Experimental study on harmful effects of zero-valent Iron on Paraprionospio patiens.

Iron is an essential trace element for living organisms, and it plays an important role in redox reactions in aquatic environments. Although many studies have investigated the application of iron materials to improve water and sediment quality, their negative effects remain unknown. Therefore, this study investigated the effects of three iron materials, i.e., zero-valent iron, iron oxide, and iron oxyhydroxide, on common benthic organisms in a coastal area via exposure experiments. In the exposure experiments, Paraprionospio patiens, a marine polychaete, exhibited abnormal behavior immediately after the addition of zero-valent iron, and the average survival rate after 14 d decreased significantly (Scheffé's test: p < 0.05). This is the first study to show that zero-valent iron on the sediment surface negatively affects the survival of P. patiens. Although Iron materials are often used to improve aquatic environments, their potential adverse effects should be addressed through continuous monitoring after use.

Enhancing the oxygen evolution reaction activity and stability of high-valent CoOOH by switching the catalytic pathway through doping low-valent Cu.

The oxygen evolution reaction (OER) is a critical process in electrochemical energy storage and conversion systems. The adsorbate evolution mechanism (AEM) pathway possesses the characteristics of high stability but slow catalytic kinetics. We propose that combining AEM with the lattice oxidation mechanism (LOM) pathway can potentially enhance the OER catalytic activity and stability. However, the triggering of LOM is an important challenge due to the high thermodynamic activation barrier of lattice oxygen. To solve this problem, we performed theoretical calculations and experiments which suggest that the introduction of low-valent Cu in CoOOH (CuxCo1-xOOH) could directionally modulate the local coordination environment of CoO bonds. This approach can activate lattice oxygen and generate oxygen vacancies to enhance the nucleophilic attack of *OH and directly establish OO coupling, thereby facilitating the smoothly switching from AEM to LOM pathway by increasing voltage and thus activating lattice oxygen in CuxCo1-xOOH. The switching of AEM and LOM enables CuxCo1-xOOH showing an outstanding overpotential of only 252 mV (10 mA cm-2) and durability of only 2.80 % degradation after 280h. This work provides a new way for designing efficient and stable electrocatalysts with AEM and LOM pathway switching.

The Use of Sucroferric Oxyhydroxide Prior to Sigmoidoscopy in Patients With End-Stage Kidney Disease: A Case Report.

Rationale: Sucroferric oxyhydroxide is an iron-based phosphate-binding medication that has been approved for the treatment of hyperphosphatemia in patients with end-stage kidney disease. Given the low overall iron release from the polynuclear iron(III)-oxyhydroxide molecule, recommendations regarding its use prior to colonoscopy/sigmoidoscopy have not been developed. Presenting concerns of the patient: A 51-year-old male with a known history of end-stage renal disease treated with hemodialysis was referred to Gastroenterology for consideration of colonoscopy to rule out malignancy because of a history of rectal bleeding. This was to be completed prior to proceeding with a living-donor kidney transplant. Diagnoses: Flexible sigmoidoscopy done after non-diagnostic colonoscopy demonstrated diffuse "charcoal-like" material that prevented adequate visualization of the bowel despite standard bowel preparation. The findings were believed to be secondary to the use of sucroferric oxyhydroxide prescribed for hyperphosphatemia. Interventions: The patient was subsequently instructed to discontinue sucroferric oxyhydroxide for 2 weeks prior to his repeat sigmoidoscopy procedure. Outcomes: The patient's repeat sigmoidoscopy after discontinuing sucroferric oxyhydroxide allowed for adequate bowel visualization that revealed only a benign lipoma. Teaching Points: This case demonstrates the potential for sucroferric oxyhydroxide use to result in poor bowel preparation and resulting inadequate visualization on lower gastrointestinal endoscopy. It serves to highlight the clinical implications leading to the need for repeated procedures, which contributes to resource waste and unnecessary costs to the healthcare system, as well as delays in diagnostic evaluation required for transplantation; patient frustration was evident.

Justification: L'oxyhydroxyde sucro-ferrique, un médicament à base de fer liant le phosphate, a été approuvé pour le traitement de l'hyperphosphatémie chez les patients atteints d'insuffisance rénale terminale. La molécule polynucléaire fer (lll) ­ oxyhydroxyde ne libérant qu'une faible quantité globale de fer, aucune recommandation n'a été développée concernant son utilisation avant une coloscopie/sigmoïdoscopie. Présentation du cas: Un homme de 51 ans connu pour insuffisance rénale terminale et traité par hémodialyse a été orienté en gastroentérologie pour subir une coloscopie afin d'exclure une tumeur maligne en raison d'antécédents de saignement rectal. L'examen devait être complété avant de procéder à la greffe de rein par donneur vivant. Diagnostic: Une sigmoïdoscopie souple réalisée après une coloscopie non diagnostique a révélé une matière diffuse de type « charbon de bois ¼ qui empêchait de bien voir l'intestin malgré une préparation intestinale adéquate. Ce résultat a été jugé secondaire à l'utilisation d'oxyhydroxyde sucro-ferrique prescrit pour traiter l'hyperphosphatémie. Intervention: On a demandé au patient d'interrompre le traitement par oxyhydroxyde sucro-ferrique pendant deux semaines avant de répéter la procédure de sigmoïdoscopie. Résultats: La sigmoïdoscopie répétée après l'arrêt de l'oxyhydroxyde sucroferrique a permis une visualisation adéquate de l'intestin qui n'a révélé qu'un lipome bénin. Enseignements tirés: Ce cas démontre que l'utilisation d'oxyhydroxyde sucro-ferrique peut entraîner une mauvaise préparation intestinale et entraver la visualisation lors d'une endoscopie gastro-intestinale basse. Il met en évidence les répercussions cliniques qui justifient des procédures répétées, lesquelles contribuent au gaspillage des ressources et entraînent des coûts inutiles pour le système de santé, ainsi que les retards dans l'évaluation diagnostique requise pour la transplantation; dans ce cas, la frustration du patient était évidente.

Extent of As(III) versus As(V) adsorption on iron (oxyhydr) oxides depends on the presence of vacancy cluster-like micropore sites: Insights into a seesaw effect.

Iron (oxyhydr)oxides are ubiquitous in terrestrial environments and play a crucial role in controling the fate of arsenic in sediments and groundwater. Although there is evidence that different iron (oxyhydr)oxides have different affinities towards As(III) and As(V), it is still unclear why As(V) adsorption on some iron (oxyhydr)oxides is larger than As(III) adsorption, while it is opposite for other ones. In this study, six typical iron (oxyhydr)oxides are selected to evaluate their adsorption capacities for As(III) and As(V). The characteristics of these iron minerals such as morphology, arsenic adsorption species, and pore size distribution are carefully examined using transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), positron annihilation lifetime (PAL) spectroscopy, and X-ray absorption spectroscopy (XAS). We confirm a seesaw effect occurred in different iron minerals for As(III) and As(V) immobilization, i.e., at pH 6.0, adsorption of As(V) on hematite (0.73 µmol m-2) and magnetite (0.33 µmol m-2) is higher than for As(III) (0.61 µmol m-2 and 0.27 µmol m-2, respectively), for goethite and lepidocrocite it is almost equal, while As(III) sorption on ferrihydrite (5.77 µmol m-2) and schwertmannite (28.41 µmol m-2) showed higher sorption than As(V) (1.53 µmol m-2 and 12.99 µmol m-2, respectively). PAL analysis demonstrates that ferrihydrite and schwertmannite have a large concentration of vacancy cluster-like micropores, significantly more than goethite and lepidocrocite, followed by hematite and magnetite. The difference of adsorption of As(III) and As(V) to different iron (oxyhydr)oxides is due to differences in the abundance of vacancy cluster-like micropore sites, which are conducive for smaller size As(III) immobilization but not for larger size of As(V). The findings of this study provide novel insights into a seesaw effect for As(III) and As(V) immobilization on naturally occurring iron mineral.

Synthesis of spinel Nickel Ferrite (NiFe2O4)/CNT electrocatalyst for ethylene glycol oxidation in alkaline medium.

Nickel-iron-based spinel oxide was prepared and supported on multi-walled carbon nanotubes to enhance the electrochemical oxidation of ethylene glycol in an alkaline medium. NiFe2O4 was prepared using facile sol-gel techniques. Then the prepared material was characterized using different bulk and surface techniques like powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and transmitted electron microscope (TEM). Different electrodes of NiFe2O4/CNT ratios were prepared to find out the optimum spinel oxide/CNT ratio. The activity of the metal spinel oxides composite was characterized toward ethylene glycol conversion by different electrochemical techniques like cyclic voltammetry (CV), Chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). The modified electrode reached an oxidation current of 43 mA cm-2 in a solution of 1.0 M ethylene glycol and 1.0 M NaOH. Furthermore, some kinetics parameters (like diffusion coefficient, and rate constant) were calculated to evaluate the catalytic performance. Additionally, the electrode showed extreme stability for long-term ethylene glycol oxidation.

Stabilizing Pure Water-Fed Anion Exchange Membrane Water Electrolyzers through Membrane-Electrode Interface Engineering.

Nickel-iron (oxy)hydroxide (NiFeOxHy) stands as a cutting-edge nonprecious electrocatalyst for the oxygen evolution reaction (OER). However, the intrinsic thermodynamic instability of nickel and iron as anode materials in pure water-fed electrolyzers poses a significant durability challenge. In this study, an anion exchange ionomer coating was applied to NiFeOxHy to modify the local pH between a membrane and an electrode. This effectively extended the diffusion length of hydroxide anions toward the electrode, establishing an alkaline local pH environment. Stability tests with the ionomer coating showed reduced Ni dissolution. Moreover, locally resolved current density measurements were used to demonstrate a notably lower degradation rate during stability testing, revealing a 6-fold increase in stability with the ionomer on NiFeOxHy. In situ Raman spectroscopy in a neutral pH electrolyte confirmed inhibited Ni oxidation with the ionomer, mitigating Ni dissolution and enhancing stability of state-of-the-art NiFeOxHy catalysts in pure water-fed water electrolyzers.

Time-varying contributions of FeII and FeIII to AsV immobilization under anoxic/oxic conditions: The impacts of biochar and dissolved organic carbon.

Engineering black carbon (e.g. biochar) has been widely found in natural environments due to natural processes and extensive applications in engineering systems, and could influence the geochemical processes of coexisting arsenic (AsV) and FeII, especially when they are exposed to oxic conditions. Here, we studied time-varying kinetics and efficiencies of AsV immobilization by solid-phase FeII (FeIIsolid) and FeIII (FeIIIsolid) in FeII-AsV-biochar systems under both anoxic and oxic conditions at pH 7.0, with focuses on the effects of biochar surface and biochar-derived dissolved organic carbon (DOC). Under anoxic conditions, FeII could rapidly immobilize AsV via co-adsorption onto biochar surfaces, which also serves as the dominant pathway of AsV immobilization at the initial stage of reaction (0-5 min) under oxic conditions at high biochar concentrations. Subsequently, with increasing biochar concentrations, FeIIIsolid precipitation from aqueous FeII (FeIIaq) oxidation (5-60 min) starts to play an important role in AsV immobilization but in decreased efficiencies of AsV immobilization per unit iron. In the following stage (60-300 min), FeIIsolid oxidation is suppressed and leads to AsV release into solutions at >1.0 g·L-1 biochar. The decreasing efficiency of AsV immobilization over time is attributed to the gradual release of DOC into solution from biochar particles, which significantly inhibit AsV immobilization when FeIIIsolid is generated from FeIIsolid oxidation in the vicinity of biochar surfaces. Specifically, 4.06 mg·L of biochar-derived DOC can completely inhibit the immobilization of AsV in the 100 µM FeII system under oxic conditions. The findings are crucial to comprehensively understand and predict the behavior of FeII and AsV with coexisting engineering black carbon in natural environments.

Direct Identification of O─O Bond Formation Through Three-Step Oxidation During Water Splitting by Operando Soft X-ray Absorption Spectroscopy.

Anionic redox allows the direct formation of O─O bonds from lattice oxygens and provides higher catalytic in the oxygen evolution reaction (OER) than does the conventional metal ion mechanism. While previous theories have predicted and experiments have suggested the possible O─O bond, it has not yet been directly observed in the OER process. In this study, operando soft X-ray absorption spectroscopy (sXAS) at the O K-edge and the operando Raman spectra is performed on layered double CoFe hydroxides (LDHs) after intercalation with [Cr(C2O4)3]3-, and revealed a three-step oxidation process, staring from Co2+ to Co3+, further to Co4+ (3d6L), and ultimately leading to the formation of O─O bonds and O2 evolution above a threshold voltage (1.4 V). In contrast, a gradual oxidation of Fe is observed in CoFe LDHs. The OER activity exhibits a significant enhancement, with the overpotential decreasing from 300 to 248 mV at 10 mA cm-2, following the intercalation of [Cr(C2O4)3]3- into CoFe LDHs, underscoring a crucial role of anionic redox in facilitating water splitting.

A High-Entropy Oxyhydroxide with a Graded Metal Network Structure for Efficient and Robust Alkaline Overall Water Splitting.

Designing high-entropy oxyhydroxides (HEOs) electrocatalysts with controlled nanostructures is vital for efficient and stable water-splitting electrocatalysts. Herein, a novel HEOs material (FeCoNiWCuOOH@Cu) containing five non-noble metal elements derived by electrodeposition on a 3D double-continuous porous Cu support is created. This support, prepared via the liquid metal dealloying method, offers a high specific surface area and rapid mass/charge transfer channels. The resulting high-entropy FeCoNiWCuOOH nanosheets provide a dense distribution of active sites. The heterostructure between Cu skeletons and FeCoNiWCuOOH nanosheets enhances mass transfer, electronic structure coupling, and overall structural stability, leading to excellent activities in the oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and water splitting reaction. At 10 mA cm-2, the overpotentials for OER, HER, and water splitting in 1.0 m KOH solution are 200, 18, and 1.40 V, respectively, outperforming most current electrocatalysts. The catalytic performance remains stable even after operating at 300 mA cm-2 for 100, 100, and over 1000 h, correspondingly. This material has potential applications in integrated hydrogen energy systems. More importantly, density functional theory (DFT) calculations demonstrate the synergy of the five elements in enhancing water-splitting activity. This work offers valuable insights for designing industrial water electrolysis systems.

Anchoring Ni(OH)2-CeOx Heterostructure on FeOOH-Modified Nickel-Mesh for Efficient Alkaline Water-Splitting Performance with Improved Stability under Quasi-Industrial Conditions.

Developing low-cost and industrially viable electrode materials for efficient water-splitting performance and constructing intrinsically active materials with abundant active sites is still challenging. In this study, a self-supported porous network Ni(OH)2-CeOx heterostructure layer on a FeOOH-modified Ni-mesh (NiCe/Fe@NM) electrode is successfully prepared by a facile, scalable two-electrode electrodeposition strategy for overall alkaline water splitting. The optimized NiCe0.05/Fe@NM catalyst reaches a current density of 100 mA cm-2 at an overpotential of 163 and 262 mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively, in 1.0 m KOH with excellent stability. Additionally, NiCe0.05/Fe@NM demonstrates exceptional HER performance in alkaline seawater, requiring only 148 mV overpotential at 100 mA cm-2. Under real water splitting conditions, NiCe0.05/Fe@NM requires only 1.701 V to achieve 100 mA cm-2 with robust stability over 1000 h in an alkaline medium. The remarkable water-splitting performance and stability of the NiCe0.05/Fe@NM catalyst result from a synergistic combination of factors, including well-optimized surface and electronic structures facilitated by an optimal Ce ratio, rapid reaction kinetics, a superhydrophilic/superaerophobic interface, and enhanced intrinsic catalytic activity. This study presents a simple two-electrode electrodeposition method for the scalable production of self-supported electrocatalysts, paving the way for their practical application in industrial water-splitting processes.

Uncovering the role of free lanthanum (La3+) ions and La oligomer on the surface of La (oxy)hydroxide particles for phosphate removal.

La (oxy)hydroxide-based materials have been recognized as promising adsorbents for aqueous phosphate (P) removal. However, comprehending the adsorption behavior of P onto La (oxy)hydroxide particles remains challenging, given the heterogeneous low-crystalline surface encompassing La oligomers and free La3+ ions. In this study, a hydrogen (H) bond capping method was developed to construct La (oxy)hydroxide oligomers (LHOs) to simulate the low-crystalline La on the surface of La (oxy)hydroxide particles. The P uptake capacity was compared among free La3+ ions, LHOs, and La nanoparticle (La-NP) with maximum capacities of 1967.3 ± 30.8 mg/g, 461.1 ± 53.7 mg/g and 62.5 ± 6.0 mg/g, respectively. The FT-IR, Raman, in situ-XRD and XPS deconvolution analyses revealed that the removal of P by free La3+ ions mainly involve the process of chemical precipitation to form LaPO4·0.5H2O. Conversely, the elimination of P by LHOs is primarily attributed to inner-sphere complexation and hydroxyl exchange effect between LaOOH and P. Based on this study, the free La3+ ions and La oligomers on the surface of La (oxy)hydroxide particles play a primary role in P adsorption. These results also suggest that the successively decreased adsorption capacity of La (oxy)hydroxide-based adsorbents in the continuously adsorption/desorption cycles might be due to the irreversible inactivation and recrystallization of free La3+ ions and La oligomers on the surface.

Single-atom Zr-doped CoOOH with enhanced electrical conductivity as a signal amplifier and detection probe for the indirect non-enzymatic electrochemical determination of malathion in foods.

Herein, a novel electrochemical sensor based on zirconium-doped cobalt oxyhydroxide (ZrCoOOH) was proposed for highly sensitive non-enzymatic determination of malathion (MAL). The doping of Zr can improve the electrical conductivity of CoOOH, of which the transfer resistance was reduced from 241.1 Ω to 140.2 Ω. Furthermore, the X-ray photoelectron spectroscopy confirmed that part of Co2+ was converted to Co3+ due to the introduction of Zr. The Co3+ in ZrCoOOH could react with MAL to form Co2+, which enhanced the electrooxidation current of Co2+. Therefore, the peak current of Co2+ was served as detection probe for MAL. Under optimal conditions, the developed sensor established the linear relationship for MAL in the concentration range of 0.001-10.0 µM with a low limit of detection (0.64 nM). The constructed sensor was employed to detect MAL in food samples (peach, kiwi fruit, spinach and tomato), verifying the accuracy and practicability of the sensor.

Management of serum phosphorus over a 1-year follow-up in patients on peritoneal dialysis prescribed sucroferric oxyhydroxide as part of routine care: a retrospective analysis.

BACKGROUND: Hyperphosphatemia is associated with increased morbidity and mortality in patients with end-stage kidney disease (ESKD). Whereas clinical and observational studies have demonstrated the effectiveness of sucroferric oxyhydroxide (SO) in controlling serum phosphorus (sP) in ESKD, data on the real-world impact of switching to SO in patients on peritoneal dialysis (PD) are limited. In this retrospective database analysis, we examine the impact of SO on sP management over a 1-year period among PD patients prescribed SO as part of routine clinical care. METHODS: We analyzed de-identified data from adults on PD in Fresenius Kidney Care clinics who were prescribed SO monotherapy between May 2018 and December 2019 as part of routine clinical management. Changes from baseline in sP levels, phosphate binder (PB) pill burden, and laboratory parameters were evaluated during the four consecutive 91-day intervals of SO treatment. RESULTS: The mean age of the 402 patients who completed 1 year of SO was 55.2 years at baseline, and they had been on PD for an average of 19.9 months. SO was initiated with no baseline PB recorded in 36.1% of patients, whereas the remaining 257 patients were switched to SO from sevelamer (39.7%), calcium acetate (30.4%), lanthanum (1.2%), ferric citrate (14.0%), or more than one PB (14.8%). Mean sP at baseline was 6.26 mg/dL. After being prescribed SO, the percentage of patients achieving sP ≤ 5.5 mg/dL increased from 32.1% (baseline) to 46.5-54.0% during the 1-year follow-up, whereas the mean number of PB pills taken per day decreased from 7.7 at baseline (among patients on a baseline PB) to 4.6 to 5.4. Serum phosphorus and PB pill burden decreased regardless of changes in residual kidney function over the 12-month period. Similar results were observed for the full cohort (976 patients who either completed or discontinued SO during the 1-year follow-up). CONCLUSIONS: Patients on PD who were prescribed SO as part of routine care for phosphorus management experienced significant reductions in SP and PB pills per day and improvements in sP target achievement, suggesting the effectiveness of SO on SP management with a concurrent reduction in pill burden.

Silicon or Calcium Doping Coordinates the Immunostimulatory Effects of Aluminum Oxyhydroxide Nanoadjuvants in Prophylactic Vaccines.

Aluminum salts still remain as the most popular adjuvants in marketed human prophylactic vaccines due to their capability to trigger humoral immune responses with a good safety record. However, insufficient induction of cellular immune responses limits their further applications. In this study, we prepare a library of silicon (Si)- or calcium (Ca)-doped aluminum oxyhydroxide (AlOOH) nanoadjuvants. They exhibit well-controlled physicochemical properties, and the dopants are homogeneously distributed in nanoadjuvants. By using Hepatitis B surface antigen (HBsAg) as the model antigen, doped AlOOH nanoadjuvants mediate higher antigen uptake and promote lysosome escape of HBsAg through lysosomal rupture induced by the dissolution of the dopant in the lysosomes in bone marrow-derived dendritic cells (BMDCs). Additionally, doped nanoadjuvants trigger higher antigen accumulation and immune cell activation in draining lymph nodes. In HBsAg and varicella-zoster virus glycoprotein E (gE) vaccination models, doped nanoadjuvants induce high IgG titer, activations of CD4+ and CD8+ T cells, cytotoxic T lymphocytes, and generations of effector memory T cells. Doping of aluminum salt-based adjuvants with biological safety profiles and immunostimulating capability is a potential strategy to mediate robust humoral and cellular immunity. It potentiates the applications of engineered adjuvants in the development of vaccines with coordinated immune responses.

A "Ferroptosis-Amplifier" Hydrogel for Eliminating Refractory Cancer Stem Cells Post-lumpectomy.

The unique "Iron Addiction" feature of cancer stem cells (CSCs) with tumorigenicity and plasticity generally contributes to the tumor recurrence and metastasis after a lumpectomy. Herein, a novel "Ferroptosis Amplification" strategy is developed based on integrating gallic acid-modified FeOOH (GFP) and gallocyanine into Pluronic F-127 (F127) and carboxylated chitosan (CC)-based hydrogel for CSCs eradication. This "Ferroptosis Amplifier" hydrogel is thermally sensitive and achieves rapid gelation at the postsurgical wound in a breast tumor model. Specifically, gallocyanine, as the Dickkopf-1 (DKK1) inhibitor, can decrease the expression of SLC7A11 and GPX4 and synergistically induce ferroptosis of CSCs with GFP. Encouragingly, it is found that this combination suppresses the migratory and invasive capability of cancer cells via the downregulation of matrix metalloproteinase 7 (MMP7). The in vivo results further confirm that this "Ferroptosis Amplification" strategy is efficient in preventing tumor relapse and lung metastasis, manifesting an effective and promising postsurgical treatment for breast cancer.

Aluminum oxyhydroxide-Poly(I:C) combination adjuvant with balanced immunostimulatory potentials for prophylactic vaccines.

The development of high-purity antigens promotes the urgent need of novel adjuvant with the capability to trigger high levels of immune response. Polyinosinic-polycytidylic (Poly(I:C)) is a synthetic double-stranded RNA (dsRNA) that can engage Toll-like receptor 3 (TLR3) to initiate immune responses. However, the Poly(I:C)-induced toxicity and inefficient delivery prevent its applications. In our study, combination adjuvants are formulated by aluminum oxyhydroxide nanorods (AlOOH NRs) and Poly(I:C), named Al-Poly(I:C), and the covalent interaction between the two components is further demonstrated. Al-Poly(I:C) mediates enhanced humoral and cellular immune responses in three antigen models, i.e., HBsAg virus-like particles (VLPs), human papilloma virus (HPV) VLPs and varicella-zoster virus (VZV) glycoprotein E (gE). Further mechanistic studies demonstrate that the dose and molecular weight (MW) of Poly(I:C) determine the physicochemical properties and adjuvanticity of the Al-Poly(I:C) combination adjuvants. Al-Poly(I:C) with higher Poly(I:C) dose promotes antigen-bearing dendritic cells (DCs) recruitment and B cells proliferation in lymph nodes. Al-Poly(I:C) formulated with higher MW Poly(I:C) induces higher activation of helper T cells, B cells, and CTLs. This study demonstrates that Al-Poly(I:C) potentiates the humoral and cellular responses in vaccine formulations. It offers insights for adjuvant design to meet the formulation requirements in both prophylactic and therapeutic vaccines.

Biocompatibility FeOOH QD@ATP-BODIPY nanocomposite for glutathione detection and intracellular imaging.

Monitoring of glutathione has attracted considerable attention owing to its biological and clinical significance. An eco-friendly, economic, simple, biocompatible probe with excellent sensitivity and selectivity is very important. Herein, FeOOH QD@ATP-BODIPY nanocomposite was fabricated from one-step synthesized FeOOH quantum dots (FeOOH QD) and commercial boron-dipyrromethene-conjugated adenosine 5'-triphosphate (ATP-BODIPY) for glutathione (GSH) sensing in solutions and living cells. Three fascinate merits of FeOOH QD were confirmed: (a) as fluorescence quencher for ATP-BODIPY, (b) as selective recognizer of GSH and (c) with carrier effects and membrane permeability. The construction and response mechanism of the nanocomposite was based on the competitive coordination chemistry and redox reaction of FeOOH QD between GSH and phosphate group of ATP-BODIPY. Under the optimal conditions, the detection limit for GSH was as low as 68.8 nM. Excellent linear range of 0.2-400 µM was obtained. Furthermore, the chemical response of the nanocomposite exhibits high selectivity toward GSH over other electrolytes and biomolecules. It was successfully applied for GSH determination in human serum samples. The MTT assay exhibited FeOOH QD@ATP-BODIPY nanocomposite own good biocompatibility. FeOOH QD@ATP-BODIPY respond to GSH in living cells in situ was also proved via fluorescence imaging. These suggested that the FeOOH QD@ATP-BODIPY nanocomposite had potential application in biological and clinical applications.

The Enhanced Performance of NiCuOOH/NiCu(OH)2 Electrode Using Pre-Conversion Treatment for the Electrochemical Oxidation of Ammonia.

Electrochemical oxidation of ammonia is an attractive process for wastewater treatment, hydrogen production, and ammonia fuel cells. However, the sluggish kinetics of the anode reaction has limited its applications, leading to a high demand for novel electrocatalysts. Herein, the electrode with the in situ growth of NiCu(OH)2 was partially transformed into the NiCuOOH phase by a pre-treatment using highly oxidative solutions. As revealed by SEM, XPS, and electrochemical analysis, such a strategy maintained the 3D structure, while inducing more active sites before the in situ generation of oxyhydroxide sites during the electrochemical reaction. The optimized NiCuOOH-1 sample exhibited the current density of 6.06 mA cm-2 at 0.5 V, which is 1.67 times higher than that of NiCu(OH)2 (3.63 mA cm-2). Moreover, the sample with a higher crystalline degree of the NiCuOOH phase exhibited lower performance, demonstrating the importance of a moderate treatment condition. In addition, the NiCuOOH-1 sample presented low selectivity (<20%) towards NO2- and stable activity during the long-term operation. The findings of this study would provide valuable insights into the development of transition metal electrocatalysts for ammonia oxidation.

Dimerization of Fe(III) Ion in an Aqueous Medium: Mechanistic Modelling and Effects of Ligands.

Aqueous iron solutions generally undergo spontaneous hydrolysis followed by aggregation resulting in the precipitation of nanocrystalline oxyhydroxide minerals. The mechanism of nucleation of such multinuclear oxyhydroxide clusters are unclear due to limited experimental evidence. Here, we investigate the mechanistic pathway of dimerization of Fe(III) ions using density functional theory (DFT) in aqueous medium considering effects of other ligands. Two hydrolyzed monomeric Fe(III) ions in aqueous medium may react to form two closely related binuclear products, the µ-oxo and the dihydroxo Fe2 dimer. Our studies indicate that the water molecules in the second coordination sphere and those co-ordinated to the Fe(III) ion, both participate in the dimerization process. The proposed mechanism effectively explains the formation of dihydroxo and µ-oxo Fe2 dimers with interconversion possibilities, for the first time. Results show, with only water molecules present in the second co-ordination sphere, dihydroxo Fe2 dimer is the thermodynamically and kinetically favored product with a low activation free energy. We calculated the step-wise reaction free energies of dimerization in the presence of nitrate ions in the first and second coordination sphere of Fe(III) ion separately, which shows that with nitrate ions in the second co-ordination sphere, the µ-oxo Fe2 dimer is the kinetically favored product.

Foldable paper-based photoelectrochemical biosensor based on etching reaction of CoOOH nanosheets-coated laser-induced PbS/CdS/graphene for sensitive detection of ampicillin.

Timely and rapid detection of antibiotic residues in the environment is conducive to safeguarding human health and promoting an ecological virtuous cycle. A foldable paper-based photoelectrochemical (PEC) sensor was successfully developed for the detection of ampicillin (AMP) based on glutathione/zirconium dioxide hollow nanorods/aptamer (GSH@ZrO2 HS@apt) modified cellulose paper as a reactive zone with laser direct-writing lead sulfide/cadmium sulfide/graphene (PbS/CdS/LIG) as photoelectrode and cobalt hydroxide (CoOOH) as a photoresist material. Initially, AMP was introduced into the paper-based reaction zone as a biogate aptamer, which specifically recognized the target and then left the ZrO2 HS surface, releasing glutathione (GSH) encapsulated inside. Subsequently, the introduction of GSH into the reaction region and etching of CoOOH nanosheets to expose the PbS/CdS/LIG photosensitive material increased photocurrent. Under optimal conditions, the paper-based PEC biosensor showed a linear response to AMP in the range of 5.0 - 2 × 104 pM with a detection limit of 1.36 pM (S/N = 3). In addition, the constructed PEC sensing platform has excellent selectivity, high stability and favorable reproducibility, and can be used to assess AMP residue levels in various real water samples (milk, tap water, river water), indicating its promising application in environmental antibiotic detection.