Reaction Rate Research Articles

An intriguing way to synthesize a TiO2–ZnO hybrid nanostructure for the pragmatic application as a photocatalyst

In an attempt to counter the problem of treating wastewater more efficiently, we report the study on photocatalytic properties of metal oxide nanostructures under different light sources. A novel sonication-assisted refluxing method was employed to synthesize a binary heterostructure consisting of TiO2 and ZnO. XRD and EDS analysis of synthesized materials confirm the presence of both TiO2 and ZnO. Also, the change in the intensity of XRD peaks and elemental composition are well observed with a change in molar concentration of Ti and Zn. HR-TEM micrographs show nanostructures having hybrid Janus and Core-shell type structures. The XPS spectra were probed to identify the surface chemical species associated with the prepared heterostructures. Raman spectra confirm the smaller ZnO particles attached over agglomerated TiO2 as a shell layer as depicted in TEM results. Optical studies exhibit the modification in the band structure of the materials due to the formation of the heterostructure. The synthesized hybrid catalyst shows impressive results in photocatalytic performance. The catalytic potency of the prepared heterostructures under UV light is reminiscent of Anatase while it gets convalescent with an increment of Zn content under visible light. The photocatalytic performance of synthesized materials under sunlight shows their potential to be utilized as commercial catalysts for direct application in wastewater treatment. The kinetic study of the degradation data reveals interesting facets of the catalysis. It suggests that the photo-corrosion of the catalyst inordinately changes the rate of photocatalytic reaction which ultimately affects the photocatalytic efficiency of the catalyst. The study also discusses the role of kinetic and validation parameters in the selection of the best-fitted kinetic model with realistic arguments.

Calibration-Free and Highly Sensitive Potentiometric Enzyme-Based Biosensors.

Enzyme-based amperometric biosensors have become popular for healthcare applications. However, they have been under constant pressure for technological innovation to improve their sensitivity and usability. An ideal biosensor has high sensitivity and calibration-free characteristics. This study aims to report enzyme-based glucose and lactate sensors that utilize a proposed "time-derivative of potential (dOCP/dt)" method, with a further aim being to prove theoretically and experimentally that dOCP/dt values are proportional to substrate concentration. High sensitivity is obtained regardless of the electrode size because the electrode potential is independent of the electrode area in the biosensor. Importantly, because the substrate diffusion determines the enzyme reaction rate on the sensors, the dOCP/dt biosensors can essentially eliminate external influences such as temperature and pH. The result is the successful realization of a biosensor that is calibration-free, making it a much more practical option.

Recent advances in microenvironment regulation for electrocatalysis

Abstract High-efficiency electrocatalysis could serve as the bridge that connects renewable energy technologies, hydrogen economy and carbon capture/utilization, promising a sustainable future for humankind. It is therefore of paramount significance to explore feasible strategies to modulate the relevant electrocatalytic reactions and optimize the device performances so as to promote their large-scale practical applications. Microenvironment regulation at the catalytic interface has been demonstrated capable of effectively enhancing the reaction rates and improving the selectivities for specific products. In this review we summarize the latest advances in microenvironment regulation in typical electrocatalytic processes (including water electrolysis, hydrogen–oxygen fuel cells, and carbon dioxide reduction) and the related in situ/operando characterization techniques and theoretical simulation methods. At the end of this article, we present an outlook on the development trends and possible future directions.

Sulfonated Hydroxyaryl‐Tetrazines with Increased pKa for Accelerated Bioorthogonal Click‐to‐Release Reactions in Cells

Bioorthogonal reactions that enable switching molecular functions by breaking chemical bonds have gained prominence, with the tetrazine‐mediated cleavage of trans‐cyclooctene caged compounds (click‐to‐release) being particularly noteworthy for its high versatility, biocompatibility, and fast reaction rates. Despite several recent advances, the development of highly reactive tetrazines enabling quantitative elimination from trans‐cyclooctene linkers remains challenging. In this study, we present the synthesis and application of sulfo‐tetrazines, a class of derivatives featuring phenolic hydroxyl groups with increased acidity constants (pKa). This unique property leads to accelerated elimination and complete release of the caged molecules within minutes. Moreover, the inclusion of sulfonate groups provides a valuable synthetic handle, enabling further derivatization into sulfonamides, modified with diverse substituents. Significantly, we demonstrate the utility of sulfo‐tetrazines in efficiently activating fluorogenic compounds and prodrugs in living cells, offering exciting prospects for their application in bioorthogonal chemistry.

Numerical Comparative Investigating of PEMFC with Novel Hybrid Zigzag Channels: Reaction, Transport and Drainage Enhancements

Abstract The impact of flow channel design on mass transport and drainage in proton exchange membrane fuel cells (PEMFCs) is significant, thereby influencing the reaction rate. Based on conventional wavy design, this study introduces two novel hybrid zigzag flow channels (asynchronous and synchronous) with both zigzag sidewalls and bottom wall, aiming in further improving mass and heat transfer, as well as drainage capacity to achieve better fuel cell performance. Numerical simulations demonstrate that the net power densities of both asynchronous and synchronous hybrid zigzag channels show a 28.7% and 44.4% improvement at low voltage, respectively. The implementation of the asynchronous hybrid zigzag flow channel has been observed to result in a notable reduction in pressure drop, amounting to 9.2%, while concurrently enhancing power output by 10.7% in comparison to a conventional zigzag channel. Additionally, the novel hybrid zigzag designs improve mass transfer efficiency at high current density and exhibits better temperature distribution uniformity. Moreover, the volume of fluid simulations illustrate that hybrid zigzag channels are highly effective in removing accumulated water, surpassing the straight channel with a drainage rate exceeding 54%, as well as a lower surface liquid coverage.

Long-term beam output stability of an accelerator-based boron neutron capture therapy system.

Accelerator-based boron neutron capture therapy (AB-BNCT) systems are becoming commercially available and are expected to be widely used in hospitals. To ensure the safety of BNCT, establishing a quality assurance (QA) program and properly managing the stability of the system are necessary. In particular, a high level of beam output stability is required to avoid accidents because beam output is a major factor in patient dose. However, no studies have analyzed the long-term beam output stability of AB-BNCT systems. This study aimed to retrospectively analyze the long-term stability of the beam output by statistical process control (SPC) based on the QA results over 3 years. The data analyzed are the results of daily QA (DQA) and weekly QA (WQA) in an AB-BNCT system and were taken between June 2020 and September 2023. The evaluation of the stability of the beam output was based on the reaction rate between gold and neutrons calculated using the activation foil method using a gold foil. In DQA, which can be performed in a short time, the gold foil was applied directly to the beam irradiation aperture in air. In WQA, measurements were performed at the phantom surface, 2-cm depth, and 6-cm depth using a dedicated water phantom. The acquired data were retrospectively analyzed by individuals and a moving range chart (I-MR chart), exponentially weighted moving average control chart (EWMA chart), and several process capability indexes (PCIs). Over 99% of the DQA I-MR chart results were within control limits, whereas the WQA I-MR chart results showed that 1.8%, 4.1%, and 2.0% of the measurements exceeded the control limits at the surface, 2-cm depth, and 6-cm depth, respectively. The variation in the reaction rate of the gold foil before and after the replacement of the target was<0.5%. The EWMA chart results revealed no significant beam output drift for either DQA or WQA. Most measured data were normal based on the results of the Anderson-Darling test and met the requirements for PCI evaluation; most PCI values were>1.0; however, the Cpmk of DQA and the 2- and 6-cm depth WQAs between August 2021 and November 2022 in treatment course 2 were 0.83, 0.77, and 0.87, respectively, which were<1.0. The long-term stability of beam output was confirmed using SPC in an AB-BNCT system. The results of the control chart revealed no significant variation or drift in the beam output, and the quantitative evaluation using PCI revealed high stability. A routine QA program will enable us to provide safe BNCT.

Peptide Catalyzed Conjugate Additions to β-Nitroacrylates - Steric Bulk Increases the Reaction Rate.

The organocatalytic conjugate addition of aldehydes to β-nitroacrylates provides direct access to β-ester-γ-nitroaldehydes and, thereby, common structural motifs of many bioactive compounds. However, the deactivation of amine-based catalysts by alkylation with the highly electrophilic nitroacrylates hampers this reaction. Here, we show that the peptide H-Mep-dPro-dGlu-NH2, which is reluctant to under alkylation,catalyzes this reaction at low catalyst loading (0.5-1 mol%) within short reaction times (15-60 min) to yield a broad range of β-ester-γ-nitroaldehydes with high stereoselectivity. Kinetic studies revealed that increased steric bulk on the β-nitroacrylate enhances the reaction rate by hindering catalyst alkylation.

The process and mechanism of coke gasification dissolution loss in hydrogen-rich blast furnace

Blast furnace (BF) hydrogen-rich smelting has become an important way for low-carbon ironmaking. The coke gasification dissolution loss will be accelerated by H2O generated through hydrogen reduction, which is the fundamental reason for the limited injection rate of hydrogen-rich gas in BF. The gasification dissolution loss experiments of coke were carried out under different conditions. Experimental results indicate that: The pore size of coke containing H2O is larger under the same gasification time. The quantitative relationship between pore size and gasification time, flow rate of H2O is obtained. The pore wall around the inner hole will gradually be eroded, the pore wall gradually dissolves along the edge of the inner hole. The connectivity between two pores starts from the deep layers of the pores, the pore walls in the deep layers of pores are first connected. The carbon layer spacing slightly decreases with gasification time, which indicates that the microcrystalline cells inside the coke have contracted in the vertical direction. The carbon layer stacking height shows an overall upward trend with the increase of temperature and gasification time, and it will reach a maximum value for a certain temperature. The carbon layer diameter increases with the prolongation of gasification time, the aromatic carbon layers continue to grow as gasification progresses. The dynamic model of H2O diffusion is established, the effective internal diffusion coefficients of H2O under different conditions are calculated, the diffusion ability of H2O is stronger than that of CO2. The mechanism of H2O dissolution loss of coke based on surface active sites is summarized, whether the gasification dissolution loss reaction can occur depends on whether there are active sites on the adsorbed surface. The competitive gasification always occurs vigorously at active sites, the gasification reaction between H2O and C is easier and the reaction rate is higher.

Efficacy and Mechanism of Alprostadil in Diabetes Mellitus Combined with Peripheral Atherosclerosis.

The aim is to investigate the clinical efficacy of Alprostadil in diabetes mellitus (DM) combined with peripheral atherosclerosis and to investigate the molecular mechanisms. Patients included 154 cases with DM combined with peripheral atherosclerosis and were divided into the conventional group (77 cases) and the Alprostadil group (77 cases). Both groups of patients were given conventional treatment, and the Alprostadil group was given Alprostadil treatment on the basis of the conventional group. The therapeutic efficacy and clinical symptom improvement were compared, and the adverse reactions were observed. An in vitro cell model was constructed using high glucose (HG) (50 mM) and oxidized low-density lipoprotein (50 μg/mL) treatment. The total effective rate of treatment in the Alprostadil group was higher than that in the conventional group. The biochemical indices of whole blood viscosity, plasma viscosity, erythrocyte pressure volume, and fibrinogen, as well as the level of inflammatory factors in the Alprostadil group were lower than those in the conventional group. The incidence rate of adverse reactions of Alprostadil administration was lower than that in the conventional group (P = .030). Alprostadil inhibited platelet aggregation and promoted platelet spreading. Alprostadil had an ameliorative effect on HG- and oxidized low-density lipoprotein cholesterol (ox-LDL)-induced human umbilical vascular endothelial cells (HUVECs), and promoted apoptosis and inflammatory response of HUVECs. Clinically, the use of Alprostadil as an adjunct to conventional therapy for the treatment of DM combined with peripheral atherosclerosis has high clinical efficacy. In addition, Alprostadil has a significant ameliorative effect on high glucose- and ox-LDL-induced HUVECs.

Macromorphological Control of Zr-Based Metal-Organic Frameworks for Hydrolysis of a Nerve Agent Simulant.

Zirconium-based metal-organic frameworks (MOFs) have become one of the most promising materials for the adsorption and destruction of chemical warfare agents. While numerous studies have shown differences in reactivity based on MOF topology and postsynthetic modification, the understanding of how modifying MOF macromorphology is less understood. MOF xerogels demonstrate modified defect levels and larger porosity, which increase the number of and access to potential active sites. Indeed, UiO-66 and NU-901 xerogels display reaction rates 2 and 3 times higher, respectively, for the hydrolysis of DMNP relative to their powder morphologies. Upon recycling, MOF-808 xerogel outperforms MOF-808 powder, previously noted as the fastest Zr6 MOF for hydrolysis of organophosphate nerve agents. The increase in reactivity is largely driven by a higher external surface area and the introduction of mesoporosity to previously microporous materials.

Catalytic Activity of Mono‐and Bimetallic Rhodium(I) and Iridium(I) Complexes Bearing Carbon‐Ether‐Carbon (COC) Ligand for the Intramolecular Cyclization of 4‐Pentynoic Acid

AbstractThe catalytic performance of a series of mono‐ and bimetallic Ir(I) and Rh(I) complexes bearing the (COC) bis‐triazolylidene ligand, coordinated in a bridging or chelating fashion, was evaluated in the cyclization of 4‐pentynoic acid. The chelated mononuclear cationic complex [Ir(cod)(COC)]PF6 (cod=1,5‐cyclooctadiene; COC=biscarbene ether) displayed the highest reaction rate for 4‐pentynoic acid to form γ‐methyl‐ene‐γ‐butyrolactone (5‐methylenedihydrofuran‐2(3H)‐one). Density Functional Theory calculations were carried out to rationalize the reaction mechanism which proceeds in three steps, namely coordination of the alkyne to the active catalyst followed by intramolecular cyclization and final reductive elimination. Its catalytic performance was further assessed against different substituted 4‐pentynoic acid derivatives.

Continuum models for meso-scale simulations of HMX (1,3,5,7-tetranitro-1,3,5,7-tetrazocane) guided by molecular dynamics: Pore collapse, shear bands, and hotspot temperature

Meso-scale calculations of energy localization and initiation in energetic material microstructures must capture the deformation and collapse of pores and high-temperature shear bands, which lead to hotspots. Because chemical reaction rates depend sensitively on temperature, predictive continuum models need to get the pore-collapse dynamics and resulting hotspot temperatures right; this imposes stringent demands on the fidelity of thermophysical model forms and parameters and on the numerical methods employed to perform high-resolution meso-scale calculations. Here, continuum material models for β-HMX are examined in the context of shock-induced pore collapse, treating predictions from all-atom molecular dynamics (MD) simulations as ground truth. Using atomistics-consistent material properties, we show that the currently available strength models for HMX fail to correctly capture pore collapse and hotspot temperatures. Insights from MD are then employed to advance a Modified Johnson–Cook (M-JC) strength model, which is shown to capture key aspects of the physics of shock-induced localization in HMX. The study culminates in a MD-guided strength model for β-HMX that produces continuum pore-collapse results in better alignment on several aspects with those predicted by MD, including pore-collapse mechanism and rate, shear-band formation in the collapse zone, and temperature, strain, and stress fields in the hotspot zone and the surrounding material. The resulting MD-informed/MD-determined M-JC model should improve the fidelity of meso-scale simulations to predict the detonation initiation of HMX-based energetic materials in microstructure-aware multi-scale frameworks.

Enhanced Piezocatalytic Water Splitting by Platinum‐Decorated Barium Titanate

AbstractPiezocatalysis has emerged as a promising field of research that uses mechanical energy to drive a chemical change. There is growing evidence that piezocatalysts can perform challenging chemical conversions from organic transformations to water splitting. A key challenge to piezocatlaysis is mitigating the inherent high relative permittivity of a ferroelectric material. This high permittivity restricts the transfer of carriers required for a chemical reaction to occur and reduces the reaction rate. Here the concept of producing a co‐catalyst system is taken to enhance carrier mobility increasing the observed reaction rate. The study highlights the importance of determining the sonochemical and piezocatalytic contributions to catalysis. The combination of a Pt metal co‐catalyst with BaTiO3 through a simple solid‐state method led to a four fold increase in the rate of H2 production compared to BaTiO3 and sonochemical reactions in the absence of a catalyst. BaTiO3/Pt is found to exhibit stable piezocatalytic performance over 12 h. Where there is a deviation from steady‐state water splitting, it is shown that this is due to mechanical removal of Pt rather than a phase change in the catalyst system. This work confirms the additive benefits of hybrid materials for improving piezocatalytic processes.

Radiative neutron capture reaction rates for stellar nucleosynthesis

AbstractThere is a high demand for nuclear data in multidisciplinary subject like nuclear astrophysics. The two areas of nuclear physics which are most clearly related to one another are stellar evolution and nucleosynthesis. The necessity for nuclear data for astrophysical applications puts experimental methods as well as reliability and predicative ability of current nuclear models to the test. Despite recent, considerable advances, there are still significant issues and mysteries. Only a few characteristics of nuclear astrophysics are covered in the current work which include $$^{52}$$ 52 Fe(n,$$\gamma $$ γ )$$^{53}$$ 53 Fe, $$^{53}$$ 53 Fe(n,$$\gamma $$ γ )$$^{54}$$ 54 Fe, $$^{54}$$ 54 Fe(n,$$\gamma $$ γ )$$^{55}$$ 55 Fe, $$^{55}$$ 55 Fe(n,$$\gamma $$ γ )$$^{56}$$ 56 Fe, $$^{56}$$ 56 Fe(n,$$\gamma $$ γ )$$^{57}$$ 57 Fe, $$^{57}$$ 57 Fe(n,$$\gamma $$ γ )$$^{58}$$ 58 Fe and $$^{58}$$ 58 Fe(n,$$\gamma $$ γ )$$^{59}$$ 59 Fe reactions which are important in stellar nucleosynthesis. The reaction rates are calculated using nuclear statistical model. These rates are subsequently fitted to polynomials of temperature T$$_9$$ 9 in order to facilitate calculations for stellar nucleosynthesis.

Fundamental Insights into the Direct Electron Transfer Mechanism on Ag Atomic Cluster.

The nonradical oxidation pathway for pollutant degradation in Fenton-like catalysis is favorable for water treatment due to the high reaction rate and superior environmental robustness. However, precise regulation of such reactions is still restricted by our poor knowledge of underlying mechanisms, especially the correlation between metal site conformation of metal atom clusters and pollutant degradation behaviors. Herein, we investigated the electron transfer and pollutant oxidation mechanisms of atomic-level exposed Ag atom clusters (AgAC) loaded on specifically crafted nitrogen-doped porous carbon (NPC). The AgAC triggered a direct electron transfer (DET) between the terminal oxygen (Oα) of surface-activated peroxodisulfate and the electron-donating substituents-containing contaminants (EDTO-DET), rendering it 11-38 times higher degradation rate than the reported carbon-supported metal catalysts system with various single-atom active centers. Heterocyclic substituents and electron-donating groups were more conducive to degradation via the EDTO-DET system, while contaminants with high electron-absorbing capacity preferred the radical pathway. Notably, the system achieved 79.5% chemical oxygen demand (COD) removal for the treatment of actual pharmaceutical wastewater containing 1053 mg/L COD within 30 min. Our study provides valuable new insights into the Fenton-like reactions of metal atom cluster catalysts and lays an important basis for revolutionizing advanced oxidation water purification technologies.

Assessment of Blast Furnace Slags as a Potential Catalyst in Ozonation to Degrade Bezafibrate: Degradation Study and Kinetic Study via Non-Parametric Modeling

This study investigates the effectiveness of blast furnace slags (BFSs) as catalysts in the ozonation process to degrade complex contaminants such as bezafibrate (BFZ) at different pH levels. The findings reveal that the presence of BFS enhances degradation efficiency, achieving a 10% improvement at pH 10 and a 30% improvement at pH 5.5 compared to simple ozonation. The highest degradation efficiency was observed in the Ozonation–BFS system at pH 10, with 90% decomposition of BFZ. These results were corroborated through ozone consumption analysis, BOD5 measurements, and the identification of oxalic acid as the final decomposition product. Due to the complexity of the reaction system, kinetic characterization was performed using non-parametric modeling based on differential neural networks. The model indicated that the observed reaction rate for BFZ degradation in the presence of ozone and BFS was 4.12 times higher at pH 5.0 and 1.08 times higher at pH 10.0 compared to simple ozonation. These results underscore the potential of using BFS in catalytic ozonation processes for the effective treatment of recalcitrant contaminants in wastewater.

Reaction Risk to Direct Penicillin Challenges

While direct penicillin challenges might support the expansion of penicillin allergy delabeling efforts, the perceived risk of reactions remains a key barrier. To evaluate the frequency of reactions to direct penicillin challenges in individuals with penicillin allergy labels and to identify factors associated with such reactions. Three electronic databases were searched (MEDLINE, Web of Science, and Scopus) from inception to July 19, 2023, for primary studies assessing patients undergoing direct penicillin challenges. Articles were included regardless of publication year, language, status, or definition of allergy risk. Two reviewers independently selected original studies reporting the frequency of immunologically mediated reactions following a direct penicillin challenge in patients reporting a penicillin allergy. Two reviewers independently extracted data and independently assessed the quality of each primary study using a risk-of-bias tool for prevalence studies. The primary outcome was the frequency of reactions to direct penicillin challenges as calculated using random-effects bayesian meta-analysis of proportions. Secondary outcomes included risk factors for reactions and the frequency of severe reactions. A total of 56 primary studies involving 9225 participants were included. Among participants, 438 experienced reactions to direct penicillin challenges without prior testing, corresponding to an overall meta-analytic frequency of 3.5% (95% credible interval [CrI], 2.5%-4.6%). Meta-regression analyses revealed that studies performed in North America had lower rates of reaction to direct challenges (odds ratio [OR], 0.36; 95% CrI, 0.20-0.61), while studies performed in children (OR, 3.37; 95% CrI, 1.98-5.98), in outpatients (OR, 2.19; 95% CrI, 1.08-4.75), and with a graded (OR, 3.24; 95% CrI, 1.50-7.06) or prolonged (OR, 5.45; 95% CrI, 2.38-13.28) challenge had higher rates of reaction. Only 5 severe reactions (3 anaphylaxis, 1 fever with rash, and 1 acute kidney injury) were reported, none of which were fatal. This systematic review and meta-analysis found that reactions to direct penicillin challenges are infrequent, with rates comparable to indirect challenges after allergy testing. These findings suggest that direct challenges are safe for incorporation into penicillin allergy evaluation efforts across age groups and clinical settings.

Surveillance of adverse events following varicella vaccine immunization in Jiangsu province, China from 2017 to 2023

To assess the safety of varicella vaccine (VarV) by conducting post-marketing surveillance on adverse events following immunization (AEFI) in Jiangsu Province, China.MethodsWe utilized the AEFI Information System of mainland China to monitor and categorize adverse reactions associated with VarV.ResultsThe incidence rate of AEFI was significantly higher after the first dose (48.79/100,000 doses) compared to the second dose (45.18/100,000 doses) (χ2 = 4.63, P = 0.031). Regional variations in AEFI incidence were observed within Jiangsu Province. Common reactions comprised 90.96% of AEFIs, while rare reactions and coincidental events accounted for 6.59% and 0.51%, respectively. Notably, there were no adverse events linked to vaccine quality, program errors, psychogenic reactions, or fatalities. Over 96% of AEFIs occurred within three days of VarV administration, with redness at the injection site (2.6 cm to 5 cm in diameter) being the most frequently observed symptom.ConclusionVarV demonstrates a commendable safety profile. Although there was a slight increase in AEFI incidence between 2022 and 2023, common vaccine reactions were predominantly observed, and the rates of rare reactions remained very low.

Mg2+ - Ca2+ chelating citric acid crosslinked gelatin, a bone adhesive composed of hydroxyapatite and calcined dolomite: Physicochemical characteristics and in-vitro biological activity

Hydroxyapatite-based bone adhesives have strong bond strength and good adsorbability, however, they also have some disadvantages such as poor mechanical strength, fast curing reaction rate and high exothermic strength, which limit their wide application in bone tissue engineering. In this study, hydroxyapatite-based bone adhesive was prepared by solid-liquid blended crosslinking followed by heating. The prepared bone adhesive has two components: (i) is a mineral composed of calcined dolomite and montmorillonite and (ii) is organic composite composed of citric acid and gelatine. The optimum solid-liquid ratio (0.50 g/mL) of the bone adhesive was determined based on the bond strength of nano-hydroxyapatite/calcined dolomite/citric acid/gelatin system. The best physicochemical properties of the bond adhesive were obtained when the composition of the bone adhesive was as follows: 20 wt% citric acid, 17 wt% gelatin and 12 wt% calcined dolomite. The acquired curing time of bone adhesive was 10.5 min, comparable to the necessity for surgery (5–30 min); moreover, the adhesive strength and compressive strength of the bone adhesive were 12.18 MPa and 9.36 MPa respectively, obtained after being placed in the air for 168 h; besides, the porosity (16.8 %) was found quite suitable. Upon this, a certain amount of montmorillonite was added with calcined dolomite to prepare bone adhesive, resulting reduction in the adhesive strength (10.19 MPa) and compressive strength (7.109 MPa), but improved the biocompatibility of the system. The absorbency of the hydroxyapatite-based bone adhesives in deionized water and Tris-HCl buffer solution was found to be 27.19 % and 18.68 %, respectively, ascertaining that such bone adhesives are efficient in absorbing certain blood and tissue fluid in the biological body and promoting the absorption of required nutrients in the process of bone repair. In addition, the formation of osteoid apatite in the In-vitro study, proved by FTIR and EDAX analysis, rationalized for improving the osteogenic activity. Furthermore, after 56 days of immersion in the Tris-HCl buffer solution, the weight loss rate of the bone adhesive reached up to 42.73 %, indicating that the bone adhesive had satisfactory degradation performance. Finally, in the cytotoxicity test, the survival rate of mouse precranial bone cells was found to be greater than 80 % after adding the prepared bone adhesive, demonstrating its sufficient biocompatibility.

Mechanism for airborne ozone decomposition on X-MIL-53(Fe) (X = H, NH2, NO2)

Ground−level ozone (O3) pollution poses a significant threat to both ecosystem sustainability and human health. The catalytic decomposition of O3 presents as a promising technology to address the issues of O3 pollution. This study undertook the synthesis of various functionalized metal−organic framework (MOF) catalysts (i.e., X-MIL-53(Fe) (X = H, NH2, NO3)) to delve into the influence of ligand functional groups on skeletal structure and catalytic efficacy, particularly focusing on unraveling the mechanism of O3 catalytic decomposition under humid conditions. NH2-MIL-53(Fe) catalyst achieved complete O3 decomposition under ambient temperature and high humidity conditions (RH=75 %), exhibiting a reaction rates (mol·m−2·s−1) 129 and 10.5 times greater than that of MIL-53(Fe) and NO2-MIL-53(Fe). The NH2 group promotes electron flow within the backbone towards the hydroxyl group (OH) linked to Fe atom. In humid O3, H2O molecules augment the interaction between O3 and NH2-MIL-53(Fe), and OH is converted to·O2− after deprotonation, promoting O3 decomposition. Additionally, leveraging three−dimensional (3D) printing technology, a monolithic catalyst for O3 decomposition was prepared for application. This study not only advances understanding of the mechanisms underlying O3 decomposition but also offers practical solutions for addressing O3 pollution at humid conditions.