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Background: Vascular calcification is a major contributor to cardiovascular disease, especially diabetes, where it exacerbates morbidity and mortality. Although pyrophosphate is a recognized natural inhibitor of vascular calcification, there have been no prior studies examining its specific deficiency in diabetic conditions. This study is the first to analyze the direct link between elevated glucose levels and disruptions in extracellular pyrophosphate metabolism. Methods: Rat aortic smooth muscle cells, streptozotocin (STZ)-induced diabetic rats, and diabetic human aortic smooth muscle cells were used to assess the effects of elevated glucose levels on pyrophosphate metabolism and vascular calcification. The techniques used include extracellular pyrophosphate metabolism assays, thin-layer chromatography, phosphate-induced calcification assays, BrdU incorporation for DNA synthesis, aortic smooth muscle cell viability and proliferation assays, and quantitative PCR for enzyme expression analysis. Additionally, extracellular pyrophosphate metabolism was examined through the use of radiolabeled isotopes to track ATP and pyrophosphate transformations. Results: Elevated glucose led to a significant reduction in extracellular pyrophosphate across all diabetic models. This metabolic disruption was marked by notable downregulation of both the expression and activity of ectonucleotide pyrophosphatase/phosphodiesterase 1, a key enzyme that converts ATP to pyrophosphate. We also observed an upregulation of ectonucleoside triphosphate diphosphohydrolase 1, which preferentially hydrolyzes ATP to inorganic phosphate rather than pyrophosphate. Moreover, tissue-nonspecific alkaline phosphatase activity was markedly elevated across all diabetic models. This shift in enzyme activity significantly reduced the pyrophosphate/phosphate ratio. In addition, we noted a marked downregulation of matrix Gla protein, another inhibitor of vascular calcification. The impaired pyrophosphate metabolism was further corroborated by calcification experiments across all three diabetic models, which demonstrated an increased propensity for vascular calcification. Conclusions: This study demonstrated that diabetes-induced high glucose disrupts extracellular pyrophosphate metabolism, compromising its protective role against vascular calcification. These findings identify pyrophosphate deficiency as a potential mechanism in diabetic vascular calcification, highlighting a new therapeutic target. Strategies aimed at restoring or enhancing pyrophosphate levels may offer significant potential in mitigating cardiovascular complications in diabetic patients, meriting further investigation. [ABSTRACT FROM AUTHOR]

Although ethers are common in secondary natural products, they are an underrepresented functional group in primary metabolism. As such, there are comparably few enzymes capable of constructing ether bonds in a general fashion. However, such enzymes are highly sought after for synthetic applications as they typically operate with higher regioselectivity and under milder conditions than traditional organochemical approaches. To expand the repertoire of well characterized ether synthases, we herein report on a promiscuous archaeal prenyltransferase from the scarcely researched family of geranylgeranylglyceryl phosphate synthases (GGGPSs or G3PSs). We show that the ultrastable Archaeoglobus fulgidus G3PS makes various (E)‐ and (Z)‐configured prenyl glycerol ethers from the corresponding pyrophosphates while exerting perfect control over the configuration at the glycerol unit. Based on experimental and computational data, we propose a mechanism for this enzyme which involves an intermediary prenyl carbocation equivalent. As such, this study provides the fundamental understanding and methods to introduce G3PSs into the biocatalytic alkylation toolbox. [ABSTRACT FROM AUTHOR]

Phosphorus is often present in meteorites as the mineral schreibersite, in which P is in a reduced oxidation state as a phosphide. Phosphides such as schreibersite have been proposed to be important to the development of life on the earth and may serve as indicators of metamorphic grade on meteorite parent bodies. Here we investigate how synthetic schreibersite (as the iron end-member, Fe 3 P) oxidizes into calcium phosphates through reaction with silicates under high temperature conditions, at specific oxygen fugacities, and in the absence of water. We find that schreibersite readily oxidizes to phosphates at temperatures of 750–850 °C over a few weeks depending on the oxygen fugacity of the environment. The rate of this process is best matched by diffusion-limited kinetics. Therefore, the metamorphic heating timescale required to equilibrate phosphorus in meteoritic samples with small schreibersite grains (∼1 μm), such as in the type 3 ordinary chondrites (3.0–3.3), was short (10–100 days). [ABSTRACT FROM AUTHOR]

The physicochemical properties of chitosan-microparticles are related to the crosslinking salts. The effects of sodium-pyrophosphate or sodium-tripolyphosphate and ultrasonication on the formation of phosphate-chitosan microparticles were evaluated. Potentiometric titration curves were used to determine the ionization degree of chitosan by employing the Henderson-Hasselbach equation and milliequivalents. Colloidal formation was validated by turbidity and conductivity at different phosphate-chitosan salt ratios. The ultrasonication effect was characterized by visual appearance, zeta potential, particle size, FTIR, SEM, and EDS analyses. Additionally, the impact of particle size on the cytotoxicity and the encapsulation properties of a curcumin microemulsion was assessed. Chitosan ionization degree was pH dependent and was fully ionized below 4.0. The milliequivalent points were estimated at 0.9 and 1.06 for the two crosslinkers and chitosan, respectively. The maximum turbidity observed during complex formation was 0.5 and 1.0 for the pyrophosphate-chitosan and tripolyphosphate-chitosan samples, respectively, showing a critical conductivity value of 1. FTIR showed the interaction between phosphate salts (PO–) and chitosan amino groups (NH3+) in the region of 1200–1650 cm–1. SEM showed that the particle size decreased with ultrasonication. After ultrasonication, the particle size of the phosphate-chitosan microparticles decreased 17-fold but the zeta potential did not change. The phosphate-chitosan complexes did not present cytotoxic activity at concentrations lower than 1000 µg/mL. The pyrophosphate-chitosan and tripolyphosphate-chitosan microparticles have remarkable loading capacities for curcumin, making them promising carriers for nutraceutical and pharmaceutical applications.

This paper describes initially the application of the Tyndall effect (TE) of metal–organic framework (MOF) materials as a colorimetric signaling strategy for the sensitive detection of pyrophosphate ion (PPi). The used MOF NH2-MIL-101(Fe) was prepared with Fe3+ ions and fluorescent ligands of 2-amino terephthalic acid (NH2-BDC). The fluorescence of NH2-BDC in MOF is quenched due to the ligand-to-metal charge transfer effect, while the NH2-MIL-101(Fe) suspension shows a strong TE. In the presence of PPi analyte, the MOFs will undergo decomposition because of the competitive binding of Fe3+ by PPi over NH2-BDC, resulting in a significant decrease in the TE signal and fluorescence restoration from the released ligands. The results demonstrate that the new method only requires a laser pointer pen (for TE creation) and a smartphone (for portable quantitative readout) to detect PPi in a linear concentration range of 1.25–800 μM, with a detection limit of ~210 nM (3σ) which is ~38 times lower than that obtained from traditional fluorescence with a spectrophotometer (linear concentration range, 50–800 µM; detection limit, 8.15 µM). Moreover, the acceptable recovery of PPi in several real samples (i.e., pond water, black tea, and human serum and urine) ranges from 97.66 to 119.15%. [ABSTRACT FROM AUTHOR]

Alkaline phosphatase (ALP) is an essential enzyme widely distributed in the human body, and it can hydrolyze pyrophosphate (PPi) under alkaline conditions. Therefore, ALP and PPi activities are associated with many diseases and it is crucial to develop sensitive and selective methods for detecting ALP and PPi. Herein, poly-(acrylic acid) (PAA)-Ca2+(Ce3+) nanoclusters fluorescent probe was synthesized aiming to detect PPi and ALP quantitatively. The nanoclusters present monodisperse, and their particle size is 0.9–2.4 nm. The probe exhibits no fluorescence due to electron transfer; whereas it can combine with PPi to yield fluorescence increase, arising from the enhanced electric-dipole transition of Ce3+ under the ligand effect of PPi. Moreover, the probe displays good selectivity to PPi, and the fluorescence changes display a linear relationship with PPi concentration of 3–20 mM (y = 11.29x – 23.47, R2 = 0.994). Furthermore, the probe was mixed with PPi to form PAA-Ca-(Ce):PPi nanoparticle (Monodisperse, average size: 1.94 nm) and showed high fluorescence selectivity and responsiveness to ALP due to the ALP hydrolyzing effect and the fluorescence difference between PAA-Ca-(Ce):PPi and PAA-Ca-(Ce):Pi. Based on the relationship between the fluorescence reduction rate of the probe and the logarithm of ALP concentration (y = 0.0594x – 0.00111, 5–200 U/L, R2 = 0.996), ALP was successfully detected quantitatively, and the detection limit is calculated to be 0.62 U/L. Through this approach, we developed a fluorescence "turn-on" for PPi detection and "turn-off" for ALP detection. This study provides a promising strategy for the diagnosis of diseases related to PPi and ALP. [ABSTRACT FROM AUTHOR]

Hypophosphatasia (HPP) is a rare genetic condition associated with poor bone mineralization, low serum alkaline phosphatase, high urinary pyrophosphate excretion, and nephrocalcinosis. Nephrocalcinosis is thought to develop due to the increased filtered loads associated with hypercalcemia and hyperphosphatemia, but the composition of these calcifications is incompletely understood. We report the first ever magnesium pyrophosphate (MgPPi) urinary stone, which prompted the new diagnosis of HPP in a 12-year-old boy. Stone analysis labs should include infrared spectra of PPi salts in their reference libraries to facilitate identification of these rare but clinically important stones.

Zn2P2O7, a representative material in the A2P2O7 family, exhibits negative thermal expansion (NTE) and possesses a remarkable negative linear expansion coefficient. Here we employ variable temperature and high-pressure Raman spectroscopy to investigate the phonon anomalies arising from the α- to β-phase transition in Zn2P2O7. Combing with the refinement results of our X-ray diffraction (XRD) experiment, we have identified the specific variations of the bond lengths, bond angles and the polyhedral distortion indexes that result in the phonon anomalies. Some certain phonons, whose energy decreases with increasing pressure, have been demonstrated to give rise to negative Grüneisen parameters that can characterize phonon anharmonicity and lead to lower thermal expansion in the α-phase of Zn2P2O7 compared to the β-phase. These results provide new insight into the relationship between lattice deformation and phonon anomalies during the structural phase transition in the NTE material Zn2P2O7.

Simple Summary: Vascular calcification is associated with cardiovascular complications due to accelerated arterial stiffening and atherosclerosis. A large body of evidence suggests that two principal processes are involved in vascular calcification: a passive process and an active process. In this review, we summarize the most important processes and risk factors involved in the complex process of vascular calcification. The primary cause of worldwide mortality and morbidity stems from complications in the cardiovascular system resulting from accelerated atherosclerosis and arterial stiffening. Frequently, both pathologies are associated with the pathological calcification of cardiovascular structures, present in areas such as cardiac valves or blood vessels (vascular calcification). The accumulation of hydroxyapatite, the predominant form of calcium phosphate crystals, is a distinctive feature of vascular calcification. This phenomenon is commonly observed as a result of aging and is also linked to various diseases such as diabetes, chronic kidney disease, and several genetic disorders. A substantial body of evidence indicates that vascular calcification involves two primary processes: a passive process and an active process. The physicochemical process of hydroxyapatite formation and deposition (a passive process) is influenced significantly by hyperphosphatemia. However, the active synthesis of calcification inhibitors, including proteins and low-molecular-weight inhibitors such as pyrophosphate, is crucial. Excessive calcification occurs when there is a loss of function in enzymes and transporters responsible for extracellular pyrophosphate metabolism. Current in vivo treatments to prevent calcification involve addressing hyperphosphatemia with phosphate binders and implementing strategies to enhance the availability of pyrophosphate. [ABSTRACT FROM AUTHOR]

The study examined the composition and forms of iron and aluminium oxides in benchmark soils of central southwestern Nigeria. Soils developed from distinct parent rock types, including coarse-grained granite and gneiss, fine grained biotite gneiss and schist, and the amphibolite complex which correspond to the parent rocks of the soils of Iwo (Typic Paleustults), Egbeda (Rhodic Kandiustults) and Itagunmodi (Typic Haplustults) Associations, respectively, were selected for the study. Notably, these soils collectively encompass approximately 60% of the total land area in central southwestern Nigeria. The less than 2 mm soil fractions were pre-treated with hydrogen peroxide to remove soil organic matter. Thereafter, oxides of Fe and Al were extracted using three different extractants: dithionite-citrate-bicarbonate (DCB) mixtures, acidified ammonium oxalate and sodium pyrophosphate solution. The quantification of Fe and Al oxides contents in the respective extracts were carried out using Inductively Coupled Plasma—Atomic Emission Spectrometry. The research findings indicated that the DCB extractable forms of Fe and Al oxides were more abundant compared to other forms of these oxides, and a substantial portion of these oxides within the soils existed in crystalline form. Among the soil series studied, Itagunmodi series exhibited the highest amount of DCB- and oxalate extractable Fe oxides, while Iwo series had the highest content of Fe and Al oxides extracted by sodium pyrophosphate solution. Importantly, the presence of Fe oxides were found to negatively impact the reactivity of SOM in the soils. [ABSTRACT FROM AUTHOR]

Vigna radiata H+–translocating pyrophosphatases (VrH+-PPases, EC 3.6.1.1) are present in various endomembranes of plants, bacteria, archaea, and certain protozoa. They transport H+ into the lumen by hydrolyzing pyrophosphate, which is a by-product of many essential anabolic reactions. Although the crystal structure of H+-PPases has been elucidated, the H+ translocation mechanism of H+-PPases in the solution state remains unclear. In this study, we used hydrogen–deuterium exchange (HDX) coupled with mass spectrometry (MS) to investigate the dynamics of H+-PPases between the previously proposed R state (resting state, Apo form), I state (intermediate state, bound to a substrate analog), and T state (transient state, bound to inorganic phosphate). When hydrogen was replaced by proteins in deuterium oxide solution, the backbone hydrogen atoms, which were exchanged with deuterium, were identified through MS. Accordingly, we used deuterium uptake to examine the structural dynamics and conformational changes of H+-PPases in solution. In the highly conserved substrate binding and proton exit regions, HDX-MS revealed the existence of a compact conformation with deuterium exchange when H+-PPases were bound with a substrate analog and product. Thus, a novel working model was developed to elucidate the in situ catalytic mechanism of pyrophosphate hydrolysis and proton transport. In this model, a proton is released in the I state, and the TM5 inner wall serves as a proton piston. [ABSTRACT FROM AUTHOR]

The deposition of calcium pyrophosphate (CPP) crystals in joint tissues causes acute and chronic arthritis that commonly affect the adult and elderly population. Experimental calcium pyrophosphate deposition disease (CPPD) models are divided into genetically modified models and crystal-induced inflammation models. The former do not reproduce phenotypes overlapping with the human disease, while in the latter, the direct injection of crystals into the ankles, dorsal air pouch or peritoneum constitutes a useful and reliable methodology that resembles the CPP induced-inflammatory condition in humans. The translational importance of the induced model is also strengthened by the fact that the key molecular and cellular mediators involved in inflammation are shared between humans and laboratory rodents. Although, in vivo models are indispensable tools for studying the pathogenesis of the CPPD and testing new therapies, their development is still at an early stage and major efforts are needed to address this issue. Here, we analyze the strenghts and limitations of each currently available CPPD in vivo model, and critically discuss their translational value.

Urolithiasis is one of the most frequently occurring diseases worldwide. Its management is related on investigation of concretion composition which helps to assess the current therapy. Fourier-transform infrared (FTIR) spectrometry gains significant importance because of its ability to determine concretion composition. Presented review shows the use of FTIR spectroscopy in detection of the very rare urinary stones including cyanoacrylate and pyrophosphate. Infrared spectroscopy made possible to identify the nature of the concretions and helped in management of urolithiasis. [ABSTRACT FROM AUTHOR]

Two siblings showed increased galactose and galactose-related metabolites in neonatal screening. Diagnostic workup did not reveal abnormalities in any of the known disease-causing enzymes involved in galactose metabolism. Using whole-exome sequencing, we identified a homozygous missense variant in PPA1 encoding the cytosolic pyrophosphatase 1 (PPA1), c.557C>T (p.Thr186Ile). The enzyme activity of PPA1 was determined using a colorimetric assay, and the protein content was visualized via western blotting in skin fibroblasts from one of the affected individuals. The galactolytic activity of the affected fibroblasts was determined by measuring extracellular acidification with a Seahorse XFe96 analyzer. PPA1 activity decreased to 22% of that of controls in the cytosolic fraction of homogenates from patient fibroblasts. PPA1 protein content decreased by 50% according to western blot analysis, indicating a reduced stability of the variant protein. The extracellular acidification rate was reduced in patient fibroblasts when galactose was used as a substrate. Untargeted metabolomics of blood samples revealed an elevation of other metabolites related to pyrophosphate metabolism. Besides hyperbilirubinemia in the neonatal period in one child, both children were clinically unremarkable at the ages of 3 and 14 years, respectively. We hypothesize that the observed metabolic derangement is a possible mild manifestation of PPA1 deficiency. Unresolved abnormalities in galactosemia screening might result in the identification of more individuals with PPA1 deficiency, a newly discovered inborn metabolic disorder (IMD). [ABSTRACT FROM AUTHOR]

Bone growth plate abnormalities and skull shape defects are seen in hypophosphatasia, a heritable disorder in humans that occurs due to the deficiency of tissue nonspecific alkaline phosphatase (TNAP, Alpl) enzyme activity. The abnormal development of the cranial base growth plates (synchondroses) and abnormal skull shapes have also been demonstrated in global Alpl−/− mice. To distinguish local vs. systemic effects of TNAP on skull development, we utilized P0-Cre to knockout Alpl only in cranial neural crest-derived tissues using Alpl flox mice. Here, we show that Alpl deficiency using P0-Cre in cranial neural crest leads to skull shape defects and the deficient growth of the intersphenoid synchondrosis (ISS). ISS chondrocyte abnormalities included increased proliferation in resting and proliferative zones with decreased apoptosis in hypertrophic zones. ColX expression was increased, which is indicative of premature differentiation in the absence of Alpl. Sox9 expression was increased in both the resting and prehypertrophic zones of mutant mice. The expression of Parathyroid hormone related protein (PTHrP) and Indian hedgehog homolog (IHH) were also increased. Finally, cranial base organ culture revealed that inorganic phosphate (Pi) and pyrophosphate (PPi) have specific effects on cell signaling and phenotype changes in the ISS. Together, these results demonstrate that the TNAP expression downstream of Alpl in growth plate chondrocytes is essential for normal development, and that the mechanism likely involves Sox9, PTHrP, IHH and PPi. [ABSTRACT FROM AUTHOR]

Gout, calcium pyrophosphate deposition disease, and apatite calcifications, the three main crystal disorders, may involve the spine. These disorders can be completely asymptomatic or associated with various clinical symptoms, such as acute flares and more chronic manifestations. This article presents the typical and more unusual imaging features encountered in these disorders. [ABSTRACT FROM AUTHOR]

In this paper, a novel amino acid surface-functionalized semiconductor CdTe quantum dot fluorescent probe amidated by carboxyl and amide groups was synthesized to detect pyrophosphate ions (P2O74−, PPi). L-Arginine (L-Arg) was grafted onto cysteine modified CdTe quantum dots (Mea-CdTe QDs) to form a new L-Arginine-functionalized quantum dot fluorescent probe (L-Arg@Mea-CdTe). The prepared probe has good optical properties with multiple grafted functional groups on the surface. The guanidine group of the L-Arg@Mea-CdTe fluorescent probe is strongly basic and will be fully protonated under physiological conditions. The resulting hydrogen bonds bound to pyrophosphate lead to significant changes in the fluorescence of CdTe quantum dots. IR and XPS characterization were performed to confirm it. The addition of PPi induces a significant fluorescence quenching of L-Arg@Mea-CdTe in aqueous solution. The fluorescent QDs probe can also detect pyrophosphate with good sensitivity and anti-interference performance. The detection limit of the L-Arg@Mea-CdTe fluorescence probe for PPi is as low as 0.30 μM. In addition, the novel nano-fluorescent probe was successfully applied to detect PPi in water and in cell imaging. [ABSTRACT FROM AUTHOR]

Ni–W alloys with a (2 2 0) or (1 1 1) preferred orientation growth and amorphous structure were prepared from a pyrophosphate bath using the electrodeposition method. Structure transformation can be the result of the bath temperature (Tb) and the concentration of sodium tungstate (CW) in the bath. Increasing the Tb and CW can change the crystal growth from (2 2 0) to (1 1 1). At a higher Tb and CW, an amorphous Ni–W alloy can be obtained. The tungsten content in the coatings should be responsible for the structure change. The three textured Ni–W alloys with a (2 2 0) texture, (1 1 1) texture and amorphous structure were annealed at different temperatures ranging from 200 to 700 °C. The microhardness, corrosion resistance and HER of the as-deposited and annealed Ni–W alloys were comparatively studied. The results show that the microhardness of the amorphous Ni–W alloy is the highest and reaches 1028 HV after annealing at 400 °C. The (2 2 0)-textured Ni–W alloy has the best corrosion resistance, which is further improved after annealing, while the HER activity of the (1 1 1) textured Ni-W alloy is superior. [ABSTRACT FROM AUTHOR]

Large negative thermal expansion (NTE) was achieved at room temperature using the structural phase transition in Zn2P2O7. Particularly, Zn1.6Mg0.4P2O7 has a negative coefficient of linear thermal expansion αL of about –60 ppm/K at temperatures of 289–374 K. Co-doping of Mg and another element at the Zn site was found to be effective for control of NTE properties and for improvement of thermal expansion compensating ability. The present phosphates are expected to have widely various practical applications as thermal expansion compensators because they contain no toxic or expensive elements. Moreover, they can be prepared using a simple solid-state reaction method in air. [ABSTRACT FROM AUTHOR]

The increased use of silica and silicon-containing nanoparticles (Si-NP) in agricultural applications has stimulated interest in determining their potential migration in the environment and their uptake by living organisms. Understanding the fate and behavior of Si-NPs will require their accurate analysis and characterization in very complex environmental matrices. In this study, we investigated Si-NP analysis in soil using single-particle ICP-MS. A magnetic sector instrument was operated at medium resolution to overcome the impact of polyatomic interferences (e.g., 14N14N and 12C16O) on 28Si determinations. Consequently, a size detection limit of 29 ± 3 nm (diameter of spherical SiO2 NP) was achieved in Milli-Q water. Si-NP were extracted from agricultural soil using several extractants, including Ca(NO3)2, Mg(NO3)2, BaCl2, NaNO3, Na4P2O7, fulvic acid (FA) and Na2H2EDTA. The best extraction efficiency was found for Na4P2O7, for which the size distribution of Si-NP in the leachates was well preserved for at least one month. On the other hand, Ca(NO3)2, Mg(NO3)2 and BaCl2 were relatively less effective and generally led to particle agglomeration. A time-of-flight ICP-MS was also used to examine the nature of the extracted Si-NP on a single-particle basis. Aluminosilicates accounted for the greatest number of extracted NP (~46%), followed by NP where Si was the only detected metal (presumably SiO2, ~30%). [ABSTRACT FROM AUTHOR]

Background: Citrate is the only anticoagulant currently Food and Drug Administration (FDA)‐approved for the long‐term storage of blood for transfusion. Citrate inhibits phosphofructokinase and may play a pro‐inflammatory role, suggesting that there may be an advantage to using alternative anticoagulants. Here, we examine the use of pyrophosphate as an anticoagulant. Study design and methods: Whole blood samples from healthy donors were anticoagulated either with citrate–phosphate–adenine–dextrose (CPDA‐1) or our novel anticoagulant mixture pyrophosphate‐phosphate–adenine–dextrose (PPDA‐1). Samples were assessed for coagulation capacity by thromboelastography immediately after anticoagulation (T0) with and without recalcification, as well as 5 hours after anticoagulation (T1) with recalcification. Complete blood counts were taken at both timepoints. Flow cytometry to evaluate platelet activation as well as blood smears to evaluate cellular morphology were performed at T1. Results: No clotting was detected in samples anticoagulated with either solution without recalcification. After recalcification, clotting function was restored in both groups. R‐Time in recalcified PPDA‐1 samples was shorter than in CPDA‐1 samples. A reduction in platelet count at T1 compared to T0 was observed in both groups. No significant platelet activation was observed in either group at T1. Blood smear indicated platelet clumping in PPDA‐1. Conclusion: We have shown initial proof of concept that pyrophosphate functions as an anticoagulant at the dose used in this study, though there is an associated loss of platelets over time that may limit its usefulness for blood storage. Further dose optimization of pyrophosphate may limit or reduce the loss of platelets. [ABSTRACT FROM AUTHOR]

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A novel pyrophosphate Na7Ni3Fe(P2O7)4 was synthesized in two distinct forms, single-crystal and powder. Single-crystal X-ray diffraction was used to determine the crystal structure, and powder X-ray diffraction and scanning electron microscopy were used to examine the purity and morphology of the elaborated powder. This phosphate crystallizes in the P 1 ¯ space group of the triclinic system with a = 6.3677 (2) Å, b = 9.3316 (4) Å, c = 10.8478 (4) Å, α = 65.191 (1)°, β = 80.533 (1)° and γ = 73.042 (1)°. The crystal framework is assembled from the linkage of centro-symmetrical clusters Ni2(Ni/Fe)2P4O28. Each cluster consists of two (Fe1/Ni1)O6 octahedra, two Ni2O6 octahedra and two P2O7 units. The linkage of these clusters is provided by two other P2O7 units to generate a three-dimensional structure with distinct tunnels in the [100], [010] and [001] directions, housing the Na+ cations. The infrared and Raman analyses show the characteristic bands of the pyrophosphate anion P2O74−. Remarkably, the magnetic investigations revealed the coexistence of two magnetic transitions at ~29 K and ~4.5 K with dominating antiferromagnetic interactions. [ABSTRACT FROM AUTHOR]

Selective and sensitive detection of inorganic pyrophosphate (PPi) are of great significance both for clinical applications and fundamental research. In this work, a ratiometric fluorescent probe was developed by decorating a porphyrin‐based metal‐organic framework (PCN‐224) with sulfur nanodots (S‐dots). The red‐fluorescence of PCN‐224 was significantly promoted (more than 6‐fold) by S‐dots through inhibiting molecular motion of porphyrin ligand, which also provided active sites for the detection of Cu2+ and PPi. Cu2+ could selectively quench the red‐fluorescence of PCN‐224 through coordination with porphyrin ligand, and the competition reaction between PPi and Cu2+ resulted in the decomposing of coordination and recovery of red‐fluorescence. The blue‐fluorescence from S‐dots was deemed as effective reference, which provided a built‐in correction in complex environments. Based on these photophysical properties, a ratiometric fluorescence assay was developed for the quantitative detection of Cu2+ and PPi, with a limit of detection of 0.11 and 2.66 μM, respectively. The accuracy and practical applications of assays were also demonstrated by detection in tap water and human serum samples. [ABSTRACT FROM AUTHOR]

Red phosphors play a key role in improving the optical quality of white light emitting diodes (WLEDs). In this work, Eu3+-activated red-emitting pyrophosphate phosphors of NaREP 2 O 7 :Eu3+ (RE = Sc, Lu) were prepared and the comparative investigations on crystal structures and luminescent properties were carried out. The X-ray diffraction (XRD), scanning electron microscope (SEM), and spectroscopy techniques were employed to characterize the materials. The features of crystal structures with regard to the Eu3+ doping were analyzed in detail on the basis of Rietveld crystal structure refinements. It is found that the Eu3+ tends to substitute Lu3+ in the NaLuP 2 O 7 :Eu3+, while in NaScP 2 O 7 :Eu3+ it tends to substitute Na+ due the principle of ionic size matching. The disparate selective occupation behaviour of Eu3+ ion in both crystals has resulted in a certain difference in fluorescence emission nature from each other. The doping concentration of Eu3+ was optimized for the strongest luminescence under near-ultraviolet (UV) excitation. The measurement of temperature-dependent luminescence showed that the emission of NaLuP 2 O 7 :Eu3+ at 150 °C maintained 77% of that at room temperature, and that for NaScP 2 O 7 :Eu3+ is 72%. Under the near-UV excitation, the fluorescence efficiency of the phosphors were assessed. The quantum efficiencies of NSPO:0.125Eu3+ and NLPO:0.125Eu3+ were measured to be 41.6% and 40.8%, respectively. The results imply that the Eu3+-activated pyrophosphate phosphors are promising red-emitting components in WLEDs. [ABSTRACT FROM AUTHOR]

Conventionally, ATP is considered to be the principal energy source in cells. However, over the last few years, a novel role for ATP as a potent extracellular signaling molecule and the principal source of extracellular pyrophosphate, the main endogenous inhibitor of vascular calcification, has emerged. A large body of evidence suggests that two principal mechanisms are involved in the initiation and progression of ectopic calcification: high phosphate concentration and pyrophosphate deficiency. Pathologic calcification of cardiovascular structures, or vascular calcification, is a feature of several genetic diseases and a common complication of chronic kidney disease, diabetes, and aging. Previous studies have shown that the loss of function of several enzymes and transporters involved in extracellular ATP/pyrophosphate metabolism is associated with vascular calcification. Therefore, pyrophosphate homeostasis should be further studied to facilitate the design of novel therapeutic approaches for ectopic calcification of cardiovascular structures, including strategies to increase pyrophosphate concentrations by targeting the ATP/pyrophosphate metabolism cycle. [ABSTRACT FROM AUTHOR]

Lignocellulosic biomass is an abundant and renewable source of carbon for chemical manufacturing, yet it is cumbersome in conventional processes. A promising, and increasingly studied, candidate for lignocellulose bioprocessing is the thermophilic anaerobe Clostridium thermocellum given its potential to produce ethanol, organic acids, and hydrogen gas from lignocellulosic biomass under high substrate loading. Possessing an atypical glycolytic pathway which substitutes GTP or pyrophosphate (PP i) for ATP in some steps, including in the energy-investment phase, identification, and manipulation of PP i sources are key to engineering its metabolism. Previous efforts to identify the primary pyrophosphate have been unsuccessful. Here, we explore pyrophosphate metabolism through reconstructing, updating, and analyzing a new genome-scale stoichiometric model for C. thermocellum , i CTH669. Hundreds of changes to the former GEM, i CBI655, including correcting cofactor usages, addressing charge and elemental balance, standardizing biomass composition, and incorporating the latest experimental evidence led to a MEMOTE score improvement to 94%. We found agreement of i CTH669 model predictions across all available fermentation and biomass yield datasets. The feasibility of hundreds of PP i synthesis routes, newly identified and previously proposed, were assessed through the lens of the i CTH669 model including biomass synthesis, tRNA synthesis, newly identified sources, and previously proposed PP i -generating cycles. In all cases, the metabolic cost of PP i synthesis is at best equivalent to investment of one ATP suggesting no direct energetic advantage for the cofactor substitution in C. thermocellum. Even though no unique source of PP i could be gleaned by the model, by combining with gene expression data two most likely scenarios emerge. First, previously investigated PP i sources likely account for most PP i production in wild-type strains. Second, alternate metabolic routes as encoded by i CTH669 can collectively maintain PP i levels even when previously investigated synthesis cycles are disrupted. Model i CTH669 is available at github.com/maranasgroup/iCTH669. • Lignocellulolytic Clostridium thermocellum glycolysis is pyrophosphate (PP i)-driven. • A highly curated genome-scale model, i CTH669, of C. thermocellum is reconstructed. • i CTH669 recapitulates recent yield data of ten PP i -linked knockout strains. • Previously proposed and newly identified sources of PP i were investigated. • PP i sources are evaluated by i CTH669, genomics, thermodynamics, and transcriptomics. [ABSTRACT FROM AUTHOR]

In this review, we will summarize a selection of articles on single-photon emission computed tomography published in the Journal of Nuclear Cardiology in 2022. The aim of this review is to concisely recap major advancements in the field to provide the reader a glimpse of the research published in the journal over the last year. This review will place emphasis on myocardial perfusion imaging using single-photon emission computed tomography summarizing advances in the field including in prognosis, non-perfusion variables, attenuation compensation, machine learning and camera design. It will also review nuclear imaging advances in amyloidosis, left ventricular mechanical dyssynchrony, cardiac innervation, and lung perfusion. We encourage interested readers to go back to the original articles, and editorials, for a comprehensive read as necessary but hope that this yearly review will be helpful in reminding readers of articles they have seen and attracting their attentions to ones they have missed. [ABSTRACT FROM AUTHOR]

Inorganic pyrophosphate anions (PPi) play a key role in various biological processes and act as an essential indicator for physiological function evaluation and disease diagnosis. However, there is still a lack of available approaches for straightforward, robust, and convenient PPi detection. Herein, we design an on-off-on fluorescent switching nanoprobe employing Fe3+-mediated fluorescent sulfur quantum dots (SQDs) for highly robust detection of PPi. The bovine serum protein (BSA)-capped SQDs with fine water dispersibility and good optical stability are synthesized by an H2O2-assisted chemical etching reaction. Specifically, Fe3+ can strongly induce the aggregation of the SQDs into relatively larger sizes, resulting in aggregation-induced fluorescence quenching behavior. PPi can selectively bind with Fe3+ via emulative coordination and in preventing the aggregation of SQDs this is accompanied by recovery of fluorescence. The physicochemical properties of aggregated and disaggregated SQDs have been systematically investigated. Aggregation and disaggregation of the SQDs and the corresponding quenching and recovery of fluorescence occurs and guarantees the high-contrast sensing performance of the SQD system in complex and challenging aquatic environments. Our designed on-off-on nanoswitch holds great potential for the design of elemental quantum dot-based biosensors for the highly robust detection of analytes in the near future. [ABSTRACT FROM AUTHOR]

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The primary cause of worldwide mortality and morbidity stems from complications in the cardiovascular system resulting from accelerated atherosclerosis and arterial stiffening. Frequently, both pathologies are associated with the pathological calcification of cardiovascular structures, present in areas such as cardiac valves or blood vessels (vascular calcification). The accumulation of hydroxyapatite, the predominant form of calcium phosphate crystals, is a distinctive feature of vascular calcification. This phenomenon is commonly observed as a result of aging and is also linked to various diseases such as diabetes, chronic kidney disease, and several genetic disorders. A substantial body of evidence indicates that vascular calcification involves two primary processes: a passive process and an active process. The physicochemical process of hydroxyapatite formation and deposition (a passive process) is influenced significantly by hyperphosphatemia. However, the active synthesis of calcification inhibitors, including proteins and low-molecular-weight inhibitors such as pyrophosphate, is crucial. Excessive calcification occurs when there is a loss of function in enzymes and transporters responsible for extracellular pyrophosphate metabolism. Current in vivo treatments to prevent calcification involve addressing hyperphosphatemia with phosphate binders and implementing strategies to enhance the availability of pyrophosphate.

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Inorganic pyrophosphate (PPi) is a crucial extracellular mineralization regulator. Low plasma PPi concentrations underlie the soft tissue calcification present in several rare hereditary mineralization disorders as well as in more common conditions like chronic kidney disease and diabetes. Even though deregulated plasma PPi homeostasis is known to be linked to multiple human diseases, there is currently no reliable assay for its quantification. We here describe a PPi assay that employs the enzyme ATP sulfurylase to convert PPi into ATP. Generated ATP is subsequently quantified by firefly luciferase–based bioluminescence. An internal ATP standard was used to correct for sample-specific interference by matrix compounds on firefly luciferase activity. The assay was validated and shows excellent precision (< 3.5%) and accuracy (93–106%) of PPi spiked into human plasma samples. We found that of several anticoagulants tested only EDTA effectively blocked conversion of ATP into PPi in plasma after blood collection. Moreover, filtration over a 300,000-Da molecular weight cut-off membrane reduced variability of plasma PPi and removed ATP present in a membrane-enclosed compartment, possibly platelets. Applied to plasma samples of wild-type and Abcc6−/− rats, an animal model with established low circulating levels of PPi, the new assay showed lower variability than the assay that was previously in routine use in our laboratory. In conclusion, we here report a new and robust assay to determine PPi concentrations in plasma, which outperforms currently available assays because of its high sensitivity, precision, and accuracy. [ABSTRACT FROM AUTHOR]

Polyphosphate fertilizer is an alternative to traditional orthophosphate fertilizer, but it is unclear whether it provides greater soil phosphorus (P) mobility and availability than orthophosphate fertilizer. This study aimed to examine the chemical behaviour of polyphosphate after its application to the soil. The hydrolysis, sorption, and P transformation of two types of polyphosphate fertilizers (short‐chain and long‐chain) were examined for two types of soils (acidic Acrisol and calcareous Cambisol), with orthophosphate serving as the control treatment. 31P NMR spectroscopic analyses indicated that polyphosphate in soil was rapidly converted to pyrophosphate, which was then hydrolyzed to orthophosphate at a slower rate. In general, in the calcareous Cambisol, the addition of short‐chain polyphosphate fertilizer resulted in greater soil P mobility as measured by greater soil pore water orthophosphate concentration than the control. Thus, short‐chain polyphosphate fertilizer tended to be more effective than orthophosphate in calcareous soils. This was in contrast to the result of an aqueous incubation experiment, in which a lower pH increased the rate of polyphosphate hydrolysis. Indeed, in both soils, the sorption of total P was greater when P was added as polyphosphate than when it was added as orthophosphate. Moreover, polyphosphate sorption appeared to be mainly controlled by soil iron and aluminium minerals, because the Acrisol showed stronger polyphosphate sorption than the Cambisol due to its greater amorphous iron content. It appears that polyphosphate was first adsorbed on soil minerals before being hydrolyzed to release orthophosphate, and calcium may have played an important role in the hydrolysis of polyphosphate as evidenced by the greater P release in calcareous Cambisol. Our results suggest that soil characteristics, such as acidity, iron, aluminium, and calcium content, should be considered when evaluating the P efficiency of polyphosphate fertilizers. Highlights: 31P NMR spectroscopy successfully tracked the fate of added Poly‐P in soilPoly‐P was rapidly converted to Pyro‐P, and then hydrolyzed to Ortho‐P slowlyP supplied as Poly‐P had stronger sorption affinity than Ortho‐P in all soilsShort‐chain Poly‐P induced greater P mobility than Ortho‐P in Cambisol but not in Acrisol [ABSTRACT FROM AUTHOR]

Novel sulfur and selenium substituted 5′,5′-linked dinucleoside pyrophate analogues were prepared in a vibration ball mill from the corresponding persilylated monophosphate. The chemical hydrolysis of pyrophosphorochalcogenolate-linked dimers was studied over a wide pH-range. The effect of the chalcogeno-substitution on the reactivity of dinucleoside pyrophosphates was surprisingly modest, and the chemical stability is promising considering the potential therapeutic or diagnostic applications. The chemical stability of the precursor phosphorochalcogenolate monoesters was also investigated. Hydrolytic desilylation of these materials was effected in aqueous buffer at pH 3, 7 or 11 and resulted in phosphorus-chalcogen bond scission which was monitored using 31P NMR. The rate of dephosphorylation was dependent upon both the nature of the chalcogen and the pH. The integrity of the P-S bond in the corresponding phosphorothiolate was maintained at high pH but rapidly degraded at pH 3. In contrast, P-Se bond cleavage of the phosphoroselenolate monoester was rapid and the rate increased with alkalinity. The results obtained in kinetic experiments provide insight on the reactivity of the novel pyrophosphates studied as well as of other types of thiosubstituted biological phosphates. At the same time, these results also provide evidence for possible formation of unexpectedly reactive intermediates as the chalcogen-substituted analogues are metabolised. [ABSTRACT FROM AUTHOR]

ABCC6 promotes ATP efflux from hepatocytes to bloodstream. ATP is metabolized to pyrophosphate, an inhibitor of ectopic calcification. Pathogenic variants of ABCC6 cause pseudoxanthoma elasticum, a highly variable recessive ectopic calcification disorder. Incomplete penetrance may initiate disease heterogeneity, hence symptoms may not, or differently manifest in carriers. Here, we investigated whether incomplete penetrance is a source of heterogeneity in pseudoxanthoma elasticum. By integrating clinical and genetic data of 589 patients, we created the largest European cohort. Based on allele frequency alterations, we identified two incomplete penetrant pathogenic variants, c.2359G>A (p.Val787Ile) and c.1171A>G (p.Arg391Gly), with 6.5% and 2% penetrance, respectively. However, when penetrant, the c.1171A>G (p.Arg391Gly) manifested a clinically unaltered severity. After applying in silico and in vitro characterization, we suggest that incomplete penetrant variants are only deleterious if a yet unknown interacting partner of ABCC6 is mutated simultaneously. The low penetrance of these variants should be contemplated in genetic counseling. [ABSTRACT FROM AUTHOR]

[Display omitted] • A highly sensitive Zn2+ and PPi sensor LP was synthesized based on bicarboxaminoquinoline. • LP showed well water solubility, the low LOD, fast response time, and wide linear range for sensing Zn2+ and PPi. • The INHIBIT logic gate was constructed by using the reversibility of LP. • LP was applied for the detection of Zn2+ and PPi in two real water samples and cells imaging. A new ratiometric fluorescent sensor (LP) based on bicarboxaminoquinoline was designed and synthesized for sequentially recognizing Zn2+ and PPi. In aqueous solution, LP exhibited the ratiometric fluorescence response towards Zn2+, along with the about 4-folds enhancement of fluorescence quantum yield. Subsequently, the LP -Zn2+ complex displayed the fluorescence recovery upon adding PPi through the displacement strategy. And the LODs of LP and its Zn2+ complex for sensing Zn2+ and PPi were found to be 15 nM and 5.5 nM, respectively. Notably, the reversibility of LP for sequentially sensing Zn2+ and PPi had been employed to construct the INHIBIT logic gate. Moreover, LP and its Zn2+ complex had been successfully utilized for the detection of Zn2+ and PPi in two real water samples and cells imaging. [ABSTRACT FROM AUTHOR]

This work shows the importance of inorganic materials Li 2 CuP 2 O 7 and Na 2 CuP 2 O 7 , especially the effect of Li and Na atoms, in their use as inhibitors that preserve Mild steel in 1.0 M HCl solution. Lithium and Sodium copper (II) pyrophosphate crystals were synthesized through solid-state reaction and characterized using Infrared Spectroscopy technique (IR), as well as X-ray diffraction (XRD). The infrared spectrum of compounds Li 2 CuP 2 O 7 and Na 2 CuP 2 O 7 was captured and interpreted, revealing a bent POP bridging angle within these compounds. Furthermore, the inhibitory effect of these pyrophosphates on Mild steel corrosion in a 1.0 M HCl solution was studied. During this investigation, electrochemical techniques alongside surface examination through SEM and EDX. The experimental findings demonstrated that Li 2 CuP 2 O 7 and Na 2 CuP 2 O 7 act as effective inhibitors, with inhibition efficiency ( η PP %) rising as the inhibitor concentration increases. At a concentration of 10−3 M, Li 2 CuP 2 O 7 exhibited a remarkable inhibition efficiency of 93 %, which appears to be mixed-type inhibitors. [Display omitted] • Innovative synthesis & characterization of Li 2 CuP 2 O 7 and Na 2 CuP 2 O 7 , advancing corrosion inhibition. • Demonstrated high efficacy as anticorrosion agents for mild steel in 1.0 M HCl, up to 93 % inhibition. • Observed mixed-type inhibition & increased efficiency with inhibitor concentration. • Utilized advanced techniques, the protective layer was analyzed by SEM and EDX. [ABSTRACT FROM AUTHOR]

Sensitive and accurate analysis of pyrophosphate (PPi) is of great importance for preventing health hazard in environment. Nevertheless, most of sensors focus on sensitivity and selectivity, but practicality is also a significant quota. How to reconciling sensitivity, selectivity and practicability in one single sensor is desirable but remains challenging. Here, we created a novel metal-carbon nanozyme V 2 O 5 @C with two-dimensional (2D) morphology and high yet exclusive peroxidase (POD)-like activity via a glucose and NH 4 NO 4 -co-directed avenue, and further showed its application in constructing a portable and disposable paper-based analytical chip (PA-chip) for rapid, visual and onsite analysis of PPi. PPi etched V 2 O 5 to prevent the decomposition of H 2 O 2 into ·OH, resulting in weakened POD-like activity. In comparison with PPi deficiency, colorless TMB couldn't be oxidized into oxidized TMB with a dropped absorption at 652 nm. Therefore, obviously shallowed blue color on PA-chip surface was recorded, and demonstrated a negative relationship with PPi dosage, enabling rapid and visual detection of PPi with a limit of detection of 2.6 nM. This study demonstrated the burgeoning applications of nanozymes with POD-like activity in construction of PA-chips for PPi and will quicken the advancement of practical sensors, guaranteeing environmental safety. [Display omitted] • A glucose and NH 4 NO 3 -co-directed avenue for preparing 2D V 2 O 5 @C was proposed. • It stood out high yet exclusive POD-like activity via decomposing H 2 O 2 into ·OH. • A portable and disposable PA-chip was successfully constructed based on 2D V 2 O 5 @C. • It achieved rapid and visual analysis of PPi with LOD of 2.6 nM. [ABSTRACT FROM AUTHOR]

Ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) codes for a type 2 transmembrane glycoprotein which hydrolyzes extracellular phosphoanhydrides into bio-active molecules that regulate, inter alia , ectopic mineralization, bone formation, vascular endothelial proliferation, and the innate immune response. The clinical phenotypes produced by ENPP1 deficiency are disparate, ranging from life-threatening arterial calcifications to cutaneous hypopigmentation. To investigate associations between disease phenotype and enzyme activity we quantified the enzyme velocities of 29 unique ENPP1 pathogenic variants in 41 patients enrolled in an NIH study along with 33 other variants reported in literature. We correlated the relative enzyme velocities with the presenting clinical diagnoses, performing the catalytic velocity measurements simultaneously in triplicate using a high-throughput assay to reduce experimental variation. We found that ENPP1 variants associated with autosomal dominant phenotypes reduced enzyme velocities by 50 % or more, whereas variants associated with insulin resistance had non-significant effects on enzyme velocity. In Cole disease the catalytic velocities of ENPP1 variants associated with AD forms trended to lower values than those associated with autosomal recessive forms – 8-32 % vs. 33 % of WT, respectively. Additionally, ENPP1 variants leading to life-threatening vascular calcifications in GACI patients had widely variable enzyme activities, ranging from no significant differences compared to WT to the complete abolishment of enzyme velocity. Finally, disease severity in GACI did not correlate with the mean enzyme velocity of the variants present in affected compound heterozygotes but did correlate with the more severely damaging variant. In summary, correlation of ENPP1 enzyme velocity with disease phenotypes demonstrate that enzyme velocities below 50 % of WT levels are likely to occur in the context of autosomal dominant disease (due to a monoallelic variant), and that disease severity in GACI infants correlates with the more severely damaging ENPP1 variant in compound heterozygotes, not the mean velocity of the pathogenic variants present. • ENPP1 pathogenic variants induce disease in AR and AD inheritance patterns. • ENPP1 enzyme velocities <50% induced disease phenotypes in an AD manner. • Compound GACI patients possessed pathogenic variants without reduced activity. • Disease severity in GACI correlated with the more severely damaging ENPP1 allele. • Variants associated with metabolic syndrome exhibit WT catalytic activities. [ABSTRACT FROM AUTHOR]

Two siblings showed increased galactose and galactose-related metabolites in neonatal screening. Diagnostic workup did not reveal abnormalities in any of the known disease-causing enzymes involved in galactose metabolism. Using whole-exome sequencing, we identified a homozygous missense variant in PPA1 encoding the cytosolic pyrophosphatase 1 (PPA1), c.557C>T (p.Thr186Ile). The enzyme activity of PPA1 was determined using a colorimetric assay, and the protein content was visualized via western blotting in skin fibroblasts from one of the affected individuals. The galactolytic activity of the affected fibroblasts was determined by measuring extracellular acidification with a Seahorse XFe96 analyzer. PPA1 activity decreased to 22% of that of controls in the cytosolic fraction of homogenates from patient fibroblasts. PPA1 protein content decreased by 50% according to western blot analysis, indicating a reduced stability of the variant protein. The extracellular acidification rate was reduced in patient fibroblasts when galactose was used as a substrate. Untargeted metabolomics of blood samples revealed an elevation of other metabolites related to pyrophosphate metabolism. Besides hyperbilirubinemia in the neonatal period in one child, both children were clinically unremarkable at the ages of 3 and 14 years, respectively. We hypothesize that the observed metabolic derangement is a possible mild manifestation of PPA1 deficiency. Unresolved abnormalities in galactosemia screening might result in the identification of more individuals with PPA1 deficiency, a newly discovered inborn metabolic disorder (IMD).

Ferric ions (Fe3+) and pyrophosphate anions (PPi) are involved in many physiological processes and play important roles in biological systems. The abnormal level of Fe3+ and PPi will cause serious damage to the environment and life. At present, the application of such probes in life, especially in vivo, is still very scarce. So, the development of a fluorescent probe to simultaneously detect Fe3+ and PPi has great significance to the health of the environment and organisms. Herein, nitrogen-doped carbon quantum dots (N-CDs) were synthesized via solvothermal treatment, using biuret and citric acid as precursors. The synthesized N-CDs showed highly selective and sensitive detection of Fe3+ through a photoluminescence quenching effect. The fluorescence of N-CDs quenched by Fe3+ could be restored with PPi, rendering the N-CDs/Fe3+ sensor promising for PPi detection ('OFF–ON'). The linear ranges of detection for Fe3+ and PPi were 3–30 and 2–12 μM, and the limits of detection were 2.71 and 1.12 μM, respectively. The practical applications of N-CDs were tested using tap water samples. Furthermore, N-CDs can be used for the detection and imaging of Fe3+ and PPi in HeLa cells and zebrafish owing to their excellent optical properties. [ABSTRACT FROM AUTHOR]

The present work is the first investigation of the electrocatalytic performances of ZrP2O7 as a cathode in a single-chamber Microbial Fuel Cell (MFC) for the conversion of chemical energy from wastewater to bioelectricity. This catalyst was prepared by a coprecipitation method, then characterized by X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), ultraviolet–visible–near-infrared spectrophotometry (UV–Vis–NIR), and cyclic voltammetry analyses. The acid–basic characteristics of the surface were probed by using 2-butanol decomposition. The conversion of 2-butanol occurs essentially through the dehydrating reaction, indicating the predominantly acidic character of the solid. The electrochemical test shows that the studied cathode material is electroactive. In addition, the ZrP2O7 in the MFC configuration exhibited high performance in terms of bioelectricity generation, giving a maximum output power density of around 449 mW m−2; moreover, it was active for wastewater treatment, reducing the chemical oxygen demand (COD) charge to 50% after three days of reaction. [ABSTRACT FROM AUTHOR]

A rapid fluorometric method was established to detect glyphosate by using cerium ion and pyrophosphate ion (Ce-PPi) coordination polymer networks (CPNs). Based on coordination of cerium ion (Ce3+) and pyrophosphate ion (PPi), fluorescent Ce-PPi CPNs were synthesized by simple selfassemble process, and the structure and properties were characterized. Upon introducing glyphosate, the ligand field effect of PPi with Ce3+ was weakened resulting in a decrease in fluorescence of Ce-PPi CPNs. Based on this principle, the quantitative detection of glyphosate was achieved by optimizing the conditions, with R² of 0.997 2 and the detection limit of 0.014 μmol/L. The established method based on Ce-PPi CPNs possessed outstanding sensitivity and exclusive selectivity for rapid detction of glyphosate, and could be used for the detection of glyphosate in tap water and apple samples. The limit of quantitation (LOQ) was 0.05 mg/kg and the recoveries were between 77% and 87%. The method provided a potential choice for the rapid, on-site and real-time, detection of glyphosate. [ABSTRACT FROM AUTHOR]