Electrical de-poling and re-poling of relaxor-PbTiO3 piezoelectric single crystals without heat treatment.

Re-poling of unexpected partially depoled piezoelectric materials conventionally needs to be first fully depoled through annealing above their Curie temperature to revive piezoelectric performances. Here, we investigated de-poling and re-poling of Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystals under electric fields at room temperature. We found that alternating current electric fields with amplitudes near the coercive field at low frequencies (<10 Hz) can be employed to successfully depolarize poled crystals at room temperature. We also demonstrated a reversible polarization switching process with a relaxor-PbTiO3 single crystal ultrasound transducer without device performance degradations. This experimental observation is supported by phase-field simulation, showing that alternating current electric fields can readily induce de-poling at room temperature, while direct current electric fields induce a transient depoled state only within an uncontrollable short period of time. The findings suggest new strategies for unprecedented in-device tailoring of the polarization states of ferroelectric materials.

Numerical modeling of ultrasound-triggered microneedle-mediated delivery of drug particles into bacterial biofilms.

Ultrasonic microneedle patches, a class of ultrasound-driven transdermal drug delivery systems, are promising in addressing bacterial biofilms. This device has been proven to be more effective in treating Staphylococcus aureus biofilms than drug in free solution. However, there exists a notable gap in understanding how various excitation conditions and material parameters affect drug delivery efficiency. This study aims to fill this void by conducting an comprehensive multi-physics numerical analysis of ultrasonic microneedle patches, with the ultimate goal of enhancing drug delivery. First, we investigate the impact of various ultrasound frequencies on drug penetration depths. The findings reveal that local resonance can accelerate drug release within a shorter time window (first 1.5 h), whereas non-resonant frequencies enable more profound and prolonged diffusion. This information is crucial for medical professionals in selecting the most effective frequency for optimal drug administration. Furthermore, our investigation extends to the effects of applied voltage on temperature distribution, a critical aspect for ensuring medical safety during the application of these patches. Additionally, we examine how particles of different sizes respond to acoustic pressure and streaming fields, providing valuable insights for tailoring drug delivery strategies to specific therapeutic needs. Overall, our findings offer comprehensive guidelines for the effective use of ultrasonic microneedle patches, potentially shifting the paradigm in patient care and enhancing the overall quality of life.

Association of impulsive behavior and cerebrospinal fluid/plasma oxidation and antioxidation ratio in Chinese men.

OBJECTIVES: Impulsive behavior is the precursor of many psychiatric and neurological conditions. High levels of impulsive behavior will increase health risk behavior and related injuries. Impulsive behavior is produced and regulated by central and peripheral biological factors, and oxidative stress (OS) can aggravate it. However, previous studies only showed that impulsive behavior was related to the level of the peripheral OS. Therefore, this study aims to clarify the relationship between OS and impulsive behavior in the brain and peripheral blood. METHODS: We recruited 64 Chinese men. We measured superoxide dismutase (SOD) (including copper, zinc and manganese) and nitric oxide synthase (NOS) (including total, inducible and constitutive) in cerebrospinal fluid (CSF) and plasma. The Barratt Impulsiveness Scale version 11 (BIS-11) was used to evaluate impulsive behavior. The relationship between OS and impulsive behavior was evaluated by partial correlation analysis and stepwise multiple regression analysis. RESULTS: Partial correlation analysis showed that the ratio of total NOS-to-MnSOD and iNOS-to-MnSOD in CSF were negatively correlated with the BIS-11 motor scores (r = -0.431, p = -0.001; r = -0.434, p = -0.001). Stepwise multiple regression analysis showed that the ratio of CSF iNOS-to-MnSOD was the most influential variable on the BIS-11 motor scores(ß = -0.434, t = -3.433, 95 %CI(-0.374, -0.098), p = 0.001). CONCLUSIONS AND RELEVANCE: The imbalance of central oxidation and antioxidation is related to impulsive behavior, which broadens our understanding of the correlation between impulsive behavior and OS.

High-Performance PMN-PT Single-Crystal-Based 1-3 Composite Transducer Integrated with a Biopsy Needle.

To address the need for high-resolution imaging in lung nodule detection and overcome the limitations of the shallow imaging depth associated with high-frequency ultrasound and the complex structure of lung tissue, we successfully integrated 50 MHz ultrasound transducers with 18-gauge biopsy needles. Featuring a miniaturized size of 0.6 × 0.5 × 0.5 mm3, the 50 MHz micromachined 1-3 composite transducer was tested to perform mechanical scanning of a nodule within a lung-tissue-mimicking phantom in vitro. The high-frequency transducer demonstrated the ability to achieve imaging with an axial resolution of 30 µm for measuring nodule edges. Moreover, the integrated biopsy needle prototype exhibited high accuracy (1.74% discrepancy) in estimating nodule area compared to actual dimensions in vitro. These results underscore the promising potential of biopsy-needle-integrated transducers in enhancing the accuracy of endoscopic ultrasound-guided fine needle aspiration biopsy (EUS-FNA) for clinical applications.

Epidemiological investigation of fowl adenovirus (FAdV) infections in ducks and geese in Shandong Province, China.

RESEARCH HIGHLIGHTS: Samples of suspected FAdV-infected waterfowl from farms in Shandong Province were collected from 2019 to 2022.Single infections with FAdV were less frequent than mixed infections.477 out of 792 samples (60.23%) tested positive for FAdV nucleic acids.Detection rate of FAdV was 65.47% in fattening duck farms, 55.73% in breeder duck farms and 54.55% in fattening geese farms.

Carbon nanofibers/liquid metal composites for high temperature laser ultrasound.

As the demand for clean energy becomes greater worldwide, there will also be an increasing demand for next generation nuclear power plants that incorporate advanced sensors and monitoring equipment. A major challenge posed by nuclear power plants is that, during normal operation, the reactor compartment is subjected to high operating temperatures and radiation flux. Diagnostic sensors monitoring such structures are also subject to temperatures reaching hundreds of degrees Celsius, which puts them at risk for heat degradation. In this work, the ability of carbon nanofibers to work in conjunction with a liquid metal as a photoacoustic transmitter was demonstrated at high temperatures. Fields metal, a Bi-In-Sn eutectic, and gallium are compared as acoustic mediums. Fields metal was shown experimentally to have superior performance over gallium and other reference cases. Under stimulation from a low fluence 6 ns pulse laser at 6 mJ/cm2 with 532 nm green light, the Fields metal transducer transmitted a 200 kHz longitudinal wave with amplitude >5.5 times that generated by a gallium transducer at 300 °C. Each high temperature test was conducted from a hot to cold progression, beginning as high as 300 °C, and then cooling down to 100 °C. Each test shows increasing signal amplitude of the liquid metal transducers as temperature decreases. Carbon nanofibers show a strong improvement over previously used candle-soot nanoparticles in both their ability to produce strong acoustic signals and absorb higher laser fluences up to 12 mJ/cm2.

Magnetic Nanoparticles Mediated Thrombolysis-A Review.

Nanoparticles containing thrombolytic medicines have been developed for thrombolysis applications in response to the increasing demand for effective, targeted treatment of thrombosis disease. In recent years, there has been a great deal of interest in nanoparticles that can be navigated and driven by a magnetic field. However, there are few review publications concerning the application of magnetic nanoparticles in thrombolysis. In this study, we examine the current state of magnetic nanoparticles in the application of in vitro and in vivo thrombolysis under a static or dynamic magnetic field, as well as the combination of magnetic nanoparticles with an acoustic field for dual-mode thrombolysis. We also discuss four primary processes of magnetic nanoparticles mediated thrombolysis, including magnetic nanoparticle targeting, magnetic nanoparticle trapping, magnetic drug release, and magnetic rupture of blood clot fibrin networks. This review will offer unique insights for the future study and clinical development of magnetic nanoparticles mediated thrombolysis approaches.

Flexible Ultrasonic Transducers for Wearable Biomedical Applications: A Review on Advanced Materials, Structural Designs, and Future Prospects.

Due to the rapid developments in materials science and fabrication techniques, wearable devices have recently received increased attention for biomedical applications, particularly in medical ultrasound imaging, sensing, and therapy. Ultrasound is ubiquitous in biomedical applications because of its non-invasive nature, nonionic radiating, high precision, and real-time capabilities. While conventional ultrasound transducers are rigid and bulky, flexible transducers can be conformed to curved body areas for continuous sensing without restricting tissue movement or transducer shifting. This article comprehensively reviews the application of flexible ultrasound transducers in the field of biomedical imaging, sensing, and therapy. First, we review the background of flexible ultrasound transducers. Following that, we discuss advanced materials and fabrication techniques for flexible ultrasound transducers and their enabling technology status. Lastly, we highlight and summarize some promising preliminary data with recent applications of flexible ultrasound transducers in biomedical imaging, sensing, and therapy. We also provide technical barriers, challenges, and future perspectives for further research and development.

Evidence of vertical transmission of fowl adenovirus 8b in ducks.

Fowl adenovirus mainly causes hydropericardium hepatitis syndrome (HHS), inclusion body hepatitis (IBH) and gizzard erosion (GE), etc. In 2015, the first outbreak of HHS was reported in broiler chickens in central China, followed by an outbreak in waterfowl. The first outbreak of HHS in broiler flocks in central China in 2015, followed by outbreaks in waterfowl, has severely restricted the healthy development of the poultry industry. During the investigation, fowl adenovirus was detected in ducklings from a total of seven hatcheries in Shandong, Inner Mongolia and Jiangsu provinces. In addition, the DNA of fowl adenovirus was detected in breeding ducks and their progeny. To test the hypothesis that FAdV can be transmitted vertically, sixty 250-day-old Cherry Valley breeder ducks were divided equally into three groups for experimental infection. FAdV-8b SDLY isolate (duck/Shandong/SDLY/2021, SDLY) preserved in our laboratory was injected intramuscularly into group A and inoculated orally into group B. FAdV-8b DNA was detected in the yolk membranes, embryos and allantoic fluid of duck embryos in the FAdV-infected group after inoculation. In addition, the FAdV-8b hexon gene isolated from yolk membranes, embryos, allantoic fluid and duck eggs was close to 100% nucleotide homology to the FAdV-8b hexon gene isolated from laying duck ovaries, indicating that fowl adenovirus can be transmitted vertically in ducks. These findings provide evidence for the possible vertical transmission of fowl adenovirus from breeder ducks to ducklings.

The use of histotripsy as intratumoral immunotherapy beyond tissue ablation-the rationale for exploring the immune effects of histotripsy.

Mechanical high-intensity focused ultrasound (M-HIFU), which includes histotripsy, is a non-ionizing, non-thermal ablation technology that can be delivered by noninvasive methods. Because acoustic cavitation is the primary mechanism of tissue disruption, histotripsy is distinct from the conventional HIFU techniques resulting in hyperthermia and thermal injury. Phase I human trials have shown the initial safety and efficacy of histotripsy in treating patients with malignant liver tumors. In addition to tissue ablation, a promising benefit of M-HIFU has been stimulating a local and systemic antitumor immune response in preclinical models and potentially in the Phase I trial. Preclinical studies combining systemic immune therapies appear promising, but clinical studies of combinations have been complicated by systemic toxicities. Consequently, combining M-HIFU with systemic immunotherapy has been demonstrated in preclinical models and may be testing in future clinical studies. An additional alternative is to combine intratumoral M-HIFU and immunotherapy using microcatheter-placed devices to deliver both M-HIFU and immunotherapy intratumorally. The promise of M-HIFU as a component of anti-cancer therapy is promising, but as forms of HIFU are tested in preclinical and clinical studies, investigators should report not only the parameters of the energy delivered but also details of the preclinical models to enable analysis of the immune responses. Ultimately, as clinical trials continue, clinical responses and immune analysis of patients undergoing M-HIFU including forms of histotripsy will provide opportunities to optimize clinical responses and to optimize application and scheduling of M-HIFU in the context of the multi-modality care of the cancer patient.

Localization and distribution of goose astrovirus 2 antigens in different tissues at different times.

Goose astrovirus 2 (GAstV-2) causes visceral gout in goslings and has resulted in significant economic losses in the goose industry of China since its outbreak in 2017. To further investigate the distribution and localization of GAstV-2 in different tissues at different times, a monoclonal antibody (mAb)-based immunohistochemical (IHC) assay was developed to detect GAstV-2. A total of 80 1-day-old healthy goslings were inoculated with GAstV-2 via the oral (n = 40) and intramuscular routes (n = 40). GAstV-2 in the tissues of interest was detected using the established IHC assay. The results showed that positive signals were detected in most tissues at 1 day post-infection (dpi). Viral antigens were mainly distributed in the cytoplasm, and the staining intensity was higher in the renal tubular epithelial cells than in other cells. Taken together, our data demonstrated that GAstV-2 has a broad tissue tropism and primarily targets the kidneys. These results are likely to provide a scientific basis for further elucidation of the pathogenesis of GAstV-2.

The isolation and characterizations of a duck adenovirus 1 causing Egg Drop Syndrome in ducks, China.

A fowl adenovirus variant designated as DAdV-JSXZ strain was isolated from the tissue specimen of fallopian tubes of a duck case, which was submitted from a 276-day-old Cherry valley breeding duck flock experienced egg-dropping syndromes in March 2022. Full-genome sequence of the DAdV-I JSXZ strain by next-generation sequencing revealed that the complete genome length of DAdV-JSXZ strain was 33,213 nucleotides and shared a high degree of nucleotide identity (97.0-99.4 %) with other DAdV-I reference strains. In pathogenicity studies, this isolated duck JSXZ strain reproduced similar egg-dropping symptoms in healthy breeding ducks, pathologic lesions of follicular hemorrhage, and the laid eggs in low fertilization and hatchability rates. Our research findings demonstrated that DAdV-I JSXZ strain was one of the causative agents of duck egg dropping syndrome in egg-laying ducks and could cause acute respiratory symptoms in ducklings.

Vortex-ultrasound for microbubble-mediated thrombolysis of retracted clots.

Endovascular sonothrombolysis has gained significant attention due to its benefits, including direct targeting of the thrombus with sonication and reduced side effects. However, the small aperture of endovascular transducers restricts the improvement of their potential clinical efficiency due to inefficient acoustic radiation. Hence, in an earlier study, we used vortex ultrasound with an endovascular ultrasound transducer to induce shear stress and enhance the clot lysis. In this study, the vortex acoustic transduction mechanism was investigated using numerical simulations and hydrophone tests. Following this characterization, we demonstrated the performance of the vortex ultrasound transducer in thrombolysis of retracted clots in in vitro tests. The test results indicated that the maximum lysis rates were 79.0% and 32.2% with the vortex ultrasound for unretracted and retracted clots, respectively. The vortex ultrasound enhanced the efficiency of the thrombolysis by approximately 49%, both for retracted and unretracted clots, compared with the typical non-vortex ultrasound technique. Therefore, the use of endovascular vortex ultrasound holds promise as a potential clinical option for the thrombolysis of retracted clots.

Synergistic pathogenicity of avian orthoreovirus and Staphylococcus aureus on SPF chickens.

Avian arthritis is a relatively common disease in the poultry industry, the cause of which is complex. Bacterial arthritis is often caused by infection of Staphylococcus aureus (S. aureus), whereas viral arthritis is caused by avian orthoreovirus (ARV). To investigate the infection of S. aureus and ARV in cases of avian arthritis, a total of 77 samples characterized by arthritis were collected and detection. The results showed that 68.83% of the samples were positive for ARV, and 66.23% were positive for S. aureus. Among them, the ARV mono-infection rate was 22.08%, the S. aureus mono-infection rate was 19.48%, and ARV and S. aureus co-infection rate was 45.45%, indicating that ARV and S. aureus co-infection is common in arthritis cases. To further investigate the synergistic pathogenicity of ARV and S. aureus, ARV and S. aureus were used to mono-infect, co-infect, and (or) sequential infect SPF chickens and the clinical indications, pathologic changes, ARV load, S. aureus bacterial distribution, and cytokine level of the challenged chickens were evaluated. Decreased weight gain, increased mortality, and difficulties in standing were observed in all dual-infected groups and the singular-infected group. There were significantly more severe macroscopic and microscopic hock lesions, and larger amounts of a wider range of tissue distribution of ARV antigens and S. aureus bacterial distribution in the dual-infected groups compared to the single-infected and control groups. Cytokine detection showed a significant change in IFN-γ, IL-1ß, and IL-6 levels in the infected groups, especially in the ARV-S. aureus co-infection, and (or) sequential infection groups, compared with the control group. Hence, ARV and S. aureus synergistically increased mortality in infected chickens, potentiated the severity of arthritis, and increased the amount of ARV RNA in tendons.

Co-circulation of multiple genotypes of ARV in poultry in Anhui, China.

ABSTRACTPoultry production in China has been experiencing a high incidence of broiler arthritis /tenosynovitis caused by avian orthoreovirus (ARV) since 2013. In the spring of 2020 severe arthritis cases from broiler flocks were identified in a large-scale commercial poultry company in Anhui Province, China. Diseased organs from dead birds were sent for diagnosis to our laboratory. ARVs, including seven broiler-isolates and two breeder-isolates, were successfully harvested and sequenced. Interestingly, the genotypes of ARVs isolated from infected chickens were inconsistent between different flocks, or even between different houses on the same flocks. Pathogenicity testing in chicks confirmed that the seven broiler-isolates were pathogenic strains, which could cause arthritis in infected chickens. Subsequently, a total of 89.66% serum samples collected from apparently healthy adult broiler flocks not vaccinated against ARV tested positive for ARV antibodies, suggesting that low and high virulence reovirus strains may be co-circulating in the farm. To this end, we collected dead embryos of unhatched chicken eggs for pathogen tracing, and the two ARV breeder-isolates isolated indicated that vertical transmission from breeders to progeny should not be underestimated for the prevalence of ARV within broiler flocks. The findings have implications for the evidenced-based formulation of prevention and control strategies.

Pathogenicity of goose astrovirus genotype 2 in chickens.

Goose astrovirus genotype 2 (GAstV-2) is the causative agent causing severe visceral gout and joint gout in goslings, with mortality rates of affected flocks up to 50%. To date, continuous GAstV-2 outbreaks still pose a great threat to goose industry in China. Although most researches on GAstV-2 have focused on its pathogenicity to geese and ducks, limited studies have been performed on chickens. Herein, we inoculated 1-day-old specific pathogen-free (SPF) White Leghorn line chickens with 0.6 mL of GAstV-2 culture supernatant (TCID50 10-5.14/0.1 mL) via orally, subcutaneously and intramuscularly, and then assessed the pathogenicity. The results revealed that the infected chickens presented depression, anorexia, diarrhea, and weight loss. The infected chickens also suffered from extensive organ damage and had histopathological changes in the heart, liver, spleen, kidney, and thymuses. The infected chickens also had high viral load in tissues and shed virus after the challenge. Overall, our research demonstrates that GAstV-2 can infect chickens and adversely affect the productivity of animals. And the viruses shed by infected chickens can pose a potential risk to the same or other domestic landfowls.

Vibration Analysis of a Unimorph Nanobeam with a Dielectric Layer of Both Flexoelectricity and Piezoelectricity.

In this study, for the first time, free and forced vibrational responses of a unimorph nanobeam consisting of a functionally graded base, along with a dielectric layer of both piezoelectricity and flexoelectricity, is investigated based on paradox-free local/nonlocal elasticity. The formulation and boundary conditions are attained by utilizing the energy method Hamilton's principle. In order to set a comparison, the formulation of a model in the framework of differential nonlocal is first presented. An effective implementation of the generalized differential quadrature method (GDQM) is then utilized to solve higher-order partial differential equations. This method can be utilized to solve the complex equations whose analytic results are quite difficult to obtain. Lastly, the impact of various parameters is studied to characterize the vibrational behavior of the system. Additionally, the major impact of flexoelectricity compared to piezoelectricity on a small scale is exhibited. The results show that small-scale flexoelectricity, rather than piezoelectricity, is dominant in electromechanical coupling. One of the results that can be mentioned is that the beams with higher nonlocality have the higher voltage and displacement under the same excitation amplitude. The findings can be helpful for further theoretical as well as experimental studies in which dielectric material is used in smart structures.

Thickness-Dependent Thermal Conductivity and Phonon Mean Free Path Distribution in Single-Crystalline Barium Titanate.

Nanosized perovskite ferroelectrics are widely employed in several electromechanical, photonics, and thermoelectric applications. Scaling of ferroelectric materials entails a severe reduction in the lattice (phonon) thermal conductivity, particularly at sub-100 nm length scales. Such thermal conductivity reduction can be accurately predicted using the information of phonon mean free path (MFP) distribution. The current understanding of phonon MFP distribution in perovskite ferroelectrics is still inconclusive despite the critical thermal management implications. Here, high-quality single-crystalline barium titanate (BTO) thin films, a representative perovskite ferroelectric material, are grown at several thicknesses. Using experimental thermal conductivity measurements and first-principles based modeling (including four-phonon scattering), the phonon MFP distribution is determined in BTO. The simulation results agree with the measured thickness-dependent thermal conductivity. The results show that the phonons with sub-100 nm MFP dominate the thermal transport in BTO, and phonons with MFP exceeding 10 nm contribute ≈35% to the total thermal conductivity, in significant contrast to previously published experimental results. The experimentally validated phonon MFP distribution is consistent with the theoretical predictions of other complex crystals with strong anharmonicity. This work paves the way for thermal management in nanostructured and ferroelectric-domain-engineered systems for oxide perovskite-based functional materials.

Miniaturized Stacked Transducer for Intravascular Sonothrombolysis With Internal-Illumination Photoacoustic Imaging Guidance and Clot Characterization.

Thromboembolism in blood vessels can lead to stroke or heart attack and even sudden death unless brought under control. Sonothrombolysis enhanced by ultrasound contrast agents has shown promising outcome on effective treatment of thromboembolism. Intravascular sonothrombolysis was also reported recently with a potential for effective and safe treatment of deep thrombosis. Despite the promising treatment results, the treatment efficiency for clinical application may not be optimized due to the lack of imaging guidance and clot characterization during the thrombolysis procedure. In this paper, a miniaturized transducer was designed to have an 8-layer PZT-5A stacked with an aperture size of 1.4 × 1.4 mm2 and assembled in a customized two-lumen 10-Fr catheter for intravascular sonothrombolysis. The treatment process was monitored with internal-illumination photoacoustic tomography (II-PAT), a hybrid imaging modality that combines the rich contrast of optical absorption and the deep penetration of ultrasound detection. With intravascular light delivery using a thin optical fiber integrated with the intravascular catheter, II-PAT overcomes the penetration depth limited by strong optical attenuation of tissue. In-vitro PAT-guided sonothrombolysis experiments were carried out with synthetic blood clots embedded in tissue phantom. Clot position, shape, stiffness, and oxygenation level can be estimated by II-PAT at clinically relevant depth of ten centimeters. Our findings have demonstrated the feasibility of the proposed PAT-guided intravascular sonothrombolysis with real-time feedback during the treatment process.

Intravascular Sono-Ablation for In-Stent Restenosis Relief: Transducer Development and the In-Vitro Demonstration.

OBJECTIVE: This study aimed to propose a new clinical modality for the relief of in-stent restenosis (ISR) using focused ultrasound (FUS) ablation. In the first research stage, a miniaturized FUS device was developed for the sonification of the remaining plaque after stenting, known as one of the causes of ISR. METHODS: This study presents a miniaturized (<2.8 mm) intravascular FUS transducer for ISR treatment. The performance of the transducer was predicted through a structural-acoustic simulation, followed by fabrication of the prototype device. Using the prototype FUS transducer, we demonstrated tissue ablation with bio-tissues over metallic stents, mimicking in-stent tissue ablation. Next, we conducted a safety test by detecting the existence of thermal damage to the arterial tissue upon sonication with a controlled dose. RESULTS: The prototype device successfully delivered sufficient acoustic intensity (>30 W/cm2) to a bio tissue (chicken breast) through a metallic stent. The ablation volume was approximately 3.9 × 7.8 × 2.6 mm3. Furthermore, 1.5 min sonication was sufficient to obtain an ablating depth of approximately 1.0 mm, not thermally damaging the underlying artery vessel. CONCLUSION: We demonstrated in-stent tissue sonoablation, suggesting it could be as a future ISR treatment modality. SIGNIFICANCE: Comprehensive test results provide a key understanding of FUS applications using metallic stents. Furthermore, the developed device can be used for sonoablation of the remaining plaque, providing a novel approach to the treatment of ISR.