Search

Polyaniline (PANI) provides an attractive organic platform for CO2 electrochemical reduction due to the ability to adsorb CO2 molecules and in providing means to interact with metal nanostructures. In this work, a novel PANI supported copper catalyst has been developed by coupling the interfacial polymerization of PANI and Cu. The hybrid catalyst demonstrates excellent activity towards production of hydrocarbon products including CH4 and C2H4, compared with the use of bare Cu. A Faradaic efficiency of 71.8 % and a current density of 16.9 mA/cm2 were achieved at −0.86 V vs. RHE, in contrast to only 22.2 % and 1.0 mA/cm2 from the counterpart Cu catalysts. The remarkably enhanced catalytic performance of the hybrid PANI/Cu catalyst can be attributed to the synergistic interaction between the PANI underlayer and copper. The PANI favours the adsorption and binding of CO2 molecules via its nitrogen sites to form *CO intermediates, while the Cu/PANI interfaces confine the diffusion or desorption of the *CO intermediates favouring their further hydrogenation or carbon‐carbon coupling to form hydrocarbon products. This work provides insights into the formation of hydrocarbon products on PANI‐modified Cu catalysts, which may guide the development of conducting polymer‐metal catalysts for CO2 electroreduction. [ABSTRACT FROM AUTHOR]

Summary: An 8‐year‐old Warmblood cross mare was presented for further investigation of an acute‐onset lameness of the right hindlimb. Three weeks prior to presentation, the horse was found markedly lame at walk following a fall during exercise. The horse was initially managed with field rest, but the lameness persisted. A marked right hindlimb lameness at trot graded 5/10 was confirmed. Atrophy of the right gluteal musculature was evident, and palpation over the region of the right coxofemoral joint provoked a pain reaction. Nuclear scintigraphy revealed a diffuse area of increased radiopharmaceutical uptake in the right femoral head, neck and greater trochanter. Radiographs identified a complete, slightly displaced fracture of the base of the greater trochanter of the right femur. Ultrasound examination of the proximal femur demonstrated an irregularity of the caudolateral bone surface of the greater trochanter, extending along its attachment to the femur; this was consistent with the radiological findings. On re‐examination, after 9 months of stable rest, the horse was found to be sound when trotted in a straight line on the hard surface. Follow‐up two and a half years after the initial incident reported the horse to be nonlame and at its previous level of work. [ABSTRACT FROM AUTHOR]

The exploration of inexpensive and efficient catalysts for oxygen reduction reaction (ORR) is crucial for chemical and energy industries. Carbon materials have been proved promising with different catalysts enabling 2 and 4e− ORR. Nevertheless, their ORR activity and selectivity is still complex and under debate in many cases. Many structures of these active carbon materials are also chemically unstable for practical implementations. Unlike the well‐discussed structures, this work presents a strategy to promote efficient and stable 2e− ORR of carbon materials through the synergistic effect of lattice distortion and H‐passivation (on the distorted structure). We show how these structures can be formed on carbon cloth, and how the reproducible chemical adsorption can be realized on these structures for efficient and stable H2O2 production. The work here gives not only new understandings on the 2e− ORR catalysis, but also the robust catalyst which can be directly used in industry. [ABSTRACT FROM AUTHOR]

The exploration of inexpensive and efficient catalysts for oxygen reduction reaction (ORR) is crucial for chemical and energy industries. Carbon materials have been proved promising with different catalysts enabling 2 and 4e− ORR. Nevertheless, their ORR activity and selectivity is still complex and under debate in many cases. Many structures of these active carbon materials are also chemically unstable for practical implementations. Unlike the well‐discussed structures, this work presents a strategy to promote efficient and stable 2e− ORR of carbon materials through the synergistic effect of lattice distortion and H‐passivation (on the distorted structure). We show how these structures can be formed on carbon cloth, and how the reproducible chemical adsorption can be realized on these structures for efficient and stable H2O2 production. The work here gives not only new understandings on the 2e− ORR catalysis, but also the robust catalyst which can be directly used in industry. [ABSTRACT FROM AUTHOR]

Maize is a vital global crop, and each seed (kernel) hosts an ecosystem of microbes living inside it. However, we know very little about these endophytes and what their role is in plant production and physiology. In this Microreview, I summarize the major questions around maize seed endophytes, including what organisms are present, how they get there, whether and how they transmit across generations, and how they and the plant affect each other. Although several studies touch on each of these areas, ultimately there are far more questions than answers. Future priorities for research on maize seed endophytes should include understanding what adaptations allow microbes to be seed endophytes, how the host genetics and the environment affect these communities, and how maize seed endophytes ultimately contribute to the next generation of plants. [ABSTRACT FROM AUTHOR]

The deployment of structures that enable localized release of bioactive molecules can result in more efficacious treatment of disease and better integration of implantable bionic devices. The strategic design of a biopolymeric coating can be used to engineer the optimal release profile depending on the task at hand. As illustrative examples, here advances in delivery of drugs from bone, brain, ocular, and cardiovascular implants are reviewed. These areas are focused to highlight that both hard and soft tissue implants can benefit from controlled localized delivery. The composition of biopolymers used to achieve appropriate delivery to the selected tissue types, and their corresponding outcomes are brought to the fore. To conclude, key factors in designing drug‐loaded biopolymeric coatings for biomedical implants are highlighted. [ABSTRACT FROM AUTHOR]

Hydrogel materials are promising candidates in cartilage tissue engineering as they provide a 3D porous environment for cell proliferation and the development of new cartilage tissue. Both the mechanical and transport properties of hydrogel scaffolds influence the ability of encapsulated cells to produce neocartilage. In photocrosslinkable hydrogels, both of these material properties can be tuned by changing the crosslinking density. However, the interdependent nature of the structural, physical and biological properties of photocrosslinkable hydrogels means that optimizing composition is typically a complicated process, involving sequential and/or iterative steps of physiochemical and biological characterization. The combinational nature of the variables indicates that an exhaustive analysis of all reasonable concentration ranges would be impractical. Herein, response surface methodology (RSM) was used to efficiently optimize the composition of a hybrid of gelatin‐methacryloyl (GelMA) and hyaluronic acid methacryloyl (HAMA) with respect to both mechanical and transport properties. RSM was employed to investigate the effect of GelMA, HAMA, and photoinitiator concentration on the shear modulus and diffusion coefficient of the hydrogel membrane. Two mathematical models were fitted to the experimental data and used to predict the optimum hydrogel composition. Finally, the optimal composition was tested and compared with the predicted values. [ABSTRACT FROM AUTHOR]

In this work, a scalable one‐step glucose blowing method has been used to prepare a porous N‐doped carbon supported Cu nanoparticles (Cu‐NC) composite catalyst for CO2 electroreduction. This Cu‐NC catalyst demonstrates efficient catalytic activity for CO2‐to‐C1 product (CO and formate) conversion, with a high efficiency of 69 % at an overpotential of 590 mV. The excellent catalytic activity is correlated to the structure of this composite and the N‐species (pyridinic and graphitic nitrogen) in the carbonaceous matrix that may promote the CO2 adsorption and subsequent formation of reduction reaction intermediates and products. [ABSTRACT FROM AUTHOR]

An efficient cathodic electrodeposition method is developed for coating Co‐based metal‐organic frameworks (Co‐MOF) on carbon fiber cloth (CFC), a widely used substrate in energy fields. The use of a highly active Co metal surface enables nucleation and growth of Co‐MOF in 3D rodlike crystal bundles. When used as a binder‐free electrode (Co‐MOF/CFC) for supercapacitors, it shows a high areal capacitance of 1784 mF cm−2 at 1 mA cm−2, good cycling stability and excellent rate capability. The assembled asymmetric all‐solid‐state supercapacitor device (Co‐MOF/CFC//AC) delivers a high energy density and power density. This work may open up an effective approach to realize the electrosynthesis of MOF films, promoting use in energy storage and conversion fields. [ABSTRACT FROM AUTHOR]

Iron is a promising material for cardiovascular stent applications, however, the low biodegradation rate presents a challenge. Here, a dynamic method to improve the degradation rate of iron and simultaneously deliver electrical energy that could potentially inhibit cell proliferation on the device is reported. It is realized by pairing iron with a biocompatible hydrogel cathode in a cell culture media‐based electrolyte forming an iron‐air battery. This system does not show cytotoxicity to human adipose‐stem cells over a period of 21 days but inhibits cell proliferation. The combination of enhanced iron degradation and inhibited cell proliferation by this dynamic method suggests it might be an approach for restenosis inhibition of biodegradable stents. [ABSTRACT FROM AUTHOR]

Background: Prenatal alcohol exposure (PAE) can produce deficits in a wide range of cognitive functions but is especially detrimental to behaviors requiring accurate spatial information processing. In open field environments, spatial behavior is organized such that animals establish "home bases" marked by long stops focused around one location. Progressions away from the home base are circuitous and slow, while progressions directed toward the home base are non‐circuitous and fast. The impact of PAE on the organization of open field behavior has not been experimentally investigated. Methods: In the present study, adult female and male rats with moderate PAE or saccharin exposure locomoted a circular high walled open field for 30 minutes under lighted conditions. Results: The findings indicate that PAE and sex influence the organization of open field behavior. Consistent with previous literature, PAE rats exhibited greater locomotion in the open field. Novel findings from the current study indicate that PAE and sex also impact open field measures specific to spatial orientation. While all rats established a home base on the periphery of the open field, PAE rats, particularly males, exhibited significantly less clustered home base stopping with smaller changes in heading between stops. PAE also impaired progression measures specific to distance estimation, while sex alone impacted progression measures specific to direction estimation. Conclusions: These findings support the conclusion that adult male rats have an increased susceptibility to the effects of PAE on the organization of open field behavior. [ABSTRACT FROM AUTHOR]

Emerging markets for wearable electronics have stimulated a rapidly growing demand for the commercialization of flexible and reliable energy storage and conversion units (including batteries, supercapacitors, and thermoelectrochemical cells). 3D printing, a rapidly growing suite of fabrication technologies, is extensively used in the above‐mentioned energy‐related areas owing to its relatively low cost, freedom of design, and controllable, reproducible prototyping capability. However, there remain challenges in processable ink formulation and accurate material/device design. By summarizing the recent progress in 3D‐printed wearable electrochemical energy devices and discussing the current limitations and future perspectives, this article is expected to serve as a reference for the scalable fabrication of advanced energy systems via 3D printing. [ABSTRACT FROM AUTHOR]

In the last decade, the advent of 3D printing for tissue engineering and regenerative medicine has engendered great interest for those involved in skin repair and regeneration. 3D bioprinting allows spatial distribution of skin cells into predefined custom‐made structures to produce living skin mimics on the bench for grafting or drug testing. The key aspect of 3D bioprinting lies in the formulation of printable bioinks serving as matrix mimics to house skin cells, alongside an appropriate combination of cells. In this review, bioink formulations, cell combinations, as well as manufacturing methods exploited to develop 3D bioprinted constructs for skin regeneration are summarized. Issues to do with the selection of suitable materials and cells to ensure the functionality of the resulting skin constructs and fabrication of skin appendages are also addressed. [ABSTRACT FROM AUTHOR]

Herein, a 3D‐printed nozzle designed for the single‐step fabrication of melt electrowritten hollow fibers is introduced. To achieve this, selective laser melting (SLM) is used to fabricate the outer part of the coaxial nozzle (800 μm inner diameter) from Ti6Al4V, into which a conventional nozzle (250 μm inner diameter) is inserted. Several iterations of coaxial nozzle design result in a well‐aligned inner core nozzle that delivers air into the Taylor cone of medical‐grade poly(ε‐caprolactone) (PCL). Air from this bubble forms the hollow part of the fiber while the PCL shell solidifies as the shell. The smallest PCL fibers have an approximate outside diameter of 10 μm and a lumen of 6 μm, making this a promising one‐step technique for small diameter hollow fiber fabrication. [ABSTRACT FROM AUTHOR]

The electrochemical oxygen reduction reaction (ORR) is the key energy conversion reaction involved in fuel cells, metal‐air batteries, and hydrogen peroxide production. Proliferation and improvement of the ORR requires wider use of new and existing high performance catalysts; unfortunately, most of these are still based on precious metals and become uneconomical in mass‐use applications. Recent progress suggests that low cost and durable carbon materials can potentially be developed as efficient ORR catalysts. Significant efforts have been made in discovering fundamental catalytic mechanisms and engineering techniques to guide and enable viable regulation of both the ORR activity and selectivity of these carbon catalysts. Starting from the fundamental understanding, this report reviews recent progress in engineering carbon materials from exotic chemical doping to intrinsic geometric defects for improved ORR. On the basis of both theoretical and experimental investigations reported so far in this area, future improvements in carbon catalysts are also discussed, providing useful pathways for more efficient and reliable energy conversion technologies. [ABSTRACT FROM AUTHOR]

Electrochemical exfoliation of graphite offers a scalable and efficient approach to synthesise graphene nanomaterials. This process is commonly performed either anodically or cathodically, whereas simultaneous dual processes offer an attractive energy efficient means to produce graphene materials with tuneable properties. Here, we demonstrate a simple electro synthetic approach to produce graphene simultaneously from both a graphite anode and a graphite cathode in K2SO4 aqueous solution. Graphite exfoliation was facilitated by employing 0.5 M K2SO4 as an electrolyte at 10 V, where efficient exfoliation simultaneously occurs at graphite foils serving as both anode and cathode. The anodically exfoliated graphene has a high defect density (ID/IG=0.58) and higher degree of oxidation (C/O=11.36), in comparison to graphene produced at cathode having a lower defect density (ID/IG=0.06) and a low oxidation degree (C/O=31.68). The usage of aqueous solution for scalable and efficient concurrent‐dual electrochemical exfoliation of graphite electrodes will facilitate the development of large‐scale production of graphene. [ABSTRACT FROM AUTHOR]

The flow‐cell design offers prospect for transition to commercial‐relevant high current density CO2 electrolysis. However, it remains to understand the fundamental interplay between the catalyst, and the electrolyte in such configuration toward CO2 reduction performance. Herein, the dramatic influence of electrolyte alkalinity in widening potential window for CO2 electroreduction in a flow‐cell system based on SnS nanosheets is reported. The optimized SnS catalyst operated in 1 m KOH achieves a maximum formate Faradaic efficiency of 88 ± 2% at −1.3 V vs reversible hydrogen electrode (RHE) with the current density of ≈120 mA cm−2. Alkaline electrolyte is found suppressing the hydrogen evolution across all potentials which is particularly dominant at the less negative potentials, as well as CO evolution at more negative potentials. This in turn widens the potential window for formate conversion (>70% across −0.5 to −1.5 V vs RHE). A comparative study to SnOx counterpart indicates sulfur also acts to suppress hydrogen evolution, although electrolyte alkalinity resulting in a greater suppression. The boosting of the electrochemical potential window, along with high current densities in SnS derived catalytic system offers a highly attractive and promising route toward industrial‐relevant electrocatalytic production of formate from CO2. [ABSTRACT FROM AUTHOR]

Safety issues currently limit the development of advanced lithium‐ion batteries (LIBs) and this is exacerbated when they are misused or abused. The addition of small amounts of fillers or additives into common liquid electrolytes can greatly improve resistance to abuse without impairing electrochemical performance. This review discusses the recent progress in such abuse‐tolerant electrolytes. It covers electrolytes with shear thickening properties for tolerating mechanical abuse, electrolytes with redox shuttle additives for suppressing electrochemical abuse, and electrolytes with flame‐retardant additives for resisting thermal abuse. It aims to provide insights into the functioning of such electrolytes and the understanding of electrolyte composition‐property relationship. Future perspectives, challenges, and opportunities towards practical applications are also presented. [ABSTRACT FROM AUTHOR]

Wild Pacific salmon, including Chinook salmon Oncorhynchus tshawytscha, have been supplemented with hatchery propagation for over 50 years in support of increased ocean harvest, mitigation for hydroelectric development, and conservation of threatened populations. In Canada, the Wild Salmon Policy for Pacific salmon was established with the goal of maintaining and restoring healthy and diverse Pacific salmon populations, making conservation of wild salmon and their habitats the highest priority for resource management decision‐making. For policy implementation, a new approach to the assessment and management of Chinook salmon and the associated hatchery production and fisheries management are needed. Implementation of genetic stock identification (GSI) and parentage‐based tagging (PBT) for marine fisheries assessment may overcome problems associated with coded‐wire tag‐based (CWT) assessment and management of Chinook salmon fisheries, providing at a minimum information equivalent to that derived from the CWT program. GSI and PBT were used to identify Chinook salmon sampled in 2018 and 2019 marine fisheries (18,819 individuals genotyped) in British Columbia to specific conservation units (CU), populations, and broodyears. Individuals were genotyped at 391 single nucleotide polymorphisms via direct sequencing of amplicons. Very high accuracy of assignment to population and age (>99.5%) via PBT was observed for 1994 Chinook salmon of ages 2–4 years, with a 105,722–individual, 380–population baseline available for assignment. Application of a GSI‐PBT system of identification to individuals in 2019 fisheries provided high‐resolution estimates of stock composition, catch, and exploitation rate by CU or population, with fishery exploitation rates directly comparable to those provided by CWTs for 13 populations. GSI and PBT provide an alternate, cheaper, and more effective method in the assessment and management of Canadian‐origin Chinook salmon relative to CWTs, and an opportunity for a genetics‐based system to replace the current CWT system for salmon assessment. [ABSTRACT FROM AUTHOR]

The impact of protein fouling on platinum electrodes was assessed by electrochemical methods. Protein fouling affected the electrode potential and charge transfer through the electrode‐solution interface. Adsorbed proteins partially blocked the electrode, with no charge passing through blocked regions. The electrochemical theory and methodology for investigating partially blocked electrodes is fully presented, applied to protein adsorption, and the implications for bionics applications are discussed. The partially blocked electrode had a reduced admittance, and increased impedance and polarization resistance consistent with a smaller effective electrode area. The charge storage capacity and charge injection capacity decreased after protein adsorption. The effective electrode area was assessed by impedance and cyclic voltammetry. The diffusion profile towards the partially blocked electrode was mixed between linear and radial diffusion. [ABSTRACT FROM AUTHOR]

Thermoelectrochemical cells (thermocells) designed for harvesting human body heat can provide constant power output for wearable electronics, supplementing state‐of‐the‐art flexible power storage and conversion solutions. However, a systematic investigation into the optimization of wearable thermocells is lacking, especially with regard to device design, n‐type electrolytes, and electrode/electrolyte integration. Here, a n‐type gel electrolyte: polyvinyl alcohol‐FeCl2/3 with outstanding flexibility and elasticity and exceptional electrolyte/electrode integration into a 3D porous poly(3,4‐ethylenedioxythiophene)/polystyrenesulfonate (PEDOT/PSS) electrode, is produced via an in situ chemical crosslinking method. The integrated n‐type cell shows excellent seebeck coefficients (0.85 mV K−1) and output current density (1.74 A m−2 K−1) that are comparable with an optimized p‐type cell consisting of a carboxymethylcellulose‐K3/4Fe(CN)6 electrolyte with a 3D PEDOT/PSS‐edge functionalized graphene/carbon nanotube electrode (−1.22 mV K−1 and 1.85 A m−2 K−1). The equivalent performance of the n‐type and p‐type cells enables the effective series connection of up to 18 pairs of p–n cells that combines to give an output voltage of 0.34 V (∆T = 10 K). This in‐series device is fabricated into a proof‐of‐concept watch strap, which can harvest body heat, charge supercapacitor (up to 470 mF) as well as illuminate a green light emitting diode, demonstrating the practical applications. [ABSTRACT FROM AUTHOR]

Electrochemical energy storage (EES) plays a critical role in tackling climate change and the energy crisis, unfortunately it faces several challenges. Unlike conventional electrode materials which are gradually approaching their capacity limit, the emerging atomically thin 2D materials can potentially open up various new possibilities for design and fabrication of novel EES devices. The studies in this area to date have laid the groundwork in understanding fundamental physics and chemistry of 2D materials, enabling a toolbox of engineering strategies to be used to improve the EES performance. This report reviews recent progress in engineering 2D materials for EES applications. Both theoretical and experimental investigations in this area are summarized, and pathways toward improved EES performance and their novel applications are highlighted based on appropriate integration of promising strategies such as the surface activation, chemical doping, phase engineering, and hybrid structures. [ABSTRACT FROM AUTHOR]

Novel conductive polymer‐based metal complexes were electrochemically synthesized and characterized in relation to (spectro)electrochemical stimuli. Particularly, we focused our attention on terthiophenes functionalized with terpyridine groups, along with Fe2+ cations present during electrochemical synthesis. The resultant electroactive films are coherent, robust, and exhibit mixed absorption profiles upon electrochemical doping, characteristic for both polyterthiophenes and metal‐ligand transitions. At certain oxidation potentials, the formation of radical cation and also dication states were observed. The latter, influence the optical transitions related to metal centers, and can reversibly be everted by switching to lower potentials. Furthermore, the polymer "cross‐linking metal" can be removed from the structure, which we obtained by partial exchange of Fe2+ with Cu2+ and Zn2+ cations. The conducted cation exchange studies however elucidate the complexity and difficulty of such an approach. With future electropolymerization "strategies" we are expecting to extend film stability during application of relatively high potentials, as well as in the interim of cation exchange. [ABSTRACT FROM AUTHOR]

Studies suggest that tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL) has vasoprotective potential, as low levels of TRAIL cause accelerated vascular calcification, whereas exogenous TRAIL administration exhibits anti‐atherosclerotic activity. The mechanism of TRAIL‐mediated vasoprotection remains unclear. We studied the effects of TRAIL (100 ng/ml) on human aortic endothelial cells (HAECs) exposed to pro‐atherogenic conditions; (a) oscillatory shear stress (±10 dynes/cm2) using the ibidi µ‐slide fluidic system; (b) pro‐inflammatory injury, that is, tumor necrosis factor alpha (TNF‐α, 100 ng/ml) and hyperglycemia (30 mM d‐glucose). End‐points examined included inflammatory gene expression and reactive oxygen species (ROS) formation. TRAIL shifted the net gene expression toward an antioxidant phenotype in HAECs exposed to oscillatory shear stress. TRAIL significantly reduced ROS formation in HAECs exposed to both TNF‐α and hyperglycemia. Therefore, TRAIL appears to confer atheroprotective effects on the endothelium, at least in part, by reducing oxidative stress. [ABSTRACT FROM AUTHOR]

Here it was demonstrated that the decoration of gold (Au) with polyaniline is an effective approach in increasing its electrocatalytic reduction of CO2 to CO. The core‐shell‐structured gold‐polyaniline (Au−PANI) nanocomposite delivered a CO2‐to‐CO conversion efficiency of 85 % with a high current density of 11.6 mA cm−2. The polyaniline shell facilitated CO2 adsorption, and the subsequent formation of reaction intermediates on the gold core contributed to the high efficiency observed. [ABSTRACT FROM AUTHOR]

To achieve the high energy densities demanded by emerging technologies, lithium battery electrodes need to approach the volumetric and specific capacity limits of their electrochemically active constituents, which requires minimization of the inactive components of the electrode. However, a reduction in the percentage of inactive conductive additives limits charge transport within the battery electrode, which results in compromised electrochemical performance. Here, an electrode design that achieves efficient electron and lithium‐ion transport kinetics at exceptionally low conductive additive levels and industrially relevant active material areal loadings is introduced. Using a scalable Pickering emulsion approach, Ni‐rich LiNi0.8Co0.15Al0.05O2 (NCA) cathode powders are conformally coated using only 0.5 wt% of solution‐processed graphene, resulting in an electrical conductivity that is comparable to 5 wt% carbon black. Moreover, the conformal graphene coating mitigates degradation at the cathode surface, thus providing improved electrochemical cycle life. The morphology of the electrodes also facilitates rapid lithium‐ion transport kinetics, which provides superlative rate capability. Overall, this electrode design concurrently approaches theoretical volumetric and specific capacity limits without tradeoffs in cycle life, rate capability, or active material areal loading. [ABSTRACT FROM AUTHOR]

The ability of boronic acids (BAs) to reversibly bind diols, such as sugars, has been widely studied in recent years. In solution, through the incorporation of additional fluorophores, the BA–sugar interaction can be monitored by changes in fluorescence. Ultimately, a practical realization of this technology requires a transition from solution‐based methodologies. Herein, the first example of 3D‐printed sugar‐sensing hydrogels, achieved through the incorporation of a BA–fluorophore pair in a gelatin methacrylamide‐based matrix is presented. Through optimization of monomeric cocktails, it is possible to use extrusion printing to generate structured porous hydrogels which show a measurable and reproducible linear fluorescence response to glucose and fructose up to 100 mm. [ABSTRACT FROM AUTHOR]

The hydrogen evolution reaction (HER) is an emerging key technology to provide clean, renewable energy. Current state‐of‐the‐art catalysts still rely on expensive and rare noble metals, however, the relatively cheap and abundant transition metal dichalcogenides (TMDs) have emerged as exceptionally promising alternatives. Early studies in developing TMD‐based catalysts laid the groundwork in understanding the fundamental catalytically active sites of different TMD phases, enabling a toolbox of physical, chemical, and electronic engineering strategies to improve the HER catalytic activity of TMDs. This report focuses on recent progress in improving the catalytic properties of TMDs toward highly efficient production of H2. Combining theoretical and experimental considerations, a summary of the progress to date is provided and a pathway forward for viable hydrogen evolution from TMD driven catalysis is concluded. [ABSTRACT FROM AUTHOR]

Regulatory T‐cells (Tregs) are important modulators of the immune system through their intrinsic suppressive functions. Systemic adoptive transfer of ex vivo expanded Tregs has been extensively investigated for allogeneic transplantation. Due to the time‐consuming and costly expansion protocols of Tregs, more targeted approaches could be beneficial. The encapsulation of human natural and induced Tregs for localized immunosuppression is described for the first time. Tregs encapsulated in alginate‐gelatin methacryloyl hydrogel remain viable, phenotypically stable, functional, and confined in the structure. Supplementation of the hydrogel with the Treg‐specific bioactive factors interleukin‐2 and chemokine ligand 1 improves Treg viability, suppressive phenotype, and function, and attracts to the structure CCR8+ T‐cells enriched with anti‐inflammatory subpopulations, including Tregs, from human peripheral blood. Furthermore, these findings are applicable to 3D bioprinting. Co‐axial printing of murine pancreatic islets with human natural and induced Tregs protects the islets from xenoresponse upon co‐culture with human peripheral blood mononuclear cells. This establishes the co‐encapsulation of Tregs by co‐axial 3D bioprinting as a valid option for providing local immune protection to allogeneic cellular transplants such as pancreatic islets. [ABSTRACT FROM AUTHOR]

Metal‐N‐C is a type of attractive electrocatalyst for efficient CO2 reduction to CO. Because of the ambiguity in their atomic structures, the active sites and catalytic mechanisms of the catalysts have remained under debate. Here, the effects of N and C hybrid coordination on the activity of Ni‐N‐C catalysts were investigated, combining theoretical and experimental methods. The theoretical calculations revealed that N and C hybrid coordination greatly enhanced the capability of single‐atom Ni active sites to provide electrons to reactant molecules and strengthens the bonding of Ni to N and C in the Ni‐N‐C complexes. During the reaction process, the C and N coordination synergistically optimized the reaction energies in the conversion of CO2 to CO. A good agreement between theoretical calculations and electrochemical experiments was achieved based on the newly developed Ni‐N‐C electrocatalysts. The activity of hybrid‐coordination NiN2C2 was more than double that of single‐coordination NiN4. [ABSTRACT FROM AUTHOR]

The application of a biodegradable conducting polymer coating based on a polythiophene composite (PTC) to mitigate degradation of magnesium in an in vitro environment is reported. The rationale behind the study is to advance a bioactive coating to control the rapid early stage degradation of the magnesium and prevent inflammatory reactions and physiological complications, while, in the long term, the coating degrades, followed by the full degradation of the magnesium implant. The conducting polymer in this study is deposited on a bioabsorbable medical grade magnesium alloy, AZNd, through layer‐by‐layer deposition, and the degradation behavior in simulated biological fluid is studied electrochemically. The possibility of a synergistic effect by combining praseodymium conversion coating together with the conducting polymer coating in protecting magnesium is also examined. Results show that the highest level of corrosion mitigation is afforded by the combination of praseodymium conversion and the conducting polymer coating layers. Electrochemical models are advanced to explain the electroactivity of the conducting polymer across the film as well as at the interface with electrolyte and substrate. Based on the physical and electrochemical evidence, the barrier effect is proposed as the main protection mechanism. [ABSTRACT FROM AUTHOR]

Key points: Maternal obesity has been associated with shifts in intestinal microbiota, which may contribute to impaired barrier functionImpaired barrier function may expose the placenta and fetus to pro‐inflammatory mediatorsWe investigated the impacts of diet‐induced obesity in mice on maternal and fetal intestinal structure and placental vascularizationDiet‐induced obesity decreased maternal intestinal short chain fatty acids and their receptors, impaired gut barrier integrity and was associated with fetal intestinal inflammation.Placenta from obese mothers showed blood vessel immaturity, hypoxia, increased transcript levels of inflammation, autophagy and altered levels of endoplasmic reticulum stress markers.These data suggest that maternal intestinal changes probably contribute to adverse placental adaptations and also impart an increased risk of obesity in the offspring via alterations in fetal gut development. Shifts in maternal intestinal microbiota have been implicated in metabolic adaptations to pregnancy. In the present study, we generated cohorts of female C57BL/6J mice fed a control (17% kcal fat, n = 10–14) or a high‐fat diet (HFD 60% kcal from fat, n = 10–14; ad libitum) aiming to investigate the impact on the maternal gut microbiota, intestinal inflammation and gut barrier integrity, placental inflammation and fetal intestinal development at embryonic day 18.5. HFD was associated with decreased relative abundances of short‐chain fatty acid (SCFA) producing genera during pregnancy. These diet‐induced shifts paralleled decreased maternal intestinal mRNA levels of SCFA receptor Gpr41, modestly decreased cecal butyrate, and altered mRNA levels of inflammatory cytokines and immune cell markers in the maternal intestine. Maternal HFD resulted in impaired gut barrier integrity, with corresponding increases in circulating maternal levels of lipopolysaccharide (LPS) and tumour necrosis factor. Placentas from HFD dams demonstrated blood vessel immaturity and hypoxia; decreased free carnitine, acylcarnitine derivatives and trimethylamine‐N‐oxide; and altered mRNA levels of inflammation, autophagy, and ER stress markers. HFD exposed fetuses had increased activation of nuclear factor‐kappa B and inhibition of the unfolded protein response in the developing intestine. Taken together, these data suggest that HFD intake prior to and during pregnancy shifts the composition of the maternal gut microbiota and impairs gut barrier integrity, resulting in increased maternal circulating LPS, which may ultimate contribute to changes in placental vascularization and fetal gut development. Key points: Maternal obesity has been associated with shifts in intestinal microbiota, which may contribute to impaired barrier functionImpaired barrier function may expose the placenta and fetus to pro‐inflammatory mediatorsWe investigated the impacts of diet‐induced obesity in mice on maternal and fetal intestinal structure and placental vascularizationDiet‐induced obesity decreased maternal intestinal short chain fatty acids and their receptors, impaired gut barrier integrity and was associated with fetal intestinal inflammation.Placenta from obese mothers showed blood vessel immaturity, hypoxia, increased transcript levels of inflammation, autophagy and altered levels of endoplasmic reticulum stress markers.These data suggest that maternal intestinal changes probably contribute to adverse placental adaptations and also impart an increased risk of obesity in the offspring via alterations in fetal gut development. [ABSTRACT FROM AUTHOR]

Abstract: Developing immobilized molecular complexes, which demonstrate high product efficiencies at low overpotential in the electrochemical reduction of CO2 in aqueous media, is essential for the practical production of reduction products. In this work, a simple and facile self‐assembly method is demonstrated by electrostatic interaction and π–π stacking for the fabrication of a porphyrin/graphene framework (FePGF) composed of Fe(III) tetraphenyltrimethylammonium porphyrin and reduced liquid crystalline graphene oxide that can be utilized for the electrocatalytic reduction of CO2 to CO on a glassy carbon electrode in aqueous electrolyte. The FePGF results in an outstanding robust catalytic performance for the production of CO with 97.0% faradaic efficiency at an overpotential of 480 mV and superior long‐term stability relative to other heterogeneous molecular complexes of over 24 h (cathodic energy efficiency: 58.1%). In addition, a high surface area carbon fiber paper is used as a substrate for FePGF catalyst, resulting in enhanced current density of 1.68 mA cm−2 with 98.7% CO faradaic efficiency at an overpotential of 430 mV for 10 h, corresponding to a turnover frequency of 2.9 s−1 and 104 400 turnover number. Furthermore, FePGF/CFP has one of the highest cathodic energy efficiencies (60.9%) reported for immobilized metal complex catalysts. [ABSTRACT FROM AUTHOR]

Abstract: Ultrasmall gold (Au) nanoparticles with high mass activity have great potential for practical applications in CO2 electroreduction. However, these nanoparticles often suffer from poor product selectivity since their abundant low‐coordinated sites are favorable for H2 evolution. In this work, a catalyst, reduced graphene oxide supported ultrasmall Au nanoparticles (≈2.4 nm) is developed which delivers high Au‐specific mass activities (>100 A g−1) and good Faradaic efficiencies (32–60%) for the CO2‐to‐CO conversion at moderate overpotentials (450–600 mV). The efficiencies can be improved to 59–75% while retaining the ultrahigh mass activities via a simple amine‐modification strategy. In addition, an amine‐structure‐dependent effect is revealed: linear amines promote the CO formation whereas the branched polyamine greatly depresses it; the increasing alkyl chain length boosts the promotion effect of linear amines. The strong Au‐amine interaction and molecular configuration induced amine coverage on the ultrasmall Au NPs may contribute to this effect. [ABSTRACT FROM AUTHOR]

Abstract: Extrusion printing of interdigitated electrodes for flexible microsupercapacitors (fMSCs) offers an attractive route to the fabrication of flexible devices where cost, scalability, and processability of ink formulations are critical. In this work, highly concentrated, viscous, and water‐dispersible inks are developed based on graphene oxide (GO)/polyaniline (PANi) composite for extrusion printing. The optimized GO/PANi‐based all‐solid‐state symmetric fMSCs obtained by extrusion printing interdigitated microelectrodes can deliver outstanding areal capacitance of 153.6 mF cm−2 and volumetric capacitance of 19.2 F cm−3 at 5 mV s−1. It is shown that by fabricating asymmetric fMSCs using the GO/PANi as positive electrode and a graphene‐based negative electrode, the voltage window can be widened from 0.8 to 1.2 V and improvements can be achieved in energy density (from 3.36 to 4.83 mWh cm−3), power density (from 9.82 to 25.3 W cm−3), and cycling stability (from 75% to 100% capacitance retention over 5000 cycles) compared with the symmetric counterpart. The simple ink preparation and facile device fabrication protocols reported here make the scalable fabrication of extrusion printed fMSCs a promising technology. [ABSTRACT FROM AUTHOR]

Abstract: Efficient and selective earth‐abundant catalysts are highly desirable to drive the electrochemical conversion of CO2 into value‐added chemicals. In this work, a low‐cost Sn modified N‐doped carbon nanofiber hybrid catalyst is developed for switchable CO2 electroreduction in aqueous medium via a straightforward electrospinning technique coupled with a pyrolysis process. The electrocatalytic performance can be tuned by the structure of Sn species on the N‐doped carbon nanofibers. Sn nanoparticles drive efficient formate formation with a high current density of 11 mA cm−2 and a faradaic efficiency of 62% at a moderate overpotential of 690 mV. Atomically dispersed Sn species promote conversion of CO2 to CO with a high faradaic efficiency of 91% at a low overpotential of 490 mV. The interaction between Sn species and pyridinic‐N may play an important role in tuning the catalytic activity and selectivity of these two materials. [ABSTRACT FROM AUTHOR]

Abstract: Managing carbon dioxide (CO2) released from large‐scale industrial processes is of great importance, yet there remain significant technical challenges. Herein, the fabrication of 1‐mm‐thick solid‐state electrochemical devices based on poly(ionic liquid) ionogels with embedded electrodes capable of both adsorption and electrochemical reduction of CO2 is reported. The ionogels are prepared via radical polymerization and chemical crosslinking of a vinyl imidazolium trifluoromethanesulfonimide ionic liquid monomer in the presence of additional ionic liquids (ILs) that act as swelling agents and enhance ionic conductivity. The effects of the ILs concentration and the degree of crosslinking on the mechanical properties, conductivity, and CO2 adsorption of the ionogels are investigated. The ionogels are shown to have ionic conductivities as high as 0.6 mS cm−1. The results of quartz crystal microbalance analyses demonstrates that the CO2 adsorption of the ionogels reaches up to ≈22 mg g−1, which is 10‐fold higher than that of their native ionic liquid. Moreover, the ionogels are easily recoverable after CO2 adsorption. The flexibility, conductivity, and CO2 capture capacity of this system can be controlled by the crosslinking ratio and ionic liquid content of the ionogels. This electrochemical device has the potential to be used in large scale plants for capturing CO2 for further electrochemical reactions. [ABSTRACT FROM AUTHOR]

Abstract: Electrodes can provide information on neural function and stimulate neural activity. These neural electrodes can provide remarkable benefit to people suffering physical trauma or neural disease. Traditional metal electrodes have shortcomings related to poor biostability, cytocompatibility, and a rigid structure that maps poorly to tissue. Organic conductors can be formed with various chemical and physical properties to create improved electrode‐neural interfaces. The processability of organic conductors enables their use in advanced fabrication methods. This review details the use of graphene, carbon nanotubes, and conducting polymers for neural interfacing. Construction of novel neural electrode architectures via advanced fabrication processes is also addressed. [ABSTRACT FROM AUTHOR]

The demands for wearable technologies continue to grow and novel approaches for powering these devices are being enabled by the advent of new electromaterials and novel fabrication strategies. Herein, a novel approach is reported to develop superelastic wet-spun hybrid carbon nanotube graphene fibers followed by electrodeposition of polyaniline to achieve a high-performance fiber-based supercapacitor. It is found that the specific capacitance of hybrid carbon nanotube (CNT)/graphene fiber is enhanced up to ≈39% using a graphene to CNT fiber ratio of 1:3. Fabrication of spring-like coiled fiber coated with an elastic polymer shows an extraordinary elasticity capable of 800% strain while affording a specific capacitance of ≈138 F g-1. The elastic rubber coating enables extreme stretchability and enabling cycles with up to 500% strain for thousands of cycles with no significant change in its performance. Multiple supercapacitors can be easily assembled in series or parallel to meet specific energy and power needs. [ABSTRACT FROM AUTHOR]

Abstract: Numerous electric and gas utilities are actively pursuing “power‐to‐gas” technology, which involves using unwanted, excess renewable energy to manufacture hydrogen gas (H2) that is then injected into the existing natural gas pipeline network in 5–10% by volume. This work reports an alkaline fuel cell that has the potential to harness such gas mixtures for downstream generation of electric power. The fuel cell, which employs novel Gortex‐based electrodes layered with Pd/Pt catalysts, generates electricity remarkably efficiently when fuelled with methane (CH4) containing 5% hydrogen. Methane constitutes the major component of natural gas. The fuel cell has been studied over a range of hydrogen to methane ratios using Tafel plots and electrochemical impedance spectroscopy. These show that, in terms of fundamental operation, there is, astonishingly, almost no difference between using pure hydrogen and 5% hydrogen in methane, as the fuel. The Gortex electrodes and alkaline electrolyte are clearly able to utilize the dilute hydrogen as a fuel with remarkable efficiency. The methane acts as an inert carrier gas and is not consumed. [ABSTRACT FROM AUTHOR]

Abstract: The demands for wearable technologies continue to grow and novel approaches for powering these devices are being enabled by the advent of new electromaterials and novel fabrication strategies. Herein, a novel approach is reported to develop superelastic wet‐spun hybrid carbon nanotube graphene fibers followed by electrodeposition of polyaniline to achieve a high‐performance fiber‐based supercapacitor. It is found that the specific capacitance of hybrid carbon nanotube (CNT)/graphene fiber is enhanced up to ≈39% using a graphene to CNT fiber ratio of 1:3. Fabrication of spring‐like coiled fiber coated with an elastic polymer shows an extraordinary elasticity capable of 800% strain while affording a specific capacitance of ≈138 F g−1. The elastic rubber coating enables extreme stretchability and enabling cycles with up to 500% strain for thousands of cycles with no significant change in its performance. Multiple supercapacitors can be easily assembled in series or parallel to meet specific energy and power needs. [ABSTRACT FROM AUTHOR]