A two-dimensional Cu-based nanosheet producing formic acid via glycerol electro-oxidation in alkaline water.

The sluggishness of the complementary oxygen evolution reaction (OER) is reckoned as one of the major drawbacks in developing an energy-efficient green hydrogen-producing electrolyzer. An array of organic molecule oxidation reactions, operational at a relatively low potential, have been explored as a substitute for the OER. Glycerol oxidation reaction (GOR) has emerged as a leading alternative in this context. Additionally, the GOR generates several value-added organic compounds following oxidation that enhance the cost viability of the overall electrolysis reaction. In this study, a low-cost, room temperature operable, and energy-efficient synthetic methodology has been developed to generate unique two-dimensional CuO nanosheets (CuO NS). This CuO NS material was embedded on a carbon paper electrode, which showcased excellent glycerol electro-oxidation performance operational at a moderately low applied potential. Formic acid is the major product of this CuO NS-driven GOR (Faradaic efficiency ~80%), as it is formed primarily via the glyceraldehyde oxidation pathway. This CuO NS material was also active for oxidizing other abundant alcohols like ethylene glycol and diethylene glycol, albeit at a relatively poor efficiency. Therefore, this robust CuO NS material has displayed the potential to be used in large-scale electrolyzers functioning with HER/GOR reactions.

Two-Dimensional Ultrathin CeVO4 Nanozyme: Fabricated through Non-Oxidic Material.

In recent years, the synthesis of materials in lower dimensions, like two-dimensional (2D) or ultrathin crystals, with distinctive characteristics has attracted substantial scientific attention. The mixed transition metal oxides (MTMOs) nanomaterials are the promising group of materials, which have been extensively utilized for various potential applications. Most of the MTMOs were explored as three-dimensional (3D) nanospheres, nanoparticles, one-dimensional (1D) nanorods, and nanotubes. However, these materials are not well explored in 2D morphology because of the difficulties in removing tightly woven thin oxide layers or exfoliations of 2D oxide layers, which hinder the exfoliation of beneficial features of MTMO. Here, through the exfoliation via Li+ ion intercalation and subsequent oxidation of CeVS3 under hydrothermal condition, we have demonstrated a novel synthetic route for the fabrication of 2D ultrathin CeVO4 NS. The as-synthesized CeVO4 NS exhibit adequate stability and activity in a harsh reaction environment, which gives excellent peroxidase-mimicking activity with a K M value of 0.04 mM, noticeably better than natural peroxidase and previously reported CeVO4 nanoparticles. We have also used this enzyme mimic activity for the efficient detection of biomolecules like glutathione with a LOD of 53 nM.

Cobalt-doped copper vanadate: a dual active electrocatalyst propelling efficient H2 evolution and glycerol oxidation in alkaline water.

Strategically doped metal oxide nanomaterials signify a rapidly growing genre of functional materials with a wide range of practical applications. Copper vanadate (CuV) represents one such highly active system, which has been rarely explored following its doping with an abundant first-row transition metal. Here, we have developed a series of CuV samples with varying cobalt(ii) doping concentrations deploying a relatively simple solid state synthetic procedure. Among the samples, the 10% Co(ii)-doped CuV (Co10%-CuV) exhibited excellent reactivity for both the H2 evolution reaction (HER) and glycerol oxidation reaction (GOR) in an alkaline aqueous medium (pH 14.0) during cathodic and anodic scans, respectively. During this dual-active catalysis, surface-immobilized Co10%-CuV operates at exceptionally low overpotentials of 176 mV and 160 mV for the HER and GOR, respectively, while achieving 10 mA cm2 current density. The detailed spectroscopic analysis revealed the formation of formate as the major product during the GOR with a faradaic efficiency of >90%. Therefore, this Co10%-CuV can be included on either side of a two-electrode electrolyzer assembly to trigger a complete biomass-driven H2 production, establishing an ideal carbon-neutral energy harvest process.

Photoinduced Enhanced Decomposition of TBHP: A Convenient and Greener Pathway for Aqueous Domino Synthesis of Quinazolinones and Quinoxalines.

Catalyst-free photoinduced processes in aqueous medium represent significant advancement toward development of green and sustainable pathways in organic synthesis. tert-Butyl hydroperoxide (TBHP) is a widely used oxidant in organic reactions, where the decomposition of TBHP into its radicals by metal catalysts or other reagents is a key factor for efficient catalytic outcome. Herein, we report a simple and environmentally friendly visible light-promoted synthetic pathway for the synthesis of N-heterocyclic moieties, such as quinazolinones and quinoxalines, in the presence of TBHP as an oxidizing agent in aqueous medium that requires no catalysts/photocatalysts. The enhanced rate of decomposition to generate free radicals from TBHP upon visible light irradiation is the driving force for the domino reaction.

Eden-Hybinette Procedure for Revision Surgery in Recurrent Anterior Shoulder Instability in Epilepsy.

AIMS: The purpose of this study was to analyze the clinical outcomes after Eden-Hybinette procedure for revision surgery in recurrent anterior shoulder instability in patients with epilepsy. MATERIALS AND METHODS: We retrospectively evaluated eight such patients between 2015 and 2018. Four patients had failed Latarjet/Bristow procedure and two had failed arthroscopic Bankart procedure, while two had history of both the procedures. After medical control of epilepsy, Eden-Hybinette procedure was performed in all patients. WOSI score and Rowe shoulder score was recorded preoperatively and in subsequent post-operative follow-up. A paired t test was used to analyze and compare preoperative and postoperative outcomes and was considered significant if p value was < 0.05. RESULTS: The average follow-up was 30 months (range 24-48 months). There was no recurrence of shoulder instability. The mean WOSI score before surgery was 77.3 (range 70-83), which improved to 24.2 (range 19-30) at 24-month follow-up. The mean Rowe score before surgery was 11.3 (range 5-15), which improved to 81.8(range 65-90) at 24-month follow-up. The improvement in WOSI and Rowe score was found to be statistically significant [p value < 0.05]. CONCLUSIONS: We conclude that Eden-Hybinette is a useful revision procedure to manage recurrent anterior shoulder dislocation in patients with epilepsy. Optimum medical control of seizure is also an important factor in preventing recurrent shoulder instability.

A Novel Anterior Bladder Tube for Traumatic Bladder Neck Contracture in Females: Initial Results.

OBJECTIVE: To describe a novel tubularized bladder flap technique for repair of post-traumatic obliterate bladder neck and urethral stricture in women. Traumatic genitourinary injury in females is rare, and generally associated with pelvic fracture. Obliterate bladder neck is frequent in such cases. The options for obliterate strictures are limited with Tanagho's repair as one option. Limitations of Tanagho's repair include bladder neck being shifted anterosuperiorly posing voiding issues, posteriorly directed suture-line risking fistula formation with vagina and rotational tug of bladder putting tension at suture line. Here we present our initial results with our novel technique. METHODS: The young females with bladder neck obliteration with or without associated urogenital fistula were operated. A novel U-shaped anterior bladder wall flap was used to fashion a urethral tube and bladder neck. Native bladder neck fibres remained at bladder neck itself after reconstruction without limitation of length of urethral tube and continence outcome. Urogenital fistula was also repaired with omental interposition. RESULTS: Three tubes 3.5, 3, and 3.5 cm tubes were fashioned in the 3 cases, respectively. No perioperative complications were reported. Catheter was removed at 3 weeks. All cases had normal voiding and continence at follow-up of 15, 7, and 3 months, respectively. CONCLUSION: Our novel flap technique has provided good early results and aims to overcome the limitations of Tanagho's repair.

Cationic Organic Nanoaggregates as AIE Luminogens for Wash-Free Imaging of Bacteria and Broad-Spectrum Antimicrobial Application.

The increase in the use of bactericides is a matter of grave concern and a serious threat to human health. The present situation demands rapid and efficient detection and elimination of antibiotic-resistant microbes. Herein, we report the synthesis of a simple C3-symmetric molecular system (TGP) with an intrinsic positive charge through a single-step Schiff base condensation. In a water-dimethyl sulfoxide (DMSO) solvent mixture (80:20 v/v), TGP molecules self-aggregate to form spherical nanoparticles with a positively charged surface that displays efficient fluorescence owing to the aggregation-induced emission (AIE) phenomenon. Both Gram-positive and Gram-negative bacteria could be effectively detected through "turn-off" fluorescence spectroscopy as the electrostatic interaction of the resultant nanoaggregates with the negatively charged bacterial surface induced quenching of fluorescence of the nanoparticles. The fluorescence analysis and steady-state lifetime studies of TGP nanoparticles suggest that a nonradiative decay through photoinduced electron transfer from the nanoparticles to the bacterial surface leads to effective fluorescence quenching. Further, the TGP nanoaggregates demonstrate potent antimicrobial activity against microbes such as multidrug-resistant bacteria and fungi at a concentration as low as 74 µg/mL. A combination of factors including ionic surface characteristics of the nanoparticles for strong electrostatic binding on the bacterial surface followed by possible photoinduced electron transfer from the nanoaggregates to the bacterial membrane and enhanced oxidative stress in the membrane resulting from reactive oxygen species (ROS) generation is found accountable for the high antimicrobial activity of the TGP nanoparticles. The effective disruption of membrane integrity in both Gram-positive and Gram-negative bacteria upon interaction with the nanoaggregates can be observed from field emission scanning electron microscopy (FESEM) studies. The development of simple pathways for the molecular design of multifunctional broad-spectrum antimicrobial systems for rapid and real-time detection, wash-free imaging, and eradication of drug-resistant microbes might be crucial to combat pathogenic agents.

Counter Anion-Directed Growth of Iron Oxide Nanorods in a Polyol Medium with Efficient Peroxidase-Mimicking Activity for Degradation of Dyes in Contaminated Water.

Development of nanozymes, which are nanomaterials with intrinsic enzymatic properties, has emerged as an appealing alternative to the natural enzymes with tremendous application potential from the chemical industry to biomedicine. The self-assembled growth of micrometer-sized oxide materials with controlled nonspherical shapes can be an important tool for enhancing activity as artificial enzymes, as the formation of these superstructures often results in high surface area with favorable impact on catalytic activity. Herein, the growth of rod-shaped Fe3O4 microstructures via a one-pot microwave-based method and using a water-poly(ethylene glycol) mixture as a solvent is reported, without the involvement of external shape-directing agents. The precursor metal salt played a key role in the size, shape, and phase selective evolution of iron oxide micro/nanomaterials. Whereas self-assembled microrod superstructures were obtained using Fe(NO3)3 as the metal salt precursor, use of FeCl3 or Fe-acetate as precursors afforded hollow Fe2O3 microparticles and Fe3O4 nanoparticles, respectively. A graphitic layer was deposited on the Fe3O4 surface, imparting a negative surface charge as a result of a high-temperature treatment of poly(ethylene glycol). The rod-shaped Fe3O4 microcrystals show efficient peroxidase-mimicking activity toward 3,3,5,5'-tetramethylbenzidine and pyrogallol as peroxidase substrates with a Michaelis-Menten rate constant (K m) value of 0.05 and 0.52 mM, respectively. The proficient enzyme mimicking behavior of these magnetic superstructures was further explored for the degradation of organic dyes that includes rhodamine B, methylene blue, and methyl orange with a rate constant (k) of 0.038, 0.011, and 0.007 min-1 respectively, using H2O2. This fast and simple method could help to develop a new pathway for differently shaped oxide nanoparticles in a sustainable and economical manner that can be harnessed as nanozymes for industrial as well as biological applications.

Biocompatible Fe3+ and Ca2+ Dual Cross-Linked G-Quadruplex Hydrogels as Effective Drug Delivery System for pH-Responsive Sustained Zero-Order Release of Doxorubicin.

The ultimate aim in developing controlled drug delivery systems is to derive formulations to achieve drug release at a constant rate over a long duration. The drug release profile that follows zero-order kinetics is crucial for reduction in the drug administration frequency, reduced cytotoxicity, and improved convenience and compliance of patients. Designed drug delivery systems for achieving zero-order release are often complex, expensive, and difficult to manufacture. Herein, we demonstrate that a supramolecular hydrogel formed through the self-assembly of guanosine monophosphate (GMP) into highly ordered G-quadruplex structure and cross-linked through Fe3+ and Ca2+ ions exhibits potential for the pH-responsive controlled zero-order drug release of doxorubicin, a model chemotherapeutic drug. The fibril formation is initiated by the self-assembly of GMP into a quadruplex complex, which is cross-linked through the complexation of the phosphate groups with Fe(III) ions, resulting in a spontaneous hydrogel formation. The Ca2+ ions facilitate the improvement in the mechanical integrity of the fibril network in the Fe-GMP hydrogel via cross-linking of sugar moieties. The hydrogel showed a high loading capacity for drug molecules and a pH-responsive sustained zero-order drug release over several days owing to the lowered degradability of the cross-linked hydrogel in acidic buffer stimulant. In vitro drug-release studies further established a controlled pH-triggered drug release profile. The Ca2+ cross-linking of the Fe-GMP hydrogel also resulted in significant enhancement in the biocompatibility of the drug delivery system. The fabrication of biocompatible, low-cost, and efficient Ca2+ cross-linked metal-organic hydrogels may present promising applications in biological fields.

Probabilistic Human Intent Recognition for Shared Autonomy in Assistive Robotics.

Effective human-robot collaboration in shared autonomy requires reasoning about the intentions of the human partner. To provide meaningful assistance, the autonomy has to first correctly predict, or infer, the intended goal of the human collaborator. In this work, we present a mathematical formulation for intent inference during assistive teleoperation under shared autonomy. Our recursive Bayesian filtering approach models and fuses multiple non-verbal observations to probabilistically reason about the intended goal of the user without explicit communication. In addition to contextual observations, we model and incorporate the human agent's behavior as goal-directed actions with adjustable rationality to inform intent recognition. Furthermore, we introduce a user-customized optimization of this adjustable rationality to achieve user personalization. We validate our approach with a human subjects study that evaluates intent inference performance under a variety of goal scenarios and tasks. Importantly, the studies are performed using multiple control interfaces that are typically available to users in the assistive domain, which differ in the continuity and dimensionality of the issued control signals. The implications of the control interface limitations on intent inference are analyzed. The study results show that our approach in many scenarios outperforms existing solutions for intent inference in assistive teleoperation, and otherwise performs comparably. Our findings demonstrate the benefit of probabilistic modeling and the incorporation of human agent behavior as goal-directed actions where the adjustable rationality model is user customized. Results further show that the underlying intent inference approach directly affects shared autonomy performance, as do control interface limitations.

Recursive Bayesian Human Intent Recognition in Shared-Control Robotics.

Effective human-robot collaboration in shared control requires reasoning about the intentions of the human user. In this work, we present a mathematical formulation for human intent recognition during assistive teleoperation under shared autonomy. Our recursive Bayesian filtering approach models and fuses multiple non-verbal observations to probabilistically reason about the intended goal of the user. In addition to contextual observations, we model and incorporate the human agent's behavior as goal-directed actions with adjustable rationality to inform the underlying intent. We examine human inference on robot motion and furthermore validate our approach with a human subjects study that evaluates autonomy intent inference performance under a variety of goal scenarios and tasks, by novice subjects. Results show that our approach outperforms existing solutions and demonstrates that the probabilistic fusion of multiple observations improves intent inference and performance for shared-control operation.

One-Pot Magnetic Iron Oxide-Carbon Nanodot Composite-Catalyzed Cyclooxidative Aqueous Tandem Synthesis of Quinazolinones in the Presence of tert-Butyl Hydroperoxide.

The development of synthetic protocols for biologically important molecules using biocompatible catalysts in aqueous medium holds the key in green and sustainable chemistry. Herein, a magnetically recoverable iron oxide-carbon dot nanocomposite has been demonstrated as an effective catalyst for cyclooxidative tandem synthesis of quinazolinones in aqueous medium using alcohols as starting materials. Fluorescent carbon dots, the newest entrant in the nanocarbon family, were used as the stabilizing agent for the iron oxide nanoparticles, and a continuous layer of carbon dots decorates the iron oxide nanoparticle surface as observed by transmission electron microscopy. The fluorescence studies demonstrated the effective electron transfer from carbon dots to the iron oxide nanoparticles resulting in complete quenching of emission owing to carbon dots, once it binds with iron oxide nanoparticles. The nanocatalyst showed high activity with significant reusability for the syntheses of quinazolinones in the presence of tert-butyl hydroperoxide (TBHP) in an aqueous medium. Controlled experiments revealed the synergistic effect of carbon dots in enhancing the catalytic activity of iron oxide, as they might influence the decomposition of TBHP into radicals owing to their peroxidase activity. These radicals stabilized over the nanoparticle surface are known to have increased lifetime compared to solution-based radicals. These surface-stabilized radicals then could catalyze the tandem reaction resulting in the formation of the quinazolinone derivatives in high yields.

Human-in-the-Loop Optimization of Shared Autonomy in Assistive Robotics.

In this paper, we propose a mathematical framework which formalizes user-driven customization of shared autonomy in assistive robotics as a nonlinear optimization problem. Our insight is to allow the end-user, rather than relying on standard optimization techniques, to perform the optimization procedure, thereby allowing us to leave the exact nature of the cost function indeterminate. We ground our formalism with an interactive optimization procedure that customizes control sharing using an assistive robotic arm. We also present a pilot study that explores interactive optimization with end-users. This study was performed with 17 subjects (4 with spinal cord injury, 13 without injury). Results show all subjects were able to converge to an assistance paradigm, suggesting the existence of optimal solutions. Notably, the amount of assistance was not always optimized for task performance. Instead, some subjects favored retaining more control during the execution over better task performance. The study supports the case for user-driven customization and provides guidance for its continued development and study.

Grasp Detection for Assistive Robotic Manipulation.

In this paper, we present a novel grasp detection algorithm targeted towards assistive robotic manipulation systems. We consider the problem of detecting robotic grasps using only the raw point cloud depth data of a scene containing unknown objects, and apply a geometric approach that categorizes objects into geometric shape primitives based on an analysis of local surface properties. Grasps are detected without a priori models, and the approach can generalize to any number of novel objects that fall within the shape primitive categories. Our approach generates multiple candidate object grasps, which moreover are semantically meaningful and similar to what a human would generate when teleoperating the robot-and thus should be suitable manipulation goals for assistive robotic systems. An evaluation of our algorithm on 30 household objects includes a pilot user study, confirms the robustness of the detected grasps and was conducted in real-world experiments using an assistive robotic arm.

Assistive Robotic Manipulation through Shared Autonomy and a Body-Machine Interface.

Assistive robotic manipulators have the potential to improve the lives of people with motor impairments. They can enable individuals to perform activities such as pick-and-place tasks, opening doors, pushing buttons, and can even provide assistance in personal hygiene and feeding. However, robotic arms often have more degrees of freedom (DoF) than the dimensionality of their control interface, making them challenging to use-especially for those with impaired motor abilities. Our research focuses on enabling the control of high-DoF manipulators to motor-impaired individuals for performing daily tasks. We make use of an individual's residual motion capabilities, captured through a Body-Machine Interface (BMI), to generate control signals for the robotic arm. These low-dimensional controls are then utilized in a shared-control framework that shares control between the human user and robot autonomy. We evaluated the system by conducting a user study in which 6 participants performed 144 trials of a manipulation task using the BMI interface and the proposed shared-control framework. The 100% success rate on task performance demonstrates the effectiveness of the proposed system for individuals with motor impairments to control assistive robotic manipulators.