Release characteristics of arsenic from sediments and its source or sink competition with phosphorus: A case of a great lake with grass-algae alternation.

The arsenic (As) release from sediments in great lakes is affected by various factors. In this study, the characteristics of As release from sediments was investigated, and the As sources and sinks with the strengths in sediments from different areas (grass-type, algae-type, and grass-algae alternation areas) in great shallow lakes (Taihu Lake, China) were analyzed, and the influence of P competition in the process of As release was also studied. The results showed that changing trend of the values of equilibrium As concentration in sediments were consistent with the regional changes (0 to 28.12 µg/L), and the sediments from algae-type areas had the higher values. The sediments from western lake and northwest lake bay were a strong As and a weak P source, and the north lake bay had the opposite trend of these two regions. Intense P source competition with As from the sediments occurred in algae-type areas. The grass-type areas had strong As and P retention capacities, indicating a sink role of sediment with high As and P sorption capacities. The degree of As and P saturation had similar trend in sediments, and the grass-type areas had the higher values, 18.3%-21.4% and 15.31%-20.34%, respectively. Contribution analysis results showed that most of As release contribution was from the bottom (30-50 cm) sediments, and the surface (0-10 cm) sediments from algae-type areas contributed more to the overlying water than other region.

How sediment dredging alters phosphorus dynamics in a lowland rural river?

China's lowland rural rivers are facing severe eutrophication problems due to excessive phosphorus (P) from anthropogenic activities. However, quantifying P dynamics in a lowland rural river is challenging due to its complex interaction with surrounding areas. A P dynamic model (River-P) was specifically designed for lowland rural rivers to address this challenge. This model was coupled with the Environmental Fluid Dynamics Code (EFDC) and the Phosphorus Dynamic Model for lowland Polder systems (PDP) to characterize P dynamics under the impact of dredging in a lowland rural river. Based on a two-year (2020-2021) dataset from a representative lowland rural river in the Lake Taihu Basin, China, the coupled model was calibrated and achieved a model performance (R2>0.59, RMSE<0.04 mg/L) for total P (TP) concentrations. Our research in the study river revealed that (1) the time scale for the effectiveness of sediment dredging for P control was ∼300 days, with an increase in P retention capacity by 74.8 kg/year and a decrease in TP concentrations of 23% after dredging. (2) Dredging significantly reduced P release from sediment by 98%, while increased P resuspension and settling capacities by 16% and 46%, respectively. (3) The sediment-water interface (SWI) plays a critical role in P transfer within the river, as resuspension accounts for 16% of TP imports, and settling accounts for 47% of TP exports. Given the large P retention capacity of lowland rural rivers, drainage ditches and ponds with macrophytes are promising approaches to enhance P retention capacity. Our study provides valuable insights for local environmental departments, allowing a comprehensive understanding of P dynamics in lowland rural rivers. This enable the evaluation of the efficacy of sediment dredging in P control and the implementation of corresponding P control measures.

Disentangling microbial coupled fillers mechanisms for the permeable layer optimization process in multi-soil-layering systems.

The multi-soil-layering (MSL) systems is an emerging solution for environmentally-friendly and cost-effective treatment of decentralized rural domestic wastewater. However, the role of the seemingly simple permeable layer has been overlooked, potentially holding the breakthroughs or directions to addressing suboptimal nitrogen removal performance in MSL systems. In this paper, the mechanism among diverse substrates (zeolite, green zeolite and biological ceramsite) coupled microorganisms in different systems (activated bacterial powder and activated sludge) for rural domestic wastewater purification was investigated. The removal efficiencies performed by zeolite coupled with microorganisms within 3 days were 93.8% for COD, 97.1% for TP, and 98.8% for NH4+-N. Notably, activated sludge showed better nitrification and comprehensive performance than specialized nitrifying bacteria powder. Zeolite attained an impressive 89.4% NH4+-N desorption efficiency, with a substantive fraction of NH4+-N manifesting as exchanged ammonium. High-throughput 16S rRNA gene sequencing revealed that aerobic and parthenogenetic anaerobic bacteria dominated the reactor, with anaerobic bacteria conspicuously absent. And the heterotrophic nitrification-aerobic denitrification (HN-AD) process was significant, with the presence of denitrifying phosphorus-accumulating organisms (DPAOs) for simultaneous nitrogen and phosphorus removal. This study not only raises awareness about the importance of the permeable layer and enhances comprehension of the HN-AD mechanism in MSL systems, but also provides valuable insights for optimizing MSL system construction, operation, and rural domestic wastewater treatment.

Calcium and phosphorus digestibility in broilers as affected by varying phytate concentrations from corn.

Dietary phytate P (PP) concentration impacts Ca and P digestibility in broilers. Research was conducted to determine the impact of increasing concentration of dietary PP, with and without phytase, on broiler standardized ileal digestibility (SID) of Ca and P. Digestible (Dig) Ca and P were calculated by multiplying SID and the analyzed dietary Ca and P concentrations. The experiment was a factorial arrangement of 2 phytase (0 and 1,000 U/kg) and 4 PP (0.16, 0.23, 0.29, and 0.34%) concentrations. Treatments were fed for 36 h from 20 to 22 d of age (4 b/pen, n ≥ 7 replicate pens/treatment). Different ratios of corn and corn germ were used to achieve the desired PP concentrations. A limestone with 800 µm geometric mean diameter was used as the sole Ca source to achieve 0.7% Ca in the final diets (96% Ca from limestone). An additional diet was fed that was N, Ca- and P-free, for the determination of endogenous losses of each nutrient. Distal ileal digesta were pooled from all birds in a pen. There were no interactions between PP and phytase on SID Ca or Dig Ca from limestone. Irrespective of phytase inclusion, increasing PP from 0.16 to 0.34% decreased SID Ca from 53.8 to 38.1% (P < 0.05). The SID Ca averaged 41.5 and 51.4% in diets containing 0 and 1000 U phytase/kg, respectively, across all PP concentrations (P < 0.05). Interactions were seen between PP and phytase on SID and Dig P (P < 0.05) with SID P of 31.1, 24.0, 20.1, and 16.3% for broilers fed 0.16, 0.23, 0.29, and 0.34% PP diets without phytase, respectively. When phytase was included at 1000 U/kg, SID P was 89.9, 87.5, 73.9 and 60.4% for diets containing 0.16, 0.23, 0.29 and 0.34% PP, respectively (P < 0.05). Overall, phytase improved SID Ca and P independent of PP concentration. However, with increasing PP concentration, both SID Ca and P were negatively affected.

Metal-Free Aminophosphonation: Eco-friendly Synthesis and Photophysical Properties of Fluorescent 3-(Aminoimidazo[1,2-a]pyridin-2-yl)phosphonates.

We report a novel, metal-free procedure for the direct aminophosphonation of imidazo[1,2-a]pyridines in green solvents under open air conditions. This method is characterized by its mild and sustainable conditions, ease of operation, scalability, and excellent functional group compatibility. The synthesized compounds exhibit promising photophysical properties, including significant Stokes shifts and quantum yields, making them potential candidates for innovative fluorescent probes.

Controllable preparation of red phosphorus nanoribbons for enhanced photocatalytic degradation of Methyl Orange and Tetracycline.

Nanoribbons (NRs), leveraging the flexibility of one-dimensional materials and the expansive surface area of two-dimensional materials, offer heightened exposure to edge sites and superior charge transfer rates. Consequently, they present promising prospects within the domain of photocatalysis. Crystalline red phosphorus (cRP), dcharacterized by its layered and fibrous structure, lends itself readily to the production of nanoribbons. Our study demonstrates a robust method for achieving high-yield, high-quality cRP by concurrently introducing mineralizing agent I2 and Si wafers into the Chemical Vapor Transport (CVT) synthesis process. Through ultrasound assistance, we transformed high-quality cRP into crystalline red phosphorus nanoribbons (cRP NRs) with an average thickness ranging from 7.5 to 17.5 nm and an average width between 75 and 175 nm. cRP NRs (I2 and Si) showcased impressive degradation capabilities towards Methyl Orange (MO) and Tetracycline (TC), achieving a remarkable 99% degradation of MO within 18 min under the simulated visible-light irradiation. The reactive species capturing experiments confirmed that ·O2- was the primary active agent responsible for the photocatalytic degradation of MO.

Saturation of intracellular phosphorus uptake and prevalence of extracellular phosphorus entrapment in fluvial biofilms after long-term P pulses: Implications for river self-purification.

Microbial consortia in riverbed substrates and their extracellular matrix (biofilms) play a key role in phosphorus (P) entrapment. When P entrapment saturates, the benthic compartment changes from a P sink to a P source thus increasing eutrophication risk. P entrapment saturation is expected to differ between intracellular and extracellular P entrapment and between different magnitudes and durations of P inputs. We studied biofilm P-entrapment following short (48 h) and long (14 days) P loading events in stream bypass flumes supplied with a gradient of dissolved P concentrations. This allowed us to link local biofilm processes in sediments to potential effects on river self-purification, via quantifying the P removal efficiency in the flumes. We found that in short-term events, biofilms develop intracellular mechanisms to cope with P inputs, while long-term events and high P inputs suppress the intracellular uptake mechanisms and increase the prevalence of extracellular entrapment. Specifically, long-term events lowered the threshold for intracellular P entrapment saturation, and decreased the ratio between intracellular and extracellular entrapment resulting in lower removal efficiency for dissolved phosphorus. Our results highlight the risk that aquatic ecosystems may face as the ratio of intracellular to extracellular P entrapment decreases, which may reduce their ability to deal with P inputs, thereby increasing risks of eutrophication.

Impact of Serum Phosphorus on Hemoglobin: A Literature Review.

Phosphorus is a macroelement found in the body, mostly in the bones as crystals of hydroxyapatite. Higher levels are found in patients affected by chronic kidney disease (CKD). Since the early stage of CKD phosphorous excretion is impaired, but the increase of PTH and FGF23 maintains its level in the normal range. In the last decades, the role of FGF23 in erythropoiesis was studied, and now it is well known for its role in anemia genesis in patients affected by conservative CKD. Both Hyperphosphatemia and anemia are two manifestations of CKD, but many studies showed a direct association between serum phosphorous and anemia. Phosphorus can be considered as the common point of more pathogenetic ways, independent of renal function: the overproduction of FGF23, the worsening of vascular disease, and the toxic impairment of erythropoiesis, including the induction of hemolysis.

Magnetic nanoparticles-immobilized phospholipase LM and phospholipase 3G: Preparation, characterization, and application on soybean crude oil degumming.

Immobilization of enzymes improves their stability and recoverability and is therefore crucial for scientific research and industrial applications. In this study, phospholipase LM (PLLM) and phospholipase 3G (PL3G) were immobilized using Fe3O4@SiO2@CS-COOH polycarboxylated magnetic nanoparticles (MNPs-COOH) as carriers and then used for degumming soybean crude oil. The immobilization rates and relative enzyme activities of these immobilized phospholipases were evaluated to determine the optimal immobilization parameters. The enzyme activities of PLLM-MNPs-COOH and PL3G-MNPs-COOH were 2830.87 and 1162.25 U/g, respectively. Enzymatic properties of the free and immobilized enzymes were compared. Both immobilized phospholipases exhibited higher condition tolerance and stability after immobilization. After 30-day storage at 4 °C, both immobilized phospholipases retained approximately 1.3 times the residual activity of the corresponding free phospholipases. When the degumming conditions were optimized, the residual phosphorus contents of the PLLM-MNPs-COOH- and PL3G-MNPs-COOH-degummed oils were 4.91 and 7.41 mg/kg, respectively, which were consistent with the safety standards for oil products. After 6 cycles, PLLM-MNPs-COOH and PL3G-MNPs-COOH continued to preserve 71.88 % and 70.00 % of their initial activities, respectively. The immobilized phospholipases are thus suitable for degumming soybean crude oil, and the mixed enzymes exhibited better degumming potential.

Neuroenergetic alterations in neurodegenerative diseases: A systematic review and meta-analysis of in vivo31P-MRS studies.

Phosphorus magnetic resonance spectroscopy (31P-MRS) is applied for non-invasive studies of neuroenergetic metabolism in neurodegenerative diseases. However, the findings are inconsistent and have not yet been tested in meta-analyses. To address this gap, we performed a systematic review of 29 studies and conducted meta-analyses for 9 studies on Alzheimer's disease (AD, n=140 patients), 9 studies on Parkinson's disease (PD, n=183 patients), 3 studies on Progressive Supranuclear Palsy (PSP, n=42 patients), and 2 studies on Multiple System Atrophy (MSA, n=24 patients). Compared to controls, AD patients had a higher ratio of phosphomonoesters/phosphodiesters (PME/PDE) in the frontal lobe (MD=0.049, p=0.0003); PD patients showed decreases in PME/PDE in the putamen (MD=-0.050, p=0.023) and adenosine triphosphate/inorganic phosphate (ATP/Pi) in the midbrain (MD=-0.274, p=0.002); PSP patients presented increased phosphocreatine (PCr)/Pi in the basal ganglia (MD=0.556, p=0.030) and adenosine diphosphate (ADP)/Pi in the occipital lobe (MD=0.005, p=0.009); no significant effects were observed in MSA. Here, our review underlines the importance of 31P-MRS in the characterization of distinct neuroenergetic changes and its potential to improve the diagnosis and follow-up of neurodegenerative diseases.

Inferences based on diatom compositions improve estimates of nutrient concentrations in streams.

Nutrient concentrations in streams vary strongly with flow conditions, and routinely gathered field measurements of nutrients reflect this variability. Diatom assemblage composition has been used in previous studies to infer nutrient concentrations, and because diatoms integrate nutrient concentrations over longer periods of time, diatom inferences may be less susceptible to fluctuations in streamflow. We tested this hypothesis by leveraging differences in the flashiness of streams across a large continental data set. More specifically, we tested whether the variabilities of direct measurements and diatom inferences of dissolved phosphorus and nitrate were greater in flashy versus non-flashy streams. We further considered whether models linking landscape predictor variables to nutrient concentrations yielded consistent results across flashy and non-flashy streams. Our analysis indicated that measured nutrient concentrations were more variable in flashy compared to non-flashy streams and that landscape models identified different important predictors of nutrient concentrations when fit using data from flashy vs. non-flashy streams. In contrast, variabilities of diatom-inferred nutrient concentrations were similar among stream types, as were the important predictor variables (e.g., manure application rates for nitrate and number of wet days for dissolved phosphorus). These analyses indicate that use of diatom-inferred nutrient concentrations can potentially improve efforts to quantify stream nutrient concentrations.

Machine learning-driven prediction of phosphorus adsorption capacity of biochar: Insights for adsorbent design and process optimization.

Phosphorus (P) pollution in aquatic environments poses significant environmental challenges, necessitating the development of effective remediation strategies, and biochar has emerged as a promising adsorbent for P removal at the cost of extensive research resources worldwide. In this study, a machine learning approach was proposed to simulate and predict the performance of biochar in removing P from water. A dataset consisting of 190 types of biochar was compiled from literature, encompassing various variables including biochar characteristics, water quality parameters, and operating conditions. Subsequently, the random forest and CatBoost algorithms were fine-tuned to establish a predictive model for P adsorption capacity. The results demonstrated that the optimized CatBoost model exhibited high prediction accuracy with an R2 value of 0.9573, and biochar dosage, initial P concentration in water, and C content in biochar were identified as the predominant factors. Furthermore, partial dependence analysis was employed to examine the impact of individual variables and interactions between two features, providing valuable insights for adsorbent design and operating condition optimization. This work presented a comprehensive framework for applying a machine learning approach to address environmental issues and provided a valuable tool for advancing the design and implementation of biochar-based water treatment systems.

Effect of a Bacillus velezensis and Lysinibacillus fusiformis-based biofertilizer on phosphorus acquisition and grain yield of soybean.

Introduction: Phosphate-solubilizing bacteria that function through acidification (organic acid synthesis) or mineralization (production of enzymes such as phytase and phosphatases) have been explored as a biotechnological alternative to enhance plant access to phosphorus (P) retained in organic and inorganic forms in agricultural soils. This study tested the hypothesis that applying a biofertilizer composed of a recognized phosphate-solubilizing bacterium (Bacillus velezensis - endophytic strain BVPS01) and an underexplored plant growth-promoting bacterium (Lysinibacillus fusiformis - endophytic strain BVPS02) would improve the growth and grain yield of Glycine max L. plants. Methods: Initial in vitro tests assessed the functional traits of these bacteria, and a mix of strains BVPS01 and BVPS02 was produced and tested under field conditions to evaluate its agronomic efficiency. Results: The results confirmed the hypothesis that the tested biofertilizer enhances the agronomic performance of G. max plants in the field. The B. velezensis strain (BVPS01) was found to be more effective than the L. fusiformis strain (BVPS02) in solubilizing phosphates via the phosphatase enzyme production pathway, indicated by the expression of the phoC and phoD genes. In contrast, L. fusiformis was more effective in solubilizing phosphates through organic acid and phytase-related pathways, in addition to synthesizing indole-3-acetic acid and increasing the mitotic index in the root meristem of G. max plants. These strains exhibited biological compatibility, and the formulated product based on these rhizobacteria enhanced root development and increased the number of nodules and flowers, positively affecting 1000-grain weight, grain yield, and grain P content. Discussion: Thus, the tested biofertilizer demonstrated potential to improve root growth and increase both the yield and quality of soybean crops, making it a sustainable and low-cost strategy.

A Mechanochemically-Triggered, Self-Powered Flash Heating Synthesis of Phosphorous/Caron Composites for Li-Ion Batteries.

"Flash heating" that transiently generates high temperatures above 1000 °C has great potential in synthesizing new materials with unprecedently properties. Up to now, the realization of "flash heating" still relies on the external power, which requires sophisticated setups for vast energy input. In this study, a mechanochemically triggered, self-powered flash heating approach is proposed by harnessing the enthalpy from chemical reactions themselves. Through a model reaction between Mg3N2/carbon and P2O5, it is demonstrated that this self-powered flash heating is controllable and compatible with conventional devices. Benefit from the self-powered flash heating, the resulting product has a nanoporous structure with a uniform distribution of phosphorus (P) nanoparticles in carbon (C) nanobowls with strong P─-C bonds. Consequently, the P/C composite demonstrates remarkable energy storage performance in lithium-ion batteries, including high capacity (1417 mAh g-1 at 0.2 A g-1), robust cyclic stability (935 mAh g-1 at 2 A g-1 after 800 cycles, 91.6% retention), high-rate capability (739 mAh g-1 at 20 A g-1), high loading performance (3.6 mAh cm-2 after 100 cycles), and full cell cyclic stability (90% retention after 100 cycles). This work broadens the flash heating concept and can potentially find application in various fields.

Reagent-free phosphorus precipitation from a denitrified swine effluent in a batch electrochemical system.

There is high interest in the recovery of phosphorus (P) from wastewater through crystallization processes. However, the addition of chemical reagents (e.g., sodium hydroxide) to raise the pH may result in high treatment costs and increased concentrations of undesired metal ions (e.g., sodium). As an alternative, in this research we considered electrochemical mediated precipitation at low current densities (0.4-1.2 A m-2) without using chemical reagents. For that purpose, a two-chamber electrochemical system was operated in batch for treating denitrified swine effluent (48 mg P L-1). By applying current at 1.2 A m-2, and targeting pH 11.5, a maximum P removal rate of 33.4 mmol P (L·d-1) was obtained while the P removal efficiency was above 90 %. New solids that formed mostly remained suspended in the catholyte. Before discharge, the catholyte effluent was recirculated to the anodic compartment to neutralize the pH, achieving a final pH of 6.4 ± 0.1. Chlorine (Cl2) production in the anodic compartment was favored by a small anode surface and a high initial pH of the catholyte. Although the production of chlorine achieved was limited (the highest concentration was 8.6 ± 0.1 mg Cl2 L-1) these findings represent a new opportunity for the recovery and onsite use of this side-product. Electrochemical impedance spectroscopy tests confirmed that the deposition of solids inside the cathodic compartment during the experimental period was limited. Membrane analysis revealed significant scaling of carbonate compounds. The electrochemical treatment described above was shown as a promising alternative to sodium hydroxide and sulfuric acid dosage for pH adjustment when crystallizing phosphate salts.

Phosphorus vacancies regulation and heterogeneous interfacial engineering of coral-like ZnO/FeCoPv@N-doped carbon hierarchical microspheres to boost overall water splitting.

Vacancy engineering and heterostructure construction are regarded as potent approaches for synergistically boosting hydrogen production in renewable energy conversion. Herein, a selective phosphorization strategy was implemented to fabricate coral-like ZnO/FeCoP@N-doped carbon hierarchical microspheres (ZnO/FeCoP@NCHMS) via only controllably phosphorizing the Co and Fe atoms in a precursor, which was formed by generating ZnCoFe LDH on the surface of a zinc cobalt coordination polymer microsphere. Then, by adopting a reduction treatment for ZnO/FeCoP@NCHMS, the innovative ZnO/FeCoPv@NCHMS with abundant phosphorus vacancies (Pv) was realized. The introduction of phosphorus vacancy could optimize the electronic structures of metal phosphides and accelerate the reconstruction of active species, thus speeding up the reaction kinetic. Likewise, the plentiful heterointerfaces greatly expedite the transfer of electrons and protons, exposing ultra-high active sites. By virtue of these fascinating characters and the unique coral-like hierarchical architecture, the as-prepared ZnO/FeCoPv@NCHMS reveal preeminent electrocatalytic activities, and the overpotentials for the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) are as low as 177 and 173 mV at 10 mA cm-2 in alkaline medium, respectively. Impressively, the water electrolysis device assembled by ZnO/FeCoPv@NCHMS requires a mere cell voltage of 1.508 V to attain a current density of 10 mA cm-2. Furthermore, the ZnO/FeCoPv@NCHMS also demonstrate extraordinary durability, sustaining operation for at least 28 h (at 100 mA cm-2) during the water splitting process. This study provides novel insights into defect regulation and heterointerface construction for overall water splitting.

Examining contaminant transport hotspots and their predictability across contrasted watersheds.

Hydrobiogeochemical processes governing water quantity and quality are highly variable in space and time. Focusing on thirty river locations in Québec, Canada, three water quality hotness indices were used to classify watersheds as contaminant transport hotspots. Concentration and load data for suspended solids (SS), total nitrogen (TN), and total phosphorous (TP) were used to identify transport hotspots, and results were compared across hotness indices with different data requirements. The role of hydroclimatic and physiographic characteristics on the occurrence and temporal persistence of transport hotspots was examined. Results show that the identification of transport hotspots was dependent on both the type of data and the hotness index used. Relationships between temporal and spatial predictors, however, were generally consistent. Annual transport hotspot occurrence was found to be related to temporal characteristics such as the number of dry days, potential evapotranspiration, and snow water equivalent, while hotspot temporal persistence was correlated to landcover characteristics. Stark differences in the identification of SS, TN, and TP transport hotspots were attributed to differences in mobilization processes and provided insights into dominant water and nutrient flowpaths in the studied watersheds. This study highlighted the importance of comparing contaminant dynamics across watersheds even when high-frequency water quality data or discharge data are not available. Characterizing hotspot occurrence and persistence, among hotness indices and water quality parameters, could be useful for watershed managers when identifying problematic watersheds, exploring legacy effects, and establishing a prioritization framework for areas that would benefit from enhanced routine monitoring or targeted mitigation strategies.

Tidal Versus Intermittent Peritoneal Dialysis in Chronic Peritoneal Dialysis Patients: Randomized, Open-Label, Prospective Control Study.

BACKGROUND: Tidal peritoneal dialysis (TPD) provides better fluid flow mechanics and is more comfortable for the patient, owing to fewer alarms and less pain during inflow and outflow. The long-term characteristics of patients with TPD were not evident. In this randomized controlled follow-up study, we aimed to explore the characteristics of patients with TPD, compared to IPD. METHODS: A total of 85 patients were randomized to either IPD or 70% TPD between January 2019 and December 2020, and all patients were followed up on December 2021. The characteristics of patients between the two groups were analyzed using a t-test or chi-square as appropriate. The overall survival and technical survival were analyzed using Kaplan-Meier analysis. RESULTS: Forty-two patients were assigned to IPD, and 43 patients were assigned to TPD. The basal characteristics of patients were not different between the two groups. In an average of 16 months of follow-up, 19 patients died, and 25 patients dropped out of peritoneal dialysis. The two groups had no difference in overall survival and technical survival. TPD was associated with high urine volume (p = 0.001), lower blood urea nitrogen (p = 0.002), lower phosphorus (p = 0.004), and fewer cycler alarms (p < 0.001). The chance of patients reporting abdominal fullness was higher in patients with TPD (p = 0.001). CONCLUSION: In the randomized, controlled, follow-up study, TPD may preserve residual renal function and is associated with lower urea nitrogen and phosphorus in chronic peritoneal dialysis patients. TPD is associated with fewer cycler alarms but may increase the chance of patients reporting abdominal distension.

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. Supplementary Information: The online version contains supplementary material available at 10.1007/s42995-024-00244-y.

Soil properties and nutrient uptake of maize (Zea mays) as influenced by mixed manure and blended inorganic fertilizer in Haramaya district, eastern Ethiopia.

The deteriorating state of soil fertility and low agricultural productivity in Ethiopia can be traced to the lack of equivalent consideration given to the soil's biological, chemical, and physical properties. A pot experiment was conducted to investigate the effect of mixed manure and blended nitrogen, phosphorus, sulfur and boron (NPSB) fertilizer on phosphorus adsorption, and other properties of Vertisols, nutrient uptake, and growth performance of maize. The study findings indicate that the combined application of mixed manure and blended NPSB significantly reduced soil pH from 7.87 to 7.68, phosphorus adsorption efficiency from 93 to 88.5 %, and Freundlich adsorption capacity from 194 to 100.75 mg kg-1 , intensity from 1.96 to 1.27 compared to control. However, combined application of these two treatments significantly increased the organic carbon from 0.81 to 1.64 %, total nitrogen from 0.04 to 0.13 %, and available phosphorus from 6.96 to 73.82 g kg-1. The study further revealed that mixed manure and blended NPSB resulted in significantly (p ≤ 0.05) higher contents of nitrogen and phosphorus in the maize leaves as well as their uptake compared to their sole application and control. The highest values of these parameters were observed in plots treated with a combined application of 15 t ha-1 mixed manure with each rate of 100 and 150 kg ha-1 blended NPSB. Additionally, the maize plant height (p ≤ 0.05) and above-ground biomass (p ≤ 0.01) also exhibited significant increase. Compared to the control and full dose of NPSB, all the treatments that received a combined application of 15 t ha-1 mixed manure with blended NPSB ranging from 50 to 150 kg ha-1 resulted in significantly higher above-ground biomass of maize. The results suggest that the combined use of mixed manure and blended NPSB could be a practical and effective approach to improve soil properties and maize above-ground biomass yield.