Phosphorus (P) is a crucial macronutrient for plant growth, root development, and yield. Commercial P fertilizers have low efficiency of delivery and utilization and are lost from plant root zones by either low availability or leaching or surface runoff that leads to environmental damage. This review investigates how nano P fertilizers (NPFs) can overcome the current inefficiencies of conventional formulations and, thus, enhance plant yield while minimizing negative environmental impacts. NPFs have significant potential for augmenting plant germination by more effectively penetrating seed coatings and facilitating greater water and nutrient uptake. The nanoscale nature of NPF also uniquely facilitates greater P absorption by roots, which in turn enhances chlorophyll synthesis, improves light absorption, and optimizes electron transport efficiency-key factors in boosting plant photosynthesis. Additionally, it stimulates overall physiological processes (e.g., secondary metabolite production, root exudation), increases antioxidant enzyme activities, and enhances plant yield. NPFs can also minimize the accumulation of toxic elements by several mechanisms, including controlling contaminant bioavailability in soil by enhancing competing plant essential element (e.g., P, Ca) uptake. Moreover, NPFs also mediate soil pH, which has important implications for soil biogeochemistry in low-pH agricultural areas. Soil microbiomes and associated processes will often improve with NPF application relative to conventional P formulations. Although great potential has been demonstrated, a mechanistic understanding of certain aspects of NPF activity remains incomplete, including impacts across diverse crop species, environmental conditions, and soil types. However, NPFs offer great potential as an important tool in the transformation of conventional agriculture, simultaneously lessening the usage of finite P resources, reducing the environmental footprint of agriculture, and improving future food security.

Despite being essentially water-free, nominally anhydrous minerals such as plagioclase and pyroxene represent the biggest reservoir of water in most lunar rocks due to their sheer abundance. Apatite, which incorporates F, Cl, and OH into its mineral structure as essential crystal components, on the other hand, is the only other volatile-bearing phase common in lunar samples. Here, we present the first coordinated study of volatiles (e.g., H2O, Cl, F, and S) in nominally anhydrous minerals combined with isotopic measurements in apatite from the ancient lunar basalt fragments from meteorite Miller Range (MIL) 13317. Apatite in MIL 13317 basalt contains similar to 2000 ppm H2O and has an elevated SD values (+ 523-737 parts per thousand), similar to Apollo mare basalts, but has high delta Cl-37 values (+ 29-36 parts per thousand), similar to apatite found in several KREEP-rich samples. MIL 13317 is unique compared with other lunar basalts; it has both elevated SD and delta Cl-37 values currently only observed in highlands sample 79215 (a granulitic impactite). Based on measurements of H2O in nominally anhydrous minerals and in apatite, the source magma of MIL 13317 basalt is estimated to contain similar to 130-330 ppm H2O. Assuming reasonable levels of partial melting of the lunar mantle and magmatic degassing during eruption of the basalt, the Moon contained at least one reservoir with < 100 ppm H2O, a delta D value of < 0 parts per thousand similar to carbonaceous chondrites, and extensively fractionated Cl isotopes prior to 4.332 Gyr, the crystallization age of the MIL 13317 basalt.

Apatite is ubiquitous in lunar samples and has been used widely for estimating volatile abundances in the lunar interior. However, apatite compositional and isotopic variations within and between samples have resulted in varying and ambiguous results. Understanding apatite petrogenesis will help with both identifying the appropriate composition for volatile estimation and interpreting isotopic variations. Here we report a comprehensive petrogenetic investigation of apatite in Chang'E-5 (CE5) basaltic sample CE5C0800YJYX013GP. Apatite displays both intra-grain and inter-grain compositional variations with F and Cl contents falling in the ranges of 0.97-2.47 wt% and 0.24-1.09 wt%, respectively. These apatite compositions show relatively low F and high Cl characteristics in comparison to apatites of Apollo high-Ti and low-Ti mare basalts, but are similar to those reported for lunar meteorites LAP 04841 and MIL 05035. We discern three zoning profiles: fractional crystallization (FC)-dominated, degassing-induced and a third indicated by REE-enriched cores, which are interpreted as representing different generations of apatite. FC-dominated zoning is characterized with decreasing F and increasing Cl and S contents from core to rim; while the opposite is true for the degassing-induced zoning. Regardless of the zoning patterns, apatite Cl and S contents display positive correlations, with S contents up to similar to 3000 ppm, much higher than previous reports for Apollo samples (up to similar to 600 ppm). We demonstrate that the fractional crystallization model proposed by Boyce et al. (2014) in combination with H2O degassing and high S contents in melt (likely at sulfide saturation) can explain these high Cl and S contents observed in CE5 apatite. Based on the core composition of the FC-dominated zoning profile, which has the lowest incompatible element concentrations, bulk F, Cl and H2O contents in the parental melt are estimated to be similar to 72 +/- 21, similar to 43 +/- 14 and similar to 1576 +/- 518 ppm, respectively. These estimates have lower F/Cl ratios than those measured in olivine-hosted melt inclusions from Apollo mare basalts. By adopting the petrogenetic model for CE5 basalt proposed by Su et al. (2022), i.e., 10 % partial melting of a hybrid mantle source, followed by similar to 30-70 % fractional crystallization (similar to 50 % for our sample), we estimate the F, Cl, H2O and S contents in the mantle source are in the ranges of similar to 2.5-4.6, similar to 0.7-1.4, similar to 53-105 and similar to 38-125 ppm, respectively, similar to estimates for both depleted Earth mantle and primitive lunar mantle. However, by adopting the model of Tian et al. (2021), 2-3 % partial melting of a mantle source composed of 86 PCS+2% TIRL (PCS, percent crystallized solid; TIRL, trapped instantaneous residual liquid), followed by 43-88 % fractional crystallization, these estimates will be 5-10 times lower. To be certain whether the relatively low F and high Cl characteristics of CE5 apatite imply an enriched mantle source requires further evaluation of the petrogenetic models for CE5 basalt.

Caries is one of the most prevalent human diseases, resulting from demineralization of tooth hard tissue caused by acids produced from bacteria, and can progress to pulpal inflammation. Filling restoration with dental resin composites (DRCs) is currently the most common treatment for caries. However, existing DRCs suffer from low fracture strength and lack comprehensive anti-caries bioactivity including remineralization, pulp protection, and anti-cariogenic bacteria effects. In this study, inspired by plant roots' ability to stabilize and improve soil, fluorinated urchin-like hydroxyapatite (FUHA) with a three-dimensional whisker structure and bioactive components of calcium, phosphorus, and fluorine was designed and synthesized by a dynamic self-assembly method. Furthermore, versatile FUHA particles with different loading fractions were used as functional fillers to fabricate methacrylate-based DRCs, where the urchin-like hydroxyapatite (UHA) filled DRCs and commercial DRCs (Z350XT and BEAUTIFIL II) served as the control groups. The results demonstrated that FUHA with 50 wt% loading in resin matrix endowed DRC (F5) with excellent physicochemical properties, dentin remineralization property, cell viability, promotion of dental pulp stem cells mineralization, and antibacterial properties. Meanwhile, F5 also presented good clinical handling and aesthetic characteristics. Therefore, structure/ functional-integrated FUHA filled DRCs have potential as a promising strategy for tooth restoration and anticaries bioactivity.

Flammability is a fatal drawback for sustainable packaging materials made from cellulose and its derivatives. Incorporating inorganic nanomaterials is a viable approach to improve the fire-resistant property. However, due to the aggregation of inorganic fillers and weak interactions between components, incorporating inorganic nanomaterials always had an adverse impact on the mechanical properties and optical transparency of cellulosebased nanocomposites. Herein, we presented a robust, biodegradable, and flame-retardant nanocomposite film composed of TEMPO-oxidized cellulose nanofibers (TOCNFs) and inorganic hydroxyapatite nanowires (HNWs). Both TOCNFs and HNWs possessed one-dimensional microstructure and could form unique organic-inorganic networks microstructure. The organic-inorganic networks interact through physical intertwinement and multiple chemical bonds, endowing nanocomposite film with outstanding mechanical properties. This nanocomposite film showed a tensile strength of 223.68 MPa and Young's modulus of 9.18 GPa, which were superior to most reported cellulose-based nanocomposite. Furthermore, this nanocomposite film demonstrated exceptional thermal stability and flame-retardant feature attributed to the inorganic framework formed by HNWs. This nanocomposite film also possessed a high optical transmittance even when HNWs content reached 30 % and could be decomposed quickly in soil. By employing organic-inorganic interpenetrating network structure design and multiple bonding interaction, cellulose-based nanocomposites can overcome inherent limitations and attain desirable comprehensive properties.

The Moon can have elevated chlorine (Cl) isotope ratios, much higher than any other Solar System objects. Deciphering the Cl isotope compositions of volcanic lunar samples is critical for unraveling the volcanic processes and volatile inventory of the Moon's interior. However, the processes and mechanisms of Cl isotope fractionation are not yet fully understood through previous studies on lunar samples. The China's Chang'e-5 (CE5) basalt samples were collected far from the Apollo and Luna landing sites, and dated at about 2.0 billion years ago (Ga), approximately 1 Ga younger than previously reported lunar basalts. The CE5 samples, therefore, provide an opportunity to investigate Cl isotope characteristics and fractionation mechanisms during a younger lunar volcanism. In this study, we performed systematic petrography, mineral chemistry, volatile abundances and distribution, and Cl isotopic studies on the CE5 apatite via a combination of scanning electron microscopy, electron probe microanalyser, and nanoscale secondary ion mass spectrometry. The CE5 apatite grains from basalt clasts and fragments have subhedral to euhedral shapes with grains sizes mostly less than 10 mu m, mainly coexisting with the mesostasis, fayalite olivine, and the margins of pyroxene. These apatites are F-dominated (0.91-3.93 wt%) with a Cl abundance range of 820 to 11989 mu g.g(-1) and a water abundance range of 134 to 6564 mu g.g-1, similar to those in the mare samples previously reported. Chlorine displays notable zoning distributions in some CE5 apatite grains with higher abundance at the rims gradually decrease towards the cores. Chlorine isotopic compositions of CE5 apatite vary from 4.5 to 18.9%o, positively correlated with the Cl abundances. These lines of evidence suggest that magmatic degassing of Cl-bearing species during the crystallisation of apatite at or near the lunar surface could have resulted in a large Cl isotope fractionation. Our new findings highlight a significant role of magmatic fractionation of Cl isotopes during crystallisation of mare lavas and provide clues for determining the primordial Cl isotopic signature of the Moon.(c) 2022 Elsevier B.V. All rights reserved.

We conducted a petrologic study of apatite within eight unbrecciated, non-cumulate eucrites and two monomict, non-cumulate eucrites. These data were combined with previously published data to quantify the abundances of F, Cl, and H2O in the bulk silicate portion of asteroid 4 Vesta (BSV). Using a combination of apatite-based melt hygrometry/chlorometry and appropriately paired volatile/refractory element ratios, we determined that BSV has 3.0-7.2 ppm F, 0.39-1.8 ppm Cl, and 3.6-22 ppm H2O. The abundances of F and H2O are depleted in BSV relative to CI chondrites to a similar degree as F and H2O in the bulk silicate portion of the Moon. This degree of volatile depletion in BSV is similar to what has been determined previously for many moderately volatile elements in 4 Vesta (e.g., Na, K, Zn, Rb, Cs, and Pb). In contrast, Cl is depleted in 4 Vesta by a greater degree than what is recorded in samples from Earth or the Moon. Based on the Clisotopic compositions of eucrites and the bulk rock Cl-/F ratios determined in this study, the eucrites likely formed through serial magmatism of a mantle with heterogeneous delta Cl-37 and Cl/F, not as extracts from a partially crystallized global magma ocean. Furthermore, the volatile depletion and Cl-isotopic heterogeneity recorded in eucrites is likely inherited, at least in part, from the precursor materials that accreted to form 4 Vesta and is unlikely to have resulted solely from degassing of a global magma ocean, magmatic degassing of eucrite melts, and/or volatile loss during thermal metamorphism. Although our results can be reconciled with the past presence of wide-scale melting on 4 Vesta (i.e., a partial magma ocean), any future models for eucrite petrogenesis involving a global magma ocean would need to account for the preservation of a heterogeneous eucrite source with respect to Cl/F ratios and Cl isotopes. Published by Elsevier Ltd.

We report the occurrence of a previously unidentified mineral in lunar samples: a Cl-,F-,REE-rich silico-phosphate identified as Cl-bearing fluorcalciobritholite. This mineral is found in late-stage crystallization assemblages of slowly cooled high-Ti basalts 10044, 10047, 75035, and 75055. It occurs as rims on fluorapatite or as a solid-solution between fluorapatite and Cl-fluorcalciobritholite. The Cl-fluorcalciobritholite appears to be nominally anhydrous. The Cl and Fe2+ of the lunar Cl-fluorcalciobritholite distinguishes it from its terrestrial analog. The textures and chemistry of the Cl-fluorcalciobritholite argue for growth during the last stages of igneous crystallization, rather than by later alteration/replacement by Cl-, REE-bearing metasomatic agents in the lunar crust. The igneous growth of this Cl- and F-bearing and OH-poor mineral after apatite in the samples we have studied suggests that the Lunar Apatite Paradox model (Boyce et al. 2014) may be inapplicable for high-Ti lunar magmas. This new volatile-bearing mineral has important potential as a geochemical tool for understanding Cl isotopes and REE chemistry of lunar samples.

The isotopes of chlorine (Cl-37 and Cl-35) are highly fractionated in lunar samples compared to most other Solar System materials. Recently, the chlorine isotope signatures of lunar rocks have been attributed to large-scale degassing processes that occurred during the existence of a magma ocean. In this study we investigated how well a suite of lunar basalts, most of which have not previously been analyzed, conform to previous models. The Cl isotope compositions (delta Cl-37 (parts per thousand) = [(Cl-37/Cl-35(sample)/Cl-37/Cl-35(SMOC)) - 1] x 1000, where SMOC refers to standard mean ocean chloride) recorded range from similar to+7 to +14 parts per thousand (Apollo 15), +10 to +19 parts per thousand (Apollo 12), +9 to +15 parts per thousand (70017), +4 to +8 parts per thousand (MIL 05035), and +15 to +22 parts per thousand (Kalahari 009). The Cl isotopic data from the present study support the mixing trends previously reported by Boyce et al. (2015) and Barnes et al. (2016), as the Cl isotopic composition of apatites are positively correlated with bulk-rock incompatible trace element abundances in the low-Ti basalts, inclusive of low-Ti and KREEP basalts. This trend has been interpreted as evidence that incompatible trace elements, including Cl, were concentrated in the urKREEP residual liquid of the lunar magma ocean, rather than the mantle cumulates, and that urKREEP Cl had a highly fractionated isotopic composition. The source regions for the basalts were thus created by variable mixing between the mantle (Cl-poor and relatively unfractionated) and urKREEP. The high-Ti basalts show much more variability in measured Cl isotope ratios and scatter around the trend formed by the low-Ti basalts. Most of the data for lunar meteorites also fits the mixing of volatiles in their sources, but Kalahari 009, which is highly depleted in incompatible trace elements, contains apatites with heavily fractionated Cl isotopic compositions. Given that Kalahari 009 is one of the oldest lunar basalts and ought to have been derived from very early-formed mantle cumulates, a heavy Cl isotopic signature is likely not related to its mantle source, but more likely to magmatic or secondary alteration processes, perhaps via impact-driven vapor metasomatism of the lunar crust. (C) 2019 The Authors. Published by Elsevier Ltd.

The traditional view of a dry, volatile-poor Moon has been challenged by the identification of water and other volatiles in lunar samples, but the volatile budget delivery time (s), source (s) and temporal evolution remain poorly constrained. Here we show that hydrogen and chlorine isotopic ratios in lunar apatite changed significantly during the Late Accretion (LA, 4.1-3.8 billion years ago). During this period, deuterium/hydrogen ratios in the Moon changed from initial carbonaceous-chondrite-like values to values consistent with an influx of ordinary-chondrite-like material and pre-LA elevated delta Cl-37 values drop towards lower chondrite-like values. Inferred pre-LA lunar interior water contents are significantly lower than pristine values suggesting degassing, followed by an increase during the LA. These trends are consistent with dynamic models of solar-system evolution, suggesting that the Moon's (and Earth's) initial volatiles were replenished similar to 0.5 Ga after their formation, with their final budgets reflecting a mixture of sources and delivery times.