Relative Stability Research Articles

Isolation and evaluation of bacteriophage cocktail for the control of colistin-resistant Escherichia coli

The frequent emergence of colistin-resistant E. coli worldwide drives the exploration of alternative therapies, and bacteriophages (phages) have emerged as promising candidates to tackle this challenge. In this study, three E. coli phages were isolated, screened, and evaluated against 96 colistin-resistant strains obtained from diverse sources. The combined recognition rate for these strains was 43.6%, while individually it ranged from 17.0% to 24.5%. Notably, among the tested phages (FJ3-79, SD1-92L, and FJ4-63), FJ4-63 demonstrated exceptional characteristics in regulating host population dynamics upon infection by exhibiting a shorter latent period (20 min) and a larger burst size (95.99 ± 3.61 PFU/cell). Furthermore, it exhibited relative stability at pH 3-11 and below 60°C. Transmission electron microscopy and genomic analysis classified phage FJ4-63 belongs to the Dhakavirus genus within the Straboviridae family. Its genome comprised a linear double-stranded DNA measuring 169,669 bp (containing 272 coding sequences) with a GC content of 39.76%, of which 93 (34.2%) had known functions, and the remaining 177 were annotated as hypothetical proteins. Additionally, two tRNAs were recognized, possess the “holin-endolysin” lytic system, and no resistance or virulence genes were detected. The phylogenetic tree and average nucleotide identity (ANI) analysis revealed that phage FJ4-63 exhibited the highest similarity to Escherichia phage C6 (679410.1), indicating a consistent close relationship within the same branch. The cocktail comprising three phages exhibits enhanced in vitro bactericidal efficacy compared to a single phage. At high doses with MOI = 100, it rapidly and completely eradicates bacteria within 1 h while significantly reducing bacterial biofilms. All this evidence suggests that lytic phages offer an effective solution for clinical treatment, with a phage cocktail demonstrating greater potential in the alternative management of colistin-resistant E. coli infections.

A importância do aprofundamento teórico-metodológico na formação docente e nas produções de materiais didáticos dialógicos no curso de Letras

The Bakhtinian approach has been present in Brazilian official curricular documents since the 1990s. However, its pedagogical appropriation has been guided by the linguistic structure to the detriment of social interaction (Faraco, 2009), demanding efforts in Portuguese school subject teacher training. In this article, the objective is to show how the dialogic discourse theory deepening can contribute to teaching materials production, based on Portuguese language major training experience at the University of São Paulo in 2020. In this experience, the theoretical-methodological approach includes the concepts of speech genres (Bakhtin, 2016 [1952-1953]) and theme (Volóchinov, 2018 [1929]) and on the production of didactic proposals aligned with the Base Nacional Comum Curricular (BNCC) (Brasil, 2018) and with the Sustainable Development Goals (SDGs) (Unesco, 2017). In this work, we analyze the proposal “Gênero do discurso e produção de texto: editorial” [“Speech genres and text production: editorial”], identifying the authors' observance of Bakhtinian discursive referents: i) sphere/field of human activity; ii) speech genre; iii) its relative stability; iv) multiple voices in statements; v) thematic totality. The results indicate dialogical quality in the material with the presence of elements that express social dynamics, confirming the relevance of theoretical deepening and its practical application in undergraduate teacher training.

Structural geology and tectonic influence on lineament density and slope variation in Southern Ebonyi, Nigeria: An ArcGIS Approach

This study investigates the structural geology and tectonic influences on lineament density and slope variation in Southern Ebonyi, Nigeria, using ArcGIS. The research aims to analyze the spatial distribution and density of lineaments and their correlation with slope variations to understand the region's geomorphology. Slope data was categorized into five classes, revealing that the majority of the area exhibits gentle slopes, indicative of tectonic stability. Conversely, regions with steeper slopes suggest localized tectonic activity. The analysis of lineament density identified areas with varying tectonic influences, with most of the study area showing low-density lineaments, suggesting relative tectonic stability. High-density lineament zones correspond to regions of significant tectonic deformation, often aligning with steeper slopes. The study concludes that the geomorphology of Southern Ebonyi is predominantly shaped by long-term erosional processes and localized tectonic activities. The novelty of this research lies in its comprehensive spatial analysis of both slope variation and lineament density, providing new insights into the tectonic and structural dynamics of the region.

Experimental synthesis of ThSiO4 by fluid-induced alteration of chevkinite-(Ce): Evidence for element mobility and variable crystal structure

During a series of high P-T experiments aimed at understanding the hydrothermal alteration of the REE,Ti silicate chevkinite-(Ce), three ThSiO4 phases (thorite, huttonite, and an amorphous ThSiO4 variety) were formed, showing a wide range of textures from small discrete grains to large-scale replacement of the chevkinite-(Ce). All three phases have compositions close to ThSiO4, except that the amorphous type contains small amounts of LREE (≤ 0.025 apfu) and inferred H2O. The three different forms have been confirmed by electron backscatter diffraction, which has also provided information on the microstructure of the crystals. The earliest phase to form was huttonite, composed of many randomly oriented microcrystals. This was later replaced by thorite via fluid-aided coupled dissolution-reprecipitation. The amorphous type formed both by apparent hydrous alteration of the original crystalline thorite and huttonite. The inferred sequence of events is compatible with thermodynamic constraints on the relative stability of thorite and huttonite.

High-ranking officials of the plenipotentiary representative offices of the President of the Russian Federation in the federal districts: recruitment channels and careers

The article covers the analysis of the main recruitment channels for high-ranking officials of the plenipotentiary representative offices of the President of the Russian Federation in the federal districts. As the empirical basis of the study serves the biographical database, that includes information on 154 presidential bureaucrats as of April 2023. Recruitment of people from various socio-professional groups to the apparatus of the plenipotentiary representative offices reveals a number of trends caused by interacting push (specific features of the candidate's position and associated resources and interests) and pull (place in the power system and functional specialisation of the plenipotentiary representative offices, specifics of leadership positions in them, as elements of the opportunity structure, as well as personal connections) factors. One of the most important trends is militarisation: most officials of the plenipotentiary representative offices have work experience in law enforcement agencies and even spent there most of their previous careers. Recruiting security officials who are, in terms of career, “ideal-typical” federal officials and professionally socialised within the framework of rigid, centralised hierarchies probably strengthens the autonomy of the plenipotentiary representations from actors and interests external to federal power, including regional administrations, that these bodies are called upon to control. The logic of autonomisation is also in line with the fact that one of the main suppliers (especially direct) of key officials of the plenipotentiary representations is the Presidential Administration, first of all, the apparatus of the representations themselves. However, a significant minority of presidential officials have experience working in regional administrations (especially among deputies and assistants to plenipotentiaries), as well as in business, both public and private (especially among plenipotentiaries and their deputies). At the same time positions in these structures rarely serve as a direct springboard to a key position in the plenipotentiary representations. Finally, the role of legislative bodies as a channel for recruiting presidential officials is insignificant. In general, the author's findings are consistent with the results of previous studies, indicating the relative stability of recruitment trends.

Transition-Metal-Mediated Radiohalogenation using Aryl Boron Reagents

AbstractBiomolecules labeled with radioisotopes of iodine and fluorine play a major role in science and medicine, with a range of applications including molecular imaging of disease, as radiopharmaceuticals for therapy and as tools for drug discovery. Due to the relative stability of Csp2–halogen bonds, radioiodine and radiofluorine labels are commonly incorporated into tracers via arene substitution. The wide availability of aryl boron reagents has led to their use for the development of radioiodination and radiofluorination methods, particularly using transition-metal complexes for accelerated reactions. Here, we review the range of transition-metal-mediated methods that have been developed for radiohalogenation of aryl boron compounds. Applications of these transformations for the preparation of molecular imaging agents and the use of new technologies to advance automated synthesis or high-throughput discovery are also described.1 Introduction2 Radioiodination Using Aryl Boron Reagents2.1 Applications of Copper-Mediated Radioiodination Reactions3 Radiofluorination Using Aryl Boron Reagents3.1 Radiofluorination Using Palladium, Nickel and Silver Complexes3.2 Radiofluorination Using Copper Complexes3.3 Applications of Copper-Mediated Radiofluorination Reactions3.4 New Technology for Copper-Mediated Radiofluorination Reactions4 Conclusions

Modelling the Non-linear Associations between Age and Health: Implications for Care

Abstract Background Ageing is a complex biological process that weakens the body's defences against various health problems and diseases. This decline is not uniform or linear; rather, it varies significantly among individuals. Understanding the non-linear progression of ageing is crucial for identifying critical periods where intervention might be most beneficial. This study aimed to explore nonlinearities in the association between age and health outcomes. Methods Using generalised additive models, we analysed data from the 2020 wave of the United States Health and Retirement Study. This modelling approach allows for the detailed examination of nonlinearities in health outcomes across different ages. Our sample consisted of adults aged over 50 (n = 1338; mean = 68; range = 50 – 95). We assessed seven health outcomes (heart conditions, diabetes, cholesterol, blood pressure, fatigue, back pain, and headaches) and seven protective behaviours (prostate exams, mammograms, cholesterol screenings, pap smears, flu vaccinations, dental check-ups, and smoking patterns) reflecting various aspects of health status and behaviour. Results The analysis indicated a significant and pronounced non-linear relationship between age and certain health outcomes, namely headaches, blood pressure, diabetes, and heart conditions. Additionally, ageing was non-linearly associated with specific health behaviours, including the uptake of prostate exams, mammograms, flu vaccinations, and smoking prevalence. Notably, distinct patterns emerged concerning health behaviours in relation to age-specific screening policies. Conclusion The findings of this study reveal that the probability of developing health problems or engaging in health protective behaviours do not increase/decrease linearly in direct proportion to age. Rather, the probability curve exhibits fluctuations, presenting periods of heightened odds interspersed with phases of relative stability. Such non-linearity may be partially attributed to policy decisions but could also reflect a complex interplay of factors such as weakened immune systems, access to healthcare, personal health beliefs, and the evolving perception of risk as one grows older.

Manuscript number: ejic.202400523Isomerism in Phenyl 2‐Pyridyl Ketoxime Metal Complexes

The octahedral complex [RhCl2(ppkoH)(ppko)] (1) was obtained from the reaction between RhCl3 and phenyl 2‐pyridyl ketoxime (ppkoH). Attempts to prepare the corresponding octahedral platinum compound from K2PtCl6 gave instead the square planar [Pt2+(ppko)2] (2), but when the halogen was changed to bromine, the octahedral [Pt4+Br2(ppko)2] (3) was formed. The crystal structures were determined by X‐Ray crystallography. All the compounds have two N,N‐chelating oxime ligands. In 1, one of them is deprotonated, while in 2 and 3 both ligands are deprotonated. Compounds 1 and 3 have two halogen ligands in trans position. In 1 the oxime groups are situated mutually in cis position with an intramolecular hydrogen bond between the two N‐O(H) groups. The formation of 2 involves reduction of the platinum metal and the complex has oximes in trans position to each other. Compound 3 has an all‐trans geometry. Since octahedral and square planar compounds have a possibility to isomerism, we studied the relative stability of different geometries by DFT calculations. A mixture of isomers is likely to be formed in the reactions, but the most stable form was found to crystallize. The properties of the electron density in the preferred isomers were also investigated via QTAIM methods.

Hydride and halide abstraction reactions behind the enhanced basicity of Be and Mg clusters with nitrogen bases.

In this study, we investigate the protonation effects on the structure, relative stability and basicity of complexes formed by the interaction of monomers and dimers of BeX2 and MgX2 (X = H, F) with NH3, CH2NH, HCN, and NC5H5 bases. Calculations were performed using the M06-2X/aug-cc-pVTZ formalism, along with QTAIM, ELF and NCI methods for electron density analysis and MBIE and LMO-EDA energy decomposition analyses for interaction enthalpies. The protonation of the MH2- and M2H4-Base complexes occurs at the negatively charged hydrogen atoms of the MH2 and M2H4 moieties through typical hydride abstraction reactions, while protonation at the N atom of the base is systematically less exothermic. The preference for the hydride transfer mechanism is directly associated with the significant exothermicity of H2 formation through the interaction between H- and H+, and the high hydride donor ability of these complexes. The basicity of both, MH2 and M2H4 compounds increases enormously upon association with the corresponding bases, with the increase exceeding 40 orders of magnitude in terms of ionization constants. Due to the smaller exothermicity of HF formation, the basicity of fluorides is lower than that of hydrides. In Be complexes, the protonation at the N atom of the base dominates over the fluoride abstraction mechanism. However, for the Mg complexes the fluoride abstraction mechanism is energetically the most favorable process, reflecting the greater facility of Mg complexes to lose F-.

Explainable machine learning model of disorganisation in swarms of drones.

The main challenges when managing a fleet of unmanned aerial vehicles are to ensure the relative stability of its formation and to minimise disorganisation, specifically when undergoing an intrusion. When planning the mission it is beneficial for the operator to set the parameters of the formation to balance the needs of the mission with the disorganisation that an intruder may cause. The model developed in this research predicts the anticipated disturbance as a function of the parameters of the formation. The effectiveness of six machine learning methods are compared with a previously established baseline, using data obtained from simulations. CatBoost (categorical boosting) delivered the best results, with an (coefficient of determination) value of 83.3%, representing an improvement of 80% over the baseline. The SHAP (Shapley Additive Explanations) method was used to extend the model beyond predictability for particular combinations of values of parameters, towards generalised recommendations for the operator of the formation.

Housing Insecurity and Older Adults' Health and Well-Being in a Gentrifying City: Results from the EPIPorto Cohort Study.

Using 2022 data from 600 adults (≥ 60years) in Porto, Portugal, we explored the association between housing insecurity and various health outcomes. We examined housing conditions, affordability, and stability in relation to loneliness, quality of life, cognitive function, perception of healthy ageing, and sleep using regression models. Older adults without house heating (β = 2.293; 95%CI = 0.753, 3.833), with leaks/dampness/rot (β = 3.741; 1.818, 5.664), insufficient daylight (β = 2.787; 0.095, 5.479), living in neighborhoods with noise (β = 1.793, 0.280 to 3.305), pollution/grime (β = 2.580; 0.746, 4.414), and violence/crime/vandalism (β = 3.940; 1.723, 6.157), who faced housing cost overburden (β = 2.001; 0.426, 3.577), eviction (β = 12.651; 0.852, 24.450), and moved frequently (β = 4.129; 1.542, 6.716) exhibited higher levels of loneliness. Similarly, lack of house heating (β = - 1.942; - 3.438, - 0.445), leaks/dampness/rot (β = - 4.157; - 5.999, - 2.316), insufficient daylight (β = - 3.124; - 5.714, - 0.534), noise (β = - 2.143; - 3.600, - 0.686), pollution/grime (β= - 2.093; - 3.860, - 0.325), violence/crime/vandalism (β= - 2.819; - 4.948, - 0.691), and those with housing cost overburden (β= - 2.435; - 3.930, - 0.940) reported lower quality of life.Those with no toilet (β = - 1.891; - 3.760, - 0.021) or shower (β = - 1.891; - 3.760, - 0.021) and who faced forced displacement (β = - 2.179; - 3.516, - 0.842) presented lower cognitive function. Furthermore, those living in neighborhoods with pollution/grime (OR = 0.494; 0.322, 0.756) and violence/crime/vandalism (OR = 0.477; 0.284, 0.801), those in social housing (OR = 0.728; 0.575, 0.922), and those who moved frequently (OR = 0.475; 0.257, 0.879) reported lower levels of perceived healthy ageing. Insufficient sleep was more common among residents in social housing (OR = 2.155; 1.102, 4.213), while poor sleep quality was least likely both among those living in social housing (OR = 0.445; 0.220, 0.900) and affordable housing (OR = 0.381; 0.162, 0.896). Good quality, stable, and affordable housing seems crucial for healthy ageing.

Understand the Relative Stability of Single-Gyroid to Double-Gyroid in AB-Type Block Copolymer: Chain Packing and Geometric Analysis

Understand the Relative Stability of Single-Gyroid to Double-Gyroid in AB-Type Block Copolymer: Chain Packing and Geometric Analysis

Leveraging neural networks to correct FoldX free energy estimates.

Proteins play a pivotal role in many biological processes, and changes in their amino acid sequences can lead to dysfunction and disease. These changes can affect protein folding or interaction with other biomolecules, such as preventing antibodies from inhibiting a viral infection or causing proteins to misfold. The ability to predict the effects of mutations in proteins is crucial. Although experimental techniques can accurately quantify the effect of mutations on protein folding free energies and protein-protein binding free energies, they are often time-consuming and costly. By contrast, computational techniques offer fast and cost-effective alternatives for estimating free energies, but they typically suffer from lower accuracy. Enhancing the accuracy of computational predictions is therefore of high importance, with the potential to greatly impact fields ranging from drug design to understanding disease mechanisms. One such widely used computational method, FoldX, is capable of rapidly predicting the relative folding stability ( ) for a protein as well as the relative binding affinity ( ) between proteins using a single protein structure as input. However, it can suffer from low accuracy, especially for antibody-antigen systems. In this work, we trained a neural network on FoldX output to enhance its prediction accuracy. We first performed FoldX calculations on the largest datasets available for mutations that affect binding (SKEMPIv2) and folding (ProTherm4) with experimentally measured . Features were then extracted from the FoldX output files including its prediction for . We then developed and optimized a neural network framework to predict the difference between FoldX's estimated and the experimental data, creating a model capable of producing a correction factor. Our approach showed significant improvements in Pearson correlation performance. For single mutations affecting folding, the correlation improved from a baseline of 0.3 to 0.66. In terms of binding, performance increased from 0.37 to 0.61 for single mutations and from 0.52 to 0.81 for double mutations. For epistasis, the correlation for binding affinity (both singles and doubles) improved from 0.19 to 0.59. Our results also indicated that models trained on double mutations enhanced accuracy when predicting higher-order mutations (such as triple or quadruple mutations), whereas models trained on singles did not. This suggests that interaction energy and epistasis effects present in the FoldX output are not fully utilized by FoldX itself. Once trained, these models add minimal computational time but provide a substantial increase in performance, especially for higher-order mutations and epistasis. This makes them a valuable addition to any free energy prediction pipeline using FoldX. Furthermore, we believe this technique can be further optimized and tested for predicting antibody escape, aiding in the efficient development of watch lists.

Thermodynamic study on the relative stability of 2-amino-1,3,4-thiadiazole and two alkyl-substituted aminothiadiazoles

Thermodynamic study on the relative stability of 2-amino-1,3,4-thiadiazole and two alkyl-substituted aminothiadiazoles

Sedimentary Greigite Formation

Revised thermodynamic data for greigite (Fe3S4) indicate that it is a stable sedimentary Fe-S phase. Greigite was previously regarded as metastable. Equilibrium computations using revised data explain apparently contradictory observations regarding greigite occurrences in sediments and sedimentary rocks. Greigite has a large stability area in pe-pH space relative to pyrite. It dominates in low pe regimes especially near the lower water stability boundary, which is consistent with its widespread occurrence in methanic sediments. It also has a small but significant stability zone near the sulfate-sulfide stability boundary. Its significance increases in regimes with relatively high dissolved Fe:S ratios, which explains its occurrence in freshwater sediments and iron-enriched marine sediments. It is also a paleoenvironmental marker for transitional environments, especially between freshwater and marine systems. It is stable relative to pyrrhotite and smythite, although their formation together with greigite in low pe environments may be facilitated by catalytic processes. The greigite-smythite (pyrrhotite)-siderite association is a potential marker for ancient methanogenesis. Greigite is relatively sensitive to oxidation and its long-term geological preservation depends mostly on protection from oxidation by low sediment permeability or enclosure in other minerals or organic remains. Most sedimentary and biological greigite forms via equilibrium reactions involving mackinawite-like precursors, with no direct coupling of greigite with pyrite; these minerals form independently during sedimentary diagenesis. Magnetosomal greigite production by magnetotactic bacteria is a consequence of relative greigite stability, its decoupling from pyrite, and its protection from oxidation by cell membranes.

Mass spectrometry provides insights into the structures of polyoxovanadate alkoxide clusters substituted with Fe and W heterometals

Atom-by-atom substitution is a promising strategy for tailoring the electronic properties of transition metal oxide clusters. This approach typically generates a mixture of species that are difficult to separate using conventional methods. As a result, the characterization of their structures and electronic properties remains challenging. Herein, we use collision-induced dissociation (CID) to study the fragmentation of well-defined Fe- and W-doped Lindquist polyoxovanadate methoxides synthesized as a mixture of singly and doubly substituted species. Fragmentation reveals that Fe heteroatoms are efficiently retained within the metal oxide core. In contrast, one W atom is incorporated into the primary WO2(OCH3)2 neutral loss from both the singly and doubly substituted W-containing clusters. Collision energy-resolved CID provides insights into the fragmentation pathways, which are compared to those of the homometallic polyoxovanadate methoxide species. The incorporation of Fe into the cluster reduces its stability towards fragmentation, which could be attributed to the increase in the relative stability of Fe-containing fragment ions with four metal atoms in comparison with their homometallic analog. The observed fragmentation is rationalized by assuming that Fe atoms are incorporated within the low valent plane, while one W atom occupies the axial out-of-plane position in the cluster.

Genetic stability evaluation of caladium somaclonal variants by morphological, cytological, and SSR analysis in three successive generations

Somaclonal variants with valuable agronomic traits play a crucial role in crop breeding, provided that they are stably passed down in subsequent generations. Although numerous somaclonal variants have been identified and studied among in vitro regenerated plants in the foliage plant caladium (Caladium × hortulanum Birdsey), no research has been carried out to evaluate their genetic stability in subsequent generations. This study aimed to evaluate the genetic stability of three types of diploid caladium somaclonal variants, previously derived from in vitro callus cultures, over three successive tuber-propagated generations. The analysis of quantitative morphological characteristics revealed a greater degree of variation among the established plants in the first generation (G1) compared to the second (G2) and third generations (G3). Seven plants exhibiting distinct leaf coloration changes were identified in the G1 generation and were found to be stably passed down to the subsequent G2 and G3 generations. These findings indicate a wide range of morphological variation in the G1 generation, followed by relative stability in subsequent generations. A comprehensive cytological and molecular analysis revealed that five of the seven newly observed variants displayed notable differences in relative nuclear DNA content, chromosome number, or SSR (simple sequence repeat) banding patterns compared to their corresponding normal counterparts. The findings of this study will be instrumental in developing new cultivars with distinctive plant morphology through the exploitation of somaclonal variation in caladium.

Modeling and control of perturbation torques and mass distribution impact on a tethered system for a 12U CubeSat in sun-synchronous orbit

Tethered CubeSat systems are characterized by momentum exchange and gravity gradient stabilization, and encounter stability challenges, especially with shorter tethers in highly inclined and eccentric orbits. This study investigates the libration dynamics of a 12U CubeSat in its stowed configuration, which separates into two satellites connected via tether, throughout its deployment, station-keeping, and retrieval phases. Two deployed configurations, symmetrical 6U-6U, and asymmetrical 8U-4U connected by a non-conductive tether with a maximum length of 100m are analyzed. The study accounts for perturbations including Earth’s oblateness, atmospheric drag, solar radiation pressure, and lunisolar gravitation, modeling the tether as a rigid, extendable rod and the satellites as lumped masses. The translational and rotational dynamics are decoupled, assuming the system’s center of mass follows an unperturbed Keplerian Sun-synchronous orbit at altitudes between 400 and 600km. A tension control strategy based on Lyapunov’s direct method and supplemented by external actuation torques is explored. Results show high orbit eccentricity significantly affects the maximum in-plane libration angle. The 6U-6U system experiences smaller disturbance torques but greater tether tension variations than the 8U-4U system. Both configurations exhibit larger in-plane oscillations compared to near-zero out-of-plane oscillations, nonetheless, eclipse passages exacerbate the out-of-plane libration of the 8U-4U system. Relative stability is maintained during deployment, however, retrieval is chaotic, with notable oscillations in libration angles and tether tension. The tension control strategy effectively dampens oscillations during retrieval but loses effectiveness as tether tension approaches zero at retrieval’s conclusion. External actuation torques, ranging from 1-2mNm for deployment to 15mNm for retrieval, complement tension control.

Reducing the Sodium Adsorption Ratio Improves the Soil Aggregates and Organic Matter in Brackish-Water-Irrigated Cotton Fields

The assessment of soil health relies on key parameters such as soil aggregates and organic matter content. Therefore, examining the impact of irrigation water ion composition and variations in salinity on soil aggregates and organic matter is imperative, which is key to developing a theoretical basis for the sustainable utilization of saline water resources, particularly in extremely arid regions. This experiment was conducted to investigate the impact of different irrigation water salinity treatments (T3: 3 g/L, T5: 5 g/L, and T7: 7 g/L) on the root zone soil of cotton fields. Each salinity treatment included three variations of the sodium adsorption ratio (SAR) at S10: 10 (mmol/L)1/2, S15: 15 (mmol/L)1/2, and S20: 20 (mmol/L)1/2. Local freshwater irrigation served as the control, resulting in a total of 10 treatments. Our findings show that the soil Ca2+ and Mg2+ content increased with higher irrigation water salinity but decreased with increasing irrigation water SAR. The relative macroaggregate stability and the content of water-stable macroaggregates and soil organic matter (SOM) decreased as the irrigation water salinity and SAR increased. In comparison to T3S20, T5S10 did not improve the soil Na+ content but significantly increased the soil Ca2+ content by 147.76%, while the water-stable aggregate and SOM saw a notable increase of 7.66% and 9.86%, respectively. Reducing the SAR in brackish water lessens its negative impact on soil aggregates in cotton fields. This is primarily because Ca2+ counteracts the dispersive effect of high Na+ concentrations and promotes aggregate formation. Irrigation water with a salinity of 3 g/L and an SAR of 10 (mmol/L)1/2 positively affected the stabilization of soil aggregates and organic matter.

CO2 hydrogenation to methanol over Pt functionalized Hf-UiO-67 versus Zr-UiO-67.

Sustainable methanol formation from CO2/H2 is potentially a key process in the post-fossil chemical industry. In this study, Hf- and Zr-based metal-organic framework (MOF) materials with UiO-67 topology, functionalized with Pt nanoparticles, have been tested for CO2 hydrogenation at 30 bar and 170-240°C. The highest methanol formation rate, 14 molmethanol molPt-1 h-1, was obtained over a Hf-based catalyst, compared with the maximum of 6.2 molmethanol molPt-1 h-1 for the best Zr-based analogue. However, changing the node metal did not significantly affect product distribution or apparent activation energy for methanol formation (44-52 kJ mol-1), strongly indicating that the higher activity of the Hf-based analogues is associated with a higher number of active sites. Both catalysts showed stable catalytic performance during testing under kinetic conditions, but the addition of 2 vol% water to the feed induced catalyst deactivation, in particular the Hf-MOFs. Interestingly, mainly methanol and methane formation rates decreased, while CO formation rates were less affected by deactivation. No direct correlation was found between catalytic stability and framework stability (crystallinity, specific surface area). Experimental and computational studies suggest that water adsorption strength to the MOF node may affect the relative catalytic stability of Hf-UiO-67-Pt versus Zr-UiO-67-Pt methanol catalysts.This article is part of the discussion meeting issue 'Green carbon for the chemical industry of the future'.