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Core–shell structured Bi0.5Na0.5TiO3KTaO3 + x% (in mass) Li2CO3 ceramics were fabricated in this study. Increasing x from 0 to 2 leads to the decrease of sintering temperature from 1 175 °C to 1 020 °C. The limited diffusion of Ta5+ results in chemical heterogeneities and core–shell microstructures. The Ta5+-depleted cores show the nanodomains (∼10 nm), while the Ta5+-rich shells display the polar nanoregions (1–2 nm). From x = 0 to 1, the appearance of cores with nanodomains contributes to the increase of dielectric constant and maximum polarization, while the further addition of Li2CO3 suppresses the dielectric and polarization responses due to the reduced grain sizes and polarization coupling. The enhanced dielectric relaxation and existence of core-shell microstructure with different polarization levels help to optimize the dielectric temperature stability. The x = 2 ceramics exhibit a stable high dielectric constant ∼1 400 over a wide temperature range of 20–520 °C. More encouragingly, the ultrafine grain size and core–shell microstructure in the x = 2 ceramics greatly benefit the improvement of breakdown strength. Combined with the delayed polarization saturation and high ergodicity, a high recoverable energy density of ∼5.07 J/cm3 is obtained under 44 kV/mm, with a high efficiency of ∼85.17%.

Lead-free BiFeO3-BaTiO3 ceramics attract widespread attention over the last two decades due to their high Curie temperature (TC) and excellent piezoelectric performance. Here, in the Nd-modified 0.67BiFeO3-0.33BaTiO3 ceramics, an excellent piezoelectric constant (d33) of 325 pC/N was achieved by applying a novel poling method (AC-bias + DC-bias) with a high TC of 455 °C. In addition, an ultrahigh normalized piezoelectric strain (d33∗ = Smax/Emax) of 808 pm/V was obtained at the normal/typical and relaxor-ferroelectrics phase boundary simultaneously with good thermal stability (Δd33∗(T) ≈ 20%) in the temperature range of 25–125 °C. The piezoelectric force microscopy results show the domain miniaturization from micro to nanoscale/polar nano-regions due to local structure heterogeneity caused by Nd doping. The mechanism for the giant piezoelectric strain is attributed to the thermal quenching, nano-domains, and reverse switching of the short-range order to the long-range order under the applied electric field. The strategic design of domain engineering and a proposed model for the high piezoelectricity is successfully supported by the phenomenological relation and Gibbs free energy profile. In this work, a new lead-free single-element modified BiFeO3-BaTiO3 ceramics was developed by applying a synergistic approach of domain engineering and phase boundary for the high-temperature piezoelectric performance.

AbstractPurpose This retrospective study assessed the incidence rate, risk factors, and clinical course of early enlarging cavitation after percutaneous microwave ablation (MWA) of primary lung cancer (PLC).Methods This study included 557 lesions of 514 patients with PLC who underwent CT-guided percutaneous MWA between 1 January 2018 and 31 December 2021. Of these patients, 29 developed early enlarging cavitation and were enrolled in the cavity group, and 173 were randomly enrolled in the control group. Early enlarging cavitation of the lung was defined as the development of a cavity ≥30 mm within 7 days after MWA.Results Overall, 31 (5.57%, 31/557 tumors) early enlarging cavitations occurred at an average of 5.83 ± 1.55 d after MWA. The risk factors were lesion contact with a large vessel (diameter ≥3 mm), lesion contact with the bronchus (diameter ≥2 mm), and a large ablated parenchymal volume. The cavity group had a higher incidence rate of delayed hydropneumothorax (12.9%) and bronchopleural fistula (9.68%) than the control group, resulting in a longer hospitalization (9.09 ± 5.26 days). Until Dec 31, 2022, 27 cavities disappeared after a mean of 217.88 ± 78.57 d (range, 111–510 d), two persisted, and two were lost to follow-up.Conclusions Early enlarging cavitation occurred in 5.57% PLC cases that underwent MWA, causing serve complications and longer hospitalization. The risk factors were ablated lesion contact with large vessels and bronchi, as well as a larger ablated parenchymal volume.

AbstractBackground This retrospective study aimed to assess the safety and efficacy of synchronous biopsy and microwave ablation (MWA) for highly suspected malignant lung ground-glass opacities (GGOs) adjacent to the mediastinum (distance ≤10 mm).Materials and methods Ninety patients with 98 GGOs (diameter range, 6–30 mm), located within 10 mm of the mediastinum, underwent synchronous biopsy and MWA at a single institution from 1 May 2020, to 31 October 2021 and were enrolled in this study. Synchronous biopsy and MWA involving the completion of the biopsy and MWA in a single procedure was performed. Safety, technical success rate, and local progression-free survival (LPFS) were evaluated. The risk factors for local progression were calculated using the Mann–Whitney U test.Results The technical success rate was 97.96% (96/98 patients). The LPFS rates at 3, 6, and 12 months were 95.0%, 90.0%, and 82.0%, respectively. The diagnostic rate of biopsy-proven malignancy was 72.45% (n = 71/98). Invasion of lesions into the mediastinum was a risk factor for local progression (p = 0.0077). The 30-day mortality rate was 0. The major complications were pneumothorax (13.27%), ventricular arrhythmias (3.06%), pleural effusion (1.02%), hemoptysis (1.02%), and infection (1.02%). Minor complications included pneumothorax (30.61%), pleural effusion (24.49%), hemoptysis (18.37%), ventricular arrhythmias (11.22%), structural changes in adjacent organs (3.06%), and infection (3.06%).Conclusions Synchronous biopsy and MWA was effective for treating GGOs adjacent to the mediastinum without severe complications (Society of Interventional Radiology classification E or F). Invasion of lesions into the mediastinum was identified as a risk factor for local progression.

AbstractPurpose This retrospective, single-center, case-control study evaluated the safety and efficacy of Computed tomography (CT)-guided microwave ablation (MWA) for pulmonary nodules located in the right middle lobe (RML), a challenging location associated with a high frequency of complications.Methods Between May 2020 and April 2022, 71 patients with 71 RML pulmonary nodules underwent 71 MWA sessions. To comparison, 142 patients with 142 pulmonary nodules in non-RML were selected using propensity score matching. The technical success, technique efficacy, complications, and associated factors were analyzed. The duration of the procedure and post-ablation hospital stay were also recorded.Results Technical success was achieved in 100% of all patients. There were no significant differences in technique efficacy rates between the RML and non-RML groups (97.2% vs. 95.1%, p = 0.721). However, both major (47.9% vs. 19.7%, p

Abstract Background This retrospective study aimed to assess the safety and efficacy of microwave ablation for lung tumors adjacent to the interlobar fissures. Methods From May 2020 to April 2021, 59 patients with 66 lung tumors (mean diameter, 16.9 ± 7.7 mm; range, 6–30 mm) adjacent to the interlobar fissures who underwent microwave ablation at our institution were identified and included in this study. Based on the relationship between the tumor and the interlobar fissure, tumors can be categorized into close to the fissure, causing the fissure, and involving the fissure. The complete ablation rate, local progression‐free survival, complications, and associated factors were analyzed. Results All 66 histologically proven tumors were treated using computed tomography‐guided microwave ablation. The complete ablation rate was 95.5%. Local progression‐free survival at 3, 6, 9, and 12 months were 89.4%, 83.3%, 74.2%, and 63.6%, respectively. The complications included pneumothorax (34.8%), pleural effusion (24.2%), cavity (18.2%), and pulmonary infection (7.6%). There were statistical differences in the incidence of pneumothorax, cavity, and delayed complications between the groups with and without antenna punctures through the fissure. Conclusions Microwave ablation is a safe and effective treatment for lung tumor adjacent to the interlobar fissure. Antenna puncturing though the interlobar fissure may be a potential risk factor for pneumothorax, cavity, and delayed complications.

Abstract In piezoceramics, the Curie temperature (TC) and piezoelectric coefficient (d33) are often inversely proportional, so it is very difficult to optimize high piezoelectricity and TC simultaneously. In addition, the high and temperature‐insensitive piezoelectric strain coefficient (d33*) with small hysteresis is also a longstanding obstacle in the development of lead‐free ceramics. In this work, a facile approach of donor doping strategy is adopted to replace Ba2+ with Yb3+, Y3+, Sm3+, and Nd3+ as a result, a high TC of 450 °C and outstanding d33 of 422–436 pC N−1 is achieved by a novel magnetic poling method. Thermally‐stable and outstanding piezoelectric strain performance (d33* ≈ 520–550 pm V−1 and ΔST ≈ 10%) with small strain hysteresis (H < 20%) results are highly encourageable in lead‐free ceramics. The main factors contributing to high piezoelectricity are the morphotropic phase boundary, suppression of defect charges by donor doping, thermal quenching, mesoscale nanodomain size, and novel poling method. The excellent piezoelectric performance and high TC of this work are superior to those of state‐of‐the‐art piezoceramics. The synergistic approaches of compositional design strategy and novel poling process in this work are highly beneficial for temperature‐insensitive piezoelectric sensor and actuator applications.

The high-performance energy-storage dielectric capacitors are increasingly important due to their wide applications in high power electronics. Here, we fabricated a novel P(VDF-HFP)-based capacitor with surface-modified NBT-xST (x=0, 0.10, 0.26) whiskers, denoted as Dop@NBT-xST/P(VDF-HFP). The influences of ST content, fillers’ volume fraction and electric field on the dielectric properties and energy-storage performance of the composites were investigated systematically. The results show that the dielectric constant monotonously increased with the increase of ST content and fillers’ volume fraction. The composite containing 10.0 vol% NBT-0.26ST whiskers possessed a dielectric constant of 39 at 1kHz, which was 5.6 times higher than that of pure P(VDF-HFP). It was noticed that the D-E loops of the composites became thinner and thinner with the increase of ST content. Due to the reduced remnant polarization, the composite with 5.0 vol% NBT-0.26ST whiskers achieved a high energy density of 6.18J/cm3 and energy efficiency of approximately 57% at a relatively low electric field of 200kV/mm. This work indicated that NBT-0.26ST whisker is a kind of potential ceramic filler in fabricating the dielectric capacitor with high discharged energy density and energy efficiency.

This work prepares (Ba0.5Sr0.5)TiO3 (BST)-doped (Bi1∕2Na1∕2)TiO3 (NBT) lead free ceramics through conventional solid reaction method and analyzes the doping effect of BST on phases, microstructure, dielectric and ferroelectric properties. The phase and structure of the NBT-BST ceramics were investigated through X-ray diffractometer (XRD) and Raman. The XRD results showed that BST has diffused into the NBT lattices to form a stable solid solution; while, Raman spectrum showed the bands at low frequency are different with that of pure NBT and divided into two ranges around 247cm−1 and 303cm−1. Relative dense and homogeneous ceramic microstructures could be achieved, with the observation of a slight decrease in average grain size with the increase of BST doping content. The dielectric and ferroelectric properties were also investigated. The dielectric constant increases gradually with increasing the temperature to Tm, and then decrease. The temperature dependence property showed diffused phase transition near Tm. The polarization-electric field (P-E) hysteresis loops of BST-doped NBT ceramics showed typical ferroelectric or relaxor nature. Both the Ec and Pr increased first, then decreased with respect to the increase of the BST content.