Publications by authors named "Zhaohui Ren"

The composition in ferroelectric oxide films is decisive for optimizing properties and device performances. Controlling a composition distribution in these films by a facile approach is thus highly desired. In this work, we report a solution epitaxy of PbZrTiO films with a continuous gradient of Zr concentration, realized by a competitive growth at ~220 °C.

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  • * Total concentrations of four PAEs in tobacco leaves ranged from 49.0 to 273 ng/g, with di-(2-ethylhexyl) phthalate (DEHP) being the most prevalent at an average of 44.4 ng/g, especially in economically developed regions.
  • * Health risk assessments indicate that while the hazard quotients for the measured PAEs are below 1, suggesting minimal non-carcinogenic risk to smokers, a low carcinogenic risk from DEHP was also identified
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This study investigated the release of aromatic compounds with distinct functional groups within bilayer microcapsules. Bilayer microcapsules of four distinctive core materials (benzyl alcohol, eugenol, cinnamaldehyde, and benzoic acid) were synthesized via freeze-drying. Chitosan (CS) and sodium alginate (ALG) were used as wall materials.

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Cyclin-dependent kinase 9 (CDK9) is a member of the transcription CDK subfamily. In this work, we preliminarily demonstrated the feasibility of CDK9 as a potent target of treatment for colorectal cancer, and a series of novel CDK9 inhibitors were rationally designed and synthesized based on the structure of AZD5438 (a pan CDKs inhibitor reported by AstraZeneca). A novel selective CDK9 inhibitor named CLZX-205, which possessed significant CDK9 inhibitory activity (IC = 2.

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Piezoelectric poly(vinylidene fluoride) (PVDF) and its copolymers have been widely investigated for applications in wearable electric devices and sensing systems, owing to their intrinsic piezoelectricity and superior flexibility. However, their weak piezoelectricity poses major challenges for practical applications. To overcome these challenges, we propose a two-step synthesis approach to fabricate sandwich-structured piezoelectric films (BaTiO@PDA/PVDF/BaTiO@PDA) with significantly enhanced ferroelectric and piezoelectric properties.

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Conventional indirect X-ray detectors employ scintillating phosphors to convert X-ray photons into photodiode-detectable visible photons, leading to low conversion efficiencies, low spatial resolutions, and optical crosstalk. Consequently, X-ray detectors that directly convert photons into electric signals have long been desired for high-performance medical imaging and industrial inspection. Although emerging hybrid inorganic-organic halide perovskites, such as CH NH PbI and CH NH PbBr , exhibit high sensitivity, they have salient drawbacks including structural instability, ion motion, and the use of toxic Pb.

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Solution growth of single-crystal ferroelectric oxide films has long been pursued for the low-cost development of high-performance electronic and optoelectronic devices. However, the established principles of vapor-phase epitaxy cannot be directly applied to solution epitaxy, as the interactions between the substrates and the grown materials in solution are quite different. Here, we report the successful epitaxy of single-domain ferroelectric oxide films on Nb-doped SrTiO single-crystal substrates by solution reaction at a low temperature of ~200 C.

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Domain-wall nanoelectronics is considered to be a new paradigm for non-volatile memory and logic technologies in which domain walls, rather than domains, serve as an active element. Especially interesting are charged domain walls in ferroelectric structures, which have subnanometre thicknesses and exhibit non-trivial electronic and transport properties that are useful for various nanoelectronics applications. The ability to deterministically create and manipulate charged domain walls is essential to realize their functional properties in electronic devices.

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Ferroelectric materials hold great promise in the field of photocatalytic water splitting due to their spontaneous polarization that sets up an inherent internal field for the spatial separation of photogenerated charges. The ferroelectric polarization, however, is generally accompanied by some intrinsic defects, particularly oxygen vacancies, whose impact upon photocatalysis is far from being fully understood and modulated. Here, we have studied the role of oxygen vacancies over the photocatalytic behavior of single-domain PbTiO through a combination of theoretical and experimental viewpoints.

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Surface oxygen vacancies have been widely discussed to be crucial for tailoring the activity of various chemical reactions from CO, NO, to water oxidation by using oxide-supported catalysts. However, the real role and potential function of surface oxygen vacancies in the reaction remains unclear because of their very short lifetime. Here, it is reported that surface oxygen vacancies can be well confined electrostatically for a polarization screening near the perimeter interface between Pt {111} nanocrystals and the negative polar surface (001) of ferroelectric PbTiO Strikingly, such a catalyst demonstrates a tunable catalytic CO oxidation kinetics from 200 °C to near room temperature by increasing the O gas pressure, accompanied by the conversion curve from a hysteresis-free loop to one with hysteresis.

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Article Synopsis
  • Researchers synthesized octahedral PbTiO-TiO nanocomposites using a hydrothermal method, featuring perovskite ferroelectric PbTiO nanooctahedra as substrates.
  • The microstructures were analyzed using various techniques (XRD, SEM, TEM, and UV-Vis spectroscopy), revealing 5 nm TiO nanocrystals on the surfaces of the nanooctahedra.
  • The photocatalytic hydrogen production rate was significantly enhanced with higher TiO loading, reaching a peak value of 630.51 μmol/h, attributed to improved UV light absorption and efficient carrier separation.
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Macromolecular films are crucial functional materials widely used in the fields of mechanics, electronics, optoelectronics, and biology, due to their superior properties of chemical stability, small density, high flexibility, and solution-processing ability. Their electronic and mechanical properties, however, are typically much lower than those of crystalline materials, as the macromolecular films have no long-range structural ordering. The state-of-the-art for producing highly ordered macromolecular films is still facing a great challenge due to the complex interactions between adjacent macromolecules.

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Oxide heterointerface is a platform to create unprecedented two-dimensional electron gas, superconductivity and ferromagnetism, arising from a polar discontinuity at the interface. In particular, the ability to tune these intriguing effects paves a way to elucidate their fundamental physics and to develop novel electronic/magnetic devices. In this work, we report for the first time that a ferroelectric polarization screening at SrTiO/PbTiO interface is able to drive an electronic construction of Ti atom, giving rise to room-temperature ferromagnetism.

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  • The study explores how the magnetoelectric effect can be used to control magnetic properties for future data storage devices, allowing for the switching of magnetic states through electric fields.
  • First-principles calculations show that changing the electric polarization of a 2D ferroelectric substrate (α-InSe) affects the magnetic properties of metal-phthalocyanine molecules (MPc), specifically OsPc.
  • The findings indicate that by modifying the system with functionalized atoms, the magnetic moments and magnetic anisotropy energies can be significantly enhanced, making this technique potentially useful for nanoscale electronics and spintronics at room temperature.
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Background: Closed-loop neuromodulation based on bladder pressure is an effective therapy for lower urinary tract dysfunction. The catheter-based cystometry normally used for bladder pressure measurement is not conducive to patient health because it will bring great mental stress to the patient and increase the risk of infection.

Method: This paper designs and implements an implantable wireless and batteryless bladder pressure monitor system that monitors bladder storage in real time by implanting a miniature packaged sensor which transmits the feedback signal to the external receiver through BLE (Bluetooth Low Energy).

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Therapeutic systems to induce reactive oxygen species (ROS) have received tremendous success in the research of tumor theranostics, but suffered daunting challenges in limited efficacy originating from low presence of reactants and reaction kinetics within cancer cells. Here, ferrous sulfide-embedded bovine serum albumin (FeS@BSA) nanoclusters, in an amorphous nature, are designed and synthesized via a self-assembly approach. In acidic conditions, the nanoclusters degrade and simultaneously release HS gas and Fe ions.

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For the first time, we report the design and fabrication of a ZnS nanoparticle-decorated silica fibre mesh (ZnS@SiO) for localized HS-amplified chemotherapy. With incorporation of DOX, implanted ZnS@SiO fibres enable sufficient on-site drug dosage and intracellular HS content, inducing significant in vitro and in vivo tumour inhibition.

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Ethnopharmacological Relevance: Chinese patent medicine Zhixiong Capsule (ZXC) is the equal mixture of the extract of leech, Ligusticum chuanxiong Hort., Salvia miltiorrhiza Bunge, Leonurus japonicus Houtt., and Pueraria lobate (Willd.

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Facet engineering of anatase TiO by controlling the {001} exposure ratio has been the focus of numerous investigations to optimize photocatalytic activity. In particular, an introduction of fluoride ions during the crystal growth has been demonstrated to be very effective and decisive in realizing the facet exposure of the crystals. However, a key role of fluoride ions in stabilizing {001} exposure and improving subsequent photocatalytic activity of anatase TiO remains unclear up to date.

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An unpredicted side effect of photothermal therapy (PTT) is agitated by hyperthermia which results in damage to healthy tissue. Developing PTT platforms, enabling effective tumor ablation under mild irradiation conditions, is of wide interest, but challenging. Here, we investigated bismuth crystals embedded silica (Bi@SiO) nanoparticles, loaded with an autophagy inhibitor (chloroquine, CQ).

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We have developed a photoluminescent membrane for microRNA detection, consisting of chemically modified mesoporous silica nanoparticles (CaF2:Yb/Ho@MSNs) attached, via single stranded DNA probes, to flexible polyurethane fibres coated with graphene oxide (GO). By detecting the release of the luminescent nanoparticles resulting from complementary co-hybridization between target miRNA sequences and the DNA probe, accurate measurements of the miRNA concentration at high sensitivity levels can be obtained. The constructs therefore offer a route to rapid detection and the potential for early cancer diagnosis.

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Objective: Epilepsy is a chronic brain disease, which is prone to relapse and affects individuals of all ages worldwide, particularly the very young and elderly. Up to one-third of these patients are medically intractable and require resection surgery. However, the outcomes of epilepsy surgery rely upon the clear identification of epileptogenic zone (EZ).

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Background And Aims: Chinese patent medicine Zhixiong Capsule (ZXC) has been used in clinical treatment against blood stasis-induced dizziness and headache for many years in China.

Hypothesis/purpose: Recent clinical observations demonstrated a good efficacy of ZXC against atherosclerotic plaque formation in carotid arteries. The aims of this study were to verify the plaque-preventing efficacy of ZXC in animals and to investigate the underlying mechanisms.

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