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This study evaluated the impact of using calcium hydroxide or antioxidant agents on the bond strength of adhesive restorations to bleached dentin. A total of 40 teeth were prepared and allocated into eight groups, first divided according to the surface treatment after bleaching (no treatment or application of calcium hydroxide, 10% sodium ascorbate, or 5% sodium thiosulfate for 10 minutes) and then according to the time of final restoration after treatment (immediate or after 7 days). Sodium perborate with 20% hydrogen peroxide was applied for 3 weeks using a developed artificial pulp chamber, with peroxide replacements provided every week. Composite resin restoration was performed, followed by a microtensile test. Then, specimens were analyzed using a stereomicroscope and scanning electron microscopy (SEM). Data were submitted to Kruskal-Wallis and Dunn tests (P < .05). The bond strength of nonbleached teeth was similar to the groups restored after 7 days of bleaching (P < .05). The lowest bond strength values were seen in groups restored immediately after bleaching (P < .05). In all groups, there was a considerable predominance of adhesive fractures. Delaying the final restoration of teeth submitted to nonvital bleaching by 7 days increased the bond strength. The immediate restoration of bleached teeth after using 10% sodium ascorbate or 5% sodium thiosulfate for 10 minutes showed unsatisfactory results. Irrespective of the dentin protocol applied before adhesion, bond strength values will be satisfactory when delaying the final restoration and unsatisfactory when immediately performing the final restoration. Therefore, after nonvital tooth bleaching, clinicians should always delay the final restoration for a minimum period of 7 days. [ABSTRACT FROM AUTHOR]

Bimetallic and trimetallic alloys are widely used as catalysts for the oxygen evolution reaction (OER) and other electrocatalytic processes. We employed a scanning electrochemical microscope (SECM) and finite-element simulations to investigate the OER at single FeCo and FeCoNi hydroxide nanoneedles and observed different distributions of catalytic activity on bimetallic and trimetallic particles. [ABSTRACT FROM AUTHOR]

In this study, the NiFe-LDH doped with different Pt group metals (Pt, Ru, Ir, Rh) was prepared as a cocatalyst for photocatalytic H2 production over g-C3N4. It is found that the doped NiFe-LDH loaded g-C3N4 generally displays higher photocatalytic activity than the raw NiFe-LDH modified one, where the NiFeRu-LDH loaded g-C3N4 shows the optimal H2 evolution rate of 77.4 μmol h−1, about 5.5 times that of the NiFe-LDH system. [ABSTRACT FROM AUTHOR]

The partial reduction of nitroarenes with hydroxides in alcoholic media is a venerable yet very direct approach to the synthesis of symmetrical azoxyarenes. Herein, the first application of this method to nitropyridines is disclosed, presenting its adaptation with these challenging but important substrates. [ABSTRACT FROM AUTHOR]

We report a facile fractionation strategy using choline hydroxide (ChOH) based alkaline deep eutectic solvents (DES) for whole-component upgrading of bagasse. Through selective lignin and xylan dissolution, along with extensive biomass swelling, high-value lignin-carbohydrate complexes (LCC, with high β-O-4 bond content of 68.9/100 Ar) and high-purity xylan were extracted without compromising cellulose recovery and hydrolysis. This work provided the key to solving the technical contradiction between cellulose availability and lignin structural integrity. [ABSTRACT FROM AUTHOR]

Herein, NiFeP/Ti2C@NF was synthesized from a hydrothermal process and chemical conversion, and exhibited a low overpotential of 177 mV at j = 50 mA cm−2, a low Tafel slope of 56 mV dec−1, and a very competitive stable activity in alkaline electrolyte, proposing a strategy for efficient OER and overall water splitting. [ABSTRACT FROM AUTHOR]

Novel catalytic silicon carbide membrane filters (SCMFs) are synthesized with Co/Al–layered double hydroxide (Co/Al-LDH)-coated silicon carbide powder. After capsuled in a self-designed membrane shell, the SCMFs are utilized in activating persulphate for aniline degradation. Thermal analysis conducted via TG/DTG/DSC examination shows that the heating treatment is beneficial in elevating the activating ability of SCMFs, and the derived Co3O4 displays superior catalytical efficiency than Co/Al-LDHs precursor. The XRD patterns and SEM images indicate the sheet-like Co/Al-LDHs are uniformly coprecipitated throughout the surface of SCMFs. Within 20 min, around 95% of aniline is eliminated under 0.7 m of flow velocity and 8:1 of persulphate to aniline ratio. Three-dimensional fluorescence and GC chromatography reveal that distinct by-products exist in the early stage of the aniline degradation process between the sintered and non-sintered Co/Al-LDH-coated SCMFs. The integration strategy of Co/Al-LDH coatings and heating treatment endows traditional SCMFs with robust catalytic properties for engineering-oriented applications in wastewater treatment. [ABSTRACT FROM AUTHOR]

On-site electrochemical treatment of LaNiO 3 and intentional trace Fe3+ introduction simultaneously boost high OER activity and durability of perovskite oxides. [Display omitted] • The in situ electrochemical strategy is more viable for activity optimization. • The on-site electrochemical approach and intentional trace Fe3+ synergistically boost the activity and durability. • The electrochemically manipulated LaNiO 3 (i.e., deficient LaNiO 3−δ and NiO) is beneficial for surface reconstruction. Although decorated nanoparticles offer a great potential to generate extra active sites, their preparation usually requires time- and energy-consuming approaches. We report the remarkable activity and durability augmentation for the oxygen evolution reaction (OER) via effective and facile on-site electrochemical manipulation, using LaNiO 3 as a model catalyst. When compared to the pristine LaNiO 3 , the electrochemically manipulated LaNiO 3 cycled in Fe3+-containing 0.1 M KOH (i.e., E-LNO+Fe) exhibits an almost three-fold improvement in current density at 1.65 V. It is experimentally and theoretically shown that the electrochemical manipulation leads to the creation of defective LaNiO 3−δ and NiO on the surfaces, which accelerate phase transformation to (oxy)hydroxides and hence the OER. Furthermore, a Zn–air battery assembled with E-LNO+Fe has demonstrated superior activity by presenting 171 mW cm−2. Thus, our work demonstrates that substantial performance increases may be achieved by decorating and reconstructing perovskite-oxide electrodes via on-site electrochemical modification. [ABSTRACT FROM AUTHOR]

A sustainable approach utilizing a low-temperature molten salt strategy is employed in this study to fabricate homogeneous and dense NiFe nitrate hydroxide needle-like arrays on a NiFe foam substrate. The electrode also achieves an ultra-low voltage of 1.77 V at 100 mA cm−2 and maintains stability for more than 120 h at a current density of 100 mA cm−2, showing excellent overall water splitting (OWS) performance and stability. Notably, the molten salt strategy enables the synthesis of electrodes at a reaction temperature as low as 125 °C. Additionally, the molten salt precursor is repeatable and renewable, thus preventing waste and presenting vast potential for application. [ABSTRACT FROM AUTHOR]

This study examines the effect of various quaternary ammonium groups on AEMWE performance and hydrogen crossover in blends of quaternized polystyrenes with O-PBI. Due to their higher hydroxide conductivity (69 mS cm-1 at 80 8C, 90% RH), trimethylammonium groups enable AEMWE to reach 1.0 A cm-2 at 2.0 V. The trimethylammonium groups exhibit low hydrogen crossover, ranging from 1.5% to 0.3%, across current densities of 50 to 1000 mA cm-2 . Low hydrogen crossover is essential for AEMWE in terms of safety and efficiency. [ABSTRACT FROM AUTHOR]

Industrial dye–contaminated wastewater needs creative techniques to effectively remove these contaminants. An easy co‐precipitation technique was used in this work to create the VNi‐layered double hydroxide (VNi‐LDH) adsorbent. VNi‐LDH was encapsulated with chitosan (CS) and carboxymethyl cellulose (CMC) that cross‐linked with itaconic acid as the cross linker via chemical crosslinking to form VNi‐LDH/CS‐CMC hydrogel beads. FT‐IR, SEM, XPS, BET, XRD, BET, and point of zero charge (pHzpc) were employed to characterize the prepared material. Examining VNi‐LDH/CS‐CMC's ability to remove rhodamine B (RB) from water waste as an adsorbent was the aim of the study. The highest adsorption capacity of RB on VNi‐LDH/CS‐CMC was found to be 653.8 mg/g. The research findings designated that the Langmuir isotherm models provided the most accurate representation of the RB adsorption procedure for VNi‐LDH/CS‐CMC. At a dosage of 0.8 g/L for the adsorbent and an equilibrium time of 100 min, it was established that the RB adsorption of VNi‐LDH/CS‐CMC hydrogel beads occurred at a pH of 8. The model of pseudo‐second order, demonstrating chemisorption with an adsorption energy of 30.34 kJ/mol along with a diffusion‐limited adsorption process, was most appropriate for the RB adsorption kinetics on VNi‐LDH/CS‐CMC hydrogel beads. The impact of temperature was also investigated, with an analysis of the thermodynamic variables (∆H°, ∆S°, and ∆G°) revealing a spontaneous increase in positive enthalpy and entropy charge, along with a decrease in ΔG°, as the temperature rose. The adsorption process outcomes were further optimized using response surface methodology (RSM) and the Box–Behnken design (BBD). It was proposed that the elimination of RB through VNi‐LDH/CS‐CMC may occur through different potential mechanisms, such as chemisorption, pore‐filling, π‐π bonding, electrostatic interactions, and hydrogen bonding. Given that the adsorbent was made of reusable materials and could be reused more than six times with high efficiency, the VNi‐LDH/CS‐CMC hydrogel beads offer a viable low‐cost option for removing RB dye from wastewater streams. [ABSTRACT FROM AUTHOR]

Objective To evaluate the efficacy of various irrigants (5.25% sodium hypochlorite [NaOCl] followed by 17% ethylenediaminetetraacetic acid [EDTA] and 0.2% chitosan nanoparticle [NP]) and different irrigation techniques (conventional and EndoVac) for the removal of Metapex from the apical third of the root canal by scanning electron microscopy (SEM) analysis. Materials and Methods Forty extracted single-rooted human premolars were instrumented using a rotary ProTaper file system up to F3. The canals were dried and Metapex was placed inside the root canal. The access cavity was sealed with a cotton pellet and Cavit followed by the storage of specimens at 37°C at 100% humidity for 1 week. Cavit was removed and the samples were divided into: Group 1 (conventional irrigation using 5.25% NaOCl and 17% EDTA, n = 10), Group 2 (conventional irrigation using 0.2% chitosan NP, n = 10), Group 3 (EndoVac using 5.25% NaOCl and 17% EDTA, n = 10), and Group 4 (EndoVac using 0.2% chitosan NP, n = 10). After irrigant activation, the roots were divided in half, and the apical third of one-half of each tooth was subjected to SEM analysis. A five-graded scoring scale was used to evaluate dentinal wall cleanliness. Data were statistically analyzed using one-way analysis of variance. Results There were statistically significant differences in mean canal cleanliness scores observed between the four groups. Chitosan NPs showed lower mean canal cleanliness scores at the apical one-third of the root canal indicating better cleanliness when compared with the other irrigants and techniques. Conclusion None of the irrigation techniques was successful in entirely removing the calcium hydroxide intracanal medicament from the apical third. [ABSTRACT FROM AUTHOR]

The influence of various operating variables on the phosphate removal by layered double hydroxide (LDH)-modified magnetic nanocomposite materials has been intensively investigated in the literature. Although many studies have demonstrated that the recovery of phosphate and simultaneous regeneration of the reusable material could be performed successfully by using several regeneration solutions, only the recovery rate has been considered as a decision-making criterion to determine the optimum conditions. This study aimed to comprehensively investigate the influence of various operating variables on the recovery of phosphate as well as its removal from aqueous solutions by a magnetic nanocomposite microparticle modified with MgFe-Zr LDH. To gain better insight on the recovery process, a multi-criteria approach, including recovery rate, structural stability, particle weight loss, dissolution of material components, and characterization of the regenerated material, was adopted. According to the results, the most important operating variable influencing both the removal process and the recovery process was determined as the solution pH. Derived from the results, the main mechanisms involved in the removal and recovery process were proposed and the kinetics and thermodynamic of the removal process were evaluated. Under the optimum conditions, the removal efficiency and the specific removal capacity was determined to be 96.4% and 9.6 mg PO4-P/g, respectively, while 84.8% of the removed PO4-P could be recovered by using 50 mL 1.0 NaOH solution within 60 min. EDS, XRD, FT-IR and ICP-OES analyses confirmed that the particle retained its initial structural stability during the removal and recovery process under the optimized operating conditions. [ABSTRACT FROM AUTHOR]

The transport of excess protons and hydroxide ions in water underlies numerous important chemical and biological processes. Accurately simulating the associated transport mechanisms ideally requires utilizing ab initio molecular dynamics simulations to model the bond breaking and formation involved in proton transfer and path-integral simulations to model the nuclear quantum effects relevant to light hydrogen atoms. These requirements result in a prohibitive computational cost, especially at the time and length scales needed to converge proton transport properties. Here, we present machine-learned potentials (MLPs) that can model both excess protons and hydroxide ions at the generalized gradient approximation and hybrid density functional theory levels of accuracy and use them to perform multiple nanoseconds of both classical and path-integral proton defect simulations at a fraction of the cost of the corresponding ab initio simulations. We show that the MLPs are able to reproduce ab initio trends and converge properties such as the diffusion coefficients of both excess protons and hydroxide ions. We use our multi-nanosecond simulations, which allow us to monitor large numbers of proton transfer events, to analyze the role of hypercoordination in the transport mechanism of the hydroxide ion and provide further evidence for the asymmetry in diffusion between excess protons and hydroxide ions. [ABSTRACT FROM AUTHOR]

This study focuses on the synthesis of a novel layered double hydroxide and its application in two environmental remediation processes. Graphene oxide, a two-dimensional material, has potential applications in this field. However, its tendency to agglomerate restricts its usability. Our objective was to increase the morphology and performance of layered double hydroxide (LDH) by combining GO with hydrotalcite. The LDH/GO nanohybrids were utilized as photocatalysts for the degradation of methylene blue (MB) dye and were investigated as sorbents for acid red (A.R) dye in water. In order to achieve this objective, ZnAl-NO3 LDH was synthesized using the co-precipitation method, with a Zn:Al ratio of ~3. Subsequently, the LDH was intercalated with varying ratios of as-received graphene oxide. An array of analytical techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) measurements, N2 physisorption, scanning electron microscopy–energy-dispersive X-ray analysis (SEM-EDX), and diffuse reflectance UV–vis spectra (DR UV-vis), were employed to examine the physicochemical properties of the synthesized LDH. These techniques confirmed that the obtained material is zinc-aluminum hydrotalcite intercalated with GO. The addition of graphene oxide (GO) to the layered double hydroxide (LDH) structure improved the performance of the hydrotalcite. As a result, the composite ZnAl-LDH-10 shows significant potential in the field of photocatalytic degradation of MB. Additionally, the incorporation of GO enhanced the absorption of light in the visible region of the spectra, leading to improved elimination of A.R compared to LDH without GO or other ratios of GO. [ABSTRACT FROM AUTHOR]

Proton exchange membrane fuel cells (PEMFCs) have been widely acknowledged as a significant advancement in achieving sustainable energy conversion. However, the activation of newly established Pt-ionomer interfaces in the catalyst layer of PEMFCs can be a time-consuming and costly process to ensure proper coupling and performance. In order to gain valuable insights into this crucial activation process, we have conducted a comprehensive analysis and comparison of the commonly employed on-line (such as current or voltage control activation, short-circuiting activation, and air interruption activation) and off-line (including boiling or steaming, acidtreatment, and ultrasonic-treatment) activation methods. Our findings shed light on the underlying mechanisms that contribute to enhanced performance within the catalyst layer, such as the reduction of Pt oxides and hydroxides, improved proton transport, and the reduction of "dead" regions. Moreover, this review emphasizes the significant challenges and future opportunities that lie in further enhancing the performance within the catalyst layer through the activation process. [ABSTRACT FROM AUTHOR]

Calcium aluminum layered double hydroxide (CaAl‐LDH) has gained significance for drug delivery applications due to its multiple advantages, including high drug‐loading capacity, pH sensitivity, biocompatibility, high acceptable intake values of metal ions, and its ability to provide sustained release of the intercalated drug. In this study, pristine CaAl‐LDH was synthesized by co‐precipitation method at different pH values (9 and 10) and aging times (16 and 24 h) to obtain LDH with higher d‐spacing, which is beneficial for achieving a high drug loading efficiency. Ofloxacin (OFX), an antibiotic drug, was loaded into CaAl‐LDH via regeneration (CaAl‐LDH‐OFX(RG)) and co‐precipitation (CaAl‐LDH‐OFX(CPT)) methods, and achieved drug loading of 28.3% and 36.5%, respectively. The release behavior of OFX from CaAl‐LDH‐OFX(RG) and CaAl‐LDH‐OFX(CPT) formulations was examined in simulated conditions representing the gastrointestinal tract. CaAl‐LDH‐OFX(RG) showed less initial burst release of OFX compared to CaAl‐LDH‐OFX(CPT) in acidic as well as neutral pH conditions. In order to overcome the degradation of the drug before reaching the target site, CaAl‐LDH‐OFX(RG) was reinforced at 1, 3, and 5 wt% in poly (3‐hydroxybutyrate) (PHB) matrix by sonication‐assisted solution casting method. The PHB‐based nanocomposites were characterized by XRD, FESEM, TGA, and FTIR analyses. FESEM characterization of PHB‐based films loaded with 3 wt% of CaAl‐LDH‐OFX(RG) revealed compact morphology without any aggregate formation. Moreover, PHB/3CaAl‐LDH‐OFX(RG) films demonstrated sustained release of OFX at pH 1.2 (95.60% in 96 h), pH 6.8 (78% in 113 h), and pH 7.4 (40.90% in 107 h). The promising potential of PHB‐based formulations for antibacterial drug delivery systems was confirmed by their significant antibacterial activity against Escherichia coli and Staphylococcus aureus. Highlights: pH and aging time influence the structural characteristics of pristine CaAl‐LDH.Ofloxacin loaded CaAl‐LDH prepared by co‐precipitation and regeneration methods.Sustained release of ofloxacin from poly (3‐hydroxybutyrate)‐based formulation.Poly (3‐hydroxybutyrate)‐based formulations exhibit excellent antibacterial activity. [ABSTRACT FROM AUTHOR]

Background: Calcium hydroxide [Ca(OH)2] is widely accepted as a biocompatible interappointment intracanal medicament. This study aimed to analyze the efficacy of Ca(OH)2 placement into the C-shaped canal system of mandibular second molars using the syringe method with and without lentulo spiral utilizing micro-computed tomography (micro-CT). Methods: Twenty-four extracted mandibular second molars were instrumented and classified into C-shaped floors (n = 12) and non-C-shaped floors (n = 12). Both groups were placed with Ca(OH)2 using the syringe system, then all teeth were scanned and cleaned, and placed with Ca(OH)2 again but with the syringe system followed by lentulo spiral and rescanned. The specimens were scanned using micro-CT to analyze the volume, volume percentage, uncontacted surface area, and uncontacted surface area percentage of Ca(OH)2 with the two delivery methods in the entire canal and at the apical 4 mm of the canal. Mann-Whitney test and Wilcoxon signed-rank test were used to determine the statistical differences among the groups. Results: Syringe administration used in conjunction with lentulo spiral presented lower uncontacted surface area, a lower percentage of uncontacted surface area, larger volume, and a higher percentage of volume than syringe without lentulo spiral (P < 0.05). There was no significant difference between the C-shaped floor group and the non-C-shaped floor group (P > 0.05) in the Ca(OH)2 uncontacted surface area, volume, and percentages at different regions of canals and among different delivery techniques groups. Conclusions: The lentulo spiral and syringe technique combination can increase the volume and contacted surface area of Ca(OH)2 in the C-shaped canal system of mandibular second molars. [ABSTRACT FROM AUTHOR]

Featured Application : The modification of natural zeolite sediments can provide a low-cost and eco-friendly adsorbent with high sorption capacity that can help to remediate mining soil and other soils contaminated with heavy metal contaminants. Soil contamination by many kinds of anthropogenic operations, such as industrial and mining activities, results in the accumulation of various heavy metal contaminants in the environment. Cadmium (Cd) and lead (Pb) are commonly found heavy metals in the Mahad Adahab mining area in Saudi Arabia. In this study, natural and modified zeolite sediments were fractioned by size to nano- and macrosizes and were applied to stabilize Cd and Pb from contaminated mining soil. Among the tested adsorbents, zeolite sediment in the nanosize that was modified by layered double hydroxides (LDH-N) showed the highest sorption and removal efficiency (>98%) for Cd and Pb, followed by nanosized natural zeolite (NZ-N) and HCl-modified nanosized natural zeolite sediment (HCl-N), which removed >90% Cd and Pb from contaminated soil. A pH of 7 was found to be optimal for Cd and Pb sorption, and the kinetics study revealed that first-order and pseudo-second-order kinetic models best fitted the experimental data (R2 = 0.94–0.98) for Cd and Pb sorption by the tested sediments. An incubation period of 16 weeks revealed that LDH-N, HCl-N, and NZ-N reduced the ammonium acetate extractable fraction of Cd by 89.26, 83.70, and 80.54% and Pb by 86.19, 81.42, and 77.98%, respectively. Electrostatic interaction and ion exchange were found to be the principal mechanisms for Cd and Pb sorption. The findings of this study indicate that the utilization of modified zeolite sediment in the nanosize fraction (LDH-N, HCl-N, and NZ-N) could be an effective and feasible strategy in stabilizing heavy metals and mitigating their toxicity in contaminated mining soil. [ABSTRACT FROM AUTHOR]

NiFe‐based hydroxides are well‐established as efficient electrocatalysts for the oxygen evolution reaction (OER) in alkaline purified water. However, they usually degrade rapidly in seawater electrolysis because of concentrated Cl− anions in seawater. In this work, a facile approach utilizing an ultrafast dipping method is presented to fabricate durable and scalable NiFe hydroxides, enhanced by interfacial akaganéite FeOOH for seawater splitting. This study reveals significantly improved electrocatalytic stability of NiFe hydroxides at an ampere‐level current density of 1000 mA cm−2 for 100 h in alkaline seawater. It is realized by the formed FeOOH in a specific akaganéite phase whose lattice tunnels are well filled by intrinsic Cl− anions, that serve to electrostatically repel corrosive chlorides in electrolyte. This anionic design also provides superior corrosion protection for other active metal‐based OER electrocatalysts when deployed in alkaline purified water and allows for facile scaling up of the anode, facilitating the practical utilization for seawater electrolysis. [ABSTRACT FROM AUTHOR]

Partial replacement of one structural element in a solid with another of a similar size was conducted to impart functionality to the solids and modify their properties. This phenomenon is found in nature in coloured gemstones and clay minerals and is used in materials chemistry and physics, endowing materials with useful properties that can be controlled by incorporated heteroelements and their amounts. Depending on the area of research (or expected functions), the replacement is referred to as "isomorphous substitution", "doping", etc. Herein, elemental replacement in two-dimensional (2D) oxides and hydroxides (nanosheets or layered materials) is summarised with emphasis on the uniqueness of their preparation, characterisation and application compared with those of the corresponding bulk materials. Among the 2D materials (graphene, metallenes, transition metal chalcogenides, metal phosphate/phosphonates, MXenes, etc.), 2D oxides and hydroxides are characterised by their presence in nature, facile synthesis and storage under ambient conditions, and possible structural variation from atomic-level nanosheets to thicker nanosheets composed of multilayered structures. The heteroelements to be doped were selected depending on the target application objectively; however, there are structural and synthetic limitations in the doping of heteroelements. In the case of layered double hydroxides (single layer) and layered alkali silicates (from single layer to multiple layers), including layered clay minerals (2 : 1 layer), the replacement (commonly called isomorphous substitution) is discussed to understand/design characteristics such as catalytic, adsorptive (including ion exchange), and swelling properties. Due to the variation in their main components, the design of layered transition metal oxide/hydroxide materials via isomorphous substitution is more versatile; in this case, tuning their band structure, doping both holes and electrons, and creating impurity levels are examined by the elemental replacement of the main components. As typical examples, material design for the photocatalytic function of an ion-exchangeable layered titanate (lepidocrocite-type titanate) and a perovskite niobate (KCa2Nb3O10) is discussed, where elemental replacement is effective in designing their multiple functions. [ABSTRACT FROM AUTHOR]

The present research utilizes the simple "plug-and-play" strategy to effectively impart layered rare-earth hydroxides with remarkable sensitivity, selectivity, and rapid fluorescence sensing detection ability towards nitroaromatic compounds, employing the excited-state proton transfer fluorescence quenching mechanism. This opens new possibilities for the efficient and accurate detection of toxic and hazardous nitroaromatic compounds and effectively protecting environmental health and public safety. [Display omitted] Convenient, rapid, and accurate detection of nitroaromatic organic toxins and harmful substances is of great significance in research. In the present study, two-dimensional layered rare-earth hydroxides (LYH) were used as ion-exchange matrix materials, and the anionic fluorescent dye molecules (HPTS) were successfully introduced into the LYH structures in situ via a simple and effective "plug-and-play" strategy, which gave the compounds ultra-sensitive fluorescence sensing detection of nitrobenzene, p-nitrotoluene and p-nitrophenol (Fluorescence response time < 1 sec , and the LOD for nitrobenzene, p-nitrophenol and p-nitrotoluene reached an impressive 349 ppb, 22 ppb and 98 ppb, respectively). Combined with theoretical calculations, we elucidated in detail the fluorescence quenching response mechanism of the LYH-HPTS towards nitroaromatic. Additionally, we also constructed fluorescent paper sensor, which effectively transformed the LYH-HPTS from theoretical detection to device application. The LYH-HPTS material is not only simple to synthesize, cost-effective and stable, but also has the features of fast response, excellent sensitivity and selectivity, and good reproducibility, which provides a new approach for the rapid and accurate detection of nitroaromatic. [ABSTRACT FROM AUTHOR]

The adsorption efficiency of Cr(VI) and anionic textile dyes onto MgAl-layered double hydroxides (LDHs) and MgAl-LDH coated on bio-silica (b-SiO2) nanoparticles (MgAl-LDH@SiO2) derived from waste rice husks was studied in this work. The material was characterized using field-emission scanning electron microscopy (FE-SEM/EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopic (XPS) techniques. The adsorption capacities of MgAl-LDH@SiO2 were increased by 12.2%, 11.7%, 10.6%, and 10.0% in the processes of Cr(VI), Acid Blue 225 (AB-225), Acid Violet 109 (AV-109), and Acid Green 40 (AG-40) dye removal versus MgAl-LDH. The obtained results indicated the contribution of b-SiO2 to the development of active surface functionalities of MgAl-LDH. A kinetic study indicated lower intraparticle diffusional transport resistance. Physisorption is the dominant mechanism for dye removal, while surface complexation dominates in the processes of Cr(VI) removal. The disposal of effluent water after five adsorption/desorption cycles was attained using enzymatic decolorization, photocatalytic degradation of the dyes, and chromate reduction, satisfying the prescribed national legislation. Under optimal conditions and using immobilized horseradish peroxidase (HRP), efficient decolorization of effluent solutions containing AB-225 and AV-109 dyes was achieved. Exhausted MgAl-LDH@SiO2 was processed by dissolution/precipitation of Mg and Al hydroxides, while residual silica was used as a reinforcing filler in polyester composites. The fire-proofing properties of composites with Mg and Al hydroxides were also improved, which provides a closed loop with zero waste generation. The development of wastewater treatment technologies and the production of potentially marketable composites led to the successful achievement of both low environmental impacts and circular economy implementation. [ABSTRACT FROM AUTHOR]

Background: Superficial cutaneous fungal infections are common dermatologic conditions. A significant proportion do not present with typical clinical findings. However, the 10% potassium hydroxide (KOH) smear, a simple bedside test, is often underused when diagnosing cutaneous fungal infections. Aims: We aimed to evaluate whether KOH smear results altered dermatologists' diagnosis and management, and the factors that influenced its ability to detect cutaneous fungal infections. Methods: A total of 373 patients with suspected cutaneous fungal infection were identified retrospectively from the dermatology database of inpatient referrals in a Singapore tertiary hospital between 1 January 2017 and 30 June 2020. The dermatologists' eventual diagnoses, based on their assessment until 2 months post-discharge to allow consideration of KOH smear results and response to treatment, were taken as a gold standard. Statistical analyses evaluated for changes between initial and eventual diagnoses and management relative to the KOH smear. Use of topical steroids, topical and/or systemic antifungals before skin sampling, and whether sampling was done by dermatologically-trained personnel, were assessed for association with KOH smear positivity in eventually diagnosed cases. Results: The percentage of uncertain diagnoses was reduced, and the use of topical antifungal as the sole treatment significantly changed after the KOH smear result was available. The adjusted odds ratio of a positive KOH smear in eventually diagnosed cases was 0.19 when systemic antifungals were used before skin sampling, and 3.03 if sampling was performed by a dermatologically-trained person. Limitations: Limitations of our study include dependence on retrospective medical records which may result in misclassification bias and the limited generalisability of our results to patients managed by non-dermatologists. Conclusions: KOH smear is a useful adjunct in diagnosing and managing cutaneous fungal infections. Clinicians should consider the presence of confounders affecting KOH smears when making an overall clinical diagnosis. Focused training of personnel on skin sample collection may improve the detection rate of KOH smear. [ABSTRACT FROM AUTHOR]

A new nanocomposite based on alginate microbeads impregnated with novel strontium–aluminum layered double hydroxide (Sr‐Al LDH) incorporated with choline chloride‐urea deep eutectic solvent (ChCl‐U DES) was introduced. The microbeads and LDH were characterized by adsorption/desorption isotherms, Fourier‐transform infrared spectroscopy, SEM, and x‐ray diffraction. The adsorbent was employed for determining penicillin G (PENG) using dispersive solid‐phase extraction prior to HPLC analysis. The extraction efficiency of the adsorbent, compared with that of unmodified alginate, showed a 2.5‐fold increase. Significant parameters, including elution conditions, sorbent composition and mass, adsorption time, and sample pH, were optimized. The LOD was 0.4 µg kg−1, and the linear range was 1.4–500 µg kg−1. The LOQ (1.4 µg kg−1) was lower than the established maximum level for PENG by the European Union (4 µg kg−1). Enrichment factor and synthesis reproducibility were also investigated. The method's accuracy was evaluated through PENG analysis in dairy products and water, with recoveries of 81%–107% (RSDs < 7.6%). The procedure's greenness was assessed using the Analytical Eco‐scale and achieved excellent green credentials. To the best of our knowledge, this is the first report on the synthesis and application of a novel alginate composite for the extraction of PENG from dairy and water samples. [ABSTRACT FROM AUTHOR]

Among the two‐dimensional (2D) materials, layered hydroxides (LHs) stand out due to their chemical versatility, allowing the modulation of physicochemical properties on demand. Specifically, LHs based on earth‐abundant elements represent promising phases as electrode materials for energy storage and conversion. However, these materials exhibit significant drawbacks, such as low conductivity and in‐plane packing that limits electrolyte diffusion. In this work, we explore the synthetic flexibility of α‐CoII hydroxides (Simonkolleite‐like structures) to overcome these limitations. We elucidate the growth mechanism of 3D flower‐like α‐CoII hydroxyhalides by using in situ SAXS experiments combined with thorough physicochemical, structural, and electrochemical characterization. Furthermore, we compared these findings with the most commonly employed Co‐based LHs: β‐Co(OH)₂ and CoAl layered double hydroxides. While α‐CoII LH phases inherently grow as 2D materials, the use of ethanol (EtOH) triggers the formation of 3D arrangements of these layers, which surpass their 2D analogues in capacitive behavior. Additionally, by taking advantage of their anion‐dependent bandgap, we demonstrate that substituting halides from chloride to iodide enhances capacitive behavior by more than 40 %. This finding confirms the role of halides in modulating the electronic properties of layered hydroxides, as supported by DFT+U calculations. Hence, this work provides fundamental insights into the 3D growth of α‐CoII LH and the critical influence of morphology and halide substitution on their electrochemical performance for energy storage applications. [ABSTRACT FROM AUTHOR]

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The synthesis and isolation of a bismuth‐based analogue of the venerable triphenylphosphine oxide (Ph3PO) has remained a chimera to synthetic chemists for many years, due to its predicted high reactivity and instability. Through the hydrolysis of a cationic fluorotriarylbismuthonium(V) salt, we report here the isolation of unique hydroxytriarylbismuth(V) complexes, which served as precursor for the formation of the elusive monomeric triarylbismuthine oxide Dipp3Bi=O. Combined spectroscopic, crystallographic and computational studies provided insight into the bonding situation of the first monomeric triorganobismuth oxide complex. The Dipp3Bi=O and Mes3BiO⋅LiBArF complex exhibits O‐atom transfer reactivity, an uncommon reactivity feature for Ar3Pn=O. [ABSTRACT FROM AUTHOR]

Zr 2 ON 2 @NiFe LDH provides a large electrochemical surface area and multiple active sites due to the heterojunction structures and the interfacial synergy between NiFe LDH and Zr 2 ON 2 , enhancing bifunctional catalytic performance with a Δ E of 0.73 V, as well as improved stability for 443 h at 5 mA cm−2 in Zn-air batteries. [Display omitted] The development of a highly efficient, stable, and low-cost bifunctional catalyst is imperative for facilitating the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). However, significant challenges are involved in extending its applications to rechargeable zinc-air batteries. This study presents a bifunctional catalyst, Zr 2 ON 2 @NiFe layered double hydroxide (LDH), that was developed by utilizing a urea-glass route for synthesizing the Zr 2 ON 2 precursor, followed by riveting NiFe LDH nanosheets using a hydrothermal method. Specifically, the vertical distribution of NiFe LDH on the Zr 2 ON 2 surface ensures the maximization of the number of accessible active sites and interfacial catalysis of NiFe LDH. Notably, Zr 2 ON 2 @NiFe LDH demonstrates ORR and OER bifunctional electrocatalytic behavior and high stability owing to its heterostructure and composition. Furthermore, a rechargeable zinc-air battery using a Zr 2 ON 2 @NiFe LDH electrocatalyst as the air cathode demonstrated a high peak power density (172 mW cm−2) and galvanostatic charge-discharge cycle stability (5 mA cm−2 over 443 h). Thus, this study presents an efficient and cost-effective strategy for the design of bifunctional electrocatalysts. [ABSTRACT FROM AUTHOR]

CeF 3 -NiFeLDH electrocatalyst enables the Oxygen Evolution Reaction to occur at a very low overpotential of 180 mV at just 20 mA cm−2. The CeF 3 -NiFeLDH catalyst manages to reach a current density of 1000 mA cm−2, at an overpotential of 340 mV. [Display omitted] The efficacy of any electrochemical reaction hinges on the extent of interaction achievable between reactive intermediates and the electrocatalytic active site. Any weak adsorption of these intermediates on the metal's active site results in low oxygen evolution reaction (OER) rates, mainly when catalysed by the Ni-based layered double hydroxide. To tackle this challenge, a heterojunction consisting of nickel-iron layered double hydroxide (NiFe-LDH) and cerium trifluoride (CeF 3) is synthesized. Both phases were developed in-situ to have an abundance of heterointerfaces. The charge transfer amid the NiFe-LDH and CeF 3 phases is brought about via these heterointerfaces. As a result, the overall charge dynamics associated with nickel (Ni) and iron (Fe) atoms are somewhat increased, and an enhanced positive charge on the metal site makes it more active in grabbing the reactive species, thereby making the entire OER process faster. The CeF 3 -NiFeLDH catalyst reaches a current density of 1000 mA cm−2 at an overpotential of 340 mV. Such a high current density is highly significant for the industrial-scale production of the products. The catalyst demonstrated impressive durability, maintaining stable performance for 90 h while operating at 500 mA cm−2. The charge dynamics between both phases were thoroughly examined using X-ray photoelectron spectroscopy (XPS). [ABSTRACT FROM AUTHOR]

[Display omitted] Designing novel rare-earth-transition metal composites is at the forefront of electrocatalyst research. However, the modulation of transition metal electronic structures by rare earths to induce vacancy defects and enhance electrochemical performance has rarely been reported. In this study, we systematically investigate the mechanism by which Ce-4f electron modulation weakens the Fe-O bond, thereby altering the electronic structure in CeFevNi hydroxide to improve oxygen evolution reaction (OER) performance. Theoretical calculations and experimental characterizations reveal that Ce-4f orbitals function as electron-modulation reservoirs, capable not only of retaining or donating electrons but also of influencing the material's electronic structure. Moreover, Ce-4f bands optimize the Fe lower Hubbard bands (LHB) and O-2p bands, leading to weakened Fe-O bonds and the formation of cationic vacancies. This change results in the upshift of the d-band center at the active sites, favoring the reaction energy barrier for oxygen intermediates in the OER process. The synthesized catalyst demonstrated an overpotential of 201 mV at 10 mA cm−2 and a lifetime exceeding 200 h at 100 mA cm−2 under alkaline conditions. This work offers a proof-of-concept for the application of the mechanism of rare earth-induced transition metal vacancy defects, providing a general guideline for the design and development of novel highly efficient catalysts. [ABSTRACT FROM AUTHOR]

This study systematically investigates the optimization of synthesis parameters for ternary layered double hydroxide (LDH) to achieve a pure phase and high crystallinity. The [Co0.52+Al0.253+Fe0.253+(OH)2].(CO32−)0.125.mH2O$[{\mathrm{Co}}_{0.5}^{2 + }{\mathrm{Al}}_{0.25}^{3 + }{\mathrm{Fe}}_{0.25}^{3 + }({\mathrm{OH}})_2 ].({\mathrm{CO}}_3^{2 - })_{0.125}.{\mathrm{m}}{\mathrm{H}}_2{\mathrm{O}}$, LDH is synthesized using the coprecipitation method and applied for wastewater treatment. The ternary LDH is synthesized at 60 °C for 24 h and exhibited maximum crystallinity with a crystallite size of 4 nm. The crystallinity index (CI) is a quantitative indicator of crystallinity, which is calculated using the X‐ray diffraction (XRD) method. The influence of reaction time on the structural characteristics of this LDH was thoroughly investigated, mainly focusing on achieving well‐crystalline LDH. Experimental results revealed a direct correlation between reaction time and crystallinity. This study highlights the significant influence of controlled synthesis and reaction time on producing high crystalline ternary LDH. The role of different parameters, such as solution pH, adsorbent dosage, contact time, and dye concentration, has been investigated. The adsorption isotherm data is analyzed using different isotherm models, which shows this material having a significant adsorption capacity of 82.92 mg/g for Congo Red dye. [ABSTRACT FROM AUTHOR]

Facile preparation of low-cost electrocatalysts for an efficient oxygen evolution reaction (OER) is significant but remains a big challenge. Herein, a novel and facile strategy for transforming intrinsic non-stoichiometric ultrathin Co5(O9.48H8.52)NO3 nanosheets into oxygen-vacancy enriched Co3O4/CoOOH heterostructure nanosheets for an efficient OER was developed. The as-synthesized Co3O4/CoOOH heterostructure nanosheets displayed excellent OER performances, showing an extremely low overpotential of 260 mV at a current density of 10 mA cm−2, a relatively small Tafel slope of 52 mV dec−1, and a long-term durability of at least 20 h. This work provides a new way for the production of oxygen vacancies on metal (oxy)hydroxide nanosheets through electric-field assisted in situ transformation of non-stoichiometric metal oxyhydroxide nanosheets. [ABSTRACT FROM AUTHOR]

Using the electrochemical polyol oxidation reaction (POR) to produce formic acid over nickel-based oxides/hydroxides (NiO x H y) is an attractive strategy for the electrochemical upgrading of biomass-derived polyols. The key step in the POR, i.e. the cleavage of the C–C bond, depends on an oxygen-vacancy-induced mechanism. However, a high-energy oxygen vacancy is usually ineffective for Schottky-type oxygen-vacancy-rich β-Ni(OH)2 (VSO-β-Ni(OH)2). As a result, both β-Ni(OH)2 and VSO-β-Ni(OH)2 cannot continuously catalyze oxygen-vacancy-induced C–C bond cleavage during PORs. Here, we report a strategy of oxygen-vacancy-filling with sulfur to synthesize a β-Ni(OH)2 (S-VO-β-Ni(OH)2) catalyst, whose oxygen vacancies are protected by filling with sulfur atoms. During PORs over S-VO-β-Ni(OH)2, the pre-electrooxidation-induced loss of sulfur and structural self-reconstruction cause the in-situ generation of stable Frenkel-type oxygen vacancies for activating vacancy-induced C–C bond cleavage, thus leading to excellent POR performances. This work provides an intelligent approach for guaranteeing the sustaining action of the oxygen-vacancy-induced catalytic mechanism in electrooxidation reactions. [ABSTRACT FROM AUTHOR]

Pollution in ecosystems has increased, especially in water, due to the pollutant agents that alter their chemical, physical and biological characteristics. This requires actions to resolve or at least reduce the harmful effects generated on the environment and people's health. Many of the contaminants present in water come from the industrial sector, with the textile industry being one of the most impactful as it uses mostly synthetic dyes, which are characterized as being recalcitrant and toxic, so they cannot be degraded by conventional water treatment methods. Advanced oxidation processes have a great potential for application, especially those that use heterogeneous photocatalysis. The present research evaluates the efficiency in the adsorption and degradation of the triazoic Direct Blue 71 dye in aqueous mediums at concentrations of 600 ppm by the heterogeneous photocatalysis method. The photocatalysts used are layered double hydroxides (LDHs) with a Mg/Al = 3 ratio and are thermally activated and doped with Fe at 1, 3 and 5% w/w. The most efficient materials achieved removal percentages greater than 80% by means of a second-order kinetic model with a DB71 half-life decolorization of less than one hour; as shown by an HPLC study, the absence of intermediate products would confirm the mineralization of the dye. [ABSTRACT FROM AUTHOR]

• Algal DOM (ADOM) showed stronger adsorption on FeOx than humic acid (HA). • ADOM had a stronger inhibition on phosphate sink than HA, promoting eutrophication. • Carboxylic-rich alicyclic molecules in ADOM contributed to strong adsorption. • Adsorption reduced source-specific compounds: aromatics in HA and proteins in ADOM. Dissolved organic matter (DOM) is a heterogeneous pool of compounds and exhibits diverse adsorption characteristics with or without phosphorous (P) competition. The impacts of these factors on the burial and mobilization of organic carbon and P in aquatic ecosystems remain uncertain. In this study, an algae-derived DOM (ADOM) and a commercially available humic acid (HA) with distinct compositions were assessed for their adsorption behaviors onto iron (oxy)hydroxides (FeO x), both in the absence and presence of phosphate. ADOM contained less aromatics but more protein-like and highly unsaturated structures with oxygen compounds (HUSO) than HA. The adsorption capacity of FeOx was significantly greater for ADOM than for HA. Protein-like and HUSO compounds in ADOM and humic-like compounds and macromolecular aromatics in HA were preferentially adsorbed by FeOx. Moreover, ADOM demonstrated a stronger inhibitory effect on phosphate adsorption than HA. This observation suggests that the substantial release of autochthonous ADOM by algae could elevate internal P loading and pose challenges for the restoration of restore eutrophic lakes. The presence of phosphate suppressed the adsorption of protein-like compounds in ADOM onto FeOx, resulting in an increase in the relative abundance of protein-like compounds and a decrease in the relative abundance of humic-like compounds in post-adsorption ADOM. In contrast, phosphate exhibited no discernible impact on the compositional fractionation of HA. Collectively, our results show the source-composition characters of DOM influence the immobilization of both DOM and P in aquatic ecosystems through adsorption processes. The preferential adsorption of proteinaceous compounds within ADOM and aromatics within HA highlights the potential for the attachment with FeO x to diminish the original source-specific signatures of DOM, thereby contributing to the shared DOM characteristics observed across diverse aquatic environments. This is special type of abstract that is so short and could be inserted after main abstract of article, as a blurb or inserted as annotations into a Table of contents [Display omitted] [ABSTRACT FROM AUTHOR]

This study reports a simple method for synthesizing the nanoflower-immobilized enzyme (LYH-HRP) using horseradish peroxidase (HRP) as the bioenzyme and layered yttrium hydroxide (LYH) as the inorganic carrier. Utilizing the structural advantage of LYH and the catalytic properties of HRP, a nanoflower-based colorimetric platform was newly designed and applied for sensitively detecting H2O2 and phenol with a detection time of as fast as 5 min. The limits of detection (LODs) for H2O2 and phenol are as low as 0.046 µM and 0.778 µM, respectively. The activity and stability tests showed that the activity of LYH-HRP was 1.52 times that of free HRP, and it maintained 75% of the initial activity after 60 days. [ABSTRACT FROM AUTHOR]

Color is one of the main attributes used to select or reject meat products, with the characteristic reddish-pink color of cured meats being developed by adding nitrate salts, which are rejected by many consumers due to their harmful effects on health. This study aimed to apply a hybrid dye (ZHN-carmine) synthesized from layered zinc hydroxide salt (ZHN) to produce a reddish-pink color in sliced cooked ham and to evaluate color stability during storage. The ham samples were prepared with cochineal carmine and hybrid dye (ZHN-carmine), sliced, vacuum-packed, and non-vacuumpacked, and exposed to white fluorescent light (1100 LUX) (5 ± 1 °C). The instrumental color measurement was performed at 0, 1, 4, 6, 8, 11, 13, and 15 day intervals. Distinction between the vacuum-packed ham samples and the nonvacuum-packed ham samples was possible based on a* value (red color intensity), which showed the importance of oxygen removal for red color stability. The reddish-pink color was more intense in the ham added with ZNHcarmine, and no color reduction was observed over the days, irrespective of it being vacuum-packed or not. Cochineal carmine adsorbed onto layered zinc hydroxide salt may be a potential replacement for curing salts regarding color formation in vacuum-packed or non-vacuum-packed cooked ham. [ABSTRACT FROM AUTHOR]

Introduction: This review evaluates the effectiveness of treatment modalities for immature teeth with pulp necrosis, focusing on calcium hydroxide (CH) and mineral trioxide aggregate (MTA) apexification, as well as regenerative endodontic treatments (RETs). Recent advancements and clinical outcomes are highlighted. Materials and Methods: A comprehensive search of MEDLINE (PubMed), Embase, Cochrane Library, Scopus, and grey literature was conducted from inception to July 2024. Systematic reviews and meta-analyses (SR/MAs) assessing apexification and RET outcomes in immature teeth with pulp necrosis were included. Studies were selected based on predefined criteria, and data on study design, interventions, and outcomes were extracted. Methodological quality was evaluated using the AMSTAR-2 tool. Results: 31 SR/MAs were included. The quality ranged from critically low to low, except one rated as high. MTA apexification was more effective than CH for faster apical barrier formation, though overall success rates were similar. MTA is preferred for its efficiency, but standardized protocols are needed, and tooth discoloration was noted as a potential complication. RET generally outperforms apexification in root maturation, with platelet concentrates like platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) showing promising results; PRP was associated with greater root length, while PRF showed superior apical healing. Variability in RET outcomes was noted due to the lack of standardized protocols. Comparative studies of RET versus apexification showed no significant differences in survival or overall success rates. RET often provides better apical closure and root development, though results vary. Both approaches are viable, but more research with standardized protocols and larger samples is needed to establish definitive clinical advantages. Conclusions: MTA apexification and RET are viable alternatives to CH apexification, with RET showing greater potential for root development and apical healing. Future research should focus on developing standardized protocols and uniform RET guidelines, and evaluating long-term outcomes to establish efficacy and safety. [ABSTRACT FROM AUTHOR]

Layered double hydroxides (LDH) can be transformed from alkaline supercapacitor material into metal-cation storage cathode working in neutral electrolytes through electrochemical activation. However, the rate performance for storing large cations is restricted by the small interlayer distance of LDH. Herein, the interlayer distance of NiCo-LDH is expanded by replacing the interlayer nitrate ions with 1,4-benzenedicarboxylic anions (BDC), leading to the enhanced rate performance for storing large cations (Na+, Mg2+, and Zn2+), whereas almost the unchanged one for storing small-radius Li+ ions. The improved rate performance of the BDC-pillared LDH (LDH-BDC) stems from the reduced charge-transfer and Warburg resistances during charge/discharge due to the increased interlayer distance, as revealed by in situ electrochemical impedance spectra. The asymmetric zinc-ion supercapacitor assembled with LDH-BDC and activated carbon presents high energy density and cycling stability. This study demonstrates an effective strategy to improve the large cation storage performance of LDH electrodes by increasing the interlayer distance. [ABSTRACT FROM AUTHOR]

Understanding ionic conduction in layered double hydroxides (LDHs) is a crucial step towards utilizing them as solid, hydroxide ion‐conducting electrolytes in energy conversion applications. We selectively modified the interlayer and external surfaces of MgAl LDHs with tris(hydroxymethyl)aminomethane (TRIS) ligands. By adjusting the concentration of the TRIS surface modifier, the LDH basal plane surfaces could be functionalized everywhere (internally and externally) or only externally. External modification resulted in loss of OH‐conductivity compared to pristine LDHs, confirming that external platelet surfaces are the primary ion conduction pathway. [ABSTRACT FROM AUTHOR]

A ternary iron–cobalt–nickel hydroxide nanoarray catalyst was fabricated, which achieves enhanced performance towards electro-oxidative depolymerization of lignin models to produce benzoic acid and phenol. [ABSTRACT FROM AUTHOR]

A microkinetic model is constructed for the electrocatalytic alkaline hydrogen oxidation reaction based on grand canonical density functional theory calculations and linear relationships with the adsorption energies of hydrogen and hydroxide as descriptors. Using this model, the activity trend suitable for efficient catalyst screening has been identified. [ABSTRACT FROM AUTHOR]

Layered double hydroxides (LDHs) are biocompatible materials with excellent anion exchange properties, making them suitable for use as drug carriers by incorporating the drug in its anionic form within their layered structure. In this study, an LDH was synthetized through ion exchange with valproate (VAL), an anticonvulsant drug, using an LDH with nitrate as the parent material. The resulting LDH-VAL sample underwent a comprehensive multi-technique characterization using XRD, TG-DSC, TEM, SEM, EDS, FTIR, XPS and zeta potential measurements. Dissolution kinetics and VAL release kinetics in an ample range of pH (3–9), along with biological assays to test biocompatibility, were also performed. All techniques confirmed the successful intercalation of the drug into the LDH structure, displacing all the nitrate ions of the parent material and increasing the basal spacing d 003 from 8.8 Å to 18.3 Å. VAL release in NaCl and physiological buffer solutions was incongruent with LDH dissolution, clearly indicating that VAL release was controlled by an ion exchange process. In 0.9 % NaCl solutions, 90–100 % of VAL was released with only 15–20 % of LDH dissolution, and in buffer solutions 100 % of VAL was released with, at the most, 30 % of LDH dissolution. Biological assays, including lactate dehydrogenase activity, serum calcium concentration and histological analysis of blood samples, confirmed that the prepared LDH-VAL is a biocompatible material with a potential use as a nanodrug carrier. [Display omitted] [ABSTRACT FROM AUTHOR]

Aiming at the low efficiency of zinc removal from nickel sulfate solution and the high number of steps in the extraction process, a new process of zinc removal from crude nickel sulfate solution by pretreatment with modified nickel hydroxide and re-extraction was carried out. The effects of the excess coefficient of modified nickel hydroxide,reaction time, reaction temperature and solution pH on the zinc removal effect of pretreatment were investigated,and the effects of the volume fraction of P204 in the re-extraction step, phase ratio(O/A) and the pH value of the pre-extraction solution on the zinc removal were also investigated. The results showed that the pretreatment of crude nickel sulfate solution with modified nickel hydroxide could effectively reduce the Zn2 concentration in the solution from 3. 25 g/L to less than 100 mg/L without Ni2+loss under the conditions of 200% excess coefficient of modified nickel hydroxide, 60 min reaction time, 60 *C reaction temperature, and solution pH = 4, while the re-extraction step with a P204 volume In the re-extraction step,P204 volume fraction is 10%,O/A is 1 : 1, and the pH value of the former liquid is 4, P204 extracts Zn2+ with the best effect, currently, the concentration of Zn2+ is about 1. 5 mg/L,the removal rate is about 98. 5%,and the loss rate of Ni2+ is only 2. 7%, and the effect of the decontamination reaches the national standard. [ABSTRACT FROM AUTHOR]

Simple Summary: Advanced urinary bladder cancer (BCa) is characterized by rapid progression and development of therapy resistance. Despite all the available therapies, the five-year survival of metastatic BCa is a dismal 8% or lower. Many conjugates and additives of the natural polyphenol curcumin were developed and tested for potential therapeutic for cancers, with little success in vivo due to their rapid elimination and poor tissue penetrance. We tested a novel molecular hybrid CMC-2 composed of a curcumin scaffold conjugated to two dichloroacetate and glycine molecules. CMC-2 showed significantly higher antiproliferative and anti-survival activities against BCa than its parent compounds. Further, it was equally effective against chemotherapy-naïve and multidrug-resistant BCas (MDR-BCa). When tested in vivo using BCa xenograft in athymic mice, CMC-2 significantly delayed tumor growth without systemic toxicity. The mechanism of anticancer activity of CMC-2 was the induction of excessive oxidative stress in the cancer cells, leading to apoptotic cell death. These results show the potential of CMC-2 as a nontoxic oral treatment for high-grade bladder cancers. Tumor cells produce excessive reactive oxygen species (ROS) but cannot detoxify ROS if they are due to an external agent. An agent that produces toxic levels of ROS, specifically in tumor cells, could be an effective anticancer drug. CMC-2 is a molecular hybrid of the bioactive polyphenol curcumin conjugated to dichloroacetate (DCA) via a glycine bridge. The CMC-2 was tested for its cytotoxic antitumor activities and killed both naïve and multidrug-resistant (MDR) bladder cancer (BCa) cells with equal potency (<1.0 µM); CMC-2 was about 10–15 folds more potent than curcumin or DCA. Growth of human BCa xenograft in mice was reduced by >50% by oral gavage of 50 mg/kg of CMC-2 without recognizable systemic toxicity. Doses that used curcumin or DCA showed minimum antitumor effects. In vitro, the toxicity of CMC-2 in both naïve and MDR cells depended on increased intracellular ROS in tumor cells but not in normal cells at comparable doses. Increased ROS caused the permeabilization of mitochondria and induced apoptosis. Further, adding N-Acetyl cysteine (NAC), a hydroxyl radical scavenger, abolished excessive ROS production and CMC-2's cytotoxicity. The lack of systemic toxicity, equal potency against chemotherapy -naïve and resistant tumors, and oral bioavailability establish the potential of CMC-2 as a potent drug against bladder cancers. [ABSTRACT FROM AUTHOR]

Earth‐abundant α‐Fe2O3 (hematite) is a convincing photoanode for photoelectrochemical (PEC) water splitting; however, its intrinsic properties of inferior charge transfer and sluggish water oxidation kinetics limit its performance. Here, we report a straightforward decoration method for transition metal hydroxides to accelerate the oxygen evolution reaction (OER) of hematite photoanodes grown by electric field‐assisted liquid phase deposition (EA‐LPD). The investigations revealed that Co(OH)2 acts as a superior co‐catalyst compared with hydroxides of Mn, Fe, Co, Ni, and Zn. EA‐LPD‐grown hematite photoanode loaded with cobalt hydroxide exhibited an excellent PEC performance. A photocurrent density of 0.93 mA.cm−2 at 1.23 V versus reversible hydrogen electrode was achieved for the modified hematite, ∼3 times more than that of pristine hematite, and a cathodic shift of 100 mV for the onset potential was observed. The proposed simple and cost‐effective co‐catalyst loading strategy provides a high degree of freedom in the design of co‐catalysts with a complex chemical composition comprising transition metal oxyhydroxides and hydroxides on different photoanodes for more efficient charge carrier separation for the PEC applications. [ABSTRACT FROM AUTHOR]

Lithium compounds such as lithium hydride (LiH) and lithium hydroxide (LiOH) have a wide range of industrial applications, but are highly reactive in environments with H2O and CO2. These reactions lead to the ingrowth of secondary lithium compounds, which can alter the homogeneity and affect the application of particular lithium chemicals. This study performed an exploratory analysis of different lithium compounds using laser-induced breakdown spectroscopy (LIBS) and Raman spectroscopy. Machine learning models are trained on the recorded spectral data to discriminate emission features that differ between LiH, LiOH, and Li2CO3 to perform high-fidelity classification. Support vector machine classifiers yield perfect prediction accuracy between the three compounds with optimal training time. Multivariate methods are then used to produce regression models quantifying the ingrowth of LiOH in LiH. Performing a mid-level data fusion of selected LIBS and Raman features with partial least-squares regression produces the superlative model with a root mean square error of 2.5 wt % and a detection limit of 6.3 wt %. [ABSTRACT FROM AUTHOR]