Obvious Enhancement Research Articles

Optical behaviors of Mn4+-modified cubic type ZnTiO3:Eu3+ nanocrystals: Application in optical thermometers based on fluorescence intensity ratio and lifetime

Cubic type ZnTiO3 nanophosphors were fabricated by using hydrothermal method. The photoluminescence behaviors of Eu3+/Mn4+ co-doped ZnTiO3 crystals and Mn4+-modified ZnTiO3:Eu3+ crystals were investigated. The red and near-infrared emissions assigned to Eu3+ and Mn4+ were observed at the excitation wavelength of 465 nm for Eu3+/Mn4+ co-doped ZnTiO3 crystals and Mn4+ modified ZnTiO3:Eu3+ crystals. Eu3+/Mn4+ co-doped ZnTiO3 crystals revealed the most intense near-infrared emission assigned to Mn4+. For Mn4+-modified ZnTiO3:Eu3+ crystals, the red emissions assigned to Mn4+ revealed an obvious enhancement with the concentration of Mn4+ increasing from 0.01 mol% to 0.1 mol%, and then revealed a concentration quenching behavior at the Mn4+ concentration of 0.5 mol% and 1 mol%. Under 465 nm excitation wavelength, the emission assigned to 2Eg → 4A2g of Mn4+ in ZnTiO3 revealed stronger temperature dependence compared with that assigned to 5D0 → 7F2 transition of Eu3+. Based on the fluorescence intensity ratio between Eu3+ and Mn4+, the maximum relative sensitivity of 3.15 %/K at 305 K for the 0.05 mol% Mn4+ modified ZnTiO3:Eu3+ was achieved, which was higher than that of 2.9 %/K for Eu3+/Mn4+ co-doping ZnTiO3 nanocrystals. Based on the lifetime of the emission of Mn4+, the highest relative sensitivity of 1.4 %/K was obtained in the 0.05 mol% Mn4+ modified ZnTiO3:Eu3+, which was lower than that based on fluorescence intensity ratio. It indicated that the surface modification by transition metals should improve the temperatures sensing performance and had potential applications in optical thermometers.

Tunable Self-Thermophoretic Nanomotors with Polymeric Coating.

Thermophoretic micro/nanomotors (MNMs) generate self-propulsion without a chemical reaction. Intrinsically, this promises excellent biocompatibility and is thus suitable for biomedical applications. However, their propulsion efficiency is severely limited due to the poor understanding of the thermophoretic process, which dominates the conversion from thermal energy into mechanical movement. We here developed a series of self-thermophoresis light-powered MNMs with variable surface coatings and discovered obvious self-thermophoresis propulsion enhancement of the polymeric layer. An intrinsically negative self-thermophoretic movement is also observed for the first time in the MNM system. We propose that enthalpic contributions from polymer-solvent interactions should play a fundamental role in the self-thermophoretic MNMs. Quantitative microcalorimetry and molecular dynamics simulations are performed to support our hypothesis. The polymer solvation enthalpy and coating thickness influences on self-thermophoresis are investigated, further highlighting the essential enthalpy contributions to thermophoresis. Our work indicates that surface grafting would be important in designing high-efficiency thermally driven nanorobotic systems for biomedical applications.

Highlights on the key roles of interfaces between CeO2-based oxide and perovskite (LaMnO3/LaFeO3) in creating active oxygen species for soot oxidation

Design efficient catalyst which can activate oxygen molecules or supply active oxygen species is a key challenge for soot abatement under the much lower concentration of oxygen from gasoline vehicle exhaust. Herein, combining with the advantages of both CeO2-based oxide (CeO2–ZrO2–Y2O3–La2O3, CZ for short) and perovskite (LaMnO3 and LaFeO3) in oxygen storage/release, two hybrids catalysts, CZ-LaMnO3 (LM) and CZ-LaFeO3 (LF), with more oxygen vacancies and enhanced lattice oxygen transport at lower temperatures due to the heterointerface effects have been successfully synthesized for soot oxidation. Combining with X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), oxygen temperature-programmed desorption (O2-TPD) and H2temperature-programmed reduction (H2-TPR), it was found that electrons transfer from Ce3+ to Fe3+ and an interfacial La diffusion from LM to CZ may have been occurred in LF-CZ and LM-CZ, respectively, which leads to the increased unsaturated sites and oxygen vacancies. More importantly, the obvious enhancement of active surface lattice oxygen transport at low temperatures due to interfacial interaction has also been demonstrated in LM-CZ, which highly promotes the soot oxidation. And consequently, 5LM-CZ (with 5 wt% content of LM) showed the highest soot conversion activity, whose T50 (50 % soot conversion temperature) (379 °C) was lower than 5LF-CZ (395 °C) and CZ (401°C) at tight contact mode in 1 %O2/N2 atmosphere, indicating that the activation of lattice oxygen at the interface plays an important role in soot oxidation. Furthermore, when further varying the content of LM in xLM-CZ (x = 5 wt%, 10 wt%, 15 wt%, 20 wt%), it was found that 10LM-CZ, whose content of LM reached the monolayer dispersion capacity of CZ, exhibited the most abundant active surface lattice oxygen species due to the optimized interface area. As a result, 10LM-CZ displayed superior activity even than pure LM in both loose and tight contact with/without NO, indicating that the composite catalyst has a wide application environment. This work has a certain guiding significance for the utilization of heterointerface effect among different components to prepare effective soot oxidation catalyst with multi-components.

Rapid microwave synthesis of N and S dual-doped carbon quantum dots for natamycin determination based on fluorescence switch-off assay

Green, one-pot, quick, and easily synthesized nitrogen and sulfur co-doped carbon quantum dots (N,S-CDs) were obtained from cheap and readily available chemicals (sucrose, urea, and thiourea) using a microwave-assisted approach in about 4 min and utilized as a turn-off fluorescent sensor for estimation of natamycin (NAT). First, the effect of N and S doping on the microwave-synthesized CDs’ quantum yield was carefully studied. CDs derived from sucrose alone failed to produce a high quantum yield; then, to increase the quantum yield, doping with heteroatoms was carried out using either urea or thiourea. A slight increase in quantum yield was observed upon using thiourea with sucrose, while an obvious enhancement of quantum yield was obtained when urea was used instead of thiourea. Surprisingly, using a combination of urea and thiourea together results in N,S-CDs with the highest quantum yield (53.5%), uniform and small particle size distribution, and extended stability. The fluorescent signal of N,S-CDs was quenched upon addition of NAT due to inner filter effect and static quenching in a manner that allowed for quantitative determination of NAT over a range of 0.5–10.0 μg ml−1 (LOD = 0.10 μg ml−1). The N,S-CDs were applicable for determination of NAT in aqueous humor, eye drops, different environmental water samples, and bread with excellent performance. The selectivity study indicated excellent selectivity of the prepared N,S-CDs toward NAT with little interference from possibly interfering substances. In-silico toxicological evaluation of NAT was conducted to estimate its long-term toxicity and drug-drug interactions. Finally, the preparation of N,S-CDs, and analytical procedure compliance with the green chemistry principles were confirmed by two greenness assessment tools.

Modulated upconversion luminescence of WO3: Yb3+/Ho3+ through non-equivalence substitution of Bi3+ ions

The upconversion luminescence (UCL) of inorganic materials doped with activators and sensitizers has great application, but its luminescence intensity always impose restrictions on its development. Herein, an obvious enhancement in luminescence intensity of the WO3: Yb3+, Ho3+ phosphor was realized through non-equivalence substitution of Bi3+ ions. The single pure phase of the synthesized WO3: Yb3+, Ho3+, and Bi3+ phosphors has been confirmed by the XRD pattern. The morphology of phosphors and valence state of elements have been performed by SEM and XPS techniques. The sample on excitation with 980 nm performs forceful green emission and weak red emission at 543 nm and 662 nm, separately. The concentrations for doped Yb3+ and Ho3+ to obtain the optimal UCL in WO3 are 8% and 1%, respectively. The optimized doping concentration for Bi3+ ions is 3%. Compared to samples without Bi3+ ions, the Yb3+/Ho3+/Bi3+ doped WO3 obtains 1.59 and 2.33 times increase in emission intensity of green and red, respectively. We also explored the UCL mechanism and enhancement mechanism on the basis of the power dependency, the UCL and the downshift luminescence. These results based on Yb3+/Ho3+ UCL phosphors research is of great significance.

Enhanced photocatalytic activity of tourmaline modified BiFeO3 nanoparticles by efficient charge transfer

The development of green and efficient photocatalytic materials for the industrial wastewater has become a current research focus. In this work, bare BiFeO3 (BFO) and tourmaline modified BFO composites were synthesized by the sol-gel method to investigate the photocatalytic degradation efficiency of the different content tourmaline modified BFO for methyl orange dyes. The SEM and elemental mapping images display that BFO nanoparticles are uniformly distributed on the surface of tourmaline. The increased photocurrent density and band gaps indicate that higher effective separation for photogenerated electron-hole pairs were obtained by introducing the tourmaline. The photocatalytic activities shows that T-BFO composite exhibits an obvious enhancement of methyl orange degradation ratio under visible light irradiation, which is higher than that of the bare BFO. Moreover, the electron transport mechanism of T-BFO composites were particularly investigated through active species trapping experiments. These results provide a new approach to develop the high performance of photocatalyst.

A simple BODIPY-based fluorescent probe for sequential recognition of Cu2+ and GSH and its application on test strips and bioimaging in living cells

A novel, highly sensitive “on-off-on” fluorescent probe (E)-N’-((1H-imidazol-2-yl) methylene) -4-(5, 5-difluoro-1, 3, 7, 9-tetramethyl-5H-4λ4,5λ4-dipyrrolo [1, 2-c:2′, 1′-f] [1,3,2] diazaborinin-10-yl) benzohydrazide (BDB) was developed in this study, and its structural and spectral properties were characterized by 13C NMR, 1H NMR, X-ray, ESI-MS, ultraviolet and fluorescence photometry. BDB could specifically and efficiently identify Cu2+ among many other metal ions with a fluorescence quenching efficiency of 92.7% and a recognition limit of 0.65 μM in CH3CN/HEPES (7:3, v/v, pH = 7.23) buffer. The energy difference between BDB and BDB-Cu2+ complex was calculated by DFT. The BDB-Cu2+ complex could continuously identify GSH in the same system and show an obvious fluorescence enhancement response with a recovery efficiency of approximately 91% and a low recognition limit of 0.02 μM, which is significantly lower than the physiological concentration of GSH in living cells. The applicability of BDB is verified by the strip test. BDB can also be used to detect GSH in HeLa cells, which expand the application of fluorescent chemical sensors in biology.

Femtosecond laser surface processing combined with thermal oxidation for enhancing corrosion resistance of AZ31B magnesium alloy in chloride solutions

A novel method of ultrafast femtosecond laser surface processing (FLSP) combined with the post thermal oxidation (TO) treatment was employed to improve the corrosion resistance of AZ31B magnesium (Mg) alloys. FLSP with laser powers (< 100 mW) mainly creates the nanostructures on AZ31B alloy surfaces, while the higher laser powers (> 200 mW) induce the hierarchical micro/nanostructures. According to the electrochemical results, the corrosion resistance of AZ31B alloys in Cl− solutions is weakened after the FLSP. However, an obvious enhancement in corrosion resistance is found when the femtosecond (fs) laser-processed samples subjected to the TO treatment in the temperature range from 100 °C to 280 °C. TO treatment actually supports the oxidation and growth of the nanostructure to form a dense film, considerably improving its protective ability and enhancing the corrosion resistance of Mg alloys in Cl− solutions. The uniform corrosion is evidently inhibited and localized corrosion emerges on laser-processed samples after the TO treatment.

Efficiency enhancement of solar cell by using methylammonium lead tribromide/polymethyl methacrylate hybrid film as luminescent down shifting layer

Luminescent down-shifting (LDS) layer was introduced to tackle the issue of poor short-wavelength response of solar cell. Besides LDS effect, coating a LDS layer on the surface of a solar cell leads to a change in surface reflectance. LDS and antireflection (AR) effect are coupled and usually reported as a single effect. For those solar cell with optimized AR, it is difficult to enhance power conversion efficiency (PCE) with the LDS layer due to the variation of reflectance. In this work, we report an obvious PCE enhancement of two mainstream commercial silicon (Si) solar cells with the optimized AR by using methylammonium lead tribromide (MAPbBr3)/polymethyl methacrylate (PMMA) hybrid film as a LDS layer. The used MAPbBr3/PMMA nanoplatelets solutions for LDS layer have an absolute photoluminescent quantum yield of ∼85 % (excited by 350 nm) in air atmosphere for more than 30 days, laying a foundation for the realization of effective LDS effect. Theoretical analysis has separated the AR and LDS effect. It has demonstrated that AR effect has a positive influence on LDS effect, and PMMA plays the key role in the improvement of AR. Experimental studies further elucidated the LDS and AR effect provided by MAPbBr3/PMMA hybrid film. Thanks to this combined effect, the application of MAPbBr3/PMMA hybrid film as a LDS layer on Si heterojunction solar cell yields a PCE gain of 0.3 % absolute and that on passivated emitter and rear cell produces an absolute PCE enhancement of about 0.7 %.

Crystal growth and infrared-to-visible upconversion luminescence in Nd-Yb-Tm: CaYAlO4 single crystal

Yb3+/Tm3+: CaYAlO4 (CYA) and Nd3+/Yb3+/Tm3+: CYA bulk single crystals were grown using the Czochralski (Cz) method. The polarized absorption, upconversion luminescence (UCL) spectra under 980 nm and 808 nm pumping, and fluorescence decay curves were measured as well as Judd-Ofelt (J-O) theory calculations were performed to investigate the sensitization effect of Yb3+ and Nd3+/Yb3+co-doping in Tm3+: CYA single crystal. Obvious enhancement was observed in Tm3+-activated crystals for the blue upconversion emission (∼474 nm) when doped with Yb3+ or co-doped with Nd3+/Yb3+. The energy transfer efficiency is 72.6% (Yb3+→Tm3+) and 71.7% (Nd3+→Yb3+/Tm3+) in Yb3+/Tm3+: CYA and Nd3+/Yb3+/Tm3+: CYA single crystals respectively. The gain cross-sections were calculated, and it can stated that the blue laser output derived from upconversion is possible around 474 nm related to the transition of 1G4→ 3H6 in Yb3+/Tm3+: CYA and Nd3+/Yb3+/Tm3+: CYA crystals.

Highly Efficient Photocatalysts: Polyoxometalate Synthons Enable Tailored CdS-MoS2 Morphologies and Enhanced H2 Evolution.

The development of photocatalysts toward highly efficient H2 evolution reactions is a feasible strategy to achieve the effective conversion of solar energy and meet the increasing demand for new energy. To this end, we prepared two different CdS-MoS2 photocatalysts with unique morphologies ranging from hexagonal prisms to tetragonal nanotubes by carefully tuning polyoxometalate synthons. These two photocatalysts, namely, CdS-MoS2-1 and CdS-MoS2-2, both exhibited remarkable photocatalytic efficiency in H2 generation, among which CdS-MoS2-2 showed superior performance. In fact, the best catalytic hydrogen desorption rate of CdS-MoS2-2 is as high as 1815.5 μmol g-1 h-1. Such performance is superior to twice that of single CdS and almost four times that of pure MoS2. This obvious enhancement can be accredited to the highly open nanotube morphology and highly dispersed heterometallic composition of CdS-MoS2-2, which represents an excellent example of the highest noble-metal-free H2 evolution photocatalysts reported so far. Taken together, these findings suggest that the development of highly dispersed heterometallic catalysts is an auspicious route to realize highly efficient conversion of solar energy and that CdS-MoS2-2 represents a major advance in this field.

An acridone-derived fluorescent off-on probe for detection and in vivo imaging of nitroreductase

Understanding the functions of enzymes in various physiological processes is important, but the design of signaling probes for fast analysis of enzymatic activity is particularly challenging. Herein, a fluorescence-enhanced probe, 10-methyl-2-nitro-acridone (MNA), was synthesized and applied to analyze nitroreductase (NTR) activity in vitro and in vivo. The detection mechanism is based on the nitro group in MNA reacting toward NTR with high reactivity and generating 10-methyl-2-amino- acridone (MAA) accompanied by an obvious fluorescence signal enhancement at 525 nm emission. The probe shows low cytotoxicity, fast response, and high selectivity and sensitivity with a limit of detection as low as 150 ng·mL−1. The probe was also employed for two-photon fluorescence imaging of NTR in zebrafish in vivo revealing the distribution of NTR. Versus existing NTR probes, the proposed probe shows favorable analytical performance including near-infrared light excitation with no other byproducts produced after the reaction. The superior properties of this signaling probe allow it to become a fluorescence imaging candidate in other biosystems.

Three-Dimensional Macroporous rGO-Aerogel-Based Composite Phase-Change Materials with High Thermal Storage Capacity and Enhanced Thermal Conductivity.

Three-dimensional porous network encapsulation strategy is an effective means to obtain composite phase-change materials (PCMs) with high heat storage capacity and enhanced thermal conductivity. Herein, macroporous reduced graphene oxide (rGO) aerogels with adjustable pore size are prepared by the emulsion template method and hydrothermal reduction process. Further, the shape-stabilized rGO-aerogel-based composite PCMs are constructed after the combination of 3D porous rGO supports and paraffin wax (PW) through vacuum melting infiltration. By regulating the pore structure of the rGO aerogel network, the rGO-based composite PCMs achieve excellent energy storage properties with a phase-change enthalpy of 179.94 J/g for the loading amount of 95.61 wt% and an obvious enhancement in thermal conductivity of 0.412 W/m-1·K-1, which is 54.89% higher than pristine PW and enduring thermal cycling stability. The obtained macroporous rGO-aerogel-based composite PCMs with high thermal storage and heat transfer performance effectively broaden the application of PCMs in the field of thermal energy storage.

The effects of Wnt, BMP, and Notch signaling pathways on cell proliferation and neural differentiation in a song control nucleus (HVC) of Lonchura striata.

There is obvious sexual dimorphism in the song control system of songbirds. In the higher vocal center (HVC), cell proliferation and neuronal differentiation contribute to the net addition of neurons. However, the mechanism underlying these changes is unclear. Given that Wnt, Bmp, and Notch pathways are involved in cell proliferation and neuronal differentiation, no reports are available to study the role of the three pathways in the song control system. To address the issue, we studied cell proliferation in the ventricle zone overlying the developing HVC and neural differentiation within the HVC of Bengalese finches (Lonchura striata) at posthatching day 15 when HVC progenitor cells are generated on a large scale and differentiate into neurons, after Wnt and Bmp pathways were activated by using a pharmacological agonist (LiCl) or Bmp4, respectively, and the Notch pathway was inhibited by an inhibitor (N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester), DAPT). The results indicated that both cell proliferation and neural differentiation toward HVC neurons increased significantly after activation of the Wnt signaling pathway or inhibition of the Notch signaling pathway. Although cell proliferation was increased, neural differentiation was inhibited after treatment with Bmp4. There was obvious synergetic enhancement in the number of proliferating cells after the coregulation of two or three signaling pathways. In addition, synergetic enhancement was also found in the Wnt and Notch pathways in neural differentiation toward neurons within HVC. These results suggest that the three signaling pathways are involved in cell proliferation and neural differentiation of HVC.

Confining manganese-based peroxymonosulfate activation in carbon nanotube membrane for phenol degradation: Combined effect of oxygen vacancy defects and nanoconfinement

In this study, an open ends carbon nanotube (OCNT) membrane, which confined fine-tuned oxygen vacancy defects (Odef) modified MnOx inside OCNT (MnOx-in-OCNT), was developed for enhancing peroxymonosulfate (PMS) activation towards phenol (PE) removal. The MnOx-in-OCNT membrane filtration coupled with PMS activation process (MFPA process) achieved outstanding removal (100%) of PE at a high permeate flux of 585.0 L m2 h−1 bar−1 (residence time of only 8.8 s). The unit degradation rate (2 min running time) and mass transfer rate of MnOx-in-OCNT were 2.0 and 8.4 times higher than that of CCNT (closed caps CNT) membrane with surface-loaded MnOx (MnOx-out-CCNT) MFPA process, and its catalytic performance was much superior to MnOx-in-OCNT powder reactions and MnOx-in-OCNT membrane batch reactions. The PMS activation mechanism experienced an obvious enhancement yield of reactive oxygen species (ROS) from MnOx-out-CCNT to MnOx-in-OCNT MFPA process. The enhanced PMS activation and boosted ROS yield of MnOx-in-OCNT was mainly attributed to the co-effect of the fine-tuned Odef and nanoconfinement. The contact frequency between PMS, pollutant and Odef was greatly enhanced via nanoconfinement effect, leading to the enhanced yield of SO4•− and •OH. Meanwhile, the O2 was enriched and reacts with enhanced Odef under nanoconfined-space to produce O2•− and 1O2. Then, the co-enhanced ROS (SO4•−, •OH, 1O2 and O2•−) displayed wide applicability for phenolic pollutants removal owing to their presence of –OH. Finally, the possible degradation pathway of PE was deduced by DFT calculations and HPLC analysis.

In situ imaging of signaling molecule carbon monoxide in plants with a fluorescent probe.

Carbon monoxide (CO) is a recently discovered gasotransmitter. In animals, it has been found that endogenously produced CO participates in the regulation of various metabolic processes. Recent research has indicated that CO, acting as a signaling molecule, plays a crucial regulatory role in plant development and their response to abiotic stress. In this work, we developed a fluorescent probe, named COP (carbonic oxide Probe), for the in situ imaging of CO in Arabidopsis thaliana plant tissues. The probe was designed by combining malononitrile-naphthalene as the fluorophore and a typical palladium-mediated reaction mechanism. When reacted with the released CO, COP showed an obvious fluorescence enhancement at 575 nm, which could be observed in naked-eye conditions. With a linear range of 0-10 μM, the limit of detection of COP was determined as 0.38 μM. The detection system based on COP indicated several advantages including relatively rapid response within 20 min, steadiness in a wide pH range of 5.0-10.0, high selectivity, and applicative anti-interference. Moreover, with a penetration depth of 30 μm, COP enabled 3D imaging of CO dynamics in plant samples, whether it was caused by agent release, heavy metal stress, or inner oxidation. This work provides a fluorescent probe for monitoring CO levels in plant samples, and it expands the application field of CO-detection technology, assisting researchers in understanding the dynamic changes in plant physiological processes, making it an important tool for studying plant physiology and biological processes.

Facet Engineering-Induced Construction of Ni2P/ZnIn2S4 Heterostructures for Boosted Photocatalytic CO2 Reduction.

Facet engineering was realized to enhance the CO2 photoreduction performance of the Ni2P/ZnIn2S4 heterostructure, in which the commonly exposed (1 0 2) face of ZnIn2S4 was converted to the (1 0 1) face due to the unique properties of the phosphide. The variation in the crystal plane strengthened the intense interfacial contact between Ni2P and ZnIn2S4, resulting in the promotion of utilization and absorption efficiency for incident light and boosting the surface reaction rate. Combined with the significant metallicity of Ni2P, inhibited recombination and strengthened transfer efficiency were achieved, leading to an obvious enhancement of photoreduction activity over Ni2P/ZnIn2S4 compared to pure samples. In particular, the optimal NZ7 composite (the mass ratio of Ni2P to ZnIn2S4) reached 68.31 μmol h-1 g-1 of CH4, 10.65 μmol h-1 g-1 of CH3OH, and 11.15 μmol h-1 g-1 of HCOOH. The mechanism of the CO2 photoreduction process was elucidated using ESR and in situ DRIFTS techniques.

Imaging Features of Primary Intraosseous Meningiomas.

To describe the imaging features of primary intraosseous meningiomas (PIMs) to aid an accurate diagnosis. Clinical materials and radiological data for 9 patients with pathologically confirmed PIMs were reviewed comprehensively. Most lesions involved inner and outer plates of the calvaria and all were relatively well circumscribed. Upon computed tomography, portions of the solid neoplasm were hyperattenuated or isoattenuated. Hyperostosis was found in many lesions, but calcification was seen rarely. On magnetic resonance imaging, most neoplasms were hypointense on T1-weighted images, hyperintense on T2-weighted images, and heterogeneous on fluid-attenuated inversion recovery images. In most cases, the soft tissue of neoplasms showed hyperintense on diffusion-weighted imaging and hypointense on apparent diffusion coefficient. All lesions were obviously enhanced after gadolinium administration. Each patient accepted surgical treatment and recurrence was not observed during follow-up. Primary intraosseous meningiomas are very rare tumors that occur usually in later life. They are well-defined and tend to involve the inner and outer plates of the calvaria, with a classic appearance of hyperostosis on computed tomography. Primary intraosseous meningiomas display hypointense on T1-weighted images, hyperintense on T2-weighted images, and hyperattenuated or isoattenuated on computed tomography. Hyperintense on diffusion-weighted imaging, hypointense on apparent diffusion coefficient can also be found. Obvious enhancement supplied additional information for an accurate diagnosis. A neoplasm with these features should raise the suspicion of a PIM.

Tunable Fluorescence via Self-Assembled Switching of AIE-Active Micelle-like Nanoaggregates.

Chemical structures bearing a combination of aggregation-induced emission enhancement (AIEE) and intramolecular charge transfer (ICT) properties attracted the attention of many researchers. Recently, there is an increasing demand to pose tunable AIEE and ICT fluorophores that could present their conformation changes-related emission colors by adjusting the medium polarity. In this study, we designed and synthesized a series of 4-alkoxyphenyl-substituted 1,8-naphthalic anhydride derivatives NAxC using the Suzuki coupling reaction to construct donor-acceptor (D-A)-type fluorophores with alkoxyl substituents of varying carbon chain lengths (x = 1, 2, 4, 6, 12 in NAxC). To explain the observation that molecules with longer carbon chains revealed unusual fluorescence enhancement in water, we study the optical properties and evaluate their locally excited (LE) and ICT states by solvent effects combined with Lippert-Mataga plots. Then, we explored the self-assembly abilities of these molecules in water-organic (W/O) mixed solutions and observed the morphology of its nanostructure using a fluorescence microscope and SEM. The results show that NAxC, x = 4, 6, 12 show different degrees of self-assembly behaviors and corresponding aggregation-induced emission enhancement (AIEE) progresses. At the same time, different nanostructures and corresponding spectral changes can be obtained by adjusting the water ratio in the mixed solution. That is, NAxC compounds present different transitions between LE, ICT and AIEE based on the polarity, water ratio and time changes. We designed NAxC as the structure-activity relationship (SAR) of the surfactant to demonstrate that AIEE comes from the formation of micelle-like nanoaggregates, which causes a restriction of the transfer from the LE state to the ICT state, and micelle formation results in a blue-shift in emission and enhances the intensity in the aggregate state. Among them, NA12C is most likely to form micelles and the most obvious fluorescence enhancement, which will switch over time due to the nano-aggregation transition.

The Ni2+-LaNiO3/CdS hollow core–shell heterojunction towards enhanced visible light overall water splitting H2 evolution via HER/OER synergism of Ni2+/Ov

The synergetic HER/OER (hydrogen evolution reaction/oxygen evolution reaction) is the crucial issue for overall water splitting. Herein, the Ni2+-LaNiO3/CdS hollow core–shell heterojunction with HER/OER synergism of Ni2+/Ov (oxygen vacancy) is synthesized by a hybrid hydrothermal-reductive-chemical method. As shown, the Ni2+-LaNiO3/CdS (∼15480.79 μmol∙g−1∙h−1) exhibits an obvious visible light photocatalytic enhancement (HER/Photodegradation) than that of single LaNiO3 (∼200/∼15 folds) and single CdS (∼120/∼6 folds), and achieves a better overall water splitting performance of ∼ 645.23(H2)/321.62(O2) μmol∙g−1∙h−1 (∼110 folds of LaNiO3), and a respectable stability (∼5.64% decreasing during 24 h). It mainly ascribes to the synergetic HER/OER via the Ni2+/Ov, formed heterojunction and hollow core–shell structure. There, the Ni2+ ions can increase solar efficiency and promote photo-generated electron diffusing for HER, the Ov induced by Ni2+ can decrease OER energy barrier and promote hole­related species transportation for OER, the LaNiO3/CdS heterojunction with appropriate potential gradient can improve carrier efficiency, and the hollow core–shell structure can increase active sites and solar efficiency. Furthermore, the quickly carrier diffusion can inhibit photocorrosion and hollow spherical structure can increase photocatalytic stability.