Browse Articles

Biocatalytic Regioselective C‐Formylation of Resorcinol Derivatives

ABSTRACT Although aromatic formylation reactions are highly valuable from a synthetic perspective, a biocatalytic version has not yet been reported. Here, the cofactor‐independent multimeric three‐component acyltransferase from Chromobacterium sphagni ( Cs ATase) was identified to enable the nonnatural promiscuous regioselective C‐formylation of polyphenolic substrates, especially resorcinol derivatives, and thus extending the reaction scope of acyltransferases. Formylation of 4‐ and 5‐substituted resorcinol derivatives gave access to regioselectively mono‐formylated products with up to 99% conversion and up to 74% isolated yield. Formylation of phloroglucinol led to the di‐formylated product with 99% conversion, outperforming chemical methods. Structural analysis of Cs ATase by X‐ray crystallography provided insights into its active site.

Types identification, patterns characterize and pathway optimization of synergistic development between urbanization and pollution control in Chinese urban agglomerations

Enhanced optical and electrical properties of polyvinyl alcohol polyethylene oxide nanocomposite films incorporating hybrid carbon nanofillers

Upcycling of atmospheric CO2 to self-healing recyclable polymers under ambient conditions

Abstract The polymer industry is confronting an urgent sustainability trilemma: accelerating plastic pollution, substantial CO 2 emissions from production processes, and dependence on diminishing fossil resources. Upcycling CO 2 into polymers presents a promising solution to these interconnected issues; however, existing CO 2 -to-polymer technologies face significant challenges: dependence on concentrated CO 2 sources rather than direct air capture (DAC), reliance on complex catalysts and energy-intensive conditions (elevated temperatures/pressures), and generation of polymers with limited self-healing and recyclability. Herein, we propose a catalyst-free strategy of converting atmospheric CO 2 into carbonate ions (CO 3 2- ) as intermediates for the synthesis of dynamic covalent polymers. This approach is based on a dynamic bond system, termed the CO 3 2- -bridged dynamic covalent bond, enabling catalyst-free synthesis of polymers from ambient air at room temperature and pressure. The resultant polymers show excellent mechanical properties, rapid self-healing, and versatile circularity through three distinct pathways: thermal reprocessing, closed-loop chemical recycling via acid-triggered depolymerization at room temperature, and upcycling of mixed CO 2 -derived polymers into hybrid materials with enhanced properties. This study provides a platform for both low-energy-consuming CO 2 valorization and the development of sustainable polymers.

3DViT-GAT: a unified atlas-based 3D vision transformer and graph learning framework for major depressive disorder detection using structural MRI data

Rab14 restricts pathogens by promoting V-ATPase lysosomal delivery to drive lysosomal acidification

Construction of Agonistic Bivalent Double‐Stranded Aptamers Targeting c‐MET

ABSTRACT Aptamers, single‐stranded oligonucleotides selected via SELEX technology, exhibit high‐affinity and selective binding to target molecules by folding into specific intramolecular tertiary structures. Importantly, aptamers can inhibit target biological functions when their binding disrupts the interaction between the target and its natural ligand. However, aptamers capable of activating target molecule functions remain rare. In this study, we performed molecular engineering on the c‐MET aptamer HF3‐58, previously identified as biologically inert. Through rational design, we successfully developed a series of bivalent double‐stranded aptamers (BVDSApts) with enhanced c‐MET binding, while their single‐stranded counterparts failed to bind c‐MET. By optimizing the central duplex length to 18, 20 and 22 base pairs (bp), these aptamers potently induced c‐MET dimerization, phosphorylation, and downstream protein phosphorylation, while significantly enhancing cell migration and dispersion. The process of reconstructing biologically inert aptamers to obtain those with agonistic activity demonstrates that, with a thorough understanding of the binding mechanisms, it is possible to design new aptamers with novel functions through sequence engineering. Additionally, the BVDSApts obtained provide precursor molecules for the further development of HGF substitutes.

Exceptional Two‐ to Five‐Photon Absorption at Mono/Bis(Donor)‐Porphyrin‐Mono/Bis(Donor) Triads and Pentads

Abstract Porphyrins are key components of biologically‐active molecules involved in oxygen transport, light harvesting, and electron transfer; their photophysical properties are consequently of considerable fundamental interest. We herein report that certain donor‐porphyrin‐donor triads and bis(donor)‐porphyrin‐bis(donor) pentads exhibit nonlinear optical activity toward femtosecond pulsed radiation over the spectral range 800–2150 nm. We show that these triads and pentads exhibit unusually strong molecular quadratic optical nonlinearity, two‐photon absorption, and three‐photon absorption, and represent a new molecular motif exhibiting four‐photon absorption. We also report the first porphyrins, and therefore a new class of molecule, to exhibit five‐photon absorption. The two‐, three‐, four‐, and five‐photon absorption maxima are found close to the corresponding multiples of intense linear absorption bands that time‐dependent density functional theory assigns as admixtures of porphyrin‐localized π* ← π and donors‐to‐porphyrin charge‐transfer transitions in the case of the donor‐porphyrin‐donor triads.

A large-effect locus underlies migration timing in North American Atlantic salmon (Salmo salar)

Abstract The timing of migration often aligns with predictable seasonal or environmental cues, allowing populations to maximise fitness by moving between habitats at optimal times. However, rapid environmental change is disrupting this predictability, leading to mismatches between expected and observed conditions with potential demographic consequences. Atlantic salmon are long-distance migrators that travel between freshwater and oceanic habitats and are experiencing widespread declines across their range. Our understanding of the genetic basis of run timing in Atlantic salmon has been limited to European populations, or at a coarse population level. We combine whole-genome sequencing of 498 individuals from seven North American populations with individual migration timing data to explore the genomic basis of adult return timing. We identify a large-effect region on chromosome 17 associated with migration timing (unimodal or bi-model), with ppfia2 explaining a substantial proportion of the variation, as well as an underlying polygenic basis to this complex life-history trait. These findings demonstrate a clear genomic basis for migration timing in Atlantic salmon, with the associated ppfia2 gene also playing a role in other long-distance migratory vertebrates. This suggests a potentially conserved evolutionary mechanism underlying migration timing across species and highlights the importance of genetic insights for understanding population resilience and declines in Atlantic salmon.

Measurement of ion acceleration and diffusion in a laser-driven magnetized plasma

Abstract Here we present results from an experiment performed at the GSI Helmholtz Center for Heavy Ion Research. A mono-energetic beam of chromium ions with initial energies of  ~ 450 MeV was fired through a magnetized interaction region formed by the collision of two counter-propagating laser-ablated plasma jets. While laser interferometry revealed the absence of strong fluid-scale turbulence, acceleration and diffusion of the beam ions was driven by wave-particle interactions. A possible mechanism is particle acceleration by electrostatic, short scale length kinetic turbulence, such as the lower-hybrid drift instability.

The role and regulatory mechanism of USP25 in pancreatic microcirculatory disturbance in severe acute pancreatitis

Spatiotemporal photon distribution control on active sites enables bio-inspired methane-to-methanol conversion

Highly Efficient Deep‐Blue Room‐Temperature Phosphorescence With Tunable Long‐Lived Afterglow and Reversible Photoactivation Behavior

ABSTRACT Wide band gap organic molecule with ultralong room‐temperature phosphorescence (RTP) remains a big challenge in optoelectronic field due to the intrinsic large Stokes shift of phosphorescence relative to fluorescence, and complexity of filling and stabilizing high‐energy triplet excited states. In this work, three organic small molecules, MSPA , BSPA , and TSPA , based on succinimide and triphenylamine groups are designed and synthesized, and deep‐blue RTP with reversible photoactivation properties is successfully realized by physically doping them into polyvinyl alcohol (PVA) matrix. Notably, MSPA ‐doped film exhibits RTP at 440 nm with ultralong lifetime of 1403 ms and phosphorescence quantum yield as high as 14.32%. Theoretical calculations reveal that the efficient intersystem crossing and strong intermolecular hydrogen‐bonding interactions leads to the ultralong RTP in MSPA /PVA doping system. Taking advantages of the wide band gaps, tunable organic afterglow, and reversible photoactivation behaviors of MSPA , BSPA , and TSPA , the amorphous and flexible films are prepared and show potential applications in photoactivated information encryption, advanced anti‐counterfeiting, and multicolored displays through triplet‐to‐singlet Förster energy transfer. This work provides a reliable strategy to realize high‐performance wide band gap RTP materials and further broadening practical applications in organic optoelectronic information.

Nonalcoholic fatty liver disease assessed by multiple tools are correlated to periodontal conditions

The key role of nanoparticle concentration gradient in aerosol initial growth

Abstract New particle formation has been estimated to produce more than half of the global cloud condensation nuclei and profoundly impacts clouds, climate, and air quality. The initial growth from the cluster size ( ~ 1 nm) to a few nanometers, for which the underlying mechanisms can be very different from the subsequent growth, is the most critical stage for new particles to become climate-relevant. However, initial growth mechanisms evidenced by controlled laboratory experiments can rarely explain observations from the real atmosphere. Here we show that a large nanoparticle concentration gradient in the size space can drive unexpected rapid initial growth based on measurements across the globe. It accelerates the condensation of globally abundant oxygenated organic molecules onto a population of new particles compared to a single particle, and substantially increases the fraction of new particles that survive to climate- and air-quality-relevant sizes. Our findings provide insights into explaining the puzzle of the frequent new particle formation events in polluted urban environments and indicate an even more important role of new particle formation in climate predictions.

Iridium‐Catalyzed Enantioselective Allylation of Alkynylboronates to Access Chiral 1,4‐Dienes

ABSTRACT Skipped dienes, particularly 1,4‐dienes, play significant roles in pharmaceuticals and organic synthesis as they serve as key intermediates for the construction of complex structures and also bioactive molecules. However, the catalytic assembly of this motif with high stereoselectivity from readily available starting materials remains a substantial synthetic challenge. Herein, we reported a direct iridium‐catalyzed enantioselective allylation reaction with allylic electrophiles and alkynyl boronates, resulting in various 1,4‐dienes with excellent Z/E ratios and enantioselectivity. The reaction proceeds through a concerted mechanism that involves an allylation‐induced 1,2‐migration of the alkynyl boronate, followed by a syn ‐addition of the migrating group and Ir( π ‐allyl) complex across the alkynyl fragment to selectively deliver the more challenging Z‐alkenes. DFT calculations clarify the origins of the observed high chemo‐ and stereoselectivity. Furthermore, this method demonstrates a broad substrate scope, and the resulting enantiomerically enriched 1,4‐diene products can be readily derivatized.

Green synthesis of silver nanoparticles from Eichhornia crassipes and evaluates their antimicrobial properties against multidrug-resistant UTI pathogens

Reversible surface modifications of functional proteins for accelerated cytosolic delivery via cell-penetrating peptide clusters

Abstract A long-standing goal in biomedical research is to label and manipulate intracellular targets, which could be achieved through the cytosolic delivery of exogenous functional proteins. The development of Tat clusters has advanced the nontoxic intracellular delivery of functional antibodies at low concentrations, but the variety of proteins that can be successfully delivered remains limited. Here, we find that by simply reversibly modifying the surface of functional proteins with anionic peptide patches, various protein cargoes (which are normally difficult to deliver) can be delivered into living cells by synergetic electrostatic interactions with the cationic cell-penetrating peptide clusters TAT 3 . To demonstrate the applicability of this approach, we successfully deliver functional proteins with widely varying molecular weights (∼1.5 kDa to 430 kDa) and isoelectric points (less than 5 to greater than 9) into the cytosol of cells. By exploiting this method, we also achieve protein delivery in plant tissues, which is more challenging due to the presence of intact plant cell walls. This strategy is further applied for the cytosolic delivery of synthetic protein probes carrying posttranslational modifications (PTMs), which can aid in in situ mapping of the intracellular PTM-mediated interactome. Overall, this strategy is expected to enrich cytosolic protein delivery technology and help to repurpose a wide range of customized and therapeutic proteins for emerging intracellular applications.

Enzyme‐Mimicking Metal–Phosphide Tandem Catalytic Centers for Efficient Electrochemical Nitrate‐to‐Ammonia Conversion and Zinc–Nitrate Battery

ABSTRACT Achieving spatially coupled and functionally complementary active sites in synthetic catalysts remains a significant challenge. Inspired by the enzymatic cascade involving nitrate reductase and nitrite reductase, we report a nanozyme comprising iron clusters and iron‐doped nickel phosphide nanoparticles on CeO 2 nanorods (Fe–Fe x Ni 2−x P/CeO 2 ) in proximity for efficient electrocatalytic nitrate‐to‐ammonia conversion and Zn–NO 3 − battery. The Fe clusters serve as nitrate reductase mimics, promoting the deoxygenation step of NO 3 − to NO 2 − , while the adjacent Fe x Ni 2−x P nanoparticles serve as nitrite reductase mimics, accelerating the subsequent hydrogenation steps to NH 3 . The CeO 2 nanorods stabilize the dual active sites and function as proton reservoirs to suppress the hydrogen evolution reaction. Thus, the nanozyme delivers exceptional performance in NH 3 electrosynthesis, achieving a high yield rate of 43.5 mg h −1 cm −2 with a Faradaic efficiency (FE) of 91.2% at –0.7 V versus RHE in an H‐type cell and an industrial‐level current density of 800 mA cm −2 for over 100 h under flow‐cell conditions (FE NH3 > 90%) at the same potential. When employed Fe–Fe x Ni 2−x P/CeO 2 as a cathode in a rechargeable Zn–NO 3 − battery, it enables simultaneous NH 3 production and power generation, delivering a peak power density of 21.1 mW cm −2 and an NH 3 yield rate of 1.9 mg h −1 cm −2 .

Evolutionary reinforcement learning framework for energy-efficient fault resilience and topological stability in WSNs