Small Methods最新文献

Atomic-level surface preparation, using additive and subtractive atomic layer processes, has gradually become crucial for the more active process variations and highly selective process requirements. Precise control of surface roughness and coverage is a critical consideration in the fabrication of metal thin films. Herein, the fabrication of ultrathin, smooth Ru films with a thickness reduced to below 3 nm is reported. This process involves etching back after depositing a thick Ru film using a synergistic combination of atomic layer deposition (ALD) and atomic layer etching (ALE) techniques. The surface smoothing effect, while preserving surface coverage, is validated by initially performing the ALD process for Ru with (ethylbenzyl)(1-ethyl-1,4-cyclohexadienyl)Ru(0) precursor and O₂ gas, followed by the ALE process with 2,4-pentanedione and O₂ radicals. Under optimized conditions for atomically flat Ru surfaces, the surface quality of Ru films processed by ALD, and the combined ALD/ALE methods are compared. Consequently, it is demonstrated for the first time that the combined ALD/ALE process effectively reduces both thickness and asperities while smoothing the surface and maintaining nearly complete surface coverage down to the ≈1 nm scale. This approach enables the production of advanced electronic devices with precise control over surface properties at the Ångström level.

Organic phototransistors (OPTs) have garnered significant attention due to their potential in wearable and flexible electronics. However, achieving high carrier mobility and broadband response in organic semiconductors for OPTs remains a challenge. In this work, a new fused diketopyrrolopyrrole (FDPP) derivative is reported, 2,9-bis(4-hexylphenyl)-7H,14H-thieno[3',2':7,8]indolizino[2,1-a]thieno[3,2-g]indolizine-7,14-dione (FDPP-p-C6), synthesized through N-cyclization of DPP with an adjacent thiophene unit. This N-cyclization ensures backbone planarity, while the hexyl side chains remain distant from the fused core, minimizing steric hindrance and promoting efficient intermolecular stacking. Consequently, single crystals of FDPP-p-C6 exhibit a planar backbone and a typical herringbone packing arrangement, facilitating charge transport. The single-crystal organic field-effect transistors (OFETs) demonstrate p-type charge transport, achieving maximum mobility of 0.20 cm² V^-¹ s^-¹. Additionally, the single-crystal OPTs show promising performance, with high responsivity across a broad spectral range and a photoresponsivity of 2.2 × 10³ A W^-¹ along with a specific detectivity, derived from the noise current, of 2.8 × 10¹⁰ Jones. This study highlights the potential of FDPP as a key material for advancing single-crystal OFET and OPT technologies, propelling relevant research forward.

Biologics have low toxicity and are highly specific and biocompatible, offering advantages over small-molecule drugs. The administration of biologics in oral form provides a significant benefit in improving patient compliance. However, oral administration faces the challenge of a harsh gastrointestinal environment, including low pH, enzyme degradation, and poor intestinal epithelium permeability, which limits the bioavailability of biologics. As a result, the administration of biologics remains primarily in the parenteral form. This review introduces the physiological barriers encountered by oral biologics delivery, describes the oral biologics currently on the market or under clinical trials, as well as oral biologics-based technologies, and discusses the recent progress on novel oral delivery technologies such as nanoparticle-delivery systems, ionic liquids, and microneedles. Specifically, colon-targeted approaches for oral biologics delivery are also explored, as the colon could be a more optimal absorption site due to having less diverse proteolytic enzymes and relatively limited digestibility compared to the upper gastrointestinal tract (GIT). Lastly, the future research directions for oral biologics are highlighted and it is concluded that with an in-depth study of biological drugs and advancement in delivery methods, oral biologics can pioneer new opportunities.

Electrochemical hydrogen purification (EHP) technology with high-efficiency and easy-operation holds great potential in blended hydrogen transportation, which is currently restricted to proton exchange membrane system and Pt-based catalysts. As promising candidates used in alkaline anion exchange membrane system, Pd-based catalysts are hampered by the intense interaction between H^* and delocalized 4d electrons, resulting in unsatisfactory catalytic activity. In this study, a marked enhancement of the alkaline membrane-based EHP performance is achieved, with hydrogen purity up to 99.96% separated from a CH₄-H₂ mixture, by strategically incorporating interstitial H atoms into Pd lattices for improving the anodic hydrogen oxidation reaction. Detailed characterizations and density functional theory calculations elucidate that the presence of interstitial H localizes free electrons into Pd-H covalent bonds, thereby weakening the interaction between surface-adsorbed H^* and the catalytic surface. Moreover, operando spectroscopies and ab initio molecular dynamic simulations reveal that the enhanced interaction between the catalyst surface and interfacial water by electron delocalization, facilitates the desorption of H^* to the interfacial water layer during catalysis. This research highlights the pivotal role of electronic localization in modulating the adsorption strength of key reaction intermediates for the design of efficient Pd-based catalysts.

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In article number 2401598, Zuo, Yamauchi, Xu, and co-workers provide an in-depth analysis of the challenges and opportunities associated with uranium extraction from seawater. The work emphasizes the development of innovative technologies, leveraging data mining techniques, to facilitate the transition from laboratory research to industrial-scale applications.

Strain Engineering

Strain engineering is a powerful tool that can strongly modulate the physical and physicochemical properties of 2D materials. Particularly, the lattice distortion-induced modification in the electronic band structure enables the emergence of many excellent properties that greatly expand the applicability of 2D materials in the fields of flexible electronics, flexible photo-/image-sensors, flexible strain sensors, and wearable bioelectronics devices. More in article number 2401404, Katiyar and Ahn.

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In article number 2401297, Ding, Kang, Yang, and co-workers integrate metabolic RNA labeling-based time-resolved scRNA-seq with spatial transcriptomics (10x Visium and in situ sequencing) to profile the transcriptional dynamics of glioblastoma cells. The spatiotemporal analysis elucidates the complex gene regulatory mechanism of EZH2-mediated mesenchymal transition in the tumor microenvironment.

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In article number 2401709, Choi and co-workers employed pulsed laser technology to develop a NiCoPt alloy electrocatalyst with superior dual-functional activity for hydrogen evolution and hydrazine oxidation reactions. This facilitated self-powered hydrogen production via Zn-hydrazine battery integrated with overall hydrazine splitting.

Atherosclerosis (AS), a chronic inflammatory disease and a leading cause of cardiovascular morbidity and mortality worldwide, is a significant contributor to disability. Neutrophil extracellular traps (NETs) have been closely associated with the progression of AS and plaque vulnerability. However, developing a treatment strategy that specifically targets neutrophils and effectively reduces NET release at the lesion site remains a major challenge. In this study, a biomimetic nanosystem with neutrophil-targeting properties is engineered. Coating Prussian blue nanoparticles with bacterial biomimetic membranes (MPB NPs) enables specific recognition and internalization by neutrophils. By hitching onto neutrophils, the MPB NPs scavenge intracellular reactive oxygen species (ROS) and suppress NET formation at the lesion site. Importantly, MPB NPs reduce the size of atherosclerotic plaques by 3.29-fold, from 22.53% to 6.85%, stabilize the plaques, and halt their progression in atherosclerotic mouse models. These findings suggest that MPB NPs offer a promising therapeutic strategy for atherosclerosis, and provide a versatile platform for the treatment of NET-associated diseases.

This work showcases the importance of developing suitable inspection and analysis methodologies with high statistical relevance data coupled with machine learning algorithms, for the detection, control, and understanding of small fluctuations in the scale-up of thin film photovoltaics to industrial sizes. To exhibit this methodology, this work investigates the effect of subtle inhomogeneities on the efficiency of thin film solar cells based on the Cu₂ZnSnSe₄/CdS interface using two large area samples subdivided in ≈400 individual solar cells. A large dataset obtained from Raman and photoluminescence spectroscopic techniques together with J–V optoelectronic data is generated to elucidate the impact of these inhomogeneities on the efficiency of the devices. Using a combination of statistical (spectral difference) and over 440 000 multivariate polynomial regressions through machine learning algorithms, it is revealed how the main limiting factor for device performance are subtle fluctuations in the nanostructure and surface defects of the CdS layer, rather than compositional fluctuations or defects in the kesterite absorber. It is estimated that the avoidance of these issues could result in an absolute increase in device efficiency of 2%. This could provide a potential avenue for further technology advancement within the kesterite community.