Polycyclic aromatic hydrocarbons (PAHs) are hazardous organic contaminants commonly found in soils. This study investigated an integrated remediation approach combining white rot fungal augmentation ...and nano-zero-valent iron (nZVI) activated persulfate oxidation to enhance the degradation of PAHs in soil. The white rot fungus Peniophora incarnata demonstrated efficient degradation of lower molecular weight PAHs including phenanthrene (91% removal) and anthracene (71% removal) in liquid culture, but had limited degradation of high molecular weight benzoapyrene (35% removal). Inoculation of P. incarnata in non-sterilized soil led to 54% phenanthrene and 46% anthracene removal after 42 days. Co-inoculation with Pseudomonas aeruginosa slightly improved the degradation by 15% and 13%, respectively. However, benzoapyrene removal was negligible through bioremediation alone. Direct nZVI/persulfate oxidation removed 55–75% of lower molecular weight PAHs and 68% of benzoapyrene in soil. Integrated treatment combining nZVI/persulfate oxidation followed by P. incarnata inoculation resulted in 92–96% degradation of phenanthrene, anthracene and benzoapyrene after 42 days, which was significantly higher than either approach alone. The enhanced PAH removal was attributed to the coupled effects of chemical oxidation and microbial degradation. P. aeruginosa is capable of directly metabolizing and mineralizing lower molecular weight PAHs such as phenanthrene and anthracene. The presence of this additional PAH-degrading bacterium likely contributed to the increased degradation observed. Overall, the sequential nZVI/persulfate and fungal treatment provides an effective and sustainable option for remediating soils co-contaminated with PAHs and other persistent organics. Further research should optimize treatment parameters and evaluate long-term impacts on soil quality.
This study presents a numerical analysis based on the combination of discrete element method and digital image processing. The actual heterogeneity with respect to The actual heterogeneity with ...respect to mineral composition of the rock was reproduced by digital image processing (DIP) method and used as input to set up a corresponding numerical discrete element model based on Voronoi tessellation method.
Polynary single‐atom structures can combine the advantages of homogeneous and heterogeneous catalysts while providing synergistic functions based on different molecules and their interfaces. However, ...the fabrication and identification of such an active‐site prototype remain elusive. Here we report isolated diatomic Ni‐Fe sites anchored on nitrogenated carbon as an efficient electrocatalyst for CO2 reduction. The catalyst exhibits high selectivity with CO Faradaic efficiency above 90 % over a wide potential range from −0.5 to −0.9 V (98 % at −0.7 V), and robust durability, retaining 99 % of its initial selectivity after 30 hours of electrolysis. Density functional theory studies reveal that the neighboring Ni‐Fe centers not only function in synergy to decrease the reaction barrier for the formation of COOH* and desorption of CO, but also undergo distinct structural evolution into a CO‐adsorbed moiety upon CO2 uptake.
The collaborative coordination of CO at diatomic Ni‐Fe sites anchored on nitrogenated carbon is the key to a new nickel–iron catalyst developed for the electroreduction of CO2. The catalyst achieves a high Faradaic efficiency of 98 % at −0.7 V, outstanding turnover frequency, and robust electrode durability.
Abstract
Efficient and selective CO
2
electroreduction into chemical fuels promises to alleviate environmental pollution and energy crisis, but it relies on catalysts with controllable product ...selectivity and reaction path. Here, by means of first-principles calculations, we identify six ferroelectric catalysts comprising transition-metal atoms anchored on In
2
Se
3
monolayer, whose catalytic performance can be controlled by ferroelectric switching based on adjusted
d
-band center and occupation of supported metal atoms. The polarization dependent activation allows effective control of the limiting potential of CO
2
reduction on TM@In
2
Se
3
(TM = Ni, Pd, Rh, Nb, and Re) as well as the reaction paths and final products on Nb@In
2
Se
3
and Re@In
2
Se
3
. Interestingly, the ferroelectric switching can even reactivate the stuck catalytic CO
2
reduction on Zr@In
2
Se
3
. The fairly low limiting potential and the unique ferroelectric controllable CO
2
catalytic performance on atomically dispersed transition-metals on In
2
Se
3
clearly distinguish them from traditional single atom catalysts, and open an avenue toward improving catalytic activity and selectivity for efficient and controllable electrochemical CO
2
reduction reaction.
Pulsed-field gel electrophoresis (PFGE) is considered the “gold standard” for bacteria typing. The method involves enzyme restriction of bacteria DNA, separation of the restricted DNA bands using a ...pulsed-field electrophoresis chamber, followed by clonal assignment of bacteria based on PFGE banding patterns. Various PFGE protocols have been developed for typing different bacteria, leading it to be one of the most widely used methods for phylogenetic studies, food safety surveillance, infection control and outbreak investigations. On the other hand, as PFGE is lengthy and labourious, several PCR-based typing methods can be used as alternatives for research purposes. Recently, matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) and whole genome sequencing (WGS) have also been proposed for bacteria typing. In fact, as WGS provides more information, such as antimicrobial resistance and virulence of the tested bacteria in comparison to PFGE, more and more laboratories are currently transitioning from PFGE to WGS for bacteria typing. Nevertheless, PFGE will remain an affordable and relevant technique for small laboratories and hospitals in years to come.
•PFGE is the “gold standard” for bacteria typing; standardized protocols are available.•PFGE is useful for phylogenetic studies, infection control and food safety monitoring.•PCR-based typing such as rep-PCR, ERIC-PCR and MLVA can be alternatives for PFGE.•Some laboratories are transitioning towards whole genome sequencing-based typing.•PFGE remains important for small hospitals and laboratories with limited resources.
The emergence of antimicrobial-resistant bacteria is an increasingly serious threat to global health, necessitating the development of innovative antimicrobials. Here we report the development of a ...series of CRISPR-Cas13a-based antibacterial nucleocapsids, termed CapsidCas13a(s), capable of sequence-specific killing of carbapenem-resistant Escherichia coli and methicillin-resistant Staphylococcus aureus by recognizing corresponding antimicrobial resistance genes. CapsidCas13a constructs are generated by packaging programmed CRISPR-Cas13a into a bacteriophage capsid to target antimicrobial resistance genes. Contrary to Cas9-based antimicrobials that lack bacterial killing capacity when the target genes are located on a plasmid, the CapsidCas13a(s) exhibit strong bacterial killing activities upon recognizing target genes regardless of their location. Moreover, we also demonstrate that the CapsidCas13a(s) can be applied to detect bacterial genes through gene-specific depletion of bacteria without employing nucleic acid manipulation and optical visualization devices. Our data underscore the potential of CapsidCas13a(s) as both therapeutic agents against antimicrobial-resistant bacteria and nonchemical agents for detection of bacterial genes.
Nickel-based catalysts are most commonly used in industrial alkaline water electrolysis. However, it remains a great challenge to address the sluggish reaction kinetics and severe deactivation ...problems of hydrogen evolution reaction (HER). Here, we show a Cu-doped Ni catalyst implanted with Ni-O-VOx sites (Ni(Cu)VOx) for alkaline HER. The optimal Ni(Cu)VOx electrode exhibits a near-zero onset overpotential and low overpotential of 21 mV to deliver -10 mA cm
, which is comparable to benchmark Pt/C catalyst. Evidence for the formation of Ni-O-VOx sites in Ni(Cu)VOx is established by systematic X-ray absorption spectroscopy studies. The VOx can cause a substantial dampening of Ni lattice and create an enlarged electrochemically active surface area. First-principles calculations support that the Ni-O-VOx sites are superactive and can promote the charge redistribution from Ni to VOx, which greatly weakens the H-adsorption and H
release free energy over Ni. This endows the Ni(Cu)VOx electrode high HER activity and long-term durability.
In recent years, coal power has obvious advantages in terms of safety, economy and stability. As people gradually realize the importance of the environment, low carbon has become one of the core ...indicators of power system evaluation, so it is particularly important to guide the coal enterprises to achieve a win-win situation of economic and environmental benefits. Combined with the carbon emission policies, this paper takes the coal supply chain network as the research object and aims to develop a comprehensive decision model for sustainable design of coal supply chain. First, this paper extracts the influencing factors of low-carbonization in coal supply chain and constructs an interpretative structural model (ISM). The results show that low-carbon green technology, low-carbon production cost, utilization level of green energy and energy efficiency are the most basic manifestations of low-carbonization of coal supply chain and interact with each other, therefore this paper builds an optimization model with the objective of minimizing the low-carbon production costs in the coal supply chain. Concurrently, this paper introduces four policies (emission cap, carbon tax, carbon trade and carbon offset) as constraint condition. Then, in the aspect of model solving, this paper combines the differential evolution (DE) strategy to mutate, cross and select the leaders generated in each iteration of the salp swarm algorithm (SSA), further increases the diversity of the salp swarm, avoids the algorithm falling into a local optimum, and proposes the salp swarm algorithm based on differential evolution (DE-SSA). Finally, this paper compares the effects of four different carbon emission policies on the optimization of coal supply chain network through empirical analysis, and finds that coal enterprises have the best emission reduction effect under the carbon trade policy. The development and implementation of this paper not only enriches the related research of efficient supply chain, but also provides scientific and quantifiable decision-making technology for coal enterprises.
•Considering the cleanliness of coal supply chain network.•A reasonable optimization objective is selected according to the results of the interpretative structural model.•Four new models are used to optimize the problem of carbon emission policy and coal supply chain network.•A new algorithm for supply chain network optimization is proposed.
At present, the remediation of heavy-metal polluted soil is a considerable problem. In this study, in situ immobilization field experiments were conducted by planting rice (Oryza sativa L.) in Cd ...contaminated paddy soil to determine the optimal remediation mode that would reduce the accumulation of Cd in brown grain. Sepiolite and palygorskite were utilized as amendments, while ordinary and low Cd-accumulating rice cultivars were selected as model plants. The remediation effects of the amendments on the soil and rice were investigated and the potential immobilization mechanisms were analyzed using X-ray diffraction and X-ray photoelectron spectroscopy. The application of sepiolite and palygorskite was found to increase the pH value of the paddy soil, by varying amounts, and significantly reduce the HCl, TCLP, CaCl2, and NH4OAc-extractable Cd concentrations resulting in a notable decrease in the Cd concentration in brown rice. Both sepiolite and palygorskite were found to reduce exchangeable Cd concentrations and increase the carbonate-bound and residual fractions in paddy soil. Precipitation of Cd as carbonates or hydroxides and surface complexation were the main immobilization mechanisms for sepiolite and palygorskite. The concentration of Cd in brown rice of the low Cd-accumulating cultivar from the control plot was 0.72mg·kg−1. Sepiolite treatment reduced the value to 0.18mg·kg−1 below the maximum levels reported by Codex Stan 193-1995 and the national standard of China. It was concluded that chemical immobilization combined with crop cultivar selection could be a suitable proposal for crop safety regulation and sustainable agriculture.
Combination of chemical immobilization and low Cd accumulating rice cultivar.
In situ chemical immobilization can significantly decrease the bioavailability and bioaccessibility of cadmium in paddy soil. Meanwhile, selection and breeding of low Cd accumulating cultivars is an environmentally friendly and cost effective method for reducing the risk of contamination from Cd in food. The results of this study suggested that safer food production was more likely to be achievable by combining low Cd accumulating cultivars with in situ immobilizing agent amendment of soils. Display omitted
•Sepiolite and palygorskite significantly reduced phytoavailable Cd in paddy soils.•Precipitation and surface complexation were main immobilization mechanisms.•Combination of chemical immobilization and low accumulating cultivar was recommended.
Nonalcoholic fatty liver disease (NAFLD) is a severe liver disease, which influences the health of people worldwide. However, the specific mechanism of the disease remains unknown, and effective ...treatments are still lacking. It was reported that Nuclear enriched abundant transcript 1 (NEAT1) obviously was up-regulated in NAFLD model. But the role and underlying mechanism of NEAT1 in NAFLD is unclear.
HepG2 cells were treated by free fatty acids (FFA) and C57BL/6J mice were treated by high-fat diet to establish NAFLD in vitro and in vivo models, respectively. Cell transfection was applied to regulate the expression of NEAT1, ROCK1, and miR-146a-5p. Western blotting and qRT-PCR were used for measuring expression of protein and mRNA level, respectively. Dual luciferase assay was used to detect the target relationship. Oil Red O staining was used to measure the lipid accumulation. HE staining was used for observing pathological feature of liver tissues.
High levels of NEAT1 and ROCK1, and low level of miR-146a-5p were identified in NAFLD models. NEAT1 could target miR-146a-5p to promote ROCK1 expression. Knockdown of NEAT1, overexpression of miR-146a-5p and knockdown of ROCK1 inhibited lipid accumulation through activating AMPK pathway.
NEAT1 may regulate NAFLD through miR-146a-5p targeting ROCK1, and further affect AMPK/SREBP pathway. This study may provide a new thought for the treatment of NAFLD.
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