There is a major challenge to attach nanostructures on to the electrode surface while retaining their engineered morphology, high surface area, physiochemical features for promising sensing ...applications. In this study, we have grown vertically-aligned ZnO nanorods (NRs) on fluorine doped tin oxide (FTO) electrodes and decorated with CuO to achieve high-performance non-enzymatic glucose sensor. This unique CuO-ZnO NRs hybrid provides large surface area and an easy substrate penetrable structure facilitating enhanced electrochemical features towards glucose oxidation. As a result, fabricated electrodes exhibit high sensitivity (2961.7 μA mM
cm
), linear range up to 8.45 mM, low limit of detection (0.40 μM), and short response time (<2 s), along with excellent reproducibility, repeatability, stability, selectivity, and applicability for glucose detection in human serum samples. Circumventing, the outstanding performance originating from CuO modified ZnO NRs acts as an efficient electrocatalyst for glucose detection and as well, provides new prospects to biomolecules detecting device fabrication.
The outstanding electrical, mechanical and chemical properties of graphene make it attractive for applications in flexible electronics. However, efforts to make transparent conducting films from ...graphene have been hampered by the lack of efficient methods for the synthesis, transfer and doping of graphene at the scale and quality required for applications. Here, we report the roll-to-roll production and wet-chemical doping of predominantly monolayer 30-inch graphene films grown by chemical vapour deposition onto flexible copper substrates. The films have sheet resistances as low as approximately 125 ohms square(-1) with 97.4% optical transmittance, and exhibit the half-integer quantum Hall effect, indicating their high quality. We further use layer-by-layer stacking to fabricate a doped four-layer film and measure its sheet resistance at values as low as approximately 30 ohms square(-1) at approximately 90% transparency, which is superior to commercial transparent electrodes such as indium tin oxides. Graphene electrodes were incorporated into a fully functional touch-screen panel device capable of withstanding high strain.
To realize a high-performance room temperature Na/S battery with an elemental sulfur cathode, it is important that sodium polysulfides stay within the cathode and that they have room enough to react ...freely. In this work, sodium polysulfides are confined to the cathode using a β″ alumina solid electrolyte separator and an optimal amount of tetraethylene glycol dimethyl ether (TEGDME) electrolyte. In addition, an activated carbon material, in the form of a sulfur/carbon (S/C) composite, with high surface area, porosity, and pore volume is employed in the cathode. The resulting Na/S battery shows a high first discharge capacity of 855 mAh g−1 and coulombic efficiency close to 100%, as well as stable cyclability, with a discharge capacity of 521 mAh g−1 at the 104th discharge.
Display omitted
•A room temperature Na/S battery was designed using a TEGDME electrolyte.•The S cathode used a S/C composite with high surface area and porosity.•The resulting Na/S battery showed a high 1st discharge capacity of 855 mAh g−1.•It also showed stable cyclability (521 mAh g−1 on 104th discharge).•Coulombic efficiency was close to 100%.
Memory T cell responses have been demonstrated in COVID-19 convalescents, but ex vivo phenotypes of SARS-CoV-2-specific T cells have been unclear. We detected SARS-CoV-2-specific CD8+ T cells by MHC ...class I multimer staining and examined their phenotypes and functions in acute and convalescent COVID-19. Multimer+ cells exhibited early differentiated effector-memory phenotypes in the early convalescent phase. The frequency of stem-like memory cells was increased among multimer+ cells in the late convalescent phase. Cytokine secretion assays combined with MHC class I multimer staining revealed that the proportion of interferon-γ (IFN-γ)-producing cells was significantly lower among SARS-CoV-2-specific CD8+ T cells than those specific to influenza A virus. Importantly, the proportion of IFN-γ-producing cells was higher in PD-1+ cells than PD-1− cells among multimer+ cells, indicating that PD-1-expressing, SARS-CoV-2-specific CD8+ T cells are not exhausted, but functional. Our current findings provide information for understanding of SARS-CoV-2-specific CD8+ T cells elicited by infection or vaccination.
Display omitted
•SARS-CoV-2-specific CD8+ T cells are effector memory cells in convalescents•CCR7+CD45RA+ cells are increased among SARS-CoV-2-specific cells in the late phase•SARS-CoV-2-specific CD8+ T cells have fewer IFN-γ+ cells than flu-specific cells•PD-1-expressing SARS-CoV-2-specific CD8+ T cells are not exhausted but functional
T cell responses have been demonstrated in COVID-19 patients, but ex vivo phenotypes and functions of SARS-CoV-2-specific T cells remain unclear. Rha et al. examined SARS-CoV-2-specific CD8+ T cells in acute and convalescent COVID-19 patients using MHC class I multimers, finding that PD-1-expressing SARS-CoV-2-specific CD8+ T cells are not exhausted but functional.
Abstract
Despite highly promising characteristics of three-dimensionally (3D) nanostructured catalysts for the oxygen evolution reaction (OER) in polymer electrolyte membrane water electrolyzers ...(PEMWEs), universal design rules for maximizing their performance have not been explored. Here we show that woodpile (WP)-structured Ir, consisting of 3D-printed, highly-ordered Ir nanowire building blocks, improve OER mass activity markedly. The WP structure secures the electrochemically active surface area (ECSA) through enhanced utilization efficiency of the extended surface area of 3D WP catalysts. Moreover, systematic control of the 3D geometry combined with theoretical calculations and various electrochemical analyses reveals that facile transport of evolved O
2
gas bubbles is an important contributor to the improved ECSA-specific activity. The 3D nanostructuring-based improvement of ECSA and ECSA-specific activity enables our well-controlled geometry to afford a 30-fold higher mass activity of the OER catalyst when used in a single-cell PEMWE than conventional nanoparticle-based catalysts.
Rare earth elements (REEs) are vital components of high-tech electrical and electronic based materials. In the global scenario, the deposits of natural rare earth elements (REEs) are limited except ...for countries such as China. This has led to a dependence on major secondary rare earth-bearing sources such as battery waste, scrap alloy, spent magnets, spent catalysts, waste light-emitting diodes (LEDs), and fly ash for a substantial recovery of REEs for their use. Recycling REEs from these secondary waste sources by hydrometallurgical routes appears to be a sustainable approach with low waste generation, few emissions, low energy consumption, economically feasible, and environmentally friendly. In most of the reported studies, secondary waste is subjected to chemical and or bioleaching followed by solvent extraction processes for clean separation of REEs. Subsequently, rare earth compound(s) are recovered through precipitation. Solvent extraction (liquid-liquid extraction) is one of the most vital stages in the overall process as REEs (light and heavy rare earths) exhibit a low separation tendency while being extracted with various solvent reagents from corresponding aqueous media. This review provides an in-depth discussion on the recycling strategies implemented to obtain REEs from numerous secondary wastes; extraction behavior of REEs; challenges, advantages, and disadvantages of the proposed methodologies; as well as proposed flowsheets for clean separation and recovery of REEs. In addition, the role of REEs in renewable and green energy technologies and the future aspects of the reprocessing technology of secondary REE sources are summarized and reported.
The role of hydro-metallurgical techniques for the processing of rare earth elements from secondary resources. Display omitted
•Review was made on rare earth elements recovery from secondary resources.•Reported flow sheets for rare earth elements was discussed.•Rare earth elements role in clean and green energy technologies were discussed.•Establishment of policy on resource circulation society was discussed.•The future energy sources for clean and green energy technologies were described.
Incidental thyroid nodules are commonly detected on ultrasonography (US). This has contributed to the rapidly rising incidence of low-risk papillary thyroid carcinoma over the last 20 years. The ...appropriate diagnosis and management of these patients is based on the risk factors related to the patients as well as the thyroid nodules. The Korean Society of Thyroid Radiology (KSThR) published consensus recommendations for US-based management of thyroid nodules in 2011 and revised them in 2016. These guidelines have been used as the standard guidelines in Korea. However, recent advances in the diagnosis and management of thyroid nodules have necessitated the revision of the original recommendations. The task force of the KSThR has revised the Korean Thyroid Imaging Reporting and Data System and recommendations for US lexicon, biopsy criteria, US criteria of extrathyroidal extension, optimal thyroid computed tomography protocol, and US follow-up of thyroid nodules before and after biopsy. The biopsy criteria were revised to reduce unnecessary biopsies for benign nodules while maintaining an appropriate sensitivity for the detection of malignant tumors in small (1-2 cm) thyroid nodules. The goal of these recommendations is to provide the optimal scientific evidence and expert opinion consensus regarding US-based diagnosis and management of thyroid nodules.
This study addresses the social geographies of justice in the urban landscapes of “Occupied Palestine” and critically examines the interwoven dynamics of power, spatial inequality and the pursuit of ...justice. By examining the complex interplay between urban inequality, resistance, and colonial legacy, it highlights the particular challenges faced by Palestinian communities, including restricted access to services and the systematic dispossession of land. Drawing on the insights of geographers on spatial justice, and incorporating ethnographic perspectives from renowned studies on Palestine, the study offers a nuanced examination of the socio-spatial dimensions of injustice in Palestinian cities. The study seeks to emphasize the crucial role of domestic spaces as sites of resistance and identity formation and to challenge prevailing narratives of occupation. Through this analysis, the study aims to contribute to a deeper understanding of the social geographies of justice and advocate for the inclusion of marginalized voices in discussions of urban inequality and spatial injustice. Ultimately, the intention is to identify pathways for transformative change to promote a more equitable, inclusive, and resilient urban environment in Palestine and beyond.
•Reveals the dynamics of justice in the urban landscape of Palestine•Analyses spatial justice through the eyes of Ibn Khaldun – “Circle of Justice”•Discusses the role of urban planning for justice and peace•Matches theory with lived reality in conflict zones•Proposes an inclusive urban policy for resilient cities
Conductive films that are both stretchable and flexible could have applications in electronic devices, sensors, actuators and speakers. A substantial amount of research has been carried out on ...conductive polymer composites, metal electrode-integrated rubber substrates and materials based on carbon nanotubes and graphene. Here we present highly conductive, printable and stretchable hybrid composites composed of micrometre-sized silver flakes and multiwalled carbon nanotubes decorated with self-assembled silver nanoparticles. The nanotubes were used as one-dimensional, flexible and conductive scaffolds to construct effective electrical networks among the silver flakes. The nanocomposites, which included polyvinylidenefluoride copolymer, were created with a hot-rolling technique, and the maximum conductivities of the hybrid silver-nanotube composites were 5,710 S cm⁻¹ at 0% strain and 20 S cm⁻¹ at 140% strain, at which point the film ruptured. Three-dimensional percolation theory reveals that Poisson's ratio for the composite is a key parameter in determining how the conductivity changes upon stretching.
We demonstrate high-performance, flexible, transparent heaters based on large-scale graphene films synthesized by chemical vapor deposition on Cu foils. After multiple transfers and chemical doping ...processes, the graphene films show sheet resistance as low as ∼43 Ohm/sq with ∼89% optical transmittance, which are ideal as low-voltage transparent heaters. Time-dependent temperature profiles and heat distribution analyses show that the performance of graphene-based heaters is superior to that of conventional transparent heaters based on indium tin oxide. In addition, we confirmed that mechanical strain as high as ∼4% did not substantially affect heater performance. Therefore, graphene-based, flexible, transparent heaters are expected to find uses in a broad range of applications, including automobile defogging/deicing systems and heatable smart windows.
PDF
