Materials Modification (United States)

High aspect ratio etching is crucial in semiconductor manufacturing, and its improvement relies on the stability and controllability of the plasma. In this study, we combine Langmuir probe diagnostics with a global model to investigate how O2 addition affects plasma characteristics in CF4/Ar radio frequency (RF) inductively coupled discharges. The key operational parameters include the CF4 mixing ratio (binary: 30%–90%, ternary: 10%–40%), working pressure (1–8 Pa), and RF power (200–500 W). The results show that in CF4/Ar discharge, the electron density decreases, whereas the effective electron temperature increases as the CF4 content is raised from 30% to 90%. When O2 is added to the CF4/Ar discharge with the Ar fraction fixed at 50%, the effective electron temperature also increases with the CF4 content in the range 10%–40%, while the electron density remains nearly constant. Analysis of the electron energy probability functions reveals that O2 addition results in low-energy electrons remaining constant with varying CF4 content. Global model calculations further indicate that O2 diversifies the plasma chemical composition and enhances the formation of F and F2 through reactions with CFx. The resulting high density of F2, combined with its large dissociative attachment cross section, makes dissociative attachment to F2 the dominant electron-loss pathway. Furthermore, as the pressure increases from 1 to 8 Pa, the electron density in CF4/Ar discharge exhibits a non-monotonic behavior characterized by an initial increase followed by a decrease. In contrast, it decreases monotonically in O2/CF4/Ar discharge. This work systematically reveals the influence of O2 addition on fluorocarbon plasma characteristics, offering guidance for optimizing plasma etching processes with improved stability and controllability.

The stability of charge density wave (CDW) in the two-dimensional limit offers crucial insights into strongly correlated electronic systems. Although reducing material dimensionality effectively modulates CDW states, the influence of substrate interface remains pivotal and warrants further investigation. In this study, we examine the evolution of CDW order in epitaxially grown single layer TiSe2 on different substrates. We observe that the 2 × 2 CDW order persists in single layer TiSe2 on bilayer graphene, yet it becomes suppressed when the material is interfaced with an SrTiO3(111) substrate. Notably, the CDW order is fully restored in bilayer TiSe2 films grown on SrTiO3(111) substrates. Through comparative analysis of the growth mode, thermal stability, and electron doping in TiSe2/SrTiO3(111) heterostructures, we attribute the suppression of the CDW phase to strong interfacial bonding between TiSe2 and the substrate. Our findings highlight the tunability of CDW via interfacial engineering in single layer transition metal dichalcogenides, paving the way for nanoscale control of correlated quantum states.

The self-assembly of rigid sphere–rod amphiphiles composed of solvophilic Keggin clusters and rigid solvophobic oligodialkylfluorene (OF) rods is explored with special attention to side-chain length effect. Such amphiphiles are known to self-assemble into onion-like structures containing concentric multilayers in a binary solvent system via the interdigitation of the OF rigid rods. Here, we demonstrate that flexible alkyl side chains (two per OF unit) are important to control the self-assembly behavior. Based on KTOF4 (Keggin T-shaped oligodialkylfluorene with 4 repeat units), regular amphiphilic vesicles, incomplete onion-like structures, and full onion-like structures are observed when the side chains are C2, C4, and C6, respectively. When the side-chain length reaches C10, the inner layers of assemblies disappear, resulting in hollow, incomplete onion-like structures. With very long C16 side chains, the assemblies become less ordered, forming spherical assemblies with near-parallel layers, i.e., pupa-like structures. These flexible side chains act as fillers in the solvophobic domain to optimize the packing of rods. In other words, tuning flexible side-chain length is a simple, rational approach to regulating the microphase transitions among different self-assembled structures for the self-assembly of rigid amphiphiles, offering a versatile design principle for creating hierarchical nanostructures in functional materials.

Skeletal High-Strength Nanoporous Copper and Metamaterials Inspired by the centuries-long mechanical resilience of Hakka Tulou walls, Jianfeng Gu, Ma Qian and co-workers engineered a strong, multifunctional and scalable hierarchical Cu lattice metamaterial via a two-phase precursor alloy design and controlled dealloying. It surpasses the Gibson-Ashby strength predictions by 800% and offers an outstanding specific surface area (≈27.6 m2 g−1), unlocking multifunctional conformal and stand-alone components for heat exchangers, reactors, antimicrobial surfaces and beyond. More details can be found in the Research Article (DOI: 10.1002/adma.202503701).

BackgroundMacrophage-mediated inflammatory signaling drives pathological inflammation in diverse diseases. Zinc oxide nanoparticles (ZnO NPs) exhibit recognized anti-inflammatory activity, but their precise molecular mechanisms remain unclear. This study investigates the modulatory effects of ZnO NPs on Lipopolysaccharide (LPS)-induced inflammatory and underlying pathways in RAW264.7 macrophages.MethodsScanning electron microscopy (SEM) was used to analyze the primary particle sizes of ZnO NPs. Their cytotoxicity on RAW264.7 cells was assessed using the CCK-8 assay. Cells were pretreated with ZnO NPs (0, 0.5, 1, 2, 5 μg/mL) for 1 h, then stimulated with LPS (1 μg/mL) for 24 h. Pro-inflammatory factors (TNF-α, IL-1β, IL-6, iNOS, and COX-2), as well as the anti-inflammatory factor Arg-1, were detected using qRT-PCR, ELISA, or Western blot. RNA-sequencing identified differentially expressed genes (DEGs). Nitric oxide (NO) production, Reactive Oxygen Species (ROS).ResultsZnO NPs reduced LPS-induced production of NO and pro-inflammatory factors but increased Arg-1 expression. RNA-sequencing identified 2638 DEGs (1822 upregulated, 816 downregulated) between LPS and LPS+ZnO NPs groups. Mechanistically, ZnO NPs exerted anti-inflammatory effects through: (1) blocking NF-κB activation by inhibiting IκB-α degradation and p65 nuclear translocation; (2) suppressing JAK1-mediated STAT1/3 activation and nuclear translocation. They also reduced LPS-induced ROS.ConclusionZnO NPs mitigate LPS-triggered inflammation by targeting NF-κB and JAK1-STAT1/3 pathways, and reducing ROS. These findings provide novel mechanistic insights into the anti-inflammatory effects of ZnO NPs, highlighting their therapeutic potential in macrophage-associated inflammatory disorders.

This study used the RF magnetron sputtering technique to deposit titanium and aluminium-doped MoS2 coatings onto M50 steel substrates. The surface morphology and structural properties of the coatings were analysed using FESEM and XRD, respectively. Different vibrational modes present in the samples were analysed using Raman spectroscopy. Energy Dispersive Spectroscopy confirms the presence of Ti and Al in MoS2 coatings. The mechanical properties, including scratch hardness and critical load of failure, were investigated via a scratch tester with a Rockwell C diamond indenter. The Ti-Al-doped MoS2 coating exhibited the maximum scratch hardness of 15.49 GPa and the highest critical load of failure of 20 N. Tribological properties of the coatings were assessed on a multifunctional tribometer under loads ranging from 200 to 600 mN. The films exhibited friction coefficients ranging from 0.028 and 0.003. The wear properties are also assessed using a multifunctional tribometer under applied loads of 200 mN, 400 mN, and 600 mN. The wear rate increased with the applied load, ranging from a minimum of 13.5× 10-4 mm3/Nm at 200 mN to a maximum of 130 × 10-4 mm3/Nm for the Ti-Al-doped MoS2 film at 600 mN.

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is an autosomal dominant cancer predisposition syndrome driven by the loss of fumarate hydratase (FH) activity. Recently, we identified a pathogenic variant in intron 9 of the FH gene that disrupts splicing by creating a novel splice acceptor site, resulting in the aberrant inclusion of a cryptic exon. Inclusion of the cryptic exon introduces a premature termination codon, leading to loss of FH activity. To restore FH expression, we sought to identify strategies to drive exclusion of the cryptic exon from the mature mRNA. To this end, we generated a minigene GFP reporter system that recapitulates the splicing defect observed in patients. We employed CRISPR-Cas9-mediated genome editing and antisense oligonucleotides (ASOs) to modulate splicing and demonstrated that both strategies can successfully promote skipping of the cryptic exon in a reporter cell line. Furthermore, we were able to show that ASOs can be used to shift the balance between the FH mRNA isoforms originated from the reference and the variant allele in patient-derived fibroblasts using ASOs. These findings support the potential for splicing modulation as a therapeutic approach for HLRCC-associated non-coding loss-of-function mutations in FH.