Chemical upcycling of polyethylene (PE) to long-chain alkylaromatics through tandem hydrocracking/aromatization has potential to provide value-added chemicals. However, the liquid product is a complex mixture of alkanes, alkylbenzenes, and polyaromatics, limiting its direct usability. The most valuable component of the product mixture is the alkylbenzenes because of their potential as precursors to anionic surfactants.
View Article and Find Full Text PDFThe large production volumes of commodity polyolefins (specifically, polyethylene, polypropylene, polystyrene, and poly(vinyl chloride)), in conjunction with their low unit values and multitude of short-term uses, have resulted in a significant and pressing waste management challenge. Only a small fraction of these polyolefins is currently mechanically recycled, with the rest being incinerated, accumulating in landfills, or leaking into the natural environment. Since polyolefins are energy-rich materials, there is considerable interest in recouping some of their chemical value while simultaneously motivating more responsible end-of-life management.
View Article and Find Full Text PDFSupported platinum nanoparticle catalysts are known to convert polyolefins to high-quality liquid hydrocarbons using hydrogen under relatively mild conditions. To date, few studies using platinum grafted onto various metal oxide (MO) supports have been undertaken to understand the role of the acidity of the oxide support in the carbon-carbon bond cleavage of polyethylene under consistent catalytic conditions. Specifically, two Pt/MO catalysts (MO = SrTiO and SiO-AlO; Al = 3.
View Article and Find Full Text PDFDepolymerization and upcycling are promising approaches to managing plastic waste. However, quantitative measurements of reaction rates and analyses of complex product mixtures arising from depolymerization of polyolefins constitute significant challenges in this emerging field. Here, we detail techniques for recovery and analysis of products arising from batch depolymerization of polyethylene.
View Article and Find Full Text PDFThe type VI secretion system (T6SS) is important for interbacterial competition and virulence in Vibrio species. It is generally agreed that T6SS provides a fitness advantage to Vibrios. Some Vibrio species possess one, while others possess two T6SSs.
View Article and Find Full Text PDFPesticides have been emerged as major organic pollutants in environment, owing to widely spread and intrinsic high toxicity in agricultural productivity. Herein, we designed and synthesized a practicability and portable metal-organic framework (MOF) based composite beads MOF-alginate-Ca-polyacrylic acid (kgd-M1@ACPs) consist of biocompatible host material (sodium alginate) and fluorescent center with blue emission (where kgd-M1 stands for {[Cd(tbia)·HO]·2HO}), which was further developed for high-efficiency and naked-eye 2,6-dichloro-4-nitroaniline (DCN) monitoring in fruits and vegetables. Significantly, the kgd-M1@ACPs shows obvious fluorescent quench towards toxic pesticide DCN with a low limit of detection (LOD) of 0.
View Article and Find Full Text PDFMetal-organic frameworks (MOFs)-based sensors for monitoring toxic substances in wastewater have attracted great attention due to the efficient and reliable performance. Here, we has synthesized two novel zinc-based MOFs [Zn(ttb)(HO)] () and {[Zn(ttb)]·0.5CHCN} () through changing the polarity of reaction solvents and finally obtained target 2D MOF material [Zn(ttb)(bdc)]() by successfully introducing an ancillary ligand Hbdc (Httb = 1-(triazo-1-ly)-4-(tetrazol-5-ylmethyl)benzene, Hbdc = 1,4-benzenedicarboxylic acid).
View Article and Find Full Text PDFTo study the effect of photobiomodulation (PBM) on axon regeneration and secretion change of dorsal root ganglion (DRG) under oxidative stress after spinal cord injury (SCI), and further explore the effect of changes in DRG secretion caused by PBM on the polarization of macrophages. The PBM-DRG model was constructed to perform PBM on neurons under oxidative stress simulated in vitro. And the irradiation conditions were as follows: wavelength, 810 nm; power density, 2 mW/cm; irradiation area, 4.
View Article and Find Full Text PDFThe current scale of plastics production and the accompanying waste disposal problems represent a largely untapped opportunity for chemical upcycling. Tandem catalytic conversion by platinum supported on γ-alumina converts various polyethylene grades in high yields (up to 80 weight percent) to low-molecular-weight liquid/wax products, in the absence of added solvent or molecular hydrogen, with little production of light gases. The major components are valuable long-chain alkylaromatics and alkylnaphthenes (average ~C, dispersity Ð = 1.
View Article and Find Full Text PDFIn spinal cord injury (SCI), inflammation is a major mediator of damage and loss of function and is regulated primarily by the bone marrow-derived macrophages (BMDMs). Photobiomodulation (PBM) or low-level light stimulation is known to have anti-inflammatory effects and has previously been used in the treatment of SCI, although its precise cellular mechanisms remain unclear. In the present study, the effect of PBM at 810 nm on classically activated BMDMs was evaluated to investigate the mechanisms underlying its anti-inflammatory effects.
View Article and Find Full Text PDFPrevious studies on spinal cord injury (SCI) have confirmed that percutaneous photobiomodulation (PBM) therapy can ameliorate immunoinflammatory responses at sites of injury, accelerate nerve regeneration, suppress glial scar formation and promote the subsequent recovery of locomotor function. The current study was performed to evaluate a large-animal model employing implanted optical fibers to accurately irradiate targeted spinal segments. The method's feasibility and irradiation parameters that do not cause phototoxic reaction were determined, and the methodology of irradiating the spinal cord with near-infrared light was investigated in detail.
View Article and Find Full Text PDFMacrophages play key roles in the secondary injury stage of spinal cord injury (SCI). M1 macrophages occupy the lesion area and secrete high levels of inflammatory factors that hinder lesion repair, and M2 macrophages can secrete neurotrophic factors and promote axonal regeneration. The regulation of macrophage secretion after SCI is critical for injury repair.
View Article and Find Full Text PDFSpinal cord injury (SCI) stimulates reactive astrogliosis and the infiltration of macrophages, which interact with each other at the injured area. We previously found Photobiomodulation (PBM) significantly decreases the number of M1 macrophages at the injured area of SCI. But the exact nature of the astrocyte response following PBM and relationship with the macrophage have not been explored in detail.
View Article and Find Full Text PDFObjective To investigate the effect of low-level laser on the polarization and secretory phenotype of primary cultured M1 bone marrow-derived macrophages (BMDMs) in neuronal axons of dorsal root ganglion (DRG). Methods BMDMs were isolated and cultured, and lipopolysaccharide (LPS) combined with IFN-γ were used to induce M1 phenotype polarization of BMDMs, and then F4/80 and CD16/32 expression was detected by flow cytometry. The mature M1 type BMDMs were randomly divided into low-level laser group and control group.
View Article and Find Full Text PDFThere is a demand to develop molecular catalysts promoting the hydrogen evolution reaction (HER) with a high catalytic rate and a high tolerance to various inhibitors, such as CO and O . Herein we report a cobalt catalyst with a penta-dentate macrocyclic ligand (1-Co), which exhibits a fast catalytic rate (TOF=2210 s ) in aqueous pH 7.0 phosphate buffer solution, in which proton transfer from a dihydrogen phosphate anion (H PO ) plays a key role in catalytic enhancement.
View Article and Find Full Text PDFBackground: Riemerella anatipestifer (R. anatipestifer) is one of the most important poultry pathogens worldwide, with associated infections causing significant economic losses. Rifampin Resistance is an important mechanism of drug resistance.
View Article and Find Full Text PDFThe reduction of carbon dioxide (CO ) has been considered as an approach to mitigate global warming and to provide renewable carbon-based fuels. Rational design of efficient, selective, and inexpensive catalysts with low overpotentials is urgently desired. In this study, four cobalt(II) tripodal complexes are tested as catalysts for CO reduction to CO in a MeCN/H O (4:1 v/v) solution.
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