Soluble Ca Research Articles

Growth performance, real-time gizzard pH and calcium solubility in the gut of broiler chickens is dependent on the interaction between dietary calcium concentration and limestone particle size

ABSTRACT 1.The purpose of this study was to determine the effect of limestone particle size and dietary Ca concentration on performance, real-time gizzard pH, and Ca and P solubility in the gastrointestinal tract of 21d broiler chickens. 2. A total of 576, one-day-old Ross 308 male broilers were randomly allocated among 4 treatments, with 8 replicate pens, and 18 birds per pen. Treatments were arranged as a 2 × 2 factorial consisting of two particle sizes of limestone (coarse, CL, 1200 µm; fine, FL, 44 µm) and two Ca concentrations (9.6 or 6.0 g/kg). On d 19 and 20, four birds per treatment were administered Heidelberg pH capsules and readings monitored for 3 h. 3. Reducing Ca concentration from 9.6 to 6.0 g/kg had no effect on d 21 weight gain or FCR of birds fed CL; however, feeding FL at 9.6 g/kg Ca increased weight gain by 10% and reduced FCR by 5% compared to FL at 6.0 g/kg Ca (P < 0.001). 4. Average gizzard pH readings ranged from pH 0.67 to 3.01 across all treatments. Birds fed CL at 6.0 g/kg Ca had lower average gizzard pH compared to birds fed 9.6 g/kg Ca, while birds fed FL at 6.0 g/kg Ca had higher gizzard pH than birds fed CL at both Ca concentrations, but was comparable to birds fed FL at 9.6 g/kg Ca (P < 0.001). 5. For birds fed CL at 6.0 g/kg Ca, soluble Ca in the gizzard was approximately 40% lower (P < 0.05) than all other treatments, and reduced by 44% (P < 0.05) in the small intestine compared with birds fed FL at 6.0 g/kg Ca. 6. These findings demonstrated that the effect of Ca concentration on gizzard pH, Ca solubility and broiler performance was dependent on limestone particle size and suggested that solubility per se had little relevance to performance.

Enhanced degradation of glucocorticoids, a potential COVID-19 remedy, by co-fermentation of waste activated sludge and animal manure: The role of manure type and degradation mechanism

Waste activated sludge (WAS) and animal manure are two significant reservoirs of glucocorticoids (GCs) in the environment. However, GC degradation during anaerobic digestion (AD) of WAS or animal manure has rarely been investigated. In this study, co-fermentation of WAS and animal manure was conducted to investigate the performance of AD in controlling GC dissemination. Effects of manure type on GC degradation and sludge acidification were investigated. The results showed that co-fermentation of WAS and chicken manure (CM) significantly enhanced the degradation of hydrocortisone (HC) to 99%, betamethasone (BT) to 99%, fluocinolone acetonide (FA) to 98%, and clobetasol propionate (CP) to 82% in 5 days with a mixing ratio of 1:1 (g TS sludge/g dw manure) at 55 °C and initial pH of 7. Simultaneously, sludge reduction was increased by 30% and value-added volatile fatty acid (VFA) production was improved by 40%. Even a high GC content of biomass (3.6 mg/g TS) did not impact both sludge hydrolysis and acidification. The amendment of WAS with CM increased soluble organic carbon, Ca2+, and relative abundance of anaerobes (Eubacterium) associated with organic compound degradation. Furthermore, 44 transformation products of HC, BT, FA, and CP with lower lipophilicity and toxicity were identified, indicating possible degradation pathways including hydroxylation, ketonization, ring cleavage, defluorination, hydrogenation, methylation, and de-esterification. Overall, this study provides a practical way to control GC pollution and simultaneously promote waste reduction and VFA production. Animal manure type as an overlooked factor for influencing co-fermentation performance and pollutant degradation was also highlighted.

Effects of Wheat Straw-derived Biochar Application on Soil Carbon Content Under Different Tillage Practices

This study intended to examine the influence of biochar application on soil carbon content under different tillage conditions. For this, an indoor incubation experiment was performed with treatments included wheat straw-derived biochar application (0, 5, and 20 g·kg-1) and soil with different tillage measures (ploughing and no-tillage). The effects of biochar addition on soil organic carbon (SOC), dissolved organic carbon (DOC), soil microbial biomass carbon (MBC), readily oxidized organic carbon (ROC), soil inorganic carbon (SIC), pH, water soluble calcium and magnesium, and soil CO2 emissions were analyzed. The results showed that:① Compared with the control, the contents of SOC, ROC, DOC, and water soluble Ca and Mg increased by 20.3%-105.6%, 0.5%-36.0%, 0.8%-30.5%, 3.5%-42.3%, and 2.4%-75.2% in the no-tillage treatments, respectively; and the contents of SOC, ROC, DOC, water-soluble Ca and Mg increased by 29.2%-145.1%, 1.3%-63.9%, 2.4%-55.6%, 18.2%-89.8%, and 10.1%-150.5% in the ploughing treatment, respectively, under different dosage biochar amendments, and was enhanced with an increase in the biochar application amount. Cumulative CO2 emissions were highest with biochar amendment at 5 g·kg-1 under the no-tillage soil condition; however, this increased with an increase in the biochar amount in the ploughing treatment. At the end of incubation experiment, the soil MBC content increased by 35.5%-45.7% compared with the control treatment; however, there was no significant effect on soil pH and SIC between the treatments. ② Compared with the ploughing treatment, the cumulative CO2 emissions, SOC, ROC, DOC, MBC, and water-soluble Ca and Mg contents of the no tillage treatment increased by 34.2%-79.0%, 8.9%-45.5%, 28.2%-73.9%, 40.4%-78.4%, 0.2%-131.7%, 8.7%-39.8%, and 0.3%-61.0%, respectively, while soil pH and SIC decreased by 0.08-0.17 unit and 2.4%-13.9%, respectively, under the same biochar amendment treatments. Overall, the addition of biochar significantly increased soil organic carbon, active organic carbon, soil water soluble calcium and magnesium content, and soil cumulative CO2 emissions, but no significant effect was observed on soil inorganic carbon content.

Mechanochemical preparation of chrysomycin A self-micelle solid dispersion with improved solubility and enhanced oral bioavailability

BackgroundChrysomycin A (CA) has been reported as numerous excellent biological activities, such as antineoplastic and antibacterial. Though, poor solubility of CA limited its application in medical field. Due to good amphiphilicity and potential anticancer effect of disodium glycyrrhizin (Na2GA) as an excipient, an amorphous solid dispersion (Na2GA/CA-BM) consisting of CA and Na2GA was prepared in the present study by mechanochemical technology (roll mill ML-007, zirconium balls, 30 rpm, 2.5 h) to improve the solubility and oral bioavailability of CA. Then, Na2GA/CA-BM was self-assembled to micelles in water. The interaction of CA and Na2GA in solid state were investigated by X-ray diffraction studies, polarized light microscopy, and scanning electron microscope. Meanwhile, the properties of the sample solution were analyzed by dynamic light scattering and transmission electron. Furthermore, the oral bioavailability and antitumor ability of Na2GA/CA-BM in vivo were tested, providing a theoretical basis for future application of CA on cancer therapy.ResultsCA encapsulated by Na2GA was self-assembled to nano-micelles in water. The average diameter of nano-micelle was 131.6 nm, and zeta potential was − 11.7 mV. Three physicochemical detections showed that CA was transformed from crystal into amorphous form after treated with ball milling and the solubility increased by 50 times. Na2GA/CA-BM showed a significant increase of the bioavailability about two time that of free CA. Compared with free CA, the in-vivo antitumor studies also exhibited that Na2GA/CA-BM had an excellent inhibition of tumor growth.ConclusionsNa2GA/CA-BM nanoparticles (131.6 nm, − 11.7 mV) prepared by simple and low-cost mechanochemical technology can improve oral bioavailability and antitumor efficacy of CA in vivo, suggesting a potential formulation for efficient anticancer treatment.Graphic abstract

Influences of Phosphogypsum Application on Soil Property and Yield and Quality of Onion (Allium cepa L.)

Phosphogypsum (PG) is a by-product obtained in the process of manufacturing phosphoric acid (H3PO4). In general, PG is characterized mainly by gypsum, phosphate, sulphate, fluoride etc. Considering the nutritional composition, PG has been globally used as soil fertilizer or amendment in agriculture for decades. This study aimed to investigate effects of PG application on soil properties and yield and quality of onion (Allium cepa L.) and to seek proper rate of PG application in a field. We applied PG into a field with four different levels: 0% (control), 50% (PG50, 104 kg 10a-1), 100% (PG100, 208 kg 10a-1), and 150% (PG150, 312 kg 10a-1). Also, oyster shell (OS) included as a comparable and chemical fertilizer (N-P-K = 8.4-37.9-8.0 kg 10a-1) was supplied into soil of all treatments. Following onion cultivation for 7 months, there was a significant change in soil pH. Indeed, PG application was more likely to lower pH relative to control. With increase in PG application rate, soil EC increased and the maximum value (1.93 dS m-1) was found in soil of PG150. In PG100 and PG150, concentration of exchangeable Ca (Ex. Ca) increased by 5% and 10%, respectively, whilst other treatments representing reduction in the Ex. Ca concentration. In addition, PG application affected concentration of water soluble Ca across the soil profile (up to 70 cm depth) and, in particular, the higher the PG application rate the higher the concentration of water soluble Ca. Similarly, water soluble S had same trend with water soluble Ca in the present study. With increase of PG application rate, yield of onion increased but decreased in PG150 which is the highest rate of PG application. Also, the plant’s uptake for N, P, Ca, K, and S affecting yield, resistance to pathogen and pest, and quality of the crop increased in PG50 and PG100. Moreover, concentrations of total amino acids, cysteine and methionine in onion bulbs that are strongly associated to S uptake increased by PG applications. The increased concentrations of amino acids with PG applications might improve yield, quality, and favor of onions. These results suggest that PG supply could have a potential to enhance soil fertility, contributing to improvement of yield and quality of onions. Further studies are needed to maximize efficiency of PG supply in agricultural lands. Vertical movement of Ca and SO4 across the soil profile following phosphogypsum application.

Molecular Structure of Cefuroxime Axetil Complexes with α-, β-, γ-, and 2-Hydroxypropyl-β-Cyclodextrins: Molecular Simulations and Raman Spectroscopic and Imaging Studies.

The formation of cefuroxime axetil+cyclodextrin (CA+CD) complexes increases the aqueous solubility of CA, improves its physico-chemical properties, and facilitates a biomembrane-mediated drug delivery process. In CD-based tablet formulations, it is crucial to investigate the molecular details of complexes in final pharmaceutical preparation. In this study, Raman spectroscopy and mapping were applied for the detection and identification of chemical groups involved in α-, β-, γ-, and 2-hydroxypropyl-β-CD (2-HP- β-CD)+CA complexation process. The experimental studies have been complemented by molecular dynamics-based investigations, providing additional molecular details of CA+CD interactions. It has been demonstrated that CA forms the guest–host type inclusion complexes with all studied CDs; however, the nature of the interactions is slightly different. It seems that both α- and β-CD interact with furanyl and methoxy moieties of CA, γ-CD forms a more diverse pattern of interactions with CA, which are not observed in other CDs, whereas 2HP-β-CD binds CA with the contribution of hydrogen bonding. Apart from supporting this interpretation of the experimental data, molecular dynamics simulations allowed for ordering the CA+CD binding affinities. The obtained results proved that the molecular details of the host–guest complexation can be successfully predicted from the combination of Raman spectroscopy and molecular modeling.

Role of Mitochondrial Calcium in the Maintenance of Skeletal Muscle Homeostasis

PV is a member of the EF-hand Ca2+-binding family of proteins, expressed in fast-twitch muscle fibers where, acting as a soluble cytoplasmic Ca2+ buffer, contributes to musclerelaxation by removing Ca2+ from the cytosol and facilitating its transport back to the SR. Furthermore, PV is one of the most downregulated “atrogenes”, the family of genes commonly up- and downregulated in both systemic and disuse-induced muscle atrophy. We exploited the murine strain lacking PV (PV-/-) to explore the link between PV function as Ca2+ buffer and as determinant of muscle trophism. First, we confirmed that PV expression is downregulated in denervated muscles and, surprisingly, we found a trend to a lower muscle atrophy in PV-/- than in wild type (WT) mice. Then, by acutely silencing and overexpressing PV in adult muscles of WT mice, we discovered that downregulation was accompanied by hypertrophy and upregulation by atrophy. The lack of PV had a minor impact on sarcoplasmic reticulum and affected the kinetics but not the amplitude of the cytosolic Ca2+ transients. In contrast, PV ablation was associated with an increased Ca2+ uptake in mitochondria, partly supported by MCU increased expression and accompanied by increased mitochondria size and number. Intriguingly, MCU silencing abolished the hypertrophic effect of PV ablation, suggesting a mitochondrial Ca2+-dependent mechanism of control of muscle trophism. This was corroborated by the enhanced expression of the mitochondrial Ca2+-dependent PGC-1α4 that promotes skeletal muscle hypertrophy. MCU silencing prevented increase of PGC-1αα4 expression and PGC-1α4 silencing prevented muscle fiber hypertrophy. These data reveal a novel role of PV that links the control of cytosolic Ca2+ concentration to mitochondrial adaptations, ultimately leading to muscle mass regulation. We believe that our results further underline that the mitochondrial pathway and its regulation are of utmost importance to uncover the molecular mechanisms of muscle atrophy.

Residual effects of calcium amendments on oil palm growth and soil properties

Residual liming is one of the measures of the efficacy of liming materials. Ca2+-amendments such as calcium hydroxide (Ca(OH)2), calcium oxide (CaO) and calcium carbonate (CaCO3) in soils may contribute to plant growth response in plant height and total dry matter yield of oil palm seedlings. The increasing of other essential elements such as nitrogen (N), phosphorus (P) and ions of potassium (K+) also play a great role in the plant growth and crop yield, conversely, the soil pH and ions of aluminium (Al3+) will inhibit the plant growth and crop yield. This main aim this experiment is to determine the residual liming effect of Ca2+-amendments to highly acidic soils collected from Jeram and Bungor series, Malaysia, which also contains 2 times of Al3+. The highly acidic soils of previously planted with oil palm seedlings initially incubated with selected Ca2+-amendments along with Mg2+-amendments such as, dolomite (CaMg.CO3) for 360 days and, kept for additional 180 days before planting for a total of 540 days in a greenhouse environment. In this experiment, the soil chemical analysis, plant growth response, and the possible mechanisms responsible for the Ca2+-amendment liming effects were measured. The results of the soil chemical analysis showed that Ca2+-amendment residues potentially reduced the soil acidity than Mg2+-amendments. Ca(OH)2 was the most prominent Ca2+-amendment to increase soil-water pH, soil solution pH, and concentrations of soluble Ca2+ and K+. While, concentration of soil solution and exchangeable Al were effectively reduced 540 days after the application of Ca-amendments. The dry shoot weight of the oil palm seedlings improved about 1.67 g/pot and 16.87 g/pot in control and Ca2+-amendment treatments, respectively. In this study, it has showed that the root dry weight of oil palm seedlings increased from 0.18 g/pot to 4.49 g/pot in pot and Ca2+-amended soil, respectively. Increased plant height and total dry matter yield of oil palm seedlings grown on the Ca-amended soils may be attributed to increased soil pH which resulted in lowered concentration and activity of soluble AI, and increased concentrations of soil solution Ca and K which were released of Ca. This finding concluded that the possible mechanisms of Ca2+-amendments from residual liming might be: a) complexation interaction between Al3+ and Ca2+; (b) capacity of Ca-amendments to increase the concentration of Ca to maintain soil desired pH; (c) alleviation effect of Ca-amendments to reduce Al toxicity concentration in the soil. Last but not least, this finding showed that dry matter yield and plant height positively associated with the presence of Al3 + in both soil conditions.

Invasion of Prosopis juliflora and its effects on soil physicochemical properties in Afar region, Northeast Ethiopia

Woody species within pastures and savannas are often associated with ‘resource islands’ characterized by higher fertility under canopies trees. The aims of this study were to evaluate (1) the effects of Prosopis juliflora on some soil physicochemical properties and (2) the impacts of Prosopis invasion on soil salinity. For soil physicochemical analysis, a total of 104 soil samples from Teru and Yalo Districts were collected. The soil samples were collected from soil depths of 0–15 cm and 15–30 cm in Prosopis invaded and non-invaded open grazing lands. Invasion of Prosopis had significantly affected soil pH, exchangeable Na+, water soluble Ca2+ + Mg2+, water soluble Na+, and exchangeable sodium percentage in Teru and Yalo Districts (p < 0.05). The invasion of Prosopis significantly increased soil pH (1.5%), but decreased exchangeable Na+ (24.2%), exchangeable sodium percentage (21.6%), and water soluble Ca2+ + Mg2+ (39.9%) than non-invaded lands. Clay content of Prosopis invaded lands was higher by 19% than non-invaded lands. However, sand content of soil was higher under non-invaded lands by 5.6% than Prosopis invaded lands. Most results indicated that invasion of Prosopis had positive effects on physicochemical properties and thus conducive for cereal crops and forages.

Effective treatment of leachate concentrate using membrane distillation coupled with electrochemical oxidation

The performance of sequential electrochemical oxidation (EO) and membrane distillation (MD) process was investigated for treating leachate concentrate with the characteristics of salinity and biorefractory organics. EO was achieved by direct and indirect oxidation on the Ti/PbO2 or Ti/Ru-Ir anode, by comparing the performance under different variations. Results showed that at an applied current density of 100 mA/cm2, operation time of 5 h and the choice of the Ti/PbO2 anode, the EO process could minimize the organic fouling by decomposing the larger molecular humic-acid that the removal efficiency was 83.4% for TOC. MD was used for treating the EO-pretreated concentrate due to its high rejection of salt and non-volatile components when treating salinity water. Flux results showed that the sequential system made the process resistant toward the sharp flux decline due to organics fouling, leading to a steady distillate flux in the earlier stage, and antiscalant was further added to retard the scaling in the long-time treatment. A strong interaction occurred between the foulants and antiscalant in the feed solution, and thus slowed down the scaling on the membrane which was reflected by the membrane flux, morphology and layer thickness. Results further showed that the ratio of actual and theoretical soluble Ca2+ was up to 61.6% and the energy barrier increased by 427.0% under optimum 20 mg/L PBTCA dosage. This study suggests that the sequential EO-DCMD system with antiscalant dosage can provide a potential alternative for treating the leachate concentrate.

Cellobiose as a Model Carbohydrate for Predicting Solubilities in Nonaqueous Solvents

The use of nonaqueous solvents for conversion of biomass molecules into platform chemicals and fuels is hindered by a lack of solubility data and models. Accordingly, the solubility of the model ca...

Aerobic treatment and acidification of pikeperch (Sander lucioperca L.) sludge for nutrient recovery

Aquaponics (AP) is an integrated multi-trophic system that combines elements of recirculating aquaculture systems (RAS) and hydroponics (HP). In AP systems, waste streams from the RAS, rich in nutrients, are reused to grow plants hydroponically. Fish sludge (the solid fraction of the waste stream) contains a major part of these nutrients (i.e. the macro and microelements and especially P) and these are discharged from the AP system in some system designs. To increase the reuse of nutrients in AP systems, processes of recovery, such as the transfer of nutrients from the solid to the soluble phase (i.e. cations, anions, and chelates), should be developed. In this study, we investigated the nutrient mineralisation performance (NMP) of pikeperch (Sander lucioperca) sludge aerobically treated in a long-term experiment (121 days) and in a short-term experiment (15 days) with artificially lowered pH (pH 6.3). Mass balance equations were used to determine and compare the NMP between experiments. NMP showed a macronutrient recovery (i.e. nutrient passing from the solid phase to the soluble phase) between 0 and 40%, while the NMP of micronutrients was 2%. In the long-term experiment, P had a negative value (− 1%) indicating that its soluble forms were lowered due to wash out and precipitation or were assimilated by the microorganisms. In the short-term experiment, a quick drop in pH had an almost immediate (1 day) increasing effect on P, K, and Ca solubility while N and Mg were better mineralised in the long-term experiment. Our study demonstrated that a low pH step is an efficient way to improve the nutrient recovery from aerobically treated sludge.

Effects of gypsum, irrigation and tillage on a sodic Yellow Kandosol at Carnarvon, Western Australia

Context Kandosol soils are widely distributed in Australia and are frequently used for irrigated cropping. However, under intensive irrigated cropping they can degrade due to poor structural stability where surface soil aggregates break down as a result of slaking and dispersion; the slaking is associated with low soil organic carbon levels (&lt;1.0 g/100 g) on these frequently cultivated soils, and the dispersion is related to the moderate level of exchangeable sodium percentage (ESP) combined with low electrical conductivity (EC) levels in the soil solution. Aims To investigate the effects of applied gypsum (0, 2 and 10 t/ha), irrigation with water of low EC (0.5 dS/m) and low sodium adsorption ratio (≤2), and two tillage practices, i.e. conventional tillage (CT) and reduced tillage (RT), on the structure of a marginally sodic (ESP 6) Yellow Kandosol soil. Methods The experiment was conducted at Carnarvon, Western Australia. Key results After 2 years the soil EC (1:5) and ESP levels were significantly reduced on all plots at the three gypsum rates. The three gypsum rates also significantly affected exchangeable calcium (Ca) and magnesium (Mg) and soluble Ca and Mg levels, as well as pH and dispersion values. Micromorphological examination indicated less dispersed clay with gypsum application. Conclusions The EC results indicated that the soil will require frequent re-application of gypsum to maintain electrolyte levels and prevent dispersion. With some of the variables, RT compared to CT demonstrated greater through-flow, which was attributed to the presence of more macropores in RT. Implications A change in management from semi-arid chenopod shrublands used for grazing to intensely cultivated horticulture will require careful consideration of factors causing soil structural instability.

Regulation of Laminaria Polysaccharides with Different Degrees of Sulfation during the Growth of Calcium Oxalate Crystals and their Protective Effects on Renal Epithelial Cells.

The original Laminaria polysaccharide (LP0) was sulfated using the sulfur trioxide-pyridine method, and four sulfated Laminaria polysaccharides (SLPs) were obtained, namely, SLP1, SLP2, SLP3, and SLP4. The sulfated (–OSO3–) contents were 8.58%, 15.1%, 22.8%, and 31.3%, respectively. The structures of the polysaccharides were characterized using a Fourier transform infrared (FT-IR) spectrometer and nuclear magnetic resonance (NMR) techniques. SLPs showed better antioxidant activity than LP0, increased the concentration of soluble Ca2+ in the solution, reduced the amount of CaOx precipitation and degree of CaOx crystal aggregation, induced COD crystal formation, and protected HK-2 cells from damage caused by nanometer calcium oxalate crystals. These effects can inhibit the formation of CaOx kidney stones. The biological activity of the polysaccharides increased with the content of –OSO3−, that is, the biological activities of the polysaccharides had the following order: LP0 < SLP1 < SLP2 < SLP3 < SLP4. These results reveal that SLPs with high –OSO3− contents are potential drugs for effectively inhibiting the formation of CaOx stones.

Component Analysis of Tooth Surface Caused by Fruit Juice using Energy Dispersive X-ray Spectroscopy

Dental erosion is the irreversible loss of dental hard tissue by acids not by bacteria. The prevalence rate of dental erosion is on the rise these days, and the consumption of acidic beverages is recognized as one of the main risk factors. Therefore, in this study, pH of certain commercial fruit juices was measured to determine whether they cause enamel corrosion of teeth, and the changes in calcium (Ca) and phosphorous (P) were evaluated by quantitative analysis using energy dispersive X-ray spectroscopy (EDS). As the pH decreased, the solubility of Ca increased, and as the exposure time increased, the loss of Ca was greater. Ingestion of fruit juice with a low pH affects the risk of dental erosion, and the retention time of the juice in oral cavity should be shortened as long-term contact with the juice may cause the tooth damage.

Soil properties as influenced by use of water having variable salinity and sodicity

A pot experiment was conducted during summer season of 2018 at Net House, Department of Agricultural Chemistry and Soil Science, College of Agriculture, Junagadh Agricultural University, Junagadh to study the influence of different levels of saline and sodic irrigation water on soil properties. The treatment consists of four levels each of salinity (2, 4, 6 and 8 dS m-1) and sodicity (5.0, 10.0, 15.0 and 20.0 SAR) of irrigation water by adopting factorial CRD with three replications. The available macronutrients (N, P2O5 and K2O) and organic carbon of soil after harvest of the crop were found maximum with EC-2 dS m-1 and SAR-5.0 level of irrigation water. The water soluble and exchangeable Ca, Mg and Na and soil properties like EC2.5, ECe, pH2.5, pHs, CEC and ESP was found maximum with EC-8 dS m-1 while water soluble and exchangeable K was found maximum with EC-2 dS m-1. The water soluble and exchangeable Na was found maximum with SAR-20.0, whereas water soluble and exchangeable Ca, Mg and K were found minimum with SAR- 20.0. The soil properties like ECe, pH2.5, pHs and ESP of the soil was found maximum with SAR- 20.0, but CEC was found maximum with SAR-5.0. The combined effect of saline and sodic irrigation water was found significant on available N and water soluble cations Ca++, Mg++, Na+, K+, exchangeable Na+, ESP, ECe and pH2.5 of soil after harvest of groundnut.

Biochar and Its Effects on Plant–Soil Macronutrient Cycling during a Three-Year Field Trial on Sandy Soil with Peppermint (Mentha piperita L.). Part I: Yield and Macro Element Content in Soil and Plant Biomass

Pyrolyzed organic residues can be incorporated as a soil additive to improve their properties, crop productivity, or to increase retention or absorption of different compounds. However, in agronomy, the practice of biochar application is still under examination. The interactions between plant, soil, and biochar can be complex, and determines the agronomic effects obtained. A three-year field experiment was conducted to determine the effects of biochar addition and nitrogen (N) fertilization on biomass productivity and nutrient uptake of Mentha piperita L. The experiment was conducted with a three-factorial design in triplicate at N fertilizer rates of 75, 100, and 125 kg N ha−1 and biochar rates of 0, 5, 15, and 45 t ha−1. Commercial wood-based biochar produced at 650 °C was incorporated into sandy soil in 2017. Generally, our results demonstrated potential for treating a sandy soil, since biochar improved the nutrient availability for peppermint. However, on average, during a three-year mint-yielding period, no significant effect of the applied dose of biochar on this parameter was found. Significantly more soluble Ca, K, and SO4-S was found in the soil amended with biochar as compared with the control soil. Biochar, in doses of 15 and 45 t ha−1, increased the NH4-N concentration in the soil in the second and third year of the study, as well as NO3-N in 2018. The greatest amount of N and P was contained in the peppermint biomass after using 15 and 45 t biochar ha−1. The highest dose of biochar (45 t ha−1) also increased the contents of K and S in plants. Nitrogen fertilization increased the dry matter yield of peppermint on the harvest sampling dates. The N content in the mint increased proportionally to the nitrogen dose in fertilization, regardless of the biochar dose applied. The use of biochar in doses of 15 and 45 t ha−1 in coarse-textured soil contributed to increased use of nitrogen by plants after nitrogen fertilization at doses of 100 and 125 kg N ha−1. These findings suggest that the time-dependent responses of soil to biochar amendment are strongly influenced by plant, microbial, and soil feedback; if so, then practical long-term biochar effectiveness requires further study.

Improved in vitro bioavailability of a newly developed functionalized calcium carbonate salt as a food ingredient and its comparison with available commercial calcium salts

The bioaccessibility and bioavailability of a functionalized Calcium (Ca) salt as food ingredient, based on modified Ca carbonate and hydroxyapatite (FCC), was determined and compared with frequently used Ca sources (Ca citrate tetrahydrate (CCT), tri-Ca phosphate (triCP) and Ca carbonate (CC). Results showed a similar Ca bioaccessibility for CCT (76.44 ± 9.73%), CC (73.7 ± 8.18%) and FCC (74.4 ± 1.87%) and a lower value for tri-CP (46.07 ± 8.68%). FCC showed the highest bioavailability, 5.68 ± 0.26%, compared to CC, CCT and tri-CP (3.93 ± 0.99%, 3.41 ± 0.33%, 1.85 ± 0.34%, respectively). The innovative chemical composition and structure of FCC based on amorphous hydroxyapatite combined with Ca carbonate, a greater porosity, lower agglomerates and particle size, improve the Ca solubility in the intestinal media, explaining the similar bioaccessibility but higher bioavailability of FCC compared to CCT, tri-CP and CC.

The devil is in the C-tail: a NBCe1-carbonic anhydrase bicarbonate transport metabolon?

The concept of metabolons is well established in biochemistry as structural–metabolic complexes in cells that facilitate substrate channelling through the complex and is best exemplified by the citric acid cycle enzymes. Similarly, an arrangement of enzymes was suggested to promote the transport of acid/base equivalents across the plasma membrane by the Reithmeier group. The concept was supported by direct evidence of physical interaction of an acid/base transporter and carbonic anhydrase (Vince & Reithmeier, 1998) and emboldened by the demonstration of a functional advantage for such an arrangement called a ‘transport metabolon’ (Sterling et al. 2001). The direct protein interaction was first reported for the C-terminal of anion exchanger AE1 (band 3) and the cytosolic ubiquitous carbonic anhydrase II (CAII). Since then, the field has evolved to other acid/base transporters of the SLC4 gene family of HCO3− transporters, the Na+/H+ exchangers (NHE) and monocarboxylate transporters interacting with soluble or membrane-bound CA isozymes in various expression systems and native tissues. Discrepancies have since evolved both regarding the direct physical interaction of acid/base transporters and CA enzymes, and regarding the functional interaction between the individual molecules of such complexes. This ‘Perspectives’ article only addresses the case of the functional interaction of the human renal form of the electrogenic Na+:HCO3− cotransporter NBCe1-A (kNBCe1) and CAII when expressed in Xenopus laevis oocytes, but may prove highly relevant for the metabolon field as such. In one study, the NBCe1 function determined as the current slope conductance (Gm INBC) was not affected by injection of CAII protein or the expression of either NBCe1-CAII or eGFP-NBCe1-CAII fusion proteins (Lu et al. 2006). No effect of the cell-permeant CA inhibitor ethoxyzolamide (EZA) on the Gm INBC was observed. In a separate and opposing study, NBCe1 function assessed as the changes in membrane current (Im), the Na+ flux (d[Na+]i/dt), as well as the membrane conductance (Gm) was augmented by bovine CA protein injection or CAII co-expression (Becker & Deitmer 2007). The induced changes in current and Na+ fluxes were EZA-sensitive in this study. Thus, although the two studies applied similar methodological set-ups at first glance, the results were contrasting. Each paper is compelling to the reader, and both studies were carefully and elegantly performed. Moss and Boron (2020) first carefully replicate the findings by Lu et al. (2006) and then elegantly rule out differences in the amount of injected cRNA, CAII protein and eGFP tag as contributing factors to conflicting results by the two groups. Furthermore, they show that prolonged EZA exposure or the high EZA concentration by Lu et al. were not causing the inconsistency between the previous studies. It also appears that the variations in voltage-clamping protocols cannot explain the contradicting results per se (Moss & Boron 2020). Remarkably, the authors are able to closely replicate the fundamental observations by Becker & Deitmer (2007) that injection of bovine CA in oocytes expressing untagged NBCe1 increases the Na+ flux (d[Na+]i/dt)max as well as the membrane current Im, effects that are sensitive to CA inhibition by EZA. This is apparently only possible 1) in the absence of eGFP tag, 2) by bovine CA injection instead of human CAII, and 3) applying the prolonged -40mV voltage clamp and 10 s step duration of I-V ramps. Surprisingly, Moss and Boron demonstrate that injection of either human CAII or bovine CA alone in oocytes induces an electroneutral process that increases Na+ uptake and acid extrusion upon CO2-induced acid loading. The authors ascribe the effects to the induction of endogenous NHE activity, as this process is inhibited by EIPA. Interestingly, EIPA also prevents the EZA-sensitive change in Im and (d[Na+]i/dt)max induced by injection of bovine CA using the prolonged -40 mV voltage clamp protocol. Thus, Moss and Boron explain the discrepancy between the previous studies (Lu et al. 2006 vs. Becker & Deitmer 2007) by the induction of native NHE activity by exogenous CA in Xenopus oocytes. With the study by Moss and Boron (2020), the specific controversy regarding enhanced NBCe1 activity by CA in oocytes has most likely been fully resolved. The authors accomplished a systematic comparison of experimental approaches resulting in a study with high internal consistency presented in a respectful and transparent manner. The take-home message is that even the most careful studies by world-renowned laboratories can reach conflicting conclusions and that unexpected sources of discrepancies can be identified by hard and meticulous work. The findings by Moss and Boron (2020) should impact the broader transport metabolon field; however, the conclusions can probably not be extrapolated to all other cases of acid/base transporters, CA forms and cell types for which transport metabolons have been suggested. Hopefully, time will tell. None. Sole author. None.

Development of calcium stabilized nitrogen rich \u03b1-sialon ceramics along the Si3N4:1/2Ca3N2:3AlN line using spark plasma sintering

Calcium stabilized nitrogen rich sialon ceramics having a general formula of CaxSi12-2xAl2xN16 with x value (x is the solubility of cation Ca in α-sialon structure) in the range of 0.2–2.2 for compositions lying along the Si3N4:1/2Ca3N2:3AlN line were synthesized using nano/submicron size starting powder precursors and spark plasma sintering (SPS) technique. The development of calcium stabilized nitrogen rich sialon ceramics at a significantly low sintering temperature of 1500 °C (typically reported a temperature of 1700 °C or greater) remains to be the highlight of the present study. The SPS processed sialons were characterized for their microstructure, phase and compositional analysis, and physical and mechanical properties. Furthermore, a correlation was developed between the lattice parameters and the content (x) of the alkaline metal cation in the α-sialon phase. Well-densified single-phase nitrogen rich α-sialon ceramics were achieved in the range of 0.53(3) ⩽ x ⩽ 1.27(3). A nitrogen rich α-sialon sample possessing a maximum hardness of 22.4 GPa and fracture toughness of 6.1 MPa·m1/2 was developed.