Phosphate Formation Research Articles

Peptide-Decorated DNA Nanostructures Promote Site-Specific Hydroxyapatite Growth.

The guiding principle for mineralized tissue formation is that mineral growth occurs through the interaction of Ca2+ and phosphate ions with extracellular matrix (ECM) proteins. Recently, nanoengineered DNA structures have been proposed as mimics to ECM scaffolds. However, these principles have not been applied to mineralized tissues. Here, we describe DNA nanostructures, namely, a DNA nanotube and a DNA origami rectangle that are site specifically functionalized with a mineral-promoting "SSEE" peptide derived from ECM proteins present in mineralized tissues. In the presence of Ca2+ and phosphate ions (mineralizing conditions), site-specific calcium phosphate formation occurred on the DNA nanostructures. Amorphous calcium phosphate or hydroxyapatite was formed depending on the incubation time, shape of the DNA nanostructure, and amount of Ca2+ and phosphate ions present. The ability to design and control the growth of hydroxyapatite through nanoengineered scaffolds provides insights into the mechanisms that may occur during crystal nucleation and growth of mineralized tissues and can inspire mineralized tissue regeneration strategies.

THE STUDY OF THE SORPTION PROPERTIES OF FILTERING MATERIALS BASED ON TITANIUM PHOSPHATE - POROUS TITANIUM COMPOSITION

Inorganic sorbents are more selective in comparison with commercial ion exchange resins towards of metal ions. However, inorganic sorbents characterized not high kinetic properties. One of the way to increase the kinetic rate of inorganic sorbents is to reduce the particle size of these materials, other way is synthesizing inorganic sorbents as porous products from powder materials. A sample of such inorganic sorbents is titanium phosphate of various compositions. Studying the properties of microfilters based on composition titanium phosphate - porous titanium has been developed. The sorbents based on acidic titanium phosphate Ti(HPO4)2∙H2O were used for filtering solution with Fe(II) content. It is found that the number of impregnations with inorganic sorbent modificator is important and influence filtration process. The obtained results demonstrated that after the first impregnation of porous material with a smaller pore size, it is possible to obtain such sorbent as a mass content of powder material. By varying the ionic form of titanium phosphate, the porosity of titanium, the amount of impregnation, it could be possible effect on the sorption Fe(II). The sorption properties of titanium-titanium phosphate microfilters were studied by potentiometric titration in the NaCl-NaOH system, as well as the sorption of Fe2+ ions. The degree of purification for Fe(II) from solution with a concentration of 10 mg/l is 64 %. Application an electric potential to the microfilter of porous titanium - phosphate titanium increases the degree of purification of Fe(II) to 88 %.

Effect of different levels of NPK in the growth and development of Jatropha shrub in displaying Samawa

Several experiments were conducted, for purpose of producing the Jatropha bushes and conduct several tests on them inAlmuthanna province, during the period between Spring 2013 until Autumn 2015. The study focused on the followings:Determine appropriate levels of NPK: to ensure high productivity, fertilizer recommendation to the Jatropha experiment which is carried out in one year age, designed by the completed random sectors and three replications using nitrogen levels ( 0, 100, and 200 kg of N/ha).form of urea (46% N) was applied twice, and the levels ofPhosphorous in form of super phosphate (46% P2O5) was applied once at a rate of 0, 100, and 200 kg of P2O5ha-1. Potassium in form of potassium (50% K2O) was applied once at a rate of (0, and 100, kg of K2O ha-1). The three combinations of these fertilizers showed growth , significant increase in the length and growth , the number of branches , leaf area and the content of chlorophyll in different proportions level.

Characterization and photocatalytic activity of titanium dioxide powder treated with PH3 gas

NH3 treatment for nitrogen doping to metal oxides is widely used as a method of band gap narrowing. However, PH3 treatment of titanium dioxide(TiO2) powders has not yet been established. In the present study, PH3 treatment of TiO2 was attempted by heating TiO2 powders and solid-state sodium hypophosphite in a sealed ampoule. The color of the powders changed from colorless for untreated TiO2 to beige for TiO2 treated at 250, 290, 350 °C, or to gray for TiO2 treated at 450 °C. X-ray photoelectron spectroscopy (XPS) analysis of the treated TiO2 revealed that the phosphorus was in a phosphate form and that a part of Ti4+ in TiO2 was reduced to Ti3+. The absorption spectra and the XPS data suggested the generation of oxygen vacancies. Adsorption experiments of methylene blue and Eosin Y onto the treated TiO2 indicated the presence of phosphate on the surface of TiO2. X-ray diffraction (XRD) analysis indicated that the crystallite sizes of the treated TiO2 increased with increasing in temperature. Photodegradation rates of the pigments by the treated TiO2 under UV light depended on phosphate, oxygen vacancy and crystallinity. PH3 treatment of crystalline TiO2 were found to give priority to phosphate formation in contrast to NH3 treatment for nitrogen doping.

Can Bottom Sediments Be a Prospective Fertilizing Material? A Chemical Composition Analysis for Potential Reuse in Agriculture.

Every year, huge amounts of bottom sediments are extracted worldwide, which need to be disposed. The recycling of bottom sediments for soil fertilization is in line with the long-promoted circular economy policy and enables the use of micro and macronutrients accumulated in sediments for soil fertilization. When considering potential agricultural reuse of the dredge sediments, the first necessary step should be to analyze whether the heavy metal content meets the obligatory criteria. Then, the contents of valuable elements required for plant growth and their ratios should be assessed. In this study, the content of nitrogen, organic carbon, phosphorus, and potassium was tested and iron, sulfur, calcium, and magnesium were also analyzed along vertical profiles of sediments extracted from four urban retention tanks in Gdańsk (Poland). The sediments were indicated to have a low content of nutrients (Ntot 0.01–0.52%, Corg 0.1–8.4%, P2O5 0.00–0.65%, K 0.0–1.0%), while being quite rich in Fe and S (0.2–3.3%, 0.0–2.5%, respectively). The C/N ratio changed in the range of 17.4–28.4, which proved good nitrogen availability for plants. The mean values of the Fe/P ratio were above 2.0, which confirms that phosphorus in the sediments would be available to the plants in the form of iron phosphate. To summarize, the bottom sediments from municipal retention reservoirs are not a perfect material for soil fertilization, but they are a free waste material which, when enriched with little cost, can be a good fertilizer. Future research should focus on cultivation experiments with the use of sediments enriched with N, P, Corg.

Potential Application of Pin-to-Liquid Dielectric Barrier Discharge Structure in Decomposing Aqueous Phosphorus Compounds for Monitoring Water Quality.

Here, we proposed a pin-to-liquid dielectric barrier discharge (DBD) structure that used a water-containing vessel body as a dielectric barrier for the stable and effective treatment of aqueous solutions in an open atmosphere. To obtain an intense pin-to-liquid alternating current discharge using a dielectric barrier, discharge characteristics, including the area and shape of a ground-plate-type electrode, were investigated after filling the vessel with equivalent amounts of water. Consequently, as the area of the ground electrode increased, the discharge current became stronger, and its timing became faster. Moreover, we proposed that the pin-to-liquid DBD reactor could be used to decompose phosphorus compounds in water in the form of phosphate as a promising pretreatment method for monitoring total phosphorus in water. The decomposition of phosphorus compounds using the pin-to-liquid DBD reactor demonstrated excellent performance—comparable to the thermochemical pretreatment method—which could be a standard pretreatment method for decomposing phosphorus compounds in water.

Charge balancing stabilized apatite enter into collagen fibers by osmotic pressure to induce the formation of intrafibrillar mineralization

Intrafibrillar mineralized collagen is the main form of natural mineralized collagen in bone matrix. However, the mechanism involved in the intrafibrillar mineralization is still unclear. Here, by measuring the changes of Zeta potential and adjusting the osmotic pressure of collagen fibers to study the mechanism of intrafibrillar mineralization. The changes in zeta potential and reduction in size during the formation of amorphous calcium phosphate (ACP) after adding negatively charged polyacrylic acid (PAA) and positively charged cationicpolyacrylamide (CPAM) indicate that the stabilization mechanism of ACP induced by polyelectrolyte compound is charge balance. Then, osmotic pressure pressures charge balancing stabilized ACP into collagen fibers to induce intrafibrillar mineralization. This discovery provides basis for further understanding the intrafibrillar mineralization, preparing new biomimetic mineralized materials and promoting the development of tissue engineering.

Deep groundwater physicochemical components affecting actinide migration

To better understand the migration behavior of actinides in deep groundwater (GW), the interactions between doped tracers and deep GW components were investigated. La, Sm, Ho, and U tracers (10 or 100 ppb) were doped into sedimentary rock GW samples collected from 250 to 350 m deep boreholes in the experimental gallery of the Horonobe Underground Research Laboratory (URL), Hokkaido, Japan. To evaluate the effect of GW composition on the chemical speciation of actinides, the same tracers were doped into crystalline rock GW samples collected from 300 to 500 m deep boreholes in the experimental gallery at the Mizunami URL, Gifu Prefecture, Japan. Each GW sample was sequentially filtered through a micro-pore filter (0.2 μm) and ultrafilters with a 10 kDa nominal molecular weight limit. Next, the filtrate solutions were analyzed using inductively coupled plasma–mass spectrometry to determine the concentration of tracers retained in solution during each filtration step, and the used filters were analyzed using time-of-flight secondary ion mass spectrometry element mapping and X-ray absorption fine structure spectroscopy to determine the chemical species of the tracers trapped on each filter. It was determined that lanthanide migration was controlled by the amount of phosphates in the Horonobe GW. Therefore, it was expected that the solubility of minor actinides (MAs), which exhibit a similar chemical behavior to that of lanthanides, would be controlled by the formation of phosphates in sedimentary rock GW. Moreover, the data on the Mizunami GW indicated that a fraction of lanthanides and MAs formed hydroxides and/or hydroxocarbonates.

Nanocomposites based on apatitic tricalcium phosphate and autofibrin

Nanocomposites based on apatitic tricalcium phosphate in an autofibrin matrix were obtained by precipitation at a Ca/P ratio of 1.50, pH 9 and a maturation time from 30 min to 7–14 days. The resorbability of nanocomposites was determined by the composition of calcium phosphates, which, during long-term maturation, formed as the calcium-deficient hydroxyapatite with a Ca/P ratio of 1.66, whereas biopolymer matrix favored the formation of more soluble calcium phosphates with a Ca/P ratio of 1.53–1.59. It was found that the fibrin clot stabilized, along with apatitic tricalcium phosphate, the phase of amorphous calcium phosphate, which after 800 °C was transformed into resorbable α-tricalcium phosphate. Citrated plasma inhibited the conversion of apatitic tricalcium phosphate into stoichiometric hydroxyapatite, which also facilitated the formation of resorbable β-tricalcium phosphate after 800 °C. The combined effect of the maturation time and the biopolymer matrix determined the composition, physicochemical and morphological properties of nanocomposites and the possibililty to control its extent of resorption

Conversion of crop residual waste in to fuel for thermal plants and fertilizer for farmers

The conversion of solid waste (dry leafs and dry seeds) into fuel and fertilizer is an idea for educating and mobilizing the farmers to stop the burning of crop residue seasonally. In India it is a common practise for the farmers to fire the crop residue after the cultivation is completed by which air and soil pollution is increasing. The idea here is to convert that crop residue (waste) into a useful form by pulverising and blending in a ratio. In this work the emphasis is made on rice stubble, wheat stubble, cotton stubble, neem leafs and Moringa oleifera leafs. In addition to them rice husk, dry neem seeds, tamarind seeds, Indian date seeds and agro waste seeds are used. The produced fuel (in powder form) has found a calorific value of 4180 Kcal/Kg and the fertilizer has shown the typical value of nitrogen in nitrate form is 24.94%, phosphorous in phosphate form of 12.35% and potassium of 61.75%. This work makes an arena to the farmers to stop burning the crop residue (agro waste) and substantially converting it into the fuel and fertilizer.

Modified phosphate coatings applied to steel by cold method

The deposition of phosphate coatings occurs on the surface of the product when it is immersed in a solution containing phosphoric acid. The formation of a film on the metal surface occurs during the deposition of insoluble two- and three-substituted phosphates of iron, manganese, and zinc from a solution. To speed up the process and conduct phosphating at low temperatures, nitrates, nitrites, and fluorides of active metals are introduced into the solution. Organic compounds, such as glucose, glycerin, Trilon A, and Trilon B, are buffer additives to maintain the pH of phosphating solutions in the range of 2.6-3.2. It was found that 10-15 minutes at a process temperature of 20-25 °C are sufficient for the formation of a protective phosphate coating from solutions containing modifiers. The content of zinc phosphates in the modified phosphate coatings is increased. Additives in cold phosphating solutions have a positive effect on the quality and protective properties of the resulting phosphate films. Modified phosphate coatings obtained by the cold method have a fine-crystalline structure, a smooth surface and low porosity.

Occurrence of novel organophosphate esters derived from organophosphite antioxidants in an e-waste dismantling area: Associations between hand wipes and dust.

Electronic waste (e-waste) is a well-known source of plastic additives in the environment. However, the e-waste-related occupational exposure to organophosphite antioxidants (OPAs) and the relevant oxidation products-novel organophosphate esters (NOPEs)-via different pathways is still unknown. In this study, six OPAs and three NOPEs were measured in 116 dust and 43 hand-wipe samples from an e-waste dismantling area in Central China. The median concentrations of ΣOPAs and ΣNOPEs were 188 and 13,900ng·g-1 in workshop dust and 5,250ng·m-2 and 53,600ng·m-2 on workers' hands, respectively. The increasing concentrations of dust in the form of triphenyl phosphate (TPHP) (p<0.01) and tris(2,4-di-tert-butylphenyl) phosphate (AO168=O) (p<0.05) were strongly associated with the corresponding concentration on workers' hands. Furthermore, men had significantly lower levels of NOPEs on their hands than did women (p<0.01). Moreover, the hand wipe levels of AO168=O (41,600ng·m-2) was significantly higher than that of the typical OPE (TPHP, 7370ng·m-2), and the hand-to-mouth contact (ΣOPAs, 9.48ng·kg bw-1·day-1; ΣNOPEs, 109ng·kg bw-1·day-1) was a more significant and integrated pathway than dust ingestion (ΣOPAs, 0.10ng·kg bw-1·day-1; ΣNOPEs, 5.01ng·kg bw-1·day-1) of e-waste related occupational exposure to these "new" chemicals.

Mechanisms and kinetics of citrate-promoted dissolution of a uranyl phosphate mineral

The formation of uranyl phosphate precipitates is a remediation strategy to limit the mobility of uranium in contaminated soils. However, exposure to organic ligands, like the plant exudate citrate, can remobilize the uranium. The purpose of this study is to provide a more thorough comprehension of citrate-promoted dissolution of a uranyl phosphate mineral, chernikovite [(H3O)(UO2)(PO4)·3H2O], by determining the extent of uranium release from chernikovite at a wide range of citrate concentrations. We have quantified the kinetics of dissolution and proposed potential mechanisms of chernikovite dissolution to gain a better understanding of the fate of uranyl phosphate precipitates in the environment. Batch dissolution and continuously stirred tank reactor (CSTR) experiments indicate that increasing citrate concentrations from 0.1 mM to 50 mM increases the concentration of dissolved uranium. However, at citrate concentrations of 10 mM and greater, the effectiveness of the ligand to enhance the dissolution decreases. Density functional theory modeling and Raman spectroscopy indicate a strong interaction between citrate and the uranyl ions at the surface of the uranyl phosphate. The interaction between citrate and uranyl suggests the formation of an alteration layer of uranyl-citrate surface complexes, which could impede uranium release at citrate concentrations of 10 mM or higher. Together, these results indicate that the citrate-promoted dissolution of chernikovite is a fast reaction that is hindered by a combination of surface saturation and a secondary-phase precipitation reaction at higher concentrations of citrate and reaction times greater than or equal to 72 min based on the hydraulic residence time of CSTR experiments. These findings improve our understanding of the stability of uranyl phosphate for use in sequestration of uranium groundwater plumes at contaminated sites.

Chemical study of bottom ash sintering in combustion of pelletized residual agricultural biomass

Although residual agricultural biomass is a high-potential energy source, its use is curtailed by the characteristics of its ash (quantity and composition). This ash can cause problems during combustion, including bottom ash sintering, which is the main focus of this study. Results of bottom ash proportion and sintering degree yielded by combustion tests carried out with four different agropellets (one was exclusively woody, and the others were blended with various herbaceous components –mixed agropellets) under different operating conditions in a laboratory fixed-grate reactor were presented in a previous paper. The inlet air temperature and the excess air were the two controlled operating parameters in the tests. To bring the analysis further, samples of bottom ash collected during these tests have been characterized using SEM-EDS and P-XRD techniques. The results confirmed that, given its high content of alkali metals and its high ratio (K+Na)/(Si+P), the differences in sintering behavior presented by the four agropellets are related to the formation of alkali metal silicates and phosphates; Si+P is the limiting and determining content that condition the sintering severity. Regarding the influence of operating conditions, only small variations in the composition of both the sintered and not sintered fractions of the bottom ash have been detected when varying inlet air temperature and excess air in the analyzed range. Nevertheless, these SEM-EDS results have led to the detection of two opposing phenomena related to increased excess air: higher ash entrainment and lower vaporization, which are associated with the increase of air velocity and the reduction of combustion temperature, respectively. Whereas in the mixed agropellets and in the range of excess air tested these two effects offset each other, woody agropellet is significantly affected by entrainment due to its lack of sintered matter. These results provide useful information towards a solution of the problem posed by sintering in the combustion of residual agricultural biomass.

Engineered biochar from sugarcane leaves with slow phosphorus release kinetics

The in-field burning of sugarcane leaf residues presents a major environmental and health burden in Thailand. In this study, sugarcane leaves were converted into a biochar-based slow release phosphorus (P) fertilizer via pyrolysis at 600 °C, and the influence of pre- and post-pyrolysis treatment on the P loading and release was investigated. The sugarcane leaves were pre-treated with an alkaline (diammonium phosphate, DAP) or an acidic P source (phosphoric acid, PA), with or without addition of MgO. Additionally, the biochar was post-treated with DAP to increase the P loading. Extraction of P in DI water and 2% formic acid were used as indicators for potential slow release. The microporous biochars had a specific surface area of 69–333 m2 g−1 and pre-treatment resulted in a P content of 34–82 g kg−1. When MgO was included in the pre-treatment, XRD analysis confirmed formation of crystalline Mg2P2O7, irrespective of the P source. This Mg2P2O7 was responsible for slow P release in DI water over 240 h via a dissolution-controlled process. Post-treatment with DAP increased the P loading to 156 g kg−1 in the form of water-soluble monoammonium phosphate (MAP), which did not contribute to slow release. The tunable P release via combinations of pre- and post-pyrolysis treatment makes these engineered biochars attractive as P sources for crops and presents an attractive solution to mitigate in-field sugarcane residue burning.

Evaluating the induction of antibacterial properties upon zinc incorporation in strontium phosphosilicate for bone regeneration applications

Synthesis of Pure phase and a series of Zinc substituted Strontium phosphosilicate was attempted in the present study and assessed structurally and biologically. The Sol-Gel technique ensured proper reactivity and apatite formation upon sintering. The acidic medium was more applicable for synthesis on account of the isoelectric point of silica and formation of secondary Sr2SiO4 phase, important and applicable in bioactivity apart from Sr2P2O7 as another secondary phase. Sintering formed agglomerated stable crystalline phases evident from diffraction further confirmed by infrared spectroscopy. The morphology showed minimal differences from the parent material increasing agglomeration upon the increment of dopant. Biological evaluations showed the successful formation of amorphous Calcium phosphate with two days of SBF immersion and proliferation of MG-63 Cells upon Zinc incorporation. The antibacterial properties were enhanced upon the incorporation of Zinc while Strontium phosphosilicate in the pure phase failed to produce favourable antibacterial activity.

Effects of Early, Small-Scale Nitrogen Addition on Germination and Early Growth of Scots Pine (Pinus sylvestris) Seedlings and on the Recruitment of the Root-Associated Fungal Community

Scots pine (Pinus sylvestris L.) is one of the most economically important species to the Swedish forest industry, and cost-efficient planting methods are needed to ensure successful reestablishment after harvesting forest stands. While the majority of clear-cuts are replanted with pre-grown seedlings, direct seeding can be a viable option on poorer sites. Organic fertilizer has been shown to improve planted seedling establishment, but the effect on direct seeding is less well known. Therefore, at a scarified (disc trencher harrowed) clear-cut site in northern Sweden, we evaluated the effect of early, small-scale nitrogen addition on establishment and early recruitment of fungi from the disturbed soil community by site-planted Scots pine seeds. Individual seeds were planted using a moisture retaining germination matrix containing 10 mg nitrogen in the form of either arginine phosphate or ammonium nitrate. After one growing season, we collected seedlings and assessed the fungal community of seedling roots and the surrounding soil. Our results demonstrate that early, small-scale N addition increases seedling survival and needle carbon content, that there is rapid recruitment of ectomycorrhizal fungi to the roots and rhizosphere of the young seedlings and that this rapid recruitment was modified but not prevented by N addition.

Catalytic Prebiotic Formation of Glycerol Phosphate Esters and an Estimation of Their Steady State Abundance under Plausible Early Earth Conditions

The emergence of biological phosphate esters of glycerol could have been a crucial step in the origin and evolution of life on the early Earth as glycerol phosphates today play a central role in biochemistry. We investigate here the formation of the glycerol phosphates by employing various rock samples, salts, and minerals as potential catalysts to aid the phosphorylation process. We report the synthesis of various phosphate esters of glycerol including glycerol-1-phosphate, glycerol-2-phosphate, cyclic glycerol-monophosphate as well as various diphosphate esters. Furthermore, the decomposition rates of glycerol phosphate under mild heating were also studied while keeping the pH constant. It was observed that glycerol phosphate starts decomposing quickly under mild heating conditions into inorganic orthophosphate and pyrophosphate, and a steady state concentration of ~0.5 M of glycerol phosphate may have been reasonable in ponds with abundant glycerol, phosphate, urea, and catalytic minerals.

Structures of prokaryotic ubiquitin-like protein Pup in complex with depupylase Dop reveal the mechanism of catalytic phosphate formation

Pupylation is the post-translational modification of lysine side chains with prokaryotic ubiquitin-like protein (Pup) that targets proteins for proteasomal degradation in mycobacteria and other members of Actinobacteria. Pup ligase PafA and depupylase Dop are the two enzymes acting in this pathway. Although they share close structural and sequence homology indicative of a common evolutionary origin, they catalyze opposing reactions. Here, we report a series of high-resolution crystal structures of Dop in different functional states along the reaction pathway, including Pup-bound states in distinct conformations. In combination with biochemical analysis, the structures explain the role of the C-terminal residue of Pup in ATP hydrolysis, the process that generates the catalytic phosphate in the active site, and suggest a role for the Dop-loop as an allosteric sensor for Pup-binding and ATP cleavage.

Cytochrome b-245 Alpha Chain Gene Variants and Arterial Function in Indonesian Short Stature Children

Background: The association between short stature, undernutrition and the risk to cardiovascular disease has been clinically established. Genetic factor, particularly the variants in cytochrome b-245 alpha chain ( CYBA ) gene, which alter the formation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase level, might affect arterial function. This study aimed to observe the association between single nucleotide variants (SNVs) of the CYBA gene and the arterial function of short stature children to understand the reason why some people with short stature develop cardiovascular disease. Methods: A total of 142 genomic deoxyribonucleic acid (DNA) samples have been collected from short stature children in Brebes, Central Java, Indonesia. Four common single-nucleotide polymorphisms (SNPs): C242T (rs4673), A640G (rs1049255), -930A>G (rs9932581) and *49A>G (rs7195830) in the CYBA gene were examined using TaqMan allelic discrimination assay. The arterial function was measured using transthoracic echocardiography and described as aortic stiffness and distensibility index. Statistical analysis was done to find a significant difference in arterial function between genotypes of each SNV. Results: A P-value of G) of CYBA gene, the subjects with GG genotype were found to have significantly lower arterial stiffness and higher distensibility compared to AA and AG genotypes. No significant difference was found in the other SNVs. Conclusion: The GG genotype in rs9932581 of the CYBA gene might have a protective effect on cardiovascular disease in short stature children. Cardiol Res. 2021;000(000):000-000 doi: https://doi.org/10.14740/cr1314