The feasibility of adding sulfidated nanoscale zero-valent iron (S-nZVI) into anaerobic systems to improve anaerobic digestion of food waste (FW) under ammonia stress was evaluated in this study. The ...addition of S-nZVI improved the methane production compared to nanoscale zero-valent iron (nZVI), indicating that sulfidation significantly reinforced the enhancement effect of nZVI in consolidating the hydrogenotrophic methanogenesis. The promoted methanogenic performance was associated with chemical reaction and variances of microbial community induced by S-nZVI. With the characteristics of generation of Fe2+ and slow-release of H2, S-nZVI made the anaerobic system respond positively in facilitating extracellular polymeric substances secretion and optimizing the microbial community structure. Moreover, microbial community analysis showed that S-nZVI addition enriched the species related to biohydrogen production (e.g., Prevotella) and ammonia-tolerant hydrogenotrophic methanogenesis (e.g., Methanoculleus), possibly enhancing the hydrogenotrophic methanogenesis pathway to accelerate methane production. Therefore, adding S-nZVI into the anaerobic systems might propose a feasible engineering strategy to improve the methanogenic performance of the anaerobic digestion of FW upon ammonia stress.
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•Inhibition of anaerobic digestion under ammonia stress was mitigated by S-nZVI.•S-nZVI improved hydrolysis process and regulated acidification process.•Hydrogenotrophic methanogenesis was consolidated by S-nZVI.•Relative abundance of hydrogenotrophic Methanoculleus increased with S-nZVI.
In our previous study, anaerobic digestion of food waste could be effectively enhanced by adding sulfidated nanoscale zero-valent iron (S-nZVI) under high-strength ammonia concentrations. In this ...study, in order to further elucidate the specific interactive effects of S-nZVI and ammonia on anaerobic digestion of nitrogen-rich food waste, the methanogenic performance of anaerobic digestion systems respectively added with nanoscale zero-valent iron (nZVI) and S-nZVI were compared and monitored under different ammonia stress conditions. Both nZVI and S-nZVI could effectively stimulate the methanogenesis process among ammonia concentrations ranging from 0 to 3500 mg/L. However, the enhancing effects of S-nZVI and nZVI on anaerobic digestion of food waste were different, in which anaerobic digestion systems added with S-nZVI and nZVI performed best under 2500 mg/L of ammonia and 1500 mg/L of ammonia, respectively. Furthermore, the analysis of microbial communities suggested that ammonia stress enriched acetoclastic methanogens, while adding nZVI and S-nZVI into anaerobic digestions stimulated the process of hydrogenotrophic methanogenesis. Moreover, S-nZVI performed better in promoting the evolution of DIET-related microorganisms than nZVI, resulting in enhanced methane production under high ammonia-stressed conditions. This work provided fundamental knowledge about the interactive effects of S-nZVI and ammonia on the anaerobic digestion of food waste.
The number of people with Alzheimer's disease (AD) is increasing annually, with the nidus mainly concentrated in the cortex and hippocampus. Despite of numerous efforts, effective treatment of AD is ...still facing great challenges due to the blood brain barrier (BBB) and limited drug distribution in the AD nidus sites. Thus, in this study, using vinpocetine (VIN) as a model drug, the objective is to explore the feasibility of tackling the above bottleneck via intranasal drug delivery in combination with a brain guider, borneol (BOR), using nanoemulsion (NE) as the carrier. First of all, the NE were prepared and characterized. In vivo behavior of the NE after intranasal administration was investigated. Influence of borneol dose, BOR administration route on drug brain targeting behavior was evaluated, and the influence of BOR addition on drug brain subregion distribution was probed. It was demonstrated that all the NE had comparable size and similar retention behavior after intranasal delivery. Compared to intravenous injection, improved brain targeting effect was observed by intranasal route, and drug targeting index (DTI) of the VINNE group was 154.1%, with the nose-to-brain direct transport percentage (DTP) 35.1%. Especially, remarkably enhanced brain distribution was achieved after BOR addition in the NE, with the extent depending on BOR dose. VIN brain concentration was the highest in the VIN-1-BOR-NE group at BOR dose of 1 mg/kg1, with the DTI reaching 596.1% and the DTP increased to 83.1%. BOR could exert better nose to brain delivery when administrated together with the drug via intranasal route. Notably, BOR can remarkably enhance drug distribution in both hippocampus and cortex, the nidus areas of AD. In conclusion, in combination with intranasal delivery and the intrinsic brain guiding effect of BOR, drug distribution not only in the brain but also in the cortex and hippocampus can be enhanced significantly, providing the perquisite for improved therapeutic efficacy of AD.
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Ni-based oxygen carriers (OCs) are considered promising materials in the chemical looping combustion (CLC) process. However, the reactivity of Ni-based OCs still offers the potential for further ...enhancement. In this work, the Li doping method has been employed for the modification of Ni-based OCs. The reactivity and microreaction mechanisms of different concentrations of Li-doped Ni-based OCs with CO in CLC are clarified using density functional theory (DFT) simulation. The structures, energy, and density of states are obtained through computational investigation of the reaction path in elementary reactions. The results show that (1) the adsorption energies of CO molecules on NiO surfaces with 4, 8, and 12% Li doping concentrations are −0.53, −0.48, and −0.54 eV, respectively, demonstrating an enhanced reactivity compared to that of pure NiO (−0.41 eV); (2) the calculation of the transition state indicates that the most favorable pathway for CO oxidation takes place on the surface of NiO with an 8% Li doping concentration, exhibiting the lowest energy barrier of 0.51 eV; and (3) the oxygen vacancy formation energies on the surface of NiO are 3.05, 2.30, and 2.10 eV for 4, 8, and 12% doping concentrations, respectively. Additionally, the decrease in oxygen vacancy formation energies exhibits a gradual decline with an increasing Li doping concentration. By comprehensive analysis, 8% is considered to be the optimal doping concentration of NiO for chemical looping combustion.
The joining of zirconium alloys is an important issue in the field of nuclear energy since zirconium alloys are often used as nuclear fuel cladding tube. The article reviews the research progress on ...the diffusion bonding, brazing and resistance welding of zirconium alloys. The main focus of this work is on the process parameters, interfacial microstructure and mechanical properties of joint. For diffusion bonding, the process parameters including temperature and interlayer have significant influence on the properties of joint. The range of temperature and the selection of interlayer was reviewed and the influence of them on interfacial microstructure and properties of joints was also discussed. For brazing, the influence of brazing filler, temperature and holding time on the properties of joint was summarized. For resistance welding, the main process parameters include welding current and contact resistance. Numerical simulation method was often used to describe the influence of process parameters on microstructure during welding end plug with cladding tube. Some suggestions for the further research direction on the welding and joining of zirconium alloys were also proposed.
•New charged state of carbon in β-Ga2O3 are found and corresponding formation energies are given.•Thermodynamics of different substitutions including phonon are explored.•The vacancy concentrations ...are predicted against oxygen partial pressure.•Electronic and optical properties are predicted, and yellow emissions are firstly observed.
Calculations using the revised Heyd-Scuseria-Ernzerhof screened hybrid functional (HSE06) reveal the opto-electronic effects of carbon in β-Ga2O3. Stable charged states with carbon dopant are proved by phonon calculations which can result in the deep levels in the band gap. Stronger distortion can happen around oxygen sites substituted by carbon than those at gallium sites leading to interactions changing. Temperature and oxygen pressure can have huge effect on the formation of substitutions and the electronic conductivity. As partial oxygen pressure increase, the substitution concentration increases, and decrease with temperature increasing. Electronic conductivity of substitution of carbon at oxygen sites can get enhanced hugely, and it increases with temperature increasing. Besides electronic properties, carbon substitution can also have great impact on optical properties. Red-infrared PL emissions can be induced with substitutions at gallium sites, and yellow and blue emissions can be achieved by substitutions with oxygen in different charged states. The work can effectively predict the impact of carbon substitution in β-Ga2O3 and be useful for improvement of device designs and optimizations.
Abstract
This study investigates the influence of Confucianism on corporate environmental protection investment among heavily polluting companies in China from 2013 to 2020. We find that Confucianism ...is positively associated with corporate environmental protection investment. This correlation is mainly reflected in preventive environmental protection investment. Mechanism tests reveal that Confucianism promotes corporate environmental protection investment by increasing environmental legitimacy pressure. Additionally, in areas with a high environmental regulation level, Confucianism plays a stronger role in promoting corporate environmental protection investment. These findings illustrate the factors that influence corporate environmental protection investment and provide insights into the impact of Confucianism on corporate behavior.
Background: Soluble epoxide hydrolase (sEH) has been demonstrated to be a key enzyme involved in the pathologic development of several cardiovascular diseases and inflammation, and inhibition of sEH ...is therefore very helpful or crucial for the treatment of ischemia-reperfusion injury, cardiac hypertrophy, hypertension and inflammation. Danshen, the dried root of Salvia miltiorrhiza (Fam. Labiatae), has been used for the treatment of cardiovascular and cerebrovascular diseases in China and other countries for hundreds of years. Recent studies indicated that Danshen and its preparations also have potential for the management of inflammation. However, little information is available about the possibility of Danshen and its components on sEH inhibition.
Purpose and methods: Danshen extracts and its constituents were tested for sEH inhibition using its physiological substrate, 8,9-EET, based on a LC–MS/MS assay in this study.
Results: Among the tested 15 compounds, tanshinone IIA and cryptotanshinone were found to be the potent (Ki = 0.87 μM) and medium (Ki = 6.7 μM) mixed-type inhibitors of sEH, respectively. Salvianolic acid C (Ki = 8.6 μM) was proved to be a moderate noncompetitive sEH inhibitor. In consistent with the inhibition results of the pure compounds, the 75% ethanol extract of Danshen (EE, IC50 = 86.5 μg/ml) which contained more tanshinone IIA and cryptotanshinone exhibited more potent inhibition on sEH than the water extract (WE, IC50 > 200 μg/ml) or 1 M NaHCO3 (BE, IC50 > 200 μg/ml) extract.
Conclusion: These data indicated that using the ethanol fraction of Danshen and increasing the amounts of tanshinone IIA, cryptotanshinone and salvianolic acid C, especially the contents of tanshinone IIA in Danshen extract or preparations to enhance the inhibitory effects on sEH might be efficient ways to improve its cardiovascular protective and anti-inflammatory effects, and that herbal medicines could be an untapped reservoir for sEH-inhibition agents and developing sEH inhibitors from the cardiovascular protective and anti-inflammatory herbs is a promising approach.
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The highly exfoliated Ti
3
C
2
T
x
nanosheets were synthesized by selective etching of the starting material of Ti
3
AlC
2
using 40 % concentrated HF solution at 65 °C for 5 h. The effect of HF ...treatment temperature on the exfoliation degree was investigated by characterizing the morphology and microstructure of the Ti
3
C
2
T
x
nanosheets using SEM, XRD, and TEM. The results showed that the exfoliation degree of Ti
3
C
2
T
x
was increased with increasing temperature. The role of the termination groups produced during HF treatment on the exfoliation degree was discussed. The tribological property of the prepared Ti
3
C
2
T
x
nanosheets as additives in PAO8 base oil was measured. The maximum reduction of friction and wear was achieved under additive concentration of 0.8 wt% for the highly exfoliated Ti
3
C
2
T
x
nanosheets. The different effects of Ti
3
C
2
T
x
additives on the average friction coefficient and wear volume were analyzed, respectively.
Leading officials’ accountability audit of natural resources (AANR) is a major institutional arrangement for China to promote the construction of an ecological civilization. Based on city-level panel ...data from 2010 to 2017, this study investigates the role of AANR on haze pollution by the difference-in-differences (DID) and spatial DID models. The results show that the AANR significantly reduces the haze pollution of pilot cities, and this conclusion remains robust under multiple scenarios, such as the parallel trend test, tendency score matching, placebo test, and excluding the policy interference in the same period. The AANR promotes the governance of haze pollution in pilot areas, mainly by improving environmental control and increasing financial investment in environmental protection. Furthermore, the promotion effect of the AANR on haze governance has strong heterogeneity with regard to urban air quality; eastern, central, and western regions; legal environment; and public attention. The AANR not only reduces the haze pollution of pilot cities but also has a spatial spillover effect on neighboring areas, but this effect is not pronounced. Therefore, it is of great significance for haze pollution control to continuously promote and improve the departure audit of natural resource assets, perform audit work according to local conditions, and establish interregional cooperative mechanisms.
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