Engineering Domain Variants in 0.7Pb(Mg1/3Nb2/3)-0.3PbTiO3 Single Crystals Using High-Frequency AC Poling.

Single crystals of (001)-oriented 0.7Pb(Mg1/3Nb2/3)-0.3PbTiO3 (PMN-30PT) with a composition near the morphotropic phase boundary have attracted considerable attention due to their superior dielectric and electromechanical performance. Recently, a new alternating current (electric field) poling approach used for the enhancement of dielectric and piezoelectric properties. However, the microscopic domain variants that govern the performance, especially under high-frequency alternating current (AC) voltages, remain largely unexplored. In this work, the domain microstructure under AC poling reveals the presence of four monoclinic (MA) domain variants using a suite of scanning probe microscopy methods, and X-ray diffraction (XRD) reciprocal space mapping is tuned. It is reported on the emergence of hierarchical fine domains - needle-shaped, and 109° domain walls under applied high-frequency AC poling. Time-resolved Kelvin probe force microscopy (KPFM) reveals the charge dynamics and relaxation behavior of these needle domains and walls. The findings provide new insight and guidance to the domain engineering by high-frequency AC poling for the development of advanced transducer technology.

Thermal Analysis Kinetics Study of Pulverized Coal Combustion under Oxygen-Rich Atmosphere.

The thermal analysis kinetic behavior of pulverized coal combustion in different oxygen-rich atmospheres is studied with a thermogravimetric (TG) analyzer. The effects of heating rate on combustion characteristic are considered. The results showed that the combustion rate of pulverized coal increased and the burnout time decreased under the conditions of an oxygen-enriched atmosphere and high heating rate. As the heating rate increases, the TG and derivative TG curves of the coal samples generally move toward the high-temperature region, and the thermal hysteresis phenomenon occurs. The changes in oxygen concentration and heating rate mainly affect the combustion stage of coal samples. The decrease in heating rate or the increase in oxygen concentration will cause a decrease in ignition point temperature and burnout temperature. Under the condition of 40% O2, the oxygen concentration and heating rate have the greatest influence on the combustion characteristic parameters. In addition, the combustion reaction of pulverized coal in the warming process was analyzed by FWO and KAS methods, respectively. The results showed that the changes in oxygen concentration and heating rate affected the activation energy, and the activation energy of coal samples increased with the increase in oxygen concentration.

Systematic Review and Meta-analysis: Macrolide in the Treatment of Chronic Rhinosinusitis After Endoscopic Sinus Surgery.

OBJECTIVES: To evaluate the efficacy and safety of macrolide antibiotics therapy in patients with chronic rhinosinusitis (CRS) receiving endoscopic sinus surgery. DATA SOURCES: PubMed, Web of Science, Embase, and Cochrane Library. REVIEW METHODS: The electronic databases were comprehensively searched on June 2, 2022, for randomized controlled trials on macrolide antibiotics in the treatment of patients undergoing CRS endoscopic surgery. The primary outcome measures were the sinonasal outcome test (SNOT) score and the visual analog scale (VAS) score. The secondary outcome measures were the nasal endoscopy score (NES), the sinus computed tomography score, and adverse events. RESULTS: A total of 8 studies were included, involving 606 patients who used macrolide for a long time. Meta-analysis showed that no significant difference was observed in SNOT (standardized mean difference [SMD] = -0.13; 95% confidence interval [CI]: -0.38 to 0.13, I2 = 0%) and VAS (SMD = -0.10; 95% CI, -0.88 to 0.68, I2 = 81%) between the macrolide and placebo groups. However, macrolide outperformed the placebo in improving NES (SMD = -0.32; 95% CI, -0.62 to -0.03, I2 = 21%). The use of macrolide did not increase the incidence of adverse events. CONCLUSION: Long-term use of macrolide after CRS surgery may not significantly improve the quality of life and disease severity of the patients but may play a role in improving postoperative NES in patients with CRS. There is still no sufficient evidence to determine whether the disease phenotype of CRS or the patient's race will affect the efficacy of long-term use of macrolide after CRS.

Nanoscale multistate resistive switching in WO3 through scanning probe induced proton evolution.

Multistate resistive switching device emerges as a promising electronic unit for energy-efficient neuromorphic computing. Electric-field induced topotactic phase transition with ionic evolution represents an important pathway for this purpose, which, however, faces significant challenges in device scaling. This work demonstrates a convenient scanning-probe-induced proton evolution within WO3, driving a reversible insulator-to-metal transition (IMT) at nanoscale. Specifically, the Pt-coated scanning probe serves as an efficient hydrogen catalysis probe, leading to a hydrogen spillover across the nano junction between the probe and sample surface. A positively biased voltage drives protons into the sample, while a negative voltage extracts protons out, giving rise to a reversible manipulation on hydrogenation-induced electron doping, accompanied by a dramatic resistive switching. The precise control of the scanning probe offers the opportunity to manipulate the local conductivity at nanoscale, which is further visualized through a printed portrait encoded by local conductivity. Notably, multistate resistive switching is successfully demonstrated via successive set and reset processes. Our work highlights the probe-induced hydrogen evolution as a new direction to engineer memristor at nanoscale.

SLCO4A1-AS1 regulates laryngeal squamous cell carcinoma cell phenotypes via the Wnt pathway.

AIM: Long non-coding RNAs were widely reported to regulate laryngeal squamous cell carcinoma (LSCC), a prevalent tumor in the head and neck. We aimed to investigate the role of solute carrier organic anion transporter family member 4A1 antisense RNA 1 (SLCO4A1-AS1) in LSCC. MATERIALS & METHODS: CCK-8 and colony formation assays were conducted to examine the viability and proliferation of LSCC cells. The apoptosis of LSCC cells was evaluated using flow cytometry and TUNEL assays. The distribution of SLCO4A1-AS1 in LSCC cells was detected by subcellular fractionation assay. The interaction between molecules was confirmed using luciferase reporter assay. RESULTS: SLCO4A1-AS1 was overexpressed in LSCC tissues and cells. Furthermore, silenced SLCO4A1-AS1 repressed the proliferation and facilitated apoptosis of LSCC cells. Mechanistical investigation revealed that SLCO4A1-AS1 was a competing endogenous RNA (ceRNA) to upregulate SETD7 by binding with miR-7855-p. Additionally, SLCO4A1-AS1 positively regulated the Wnt/ß-catenin signaling pathway by upregulating SETD7. Rescue experiments demonstrated that SLCO4A1-AS1 promoted LSCC proliferation and inhibited LSCC apoptosis by upregulation of SETD7 and activation of the Wnt/ß-catenin pathway. CONCLUSION: SLCO4A1-AS1 promotes proliferation and inhibits apoptosis of LSCC cells by upregulation of SETD7 in a miR-7855-5p dependent way to activate the Wnt/ß-catenin pathway.

Medical Therapy of Hearing Impairment and Tinnitus with Chinese Medicine: An Overview.

The current review gives a comprehensive overview of the recent development in Chinese medicine (CM) for treating several kinds of acquired nerve deafness and tinnitus, as well as links the traditional principle to well-established pharmacological mechanisms for future research. To date, about 24 herbal species and 40 related ingredients used in CM to treat hearing loss and tinnitus are reported for the treatment of endocochlear potential, endolymph growth, lowering toxic and provocative substance aggregation, inhibiting sensory cell death, and retaining sensory transfer. However, there are a few herbal species that can be used for medicinal purposes. Nevertheless, clinical studies have been hampered by a limited population sample, a deficiency of a suitable control research group, or contradictory results. Enhanced cochlear blood flow, antiinflammatory antioxidant, neuroprotective effects, and anti-apoptotic, as well as multi-target approach on different auditory sections of the inner ear, are all possible benefits of CM medications. There are numerous unknown natural products for aural ailment and tinnitus identified in CM that are expected to be examined in the future utilizing various aural ailment models and processes.

Nonvolatile Electrical Valley Manipulation in WS2 by Ferroelectric Gating.

Valleytronics in transition metal dichalcogenides has been intensively investigated for potential applications in next-generation information storage, data processing, and signal transmission devices. Here a ferroelectric gating approach is engaged in achieving nonvolatile electrical tuning of the valley-excitonic properties of monolayer and bilayer WS2. The gating effects include carrier doping and ferroelectric coupling, which are further distinguished by comparing two geometries where the gate electrodes are in direct contact with or insulated from the WS2 crystal. The results show that the carrier doping from gate electrodes acts on WS2 through carrier screening, which only moderately alters the valley polarization. In contrast, the ferroelectric gating promotes electron-phonon interaction, introduces a strong surface polarization field, and controls the interfacial charge trapping/detrapping, causing a Stark shift in exciton energy and strongly enhancing room-temperature valley polarization. In bilayer WS2, the intralayer-interlayer exciton transition is further induced, contributing to even higher valley polarization. The ferroelectric coupling effect can still be maintained after the removal of gate voltage, showing its nonvolatile nature. The role of ferroelectricity is further verified by the anomalous temperature dependence in valley polarization. This work has revealed effective electrical control over valley excitons in semiconductors through interaction with ferroelectric materials. The reported high room-temperature valley polarization in WS2 will boost the development of valleytronics devices.

Manipulating the insulator-metal transition through tip-induced hydrogenation.

Manipulating the insulator-metal transition in strongly correlated materials has attracted a broad range of research activity due to its promising applications in, for example, memories, electrochromic windows and optical modulators1,2. Electric-field-controlled hydrogenation using ionic liquids3-6 and solid electrolytes7-9 is a useful strategy to obtain the insulator-metal transition with corresponding electron filling, but faces technical challenges for miniaturization due to the complicated device architecture. Here we demonstrate reversible electric-field control of nanoscale hydrogenation into VO2 with a tunable insulator-metal transition using a scanning probe. The Pt-coated probe serves as an efficient catalyst to split hydrogen molecules, while the positive-biased voltage accelerates hydrogen ions between the tip and sample surface to facilitate their incorporation, leading to non-volatile transformation from insulating VO2 into conducting HxVO2. Remarkably, a negative-biased voltage triggers dehydrogenation to restore the insulating VO2. This work demonstrates a local and reversible electric-field-controlled insulator-metal transition through hydrogen evolution and presents a versatile pathway to exploit multiple functional devices at the nanoscale.

Direct observation of geometric and sliding ferroelectricity in an amphidynamic crystal.

Sliding ferroelectricity is a recently observed polarity existing in two-dimensional materials. However, due to the weak polarization and poor electrical insulation in these materials, existing experimental evidences are indirect and mostly based on nanoscale transport properties or piezoresponse force microscopy. We report the direct observation of sliding ferroelectricity, using a high-quality amphidynamic single crystal (15-crown-5)Cd3Cl6, which possesses a large bandgap and so allows direct measurement of polarization-electric field hysteresis. This coordination polymer is a van der Waals material, which is composed of inorganic stators and organic rotators as determined by X-ray diffraction and NMR characterization. From density functional theory calculations, we find that after freezing the rotators, an electric dipole is generated in each layer driven by the geometric mechanism, while a comparable ferroelectric polarization originates from the interlayer sliding. The net polarization of these two components can be directly measured and manipulated. Our finding provides insight into low-dimensional ferroelectrics, especially control of the synchronous dynamics of rotating molecules and sliding layers in solids.

Recent Progress in Traditional Chinese Medicines and Their Mechanism in the Treatment of Allergic Rhinitis.

Objective: To conduct a systematic review on the mechanism of action and use of traditional Chinese medicines (TCM) in allergic rhinitis treatment. Background: Allergic rhinitis (AR) is a type I allergic disease of the immune system induced by immunoglobulin E mediated inflammation and is characterized by sneezing, nasal itching, paroxysmal nasal obstruction, mucosal edema, cough, and rhinorrhea. More than 500 million people have been affected by rhinitis worldwide in the past 20 years, leading to negative effects on health, quality of life, and social relationships. Currently, the trending medicines used in the case of AR include intranasal corticosteroids and oral H1 antihistamines, which are given as combinatorial medicines supplemented with immune therapy. These medications have been found to be very effective in either the short term or long term; however, they have been found to possess some serious side effects. Search Methodology. The information in this article on classical and traditional Chinese medications used to treat AR was derived from original papers and reviews published in Chinese and English language journals. Two Chinese databases (Wanfang and CNKI) and three English databases (Cochrane Library, PubMed, and Embase) were utilized for data gathering. Results: Traditional Chinese remedies have been identified to influence the production of cytokines such as IL-5 and IL-6, which are key mediators of eosinophilic inflammation, TNF-α, which stimulates TH2 cells at the site of inflammation, and NF-кB, which is required for cytokine and IgE antibody production. TCM has also been shown to be successful in lowering histamine levels, preserving histological changes by decreasing the thickness of the lamina propria, and downregulating the expression of Orai1, STIM1, and TRYC1, showing low expression of Ca+2 channel proteins. Conclusion: In this review, we discussed a series of classical, traditional Chinese medications, including Centipeda minima, Scutellaria baicalensis, licorice root (Glycyrrhiza uralensis), and others, as potential antiallergic agents and investigate their in vivo effect upon the production of cytokines and release of histamines for allergic rhinitis treatment.

Effect and mechanism of BDNF/TrkB signaling on vestibular compensation.

Brain-derived neurotrophic factor (BDNF) regulates neuronal plasticity by targeting the tyrosine kinase B receptor (TrkB) receptor, but limited researches concentrate on the role of BDNF/TrkB signaling in vestibular compensation. In this study, rats with unilateral vestibular dysfunction were established by unilateral labyrinthectomy (UL) and infusion with siBDNF or 7, 8-Dihydroxyflavone (7,8-DHF, a TrkB receptor agonist). The behavioral scores of rats with vestibular deficits were determined and the rotarod test was performed after UL. BDNF and TrkB levels after UL were determined by western blot and quantitative reverse transcription PCR (qRT-PCR). 5-bromo-2'-deoxyuridine (BrdU)-positive cells (newly generated cells) and GAD67-positive cells (GABAergic neurons) were identified by immunohistochemistry. Glial fibrillary acidic protein (GFAP) (astrocyte marker)-positive cells were identified and GABA type A receptor (GABAAR) expression was detected by immunofluorescence. We found that after UL, BDNF and TrkB levels were up-regulated with a maximum value at 4 h, and then progressively down-regulated during 4 h ~ 7 d. Blocking BDNF/TrkB signaling inhibited the recovery from vestibular deficits, decreased the numbers of newly generated cells and astrocytes in medial vestibular nucleus (MVN), inferior vestibular nerve (IVN), superior vestibular nerve (SVN) and lateral vestibular nucleus (LVN), and disrupted the balances of GABAergic neurons and GABAAR expressions in the left (lesioned) side and right (intact) side of MVN, whereas activation of BDNF/TrkB signaling caused opposite results. The current study indicated that BDNF/TrkB signaling avails vestibular compensation, depending on the number of newly generated cells and astrocytes, the rebalance of GABAergic neurons, and GABAAR expression in bilateral MVN.

Strain-Engineered Nano-Ferroelectrics for High-Efficiency Piezocatalytic Overall Water Splitting.

Developing nano-ferroelectric materials with excellent piezoelectric performance for piezocatalysts used in water splitting is highly desired but also challenging, especially with respect to reaching large piezo-potentials that fully align with required redox levels. Herein, heteroepitaxial strain in BaTiO3 nanoparticles with a designed porous structure is successfully induced by engineering their surface reconstruction to dramatically enhance their piezoelectricity. The strain coherence can be maintained throughout the nanoparticle bulk, resulting in a significant increase of the BaTiO3 tetragonality and thus its piezoelectricity. Benefiting from high piezoelectricity, the as-synthesized blue-colored BaTiO3 nanoparticles possess a superb overall water-splitting activity, with H2 production rates of 159 µmol g-1 h-1 , which is almost 130 times higher than that of the pristine BaTiO3 nanoparticles. Thus, this work provides a generic approach for designing highly efficient piezoelectric nanomaterials by strain engineering that can be further extended to various other perovskite oxides, including SrTiO3 , thereby enhancing their potential for piezoelectric catalysis.

Engineering of multiferroic BiFeO3 grain boundaries with head-to-head polarization configurations.

Confined low dimensional charges with high density such as two-dimensional electron gas (2DEG) at interfaces and charged domain walls in ferroelectrics show great potential to serve as functional elements in future nanoelectronics. However, stabilization and control of low dimensional charges is challenging, as they are usually subject to enormous depolarization fields. Here, we demonstrate a method to fabricate tunable charged interfaces with ~77°, 86° and 94° head-to-head polarization configurations in multiferroic BiFeO3 thin films by grain boundary engineering. The adjacent grains are cohesively bonded and the boundary is about 1 nm in width and devoid of any amorphous region. Remarkably, the polarization remains almost unchanged near the grain boundaries, indicating the polarization charges are well compensated, i.e., there should be two-dimensional charge gas confined at grain boundaries. Adjusting the tilt angle of the grain boundaries enables tuning the angle of polarization configurations from 71° to 109°, which in turn allows the control of charge density at the grain boundaries. This general and feasible method opens new doors for the application of charged interfaces in next generation nanoelectronics.

Machine learning-enabled identification of material phase transitions based on experimental data: Exploring collective dynamics in ferroelectric relaxors.

Exploration of phase transitions and construction of associated phase diagrams are of fundamental importance for condensed matter physics and materials science alike, and remain the focus of extensive research for both theoretical and experimental studies. For the latter, comprehensive studies involving scattering, thermodynamics, and modeling are typically required. We present a new approach to data mining multiple realizations of collective dynamics, measured through piezoelectric relaxation studies, to identify the onset of a structural phase transition in nanometer-scale volumes, that is, the probed volume of an atomic force microscope tip. Machine learning is used to analyze the multidimensional data sets describing relaxation to voltage and thermal stimuli, producing the temperature-bias phase diagram for a relaxor crystal without the need to measure (or know) the order parameter. The suitability of the approach to determine the phase diagram is shown with simulations based on a two-dimensional Ising model. These results indicate that machine learning approaches can be used to determine phase transitions in ferroelectrics, providing a general, statistically significant, and robust approach toward determining the presence of critical regimes and phase boundaries.

Field enhancement of electronic conductance at ferroelectric domain walls.

Ferroelectric domain walls have continued to attract widespread attention due to both the novelty of the phenomena observed and the ability to reliably pattern them in nanoscale dimensions. However, the conductivity mechanisms remain in debate, particularly around nominally uncharged walls. Here, we posit a conduction mechanism relying on field-modification effect from polarization re-orientation and the structure of the reverse-domain nucleus. Through conductive atomic force microscopy measurements on an ultra-thin (001) BiFeO3 thin film, in combination with phase-field simulations, we show that the field-induced twisted domain nucleus formed at domain walls results in local-field enhancement around the region of the atomic force microscope tip. In conjunction with slight barrier lowering, these two effects are sufficient to explain the observed emission current distribution. These results suggest that different electronic properties at domain walls are not necessary to observe localized enhancement in domain wall currents.

Novel lead-free ferroelectric film by ultra-small Ba0.8Sr0.2TiO3 nanocubes assembled for a large electrocaloric effect.

A giant electrocaloric effect (ECE) can be achieved in ferroelectric thin films, which demonstrates the applications of thin films in alternative cooling. However, electrocaloric thin films fabricated by conventional techniques, such as the pulsed laser deposition or sol-gel methods, may be limited by high costs, low yield and their dependence on substrates. In this study, we present a new bottom-up strategy to construct electrocaloric Ba0.8Sr0.2TiO3 thin films by assembling precisely designed building blocks of ferroelectric nanocubes, which is supported by detailed structural characterization. Moreover, it is found that our assembled Ba0.8Sr0.2TiO3 films differ remarkably from both individual Ba0.8Sr0.2TiO3 NPs and bulk Ba0.8Sr0.2TiO3 ceramics in terms of new collective ferroelectric properties, including superior and diffused permittivity constants and polarization-electric field loops. Benefiting from these unique ferroelectric properties, a giant ECE (9.1 K) over a broad temperature range (20 °C to 60 °C) is achieved, which is very large in the lead-free oxide film. Clearly, this bottom-up strategy provides a promising pathway for developing high electrocaloric effect devices.

Te inclusion-induced electrical field perturbation in CdZnTe single crystals revealed by Kelvin probe force microscopy.

To understand the effects of tellurium (Te) inclusions on the device performance of CdZnTe radiation detectors, the perturbation of the electrical field in and around Te inclusions was studied in CdZnTe single crystals via Kelvin probe force microscopy (KPFM). Te inclusions were proved to act as lower potential centers with respect to surrounding CdZnTe matrix. Based on the KPFM results, the energy band diagram at the Te/CdZnTe interface was established, and the bias-dependent effects of Te inclusion on carrier transportation is discussed.

Direct Observation of Magnetic Field Induced Ferroelectric Domain Evolution in Self-Assembled Quasi (0-3) BiFeO3-CoFe2O4 Thin Films.

Strain-mediated magnetoelectric (ME) coupling effect is expected in self-assembly heterostructures engineered by ferroelectric and ferromagnetic materials, contributing to the enhanced overall magnetoelectric effect. Microstructures as well as the connectivity configuration are considered to play a significant role in achieving efficient magnetoelectric properties. Different from the conventional (1-3) and (2-2) type composite films, we fabricate BiFeO3-CoFe2O4 (BFO-CFO) composite thin films with a novel quasi (0-3) type connectivity via a dual-target pulsed laser deposition process. The self-assembly growth mechanism has been studied, which demonstrates that the perovskite (BFO) matrix segments the connectivity of spinel (CFO) resulting in a quasi (0-3) composite. Direct observation of ferroelectric domain wall motion under external magnetic fields proves a strong magnetoelectric coupling effect in these (0-3) thin films. Our preliminary findings reveal the promising application potential of this new structure as multiferroic domain wall devices.

Anatomy of vertical heteroepitaxial interfaces reveals the memristive mechanism in Nb2O5-NaNbO3 thin films.

Dynamic oxygen vacancies play a significant role in memristive switching materials and memristors can be realized via well controlled doping. Based on this idea we deposite Nb2O5-NaNbO3 nanocomposite thin films on SrRuO3-buffered LaAlO3 substrates. Through the spontaneous phase separation and self-assembly growth, two phases form clear vertical heteroepitaxial nanostructures. The interfaces between niobium oxide and sodium niobate full of ion vacancies form the conductive channels. Alternative I-V behavior attributed to dynamic ion migration reveals the memristive switching mechanism under the external bias. We believe that this phenomenon has a great potential in future device applications.

Silver-modified nanosized ferroelectrics as a novel photocatalyst.

Monodispersed ferroelectric BaTiO3 nanoparticles are synthesized as a model system to investigate the effect of ferroelectricity on a photocatalytic process. The results demonstrate that ferroelectricity can directly affect the photocatalytic activity due to promotion of the separation of photo-excited carriers by spontaneous polarization in ferroelectric materials. Moreover, Ag nanoparticles are attached on these BaTiO3 to further improve the photocatalytic property.