Engineering Multiphase Phase Transitions for Exceptional Electrocaloric Performance and Ultraweak Electrostrictive Response in Ferroelectrics.

In the pursuit of eco-friendly alternatives for refrigeration technology, electrocaloric materials have emerged as promising candidates for efficient solid-state refrigeration due to their high efficiency and integrability. However, current advancements in electrocaloric effects (ECEs) are often constrained by high temperatures and elevated electric fields (E-field), limiting practical applicability. Informed by phase-field simulation, this study introduces a (1-x)Pb(Yb1/2Nb1/2)O3-xPb(Mg1/3Nb2/3)O3 system, strategically engineered to incorporate highly ordered YN and disordered MN mixtures. The synergistic interplay between E-field/temperature-induced polarization reorientation and cation shift initiates multiple ferroelectric-antiferroelectric-paraelectric phase transitions. Our results demonstrate that under a moderate E-field of 50 kV cm-1, the x = 0.22 composition achieves remarkable performance with a giant temperature change (ΔT) of 3.48 K, a robust ECE strength (ΔT/ΔE) of 0.095 K cm kV-1, and a wide temperature span (Tspan) of 38 °C. Notably, the disrupted lattice structure contributes to ultralow electrostrains below 0.008%, with an average electrostrictive coefficient Q33 of 0.007 m4 C-2. The significantly weakened electrostrictive activity favors enhancing the performance stability of subsequent devices. This work introduces an innovative strategy for developing robust electrocaloric materials, offering substantial ΔT and low electrostrains, presenting promising advancements in ECE applications with an extended lifetime.

Ultra-Weak Polarization-Strain Coupling Effect Boosts Capacitive Energy Storage.

In pulse power systems, multilayer ceramic capacitors (MLCCs) encounter significant challenges due to the heightened loading electric field (E), which can lead to fatigue damage and ultrasonic concussion caused by electrostrictive strain. To address these issues, an innovative strategy focused on achieving an ultra-weak polarization-strain coupling effect is proposed, which effectively reduces strain in MLCCs. Remarkably, an ultra-low electrostrictive coefficient (Q33) of 0.012 m4 C-2 is achieved in the composition 0.55(Bi0.5Na0.5)TiO3-0.45Pb(Mg1/3Nb2/3)O3, resulting in a significantly reduced strain of 0.118% at 330 kV cm-1. At the atomic scale, the local structural heterogeneity leads to an expanded and loose lattice structure, providing ample space for large ionic displacement polarization instead of lattice stretching when subjected to the applied E. This unique behavior not only promotes energy storage performance (ESP) but also accounts for the observed ultra-low Q33 and strain. Consequently, the MLCC device exhibits an impressive energy storage density of 14.6 J cm-3 and an ultrahigh efficiency of 93% at 720 kV cm-1. Furthermore, the superior ESP of the MLCC demonstrates excellent fatigue resistance and temperature stability, making it a promising solution for practical applications. Overall, this pivotal strategy offers a cost-effective solution for state-of-the-art MLCCs with ultra-low strain-vibration in pulse power systems.

Potential damage to ovarian reserve from laparoscopic electrocoagulation in endometriomas and benign ovarian cysts: a systematic review and meta-analysis.

PURPOSE: Laparoscopic cystectomy for ovarian endometriomas and benign ovarian cysts is often conducted through hemostatic methods, with bipolar electrocoagulation as a common approach. This study evaluated the impact of electrocoagulation, primarily through bipolar energy, versus nonthermal hemostatic methods on ovarian reserve in patients undergoing laparoscopic cystectomy for ovarian endometriomas and benign ovarian cysts. METHODS: A systematic review with meta-analysis was conducted by searching the Cochrane Library, PubMed, EMBASE, and Web of Science databases. Randomized controlled trials (RCTs) comparing the impact of nonthermal hemostatic methods and electrocoagulation on the ovarian reserve during laparoscopic cystectomy were included. The Cochrane Risk of Bias Tool for Randomized Controlled Trials (ROB 2.0) was utilized to assess the quality of the included studies. The meta-analysis included 13 RCTs involving 1043 patients. Postoperative serum anti-Müllerian hormone (AMH) levels and antral follicle counts (AFCs) were analyzed using Review Manager ver. 5.4. RESULTS: Compared with the bipolar group, patients with endometriomas in the nonthermal hemostatic group exhibited significantly higher postoperative AMH levels at 1, 3, 6, and 12 months. Conversely, no significant differences in AMH levels were observed in patients with benign ovarian cysts. Similarly, AFCs showed no significant differences, except for lower postoperative AFCs in patients with endometrioma in the electrocoagulation group. CONCLUSION: Nonthermal hemostatic methods are associated with more effective preservation of the ovarian reserve compared with bipolar electrocoagulation in laparoscopic cystectomy for ovarian endometriomas. However, no significant impact of bipolar electrocoagulation on the ovarian reserve was observed in patients with benign ovarian cysts. TRIAL REGISTRATION: Registered in PROSPERO on April 10, 2023; ID # CRD42023413158.

Innovative Design of BNKT-xSLZT Ceramics: Maximizing the Polarization Difference for Enhanced Energy Storage.

Lead-free relaxor ferroelectric ceramics with outstanding energy-storage (ES) density (Wrec) and high ES efficiency (η) are crucial for advanced pulse-power capacitors. This study introduces a strategic approach to maximizing the polarization difference (ΔP) by inducing a transition from the ferroelectric phase to the ergodic relaxor (ER) phase. By employing this strategy, a series of ceramics, (1 - x)(Bi0.5Na0.4K0.1)TiO3-x(Sr0.85La0.1)(Zr0.5Ti0.5)O3 (BNKT-xSLZT), with varying SLZT content (x = 0.05, 0.10, 0.15, and 0.20), were designed. The addition of SLZT enhances cationic disorder, induces vacancies at A sites, and disrupts long-range ferroelectric order, facilitating the formation of polar nanoregions and enhancing relaxor ferroelectric behavior. Furthermore, a viscous polymer process (VPP) technology is employed to optimize the ceramics' structure, aiming to increase the breakdown strength (Eb) and enhance ΔP. Ultimately, enhanced ES performance is demonstrated in BNKT-0.15SLZTVPP, achieving a remarkable Wrec of 6.85 J/cm3 and η of 84% under 470 kV/cm. This composition demonstrates excellent stability with minimal variations in Wrec (3.0%) and η (4.4%) over the temperature range of 20-110 °C. Additionally, BNKT-0.15SLZTVPP exhibits exceptional pulse charge-discharge properties, featuring a high discharge density of 3.72 J/cm3, a large power density of 164.2 MW/cm3, and a short discharge time (t0.9) of 193 ns under 300 kV/cm. The study validates the practicality of BNKT-0.15SLZTVPP for pulse capacitors and underscores the potential to enhance ES performance through A-site donor doping and VPP technology. This work provides a comprehensive understanding of the interplay among composition, structure, and ES properties in lead-free relaxor dielectric ceramics, laying the groundwork for innovative advancements in the field.

Moderate Fields, Maximum Potential: Achieving High Records with Temperature-Stable Energy Storage in Lead-Free BNT-Based Ceramics.

The increasing awareness of environmental concerns has prompted a surge in the exploration of lead-free, high-power ceramic capacitors. Ongoing efforts to develop lead-free dielectric ceramics with exceptional energy-storage performance (ESP) have predominantly relied on multi-component composite strategies, often accomplished under ultrahigh electric fields. However, this approach poses challenges in insulation and system downsizing due to the necessary working voltage under such conditions. Despite extensive study, bulk ceramics of (Bi0.5Na0.5)TiO3 (BNT), a prominent lead-free dielectric ceramic family, have seldom achieved a recoverable energy-storage (ES) density (Wrec) exceeding 7 J cm-3. This study introduces a novel approach to attain ceramic capacitors with high ESP under moderate electric fields by regulating permittivity based on a linear dielectric model, enhancing insulation quality, and engineering domain structures through chemical formula optimization. The incorporation of SrTiO3 (ST) into the BNT matrix is revealed to reduce the dielectric constant, while the addition of Bi(Mg2/3Nb1/3)O3 (BMN) aids in maintaining polarization. Additionally, the study elucidates the methodology to achieve high ESP at moderate electric fields ranging from 300 to 500 kV cm-1. In our optimized composition, 0.5(Bi0.5Na0.4K0.1)TiO3-0.5(2/3ST-1/3BMN) (B-0.5SB) ceramics, we achieved a Wrec of 7.19 J cm-3 with an efficiency of 93.8% at 460 kV cm-1. Impressively, the B-0.5SB ceramics exhibit remarkable thermal stability between 30 and 140 °C under 365 kV cm-1, maintaining a Wrec exceeding 5 J cm-3. This study not only establishes the B-0.5SB ceramics as promising candidates for ES materials but also demonstrates the feasibility of optimizing ESP by modifying the dielectric constant under specific electric field conditions. Simultaneously, it provides valuable insights for the future design of ceramic capacitors with high ESP under constraints of limited electric field.

Ultrahigh Electrostrictive Effect in Lead-Free Ferroelectric Ceramics Via Texture Engineering.

The electrostrictive effect, which induces strain in ferroelectric ceramics, offers distinct advantages over its piezoelectric counterpart for high-precision actuator applications, including anhysteretic behavior even at high frequencies, rapid reaction times, and no requirement for poling. Historically, commercially available electrostrictive materials have been lead oxide-based. However, global restrictions on the use of lead in electronic components necessitate the exploration of lead-free electrostrictive ceramics with a high strain performance. Although various engineering strategies for producing materials with high strain have been proposed, they typically come at the expense of increased strain hysteresis. Here, we describe the extraordinary electrostrictive response of (Ba0.95Ca0.05)(Ti0.88Sn0.12)O3 (BCTS) ceramics with ultrahigh electrostrictive strain and negligible hysteresis achieved through texture engineering leveraging the anisotropic intrinsic lattice contribution. The BCTS ceramics exhibit a high unipolar strain of 0.175%, a substantial electrostrictive coefficient Q33 of 0.0715 m4 C-2, and an ultralow hysteresis of less than 0.8%. Notably, the Q33 value is three times greater than that of high-performance lead-based Pb(Mg1/3Nb2/3)O3 electrostrictive ceramics. Multiscale structural analyses demonstrate that the electrostrictive effect dominates the BCTS strain response. This research introduces a novel approach to texture engineering to enhance the electrostrictive effect, offering a promising paradigm for future advancements in this field.

Dual trigger improves the pregnancy rate in fresh in vitro fertilization (IVF) cycles compared with the human chorionic gonadotropin (hCG) trigger: a systematic review and meta-analysis of randomized trials.

PROPOSE: The purpose of this study was to assess whether the implementation of a "dual trigger" approach, utilizing gonadotropin-releasing hormone agonist (GnRHa) and human chorionic gonadotropin (hCG) in the GnRH antagonist protocol for in vitro fertilization (IVF), leads to improved pregnancy outcomes compared to the conventional hCG trigger alone. Previous meta-analyses have not provided sufficient evidence to support the superiority of the dual trigger over the hCG trigger in fresh or frozen embryo transfer cycles. Thus, a systematic review and meta-analysis of randomized trials were conducted to provide a comprehensive evaluation of the impact of the dual trigger on pregnancy outcomes in fresh or frozen embryo transfer cycles. METHOD: A systematic review and meta-analysis of randomised controlled trials (RCTs) were conducted. We searched the Medline and Embase databases for articles up to 2023 by using search terms: "dual trigger," "GnRHa," "hCG," "IVF." Eligible RCTs comparing the dual trigger with the hCG trigger were included. The primary outcome was the live birth rate (LBR) per cycle. The secondary outcomes were the number of oocytes retrieved, number of mature oocytes retrieved, implantation rate, biochemical pregnancy rate, CPR, miscarriage rate and ovarian hyperstimulation syndrome (OHSS) rate per started cycle We compared the oocyte maturation and pregnancy outcomes in the dual trigger and hCG trigger groups. In patients undergoing fresh embryo transfer (ET) and frozen-thawed ET, we also conducted a subgroup analysis to evaluate whether dual trigger improves the clinical pregnancy rate (CPR). RESULTS: We included 10 randomised studies, with 825 participants in the dual trigger group and 813 in the hCG trigger group. Compared with the hCG trigger, dual trigger was associated with a significant increase in the LBR per cycle (odds ratio (OR) = 1.61[1.16, 2.25]), number of oocytes retrieved (mean difference [MD] = 1.05 [0.43, 1.68]), number of mature oocytes retrieved (MD = 0.82 [0. 84, 1.16]), and CPR (OR = 1.48 [1.08, 2.01]). Subgroup analyses revealed that dual trigger was associated with a significantly increased CPR in patients who received fresh ET (OR = 1.68 [1.14, 2.48]). By contrast, the dual trigger was not associated with an increased CPR in the patient group with frozen-thawed ET (OR = 1.15 [0.64, 2.08]). CONCLUSION: The dual trigger was associated with a significantly higher number of retrieved oocytes, number of mature oocytes, CPR, and LBR in IVF than the hCG trigger. The beneficial effect for fresh ET cycles compared with frozen-thawed ET might be associated with increased endometrial receptivity. RELEVANCE: After dual trigger, delaying ET due to the concern of endometrial receptivity might not be needed.

Association between the Genetic Variants of Glutathione Peroxidase 4 and Severity of Endometriosis.

It has been reported that oxidative and nitrative stress might be the pathogenesis of endometriosis. This prospective case-control study attempted to check the connection between single nucleotide polymorphism (SNP) of three antioxidant enzymes (glutathione peroxidase 4 (GPX4), thioredoxin 2 (TXN2), thioredoxin reductase 1 (TXNRD1)) and endometriosis. We recruited 90 patients with histology-approved endometriosis as the case group and 130 age-matched women for an annual pap smear examination as the control group. The stage of endometriosis was evaluated with revised ASRM score. Both groups were genotyped in the peripheral leukocytes for the SNP of GPX4 (rs713041), TXN2 (rs4821494) and TXNRD1 (rs1128446) by PCR-based methods. An X2 test was used to analysis of the difference of allele frequency and SNP distribution between two groups. The results revealed GPX4 (rs713041) has a significantly different distribution between two groups (C:T = 116 (44.6%):144 (55.4%) in control and C:T = 104 (57.8%): 76 (42.2%) in endometriosis groups, p = 0.007). The SNP in TXN2 (rs4821494) also showed a difference in allele frequency (G:T = 180 (69.2%):80 (30.8%) in control and G:T = 141 (78.3%):39 (21.6%) in endometriosis group, p = 0.030). In addition, the SNP GPX4 (rs713041) was associated with the severity of the endometriosis. Women who have advanced stage endometriosis were different from mild endometriosis in genetic variants of GPX4 gene (p = 0.001). In conclusion, the relationship between endometriosis and SNP of antioxidant enzymes, GPX4 and TXN2, was confirmed by the present study. According to the result, we suggested that the GPX4 might contribute to the pathogenesis of endometriosis.