Promising Applications Research Articles

Evaluation of the Composite Skin Patch Loaded with Bioactive Functional Factors Derived from Multicellular Spheres of EMSCs for Regeneration of Full-thickness Skin Defects in Rats.

Transplantation of stem cells/scaffold is an efficient approach for treating tissue injury including full-thickness skin defects. However, the application of stem cells is limited by preservation issues, ethical restriction, low viability, and immune rejection in vivo. The mesenchymal stem cell conditioned medium is abundant in bioactive functional factors, making it a viable alternative to living cells in regeneration medicine. Nasal mucosa-derived ecto-mesenchymal stem cells (EMSCs) of rats were identified and grown in suspension sphere-forming 3D culture. The EMSCs-conditioned medium (EMSCs-CM) was collected, lyophilized, and analyzed for its bioactive components. Next, fibrinogen and chitosan were further mixed and cross-linked with the lyophilized powder to obtain functional skin patches. Their capacity to gradually release bioactive substances and biocompatibility with epidermal cells were assessed in vitro. Finally, a full-thickness skin defect model was established to evaluate the therapeutic efficacy of the skin patch. The EMSCs-CM contains abundant bioactive proteins including VEGF, KGF, EGF, bFGF, SHH, IL-10, and fibronectin. The bioactive functional composite skin patch containing EMSCs-CM lyophilized powder showed the network-like microstructure could continuously release the bioactive proteins, and possessed ideal biocompatibility with rat epidermal cells in vitro. Transplantation of the composite skin patch could expedite the healing of the full-thickness skin defect by promoting endogenous epidermal stem cell proliferation and skin appendage regeneration in rats. In summary, the bioactive functional composite skin patch containing EMSCs-CM lyophilized powder can effectively accelerate skin repair, which has promising application prospects in the treatment of skin defects.

The Cutting-edge of CRISPR for Cancer Treatment and its Future Prospects.

CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) is a versatile technology that allows precise modification of genes. One of its most promising applications is in cancer treatment. By targeting and editing specific genes involved in cancer development and progression, CRISPR has the potential to become a powerful tool in the fight against cancer. This review aims to assess the recent progress in CRISPR technology for cancer research and to examine the obstacles and potential strategies to address them. The two most commonly used CRISPR systems for gene editing are CRISPR/Cas9 and CRISPR/Cas12a. CRISPR/Cas9 employs different repairing systems, including homologous recombination (HR) and nonhomologous end joining (NHEJ), to introduce precise modifications to the target genes. However, off-target effects and low editing efficiency are some of the main challenges associated with this technology. To overcome these issues, researchers are exploring new delivery methods and developing CRISPR/Cas systems with improved specificity. Moreover, there are ethical concerns surrounding using CRISPR in gene editing, including the potential for unintended consequences and the creation of genetically modified organisms. It is important to address these issues through rigorous testing and strict regulations. Despite these challenges, the potential benefits of CRISPR in cancer therapy cannot be overlooked. By introducing precise modifications to cancer cells, CRISPR could offer a targeted and effective treatment option for patients with different types of cancer. Further investigation and development of CRISPR technology are necessary to overcome the existing challenges and harness its full potential in cancer therapy.

Efficient peroxydisulfate activation with γ-Al2O3-C-MIL-100(Fe) framework for sulfamethazine degradation: Enhanced oxidant utilization and reduced metal leaching

Low degradation efficiency and significant transition metal leaching are two challenges in persulfate activation systems based on metal-organic frameworks (MOFs) for organic pollutant degradation. Here, the challenges were solved by designing and synthesizing a micron-sized core-shell material, γ-Al2O3-C-MIL-100(Fe) (γACM), by coating the γ-Al2O3 core with carbon (γ-Al2O3-C) and futher modifying with MIL-100(Fe). Testing γACM with sulfamethazine (SMZ) demonstrated its outstanding peroxydisulfate (PDS) activation, achieving 92.5 % SMZ removal within 20 min at a low oxidant/pollutant ratio. Fe leaching from γACM was effectively inhibited, with only 3.59 % Fe lost after three recycles. The system showed adaptability across a wide pH range, and usability in sewage effluent, indicating promise for practical application. The hydrophobicity of γ-Al2O3-C, the coordinatively unsaturated sites in MIL-100(Fe), and the strong bounding of MIL-100(Fe) on γ-Al2O3-C ensured the effective SMZ gather, PDS activation, and Fe stability respectively, which led to the excellent performances of γACM.

Dual-wavelength superscattering in plasmonic core-shell nanostructures for transparent structural color

Structural coloration generates some of the most vibrant colors in nature and has numerous applications. Inspired by the recently reported transparent displays relying on wavelength-selective scattering, we address the novel problem of transparent structural color, which requires nanoparticles to have a narrow-band and broad-angle scattering response. Although superscattering beyond the single-channel limit has important prospects for enhancing transparent displays, it has not yet been reported. Here, we propose a simple dielectric-gold core–shell nanoparticle capable of superscattering at blue (λ = 450 nm) and green (λ = 532 nm) wavelengths, along with a dipolar surface plasmon resonance (SPR) at the red wavelength (λ = 640 nm), making it suitable for full-color transparent displays. We demonstrate that the superscattering at λ = 450 nm arises from the overlap of the epsilon-near-zero (ENZ) dipolar and quadrupolar modes. Furthermore, the coupling of conventional quadrupolar and dipolar modes can also enhance the scattering efficiency at λ = 532 nm, breaking the single-channel limit. Lastly, we show that the optimized nanoparticles can confine the scattering light within the forward hemisphere at λ = 450 nm and 532 nm, due to the interaction of quadrupolar and dipolar modes. Additionally, they exhibit dipole far-field radiation characteristics at λ = 640 nm with a wide angular beamwidth > 60°. The simple structural nature and unique scattering properties of proposed dielectric-gold core–shell nanoparticles hold promise applications in full-color transparent displays, spectroscopy, and biomedical imaging.

Identification of PLAC8 as a Potential Biomarker for the Diagnosis of Interstitial Cystitis.

Interstitial cystitis is a diagnosis of exclusion due to the complexity of its etiology and pathology, which is a chronic disease with an unknown etiology. To our knowledge, few studies were performed to identify predictive biomarkers for interstitial cystitis. This study aimed to identify and validate potential biomarkers for Interstitial Cystitis (IC). The interstitial cystitis datasets were retrieved from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified by using the R package and were subjected to functional and pathway enrichment analysis. Key biomarkers of interstitial cystitis were identified by using Lasso regression analysis and the SVM-RFE algorithm. The diagnostic value of key biomarkers was validated in internal and external datasets, and pathways that relate to biomarkers of interstitial cystitis were screened. The ssGSEA was employed to identify the immune cells closely related to biomarkers. The expression of PLAC8 in patients with interstitial cystitis was detected by Immune-Histochemistry (IHC). Sixteen differentially expressed genes associated with interstitial cystitis were identified, which were primarily linked to the biological process of the chemokine signaling pathway. PLAC8, identified as a biomarker for interstitial cystitis, was validated to express a significantly different between IC and normal bladder tissues. PLAC8-related pathways were analyzed, with a focus on NF-κB, TNF, Toll-like receptor, chemokine, IL-17, and JAK-STAT signaling pathways. PLAC8 was proved to be closely related to immune activations, which is similar to the pathogenesis of IC, which is a chronic dysregulated immune disease. Meanwhile, we also observed a higher level of PLAC8 in IC tissues. PLAC8 has promising application prospects as a biomarker for interstitial cystitis diagnosis. These findings could aid in the diagnosis and treatment of interstitial cystitis.

Impact of Mesenchymal Stem Cells on the Gut Microbiota and Microbiota Associated Functions in Inflammatory Bowel Disease: A Systematic Review of Preclinical Evidence on Animal Models.

Inflammatory bowel disease (IBD) is a global health problem in which gut microbiota dysbiosis plays a pivotal pathogenic role. Mesenchymal stem cells (MSCs) therapy has shown promising application prospects for its powerful immune regulation and tissue repair ability. Recent experimental data suggest that MSCs also regulate the composition of gut microbiota. The current review analyzed, for the first time, the research data linking MSCs and gut microbiota modulation in IBD models aiming at assessing the role of gut microbiota in MSCs repair of IBD. A comprehensive and structured literature search was performed up to January 2023 on the PubMed, Web of Science, and Scopus databases. The quality and risk of bias assessment followed the PRISMA guidelines and SYRCLE's tool. A total of nine pre-clinical studies on animal models were included. Although the dose and route of MSCs applied were quite heterogeneous, results showed that MSCs displayed protective effects on intestinal inflammation, including mice general assessment, immunoregulation, and intestinal barrier integrity. Meanwhile, studies showed positive effects on the composition of gut flora with MSCs administration, which had been characterized by restoration of Firmicutes/ Bacteroides balance and reduction of Proteobacteria. The beneficial bacteria Akkermansia, Bifidobacterium, and Lactobacillus were also distinctly enriched, and the pathogenic bacteria Escherichia-Shigella was conversely decreased. The alpha and beta diversity were also regulated to resemble those of healthy mice. Microbial metabolic functions, such as biosynthesis of secondary bile acid and sphingolipid metabolism, and some biological behaviors related to cell regeneration were also up-regulated, while cancer function and poorly characterized cellular function were down-regulated. Current data support the remodeling effect on gut microbiota with MSC administration, which provides a potential therapeutic mechanism for MSCs in the treatment of IBD. Additional studies in humans and animal models are warranted to further confirm the role of gut microflora in MSCs repairing IBD.

Improving unbalanced image classification through fine-tuning method of reinforcement learning

Image classification, especially unbalanced image classification, holds considerable promise for practical applications. Existing research focuses mainly on enhancing the effectiveness of classifiers through approaches such as data resampling and loss function adjustments. To date, most of the approaches address the class unbalanced issue by transforming unbalanced data distributions into balanced [id=SecondEdit]ones. Consequently, a critical challenge is to directly develop high-performance classifiers that are adaptive to diverse unbalanced data distributions. In this paper, for unbalanced image classification tasks, we propose a Reinforcement Learning Fine-tuning approach to Unbalanced image Classification (RLF-UC). Specifically, we train classification pretraining models on [d=FirstEdit]fivethree unbalanced datasetsid=SecondEdit], and train [d=FirstEdit]the correspondinga reward function model designed to optimize fine-tuning policy. Then, we train a reinforcement learning fine-tuning classification model and optimize its policy to maximize the cumulative expected reward. Finally, we guide the model to prioritize minority category knowledge and incorporate distribution distance constraints, which are derived from the disparities between the [d=SecondEdit]pre-trainedpretrained model and the fine-tuning model to dynamically adjust the fine-tuning classifier model. Experimental results on [d=FirstEdit]fivethree reprocessed unbalanced image datasets demonstrate that our RLF-UC method provides comparable or better classification and generalization capabilities than other baselines.

Low‐temperature chemical vapor deposition growth of 2D materials

AbstractTwo‐dimensional (2D) materials have atomic thickness, and thickness‐dependent electronic transport, optical and thermal properties, highlighting great promise applications in future semiconductor devices. Chemical vapor deposition (CVD) is considered as an industry‐oriented method for macro‐synthesis of 2D materials. In conventional CVD, high temperatures are required for the synthesis of high‐quality large‐size 2D materials, which is incompatible with of back‐end‐of‐line of the complementary metal oxide semiconductor (CMOS) techniques. Therefore, low‐temperature synthesis of 2D materials is of critical importance for the advancement toward practical applications of 2D materials with the CMOS technologies. In this review, we focus on strategies for the low‐temperature growth of 2D materials, including the use of low‐melting‐point precursors, metal‐organic CVD, plasma‐enhanced CVD, van der Waals‐substrate vapor phase epitaxy, tellurium‐assisted CVD, salt‐assisted CVD, etc., with discussions of their reaction mechanisms, applications, associated advantages, and limitations. We also provide an outlook and perspectives of future low‐temperature chemical vapor deposition growth of 2D materials.

Arc-Discharge In Situ Synthesis of Dual-Carbonaceous-Layer-Coated SnS Nanoparticles with High Lithium-Ion Storage Capacity.

SnS-based carbon composites have garnered considerable concentration as prospective anode materials (AMs) for lithium-ion batteries (LIBs). Nevertheless, most SnS-based carbon composites underwent a two-phase or multistep preparation process and exhibited unsatisfactory LIB performance. In this investigation, we introduce a straightforward and efficient one-step arc-discharge technique for the production of dual-layer carbon-coated tin sulfide nanoparticles (SnS@C). The as-prepared composite is used as an AM for LIBs and delivers a high capacity of 1000.4 mAh g-1 at 1.0 A g-1 after 520 cycles. The SnS@C still maintains a capacity of 476 mAh g-1 after 390 cycles despite a higher current of 5.0 A g-1. The high specific capacity and long life are mainly attributed to a unique dual-carbon layers coating structure. The dual-carbon layers not only could effectively improve electrical conductivity and reduce charge-transfer resistance but also limit the alteration in bulk and self-aggregation of SnS nanoparticles. The SnS@C produced by the arc-discharge technique emerges as a promising applicant for AM in LIBs, and the arc-discharge technique provides an alternative way for synthesizing other transition metal sulfides supported on carbonaceous materials.

Inspection of Liner Wall Thinning and Interface Debonding in Bimetallic Lined Pipes Using Pulsed Eddy Current Testing.

Bimetallic lined pipe (BLP) has been increasingly used in offshore and subsea oil and gas structures, but how to identify the invisible inner defects such as liner wall thinning and interface debonding is a challenge for future development. A nondestructive testing (NDT) method based on pulsed eddy current testing (PECT) has been proposed to face these difficulties. The inspection of the BLP specimen (AISI1020 base tube and SS304 liner) is implemented from outside of the pipe by using a transmitter-receiver-type PECT probe consisting of two induction coils. By simplifying the BLP specimen to stratified conductive plates, the electromagnetic field interaction between the PECT probe and specimen is analytically modeled, and the probe inspection signals due to liner wall thinning and interface debonding are calculated. In order to highlight the weak response (in microvolts) from the liner, the inspection signals are subtracted by the signal, which is calculated in the case of only having a base tube, yielding differential PECT signals. The peak voltage of the differential signal is selected to characterize the liner wall thinning and interface debonding due to its distinguishable and linear variation. Experiment verification is also carried out on a double-walled specimen simulated by a combination of a Q235 casing pipe and SS304 tubes of different sizes. The experimental results basically agree with the analytical predictions. The peak value of the PECT signal has an ascending and descending variation with the increase in the remaining liner wall thickness and debonding gap, respectively, while the negative peak value shows opposite changes. The peak value exhibits a larger sensitivity than the negative peak value. The proposed method shows potential promise in practical applications for the evaluation of the inner defects in BLP lines.

Synthesis, X-ray, Hirshfeld combined with DFT, anticancer effects with molecular docking confirmation of (E)-4-cyanobenzaldehyde oxime and (Z)–N-methyl-C-4-substituted phenyl aldonitrones

(E)-4-cyanobenzaldehyde oxime 1 and (Z)–N-methyl-C-4-substituted phenyl aldonitrones 2 and 3 were synthesised and fully characterised. With the help of Hirshfeld calculations, the molecular packing of 1 is found to be controlled by short N…H contacts (28.3%) in addition to the aromatic π-π stacking where the%C…C interactions is calculated to be 9.7%. In this case, the second most abundant interaction is H…H contact (28.1%). For 2, the N…H (24.4%) and O…H (13.8%) contacts are the most important while the most abundant interaction is H…H contacts (36.0%). DFT calculations were utilised to explore the structural and electronic parameters of both compounds at their optimised geometries which were found in good agreement with the X-ray structures. The structure of 2 (6.9829 Debye) is more polar than 1 (4.5282 Debye). The compounds 1–3 reduced the growth of MCF-7 and T47D. Compound 1 which has the lowest IC50 values against the MCF-7 and T47D cell lines, is thought to be the most promising applicant as an anticancer drug. The in-silico combination of compounds 1–3 with proliferative proteins PIK3 and CDK5, autophagic proteins mTOR and beclin, antiapoptotic proteins BCL2, and apoptotic proteins caspase 3 was examined. Compound 3 binds to PIK3, CDK5, mTOR, Beclin, BCL2 and caspase 3, and displays higher free energy bindings of −5.12, −5.45, −4.923, −5.72, −4.45 and −4.73 kcal/mol, which suggested that these proteins had the strongest inhibitory or enhanced effects. The findings show that compound 3 was the most well-docked chemical with the greatest IC50. Compound 3 impacted the autophagy, apoptotic and mitotic proteins of cell growth.

Marine Microalgae Schizochytrium sp. S31: Potential Source for New Antimicrobial and Antibiofilm Agent.

The rise of antibiotic-resistant bacteria necessitates the discovery of new, safe, and bioactive antimicrobial compounds. The antibacterial and antibiofilm activity of microalgae makes them a potential candidate for developing natural antibiotics to limit microbial infection in various fields. This study aimed to analyze the antibacterial effect of the methanolic extract of Schizochytrium sp. S31 microalgae by broth microdilution and spot plate assays. The antibacterial effects of Schizochytrium sp. S31 extract was studied on gramnegative pathogens, Pseudomonas aeruginosa, Escherichia coli 35218, Klebsiella pneumonia, which cause many different human infections, and the gram-positive pathogen Streptococcus mutans. At the same time, the antibiofilm activity of the Schizochytrium sp. S31 extract on Pseudomonas aeruginosa and Escherichia coli 35218 bacteria were investigated by crystal violet staining method. Schizochytrium sp. S31 extract at a 60% concentration for 8 hours displayed the highest antibacterial activity against P. aeruginosa, E. coli 35218, and K. pneumonia, with a decrease of 87%, 92%, and 98% in cell viability, respectively. The experiment with Streptococcus mutans revealed a remarkable antibacterial effect at a 60% extract concentration for 24 hours, leading to a notable 93% reduction in cell viability. Furthermore, the extract exhibited a dose-dependent inhibition of biofilm formation in P. aeruginosa and E. coli 35218. The concentration of 60% extract was identified as the most effective dosage in terms of inhibition. This research emphasizes the potential of Schizochytrium sp. S31 as a natural antibacterial and antibiofilm agent with promising applications in the pharmaceutical sectors. This is the first study to examine the antibacterial activity of Schizochytrium sp. S31 microalgae using broth microdilution, spot plate assays, and the antibiofilm activity by a crystal staining method. The findings of this study show that Schizochytrium sp. S31 has antibacterial and antibiofilm activities against critical bacterial pathogens.

Molecular Engineering to Achieve AIE-active Fluorophore with Near-infrared (NIR) Emission and Temperature-sensitive Property.

Near-infrared organic small molecule luminescent materials have the advantages of easy modification, high quantum efficiency, good biological affinity, and color adjustability; thus, have promising application prospects in the fields of photoelectric devices, sensitive detection, photodynamic therapy, and biomedical imaging. However, traditional organic luminescent molecules have the problems of short emission wavelength, aggregation-causing emission quenching, and low quantum yield. Herein, we successfully synthesized four D-π-A-D light-emitting molecules based on electron-withdrawing malonitrile group and different electron-donating arylamine groups. These compounds showed satisfactory solvatochromism, aggregation-induced emission, red and near-infrared fluorescence, high photoluminescence quantum efficiency and temperature response properties. This successful example of molecular engineering provides a valuable reference for the development of advanced NIR materials with AIE and temperature-sensitive properties.

Naphthalene diimide-Annulated Heterocyclic Acenes: Synthesis, Electrochemical and Semiconductor Properties and their Multifaceted Applications.

Acenes and Naphthalene Diimides (NDIs) stand as distinguished classes of organic compounds, each possessing unique and intriguing properties that have garnered significant attention across various scientific disciplines. Acenes, characterized by linearly fused aromatic rings, have captivated researchers due to their diverse electronic structures and promising applications in materials science. On the other hand, NDIs, known for their distinctive electron-accepting properties, exhibit remarkable versatility in fields ranging from organic electronics, supramolecular to spin chemistry. In this review, we navigate through the fascinating realms of both acenes and NDIs before converging our focus on the highly diverse and distinctive subgroup of NDI-annulated heterocyclic acenes. This potentially important subgroup, has emerged as a subject of intense investigation, encapsulating their fascinating synthesis, optical and electrochemical characteristics, and multifaceted applications that span the realms of chemistry, physics, and biology. Through the exploration of their synthetic strategies, unique properties, and diverse applications, this review aims to offer a comprehensive understanding of the pivotal role played by NDI-based heterocyclic acenes in contemporary multidisciplinary research and technological innovation.

Complete Genome Resource of a Fungal Antagonistic Strain: Pseudomonas tohonis

KRS022 was isolated from the rhizosphere soil of a healthy plant in a pathogen-infested cotton field in Xinjiang, China. Previous studies have demonstrated that KRS022 possesses the ability to trigger plant immune responses, inhibit the growth of various pathogenic fungi, including Verticillium dahliae, and promote plant growth. The antagonistic properties of KRS022 primarily stem from its bioactive metabolites. In this study, the high-quality genome of KRS022 was obtained. The KRS022 genome consists of a chromosome of 6,369,026 bp with 67.09% GC content and possesses 5,830 open reading frames, of which 5,186 genes were annotated, and 119 were ncRNA genes. Additionally, 11 gene clusters of secondary metabolites biosynthesis were predicted, involved in polyketide synthase, arylpolyene, NAGGN, beta-lactone, ranthipeptide, PiPP-like, redox cofactor, and non-ribosomal peptide-synthetase clusters. It could be useful to explore the biocontrol potential of P. tohonis, implying promising application of KRS022 to biological control. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Optimized Incorporation of Furan into Diketopyrrolopyrrole-Based Conjugated Polymers for Organic Field-Effect Transistors.

Flexible electronics have received considerable attention in the past decades due to their promising application in rollable display screens, wearable devices, implantable devices, and other electronic applications. In particular, conjugated polymers are favored for flexible electronics due to their mechanical flexibility and potential for solution-processed fabrication techniques, such as blade-coating, roll-to-roll printing, and high-throughput printing allowing for high-performance transistor devices. Thiophene is the prevailing conjugated unit to construct these conjugated polymers due to its favorable electronic properties. On the other hand, furans are among the few conjugated moieties that are easily derived from bio renewable resources. To promote sustainability, we selectively introduced furan into the conjugated backbone of a high-mobility polymer scaffold and systematically studied the effect on the microstructure and charge transport. We show that partially and selectively replacing thiophene units with furan can yield nearly comparable performance compared to the all-thiophene polymer. This strategy offers an improvement in the sustainability of the polymer by incorporating bio-sourced furan without sacrificing the high-performance characteristics. Meanwhile, polymers with incorrect or complete furan incorporation show reduced mobilities. This work serves to develop coherent structure-morphology-performance relationships; such knowledge will establish guidelines for the future development of sustainable, furan-based conjugated materials.

Multiple Natural Polymers in Drug and Gene Delivery Systems.

Natural polymers are organic compounds produced by living organisms. In nature, they exist in three main forms, including proteins, polysaccharides, and nucleic acids. In recent years, with the continuous research on drug and gene delivery systems, scholars have found that natural polymers have promising applications in drug and gene delivery systems due to their excellent properties such as biocompatibility, biodegradability, low immunogenicity, and easy modification. However, since the structure, physicochemical properties, pharmacological properties and biological characteristics of biopolymer molecules have not yet been entirely understood, further studies are required before large-scale clinical application. This review focuses on recent advances in the representative natural polymers such as proteins (albumin, collagen, elastin), polysaccharides (chitosan, alginate, cellulose) and nucleic acids. We introduce the characteristics of various types of natural polymers, and further outline the characterization methods and delivery forms of these natural polymers. Finally, we discuss possible challenges for natural polymers in subsequent experimental studies and clinical applications. It provides an important strategy for the clinical application of natural polymers in drug and gene delivery systems.

Enhanced electrical, optical and magnetic properties of BiFeO3 perovskite nanoparticles co-doped with Y and Cu

The present work includes the fabrication of pure BiFeO3 and Bi0.9Y0.1Fe1−xCuxO3 (x = 0.05, 0.10, 0.15) nanoparticles by the usual sol-gel route. The characterization of structural, morphological, optical, electrical, and magnetic properties of the synthesized samples was achieved through x-ray diffraction spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, an impedance analyzer, and a vibrating sample magnetometer. The Fourier transform infrared study confirmed the presence of Bi–O and Fe–O bonds. The x-ray diffraction patterns confirmed the rhombohedral (R3c) structure as a major phase with the orthorhombic (Pnma) structure as a secondary phase in all samples, and few amount of impurity phase of Bi25FeO40 was also determined. The surface morphology analysis showed the variation of particle size from 63 to 174 nm. The Raman spectra of 13 optical phonon modes, including 4A1 and 9E symmetric phonons, are observed for all samples, and the positions of these modes are almost similar, except the intensities of A1 modes. The optical measurements show a reduction in bandgap from 2.17 to 2.03 eV with co-doping, revealing itself as a more promising applicant in photovoltaics. An enhanced value of the dielectric constant is observed for different doped samples at different frequency regions from 100 Hz to 10 MHz. Magnetic investigation demonstrates the improved ferromagnetism with co-doping of Y and Cu due to distortion in the FeO6 octahedron. A maximum saturation magnetization of 0.26 emu/gm and a coercivity of 2915 Oe were found for Y concentration of 10% and Cu concentration of 15%.

A high-power ultrasonic transducer operated in MHz range by circular plate bending mode using a single parabolic reflector

This research developed a HF, high-power ultrasonic transducer. Operating at 1.54 MHz, the transducer generated plane waves through the excitation of the thickness mode of a piezoelectric ring. These waves are subsequently focused by a parabolic reflector, exciting the bending mode of a circular plate and yielding substantial mechanical output at the center. Under a driving voltage of 48 Vpp, the transducer achieved a saturation velocity of 11.7 mpp/s. The mechanical quality factor ( Qm ) of the resonant mode is calculated using the half-power bandwidth method, resulting in a value of approximately 1250. The proposed transducer exhibits outstanding performance and holds promising applications in the fields of biology, medicine, and sonochemistry.

In-situ exfoliation of hexagonal boron nitride during the forced flow of highly elastic polylactide to fabricate electrospun fibrous film with high thermal conductivity and low dielectric loss

Boron nitride nanosheets (BNNS) have promising applications in thermal management materials, due to their high thermal conductivity and low dielectric loss. However, it is still challenging to fabricate BNNS with large lateral size and structural integrity via solvent-free methods. Here, we report a novel processing method for in-situ exfoliation of hexagonal boron nitride (h-BN) to fabricate BNNS with an average lateral size of 1.45 μm, average thickness of 4.88 nm and few lattice defects during the forced flow of polylactide (PLA) in a highly elastic state. We further fabricate flexible and bio-degradable PLA/BNNS electrospun fibrous film for electronic devices to replace petroleum-based composites. The PLA/BNNS fibrous film exhibits an in-plane thermal conductivity of 4.9 W/(m·K) at the BNNS loading of 20 wt%. Moreover, the fibrous film also has a low dielectric loss (0.007 at 1 kHz) and good electrical insulation. The in-situ exfoliation strategy is simple, economical and environmentally friendly, providing an effective route to design thermal management materials with high thermal conductivity and low dielectric loss in the future of electronic devices.