Phosphate Components Research Articles

A simplified silver phosphate extraction method for oxygen isotope analysis of bioapatite.

Although phosphatic materials are chemically complex and are prone to exchange oxygen isotopes with their environments, the phosphate (PO43- ) component of these materials is robust and retains its original oxygen isotopic composition. As a result, there are currently several methods for the isolation of phosphate oxygen through the precipitation of silver phosphate (Ag3 PO4 ). However, some of these techniques produce Ag3 PO4 of questionable purity, while nearly all are lengthy and/or require relatively large sample sizes. Five milligrams of bioapatite from modern cow teeth (enamel and cementum) were pre-treated for removal of organic material prior to digestion in 2M HF. The digested samples were titrated with silver ammine solution at 50°C to precipitate Ag3 PO4 . Oxygen isotopic data were collected using a Thermal Combustion Elemental Analyzer (TC/EA) paired with a Delta VPlus isotope ratio mass spectrometer via a ConFlo III universal interface. The quality of Ag3 PO4 is dependent on effective removal of organic material and the volume of silver ammine solution used during titration. A two-step pre-treatment of 2.5% NaOCl, followed by a 0.125M NaOH solution, is the most effective treatment for the removal of organic material from both enamel and cementum. Optimal yields of Ag3 PO4 were achieved using 1.8mL of silver ammine solution. The reproducibility of the phosphate δ18 O compositions ranges from 0.3 to 0.4‰ (1σ) for modern cow teeth. We present a simplified method for phosphate extraction from organic-rich phosphatic material. Our method gave reproducible δ18 O values for enamel and cementum from cows' teeth.

Spatial and inter-annual variability of proto- and metazooplankton during summer around the Kneiss Islands (Tunisia, Central Mediterranean Sea)

We studied the distribution of proto- and metazooplankton coupled with environmental factors in the coast area around Kneiss Islands (Central Mediterranean Sea). Zooplanktonic communities were sampled during summer 2009 and summer 2010 at three stations. Our results showed difference in suspended matter concentrations between summer 2009 (92.88 ± 7.15 mg L−1) and summer 2010 (47.37 ± 23.12 mg L−1). Large variations in the N/P ratio were recorded (6.94–36.76) due to the direct influence of the variability in concentration of both the dissolved inorganic nitrogen and dissolved inorganic phosphate components of the ratio. Ciliates abundance peaked in summer 2009 and was 3 times more abundant than summer 2010. Ciliates community composition was dominated by loricate ciliates (75% of total ciliates) in summer 2009 and naked ciliates (56% of total ciliates) in summer 2010. Copepods were the most abundant metazooplankton present during the entire study period, comprising 30–96% of the total metazooplankton community. Small planktonic copepods reached important abundance, particularly oithonids, were found to largely dominate copepods community in both summer 2009 (Oithona nana, 45% of total copepods) and summer 2010 (Oithona similis, 22% of total copepods). The small planktonic species Paracalanus parvus (54% of total copepods) was abundant during summer 2010. The results also indicate that (1) ciliates abundance was very low, showing a possible predation by copepods and also by heterotrophic dinoflagellates, (2) copepods capable to complete a top-down control on phytoplankton and ciliates, with preference to ciliates more than diatoms of similar size and shape and (3) the resistance of loricate ciliates compared to naked ciliates may be explained by their capacity to escape grazing due to the existence of a protective lorica.

Soil extract calcium phosphate media for screening of phosphate-solubilizing bacteria

Media development for screening bacteria capable of solubilizing inorganic complex forms of phosphorous to a soluble form is a major concern in agricultural research. This study formulated an effective, alternative solid and liquid media to the currently available Pikovskaya (PVK) medium, which relies on the use of calcium phosphate and numerous inorganic components for the screening of phosphate-solubilizing bacteria. In this present study, soil extract calcium phosphate (SECP) broth was formulated with simple medium requirements. SECP broth performed better than PVK broth as evidenced by its ability to support a higher bacterial population, higher reduction in broth pH and higher organic acid production and ultimately a better phosphate solubilization, based on the zone of clearance using bromocresol green or congo red in addition to bromothymol blue. Apart from calcium phosphate, rock phosphate and aluminum phosphate were also used as phosphate sources for the screening of different phosphate-solubilizing strains. This solid SECP medium could be used effectively with other phosphorous sources such as rock phosphate and aluminum phosphate. A high correlation between solid-based assay and broth-based assay for screening of phosphate-solubilizing bacteria was observed in the study.

SPS-RS technique for solid-phase “in situ” synthesis of biocompatible ZrO2 porous ceramics

The prospective method of spark plasma sintering-reaction synthesis (SPS-RS) for fabrication of ceramics based on ZrO2 and biocompatible with living tissue is presented. Nanostructured ceramics has high mechanical strength (more than 400 MPa) and controlled porosity depending on specified sintering conditions. Biocompatible phases Ca10(PO4)6(OH)2 are formed “in situ” during SPS sintering of ZrO2 powder due to chemical interaction of phosphate precursors preliminary introduced into the mixture. The effective method to improve (to develop) porous structure of bioceramics obtained by SPS or SPS-RS techniques using poreforming agent (carbon black) is proposed. Suggested original SPS-RS “in situ” technique provides fabrication of new ZrO2 ceramics containing biocompatible phosphate components and possessing unique structural and mechanical characteristics. Such ceramics is indispensable for bone-ceramic implants that are able to activate processes of osteogenesis during bone tissue recovery.

A Direct Prebiotic Synthesis of Nicotinamide Nucleotide.

The "RNA World" hypothesis proposes an early episode of the natural history of Earth, where RNA was used as the only genetically encoded molecule to catalyze steps in its metabolism. This, according to the hypothesis, included RNA catalysts that used RNA cofactors. However, the RNA World hypothesis places special demands on prebiotic chemistry, which must now deliver not only four ribonucleosides, but also must deliver the "functional" portion of these RNA cofactors. While some (e.g., methionine) present no particular challenges, nicotinamide ribose is special. Essential to its role in biological oxidations and reductions, its glycosidic bond that holds a positively charged heterocycle is especially unstable with respect to cleavage. Nevertheless, we are able to report here a prebiotic synthesis of phosphorylated nicotinamide ribose under conditions that also conveniently lead to the adenosine phosphate components of this and other RNA cofactors.

INVESTIGATION OF SOLID PHASE BEHAVIOR DURING PROCESS OF ACIDIC DECOMPOSITION OF POLPINO PHOSPHORITE

The deficiency and growing price of phosphate fertilizers are becoming a major problem in Russia. Most of more than 200 proved phosphorite deposits have enough recourse to exploit them but processing the ore from these deposits presents severe difficulties, and it can’t be effectively implemented at this moment. The result of the decomposition process heavily depends on the origin of the ore, their chemical and mineralogical composition and other factors. Three types of phosphorites (carbonated, siliceous, and argillaceous) can be distinguished, and these types of phosphorites behave differently during the acidic decomposition, which leads to the differences in the conditions and performances in the process of their treatment. Phosphorite from Polpino deposit can be considered poor with total component content P2O5≈15.3%, and by the level of SiO2 it can be qualified as siliceous type. The stock from this deposit is highly reactive because of the carbonated additions and its mineral structure. The aim of the research is to study the dynamics of particle shape and size change during the acidic decomposition of a representative quartered sample of Polpino phosphorite. The decomposition was performed using nitric acid with temporary inhibition of the reaction at 0, 10, 30, 60, 300, 600 seconds by neutralization of acid with potassium hydroxide. Solid phase behavior was investigated using microscopic analysis (scanning electronic microscopy) with multi-purpose module microscope JEOL JSM-6510, and then obtained micrographs were edited with special software. Analysis of the behavior of the particles shows that their total number was nearly constant for each experiment, and the number of particles for every fraction almost didn’t change in time. This leads to assumption that the phosphate component in phosphorite from Polpino deposit is located inside of the porous alpha-quartz. It was determined that alpha-quartz from the phosphorite forms a matrix structure and doesn’t undergo changes, and its pore size doesn’t prevent acidic extraction of calcium and phosphate from the inner volume.Forcitation:Pochitalkina I.A., Kondakov D.F., Syromyatnikov A.S., Makaev S.V. Investigation of solid phase behavior during process of acidic decomposition of polpino phosphorite. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 10. P. 47-52

Age distribution and composition analysis of 198 female cases with urinary calculi

Objective To analyze the age distribution and stone composition of female patients with urinary calculi, and to provide the direction and ideas for clinical treatment. Methods 198 patients with urinary calculi were selected.The age, stone parts of patients were recorded, the stone composition was analyzed. Results In this study, there were 198 female patients with urinary calculi, 2 cases≤25 years old, accounting for 1.01%, 20 patients >25~45 years, accounting for 10.10%, 109 patients >45~65 years, accounting for 55.05 %, >65 years old patients in 67 cases, accounting for 33.84%.The main components of calcium stones were calcium carbonate components, carbonated apatite components, magnesium hexahydrate phosphate components, uric acid components, cystine components.The calcium oxalate composition stone in 158 cases, accounting for 79.80%.There were 135 cases (68.18%) of carbonate-containing apatite.8 cases of magnesium sulfate hexahydrate, accounting for 4.04%.40 cases of uric acid-containing stones, accounting for 20.20%.12 cases of cystic acid containing stones, accounting for 6.06%.198 female cases with stones were divided into mixed stones and simple stones.The mixed stones were mainly calcium oxalate + carbonate apatite, calcium oxalate + urate, calcium oxalate + cystine, carbonate apatite + magnesium phosphate hexahydrate, calcium oxalate + carbonated apatite + uric acid, calcium oxalate + carbonate apatite + cystine, carbonate apatite + magnesium phosphate hexahydrate + uric acid) .The simple stones were mainly calcium oxalate, carbonated apatite, uric acid and uric acid.According to the main components of the stone, they were divided into 131 cases of calcium oxalate, uric acid-based 23 cases, cystine-based 8 cases, 21 cases of carbonate apatite, magnesium phosphate hexahydrate mainly in 15 cases.According to the position of urinary tract stones, they were divided into upper urinary tract stones in 171 cases, 27 cases of lower urinary tract stones. Conclusion Female urinary tract stones in patients with high incidence in postmenopausal and old age, according to different components of stones should avoid the relevant dietary intake in order to avoid recurrence. Key words: Urinary calculi; Age distribution; Principal component analysis; Female

Influence of composting and thermal processing on the survival of microbial pathogens and nutritional status of Nigeria sewage sludge

PurposeSewage sludge samples from a water treatment plant in Nigeria were subjected to an in-vessel composting (using sawdust as a bulking agent) and thermal sludge processing to improve its quality for agricultural applications.MethodsTreated samples were analyzed for physicochemical and microbiological properties using standard analytical and aerobic culture protocols.ResultsMicrobiological analysis of the initial fresh mixture (sewage sludge/sawdust) showed that the total heterotrophic bacteria was 1.17 × 106 CFU/g of fresh compost, coliforms 4.7 × 104 CFU/g, Salmonella sp., and Shigella sp. 7.3 × 104 CFU/g, yeasts and moulds 9.0 × 104 CFU/g. These values were significantly (p = 0.05) reduced after 40 days of in-vessel composting to 4.3 × 104 CFU/g for total heterotrophic bacteria, 7.4 × 102 CFU/g for coliforms, while yeasts and moulds, Salmonella and Shigella sp. were not detected in the final compost. The results of the physicochemistry revealed variation in pH, temperature, and nutrients status of treated sludge.ConclusionSalmonella sp., Staphylococcus aureus, and Shigella sp. were eliminated, while a 2-log reduction in coliform counts occurred after 40 days of composting. Composting had a better processing impact by increasing the ash as well as reducing the carbon/nitrogen ratio of treated sludge, while thermal processing improved the sulfate and phosphate components of treated sludge. The treated sludge (biosolids) met the permissible limits of microbiological and nutritional standards recommended by US EPA for land application of sludge and could, therefore, be used as a biofertilizer, soil conditioner and also for land reclamation.

Three novel mutations in CYBA among 22 Iranians with Chronic granulomatous disease.

Chronic granulomatous disease (CGD) is a rare primary immunodeficiency caused by defect in one of the components of nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase enzyme. The enzyme is at least composed of membrane-bound subunits gp91-phox and p22-phox (also named cytochrome b558 ), and cytosolic ones p40-phox, p47-phox and p67-phox. A defect in the enzyme activity leads to impaired intracellular killing of phagocytic cells. The CYBA gene encoding p22-phox is located on chromosome 16q24. In this study, new genetic changes of CYBA gene in 22 Iranian patients with autosomal recessive-CGD (AR-CGD) were identified. Twenty-two patients with CGD were referred to Immunology, Asthma and Allergy Research Institute (IAARI) and enrolled in this study based on defect in NADPH oxidase activity, demographic data and clinical histories. All patients had p22-phox deficiency based on Western blotting. Genomic DNA was extracted from peripheral blood mononuclear cells (PBMCs), and PCR followed by direct sequencing was performed to find p22-phox mutations. Mutation analysis of CYBA revealed 12 different mutations, including three novel mutations: one was deletion of exon 1, and two were point mutations in exon 3 (c.136G>A (p.Gly46Ser)), and exon 6 (c.388C>T (p.Gln130X)). Three new mutations of CYBA gene in four of 22 Iranian patients with AR-CGD were found. These three novel mutations can partly complete the database of Human Gene Mutation Database (HGMD) and other related ones. It can also be helpful for further prenatal diagnosis in the affected families. Given that currently bone marrow transplantation is considered to be the curative treatment for patients with CGD, finding mutations will also be useful for timely decision-making in bone marrow transplantation.

Study of thermal dehydration of sodium orthophosphate monosubstituted

Depending on the conditions of conducting the synthesis, it is possible to obtain polymeric phosphates of different composition and structure. The mixtures of polyphosphates, employed in the production of technological lubricants, are expedient to synthesize by the high-temperature dehydration of sodium orthophosphate monosubstituted. The temperature ranges, over which the thermochemical transformations of sodium orthophosphate monosubstituted with the formation of polyphosphates proceed, are established by the thermogravimetric method. The composition of polyphosphates is determined using the X-ray phase analysis. Quantitative composition of the mixtures of polyphosphates is determined by applying the original method of eluent ion-exchange chromatography. It is established that the basic products of thermal dehydration of sodium orthophosphate monosubstituted in the range of temperatures 200–650 °C are Na 3 Р 3 О 9 , Na 2 H 2 P 2 O 7 and Na 6 P 6 O 18 . Thermochemical transformations of NaH 2 PO 4 into Na 6 P 6 O 18 at temperature 650 °C are accompanied by the side reactions of formation of Na 3 H 2 P 3 O 10 . We proposed the chemical scheme of the high-temperature dehydration of sodium orthophosphate monosubstituted. Kinetics of the isothermal process of obtaining the polymeric phosphates from sodium orthophosphate monosubstituted at different temperatures is examined. We established quantitative composition of the mixtures of inorganic polymeric phosphates depending on the duration of isothermal process of dehydration. The possibility of obtaining a salt mixture of polymeric phosphates of the assigned qualitative and quantitative composition is demonstrated. We proposed to use the mixture: 76 % Na 6 P 6 O 18 , 8 % Na 2 H 2 P 2 O 7 , 8 % Na 3 H 2 P 3 O 10, 8 % NaH 2 PO 4 , obtained at 650 °C, as the basic phosphate component of technological lubricants for the hot rolling of pipes.

ARALAR/AGC1 deficiency, a neurodevelopmental disorder with severe impairment of neuronal mitochondrial respiration, does not produce a primary increase in brain lactate.

ARALAR/AGC1 (aspartate-glutamate mitochondrial carrier 1) is an important component of the NADH malate-aspartate shuttle (MAS). AGC1-deficiency is a rare disease causing global cerebral hypomyelination, developmental arrest, hypotonia, and epilepsy (OMIM ID #612949); the aralar-KO mouse recapitulates the major findings in humans. This study was aimed at understanding the impact of ARALAR-deficiency in brain lactate levels as a biomarker. We report that lactate was equally abundant in wild-type and aralar-KO mouse brain invivo at postnatal day 17. We find that lactate production upon mitochondrial blockade depends on up-regulation of lactate formation in astrocytes rather than in neurons. However, ARALAR-deficiency decreased cell respiration in neurons, not astrocytes, which maintained unchanged respiration and lactate production. As the primary site of ARALAR-deficiency is neuronal, this explains the lack of accumulation of brain lactate in ARALAR-deficiency in humans and mice. On the other hand, we find that the cytosolic and mitochondrial components of the glycerol phosphate shuttle are present in astrocytes with similar activities. This suggests that glycerol phosphate shuttle is the main NADH shuttle in astrocytes and explains the absence of effects of ARALAR-deficiency in these cells.

Ways to improve physical and thermal performance of refractory lining materials

Refractory lining materials, which include ceramic refractories and nonfired heat-resistant concretes, have a very short lifespan during the turnaround time measured in years and sometimes months. Therefore, increasing the service life of thermal generating units by 1.5-2 times will bring significant economic benefits. The main factor that determines the durability of refractory lining materials is the thermal resistance. It is possible to increase the thermal resistance by improving such physical and mechanical properties as strength and density. As for the ceramic refractory performance improvement, such technological methods as their structural and chemical modification by phosphate binder impregnation, as well as introduction of phosphate components into the ceramic batches during the molding process increase, in particular, their thermal stability. The use of aluminous and high-alumina cements contributes to a significant increase of not only strength, but also physical and thermal performance of heat-resistant concretes with different fillers. Switching to the use of chemical binders in the compositions of heat-resistant concretes (liquid glass with effective hardeners; silicate-block and phosphate binders) enables to develop high-heat resistant materials which do not soften in a wide range of heating temperatures from 400 °С to 1600 °С. The positive results on increasing the thermal resistance of heat-resistant composites can be obtained by reinforcing them with high temperature fibers.

Impact of phosphate and other medium components on physiological regulation of bacterial laccase production.

Laccases are multicopper oxidases known to catalyze the transformation of a wide range of phenolic and non-phenolic substrates using oxygen as electron acceptor and forming water as the only by product. Their potential relevance in several industries requires the constant search for novel laccases. Positive outcome of the isolation of laccase producing bacteria depends on the nature and concentration of media constituents. Several attempts to isolate laccase producing bacteria failed when the phosphate-containing M9 minimal medium was used. Shift to phosphate-less M162 medium led to successful isolations. Seven bacterial isolates belonging to genera Bacillus, Lysinibacillus, Bhargavaea and Rheinheimera were used to study the effect of medium constituents on laccase production. Inorganic phosphate (≥50 mM) was found to regulate laccase synthesis negatively though no inhibitory effect of phosphate (10-500 mM) was seen on laccase activity. All isolates ceased laccase synthesis when grown in the presence of tryptone (0.2-1%), with R. tangshanensis as an exception, or yeast extract (1.5-2%) as the only C/N source in M162 medium. Supplementation upto 0.1% of glucose in basal M162 medium increased laccase production in five isolates but decreased at higher concentrations. The influence of medium components on laccase synthesis was further affirmed by zymographic studies. These observations offer possibilities of isolating promising laccase producers from diverse environmental sources. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:541-548, 2017.

Physical compatibility of tedizolid phosphate with selected i.v. drugs during simulated Y-site administration.

The physical compatibility of commonly used agents that could be coadministered in the clinical setting with tedizolid phosphate during Y-site administration was evaluated. Tedizolid phosphate vials were reconstituted to a final concentration of 0.8 mg/mL. All other drugs were prepared according to manufacturers' recommendations and diluted with 0.9% sodium chloride injection (where applicable) to the highest standard concentrations used clinically. Y-site conditions were simulated in culture tubes by mixing 5 mL of tedizolid phosphate solution with 5 mL of the test drug solutions. The physical characteristics, turbidity, and pH of all admixtures were examined immediately after mixing and at 15, 60, and 120 minutes. Incompatibility was defined as gross precipitation, a positive Tyndall beam test, color changes, or increases in turbidity. With simulated Y-site administration, tedizolid phosphate was compatible with 69 of 86 drugs in 0.9% sodium chloride injection, including 24 of 31 antimicrobial agents. Of note, incompatibility was observed immediately after mixing except with ceftaroline and diphenhydramine, whose incompatibility with tedizolid phosphate was apparent after 15 and 60 minutes, respectively. Among the drug classes tested, tedizolid phosphate was compatible only with 1 aminoglycoside (amikacin) and incompatible with 1 echinocandin (caspofungin) and 1 cephalosporin (ceftaroline). In addition, tedizolid phosphate was incompatible with divalent cations (calcium chloride, calcium gluconate, and magnesium sulfate), probably due to precipitation with the phosphate component. A pH change of >1 unit occurred only with epinephrine (at 120 minutes). Tedizolid phosphate 0.8 mg/mL in 0.9% sodium chloride injection was physically compatible with 69 of 86 study drugs during simulated Y-site administration.

Impact of FGF23 level on calcium and phosphorus levels in post-renal transplantation.

Introduction: The level of fibroblast growth factor 23 (FGF23) may be considered as a prognostic factor for assessing renal function in regulating components of phosphate and vitamin D hemostasis. Objectives: The present study aimed to evaluate the prognostic value of FGF23 level to predict renal function after renal transplantation. Patients and Methods: Fifteen consecutive patients scheduled for renal transplantation. To assess renal function status, the MDRD formula and isotope scan were applied. The study endpoint was to assess the level of FGF23 and other factors involving calcium and phosphorus metabolism before and also 3 and 12 months after transplantation and also to determine role of FGF23 to predict postoperative renal function. Results: The mean level of FGF23 was 839.51±694.56 ρg/mL at baseline that reduced to 44.31±22.01 ρg/mL and 20.13±36.50 ρg/mL, 3 and 12 months after initial assessment. The levels of FGF23 was significantly lower at 3 and 12 months after baseline (P=0.01 and P=0.02, respectively) with no difference in FGF23 level between the time points of 3 and 12 months after transplantation. Baseline level of FGF23 was found to be higher in the patients with higher glomerular filtration rate (GFR), in older patients, in males, in those patients with diabetic nephropathy, in those with acceptable renal function than in patients who suffered transplant rejection. Conclusion: The level of postoperative FGF23 is an important marker for secretion of phosphorus from kidneys emphasizing the central role of FGF23 marker to regulate calcium and phosphorus metabolism after a successful renal transplantation.

Changes in morphology of actin filaments and expression of alkaline phosphatase at 3D cultivation of MG-63 osteoblast-like cells on mineralized fibroin scaffolds.

3D cultivation of MG-63 osteoblast-like cells on mineralized fibroin scaffolds leads to an increase in the expression of alkaline phosphatase, an early marker of bone formation. Increased expression is associated with the actin cytoskeleton reorganization under the influence of 3D cultivation and osteogenic calcium phosphate component of the microcarrier.

Biofilm formation of periodontal pathogens on hydroxyapatite surfaces: Implications for periodontium damage.

Biofilm formation of periodontal pathogens on teeth surfaces promotes the progression of periodontal disease. Hence, understanding the mechanisms of bacterial attachment to the dental surfaces may inform strategies for the maintenance of oral health. Although hydroxyapatite (HA) is a major calcium phosphate component of teeth, effect of biofilm formation on HA surfaces remains poorly characterized. In this study, biofilm-forming abilities by the periodontal pathogens Aggregatibacter actinomycetemcomitans Y4 and Porphyromonas gingivalis 381 were investigated on dense and porous HAs that represent enamel and dentin surfaces, respectively. These experiments showed greater biofilm formation on porous HA, but differing attachment profiles and effects of the two pathogens. Specifically, while the detachment of A. actinomycetemcomitans Y4 biofilm was observed, P. gingivalis 381 biofilm increased with time. Moreover, observations of HA morphology following formation of A. actinomycetemcomitans Y4 biofilm revealed gaps between particles, whereas no significant changes were observed in the presence of P. gingivalis 381. Finally, comparisons of calcium leakage showed only slight differences between bacterial species and HA types and may be masked by bacterial calcium uptake. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2873-2880, 2016.

Tracking the spatiotemporal variations of statistically independent components involving enrichment of rare-earth elements in deep-sea sediments.

Deep-sea sediments have attracted much attention as a promising resource for rare-earth elements and yttrium (REY). In this study, we show statistically independent components characterising REY-enrichment in the abyssal ocean that are decoded by Independent Component Analysis of a multi-elemental dataset of 3,968 bulk sediment samples from 101 sites in the Pacific and Indian oceans. This study for the first time reconstructs the spatiotemporal variations of the geochemical signatures, including hydrothermal, hydrogenous, and biogenic calcium phosphate components that were closely involved in the formation of REY-rich mud over the past 65 million years. An underlying key factor of significant REY-enrichment is a sufficiently low sedimentation rate that enables the mud to accumulate REY from seawater. In the early Cenozoic, a remarkably small supply of aeolian dust, compared with any other time and region, facilitated the deposition of very high-grade REY-rich mud in the South Pacific. This indicates an important link between the genesis of the seafloor mineral resources and Earth’s dynamic phenomena such as climate change and plate tectonics.

Topography, Composition and Structure of Incipient Randall Plaque at the Nanoscale Level

Randall identified calcium phosphate plaques in renal papillae as the origin of kidney stones. However, little is known about the early steps of Randall plaque formation preceding the onset of urolithiasis. Our objective was to characterize the composition and the initial formation site of incipient Randall plaque in nonstone forming, living patients. Median patient age was 67.7 years. A total of 54 healthy papillae from kidneys removed for cancer and without stones were analyzed by immunohistochemistry and von Kossa staining, field emission-scanning electron microscopy with energy dispersive x-ray analysis, μ-Fourier transform infrared spectroscopy, cryo-transmission electron microscopy coupled to selected area electron diffraction and electron energy loss spectroscopy. Incipient Randall plaque was observed in 72.7% of kidneys. As expected, carbonated apatite was the main component of microcalcifications but amorphous calcium phosphate and whitlockite were identified in 80% and 40% of papillae, respectively. Incipient plaques were noted in the deepest part of the papillae around the loop of Henle tip as well as around the vasa recta, representing 62.4% and 37.2% of microcalcifications, respectively. Plaques were rarely close to collecting ducts. At the nanoscale level incipient calcifications were often composed of several nanocrystals in organic material that looked like microvesicles. Incipient Randall plaque is frequent. It appears not only at the extreme tip of the renal papillae around the hairpin structure of the loop of Henle but also around the vasa recta. Nanoscale analyses suggest a local nucleation process promoting nanocrystal growth in a supersaturated milieu. In addition, plaques contain various calcium and magnesium phosphates, and not only carbonated apatite.

Serum-free non-toxic freezing solution for cryopreservation of human adipose tissue-derived mesenchymal stem cells

To develop a cost-effective, non-toxic and xeno-free freezing solution for the preservation of adipose tissue-derived stem cells (hADSC) with a long shelf-life. The potential of various hydrocolloids and organic osmolytes as cryoprotectants and individual components of phosphate buffered saline (PBS) as carrier media were evaluated to formulate a freezing solution for the cryopreservation of hADSCs. Among the hydrocolloids, the highest viability, 55%, was achieved with post-thawed (after 48h storage at -80°C) hADSCs cryopreserved in 10% (v/v) polyvinylpyrrolidone (PVP) using PBS as carrier media. 0.9% NaCl was a superior carrier medium resulting an enhanced cell viability (70%) when used in 10% PVP than other components of PBS. A higher cell viability (81%) was achieved when 10% PVP/0.9% NaCl was supplemented with 60mM ectoin. The cryopreserved cells retained normal cytoskeletal distribution pattern and adipogenic and osteogenic differentiation ability during 14 and 21days of incubation. A serum-free and non-toxic 10% PVP/0.9% NaCl/60mM ectoin freezing solution was developed for cryopreservation of hADSC for application in tissue engineering and regenerative medicine.