ACS Applied Electronic Materials最新文献

Thermoplastic polyurethane (TPU) is essential in resource exploration, healthcare, automotive, and high-end recreational sports. Despite extensive research on TPU’s microstructures and their macroscopic properties, the impact of processing conditions like compression and injection molding remains underexplored. This study investigates the influence of processing conditions on TPU by preparing samples with varying hard segment contents using compression molding at 205 °C and injection molding at melt temperatures of 205, 210, 215, and 220 °C, followed by heat treatment at 120 °C for 12 h. Results indicate that injection-molded TPU at 205 °C exhibits lower hydrogen bonding, crystallinity, long period, interfacial thickness, and lamella thickness than compression-molded TPU, leading to higher Young’s modulus but lower elongation at break. As melt temperatures increase, these microstructural parameters decrease, reducing Young’s modulus and increasing elongation at break. Post heat treatment, microstructural parameters increase, aligning Young’s modulus with that of compression-molded samples, while elongation at break surpasses them. This suggests that heat treatment enhances microphase separation by rearranging hard and soft segments. our research reveals a consistent pattern across TPUs with varying hard segment contents, indicating that adjusting processing parameters can effectively regulate microstructure and performance, offering valuable insights for developing high-performance polyurethanes.

The tumor suppressor protein p53 is among the most commonly mutated proteins across a variety of cancer types. Notably, the p53 R175H mutation ranks as one of the most prevalent hotspot mutations. Proteolysis-targeting chimeras (PROTACs) represent a class of bifunctional molecules capable of harnessing the cellular ubiquitin-proteasome pathway to facilitate targeted protein degradation. Despite the potential of PROTACs, limited research has been directed toward the degradation of the p53-R175H mutant protein. In this study, we developed a series of peptide-based PROTACs, leveraging known peptide ligands for both the p53-R175H mutation and the E3 ubiquitin ligase VHL. Our findings indicate that one of these peptide-based PROTACs is capable of directing the p53-R175H protein to the proteasome for degradation within a recombinant expression system. Moreover, by synthesizing a fusion peptide PROTAC molecule that incorporates a membrane-penetrating peptide, we have demonstrated its ability to traverse cellular membranes and subsequently reduce the levels of the p53-R175H mutant protein. Importantly, the degradation of p53-R175H was found to mitigate the cellular migration and invasion. In summary, our study introduces a novel class of protein degraders and establishes a foundational framework for the therapeutic management of cancers associated with p53 mutations.

The use of nucleic acid-based detection tools for microorganisms and fungi has become a gold standard. This is particularly the case for wood-decaying fungi like Serpula lacrymans, which are hard to discriminate based on macroscopic and microscopic observations. This dry rot is important to detect as it is particularly destructive in an infested building, which requires immediate action to prevent spreading and significant damage to structural elements. Through the development and optimization of loop-mediated isothermal amplification against S. lacrymans-specific rDNA internal transcribed spacer region, we demonstrate that it is possible to achieve rapid and specific amplification without nonspecific self-amplification in a similar range as real-time quantitative PCR without any necessary DNA isolation using a colorimetric detection assay. Through a combined set of self-amplification minimization along with hand-held sample homogenization, the LAMP assay was optimized to provide a femtogram-range assay capable of confirming identification in a real field sample either predominantly composed of S. lacrymans or containing the fungus while remaining negative when tested on different types of fungi found in basement-collected samples.

Magnetic Weyl semimetals can exhibit a significant electronic transport behavior known as the anomalous Hall effect caused by the inherent Berry curvature generated by Weyl fermions. This study presents the result of density-functional theory analysis focusing on the magnetic ground state, electronic properties, topological Weyl properties, nontrivial surface state, and anomalous Hall effect of the double half-Heusler compound Cr₂FeCoAs₂. We determined that Cr₂FeCoAs₂ acts as a ferrimagnetic half-metal with a total spin magnetic moment of 6 μ_B per unit cell. This system is particularly interesting as it features one insulating and one metallic topological channel. The minority-spin insulating channel shows an energy band gap of 1.26 eV. The majority spin channel consists of several sets of low-energy Weyl points. Among them, four exactly lie at the Fermi level. The chiral Weyl nodes, breaking time-reversal symmetry and protected by mirror symmetry, act as the monopole source and sink of the Berry curvature and provide a large intrinsic anomalous Hall conductivity approaching −190 Ω^–1 cm^–1 at the Fermi level and −370 Ω^–1 cm^–1 at 170 meV, which is comparable to those of topological magnetic materials. Additionally, nontrivial surface states are clearly present in Cr₂FeCoAs₂. Our work will support future experimental investigations into the previously unexplored topological phenomena of Cr₂FeCoAs₂.

This study presents a trench structured gallium nitride (GaN)-based light emitting transistor (LET) that integrates the functionalities of both a transistor and a light emitting diode into a single compact unit. Utilizing the superior material properties of GaN, these items surpass the performance of their silicon- or organic-based counterparts. However, due to polarization effects caused by the wurtzite crystal structure of GaN, the LET operates in depletion mode (D-mode). A metal-insulator-semiconductor gate was employed in the deep trench to mitigate prevalent issues such as poor gate controllability and high off-current in GaN-based devices. This work outlines the integrated device concept, operational mechanism, and fabrication process details and discusses the results of the characteristic assessment. The epitaxial wafer structure was optimized to enhance light emission, yielding a device capable of switching with an on/off ratio of approximately 10⁷ and emitting visible blue light through a multi-quantum well layer, fabricated using state-of-the-art semiconductor fabrication technology.

Using a rapid compression machine, fuel autoignition resistance can be quantified by the ignition delay time measurements of homogeneous mixtures. As the occurrence and intensity of knock in spark ignition engines are related to autoignition resistance, ignition delay time measurements give valuable insight into fundamental fuel combustion properties that can be used to predict undesirable combustion behavior. Therefore, the work presented in this paper aims to understand the autoignition resistance of a gasoline surrogate fuel and how it is affected by the addition of substituted phenol additives from ignition delay time measurements in a rapid compression machine. Six substituted phenols were tested: p-cresol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, and 3,5-xylenol. Lean and stoichiometric mixtures, as well as stoichiometric mixtures with N₂ dilution, were studied at engine-relevant conditions of 20 bar between 700 and 950 K. It was found that most additives were able to lengthen the base fuel ignition delay time at high and low temperatures, but that the most effective had two methyl groups located adjacent to each other.

Polyphenol oxidase (PPO) is the culprit behind the browning of fruits and vegetables. Therefore, how to reduce the thermal deactivation temperature of PPO or use as few safe reagents as possible to inhibit enzymatic browning has practical significance. Mesoporous silica nanoparticles (MSNs) and multiwalled carbon nanotubes (MWCNTs) are stable and have high biosafety. In the present study, efficient PPO inhibitors were developed based on MSNs and MWCNTs. It is found that after modification with a very small amount of dodecyl trimethylammonium bromide (DTAB, ≥60 μg/mL), MSNs can significantly inhibit the activity of PPO although single MSNs and single DTAB show very limited effect on PPO activity. After modification with a very small amount of sodium dodecyl sulfate (SDS, 5.7–9.5 μg/mL), MWCNTs almost completely inactivate PPO. However, SDS@MSN and DTAB@MWCNT cannot decrease PPO activity significantly.

Acyclovir (ACV) is a vital treatment for herpes simplex (HSV) and varicella-zoster virus (VZV) infections that inhibit viral DNA polymerase. Phosphoramidate ProTides-ACV, a promising technology, circumvents the reliance on thymidine kinase (TK) for activation. Twelve novel single isomers of phosphoramidate ProTide-ACV were synthesized. Successful isomer separation was achieved, emphasizing the importance of single isomers in medical advancements. The enzymatic hydrolysis kinetics of the synthesized compounds were investigated by using carboxypeptidase Y (CPY). The results revealed a faster conversion for the isomer Rp- than for the Sp-diastereomer. Hydrolysis experiments confirmed steric hindrance effects, particularly with the tert-butyl and isopropyl groups. Molecular modeling elucidated the mechanisms of hydrolysis, supporting the results of the experiments. This research sheds light on the potential of phosphoramidate ProTides-ACV, bridging the gap in understanding their biological and metabolic properties, while supporting future investigations into anti-HSV activity. Preliminary screening revealed that three of the four single isomers demonstrated superior antiviral efficacy against wild-type HSV-1 compared to acyclovir, with isomer 24a ultimately reducing the viral yield at 200 μM. These findings emphasize the importance of isolating racemic ACV-ProTides as pure single isomers for future drug development.

Carbons with Brønsted acidic sites and iron oxide modifications were prepared through hydrothermal carbonization and glycerol pyrolysis in the presence of sulfuric acid, magnetite, and iron(III) nitrate. The solids were tested as catalysts in converting fructose to 5-hydroxymethylfurfural (5-HMF). Characterization techniques revealed a uniform presence of 4.89 mmol g^–1 total acidic groups, including up to 1.87 mmol g^–1 sulfonic and carboxylic groups. Combined with a reduced surface area, the Brønsted and Lewis acidity enabled the conversion of 94% of fructose with selectivity values as high as 95% for 5-HMF in just 10 min at 140 °C, using microwave heating and dimethyl sulfoxide (DMSO) as the solvent. This performance was attributed to the selective heating of the catalyst surface by the microwave absorption capacity of the acidic groups and iron oxide, leading to the formation of “hot spots.” The catalyst obtained by hydrothermal carbonization in the presence of Fe₃O₄, HCC-20% Fe₃O₄, demonstrated stability when reused for up to four consecutive cycles. A slight reduction in conversion and selectivity was observed after the first use, attributed to the presence of acid species not incorporated into the solid during the synthesis process.

Microfluidics offer user-friendly liquid handling for a range of biochemical applications. 3D printing microfluidics is rapid and cost-effective compared to conventional cleanroom fabrication. Typically, microfluidics are 3D printed using digital light projection (DLP) stereolithography (SLA), but many models in use are expensive (≥$10,000 USD), limiting widespread use. Recent liquid crystal display (LCD) technology advancements have provided inexpensive (<$500 USD) SLA 3D printers with sufficient pixel resolution for microfluidic applications. However, there are only a few demonstrations of microfluidic fabrication, limited validation of print fidelity, and no direct comparisons between LCD and DLP printers. We compared a 40 μm pixel DLP printer (∼$18,000 USD) with a 34.4 μm pixel LCD printer (<$380 USD). Consistent with prior work, we observed linear trends between designed and measured channel widths ≥4 pixels on both printers, so we calculated accuracy above this size threshold. Using a standard IPA-wash resin and optimized parameters for each printer, the average error between designed and measured widths was 2.11 ± 1.26% with the DLP printer and 15.4 ± 2.57% with the 34.4 μm LCD printer. Printing with optimized conditions for a low-cost water-wash resin designed for LCD-SLA printers resulted in an average error of 2.53 ± 0.94% with the 34.4 μm LCD printer and 5.35 ± 4.49% with a 22 μm LCD printer. We characterized additional parameters including surface roughness, channel perpendicularity, and light intensity uniformity, and as an application of LCD-printed devices, we demonstrated consistent flow rates in capillaric circuits for self-regulated and self-powered delivery of multiple liquids. LCD printers are an inexpensive alternative for fabricating microfluidics, with minimal differences in fidelity and accuracy compared with a 40X more expensive DLP printer.