Complex Equilibrium Research Articles

Screening and unveiling antibacterial mechanism of dandelion phenolic extracts against Staphylococcus aureus by inhibiting intracellular Na+–K+ ATPase based on molecular docking and molecular dynamics simulation

Staphylococcus aureus is one of the most frequently food-contaminated incidence of healthcare-associated Gram-positive bacteria. The antibacterial function and mechanism of phenolic compounds from dandelion are still unclear. Herein, this work aims to screen one of dandelion phenolic extracts with the strongest antibacterial function from its organ such as flower, stem, leaf and root, and to reveal its antibacterial mechanism. The results indicated dandelion flower phenolic extract (DFPE) containing the highest content of caffeic acid, followed by luteolin and luteolin-7-O-glucoside. They, especially caffeic acid and luteolin-7-O-glucoside, played a key role in making the bacterial cellular-membrane ruptured against the bacteria. The leakage of the intracellular substances (adenosine triphosphate and Na+–K+ ATPase) was further confirmed. Conventional hydrogen bond, pi-anion, pi-alkyl were involved in the interaction between caffeic acid or luteolin-7-O-glucoside and Na+–K+ ATPase. Additionally, the dynamic equilibrium of the liganded ATPase complex were achieved after 105 ns, and the lower values from the radius of gyration and solvent accessible surface area in the complex demonstrated the highly tight and compact structure of the liganded protein. The highest free binding energy (ΔGbind = −47.80 kJ/mol) between Na+–K+ ATPase and luteolin-7-O-glycloside was observed. Overall, DFPE can be used as an effective anti-bacterial agent due to the contribution of its bioactive ingredients such as caffeic acid and luteolin-7-O-glucoside for membrane-breaking. Communicated by Ramaswamy H. Sarma

Influence of Cyclic Alkyl Carbonate Ring-Opening Processes on Electrode/Electrolyte Interphase Formation in Li-Ion Batteries

Cyclic alkyl carbonates, such as ethylene and vinylene carbonate (EC and VC), form solid electrolyte interphases (SEI) suppressing continuous solvent reduction at the graphite anode. There is a consensus that the choice of carbonate clearly affects SEI performance. VC has been observed to polymerize, forming poly(VC), but also to release major amounts of CO2,1,2 which are two seemingly contradictory processes. In this work, we present a detailed study of reaction pathways of EC and VC in typical Li-ion battery electrolytes. The rate of the decomposition reactions of these carbonates in presence of hydroxide is monitored using an injection cell coupled mass spectrometer at varying temperatures ranging from 30°C to 60°C. The activation energies from the Arrhenius relationship between the CO2 evolution rate and the cell temperature confirms that VC hydrolysis is autocatalytic rather than stoichiometric. Direct quantifications and comparisons of the solubilized reaction products will be done over varying times and temperatures with the help of in-situ nuclear magnetic resonance (NMR) and Raman spectroscopy that will help in clarifying the individual steps in the reaction process. The kinetic studies of EC and VC hydrolysis in model systems like this is an important step towards improving our understanding towards carbonates as there is always some trace amounts of hydroxides present in the cells. The complex interconversions and equilibria of these organic alkyl carbonates and oxides investigated herein, will add to the knowledge of interphase formation processes, and support the tailoring of electrolyte formulations in order to enhance performance of future Li-ion batteries.

Synthesis, equilibrium, DFT, and docking studies of a homopiperazine complex with dibutyltin(IV)

The interaction of dibutyltin(IV) dichloride (DBT) with 1,4-diazacycloheptane (homopiperazine, HP) was investigated. In solutions, the complexes formed a 1:1 complex, its protonated and hydrolyzed forms. The formation constants of the complexes and thermodynamic parameters as ΔH° and ΔS° were estimated. The optimization of the structure of the (Bu)2Sn(HP)Cl2 complex reveals that the tin is six-coordinate in a distorted octahedral geometry, where the two nitrogen atoms of homopiperazine and the two chloride ions are in one plane. The solid (Bu)2Sn(HP)Cl2 complex with homopiperazine was synthesized, and the composition was assigned by elemental micro-analysis and mass spectrum. The complex was investigated by infrared, mass spectra, and thermal measurements. The ligand and its complex were tested against antimicrobial Staphylococcus aureus (+ve), Escherichia coli (−ve), and antifungal Candida albicans and Aspergillus flavus. Anticancer activities of homopiperazine and its dibutyltin(IV) complex were tested against breast cancer cell lines. The molecular docking investigations were performed to know the possible modes of binding to the most active sites of the breast cancer oxidoreductase receptor and those of Escherichia coli.

A Spiropyran-Doped Poly(methyl methacrylate) Matrix for Sensor Applications

In this paper, the relaxation isomerization properties of a spiropyran-doped poly(methyl methacrylate) (PMMA) UV light-responsive dynamic material are presented. The polar liquid (acetonitrile) and solid (PMMA matrix) medium may contain two merocyanine isoforms of the selected spiropyran. A complex equilibrium of the colored and colorless spiropyran isoforms resulted in specific transformations of the absorption spectra during the relaxation process. Bands at 522 nm and 580 nm characterized the absorption of the fabricated dynamic material in the ground (non-activated) state in the visible range. The presence of colored and colorless isoforms of spiropyran incorporated into the PMMA matrix using Raman spectroscopy was revealed. The photosensitive polymer samples were irradiated with a UV LED (365 nm and 390 nm) under various temperatures (0–30 °C). Spectral changes within the relaxation process demonstrated their complex dynamics. Surprisingly, the photodegradation of the dynamic material was estimated at about 25% (using 390 nm) and 7% (using 365 nm) after eight photoswitch cycles for one isoform, and no fatigue after an additional one (using 390 nm) was discovered. The presented light-responsive material is of interest for UV sensors and new hybrid material design.

Multi-patch isogeometric Kirchhoff–Love shell analysis for post-buckling of functionally graded graphene platelets reinforced composite shells

This paper develops a multi-patch isogeometric Kirchhoff–Love shell method for post-buckling of functionally graded graphene platelets reinforced composite (FG-GPLRC) cylindrical, spherical, and conoidal shell structures, which are built with single or multiple NURBS patches. A penalty strategy is employed to weakly couple nonconforming interfaces between adjacent patches. The coupling work induced by enforcing displacement continuity and rotational continuity is added to the equilibrium equation, and the corresponding stiffness matrix is derived in detail. A simplified arc-length method is utilized to capture the complex equilibrium paths including snap-through and snap-back behaviors. Five distribution patterns of the shells including uniform (UD), V-type, A-type, O-type, and X-type are considered. The cylindrical and spherical shells are subjected to concentrated loadings at central points while for conoidal shells the concentrated loadings are enforced at the center points of an edge. The post-buckling of isotropic and laminated shell structures is first studied to validate the developed formulations by comparing the obtained results with those given in existing literature. Then a series of numerical examples considering nonlinear FG-GPLRC shell problems are conducted to explore the effect of various parameters like geometric dimensions, GPL distribution patterns, and shell thickness on the mechanical performance. Finally, the post-buckling of a cylindrical shell subjected to an offset concentrated load, with extremely complicated equilibrium paths, is modeled and analyzed by using the developed multi-patch isogeometric method. The numerical results reveal that the X-type GPL distribution pattern demonstrates better performance in load–deflection responses and provides the largest buckling critical load among the five patterns. Additionally, the increase in height ratio could deteriorate the stability performance of FG-GPLRC conoidal shells.

A Long-Term Follow-Up Study in Immune-Mediated Thrombotic Thrombocytopenic Purpura: What Are the Outcomes?

Endothelium damage triggers the multimeric protein von Willebrand factor (VWF) release and subsequent binding to platelets, which are recruited at sites of vascular injury. A complex and fragile equilibrium between circulating levels of von Willebrand factor and its metalloprotease, ADAMTS13, is responsible for the hemostatic balance. However, the presence of autoantibodies targeting ADAMTS13 results in an increase in von Willebrand factor, mainly in its ultra-large multimers. The latter lead to platelet aggregation, the formation of thrombi and microangiopathic hemolytic anemia. This pathologic condition, known as immune-mediated thrombotic thrombocytopenic purpura (iTTP), occurs with high morbidity and a high rate of relapses. In this work, the long-term follow-up of 40 patients with iTTP is reported. We assessed ADAMTS13 activity, plasmatic VWF levels and the ADAMTS13/VWF ratio, comparing iTTP relapsing patients with remitting ones. A decrease in the ADAMTS13/VWF ratio, along with a reduced ADAMTS13 activity, could serve as predictive and sensitive biomarkers of incoming relapses.

Hydrogen bond liquid cystals formed between pentyloxy benzoic acid and alkyl benzoic acids: chemical, optical, and thermal investigations

Chemical, optical, and thermal characterization are carried out for seven hydrogen bond thermotropic liquid crystalline complexes formed between pentyloxy benzoic acid (5BAO) and p-n-alkyl benzoic acids (nBA, where n refers alkyl carbon chain length which varies from ethyl to octyl. FTIR, 1H, and 13C Nuclear Magnetic Resonance (NMR) establishes the chemical investigations. Nematic and smectic F are the mesophases observed. Polarizing Optical Microscopic (POM) studies ensures the mesophases identified. Thermal investigation using Differential Scanning Calorimeter (DSC), provides the phase transition temperatures, enthalpy values, thermal stability factor, specific heat capacity values, and thermal equilibrium of the mesogenic complexes.

Calculation of Complex Chemical Equilibrium Using Optimization Package Ipopt

An approach to the calculation of complex chemical equilibrium using the open-source optimization package Ipopt and the open-source package JuMP is proposed. The code of two procedures written in the open-source Julia programming language for calculating the equilibrium composition and properties of multicomponent heterogeneous thermodynamic systems is presented. The results of the test calculations showed a good performance of the code and a relatively high speed of calculations. Due to the compactness and simplicity of the code, it can be easily integrated into other applications, or used in combination with more complex models.

Synthesis, Characterization, and Spectroscopic Studies of 2,6-Dimethylpyridyl-Linked Cu(I)-CNC Complexes: The Electronic Influence of Aryl Wingtips on Copper Centers.

Six new Cu(I) complexes containing pincer ligands of the type 2,6-bis(3-alkyl/arylimidazol-2-ylidene) methylpyridine I(R/R'Ar) ĈN̂C, where R = trifluoroethyl (TFE) and R' = 4-CF3, 4-NO2, 4-CN, 4-H, and 4-CH3, have been synthesized. These complexes, namely, [Cu(I(TFE)ĈN̂C)]PF6, 1-TFE; [Cu(ICF3Ar ĈN̂C]PF6, 2-CF3; [Cu(INO2Ar ĈN̂C)]PF6, 3-NO2; [Cu(ICNAr ĈN̂C]PF6, 4-CN; [Cu(IHAr ĈN̂C)]2(PF6)2, 5-H; and [Cu(ICH3Ar ĈN̂C)]2(PF6)2, 6-CH3, were fully characterized by 1H, 13C, and HMBC NMR spectroscopy, elemental analysis, electrochemical studies, and single-crystal X-ray crystallography. The crystallographic data revealed different structures and copper nuclearities for the complexes bearing aryl wingtips with electron-withdrawing (2-CF3, 3-NO2, and 4-CN) and electron-donating (5-H and 6-CH3) substituents. The solution-phase conductivity measurements in acetonitrile revealed a mix-electrolyte behavior for these complexes, supporting the presence of both mono- and binuclear forms of each complex. The fast monomer-dimer equilibrium of the Cu-CNC complexes at room temperature is reflected in their simple 1H NMR spectra in acetonitrile. However, both mono- and binuclear forms were identifiable in 1H diffusion-ordered spectroscopy (DOSY) at low temperatures. The dynamic behavior of these complexes in solution was further examined by variable-temperature 1H NMR (VT 1H NMR) experiments, and the relevant thermodynamic parameters were determined. The process was also probed by one-dimensional rotating-frame Overhauser enhancement spectroscopy (1D ROESY) experiments to elucidate the coexisting species in solution. The 2,6-dimethylpyridyl-linked Cu-CNC complexes also presented a quasi-reversible Cu(II)/Cu(I) couple in cyclic voltammetry studies, wherein a clear influence of the aryl wingtips on the E1/2 values was observed. Furthermore, the percent buried volumes (% Vbur) of the complexes were calculated, showing a similar steric hindrance around copper in all complexes. These findings support the importance of electronic effects, induced by the aryl wingtips, on the preferred coordination geometry, copper nuclearity, and redox properties of the Cu-CNC complexes.

Kinetic mechanism of wheat straw pellets combustion process with a thermogravimetric analyser

In this study, the combustion characteristics of two wheat straw pellets (WSP) (T1: 100% wheat straw and T5: 70% wheat straw; 10% sawdust, 10% biochar; 10% bentonite clay) were performed at a heating rate 20 °C/min under a temperature from 25 to 1200 °C in air atmosphere. A thermogravimetric analyser (TGA) was used to investigate the activation energy (Eα), pre-exponential factor (A), and thermodynamic parameters. The DTG/TG profile of WSP was evaluated by model-free and model-based methods and found the model-based method was suitable for WSP thermal characterisation. The result demonstrates that the thermal decomposition occurred in four stages, comprising four consecutive reaction steps. A→B→C→D→E→F. Further, the model-based techniques were best fitted with kinetic reaction models like Cn (nth-order reaction with auto-catalyst), Fn (reaction of nth order), F2 (second-order phase interfacial reaction) and D3 (diffusion control). The average Eα for Fn, Cn, D3 and F2 models were 164.723, 189.782, 273.88, and 45.0 kJ/mol, respectively, for the T1 pellets. Alternatively, for T5 pellets, the A was 1.17E+2, 1.76E+16, 5.5E+23, and 1.1E+3 (1/s) for F2, D3, Cn and Fn models. Overall, the thermodynamic properties showed that WSP thermokinetic reactions were complex and multi-point equilibrium, indicating a potentiality as a bioenergy feedstock.

The complexation of atmospheric Brown carbon surrogates on the generation of hydroxyl radical from transition metals in simulated lung fluid

Atmospheric particulate matter (PM) poses great adverse effects through the production of reactive oxygen species (ROS). Various components in PM are acknowledged to induce ROS formation, while the interactions among chemicals remain to be elucidated. Here, we systematically investigate the influence of Brown carbon (BrC) surrogates (e.g., imidazoles, nitrocatechols and humic acid) on hydroxyl radical (OH) generation from transition metals (TMs) in simulated lung fluid. Present results show that BrC has an antagonism (interaction factor: 20–90 %) with Cu2+ in OH generation upon the interaction with glutathione, in which the concentrations of BrC and TMs influence the extent of antagonism. Rapid OH generation in glutathione is observed for Fe2+, while OH formation is very little for Fe3+. The compositions of antioxidants (e.g., glutathione, ascorbate, urate), resembling the upper and lower respiratory tract, respond differently to BrC and TMs (Cu2+, Fe2+ and Fe3+) in OH generation and the degree of antagonism. The complexation equilibrium constants and site numbers between Cu2+ and humic acid were further analyzed using fluorescence quenching experiments. Possible complexation products among TMs, 4-nitrocatechol and glutathione were also identified using quadropule-time-of-flight mass spectrometry. The results suggest atmospheric BrC widely participate in complexation with TMs which influence OH formation in the human lung fluid, and complexation should be considered in evaluating ROS formation mediated by ambient PM.

Influence of doping with Co, Cu and Ni on the morphological and structural parameters and functional properties of ZnO nanoobjects

Recently, ZnO nanoobjects (nanoparticles, nanosheets, nanorods, nanoflowers, etc.) have been extensively studied due to their unique dielectric, optical and photocatalytic properties. Appearing on a nanoscale, these properties make ZnO nanoobjects a promising material in optoelectronics, photocatalytic degradation of cyclic pollutants in wastewater and other applications. Introducing 3d elements into the ZnO lattice not only results in appearing additional levels in the band gap, but also significantly impacts the process of nanoobject formation. While many works were devoted to the former issue, the latter has not been fully studied yet, which determined the direction of this work.In this context, we obtained undoped and Cu-, Co- and Ni-doped ZnO nanoobjects by the precipitation method. To study morphological and structural parameters of the samples obtained, they were characterised by a set of methods (XRD, SEM, FTIR, AES-ICP, SSA, XPS, Raman and absorbance spectroscopy). The developed approach was used in order to evaluate the amount of oxygen vacancies and defects in (un)doped ZnO from XPS and Raman spectra. As for functional properties, impedance spectroscopy as well as photoluminescence and photocatalytic activity studies were conducted.In this work, it was discovered that crystallite sizes become greater for doped ZnO nanoobjects and their values depend on the dopant hydroxo complex equilibrium constants. Doping changes a shape of nanoobjects: ZnO, Cu–ZnO and Ni–ZnO are nanosheets of different thickness, but Co–ZnO has a shape of nanoflowers. Oxygen vacancy and defect amount also changes in case of doped samples. As for functional properties, doping leads to an increase of photoluminescence, reduces ZnO nanoobjects’ dielectric losses and enhance photodegradation velocity of methylene blue.The results of the comprehensive study reveal the possibility of changing morphological, structural and consequently, functional parameters of ZnO nanoobjects by varying the chemical nature of the dopant. This leads to new opportunities in developing materials with desired properties.

Hydrophobically driven hosting – What about the guest?

The hosting of cyclic and linear aliphatic moieties by cucurbit[7]uril and β-cyclodextrin was investigated by means of ITC, 2D ROESY NMR spectroscopy, and by classical MD simulations. The cyclodextrin complexation thermodynamics at 298 K revealed classical hydration of the investigated guests. The results of the comparative calorimetric study clearly pointed out that the dehydration of cucurbituril cavity is accompanied with lower entropy changes compared to the analogous process involving cyclodextrin. A pronounced temperature dependence of ΔrH° (hence ΔrS°) unaccompanied by changes in product structure was observed for all studied systems. The effect was primarily due to temperature-induced disordering of the guest-hydrating water, i.e. gradual change from classical- towards non-classical hydration of the aliphatic moieties. The study thus reveals the effect of the guest and the cavity dehydration on the complexation thermodynamics while simultaneously providing rationale bridging the classical and non-classical hydrophobic effect. The obtained results also indicate that closer examination of the temperature influence on the corresponding complexation equilibria could further enhance the utilisation of the thermodynamic potential of hydrophobically driven association and result in a better understanding of water solvation properties.

Quantitative Proteomics of the CDK9 Interactome Reveals a Function of the HSP90-CDC37-P-TEFb Complex for BETi-Induced HIV-1 Latency Reactivation.

Brd4 has been intensively investigated as a promising drug target because of its implicated functions in oncogenesis, inflammation, and HIV-1 transcription. The formation of the Brd4-P-TEFb (CDK9/Cyclin T1) complex and its regulation of transcriptional elongation are critical for HIV latency reactivation and expression of many oncogenes. To further investigate the mechanism of the Brd4-P-TEFb complex in controlling elongation, mass spectrometry-based quantitative proteomics of the CDK9 interactome was performed. Upon treatment with the selective BET bromodomain inhibitor JQ1, 352 proteins were successfully identified with high confidence as CDK9-interacting proteins. Among them, increased bindings of HSP90 and CDC37 to CDK9 were particularly striking, and our data suggest that the HSP90-CDC37-P-TEFb complex is involved in controlling the dynamic equilibrium of the P-TEFb complex during BETi-induced reactivation of HIV-1 latency. Furthermore, the HSP90-CDC37-P-TEFb complex directly regulates HIV-1 transcription and relies on recruitment by heat shock factor 1 (HSF1) for binding to the HIV-1 promoter. These results advance the understanding of HSP90-CDC37-P-TEFb in HIV-1 latency reversal and enlighten the development of potential strategies to eradicate HIV-1 using a combination of targeted drugs.

Epoxy Phase-Change Materials Based on Paraffin Wax Stabilized by Asphaltenes.

The usual problem of meltable phase-change agents is the instability in their form upon heating, which can be solved by placing them into a continuous polymer matrix. Epoxy resin is a suitable medium for dispersing molten agents, but it is necessary to make the obtained droplets stable during the curing of the formed phase-change material. This work shows that molten paraffin wax forms a Pickering emulsion in an epoxy medium and in the presence of asphaltenes extracted from heavy crude oil. Theoretical calculations revealed the complex equilibrium in the epoxy/wax/asphaltene triple system due to their low mutual solubility. Rheological studies showed the viscoplastic behavior of the obtained dispersions at 25 °C, which disappears upon the heating and melting of the paraffin phase. Wax and asphaltenes increased the viscosity of the epoxy medium during its curing but did not inhibit cross-linking or reduce the glass transition temperature of the cured polymer. As a result of curing, it is possible to obtain phase-change materials containing up to 45% paraffin wax that forms a dispersed phase with a size of 0.2-6.5 μm. The small size of dispersed wax can decrease its degree of crystallinity to 13-29% of its original value, reducing the efficiency of the phase-change material.

Geometric acceleration of complex chemical equilibrium calculations — Performance in two- to five-component systems

Incorporating multicomponent, multiphase, complex chemical equilibrium calculations into process and multiphysics models can provide significant insights into industrial processes that current modelling or measurements cannot. Equilibrium calculations are however, in general, omitted or incorporated in a simplified manner due to their computational expense. Several methods have been developed to accelerate these calculations.A new accelerator algorithm was developed (Roos and Zietsman, 2021) based on phase diagram geometry, the Gibbs phase rule, and the lever rule to include equilibrium calculations into models more efficiently. This framework of established thermochemical theory provides a sound basis for discretisation and interpolation, and allows the accelerator algorithm to work in systems with any number of components. The work presented here aimed to test accelerator performance and demonstrate that it has the capability of achieving noteworthy levels of acceleration while maintaining acceptable accuracy.The accelerator was tested on ten 2-component systems, four 3-component systems, a simplified 4-component ilmenite smelting system, and a simplified 5-component iron- and steelmaking system. As the number of system components increased, so did the computational expense of direct equilibrium calculations. This translated to larger acceleration factors for higher-order systems — from 20 in 2-component systems to 1000 in the 5-component system. In a small number of cases it was observed that the acceleration factor was smaller than one during interpolation. This was attributed to slow searching times for suitable interpolation cells from the database.Phase composition interpolation errors are less than 1 × 10-2molmol−1. This translates to an interpolated phase composition being accurate to within 99% of the calculated composition and results in phase fraction errors of 1 × 10-2 and less. In a very small number of cases the interpolation errors made on physical and thermochemical properties are as high 10%. This is because system properties are calculated as a phase fraction weighted sum of phase properties and errors made on system properties can therefore become large due to interpolation errors being made twice. However, the majority of errors made on physical and thermochemical properties are in the order of 1% and less. The level of accuracy achieved by the accelerator algorithm was acceptable for the chosen discretisation tolerances.

Research Progress and Hot Spot Analysis of the Propagation and Evolution Law of Prefabricated Cracks in Defective Rocks.

The generation of rock mass disasters in underground engineering essentially arises from the disruption of the original three-dimensional stress equilibrium of the rock mass caused by excavation and other activities, leading to the redistribution of stress fields. During the excavation process, the engineering rock mass undergoes complex dynamic stress equilibrium processes involving loading and unloading. This equilibrium process promotes the nucleation, initiation, and propagation of pre-existing cracks in the surrounding rock, resulting in changes in the internal structure of the rock mass and a weakening of its strength. Eventually, this localized cracking extends to global failure. In order to understand the current status better and study the development trends in the study of crack propagation and evolution in defective rock, this study conducts a bibliometric analysis of 288 articles from the Web of Science Core Collection database using CiteSpace software (version 6.1.R4). The results indicate an increasing trend in the annual publication output, characterized by two phases of emergence and rapid development. The countries of China, the United States, and Iran have the highest publication output in this field. The most frequently cited journals include INT J ROCK MECH MIN, ENG FRACT MECH, and ROCK MECH ROCK ENG. This study provides a comprehensive analysis of the current status and development trends in the research on the propagation and evolution of pre-existing cracks. This study enhances the comprehension of crucial aspects of crack propagation and evolution in rock materials with defects. Moreover, it opens up new possibilities for future investigations and holds promising implications for researchers and practitioners in the field.

Water Consumption by Livestock Systems from 2002–2020 and Predictions for 2030–2050 under Climate Changes in the Czech Republic

The livestock system in Europe relies on a complex holistic equilibrium that is the outcome of an interplay of demand, market, crop production, livestock production, land use, water availability, and other factors. When modeling future scenarios of water consumption by livestock systems, the most suitable tools result from the interconnectivity of growth models, economic models, and climate models. We integrated the Environmental Policy Integrated Climate growth model (EPIC), animal-level model (RUMINANT), economic model (Global Biosphere Management Model, GLOBIOM), EURO-CORDEX climate models, and regression models. This study developed novel livestock production scenarios for individual regions of the Czech Republic with estimations of the categories of livestock that have been bred during the last 20 years and will be bred in the future and what their water consumption will be, both throughout the year and in particular seasons. First, the numbers of farm animals, namely, cattle, pigs, sheep, horses, goats, and poultry in 2002–2020 were evaluated, and their numbers were predicted for the following years until 2050. Second, livestock water consumption per region was determined based on the number of livestock individuals. Third, changes in the amount of water consumed by livestock per year in individual regions in 2050 compared to 2005 were estimated.

Global Renormalised Solutions and Equilibration of Reaction–Diffusion Systems with Nonlinear Diffusion

The global existence of renormalised solutions and convergence to equilibrium for reaction–diffusion systems with nonlinear diffusion are investigated. The system is assumed to have quasi-positive nonlinearities and to satisfy an entropy inequality. The difficulties in establishing global renormalised solutions caused by possibly degenerate diffusion are overcome by introducing a new class of weighted truncation functions. By means of the obtained global renormalised solutions, we study the large-time behaviour of complex balanced systems arising from chemical reaction network theory with nonlinear diffusion. When the reaction network does not admit boundary equilibria, the complex balanced equilibrium is shown, by using the entropy method, to exponentially attract renormalised solutions in the same compatibility class. This convergence extends even to a range of nonlinear diffusion, where global existence is an open problem, yet we are able to show that solutions to approximate systems converge exponentially to equilibrium uniformly in the regularisation parameter.

A sulfonated ligand-aqueous two-phase system for selective extraction of thorium from mining wastewater: Process optimization, structural characterization and mechanism exploration

As a potential nuclear fuel, the recovery of thorium with high efficiency, high selectivity and high extraction capacity from thorium-containing wastewater is considered to be one of the effective ways to reduce pollution and solve the shortage of thorium resources. However, the problem of efficient and selective separation of thorium from the complex environment has not been completely solved. Herein, a functional ligand called arsenazo (ASA), polyethylene glycol, and sodium sulphate were used to construct an aqueous two-phase system (ATPs) for the selectivity extraction and separation of thorium from mining wastewater. Furthermore, the complex agent, pH value, temperature, equilibrium time, coexisting substances, and other conditions for the extraction and separation of thorium were optimized, indicating that 98.7 % of thorium was efficiently and precisely separated from the acid-leaching solution to the pH of 2–3 or 5–6 with 0.08 g/L of ASA within 10 min, and the interference with multiple coexisting ions and organic substances was avoided. Importantly, the analysis of water quality parameters, thermogravimetry, infrared spectroscopy, and ultraviolet–visible spectroscopy revealed the coordination relationship between thorium ions and complex agents, indicating that the extraction of thorium in the aqueous two-phase system was a cation exchange mechanism. More importantly, SEM, TEM, EDX, and XRD verified that thorium was efficiently and selectively separated by a sulfone acid ligand-aqueous two-phase system, providing quantitative information on thorium-containing product distribution of relatively high accuracy and avoiding the interference with coexisting substance. Therefore, this work provided theoretical guidance on treating and reusing thorium in wastewater and enriched the content of functional ligand-aqueous two-phase extraction systems in green production technology.