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The presence of nitrate in groundwater and surface water in concentrations above levels suitable for human consumption is an increasingly common problem. This is mainly due to human activity, such as the excessive use of fertilizers and the inadequate deactivation of pits. Water analysis laboratories very often carry out analyses to determine nitrate to control the presence of this anion in water intended for human consumption. One of the most commonly used methods is spectrophotometry, both with commercially available kits and by direct measurement of specific wavelengths. However, in these methods, the presence of organic matter and chloride can influence the results obtained. Thus, in this study, the applicability of the simplification (without acidification) of two methods for the determination of nitrate in water by ultraviolet–visible absorbance was verified in the presence of the above-mentioned interfering factors, and it was found that the absorbance method at 220 nm corrected for the absorbance at 275 nm, in its simplified form without acidification, can be used with concentrations of organic matter of 20 mg L−1 for high nitrate concentrations (10 mg L−1 NO3-N). HIGHLIGHTS SM-4500 without acidification is suitable for nitrate determination in the presence of chloride and organic matter.; The presence of organic matter up to 20 mg L−1 did not interfere with the analysis of nitrate by the simplified method.; The SM-4500 method should not be used at nitrate concentrations up to 10 and 20 mg L−1 of organic matter.; Avoiding the use of HCl is in line with the fifth principle of green chemistry.;

Abstract Objectives The endosymbiosis with Symbiodiniaceae is key to the ecological success of reef-building corals. However, climate change is threatening to destabilize this symbiosis on a global scale. Most studies looking into the response of corals to heat stress and ocean acidification focus on coral colonies. As such, our knowledge of symbiotic interactions and stress response in other stages of the coral lifecycle remains limited. Establishing transcriptomic resources for coral larvae under stress can thus provide a foundation for understanding the genomic basis of symbiosis, and its susceptibility to climate change. Here, we present a gene expression dataset generated from larvae of the coral Pocillopora damicornis in response to exposure to acidification and elevated temperature conditions below the bleaching threshold of the symbiosis. Data description This dataset is comprised of 16 samples (30 larvae per sample) collected from four treatments (Control, High pCO2, High Temperature, and Combined pCO2 and Temperature treatments). Freshly collected larvae were exposed to treatment conditions for five days, providing valuable insights into gene expression in this vulnerable stage of the lifecycle. In combination with previously published datasets, this transcriptomic resource will facilitate the in-depth investigation of the effects of ocean acidification and elevated temperature on coral larvae and its implication for symbiosis.

Whether the oilfield sewage index can reach the reinjection specification is a crucial issue that is urgently need to be solved in polymer flooding systems. Thus the coagulability and floc morphology development of dual coagulants was systematically studied in different pH oily wastewaters. Acidification improved the deprotonation ability of coagulant. Hydrophobic associative polyaluminum silicate-poly dimethyl diallyl ammonium chloride (PASSC-PD) resolved the problem of excessive acid addition. The dual coagulants prepared not only preserved the high charge density of polyaluminum silicate (PASS) itself but also made it have the hydrophobic association and strong bridging ability. Besides, PASSC-PD was compared with hydrophobic associative polyaluminum silicate (PASS-C), PASS, and poly dimethyl diallyl ammonium chloride (PDMDAAC) pertaining to the polymer flooding oily sewage of Daqing Oilfield. The coagulation result demonstrated that PASSC-PD exhibited more advantageous turbidity and oil removal efficiencies than PASS-C, PASS, and PDMDAAC. The floc morphology result showed that adding dual coagulant made the petal-like floc of oily sewage larger at the pH value of 6. Furthermore relevant results evidenced that the coagulant had more successful fruits of turbidity removal of 96.5% and oil removal of 96.3% under weak acid conditions. These can satisfy the reinjection condition of oily sewage. [ABSTRACT FROM AUTHOR]

Aims Methods Results Conclusion As uterine extracellular pH decreases during the ischemic conditions of labor, but its effects on myometrial contraction are largely unknown, there is a need to elucidate its physiological effects and mechanisms of action. Furthermore, it is not known if any of the effects of extracellular acidification are affected by pregnancy, thus we also determined how gestation affects the response to acidification.Nonpregnant, mid‐, and term‐pregnant myometrial strips were obtained from humanely killed mice. Contractions were recorded under spontaneous, depolarized, and oxytocin‐stimulated conditions. The extracellular pH of the perfusate was changed from 7.4 to 6.9 or 7.9 in HEPES‐buffered physiological saline. Intracellular pH was measured using SNARF, and intracellular calcium was measured using Indo‐1. Statistical differences were tested using the appropriate t‐test.Extracellular acidification significantly increased the frequency and amplitude of spontaneous contractions in pregnant, but not nonpregnant, myometrium, whereas alkalinization decreased contractions. Intracellular acidification, via Na‐butyrate, transiently increased force in pregnant tissue. Intracellular pH was gradually acidified when extracellular pH was acidified, but extracellular acidification increased contractility before any significant change in intracellular pH. If myometrial force was driven by oxytocin or high‐K depolarization, then extracellular pH did not further increase force. Intracellular calcium changes mirrored those of force in the spontaneously contracting pregnant myometrium, and if calcium entry was prevented by nifedipine, extracellular acidification could not induce a rise in force.Extracellular acidification increases excitability, calcium entry, and thus force in pregnant mouse myometrium, and this may contribute to increasing contractions during labor when ischemic conditions and acidemia occur. [ABSTRACT FROM AUTHOR]

[Display omitted] • Acidification, coverage, microbe N conversion, adsorption combined for NH 3 reduction. • Rich H 2 SO 4 and sulfate remained on the vermiculite (VM) after 5 M H+ modification. • Giant CO 2 bubbles due to initial slurry acidification promoted the cover floating. • Vermiculite after 5 M H+ modification performed highest NH 3 reduction (68 %). • NH 4 +/ NH 3 adsorption by VM contributed little (4.7%) to the overall NH 3 mitigation. Animal slurry storage is an important ammonia (NH 3) emission source. Sulfuric acid (H 2 SO 4)-modified vermiculite coverage is a new promising technology for controlling NH 3 emission from slurry storage. However, the underlying mechanisms in controlling the mitigation effect remain unclear. Here, a series of experiments to determine the effect of H 2 SO 4 on the modified vermiculite properties, floating persistence, and NH 3 mitigation effect was conducted. Results showed that abundant H 2 SO 4 and sulfate remained on the outer surface and in the extended inner pores of the vermiculite with acidifying H+ concentrations higher than 5 M. An initial strong instantaneous acidification of surface slurry released rich carbon dioxide bubbles, strengthening cover floating performance. An acidification in the vermiculite cover layer and a good coverage inhibition interacted, being the two leading mechanisms for mitigating NH 3 during initial 40–50 days of storage. The bacterial-amoA gene dominated the conversion of NH 3 to nitrous oxide after 50 days of storage. Vermiculite with 5 M H+ modification reduced the NH 3 emissions by 90 % within the first month of slurry storage and achieved a 64 % mitigation efficiency throughout the 84 days period. With the development of the aerial spraying equipment such as agricultural drones, acidifying vermiculite coverage hold promise as an effective method for reducing NH 3 emission while absorbing nutrients from liquid slurry storage tank or lagoon. This design should now be tested under field conditions. [ABSTRACT FROM AUTHOR]

Background: Hyperosmolar aerosols appear to promote or suppress upper airway dysfunction caused by dehydration in a composition-dependent manner. We sought to explore this composition dependence experimentally, in an interventional human clinical study, and theoretically, by numerical analysis of upper airway ion and water transport. Methods: In a double-blinded, placebo-controlled clinical study, phonation threshold pressure (PTP) was measured prenasal and postnasal inhalation of hypertonic aerosols of NaCl, KCl, CaCl2, and MgCl2 in seven human subjects. Numerical analysis of water and solute exchanges in the upper airways following deposition of these same aerosols was performed using a mathematical model previously described in the literature. Results: PTP decreased by 9%–22% relative to baseline (p < 0.05) for all salts within the first 30 minutes postadministration, indicating effective laryngeal hydration. Only MgCl2 reduced PTP beyond 90 minutes (21% below baseline at 2 hours postadministration). By numerical analysis, we determined that, while airway water volume up to 15 minutes postdeposition is dictated by osmolarity, after 30 minutes, divalent cation salts, such as MgCl2, better retain airway surface liquid (ASL) volume by slow paracellular clearance of the divalent cation. Fall of CFTR chloride flux with rise in ASL height, a promoter of airway acidification, appears to be a signature of permeating cation (NaCl) and nonpermeating anion (mannitol) aerosol deposition. For hypertonic aerosols that lack permeating cation and include permeating anion (CaCl2 and MgCl2), this acid-trigger signature does not exist. Conclusions: Nonpermeating cation and permeating anion hypertonic aerosols appear to hydrate upper airways longer and, rather than provoke, may reduce laryngeal dysfunction such as cough and bronchoconstriction. [ABSTRACT FROM AUTHOR]

Acidification is a well-known treatment to reduce NH 3 emissions from livestock slurries by lowering their pH, but its application at the farm scale is still limited. The acid dosage depends on the acid strength and slurries composition. Acidification does not have a lasting effect and after the acid addition the slurry pH tends to rise due to its buffer system. By studying 54 samples of pig slurry, dairy cattle slurry and digestate, this study aimed to: (i) identify the chemical-physical parameters related to the sulphuric acid (98% w/w) dosage necessary to reduce pH at 5.5, and pH variation over time; (ii) develop predictive models for the acid dosage and the pH after one (pH1w) and two weeks (pH2w) of storage based on slurry composition by using regression trees (RT) and random forests (RF). Acid dosage ranged between 0.8 and 11.7 ml kg−1 increasing with slurry alkalinity, with digestate requiring significantly higher dosage than slurries. Pig slurry showed significantly higher pH increase than the other two slurries. Finally, the pH trend over time was negatively correlated with the solids content. The RF identified the alkalinity and the initial slurry pH as the most important variables in explaining the required acid dosage, while for pH1w and pH2w it identified the total organic carbon and volatile solids. Based on RF results, RT models accurately predicted required acid dosage (r2 = 0.881), the pH1w (r2 = 0.728) and pH2w (r2 = 0.667). Therefore, these simple models can have practical applications for reducing NH 3 emissions. • Acidification treatment reduces ammonia emissions from livestock slurry and digestate. • Correlations among slurry composition variables, acid dosage and pH trends were studied. • Needed acid dosage and pH trends were predicted with regression trees and random forests. • Needed acid dosage was accurately predicted by alkalinity and initial pH of the slurry. • PH trends over time were accurately predicted by total organic carbon and volatile solids. [ABSTRACT FROM AUTHOR]

BACKGROUND: Developing the stable and healthy emulsion-based food is in accord with the needs of people for health. In the present study, acidification at pH 3.0 of peanut polysaccharide (APPSI) was employed to regulate its conformation and further improve its advantages in preparing oil-in-water emulsion. RESULTS: The results indicated that acidification induced conversion of PPSI aggregates into linear chains. Increasing concentration promoted formation of cross-linked network structure shown in transmission electron microscopy images. Consequently, the viscosity, yield stress, storage modulus and flow activation energy significantly increased, further fabricating gel structure. Moreover, aggregation behavior suggested that more exposed proteins were involved in gel structure, thereby forming many hydrophobic cores as verified by fluorescence spectroscopy of pyrene. Afterwards, emulsion characteristics indicated that APPSI produced strong and thick steric hindrance around oil droplets and the coil-like interweaved chains locked the continuous phase, bringing strong elasticity and resistance to stress and creaming. Meanwhile, the lower fatty acid in APPSI-emulsion was released after simulated gastrointestinal digestion, mainly as a result of the high retention ratio of emulsion droplets. Furthermore, the elastic and viscous Lissajous curves suggested that the structure strength of APPSI-emulsion was similar to that of the salad dressing within the strain 53.22%. CONCLUSION: The conformation of PPSI after acidification at pH 3.0 was suitable for preparing the stable emulsion. The obtained emulsion could resist digestion and maintain a strong structure, comprising a cholesterol-free and low-fat salad dressing substitute. [ABSTRACT FROM AUTHOR]

Coastal waters often experience enhanced ocean acidification due to the combined effects of climate change and regional biological and anthropogenic activities. Through reconstructing summertime bottom pH in the northern Gulf of Mexico from 1986 to 2019, we demonstrated that eutrophication‐fueled respiration dominated bottom pH changes on intra‐seasonal and interannual timescales, resulting in recurring acidification coinciding with hypoxia. However, the multi‐decadal acidification trend was principally driven by rising atmospheric CO2 and ocean warming, with more acidified and less buffered hypoxic waters exhibiting a higher rate of pH decline (−0.0023 yr−1) compared to non‐hypoxic waters (−0.014 yr−1). The cumulative effect of climate‐driven decrease in pH baseline is projected to become more significant over time, while the potential eutrophication‐induced seasonal exacerbation of acidification may lessen with decreasing oxygen availability resulting from ocean warming. Mitigating coastal acidification requires both global reduction in CO2 emissions and regional management of riverine nutrient loads. Plain Language Summary: The northern Gulf of Mexico is an ecologically and economically vital coastal system facing acidification threats from both climate change and eutrophication (excess nutrients). The first robust multi‐decadal pH reconstruction from 1986 to 2019 revealed recurring summer bottom acidification in the Gulf's oxygen‐depleted "dead zone." These seasonal acidification and year‐to‐year differences were driven predominantly by respiration intensified by eutrophication. However, over multi‐decadal timescale, rising atmospheric CO2 and ocean warming emerged as the dominant acidification drivers. More severe acidification occurred in the "dead zone" each summer, and these waters were acidifying more rapidly over decades. Looking ahead, climate‐driven pH decline is projected to become more pronounced over time, while potential eutrophication impacts may lessen as warming reduces oxygen availability. Mitigating acidification requires global actions to curb CO2 emissions for slowing long‐term trends, as well as regional nutrient management for restraining seasonal intensification of acidification in nutrient‐rich coastal ecosystems. Key Points: We reconstructed summertime bottom acidification history (1986–2019) in the northern Gulf of Mexico and predicted future trends toward 2100Rising atmospheric CO2 and ocean warming drive decadal decline in pH baseline while eutrophication exacerbates summer acidificationLess buffered hypoxic bottom waters showed a higher decadal acidification rate (−0.0023 yr−1) than non‐hypoxic waters (−0.014 yr−1) [ABSTRACT FROM AUTHOR]

Objectives: The endosymbiosis with Symbiodiniaceae is key to the ecological success of reef-building corals. However, climate change is threatening to destabilize this symbiosis on a global scale. Most studies looking into the response of corals to heat stress and ocean acidification focus on coral colonies. As such, our knowledge of symbiotic interactions and stress response in other stages of the coral lifecycle remains limited. Establishing transcriptomic resources for coral larvae under stress can thus provide a foundation for understanding the genomic basis of symbiosis, and its susceptibility to climate change. Here, we present a gene expression dataset generated from larvae of the coral Pocillopora damicornis in response to exposure to acidification and elevated temperature conditions below the bleaching threshold of the symbiosis. Data description: This dataset is comprised of 16 samples (30 larvae per sample) collected from four treatments (Control, High pCO2, High Temperature, and Combined pCO2 and Temperature treatments). Freshly collected larvae were exposed to treatment conditions for five days, providing valuable insights into gene expression in this vulnerable stage of the lifecycle. In combination with previously published datasets, this transcriptomic resource will facilitate the in-depth investigation of the effects of ocean acidification and elevated temperature on coral larvae and its implication for symbiosis. [ABSTRACT FROM AUTHOR]

Chemodynamic therapy (CDT) based on intracellular Fenton reaction to produce highly cytotoxic reactive oxygen species (ROS) has played an essential role in tumor therapy. However, this therapy still needs to be improved by weakly acidic pH and over-expression of glutathione (GSH) in tumor microenvironment (TEM), which hinders its future application. Herein, we reported a multifunctional bimetallic composite nanoparticle MnO2@GA-Fe@CAI based on a metal polyphenol network (MPN) structure, which could reduce intracellular pH and endogenous GSH by remodeling tumor microenvironment to improve Fenton activity. MnO2 nanoparticles were prepared first and MnO2@GA-Fe nanoparticles with Fe3+ as central ion and gallic acid (GA) as surface ligands were prepared by the chelation reaction. Then, carbonic anhydrase inhibitor (CAI) was coupled with GA to form MnO2@GA-Fe@CAI. The properties of the bimetallic composite nanoparticles were studied, and the results showed that CAI could reduce intracellular pH. At the same time, MnO2 could deplete intracellular GSH and produce Mn2+ via redox reactions, which re-established the TME with low pH and GSH. In addition, GA reduced Fe3+ to Fe2+. Mn2+ and Fe2+ catalyzed the endogenous H2O2 to produce high-lever ROS to kill tumor cells. Compared with MnO2, MnO2@GA-Fe@CAI could reduce the tumor weight and volume for the xenograft MDA-MB-231 tumor-bearing mice and the final tumor inhibition rate of 58.09 ± 5.77%, showing the improved therapeutic effect as well as the biological safety. Therefore, this study achieved the high-efficiency CDT effect catalyzed by bimetallic through reshaping the tumor microenvironment. [ABSTRACT FROM AUTHOR]

In this article, we investigate acid fracturing, a promising method to increase the effectiveness of fractures in high temperature carbonate reservoirs. In order to determine the performance of acid fracturing in carbonate reservoirs, we conducted a lab scaled true triaxial acid fracturing experiment on high temperature carbonate rock. The fracture initiation, propagation behavior, and conductivity under the action of acid solution were analyzed. The 3-D micro computed tomography was applied to illuminate the fracture network patterns; coefficient of stress difference, acid etching time, and acid concentration were also analyzed. Results show acidification exhibits the lowest breakdown pressure compared with no-acidification, reduced by 58%. [ABSTRACT FROM AUTHOR]

Two acid thickeners, ADMC and ADOM, were prepared by aqueous solution polymerization using acrylamide (AM) and methacryloyloxyethyl trimethyl ammonium chloride (DMC) as raw materials, with or without the introduction of octadecyl polyoxyethylene ether methacrylate (OEMA). It was characterized by FTIR, 1H NMR, and the fluorescence spectra of pyrene. The double-layer thickening mechanism of ADOM was proved by comparing the thickening and rheological properties of ADMC and ADOM tested by a six-speed rotary viscometer and a HAKKE MARSIV rheometer during the acidification process. The results showed that the synthetic product was the target product; the first stage of the self-thickening ADOM fresh acid solution during high-temperature acidification was mainly affected by Ca2+ concentration, and the second stage of self-thickening was mainly affected by temperature. The residual viscosity of the 0.8 wt% ADOM residual acid solution was 250, 201.5, and 61.3 mPa·s, respectively, after shearing at 90, 120, and 150 °C for 60 min at a shear rate of 170 s−1. The thickening acid ADOM with a hydrophobic association structure has good temperature resistance and shear resistance, which can be used for high-temperature deep-well acid fracturing. In addition, no metal crosslinking agent was introduced in the system to avoid damage to its formation, and ADOM exhibited good resistance to Ca2+, which could provide ideas for the reinjection of the acidizing flowback fluid. It also has certain advantages for environmental protection. [ABSTRACT FROM AUTHOR]

Osteosarcoma (OS) is an aggressive primary tumor with the highest incidence in children and adolescents. Natural plant compounds (NPCs) have long been promising resources in the field of antitumor drug discovery because of their high efficacy and low toxicity. Here, the aim of this study is to investigate the potential inhibitory effects of Cyclovirobuxine D (CVB-D), a natural bioactive isolated from the traditional Chinese medicinal herb Huangyang, on OS cells. We showed that CVB-D reduced OS cell growth in vitro and in vivo. Mechanistically, CVB-D inhibited PI3K-AKT-mTOR pathway and initiated autophagy. On the other hand, CVB-D induced lysosomal over-acidification by interacting with the V-type proton ATPase 116 kDa subunit a1 (ATP6V0A1), ultimately leading to autophagy flux arrest which might be related to the inhibitory effect of CVB-D on OS cells. Conclusively, our results propose a potential foundation for CVB-D to be developed into an anti-OS drug and an autophagy inhibitor.

Our study aimed to investigate the use of verjus (green grape juice) as an acidifying agentfor improving the overall acid profile and balance of wine, lowering the pH and alcohol content and creating a sustainable winemaking practice that can be utilised in warm grape-growing regions, such as Texas, where pH levels range from 3.5 to over 4.0 in white juice and wine. Muscat Canelli wines were produced using two different treatments for pH and acidity balance. Verjus was produced by pressing under-ripe grapes resulting from crop thinning practices and added at two different rates of 2 % and 11 % to juice obtained from ripe grapes prior to fermentation. For all the wines produced, pH, titratable acidity (expressed as g/L Tartaric Acid), alcohol, glucose-fructose, l-malic acid, tartaric acid, potassium, polyphenols were analysed, and preference testing was performed via consumer sensory panels. Results obtained indicate that verjus can be used to balance pH and acidity as well as lower alcohol content. Consumer preference ranking indicated no significant differences between any of the treatments, while acidity rankings correctly distinguished the wines according to their acid levels. This work shows that the use of verjus as a pre-fermentation acidification agent could be a potential tool for winemaking to help mitigate the negative effects associated with climate change.

Ocean acidification, caused by the absorption of carbon dioxide (CO2) from the atmosphere into the ocean, ranks among the most critical consequences of climate change for marine ecosystems. Most studies have examined pH and CO2 trends in the open ocean through oceanic time-series research. The analysis in coastal waters, particularly in island environments, remains relatively underexplored. This gap in our understanding is particularly important given the profound implications of these changes for coastal ecosystems and the blue economy. The present study focuses on the ongoing monitoring effort that started in March 2020 along the east coast of Gran Canaria, within the Gando Bay, by the CanOA-1 buoy. This monitoring initiative focuses on the systematic collection of multiple variables within the CO2 system, such as CO2 fugacity (fCO2), pH (in total scale, pHT), total inorganic carbon (CT), and other hydrographic variables including sea surface salinity (SSS), sea surface temperature (SST) and wind intensity and direction. Accordingly, the study allows the computation of the CO2 flux (FCO2) between the surface waters and the atmosphere. During the study period, stational (warm and cold periods) behavior was found for all the variables. The lowest SST values were recorded in March, with a range of 18.8-19.3°C, while the highest SST were observed in September and October, ranging from 24.5-24.8°C. SST exhibited an annual increase with a rate of 0.007°C yr-1. Warmer months increased SSS, while colder periods, influenced by extreme events like tropical storms, led to lower salinity (SSS=34.02). The predominant Trade Winds facilitated the arrival of deeper water, replenishing seawater. The study provided insights into atmospheric CO2. Atmospheric fCO2 averaged 415 ± 4 µatm (2020-2023). Surface water fCO2sw presented variability, with the highest values recorded in September and October, peaking at 437 µatm in September 2021. The lowest values for fCO2sw were found in February 2021 (368 µatm). From 2020 to 2023, surface water fCO2sw values displayed an increasing rate of 1.9 µatm yr-1 in the study area. The assessment of fCO2sw decomposition into thermal and non-thermal processes revealed the importance of SST on the fCO2sw. Nevertheless, in the present study, it is crucial to remark the impact of non-thermal factors on near-shallow coastal regions. Our findings highlight the influence of physical factors such as tides, and wind effect to horizontal mixing in these areas. The CT showed a mean concentration of 2113 ± 8 μmol kg-1 and pH at in-situ temperature (pHT,IS) has a mean value of 8.05 ± 0.02. The mean FCO2 from 2020 to 2023 was 0.34 ± 0.04 mmol m-2 d-1 (126 ± 13 mmol m-2 yr-1) acting as a slight CO2 source. In general, between May and December were the months when the area was a source of CO2. Extrapolating to the entire 6 km2 of Gando Bay, the region sourced 33 ± 4 Tons of CO2 yr-1.

A basin-scale Mediterranean carbonate system model has been setup, building on the POSEIDON operational biogeochemical model. The spatial variability of carbonate system variables from a 13-year simulation (2010-2022) was validated against CARIMED in situ data (DIC, TA, pCO2), showing reasonable agreement in reproducing the observed patterns and preserving the dynamics in different areas, except a slight overestimation (~15 µmol/kg) of TA in the Eastern Levantine. The time-variability of model outputs (DIC, TA, pCO2, pH) was validated, against available time-series from Western (DYFAMED, Villefranche-PointB) and Eastern Mediterranean (HCB) sites, showing good agreement with the data, particularly for pCO2, pH and DIC. The model failed to reproduce the observed late summer peak of TA at DYFAMED/PointB sites, which may be partly attributed to the advection of lower alkalinity Atlantic water in the area. The seasonal variability of DIC and pCO2@20°C was found to be mainly controlled by winter mixing and the subsequent increase of primary production and net CO2 biological uptake, which appeared overestimated at HCB. Along with the reference simulation, three sensitivity simulations were performed, de-activating the effect of biology, evaporation and CO2 air-sea fluxes on DIC and TA, in order to gain insight on the processes regulating the simulated carbonate system variability. The effect of biological processes on DIC was found more significant (peak during spring) in the more productive North Western Mediterranean, while evaporation had a stronger impact (peak during late summer) in the Levantine basin. CO2 air-sea flux was higher in the Western Mediterranean, particularly the Gulf of Lions and Alboran Sea, as well as in river influenced areas, such as the N. Adriatic and along the pathway of the Black Sea Water in the Aegean. A weak release of CO2 was found in the Eastern Levantine and Libyan Sea. Its basin average (+2.1 mmol/m2/day) and positive trend (+0.1 mmol/m2/day/year) indicates a gradually increasing net CO2 ocean uptake. The simulated positive trends of DIC (0.77 μmol/kg/year) and TA (0.53 μmol/kg/year) in the North Western Mediterranean were consistent with observational and modelling studies, in constrast with the Levantine basin, where no significant trends were found for TA.

Mollusca species shell such as oyster shell (OS) and snail shell (SS), are discarded after taking the meat, and the discarded shell causes the environmental problems. Therefore, recycling shell waste could potentially eliminate the environmental problems. This study aimed to evaluate the potential of OS and SS as natural calcium resources. The minerals, calcium, magnesium, potassium, phosphorus and sodium were analyzed in OS and SS extracts. Among them, the calcium content was the highest: 36.87 (%) and 33.42 (%) in the OS and SS extracts, respectively. Further, the content of ionized bioavailable form of calcium in OS and SS was higher than that of CaCO3 under simulated gastrointestinal digestion conditions. Additionally, OS and SS were added to kimchi, and their inhibitory effect on kimchi acidification was evaluated by assessing pH, titratable acidity and microbial analysis. As the results indicated that the addition of OS and SS had little effect on inhibiting the growth of lactic acid bacteria. However, it was confirmed that calcium neutralizes the organic acids produced during fermentation. Overall, the results of this study provide preliminary information on the re-use of OS and SS extracts as ionized natural calcium supplements and fermentation retardants.

In order to further improve the adsorption performance of activated alumina, two kinds of adsorbents, rdtrate acidified activated alumina loaded lanthanum (LHAA) and loaded magnesium (MHAA), were prepared with the combination of nitrate acidification and chemical impregnation. The adsorption performance of LHAA and MHAA was studied, and the mechanism of fluoride removal was explored・ The results showed that the optimal removal rate of 20 mg/L fluoride water were 93% and 90% respectively, and the maximum adsorption capacities were 17. 64 mg/g and 10. 96 mg/g, respectively, when the adsorption time was 2 h, the dosage was 2 g/L, pH = 6, and the oscillation frequency was 180 r/min. The adsorption isotherms of fluoride ions by both of them conformed to the Langmuir isotherm model, and the adsorption kinetics fitting conformed to the pseudo second order kinetics. [ABSTRACT FROM AUTHOR]

A substantial amount of phosphorus (P) in the soil is not readily available for plant uptake. Certain species may enhance P availability from poorly soluble P forms. This study focused on improving our comprehension of the effect of two lupine species (L. albus and L. angustifolius) on soil's P mobilization and its link with soil acidity variations, comparing the response of the lupine species in terms of plant traits (i.e., aboveground biomass and nutrient uptake) with that of oats (Avena strigosa L.) in four contrasting soils (i.e., available P in soil, soil acidity, soil fertility, and texture). The phosphorus solubilization capacity was assessed on variations of P availability (PBray1) at four points in time, comparing soils with lupine to oat-containing soils and their baseline values. Compared to soils containing oats, at harvest, lupine soils had significantly increased PBray1 concentrations; the maximum average increment was around 5.3 mg kg−1, with L. albus in Sites 1 and 2, which presented higher organic matter (OM) contents than the other two sites. Lupine-induced soil acidification did not fully explain that P increase. Oats exhibited the highest increase in shoot dry weight in response to soil's P availability, while lupine was the least affected. Nevertheless, L. albus showed similar or higher nutrient uptake than oats across all soils. The manganese (Mn) concentration was high in both lupine species' shoot biomass; however, within each lupine species, across all soil types tested, these legumes had different Mn accumulation levels depending on the soil acidity. Lupinus albus had a higher ability to mobilize non-labile P in the light-textured soil with a high OM content, achieving comparable and higher plant P status than oats and providing N through biological N fixation (BNF), positioning it as a suitable crop for diversifying Uruguay's agricultural crop rotation systems. [ABSTRACT FROM AUTHOR]

Generic electromembrane extraction (EME) methods were developed and optimized for basic analytes of moderate or low polarity, employing prototype conductive vial EME equipment. Two generic methods, B1 and B2, were devised for mono‐ and dibasic compounds with distinct polarity windows: 2.0 < log P < 6.0 for B1 and 1.0 < log P < 4.5 for B2. In B1, 10 μL of 2‐nitrophenyl octyl ether served as the liquid membrane, while B2 utilized 10 μL of 2‐undecanone. Both methods involved the acidification of 125 μL of human plasma samples with 125 μL of sample diluent (0.5 M HCOOH for B1 and 1.0 M HCOOH for B2). The acceptor phase consisted of 250 μL of 100 mM HCOOH. Extraction was conducted for 30 min with agitation at 800 rpm, employing an extraction potential of 100 V for B1 and 50 V for B2. A set of 90 pharmaceutical compounds was employed as model analytes. Both B1 and B2 demonstrated high recoveries (40%–100%) for the majority of model analytes within their respective polarity windows. Intra‐day precision was within 2.2% and 9.7% relative standard deviation. Both extraction systems exhibited stability in terms of current, matrix effect values were between 90% and 109%. [ABSTRACT FROM AUTHOR]

The Dja2 knockout (Dja2−/−) mice had respiratory distress, and >60% died within 2 days after birth. The surviving adult Dja2−/− mice were infertile and the lungs of Dja2−/− mice showed several abnormalities, including the processing defect of prosurfactant protein C in the alveolar epithelial type II cells and the accumulation of glycolipids in enlarged alveolar macrophages. The luminal pH of acidic organelles in Dja2−/− cells was shifted to pH 5.37–5.45. This deviated pH was immediately restored to control levels (pH 4.56–4.65) by the addition of a diuretic, ethyl isopropyl amiloride (EIPA). Although the role of DJA2 in maintaining the pH homeostasis of lysosome‐related organelles is currently obscure, this rapid and remarkable pH resilience is best explained by an EIPA‐sensitive proton efflux machinery that is disorganized and overactivated due to the loss of Dja2. [ABSTRACT FROM AUTHOR]

Patients with mutations in Cldn16 suffer from familial hypomagnesaemia with hypercalciuria and nephrocalcinosis (FHHNC) which can lead to renal insufficiency. Mice lacking claudin-16 show hypomagnesemia and hypercalciuria, but no nephrocalcinosis. Calcium oxalate and calcium phosphate are the most common insoluble calcium salts that accumulate in the kidney in the case of nephrocalcinosis, however, the formation of these salts is less favored in acidic conditions. Therefore, urine acidification has been suggested to limit the formation of calcium deposits in the kidney. Assuming that urine acidification is causative for the absence of nephrocalcinosis in the claudin-16-deficient mouse model, we aimed to alkalinize the urine of these mice by the ablation of the subunit B1 of the vesicular ATPase in addition to claudin-16. In spite of an increased urinary pH in mice lacking claudin-16 and the B1 subunit, nephrocalcinosis did not develop. Thus, urinary acidification is not the only factor preventing nephrocalcinosis in claudin-16 deficient mice. [ABSTRACT FROM AUTHOR]

We re-examined the effects of acidification on Scandinavian freshwater lakes using paleolimnological reconstructions focused on subfossil chironomids. Our study showed a widespread shift in chironomid community composition occurring at around 1960 and corresponding with the maximum fallout of anthropogenic SO42− deposition. Results also showed that taxonomic turn-over was higher in chironomid records from nitrogen-limited lakes, likely due to the cumulative effects of acidification and eutrophication driven by atmospheric nitrogen deposition. Despite strong evidence of chemical recovery from acidification, all lake records failed to show a return to pre-acidified community compositions and most chironomid communities instead continue to follow the trajectories triggered by acidification. We hypothesized that when SO42− deposition started to decrease after 1980, a period also marked by rapid environmental and climatic changes, the influence of pH and/or other acidification-related variables in structuring chironomid community became less important, thus, giving more relative importance to other drivers, such as brownification and climatic processes. Results, therefore, suggest the key role of acidification in shaping the response of chironomid communities to future environmental changes. Future paleolimnological studies will contribute to better manage aquatic ecosystems recovering from acidification worldwide by allowing managers to quantify the efficacy of different management actions taken to mitigate acidification as well as to redefine appropriate restoration targets. [ABSTRACT FROM AUTHOR]

Gap junction channels are regulated by gates sensitive to cytosolic acidification and trans-junctional voltage (Vj). We propose that the chemical gate is a calmodulin (CaM) lobe. The fast-Vj gate is made primarily by the connexin's NH2-terminus domain (NT). The chemical gate closes the channel slowly and completely, while the fast-Vj gate closes the channel rapidly but incompletely. The chemical gate closes with increased cytosolic calcium concentration [Ca2+]i and with Vj gradients at Vj's negative side. In contrast, the fast-Vj gate closes at the positive or negative side of Vj depending on the connexin (Cx) type. Cxs with positively charged NT close at Vj's negative side, while those with negatively charged NT close at Vj's positive side. Cytosolic acidification alters in opposite ways the sensitivity of the fast-Vj gate: it increases the Vj sensitivity of negative gaters and decreases that of positive gaters. While the fast-Vj gate closes and opens instantaneously, the chemical gate often shows fluctuations, likely to reflect the shifting of the gate (CaM's N-lobe) in and out of the channel's pore. [ABSTRACT FROM AUTHOR]

Simple Summary: Creatinine is a marker commonly employed to quantify the amount of urine produced by dairy cattle, when a representative spot urine sample is collected. Combined with urine nitrogen content, the latter allows the measurement of the urinary nitrogen excretion, which is needed to partially assess the environmental impact of dairy farming. However, when urine is sampled, a quota of ammonia nitrogen tends to volatilize, potentially leading to an underestimation of the content of this element. This issue is normally prevented by sample acidification with sulphuric acid which, along with diluting the sample itself, could chemically alter the creatinine content, leading to bias in N excretion quantification. The purpose of our study was to assess whether acidification could affect the creatinine content and detection in urine, and the results demonstrate that acidification can influence its measurement in urine samples from dairy cattle. Nitrogen content in urine plays a crucial role in assessing the environmental impact of dairy farming. Urine acidifications avoid urine nitrogen volatilization, but potentially lead to a degradation of creatinine, the most dependable marker for quantifying total urine excretion volume, affecting its measurement. This study aimed to assess how acidifying urine samples affects the concentration and detection of creatinine in dairy cattle. In this trial, individual urine samples from 20 Holstein lactating dairy cows were divided into three subsamples, allocated to 1 of 3 groups consisting of 20 samples each. Samples were immediately treated as follows: acidification with H2SO4 (1 mL of acid in 30 mL of sample) to achieve a pH < 2 (Group 1)); addition of an equal volume of distilled water (1 mL of distilled water in 30 mL of sample) to investigate dilution effects (Group 2); or storage without any acid or water treatment (Group 3). An analysis of creatinine levels was carried out using the Jaffe method. The Friedman test was employed to compare urine groups across treatments, and the Bland–Altman test was used to assess the agreement between measurements in Group 1 and Group 3. Urinary creatinine values were statistically different (p < 0.001) between Group 1 (median 48.5 mg/dL; range 36.9–83 mg/dL), Group 2 (median 47.5 mg/dL; range 36.5–80.7 mg/dL), and Group 3 (median 48.9 mg/dL, range 37.2–84). Bland–Altman analysis demonstrates agreement between Group 3 and Group 1. The measurement of urinary creatinine using the Jaffe method is affected by sample acidification, but the use of creatinine as a marker for total urine output could remain a viable tool when urine samples are acidified. [ABSTRACT FROM AUTHOR]

Background: Acidification of equine urine to promote dissociation of ion complexes is a common practice for urine ion concentration measurements. The objective of this study was to evaluate the effect of acidification and storage after acidification on calcium (Ca), magnesium (Mg) and phosphate (P) concentrations and on fractional excretion (FE) of these electrolytes. Thirty-two fresh equine urine samples were analysed between December 2016 and July 2020. Complete urinalysis (stick and sediment) was performed on all samples. Ca, Mg, P and creatinine concentrations were measured in supernatant of centrifuged native urine, urine directly centrifuged after acidification and urine centrifuged 1 hour after acidification. Urine was acidified with hydrochloric acid to reach a pH of 1–2. Ca, Mg, P and creatinine concentrations were also measured in blood plasma, and fractional excretion of each electrolyte was calculated. Equality of medians was tested with Friedman tests and Bland-Altman bias plots were used to show the agreement between conditions. Results: Acidification had a statistically significant effect on Ca and Mg concentrations, FECa and FEMg. Bland-Altman plot revealed a strong positive proportional bias between Ca concentration in native and acidified urine with a mean bias of 17.6 mmol/l. For Mg concentration, the difference between native and acidified urine was small with a mean bias of 1.8 mmol/l. The increase in FECa was clinically relevant. Storage of acidified urine had no effect on any of the measured ion concentrations. All P concentrations in native urine samples were below the detection limit of the assay and statistical analysis and calculation of FEP was not possible. Conclusions: Urine acidification is essential for accurate measurement of Ca and Mg concentrations and therefore FE calculations in equine urine. Storage time of 1 hour after acidification does not significantly change Ca and Mg concentrations. [ABSTRACT FROM AUTHOR]

Starch production from fresh sweet potatoes generates process wastewater called sweet potato cell liquid (SPCL), which is rich in sweet potato protein (SPP). Currently, the commonly used protein recovery methods, such as isoelectric point precipitation and ultrafiltration, were not suitable for SPP recovery due to the low protein content of SPCL and the high cost of recovery. The feasibility of recovering SPP by SPCL acidification via inoculation-assisted fermentation was investigated in this study. The results indicated that the pH of SPCL could be reduced to approximately 4.0 within 6 h of fermentation with inoculation, resulting in an SPP extraction yield of 55.45% and purity of 66.23 g protein/100 g. With the addition of heating treatment, the extraction yield of SPP increased to 76.97-95.34%, while it maintained the purity of 66.36-70.12 g protein/100 g. The composition analysis revealed that SPP products contained sugars (below 11.5 g/100 g) in addition to protein and trace amounts of lignin and phenolics. Functional properties analysis showed that the SPP recovered by inoculation-enhanced fermentation exhibited better emulsifying and foaming properties, and higher digestibility compared to the SPP precipitated using hydrochloric acid. The method of extracting SPP from SPCL by inoculation-enhanced fermentation, as developed in this study, was a straightforward and cost-effective process that fosters significant potential for industrial applications. [ABSTRACT FROM AUTHOR]

An underemphasized aspect of sampling strategies in effect-based in vitro testing is to determine suitable collection and preparation techniques. In the current study, the impact of sample acidification on bioactivities was assessed using in vitro bioassays for hormone receptor-mediated effects (estrogen receptor [ER] and androgen receptor [AR]) and the oxidative stress response (Nrf2 activity). Sampling was conducted at a recently upgraded Swedish wastewater treatment plant. Future plans for the treated wastewater include reuse for irrigation or as a potential drinking water source. In the AR and Nrf2 assays, acidification decreased bioactivities in the wastewater influent sample extracts, whereas acidification increased bioactivities following further treatment (disc filtration). In the ER assay, acidification had no impact on the observed bioactivities in the sample extracts. A secondary objective of the study was to assess the stability of the sample extracts over time. Lower activities were detected in the ER and AR assays in all extracts after storage for approximately 1 year. Nrf2 activities did not decrease over time, but rather increased in some of the acidified sample extracts. Overall, the findings suggest that sampling strategies involving acidification may need to be tailored depending on the selected bioassay(s) and the type of wastewater treatments being assessed. [ABSTRACT FROM AUTHOR]

Crop removal of cations and anions is one of the main factors causing soil acidification. Mollisols, also known as black soils, which are inherently neutral soils, have been acidified due to irrational land use. However, the magnitude of acidification of black soils in relation to crop removal under crop rotation and field management remains unclear. In this study, we collect soil samples from 9- and 10-year long-term trials with seven treatments of soybean and corn monoculture, and corn–soybean rotation under different fertilization or straw return in the Mollisol region of Northeast China. Total removal of cations and anions is 371–508 and 92–125 kg ha−1 in corn but 166–250 and 56–82 kg ha−1 in soybean, which leads to the production of 7.06–10.2 kmol ha−1 H+ for corn and 4.43–5.77 kmol ha−1 H+ for soybean. Among the four cations (K+, Ca2+, Na+, and Mg2+) analyzed in different tissues of crops, K+ contributes more to the total H+ production, where K+ in corn stem contributes more than 55% H+, while K+ in soybean seed contributes more than 64% H+. The sum of Ca2+ and Mg2+ removal for soybean is 37.6–66.9 kg ha−1, 1.26–2.07 times (p < 0.05) greater than for corn. Net H+ produced by corn and soybean removal may potentially lead to a soil acidification of 0.053–0.074 and 0.032–0.045 year−1 units pH, respectively. The greater the corn or soybean biomass, the higher the net H+ production. Continuous soybean and combination of chemical fertilizer for corn but no chemical fertilizer for soybean reduce the soil pH buffering capacity (pHBC), while other treatments increase the soil pHBC, but there is no effect for continuous corn. Compared to normal corn–soybean rotation, soil pH in 9-year continuous corn declines from 5.76 to 5.63, while 10-year continuous soybean declines from 5.68 to 5.43 (p < 0.05). However, soil pH with chemical fertilizer for corn and dairy manure for soybean increases by 0.60 and 0.89 units (p < 0.05). Changes in pH might not be fully related to crop ion removal. Manure application with crop rotation is an effective approach to alleviate soil acidification. [ABSTRACT FROM AUTHOR]

Nitrous oxide (N2O) is a potent greenhouse gas, and its mitigation is a pressing task in the coming decade. However, it remains unclear which specific process between concurrent nitrification and denitrification dominates worldwide N2O emission. We snagged an opportunity to ascertain whence the N2O came and which were the controlling factors on the basis of 1315 soil N2O observations from 74 peer‐reviewed articles. The average N2O emission derived from nitrification (N2On) was higher than that from denitrification (N2Od) worldwide. The ratios of nitrification‐derived N2O to denitrification‐derived N2O, hereof N2On:N2Od, exhibited large variations across terrestrial ecosystems. Although soil carbon and nitrogen content, pH, moisture, and clay content accounted for a part of the geographical variations in the N2On:N2Od ratio, ammonia‐oxidizing microorganisms (AOM):denitrifier ratio was the pivotal driver for the N2On:N2Od ratios, since the AOM:denitrfier ratio accounted for 53.7% of geographical variations in N2On:N2Od ratios. Compared with natural ecosystems, soil pH exerted a more remarkable role to dictate the N2On:N2Od ratio in croplands. This study emphasizes the vital role of functional soil microorganisms in geographical variations of N2On:N2Od ratio and lays the foundation for the incorporation of soil AOM:denitrfier ratio into models to better predict N2On:N2Od ratio. Identifying soil N2O derivation will provide a global potential benchmark for N2O mitigation by manipulating the nitrification or denitrification. [ABSTRACT FROM AUTHOR]

In this study, the impact of high pressure homogenization at 50, 100 and 150 MPa, on the physicochemical, rheological, textural, microstructural, and sensory properties as well as acidification kinetics of low-fat yoghurt was investigated. The results showed that a shorter fermentation time was obtained for yoghurt samples produced from high-pressure homogenized milk compared to the control sample. Homogenization of milk at high pressures resulted in an increase in the water holding capacity from 42.83 to 52.67 % and firmness from 1.01 to 1.45 N of yoghurt samples. The viscosity (Ƞ50) of yoghurt increased up to 0.446 Pa.s by milk homogenization and all yoghurt samples showed shear thinning behaviour. Microstructural analyses revealed that control sample had a typical open porous gel network of casein, while fewer porous and more dense protein network was observed in yoghurts from high pressure homogenized milk. The positive effect of the milk homogenization treatment on the sensory properties of yoghurts was observed as well. Principal component analysis visualized the effect of high pressure homogenization treatment and confirmed the close relationship between structural properties and overall acceptability. Among the tested low-fat yoghurts, high pressure milk homogenization at 150 MPa had the greatest potential for improving yoghurt structure, whereas 100 MPa pressure imparted the most acceptable sensorial properties. [ABSTRACT FROM AUTHOR]

Global freshwater acidification, accelerated by rising pCO2, remains a critical ecological concern. Despite the prevalence of carboxylic acids like acetic acid (AA) and benzoic acid (BA) in freshwater, their potential to exacerbate acidification and impact biota is not fully understood. In this study, we examined behavioural disruptions during acute exposures (96 h) and operculum ultrastructure changes during chronic exposures (28 days) to ecologically-relevant concentrations of AA (39.7, 79.5, and 99.4 mg/L) and BA (31.4, 62.8, and 78.5 mg/L) in Bellamya bengalensis. Acute exposures revealed significant behavioural disruption, including reduced activity and impaired escape behaviour. Chronic exposures led to ultrastructural defects in the operculum, with more pronounced effects in BA-exposed groups. Acidification scenarios appeared to impact calcium carbonate crystal formation, compromising opercula structure. Our study underscores the importance of understanding both acute and chronic effects of freshwater acidification on molluscan species, emphasising the need for further research into the underlying mechanisms and thresholds of acidification tolerance. [ABSTRACT FROM AUTHOR]

The modification of substrate concentration and acidification level in inoculum treatment can significantly enhance hydrogen production while reducing costs. Hydrogen production showed a significant variation with food waste (FW) concentration, ranging from 10 to 120 gVS/L. Insufficient acidity at lower FW concentrations of 10, 20, and 40 gVS/L limited hydrogen production to 9.14, 5.70, and 7.78 mL/gVS, respectively, hindering hydrogen-producing bacteria dominance. However, higher FW concentrations facilitated rapid and strong substrate acidification at fermentation onset, effectively inhibiting the non-hydrogen producing bacteria and leading to a vast hydrogen production capacity of 68.63–120.78 mL/gVS. Rapid and substantial FW acidification is vital for effective inoculum treatment, highlighting its crucial role in this study. The findings support the potential use of FW inoculum treatment in generating highly productive microbial communities for hydrogen production. [Display omitted] • Acidification-based inoculum treatment of substrate enables cost-efficient H 2 production. • Variation in hydrogen production observed based on food waste concentrations. • Limited acidity inhibits H 2 production in low food waste concentration groups. • Rapid and strong acidification of substrate is crucial for successful inoculum pretreatment. • Inoculum treatment by food waste can generate productive microbial communities for H 2 production. [ABSTRACT FROM AUTHOR]

Hydrotropism is an important adaptation of plant roots to the uneven distribution of water, with current research mainly focused on Arabidopsis thaliana. To examine hydrotropism in tomato (Solanum lycopersicum) primary roots, we used RNA sequencing to determine gene expression of root tips (apical 5 mm) on dry and wet sides of hydrostimulated roots grown on agar plates. Hydrostimulation enhances cell division and expansion on the dry side compared with the wet side of the root tip. In hydrostimulated roots, the abscisic acid (ABA) biosynthesis gene ABA4 was induced more on the dry than the wet side of root tips. The ABA biosynthesis inhibitor Fluridone and the ABA‐deficient mutant notabilis (not) significantly decreased hydrotropic curvature. Wild‐type, but not the ABA biosynthesis mutant not, root tips showed asymmetric H+ efflux, with greater efflux on the dry than on the wet side of root tips. Thus, ABA mediates asymmetric H+ efflux, allowing the root to bend towards the wet side to take up more water. Summary statement: ABA regulates asymmetric H+ efflux, which is required for the root hydrotropic bending. [ABSTRACT FROM AUTHOR]

Acid-sensing ion channels (ASICs) are trimeric proton-gated sodium channels. Recent work has shown that these channels play a role in necroptosis following prolonged acidic exposure like occurs in stroke. The C-terminus of ASIC1a is thought to mediate necroptotic cell death through interaction with receptor interacting serine threonine kinase 1 (RIPK1). This interaction is hypothesized to be inhibited at rest via an interaction between the C- and N-termini which blocks the RIPK1 binding site. Here, we use two transition metal ion FRET methods to investigate the conformational dynamics of the termini at neutral and acidic pH. We do not find evidence that the termini are close enough to be bound while the channel is at rest and find that the termini may modestly move closer together during acidification. At rest, the N-terminus adopts a conformation parallel to the membrane about 10 Å away. The distal end of the C-terminus may also spend time close to the membrane at rest. After acidification, the proximal portion of the N-terminus moves marginally closer to the membrane whereas the distal portion of the C-terminus swings away from the membrane. Together these data suggest that a new hypothesis for RIPK1 binding during stroke is needed. [ABSTRACT FROM AUTHOR]

The research focuses on the features of acid sulfate soils formed in southern taiga on the territory of the closed Kizel Coal Basin in Perm Krai. The studied soils are Technosols (Thionic, Gleyic, Toxic), formed in the area of acid mine water outflow from the pit, and Technosols (Thionic, Toxic), formed as a result of acid mine water runoff from a coal dump that contains sulfide minerals. The purpose of the research was to establish the degree of technogenic soil transformation in comparison to natural soils and to conduct an ecological and geochemical assessment of those soils. The research used both conventional and customized methods. Inductively coupled plasma mass spectrometry was used to determine the concentration of heavy metals, trace elements, and iron in soil. It has been established, that the morphological and chemical properties of Technosols (Thionic, Gleyic, Toxic) and Technosols (Thionic, Toxic) differ. The continuous inflow of acid mine water to the surface is a more important transformation factor than intermittent dump runoff. Thus, the formation of a new technogenic layer, the production of an iron-bearing crust on the surface, gleyzation, and acidity ( 2.3–4.6) are typical of Technosols (Thionic, Gleyic, Toxic). Technosols (Thionic, Toxic) retain the profile of the background raw-humified gray-humus soil while also exhibiting acidity ( 2.8–3.1), clay loss, and no evidence of gleyzation along the profile. There is no heavy metal or microelement pollution in the studied soils. [ABSTRACT FROM AUTHOR]

Periphytic rotifer assemblages from lentic habitats are understudied. To improve knowledge on the principal environmental determinants of their structure and composition, we examined summer periphyton from 184 freshwater bodies from a taxonomic and multi-trait-based perspective. Only the latter allowed consideration of all bdelloids. Alpha diversity decreased with electrolyte and aluminium concentration but increased with macrophyte richness, pointing at salinization, metal toxicity and loss of structural niche heterogeneity as potential threats for rotifer diversity. Replacement was the prominent component of beta diversity, with acidified sites showing the highest local contributions. Variation partitioning indicated that local conditions explained variation in species composition best, but general setting (soil type, land cover, connectivity) and spatial context were also not insignificant. Redundancy analysis related species composition more particularly to gradients of pH and trophic status, whereas the representation of functional groups was structured mainly by phytoplankton productivity. Mirroring shifts observed in the plankton, high phytoplankton productivity associated with larger size and more detritibacterivory. Dominance of collectors constrained variation in guild ratios, underlining the need for more refined functional approaches. To aid the use of periphytic rotifers in regional water quality assessment, we identified indicators and community thresholds for pH and trophic variables and determined optima and tolerances for individual taxa. [ABSTRACT FROM AUTHOR]

Sodium caseinates–kefiran systems were studied to explore whether any potential interactions between them might exist. The study was performed using low‐deformation rheological techniques, which were dynamic and creep tests. The systems were prepared under various experimental conditions such as heating and acidification. Besides, the structure development of the systems in relation to time was also monitored using oscillatory shear rheometry. The results indicated that the structural characteristics of the systems were mainly affected by the state of the caseinates such as the formation of aggregates and to a lesser degree by the interactions of kefiran molecules with the caseinates. Freeze–thaw treatment produced cryogels with good thermal stability and fairly satisfactory mechanical properties. The morphology of the caseinate‐kefiran systems was also investigated by means of confocal laser scanning microscopy. [ABSTRACT FROM AUTHOR]

The current study conducted in March–April 2021 elucidated the acidification process of books using alkaline text paper and improved the method of pH measurement in a previous study from 2016. The pH was measured on various positions of Japanese books published in 2000–2020 using the same type of pH-indicator strip as used in 2016; however, a wetted pH-indicator strip was kept pressed to the text paper with fingers at approximately 5 kgf for 90 s to secure the transfer of water-extracted components for four times while a 250 g paperweight was mounted and kept for 60 s for two times in the 2016-study. This time, the pH was found to decrease faster in positions more readily exposed to outside air compared to the 2016-study. Immediately after publication of the book, the pH was approximately 7.8 in every position. The pH of the top edge corner and the surface near the top edge corner later decreased to a neutral pH 7.0 4–6 years and 7–9 years after publication, respectively. Approximately 20 years after publication, the centre of the page in the interior of the book also dropped to pH 7.1, suggesting that acidification steadily progressed, albeit slightly, even on alkaline paper. [ABSTRACT FROM AUTHOR]

Marine organisms are simultaneously exposed to anthropogenic stressors associated with ocean acidification and ocean warming, with expected interactive effects. Species from different trophic levels with dissimilar characteristics and evolutionary histories are likely to respond differently. Here, we perform a meta-analysis of controlled experiments including both ocean acidification and ocean warming factors to investigate single and interactive effects of these stressors on marine species. Contrary to expectations, we find that synergistic interactions are less common (16%) than additive (40%) and antagonistic (44%) interactions overall and their proportion decreases with increasing trophic level. Predators are the most tolerant trophic level to both individual and combined effects. For interactive effects, calcifying and non-calcifying species show similar patterns. We also identify climate region-specific patterns, with interactive effects ranging from synergistic in temperate regions to compensatory in subtropical regions, to positive in tropical regions. Our findings improve understanding of how ocean warming, and acidification affect marine trophic levels and highlight the need for deeper consideration of multiple stressors in conservation efforts. Marine organisms are increasingly exposed to both ocean acidification and warming. Here, the authors report a meta-analysis of fully factorial experiments with both acidification and warming treatments, finding that synergistic interactions are less common than expected. [ABSTRACT FROM AUTHOR]

Ocean acidification, caused by the absorption of carbon dioxide (CO2) from the atmosphere into the ocean, ranks among the most critical consequences of climate change for marine ecosystems. Most studies have examined pH and CO2 trends in the open ocean through oceanic time-series research. The analysis in coastal waters, particularly in island environments, remains relatively underexplored. This gap in our understanding is particularly important given the profound implications of these changes for coastal ecosystems and the blue economy. The present study focuses on the ongoing monitoring effort that started in March 2020 along the east coast of Gran Canaria, within the Gando Bay, by the CanOA-1 buoy. This monitoring initiative focuses on the systematic collection of multiple variables within the CO2 system, such as CO2 fugacity (fCO2), pH (in total scale, pHT), total inorganic carbon (CT), and other hydrographic variables including sea surface salinity (SSS), sea surface temperature (SST) and wind intensity and direction. Accordingly, the study allows the computation of the CO2 flux (FCO2) between the surface waters and the atmosphere. During the study period, stational (warm and cold periods) behavior was found for all the variables. The lowest SST values were recorded in March, with a range of 18.8-19.3°C, while the highest SST were observed in September and October, ranging from 24.5-24.8°C. SST exhibited an annual increase with a rate of 0.007°C yr-1. Warmer months increased SSS, while colder periods, influenced by extreme events like tropical storms, led to lower salinity (SSS=34.02). The predominant Trade Winds facilitated the arrival of deeper water, replenishing seawater. The study provided insights into atmospheric CO2. Atmospheric fCO2 averaged 415 ± 4 µatm (2020-2023). Surface water fCO2sw presented variability, with the highest values recorded in September and October, peaking at 437 µatm in September 2021. The lowest values for fCO2sw were found in February 2021 (368 µatm). From 2020 to 2023, surface water fCO2sw values displayed an increasing rate of 1.9 µatm yr-1 in the study area. The assessment of fCO2sw decomposition into thermal and non-thermal processes revealed the importance of SST on the fCO2sw. Nevertheless, in the present study, it is crucial to remark the impact of non-thermal factors on nearshallow coastal regions. Our findings highlight the influence of physical factors such as tides, and wind effect to horizontal mixing in these areas. The CT showed a mean concentration of 2113 ± 8 mmol kg-1 and pH at in-situ temperature (pHT, IS) has a mean value of 8.05 ± 0.02. The mean FCO2 from 2020 to 2023 was 0.34 ± 0.04 mmol m-2 d-1 (126 ± 13 mmol m-2 yr-1) acting as a slight CO2 source. In general, between May and December were the months when the area was a source of CO2. Extrapolating to the entire 6 km² of Gando Bay, the region sourced 33 ± 4 Tons of CO2 yr-1. [ABSTRACT FROM AUTHOR]

A basin-scale Mediterranean carbonate system model has been setup, building on the POSEIDON operational biogeochemical model. The spatial variability of carbonate system variables from a 13-year simulation (2010-2022) was validated against CARIMED in situ data (DIC, TA, pCO2), showing reasonable agreement in reproducing the observed patterns and preserving the dynamics in different areas, except a slight overestimation (~15 µmol/kg) of TA in the Eastern Levantine. The time-variability of model outputs (DIC, TA, pCO2, pH) was validated, against available time-series from Western (DYFAMED, Villefranche-PointB) and Eastern Mediterranean (HCB) sites, showing good agreement with the data, particularly for pCO², pH and DIC. The model failed to reproduce the observed late summer peak of TA at DYFAMED/PointB sites, which may be partly attributed to the advection of lower alkalinity Atlantic water in the area. The seasonal variability of DIC and pCO2@20°C was found to be mainly controlled by winter mixing and the subsequent increase of primary production and net CO2 biological uptake, which appeared overestimated at HCB. Along with the reference simulation, three sensitivity simulations were performed, de-activating the effect of biology, evaporation and CO2 air-sea fluxes on DIC and TA, in order to gain insight on the processes regulating the simulated carbonate system variability. The effect of biological processes on DIC was found more significant (peak during spring) in the more productive North Western Mediterranean, while evaporation had a stronger impact (peak during late summer) in the Levantine basin. CO2 air-sea flux was higher in the Western Mediterranean, particularly the Gulf of Lions and Alboran Sea, as well as in river influenced areas, such as the N. Adriatic and along the pathway of the Black Sea Water in the Aegean. A weak release of CO2 was found in the Eastern Levantine and Libyan Sea. Its basin average (+2.1 mmol/m² / day) and positive trend (+0.1 mmol/m² /day/year) indicates a gradually increasing net CO2 ocean uptake. The simulated positive trends of DIC (0.77 mmol/kg/year) and TA (0.53 mmol/kg/year) in the North Western Mediterranean were consistent with observational and modelling studies, in constrast with the Levantine basin, where no significant trends were found for TA. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of two chemical additives or a microbial inoculant on chemical composition and DM losses in whole-plant soybean silage. One-hundred and twenty mini-silos were used in a completely randomized design experiment with the following treatments: water without chloride (control, CON); a microbial inoculant (INO); a chemical additive containing 35–45% formic acid (FA type); and another chemical additive containing 50–60% propionic acid (PA type). Data were analyzed using mixed models of SAS, and treatment differences were evaluated by the following orthogonal contrasts: C1 = CON vs. additives (INO + FA type + PA type); C2 = INO vs. chemical additives (FA type + PA type); and C3 = PA type vs. FA type. Silage pH and ammonia nitrogen concentration were decreased, and concentrations of lactic acid and acetic acid were increased with additives. Counts of lactic acid bacteria were higher in silages with INO than with chemical additives. DM recovery increased with FA type and PA type. Additives increased DM and CP concentrations. Silage A-fraction proportion was greater with additives. Additives, particularly FA type and PA type, improved chemical composition and fermentative profile and reduced undigestible proportions of protein in whole-plant soybean silage. Chemical additives were more effective in reducing silage DM losses than INO. [ABSTRACT FROM AUTHOR]

The seawater fugacity of CO2 (fCO2) has been monitored hourly at an instrumented mooring at 6°S, 10°W since 2006. The mooring is located in the South Equatorial Current and is affected by the equatorial Atlantic cold tongue. This site is characterized by large seasonal sea surface temperature variations (>4°C). The fCO2 is measured by a spectrophotometric sensor deployed at about 1.5 meters deep. Measurements of seawater fCO2, sea surface temperature (SST) and sea surface salinity (SSS) are used to calculate total dissolved inorganic carbon (TCO2) and pH. Total alkalinity (TA) is calculated using an empirical relationship with SSS determined for this region. Satellite chlorophyll-a concentrations at 6°S, 10°W are low (<0.2 mg m-3) but some peaks over 0.8 mg m-3 are sometimes detected in August. Nevertheless, the site is a permanent source of CO2 to the atmosphere, averaging 4.7 ± 2.4 mmol m-2d-1 over 2006-2021. Despite the weakening of the wind, the CO2 flux increases significantly by 0.20 ± 0.05 mmol m-2d-1 yr-1. This suggests that the source of CO2 is increasing in this region. This is explained by seawater fCO2 increasing faster than the atmospheric increase during 2006-2021. Most of the seawater fCO2 increase is driven by the increase of TCO2, followed by SST. The fCO2 increase leads to a pH decrease of -0.0030 ± 0.0004 yr-1. The SST anomalies (SSTA) at 6°S, 10°W are correlated to the Tropical Southern Atlantic (TSA) index and to the Atlantic 3 region (ATL3) index with a correlation coefficient higher than 0.75. The strong positive phase of both ATL3 and TSA, observed towards the end of the time-series, is likely contributing to the strong increase of seawater fCO2. [ABSTRACT FROM AUTHOR]

Noninvasive phenotyping can quantify dynamic plant growth processes at higher temporal resolution than destructive phenotyping and can reveal phenomena that would be missed by end‐point analysis alone. Additionally, whole‐plant phenotyping can identify growth conditions that are optimal for both above‐ and below‐ground tissues. However, noninvasive, whole‐plant phenotyping approaches available today are generally expensive, complex, and non‐modular. We developed a low‐cost and versatile approach to noninvasively measure whole‐plant physiology over time by growing plants in isolated hydroponic chambers. We demonstrate the versatility of our approach by measuring whole‐plant biomass accumulation, water use, and water use efficiency every two days on unstressed and osmotically stressed sorghum accessions. We identified relationships between root zone acidification and photosynthesis on whole‐plant water use efficiency over time. Our system can be implemented using cheap, basic components, requires no specific technical expertise, and should be suitable for any non‐aquatic vascular plant species. [ABSTRACT FROM AUTHOR]