Flexible solid-state Zn-air battery based on polymer-oxygen-functionalized g-C3N4 composite membrane.

Personalized healthcare devices require an energy storage system that is flexible and has good mechanical strength and stability for long periods. Zn-air batteries show promise as an alternative to Li-air batteries for this purpose. Zn-air batteries with a high theoretical specific energy density of 1350 W h kg-1 have the potential to replace other metal-air batteries but faces the challenges, such as dendrite formation and Zn corrosion, hindering their successful commercialization. In this work, we report the design and performance optimization of a solid-state flexible Zn-air battery with superior performance and good mechanical property. In addition, we focused on the development of a gel-polymer composite membrane as the electrolyte. The main advantage of the flexible electrolyte is its optimum combination of good ionic conductivity and mechanical strength. Thus, we attempted to address the above-mentioned issues by modifying poly(vinyl alcohol) (PVA) with o-g-C3N4 through the in situ formation of a composite. The interaction between the functional groups of o-g-C3N4 and PVA increased the conductivity without compromising the mechanical behavior of the composite. According to the optimization of the composite composition, it was concluded that 0.32 wt% o-g-C3N4 in PVA showed the highest conductivity and excellent mechanical strength (increase from 25 MPa for pristine PVA membrane to 35 MPa for g-C3N4-PVA composite membrane). The performance of the solid-state battery was better (40 hours) than the standard PVA KOH (13 hours) membrane. Moreover, the stability of the battery was retained at various bending angles, demonstrating its potential to be used in flexible electronic devices.

Substrate Versatile Roller Ball Pen Writing of Nanoporous MoS2 for Energy Storage Devices.

Low-cost fabrication of customizable supercapacitors and batteries to power up portable electronic devices is a much-needed step in advancing energy storage devices. The processing methods and techniques involved in developing small-sized entities in complex patterns are expensive, tedious, and time-consuming. Here, we demonstrate the fabrication of customizable electrochemical supercapacitors and batteries by simply employing the universal and conventional paradigm of direct pen writing with hands and evaluating their energy storage performance. The fabrication technique involves the refilling of MoS2 ink into the pen and then scripting of MoS2 nanostructures onto various substrates. The electrode material employed here consists of nanoporous microspheres of MoS2 synthesized by a simple one-step hydrothermal method. Direct pen writing with porous MoS2 in complex patterns enables easy, affordable, and simple fabrication of energy storage devices as and when required based on user choice toward distributed manufacturing and sustainability.

NiFe-Coordination Polymers-Derived Layered Double Hydroxides as Bifunctional Materials: Effect of the Ni : Fe Ratio on the Electrochemical Performance.

The development of an efficient and cost-effective material is highly desirable for electrochemical devices such as electrolyzers and supercapacitors. Especially, pseudomorphic transformations of metal-organic frameworks (MOFs)/coordination polymers (CPs) into layered double hydroxides (LDHs) materials endow well-defined porosities, high surface area, exchangeable interlayer anions and easily adjustable electronic structure that are truly required for oxygen evolution reaction (OER) and high-performance supercapacitor applications. Herein, we have prepared NiFe-LDHs of various Ni/Fe ratios via a facile room-temperature alkaline hydrolysis of NiFe-CPs precursors. Electrochemical studies reveal that the catalyst having high amount of Fe (Ni1.2 Fe1 -LDH) showed the better OER activity with a low Tafel slope (65 mV dec-1 ) in 1 M KOH. On the other hand, the catalyst containing higher amount of Ni with better layered structure (Ni11.7 Fe1 -LDH) showed high performance for supercapacitor (702 F g-1 at 0.25 A g-1 ) in 3 M KOH. Moreover, a solid-state asymmetric supercapacitor device Ni11.7 Fe1 -LDH/AC was fabricated which exhibited a specific capacitance of 18 F g-1 at a current density of 1 A g-1 . The device displayed high cycling stability with 88% of capacitance retention after 7000 cycles. The experimental findings in this work will help in the futuristic development of NiFe-LDH based electrocatalysts for the enhanced electrochemical performances.

Tau interactome and RNA binding proteins in neurodegenerative diseases.

Pathological tau aggregation is a primary neuropathological feature of many neurodegenerative diseases. Intriguingly, despite the common presence of tau aggregates in these diseases the affected brain regions, clinical symptoms, and morphology, conformation, and isoform ratio present in tau aggregates varies widely. The tau-mediated disease mechanisms that drive neurodegenerative disease are still unknown. Tau interactome studies are critically important for understanding tauopathy. They reveal the interacting partners that define disease pathways, and the tau interactions present in neuropathological aggregates provide potential insight into the cellular environment and protein interactions present during pathological tau aggregation. Here we provide a combined analysis of 12 tau interactome studies of human brain tissue, human cell culture models and rodent models of disease. Together, these studies identified 2084 proteins that interact with tau in human tissue and 1152 proteins that interact with tau in rodent models of disease. Our combined analysis of the tau interactome revealed consistent enrichment of interactions between tau and proteins involved in RNA binding, ribosome, and proteasome function. Comparison of human and rodent tau interactome studies revealed substantial differences between the two species. We also performed a second analysis to identify the tau interacting proteins that are enriched in neurons containing granulovacuolar degeneration or neurofibrillary tangle pathology. These results revealed a timed dysregulation of tau interactions as pathology develops. RNA binding proteins, particularly HNRNPs, emerged as early disease-associated tau interactors and therefore may have an important role in driving tau pathology.

Correction: Engineering the morphology of palladium nanostructures to tune their electrocatalytic activity in formic acid oxidation reactions.

[This corrects the article DOI: 10.1039/D0NA00798F.].

Exploring multifunctional behaviour of g-C3N4 decorated BiVO4/Ag2CO3 hierarchical nanocomposite for simultaneous electrochemical detection of two nitroaromatic compounds and water splitting applications.

Development of multifunctional ternary nanocomposite based electrocatalysts for detection of toxic elements and generation of renewable energy describes an environmentally sustainable technique to address the dual challenges of pollution and energy. Herein, we adopted microwave-assisted synthesis to design a multifunctional graphitic carbon nitride (g-C3N4) decorated BiVO4/Ag2CO3 (BVG@C) hierarchical ternary nanocomposite for sensing and water splitting applications. The morphological, structural and elemental characterizations demonstrate the successful decoration of carbon nitride on the composite surface. The electrochemical activity of BVG@C modified glassy carbon electrode reveals excellent redox behaviour towards simultaneous detection of 4-Nitrophenol (4-NP) and 4-Nitroaniline (PNA). The modified electrode shows rapid amperometric current response with high sensitivity of 2.368 µA mM cm-2 and 1.534 mA mM cm-2 and low detection limit of 0.012 µmol L-1and 0.028 µmol L-1, respectively for 4-NP and PNA. Moreover, the modified electrode was further investigated for hydrogen evolution and oxygen evolution reactions and the electrocatalytic results show admirable activity and good stability for oxygen evolution with very low overpotential of 136 mV in alkaline medium. It is worthwhile to mention that the excellent activity of electrocatalyst can be ascribed to the decoration and electronic interaction of g-C3N4 with the BiVO4/Ag2CO3 nanocomposite, increasing its surface area, active sites, charge transfer and decreasing resistance.

Pfizer/BioNtech BNT162b2: adverse events and insights from an Australian mass vaccination clinic for COVID-19.

The Pfizer/BioNtech BNT162b2 is a major vaccine used in the Australian COVID-19 immunisation programme. We report on BNT162b2 safety in the observation period in a dedicated vaccination clinic linked to a quaternary teaching hospital. We performed a retrospective review of medical records for 57 842 vaccinations, and describe the model of care and adverse event rate at the clinic during its first 2 months of operation. A total of 243 adverse events following immunisation (0.42% of total vaccine doses) were recorded in the immediate observation period post-vaccination, which were predominantly immunisation stress-related responses. Of the 110 patients who experienced an adverse event with their first dose of the vaccine, 90% returned for their second dose of the vaccine, with 87% not reporting any further adverse reaction with the subsequent dose. Nineteen (0.03% of total doses) people were reviewed for an allergic reaction, of which 10 (53%) reported a history of prior allergies. A female predominance was present in both total adverse reactions (70%) and allergic vaccine reactions (79%). Only two patients experienced anaphylaxis (0.003% of total doses), in keeping with low rates of adverse reactions to the BNT162b2 vaccine in the current literature. Overall, the present study reinforces the safety of BNT162b2 in the Australian population, describes vaccination completion rates after adverse events and identifies predisposing factors for rare allergic reactions to the vaccine.

Engineering the morphology of palladium nanostructures to tune their electrocatalytic activity in formic acid oxidation reactions.

Pd nanomaterials can be cheaper alternative catalysts for the electrocatalytic formic acid oxidation reaction (FAOR) in fuel cells. The size and shape of the nanoparticles and crystal engineering can play a crucial role in enhancing the catalytic activities of Pd nanostructures. A systematic study on the effect of varying the morphology of Pd nanostructures on their catalytic activities for FAOR is reported here. Palladium nanoparticles (Pd0D), nanowires (Pd1D) and nanosheets (Pd2D) could be synthesized by using swollen liquid crystals as 'soft' templates. Swollen liquid crystals are lyotropic liquid crystals that are formed from a quaternary mixture of a surfactant, cosurfactant, brine and Pd salt dissolved in oil. Pd1D nanostructures exhibited 2.7 and 19 fold higher current density than Pd0D and Pd2D nanostructures in the FAOR. The Pd1D nanostructure possess higher electrochemically active surface area (ECSA), better catalytic activity, stability, and lower impedance to charge transfer when compared to the Pd0D and Pd2D nanostructures. The presence of relatively higher amounts of crystal defects and enriched (100) crystal facets in the Pd1D nanostructure were found to be the reasons for their enhanced catalytic activities.

Zn(ii)-based coordination polymer: An emissive signaling platform for the recognition of an explosive and a pesticide in an aqueous system.

A new emissive Zn(ii)-based coordination polymer (Zn-CP) bearing paddle-wheel clusters has been developed and the same has been demonstrated to have potential for recognising a nitroaromatic-based explosive (TNP) and a pesticide (2,6-DCNA) in aqueous solution. The structural integrity of this newly developed 2D material was established through single-crystal analysis, whereas the stability of Zn-CP in aqueous medium after the recognition process was investigated by the powder-XRD technique. A combination of experimental and theoretical studies revealed that the change in fluorescence intensity of Zn-CP while interacting with TNP and 2,6-DCNA was possibly due to simultaneous operation of PET and FRET. Experimentally, it was also established that Zn-CP can be reused in up to three cycles for the detection of TNP and 2,6-DCNA.

A Polycarboxyl-Decorated FeIII -Based Xerogel-Derived Multifunctional Composite (Fe3 O4 /Fe/C) as an Efficient Electrode Material towards Oxygen Reduction Reaction and Supercapacitor Application.

Low cost, non-noble metal catalysts with a good oxygen reduction reaction (ORR) activity comparable to that of platinum and also having good energy storage properties are highly desirable but challenging. Several challenges are associated with the development of such materials. Herein, we demonstrate a new polycarboxyl-functionalised FeIII -based gel material, synthesised following a solvothermal method and the development of its composite (Fe3 O4 /Fe/C) by annealing at optimised temperature. The developed composite displayed excellent electrocatalytic activity for the oxygen reduction reaction with an onset potential of 0.87 V (vs. RHE) and a current density value of -5 mA cm-2 , which are comparable with commercial 20 wt % Pt/C. In addition, as one of the most desirable properties, the composite exhibits a better methanol tolerance and greater durability than Pt/C. The same material was explored as an energy storage material for supercapacitors, which showed a specific capacitance of 245 F g-1 at a current density of 1 A g-1 . It is expected that this Fe3 O4 /Fe/C composite with a disordered graphitised carbon matrix will pave a horizon for developing energy conversion and energy storage devices.

High-Rate Assembly of Nanomaterials on Insulating Surfaces Using Electro-Fluidic Directed Assembly.

Conductive or semiconducting nanomaterials-based applications such as electronics and sensors often require direct placement of such nanomaterials on insulating surfaces. Most fluidic-based directed assembly techniques on insulating surfaces utilize capillary force and evaporation but are diffusion limited and slow. Electrophoretic-based assembly, on the other hand, is fast but can only be utilized for assembly on a conductive surface. Here, we present a directed assembly technique that enables rapid assembly of nanomaterials on insulating surfaces. The approach leverages and combines fluidic and electrophoretic assembly by applying the electric field through an insulating surface via a conductive film underneath. The approach (called electro-fluidic) yields an assembly process that is 2 orders of magnitude faster compared to fluidic assembly. By understanding the forces on the assembly process, we have demonstrated the controlled assembly of various types of nanomaterials that are conducting, semiconducting, and insulating including nanoparticles and single-walled carbon nanotubes on insulating rigid and flexible substrates. The presented approach shows great promise for making practical devices in miniaturized sensors and flexible electronics.

Efficient Electron Transfer across a ZnO-MoS2 -Reduced Graphene Oxide Heterojunction for Enhanced Sunlight-Driven Photocatalytic Hydrogen Evolution.

The development of noble metal-free catalysts for hydrogen evolution is required for energy applications. In this regard, ternary heterojunction nanocomposites consisting of ZnO nanoparticles anchored on MoS2 -RGO (RGO=reduced graphene oxide) nanosheets as heterogeneous catalysts show highly efficient photocatalytic H2 evolution. In the photocatalytic process, the catalyst dispersed in an electrolytic solution (S2- and SO32- ions) exhibits an enhanced rate of H2 evolution, and optimization experiments reveal that ZnO with 4.0 wt % of MoS2 -RGO nanosheets gives the highest photocatalytic H2 production of 28.616 mmol h-1 gcat-1 under sunlight irradiation; approximately 56 times higher than that on bare ZnO and several times higher than those of other ternary photocatalysts. The superior catalytic activity can be attributed to the in situ generation of ZnS, which leads to improved interfacial charge transfer to the MoS2 cocatalyst and RGO, which has plenty of active sites available for photocatalytic reactions. Recycling experiments also proved the stability of the optimized photocatalyst. In addition, the ternary nanocomposite displayed multifunctional properties for hydrogen evolution activity under electrocatalytic and photoelectrocatalytic conditions owing to the high electrode-electrolyte contact area. Thus, the present work provides very useful insights for the development of inexpensive, multifunctional catalysts without noble metal loading to achieve a high rate of H2 generation.

Cutaneous presentation of gastrointestinal adenocarcinoma.

Seeding of a central nervous system malignancy to the abdominal cavity is an uncommon but well documented complication of a ventriculoperitoneal (VP) shunt. However, the metastasis of a primary gastrointestinal cancer to the skin via a VP shunt is extremely rare. We report the clinical case of an 85-year-old male who presented with a right upper quadrant nodule over his shunt, which on histopathology and tumour marker profile was diagnosed as an adenocarcinoma of likely upper gastrointestinal origin. This case illustrates the importance of proceeding to biopsy to inform prognosis and management, despite the risks of shunt infection.

Efficient Solar Energy Conversion Using CaCu3Ti4O12 Photoanode for Photocatalysis and Photoelectrocatalysis.

A highly efficient third generation catalyst, CaCu3Ti4O12 (CCTO) shows excellent photoelectrochemical (PEC) and photocatalytic ability. As only 4% part of the solar spectrum covers UV light, thus it is highly desirable to develop visible light active photocatalyst materials like CCTO for effective solar energy conversion. A direct band transition with a narrow band gap (1.5 eV) was observed. Under light irradiation, high photocurrent density was found to be 0.96 mA/cm(2), indicating the visible light induced photocatalytic ability of CCTO. Visible light mediated photocatalytic and photoelectrocatalytic degradation efficiency of CaCu3Ti4O12 pellets (CCTO) was investigated for three classes of pharmaceutical waste: erythrosin (dye), ciprofloxacin (antibiotic) and estriol (steroid). It is found that the degradation process follows first order kinetic reaction in electrocatalysis, photocatalysis and photoelectrocatalysis and high kinetic rate constant was observed in photoelectrocatalysis. This was quite high in comparison to previously reported methods.

Porous, catalytically active palladium nanostructures by tuning nanoparticle interactions in an organic medium.

We present a simple template-free method for the synthesis of interconnected hierarchical porous palladium nanostructures by controlling the aggregation of nanoparticles in organic media. The interaction between the nanoparticles is tuned by varying the dielectric constant of the medium consistent with DLVO calculations. The reaction products range from discrete nanoparticles to compact porous clusters with large specific surface areas. The nanoclusters exhibit hierarchical porosity and are found to exhibit excellent activity towards the reduction of 4-nitrophenol into 4-aminophenol and hydrogen oxidation. The method opens up possibilities for synthesizing porous clusters of other functional inorganics in organic media.

Nanoscale heterostructures with molecular-scale single-crystal metal wires.

Creating nanoscale heterostructures with molecular-scale (<2 nm) metal wires is critical for many applications and remains a challenge. Here, we report the first time synthesis of nanoscale heterostructures with single-crystal molecular-scale Au nanowires attached to different nanostructure substrates. Our method involves the formation of Au nanoparticle seeds by the reduction of rocksalt AuCl nanocubes heterogeneously nucleated on the substrates and subsequent nanowire growth by oriented attachment of Au nanoparticles from the solution phase. Nanoscale heterostructures fabricated by such site-specific nucleation and growth are attractive for many applications including nanoelectronic device wiring, catalysis, and sensing.

Gold nanostructures from cube-shaped crystalline intermediates.

Conventional bottom-up approaches for building nanostructures rely on the ability to synthesize nanoparticles of different shapes and sizes in a controlled manner that are then assembled to produce useful structures. Here, we present an alternate approach for producing nanostructures based on the formation of a crystalline intermediate in which the metal ion can be reduced in a controlled manner. Partial reduction of HAuCl4 by a long-chain amine results in the formation of a cube-shaped crystalline intermediate in which Au is present in a +1 oxidation state. By control of the nucleation of the metal in the intermediate, a variety of nanostructures can be synthesized. Here, we present results on the formation of superlattices, hollow cubes, nanotubes, and extended hollow structures starting from the intermediate. Direct evidence for the formation of metal within the intermediate by in situ electron-beam-induced reduction in the transmission electron microscope is presented.