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ZrB2 is widely used in refractory linings and electrodes as well as in a range of applications including microelectronics and cutting tools, owing to its excellent characteristics, such as high hardness, high melting point, high strength, high thermal conductivity, and good thermal shock resistance. However, ZrB2 readily oxidizes, especially at high temperatures, which is ascribed to the reaction between ZrB2 and O2 in air. This study shows that a structural self-deterioration phenomenon occurs in ZrB2, even in vacuum or inert atmosphere. ZrB2 exhibits a characteristic, irreversible increase in resistivity in a high vacuum–high temperature environment. During repeated variable temperature resistivity testing, the resistivity of ZrB2 increases by 3.28% in the first cycle and 0.61% in the second. To investigate further, in-situ TEM showed that ZrB2 experiences an unusual phase transition reaction at high temperatures, even under a high vacuum environment. Oxidation results in a large number of disordered, layered structures and holes inside the ZrB2 particles. This microstructure evolution mechanism decreases the electrical conductivity and affects the performance of ZrB2. The study demonstrates the need to thoroughly investigate the microstructure changes in ZrB2 at high temperatures, under an inert atmosphere or high vacuum, and to widen the investigations to other properties beyond electrical resistivity.

The hydrogen evolution reaction (HER) is an emerging renewable energy source to derive clean, efficient, and high-energy-density hydrogen fuel from electrochemical water splitting mostly by using t...

Traditional fluorinated carbon (CFx) batteries are greatly limited in their applications mostly because of inferior rate performances, initial voltage delay and low fluorine-to-carbon ratio below one. This work innovatively applies graphite nanosheets (NSs) as carbon source and optimizes the fluorination process at temperature range of 250–400 °C to prepare CFx NSs. Specifically, the edge defects and –CF2, –CF3 perfluorinated functional group active sites are introduced into NSs in the form of covalent/semi-covalent/semi-ionic bonds by adjusting the temperature which also breaks the limit of fluorocarbon ratio to achieve ultra-thin microstructure with high performances. In the battery assembly process, a series of discharge electrolytes are introduced to improve the quality and realize the ultrahigh specific capacity. The optimized CFx-400 °C NSs deliver an excellent specific capacity of 921 mAh·g−1 at a current density of 10 mA·g−1 with a high energy density value of 2210 Wh·kg−1. Moreover, the new electrolytes are selected which not only serve as electrolytes but also can be loaded on CFx surface for various discharge reactions without affecting the actual battery function. Thus, the lightweight tabs and current collectors are selected to control the loading of active material and injection coefficient. The presented battery design strategy provides a new strategy to achieve an ultrahigh specific energy density of 1116 Wh·kg−1.

Most of the magnetic microwave absorbers are ineffective in extreme corrosive environments of acids and alkalis which abruptly reduce their performance. Therefore, it is urgent and worthwhile to produce the bifunctional materials with excellent corrosion resistance and microwave absorption property. This work presents the in-situ growth of double shells of silica and carbon on FeSiAl (FSA) alloy surface to obtain an integrated FSA@SiO2@C hybrid structure via combined Stober and catalytic chemical vapor deposition (CCVD) techniques. The hybrid structure acquires the strengthened bi-functional for anti-corrosion and microwave absorption due to the excellent corrosion shielding protection and well dielectric properties of SiO2 and carbon hybrid structure. Importantly, the hybrid morphology retains excellent stability of more than 150 h in 5.0 wt% NaCl acid solution. Moreover, FSA@SiO2@C hybrid possesses enhanced microwave absorption performance with a minimum reflection loss (RLmin) of −46.75 dB at 5.74 GHz with a matching thickness of 3.5 mm, and the effective bandwidth (RL

The sensitivity of ethanol sensor is of paramount importance in a variety of areas, including chemical production with ethanol, alcohol testing for driving safety, etc. Herein, α-Fe2O3 nano-cylinders with atomic carbon layers are synthesized, for the first time, through in-situ catalytic chemical vapor deposition combined with hydrothermal techniques for the detection of ethanol. The reported α-Fe2O3@C nano-cylinders with double surficial strain effects deliver an ethanol detection sensitivity of ～8 times as compared with α-Fe2O3 nano-cylinders, ∼10 times higher as compared with its detection sensitivity to ammonia, para-xylene, methanol and benzene. The sensor also exhibits over-14-day operation stability and the minimum detection limit of 10 ppm. To our best knowledge, the performances surpass those of previously reported α-Fe2O3. Such attractive performances are attributed to the enhanced charge transfer in α-Fe2O3 owing to the double surficial strain effects of α-Fe2O3@C nano-cylinders and the efficient adsorption of ethanol with atomic carbon layers.

The helical structures possess unique physical and chemical properties, such as superelasticity, high specific strength, chirality, and electromagnetic cross-polarization characteristics. With the development of nanoscience and nanotechnology, helical structures with various scales have been discovered or synthesized artificially. Among them, the helical carbon materials receive much attention around the world. Herein, we present a brief review of the development of helical carbon materials in terms of structures, synthesis techniques and mechanisms, and applications. The controllable designing of catalysts, carbon sources and reaction parameters plays a key role to optimize the properties of the helical carbon materials. At the same time, the applications in microwave absorption devices, sensors, catalysts, energy conversions and storage devices, and solar cell are also presented. For the good chemical and physical properties, helical carbon materials have a good application prospect in many fields. The potential issues and future opportunities of the helical carbon materials are also proposed.

K2SiF6:Mn4+ phosphor is well known for its excellent red emission performance which is vital for improving the color rendering of white light-emitting diodes. However, the poor moisture resistance limits its application in optical devices. In this paper, K2SiF6:Mn4+ phosphor is coated with an inorganic hydrophobic protective layer to obtain good moisture resistance. Chemical vapor deposition method was used to decompose acetylene at high temperature, and the generated nanoscale carbon layer worked as a hydrophobic protective coating on the surface of the phosphor. Microstructure, compositions and properties of the synthesized K2SiF6:Mn4+@C phosphor were investigated in detail. It is found that most of the deposited carbon is coated on the surface of phosphor crystals in amorphous state. The carbon atoms are bonded with the fluorine element in K2SiF6:Mn4+ phosphor, forming carbon-fluorine (C–F) covalent bonds. The moisture resistance of K2SiF6:Mn4+@C phosphor is improved owing to the protection of the hydrophobic carbon. The relative emission intensity of K2SiF6:Mn4+@C phosphor could maintain 73% of the initial luminous intensity after immersing in the aqueous solution at room temperature for 8 h, whereas K2SiF6:Mn4+ phosphor without carbon coating was only 0.7% remaining of the initial value under the same conditions.

Bifunctional catalysts for water-electrolysis are developed to simplify electrode- and cell-manufacturing. Hitherto, screening bifunction catalysts relies on experimental trials of high-performance cells and theoretical calculations of free-energy changes in the HER/OER intermediate steps, with high costs and constraints. Herein, we derive from the inevitable electrode-surface oxidation in water electrolysis and the semiconductor physics of such an oxidized electrode surface a band-diagram perspective: the oxidized electrode surface governing the catalytic activities in a bifunctional water-electrolysis cell should be a semiconductor with an effective bandgap not much larger than the HER-OER electrochemical potential gap of 1.23 eV. This perspective and its applications are elaborated with a set of experimental and DFT-computational results with FeP as a nominal bifunctional catalyst on nickel electrodes for the construction of a high-performance cell exhibiting 10 mA cm−2 at 1.40 V. The proposed “bandgap screening” is easy, low-cost, and applicable for expediting the development of new bifunctional catalysts.

The large size of sodium ions (Na+) restricts the choice of electrode materials; therefore, to realize low-cost energy storage systems, exceptional electrodes are required. Here, we have overcome this bottleneck by developing porous quasi-graphitic carbon (PGC) sheets at the surface of water-soluble KCl crystals as a green catalyst. The KCl crystals not only avoid the use of hazardous chemicals but also provide easy manipulation of the structural and surface chemistry of PGC sheets on a large-scale. The as-synthesized PGC sheets are enriched with micropores and amorphous reservoirs, which serve as mass transport channels and storage sites for Na+, respectively. Interestingly, when PGC sheets are employed as an anode in the sodium-ion battery, they showed an excellent reversible specific capacity of 237 mA h g−1 with outstanding cyclic stability by retaining 83.5% capacity after 250 cycles at 0.1 A g−1 at a capacity decay of 0.07% per cycle, while remaining stable up to 550 cycles when tested at 0.5 A g−1. Thus, the simple synthesis and large-scale production of PGC with high sodium storage capacity make it a potential candidate for secondary ion batteries.

Excessive activation of voltage-gated sodium channel Nav1.3 has been recently reported in secondary traumatic brain injury (TBI). However, the molecular mechanisms underlying regulating voltage-gated sodium channel (Nav1.3) has not been well understood. The present study used a TBI rat model induced by a fluid percussion device and performed a circRNA microarray (n=3) to profile the altered circRNAs in the hippocampus after TBI. After PCR validation, certain circRNA was selected to investigate the function and mechanism in regulating Nav1.3 in the TBI rat model by intracerebroventricular (ICV) injection with lentivirus. The neurological outcome was evaluated by Morris water maze (MWM) test, modified Neurological Severity Score (mNSS), brain water content measurement, hematoxylin, and eosin (H&E) staining. The related molecular mechanisms were explored with PCR, western blotting, luciferase reporter, chromatin immunoprecipitation (ChIP), and electrophoretic mobility shift assay (EMSA). A total of 347 circRNAs were observed to be differentially expressed (FC ≥1.2 and p < 0.05) after TBI, including 234 up-regulated and 113 down-regulated circRNAs. Among 10 validated circRNAs, we selected circRNA_009194 with the maximized up-regulated fold change (n=5, FC=4.45, p

Fluorinated carbon (CFx), a thriving member of the carbonaceous derivative, possesses various excellent properties of chemically stable, tunable bandgap, good thermal conductivity and stability, and super-hydrophobic due to its unique structures and polar C-F bonding. Herein, we present a brief review of the recent development of fluorinated carbon materials in terms of structures, properties and preparation techniques. Meanwhile, the applications in energy conversions and storage devices, biomedicines, gas sensors, electronic devices, and microwave absorption devices are also presented. The fluorinated carbon contains various types of C-F bonds including ionic, semi-ionic and covalent C-F, C-F2, C-F3 bonds with tunable F/C ratios. The controllable designing of C-F bonding and F/C ratios play a key role to optimize the properties of fluorinated carbon materials. Until now, the potential issues and future opportunities of fluorinated carbon are proposed. The present review will provide a direction for tuning C-F bonding and F/C ratios, developing a safe and efficient fluorination method and popularizing the applications of fluorinated carbon materials.

The interface characteristics of electrode materials are of tremendous value for supercapacitors, however, poor conductivity, instability in harsh reaction conditions and limited ion mobility in oxide materials are identified as immense challenges for generating high energy density without renouncing the power capability. Herein, a peculiar catalytic chemical vapour deposition (CCVD) approach is employed to decorate a very thin carbon capsules (CCs) on the surface of LiMn2O4 nanorods to synthesize a very active and uniformly distributed LiMn2O4/CCs nano-hybrid material with modified interface characteristics. The CCs not only provide the physicochemical protection as well as improve the electrical conductivity. As an electrode material, LiMn2O4/CCs possess the specific discharge capacitance of 451 F/g which is far superior to LiMn2O4 (304 F/g) at the current density of 0.5 A/g in 0.5 M Li2SO4 aqueous solution. In addition, the LiMn2O4/CCs exhibit an outstanding specific capacitance of 380 F/g even at a much higher current density of 8 A/g. Moreover, after 3000 charge and discharge cycles, LiMn2O4/CCs electrode retains nearly 95% of initial capacity, higher than that of spinel LiMn2O4 electrode which retains only 93%. This innovative technique can be adopted to construct a large variety of other nano-hybrid materials for consumer utilization in the field of supercapacitors.

Designing sensing materials with novel morphologies and compositions is eminently challenging to achieve high-performance gas sensor devices. Herein, an in situ oxidative polymerization approach is developed to construct three-dimensional (3D) hollow quasi-graphite capsules/polyaniline (GCs/PANI) hierarchical hybrids by decorating protonated PANI on the surface of GCs; as a result, an immensely active and sensitive material was developed for sensing ammonia gas at room temperature. Moreover, the GCs possessed a capsule-like hollow/open structure with partially graphitized walls, and PANI nanospheres were uniformly decorated on the GC surfaces. Furthermore, the inflexible and rigid 3D ordered chemistry of these materials provides the resulting hybrids with a large interfacial surface area, which not only allows for rapid adsorption and charge transfer but also provides the necessary structural stability. The 3D hollow GCs/PANI hybrids exhibit excellent performance; the GCs/PANI-3 hybrid is highly sensitive (with a response value of 1.30) toward 10 ppm NH3 gas and has short response and recovery times of 34 and 42 s, respectively. The GCs/PANI-3 hybrid also demonstrates a good selectivity, repeatability, and long-term stability, which are attributed to the substantial synergistic effect of the GCs and PANI. The design of such a unique 3D ordered framework provides a promising pathway to achieve room-temperature gas sensors for commercial applications.

Zirconium Boride is widely used as thermal protection materials. However, the characteristics of poor oxidation resistance of ZrB2 at high temperatures limits its applications. In order to improve the anti-oxidation performance of ZrB2, a novel method of doping LaF3 is adopted in present study. In the synthesis process of ZrB2 via carbothermal reduction method, LaF3 was introduced to the initial materials. Motivated by the slightly higher formation temperature of ZrB2 than the melting point of LaF3, a liquid glass phase composed of F and La was deposited on the surface of ZrB2, which naturally brought in oxygen starvation and contributed to improved oxidation resistance performance. The crystal lattice parameters and the anti-oxidation ability of ZrB2 are closely dependent on the added LaF3 content, which can ascribe to La3+/Zr2+ substitution and the amount of glass phase on the surface of ZrB2.

Summary: Additive engineering has become increasingly important for making high-quality perovskite solar cells (PSCs), with a recent example involving acid during fabrication of cesium-based perovskites. Lately, it has been suggested that this process would introduce dimethylammonium ((CH3)2NH2+, DMA+) through hydrolysis of the organic solvent. However, material composition of the hydrolyzed product and its effect on the device performance remain to be understood. Here, we present an in-depth investigation of the hydrolysis-derived material (i.e., DMAPbI3) and detailed analysis of its role in producing high-quality PSCs. By varying the ratio of CsI/DMAPbI3 in the precursor, we achieve high-quality CsxDMA1-xPbI3 perovskite films with uniform morphology, low density of trap states, and good stability, leading to optimized power conversion efficiency up to 14.3%, with over 85% of the initial efficiency retained after ∼20 days in air without encapsulation. Our findings offer new insights into producing high-quality Cs-based perovskite materials. : Energy Sustainability; Materials Characterization; Energy Materials Subject Areas: Energy Sustainability, Materials Characterization, Energy Materials

Structural instability and limited operational efficiency of sodium-ion battery (SIB) anodes, compared lithium-ion battery (LIB) anodes, are main hurdles for their large-scale applications that can be tackled using self-tunable electrode materials. Here, we created and utilized ultrathin partially-crystalline carbon nanocups (CNCs) that have the ability to self-tune their structure, contain highly tangled walls and present open framework for enhanced energy densities for SIBs and the outcomes are benchmarked with LIBs. The tangled wall structure offers enhanced spacings for ionic storage and the open framework supports enhanced mass transport, while partial-crystallinity of CNCs provides high conductivity and stabilizes the structure for long cycle life. The CNCs delivered high capacities up to 468 mAh/g for SIBs at 25 mA/g and 953 mAh/g for LIBs at 50 mA/g after 100 cycles, respectively, while bore excellent stability by delivering highly stable performance exceeding 1000 cycles for SIBs at 1.5 A/g and 5000 cycles for LIBs at 7.5 A/g (20 C) with only a loss of 0.013 mAh/g per cycle. Moreover, when tested in lower voltage ranges, the CNCs delivered unprecedented capacity of 368 mAh/g (0.01–2.0 V) for SIBs and 671 mAh/g (0.01–2.0 V) and 449 mAh/g (0.01–1.5 V) for LIBs at 25 and 50 mA/g, respectively, which indicate the usability of the CNCs in full-cells. The post-electrochemical characterizations revealed that the developed CNCs self-modified their interlayer spacings (average spacing increased to 0.44 nm from 0.42 nm) during charge-discharge to create additional voids for increased ionic storage and stable performance, especially for Na+, while maintaining their overall morphology, composition and structure. The structural design presented here will provide new pathways of tailoring carbonaceous nanostructures for future high-performance energy storage devices.

Most microwave absorbers lose their function under harsh working conditions, such as a high temperature and an oxidative environment. Here, we developed a heterogeneous ZrN0.4B0.6/SiC nanohybrid via combined catalytic chemical vapor deposition (CCVD) and chemical vapor infiltration (CVI) processes using ZrB2 as the starting material. The composition and structure of the ZrN0.4B0.6/SiC nanohybrid were controlled by tuning the CCVD and CVI parameters, such as reaction temperature, time, and reactant concentration. The optimal heterogeneous ZrN0.4B0.6/SiC nanohybrids were obtained initially by preparing ZrB2@C via the CCVD process at 650 °C for 30 min and the subsequent CVI at 1500 °C, where the ZrB2@C reacted with Si under N2. The ZrN0.4B0.6/SiC nanohybrid exhibited enhanced microwave absorption ability with a minimum reflection loss value of approximately -50.8 dB at 7.7 GHz, a thickness of ∼3.05 mm, and antioxidation features at a high temperature of 600 °C. The heterogeneous ZrN0.4B0.6/SiC nanohybrid possessed reasonable conductivity, leading to dielectric loss, whereas SiC nanofibers formed a three-dimensional network that brought higher dipole moments, whereas a small part of the ZrN0.4B0.6/SiC nanohybrid structure generated an effective interface for higher attenuation of microwaves. Therefore, these material features synergistically resulted in a well-defined Debye relaxation, Maxwell-Wagner relaxation, dipole polarization, and the quarter-wavelength cancellation, which accounted for the enhanced microwave absorption.

The effective treatment of industrial wastewater to protect freshwater reserves for the survival of life is a primary focus of current research. Herein, a multicomponent Eleocharis-manganese peroxidase enzyme (Eleocharis@MnPE) layered hybrid with high surface area (1200 m2/m3), with a strong synergistic adsorption and catalytic biodegradation (SACB), has been developed through a facile method. A combination of outer porous (Eleocharis) and inner catalytically active (MnPE) components of the hybrid resulted in highly efficient SACB system, evidenced by high removal rate of 15 kg m-3 day-1 (100%) and complete degradation of toxic Orange II (OR) azo dye into nontoxic products (gases and weak acids). The Eleocharis@MnPE layered hybrid efficiently degraded both OR in synthetic wastewater and also other azo dyes (red, pink, and yellow dyes) present in three different textile industrial effluents. For the industrial effluents, these were evidenced by the color disappearance and reduction in biological oxygen demand (BOD), chemical oxygen demand (COD), and total organic carbon (TOC) of up to 97%, 92%, and 76%, respectively. Furthermore, reduced toxicity of treated wastewater was confirmed by decreased cell toxicity to 0.1%-1% and increased cell viability to 90%. We believe that designing a hybrid system with strong ability of SACB could be highly effective for industrial-scale treatment of wastewater.

Activated microglia can suppress neurite outgrowth and synapse recovery in the acute stage following traumatic brain injury (TBI). However, the underlying mechanism has not been clearly elucidated. Exosomes derived from microglia have been reported to play a critical role in microglia-neuron interaction in healthy and pathological brains. Here, we aimed to investigate the role of microglia-derived exosomes in regulating neurite outgrowth and synapse recovery following TBI. In our study, exosomes derived from microglia were co-cultured with stretch-injured neurons in vitro and intravenously injected into mice that underwent fluid percussion injury (FPI) by tail vein injection in vivo. The results showed that microglia-derived exosomes could be absorbed by neurons in vitro and in vivo. Moreover, exosomes derived from stretch-injured microglia decreased the protein levels of GAP43, PSD-95, GluR1, and Synaptophysin and dendritic complexity in stretch-injured neurons in vitro, and reduced GAP43+ NEUN cell percentage and apical dendritic spine density in the pericontusion region in vivo. Motor coordination was also impaired in mice treated with stretch-injured microglia-derived exosomes after FPI. A microRNA microarray showed that the level of miR-5121 was decreased most greatly in exosomes derived from stretch-injured microglia. Overexpression of miR-5121 in stretch-injured microglia-derived exosomes partly reversed the suppression of neurite outgrowth and synapse recovery of neurons both in vitro and in vivo. Moreover, motor coordination in miR-5121 overexpressed exosomes treated mice was significantly improved after FPI. Following mechanistic study demonstrated that miR-5121 might promote neurite outgrowth and synapse recovery by directly targeting RGMa. In conclusion, our finding revealed a novel exosome-mediated mechanism of microglia-neuron interaction that suppressed neurite outgrowth and synapse recovery of neurons following TBI. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13311-020-00999-z.

Background Glioblastoma multiforme, the most aggressive and malignant primary brain tumor, is characterized by rapid growth and extensive infiltration to neighboring normal brain parenchyma. Our previous studies delineated a crosstalk between PI3K/Akt and JNK signaling pathways, and a moderate anti-glioblastoma synergism caused by the combined inhibition of PI3K p110β (PI3Kβ) isoform and JNK. However, this combination strategy is not potent enough. MLK3, an upstream regulator of ERK and JNK, may replace JNK to exert stronger synergism with PI3Kβ. Methods To develop a new combination strategy with stronger synergism, the expression pattern and roles of MLK3 in glioblastoma patient’s specimens and cell lines were firstly investigated. Then glioblastoma cells and xenografts in nude mice were treated with the PI3Kβ inhibitor AZD6482 and the MLK3 inhibitor URMC-099 alone or in combination to evaluate their combination effects on tumor cell growth and motility. The combination effects on cytoskeletal structures such as lamellipodia and focal adhesions were also evaluated. Results MLK3 protein was overexpressed in both newly diagnosed and relapsing glioblastoma patients’ specimens. Silencing of MLK3 using siRNA duplexes significantly suppressed migration and invasion, but promoted attachment of glioblastoma cells. Combined inhibition of PI3Kβ and MLK3 exhibited synergistic inhibitory effects on glioblastoma cell proliferation, migration and invasion, as well as the formation of lamellipodia and focal adhesions. Furthermore, combination of AZD6482 and URMC-099 effectively decreased glioblastoma xenograft growth in nude mice. Glioblastoma cells treated with this drug combination showed reduced phosphorylation of Akt and ERK, and decreased protein expression of ROCK2 and Zyxin. Conclusion Taken together, combination of AZD6482 and URMC-099 showed strong synergistic anti-tumor effects on glioblastoma in vitro and in vivo. Our findings suggest that combined inhibition of PI3Kβ and MLK3 may serve as an attractive therapeutic approach for glioblastoma multiforme.

Li/CFx batteries are widely applied in medical and electronic products because of their outstanding electrochemical performance. However, the poor intrinsic conductivity and inevitable polarization of the CFx material result in low ion migration and rate performance. Herein, an ultraviolet (UV)-radiation inducing technology to adjust the C–F bonding types, which improved the rate performance of the Li/CFx battery. UV radiations reasonably change the ratio of various C–F bonds, namely, not only increased the concentration of semi-ionic C–F bonds, but also reduced the relative proportion of inert C–F2 and inactive C–F3. Then this technology further increases the conductivity of the CFx and improves the rate performance of Li/CFx batteries. After UV-modification, the CFx possesses more multi-level channels to favor the electrolyte infiltration, shortening the charge transmission distance. And the in situ formed carbon coating also contributes to the enhanced conductivity. Compared with the original FSC losing the discharge capacity at 1 C, the optimal FSC-5W-72h has a specific capacity of 762.1 mAh/g and a specific energy of 1615.4 Wh/kg at 1 C. This UV radiation technology has created a novel way to address the reasonable C–F bonds of CFx and in-situ carbon coating, improving the rate performance of Li/CFx battery.

Corrosive ions with immense penetrating ability often invalidate the traditional microwave absorber as well as cause severe corrosion. Herein, an inorganic/organic bilayer structure of silicon dioxide/polyurethane-acrylic (SiO2@PUA) is developed layer by layer on FeSiAl surface for addressing the dual-function of microwave absorption and anti-corrosion properties. The bilayer structure possesses the inorganic SiO2 layer with physical barrier function and organic outer layer (PUA) of hydrophobic nature. The as-prepared FeSiAl@SiO2@PUA composite structure filled with 20 wt% of paraffin wax displays a maximum reflection loss of −49 dB at 5.8 GHz, and a broad effective absorption bandwidth reaches 7.8 GHz (10.2–18 GHz) at 2.5 mm thickness. Besides, the corrosion behavior of FeSiAl, FeSiAl@SiO2, and FeSiAl@SiO2@PUA is investigated by immersing in a corrosive environment and electrochemical testing. Due to the multi-level protection of SiO2/PUA bilayer, the FeSiAl@SiO2@PUA is immersed in an alkaline salty environment (pH = 12) for 3930 h and the corresponding corrosion potential significantly increases from −0.166 to −0.047 V, indicating the enhanced anti-corrosion with relatively low corrosion current 2.16 × 10-6 A/cm2 and corrosion rate (6.94 × 10-13 m/s). The designing inorganic/organic hybrid structure provides an effective strategy to enhance the dual-function of microwave absorption and anti-corrosion and its application at the commercial level.

Copper nanostructures have aroused extensive research interests due to their large number of applications in phonology, electronics, catalysis, etc . Here, we have developed a novel single-step redox colloidal route to construct three-dimensional (3D) nanoporous Cu leaves. By tuning the surface chemistry of copper nuclei, the morphology of as-prepared copper nanocrystals can be adjusted from nanoparticles to leaves. The 3D Cu leaves own anisotropic nanoporous structure and exhibit surface-enhanced Raman scattering (SERS) performance with an enhancement factor of ∼10 6 . The present facile and low-cost route to develop 3D nanoporous Cu leaves provides an efficient platform for achieving high-performance nanostructures for next generation photocathode applications.

Designable control over the morphology and structure of active materials is highly desirable for achieving high-performance devices. Here, we develop a facile microwave-assisted synthesis to decorate MnO2 nanocrystals on three-dimensional (3D) graphite-like capsules (GCs) to obtain sandwich nanostructures (3D MnO2@GCs@MnO2) as electrode materials for electrochemical capacitors (ECs). A templated growth of the 3D GCs was carried out via catalytic chemical vapor deposition and MnO2 was decorated on the exterior and interior surfaces of the GC walls through microwave irradiation to build an engineered architecture with robust structural and morphological stability. The unique sandwiched architecture has a large interfacial surface area, and allows for rapid electrolyte diffusion through its hollow/open framework and fast electronic motion via the carbon backbone. Furthermore, the tough and rigid nature of GCs provides the necessary structural stability, and the strong synergy between MnO2 and GCs leads to hi...

In this study, hydroxyapatite-containing coatings were prepared by microarc oxidation on AZ31 magnesium alloy surface to improve its biodegradation performance. Five applied voltages were chosen to prepare the MAO coatings. The results demonstrate that the number of micropores in the films increases but their dimensions decrease after higher voltage is applied. As the surface roughness of the MAO coatings increases with the applied voltage, the wettability of the coatings improves continuously. The MAO coatings were mainly composed of magnesium oxide (MgO) and hydroxyapatite. The amount of hydroxyapatite phase increased with increasing voltage that was applied. The bonding strength became slightly weaker after a higher voltage was applied. But the bonding strengths of all the coatings were consistently higher than 37 MPa, which met the requirement of implant biomaterials. All coatings exhibited higher corrosion resistances and lower hydrogen evolution rate than the bare AZ31 Mg substrate, implying that the degradation rate of the AZ31 Mg alloy was enhanced by the hydroxyapatite-containing coatings. The results indicate that the present treatment of applying hydroxyapatite-containing coatings is a promising technique for the degradable Mg-based biomaterials for orthopedic applications.

As a novel alternative biodegradable metal, magnesium possesses great potential and feasibility for bone fracture fixation due to its suitable mechanical properties, high degradability and biocompatibility. However, poor corrosion resistance in physiological fluids restricts their practical applications. In this study, HA contained coating on AZ31 Mg alloy substrate is prepared by MAO technique under various treatment times. The effect of treatment time on microstructure, composition, mechanical and corrosion properties is systematically investigated. The results indicate that MAO treatment is an effective route to improve the corrosion resistance. The enhanced corrosion is attributed to the barrier effect of the coatings. The failure mechanism of the MAO samples in Hank's solution is studied by long time immersion. A model for corrosion mechanism and corrosion process of the MAO coating on AZ31 Mg alloy in Hank's solution is proposed.

Graphitic carbon (GC) coatings on the surface of functional materials have received tremendous attention because of their significant effect on surface chemistry. Herein, we have explained the interactions of a carbon source (acetylene) on the surface of functional material (tetrapod-zinc oxide, T-ZnO) through Density Functional Theory (DFT) calculations. DFT studies suggested that the growth of GC in the catalytic chemical vapour deposition (CCVD) process follows two typical pathways: one is chemo/physioadsorption of acetelyne on the T-ZnO surface, and the second one is decomposition of acetylene on the T-ZnO surface to activate carbon atoms that are restructured to generate a GC layer on the T-ZnO surface. Therefore, such a growth through catalytic accumulation reaction of carbon species on the substrate surface is named as vapour-dissociation-solid (VDS) growth. To support our theoretical observation, the GCs on the surface of T-ZnO are grown using acetylene through CCVD, and the results strongly support the VDS growth mechanism. The varying conditions of the CCVD process results in two types of microstructures including a smooth GC coating on T-ZnO that can also yield functional hollow GC nanostructures through acid leaching of the metallic part and ZnC8 nanoparticles embedded in GC walls. The high resolution microscopic analyses confirm the existence of ZnC8 in the nanospheres with an average size of 5.36 nm, which authenticates the decomposition followed by the solid deposition to form the GC on the substrate surface and supports a unique VDS growth mechanism. Therefore, an in-depth study of the GC growth mechanism and its fine coating on complex structures will facilitate research in the prevention of metal oxidation and the design of novel active materials for sensors, environment, energy and medical applications.

Early detection of peptide aggregate intermediates is quite challenging because of their variable and complex nature as well as due to lack of reliable sensors for diagnosis. Herein, we report the detection of monomers and oligomers using specified fluorescence and a magnetic resonance imaging (MRI) multimodal probe based on bovine-serum-albumin-capped fluorine functionalized graphene quantum dots (BSA@FGQDs). This probe enables in vitro fluorescence-based monitoring of human islet amyloid polypeptide (hIAPP), insulin, and amyloid β(1–42) (Aβ42) monomers and oligomers during the fibrillogenesis dynamic. Up to 90% fluorescence quenching of BSA@FGQDs probe upon addition of amyloid monomers/oligomers was observed due to static quenching and nonradiative energy transfer. Moreover, the BSA@FGQDs probe shows 10 times higher signals in detecting amyloid intermediates and fibrils than that of conventional thioflavin dye. A negative ΔG° value (−36.21 kJ/mol) indicates spontaneous interaction of probe with the pept...

Zirconium diboride exhibits high thermal conductivities and high melting point, which are beneficial for use in extreme environments. Examples including cutting tools, high-temperature electrodes and leading edges of hypersonic space vehicles. However, there is limited literature on the infrared properties of ZrB2 thin films. In this study, we report the results of infrared emissivity of sputter-deposited films and post-annealed films. X-ray diffraction shows promoted crystalline quality and grains growth for ZrB2 films with the increasing annealing temperature and time. The thin film exhibits high thermal stability and a low infrared emissivity of 0.01 (8 ~ 14 μm) after annealed at 1000℃ for 10 h. Besides, with an increase in annealing temperature and annealing time, film densification and grains growth were observed, leading to decrease of electrical resistivity and infrared emissivity.

As a promising material for electromagnetic microwave absorption, FeSiAl (FSA) alloy always suffers from inadequate corrosion resistance in the marine environment. Herein, the Raman and X-ray photoelectron spectroscopy (XPS) depth profiling techniques are adopted to investigate the basic corrosion behavior of FSA in salt spray environment. The Raman analysis contributes to the understanding of the composition change at various corrosive periods while the XPS depth profiling reveals the corrosion process of Fe0→Fe2+→Fe3+ in a sequence. The observed corrosion rates (CRs) of FSA immersed in 5 wt% NaCl solution for 1, 24 and 48 h are 2.99 × 10−12, 4.90 × 10−12 and 5.85 × 10−12 m/s, respectively. The increasing value of CRs as a function of time demonstrates the accelerated corrosion tendency. Moreover, to suppress the corrosive behavior of FSA alloy, carbon is decorated on its surface by catalytic chemical vapor deposition method using acetylene as the carbon source. The carbon coating restrains the corrosion process by impermeability and hydrophobicity of carbon materials in corrosive mediums. This study will help in the designing of microwave absorbers which can resist corrosion in harsh reaction conditions as well as available at commercial level to save the economy.

It is a challenge to recover copper from low grade ore in an environmentally sustainable way, especially from low-grade copper sulfide resources. This paper introduces Zijinshan Mine where an integrated process was developed and applied to recover copper from low-grade copper sulfide ore and acid mine drainage (AMD). The process includes the main operations of milling-flotation, heap bioleaching, solvent extraction-electrowinning (HBL-SX-EW) and copper precipitation. Ore with a grade higher than 0.25% Cu is fed to milling-flotation plant to produce copper concentrates, while the ore with grade lower than 0.25% Cu is sent to HBL-SX-EW to produce copper cathode via SX-EW. Because the copper resource consists mainly of secondary copper sulfides with high pyrite, and the mine is located in a region of high rainfall, a large volume of acid mine drainage is generated. In order to protect the environment, recover copper and make acid and iron balance, the acid mine drainage is respectively distributed to heap bioleaching, SX and sulfide precipitation, depending on the copper concentration of the wastewater. The paper also introduces the progress of tailings utilization, environmental protection and mine ecological restoration at Zijinshan mine.

In rechargeable lithium ion batteries (LIBs), the separator undergoes stresses in repeated charge and discharge processes. Polyvinylidene fluoride (PVDF) gel separators own excellent thermal stability and electrolyte wettability, but their limited mechanical strength cannot sustain severe strains under the conditions of large Li ion fluxes, mechanical and thermal shocks of batteries. In this report, a solid-electrolyte-reinforced gel separator is prepared through a single-step electrophoretic deposition on a stable surfactant-free colloid of PVDF-HFP and Al-doped Li6.75La3Zr1.75Ta0.25O12 (LLZTO). The LLZTO/PVDF-HFP separator owns a 3D laminated structure, a mechanical strength of 28.6 MPa, a room-temperature ionic conductivity of 7.13 × 10−4 S cm−1 and improved thermal stability. With the LLZTO/PVDF-HFP separator, LiFePO4 LIBs deliver a threshold discharge capacity of 170 mAh g−1 at 0.1 C and stable cycling with nearly zero capacity decay over 100 cycles at 0.5 C.

Liver cancer is considered the sixth most commonly diagnosed cancer and the fourth leading cause of cancer-related deaths worldwide. Currently, there is no specific and effective therapy for hepatocellular carcinoma. Therefore, developing novel diagnostic and therapeutic strategies against hepatocellular carcinoma is of paramount importance. Solute carrier family 6 member 8 (SLC6A8) encodes the solute carrier family 6-8 to transport creatine into cells in a Na+ and Cl-- dependent manner. SLC6A8 deficiency is characterized by intellectual disabilities, loss of speech, and behavioral abnormalities. Of concern, the association of SLC6A8 with hepatocellular carcinoma remains elusive. In this study, we revealed that SLC6A8 knockdown significantly induced apoptosis and suppressed the migration and invasion of Hep3B and Huh-7 cells. These findings depicted the vital role of SLC6A8 in the initiation and progression of human hepatocellular carcinoma.

Three new C20-diterpenoid alkaloids vilmorrianines E (1), F (2), and G (3) were isolated from the whole plants of Aconitum vilmorrianum, along with one artifact N-chloromethyl vilmorrianine E hydrochloride (4), as well as two known alkaloids hemsleyaconitines F (5) and G (6). The structures of 1-4 were established by HR-ESI-MS, 1D-, 2D-NMR (HMQC, HMBC, and NOESY), and single-crystal X-ray diffraction analysis. In addition, the structures of naturally occurring 2-O-acetylorochrine (7) and orochrine (8) were revised to be the known alkaloids heterophylloidine (9) and deacetyl heterophylloidine (10), respectively, on the basis of consideration of transannular effect and chemical correlations.

Lysyl oxidase (LOX) is frequently overexpressed in a variety of malignancies and involved in tumor invasion and metastasis. Furthermore, it has been shown that LOX is closely related to vascular endothelial growth factor (VEGF). In this study, we aimed to investigate the exact role of LOX and the correlation between LOX and VEGF in hepatocellular carcinoma (HCC). The expression levels of LOX in HCC tissue and adjacent noncancerous tissue were evaluated by quantitative reverse transcription polymerase chain reaction and immunohistochemical analysis. The effect of LOX knockdown on cell proliferation, migration, and invasion was investigated in vitro. The role of LOX in the regulation of VEGF was further characterized in HCC cells that had been treated with transforming growth factor beta (TGF-β). Our study showed that LOX was up-regulated in HCC cell lines and tissue. HCC patients with elevated expression of LOX had relatively shorter disease-free survival and overall survival. Knockdown of LOX reduced the proliferation, migration, and invasion of HCC cells. Additionally, the expression level of LOX positively correlated with that of VEGF. After treatment with TGF-β, the levels of LOX and VEGF were both up-regulated in a dose-dependent manner. In the cells treated with siRNA of LOX, levels of VEGF and phosphorylated p38 were significantly decreased and could not be up-regulated by TGF-β. Inhibition of p38 MAPK signaling abrogated TGF-β-mediated up-regulation of VGEF but did not affect LOX expression. LOX appears to be a predictor of less favorable outcomes and may regulate the expression of VEGF via p38 MAPK signaling.

CuO nanocrystals with as-designed morphologies such as uniform quasi-spherical nanoparticles and high-purity nanoleaves were synthesized by adjusting the addition of sodium hydroxide and hydrazine hydrate in aqueous solution at room temperature (25 °C). The increase of sodium hydroxide would accelerate the reaction rate and favor the nucleation of CuO nanocrystals. The decrease of the surface energy will promote the oriented attachment of nanocrystallites along the [−111] direction into nanowires and the final formation of two dimensional (2D) nanoleaves. Increasing the quantity of hydrazine hydrate could decrease the solution system energy and promote the aggregation of CuO nanocrystals from 2D nanoleaves into 3D quasi-spherical nanoparticles. All the CuO nanocrystals with different morphologies were characterized via transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The CuO nanoleaves exhibit excellent gas sensing performance in response to ethanol, showing the strongest response value of 8.22 at 1500 ppm ethanol for ∼260 °C.

A three-dimensional (3-D) multi-functional mixed valence CuII/CuI-MOF, {[Cu(CuI)2(2-pyzc)2H2O]2·H2O}n (Hpyzc = pyrazine-2-carboxylic acid), has been solvothermally synthesized and successfully characterized by FT-IR spectroscopy, elemental analysis, powder X-ray diffraction, thermal gravimetric analysis (TGA) and single-crystal X-ray diffraction. The structure posesses a 3-D open framework containing 1-D channels and shows a tcj topological network with the Schlafli symbol (43·612)(43)2. This MOF exhibits selective adsorption of CO2/H2 over CH4/N2 and excellent catalytic activity in the oxidation of benzylic compounds and three-component coupling reactions of aromatic alkynes, tosyl azide and diisopropylamine as a cooperative catalyst. The catalyst could be reused several times without significant degradation in catalytic activity.

Aiming to the problem that the removal rates of COD, BOD5, SS is low, economic benefits and efficiency are poor on traditional treatment of cassava starch wastewater, a new treatment which combines UASB,CASS with coagulation was presented. The UASB anaerobic reactor is used to remove most of the wastewater containing organic carbon as a pretreatment. Then, CASS aerobic treatment equipment is presented to dislodge organic carbon left and materials such as nitrogen and phosphorus as a secondary process. The coagulation process combined with UASB and CASS was applied to eliminate the residual organic matter in waste water and make the emission up to the standard finally. The UASB-CASS-Coagulation treatment was applying in a certain starch factory and the results show that the proposed method has higher efficiency compared to traditional treatment of cassava starch wastewater. It can directly bring environmental benefits by reducing emissions and economic benefits by recycling methane and yellow pulp. So it has a wider application prospects, and can be popularized easily.

We have corrected (Tetrahedron 2013, 69, 5859–5866) the structures of diterpenoid alkaloids reported in the Journal of Natural Products 2012, 75, 1145–1159. Our follow-up experiments compel us to present further revisions and clarifications on the diterpenoid alkaloids: (1) The naturally occurring forms of carmichaelines B, C, and D in Shi's paper (Journal of Natural Products 2012, 75, 1145–1159) are neither quaternary ammonium hydroxides 2–4 nor the initially revised trifluoroacetates. They are indeed the vakognavine-type C20-diterpenoid alkaloids 11–13. (2) The samples' concentration is the critical factor to the signals' intensity for F3CCOO− in the alkaloid trifluoroacetates. Incorporation of TFA into the corresponding salts resulted in signals' enhancement due to the closeness of δ values (∼116 ppm, ∼159 ppm) of free TFA and those of F3CCOO−. After removal of free TFA, the carbon signals of CF3COO− could become weaker, but their chemical shifts remained almost unchanged. The possible reason might be the ionization of TFA in acetone. (3) The NMR data cannot distinguish TFA from trifluoroacetates (e.g., F3CCOONa and C19-diterpenoid alkaloid trifluoroacetates), indicating that the signal at around δ −76 cannot be used to exclude the existence of trifluoroacetates. In addition to the NMR and CSI-MS data, 1H–15N HMBC technique was also used to distinguish the free alkaloids from their trifluoroacetates. (4) The X-ray crystallographic analysis of compound 20 confirmed that the ‘new alkaloid’ (-b) in the Shi's paper is indeed the known compound aconifine trifluoroacetate. (5) Collectively, Shi's paper mixed-up the free alkaloids with their salts and the concepts of structure and conformation. Naming different structures with A-b and A-c is also confusing.

Traditional photocatalysts are difficile to conform the provision of visible light catalysis, conducive recycling and eminent efficiency, which limits their practical applications for decomposing organic pollutants in wastewater. Herein, a multi-layered porous hierarchical titanium dioxide/graphitic carbon nitride (TiO2/g-C3N4) hybrid coating is in-situ generated on titanium (Ti) substrate by sequentially employing plasma electrolytic oxidation (PEO), alkali immersing and hydrothermal reaction. The as-prepared coating exhibits surpassing photocatalytic performance to decay Rhodamine B (RhB) than g-C3N4 and TiO2 photocatalysts under 5 W LED visible light with 240 h cyclic stability. Moreover, the electrons transport and Z-scheme mechanism for TiO2/g-C3N4 hetero-junction is pursued to account for the ultralow recombination of photo-induced electron-hole and the enhanced catalytic properties. Not only that, it inhibits the secondary pollution which has further intensified its significance for degradation of organic pollution in sewage treatment systems.

Cobalt selenide@reduced graphene oxide (CoSe2@rGO) nanohybrid was successfully synthesized by a facile one-pot hydrothermal method and the electrochemical performance of the nanohybrid was evaluated for supercapacitor applications. The CoSe2@rGO nanohybrid show superior electrochemical performance in terms of the specific capacitance (449 F g−1 at 2 mV s−1, 219 F g−1 at 0.5 A g−1) and enhanced cyclic stability (91.3% capacitance retention for 5000 cycles) relative to pure CoSe2 (196 F g−1 at 2 mV s−1, 99 F g−1 at 0.5 A g−1). Such a highly improved specific capacitance found in the CoSe2@rGO nanohybrid electrode is mainly attributed to the nanosized CoSe2 grains with perfect redox property, more electro-active sites induced by synergetic effect at the interface of CoSe2 and rGO, and high specific area of rGO nanosheets. Besides, with the combination of rGO, the electrical conductivity of the CoSe2@rGO nanohybrid is highly enhanced, the ion/electron diffusion path is also reduced leading to faster charge transport during charging/discharging process with an improved cyclic stability.

The cardiac effect of thirty-eight diterpenoid alkaloids was evaluated on the isolated bullfrog heart model. Among them, twelve compounds exhibited appreciable cardiac activity, with compounds 3 and 35 being more active than the reference drug lanatoside. The structure-cardiac activity relationships of the diterpenoid alkaloids were summarized based on our present and previous studies [2]: i) 1α-OMe or 1α-OH, 8-OH, 14-OH, and NH (or NMe) are key structural features important for the cardiac effect of the aconitine-type C19-diterpenoid alkaloids without any esters. C18-diterpenoid alkaloids, lycoctonine-type C19-diterpenoid alkaloids, and the veatchine- and denudatine-type C20-diterpenoid alkaloids did not show any cardiac activity; ii) the presence of 3α-OH is beneficial to the cardiac activity; iii) the effect on the cardiac action of 6α-OMe, 13-OH, 15α-OH, and 16-demethoxy or a double bond between C-15 and C-16 depends on the substituent pattern on the nitrogen atom.

Treatment of imines 5 and 7 , both prepared from the C 19 -diterpenoid alkaloid deltaline ( 1 ), with NaNO 2 –HCl resulted in the formation of diterpene 6 with an eight-membered ring through a sequence of denitrogenation and enlargement of ring B. In addition, two unusual skeletal rearrangements of diterpene 6 were also observed, leading to two structurally novel products 8 and 10 . The structures of compounds 8 and 10 were confirmed by their X-ray crystallographic analyses and 2D NMR data.

O-Demethylation at C-1 in the C19-diterpenoid alkaloids is very challenging. In this paper, it was firstly observed that 10-OH group in deltaline (1) is a determining factor for the O-demethylation reaction. After removal of this hydroxyl group, 1-O-methyl group in the corresponding deltaline analogs can be readily removed by treatment with HBr–HOAc. Meanwhile, the C-14 atom in bromides 18 or 20 can be extruded under basic condition probably via a sequence, including Grob fragmentation, aerobic oxidation, deformylation, and SN2 nucleophilic substitution, to give enone 21 (70%) and oxetane 22 (14%). The structure of compound 22 was confirmed by X-ray crystallographic analysis of its derivative 21.

The O-acyl group at C-1 of two C19-diterpenoid alkaloids 2 and 5 was transferred to the secondary amine nitrogen to form amides 3 and 6 in the basic condition. This kind of O-to-N intramolecular acyl migration could be caused by the near distance between the nucleophilic nitrogen atom and the carbonyl group of the ester at C-1 in the C19-diterpenoid alkaloids, which is consistent with the conformation of rings A and E in the C19-diterpenoid alkaloids.

Lactam 2, prepared from deltaline (1), is an analog of C19-diterpenoid alkaloid with a hydroxyl group at C-6 and a ketone carbonyl group at C-7. Treatment of this lactam with thionyl chloride or methanesulfonyl chloride, or reaction of this lactam under Chugaev condition led to an unusual rearrangement of its E/F ring system to yield a lactone 10 in a yield range of 43–74%. The structure of 10 was confirmed by its 2D NMR data and X-ray crystallographic analysis.

Polypyrrole (PPY) was prepared by the method of chemical oxidation polymerization in ice bath, and a series of products with different morphology or particle size were obtained through changing volume ratio of acetonitrile to water (VRAW) in the mixed reaction solvents. The structures, morphologies, yield, and conductivities of the as-prepared PPY were characterized by FTIR, SEM, electronic balance, and Four-probe conductivity meter. Furthermore, the effect of VRAW on the morphology of the obtained PPY was investigated in detail. As shown from the corresponding results, PPY's average diameter decreased with the increase of VRAW in the range of 1:9 to 4:6, with particle morphology; the film-shaped PPY was obtained when VRAW was in the scope of 5:5 to 7:3. According to the analysis on the polymerization mechanism of pyrrole in the reaction mixture, the change of PPY's morphology was attributed to the structure change of acetonitrile micelle from spherical structure to double layered structure. As the further study shown, the PPY synthesized at a VRAW of 1:9 shows higher yield and conductivity than which prepared in pure water without acetonitrile; however, the further increase of VRAW results in the decrease of the yield and conductivity. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers

Bioassay-guided fractionation of an n-BuOH extract of the lateral roots of Aconitum carmichaeli. led to the isolation of 5 cardioactive C(19)-diterpenoid alkaloids: N-deethylaconine (1), beiwutinine (2), hypaconine (3), mesaconine (4), and 15α-hydroxyneoline (5). N-Deethylaconine and beiwutinine are new aconitine-type C(19)-diterpenoid alkaloids. Hypaconine was isolated from this species for the first time. Among them, mesaconine, hypaconine, and beiwutinine showed the strongest cardiac actions on the isolated perfused bullfrog heart. Furthermore, mesaconine has protective effects, including improved inotropic effect and left ventricular diastolic function, on myocardial ischemia-reperfusion injury in rat at a dose of 10(-9) mol/L. However, mesaconine has almost no effect on heart rate.