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Changes in structure of oral solid dosage forms (OSDF) elementally determine the drug release and its therapeutic effects. In this research, synchrotron radiation X-ray micro-computed tomography was utilized to visualize the 3D structure of enteric coated pellets recovered from the gastrointestinal tract of rats. The structures of pellets in solid state and in vitro compendium media were measured. Pellets in vivo underwent morphological and structural changes which differed significantly from those in vitro compendium media. Thus, optimizations of the dissolution media were performed to mimic the appropriate in vivo conditions by introducing pepsin and glass microspheres in media. The sphericity, pellet volume, pore volume and porosity of the in vivo esomeprazole magnesium pellets in stomach for 2 h were recorded 0.47, 1.55 × 108 μm3, 0.44 × 108 μm3 and 27.6%, respectively. After adding pepsin and glass microspheres, the above parameters in vitro reached to 0.44, 1.64 × 108 μm3, 0.38 × 108 μm3 and 23.0%, respectively. Omeprazole magnesium pellets behaved similarly. The structural features of pellets between in vitro media and in vivo condition were bridged successfully in terms of 3D structures to ensure better design, characterization and quality control of advanced OSDF., Graphical abstract The differences in dynamic structure of enteric pellets during dissolution in vitro and in vivo were first observed. By introducing pepsin and glass microspheres into pharmacopoeia medium, the structures of pellets were bridged.Image 1

High-entropy materials (HEMs) have attracted extensive interests in exploring multicomponent systems for highly efficient and durable catalysts. Tuning composition and configuration of HEMs provides untapped opportunities for accessing better catalytic performance. Herein, we report three amorphous high-entropy transition metal oxides catalysts with uniform composition through a simple and controllable liquid phase non-equilibrium reduction method. The self-made catalyst FeCoNiMnBOx exhibits excellent oxygen evolution performance, including a low overpotential (266 mV at 10 mA cm−2), small Tafel slope (64.5 mV dec-1) and extremely high stability (only 3.71% increase of potential after 100 h test and no current decay after cyclic voltammetry of 31,000 cycles). The outstanding performance can be attributed to the in-situ electrochemical activation induced surface reconstruction to form a stable oxyhydroxide surface layer, the cocktail effect (multi-metal synergy) brought by high entropy, and the advantages of amorphous structure itself. The outstanding catalytic properties of the new high-entropy amorphous metal oxide, as well as its advantages of low cost and simple preparation, suggest its great potential in water splitting.

Metal antimony (Sb) is a promising anode material of potassium-ion batteries (PIBs) for its high theoretical capacity but limited by its inferior cycle stability due to the serious volume expansion during cycling. Herein, we design and construct a kind of low-crystalline Sb nanoparticles coated with amorphous Sb2O3 and dispersed into three-dimensional porous carbon via a strategy involving NaCl template-assisted in-situ pyrolysis and subsequent low-temperature heat-treated in air. Significantly, the crystallinity and ratio of Sb/Sb2O3 have been precisely tuned and controlled, and the optimized sample of HTSb@Sb2O3@C-4 displays a high reversible specific capacity of 543.9 mAh g−1 at 0.1 A g−1, superior rate capability and excellent cycle stability (~273 mAh g−1 at 2 A g−1 after 2000 cycles) as an anode of PIBs. The outstanding potassium-ion storage performance can be ascribed to the appropriate crystallinity and the multiple-buffer-matrix structure comprising an interconnected porous conductive carbon to relieve the volume changes and suppress the aggregation of Sb, a Sb nanoparticle core to shorten the ion transport pathways and decrease the mechanical stress, and a low-crystalline Sb2O3 as the shell to consolidate the interface between Sb and carbon as well as facilitate the rapid electron transport. The dynamic analysis shows that the composite is mainly controlled by pseudocapacitance mechanism. This work provides a novel thought to design high-performance composite electrode in energy storage devices.

High entropy oxides (HEOs), as a new type of single-phase multielement solid solution materials, have shown many attractive features and promising application prospect in the energy storage field. Herein, six-element HEOs (CoNiZnFeMnLi)3O4 and (CoNiZnCrMnLi)3O4 with spinel structure are successfully prepared by conventional solid-phase method and present outstanding lithium storage performances due to the synergy effect of various electrochemically active elements and the entropy stabilization. By contrast, (CoNiZnFeMnLi)3O4 delivers higher initial discharge specific capacity of 1104.3 mAh·g−1, better cycle stability (84% capacity retention after 100 cycles at 100 mA·g−1) and rate performance (293 mAh·g−1 at 2000 mA·g−1) in the half-cell. Moreover, the full-cell assembled with (CoNiZnFeMnLi)3O4 and LiCoO2 provides a reversible specific capacity of 260.2 mAh·g−1 after 100 cycles at 500 mA·g−1. Ex situ X-ray diffraction reveals the electrochemical reaction mechanism of HEOs (CoNiZnFeMnLi)3O4, and the amorphous phase and the large amount of oxygen vacancies were obtained after the initial discharge process, which are responsible for the excellent cycle and rate performance. This research puts forward fresh insights for the development of advanced energy storage materials for high-performance batteries.

BACKGROUND Severe acute pancreatitis (SAP) is a deadly inflammatory disease with complex pathogenesis and lack of effective therapeutic options. N6-methyladenosine (m6A) modification of circRNAs plays important roles in physiological and pathological processes. However, the roles of m6A circRNA in the pathological process of SAP remains unknown. AIM To identify transcriptome-wide map of m6A circRNAs and to determine their biological significance and potential mechanisms in SAP. METHODS The SAP in C57BL/6 mice was induced using 4% sodium taurocholate salt. The transcriptome-wide map of m6A circRNAs was identified by m6A-modified RNA immunoprecipitation sequencing. The biological significance of circRNAs with differentially expressed m6A peaks was evaluated through gene ontology and Kyoto Encyclopedia of Genes and Genomes analysis. The underlying mechanism of m6A circRNAs in SAP was analyzed by constructing of m6A circRNA-microRNA networks. The expression of demethylases was determined by quantitative polymerase chain reaction and western blot to deduce the possible mechanism of reversible m6A process in SAP. RESULTS Fifty-seven circRNAs with differentially expressed m6A peaks were identified by m6A-modified RNA immunoprecipitation sequencing, of which 32 were upregulated and 25 downregulated. Functional analysis of these m6A circRNAs in SAP found some important pathways involved in the pathogenesis of SAP, such as regulation of autophagy and protein digestion. In m6A circRNA–miRNA networks, several important miRNAs participated in the occurrence and progression of SAP were found to bind to these m6A circRNAs, such as miR-24-3p, miR-26a, miR-92b, miR-216b, miR-324-5p and miR-762. Notably, the total m6A level of circRNAs was reduced, while the demethylase alkylation repair homolog 5 was upregulated in SAP. CONCLUSION m6A modification of circRNAs may be involved in the pathogenesis of SAP. Our findings may provide novel insights to explore the possible pathogenetic mechanism of SAP and seek new potential therapeutic targets for SAP.

High-entropy oxides (HEOs) with numerous functional features such as high structure stability and superionic conductivity are considered as promising candidates of electrode materials for lithium-ion batteries (LIBs). In this study, a series of single-phase spinel-structured high-entropy oxides (FeCoNiCrMnXLi)3O4 (X = Cu, Mg, Zn) consisted of seven metal elements at equal molar ratio were synthesized by solid phase method. In-situ high-temperature XRD technique was used to investigate the structure evolution of (FeCoNiCrMnZnLi)3O4 and a single-phase HEO was acquired at 900 °C. As the anode of LIBs, all the HEOs (FeCoNiCrMnXLi)3O4 display excellent cyclic stability and rate capability owe to the expedite three-dimensional Li+ transport pathways of spinel structure, the entropy-dominated phase stabilization effect together with the abundant oxygen vacancies introduced by the incorporation of Li+. In comparison, the (FeCoNiCrMnZnLi)3O4 anode containing electrochemical active Zn with tetrahedral coordination structure shows better electrochemical lithium storage performances among the three samples. The ex-situ XRD of (FeCoNiCrMnZnLi)3O4 during the discharge/charge procedure shows an amorphous state structure after the first lithiation process and it retained for the de-lithiation process. This work provides a new strategy to design high-entropy energy-storage material and pave the way for understanding the storage mechanism of HEOs.

Niobium pentoxide (Nb2O5) material is a promising anode for lithium-ion batteries (LIBs) due to the outstanding cycle performance and rate capability. However, the relatively low capacity severely ...

Single-atom catalysts (SACs) have recently attracted broad scientific interests due to their unique structural feature, the single-atom dispersion. Optimized electronic structure as well as high stability are required for single-atom catalysts to enable efficient electrochemical production of H2O2. Herein, we report a facile synthesis method that stabilizes atomic Pd species on the reduced graphene oxide/N-doped carbon hollow carbon nanospheres (Pd1/N-C). Pd1/N-C exhibited remarkable electrochemical H2O2 production rate with high faradaic efficiency, reaching 80%. The single-atom structure and its high H2O2 production rate were maintained even after 10,000 cycle stability test. The existence of single-atom Pd as well as its coordination with N species is responsible for its high activity, selectivity, and stability. The N coordination number and substrate doping around Pd atoms are found to be critical for an optimized adsorption energy of intermediate *OOH, resulting in efficient electrochemical H2O2 production.

Cobalt sulfides have attracted much attention as multifunctional electrocatalysts to trigger important reactions, for example, hydrogen evolution, oxygen evolution, and oxygen reduction reactions, and as electrodes for lithium or sodium ion storage. Nevertheless, the delivery of cobalt sulfide structures with high performance with long-term stability is still a challenge. In the current work reported here, via employing a metal–organic framework (MOF) as the starting material, a simple oxygen-assisted etching strategy to synthesize Co9S8 nanoparticles coated with N-doped few-layer graphene (CS@NFLG) was developed. Microstructure studies show that the graphene layer is doped with the nitrogen element and forms a continuous three-dimensional (3D) conductive network, which protects the inner Co9S8 nanoparticles in the harsh reaction environment and modulates the electronic interactions with the Co9S8 particle surface. Because of the advantages of the unique microstructure, CS@NFLG possesses excellent HER activity in an acidic medium (0.5 M H2SO4) at a low onset overpotential of 50 mV with a small Tafel slope of 73 mV dec−1. Meanwhile, the sample presents remarkable sodium storage properties in terms of a high reversible capacity, good rate capabilities, and good stability. In particular, the CS@NFLG electrode delivers a specific capacity of 505 mA h g−1 after 100 cycles at 0.5 A g−1. Moreover, the CS@NFLG electrode still maintains a high specific capacity of 442.3 mA h g−1 after 400 cycles at a high current density of 1.2 A g−1. This work shows that nanoscale “top-down” etching from the bottom is a promising route for the fine modulation of the structure and composition at the electronic and atomic scales, thus showing great prospects for use in energy storage and conversion applications.

Oxide perovskites have emerged as an important class of materials with important applications in many technological areas, particularly thermocatalysis, electrocatalysis, photocatalysis, and energy storage. However, their implementation faces numerous challenges that are familiar to the chemist and materials scientist. The present work surveys the state-of-the-art by integrating these two viewpoints, focusing on the critical role that defect engineering plays in the design, fabrication, modification, and application of these materials. An extensive review of experimental and simulation studies of the synthesis and performance of oxide perovskites and devices containing these materials is coupled with exposition of the fundamental and applied aspects of defect equilibria. The aim of this approach is to elucidate how these issues can be integrated in order to shed light on the interpretation of the data and what trajectories are suggested by them. This critical examination has revealed a number of areas in which the review can provide a greater understanding. These include considerations of (1) the nature and formation of solid solutions, (2) site filling and stoichiometry, (3) the rationale for the design of defective oxide perovskites, and (4) the complex mechanisms of charge compensation and charge transfer. The review concludes with some proposed strategies to address the challenges in the future development of oxide perovskites and their applications.

In recent years, Nb-based oxides, especially Nb2O5, due to their unique structural advantages, have stimulated scholars’ extensive research enthusiasm in the field of energy storage systems including lithium ion batteries (LIBs) and sodium ion batteries (SIBs), excellent chemical stability and outstanding rate capability dominated by pseudocapacitive nature. In addition, Nb-based oxides usually have a higher operating voltage (> 1.0 V vs Li+/Li), which can effectively prevent the decomposition of organic electrolytes and the formation of solid electrolyte interface films in batteries. This review systematically summarizes the different crystal structures of Nb2O5 and the lithium storage mechanism based on theoretical calculations, as well as the comparison of various synthesis strategies. In addition, the advanced research progress of niobium-based oxides as anode materials in LIBs and SIBs is summarized from the perspective of nanostructure control engineering that affects electrochemical performance. It also puts forward reasonable cognition and challenges for future research, which is conducive to the design of energy storage equipment that meets the needs of sustainable development. The design and optimization of various synthesis methods facilitate the formation of a variety of heterogeneous nanostructures, leading to reversible storage of Li and Na ions.

Parkinson’s disease (PD) is characterized by the formation of toxic, fibrillar form alpha-synuclein (α-Syn) protein aggregates in dopaminergic neurons. Accumulating evidence has shown a multifactorial interplay between the intracellular calcium elevation and α-Syn dynamics. However, whether membrane depolarization regulates toxic α-Syn aggregates remains unclear. To understand this better, we used an in vitro α-Syn preformed fibrils (PFF) model of PD in human neural cells. We demonstrated functional membrane depolarization in differentiated SH-SY5Y cells induced by two independent treatments: high extracellular K+ and the GABAA receptor blocker picrotoxin. We then observed that these treatments significantly alleviated toxic α-Syn aggregation in PFF-treated SH-SY5Y cells. Moreover, clinically relevant direct current stimulation (DCS) also remarkably decreased toxic α-Syn aggregation in PFF-treated SH-SY5Y cells. Taken together, our findings suggest that membrane depolarization plays an important role in alleviating PFF-induced toxic α-Syn aggregates, and that it may represent a novel therapeutic mechanism for PD.

The emergence of resistance to chemotherapy drugs in patients with ovarian cancer is still the main cause of low survival rates. The present study aimed to identify key genes that may provide treatment guidance to reduce the incidence of drug resistance in patients with ovarian cancer. Original data of chemotherapy sensitivity and chemoresistance of ovarian cancer were obtained from the Gene Expression Omnibus dataset GSE73935. Differentially expressed genes (DEGs) between sensitive and resistant ovarian cancer cell lines were screened by Empirical Bayes methods. Overlapping DEGs between four chemoresistant groups were identified by Venn map analysis. Protein-protein interaction networks were also constructed, and hub genes were identified. The hub genes were verified by in vitro experiments as well as The Cancer Genome Atlas data. Results from the present study identified eight important genes that may guide treatment decisions regarding chemotherapy regimens for ovarian cancer, including epidermal growth factor-like repeats and discoidin I-like domains 3, NRAS proto-oncogene, hyaluronan and proteoglycan link protein 1, activated protein C receptor, CD53, cyclin-dependent kinase inhibitor 2A, insulin-like growth factor 1 receptor and roundabout guidance receptor 2 genes. Their expressions were found to have an impact on the prognosis of different treatment groups (cisplatin, paclitaxel, cisplatin + paclitaxel, cisplatin + doxorubicin and cisplatin + topotecan). The results indicated that these genes may minimise the occurrence of ovarian cancer drug resistance and may provide effective treatment options for patients with ovarian cancer.

Design and synthesis of advanced electrode materials with fast and stable ion storage are of importance for energy storage applications. Herein, we propose that introducing the heterogeneous interf...

Transition metal oxides nanostructures are drawing much attention as promising electrodes for advanced rechargeable batteries. However, due to the intrinsic low electronic conductivity and substant...

Two-dimensional (2D) transition-metal dichalcogenide materials show potential for use in alkali metal ion batteries owing to their remarkable physical and chemical properties. Nevertheless, the electrochemical energy storage performance is still impaired by the tendency of aggregation, volume, and morphological change during the conversion reaction and poor intrinsic conductivity. Until now, ultrathin molybdenum disulfide nanosheets with a metallic-phase structure on the inner surface of mesoporous hollow carbon spheres (M-MoS2@HCS) have rarely been investigated as an anode for sodium-ion batteries. In this work, a novel M-MoS2@HCS anode was designed and synthesized by employing a template-assisted solvothermal reaction. Structural and chemical analyses indicate that the M-MoS2 nanosheets with a larger interlayer spacing compared to their semiconductor counterpart grow on the inner surface of HCS via covalent interactions. When used as the anode materials for Na+ storage, the M-MoS2@HCS anode presents durable and rapid sodium storage properties. The developed electrode shows a reversible capacity of 291.2 mAh g-1 at a high current density of 5 A g-1. After 100 cycles at 0.1 A g-1, the reversible capacity is 401.3 mAh g-1 with a capacity retention rate of 79%. After 2500 cycles at 1.0 A g-1, the electrode still delivers a reversible capacity of 320.1 mAh g-1 with a capacity retention rate of 75%. The excellent sodium storage capability of the MoS2@HCS electrode is explained by the special structural design, which reveals great potential to accelerate the practical applications of transition-metal dichalcogenide electrodes for sodium storage.

BACKGROUND: Magnesium (Mg) alloy have biodegradation and mechanical properties that are similar to those of human bone, making it a promising candidate material for inclusion in implantable medical devices. OBJECTIVE: The osteointegration effect of Mg alloy scaffolds with different corrosion rates were studied and evaluated in large bone defect models. METHOD: Mg–Sr and Mg–Ca alloy scaffolds with a 20-μm Micro-arc oxidation (MAO) coating were used to repair critical bone defects for subsequent assessment of each alloy’s degradation and osteointegration by X-ray, Micro-CT, fluorescence and histological examination. RESULTS: At 12 weeks post-implantation, each defect was found to be effectively reconstructed by either of the Mg alloys based on X-ray and Micro-CT images. The corrosion rate (CR) of each Mg alloy – as calculated based on micro-computed tomography information – demonstrated that the MAO coating could provide effective protection for only 4 weeks post-surgery. From weeks 8 to 12, the CR of the Mg–Ca alloy scaffold increased from 1.34 ± 0.23 mm/y to 1.57 ± 0.16 mm/y. In contrast, the CR of the Mg–Sr alloy scaffold decreased from 0.58 ± 0.14 mm/y to 0.54 ± 0.16 mm/y. However, fluorescence and histological examination revealed more mature, closely and regularly arranged newborn osteocytes at the Mg–Ca scaffold-fracture interface e from weeks 8 to 12 after surgery. CONCLUSION: The Mg–Sr scaffold was more corrosion resistant and the Mg–Ca scaffold yielded a better overall repair, which indicates that the CR of magnesium alloys matches the rate of new bone formation and is the key to repair bone defects as a bone substitute.

Micro- A nd nanoscale surface wrinkling has been widely studied in artificial systems, mostly in soft substrates like polydimethylsiloxane or polystyrene, where the wrinkling dynamics are triggered by thermal stresses or tensile prestrains. Here, we introduce a new wrinkling regime based on photoresist layers on top of a rigid substrate. By introducing a bending deformation, combined with fluorine-based plasma treatment, wrinkles with a characteristic wavelength less than 1 μm can be created. By adding micropatterns on photoresists with standard UV exposure, ordered wrinkles can also be realized. This technique is demonstrated to be applicable in several commercially available photoresists, and the wrinkled patterns can be employed conveniently to create high-aspect-ratio silicon gratings and large-area silicon dioxide membranes. This unique strategy broadens the spectrum of available materials to create wrinkled surfaces in a controllable manner and provides a platform for the easier fabrication of wrinkle-based devices.

The development of a reliable non-enzymatic multi-analyte biosensor is remained a great challenge for biomedical and industrial applications. In this prospective, rationally designed electrode materials having voltage switchable electrocatalytic properties are highly promising. Here, we report vanadium doped ZnO engineered nanostructures (Zn1-xVxO where 0 ≤ x ≤ 0.1) which exhibit voltage switchable electrocatalytic properties for accurate measurements of glucose and hydrogen peroxide. Microstructures and chemical analysis show that the oxygen vacancies in the material can be tuned by controlling the stoichiometric ratios which play key role for voltage dependent measurements of different analytes. The developed Zn1-xVxO nanostructures exhibit outstanding sensing ability for binary analytes with a high selectivity, low detection limit, thermal stability and long-term stability. The Zn0.9V0.1O/glassy carbon (GC) electrode shows 3-fold increase in reproducible sensitivity for both glucose (655.24μA mM-1cm-2) and H2O2(13309.37μA mM-1cm-2) as compared to the pristine ZnO/GC electrode. Moreover, the electrode also shows good response for human blood serum and commercially available samples. The results demonstrate that defect engineering is a promising route for the development of cost-effective non-enzymatic multi-analyte sensors for practical applications.

As the most abundant internal modification in eukaryotic cells, N6-methyladenosine (m6A) in mRNA has shown widespread regulatory roles in a variety of physiological processes and disease progressions. Circular RNAs (circRNAs) are a class of covalently closed circular RNA molecules and play an essential role in the pathogenesis of various diseases. Recently, accumulating evidence has shown that m6A modification is widely existed in circRNAs and found its key biological functions in regulating circRNA metabolism, including biogenesis, translation, degradation and cellular localization. Through regulating circRNAs, studies have shown the important roles of m6A modification in circRNAs during immunity and multiple diseases, which represents a new layer of control in physiological processes and disease progressions. In this review, we focused on the roles played by m6A in circRNA metabolism, summarized the regulatory mechanisms of m6A-modified circRNAs in immunity and diseases, and discussed the current challenges to study m6A modification in circRNAs and the possible future directions, providing a comprehensive insight into understanding m6A modification of circRNAs in RNA epigenetics.

Cobalt (II, III) oxide (Co3O4) nanostructures have attracted much attention as a candidate for anode materials in lithium-ion batteries (LIBs) due to its unique physical/chemical properties and high specific capacity. However, critical issues, such as low electronic conductivity, inefficient ionic diffusion, and large volume change during battery operation, have to be addressed before practical applications. In this work, we report a facile chemical reduction approach to modify Co3O4 nanocubes by NaBH4 solution treatment. The microstructure and chemical composition analysis indicate that the modified Co3O4 nanocubes are oxygen deficient and other secondary phases are not formed during the processing. The degree of oxygen deficiency can be well controlled by altering the concentration of NaBH4 solution. When evaluated as the anodes for LIBs, the optimized sample shows a reversible capacity of 873.5 mAhg−1 after 50 cycles at a current density of 0.1 Ag−1, and a charge-discharge capacity of 569.1 mAhg−1 at a higher current density of 5 Ag−1. The balanced oxygen deficiency and crystallinity in the chemically reduced nanostructured electrodes are supposed to be responsible for the improved lithium storage properties. We believe that the facile solution-based chemical reduction strategy provides an alternative way to control the defects in different functional nanostructures for broader applications.

Transition metal oxides show unique physical and chemical properties, and thus have a wide range of applications, including the electrodes for batteries, supercapacitors, and catalysts. However, poor electrical conductivity of the metal oxides hinder the above applications. In this work, we report a facile method to generate oxygen vacancies in cubic Co3O4 particles by thermal annealing in Ar atmosphere. By carefully controlling annealing condition, the oxygen vacancies can be well modulated while the formation of any other phases is avoided. The microstructure and chemical composition of the Co3O4 particles are studied by different methods. Lithium storage measurements show that the Co3O4 anodes with optimized oxygen vacancies (Co3O4-250) show a specific capacity of 904.2 mAhg−1 at a current density of 0.1 Ag−1, and charge/discharge rate capability of 530.5 mAhg−1 at 5.0 Ag−1. Well controlled oxygen vacancies together with sub-micrometer scale morphology in the annealed Co3O4 electrodes are responsible for the enhanced lithium storage properties. The current oxygen vacancy modulation strategy can also be used for other energy related applications, such as sodium ion batteries and electrocatalysts, with improved performance.

In this study hybrid nanostructures of Au–graphene oxide (Au–GO) were synthesized via a two-step process and used to modify the glassy carbon electrode (GCE) for electrochemical measurements of glucose. The modified electrode exhibits a fast response less than 4 s, a low detection limit of 0.025 μM and a high signal-to-noise ratio (S/N) of 3.5. The fabricated sensor shows a linear response in a large concentration range from 0.0025 mM to 15 mM with a reproducible sensitivity of 84.53 μA cm−2 mM−1, which is much higher than that of the individual Au, GO and previously reported GO/rGO based sensors. In addition, the biosensor shows excellent results for human serum which agree well with those obtained using a laboratory glucometer. Moreover, the glucose amount in selective commercially available food samples and fresh juices was also successfully measured. The biosensor exhibits excellent selectivity, thermal stability and reproducibility. The enhanced and efficient sensitivity of the developed Au–GO based biosensor may be due to the synergic effects of the plasmonic Au-nanoparticles and GO. The performance of the biosensor suggests that the reported Au–GO hybrid nanostructures can provide a novel platform for developing non-enzymatic biosensors for biomedical and industrial applications.

NiCo2O4 is a potential anode material for lithium ion battery due to its many advantages, such as high theoretical capacitance, low cost, and good electrochemical activity. In this study, mesoporous NiCo2O4 double-hemisphere (3–5 μm) with high surface area (270.68 m2·g−1) and excellent electrochemical performances has been synthesized through a facile precipitation method followed with thermal treatment process. The prepared NiCo2O4 is pure phase and can be indexed as a face-centered-cubic with a typical spinel structure. Electrochemical tests show the prepared material has high specific capacities (910 mAh·g−1 at 100 mA·g−1), excellent cyclicity (908 mAh·g−1 at 100 mA·g−1 after 60 cycles) and remarkable high rate performance (after 100 cycles, 585 mAh·g−1 at 400 mAh·g−1, 415 mAh·g−1 at 800 mAh·g−1 and 320 mAh·g−1 at 1600 mAh·g−1 with coulombic efficiencies of almost 100%). The excellent performances of prepared NiCo2O4 are mainly caused by the unique double-hemisphere structure, which has large surface area, gives material more opportunity to contact with electrolyte and facilitates lithium ion spreading into the material along the radical direction, resulting in a promising application for next-generation lithium-ion batteries.

Injectable acellular matrix hydrogels are proven to be potential translational materials to facilitate the repairment in various tissues. However, their potential to repair hepatic ischemia/reperfusion injury (IRI) has not been explored. In this work, we made hepatic acellular matrix (HAM) hydrogels based on the decellularized process and evaluated the biocompatibility and hepatoprotective effects in a rat IRI model. HAM hydrogels supported viability, proliferation, and attachment of hepatocytes in vitro. Treatment with HAM hydrogels significantly attenuated hepatic damage caused by IRI, as evidenced by hepatic biochemistry, histology, and inflammatory responses. Importantly, HAM hydrogels inhibited macrophage M1 (CD68/CCR7) differentiation but promoted M2 (CD68/CD206) differentiation. Additionally, TLR4/NF-κB signaling was found to be involved in the hepatoprotective effect of HAM hydrogels. Collectively, our study reveals that HAM hydrogels ameliorate hepatic IRI by facilitating M2 polarization via TLR4/NF-κB signaling.

The development of a highly sensitive and selective non-enzymatic electrode catalyst for the detection of a target molecule was remained a great challenge. In this regard, bimetallic nanowires (BMNWs) are considered as promising electrode material for their fascinating physical/chemical properties superior to a single system. In this article, nickel cobalt (Ni x –Co) BMNWs with tunable stoichiometry were prepared by a template assisted electrodeposition method and their catalytic performance was investigated for the detection of hydrogen peroxide (H2O2). It has been found that Ni–Co (0.5:1) BMNWs/PC electrode exhibits superior non-enzymatic sensing ability toward H2O2 detection with a high selectivity. The electrode shows fast response within ∼3 s and an excellent reproducible sensitivity of 2211.4 μAmM−1 cm−2, which is the best compared to the individual Ni, Co, Ni–Co (0.3:1) BMNWs and previously reported electrodes. In addition, the electrode shows a linear response in the wide concentration range from 0.005 mM to 9 mM, low detection limit of 0.5 μM (S/N = 3.2) and a relatively long-term storage (50 d). Moreover, the sensor reveals excellent results for H2O2 detection in the real samples. The enhanced sensitivity of the Ni–Co (0.5:1) BMNWs based electrode may be due to the stable structure and synergy of Ni and Co. The results demonstrate that the catalytic activity of the electrode binary catalyst towards H2O2 detection can be improved by adjusting the Ni/Co ratio in BMNWs. The excellent performance of the electrode suggests that Ni–Co BMNWs are promising candidate for the construction of cost-effective electrochemical sensors for medical and industrial applications.

There has been a persistent effort to understand and control the incorporation of metal impurities in semiconductors at nanoscale, as it is important for semiconductor processing from growth, doping to making contact. Previously, the injection of metal atoms into nanoscaled semiconductor, with concentrations orders of magnitude higher than the equilibrium solid solubility, has been reported, which is often deemed to be detrimental. Here our theoretical exploration reveals that this colossal injection is because gold or aluminum atoms tend to substitute Si atoms and thus are not mobile in the lattice of Si. In contrast, the interstitial atoms in the Si lattice such as manganese (Mn) are expected to quickly diffuse out conveniently. Experimentally, we confirm the self-inhibition effect of Mn incorporation in nanoscaled silicon, as no metal atoms can be found in the body of silicon (below 10(17) atoms per cm(−3)) by careful three-dimensional atomic mappings using highly focused ultraviolet-laser-assisted atom-probe tomography. As a result of self-inhibition effect of metal incorporation, the corresponding field-effect devices demonstrate superior transport properties. This finding of self-inhibition effect provides a missing piece for understanding the metal incorporation in semiconductor at nanoscale, which is critical not only for growing nanoscale building blocks, but also for designing and processing metal–semiconductor structures and fine-tuning their properties at nanoscale.

Transition metal phosphides are promising oxygen evolution reaction (OER) catalysts due to their earth-abundant and cost-effective features. Here, nanostructured CoP nanoparticles locked in hollow nitrogen doped carbon frameworks (CoP@HNC) were successfully designed and characterized for their morphology, composition, and electrochemistry. In a typical low-temperature phosphorization process, the Co species in carbonized poly-dopamine (PDA) coated ZIF-67 are converted to either hollow CoP or small-sized solid CoP nanoparticles governed by the nanoscale Kirkendall effect. The PDA layers derived nitrogen-doped carbon components feature a hollow polyhedral structure, with CoP nanoparticles imbedded in the shell. CoP@HNC demonstrates a low overpotential of 327 mV for 10 mA cm-2 and a good operational stability (72 h) for alkaline OER. The HNC encapsulation affords the low electronic resistance between CoP nanoparticles, as well as the mechanical and chemical stability of composites by preventing the aggregation of CoP nanoparticles during the OER process.

During a primary screening in 2015 and 2016, tris(trifluoropropyl)trimethylcyclotrisiloxane (D3F) and cis-/trans-tetrakis(trifluoropropyl)tetramethylcyclotetrasiloxane isomers (cis-D4F, trans-D4Fa,b,c) were detected in 12 biosolid-amended soils from Laixi and Shijiazhuang Cities of China, with mean concentrations being 10.3 ng/g dry weight (dw) and 2.7 ng/g dw for D3F and D4F, respectively. Subsequently, one further systematical survey found that although repeatedly amended by biosolids containing trifluoropropylmethylsiloxanes (4.2-724 ng/g dw), these compounds had no increasing trend in biosolid-amended soils (n = 100) collected from Laixi City at five sampling events from February 2017 to June 2019. Simulated experiments indicated that hydrolysis half-lives (1.8-28.0 days) of trifluoropropylmethylsiloxanes in soils were 3.0-18.3 times shorter than volatilization half-lives (7.4-362 days). Compared with those of octamethylcyclotetrasiloxane (D4), the hydrolysis rates of D4F isomers were faster in soils with total organic carbon (TOC) ≤80 mg/g but lower in soils with TOC ≥ 150 mg/g. In earthworm bodies, trifluoropropylmethylsiloxanes had 1.03-1.5 times lower biota-soil accumulation factors (1.3-3.2) but 1.4-3.0 times longer half-lives (2.6-5.7 days) than D4. The stronger persistence of fluorinated-siloxane than the corresponding dimethylsiloxane in both soils (at high TOC levels) and earthworms indicated that environmental risks of these compounds deserve further investigation.

CO2 utilisation as a chemical feedstock could transform fuels production and help mitigate climate change. Direct CO2 reduction for energy production requires the development of active, stable, and low-cost catalysts selective for methane. A bimetallic Ni@Rh core-shell catalyst prepared by galvanic replacement (GR) exhibits a 3.5-fold rate enhancement for CO2 methanation relative to an analogue prepared by chemical reduction (CR) and is twice as active as monometallic Rh/Al2O3. Superior performance of RhNi/Al2O3 (GR) is attributed to Rh dispersion as an atomically thin RhOx shell encapsulating Ni nanoparticles, stabilised by a strong Rh-Ni interaction. Operando IR spectroscopy identifies reactively-formed CO from the dissociative chemisorption of CO2 over Rh as the key intermediate for methane production. Surface formate from the dissociative chemisorption of CO2 and subsequent hydrogenation (via spillover from Rh sites) over alumina is a catalytic spectator. This mechanistic insight paves the way to high activity nanostructured catalysts for CO2 methanation.

Carbonaceous materials are used as the anode for rechargeable lithium-ion batteries (LIBs), however, lithium dendrites are easily formed during cycling due to the low lithium insertion potential (~0.1 V versus Li+/Li). As alternative anodes, transition metal oxides based on conversion mechanism have attached much attention. But the high lithiation potential (>1.0 V vs. Li+/Li) usually leads to a low output voltage and energy density when used in a full cell configuration. Herein, Zn-substituted Co3O4 submicron spheres are successfully synthesized by a facile solvothermal reaction and subsequent calcination method. When used as the anode for LIB, the optimized sample shows a specific capacity of 686 mAh g−1 at 0.8 A g−1 after 500 cycles, and a specific capacity of 692.9 mAh g−1 at a higher current density of 3.2 A g−1 in a half-cell. Thanks to the controlled Zn substitution, the discharge voltage plateau is 0.16 V lower than that of the pure Co3O4 anode at a current density of 0.4 A g−1. Further investigation of the 0.5Zn-Co3O4//LiCoO2 full cells also displays a high capacity (400.7 mAh g−1 after 200 cycles at 0.4 A g−1) and an excellent rate capability (658.1 mAh g−1 at 1.6 A g−1) compared with the Co3O4//LiCoO2 full cells. This work confirms that substituting suitable metal elements into sub-micron conversion based anodes can reduce the voltage plateau, which is of great significance for the practical applications in high performance energy storage devices.

Background Recent work has established that Parkinson’s disease (PD) patients have an altered gut microbiome, along with signs of intestinal inflammation. This could help explain the high degree of gastric disturbances in PD patients, as well as potentially be linked to the migration of peripheral inflammatory factors into the brain. To our knowledge, this is the first study to examine microbiome alteration prior to the induction of a PD murine model. Methods We presently assessed whether pre-treatment with the probiotic, VSL #3, or the inflammatory inducer, dextran sodium sulphate (DSS), would influence the PD-like pathology provoked by a dual hit toxin model using lipopolysaccharide (LPS) and paraquat exposure. Results While VSL #3 has been reported to have anti-inflammatory effects, DSS is often used as a model of colitis because of the gut inflammation and the breach of the intestinal barrier that it induces. We found that VSL#3 did not have any significant effects (beyond a blunting of LPS paraquat-induced weight loss). However, the DSS treatment caused marked changes in the gut microbiome and was also associated with augmented behavioral and inflammatory outcomes. In fact, DSS markedly increased taxa belonging to the Bacteroidaceae and Porphyromonadaceae families but reduced those from Rikencellaceae and S24-7, as well as provoking colonic pro-inflammatory cytokine expression, consistent with an inflamed gut. The DSS also increased the impact of LPS plus paraquat upon microglial morphology, along with circulating lipocalin-2 (neutrophil marker) and IL-6. Yet, neither DSS nor VSL#3 influenced the loss of substantia nigra dopamine neurons or the astrocytic and cytoskeleton remodeling protein changes that were provoked by the LPS followed by paraquat treatment. Conclusions These data suggest that disruption of the intestinal integrity and the associated microbiome can interact with systemic inflammatory events to promote widespread brain-gut changes that could be relevant for PD and at the very least, suggestive of novel neuro-immune communication.

The inferior colliculus (IC) is an auditory midbrain structure involved in processing biologically important temporal features of sounds. The responses of IC neurons to these temporal features reflect an interaction of synaptic inputs and neuronal biophysical properties. One striking biophysical property of IC neurons is the rebound depolarization produced following membrane hyperpolarization. To understand how the rebound depolarization is involved in spike timing, we made whole-cell patch clamp recordings from IC neurons in brain slices of P9-21 rats. We found that the percentage of rebound neurons was developmentally regulated. The precision of the timing of the first spike on the rebound increased when the neuron was repetitively injected with a depolarizing current following membrane hyperpolarization. The average jitter of the first spikes was only 0.5 ms. The selective T-type Ca2+ channel antagonist, mibefradil, significantly increased the jitter of the first spike of neurons in response to repetitive depolarization following membrane hyperpolarization. Furthermore, the rebound was potentiated by one to two preceding rebounds within a few hundred milliseconds. The first spike generated on the potentiated rebound was more precise than that on the non-potentiated rebound. With the addition of a calcium chelator, BAPTA, into the cell, the rebound potentiation no longer occurred, and the precision of the first spike on the rebound was not improved. These results suggest that the postinhibitory rebound mediated by T-type Ca2+ channel promotes spike timing precision in IC neurons. The rebound potentiation and precise spikes may be induced by increases in intracellular calcium levels.

Background Substantial data have implicated microglial-driven neuroinflammation in Parkinson’s disease (PD) and environmental toxicants have been long expected as triggers of such inflammatory processes. Of course, these environmental insults act in the context of genetic vulnerability factors and in this regard, leucine rich repeat kinase 2 (LRRK2), may play a prominent role. Methods We used a double hit, lipopolysaccharide (LPS; endotoxin) followed by paraquat (pesticide toxicant) model of PD in mice with the most common LRRK2 mutation G2019S, knockin mice and wild type littermates. In order to assess the contribution of microglia, we depleted these cells (through 14 days of the CSF-1 antagonist, PLX-3397) prior to LPS and paraquat exposure. Results We found that the G2019S mice displayed the greatest signs of behavioral pathology, but that the PLX-3397 induced microglial depletion at the time of LPS exposure diminished toxicity and weight loss and blunted the reduction in home-cage activity with subsequent paraquat exposure. However, neither the PLX-3397 pre-treatment nor the G2019S mutation affected the LPS ​+ ​paraquat induced loss of substantia nigra pars compacta (SNc) dopamine neurons or elevation of circulating immune (IL-6) or stress (corticosterone) factors. Intriguingly, microglial morphological ratings were basally enhanced in G2019S mice and the PLX-3397 pre-treatment reversed this effect. Moreover, PLX-3397 pre-treatment selectively elevated soluble a-synuclein and SIRT3 levels, while reducing SNc caspase-1 and 3, along with CX3CR1. Hence, the re-populated “new” microglia following cessation of PLX-3397 clearly had an altered phenotype or were immature at the time of sacrifice (i.e. after 11 days). Conclusions Collectively, these findings suggest that G2019S knock-in and PLX-3397 microglial depletion at the time of LPS exposure affects behavioral, but not neurodegenerative responses to subsequent environmental toxin exposure., Highlights • The G2019S LRRK2 mutant augmented behavioral pathology, but not substantia nigra pars compacta (SNc) dopamine neuron loss. • PLX-3397 induced microglial depletion diminished toxicity and behavioral changes with subsequent paraquat exposure. • Re-populated “new” microglia following PLX-3397 had an altered phenotype or were immature at the time of sacrifice. • The G2019S knock-in and PLX-3397 microglial depletion affected behavioral, but not neurodegenerative responses.

Manganese oxides (MnOx) and derivations are considered as one of the most attractive anode materials for lithium-ion batteries (LIBs) due to their earth-abundant, cost-effective and low-toxic specialties. Herein, we report a flower-like composite consisting of internal Fe2O3 nanocrystals and outer hierarchal iron doped K-birnessite type MnOx layers (Fe2O3@Fe doped K-birnessite), which is synthesized by a facile one-pot microwave-assisted heating synthesis (MAHS). The crystalline and morphology evolution of Fe2O3@Fe doped K-birnessite composite are studied by checking the products at various reaction durations, using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning & transmission electron microscopy (SEM & TEM). Key factors affecting the morphology such as reactive temperature and stoichiometric ratio are systematically investigated. When tested for LIBs, the optimized hybrid Fe2O3@Fe doped K-birnessite composite exhibits a high reversible capacity of 758 mA h g−1 at 500 mA g−1 after 200 cycles, outperforming the pure K-birnessite (203 mA h g−1). The excellent electrochemical performance is assigned to the efficient utilization of the merits of the flower-like structure and strong interaction between MnOx and Fe2O3. Further, crucial factors associated with structural stability of Fe2O3@Fe doped K-birnessite composite during cycling are identified.

The field of electrochemistry promises solutions for the future energy crisis and environmental deterioration by developing optimized batteries, fuel-cells and catalysts. Combined with in situ transmission electron microscopy (TEM), it can reveal functional and structural changes. A drawback of this relatively young field is lack of reproducibility in controlling the liquid environment while retaining the imaging and analytical capabilities. Here, a platform for in situ electrochemical studies inside a TEM with a pressure-driven flow is presented, with the capability to control the flow direction and to ensure the liquid will always pass through the region of interest. As a result, the system offers the opportunity to define the mass transport and control the electric potential, giving access to the full kinetics of the redox reaction. In order to show the benefits of the system, copper dendrites are electrodeposited and show reliable electric potential control. Next, their morphology is changed by tuning the mass transport conditions. Finally, at a liquid thickness of approximately 100 nm, the diffraction pattern revealed the 〈1,1,1〉 planes of the copper crystals, indicating an atomic resolution down to 2.15 A. Such control of the liquid thickness enabled elemental mapping, allowing us to distinguish the spatial distribution of different elements in liquid.

Invasiveness and metastatic potential are among the most essential characteristics of malignant tumors. Furthermore, it has been reported that autophagy and invasion are enhanced when tumor cells are grown in adverse conditions, such as nutritional deficiency and starvation. However, the association between autophagy and invasion remains largely unclear. In the present study, Earle's balanced salt solution (EBSS) was used to induce autophagy and an autophagy inhibitor was used to block autophagy. The results of Transwell assays revealed that autophagy inhibition limited the invasiveness of human ovarian cancer cells. Furthermore, the results of invadopodia formation assay indicated that autophagy stimulated invadopodia formation, and the selective autophagy receptor and signaling adaptor, sequestosome-1 (SQSTM1/p62 or simply p62), was closely associated with invadopodia formation in human ovarian cancer SKOV3 cells. The results of western blot analysis indicated that autophagy induced changes in p62 protein levels and p62 then functioned as a negative regulator of extracellular signal-regulated kinase 1/2 (ERK1/2) activity and invadopodia formation. The interaction between autophagy and invasion may thus be a self-protective mechanism for tumor cells in an unfavorable environment of nutritional deficiency, that maintains their survival and leads to increased invasiveness. An exploration of the intrinsic link between autophagy and invasion may provide a novel theoretical basis to reverse the resistance of tumor cells to a nutritional deficient environment.

The multiple-unit sustained-release (MUSR) dosage forms containing numerous sustained-release subunits present a reliable choice for oral formulation of controlled release systems. As a typical MUSR, the metoprolol succinate sustained-release tablet is an advanced system with limited researches devoted to relating its structure to the drug release phase other than the preparation process and modulation to the release behaviors. This research details a three-dimension method to image the internal structure and detail drug release features of commercial metoprolol succinate sustained-release tablets and component individual single pellets. As such, a new perspective for MUSR dosage form is provided. Using high energy synchrotron radiation X-ray microcomputed tomography (SR-μCT), the in-situ structure parameters were obtained nondestructively. It was demonstrated that the average number of spherical pellets in a tablet was 853 ± 12 (n = 3). The average volume of the pellets was 0.09 ± 0.01 mm3, the diameter was 0.55 ± 0.03 mm, and the sphericity was 0.87 ± 0.06. These data reflected the numerical features of pellets in MUSR tablets, which were helpful for reverse engineering to MUSR. Based on the three dimensional model generated by image processing and analysis software, the pellet structures were divided into three layers of typical depot sustained release system: pellet core, drug-containing layer and outer film. The dynamic structural features determined refer to the changes of structures in pellets during in vitro drug release, with evidence that the coating layer on the pellets maintained a spherical morphology whilst numerous valleys appeared on the surface. The material constitution and distribution in coating layer were evaluated by synchrotron radiation-based Fourier transform infrared mapping and results indicated a composition of hydroxypropyl methylcellulose dispersed in ethyl cellulose. Knowledge of these structural characteristics confirmed that the mechanism of sustained drug release was membrane controlled and consistent with the drug release profiles. In conclusion, the structural investigation provided knowledge of the intrinsic quality of metoprolol succinate sustained-release tablets and offers guidance for reverse engineering of MUSR.

Transition metal oxides have attracted considerable attention as possible electrode materials for lithium-ion batteries. However, poor electrical conductivity and volume change during cycling result in low rate capacity and rapid capacity fading, which hinder the practical applications of those electrodes. In this work, we report a facile approach to modify Co3O4 nanoparticles (NPs) by laser irradiation treatment. The structural and composition of the samples were studied by different techniques. The results show that the surface of the as-prepared particles transforms to a thin CoO layer, and oxygen vacancies are generated after the laser treatment. Compared to the as-prepared Co3O4 NPs, the laser treated sample shows a higher reversible capacity of 833.4 mAhg−1 after 100 cycles at a current density of 0.1 Ag-1. A capacity of 348.4 mAhg−1 can be obtained at a rate of 5 Ag-1. The unique microstructure that induced by laser irradiation in the Co3O4 NPs is responsible for the improved lithium storage properties.

Development of the Li-O2 battery into a practical technology hinges on the availability of a stable electrolyte. Because of the high reactivity of oxygen species in the system, no known organic electrolytes meet the stability requirements. The search for a suitable electrolyte system remains an outstanding challenge in Li-O2 battery research. Here, we show that the issue can be solved with the use of a water-in-salt electrolyte system that involves no organic solvents. In essence, the electrolyte consists of super-concentrated LiTFSI (lithium bis(trifluoromethanesulfonyl)imide), in which H2O molecules are locked to the ions and exhibit little reactivity toward Li2O2 or other oxygen species. The net result is a highly effective electrolyte that permits stable Li-O2 battery operations on the cathode with superior cycle lifetimes. A new door to practical Li-O2 batteries with high performance is opened up. As an electrochemical energy storage technology that holds the highest theoretical energy density, the Li-O2 battery has been studied for over two decades. Its reported performance, however, remains much lower than expected. An important reason for the slow progress is the lack of stable electrolytes. Here, we present a solution to such a challenge. We show that the “water-in-salt� electrolyte, which is essentially a super-concentrated aqueous solution, enables stable operation of a Li-O2 battery on the basis of reversible formation and decomposition of Li2O2 for superior long cycle lifetimes. More importantly, it presents a platform for future optimizations to realize the full potential of the Li-O2 battery as a stable, high-capacity electrochemical energy storage technology. Development of the Li-O2 battery as a practical energy storage technology has been underpinned by the lack of a stable electrolyte to enable reversible conversion between O2 and Li2O2, given that previous applied organic electrolytes all show reactivity toward reactive oxygen species. Wang and colleagues show that this issue can be solved with a water-in-salt electrolyte that contains no organic solvent molecules. The net result is a highly effective electrolyte that enables stable Li-O2 battery operations up to 300 cycles.

The maximized atomic efficiency of supported catalysts is highly desired in heterogeneous catalysis. Therefore, the design and development of active, stable, and atomic metal-based catalysts remains a formidable challenge. To tackle these problems, it is necessary to investigate the interaction between single atoms and supports. Theoretical calculations indicate that the Pd binding strength is higher on graphene/amorphous carbon (AC) than that on graphene or AC substrate. Based on these predictions, we present a facile confined-interface-directed synthesis route for the preparation of single-atom catalysts (SACs) in which Pd atoms are well-dispersed on the interface of double-shelled hollow carbon nanospheres with reduced graphene oxide (RGO) as the inner shell and AC as the outer shell. Owing to the synergetic effect of the RGO/AC confined interface and the atomically dispersed Pd, the as-made RGO@AC/Pd SAC achieves the maximum atomic efficiency (catalytic activity) of Pd species and exhibits an excellent stability in chemical catalysis. This confined-interface-directed synthesis method provides a novel direction to maximize the atomic efficiency, improve the activity, and enhance the stability of metal-based catalysts.

We introduced a simple method to construct novel three-dimensional (3D) flexible hierarchical nanocomposites by combining (1D) NiCo2O4 nanowires with 2D reduced graphene oxide (rGO) sheets. The hierarchical nanocomposite structure of rGO-wrapped NiCo2O4 (rGO-NiCo2O4) was confirmed by X-ray diffraction (XRD), Raman spectra, scanning electron microscopy (SEM), transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS). The results indicated that NiCo2O4 nanowires were successfully wrapped in rGO and the morphology of the rGO-NiCo2O4 showed a three-dimensional porous structure with NiCo2O4 being homogeneously distributed in the rGO. Given their apparent advantages, these two different nanostructures were evaluated as electrodes for high-performance supercapacitors. These electrodes exhibited a high capacitance of 1824.8 F·g–1 at a current density of 0.5 A·g–1, and an excellent cycling performance extending to 5000 cycles at a high current density of 4 A·g–1. Our results clearly demonstrate that rGO sheets on NiCo2O4 nanowires can substantially improve the capacitive performance of materials and ultimately increase the cycling stability of supercapacitors. The hierarchical binary nanocomposites show excellent electrochemical properties for energy storage applications, evidencing their potential application as supercapacitors.

The synthesis of monodisperse size- and shape-controlled Au nanocrystals is often achieved with cetyltrimethylammonium bromide (CTAB) surfactant; however, its role in the growth of such tailored nanostructures is not well understood. To elucidate the formation mechanism(s) and evolution of the morphology of Au nanocrystals in the early growth stage, we present an in situ liquid-cell scanning transmission electron microscopy (STEM) investigation using electron beam-induced radiolytic species as the reductant. The resulting particle shape at a low beam dose rate is shown to be strongly influenced by the surfactant; the Au nanocrystal growth rate is suppressed by increasing the CTAB concentration. At a low CTAB concentration, the nanoparticles (NPs) follow a reaction-limited growth mechanism, while at high a CTAB concentration the NPs follow a diffusion-limited mechanism, as described by the Lifshitz–Slyozov–Wagner (LSW) model. Moreover, we investigate the temporal evolution of specific NP geometries. The am...

Unique Fe3O4/polyaniline (PANI) composite with yolk-shell micro/nanostructure (FPys) has been successfully synthesized by a facile silica-assisted in-situ polymerization and subsequent etching strategy. The structural and compositional studies of the FPys composites are performed by employing X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The yolk-shell morphology of the products is confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations. When evaluated as anode material for lithium-ion batteries, the as-prepared FPys electrodes deliver superior capacity, better cycling stability and rate capability than those of bare Fe3O4 micro/nanospheres and Fe3O4/PANI core-shell (FPcs) electrodes. Moreover, FPys also exhibits excellent electromagnetic wave absorption performance when comparing to the synthesized Fe3O4-based electromagnetic wave absorbers, in which strong reflection loss and extensive response bandwidth can be achieved simultaneously. The excellent bifunctional properties of FPys material are associated with the specially designed hierarchical micro/nanostructures. The current strategy that application directed structural design can be applied to the synthesis of other multifunctional materials.

By using the intrinsic polymorphism nature of Nb2O5 material, we employ three typical Nb2O5 phases (orthorhombic (T), tetragonal (M) and monoclinic (H) phases) in a single material, and optimize the phase composition to form nanodomains, which are achieved by carefully adjusting the calcination parameters. The resulting sponge-like Nb2O5 nanoplate anodes exhibit attractive rate performance and cycle stability. Specifically, the optimized electrode shows a reversible capacity of 321 mAh g−1 at 1 C (1 C = 200 mA g−1) after 200 cycles. At a high current density of 10 C, the electrode delivers a reversible capacity of 152 mAh g−1. Long term durability tests show that the electrode performs an excellent cycling performance at a current density of 5 C over 1000 cycles with a capacity loss of 0.06 mAh g−1 per cycle. The excellent lithium storage properties are due to the unique multiple phases and nanoscale interface inside the electrode, which facilitate the storing of more ions and the rapid ion transportation during the charging/discharging process. The proposed electrode design strategy provides an alternative route to develop advanced electrodes for energy storage.