Fe Release Research Articles

Responsive Magnetic Particle Imaging Tracer: Overcoming "Always-On" Limitation, Eliminating Interference, and Ensuring Safety in Adaptive Therapy.

Magnetic particle imaging (MPI) has emerged as a novel technology utilizing superparamagnetic nanoparticles as tracers, essential for disease diagnosis and treatment guidance in preclinical animal models. Unlike other modalities, MPI provides high sensitivity, deep tissue penetration, and no signal attenuation. However, existing MPI tracers suffer from "always-on" signals, which complicate organ-specific imaging and hinder accuracy. To overcome these challenges, we have developed a responsive MPI tracer using pH-responsive PdFe alloy particles coated with a gatekeeper polymer. This tracer exhibits pH-sensitive Fe release and modulation of the MPI signal, enabling selective imaging with a higher signal-to-noise ratio and intratumoral pH quantification. Notably, this responsive tracer facilitates subtraction-enhanced MPI imaging, effectively eliminating interference from liver uptake and expanding the scope of abdominal imaging. Additionally, the tracer employs a dual-function mechanism for adaptive cancer therapy, combining pH-switchable enzyme-like catalysis with dual-key co-activation of ROS generation, and Pd skeleton that scavenges free radicals to minimize Fe-related toxicity. This advancement promises to significantly expand MPI's applicability in diagnostics and therapeutic monitoring, marking a leap forward in imaging technology.

Spatial and temporal dynamics of groundwater biogeochemistry in the deep subsurface of a high-energy beach

Intertidal sandy beach systems are considered complex biogeochemical reactors. At beach sites that are subject to high tidal and wave energy, seawater circulation can reach tens of meters deep into the subsurface and changing environmental conditions are assumed to lead to dynamic groundwater flow paths, saltwater-freshwater mixing zones, and a spatio-temporally variable groundwater biogeochemistry. Previous studies mainly focused on the upper meters of subterranean estuaries (STE), while the deep subsurface remained a black box. This study presents spatial (cross-shore) and temporal (~six-weekly, over 1.5 years) dynamics of the groundwater biogeochemistry that were observed down to 24 m below the ground surface (mbgs) of a sandy high-energy beach on Spiekeroog Island (Germany).In addition to redox conditions along a cross-shore transect ranging from oxic to Fe oxide reducing/slightly sulfidic, we found a previously unknown, distinct vertical redox zonation as well. Temporal variations of the biogeochemistry within low salinity groundwater at the most landward station close to the dune base were mainly driven by storm flood related seawater infiltration. Around the high water line, the extent of the upper saline plume (USP) varied over time. Furthermore, temporal dynamics of the O2 saturation at 6 mbgs indicated a seasonally shifting depth of the oxycline at this location. In the lower intertidal zone, groundwater solute concentrations displayed a temporally variable zone of deep freshwater discharge.Regarding the impact of the deep STE on the groundwater biogeochemistry of the discharge zone, our data revealed that nutrient, Mn, and Fe release along the deep flow paths through the USP towards the discharge zone was limited, likely due decreasing availability of labile organic matter and subsequent slowing down of metabolic processes with depth. High concentrations of metabolites in the upper ~2 mbgs of the discharge zone were, therefore, rather attributed to the incorporation of labile organic matter during continuous and storm flood related sediment relocation and/or the contribution of older waters, e.g., the subtidal saltwater wedge.

Iron redox shuttling and uptake by silicate minerals on the Namibian mud belt

Anoxic marine sediments represent an important source of bioavailable iron (Fe) to the ocean. The highest sedimentary Fe fluxes are observed in open-marine oxygen minimum zones where anoxic bottom waters are in contact with ferruginous surface sediments. Here, sedimentary Fe release, transport and re-deposition (i.e., Fe shuttling) may generate a lateral pattern of sedimentary Fe enrichment and depletion, which can be used to trace redox-related Fe mobility in the paleo-record. However, depending on the balance between terrigenous and authigenic (i.e., shuttle-related) Fe flux, the stability of bottom water redox conditions as well as post-depositional processes of mineral alteration, the sedimentary fingerprint of an Fe redox shuttle may be obscured and difficult to identify.We investigated sedimentary Fe cycling along two transects across the Namibian mud belt with variable terrigenous sedimentation (23°S < 25°S) and during two seasons with opposing bottom water redox conditions (oxic in austral winter versus anoxic to sulfidic in austral summer). On both transects, substantial benthic Fe fluxes up to −50 µmol m−2 d−1 were inferred based on pore water profiles. The magnitude of these fluxes is comparable to those reported for other open-marine oxygen minimum zones. On the transect at 23°S, Fe source areas with ferruginous surface sediments were clearly separated from Fe sink areas with highly sulfidic surface sediments. Therefore, Fe redox shuttling was reflected by a lateral pattern of reactive Fe depletion and enrichment relative to the terrigenous background sedimentation. By contrast, on the transect at 25°S, benthic Fe fluxes were temporally and spatially more variable and surface sediments were ferruginous or only weakly sulfidic. Therefore, sedimentary Fe depletion and enrichment was less pronounced at 25°S. In the Fe sink area at 23°S, hydrogen sulfide was present at the sediment surface during both sampling campaigns and solid phase data suggest that Fe sulfide minerals represented the main burial phase of reactive Fe. By contrast, at 25°S excess Fe was associated with potassium (K) rather than reduced sulfur. While a differing sediment provenance cannot be ruled out entirely, combined evidence from pore water silica profiles, K to Fe stoichiometric relationships and electron microprobe images suggest that laterally derived excess Fe was incorporated into pre-existing and/or authigenic clay minerals during early diagenesis. Iron uptake by clay minerals may be supported by frequent redox oscillations and sediment mixing preventing preservation of Fe sulfide minerals and promoting Fe and K fixation in clay minerals. The burial fluxes of excess Fe associated with sulfide minerals at 23°S and silicate minerals at 25°S were similar. Our findings thus underscore that neoformation or alteration of silicate minerals can be important processes within the low-temperature marine Fe cycle.

The quorum-sensing TraI/TraR system contributes to the release of Fe and Al from biotite by Agrobacterium pusense SX41

The quorum-sensing (QS) system in Rhizobiaceae has been studied, however, the mechanisms of QS system-mediated mineral dissolution by bacteria remain poorly understood. Here, the mineral-solubilizing Agrobacterium pusense SX41 harboring the QS system (responsible for N-acyl homoserine lactone (AHL) production) was characterized for QS system-mediated Al and Fe release from biotite. Whole-genome sequence analysis revealed that SX41 contains the QS TraI/TraR system. SX41 and the SX41∆traI, SX41∆traR, and SX41∆traI/R mutants were constructed from SX41 and compared for QS TraI/R system-mediated Fe and Al release from biotite in the solution and the underlying mechanisms. The SX41∆traI, SX41∆traR, and SX41∆traI/R mutants significantly decreased the Al and Fe concentrations in the medium by 24 % to 54 % on day 1 and 25 % to 42 % on day 5, while these mutants significantly reduced exopolysaccharide (EPS) concentrations in the medium by 21 % to 55 % on day 5, compared with those of SX41. Furthermore, these mutants demonstrated decreased cell counts and biofilm formation on biotite surfaces compared with SX41. Notably, the SX41∆traR mutant exhibited more pronounced effects on Al and Fe release from biotite, EPS production, and cell adsorption and biofilm formation on biotite surfaces compared with the SX41∆traI mutant. Moreover, the addition of biotite significantly upregulated the expression of traI and traR in SX41 and the complemented strains SX41∆traIR and SX41∆traRR. These findings underscore the pivotal role of the TraI/R system in the interactions between SX41 and biotite and highlight the distinct influences of traI and traR on Al and Fe release from biotite by SX41.

Effect of Oxidation on Vivianite Dissolution Rates and Mechanism.

The interest in the mineral vivianite (Fe3(PO4)2·8H2O) as a more sustainable P resource has grown significantly in recent years owing to its efficient recovery from wastewater and its potential use as a P fertilizer. Vivianite is metastable in oxic environments and readily oxidizes. As dissolution and oxidation occur concurrently, the impact of oxidation on the dissolution rate and mechanism is not fully understood. In this study, we disentangled the oxidation and dissolution of vivianite to develop a quantitative and mechanistic understanding of dissolution rates and mechanisms under oxic conditions. Controlled batch and flow-through experiments with pristine and preoxidized vivianite were conducted to systematically investigate the effect of oxidation on vivianite dissolution at various pH-values and temperatures. Using X-ray absorption spectroscopy and scanning transmission X-ray microscopy techniques, we demonstrated that oxidation of vivianite generated a core-shell structure with a passivating oxidized amorphous Fe(III)-PO4 surface layer and a pristine vivianite core, leading to diffusion-controlled oxidation kinetics. Initial (<1 h) dissolution rates and concomitant P and Fe release (∼48 h) decreased strongly with increasing degree of oxidation (0-≤ 100%). Both increasing temperature (5-75 °C) and pH (5-9) accelerated oxidation, and, consequently, slowed down dissolution kinetics.

Design and Implementation of Iron-Based Electrochemical System for Simultaneous Carbon Capture and Hydrogen Gas Recovery

The catastrophic results of climate change and energy crisis, such as the rise in wildfires, floods, and ecosystem disruptions highlight the critical need of urgent and innovative global-scale solutions for carbon dioxide (CO2) removal (CDR). Ocean-based CDR methods, leveraging the ocean's capacity as a large sink to sequester up to 30% of emissions, offer a great promise. Yet, implementing and testing marine CO2 removal (mCDR) techniques such as ocean iron fertilization (OIF) or ocean alkalinity enhancement (OAE) face significant challenges. To overcome these challenges, a novel self-operating electrochemical technology is designed and presented in this work. The proposed technology, namely electrochemical OIF (EOIF), does not only combine OIF and OAE, but also recovers hydrogen gas (H2) from seawater, offering a promising solution for achieving quantifiable and transparent large-scale mCDR. The EOIF design s focused on employing Fe/Fe-producing anodes to eliminate the production of acids at the anode in traditional electrochemical OAE systems and replace it with Fe release, where the cathode can be made from naturally abundant cost-effective materials, such as carbon. The obtained results show that the EOIF system can be implemented to increase both the concentration of ferrous iron (Fe+2) by 0-0.5 mg/L, and the seawater pH by 8% (i.e., 25% decrease in the hydrogen ions concentration). It also offers the flexibility to optimize the release of iron (Fe+2/Fe+3) by adjusting the magnitude of the electric current in the systems, as well as by optimizing the electrode material and geometry. In certain ocean regions, enhanced iron concentrations stimulate the naturally occurring biological carbon pump (BCP), leading to increased phytoplankton growth, CO2 uptake, and subsequent export of carbon to the deep ocean. Simultaneously, the system increases seawater alkalinity and the buffer capacity, enhancing CO2 solubility and storage in the shallow ocean through the solubility pump. The techno-economic assessment shows that the combined advantages of the EOIF system can lower the mCDR cost by more than 95% compared to the traditional methods. The obtained measurements demonstrate the scalability of EOIF and its ability to operate using solar energy at a lower cost. Overall, the proposed EOIF technology offers a practical, effective, and sustainable solution for addressing climate change and energy recovery on a large-scale.

FeAu Bimetallic Nanoparticle as Fe(0) Reservoir for Near Infrared Laser Enhanced Ferroptosis/Pyroptosis‐Based Tumor Immunotherapy

AbstractIron (Fe)‐based nanoparticles (NPs) have attracted considerable attention in nanomedicine research due to their enhancement effects in magnetic resonance imaging (MRI) and cancer therapy. Although zero‐valent Fe (Fe(0)) can serve as an active catalyst to decompose H2O2 into reactive oxygen species (ROS), its activity is compromised in physiological conditions due to its susceptibility to oxidation. Here it is reported that a 9 nm FeAu alloy NP system can efficiently stabilize Fe(0) in neutral pH solution, but release Fe(0) in tumor‐bearing environment, catalyzing H2O2 decomposition to ROS. Although Fe3O4 NPs and Au NPs are well‐known for their biocompatible, FeAu NPs effectively eliminate cancer cells at an IC50 as low as 15 µg mL−1 Fe. Further proteomics analysis reveals that FeAu NPs can concomitantly induce both ferroptosis and pyroptosis. Additional near‐infrared (NIR) irradiation further increases cell death and promotes maturation of dendritic cells within tumor‐draining lymph nodes and infiltration of helper T cells and cytotoxic T lymphocytes within tumor sites, resulting in significant reduction in tumor growth and metastasis. The studies demonstrate a great potential of FeAu NPs as a stable Fe(0) reservoir for pH/NIR controlled Fe(0) release and further for ferroptosis and pyroptosis co‐mediated tumor immunotherapy.

Numerical exploration of a fully mechanistic mathematical model of aqueous CO2 corrosion in steel pipelines

A numerical exploration of a comprehensive mechanistic aqueous carbon dioxide (CO2) corrosion model is conducted across a range of temperatures (273–313 K), CO2 partial pressures (0.1–1 bar), and bulk pHs (5–6.5). Contour plots are produced to examine the impact on corrosion rate, surface pH, and surface saturation index of iron carbonate (FeCO3). Two response patterns are identified depending upon the limiting behaviour of the system, with a transition from charge-transfer control to mass-transport control as temperature is increased and partial pressure is reduced. FeCO3 surface saturation shows a strong correlation with the release of Fe2+ and increase in bulk pH.

Augmenting barrier efficiency in clay‐based starch composite films for enhanced packaging sustainability

AbstractThe pervasive utilization of plastic as a cost‐effective packaging material for food has led to environmental concerns, primarily due to its non‐biodegradable nature and the ensuing release of carbon dioxide gas that contributes to global warming. In response to these challenges, researchers have shifted their focus toward biopolymers to develop eco‐friendly packaging solutions. The present study introduces a novel approach to study the release of micronutrient (Fe) from clay free starch‐glycerol film and clay‐starch‐glycerol composite film. The structural composition and characteristics of the synthesized film are meticulously examined using x‐ray diffraction (XRD), ATR, scanning electron microscopy and transmission electron microscopy analytical techniques. Notably, XRD analysis reveals a significant interaction between the starch chains and Mt through hydrogen bonding, indicative of starch and glycerol intercalation within the nanoclay gallery—a phenomenon further corroborated by IR spectra analysis. The nanoclay‐infused starch/glycerol composite film exhibits a noteworthy 2.22‐fold increase in water vapor permeability compared to clay free film, attributed to the formation of a convoluted diffusion path indicating the enhancement of the barrier performance of starch‐based films. Comparative evaluations against earlier studies are undertaken to elucidate the advancements in barrier properties, subsequently elucidating the underlying mechanisms through analytical interpretations. From the release study, the release of Fe2+ from the film with clay was observed to be more prolonged compared to a film without clay. As a result, the Montmorillonite clay–polymer composite film was selected for coating rice seeds using the dip‐coating method.

Joint r-process Enrichment by Supernovae with a Metallicity Threshold and Neutron Star Mergers

The enrichment history of r-process elements has been imprinted on the stellar abundances that change in accordance with increasing metallicity in galaxies. Close examination of the [Eu/Fe] feature caused by stars in nearby galaxies, including the Large Magellanic Cloud (LMC), shows its perplexity. The decreasing trend of the [Eu/Fe] feature is followed by a nearly constant value; this trend is generally attributed to an onset of the delayed Fe release from Type Ia supernovae (SNe Ia), which is the same interpretation of the [α/Fe] feature. However, this feature appears in the LMC at [Fe/H] of approximately −0.7, which is significantly higher than that for the [α/Fe] case (≈−2). This result potentially indicates the presence of an overlooked property of the r-process site that remains unseen in the study of the Milky Way. Here, we propose that this [Eu/Fe]-knee feature is created by a fade-out of core-collapse SNe producing r-process elements; these elements along with neutron star mergers (NSMs) promote the r-process enrichment under the condition for this specific SNe such that their occurrence is limited to a low-metallicity environment. This metallicity threshold for the occurrence rate of r-process SNe at a subsolar is nearly identical to that for long gamma-ray bursts whose origin may be connected to fast-rotating massive stars. Moreover, we reason that the contribution of Eu from NSMs is crucial to maintain a high [Eu/Fe] at an early stage in dwarf galaxies by a balance with Fe from SNe Ia; both enrichments via NSMs and SNe Ia proceed with similar delay time distributions.

Enhanced Fenton performance of wet-mechanochemically synthesized FeS2/Biochar: The multiple synergistic effect derived from mutual element doping

FeS2-biochar composites have been considered as promising heterogeneous Fenton materials for pollutants removal. However, the chemical synthesis of element-doped FeS2-biochar composite with superior performance and the comprehensive investigation for its underlying multiple synergistic mechanism remain a difficult endeavor. Herein, a novel FeS2/Biochar nanocomposite with mutual element doping was firstly synthesized by facile wet-mechanochemical method using iron, sulfur and bamboo-biochar for efficient organic pollutant (sulfamonomethoxine, SMM) removal. Experiment and DFT calculation results revealed that multiple synergistic effect between FeS2 and biochar derived from newly formed Fe-C and C-S-C bonds induced the abundant reactive oxygen species (ROS) and excellent electron transfer capacity. Fe-C sites facilitated the H2O2 adsorption and populated O-O bond in H2O2 for its barrierless dissociation into •OH via forming bridging C-Fe-O-O-Fe bond. Oxygen vacancy, C-S-C and Fe-C bonds, persistent free radicals (PFRs) accelerated the generation and transformation of ROS, which resulted in dominating free radical (•OH, •O2–, •SO4-) and auxiliary non-radical (1O2) pathway. Meanwhile, Fe3+/Fe2+ redox-cycle was expedited by electron donor/shuttle (S22-, BC, •O2–, C-S-C and Fe-C bonds). All these specialties contributed to the superior performance of FeS2/Biochar Fenton system for SMM removal at wide pH range (3–11) with negligible Fe release. Completely SMM (50 mg/L) removal was achieved within 20 min for 8 successive reuses. This work emphasized the concept of building mutual element doping on molecular level in enhancing FeS2-Biochar synergy towards efficient environmental remediation.

Synergistic Effect of Layered Double Hydroxides Nanodosage Form to Induce Apoptosis and Ferroptosis in Breast Cancer.

Breast cancer is the most common cancer in women and one of the leading causes of cancer death worldwide. Ferroptosis, a promising mechanism of killing cancer cells, has become a research hotspot in cancer therapy. Simvastatin (SIM), as a potential new anti-breast cancer drug, has been shown to cause ferroptosis of cancer cells and inhibit breast cancer metastasis and recurrence. The purpose of this study is to develop a novel strategy boosting ferroptotic cascade for synergistic cancer therapy. In this paper, iron base form of layered double hydroxide supported simvastatin (LDHs-SIM) was synthesized by hydrothermal co-precipitation method. The characterization of LDHs-SIM were assessed by various analytical techniques, including ultraviolet-visible (UV-vis) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM). Biological activity, ferroptosis mechanism and biocompatibility were analyzed through in vivo and in vitro analysis, so as to evaluate its therapeutic effect on breast cancer. The constructed LDHs-SIM nanosystem can not only release SIM through mevalonate (MVA) pathway, inhibit the expression of glutathione peroxidase 4 (GPX4), inhibit the expression of SLC7A11 and reduce the synthesis efficiency of GSH, but also promote the accumulation of Fe2+ in cells through the release of Fe3+, and increase the intracellular ROS content. In addition, LDHs-SIM nanosystem can induce apoptosis of breast cancer cells to a certain extent, and achieve the synergistic effect of apoptosis and ferroptosis. In the present study, we demonstrated that nanoparticles of layered double hydroxides (LDHs) loaded with simvastatin were more effective than a free drug at inhibiting breast cancer cell growth, In addition, superior anticancer therapeutic effects were achieved with little systemic toxicity, indicating that LDHs-SIM could serve as a safe and high-performance platform for ferroptosis-apoptosis combined anticancer therapy.

The Shelf‐To‐Basin Transport of Iron From the Northern U.S. West Coast to the Pacific Ocean

AbstractRelease of iron (Fe) from continental shelves is a major source of this limiting nutrient for phytoplankton in the open ocean, including productive Eastern Boundary Upwelling Systems. The mechanisms governing the transport and fate of Fe along continental margins remain poorly understood, reflecting interaction of physical and biogeochemical processes that are crudely represented by global ocean biogeochemical models. Here, we use a submesoscale‐permitting physical‐biogeochemical model to investigate processes governing the delivery of shelf‐derived Fe to the open ocean along the northern U.S. West Coast. We find that a significant fraction (∼20%) of the Fe released by sediments on the shelf is transported offshore, fertilizing the broader Northeast Pacific Ocean. This transport is governed by two main pathways that reflect interaction between the wind‐driven ocean circulation and Fe release by low‐oxygen sediments: the first in the surface boundary layer during upwelling events; the second in the bottom boundary layer, associated with pervasive interactions of the poleward California Undercurrent with bottom topography. In the water column interior, transient and standing eddies strengthen offshore transport, counteracting the onshore pull of the mean upwelling circulation. Several hot‐spots of intense Fe delivery to the open ocean are maintained by standing meanders in the mean current and enhanced by transient eddies and seasonal oxygen depletion. Our results highlight the importance of fine‐scale dynamics for the transport of Fe and shelf‐derived elements from continental margins to the open ocean, and the need to improve representation of these processes in biogeochemical models used for climate studies.

Selected humanization of yeast U1 snRNP leads to global suppression of pre-mRNA splicing and mitochondrial dysfunction in the budding yeast.

The recognition of the 5' splice site (5' ss) is one of the earliest steps of pre-mRNA splicing. To better understand, the mechanism and regulation of 5' ss recognition, we selectively humanized components of the yeast U1 (yU1) snRNP to reveal the function of these components in 5' ss recognition and splicing. We targeted U1C and Luc7, two proteins that interact with and stabilize the yU1 snRNA and the 5' ss RNA duplex. We replaced the zinc-finger (ZnF) domain of yeast U1C (yU1C) with its human counterpart, which resulted in a cold-sensitive growth phenotype and moderate splicing defects. We next added an auxin-inducible degron to yeast Luc7 (yLuc7) protein (to mimic the lack of Luc7Ls in human U1 snRNP). We found that Luc7-depleted yU1 snRNP resulted in the concomitant loss of Prp40 and Snu71 (two other essential yU1 snRNP proteins), and further biochemical analyses suggest a model of how these three proteins interact with each other in the U1 snRNP. The loss of these proteins resulted in a significant growth retardation accompanied by a global suppression of pre-mRNA splicing. The splicing suppression led to mitochondrial dysfunction as revealed by a release of Fe2+ into the growth medium and an induction of mitochondrial reactive oxygen species. Together, these observations indicate that the human U1C ZnF can substitute that of yeast, Luc7 is essential for the incorporation of the Luc7-Prp40-Snu71 trimer into yU1 snRNP, and splicing plays a major role in the regulation of mitochondrial function in yeast.

Hexavalent chromium removal by green synthesized nano-size iron particles combined with iron sulfides: Effects of dissolved oxygen and phosphate

The removal of hexavalent chromium (Cr(VI)) from wastewater using the green synthesized nano-zero-valent-iron (GnZVI) has attracted great attention. However, the Cr(VI) removal capacity of GnZVI remains limited by dissolved oxygen (DO) or phosphate in wastewater. Therefore, Cr(VI) removal by GnZVI combined with iron sulfides (i.e., FeS or FeS2) impacting by DO and phosphate was investigated at pH 2.0 and 6.0. Experimental results showed that DO inhibited the Cr(VI) removal by GnZVI with FeS at pH 2.0, because high DO saturation was beneficial to Fe(II) oxidization into Fe(III). Nevertheless, DO promoted the corrosion and dissolution of FeS2 but GnZVI for Cr(VI) reduction at pH 2.0. Especially, phosphate inhibited the Cr(VI) reduction by the combination of GnZVI and iron sulfides at pH 2.0, likely because phosphate inhibited Fe(II) release from GnZVI hybrid materials during the reduction process from Cr(VI) to Cr (III). Differently, at pH 6.0, phosphate mainly promoted Cr(VI) removal by FeS compared with GnZVI via the formation of phosphate complexation, while it inhibited Cr(VI) removal using GnZVI combined with FeS2 through the competitive adsorption. This study reveals the potential inherent mechanisms and emphasizes a sustainable strategy for the effective removal of Cr(VI) using a hybrid technique that combines GnZVI and iron sulfides under complex wastewater conditions.

Smart epoxy coating: g-C3N4 nanosheets loaded MOFs for enhanced anti-corrosion and UV resistance

Large lateral size g-C3N4 nanosheets (Graphite-like carbon nitride) were successfully prepared by surface polymerization. NH2-MIL-101 (Amino-functionalized iron-based metal–organic framework) was then modified on the surface of g-C3N4 nanosheets (NH2-MIL-101@g-C3N4) by an in-situ loading method to construct a long-term smart coating with high barrier, activity inhibition, and anti-UV aging. This novel approach marks a significant advancement in the development of smart coatings for long-term corrosion protection. Evaluation of the active corrosion inhibition of NH2-MIL-101@g-C3N4 (MCN) nanoparticles showed that the corrosion inhibition efficiency of MCN nanoparticles on carbon steel reached 79.3 % after 5 h. The addition of MCN nanoparticles to the epoxy coatings (MCN/EP) endowed the coatings with the ability to actively inhibit corrosion. The release of Fe3+ cations and NH2-BDC (2-aminoterephthalic acid) organic ligands from MCN at defects formed a protective film, effectively preventing further corrosion. The MCN/EP coating maintained a high Log|Z|0.01 Hz value (Impedance modulus at a frequency of 0.01 Hz) during the immersion period with excellent barrier properties. Notably, MCN significantly improved the water resistance, water contact angle, tensile properties, and thermomechanical properties of epoxy coatings after ultraviolet (UV) radiation, highlighting a remarkable enhancement in the coating's performance. The anti-corrosion of MCN/EP coating was unaffected by UV radiation, extending service life of the smart coating, with Log|Z|0.01 Hz values two orders of magnitude higher than pure EP after 300 h of UV radiation. This work presented innovative coating design and preparation methods to improve the performance and functionality of anti-corrosion coatings, making significant attempts in the field.

Manganese and iron oxides on pipe surface promote dissolved aluminum accumulation in drinking water distribution systems

Aluminum-containing deposits are pervasive in drinking water distribution systems (DWDSs). However, the mechanisms driving dissolved Al transformation to pipe deposits remain elusive. This study investigated dissolved Al accumulation in DWDSs by batch experiments and long-term pipe experiments using actual finished water. PVC pipe experiments showed that dissolved Al hardly deposited on clean PVC pipe walls at alkaline pH. However, it could be substantially anchored by the pipe surface covered with Mn and Fe deposits formed from Mn(II) oxidation and Fe(III) precipitation. Batch experiments verified that the synthesized Mn and Fe oxides exhibited a strong capacity for dissolved Al uptake at pH 7.7 and 9.0 (dissolved Al was the dominant form). Biofilms on pipe walls also enhanced dissolved Al accumulation. Iron pipe experiments showed that corroded iron pipes with abundant iron corrosion products readily accumulated Al. Compared to chlorination and chloramination, non-disinfected conditions were more favorable for particulate Al deposition on iron pipe surface, probably due to Al immobilization by biofilms. In addition, continuous Al accumulation in iron pipes enhanced Fe release to pipe water. This study highlighted the important role of metal oxides in dissolved Al accumulation in DWDSs with abundant Mn and Fe solids, which provided new insights into deposit formation and control strategies.

Enhancing iron bioavailability in lentil grains circumventing the phytate barrier

The study aimed at examining the effect of Iron (Fe) management strategies on the redistribution of Fe fractions in soil and on the Fe bioavailability and phytic acid (PA) content in lentil grains. A pot experiment was conducted in Completely Randomized Design with 8 treatments replicated thrice. The treatments were Control (no fertilizer); Recommended dose of fertilizers (RDF) i.e. 20:40 (N: P2O5); RDF + Fe (basal application @10 kg/ha); RDF + Fe (foliar@ 1% (w/v) solution); RDF + Fe (basal + foliar); RDF + FeSB (biopriming with Fe solubilizing bacteria (Enterobacter cloacae strain BAU3) @ 5 mL/kg seed (1 x109 cfu mL−1)); RDF + Fe (seed nutripriming with 1% (w/v) solution); and RDF + (biopriming + nutripriming). Fe source for the treatments was Fe-EDDHA chelate. Higher Fe release from these fractions was observed under biopriming + nutripriming with water soluble Fe of 21.09 and 20.82 mg kg−1, respectively for the biopriming + nutripriming and sole biopriming treatments; and organically bound Fe of 230.95 and 211.36 mg kg−1 for the same treatments. These fractions contributed toward higher Fe uptake which was highest under biopriming + nutripriming. Values were statistically significant for biopriming and nutripriming and basal + foliar treatment. Lowest PA values in lentil grains as well as PA/Fe ratio were estimated under basal + foliar and biopriming + nutripriming treatments. Combined basal and foliar application of Fe esp. in chelated form and use of seed priming strategies have immense potential in enhancing the Fe bioavailability in grains from soil, seed or foliage.

MRI-Guided Tumor Therapy Based on Synergy of Ferroptosis, Immunosuppression Reversal and Disulfidptosis.

Triple negative breast cancer (TNBC) cells have a high demand for oxygen and glucose to fuel their growth and spread, shaping the tumor microenvironment (TME) that can lead to a weakened immune system by hypoxia and increased risk of metastasis. To disrupt this vicious circle and improve cancer therapeutic efficacy, a strategy is proposed with the synergy of ferroptosis, immunosuppression reversal and disulfidptosis. An intelligent nanomedicine GOx-IA@HMON@IO is successfully developed to realize this strategy. The Fe release behaviors indicate the glutathione (GSH)-responsive degradation of HMON. The results of titanium sulfate assay, electron spin resonance (ESR) spectra, 5,5'-Dithiobis-(2-nitrobenzoicacid (DTNB) assay and T1-weighted magnetic resonance imaging (MRI) demonstrate the mechanism of the intelligent iron atom (IA)-based cascade reactions for GOx-IA@HMON@IO, generating robust reactive oxygen species (ROS). The results on cells and mice reinforce the synergistic mechanisms of ferroptosis, immunosuppression reversal and disulfidptosis triggered by the GOx-IA@HMON@IO with the following steps: 1) GSH peroxidase 4 (GPX4) depletion by disulfidptosis; 2) IA-based cascade reactions; 3) tumor hypoxia reversal; 4) immunosuppression reversal; 5) GPX4 depletion by immunotherapy. Based on the synergistic mechanisms of ferroptosis, immunosuppression reversal and disulfidptosis, the intelligent nanomedicine GOx-IA@HMON@IO can be used for MRI-guided tumor therapy with excellent biocompatibility and safety.

Synthesis and Characterization of Activated Carbon/Alginate-Fe Composites as Slow Release Fertilizer

Research on the slow release kinetics of Fe(III) ions from Activated Carbon/Alginate-Fe(III) composites or abbreviated as K/A-Fe(III) has been carried out. The aim of this research was to synthesize K/A-Fe(III) composite as a material that has the potential to become a slow release micronutrient fertilizer and to study the kinetics of slow release of Fe(III) ions from the composite. The K/A-Fe(III) composite was synthesized by mixing alginate suspension and activated carbon (alginate: activated carbon weight ratio = 1:3 and 3:1) until homogeneous. Composite grains were characterized using Fourier Transformed Infrared (FTIR) spectroscopy, the kinetics of Fe(III) release from the three composite variations found that KAlg31 composite showed more absorption and release of Fe ions than KAlg13.