Phosphate Concentration Research Articles

Calcium phosphate nanoclusters modify periodontium remodeling and minimize orthodontic relapse.

Orthodontic relapse is one of the most prevalent concerns of orthodontic therapy. Relapse results in patients' teeth reverting towards their pretreatment positions, which increases the susceptibility to functional problems, dental disease, and substantially increases the financial burden for retreatment. This phenomenon is thought to be induced by rapid remodeling of the periodontal ligament (PDL) in the early stages and poor bone quality in the later stages. Current therapies, including fixed or removable retainers and fiberotomies, have limitations with patient compliance and invasiveness. Approaches using biocompatible biomaterials, such as calcium phosphate polymer-induced liquid precursors (PILP), is an ideal translational approach for minimizing orthodontic relapse. Here, post-orthodontic relapse is reduced after a single injection of high concentration PILP (HC-PILP) nanoclusters by altering PDL remodeling in the early stage of relapse and improving trabecular bone quality in the later phase. HC-PILP nanoclusters are achieved by using high molecular weight poly aspartic acid (PASP, 14 kDa) and poly acrylic acid (PAA, 450 kDa), which resulted in a stable solution of high calcium and phosphate concentrations without premature precipitation. In vitro results show that HC-PILP nanoclusters prevented collagen type-I mineralization, which is essential for the tooth-periodontal ligament (PDL)-bone interphase. In vivo experiments show that the PILP nanoclusters minimize relapse and improve the trabecular bone quality in the late stages of relapse. Interestingly, PILP nanoclusters also altered the remodeling of the PDL collagen during the early stages of relapse. Further in vitro experiments showed that PILP nanoclusters alter the fibrillogenesis of collagen type-I by impacting the protein secondary structure. These findings propose a novel approach for treating orthodontic relapse and provide additional insight into the PILP nanocluster's structure and properties on collagenous structure repair.

U(VI) sorption by CTAB/Bent–MOF-74 from various carbonate solutions

CTAB/Bent-MOF-74 was synthesized via hydrothermal method to investigate its U(VI) sorption in carbonate solutions. Generally, CTAB/Bent-MOF-74 (∼87.6 mg·g−1) showed better sorption capacity than CTAB/Bent-MOF-71 (∼64.2 mg·g−1) and CTAB/Bent-CS-35 (∼81.4 mg·g−1) in U(VI)-Cl coexist carbonate solutions when pH = 8.0, [NaHCO3] =2 mmol·L−1, [NaCl] =0.1 mol·L−1 and [U(VI)] =50 mg L−1. The competitive sorption between HCO3−/CO32−, OH−, halide ions and U(VI) complexes ions as well as the weakened electrostatic attraction decreased the composite's uranium sorption efficiency and capacity at high pHinitial, NaHCO3, phosphate, Ca/Mg and halide ions concentrations. The pseudo-second-order kinetics and Langmuir models indicated a monolayer homogeneous chemisorption process. Besides, 0.1mol·L−1 HCl shows the highest desorption efficiency among the selected desorbents, and the sorption rate is still high even after four times of desorption. In particular, the decreasing inhibitory capacity of the halide ions was on the order of I−, F−, Br−, Cl−. Characterization analyzes confirmed the good structural stability and Br anion exchange as well as the -OH/-COOH coordination and electrostatic attraction, which could be the predominant sorption mechanisms of U(VI) by CTAB/Bent-MOF-74. The results provided theoretical references for understanding the uranium sorption in natural uranium-containing water and designing potential uranium-extracting materials.

Assessment of Nitrate and Phosphate Concentrations in Discharge Water from Ditch Networks across Different Peatland Use Types: Implications for Sustainable Peatland Use Management

Assessment of Nitrate and Phosphate Concentrations in Discharge Water from Ditch Networks across Different Peatland Use Types: Implications for Sustainable Peatland Use Management

Understanding environmental drivers and trends in chlorophyll-a and related factors across equatorial Indian Ocean regions: implications for marine ecosystem dynamics and vulnerability

ABSTRACT We estimated the concentration of Chlorophyll-a (Chl-a) along with physical and biological factors including sea surface temperature (SST), wind speed and concentration of nitrate and phosphate in the Western, Central and Eastern Equatorial Indian Oceans (WEIO, CEIO and EEIO) using data from the Copernicus Marine Service and ERA-5 for the years 1994 to 2019. Our results show that along with the concentration of Chl-a, nitrate and phosphate have decreased, and sea surface temperature has increased in the EEIO. Due to coastal upwelling off the coast of Somalia and offshore Ekman transport throughout the summer, the southwest monsoon caused a significant increase in concentrations of Chl-a, nitrate, phosphate and wind speed in WEIO during June-July-August-September (JJAS) and October-November-December (OND). SST decreased at this time and deeper water interacted with surface water, increasing biological production. In EEIO, the upwelling zone is primarily maintained by wind-induced divergence throughout the year, whereas stratification in winter prevented surface Chl-a increase. High wind speed and low SST led to increased productivity in WEIO. Comparison of EEIO with WEIO and CEIO demonstrates low levels of Chl-a, phosphate and nitrate. The trends signify that these oceanic zones are highly vulnerable to developing into ecological deserts in the near future.

Influence of phosphates on phase formation in alkali‐activated MgO‐Al2O3‐SiO2‐P2O5 cements

AbstractThe impact of phosphates on phase formation in low Ca alkali‐activated materials (AAMs) is investigated using a polymer‐assisted sol‐gel process to fabricate MgO‐Al2O3‐SiO2‐P2O5 cement precursors covering a broad range of compositions activated with sodium hydroxide. X‐ray diffraction and magic angle spinning‐nuclear magnetic resonance are used to examine the crystalline and amorphous phases that form over 470 days of curing (35°C, 90% relative humidity). The results confirm that Al is preferentially incorporated into hydrotalcite‐like layered double hydroxides (LDH) over zeolites. Zeolites form when more Al is present than can be incorporated into the LDH. Little evidence of phosphate incorporation into aluminosilicate networks (such as zeolites or disordered aluminosilicate hydrate) was observed. The phosphates present in the precursor favor reaction with sodium to form water‐soluble sodium phosphate phases. In most cases, the remainder of the phosphates become adsorbed to the surface of other phases and are not intercalated into the LDH, though at high phosphate concentrations (26.6 wt. % P2O5) and extended curing times (470 days), phosphates are observed to intercalate into LDH phases. These results provide preliminary evidence that phosphates are compatible with low Ca AAMs, which is consequential as there is a growing interest in both the use of AAM and phosphate‐based corrosion inhibiter in steel‐reinforced concrete.

Use of environmental indicators to assess the state of forest ecosystems

The purpose of the study was to comprehensively analyse the effectiveness of environmental indicators in determining the state of forest ecosystems and their ability to reflect changes in the ecological balance. During the study, the influence of anthropogenic factors on biomass, soil acidity, and species diversity of forest ecosystems in the Sumy Oblast of Ukraine was evaluated. Field studies were conducted to determine the soil acidity, the biomass of plants and animals in anthropogenic and natural forest areas, followed by statistical analysis of the data. The degree of degradation of forest areas as a result of human activity was determined and the environmental consequences of these changes for natural systems were evaluated. The results showed that anthropogenically modified areas have reduced biomass (100 t/ha) and species diversity (20 plant species), increased soil acidity (pH 6.5-7) and high concentrations of nitrates and phosphates, compared to mixed forests, where biomass reaches 200 t/ha, species diversity – 50 species of flora, and soil acidity varies from moderately acidic to neutral (pH 5.5-6). These data confirmed the negative impact of human activity on ecosystems, in particular on biomass and soil acidity. It was established that environmental indicators allow forming a comprehensive picture of the state of ecosystems, which is necessary for making informed management decisions aimed at preserving and restoring ecosystems, and at effective management of natural resources. The results obtained demonstrated serious environmental problems as a result of anthropogenic impact on forest ecosystems. A decrease in biomass and species diversity, and an increase in soil acidity in anthropogenic zones indicate the need for urgent implementation of measures for the conservation and restoration of natural forests. The study will be useful in the context of long-term monitoring of ecosystems, which would allow a more detailed investigation of the dynamics of their changes

Molecular mechanism of a coastal cyanobacterium Synechococcus sp. PCC 7002 adapting to changing phosphate concentrations

Phosphorus concentration on the surface of seawater varies greatly with different environments, especially in coastal. The molecular mechanism by which cyanobacteria adapt to fluctuating phosphorus bioavailability is still unclear. In this study, transcriptomes and gene knockouts were used to investigate the adaptive molecular mechanism of a model coastal cyanobacterium Synechococcus sp. PCC 7002 during periods of phosphorus starvation and phosphorus recovery (adding sufficient phosphorus after phosphorus starvation). The findings indicated that phosphorus deficiency affected the photosynthesis, ribosome synthesis, and bacterial motility pathways, which recommenced after phosphorus was resupplied. Even more, most of the metabolic pathways of cyanobacteria were enhanced after phosphorus recovery compared to the control which was kept in continuous phosphorus replete conditions. Based on transcriptome, 54 genes potentially related to phosphorus-deficiency adaptation were selected and knocked out individually or in combination. It was found that five mutants showed weak growth phenotype under phosphorus deficiency, indicating the importance of the genes (A0076, A0549-50, A1094, A1320, A1895) in the adaptation of phosphorus deficiency. Three mutants were found to grow better than the wild type under phosphorus deficiency, suggesting that the products of these genes (A0079, A0340, A2284–86) might influence the adaptation to phosphorus deficiency. Bioinformatics analysis revealed that cyanobacteria exposed to highly fluctuating phosphorus concentrations have more sophisticated phosphorus acquisition strategies. These results elucidated that Synechococcus sp. PCC 7002 have variable phosphorus response mechanisms to adapt to fluctuating phosphorus concentration, providing a novel perspective of how cyanobacteria may respond to the complex and dynamic environments.

A de novo PRPF8 Pathogenic Variant in Transient Severe Hypophosphatemia with Delayed Puberty and Growth Failure.

Childhood hypophosphatemia is a rare condition and may be caused by malabsorption, malignancies, or genetic factors. Prolonged hypophosphatemia leads to impaired growth and radiographic signs of rickets. We performed a detailed clinical and genetic evaluation of an adolescent boy with repeatedly low plasma phosphate concentrations (below 0.60 mmol/L) and growth failure. At 14 years, the patient presented with decelerating growth and delayed puberty. Biochemistry showed hypophosphatemia due to increased urinary phosphate loss; kidney function and vitamin D status were normal. Radiographs showed mild metaphyseal changes. A gene panel for known genetic hypophosphatemia was negative. Trio exome analysis followed by Sanger sequencing identified a pathogenic heterozygous de novo stop-gain variant in PRPF8 gene, c.5548C>T p.(Arg1850*), in the conserved RNase H homology domain. PRPF8 encodes the pre-RNA protein 8, which has a role in RNA processing. Heterozygous PRPF8 variants have been associated with retinitis pigmentosa and neurodevelopmental disorders but not with phosphate metabolism. The patient underwent growth hormone (GH) stimulation tests which confirmed GH deficiency. Head MRI indicated partially empty sella. GH treatment was started at 15 years. Surprisingly, phosphate metabolism normalized during GH treatment, suggesting that hypophosphatemia was at least partly secondary to GH deficiency. The evaluation of an adolescent with profound long-term hypophosphatemia revealed a pituitary developmental defect associated with a stop-gain variant in PRPF8. Hypophosphatemia alleviated with GH treatment. The pathological PRPF8 variant may contribute to abnormal pituitary development; however, its role in phosphate metabolism remains uncertain.

In situ Measurement of Phosphate using Fe3O4/Chelex®100-Agarose-Oxalic Acid Hydrogel in Diffusive Gradient in Thin Films

ABSTRACT. This study would be the first to develop a novel combination of Chelex®100 and Fe3O4 as a mixed binding gel for in situ phosphate measurement employing Diffusive Gradient in Thin Films (DGT). Fe3O4 and Chelex®100 were utilized as binding agents within a single binding layer for phosphate measurements in laboratory and natural water settings. The synthesized Fe3O4 was identified as magnetite and consisted of micro-sized particles. The pore size of the mixed binding gel ranged from 22.39 to 112.5 µm. Incorporating Chelex®100 with Fe3O4 in oxalic acid cross-linked agarose did not diminish phosphate adsorption efficiency. As adsorption time and phosphate concentration in solution increased, the quantity of adsorbed phosphate in the mixed binding gel also increased. Optimal phosphate elution was achieved using a basic solution, with a phosphate elution efficiency of 95.3 ± 0.4% observed with 0.4 M NaOH. The diffusion coefficient measured using the mixed binding gel was 1.08 times greater than that of polyacrylamide cross-linked with an agarose derivative (APA) gel, typically employed in the DGT technique. Phosphate concentration measurement with Fe3O4/Chelex®100-agarose oxalic acid in a DGT passive sampler at pH 4-8 yielded values twice those in bulk solution. Similar results were obtained when measuring phosphate in a 0.01 – 0.1 M NaNO3 solution. A T-test showed that the phosphate concentration obtained from mixed binding layer-DGT as an alternate passive sampler was not significantly different from grab sampling. This study underscores the suitability of Fe3O4-Chelex®100 impregnated in agarose-oxalic acid gel for monitoring phosphate in natural water via DGT. Keywords: Agarose, diffusive gradient in thin films, mixed binding gel Fe3O4, oxalic acid.

Bottom water quality plasticity in the northern gulf of Mexico hypoxic zone

The growth of the now ubiquitous hypoxic zones found throughout the global coastal ocean are primarily a consequence of nutrient enrichment in surface waters increasing organic production that sinks into bottom waters where oxygen is depleted faster than it is replenished. Hypoxic zones may increase or decline in number because of future climate changes. Here we summarize the summertime variations of dissolved inorganic silicate (DSi), phosphate (DIP), nitrogen (DIN; nitrate + nitrite and ammonium) and ammonium concentrations in the bottom waters of the northern Gulf of Mexico continental shelf from 1985 to 2022. The concentrations of all three are strongly correlated to oxygen concentrations, but not in the same way. At zero oxygen concentration, the annual concentrations of DSi, DIP, and ammonium changed over 38 years at a rate of 1.6 % y−1, 2.0 % y−1 and -1.7 % y−1, respectively. However, the nitrate + nitrite concentrations at zero oxygen concentrations did not change over the same interval. The silicate efflux from anoxic sediments is directly related to warming temperatures and is co-related to phosphate concentrations. The bottom water DSi:DIN molar ratios increased over three decades as DIN:DIP molar ratios decreased, suggesting strong nitrogen limitation compared to silicate and phosphate, and reveal significant plasticity in regeneration rates in the bottom waters that may be dependent on changes in the surface waters. Hypoxia and food web models based on a stationary equipoise of these amounts and ratios in surface and bottom waters will likely be deficient as coastal waters warm, acidification increases, and river water quality changes. Data refreshment and improved understanding of food web changes and warming futures are recommended.

Burosumab Efficacy and Safety in Patients with X-Linked Hypophosphatemia: Systematic Review and Meta-analysis of Real-World Data.

To assess the efficacy and safety of burosumab in children and adults with X-linked hypophosphatemia based on real-world evidence. MEDLINE (via PubMed) and Cochrane Library were searched until 18 October 2023 for single-arm (before-after) studies. Registries including Clinicaltrials.gov, EU Clinical Trials, WHO International Clinical Trials Registry Platform, and conference abstracts. The outcomes were a change in serum phosphorus concentrations and change in RSS, a change in serum ALP, bone-specific ALP, a change in the ratio of Tubular maximum reabsorption of Phosphate to Glomerular Filtrate rate, a change in serum 1,25(OH)2D and 25(OH)2D concentrations, change in height Z-score, McMaster Universities Osteoarthritis Index (WOMAC) and safety outcomes. An inverse variance random-effects meta-analysis was applied for data synthesis. Fifteen studies (289 participants) were included. Burosumab treatment improved serum phosphate concentrations [mean difference 0.88mg/dl, 95% confidence interval 0.70 to 1.07, I2 = 92%), Rickets Severity score (mean difference -1.86, 95% confidence interval -2.5 to -1.21, I2 = 71%), serum alkaline phosphate concentrations (mean difference -1.86, 95% confidence interval -2.5 to -1.21, I2 = 71%), serum 1,25(OH)2D concentrations (mean difference 18.91pg/ml, 95% confidence interval 6.39 to 31.43, I2 = 96%) and renal phosphate reabsorption (mean difference 1.22 mg/dl, 95% confidence interval 0.70 to 1.74, I2 93%). Burosumab treatment improved overall clinical and laboratory findings in patients with X-linked hypophosphatemia.

Structure and diversity patterns of coralligenous cliffs across three ecoregions in the Central‐Western Mediterranean Sea

AbstractAimCoralligenous reefs are the main marine bioconstructions in terms of spatial distribution within the Mediterranean basin. Two distinct reef morphologies can be distinguished based on the surface and topographical features of the seafloor: cliffs developing vertical slopes and banks found on gently steep or horizontal bottoms. Despite their importance for monitoring and conservation efforts, observations regarding the variability of biogeographical patterns are scarce. Here, we aimed to assess the differences in the composition and structure of these cliffs across ecoregions and estimate the relative role of abiotic environmental features, geographic location, and connectivity in shaping diversity patterns.LocationThe study was carried out in the Central‐Western Mediterranean Sea. Samples were collected at 65 sites across the Algero‐Provençal Basin, the Ionian Sea and the Tyrrhenian Sea.MethodsWe assessed the composition and structure of coralligenous cliffs through photographic samplings collected by scuba divers. Patterns in α‐ and β‐diversity were associated with 9 abiotic environmental variables, latitudinal and longitudinal gradients, and connectivity measures using Generalized Additive (GAM) and Conditional Autoregressive (CAR) models.ResultsCoralligenous cliffs were primarily composed of algae and displayed a high degree of variability. The Partition Around Medoids (PAM) clustering method successfully delineated seven distinct clusters with a non‐uniform distribution within the studied ecoregions. The α‐diversity increased in eastern and northern sites and with phosphate concentration, while decreased with temperature, chlorophyll and nitrates concentration. β‐diversity at the site level increased with temperature, while it was negatively affected by northward current speed and chlorophyll concentration. Moveover, β‐diversity increased within connected sites.Main ConclusionsCoralligenous cliff diversity responds both to the physico‐chemical features of the habitat and between‐habitats connectivity. However, our findings suggest that small‐scale abiotic and biotic processes could contribute to explaining the variability observed. These findings can significantly enhance the monitoring and conservation efforts of this Mediterranean endemic ecosystem.

Crystallization of Calcium Carbonate and Calcium Phosphate Phases in Silica Hydrogel: Morphological and Compositional Characterization

The present study showcases a series of crystallization experiments using a specially designed double diffusion system to grow crystals belonging to the calcium carbonate–phosphate system. The experimental U-shaped device comprised two vertical solution containers, separated by a horizontal column of silica hydrogel. Each container was filled with 0.5 M CaCl2 and 0.5 M Na2CO3 solutions, which diffused through the gel column over time. Na3PO4 solutions, with 50 and 500 ppm concentrations, were incorporated into the gel in different experiments, resulting in a homogeneous distribution of phosphate concentrations within the diffusion column. After 15- and 30-day incubation periods post-nucleation, the crystals formed in different sections of the gel were carefully extracted and studied with scanning electron microscopy and electron microprobe. Additionally, Raman spectra were collected from the samples using a confocal Raman microscope, providing further insights into their molecular composition and structural properties. The obtained results show that under the induced experimental conditions (i) phosphate incorporates into calcite’s structure, and (ii) the growth of calcium phosphates in the presence of carbonate ions involves the sequential, heterogeneous nucleation of CO3-bearing OCP/HAP-like phases, with Raman spectral characteristics very similar to those of bioapatites.

Evaluating impacts of climate and management on reservoir water quality using environmental fluid dynamics code

Climate change and human interference, notably nutrient input, affect the water quality. Nitrogen (N) and phosphorus (P) are pivotal in managing eutrophication. This study investigated the effects of water dynamics and chemical constituents on water quality in Hongfeng Lake, a typical weakly stratified reservoir suffering from algae blooms in Southwest China, using the Environmental Fluid Dynamics Code. Leveraging climate, hydrological, and water quality data, we constructed, calibrated, and validated the temperature-hydrodynamics-water quality-sediment model. Various scenarios were analyzed, including wind speed, air temperature, solar radiation, rainfall, water discharge, N and P external input, and internal release. The findings revealed that no rain and warming increased trophic state index (TSI) and chlorophyll-a (Chl-a) concentration, and no solar radiation initially elevated nitrate concentration, followed by an increase in ammonium concentration. Besides, no solar radiation and changes in rainfall significantly increased total phosphate concentration. The management scenarios of N and P reduction, halving tributary, and mainstream flow scenarios improved water quality and reduced eutrophication. The wind speed under the N and P reduced scenarios showed that a doubling in wind led to increased concentrations of the particulate organic matter, Chl-a, and dissolved oxygen, alongside decreased ammonium and nitrate, while TSI exhibited minimal change. However, 5- and 10-times wind speed scenarios amplified TSI in shallow water, potentially due to a substantial rise in internal nutrient release. The degradation trend observed in drinking water quality amid climate change (warming and flooding) raises concerns regarding health-related risks. These simulations provided the quantified influence of climate change and environmental management strategies on water quality in the weakly stratified reservoir, notably highlighting the looming threat of exacerbated eutrophication due to warming, necessitating more stringent N and P reduction measures compared to current practices.

A novel indicator of anthropogenic influence on the fluctuability and stability of phytoplankton community composition

Marine community composition is expected to be relatively stable in a natural environment over time but shift under increasing anthropogenic disturbances. In coastal waters, diatoms and dinoflagellates are two dominant phytoplankton functional groups. In this study, we developed an areal phytoplankton community composition index (APCI) that is based on the area of a scatter plot of dinoflagellate abundance (y-axis) vs diatom abundance (x-axis) using a time window of 1 year, 2 years or 3 years data. An APCI allows an ecological interpretation: it represents the fluctuability of a community composition within a time window and a temporal change between two neighbouring APCIs in a time series represents the stability of the composition. We used a 28-yr time series of monthly data on diatom and dinoflagellate abundance at four stations in Tolo Harbour and Channel (Tolo), Hong Kong to test the hypothesis that temporal changes in APCIs indicate environmental disturbances and to examine the applicability of APCI to indicate changes in nutrient conditions. We calculated the area (APCI) of a scatter plot of monthly data for 1-year, 2-year and 3-year windows, referred to as APCI-1y, −2y and -3y, respectively. The results show that, the fluctuability, is larger in APCI-3y than in APCI-1y, while the stability is stronger as temporal changes between neighbouring APCI-3y are smaller than between APCI-1ys. Temporal trends of APCIs are significantly correlated with those of dissolved inorganic nitrogen and phosphate concentration, which have declined after the implementation of a sewage diversion management plan in 1998. Hence, the APCI method is likely a robust indicator to assess a response of the phytoplankton community composition in a water body to environmental disturbances.

Contribution of Gas Flare on the Rainwater of the Braced States in the Niger Delta

Gas flaring contaminates rainwater, which harms the ecology. Exposure to flared gas turns rainwater acidic. The study examined the rainwater quality in gas flare areas of the BRACED states of the Niger Delta. The study employed an ex-post facto research design to assess the quality of rainwater in the industrial regions of the BRACED Niger Delta states. Rainwater samples were collected from twelve (12) locations in the BRACED Niger Delta states near refineries and gas flaring sites. The results show that the rainwater near GHG-impacted areas of the BRACED states has an average pH of 6.7, which is below the guidelines set by the World Health Organisation (WHO). A pH lower than the required WHO standards suggests acidic rainwater. The temperature is 27.4 °C, the conductivity is 37.1µS/cm, and the phosphate concentration exceeds WHO guidelines. Nitrate and sulphate levels are below WHO guidelines. P<0.05 indicates substantial changes in pH value and temperature amount in rainwater quality. Acidic rains, high temperatures, and high phosphate concentrations characterise the BRACED States, raising concerns about the suitability of rainwater for drinking. The study underscores the need for a comprehensive approach to controlling gas flaring, which includes taxation, anti-acidic coating measures, and infrastructure upgrades.

Analytically monitored cultivation of Arthrospira platensis on food waste extracts to compose a sustainable, low-prized, Zarrouk-based medium

ABSTRACT A sustainable, low-cost medium based on food waste for cultivating the cyanobacterium Arthrospira platensis (A. platensis) was investigated. Zarrouk medium components, especially phosphate, were substituted with extracts from beetroot peel, brewer’s grains, and walnut press cake. Ion concentrations of magnesium, calcium, iron, potassium, sodium, phos-phate, nitrate, sulfate, and chloride were analyzed to determine the optimal medium composition. Walnut press cake and brewer’s grains extracts showed high potential due to their magnesium, calcium, and phosphate content. Brewer’s grains extracts also provided glucose as an additional carbon source. Cultivations in shaking flasks and a photobioreactor (PBR) monitored cell growth through optical density and biomass concentration. The excess of magnesium and reduced phos-phate concentrations positively affected biomass production. A. platensis’s ability to metabolize glucose resulted in 68% higher biomass production. Growth in brewer’s grains extract required no additional phosphate. PBR cultivation showed A. platensis consumed significant magnesium and nitrate, achieving higher biomass concentrations with optimized gas exchange and light reflection systems.

Effects of Rice Mill Wastewater on Cocoon Production and Total Population of Earthworm, Eisenia Fetida (Savigny 1826) under Laboratory Condition

Water scarcity can be overcome through the reuse of treated wastewater for irrigation especially in arid and semiarid regions. However, there are several potential environmental and health risks associated with this practices. Improved plant growth and nutrients for microorganisms are also gotten from wastewater which has high nutritive value. This study investigated the effect of rice mill waste water on cocoon production and total population of earthworm Eisenia fetida under laboratory conditions. A total of five hundred (500) clitella earthworms were used for this study. The physico-chemical parameters of the rice mill wastewater were analyzed using standard methods of APHA-AWWA-WEF (2000). The study on the cocoon production and total population of E. fetida were conducted from 0 to 100% wastewater (0, 25, 50, 75 and 100%) by serial dilution for a period of 60 days to assess the suitability of rice mill wastewater for irrigational purpose. The significant difference between treatments was tested by one-way ANOVA. The wastewater had an alkaline pH (8.5), low sulphate (0.95 mg/l), DO (3.10mg/l) and COD (2.0mg/l); moderate concentration of TDS (421mg/l), calcium (47.7 mg/l), phosphate(102.27 mg/l) and high concentration of conductivity (20.50 dsm-1), total solid (2550mg/l), total dissolved solids (2028 mg/l), total hardness (100 mg/l) and sodium (25.0 mg/l), earth population(53.2) At 50% of the wastewater usage there was a significant increase in cocoon production (24.24). On the basis of this research, it shows that rice mill wastewater should be either diluted to at least 50% or treated to make it suitable for irrigational purpose.

Estimated Proximal Tubule Fluid Phosphate Concentration and Renal Tubular Damage Biomarkers in Early Stages of Chronic Kidney Disease

IntroductionAn increase in proximal tubule fluid phosphate concentration is caused by increased serum fibroblast growth factor 23 (FGF23) levels, which resulted in renal tubular damage in a mouse model of chronic kidney disease (CKD). However, few human studies have supported this concept. This study aimed to explore the association among estimated proximal tubule fluid phosphate concentration (ePTFp), serum FGF23 levels, and renal tubular damage biomarkers in middle-aged and older populations with mild decline in renal function. MethodsThis cross-sectional study included 218 participants aged ≥45 with CKD stages G2–G4. Anthropometric measurements, blood tests, spot urine biomarkers, renal ultrasonography, cardiovascular assessment, smoking status, and medication usage were obtained in the morning in fasted states. The ePTFp was calculated using serum creatinine, urine phosphate, and creatinine concentrations. Urinary β2-microglobulin and liver-type fatty acid-binding protein (L-FABP) levels were evaluated to assess renal tubular damage.Results: ePTFp, serum FGF23, urinary β2-microglobulin, and urinary L-FABP levels increased with CKD stage progression (stages G2, G3, and G4). However, serum and urine phosphate concentrations were comparable across the CKD stages. Univariate analysis revealed a stronger correlation of ePTFp with serum FGF23, urinary β2-microglobulin, and urinary L-FABP levels than with the corresponding serum and urine phosphate concentrations. Multivariate analyses demonstrated that increased ePTFp was independently associated with elevated serum FGF23 and urinary β2-microglobulin levels, even after adjusting for potential covariates, including the estimated glomerular filtration rate and urinary albumin-to-creatinine ratio. ConclusionsOur results are consistent with the concept in mouse model and suggest that increased ePTFp are associated with increased serum FGF23 levels and renal tubular damage during the early stages of CKD.

Organophosphate Ester Flame Retardants and Plasticizers in Relation to Fetal Growth in the LIFECODES Fetal Growth Study.

Organophosphate esters (OPEs), used ubiquitously as flame retardants and plasticizers in consumer products, are suspected of having developmental toxicity. Our study aimed to estimate associations between prenatal exposure to OPEs and fetal growth, including both ultrasound (head circumference, abdominal circumference, femur length, and estimated fetal weight) and delivery [birth weight z-score, small-for-gestational age (SGA), and large-for-gestational age (LGA)] measures of growth. In the LIFECODES Fetal Growth Study (2008-2018), an enriched case-cohort of 900 babies born at the small and large ends of the growth spectrum, we quantified OPE biomarkers in three urine samples per pregnant participant and abstracted ultrasound and delivery measures of fetal growth from medical records. We estimated associations between pregnancy-averaged log-transformed OPE biomarkers and repeated ultrasound measures of fetal growth using linear mixed-effects models, and delivery measures of fetal growth using linear (birth weight) and logistic (SGA and LGA) regression models. Most OPE biomarkers were positively associated with at least one ultrasound measure of fetal growth, but associations with delivery measures were largely null. For example, an interquartile range (IQR; ) increase in bis(2-chloroethyl) phosphate concentration was associated with larger z-scores in head circumference [mean difference (difference): 0.09; 95% confidence interval (CI): 0.01, 0.17], abdominal circumference (difference: 0.10; 95% CI: 0.02, 0.18), femur length (difference: 0.11; 95% CI: 0.03, 0.19), and estimated fetal weight (difference: 0.13; 95% CI: 0.04, 0.22) but not birth weight (difference: 0.04; 95% CI: , 0.17). At delivery, an IQR () increase in diphenyl phosphate (DPHP) concentration was associated with an SGA birth (odds ratio: 1.46; 95% CI: 1.10, 1.94). In a large prospective cohort, gestational OPE exposures were associated with larger fetal size during pregnancy, but associations at delivery were null. DPHP concentrations were associated with heightened risk of an SGA birth. These findings suggest that OPE exposure may affect fetal development. https://doi.org/10.1289/EHP14647.