Electrically induced dynamic spreading of a droplet on a soft surface is characterized by intricate interactions between the moving contact line and the substrate deformation, which are explained by a complex interaction between elastic recovery and viscous dissipation that take place simultaneously. Here, we highlight the significance of an additional modulation in the interfacial energy brought about by the distribution of surfactant molecules surrounding the droplet, which causes an increase in the droplet's spreading rate, rather than the expected decrease in it due to energy dissipation at the viscoelastic interface. We attribute this to repartitioning of the surface energy that results in the dynamic reduction in the solid-liquid interfacial tension, overcoming the substrate viscosity-induced attenuation in the spreading rate. Using a scaling theory on the ensuing change in the contact angle as the droplet spreads dynamically, we further offer quantitative insights into the observed spreading dynamics. These findings allow for the rationalization of the sensitive reliance of droplet spreading on the initial contact angle, a phenomenon that has not yet been understood, in addition to providing a scientific basis for dynamic regulation of droplet spreading on soft biomimetic interfaces.
Due to their high energy density (2600 Wh/kg), low cost, and low environmental impact, lithium-sulfur batteries are considered a promising alternative to lithium-ion batteries. However, their commercial viability remains a formidable scientific challenge mainly because of the sluggish reaction kinetics at the cathode and the so-called "shuttling effect" of soluble polysulfides, which results in capacity decay and a shortened lifespan. Herein, molecular imprinting with Li$_2$S$_8$ as a target molecule in combination with a two-dimensional material, MXene, is proposed to overcome these issues. Molecularly imprinted polymer-coated nitrogen-doped Ti-based MXene was successfully synthesized and demonstrated to exhibit an appealing electrochemical performance, namely a high specific capacity of 1095 mAh/g at 0.1 C and an extended cycling stability (300 mAh/g at 1.0 C after 300 cycles). X-ray photoelectron spectroscopy was applied to elucidate the underlying mechanisms and proved that Li$_2$S$_8$-imprinted polymer polyacrylamide serves as a polysulfide trap through strong chemical affinity towards the long-chain lithium polysulfides, while N-doped Ti-based MXene promotes the redox kinetics by accelerating the conversion of lithium polysulfides. This distinct interfacial strategy is expected to result in more effective and stable Li-S batteries.
Whether plastic waste ends up in a landfill or washed into the ocean, the ecological consequences of plastic pollution remain a constant challenge. In this work, we showcased how plastic waste derived reduced graphene oxide (WrGOs) and its composite with Fe3O4 (WrGOs-Fe3O4) can be used to remove drugs from water treatment plants and for energy storage applications specifically supercapacitors. WrGOs and WrGOs-Fe3O4 showed the removal efficacy of diclofenac and caffeine drugs from water samples with Qmax 11.06 mg/g and 15.1 mg/g for diclofenac, and 8.77 mg/g and 15.24 mg/g for caffeine. For energy storage purposes, WrGOs-Fe3O4 was first examined in a three-electrode setup using 1 M H2SO4 as an electrolyte along with the WrGOs. The composite WrGOs-Fe3O4 demonstrated a good specific capacitance of 488F/g at 1 A/g current density. For practical application, a Supercapacitor (SC) device was fabricated using WrGOs-Fe3O4 as electrode material in a two-electrode setup which exhibited excellent energy density (52.57 Wh/Kg at 0.5 A/g), high cyclic stability (90.03 %) and wider potential window of 1.4 V in 1 M H2SO4 aqueous electrolyte due to stronger ionic diffusion. Thus, this study begs the question: Can graphene-based composite products derived from waste plastic be exploited for drug removal and super capacitor applications?(c) 2023 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
In decentralized systems, adsorption-based strategies offer inherent advantages for the treatment of drinking water contaminated with oxoanion. However, these strategies only involve phase transfer and not the transformation to an innocuous state. The requirement for an after-treatment procedure to manage the hazardous adsorbent further complicates the process. Here we formulate green bifunctional ZnO composites for the simultaneous adsorption and photoreduction of Cr(VI) to Cr(III). Three non-metal-ZnO composites based on raw charcoal- ZnO, modified charcoal- ZnO charcoal, and chicken feather- ZnO were prepared from the combination of ZnO with non-metal precursors. The composites were characterized and both the adsorption and photocatalyst features were studied, separately, in synthetic feedwater and groundwater contaminated with Cr(VI). The adsorption efficiency of the composites for Cr(VI) at different initial concentrations, under solar illumination without hole scavenger, and in the dark without hole scavenger, were appreciable (between 48 and 71
Mantle cell lymphoma is a rare type of B cell non-Hodgkin's lymphoma (NHL) comprising only 3%–6% of all NHL. It is aggressive and prone to relapse. Around 15%–30% of the patients present with gastrointestinal tract involvement. Solitary rectal mantle cell lymphoma is rare and there are very few reports of the same. Till date, there is no report of a solitary rectal relapse of mantle cell lymphoma occurring after second remission. We report a relapse of solitary rectal mantle cell lymphoma presenting with rectal bleeding after second remission in primary gastric mantle cell lymphoma.
Benzene, toluene, ethylbenzene, and xylene (BTEX) are commonly encountered as industrial contaminants.
Upcycling waste into value-added products for utilization in wastewater abatements has been explored in a number of treatment technologies. One such waste, single-use plastic, which poses significant adverse environmental and economic impact, has been chosen and converted into graphitic carbon to reduce the waste burden sustainably and economically. The sorptive and catalytic performance of synthesized plastic waste-derived carbon (PWC) was evaluated using brilliant green (BG) and eosin yellow (EY) as target pollutants. The adsorption capacity of PWC was very low for BG (7.41 mg/g) and EY (4.93 mg/g). The coupling of PWC with peroxymonosulfate (PMS) promoted dye degradation. Complete degradation of the dye, with ~61% reduction in TOC and ~95% reduction in toxicity, was achieved by oxidative treatment (initial concentration: 10 mg/L). The functionalities of PWC facilitated better electron transfer to PMS for its effective activation, which led to the production of SO4•- and OH•. The quenching study confirmed that the degradation of dyes was primarily due to SO4•-. Additionally, the pathways of dye degradation were proposed based on the intermediates identified. Thus, this study established the high potential of PWC as a metal-free catalyst in PMS activation for the abatement of organic pollutants.
This paper describes a simple model for comparing the degree of electronic coupling between molecules and electrodes across different large-area molecular junctions. The resulting coupling parameter can be obtained directly from current-voltage data or extracted from published data without fitting. We demonstrate the generalizability of this model by comparing over 40 different junctions comprising different molecules and measured by different laboratories. The results agree with existing models, reflect differences in mechanisms of charge transport and rectification, and are predictive in cases where experimental limitations preclude more sophisticated modeling. We also synthesized a series of conjugated molecular wires, in which embedded dipoles are varied systematically and at both molecule-electrode interfaces. The resulting current-voltage characteristics vary in nonintuitive ways that are not captured by existing models, but which produce trends using our simple model, providing insights that are otherwise difficult or impossible to explain. The utility of our model is its demonstrative generalizability, which is why simple observables like tunneling decay coefficients remain so widely used in molecular electronics despite the existence of much more sophisticated models. Our model is complementary, giving insights into molecule-electrode coupling across series of molecules that can guide synthetic chemists in the design of new molecular motifs, particularly in the context of devices comprising large-area molecular junctions.
We developed a nitrogen and boron-doped reduced graphene oxide (N, B-HRGO) based chemiresistive sensor to measure dissolved oxygen (DO) in a complex biological medium. The N, B-HRGO modified interdigitated micro electrode arrays (IDE) constructed as a chemiresistor by the drop-cast method. A silicon based fluorinated oxygen permeable membrane protects the surface from the interference and provides a specificity to the sensor. The sensor responded to the DO concentration changes due to modulated surface charge carrier concentration by the adsorbed dissolved oxygen molecule (Oad). For DO concentration range 0–5 mg.L−1 there was nearly 80% change in response for the sensor with membrane. The resistance of the N, B-HRGO film was measured at different DO concentrations in KNO3 solution and during the growth of Amycalotopsis methanolica bacterial fermentation. The study showed that the sensor is sensitive to the oxygen present in the solution and can detect DO consumption in a complex fermentation medium. The effect of water and the electrolyte salt ions present in the electrolyte was studied in detail. It was observed that the adsorption of water molecule increases the sensor resistance, whereas the salt ions have negligible effect on the sensor response. Because of the simple electrode structure, this chemiresistive sensor can measure DO in the micro bioreactors with a volume of few microliters. The N, B-HRGO chemiresistive sensor can also be used for DO measurement in other bioprocess applications.
Introduction: There has been a drastic reduction in the number of neurosurgeries performed during the COVID-19 pandemic due to a multitude of challenges prompting restructuring of neurosurgical services. The present study describes the challenges and outcomes of non-elective neurosurgical procedures done on COVID-19 positive patients along with the modifications in neurosurgical practice during the pandemic. Methods: A retrospective study was done in the Department of Neurosurgery over a period of one year and three months. Demographic and clinical details including outcomes of the COVID-19 positive patients, who had undergone non-elective neurosurgical interventions, were collected. Results: Ten patients (3.8%) were COVID-19 positive out of 262 neurosurgical interventions done. The age of the patients ranged from 5 days to 78 years with five males and five females. Out of the 10 patients, five were neurotrauma cases including one patient of head injury with craniovertebral junction injury. The patient with craniovertebral junction injury underwent foramen magnum decompression with C1 lateral mass-C2 pedicle screw on the right and C0-C2 pedicle screw and rod fixation on the left. The rest of the neurotrauma cases underwent craniotomy or burr-hole craniostomy followed by evacuation. Only one patient (10%) had postoperative 30-day mortality. The rest nine patients (90%) survived the post-operative 30-day mortality. The various modifications incorporated in the neurosurgical practice included categorizing the emergency room into various zones, a separate operating theatre for COVID-19 patients, limiting the number of operating members as well as minor modifications in the operating procedures. Conclusions: The postoperative surgical outcome is favorable in COVID-19 positive patients with modifications of the existing neurosurgical practices.
The contamination of aqueous environments by aromatic pollutants has become a global issue. Chloridazon, a herbicide considered as harmless to the ecosystem, has been widely used in recent decades ...