS remain contested, particularly since these systems lack a metal interface. Here, we introduce an intramolecular spinterface-like mechanism that naturally arises within donor–chiral bridge–acceptor (D−χB–A) complexes and quantitatively reproduces experimentally reported observed spin polarization in time-resolved EPR studies. In our two-electron Lindblad model, the photoexcited charge-transfer electron traversing the chiral bridge exchanges with the residual donor electron, which acts as a localized magnetic moment analogous to an induced magnetic moment on an electrode surface. The resulting through-bridge charge current produces an effective solenoidal field at the donor–bridge interface, breaking spin degeneracy and directional symmetry, thus enabling spin-selective transport without invoking intrinsic spin–orbit coupling on the bridge. We show that the interplay among this current-induced field, donor thermalization (which breaks time-reversal symmetry), and bridge spin mixing yields tens-of-percent polarization over realistic experimental conditions and charge-transfer time scales, matching reported CISS signatures in triads and DNA hairpins. By explicitly resolving the dependence on solenoidal coupling strength, temperature, and spin-mixing rates, the model identifies the regime in which internal spinterfaces can generate robust CISS-like spin filtering. These findings demonstrate that CISS-like signals in isolated D−χB–A complexes are fully compatible with a spinterface mechanism, providing a unified conceptual framework for interpreting both device-based and molecule-internal CISS platforms.

Microstructure-driven description of drug release in tablets containing solid dispersions

Abstract In pharmaceutical formulations, the description or prediction of the final drug form (i.e. tablet) performance remains challenging when relying solely on material or process input parameters. Tablet microstructure analysis offers a beneficial alternative, particularly when solid dispersions are in the formulation. They provide a way to enhance drug bioavailability via partial or full amorphisation of the active substance (API) and stabilisation of the amorphous form. Moreover, they can have specific particulate properties that favour tablet performance description via microstructure (deformability due to higher amounts of polymer - especially in hot-melt extrudates). The purpose of this work was to apply an image-based method for tablet microstructure description to model systems containing solid dispersions. Two binary systems containing solid dispersion of API prepared via hot-melt extrusion and CaHPO 4 ∙2H 2 O were tested. One, containing API rivaroxaban, varying extrudate properties (particle size, plasticiser content) with fixed tablet composition, the second with fixed extrudate properties and variable composition containing API indomethacin. When tablet composition remained constant, extrudate characteristics dominated tablet performance description over tablet microstructure and porosity. With fixed extrudate properties, the application of the image-based microstructure evaluation method proved to be sensible and provided further insight into its application. For the tested combination of indomethacin-Kollidon VA64 extrudate with excipient CaHPO 4 ∙2H 2 O, the best description of dissolution properties was achieved using the d (10) values (excipient observable areas on tablet cross-sections). The obtained results extend the previously proposed microstructure-based approach for describing dissolution performance to solid-dispersion-based tablets, providing a more specialised possible model system.

Structural Chemistry of [V2As17]3– and [V2Sb17]4–: A Complex Interplay between V-Pn and Pn-Pn Bonding

Abstract The ability of the heavier pnictogen elements, P, As, Sb and Bi, to form extensively catenated structures is well established, and a wide range of architectures is known, both for the isolated ions and for their coordination complexes. In this work, we report two new vanadium clusters, [V2As17]3– and [V2Sb17]4–, which contain crown-like VPn8 units, linked by a single bridging atom. Reaction monitoring using ESI-MS suggests a growth pathway involving both VPn8 and VPn9 units, the latter appearing transiently in the reaction mixture. Density functional theory reveals that the redox-active orbital has Pn–Pn antibonding character: the two clusters can therefore be considered to map a segment of the potential energy surface linking the entirely separated fragments to a single fused Pn17 unit.

Reprogramming ThDP Enzymes for <i>Z</i> -Alkenes: Overriding Thermodynamic Preference via Noncovalent Controls

Abstract Most conventional alkene synthesis reactions (e.g., elimination et al.) inherently favor the formation of thermodynamically more stable E-isomers, posing a long-standing challenge for direct access to Z-alkenes. Here, we report the reprogramming of a thiamine diphosphate (ThDP)-dependent enzyme to catalyze a formal dehalogenative elimination that overrides this intrinsic thermodynamic bias, enabling the direct and selective synthesis of Z-α,β-unsaturated carboxylic acids. In contrast to classical approaches that rely on substrate control, directing groups, or complex ligand architectures, our strategy harnesses the enzyme’s confined active site to achieve kinetic control exclusively via noncovalent interactions─representing a fundamentally distinct and more sustainable approach to stereochemical programming. This transformation diverts the enzyme from its native function in C–C bond formation by channeling the Breslow intermediate toward a homoenolate-mediated pathway, wherein specific noncovalent interactions stabilize the syn-periplanar geometry required for Z-selective dehalogenative elimination. Through rational active-site engineering, the stereochemical trajectory can be inverted to furnish the complementary E-isomer, enabling stereodivergent synthesis from a common scaffold. This work establishes a biocatalytic platform that addresses a critical gap in Z-alkene synthesis, expands the catalytic repertoire of ThDP-dependent enzymes, and provides a sustainable alternative to conventional methodologies.

Dual bispecific protein engagers targeting mesothelin and NECTIN2 deliver CD3/CD28 signals to activate cytotoxic T cells against colorectal cancer patient-derived organoids

Pulse-Driven Paired Electrosynthesis of Formamide via Redox-Tuned Intermediate Management

Abstract Renewable electricity-driven electrocatalytic systems hold promise for the sustainable formamide (HCONH2) synthesis. However, a major bottleneck remains the low Faradaic efficiency (FE) and overall electron utilization inherent to current unipolar C–N coupling strategies, where substantial electron consumption at the counter electrode severely limits system efficiency. Here, we propose a redox-tuned paradigm (Ared+ Boxi→ C) through a pulsed paired electrosynthesis strategy. Using an atomically ordered CuPd catalyst with CH3OH and NO2– as feedstocks in an undivided cell, HCONH2 is simultaneously produced at both electrodes under optimized pulse conditions with alternating change in potential periodically (Ea = 1.3 V, ta = 10 s; Ec = −0.7 V, tc = 10 s). This system achieves an FE of 85.6% for HCONH2 at a current density of 81.5 mA cm–2, with a yield of 263.3 μmol·h–1·cm–2. The FE is higher than those reported to date. Mechanism studies reveal that pulsed operation creates a periodically switching cathode/anode environment. This enables the ordered CuPd catalyst to function sequentially as a reduction site (converting NO2– to *NH3) during cathodic pulses and as a co-oxidation site (converting *NH3 to *NH2 along with CH3OH to *HCOH) during anodic pulses, thereby driving efficient C–N bond coupling to form HCONH2. Techno-economic analysis further confirmed the significant industrial potential of this strategy in the future renewable energy market.

All-optical single-shot mapping of cluster radius and density in an axisymmetric gas jet

Abstract We demonstrate an all-optical, single-shot diagnostic enabling spatially resolved two-dimensional reconstruction of cluster radius and number density in a cryocooled deuterium jet. Conventional characterizations based on one-dimensional mechanical scanning or projection-only measurements obscure local heterogeneity and complicate quantitative interpretation of cluster formation and scaling. By combining Mach–Zehnder interferometry and Rayleigh scattering with Abel-based tomographic reconstruction, we retrieve local maps of cluster size and density across an extended cross section of the jet in a single acquisition. The measurements reveal that the cluster radius remains nearly uniform (~11 nm) within the jet interior despite pronounced radial and axial density gradients, indicating that nucleation is largely completed near the nozzle exit while subsequent expansion predominantly governs density evolution. This spatial decoupling between cluster size and density demonstrates that region-dependent averaging can substantially bias inferred scaling relations. The resulting scan-free tomographic framework establishes a physically consistent basis for analyzing nucleation and growth in cryogenic cluster jets and for quantitative, region-selective optimization in laser–plasma applications.

The sense of self shapes the impact of environmental factors on technostress and mental health: a two-wave longitudinal study

Efficient Synthesis of N-Bridged Annulenes

Abstract The most commonly encountered aromatic structure is the benzenoid ring, which is observed in a wide variety of pharmaceuticals and organic materials. However, studies on nonbenzenoid conjugated polyene aromatic molecules remain scarce, largely due to synthetic challenges and inherent angle strain. Herein, we report an unprecedented single-copper relay dual-catalyzed cascade sequence for the efficient construction of a unique aromatic N-bridged [10]annulene (NBA) framework (also called cycl[3,2,2]azine), in which a copper-catalyzed 10π electrocyclization is involved. To gain insight into the reaction mechanism, a series of control experiments and density functional theory calculations were conducted. The developed reaction exhibits broad functional-group tolerance and can be extended to different classes of 14π components. Significantly, the resulting NBA compounds display strong fluorescence with full-color tunability. Therefore, these innovations not only deepen our understanding of the aromaticity of nonbenzenoid systems but also highlight the potential of metal-catalyzed electrocyclization in synthetic chemistry.

A new hybrid uncertainty controlling framework for optimal scheduling of power-gas networks connected to industrial energy hubs considering hydrogen vehicles and flexibility resources

Identifying Disordered Intermediates in the Reaction of Cu3– <i>x</i> P and Dibenzyl Diselenide to form Cu3PSe4 Nanoparticles

Abstract Developing a detailed understanding of ternary nanoparticle (TNP) formation is essential for their optimized rational synthesis and development of synthetic routes for new TNPs. Herein, we explore the reaction of Cu3–xP and dibenzyl diselenide (Bn2Se2) to form colloidal Cu3PSe4 TNPs. Temperature-resolved X-ray scattering (XRD and PDF), electron microscopy (TEM and STEM), and spectroscopy (EDS, EELS, XPS, and MAS NMR) reveal that Cu3–xP reacts by surface coordination of Se leading to fragmentation followed by rearrangement to Cu–Se binary phases, during which all obvious crystalline P-containing phases disappear via XRD. However, partially oxidized P in solid phases was observed using STEM-EDS and XPS, in which P is found to preform P–Se bonds prior to Cu3PSe4 formation. Using a combination of 31P MAS NMR and PDF analysis obtained from synchrotron total scattering data, P–Se bonds in [PSe4]3– tetrahedral building blocks were identified within intermediate Cu–Se phases containing P cation substitution (PCu), denoted (Cu,P)–Se, that assemble into Cu3PSe4. We hypothesize that these intermediate compounds with their substoichiometric, vacancy-rich structures and significant Cu disorder are important for accessing Cu3PSe4─offering a new insight into complex TNP syntheses. We summarize our findings by writing plausible pseudoelementary steps (PESteps) in which the Cu3–xP precursor converts to smaller fragments of Cu–Se phases containing P en route to the final Cu3PSe4 product. Additional interesting aspects of this system include the use of Bn2Se2 as a readily monitorable probe for the reaction and the Se–P bond formation that facilitates Cu–P bond cleavage in an overall 8-electron redox reaction involving P3– and 4 Se0. The results obtained lay the groundwork for future mechanistic investigations, notably kinetics studies working from the PESteps aimed ultimately at the rational design and synthesis of complex ternary pnictogen chalcogenide nanoparticles.

Association of the red blood cell distribution width-to-albumin ratio with subsequent cognitive impairment and adverse cognitive trajectories in older adults

Abstract The red blood cell distribution width-to-albumin ratio (RAR) is an index reflecting inflammatory and nutritional status. While prior studies reported cross-sectional associations between RAR and cognitive performance, its link to future cognitive outcomes has yet to be determined. Our research assessed the longitudinal associations of baseline RAR with subsequent incidence of cognitive impairment and with multi-year trajectories of cognitive change. This longitudinal cohort study included 5896 participants aged over 60 years from the Health and Retirement Study. During a 6-year follow-up, baseline RAR was examined in relation to incident cognitive impairment and membership in distinct cognitive trajectories identified with group-based trajectory modeling. Associations were assessed using multivariable Cox and logistic regression after adjustment. Restricted cubic splines (RCS) were also used to examine dose-response relationships, and we conducted sensitivity analyses to evaluate the stability of findings. During Follow-up, we identified 1586 incident cases of cognitive impairment and three distinct cognitive trajectories: High-stable (40.47%), Middle-slow decline (43.14%), and Low-rapid decline (16.39%). After full adjustment, one unit increase in baseline RAR was linked to a 18% higher incidence of cognitive impairment (HR = 1.18; 95% CI 1.06–1.31), and RCS analysis indicated the association to be linear ( P for non-linearity = 0.851). An elevated baseline RAR was also associated with a greater likelihood of membership in the Middle-slow decline (OR = 1.22; 95% CI 1.06–1.40) and Low-rapid decline (OR = 1.27; 95% CI 1.05–1.52) groups, relative to the High-stable group. In addition, these associations were consistent across all examined subgroups (all P  &gt; 0.05) and remained robust in sensitivity analyses. Within this study population, a higher RAR was associated with increased risk of cognitive impairment and membership in unfavorable cognitive trajectories. RAR therefore warrants further investigation as a potential indicator of susceptibility to long-term cognitive decline.

Reaction Medium as an Architect of Nanocrystal Superlattices

Abstract Nanocrystal superlattices are commonly formed by changing concentration, solvent conditions, or particle surface chemistry. Although effective, these approaches alter multiple contributions to the interparticle potential simultaneously, making it difficult to isolate the interactions responsible for ordering or to control assembly in chemically complex environments. Here, we show that oligomeric species present in a nanocrystal reaction medium drive superlattice formation through a depletion mechanism. Using PbTe nanocrystals as a model system, we identify Pb–oleate oligomers in the crude reaction mixture, characterize their solution structure, and quantify their contribution to the interparticle potential, establishing depletion as the dominant short-range interaction governing spontaneous body-centered cubic superlattice formation. We then confirm the depletion origin of ordering by showing that varying depletant concentration predictably shifts the order–disorder boundary and produces a thermally reversible transition between dispersed and ordered states ─ behavior that is inconsistent with van der Waals or ligand-mediated mechanisms but is a direct consequence of depletion control. Having established and validated the mechanism, we demonstrate that the same depletion framework can be deliberately activated in purified dispersions and transferred across nanocrystal systems of different composition and shape, including anisotropic and binary assemblies. These results establish precursor-derived depletion as a general and chemically grounded mechanism for nanocrystal superlattice formation, and show that collective ordering can be programmed through the surrounding medium rather than through particle surface modification.

Correction: Fabrication of atomically flat cleavage planes with ultrafast laser scribing

Impact of urban air ultrafine particles on embryonic development and their association to transport emissions

Abstract Airborne ultrafine particles (UFP) constitute a potential risk factor for human health, being transport one of the most relevant sources, particularly in urban environments. We collected UFP from outdoor sites in Barcelona and Valencia (Spain) that were differently impacted by air pollution from road traffic, trains, ships, or planes. Zebrafish embryos were exposed to organic extracts from collection filters, and their transcriptomes were analysed by RNA deep sequencing. Functional analysis of 2,941 significantly affected transcripts revealed a strong enrichment in functions related to general embryotoxicity, like induction of degradation pathways (endocytosis, necroptosis), and inhibition of development- and cell division-related genes. This embryotoxicity-related transcriptional response was linked to samples exhibiting elevated concentrations of UFP and several inorganic and organic pollutants. It was particularly strong in airport samples, which were relatively poor on aromatic polycyclic hydrocarbons (PAHs). The functional analysis also identified a relatively small subset of genes configuring a typical dioxin-like response linked to PAH-rich emissions from harbour and traffic samples. Our findings indicate that the parameters currently used to assess air quality overlook the contribution of UFP and other non-regulated pollutants in the total airborne toxicity and, therefore, they do not adequately protect human populations.

Ultrabright Near-Infrared Lead-Free Perovskite Light-Emitting Diodes with Negligible Efficiency Roll-Off

Abstract Lead-free halide perovskite semiconductors show great promise for light-emitting diodes (LEDs), benefiting from tunable optoelectronic properties and solution processability. However, their practical applications in high-current-density LEDs are fundamentally constrained by severe efficiency roll-off, primarily caused by nonradiative recombination and carrier-induced structural instabilities. In this study, we introduce a molecular N,N′-diphenylthiourea (DPTA)-engineered tin perovskite semiconductor (CsSnI3) that achieves a photoluminescence quantum efficiency (PLQE) of 36% at a carrier concentration of 1018 cm–3. Our approach enables precise control over the charge-carrier concentration and lattice growth. High-resolution transmission electron microscopy further demonstrates that the uniform local strain distribution in the doped films enhances carrier wave-function overlap, leading to a substantial boost in PLQE. Leveraging the enhanced optoelectronic properties of DPTA-treated CsSnI3, we fabricate near-infrared LEDs that exhibit an external quantum efficiency (EQE) of 13.4% and an unprecedented peak radiance of 1248 W sr–1 m–2, with minimal efficiency roll-off even at high current densities exceeding 3500 mA cm–2 in pulse-mode operation. This work introduces a new material-doping strategy for lead-free perovskites, demonstrating their potential for high-power optoelectronic applications and advancing the feasibility of electrically pumped perovskite laser diodes.

Circulating SDF4 as a potential diagnostic marker for early-stage pancreatic cancer

Highly Dynamic Yet Stable Polyketimine Networks with Closed-Loop Recyclability and Topological Programmability

Abstract Closed-loop recycling via depolymerization has emerged as a promising strategy to mitigate plastic pollution. Ideal recyclable polymer networks should feature highly dynamic bonds that depolymerize efficiently into monomers/oligomers. However, this intrinsic bond lability inevitably introduces a critical trade-off, as it typically undermines the material’s stability. In this work, we design a polyketimine network that can be closed-loop recycled under mild conditions, without the need for consumable reagents or catalysts, while retaining robust mechanical properties during use. At the molecular level, hindered ketimine bonds remain sufficiently labile to depolymerize back to the designed oligomers, due to the steric hindrance from the ketone and amine reactants. At the network level, however, hydrophobic phases block water ingress, effectively “locking” the network and preserving mechanical performance even under harsh conditions (85 °C, 85% relative humidity, 48 h). When recycling is desired, a compatible organic solvent disrupts these hydrophobic phases, allowing water to penetrate the network and trigger depolymerization. Consequently, depolymerization and repolymerization cycles can be conducted using only easily recoverable water and solvents under mild conditions. By leveraging this dynamic chemistry, the synthesized polymers can be disassembled and reassembled into diverse network topologies, corresponding to a Young’s modulus that spans 6 orders of magnitude. Our work demonstrates that intrinsically labile dynamic bonds can be harnessed to build stable materials with tunable properties, offering a versatile platform for next-generation closed-loop recyclable polymers.

Molecular dynamics simulation of polymer-ceramic composites for the prediction of mechanical properties by investigating the role of binders in 3D printing applications