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With the development of new sensor technology, flexible piezoelectric materials possessing exceptional mechanical-to-electrical energy conversion capabilities hold great promise for application in a variety of sectors, including biomedicine, flexible robotics, and wearable electronic devices. This work reports the successful growth of an all-inorganic transparent Bi(Fe0.95Mn0.05)O3 (BFOMn) film on the Mica substrate using a straightforward one-step sol–gel method. The prepared BFOMn thin film enables the optimum electrical properties with a saturated polarization of ~ 92 μC/cm2, a remanent polarization of ~ 74 μC/cm2, and a high piezoelectric constant d33 of ~ 405 pm/V. Concurrently, the film exhibits exceptional adaptability without compromising its electrical performance, as evidenced by its capacity to undergo a tight curve with a radius of just 2 mm. Utilizing this BFOMn film, the fabricated flexible piezoelectric energy harvester (FPEH) has exceptional energy collecting capabilities, producing an output voltage of 15 V, a short current of 130 nA, and a notable force sensitivity of 4 V·N−1 before poling. It can also be employed to monitor human actions, such as hand hammering, hand clapping, and foot stepping. This work demonstrates the potential of the BiFeO3-based FPEH/sensor in the field of new intelligent electronics. [ABSTRACT FROM AUTHOR]

In this paper, we present a method to achieve exponential stability in a class of impulsive delayed neural networks containing parameter uncertainties, time-varying delays, and impulsive effect and reaction–diffusion terms. By using an integro-differential inequality with impulsive initial conditions and employing the M-matrix theory and the nonlinear measure approach, some new sufficient conditions ensuring the global exponential stability and global robust exponential stability of the considered system are derived. In particular, the results obtained are presented by simple algebraic inequalities, which are certainly more concise than the previous methods. By comparisons and examples, it is shown that the results obtained are effective and useful. [ABSTRACT FROM AUTHOR]

BiFeO3 (BFO), Mn-doped-BFO (BFMO), Ti-doped-BFO (BFTO), and (Mn,Ti)-codoped-BFO (BFMTO) thin films are fabricated on the Pt/TiO2/SiO2/Si substrates via a sol–gel method combined with spin-coating and the subsequent layer-by-layer annealing technique. Compared with BFO film, the BFMTO film exhibits the lowest leakage current density (∼ 1 0 − 4 A/cm2@290 kV/cm). Notably, the polarization–electric field (P–E) loop of BFMTO film exhibits a positive displacement along the x-axis due to the existence of internal bias electric field, which is in agreement with the results of the PFM phase and amplitude curves. Especially, a very prominent inverse piezoelectric constant of d 3 3 ∼ 1 6 0 pm/V was obtained, which overcomes other related thin films. The internal bias electric field of BFMTO film can be caused by the different work functions of the thin film and the bottom electrode, accumulation of oxygen vacancies and the formation of defect dipoles. Besides, the internal bias electric field of BFMTO film has a good stability at the same electric field after experiencing the test cycle from low electric field to high electric field (400–1900 kV/cm). These results indicate that self-polarized BFMTO film can be integrated to devices without additional polarization process, and have a wide range of application in microelectromechanical systems. [ABSTRACT FROM AUTHOR]

(1 - x) CaBi4Ti4O15-xBi(Fe0.93Mn0.05Ti0.02)O3 (CBT-xBFMT, x = 0, 0.05, 0.10, 0.15) solid solution films were successfully prepared on Pt (111)/TiO2/SiO2/Si substrates using metal organic decomposition combined with spin coating technology. And the energy storage properties of CBT thin films were systematically studied by X-ray diffractometer, field emission scanning electron microscope, ferroelectric analyzer and impedance analyzer. The results show that the prepared films all exhibit a polycrystalline bismuth layered structure without other phase formation. The addition of BFMT into thin film obviously enhances the maximum polarization strength Pm and breakdown field strength Eb, reduces the leakage current density. With the increase of BFMT solid solution, the breakdown field strength Eb of CBT-xBFMT film increases first and then decreases, and reaches the maximum value at x = 0.10. The maximum polarization strength Pm gradually increases, and the largest polarization strength difference is obtained at x = 0.10. The largest polarization intensity difference and breakdown field strength make CBT-0.10BFMT film has the best energy storage properties. The recoverable energy storage density Wrec and energy storage efficiency η of CBT-0.10BFMT film are up to 82.8 J/cm³ and 78.3%, respectively. And its energy storage characteristic has good temperature stability in the temperature range of 25 ~ 150 °C. Therefore, CBT-0.10BFMT ferroelectric film is expected to be used in environmentally friendly micro energy storage devices. [ABSTRACT FROM AUTHOR]

With the urgent need for antiviral agents, antiviral materials with high biocompatibility and antiviral effects have attracted a lot of attention. In this study, gallic acid, a natural polyphenolic compound, was transformed into biocompatible graphene quantum dots (GAGQDs) which exhibit enhanced antiviral activity against pseudorabies virus (PRV). The as-prepared GAGQDs inhibit PRV proliferation with a 104-fold reduction in viral titers. Investigation of the antiviral mechanism revealed that GAGQDs inhibit the adsorption, invasion and replication of PRV infection. Treatment with GAGQDs regulates the expression levels of interferon-related antiviral proteins, including mitochondrial antiviral-signaling protein (MAVS), signal transducer and activator of transcription 1 (STAT1) and 2′,5′-oligoadenylate synthetase 1 (OAS1), suggesting that GAGQDs can stimulate innate antiviral immune responses, resulting in enhanced antiviral effects. More importantly, GAGQD treatments alleviate clinical symptoms and reduce mortality in PRV-infected mice. Our results reveal the enhanced therapeutic effects of GAGQDs against PRV infection in vitro and in vivo, suggesting the potential of GAGQDs as a promising novel antiviral agent. [ABSTRACT FROM AUTHOR]

Developing aqueous-phase and metal-free room temperature (RT) long-afterglow materials should be of great significance for printable anti-counterfeiting encryption, LEDs and autofluorescence-free biosensing and bioimaging. However, the utility and reliability are greatly limited by the unstable structure of organic phosphors and thermally and moisture-induced emission quenching. Herein, silane-derived aqueous-phase delayed fluorescence (DF) carbon dots (CDs) were prepared using a hydrothermal route with 1,3-bis (3-aminopropyl)-1, 1,3,3-tetramethyldisiloxane as a single carbon precursor. The formed Si, N self-doped CDs subsequently embedded in a silica matrix (denoted as DF-CDs@SiO2) display bright blue RT-DF with a fluorescence quantum yield (QY) of 35.11% and an afterglow lifetime of about 434 ms, which can be observed with the naked eye for 10 s. The silica network formed by the hydrolysis of the silica–oxygen bonds in the silane can effectively limit the vibrations of the underlying chromophore of the CDs and achieve efficient DF emission. In particular, DF-CDs@SiO2 can be used as an efficient donor for multicolor afterglow via Förster resonance energy transfer, which has strong potential for applications in advanced information encryption, LEDs, hydrogel-based biosensing, and autofluorescence-free bioimaging. [ABSTRACT FROM AUTHOR]

Ferroelectric Aurivillius compounds have the unique electric resistance and fatigue-free features due to the natural superlattice structure, which is benefit for exploring high energy storage performance. However, the inherent constraints of relatively low polarization and large hysteresis seriously hamper their applications in energy storage field. In this work, the CaBi4Ti4O15 (CBTi) is taken as a research sample, and a multilayer structure based on CBTi and Bi(Fe0.93Mn0.05Ti0.02)O3 (BFO) is designed. A good balance among the ferroelectric polarization, breakdown strength, and the shape of ferroelectric hysteresis is proposed by regulating by optimizing the BFO sublayer number (N). A large energy density of 70.4 J cm−3 and high efficiency of 73.8% are simultaneously obtained in CBTi/BFO multilayer film with N = 2. Meanwhile, no obvious deterioration of the energy storage performance is observed in a wide range of working temperature (− 25–200 °C), operating frequency (500 Hz to 20 kHz), and fatigue cycles (107). This work exhibits an effective route for designing high-performance Aurivillius structure films in energy storage in the future by constructing multilayer structure. [ABSTRACT FROM AUTHOR]

Piezoelectric micromachined ultrasound transducers (pMUTs), especially those using lead-free materials, are crucial next-generation microdevices for precise actuation and sensing, driving advancements in medical, industrial, and environmental applications. Bismuth ferrite (BiFeO 3 ) is emerging as a promising lead-free piezoelectric material to replace Pb(Zr,Ti)O 3 in pMUTs. Despite its potential, the integration of BiFeO 3 thin films into pMUTs has been hindered by poling issues. Here, a BiFeO 3 heterostructure compositionally downgraded with Gd doping is developed to introduce compressive strain, resulting in strong self-poling. Utilizing a large-area self-poled thin film over an entire 6-inch wafer, a pMUT with a 6 × 6 array at the device level is designed and evaluated. At a resonant frequency of 21 kHz, the dynamic vibration displacement can reach 24.0 nm. At 500 Hz, far below the resonant frequency of 21 kHz, the pMUT also displays sensitive converse piezoelectric response, even at a high temperature of 200 °C. This work represents a significant breakthrough in lead-free BiFeO 3 thin film for practical sensing applications, paving the way for the transformation of macro-transducers into next-generation functional microdevices., (© 2024 Wiley‐VCH GmbH.)

Glaesserella parasuis is the pathogen that causes Glässer's disease in pigs, which is characterized by fibrinous polyserositis, arthritis and meningitis. Research on ribosomal protein L32 in microorganisms has mainly focused on regulating gene transcription and translation, but its effect on bacterial virulence is unclear. The role of L32 gene in G. parasuis is not clear, and in order to study the function of L32 gene, a suicide plasmid-mediated natural transformation method was used to construct a L32 gene deletion mutant. We found that although L32 was shown to be non-essential for cell proliferation, the growth curve of Δ L32 is clearly different compared with that of ZJ1208. Δ L32 produced more outer membrane vesicles (OMVs) with a variety of irregular shapes, but produced similar biofilm to the parental strain. Δ L32 is more sensitive to osmotic pressure, oxidation pressure and heat shock stress. Meanwhile, Δ L32 is significantly more susceptible to antimicrobials such as spectinomycin, apramycin, sulfafurazole, but not to other antibiotics used in this study. In the mouse challenge experiment, the mortality of mice infected with the mutant strain decreased by 40% compared to those infected with the wild-type strain, indicating that L32 is a virulence-associated factor which contributes to bacterial fitness in host environments. The above results show that L32 is important for the growth, stress resistance and virulence of G. parasuis , and this study also confirms for the first time that L32 plays an important role in antibiotic resistance against aminoglycosides and sulfonamides., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Chen, Yu, Su, Ye, Xu, Yuan, Wu, Zhang and Li.)

Haemophilus parasuis is an economically important bacterial pathogen of swine. Extensive genetic and phenotypic heterogeneity among H. parasuis strains have been observed, which hinders the deciphering of the population structure and its association with clinical virulence. In this study, two highly divergent clades were defined according to iron-sulphur cluster regulator ( iscR )-based phylogeny analysis of 148 isolates. Clear separation of serovars and potential virulence markers (PVMs) were observed between the two clades, which are indicative of independent evolution of the two lineages. Previously suggested virulence factors showed no correlation with clinical virulence, and were probably clade or serovar specific genes emerged during different stage of evolution. PVMs profiles varied widely among isolates in the same serovar. Higher strain diversity in respect of PVMs was found for isolates from multi-strain infected farms than those from single strain infected ones, which indicates that multi-strain infection in one farm may increase the frequency of gene transfer in H. parasuis . Systemic isolates were more frequently found in serovar 13 and serovar 12, while no correlation between clinical virulence and iscR -based phylogeny was observed. It shows that iscR is a reliable marker for studying population structure of H. parasuis , while other factors should be included to avoid the interference of gene exchange of iscR between isolates. The two lineages of H. parasuis may have undergone independent evolution, but show no difference in clinical virulence. Wide distribution of systemic isolates across the entire population poses new challenge for development of vaccine with better cross-protection. Our study provides new information for better deciphering the population structure of H. parasuis , which helps understanding the extreme diversity within this pathogenic bacterium., Competing Interests: The authors declare that they have no competing interests.

Studies on virulence factors and pathogenecity of Haemophilus parasuis have long been hindered by a lack of a consistent system for genetic manipulation. In this study, competence was induced by transferring H. parasuis from rich medium to starvation medium media-IV (M-IV) and iscR gene deficient mutants of H. parasuis were generated efficiently. Transformation frequency varied from 4.1 × 10 -5 to 1.1 × 10 -8 when using circular plasmid, and increased to about 2- to 31-fold when transformed using linearized plasmid. Allele replacement occurred efficiently in 6 strains, which are transformable using both circular and linearized pTRU, but not in another 2 strains which could only be transformed using linearized plasmid. The iscR mutants were stable for at least 20 passages in vitro . Haemophilus parasuis strains vary extensively in natural transformation efficiency and the method established here allows for transformation of a larger spectrum of strains with an easily accessed plasmid. This provides important tools for genetic manipulation of H. parasuis .