Decomposition Of Acid Research Articles

Bacteriocin Microcin J25's antibacterial infection effects and novel non-microbial regulatory mechanisms: differential regulation of dopaminergic receptors.

The antibacterial and immunomodulatory activities of bacteriocins make them attractive targets for development as anti-infective drugs. Although the importance of the enteric nervous system (ENS) in the struggle against infections of the intestine has been demonstrated, whether it is involved in bacteriocins anti-infective mechanisms is poorly defined. Here, we demonstrated that the bacteriocin Microcin J25 (J25) significantly alleviated diarrhea and intestinal inflammation in piglets caused by enterotoxigenic Escherichia coli (ETEC) infection. Mechanistically, macrophage levels were significantly downregulated after J25 treatment, and this was replicated in a mouse model. Omics analysis and validation screening revealed that J25 treatment induced significant changes in the dopaminergic neuron pathway, but little change in microbial structure. The alleviation of inflammation may occur by down-regulating dopamine receptor (DR) D1 and the downstream DAG-PKC pathway, thus inhibiting arachidonic acid decomposition, and the inhibition of macrophages may occur through the up-regulation of DRD5 and the downstream cAMP-PKA pathway, thus inhibiting NF-κB. Our studies' findings provide insight into the changes and possible roles of the ENS in J25 treatment of ETEC infection, providing a more sophisticated foundational understanding for developing the application potential of J25.

High-purity carbon monoxide production via photothermal formic acid decomposition over fluorite ZrO2

High-purity carbon monoxide production via photothermal formic acid decomposition over fluorite ZrO2

Effects of compound fermentation of lactic acid bacteria IMAUJBP3 and IMAUJBR3 on the characteristic flavors and metabolites of mutton fermented sausages

Lactobacillus plantarum IMAUJBP3 and Limosilactobacillus reuteri IMAUJBR3 were used to prepare starter cultures. Through the electronic nose (E-nose), it was found that the compound fermentation can enhance the aromatic components in the product. Further analyses using Headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPMEGC–MS) and metabolomics revealed that the complex fermentation affected the oxidative breakdown of amino acids and lipids. HS-SPMEGC-MS identified 72 flavour compounds and found that the Mix group had the highest amount of ester compounds relative to the ZR group. In addition, of the 1402 metabolites identified by metabolomics, dihydroxyacetone phosphate was upregulated and most abundance in the Mix group. Dihydroxyacetone phosphate promotes the metabolism of carbohydrates and lipids, and affects the oxidative decomposition of amino acids and lipids, resulting in differences in flavor among meat products inoculated with different starter cultures. At the same time, it was also found that compound fermentation could down-regulate the compounds affecting product quality such as histamine, putrescine and phenethylamine. Overall, this study found that JBP3 and JBR3 in combination could improve the flavour quality of fermented lamb sausages. These findings may provide a good strain resource for improving the quality of lamb sausage.

Dietary β-hydroxybutyrate sodium alters rumen microbiome and nutrient metabolism in the rumen epithelium of young goats

The role of β-hydroxybutyric acid (BHBA) includes providing energy, regulating signaling pathways, and ameliorating the gut microbiota in the host, while its nutrient mechanism to improve rumen epithelium development in young ruminants is still unclear. In this study, a total of 12 female Haimen goats with 30 days of age were chosen and divided into two groups. One group was fed with basic diet (CON), and the other group was fed a basal diet supplemented with 6 g d-1 dietary β-hydroxybutyrate sodium (BHBA-Na). The experimental period was 30 days, and all goats were slaughtered at 60 days of age. The joint analysis of multi-omics, including rumen microbiota, rumen epithelial transcriptome and rumen epithelial metabolomics in young goat model, was performed to systematically investigate the effect of dietary BHBA-Na on rumen development in young goats. As the results, we found that dietary BHBA-Na improved the growth performance of young goat including body weight, average daily gain (ADG) and dry matter intake (DMI) (P<0.05). Dietary BHBA-Na also increased the weight of rumen, and promoted the growth of rumen epithelium development (P < 0.05). The abundance of several beneficial bacteria was increased (Fibrobacter, Succinivibrio, Clostridiales, etc.,). The rumen epithelium transcriptome and metabolomics indicated that BHBA-Na supplementation showed a remarkable effect on the nutrient metabolism of the rumen epithelium. Specifically, the pathways of “fatty acid metabolism”, “cholesterol homeostasis”, “reactive oxygen species (ROS) pathway” and “peroxisome” were activated in response to BHBA-Na addition (P < 0.05). Moreover, the genes (HMGCS2, ECSH1, ACAA2, ECH1, ACADS etc.) and metabolites (succinic acid, alpha-ketoisovaleric acid, etc.) involved in these pathways were also regulated positively (P < 0.05). The rumen epithelium obtained the energy for its development from the process of volatile fatty acids (VFAs) decomposition. Finally, we observed the close correlations among the phenotypes, ruminal microbiota, host genes and epithelial metabolites. Overall, our results revealed that the BHBA-Na promoted the growth and rumen development of young goats possibly by enhancing DMI and regulating the rumen microbiota and the metabolisms of VFA and amino acid in the rumen epithelium.

IMPROVEMENT OF THE PRODUCT COMPOSITION FROM NITRIC ACID PROCESSING OF KYZYLKUM CARBONATE PHOSPHORITES

The process of producing NP-fertilizers by nitric-sulfuric acid decomposition of phosphate rock (17.20% P2O5) under thickening slurry conditions has been studied. It was shown that the higher the recycle ratio, the lower the moisture content of the final product. Increasing the HNO3 dosage above 30% and H2SO4 above 70% is undesirable, as the product's moisture content exceeds 6.03% and it has increased acidity. To avoid issues during ammoniation, an optimal rate of nitric and sulfuric acid was proposed—73.5-91%, which produced products containing 9.34-10.61% -P2O5total; 3.04-4.54% N; P2O5 digestive:P2O5 total = 73.4-82.3%; pH = 3.3-3.6, and granule strength of 2.1-2.3 MPa. The process of producing NPK-fertilizers was also studied by adding nitrogen components such as K2SO4, KCl, and K2CO3 to the products of complete nitric acid decomposition of washed and dried concentrate (24.10% P2O5) and fine fractions (18.55% P2O5). The process includes decarbonization and decomposition of the phosphate raw material (simultaneously in one apparatus), neutralization to a pH not lower than 3.5, evaporation of the slurry to a density of at least 1750 kg/m3, the addition of potassium salts at N:P2O5:K2O ratios of 1:1:1, 1.5:1:1, and 1:1.5:1, product granulation, drying in the presence of recycle, and cooling.

Microwave-assisted microscale acid decomposition for determination of essential elements in processed meats by MIP OES

Microwave-assisted microscale acid decomposition for determination of essential elements in processed meats by MIP OES

Effect of Electric Field on Carbon Encapsulation and Catalytic Activity of Pd for Efficient Formic Acid Decomposition

Utilizing carbon coated ferroelectric materials to introduce polarization‐induced electric field (PIEF) stimulates research of electric field‐assisted catalysts for various reactions. However, effect of PIEF on carbon coating mechanism has not been studied. Herein, tourmaline nanoparticles (TNPs) with spontaneous dipole moments were applied as the PIEF supplier and sucrose was utilized as the carbon precursor to synthesize carbon coated TNPs (TNP@SC) to uncover the influence of PIEF on the carbon coating and catalytic activity of Pd toward formic acid decomposition (FAD). PIEF enhanced the adsorption capacity of TNPs for the caramelized intermediate species and increased H+ concentration by facilitating water ionization. Polymerization of adsorbed caramelized intermediate species on TNPs was accelerated. Uniformly coated carbon layer with more defects, larger specific surface area, and higher porosity was coated on TNP. Such surface properties of the carbon layer were beneficial for strongly anchoring ultrafine Pd nanoparticles. Owing to the specific properties of carbon layer and existence of PIEF, Pd/TNP@SC exhibited higher FAD activity than the catalysts absent of PIEF. Stronger PIEF leaded to higher initial turnover frequency. This study provides guidance to supply electric field for catalysis.

Freestanding Penta-Twinned Pd-Ag Nanosheets.

2D metal nanosheets have attracted significant attention as efficient catalysts for various important chemical reactions. However, the development of metal nanosheets with controlled compositions and morphologies has been slow due to the challenges associated with synthesizing thermodynamically unfavorable 2D structures. Herein, we report a synthesis route of freestanding Pd-Ag penta-twinned nanosheets (Pd-Ag ptNSs) with distinct 5-fold twin boundaries. Through the coreduction of Ag and Pd precursors on presynthesized Pd ptNSs, Ag could be homogeneously alloyed with Pd, leading to the formation of well-defined Pd-Ag ptNSs. The promotional effects of the bimetallic composition, 2D structure, and twin boundaries on catalysis were studied by using Pd-Ag ptNS-catalyzed H2 production from formic acid decomposition as a model reaction. Notably, the catalytic activity of the Pd-Ag ptNSs drastically outperformed those of monometallic, bimetallic, and 3D counterparts, such as Pd ptNSs, Pd-Ag nanosheets without a TB, and Pd-Ag octahedral nanocrystals, demonstrating the promising potential of the integration of twin boundaries and multiple compositions in the development of high-performance 2D nanocatalysts.

Metabolic mechanisms of carbon and nitrogen interactions during anaerobic digestion of coal

There was limited research on the impact of nitrogen metabolism in the process of methane production with coal, even if carbon and nitrogen metabolism were closely interconnected. Lignite was the source of carbon and nitrogen in anaerobic digestion system. The relationship between carbon and nitrogen metabolism was systematically discussed during the anaerobic digestion process. The results showed that phenolic carbon or ether carbon (C-O), pyridine-type nitrogen (N-6) and nitrogen oxide compound (N-X) in coal were decomposed under the action of Macellibacteroides, Sphaerochaeta and Trichococcus in the hydrolysis stage, respectively. In the acidogenesis stage, the stress of volatile fatty acids and ammonia produced by dissolved organic matter under the action of Syner-01 and Sphaerochaeta on hydrogenotrophic and acetoclastic methanogens was alleviated during the nitrogen cycle. In the acetogenesis stage, acetic acid produced from the decomposition of organic acids and alcohols by Synergistaceae and Sedimentibacter was competed by denitrifying bacteria and acetogenic methanogens. In the methanogenesis stage, CO2 was reduced by Methanobacterium and Methanoculleus to produce CH4, while acetic acid was decomposed by Methanosaeta to produce CH4. And methyl substances were generated into CH4 by Methanosarcina and Methanofastidiosum. This understanding will provide a basis for strengthening the favorable factors in biomethane production.

Novel oxygen vacancies-rich 3D porous ZnO for highly sensitive 3-hydroxy-2-butanone biomarker gas sensors

Listeriosis can cause human death via infection by Listeria monocytogenes (LMs) with a high fatality rate of 20–30 %. Detection of 3-hydroxy-2-butanone (3H-2B) biomarker of LMs can achieve estimation of LMs content, which is of great significance for human health. Exploring porous metal oxide semiconductors (MOSs) with rich vacancies towards 3H-2B sensing is quite promising for achieving this goal. Herein, we report a highly sensitive 3H-2B sensor based on novel 3D porous ZnO with rich oxygen vacancies which was facilely obtained by sacrificing Zn foam in oxalic acid and subsequent thermal decomposition. The ZnO sensor displays ultrahigh sensor response of Ra/Rg = 328@5 ppm, super-low detection limit of 0.001 ppm, excellent cycling stability and selectivity and good linear response at 120 °C, showing great potential for precise detection of 3H-2B biomarker. The porous structure and increased oxygen vacancies contribute greatly to the adsorption of active oxygen species therefore the sensing reactions on ZnO surface, which accounts for the high sensing performance. Our work provides an ingenious strategy to produce novel 3D ZnO with rich oxygen vacancies as well as new insights for boosting the detection of LMs.

In-situ decomposition of citric acid for eliminating coking in steam reforming of acetic acid through enhanced gasification of coke precursors

H2O and CO2 are two important agents for gasification of precursors of coke in steam reforming (SR). Their in-situ formation from decomposition of reactant might facilitate removal of coke deposit from surface of catalyst. This was investigated in SR of acetic acid (HAc) mixed with presence of citric acid (CA) over Ni/SBA-15 catalyst, as CA could decompose to form simultaneously H2O and CO2 for potentially involving in gasification reactions. The results showed that CA presence could not enhance catalytic activity of Ni/SBA-15 but remarkably promoted the catalytic stability. This was due to effective suppression of coking by CA (42.3 % coke in SR of HAc versus ca. 10 % coke in co-reforming of HAc and CA and 6.7 % coke in SR of CA). The adsorbed *CO2 and *OH species produced in-situ by decomposition of CA effectively gasified the precursors of coke such as *CxHy and O-containing species like *CO and *C-O-C.

Dual optimization strategy assisted m-phenylenediamine-based hypercrosslinked polymer loaded ultrafine bimetallic nanoparticles for efficient formic acid dehydrogenation

Heterogeneous catalysts based on Pd play a vital role in enabling efficient formic acid decomposition (FAD). Nevertheless, the performance of Pd-based catalysts is constrained by inherent challenges, such as Pd particles’ tendency to aggregate and possess localized electronic structures. Therefore, there is an urgent need to develop an effective strategy to simultaneously overcome these challenges. In response to this, we synthesized knitting hypercrosslinked polymers (HCPs) using m-phenylenediamine (MPD) as the aromatic monomer. A dual-optimization approach was proposed, aiming to mitigate the adverse effects of excessive coordination and maximize the involvement of residual Fe3+ in the bimetallic synergistic effect. Experimental findings, DFT calculations, and ab initio molecular dynamics simulations (AIMDs) collectively suggest that reducing the coordination effect leads to enhanced nitrogen exposure in the HCPs, consequently reducing the size of Pd species. Furthermore, the incorporation of residual Fe3+ into Pd forms Pd-Fe bimetallic species, which then adjusts the catalytic reaction barrier and enhances catalytic activity. Notably, the optimized Pd@MHCP-2 catalyst exhibited exceptional performance in the FAD reaction at 323 K, achieving a remarkable turnover frequency (TOF) value of 1486 h−1. This research introduces a novel perspective for the design and development of next-generation Pd-based catalysts.

Study on the integrated technology of arsenic removal and tungsten extraction based on the formation and decomposition of arsenotungstic acid

Study on the integrated technology of arsenic removal and tungsten extraction based on the formation and decomposition of arsenotungstic acid

A char removal protocol to visualize fiber cross‐sections of carbon/epoxy composites subjected to flame

AbstractPost‐crash fires obscure or destroy critical fracture surfaces needed to determine the origin of aircraft structural failures. Our goal is to eliminate combustion residue from carbon fiber‐reinforced polymer composites to enable fractographic examination during aviation accident investigations. In this work, combustion residues were removed from burned Hexcel SGP370‐8H/8552 woven‐fabric carbon/epoxy specimens by nitric/sulfuric acid oxidations. Scanning electron microscopy identified various types of char obscuring the fiber ends. For char removal, the burned specimens were immersed in a nitric acid/sulfuric acid/water solution (0.18 wt.%, 96.25 wt.%, 3.57 wt.%) at elevated temperatures (75–150°C). Higher temperatures enhanced nitric acid decomposition in this highly acidic, low‐water environment, accelerating char oxidation and progressively enhancing the extent of char removal. At lower temperatures (T &lt; 100°C), char deposits were partially oxidized after 60 mins. At 125 and 150°C, the char was removed within 30 mins of immersion. The epoxy matrix both chemically decomposed and oxidized and the char oxidized during these oxidation treatments. Gas evolution and soluble products dissolved in the HNO3/H2SO4 media. The damage morphology created by the sawing action on the fiber ends, created before flame exposure, remained clearly visible after the acid oxidations. This occurs because oxidation rates at the carbon fiber ends are much slower than the char oxidation in these acid treatments. If the acid treatment temperature raised above 185°C, then this sawing‐induced fiber damage morphology will also be destroyed. This preliminary understanding can be applied to develop a comprehensive forensic analysis procedure for post‐crash fire investigations.Highlights Flame exposure of sawed specimen cross‐sections leads to char formation, obscuring fiber damage morphologies. HNO3/H2SO4 oxidations at elevated temperatures (75–150°C) resulted in char removal from fiber ends. Higher temperatures (T = 125 and 150°C) accelerated char oxidation. The sawing of carbon/epoxy composites caused extensive fiber damage and ply delamination. Residual decomposed resin matrix and char oxidized faster than the carbon fibers and the fiber sawing‐induced fiber damage morphologies created before flame exposure and were preserved after char removal.

1-Dimensional metal Nitride-Supported platinum nanoclusters for Low-Temperature hydrogen production from formic acid

Formic acid is widely recognized as a suitable liquid hydrogen carrier for linking renewable energies toward various economic sectors. Designing efficient and stable heterogeneous catalysts for low-temperature hydrogen generation from formic acid is vital for this topic. In this study, a rational hierarchical architecture is explored by assembling Pt nanoclusters with 1-dimensional (1D) GaN nanowires. The catalytic architecture describes a considerable hydrogen production activity of 54.89 mmol·gcat−1·h−1 with a nearly 100 % selectivity and a turnover frequency (TOFPt) of 505.7 h−1 under near ambient condition, enables the achievement of a high turnover number of 306,981 mol H2 per mole Pt over 200 h of long-term operation. Through comprehensive mechanistic studies, it is unraveled that the synergistic effect between Pt nanoclusters and GaN significantly reduces the energy barrier for the formation of the key HCOO* intermediate from formic acid dehydrogenation whereas significantly increase the energy barrier of HCOOH → HCO* + *OH. It thus simultaneously contributes to improving the activity and selectivity of formic acid decomposition toward H2. This study proposes a promising strategy for hydrogen generation from formic acid at low temperatures, which is critical for achieving carbon neutrality by coordinating industrial waste heat with renewable energies via liquid hydrogen carriers.

IMPROVEMENT OF METHODS FOR DECOMPOSING MOLYBDENUM IN INDUSTRIAL PRODUCTS

The study of methods for extracting molybdenum into solutions from industrial ores and concentrates is an important task in the mining and metallurgical industry. Molybdenum (Mo) is used in the production of steel, alloys, electrode materials, and catalysts. The purpose of this work is to increase the efficiency of decomposition of molybdenum-containing materials, reduce production and processing costs, and minimize environmental impact. The tasks include the development of new chemical and metallurgical processes for processing various ores and concentrates, involving their decomposition and the extraction of molybdenum into a solution. Methodology. The study used microwave autoclave decomposition methods and chemical decomposition (acidic and fusion). The composition of the solution was determined using the atomic absorption method. The novelty of the research lies in the use of isolated microwave autoclave decomposition, which combines high efficiency and environmental safety. Results and discussion. The study compared the results obtained by the method of acidic decomposition and fusion in an open system with those from microwave autoclave decomposition in a closed system. Each method has its own advantages and disadvantages. The results of acidic and autoclave decompositions were similar to each other, while the results of fusion showed increased metal contents. The values of decomposition methods for standard copper and molybdenum concentrates showed results of 0.1-2.4%, respectively. The values of acidic (0.8%; 0.98%) and autoclave (0.9%; 1.04%) decompositions for samples from Chirchik and Stepnogorsk concentrates yielded similar results. Conclusion. The results of the decomposition methods of the materials do not differ significantly from each other from a production or industrial point of view. The analysis results can be applied in practice or used as reference values for scientific research.

Multi-energy calibration and induced plasma optical emission spectrometry (MEC-MIP OES) as an alternative method for the multi-elemental determination of essential elements in cocoa.

The challenge of combining MEC-MIP OES arises from the limited number of emission lines available in this analytical technique. For the MEC-MIP OES optimization, the emission line wavelengths, sample dilution, proportion sample:standard for preparing MEC solutions, and nebulizer gas flow rate were studied. Then, the use of multi-energy calibration (MEC) and microwave-induced plasma optical emission spectrometry (MIP OES) was proposed as an alternative method for the determination of essential elements (Ca, K, Mg, Mn, and Na) in cocoa. In the optimized conditions, the method presented adequate analytical performance, with recoveries of 94-104% and relative standard deviations lower than 5%, showing adequate precision. The limits of detection (mg kg-1) were 12 for Ca, 2 for K, 3 for Mg, 3 for Mn, and 6 for Na. The proposed method was applied to analyze cocoa samples cultivated in Brazil and Ecuador after acid decomposition. The results were in the range (mg kg-1) of 409-1530 for Ca, 5520-13300 for K, 1460-3210 for Mg, 16-34 for Mn, and 28-61 for Na. Samples cultivated in Ecuador presented higher metal concentrations than the Brazilian samples. The proposed procedure was an easy and reliable approach for determining metals in cocoa samples, enabling multi-elemental determination with a lower cost and simplified calibration to be applied in routine applications.

Integrated Metabolome, Transcriptome and Long Non-Coding RNA Analysis Reveals Potential Molecular Mechanisms of Sweet Cherry Fruit Ripening.

Long non-coding RNAs (lncRNAs), a class of important regulatory factors for many biological processes in plants, have received much attention in recent years. To explore the molecular roles of lncRNAs in sweet cherry fruit ripening, we conducted widely targeted metabolome, transcriptome and lncRNA analyses of sweet cherry fruit at three ripening stages (yellow stage, pink stage, and dark red stage). The results show that the ripening of sweet cherry fruit involves substantial metabolic changes, and the rapid accumulation of anthocyanins (cyanidin 3-rutinoside, cyanidin 3-O-galactoside, and cyanidin 3-O-glucoside) is the main cause of fruit coloration. These ripening-related alterations in the metabolic profile are driven by specific enzyme genes related to the synthesis and decomposition of abscisic acid (ABA), cell wall disintegration, and anthocyanin biosynthesis, as well as transcription factor genes, such as MYBs, bHLHs, and WD40s. LncRNAs can target these ripening-related genes to form regulatory modules, incorporated into the sweet cherry fruit ripening regulatory network. Our study reveals that the lncRNA-mRNA module is an important component of the sweet cherry fruit ripening regulatory network. During sweet cherry fruit ripening, the differential expression of lncRNAs will meditate the spatio-temporal specific expression of ripening-related target genes (encoding enzymes and transcription factors related to ABA metabolism, cell wall metabolism and anthocyanin metabolism), thus driving fruit ripening.

White phosphorus production by a carbothermic reduction of upcycled crude phosphoric acid

White phosphorous is a critically important material in manufacturing semiconductors and advanced pharmaceuticals. However, white phosphorus is produced by only four countries using the huge energy-consuming electric arc furnace process. These four countries have resorted to banning or restricting their exports causing a supply risk for white phosphorus for many industrialized countries.To meet the white phosphorous supply risk, the never-existing white phosphorous production process has been developed by applying the carbothermic reduction of P2O5 gas provided by the thermal decomposition of phosphoric acid. The novel process can produce semiconductor-grade high-purity white phosphorous from crude phosphoric acid recovered from secondary phosphorous resources.By supplying phosphoric acid in the form of small droplets, we have achieved continuous operation of white phosphorus production, which was previously impossible, and brings production efficiency to an industrial level. This process could significantly reduce the supply risk for countries that rely entirely on imported white phosphorus.

Allothermally Heated Reactors for Solar-Powered Implementation of Sulphur-Based Thermochemical Cycles

Catalytic sulphur trioxide splitting is the highest-temperature (650-950oC), endothermic step of several sulphur-based thermochemical cycles targeted to production of hydrogen or solid sulphur. Concentrated solar power tower plants are an attractive renewable energy source to provide the necessary heat. Furthermore, the development of solar receivers capable of delivering solid or gaseous heat transfer fluids at these temperature ranges enable the implementation of such endothermic reactions in allothermally-heated reactors/heat exchangers placed away from the solar receiver. In this context, a 2-kW laboratory-scale shelland-tube reactor/heat exchanger to perform thermal sulphuric acid decomposition and catalytic sulphur trioxide splitting was in-house designed, built and tested with electrically heated bauxite particles, in the perspective of eventually coupling such a reactor with a centrifugal particle solar receiver. Thermal test runs demonstrated the in-principle feasibility of the concept. The temperatures reached were sufficient to ensure complete sulphuric acid evaporation. However, the ones in the SO3 splitting zone were of the order of 750°C, high enough to demonstrate SO3 splitting but not reaching the levels required for close-toequilibrium conversion of the Fe2O3 catalyst system used (~ 850oC). An improved version of the reactor is under construction incorporating design modifications based on lessons learned from the test campaigns, in the perspective of scaling up the process.