Iron Oxide Crystals Research Articles

Non-destructive identification of iron oxide crystals in 15th century A.D. Chinese imperial red overglaze decoration

Red overglaze decoration is one of the earliest and most important colorful overglaze decorations in China, which had a remarkable influence on the successful firing and development of polychrome overglaze porcelains. The uncontrollability of red overglaze decoration led to a certain proportion of defective porcelain products in the Ming Dynasty (1368–1644 CE). To investigate and identify the coloring effect of iron oxide crystals in red overglaze decoration, three groups of samples with different color appearance were non-destructively analyzed and observed by OM, spectrophotometer, XRF, Raman spectroscopy, XRD and SEM. The results show that the hue of red overglaze decoration was caused by the different crystal forms of iron oxide. Hematite (α-Fe2O3) displays red color, while maghemite (γ-Fe2O3) and magnetite (Fe3O4) yield orange-red and dark red colors. With the similar raw materials and manufacturing processes, the presence of maghemite and magnetite are relatedto subtle differences in processing raw materials and firing them.

Maximizing pollutant removal and greenhouse gas emission reduction in vertical flow constructed wetlands: an orthogonal experimental approach.

Owing to the impact of the effluent C/N from the secondary structures of urban domestic wastewater treatment plants, the denitrification efficiency in constructed wetlands (CWs) is not satisfactory, limiting their widespread application in the deep treatment of urban domestic wastewater. To address this issue, we constructed enhanced CWs and conducted orthogonal experiments to investigate the effects of different factors (C/N, fillers, and plants) on the removal of conventional pollutants and the reduction of greenhouse gas (GHG) emission. The experimental results indicated that a C/N of 8, manganese sand, and calamus achieved the best denitrification efficiencies with removal efficiencies of 85.7%, 95.9%, and 88.6% for TN, NH4+-N, and COD, respectively. In terms of GHG emission reduction, this combination resulted in the lowest global warming potential (176.8mg/m2·day), with N2O and CH4 emissions of 0.53 and 1.25mg/m2·day, respectively. Characterization of the fillers revealed the formation of small spherical clusters of phosphates on the surfaces of manganese sand and pyrite and iron oxide crystals on the surface of pyrite. Additionally, the surface Mn (II) content of the manganese sand increased by 8.8%, and the Fe (III)/Fe (II) and SO42-/S2- on pyrite increased by 2.05 and 0.26, respectively, compared to pre-experiment levels. High-throughput sequencing indicated the presence of abundant autotrophic denitrifying bacteria (Sulfuriferula, Sulfuritalea, and Thiobacillus) in the CWs, which explains denitrification performance of the enhanced CWs. This study aimed to explore the mechanism of efficient denitrification and GHG emission reduction in the enhanced CWs, providing theoretical guidance for the deep treatment of urban domestic wastewater.

Exploring uncommon Fe-oxides in non-metallic inclusions in ultra-high-strength steel

Investigating non-metallic inclusions within ultra-high-strength-steel via conventional methods is a known: however, the challenge is to obtain chemical information of such inclusions at the sub-micrometer level. In this context, probing Fe-based oxide in inclusions is a vital aspect for guiding steel’ performance. The vibrational properties of sub micrometer size Fe-based oxides were investigated by Raman mapping along with chemometric analysis with the aim of probing their chemical composition. Highly contrasted Raman spectra were recorded from several inclusions embedded at different spatial locations. The observed spectral features were identified as specific markers of hematite (α-Fe2O3) and magnetite (Fe3O4). Principal Component Analysis was used to confirm the presence of these markers and potentially revealing additional patterns. Their unambiguous assignment has been inferred by comparing our experimental findings with the literature data recorded either in single crystals of iron oxides or oxyhydroxides. Micro-Raman spectroscopy is proven to be a reliable, cost-effective, and non-invasive tool for the unambiguous identification of subsurface regions of steel.

Pharmacokinetic Study of Ultrasmall Superparamagnetic Iron Oxide Nanoparticles HY-088 in Rats.

HY-088 injection is an ultrasmall superparamagnetic iron oxide nanoparticle (USPIOs) composed of iron oxide crystals coated with polyacrylic acid (PAA) on the surface. The purpose of this study was to investigate the pharmacokinetics, tissue distribution, and mass balance of HY-088 injection. The pharmacokinetics of [55Fe]-HY-088 and [14C]-HY-088 were investigated in 48 SD rats by intravenous injection of 8.5 (low-dose group), 25.5 (medium-dose group), and 85 (high-dose group) mg/100 μCi/kg. Tissue distribution was studied by intravenous injection of 35 mg/100 μCi/kg in 48 SD rats, and its tissue distribution in vivo was obtained by ex vivo tissue assay. At the same time, [14C]-HY-088 was injected intravenously at a dose of 25.5 mg/100 μCi/kg into 16 SD rats, and its tissue distribution in vivo was studied by quantitative whole-body autoradiography. [14C]-HY-088 and [55Fe]-HY-088 were injected intravenously into 24 SD rats at a dose of 35 mg/100 μCi/kg, and their metabolism was observed. In the pharmacokinetic study, [55Fe]-HY-088 reached the maximum observed concentration (Cmax) at 0.08 h in the low- and medium-dose groups of SD rats. [14C]-HY-088 reached Cmax at 0.08 h in the three groups of SD rats. The area under the concentration-time curve (AUC) of [55Fe]-HY-088 and [14C]-HY-088 increased with increasing dose. In the tissue distribution study, [55Fe]-HY-088 and [14C]-HY-088 were primarily distributed in the liver, spleen, and lymph nodes of both female and male rats. In the mass balance study conducted over 57 days, the radioactive content of 55Fe from [55Fe]-HY-088 was primarily found in the carcass, accounting for 86.42±4.18% in females and 95.46±6.42% in males. The radioactive recovery rates of [14C]-HY-088 in the urine of female and male rats were 52.99±5.48% and 60.66±2.23%, respectively. Following single intravenous administration of [55Fe]-HY-088 and [14C]-HY-088 in SD rats, rapid absorption was observed. Both [55Fe]-HY-088 and [14C]-HY-088 were primarily distributed in the liver, spleen, and lymph nodes. During metabolism, the radioactivity of [55Fe]-HY-088 is mainly present in the carcass, whereas the 14C-labeled [14C]-HY-088 shell PAA is eliminated from the body mainly through the urine.

Rock magnetic analyses as a tool to investigate diversity of drift pumice clasts: An example from Japan's 2021 Fukutoku‐Oka‐no‐Ba (FOB) eruption

AbstractThe crystallization of nanolites within magma chambers has recently raised a strong interest due to their impact on increasing melt viscosity and triggering magmatic eruptions. In 2021, the Fukutoku‐Oka‐no‐Ba (FOB) underwater eruption produced large quantities of pumices that eventually formed rafts drifting at the surface of the ocean to the East coasts of Japan. Pumices collected along the shore shortly after grounding show various colors, microscopic and Raman analyses made by Yoshida et al. (Island Arc, 31, 1, 2022) revealed the presence of magnetite nanolites in some of them. In this study, we explore the magnetic properties of a batch of pumices of different colors from the FOB eruption, aiming to refine characterization of iron oxide nanolites. We used various analytical techniques such as SEM and FEG‐SEM observations, EDS‐X analyses, and rock magnetic experiments, including thermomagnetic analyses, hysteresis curves, coercivity analyses and FORC measurements. Our findings reveal that the iron oxides present in the FOB samples are Ti‐magnetite, with minor amounts of Mg and Al. The magnetic crystals show a wide range of sizes, from extra small iron oxide nanolites (ESION) in the pumices with the lighter colors, to more bulky grains reaching the micrometer size in some of the dark color samples, significant diffusion is inferred in that case. Consequently, the magnetic characterization of iron oxide crystals within the Fukutoku‐Oka‐no‐Ba pumices reveals varying stages of nucleation, dissolution, growth, and diffusion processes, providing evidences for the heterogeneous state of the magma during the eruption.

Washing antimony and arsenic from agricultural soil with eco-friendly organic acids and the relevant bioavailability assessment.

Antimony (Sb) and arsenic (As) contamination in agricultural soil poses human health risks through agricultural products. Soil washing with degradable low molecular weight organic acids (LMWOAs) is an eco-friendly strategy to remediate agricultural soils. In this study, three eco-friendly LMWOAs, oxalic acid (OA), tartaric acid (TA), and citric acid (CA), were used to treat Sb and As co-contaminated agricultural soil from Xikuangshan mine area. The OA, TA, and CA washed out 18.4, 16.8, and 26.6% of Sb and 15.3, 19.9, and 23.8% of As from the agricultural soil, with CA being the most efficient reagent for the soil washing. These organic acids also led to pH decline and macronutrients losses. Fraction analysis using a sequential extraction procedure showed that the three organic acids targeted and decreased the specifically sorbed (F2) (by 19.3-37.6% and 2.41-23.5%), amorphous iron oxide associated (F3) (by 49.1-61.2% and 51.2-70.2%), and crystallized iron oxide associated (F4) (by 12.3-26.0% and 26.1-29.1%) Sb and As. The leachability of Sb and As, as well as their concentrations and bioconcentration factor (BCF) in vegetables reduced due to the soil washing. It demonstrated that the bioavailability of both the elements was decreased by the organic acids washing. The concentrations of Sb and As in typical vegetable species cultivated in CA washed soil were less than the threshold value for consumption safety, while those in OA and TA washed soils were still higher than the value, suggesting that only CA is a potential washing reagent in soil washing for Sb- and As-contaminated agricultural soil.

Behavior and Distribution of Free Iron Oxides in Some Soil Orders in Iraq

This study was conducted to investigating the behavior of free iron oxides in some soil orders in Iraq. Soil samples were collected from five Pedons for soil orders Entisols, Aridisols, Inceptisols, Vertisols and Mollisols. Total free iron oxides (Fed) were extracted by CBD, amorphous iron oxides by acid ammonium oxalate and iron oxide linked with organic matter by alkaline Sodium pyrophosphate. the distribution of iron oxides in (Fep) to crystallized iron oxides were compared. The results showed that (Fed-Feo) there is no particular direction that controls the vertical distribution of Fed Mollisols and Vertisols pedons excelled in the content of Fed compared to the other orders. Amorphous Feo accumulates in surface horizons and Mollisols pedon was excelled on all pedons in Feo content followed by Vertisols, Inceptisols, Aridisols and Entisols. The Pedons of Inceptisols, Aridisols and Entisols soil order contain higher amounts of crystalline Fed-O oxides compared to the Mollisols and Vertisols as well the vertical distribution taken a different pattern for all pedons. (Fep) was low compared to other forms of iron oxides and is accumulated in surface soil horizon in all pedons.

Phase formation and electrical properties of reactively sputtered Fe1−x O thin films

Wüstite, Fe1−x O, is a crucial phase for the transition to CO2-free steel manufacturing as well as promising for electrochemical applications such as water splitting and ammonia synthesis. To study the effect of interfaces in these applications, thin-film model systems with defined interfaces are ideal. Previous studies lack a description of the growth mechanism to obtain Fe1−x O thin films. Here, we investigate the phase formation of metastable Fe1−x O during reactive magnetron sputtering while systematically varying the O2/Ar flow ratio from 1.8% to 7.2% and the pressure–distance product between 3.5 and 7.2 Pa cm. If bulk diffusion is minimized, thin films containing 96 vol.% wüstite and 4 vol.% Fe as impurity phase were achieved. Therefore, the wüstite phase formation appears to be surface diffusion dominated. To reveal the influence of impurity phases in wüstite on the electrical resistivity, systematic electrical resistivity measurements while cooling in situ were performed for the first time. The electrical resistivity was lower than that of single crystals of the respective iron oxides. This is attributed to the formation of Fe-rich layers at the substrate-film interface, which serve as additional conduction paths.

Manufacturing technique for Jizhou painted porcelains in the Yuan dynasty and its influence on coloring

The Jizhou kiln was an important production center of the painted porcelains in Southern China during the Song and Yuan dynasties. The manufacturing technique of the painted porcelains in the Jizhou kiln potentially facilitated the emergence of the well-known blue-and-white porcelains in Jingdezhen. Herein, the chemical compositions and microstructures of the bodies, glazes and paintings of Jizhou painted porcelains from the Yuan dynasty were investigated through X-ray fluorescence (XRF), optical microscopy (OM), Raman spectroscopy and field emission scanning electron microscopy with energy dispersive spectroscopy (SEM‒EDS) to clarify the manufacturing characteristics of Jizhou painted porcelains and their impact on the coloring mechanism. The results showed that the bodies of Jizhou painted porcelains were made of local clay and those transparent glazes were made of local sericite-rich clay and botanic ashes. Black‒brown painted porcelains and red‒brown painted porcelains were methodically made by ancient potters by controlling pigment formulation, painting techniques and firing schedules. The colors of the black‒brown painting and the red‒brown painting were related to the α-Fe2O3 particles in the iron-rich minerals used in the pigment and the iron oxide crystals (α-Fe2O3 and ε-Fe2O3) precipitated on the glaze surface, respectively.

Impact of Hard Magnetic Nanocrystals on the Properties of Hardened Cement Paste

AbstractIn this work, nano‐sized hard magnetic gallium‐substituted iron oxide crystals, wherein gallium is used to stabilize the metastable epsilon iron oxide phase, were added to cement‐water suspensions at different ratios, which were subsequently hydrated for at least 28 days. It is shown that higher contents of such nanocrystals in the hardened cement paste introduce a magnetic moment, whereas the mechanical properties remain unchanged compared to non‐blended hardened cement paste for a wide concentration range.

Cobalt Ferrite Nanoparticles Capped with Perchloric Acid for Life-Science Application

Among the modern oncological therapies, one of the most promising is based on tumor hyperthermia with magnetic nanoparticles resulting from the crystallization of iron and cobalt oxides. We synthesized core–shell magnetic nanoparticles of perchlorate-CoxFe3−xO4 (x = 0; 0.5; 1.0) via the co-precipitation method and stabilized them in aqueous suspensions. Fine granulation of the dispersed ferrophase was revealed by Transmission Electron Microscopy and Dynamical Light Scattering, with FTIR data detailing the surface-interaction phenomena. X-ray diffractometry revealed specific crystallization features of inverse spinel lattice, providing crystallite size and lattice parameters dependent on the cobalt content. The results of the Vibrating Sample Magnetometry investigations indicated that cobalt doping has reduced the magnetic core size and increased the nanoparticle dimension, which could be the result of crystallization defects at the nanoparticle surface related to the presence of cobalt ions. A mathematical model was applied with a focus on the quantitative description of the temperature distribution around magnetic nanoparticles. Further development of our research will consider new cobalt ferrite nanoparticles with new cobalt contents and different organic coatings to contribute to their biocompatibility and stability in aqueous suspensions, as required by administration in living organisms.

New insights into the Piedra de Afilar Formation, Canelones department of Uruguay: Very-low-grade metamorphism, pressure solution, and age

A detailed microstructural, mineralogical, and geochronological study was carried out along a profile in the Piedras de Afilar Formation (PAF) at the González quarry and surroundings (Uruguay). Both the PAF and the Soca granite were affected by very-low-grade metamorphism and pressure-induced dissolution. These post-diagenetic processes resulted in intense corrosion and alteration indicated by sericitization, silicification, and crystallization of iron oxides. Major auto-metamorphism was identified between the intrusive gabbro and the PAF, with almost no effects on the wall rock. K–Ar ages of sericite indicate 609-604 Ma for the metamorphism and related pressure-solution in the PAF. This age is in agreement with the juxtaposition of the Edén or Nico Pérez terranes and the Piedra Alta Terrane along the Sarandí del Yí shear zone. K–Ar dating of the gabbro wall rock constrained a deposition age of the PAF between 1000 and ca. 734 Ma.

Periodic aggregation patterns of oxide particles on corroding metals: chemical waves due to solution feedback processes.

Chemical waves that produce periodic patterns are common occurrences in nature. The underlying processes involved have been studied in many disciplines of science, but rarely reported in the chemistry of corrosion. In this study of carbon steel corrosion, iron oxide crystals are observed to deposit in concentric wave patterns or in discrete bands, known as Liesegang patterns. We demonstrate that oxide growth in these patterns is preceded by the formation of a hydrogel network, which consists of a semi-stationary phase of loosely connected metal-hydroxide colloids and a mobile phase of solution saturated with metal cations. Once the hydrogel network covers the metal surface, a metal cation produced by corrosion reactions at the metal surface must diffuse through the layer into the bulk solution. While diffusing through the porous network, the metal cation undergoes adsorption-precipitation as metal-hydroxide colloids which later can dissolve back into the solution. When the kinetics of precipitation and dissolution of the metal cation can be effectively coupled with the transport flux of the dissolved metal cation, the precipitation-dissolution-diffusion cycles can be sustained over time which can lead to periodic aggregation patterns of metal-hydroxide colloids at a specific time. We also establish that for transition metal cations the precipitation-dissolution-diffusion process can couple with reversible redox reactions between the soluble and less soluble metal cations, which can affect the overall transport of banded aggregates of metal-hydroxide colloids and the growth and transformation of metal-hydroxides into crystalline oxides. If systemic feedback between different elementary processes is sustained over long durations, iron-oxide crystals of different chemical compositions and shapes aggregate in Liesegang patterns. This work demonstrates unequivocally that non-uniform deposition of metal oxides during corrosion can occur via strongly coupled solution reactions and transport processes, and not simply as a result of metallurgical non-uniformity and/or localized solution environments.

The interface mechanism of sludge biochar activating persulfate to remove tetracycline: The role of the C-O-Fe bridge at the carbon surface

In recent years, with the widespread use of antibiotics and the dramatic increase in municipal sludge production, the removal of antibiotics from the water environment and the resourceful and harmless treatment of municipal sludge have become major issues in environmental management. Herein, sewage sludge containing Fe was prepared as biochar (SSBC) for activating peroxydisulfate (PDS) to remove tetracycline (TC) in water. The results showed that SSBC/PDS system removed 86.7% of TC, which was higher than the removal of TC by PDS alone (29%). SEM-EDS, FT-IR, XRD, and other characterizations showed that the Fe on SSBC existed as functional groups rather than as iron oxide crystals. Based on this, we proposed the presence of a C-O-Fe structure on the surface of unmodified SSBC. XPS analysis and DFT calculations showed that the presence of C-O-Fe changed the charge distribution on the SSBC surface and formed a Fe-centered electron reaction zone to better activate PDS for TC degradation. The active species in the degradation process included 1O2, ·OH, SO4·-, O2·-, where ·OH originated from activating PDS by C-O-Fe. Toxicity prediction of intermediates showed that hydroxylation and demethylation were the major degradation steps and most intermediates were less toxic than TC.

Combined Focused Ion Beam – Scanning Electron Microscope and Synchrotron X-ray Fluorescence analysis of multi-solid and melt inclusions from the super-giant Grasberg Cu[sbnd]Au deposit, Indonesia

Previous studies of the mineralised quartz veins from the Grasberg CuAu deposit in Indonesia have shown that they contain multi-solid inclusions and silicate melt inclusions. The multi-solid inclusions exhibit salinities up to 75 wt% NaCl equiv. and ultrahigh homogenisation (Vapour + Liquid + Solid → Liquid) temperatures, up to 1281 °C, but the processes leading to their formation are poorly understood. To determine the composition of these inclusions they were analysed by Focused Ion Beam – Scanning Electron Microscope (FIB-SEM) and Synchrotron X-ray Fluorescence (SXRF) techniques. FIB-SEM analysis of two representative multi-solid inclusions (MSI) showed that they contain a large halite and a smaller sylvite crystal and mixed KFe chloride crystals. K-feldspar crystals occurring inside and outside the multi-solid inclusions indicate that they were trapped from a melt phase. The ore-mineral chalcopyrite was also identified in one inclusion. Opening the multi-solid inclusions under vacuum resulted in a coating enriched in Na, K, Fe and Cl that precipitated on the crystals and walls of the inclusions. FIB-SEM analysis of a coexisting silicate melt inclusion showed that it consisted mainly of a devitrified glass with approximately K-feldspar composition that also contained small crystals of iron oxide. Further milling of the melt inclusion exposed a CuFe-rich silicate mineral. SXRF analysis of another multi-solid inclusion indicated that Br and Zn occur in the aqueous phase whereas K, Ca, Fe, Pb and Mn are hosted by solid phases within the inclusion.Modelling of mineralisation processes demonstrate that a supercritical, intermediate density fluid (with ~5 wt% NaCl) underwent an initial pressure drop causing phase separation and the formation of a vapour-rich fluid and a small fraction of brine, which led to the formation of salt hydrates, salt melts or both within the MSI. The coexistence of silicate melt inclusions and the occurrence of hematite and, K-feldspar in MSI suggest that a coeval silicate melt is also associated with mineralisation at the Grasberg deposit. The high salinity, multi-solid inclusions and melt inclusions form early in the vein paragenesis and record the origin and initial processes of ore deposition. Furthermore, the high metal-bearing capacity of salt melts suggests that the observation of coexisting silicate and salt melts may indicate the presence of a fertile mineral system.

Multifunctional Core@Satellite Magnetic Particles for Magnetoresistive Biosensors.

Magnetoresistive (MR) biosensors combine distinctive features such as small size, low cost, good sensitivity, and propensity to be arrayed to perform multiplexed analysis. Magnetic nanoparticles (MNPs) are the ideal target for this platform, especially if modified not only to overcome their intrinsic tendency to aggregate and lack of stability but also to realize an interacting surface suitable for biofunctionalization without strongly losing their magnetic response. Here, we describe an MR biosensor in which commercial MNP clusters were coated with gold nanoparticles (AuNPs) and used to detect human IgG in water using an MR biochip that comprises six sensing regions, each one containing five U-shaped spin valve sensors. The isolated AuNPs (satellites) were stuck onto an aggregate of individual iron oxide crystals (core) so that the resulting core@satellite magnetic particles (CSMPs) could be functionalized by the photochemical immobilization technique—an easy procedure that leads to oriented antibodies immobilized upright onto gold. The morphological, optical, hydrodynamic, magnetic, and surface charge properties of CSMPs were compared with those exhibited by the commercial MNP clusters showing that the proposed coating procedure endows the MNP clusters with stability and ductility without being detrimental to magnetic properties. Eventually, the high-performance MR biosensor allowed us to detect human IgG in water with a detection limit of 13 pM (2 ng mL–1). Given its portability, the biosensor described in this paper lends itself to a point-of-care device; moreover, the features of the MR biochip also make it suitable for multiplexed analysis.

A model towards understanding stabilities and crystallization pathways of iron (oxyhydr)oxides in redox-dynamic environments

Crystallization and transformation of iron (oxyhydr)oxides occur widely in redox-dynamic environments, which are closely linked to iron cycling, (im)mobilization of co-associated elements, and microbial iron metabolisms. Although numerous studies have been conducted to investigate the occurrence and fate of iron (oxyhydr)oxides under various redox conditions, the mechanism controlling these processes is still incompletely understood. Here, we present a theoretical model, based on Classical Nucleation Theory (CNT), that can be used to predict and rationalize phase-selection and crystallization pathways of iron (oxyhydr)oxides under different redox conditions. By calculating the energy landscapes of dissolved or solid-phase iron species in a Fe-H2O system as a function of Eh, pH, and particle size, we show how the stability regions of iron (oxyhydr)oxides change with geochemical environments (pH and redox potential) and initial properties of precursors (particle size and crystallinity). Through the calculation of thermodynamic driving forces and energy barriers for the nucleation of different metastable phases, the crystallization pathways of iron (oxyhydr)oxides via hydrolysis of Fe3+(aq), oxidation of Fe2+(aq), and Fe(II)-catalyzed ferrihydrite transformation can be predicted. The computational results show good agreement with previously reported experimental data. This study provides a unified model to predict and understand relative stability, transformation, and persistence of iron (oxyhydr)oxides under varying pH and redox conditions in natural environments.

Zinc Fertilizers Modified the Formation and Properties of Iron Plaque and Arsenic Accumulation in Rice (Oryza sativa L.) in a Life Cycle Study.

This study examined the effect of three forms of zinc fertilizers on arsenic (As) accumulation and speciation in rice tissues over the life cycle of this cereal crop in a paddy soil. The formation and properties of iron plaque on rice roots at the maximum tillering stage and the mature stage were also determined. Elevated As at 5 mg/kg markedly lowered the rice yield by 86%; however, 100 mg/kg Zn fertilizers significantly increased the rice yield by 354-686%, regardless of the Zn form. Interestingly, only Zn2+ significantly lowered the total As in rice grains by 17% to 3.5 mg/kg and As(III) by 64% to around 0.5 mg/kg. Zinc amendments substantially hindered and, in the case of zinc oxide bulk particles (ZnOBPs), fully prevented the crystallization of iron oxides (Fe3O4 and Fe2O3) and silicon oxide (SiO2) and altered the composition of iron plaques on rice roots. SiO2 was first reported to be a significant component of iron plaque. Overall, ZnOBPs, ZnO nanoparticles, and Zn2+ displayed significant yet distinctive effects on the properties of iron plaque and As accumulation in rice grains, providing a fresh perspective on the potentially unintended consequences of different Zn fertilizers on food safety.

Self-Confirming Magnetosomes for Tumor-Targeted T1 /T2 Dual-Mode MRI and MRI-Guided Photothermal Therapy.

Nanomaterials as T1 /T2 dual-mode magnetic resonance imaging (MRI) contrast agents have great potential in improving the accuracy of tumor diagnosis. Applications of such materials, however, are limited by the complicated chemical synthesis process and potential biosafety issues. In this study, the biosynthesis of manganese (Mn)-doped magnetosomes (MagMn) that not only can be used in T1 /T2 dual-mode MR imaging with self-confirmation for tumor detection, but also improve the photothermal conversion efficiency for MRI-guided photothermal therapy (PTT) is reported. The MagMn nanoparticles (NPs) are naturally produced through the biomineralization of magnetotactic bacteria by doping Mn into the ferromagnetic iron oxide crystals. In vitro and in vivo studies demonstrated that targeting peptides functionalized MagMn enhanced both T1 and T2 MRI signals in tumor tissue and significantly inhibited tumor growth by the further MRI-guided PTT. It is envisioned that the biosynthesized multifunctional MagMn nanoplatform may serve as a potential theranostic agent for cancer diagnosis and treatment.

Applying Saudi clay deposits for treatment of household water at the point-of-use

This research aims to beneficiate the clay deposits abundant in the Al Baha district to produce ceramic filters for “point-of-use” household water treatment technology to remove dissolved solids from water that is no longer valid for drinking purposes to meet the needs of the community through a safe household and industrial water supply after further treatment purposes. In addition, it helps to reduce the expenses of citizens earmarked to buy drinking water. A sample of laterite, clay, and kaolin from Al Baha district was thermally treated at 800 °C, acid treated with HCl, analyzed by XRD, FTIR, and SEM, and tested for treatment of household water. The temperature, pH, electrical conductivity (EC), and total dissolved solids (TDS) were measured. In the application step for point-of-use water treatment of household water, the treated materials were introduced in calcined kaolin filters and commercial polypropylene filters. Based on the results of household water treatment with raw and treated clay materials, the raw clay materials, has poor adsorption capacity. The thermal treatment of clay samples dehydrates the clay minerals into sintered aluminosilicates and enhances the conversion of poorly crystallized iron oxide to α-Fe2O3 without improving the adsorption capacity of clay materials. However, the acid treatment of the clay samples removes iron-bearing minerals leaving behind amorphous aluminosilicate matter characterized with improved adsorption capacity. It was concluded that the acid treatment of clay material by concentrated HCl acid completely leaches iron oxide phases and broke down and disintegrated the clay minerals into the amorphous matter with enhanced the adsorption capacity. The combination of selected acid-treated laterite, clay, and charcoal for the household water treatment filter at the point of use in the calcined kaolin filter and the polypropylene filter reduced the TDS content by 40–42%.