1.8 -μm-(Pb0.97La0.02)(Zr0.95−xSnxTi0.05)O3 antiferroelectric thick films with orthorhombic (x = 0.05 and 0.25) and tetragonal (x = 0.40) structure were deposited on platinum-buffered silicon substrates by using a chemical solution way. All the films had a uniform microstructure with pure perovskite phase. With increasing x value, dielectric constant and critical electric breakdown field of the thick films were gradually increased, while their saturated polarizations were decreased. As a result, their maximum recoverable energy-storage density was increased for the thick films with larger x values. A huge recoverable energy-storage density of 56 J/cm3 was obtained in antiferroelectric thick films with x = 0.40. Moreover, a good temperature-dependent stability of the energy storage was obtained in the all films from 20 to 120 °C.

Magnetic resonance imaging (MRI) is an essential modality for clinical diagnosis, and MRI-guided high-intensity focused ultrasound (MRgHIFU) is a powerful technology for targeted therapy. Clinical applications of MRgHIFU primarily utilize hyperthermia and ablation to treat cancerous tissue, but for drug delivery applications thermal damage is undesirable. A biofriendly MRgHIFUresponsive mesoporous silica nanoparticle (MSN) platform that is stimulated within a physiological safe temperature range has been developed, reducing the possibility of thermal damage to the surrounding healthy tissues. Biocompatible polyethylene glycol (PEG) was employed to cap the pores of MSNs, and the release of cargo molecules by HIFU occurs without substantial temperature increase (∼4 °C). To visualize by MRI and measure the stimulated delivery in situ, a U.S. Food and Drug Administration (FDA)-approved gadolinium-based contrast agent, gadopentetate dimeglumine (Gd(DTPA) 2− ), was used as the imageable cargo. Taking advantage of the three-dimensional (3-D) imaging and targeting capabilities of MRgHIFU, the release of Gd(DTPA) 2− stimulated by HIFU was pinpointed at the HIFU focal point in 3-D space in a tissue-mimicking gel phantom. The amount of Gd(DTPA) 2− released was controlled by HIFU stimulation times and power levels. A positive correlation between the amount of Gd(DTPA) 2− released and T 1 was found. The MRgHIFU-stimulated cargo release was further imaged in a sample of ex vivo animal tissue. With this technology, the biodistribution of the nanocarriers can be tracked and the MRgHIFU-stimulated cargo release can be pinpointed, opening up an opportunity for future image-guided theranostic applications.

Purpose To develop and evaluate a variable‐flip‐angle golden‐angle‐ordered 3D stack‐of‐radial MRI technique for simultaneous proton resonance frequency shift (PRF) and T1‐based thermometry in aqueous and adipose tissues, respectively. Methods The proposed technique acquires multiecho radial k‐space data in segments with alternating flip angles to measure 3D temperature maps dynamically on the basis of PRF and T1. A sliding‐window k‐space weighted image contrast filter is used to increase temporal resolution. PRF is measured in aqueous tissues and T1 in adipose tissues using fat/water masks. The accuracy for T1 quantification was evaluated in a reference T1/T2 phantom. In vivo nonheating experiments were conducted in healthy subjects to evaluate the stability of PRF and T1 in the brain, prostate, and breast. The proposed technique was used to monitor high‐intensity focused ultrasound (HIFU) ablation in ex vivo porcine fat/muscle tissues and compared to temperature probe readings. Results The proposed technique achieved 3D coverage with 1.1‐mm to 1.3‐mm in‐plane resolution and 2‐s to 5‐s temporal resolution. During 20 to 30 min of nonheating in vivo scans, the temporal coefficient of variation for T1 was <5% in the brain, prostate, and breast fatty tissues, while the standard deviation of relative PRF temperature change was within 3°C in aqueous tissues. During ex vivo HIFU ablation, the temperatures measured by PRF and T1 were consistent with temperature probe readings, with an absolute mean difference within 2°C. Conclusion The proposed technique achieves simultaneous PRF and T1‐based dynamic 3D MR temperature mapping in aqueous and adipose tissues. It may be used to improve MRI‐guided thermal procedures.

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Acetaminophen (APAP) is a well-known antipyretic and analgesic drug. However, the accidental or intentional APAP overdose will induce liver injury and even acute liver failure. Astragaloside IV (AS-IV), a bioactive compound isolated from Astragali Radix, has been reported to have protective effects on the digestive and immune systems because of its anti-oxidant and anti-inflammatory properties. This study aims to observe whether AS-IV pretreatment provides protection against APAP-induced liver failure. The results of serum alanine/aspartate aminotransferases (ALT/AST) analysis, hepatic glutathione (GSH), and malondialdehyde (MDA) amounts, and liver superoxide dismutase (SOD) activity showed that AS-IV protected against APAP-induced hepatotoxicity. Liver histological observation further evidenced this protection provided by AS-IV. AS-IV was found to reverse the APAP-induced increased amounts of pro-inflammatory cytokines, including interleukin 1β (IL-1β), interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α). Western-blot analysis showed that AS-IV increased the transcriptional activation of nuclear factor erythroid 2-related factor 2 (Nrf2), and enhanced the expression of heme oxygenase 1 (HO-1) and reduced nicotinamide adenine dinucleotide phosphate (NAD(P)H): quinone oxidoreductase 1 (NQO1) in the presence of APAP. AS-IV also decreased the expression of kelch-like ECH-associated protein-1 (Keap1). In conclusion, we demonstrated that AS-IV exerted a strong protection against APAP-induced hepatotoxicity by activating Nrf2 antioxidant signaling pathways.