Wurtzite‐type nitride ferroelectrics emerge as a breakthrough platform for silicon‐compatible nonvolatile memory technology. However, the inherent polarization reversal mechanisms involving diatomic displacements introduce complex domain dynamics and elevate energy barriers, manifesting as excessive coercive fields ( E c ) and pronounced wake‐up effects that hinder reliable device operation. Here, these challenges are resolved by enabling the low‐field‐driven domain wall motion in representative wurtzite ferroelectrics (Al 0.75 Sc 0.25 N). In situ transmission electron microscopy measurements reveal that polarization switching proceeds via preferential domain‐wall transverse propagation perpendicular to the [0001] axis, preceding longitudinal propagation along the [0001] axis. First‐principles simulations quantify a striking 98% reduction in energy barrier for transverse migration (0.00188 eV f.u −1 ). Compared to longitudinal motion (0.092 eV f.u −1 ). This switching kinetic fundamentally challenges the conventional Kolmogorov‐Avrami‐Ishibashi model. By controlling nucleation polarity to promote the transverse motion of the domain wall, E c is reduced by 25%, with a high remanent polarization maintained and wake‐up effects eliminated across 6‐inch films. The methodology establishes a universal design principle for manipulating polarization switching in wurtzite ferroelectrics, paving the way for integrated low‐energy, high‐stability, uniformly‐performing ferroelectric devices in large‐scale complementary metal oxide semiconductor (CMOS) architectures.

The impact of optically active biomaterials on drug delivery remains a vital and hot topic. To reveal special advantages of optically active mesoporous silica nanoparticles in delivering drug in cells, optically active mesoporous silica nanoparticles deliver doxorubicin (DOX) with chiral behavior in cancer cells was studied. The present work focused on two types of optically active mesoporous silica nanoparticles named as levorotatory optically active mesoporous silica nanoparticles (LOA-MSNs) and dextrorotatory optically active mesoporous silica nanoparticles (DOA-MSNs) and examined their effects on cellular DOX delivery in cancer cells. The obtained LOA-MSNs and DOA-MSNs were regular spheres with particle diameters ranging from 200 to 250 nm, and their shell layer was filled with interlaced channels. Our results indicated that LOA-MSNs and DOA-MSNs did not exhibit cytotoxicity towards MCF-7 cells and B16 cells. The cytotoxicity of DOX-loaded LOA-MSNs and DOX-loaded DOA-MSNs were stronger than DOX owing to the synergistic retention and accumulation effect of nanoparticles. More importantly, DOX-loaded DOA-MSNs presented stronger cytotoxicity due to the higher synergistic retention and accumulation effect of DOA-MSNs. These findings suggest that DOA-MSNs with superior cellular delivery of DOX have great potential to advance the development of optical anti-tumor delivery system.

Oxygen vacancies of perovskite oxides are crucial for improving catalytic oxidation activities. However, the effect of oxygen vacancy concentration on catalytic performance and mechanism have not been revealed unambiguously. Herein, cobalt-based perovskites catalysts La0.8X0.2CoO3 (LXCO) with different oxygen vacancy (VO) concentrations were obtained by A-site equivalent and aliovalent doping. Moderate oxygen vacancy concentration was conductive to the CO and toluene catalytic activities, and too little or too much oxygen vacancies could reduce the catalytic properties. Based on the experimental of XPS, NAP-XPS, and O2-TPD, the La0.8Ca0.2CoO3 (LCaCO) catalyst with moderate oxygen vacancy concentration promoted the adsorption and activation of oxygen, forming more reactive oxygen species, ulteriorly improving the oxygen mobility, compared to La0.8Nd0.2CoO3 (LNdCO) catalyst with high oxygen vacancy concentration. In situ DRIFTS studies indicated that surface reactive oxygen species could be continuously replenished for LCaCO catalyst. In the reaction process, methyl C-H broke and combined with active oxygen species to form OH species, accelerating the formation of intermediates such as benzyl alcohol, and promoting toluene oxidation. This study could provide a relationship between the concentration of oxygen vacancy and the catalytic performance of perovskite oxide catalysts, thereby guiding the design of catalysts with superior catalytic activity.

Endoplasmic reticulum, the largest cellular organelle where protein synthesis, folding, transportation, and the maintenance of Ca2+ homeostasis occurred, is sensitive to the imbalance of its inner environment. Particularly, overproduction of reactive oxygen species in endoplasmic reticulum region can initiate endoplasmic reticulum stress and is tightly related to many metabolic diseases. In this respect, to retain normal function of endoplasmic reticulum, it is highly important to synthesize antioxidants with endoplasmic reticulum-targeting capability for precisely clearing excessively generated reactive oxygen species in endoplasmic reticulum. Herein, we demonstrate the preparation of endoplasmic reticulum-targeting Se-doped carbon nanodots and assays with HeLa cells as well as in vivo tests with mice have shown that the prepared carbon nanodots can significantly eliminate both •OH and O2•−. Experimental results declared that the fabricated carbon nanodots with powerful scavenging capabilities toward •OH and O2•-, low cytotoxicity and endoplasmic reticulum targetability can be utilized to protect cells against raised levels of reactive oxygen species in endoplasmic reticulum. What’s more, the fabricated carbon nanodots effectively alleviated phorbol 12-myristate 13-acetate induced ear inflammation in live mice.

The long-term successes of implant restorations rely on both appropriate osseointegration and robust soft tissue integration (STI). Numerous studies have reported that titanium dioxide nanotube (TNT) arrays formed by electrochemical anodization (EA) can promote early osteogenesis, but the mechanical stability of such modifications is often ignored and remains underexplored. In addition, relatively little research has been done on their effects on soft tissues integration. In this study, we developed mechanically robust TNT arrays using an optimized EA system. Subsequently, we immobilized a peptide, specifically D-amino K122-4, onto the anodized TNTs via polydopamine (PDA) films to enhance their mechanical properties. Surface morphology and composition were characterized by scanning electron microscopy (SEM), atomic force microscopy, and X-ray photoelectron spectroscopy. Mechanical properties, including the elastic modulus and hardness of TNTs modified Ti surfaces, were assessed using the nano-indention test. The adhesive strength of TNTs films to the substrate was measured using the nano scratch test. Furthermore, we evaluated the adhesion, spreading, and proliferation of human gingival fibroblasts (HGFs) and periodontal pathogenic bacteria such as Streptococcus mutans (S.m) and F. nucleatum (F.n) on the surface. Results showed that the elastic modulus, hardness, and adhesive strength of anodized TNTs were significantly enhanced by the incorporation of the D-amino K122-4 peptide. Live-dead staining and SEM observation suggested a decreased surface colonization by both bacterial species. The antibacterial rate of S.m and F. n was 81.5% and 71.7%, respectively, evaluated by colony counting method. Additionally, results of CCK8 assay showed that modified TNTs slightly stimulated HGFs attachment and proliferation while producing enhanced fluorescence of integrin β1 and F-actin, confirmed by laser confocal microscopy observation. Thus, D-amino K122-4 biofunctionalized TNTs present significantly improved mechanical properties, and the mechanically robust structures modulate HGFs proliferation and alignment, resulting in decreased bacteria growth. This novel strategy has the potential to create a surface coating for implants that exhibits superior mechanical robustness and enhanced surface-to-implant interactions.

Gold nanoparticles (AuNPs) have been widely studied in a great mass of cellular biomarkers detection and diagnostics due to their unique combination of physical and optical properties. Sea urchin-like gold nanoparticles (SUL-AuNPs) are well characterized multi-thorn gold nanostructures which possess at least four gold nanothorns on spherical gold surface, mimicking the morphology of sea urchin. Compared to spherical AuNPs, SUL-AuNPs showed a wide variety of light absorption and scattering properties, and the Surface-enhanced Raman Scattering (SERS) properties of SUL-AuNPs were also widely studied dependent on their surface morphology. Herein, three different diameters of SUL-AuNPs based on spherical AuNPs seed-mediated growth method by altering the amount of AuNPs in reaction system had been synthesized. The UV-vis spectrum of synthesized SUL-AuNPs displayed a shift from 550 nm to 650 nm compared to spherical AuNPs. FRET method was applied for the detection of GSH in hepatocytes and cell extracts using rhodamine B (RB) functionalized SUL-AuNPs, among the synthesized three different diameters SUL-AuNPs, 100nm RB-SUL-AuNPs displayed highest sensitivity for GSH detection. What's more, all synthesized SUL-AuNPs turned out to be membrane-permeable, and displayed ignorable cytotoxicity, which make SUL-AuNPs promising cellular thiols detection probes. In particular, it should be noted that the application of RB functionalized SUL-AuNPs exemplify ongoing efforts in design and utility of multifunctional nanoplatforms of SUL-AuNPs.

Carbon nanomaterial/polymer-based flexible strain sensors form the foundations of many cutting-edge applications, e.g., personalized health monitoring, human-machine interaction, etc. However, achieving a high sensitivity to slight deformations remains a challenging task for the existing technologies. Herein, we immobilize silver nanoparticles (AgNPs) onto the surfaces of multi-wall carbon nanotubes (MWNTs) by a polydopamine (PDA)-assisted process, in order to fabricate a new nanocomposite sensor for capturing microscopic static deformations (strain: <1%) and microscopic high-frequency vibrations (strain: <0.001%, frequency: up to 100 s kHz). The material characterizations performed show that AgNPs are compounded, in their elemental state, with the PDA nanolayers on the surfaces of MWNTs, and help to lower the potential barriers between nanofillers. As such, the tunneling of electrons across adjacent nanofillers, which underpins the sensing of slight deformations, is promoted. The proposed nanocomposite sensor demonstrates a significantly higher sensitivity to both static (gauge factor: similar to 38) and dynamic deformations, than control specimens that are fabricated from pure MWNTs or PDA-coated MWNTs. Moreover, the sensitivity of the new sensor to microscopic high-frequency vibrations is positively related to the mass of the AgNPs added. This study presents a promising surface modification approach for optimizing the sensitivities of carbon nanomaterial/polymer-based strain sensors to slight deformations.

Owing to their physical flexibility and exceptional sensitivity to ultrasonic waves, thin-film graphene-based nanocomposite sensors have been gaining prominence in ultrasonic testing-based structural health monitoring (UT-SHM) applications. However, both the electrical conductivities of this new class of sensors and their adhesion on monitoring targets have been found to be highly dependent on temperature. Consequently, under excessive temperature variations, signals that would be output would be disturbed and unable to reflect the health conditions of the monitoring targets, undermining the accuracy of the health monitoring. Herein, we propose a high-thermal-stability thin-film graphene/polyamide-imide sensor for acquiring ultrasonic waves under unstable temperature conditions. The sensor consists of three layers, namely a polyamide-imide-based insulation/adhesion layer (bottom), a graphene/polyamide-imide-based sensing layer (middle), and a silver-based electrode layer (top). It is fabricated by ultrasonic atomization-assisted spray coating and can be formed directly on monitoring targets. Thanks to the adoption of polyamide-imide, the sensor retains a steady electrical conductivity and a strong adhesion on monitoring targets up to 160 degrees C. As a result, its sensitivity to ultrasonic waves exhibits only marginal changes. All in all, this work further promotes the implementation of thin-film graphene-based nanocomposite sensors in real-life UT-SHM applications.

Thin-film graphene/polymer nanocomposite sensors have been shown to be exceptionally sensitive to ultrasonic waves, making them promising next-generation candidates for structural integrity monitoring. However, the ultrasonic sensing mechanism of these sensors has never been scrutinized, restricting the deployment of these sensors to real-life applications. Herein, we carry out the first-ever study on the ultrasonic sensing mechanism of thin-film graphene/polymer nanocomposite sensors, through complementary physical experiments and analytical modelling. At first, sensors were precisely fabricated from nanofillers of different sizes and different matrix materials, and their electrical conductivities and ultrasonic sensitivities were measured. Analytical models that are based on the effective medium theory and the various contact modes between graphene nanofillers, entailing interphase regions and the quantum tunneling effect, were then established and fitted to the experimental results to reveal a series of microscopic characteristics of the sensors fabricated. Through a systematic analysis, it was found that the sizes of nanofillers and the properties of matrices significantly influence the microscopic morphologies and strain-induced dynamics of the sensors, in turn dictating their electrical conductivities and ultrasonic sensitivities. This insightful study will serve as the foundation for realizing applications of high-sensitivity thin-film graphene/polymer nanocomposite sensors in real-life ultrasound-based structural integrity monitoring scenarios.

A fluorescence sensor for Pb2+ detection was developed on the basis of a DNAzyme cleavage and exonuclease III assistant amplification strategy. In the presence of Pb2+, the DNAzyme hybridized with substrate strand and catalyzed the hydrolytic cleavage of the substrate strand, and then the DNAzyme released from the substrate strand and bound another substrate strand to trigger another cycle of hydrolytic cleavage. The DNAzymes were used as catalysts for amplified sensing through multiple turnover reactions. The substrate probe was cleavaged and broken to form a Y-shaped probe which could hybridize and open the molecular beacon, resulting in the increase of the fluorescence signal. At the same time, exonuclease. catalytically digested the molecular beacon from 3'-end and released the Y-shaped substrate strand. The released Y-shaped substrate strand could directly hybridize with another molecular beacon to generate fluorescence signal, and thus was further recognized and cleaved by exonuclease III from the second step of cyclic signal amplification. Accompanying with each cleavage toward molecular probe by exonuclease III the fluorescence signal was accumulated, which resulted in a cyclic amplification format for the fluorescence response toward Pb2+ detection. The fluorescence response was detected in a 200 mu L reaction system that was incubated at 37 degrees C for 60 min. The linear range for detection of Pb2+ was 0.05-200 nmol/L with a detection limit of 0.01 nmol/L, and the recoveries of environmental water samples were 96.3% - 108.3%. This method had many advantages such as simple operation, rapid detection, high selectivity and high sensitivity, and showed great application potential in Pb2+ detection.

为了对内含铝塑板的药盒进行射频识别(RFID),设计了一种无源超高频(UHF)锯齿偶极子抗金属标签天线.采用Ansoft HFSS软件建模仿真,分析了主要结构参数以及铝塑板在药盒中位置的变化对标签天线性能的影响.优化后的结果表明,上述天线具有良好的方向性、抗干扰性和阻抗匹配特性,且带宽能够覆盖UHF RFID频段范围.制作了标签样品并进行了测试,结果表明实测最大阅读距离能满足实际应用的需求.上述天线性能好、尺寸小、结构简单,并可印刷于药盒表面,具有较好的实用价值.

A sensitive method for simultaneous determination of amantadine and rimantadine in feed was developed using an ultra-high-performance liquid chromatography-triple quadrupole linear ion trap mass spectrometry (UHPLC-Qtrap-MS) in the multiple reaction monitoring information-dependent acquisition-enhanced product ion (MRM-IDA-EPI) mode, and employing the mixed cation exchange (MCX) solid-phase extraction column as sample cleanup and amantadine-d15 and rimantadine-d4 as internal standards, respectively. Compared to traditional MRM mode, for the targeted drugs in feed simultaneously both the secondary mass spectra and MRM information can be obtained using UHPLC-Qtrap-MS with MRM-IDA-EPI mode, and thus more accurate qualitative confirmation results achieved even at lower concentration of 0.2 μg/L in acceptable purity fit values. After optimization of sample preparation, good linearities (R > 0.9994) were obtained over the concentration range from 1 to 200 μg/L for amantadine and rimantadine. The precision was validated by intra-day and inter-day, and the relative standard deviations were all within 9.61%. Mean recoveries ranged from 76.1 to 112% at spiked concentrations of 0.5–100 μg/kg in three types of feed samples, including formula feed and complex concentrated feed for pigs and premix feed for chicken. The limits of detection (LODs) and quantification (LOQs) were 0.2 and 0.5 μg/kg for both drugs, respectively. The application in real feed samples further proved the accuracy and reliability of the developed method. This method provides an important tool to detect illegal uses of amantadine and rimantadine in feed.

Implant-associated infections in orthopaedic surgeries are very critical as they may hinder bone healing, cause implant failure and even progress to osteomyelitis. Drug-eluting implants for local delivery of antibiotics at surgical sites are thought to be promising in preventing infections. Herein, the antibiotic vancomycin was encapsulated in a poly(ethylene glycol) (PEG)-based hydrogel film that was covalently bound to Ti implants and subsequently covered by a PEG-poly(lactic-co-caprolactone) (PEG-PLC) membrane. Additionally, crosslinked starch (CSt) was mixed with the hydrogel because its porous microstructure is able to inhibit hydrogel swelling and thus slow down drug release. The release behavior could be regulated by the drug loading and the coating thickness. The vancomycin-loaded Ti implants showed no initial burst release, offering a sustained drug release for nearly 3 weeks in vitro and more than 4 weeks in vivo. In a rabbit model of S. aureus infection, the implants with a 4 mg vancomycin loading significantly reduced the inflammatory reaction and exhibited a good antimicrobial capability. The immobilization of the antibiotic-loaded polymeric coatings on orthopaedic implants can offer a sustainable drug release with no initial burst release and maintain an effective concentration for a longer time, so it is expected to be an effective strategy to treat and prevent local bone infections.

Currently, the major issues in the treatment of osteoarticular tuberculosis (TB) after implant placement are low drug concentration at the infected focus and drug resistance resulting from the long-term chemotherapy. The application of drug-loaded polymeric multilayers on implantable devices offers a promising solution to the problems. Herein, a poly(ethylene glycol)-based hydrogel film embedded with isoniazid (INH)-loaded alginate microparticles was fixed to Ti implants via adhesive polydopamine, subsequently capped by poly(lactic-co-glycolic acid) membranes for the sustained and localized delivery of the anti-TB drug. The antibacterial efficacy of the released INH was confirmed by a 4.5 ± 0.8 cm inhibition zone formed in the fourth week after inoculation of Mycobacterium tuberculosis. The INH-loaded Ti implants showed no toxicity to the osteoblast cell and provided a consistent drug release for nearly one week in vitro. The release profile in vivo showed a high local concentration and low systemic exposure. The local INH concentration could be kept higher than its minimum inhibitory concentration over a period of 8 weeks, which proves that it is a promising strategy to improve the severe osteoarticular TB treatment.

Here, we demonstrate the first known approach to create G1 and G2 POSS dendrimers with 9 and 65 POSS units, and 56 and 392 terminal vinyl groups from a 1 → 7 branching monomer in only one and three steps.

A fast method for simultaneous determination of amantadine, rimantadine, and chlorpheniramine in seven animal derived samples was developed using LC-MS/MS with a new multifunctional syringe filter based on the QuEChERS method.