Sodium hexametaphosphate-mediated electrostatic-hydration coupling: interfacial complexation and in situ montmorillonite-C-(A)-S-H intergrowth in low-carbon barrier systems.

Synthetic dyes discharged from textile and industrial activities are persistent, toxic, and difficult to degrade, posing serious risks to aquatic ecosystems and human health. Therefore, developing rapid and effective technologies for removing dye pollutants from water is of significant environmental importance. A flotation method using dispersive clay (DC) was designed for the rapid and simultaneous removal of a basic dye, methylene blue (MB), and an acidic dye, methyl orange (MO), from water. The DC was successfully prepared by immersing montmorillonite K-30 (MT) in sodium fluoride solution, followed by sonicating in sodium hexametaphosphate solution. It lost the layered structure but possessed almost the same surface area (278 ± 8m2g-1) as the original MT (253 ± 7m2g-1), meeting the requirement of a large-capacity adsorbent. However, the DC particles were difficult to separate from water because of their high dispersibility in the aqueous solution. When flotation was carried out in the presence of a cationic surfactant, cetyltrimethylammonium chloride (CTAC), the DC particles rapidly coagulated to rise to the surface of water and were readily separated. MB in water was > 98% adsorbed on 100mg L-1 of DC because of its electrostatic interaction with the negatively charged DC surfaces. The removal ratio remained greater than 95% after adding up to 7.5mg L-1 of CTAC, after which the zeta potential of DC was nearly zero. Although very little MO adsorbed onto unmodified DC, the adsorption rate increased as added CTAC increased and exceeded 96% in the presence of 100mg L-1 DC and 7.5mg L-1 CTAC. The proposed method successfully removed MB and MO simultaneously from water within 5min.

The rapid development of the new energy industry has led to an increase in the demand for lithium metal. Lepidolite is the main source of lithium metal, but the common collector dodecylamine (DDA) can only separate lepidolite from its gangue (i.e., orthoclase) in a strong acid environment (pH ∼ 2) in the presence of depressants due to its weak selectivity. The heavy consumption of inorganic acid will corrode flotation equipment and bring challenges for wastewater treatment. In this study, the amidoxime collector 3-dodecylamine propyl amidoxime (DPA) was synthesized in our lab and introduced as the collector to efficiently recover lepidolite from orthoclase. In single mineral flotation, 80 mg/L DPA could float out 91.00% lepidolite and 85.50% orthoclase at pH 6.0, and DDA recovered 77.71% lepidolite and 90.02% orthoclase under the same conditions. For mixed mineral, 80 mg/L DPA combined with 100 mg/L sodium hexametaphosphate (SHMP) at pH 6.0 could obtain a Li2O concentrate with a grade of 3.87% and a recovery of 76.86%. The surface contact angle of lepidolite could be selectively enhanced to 78°, but that of orthoclase only exhibited to 40°. Zeta potential and FTIR spectra exhibited that DPA would physically adsorb onto lepidolite. Quantum chemical calculations proved that compared with DDA+ (0.178 and 0.1942 a.u.), DPA+ had a larger electrostatic group (0.274) and a smaller ΔELUMO-HOMO (0.1431 a.u.) to adsorb on the lepidolite surface. Thus, the DPA-SHMP agent system had the ability to separate lepidolite from orthoclase in a weak acid environment.

IntroductionUnderstanding the dynamics of soil organic carbon (SOC) in sloping farmlands is critical, as they play a vital role in the global carbon cycle and soil health. Although prior research has focused on physical carbon loss due to erosion, the biological mechanisms by which slope gradients affect microbial carbon cycling remain poorly understood.MethodsSoil samples were collected from maize fields with three slope gradients (30°, 45°, and 60°) across different growth stages. Key indicators were determined as follows: SOC by potassium dichromate oxidation (external heating method); DOC by ultrapure water extraction (1:5 ratio) and organic carbon analyzer; POC by sodium hexametaphosphate dispersion, 53-μm sieving, and chromic acid oxidation; soil Ca2+, Mg2+, and Cl− by EDTA complexometric titration and silver nitrate titration, respectively; invertase (SUC) by 3,5-dinitrosalicylic acid colorimetry; polyphenol oxidase (SPPO) and peroxidase (SPOD) by commercial kits with L-dopa as substrate. Statistical analyses were performed using IBM SPSS 26 (One-way ANOVA with LSD post-hoc test, Pearson correlation analysis) and Origin 2024 (Principal Component Analysis, PCA). Normality of data was verified prior to analysis, and significance was set at P < 0.05.ResultsResults showed that SOC levels decreased with increasing slope steepness, while DOC peaked at 45°. SPPO and SPOD activities (involved in recalcitrant carbon decomposition) were significantly elevated at 60°. SUC activity was positively correlated with DOC, while oxidase activities were positively associated with POC and negatively with Mg2+.DiscussionThis study identifies a critical slope threshold (30°–45°) for DOC loss: DOC availability on steeper slopes stimulates microbial synthesis of SPPO and SPOD, enhancing recalcitrant carbon degradation and potentially intensifying long-term SOC depletion. The identification of this threshold provides insights for designing microbiome-informed strategies to mitigate soil degradation and safeguard ecological security.

Dispersion or inhibition? A new insight into the mechanism of sodium hexametaphosphate on the improvement of flotation of clay-containing fine coal slime

Effect of sodium hexametaphosphate and trisodium citrate on the heat stability, rheological and functional properties of microfiltered retentate of buffalo milk

Abstract To investigate the effects of key chemical mechanical polishing (CMP) parameters on the material removal rate (MRR) and surface roughness (Ra) of BK7 optical glass, single-factor experiments were conducted to examine the influence of polishing time, polishing disc rotational speed, CeO2 concentration and slurry pH. Using polyacrylic acid (PAA) and sodium hexametaphosphate (SHMP) as dispersants, MRR and Ra were evaluated under varying conditions, and EDS, XPS, and SEM analyses were performed to assess Ce³⁺ concentration on abrasive surfaces and CeO2 particle behavior. The optimal CMP parameters were identified as: polishing time 50 min, polishing disc rotation speed 60 r/min, slurry pH = 6, citric acid 2.0 wt%, CeO2 0.5 wt%, and PAA 2.0 wt%. Under these conditions, the slurry exhibited a zeta potential absolute value of 19.77 mV, indicating excellent dispersibility, which resulted in an MRR of 140.34 µm/h and a final Ra of 1.2 nm, corresponding to a 99.7% reduction in surface roughness, with no abrasive residue observed on the polished surface. with no abrasive residue observed on the polished surface. The CMP mechanism for BK7 glass is proposed, PAA acts as a dispersant by ionizing in the polishing slurry to generate -COO- groups, which adsorb onto the CeO2 abrasive particles and improve dispersion stability via steric hindrance. Meanwhile, citric acid acts as a reducing agent, converting surface Ce4+ to Ce3+ on the CeO2 abrasives. The increased Ce³⁺ concentration promotes the formation of oxygen vacancies, thereby accelerating the reaction kinetics between CeO2 abrasives and the BK7 glass surface and significantly improving polishing efficiency.

Aluminum alloys used in harsh environments often suffer from inadequate protection due to the limited compactness and stability of existing chromate-free conversion coatings. This study designs and optimizes a corrosion-resistant vanadium-based conversion coating on 6061 aluminum alloy and investigates the influence of additives on its structure and performance. The effects of solution pH (2–4), reaction temperature (35–75 °C), and immersion time (10–30 min) on coating corrosion resistance were examined. The optimal parameters were determined as pH = 3, 55 °C, and 25 min, yielding a compact coating with excellent corrosion resistance (icorr = 0.335 μA·cm−2, Ecorr = −0.596 V, |Z| = 48.7 kΩ·cm2). To further enhance performance, polyvinyl alcohol (PVA), chitosan (CS), and a combination of sodium hexametaphosphate and cerium nitrate (SHMP + Ce(NO3)3) were introduced into the conversion solution. Characterization by SEM, AFM, and contact angle measurements showed that SHMP + Ce(NO3)3 significantly improved coating uniformity and compactness (Rq = 131 nm, Ra = 107 nm), resulting in superior corrosion resistance (icorr = 0.055 μA·cm−2, |Z| = 67.9 kΩ·cm2). The coating exhibited strong adhesion (grade 5B) and no visible corrosion after 72 h of neutral salt spray exposure, demonstrating excellent protective capability. In contrast, PVA produced porous coatings with reduced resistance, while CS provided only limited improvement.

Kidney stones are common diseases in the urinary system, characterized by high morbidity and recurrence rates, but effective drug treatments are limited. We chose sodium hexametaphosphate (HMP) to investigate its role in inhibiting calcium oxalate (CaOx) crystallization in vitro and in vivo. We predicted potential targets of HMP using bioinformatics, simulated drug molecular docking, and explored the molecular mechanism of HMP inhibition of CaOx stone formation in a cellular model and hyperoxaluria-induced crystallization rat model. HMP specifically adsorbed on high-energy crystal surfaces, inhibiting the growth of CaOx monohydrate (COM), significantly reducing crystal size, and promoting the conversion to CaOx dihydrate (COD). At higher concentrations, CaOx crystals transformed from micrometer to nanometer scale, achieving complete conversion from COM to COD and almost complete inhibition of CaOx crystal formation. Additionally, HMP significantly reduced oxidative damage caused by high oxalate in NRK-52E cells, decreased reactive oxygen species production, inhibited mitochondrial membrane potential depolarization, and subsequently inhibited cell apoptosis. By integrating the transcriptomic data and the crystallization results, HMP primarily acts by modulating CaOx crystallization, upregulating PPARα to promote fatty-acid transport and β-oxidation, thereby enhancing the expression of downstream antioxidant factors NRF2 and SOD1 and, in turn, attenuating hyperoxaluria-induced renal oxidative injury. The novel drug HMP, combining CaOx crystallization modulation and oxidative stress inhibition, may be a treatment option for kidney stones.

Flotation Recovery of Silicon from Metallurgical-Grade Silicon Refining Slag Using Sodium Hexametaphosphate as a Depressant

The influence of the technology for obtaining fire-retardant compositions based on liquid glass for fire protection of building finishing materials was studied. The influence of the silicate module of liquid glass on the rheological properties of silicic acid sols modified with phosphate-containing compounds was studied. According to the results of spectrophotometric measurements, it was established that the ratio n(SiO₂)/n(Na₂O) in liquid glass within 2.5–3 does not significantly affect the survivability of the compositions. The influence of the ratio of the initial components on the duration of solidification of the sols was determined. It was established that the preliminary introduction of 0.1 wt. % Trilon B into tap water allows obtaining stable silicic acid sols over time, which is a prerequisite for the formation of a homogeneous fire-retardant coating. Fire tests were carried out on samples of wood and extruded polystyrene foam coated with compositions of the studied composition. It was found that the content of 2 % orthophosphoric acid and 0.1 % sodium hexametaphosphate provides mass loss of wood samples less than 7.5 %, which corresponds to the I group of fire-retardant efficiency of coatings, and the protected material belongs to the group of low-flammability. For extruded polystyrene foam, the best fire-retardant effect was demonstrated by compositions with a sodium hexametaphosphate content of 1 %: mass loss of samples varied within 1–3 %, burning drops were not formed, and the samples did not support combustion. It is assumed that the increased fire resistance of coatings with a higher content of phosphorus-containing additive is associated with the fusibility of sodium compounds and their ability to transfer the fire-retardant coating to a visco-plastic state, which contributes to the dissipation of deformation stresses and prevents the formation of cracks in the coating.

It is difficult to collect fine graphite particles because of the large size and small specific area of traditional flotation bubbles. The contrast experiment between nanobubble flotation and traditional flotation of micro-fine flake graphite in the Hegang area of Heilongjiang Province was carried out in this paper. Under the conditions of feed fineness 78% (−74 μm), pH 10.5, sodium hexametaphosphate 800 g/t, No. 2 oil 350 g/t, pulp concentration 10%, diesel 400 g/t, and pulp cycle time 3 min, the enhanced behavior of nanobubbles on micro-flake graphite flotation was discussed by studying the differences in the flotation rate, selectivity, pulp size, and concentrate size between traditional flotation and nanobubble flotation. The results showed that the nanobubble flotation completed the flotation 20 s earlier than the traditional flotation, and the final concentrate recovery of nanobubble flotation was 1.5 percentage points higher than the traditional flotation. In addition, the average particle size of the slurry from nanobubble flotation is 13 μm larger than that from traditional flotation. In addition, the minimum size of nanobubble flotation is only 2 μm, 11 μm smaller than the minimum size of traditional flotation. Nanobubbles effectively reduce the electrostatic repulsion between fine particles and enhance the hydrophobic attraction, making the hydrophobic aggregates of fine particle graphite more stable. At the same time, the presence of nanobubbles makes the surface hydrophobicity of graphite stronger, effectively promoting the recovery of fine particle graphite.

This study investigates the flotation separation of rutile and hornblende, with particular emphasis on the selective depression mechanism of sodium hexametaphosphate (SHMP) and carboxymethyl cellulose (CMC). Benzohydroxamic acid (BHA) was used as the collector to evaluate its interaction with both minerals in the presence of the depressants. A series of flotation experiments, zeta potential measurements, X-ray photoelectron spectroscopy (XPS), infrared spectroscopy, and nuclear magnetic resonance (NMR) analyses were conducted to examine the behavior of rutile and hornblende under varying pH and reagent conditions. The results show that BHA exhibits significantly stronger adsorption on the rutile surface compared to hornblende. Meanwhile, SHMP and CMC selectively adsorb onto the hornblende surface, effectively suppressing its floatability. SHMP interacts with two forms of Ca2+ on the hornblende surface to form calcium hydrogen phosphate (CaHPO3), while CMC primarily binds with Al3+ and Fe3+ to form stable metal complexes. These surface products markedly reduce hornblende's flotation performance and enhance the selectivity of the separation process. The findings provide important insights and a theoretical foundation for improving the flotation separation of rutile and hornblende.

This study presents a comparative framework for evaluating the predictive performance of four machine learning models namely Gradient Boosting Machine (GBM), Random Decision Forest (RDF), Non-Parametric Regression (NP), and Decision Tree (TREE), in estimating the Unconfined Compressive Strength (UCS) of nano-doped fly ash reinforced clayey soil. The key innovation lies in combining ensemble learning with sensitivity, monotonicity, and SHAP (SHapley Additive exPlanations) analyses to enhance predictive accuracy and interpretability in geotechnical applications. Using a comprehensive dataset of key variables (Curing Days, Maximum Dry Density (MDD), Optimum Moisture Content (OMC), Fly Ash, Multi-Walled Carbon Nanotubes (MWCNT), and Sodium Hexametaphosphate (SHMP)) models were trained and validated using various statistical metrics (R², MAE, MSE etc.). GBM achieved the best performance (R²: 1.000, 0.955; MAE: 0.001, 0.022; MSE: 0.000, 0.001 in training and testing respectively), consistently outperforming RDF, NP, and TREE. Taylor diagrams, REC curves, and AOC analysis further confirmed GBM's superior generalization and minimal error rates. Sensitivity analysis identified Days (0.4556), MDD (0.2458), and SHMP (0.1558) as the most influential factors, trends that were corroborated by SHAP analysis. Monotonicity analysis validated positive relationships with Days (R² = 0.9845) and MDD (R² = 0.689), while OMC and SHMP showed inverse effects. These results establish GBM as a highly accurate and interpretable model for UCS prediction, offering a powerful tool for optimizing soil stabilization in construction and geotechnical engineering.

Parasitic diseases in animals are widespread throughout the world and cause significant economic losses to the livestock industry. The most effective and economically justified measure for preventing these diseases among susceptible livestock is to implement high-quality veterinary and sanitary measures. To achieve this, it is essential to use effective disinfectants that have been proven to work in both laboratory and production environments. The work was carried out at the Laboratory of Veterinary Sanitation, Parasitology and Bee Diseases Study in the National Scientific Center ‘Institute of Experimental and Clinical Veterinary Medicine’ (Kharkiv, Ukraine). The effectiveness of the disinfectants was determined in accordance with existing regulatory documents. Based on these results, a method for disinfecting livestock facilities was developed. This method involves using a preparation containing peroxyacetic acid, hydrogen peroxide, acetic acid, stabilizing additives, and water. The exposure time ranges from 6 to 48 h, and the consumption rate is 500 ml/m². We propose a disinfection method involving a disinfectant containing potassium monopersulfate, sodium dichloroisocyanurate, sodium hexametaphosphate, sulfamic acid, malic acid, sodium alkylbenzyl sulfonate, sodium sulfate, and water. The exposure time is 3 h, and the consumption rate is 300 ml/m². Another method involves a preparation containing a mixture of quaternary ammonium compounds, glutaraldehyde, isopropyl alcohol, nonionic surfactants, and deionized water. This method requires an exposure time of 3–24 h and a consumption rate of 500 ml/m². The disinfectant, containing didecyldimethylammonium chloride, glutaraldehyde, benzalkonium chloride, surfactants, orthophosphoric acid, and water, has been proven effective at a 72 hour exposure rate of 500 ml/m² for soil disinfection. The proposed disinfection methods have been proven to meet biosafety and bioprotection requirements, and are easy to use, environmentally friendly, highly effective, and cost-effective. The results presented in this article significantly supplement existing sanitary and hygienic protocols in animal husbandry. Further research should focus on developing a comprehensive, scientifically based, integrated system for protecting farm animals

This work examines the colloidal properties of clays sampled from two different locations in Ventzia basin processed as low-density solid additives for water-based drilling fluid applications. The obtained samples were mechanically processed to reach a size less than 2 cm. The material was then activated with 3 wt% soda ash without oven drying, keeping the moisture in environmental conditions to simulate industrial activation conditions. After laying for one month curing time, samples were oven dried at 60 °C and further ground to &lt;120 μm. Two groups of samples were created mixing clays from Ventzia basin and additives. The first group contained clay, xanthan gum and sodium polyacrylate (PAA), while the second group contained clay, xanthan gum and sodium hexametaphosphate (SHMP). Standard tests were performed for the rheological behavior and filtration properties prior to and after dynamic thermal aging. Results obtained were compared with commercial clays from Milos and Wyoming used in drilling fluid systems, after thermally deteriorating also their properties. The obtained results revealed that the enhanced clays under study maintain excellent thermal stability. Notably, the top-performing formulation met the critical American Petroleum Institute (API) benchmark for filtrate loss (&lt;15 mL) and exhibited a robust rheological profile at temperatures up to 105 °C, demonstrating its suitability for water-based fluid (WBF) applications.

Northern Shaanxi’s oil-gas drilling produces large amounts of waste drilling fluids with high-value solids (barite, bentonite). Traditional disposal causes resource waste and pollution. This study proposes a stepwise flotation process for typical local oil-based waste: surface cleaning to break oil film wrapping and combined reagents to regulate mineral surface hydrophobicity differences, enabling efficient separation and recovery of barite and bentonite. The flotation mechanism is also preliminarily explored. The experimental results show that: ultrasonic cleaning with 0.5% sodium dodecyl sulfate (SDS) solution makes the oil desorption rate of solid phase >95%, restoring the natural surface properties of minerals. Through the stepwise flotation design, in the first stage at pH = 4.0, 0.8 kg/t sodium dodecyl sulfate and 0.6 kg/t sodium hexametaphosphate are added, and the recovery rate of bentonite reaches 86.3%; in the second stage at pH = 8.0, 1.2 kg/t sodium dodecyl sulfate and 0.7 kg/t gellan gum are added, and the grade of barite concentrate is 92.1% (BaSO₄ content), with a recovery rate of 88.7%. Through the flotation closed-circuit experiment, using the process of “one roughing, two cleaning and three scavenging”, the first stage can obtain bentonite concentrate with a recovery rate of 91.4% and a grade of 91.5%; the second stage can obtain barite concentrate with a recovery rate of 90.2% and a grade of 92.1%. SEM shows that bentonite is dissociated lamella, and barite presents clean prismatic crystals without oil film impurities, verifying the high efficiency of separation. Mechanism studies show that SDS has dual functions of oil breaking and collecting. Sodium hexametaphosphate inhibits the flotation of barite by chelating Ba²⁺ in barite. Gellan gum realizes separation by shielding the active sites of bentonite through hydrogen bonds. This study provides an efficient and low-consumption solution for the resource utilization of drilling waste liquid in northern Shaanxi.

Abstract Hexagonal boron nitride (h‐BN) is a highly stable, thermally conductive, and chemically inert material. However, it has several drawbacks as a flame retardant, including limited flame‐retarding performance, poor dispersibility in polymer matrices, and adverse effects on the mechanical properties of composite materials. To address these issues, we propose a new method that combines physical dispersion with chemical functionalization of h‐BN, using which we successfully developed an h‐BN‐based flame‐retardant material, significantly enhancing the flame‐retardant and mechanical properties of wood. Specifically, 3,5‐diamino‐1,2,4‐triazole and sodium hexametaphosphate were used to create layered sandwich structures with h‐BN. The resulting h‐BN‐guanazole‐sodium hexametaphosphate (BNGS) composite was then mixed with a urea–formaldehyde (UF) resin to form a cross‐linked macromolecular flame‐retardant resin. Wood coated with a UF resin containing 2 wt.% BNGS has a limiting oxygen index of 33.80 % and passes the UL‐94 V‐0 test. Compared with those of untreated natural wood (NW), the heat release rate and total heat release of the resin‐coated wood decreased dramatically by 76.00 and 80.67%, respectively. Moreover, the coating increases the impact strength of the NW, which is originally 7.35 kJ/m 2 , to 13.10 kJ/m 2 . This work provides a simple and high‐performance solution for wood protection.

Starch particles (SPs) were extracted from underutilized wild yam (Dioscorea remotiflora) tubers using two methods: (1) acid hydrolysis (AH) alone and (2) acid hydrolysis assisted by ultrasound (AH-US). The SPs were chemically modified through esterification (using acetic anhydride [AA] and lauroyl chloride [LC]) and crosslinking (with citric acid [CA] and sodium hexametaphosphate [SHMP]). They were subsequently characterized by their yield, amylose content, and structural and physical properties. The yield of particles was 17.5–19.7%, and the residual amylose content was 2.8–3.2%. Particle sizes ranged from 0.46 to 0.55 µm, which exhibited mono-modal and bi-modal distributions for AH and AH-US treatments, respectively. Following chemical modification, yield notably increased, especially with substitution by LC (33.6–36.5%) and CA (32.6–38.7%). Modified SPs exhibited bi-modal particle distributions with micro- and nanoparticles and variable peak intensities depending on the chemical compound used. Unmodified SPs displayed irregular morphologies, showing disruptions (AH) or aggregation (AH-US). Chemical substitutions altered morphologies, leading to amorphous surfaces (CA: AH), clustering (LC), or fragmentation into smaller particles (SHMP) under AH-US treatment. FT-IR analysis indicated a decrease in hydroxyl groups’ peak area (A(-OH)), confirming the substitution of these groups in the starch structure. Crosslinking with CA resulted in the highest degree of substitution (AH: 0.43; AH-US: 0.44) and melting enthalpy (ΔHf: 343.0 J/g for AH-US), revealing stronger interactions between SPs from both methods. These findings demonstrate that the extraction treatment of D. remotiflora SPs and the type of chemical modifier significantly influence the properties of SPs, underscoring their potential applications as natural biocarriers.

Gelatin is a commonly used protein-based hydrogel. However, the thermo-reversible nature of gelatin makes it unstable at physiological and higher temperatures. Therefore, this study adopted phosphates and glutaminase transaminase (TG) to modify gelation and studied the effects of combining sodium hexametaphosphate (SHP) and TG on the structure and gel properties of TG-crosslinked gelatin. This study focused on the effects of different SHP concentrations (0, 0.4, 0.8, 1.2, 1.6, 2.0, 2.4, 2.8 mmol/L) on the water distribution, textural properties, rheological properties, and microstructure of the TG-crosslinked gelatin gels. Results showed that the free water content in the TG-crosslinked gelatin gel declined with the increasing SHP addition when the concentration of SHP was kept below 2.0 mmol/L. The gel of TG-crosslinked gelatin at the SHP concentration of 1.6 mmol/L exhibited the highest hardness (304.258 g), chewiness (366.916 g) and η50. All the TG-crosslinked gelatin gels with SHP modification were non-Newtonian pseudoplastic fluids. The G' and G″ of TG-crosslinked gelatin increased before the SHP concentration reached 1.6 mmol/L, and the TG-crosslinked gelatin with 1.6 mmol/L SHP exhibited the largest G″ and G'. The fluorescence intensity of TG-crosslinked gelatin with SHP concentration above 1.6 mmol/L decreased with the increasing SHP concentration. SHP modified the secondary structure of TG-crosslinked gelatin gels. The gel of TG-crosslinked gelatin with the SHP concentration of 1.6 mmol/L exhibited a porous, smooth, and dense network structure. This research provides references for modifying gelatin and the application of gels in the encapsulation of bioactive ingredients and probiotics.