Phosphorus Salts Research Articles

The Impact of Suspension Fertilizers Based on Waste Phosphorus Salts from Polyol Production on the Content of Macronutrients in Maize Grown for Green Fodder

The Impact of Suspension Fertilizers Based on Waste Phosphorus Salts from Polyol Production on the Content of Macronutrients in Maize Grown for Green Fodder

Ammonium polyphosphate combined with potassium nitrate was used to modify the anti-caking property of nitro-compound fertilizer

Objective Although increasing the amount of inert hydrophobic material can improve the anti-caking performance of compound fertilizer, carrying inert hydrophobic material hinders the applicability of compound fertilizer in mechanized fertilization and the integrated technology of water and fertilizer. In order to reduce the amount of inert hydrophobic material applied to the outer surface of the compound fertilizer particles, in this article, the type and proportion of nitrogen salt, phosphorus salt, and potassium salt were limited so as to increase the anti-caking performance of the particles. Methods The anti-caking performance of 17-17-17SOP nitro-compound fertilizer granules (AN-NPK) was modified by the following three measures: (1) APP (ammonium polyphosphate) was used to replace some inorganic phosphates; (2) reducing the mass fraction of AN (ammonium nitrate) and introducing KN (potassium nitrate) to supplement the nitrate nitrogen in the compound fertilizer, and maintain the same ratio of nitrate nitrogen and ammonium nitrogen in AN-NPK; (3) reduce the mass fraction of KS (potassium sulfate), and shift the molar ratio of NO3/SO4 away from 2.0. The AN modified by APP and KN was characterized by X-ray diffraction and differential scanning calorimetry. The mechanism of improving the anti-caking performance of AN-NPK was demonstrated. Results The results showed that when the mass fraction of APP in the formula was 0%, 8%, 16%, and 21%, the anti-caking performance of AN-NPK is gradually increased, the transverse shear force of the agglomerates decreased from 135.65 N to 94.02, 67.45, and 60.32 N. When 10% KN and 12% APP were added to AN-NPK, the transverse shear force continued to decrease to 33.25 N. Conclusion The mechanism of improving anti-caking performance of AN-NPK is as follows:(1) APP with oligomeric degree has higher solubility and mobility than monoammonium phosphate and diammonium phosphate, resulting in higher enrichment on the surface of AN-NPK; (2) at the granulation temperature of 80 °C, KN releases more potassium ions than KS, and more AN was modified in the granulation process of AN-NPK. In summary, APP combined with KN weakens the phase transition effect of AN and reduces the salt ion concentration on the surface of AN-NPK.

Preparation and Characterization of Chitosan/Hydroxypropyl Methylcellulose Temperature-Sensitive Hydrogel Containing Inorganic Salts for Forest Fire Suppression.

Effective forest fire suppression remains a critical challenge, necessitating innovative solutions. Temperature-sensitive hydrogels represent a promising avenue in this endeavor. Traditional firefighting methods often struggle to address forest fires efficiently while mitigating ecological harm and optimizing resource utilization. In this study, a novel intelligent temperature-sensitive hydrogel was prepared specially for forest fire extinguishment. Utilizing a one-pot synthesis approach, this material demonstrates exceptional fluidity at ambient temperatures, facilitating convenient application and transport. Upon exposure to elevated temperatures, it undergoes a phase transition to form a solid, barrier-like structure essential for containing forest fires. The incorporation of environmentally friendly phosphorus salts into the chitosan/hydroxypropyl methylcellulose gel system enhances the formation of temperature-sensitive hydrogels, thereby enhancing their structural integrity and firefighting efficacy. Morphological and thermal stability analyses elucidate the outstanding performance, with the hydrogel forming a dense carbonized layer that acts as a robust barrier against the spread of forest fires. Additionally, comprehensive evaluations employing rheological tests, cone calorimeter tests, a swelling test, and infrared thermography reveal the multifaceted roles of temperature-sensitive hydrogels in forest fire prevention and suppression strategies.

The Impact of Suspension Fertilizers Based on Waste Phosphorus Salts from Polyol Production on the Yield of Maize Intended for Green Fodder

The need to import phosphorus raw materials for fertilizer purposes in Europe as well as the need to manage increasing amounts of waste contributed to the search for alternative sources of phosphorus. One of these is waste sodium–potassium phosphate from the production of polyols. Additionally, a current problem is providing an adequate amount of food, where fertilizers play the main role. Due to the increase in meat consumption, the attractiveness of growing corn for feed is increasing due to its high yield potential and rich composition. The article presents the impact of suspension fertilizers based on waste from the production of polyols on the yield of corn intended for green fodder. In a 3-year field study, the effects of a waste phosphorus source were compared with a commercial granulated phosphorus fertilizer—fosdar. In addition, the suspension fertilizers were assessed according to their composition by testing fertilizers containing only basic nutrients (NPK) and ones enriched with secondary ingredients (S and Mg) and microelements (Zn, Mn and B). The research confirmed the effectiveness of the tested suspension fertilizers. Although the yield obtained was lower than in the case of fosdar fertilization, it still remained at a high level of over 70 t∙ha−1 of fresh yield.

Curing kinetics of composites based on benzoxazine resin and microcrystalline cellulose modified by phosphorus salt

A comprehensive investigation into the curing kinetics of composites based on bisphenol A aniline benzoxazine resin (BA-a) and microcrystalline cellulose (MCC) modified by phosphorylation (MCC-pH), was conducted in this study. For this purpose, differential scanning calorimetry (DSC) analysis, at different heating rates, was used to examine the curing process. The kinetic parameters as a function of conversion were determined using isoconversional approaches, i.e., iterative Kissinger-Akahira-Sunose (it-KAS), Trache-Abdelaziz-Siwani methodology (TAS), and Vyazovkin methodology. The incorporation of MCC-pH reduced considerably the curing temperatures, indicating their catalytic effect. A combination of isoconversional methods and multi-step kinetic fitting was done to elucidate the effect of adding MCC-pH on BA-a curing. The reported data exhibited the enhanced reactivity of the composite systems, which was associated with the acceleration of the regular polymerization reaction. The possible pathway of the polymerization in the presence of phosphorylated cellulose was also discussed.

Hydrothermal Ammonia Carbonization of Rice Straw for Hydrochar to Separate Cd(II) and Zn(II) Ions from Aqueous Solution.

Hydrochar is considered to be a good adsorbent for the separation of metal ions from aqueous solutions. However, the yield of hydrochar from raw straw is generally low, because the hydrothermal carbonization occurs via dehydration, polymerization, and carbonization. In this work, various hydrochar samples were prepared from rice straw with nitrogen and phosphorus salt; moreover, toilet sewage was used instead of nitrogen, and phosphorus salt and water were used to promote the polymerization and carbonization process. The modified carbon was characterized using XRD, XPS, SEM, and FTIR, and the adsorption capacity was investigated. A significant increase in hydrochar yield was observed when toilet sewage was used as the solvent in the hydrothermal carbonization process. The adsorption capacity of N/P-doped rice straw hydrochar for Cd2+ and Zn2+ metal ions was 1.1-1.4 times higher than that those using the rice straw hydrochar. The Langmuir models and pseudo-second-order models described the metal adsorption processes in both the single and binary-metal systems well. The characterization results showed the contribution of the surface complexation, the electrostatic interaction, the hydrogen bond, and the ion exchange to the extraction of Cd2+ and Zn2+ using N/P-doped rice straw hydrochar.

Efficient (Bio)emulsification/Degradation of Crude Oil Using Cellulose Nanocrystals

This study has investigated the influence of cellulose nanocrystals (CNCs) with partially acetylated surfaces on the formation, stability, rheology and biodegradability of the Pickering emulsion in a crude oil/water (co/w) system. In all investigated systems, it was observed that the CNC concentrations of 7 mg/mL led to the emulsions showing stability over time. It was also noticed that the increase in concentration of background electrolyte (NaCl) leds to the droplets of emulsions becoming smaller. It was demonstrated that the rheology of the o/w emulsions of the oil products and crude oil stabilized by CNCs depends, to a large extent, on the colloid chemical properties of nanocellulose particles. Calculations and experimental methods were used to study the changes in the acid–base properties of CNCs on the surface of emulsion droplets, depending on a type of hydrophobic components (crude oil and liquid paraffin). The formation of Pickering emulsions leads to the oxidation of oil by Rhodococcus egvi in aerobic conditions becoming more effective, provided that the environment includes mineral salts of nitrogen, potassium and phosphorus. The results obtained present a scientific basis for the development of technologies for the disposal of oil spills on water surfaces.

Multi-dimensional application of quaternary phosphonium salt functionalized fiber with high polarization performance: Efficient adsorption of SDBS and green conversion of CO2

A novel mono-quaternary phosphorus salt functionalized fiber (PANQPSF) was developed as the multifunctional material to simultaneously realize selective removal of sodium dodecyl benzene sulfonate (SDBS) from water and green conversion of CO2. Compared with other adsorption materials and functionalized fibers, PANQPSF exhibits the eminent adsorption performance for SDBS due to its high polarization and hydrophobicity, and the adsorption capacity can reach 5.1 mol mol−1, equivalenting to 1066 mg g−1. And the synergistic adsorption mechanism of electrostatic interaction and lipophilic interaction between PANQPSF and SDBS is proposed. Furthermore, the PANQPSF still keeps excellent adsorption capacity even after 10 cycles. More satisfactorily, PANQPSF is used to catalyze the cycloaddition reaction of CO2 and epoxy compounds. The catalytic mechanism based on the nucleophilicity of Br− and the stabilizing effect of electrostatic interaction is promoted. In summary, the adsorption and catalytic performance prove that PANQPSF is an outstanding material with multi-dimensional applications.

Diversification of product-derived ionic liquids and application in DMC synthesis without introducing any impurities

Various strongly basic ionic liquids with distinctive structures, including single and double ended quaternary ammonium and phosphorus salts, were first synthesized based on hydroxyethoxy anion (HOCH2CH2O–) from the product ethylene glycol. Nature was characterized by NMR, FTIR, TG and acid-base titration. Its alkali strength was equivalent to that of sodium methoxide, demonstrating superior alkalinity. Influences of cation structures and C1-C4 alcohols structures on transesterification efficiency were investigated. Under mild conditions (68 °C for 5 min), DMC yield was 42.8% with a TOF value of 2853.6 h−1 when [TBAB]OCH2CH2OH as catalyst with only 0.18% EC molar content, indicating good catalytic performance. Comparison was made for reaction results between the synthesized catalysts and reported catalysts in literatures. The reaction mechanism was further deduced. Activation energies of positive and reverse reactions were determined as Ea+=32.0 kJ·mol−1 and Ea-=15.3 kJ·mol−1 through kinetics calculation. Relying on its decomposability and recyclability of decomposition products, a new catalyst circulation process without introducing any impurities was proposed and verified.

Hyperspectral Imaging Sorting of Refurbishment Plasterboard Waste

Post-consumer plasterboard waste sorting is carried out manually by operators, which is time-consuming and costly. In this work, a laboratory-scale hyperspectral imaging (HSI) system was evaluated for automatic refurbishment plasterboard waste sorting. The HSI system was trained to differentiate between plasterboard (gypsum core between two lining papers) and contaminants (e.g., wood, plastics, mortar or ceramics). Segregated plasterboard samples were crushed and sieved to obtain gypsum particles of less than 250 microns, which were characterized through X-ray fluorescence to determine their chemical purity levels. Refurbishment plasterboard waste particles <10 mm in size were not processed with the HSI-based sorting system because the manual processing of these particles at a laboratory scale would have been very time-consuming. Gypsum from refurbishment plasterboard waste particles <10 mm in size contained very small amounts of undesirable chemical impurities for plasterboard manufacturing (chloride, magnesium, sodium, potassium and phosphorus salts), and its chemical purity was similar to that of the gypsum from HSI-sorted plasterboard (96 wt%). The combination of unprocessed refurbishment plasterboard waste <10 mm with HSI-sorted plasterboard ≥10 mm in size led to a plasterboard recovery yield >98 wt%. These findings underpin the potential implementation of an industrial-scale HSI system for plasterboard waste sorting.

Phosphorus Additives and Their Impact on Phosphorus Content in Foods—An Analysis of the USDAs Branded Foods Product Database

The frequency of phosphate additives reported in the United States Department of Agriculture Branded Foods Product Database and how these additives impact phosphate content is unknown. All products included in the Branded Foods Product Database reporting phosphorus content were reviewed for presence of phosphate salts and/or lecithin additives. Phosphorus content information was available for 3,466 (1.45%) food items, of these 1791 (51.6%) contained additives. Median phosphorus content was lowest in products with lecithin only compared to products without phosphorus additives (86 [54-200] vs. 145 [77-351] mg per 100 g, P<.01), which was not different from products with phosphate salts (176 [101-276] mg per 100 g, P=.22) or products with both phosphate salts and lecithin (161 [99-285] mg per 100 g, P=1.00). The impact of a phosphorus salt on phosphorus content (mg per 100) was explored among ultra-processed products grouped by similar phosphorus contents. The phosphorus content of in in nondairy alternatives, dairy, plant proteins, and grains were significantly higher when the product contained a phosphate salt compared to products without a phosphate salt. For all products phosphorus and potassium content were correlated, but the relationship was stronger for when a potassium phosphate additive was present compared to absent (rho=0.81 vs. 0.53, P<.05). Similar patterns were seen for sodium, calcium, and iron with stronger correlations with phosphate content for products with additives than those without (calcium phosphate: rho=0.47 vs. 0.32; iron phosphate: rho=0.47 vs. 0.33; sodium phosphate: rho=0.45 vs. 0.07. All P<.05). The relationship between phosphate and sodium for products without phosphate additives was weak. Lecithin may not be associated with increased phosphorus content. Calcium, potassium, sodium, and iron phosphorus salts appear to be associated with increases in the composite mineral and phosphorus content, with the strongest correlation between potassium and phosphorus content.

FGF23 tumor induced osteomalacia

Tumor induced osteomalacia is a rare acquired disease. The cause is a mesenchymal tumor secreting fibroblast growth factor 23 (FGF23). An excessive amount of FGF 23 disrupts the metabolism of phosphorus and vitamin D, which leads to severe paraneoplastic syndrome, manifested in the form of multiple fractures, severe pain in the bones and generalized myopathy. With oncogenic osteomalacia, a complete cure is possible with radical resection of the tumor. Unfortunately, localization, small size of formations and rare frequency of occurrence lead to the fact that the disease remains unrecognized for a long time and leads to severe, disabling consequences. A step-by-step approach to diagnosis improves treatment outcomes. First, a thorough anamnesis is collected, then functional visualization is performed and the diagnosis is confirmed by anatomical visualization of the tumor. After that, the method of choice is a surgical treatment. If resection is not possible, then conservative therapy with active metabolites of vitamin D and phosphorus salts is indicated. New therapeutic approaches, such as the antibody to FGF23 or the pan-inhibitor of receptors to FGF, are actively developing. This article provides an overview of modern approaches to the diagnosis and treatment of this disease.

Girasol syrup in creation of special fermented milk drinks

The high content of inulin in girasol tubers makes it possible to use it as raw material for the diabetic food production: juice, flour, syrup, confectionery and bakery products. The rich composition of biologically active substances in girasol tubers gives this plant advantages for creating highly effective medicines. The beneficial effect of girasol on the metabolism regulation diseases of diabetes, hypertension, arrhythmia, atherosclerosis, coronary heart disease, obesity has been proven. The use of girasol in food causes a diuretic, choleretic, laxative, restorative and tonic effect, it is recommended for gastrointestinal tract diseases, urolithiasis and cholelithiasis, removes toxins and slags from the body, calms the nervous system. Girasol syrup surpasses many other vegetable syrups in terms of the concentration of carbohydrates, minerals and vitamins. It contains sugar, calcium, magnesium, and phosphorus salts. A large amount of iron is present, which is necessary for the processes of hematopoiesis. Easy digestibility and nutritional value make it indispensable for impaired liver and kidney function. New fermented baked milk is a functional food product that is useful for people with diabetes, obesity and other diseases that exclude or limit sugar consumption. Girasol activates the nervous, immune, and endocrine systems, improves blood quality. Organic acids in girasol have an antioxidant effect.

Mechanical properties and in vitro biodegradation behavior of GASAR porous Mg-Ag alloy

In this thesis, porous pure Mg and Mg-3 wt%Ag alloys with oriented regular pore structures were prepared by the metal/gas eutectic unidirectional solidification method (GASAR process). The effects of the Ag content on the mechanical properties and early in vitro biodegradation behavior of porous Mg-Ag alloys were investigated. The results of compression experiments showed that Ag addition significantly enhanced the compressive strength and elastic modulus of the porous Mg-Ag alloy. Immersion experiments in SBF at 37℃ showed that although the Mg-3 wt%Ag alloy exhibited a faster corrosion reaction, the addition of Ag facilitated the precipitation of calcium and phosphorus salts, resulting in better osteoinductivity of the samples, which indicates its feasibility as a potential tissue engineering scaffold.

A tetrameric praseodymium substituted arsenotungstate (III) – Synthesis & characterization, electrochemistry, catalytic and its magnetic applications

A praseodymium-substituted lone pair containing arsenotungstate with the formula Na28[Pr4As2O6(OH)2(WO)(WO3)2(AsW9O33)4].70H2O has been synthesized under mild reaction conditions. The compound was isolated in 1 M NaCl solution with the trilacunary {AsW9O33} precursor along with the addition of sodium dihydrogen phosphate during the reaction procedure. Here, the addition of the phosphorus salt played an important role in the synthetic procedure. The polyanion was characterized by various analytical techniques such as Fourier-Transform Infrared spectroscopy (FT-IR), Single Crystal X-Ray Diffraction (SC-XRD), Powder X-ray diffraction (P-XRD), Thermogravimetric Analysis (TGA), Elemental analysis (ICP-AES) and Cyclic voltammetry (CV). The catalytic activity of the polyanion was studied for thioether oxidation as a heterogeneous catalyst. The magnetic properties of the complex were also investigated.

REQUIREMENTS FOR THE QUALITY OF MILK AS RAW MATERIAL FOR THE PRODUCTION OF CHEESE

Requirements for the quality of "raw milk" used for processing into dairy products are different. Depending on the purpose, type and technology of production of various dairy products, milk must have certain properties. The most important dairy product in human nutrition is cheese. Cheese contains all the nutrients of milk in concentrated form. It is a source of biologically complete protein, rich in fats and vitamins. The calcium and phosphorus salts it contains help to strengthen bone tissue. In this regard, cheeses should be included in the daily diet of various categories and age groups of the population, especially in regions with a difficult ecological situation. When producing any kind of cheese, an important place is given to the composition and properties of milk, processed raw materials. There is a special concept - "Cheese milk", so the organization of cheese production should begin with the study of milk, the characteristics of its properties and composition. In terms of density and acidity, milk from cows of all groups at different periods of calving met the requirements of DSTU for premium milk. The density of milk was in the range of 1.027-1.028 g / cm3, acidity 16.50-17.45 ° T, mass fraction of fat 4.11-4.43%, protein 3.25-3.29%. With an increase in the amount of fat in milk, the protein content decreased, the highest fat content was observed in cows of the fourth group (4.43%), while the group had the lowest protein content - 3.25%. The lowest indicators in terms of fat content of milk were in cows of the second group (4.11%), and in terms of protein content - the highest in the first group (3.29%). The higher the fat utilization, the lower the milk consumption per kg of cheese derived from it. They were the smallest in cows of autumn (7.29 kg) and spring (7.43 kg) calving, and the highest in cows of winter (8.05 kg) and summer (7.96 kg) calving. At the same time, the difference between the minimum and maximum indicators was 0.76 kg or 10.4%. Low milk costs per 1 kg of cheese obtained from it were found in autumn (7.29 kg) and spring (7.43 kg) calving cows, high in winter (8.05 kg) and summer (7.96 kg) calving cows.

NUTRIENT INTAKE OF WEST AFRICAN DWARF GOATS FED DIETARY MODELS OF ENSILED CASSAVA PEEL MEAL FORTIFIED WITH CALCIUM-PHOSPHORUS SALT

Objective: This study was conducted to determine nutrient intake of growing West African Dwarf goats fed different dietary models of ensiled cassava peel meal fortified with Calcium-Phosphorus salt mix. Methods: Twenty (20) growing West African Dwarf female goats aged 6–8 months with an initial weight of 8.2 kg ± 0.25 were used for the study. They were randomly allotted to four dietary treatments with five goats per treatment in a completely randomized design. The dietary treatments were Diet 1 (block), Diet 2 (crunchy), Diet 3 (pellet), and Diet 4 (mash). Results: Results obtained indicated that dry matter intake ranged from 466.18 g/d to 575.53 g/day with significantly (p&lt;0.05) higher value in pellet model while crude protein intake was higher in mash model than other treatments. Ether extract and crude fiber intake values were higher 40.13 g/day and 148.08 g/day in pellet feed model. Ash intake ranged from 61.32 g/day to 95.86 g/day. Block and crunchy models had significantly (p&lt;0.05) higher value for ash intake while values obtained for nitrogen-free extract intake was also higher (p&lt;0.05) in pellet model 22.62 g/day than other models. Values of fiber fractions intake obtained were significantly (p&lt;0.05) influenced by dietary models with higher values for neutral detergent fiber, acid detergent fiber and hemicellulose in mash while acid detergent lignin was significantly (p&lt;0.05) for pellet model. Conclusion: It can be concluded that supplementing goat diets with different dietary models of ensiled cassava peel meal fortified with Calcium- Phosphorus salt mix can boost intake of goats for better productive performance and productivity.

Phosphorus, Tungsten, and Molybdenum – from Brilliant to Fanal®: Unusual Precipitation Methods of Triphenylmethane Dyes in the Early Twentieth Century

ABSTRACT Triphenylmethane based dyes became popular after their invention in 1858 due to their brilliant shades and high tinting strengths and were used not only as colourants for textile and paper dyeing, but also as pigments in artists' materials under the commercial name ‘Fanal®’. However, the extent of their use as pigments in artists’ paints has thus far remained unknown. Despite their bright colours, the characteristic low lightfastness of their dyes and pigments inspired further research for new precipitation methods to increase lightfastness, which ultimately resulted in precipitation using complex salts of phosphorus, tungsten, and molybdenum. The present study is based on archival source research from I.G. Farben, the former producer of Fanal®, and Royal Talens, an artists’ paint manufacturer that used these pigments. This research focuses on the history of developments in precipitation methodologies employed for early triphenylmethane dyes and the development of the various lines of Fanal® pigments in oil paints produced by the Dutch manufacturer Talens in the late 1920s and onwards. Historic literature sources, such as the Talens publication Kunstschildersmaterialen en Schildertechniek by Frits Kerdijk that document the application of Fanal® pigments, are also highlighted.

Facile Synthesis of In Situ Formable Alginate Composite Hydrogels with Ca2+-Induced Healing Ability.

Dental caries have plagued humans for many years. At present, photocrosslinking resin is commonly used in clinics to repair narrow tooth defects, but the ultraviolet light used in this process has unavoidable cytotoxicity. In situ hydrogels with a similar structure to that of the natural extracellular matrix have gradually attracted attention in the field of hard tissue repair engineering. The injectable molding properties of hydrogel also give it the potential to fill irregularly shaped or fine tissue defects. Through a rapid and facile Michael addition reaction, we prepared maleic chitosan (CS-maleic anhydride [MA]) and thiolated alginate (sodium alginate [SA]-SH) to form a CS-MA/SA-SH hydrogel. To endue its mineralize ability, β-glycerophosphate calcium phosphate and calcium carbonate as the precursor of hydroxyapatite (HAp) were premixed in the hydrogel at certain ratios. This kind of hydrogel can quickly form into different shapes within 10 min. It is worth noting that external Ca2+ can react with the residual carboxyl groups of SA and provide the hydrogel with a self-healing ability. At the same time, we creatively propose a method that uses alkaline phosphatase to promote the mineralization of HAp in hydrogels, to achieve the purpose of regenerating hard tissue in situ. By examining the properties of hydrogels at different concentrations of calcium and phosphorus salts, we find that the CS-MA/SA-SH hydrogel with 50% (wt.%) inorganic matter presented the best self-healing properties, excellent mineralization of highly crystallized Hap, and has ideal cell compatibility. The potential application of the CS-MA/SA-SH hydrogel in repairing exposed dentin tubules in decayed teeth was explored through preliminary in vitro dental restoration experiments. Obviously, the penetration depth through dentin tubules was better than that of commercial dental sensitizers. In addition, the HAp morphology was affected by the local environment. We believe that this hydrogel can utilize tissues for dental regeneration and mineralization, and the healing ability provides the hydrogel flexibility for further application in hard tissue regeneration. Impact statement In this article, we report a simple, gentle, and rapid method for the synthesis of new, in situ-formable polysaccharide-based hydrogels that are capable of healing through the Michael addition reaction, which does not require any crosslinking agents. The rapid healing ability of the hydrogel can be obtained within 1 min by introducing calcium ions, giving the hydrogel the possibility of self-healing in the cap-enriched state. Second, we conferred in vitro mineralization of hydrogels and used a simple novel "enzyme-promoted" approach. Simulated mineralization using human body-enriched alkaline phosphatase as an inducer, allowing hydrogels rich in calcium glycerophosphate and calcium chloride to be highly similar to natural hydroxyphospholipids in a simulated body fluid environment at 37°C, stone-structured, and well-shaped thin-section mineralized products. Finally, we use the self-healing hydrogel with in vitro mineralization ability to carry out simple repair and mineralization regeneration of enamel and dentin, and this result is related to the tooth desensitizing agent commonly used in Chinese dental clinics. Comparison of commercial hydrogels further proves that this polysaccharide-based hydrogel is not only convenient for clinical operation in oral prosthesis but also has obvious advantages in the sealing of enamel by dental tubules and the enhancement of tooth hardness.

Metals bioremediation potential using Pseudokirchneriella subcapitata

Microalgae are unicellular organisms, photosynthesizers that present cell duplication exponentially and biosorption capacity of nutrients dissolved in water. The objective of this work was to evaluate the capacity of the microalga Pseudokirchneriella subcapitata for bioremediation of metals and salts. In this aspect, the reduction of the metals and salts in the synthetic effluents by the microalga P. subcapitata was evaluated: (T1) culture medium (control); (T2) culture medium contaminated with aluminum chloride; (T3) culture medium contaminated with ferrous sulfate; (T4) culture medium contaminated with zinc sulfate; (T5) culture medium contaminated with the combination of aluminum chloride, ferrous sulfate and zinc sulfate. The bioremediation process was evaluated by comparing culture media with suspended microalgae to a filtrate version of the same medium. Iron and zinc metals, as well as nitrogen and phosphorus salts, showed depleted values in the filtered medium, indicating efficiency in the treatment of water by microalgae. Aluminum content was below the limit of detection in all treatments. The cumulative values in the microalgae biomass were, in descending order: nitrogen, zinc, iron and phosphorus, thus indicating the assimilation of the contaminants in the algal biomass. In addition, high biomass production of the microalgae was observed. The highest production rate was verified in the synthetic effluent with the association of metals, indicating a synergy between contaminants, which was probably responsible for reducing the toxic effect on the microalgae. These results indicated high potential for bioremediation by microalga P. subcapitata, besides the possibility of using algal biomass for biotechnological applications.