Small Methods最新文献

Spatial transcriptomics has transformed the understanding of gene regulation by enabling high-resolution mapping of RNA molecules within their native cellular and tissue environments. This is typically accomplished by capturing or imaging RNA in situ, thereby preserving spatial context. Here, an in situ RNA imaging method based on split-probe ligation and rolling circle amplification (RCA) for profiling spatial gene expression is introduced. In this approach, split-probes hybridize to adjacent regions of a target RNA fragment and are then enzymatically ligated to form circular DNA templates, which are subsequently amplified via RCA to boost the signal. It is demonstrated that this method enables robust in situ RNA detection and genotyping in both tissue sections and whole-mount tissue samples. By coupling this technique with in situ sequencing, the spatial expression patterns of 82 genes in the kidneys of healthy and diabetic male and female mice are mapped. This analysis reveals distinct localization of Aqp4 in proximal tubules and principal cells of the collecting ducts, and uncovers sex-specific transcriptomic alterations in diabetic kidneys with spatial resolution.

The formation of lithium dendrites and dead lithium during deposition/stripping process restricts battery performance especially in wide temperature range. However, due to the lack of real-time detection methods, the intrinsic mechanism of how operational temperature affects the dynamic process on lithium metal anodes is still unclear. Here, an in situ investigation of lithium deposition and dead lithium formation during the first charge-discharge cycle in an ether-based electrolyte system is presented. Both the deposition process and stripping process are found to be temperature dependent. Below 293 K, the lithium deposition is less dense plating and the dead lithium is formed, which contributes to the capacity loss. Above 293 K, the lithium deposition becomes denser, and dead lithium formation is significantly reduced. The capacity loss is primarily driven by the formation of solid electrolyte interphase (SEI) resulting from reactions between lithium and ether-based electrolyte. Further study reveals that the ratio of lithium oligoethoxides on the SEI changes abruptly with temperature above 293 K and thus significantly alters the conductivity and reactivity of SEI, which leads to the abrupt change of the deposition/stripping process. These findings highlight the critical role of temperature in lithium deposition/stripping processes in ether-based anode-free lithium metal batteries.

Solid polymer electrolytes (SPEs) offer flexibility and processability but suffer from low ionic conductivity and inadequate mechanical strength. Here, a facile, solvent-free electron beam (EB) irradiation method is introduced to modify poly(diallyldimethylammonium) bis(trifluoromethanesulfonyl)imide (PDADMATFSI)-based SPEs for lithium metal batteries. At an optimal dose, EB irradiation simultaneously generates polar carbonyl groups and induces a crosslinked network. The carbonyl groups facilitate lithium-ion transport and contribute to forming a robust, Li₂O-rich solid electrolyte interphase. Concurrently, the crosslinked architecture enhances mechanical integrity and suppresses the growth of lithium dendrites. As a result, Young's modulus increases from 170 to 921 MPa, ionic conductivity rises from 4.7 × 10^-4 to 8.2 × 10^-4 S cm^-1, the lithium-ion transference number (t_Li ⁺) improves from 0.29 to 0.48, and the dielectric constant increases from 6.5 to 16.6. Consequently, Li||Li symmetric cells with modified SPE cycle stably for 2000 h (0.05 mA cm^-2), 600 h (0.1 mA cm^-2), and 180 h (0.2 mA cm^-2), with a critical current density of 1.1 mA cm^-2. Li||NCM811 (LiNi_0.8Co_0.1Mn_0.1O₂) full cells deliver 83.7% capacity retention after 300 cycles at 1C and superior rate performance. This work demonstrates that EB irradiation is a promising and effective strategy for developing high-performance solid-state lithium metal batteries.

Molybdenum disulfide (MoS₂) has attracted a wide range of research attention due to its distinct electronic structures and the great potential for use in emerging microelectronic and photonic devices. However, the development of MoS₂-based micro-electronic/photonic devices lags far behind expectations mainly because of the lack of efficient microfabrication technology. Here, a high-resolution precision photoreduction technology is presented for directly printing MoS₂ micropatterns that can be decorated into gold nanoparticle (AuNP)/ MoS₂ heterostructure for ultrasensitive surface-enhanced Raman spectroscopy (SERS) sensing. Micropatterns of MoS_x nanoparticles are initially grown toward a target size in a light-controlled manner and then transformed into a micropatterned pure MoS₂ nanofilm through thermal annealing. Thereafter, size and gap-controlled AuNPs are grown selectively on the surface of MoS₂ to form a self-aligned AuNP/MoS₂ heterostructure with desired optical properties. Thanks to both electromagnetic and chemical enhancements, the directly printed plasmonic AuNP/ MoS₂ substrate can greatly enhance Raman signals to detect crystal violet (CV) and 4-mercaptobenzoic acid (4-MBA) at 10^-12 m under the excitation of 785-nm laser. This multiscale-engineered plasmonic AuNP/MoS₂ substrate is rapidly printed without relying on expensive and time-consuming nanofabrication processes, offering a new technical approach for future development of MoS₂-based micro-devices and sensing platforms.

Covalent organic frameworks (COFs) have recently emerged as promising candidates for solar fuel production due to their broad spectral absorption and readily tunable optoelectronic properties. However, their photocatalytic performance is often limited by inefficient charge separation and rapid charge recombination. Herein, novel S-scheme COF heterojunctions is reported by integrating a negatively charged COF host with a positively charged linear conjugated polymer. The electrostatic attraction between them spontaneously generates a robust Coulombic electric field at the heterojunction interface, which shows an identical electric field direction with the intrinsic built-in electric field of S-scheme configuration.The control experiments and spectroscopic characterizations reveal that this dual-field approach significantly enhances directional charge separation and transfer at the interface, effectively suppressing charge recombination. The optimized sample exhibits a highly enhanced photocatalytic hydrogen production rate of 339.4 µmol g^-1 h^-1 while coupling with a stoichiometric conversion of 5-hydroxymethyl furfural to 2,5-diformylfuran.

Engineered bacterial therapeutics are gaining attention in tumor therapy, showing significant clinical potential. However, their clinical translation requires stricter regulation of biosafety and targeting specificity. Controlled release systems offer a key strategy to optimize engineered bacteria through precise spatiotemporal gene expression and motility modulation. This review systematically evaluates two core controlled-release platforms in tumor treatment-tumor microenvironment-responsive systems and intelligent controllable systems-summarizes representative therapeutic paradigms and critically analyzes the merits and limitations of each. Therefore, this review aims to provide a theoretical foundation for refining controlled-release strategies in engineered bacteria-mediated antitumor therapy.

The peripheral nervous system (PNS) has emerged as a versatile and clinically accessible target for neuroengineering, offering unique advantages in modularity, surgical accessibility, and regenerative capacity. These characteristics have led to the development of peripheral nerve interfaces aimed at clinical implementation across therapeutic and prosthetic applications. Peripheral nerve interfaces involve a broad range of technologies designed to record, stimulate, or repair neural pathways. These technologies are increasingly converging toward systems that are not only surgically and functionally integrated, but also capable of adaptive, closed-loop control. Collectively, these developments represent an advancement in peripheral nerve interface design from passive or pre-programmed interventions to interactive, responsive, and personalized platforms for neural repair and modulation. This review highlights recent advances in biotic-abiotic interface engineering for peripheral nerve applications, encompassing wearable and implantable approaches, as well as addressing current challenges and discussing future perspectives.

Cuprous oxide (Cu₂O) has demonstrated great potential in photochemical, electrochemical, and organic catalysis. Developing surfactant-free and scalable synthesis methods is essential for its real application. Conventional batch methods often suffer from inconsistent product quality and limited scalability. In this work, an efficient continuous microflow synthesis system is developed, and the design principles of the flow synthesis system are systematically elucidated. A kinetic control strategy on the millisecond-to-second timescale is proposed to precisely regulate intermediate size and dynamic structural evolution without using surfactants, thereby adjusting particle size and exposed crystal facets, which transformed the conventional thermodynamic control paradigm. Specifically, varying the interval time (0.02→6 s) between precipitant (sodium hydroxide, NaOH) and reductant (ascorbic acid, AA) addition significantly altered nanocube size (75→196 nm), while reversing the feeding sequence (AA before NaOH) led to much smaller nanocubes (76→14 nm) due to changes in the microenvironments for particle formation. Moreover, Cu₂O polyhedrons exhibited a greater number of exposed facets at shorter residence times, indicating a non-equilibrium state from the thermodynamic perspective. It is expected that such a continuous microflow synthesis system can be directly integrated with downstream catalytic processes to fully exploit the activity of Cu₂O.

Graphene nanoribbons (GNRs) with well-defined structures have been prepared via on-surface synthesis through polymerization and dehydrocyclization of on-purpose designed precursor molecules. Although nitrogen-doped (N-doped) GNRs have been achieved using nitrogen-containing precursors, the synthesis of N-doped armchair GNRs with subnanometer width remains challenging due to the difficulties associated with designing appropriately small nitrogen-containing precursor molecules. Here, a confined synthesis approach is employed to synthesize N-doped GNRs with subnanometer width using nitrogen-containing molecules through a decomposition-recombination mechanism. Raman spectroscopy and X-ray photoelectron spectroscopy analyses confirmed the effectiveness of aminoferrocene and cyanoferrocene as precursor molecules for synthesizing N-doped GNRs, achieving nitrogen-to-carbon ratios of ≈9.20 and 5.96 at.%, respectively. Additionally, using a dual precursor mixture of ferrocene and cyanoferrocene allows for the synthesis of N-doped GNRs with tunable doping levels by adjusting the precursor ratio. The thermal conductivity of N-doped GNRs is increased by a factor of 1.4 compared to its undoped counterpart. These findings contribute to the precision synthesis of GNRs with controlled edge structures, widths, and doping levels, paving the way for expanded applications of N-doped GNRs.

Direct seawater electrolysis presents significant challenges due to chloride-induced corrosion and the competitive Cl^- oxidation, which undermines the efficiency and durability of anode materials. In this study, the rationally synthesized Ag nanocluster-decorated calcium-manganese borate (AgNCs@Ca-MnB) nanosheets are reported as a highly efficient and corrosionresistant electrocatalyst for oxygen evolution in alkaline seawater. Incorporating boron into the Ca─Mn lattice creates electron-deficient sites that enhance the covalency of Mn─O bonds, promoting favorable adsorption energies for OER intermediates while stabilizing the catalyst structure under oxidative conditions. Ag nanoclusters are strategically introduced to the surface, functioning as selective Cl^- traps through Ag─Cl complexation, effectively suppressing the Cl^- oxidation pathway. The hybrid design further boosts electrochemical surface area and electronic conductivity, ensuring high current density operation with minimal degradation. The AgNCs@Ca-MnB catalyst achieves an overpotential of ≈310 mV at 10 mA cm^{- 2} in real seawater and demonstrates exceptional operational stability over 100 h, outperforming many reported transition metal-based systems. This study introduces a synergistic strategy combining boron-induced electronic modulation and silver-mediated chloride immobilization, offering a new direction in designing durable and selective seawater oxidation catalysts.