To better understand the pozzolanic activity in fly ash used as a supplementary cementitious material in cement or concrete, calcium silicate hydrate (C-S-H) has been synthesized by adding silica ...fume to a supersaturated calcium hydroxide solution prepared by mixing calcium oxide and ultrapure water. Thermogravimetric analysis results have revealed the variation in the weight loss due to C-S-H in the samples and the conversion ratio of calcium oxide (the μCaO value), which represents the proportion of calcium oxide in the initial reaction mixture used to produce C-S-H, with curing time. The weight loss due to C-S-H and the μCaO value were both maximized (13.5% and 90.4%, respectively) when the initial C/S molar ratio was 1.0 and the curing time was 90 d. X-ray diffraction (XRD) analysis has indicated that C-S-H in the samples after curing for 7 d had the composition Ca1.5SiO3.5·xH2O. 29Si magic angle spinning (MAS) nuclear magnetic resonance (NMR) analysis has revealed that the degree of polymerization of C-S-H increased with an increase in curing time for samples with an initial C/S molar ratio of 1.0. The ratio of internal to terminal tetrahedra (Q2/Q1) increased from 2.29 to 4.28 with the increase in curing time from 7 d to 90 d. At curing times ≥ 28 d, a leaf-like C-S-H structure was observed by scanning electron microscopy (SEM). An ectopic nucleation–polymerization reaction process is proposed for the formation mechanism of C-S-H.
•The use of supersonic steam jet technology to smash steel slag can not only achieve ultrafine steel slag, but also optimize the composition characteristics of steel slag.•The replacement of cement ...by USS converted the fly ash–cement binary system block into fly ash–cement–USS ternary system block, high strength and good wear resistance inorganic gelling material may be prepared.
We studied the properties and activity index on ultrafine steel slag (USS) ground with a supersonic steam-jet smasher. We show that the use of supersonic steam-jet technology to smash steel slag not only significantly increases its specific surface areas (768 m2/kg), but also optimizes its composition characteristics and improves its activity. We prepared a fly ash–cement gelation block and a fly ash–cement block in which the cement was partially replaced by USS. We then analyzed its compressive strength, water absorption, frost resistance, and wear resistance. The results showed that the replacement of cement with USS converted the fly ash–cement binary system block into a fly ash–cement–USS ternary system block, increasing the compressive strength and wear resistance of the block. In this paper, the enhancement mechanism of USS on a gelation block was studied based on X-ray diffraction and thermogravimetric analysis. The results reveal the effectiveness of USS at producing a certain amount of hydrated iron calcium aluminate, improving the late compressive strength of a fly ash–cement–USS block.
The waterproof and thermal insulation property of foamed concrete is very important. In this study, the ultrafine fly ash (UFA)-based superhydrophobic composite coating was applied onto foam ...concrete. The UFA-based base coating that closely adhered to the concrete initially improved the waterproofness of the test block, and the silane coupling agent-modified UFA-based surface coating further achieved superhydrophobicity. The UFA on the coating surface and the asperities on the surface jointly formed a lotus leaf-like rough micro–nanostructure. The 154.34° water drop contact angle and 2.41° sliding angle on No. 5 coating were reached, indicating that it was a superhydrophobic surface. The water absorption ratios of the composite coating block were 1.87% and 16.6% at 4 h and 7 days, which were reduced by 97% and 75% in comparison with the original foam concrete. The compressive strength and heat conductivity coefficient after soaking for 4 h of the composite coating block were higher than 4.0 MPa and 0.225 W·m−1·K−1, respectively. The UFA-based superhydrophobic composite coating proposed in this study and applied onto foam concrete is simple and cheap, requires no precise instrument, and can be applied in a large area.
Based on network meta-analysis (NMA) and network pharmacology approaches, we explored the clinical efficacy of different regimens, and clarified the pharmacological mechanisms of N-butylphthalide ...(NBP) in the treatment of delayed encephalopathy after acute carbon monoxide poisoning (DEACMP).
Firstly, NMA was conducted to obtain the ranking of the efficacy of different regimens for the treatment of DEACMP. Secondly, the drug with a relatively high efficacy ranking was selected and its mechanism of treatment for DEACMP was identified through a network pharmacology analysis. By the use of protein interaction and enrichment analysis, the pharmacological mechanism was predicted, and molecular docking was subsequently carried out to verify the reliability of the results.
A total of 17 eligible randomized controlled trials (RCTs) involving 1293 patients and 16 interventions were eventually included in our analysis from NMA. Mesenchymal stem cells (MSCs) + NBP significantly increased mini-mental state examination (MMSE) and Barthel index (BI) scores; NBP + dexamethasone (DXM) was the most effective treatment in improving the activity of daily living (ADL) scores; NBP significantly decreased national institutes of health stroke scale (NIHSS) scores; Xingzhi-Yinao granules (XZYN) had more advantages in improving Montreal cognitive assessment (MoCA) scores, translational direct current stimulation (tDCS) had a significant effect in improving P300 latency and P300 amplitude and Kinnado + Citicoline had the most obvious effect in improving malondialdehyde (MDA). Meanwhile, by network pharmacology analysis, 33 interaction genes between NBP and DEACMP were obtained, and 4 of them were identified as possible key targets in the process of MCODE analysis. 516 Gene ontology (GO) entries and 116 Kyoto Encyclopedia of Gene and Genome (KEGG) entries were achieved by enrichment analysis. Molecular docking showed that NBP had good docking activity with the key targets.
The NMA screened for regimens with better efficacy for each outcome indicator in order to provide a reference for clinical treatment. NBP can stably bind
, and other targets, and may play a role in neuroprotection for patients with DEACMP by modulating Lipid and atherosclerosis,
signaling pathway,
signaling pathway,
signaling pathway,
signaling pathway.
Aluminium adjuvants are commonly used in vaccines to stimulate the immune system, but they have limited ability to promote cellular immunity which is necessary for clearing viral infections like ...hepatitis B. Current adjuvants that do promote cellular immunity often have undesired side effects due to the immunostimulants they contain. In this study, a hybrid polymer lipid nanoparticle (HPLNP) was developed as an efficient adjuvant for the hepatitis B surface antigen (HBsAg) virus-like particle (VLP) vaccine to potentiate both humoral and cellular immunity. The HPLNP is composed of FDA approved polyethylene glycol-b-poly (l-lactic acid) (PEG-PLLA) polymer and cationic lipid 1, 2-dioleoyl-3-trimethylammonium-propane (DOTAP), and can be easily prepared by a one-step method. The cationic optimised vaccine formulation HBsAg/HPLNP (w/w = 1/600) can maximise the cell uptake of the antigen due to the electrostatic adsorption between the vaccine nanoparticle and the cell membrane of antigen-presenting cells. The HPLNP prolonged the retention of the antigen at the injection site and enhanced the lymph node drainage of antigen, resulting in a higher concentration of serum anti-HBsAg IgG compared to the HBsAg group or the HBsAg/Al group after the boost immunisation in mice. The HPLNP also promoted a strong Th1-driven immune response, as demonstrated by the significantly improved IgG2a/IgG1 ratio, increased production of IFN-gamma, and activation of CD4 + and CD8 + T cells in the spleen and lymph nodes. Importantly, the HPLNP demonstrated no systemic toxicity during immunisation. The advantages of the HPLNP, including good biocompatibility, easy preparation, low cost, and its ability to enhance both humoral and cellular immune responses, suggest its suitability as an efficient adjuvant for protein-based vaccines such as HBsAg-VLP. These findings highlight the promising potential of the HPLNP as an HBV vaccine adjuvant, offering an alternative to aluminium adjuvants currently used in vaccines.
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The utilization of coal fly ash derived from circulating fluidized bed combustion (CFBFA) still faces great challenges because of its unique characteristics. In this study, a zeolitic ...material with Na-P1 zeolite as the main phase was successfully synthesized via a hydrothermal method by using CFBFA as the raw material. The effects of hydrothermal temperature, time, and added CTAB amount on the characterizations of synthesized materials were investigated by XRD, SEM, and XPS. The properties of the optimal zeolitic material and its adsorption performance for Pb2+ in aqueous solution were evaluated. The influences of pH, initial concentration, dosage, and temperature on Pb2+ adsorption were also examined. Results revealed the following optimal parameters for the synthesis of zeolitic material: NaOH concentration of 2 mol·L−1, solid-to-liquid ratio of 1:10 g·ml−1, hydrothermal temperature of 110 °C, hydrothermal time of 9 h, and CTAB amount of 1 g (per 100 ml solution). The adsorption capacities of the zeolitic material reached 329.67, 424.69, and 542.22 mg·g−1 when the pH values of aqueous solution were 5, 6, and 7, respectively. The Pb2+removal efficiency can reach more than 99% in aqueous solution with the initial concentrations of 100–300 mg·L−1 under pH 6 and suitable adsorbent dosage. The adsorption and kinetics of Pb2+ on the zeolitic material can be described by Langmuir isotherm and pseudo-second-order kinetic models, respectively. The ion exchange between Pb2+ and Na+ and chemisorption are the main adsorption mechanism. All these findings imply that the synthesis of low-cost adsorbent for Pb2+ removal from weak acid and neutral aqueous solution provides a highly effective method to utilize CFBFA.
The slow startup and suboptimal efficiency of microbial carbon sequestration and methane-production systems have not been fully resolved despite their contribution to sustainable energy production ...and the reduction of greenhouse gas emissions. These systems often grapple with persistent hurdles, including interference from miscellaneous bacteria and the slow enrichment of methanogens. To address these issues, this paper examines the synergistic effect of coupling β-lactam antibiotics with an electrolytic cell on the methanogenic process. The results indicated that β-lactam antibiotics exhibited inhibitory effects on
and
(two types of miscellaneous bacteria), reducing their relative abundance by 53.03% and 87.78%, respectively. Nevertheless, it also resulted in a decrease in hydrogenogens and hindered the CO
reduction pathway. When coupled with an electrolytic cell, sufficient electrons were supplied for CO
reduction to compensate for the hydrogen deficiency, effectively mitigating the side effects of antibiotics. Consequently, a substantial improvement in methane production was observed, reaching 0.57 mL·L
·d
, exemplifying a remarkable 6.3-fold increase over the control group. This discovery reinforces the efficiency of methanogen enrichment and enhances methane-production levels.
Amine-basedcarbon-capture technologies have been shown to be energetically expensive and to cause significant environmental and epidemiological impacts due to their volatility. Bicarbonate formation ...from carbon dioxide's reaction with water has been suggested as an effective alternative for capturing CO2; however, the thermodynamics of this reaction are not well understood. This study experimentally determined the equilibrium constant of sodium bicarbonate (NaHCO3) decomposition to sodium, water, and carbon dioxide; the study also compared the equilibrium constant to theoretical calculations. Using a combination of experimentation and thermodynamic relationships, the unitless equilibrium constants of the forward and reverse reactions were calculated accurately (error <±9% and <±4%, respectively). Equilibrium data were calculated using enthalpy and entropy values of each component of NaHCO3 decomposition at temperatures ranging from 25 to 155°C respectively. These results offer more data essential to optimizing NaHCO3 use in environmentally friendly next-generation CO2-capture technologies.
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Ultrafine calcium carbonate is a widely used cheap additive. The research is conducted in low degree supersaturation solution in order to study the polymorphic phases’ change and its factors of the ...calcium carbonate precipitate in the ammonification-carbonization process of the solution with calcium. Fine particles of calcium carbonate are made in the solution containing 0.015 mol/L of Ca2+. Over 98% of the calcium carbonate precipitate without ammonification resembles the morphology of calcite, while the introduction of ammonia can benefit the formation of vaterite. It was inferred that the main cause should be serious partial oversaturation or steric effects. Ammonia also helps to form the twin spherical calcium carbonate. However, particles formed in the process of ammonification-carbonization in solution with low concentration degree of calcium are not even with a scale of the particle diameter from 5 to 12 μm. Inorganic salts, alcohol, or organic acid salts have significant controlling effect on the particle diameter of calcium carbonate and can help to decrease the particle diameter to about 3 μm. Anionic surfactants can prevent the conglobation of calcium carbonate particles and shrink its diameter to 500 nm–1 μm.
► A severe membrane fouling is observed during start-up of a hybrid anoxic–oxic membrane bioreactor (MBR). ► Microbial community shifts dynamically during start-up period, which leads to variations ...of several activated sludge properties. ► Small floc size, high fractal dimension and high EPS production are major contributors to the initial severe fouling. ► Microbial community shift is most likely the ultimate factor responsible for the severe membrane fouling of this period.
In MBR, severe membrane fouling is often observed in the initial phase in which biomass is yet fully acclimated and stabilized in terms of microbial community structure and biomass characteristics. The focus of this study was to investigate the microbial community development and its influence on biomass characteristics and membrane fouling during start-up of a hybrid anoxic–oxic MBR. PCR–DGGE analysis indicated that the microbial community shifted in start-up period when a severe membrane fouling was observed. Small particle size, high fractal dimension (DF) and high EPS production, which were closely associated with microbial community, were found to be the major contributors to the severe fouling. Microbial community development was most likely the ultimate factor responsible for the severe membrane fouling.
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