RESUMO

Post-etching method using dilute acid solutions is an effective technology to modulate the surface compositions of metal-oxide catalysts. Here the α-MnO2 catalyst treated with 0.1 mol/L nitric acid exhibits higher ozone decomposition activity at high relative humidity than the counterpart treated with acetic acid. Besides the increases in surface area and lattice dislocation, the improved activity can be due to relatively higher Mn valence on the surface and newly-formed Brønsted acid sites adjacent to oxygen vacancies. The remnant nitro species deposited on the catalyst by nitric acid treatment is ideal hydrophobic groups at ambient conditions. The decomposition route is also proposed based on the DRIFTS and DFT calculations: ozone is facile to adsorb on the oxygen vacancy, and the protonic H of Brønsted acid sites bonds to the terminal oxygen of ozone to accelerate its cleavage to O2, reducing the reaction energy barrier of O2 desorption.

Assuntos

Umidade , Compostos de Manganês , Óxidos , Ozônio , Ozônio/química , Óxidos/química , Compostos de Manganês/química , Catálise , Modelos Químicos

RESUMO

The manganese-cobalt mixed oxide nanorods were fabricated using a hydrothermal method with different metal precursors (KMnO4 and MnSO4·H2O for MnOx and Co(NO3)2⋅6H2O and CoCl2⋅6H2O for Co3O4). Bamboo-like MnO2⋅Co3O4 (B-MnO2⋅Co3O4 (S)) was derived from repeated hydrothermal treatments with Co3O4@MnO2 and MnSO4⋅H2O, whereas Co3O4@MnO2 nanorods were derived from hydrothermal treatment with Co3O4 nanorods and KMnO4. The study shows that manganese oxide was tetragonal, while the cobalt oxide was found to be cubic in the crystalline arrangement. Mn surface ions were present in multiple oxidation states (e.g., Mn4+ and Mn3+) and surface oxygen deficiencies. The content of adsorbed oxygen species and reducibility at low temperature declined in the sequence of B-MnO2⋅Co3O4 (S) > Co3O4@MnO2 > MnO2 > Co3O4, matching the changing trend in activity. Among all the samples, B-MnO2⋅Co3O4 (S) showed the preeminent catalytic performance for the oxidation of toluene (T10% = 187°C, T50% = 276°C, and T90% = 339°C). In addition, the B-MnO2⋅Co3O4 (S) sample also exhibited good H2O-, CO2-, and SO2-resistant performance. The good catalytic performance of B-MnO2⋅Co3O4 (S) is due to the high concentration of adsorbed oxygen species and good reducibility at low temperature. Toluene oxidation over B-MnO2⋅Co3O4 (S) proceeds through the adsorption of O2 and toluene to form O*, OH*, and H2C(C6H5)* species, which then react to produce benzyl alcohol, benzoic acid, and benzaldehyde, ultimately converting to CO2 and H2O. The findings suggest that B-MnO2⋅Co3O4 (S) has promising potential for use as an effective catalyst in practical applications.

Assuntos

Cobalto , Compostos de Manganês , Oxirredução , Óxidos , Tolueno , Óxidos/química , Compostos de Manganês/química , Catálise , Cobalto/química , Tolueno/química , Poluentes Atmosféricos/química

RESUMO

Nowadays, it is still a challenge to prepared high efficiency and low cost formaldehyde (HCHO) removal catalysts in order to tackle the long-living indoor air pollution. Herein, δ-MnO2 is successfully synthesized by a facile ozonation strategy, where Mn2+ is oxidized by ozone (O3) bubble in an alkaline solution. It presents one of the best catalytic properties with a low 100% conversion temperature of 85°C for 50 ppm of HCHO under a GHSV of 48,000 mL/(g·hr). As a comparison, more than 6 times far longer oxidation time is needed if O3 is replaced by O2. Characterizations show that ozonation process generates a different intermediate of tetragonal ß-HMnO2, which would favor the quick transformation into the final product δ-MnO2, as compared with the relatively more thermodynamically stable monoclinic γ-HMnO2 in the O2 process. Finally, HCHO is found to be decomposed into CO2 via formate, dioxymethylene and carbonate species as identified by room temperature in-situ diffuse reflectance infrared fourier transform spectroscopy. All these results show great potency of this facile ozonation routine for the highly active δ-MnO2 synthesis in order to remove the HCHO contamination.

Assuntos

Formaldeído , Compostos de Manganês , Óxidos , Ozônio , Ozônio/química , Compostos de Manganês/química , Formaldeído/química , Óxidos/química , Poluentes Atmosféricos/química , Oxirredução , Temperatura , Poluição do Ar em Ambientes Fechados/prevenção & controle , Catálise

RESUMO

The environmental threat posed by stibnite is an important geoenvironmental issue of current concern. To better understand stibnite oxidation pathways, aerobic abiotic batch experiments were conducted in aqueous solution with varying δ18OH2O value at initial neutral pH for different lengths of time (15-300 days). The sulfate oxygen and sulfur isotope compositions as well as concentrations of sulfur and antimony species were determined. The sulfur isotope fractionation factor (Δ34SSO4-stibnite) values decreased from 0.8‰ to -2.1‰ during the first 90 days, and increased to 2.6‰ at the 180 days, indicating the dominated intermediate sulfur species such as S2O32-, S0, and H2S (g) involved in Sb2S3 oxidation processes. The incorporation of O into sulfate derived from O2 (∼100%) indicated that the dissociated O2 was only directly adsorbed on the stibnite-S sites in the initial stage (0-90 days). The proportion of O incorporation into sulfate from water (27%-52%) increased in the late stage (90-300 days), which suggested the oxidation mechanism changed to hydroxyl attack on stibnite-S sites promoted by nearby adsorbed O2 on stibnite-Sb sites. The exchange of oxygen between sulfite and water may also contributed to the increase of water derived O into SO42-. The new insight of stibnite oxidation pathway contributes to the understanding of sulfide oxidation mechanism and helps to interpret field data.

Assuntos

Oxirredução , Isótopos de Oxigênio , Sulfatos , Isótopos de Enxofre , Isótopos de Enxofre/análise , Sulfatos/química , Isótopos de Oxigênio/análise , Antimônio/química , Modelos Químicos , Aerobiose , Oxigênio/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Óxidos

RESUMO

A mixed oxidant of chlorine dioxide (ClO2) and NaClO was often used in water treatment. A novel UVA-LED (365 nm)-activated mixed ClO2/NaClO process was proposed for the degradation of micropollutants in this study. Carbamazepine (CBZ) was selected as the target pollutant. Compared with the UVA365/ClO2 process, the UVA365/ClO2/NaClO process can improve the degradation of CBZ, with the rate constant increasing from 2.11×10-4 sec-1 to 2.74×10-4 sec-1. In addition, the consumption of oxidants in the UVA365/ClO2/NaClO process (73.67%) can also be lower than that of UVA365/NaClO (86.42%). When the NaClO ratio increased, both the degradation efficiency of CBZ and the consumption of oxidants can increase in the UVA365/ClO2/NaClO process. The solution pH can affect the contribution of NaClO in the total oxidant ratio. When the pH range of 6.0-8.0, the combination process can generate more active species to promote the degradation of CBZ. The change of active species with oxidant molar ratio was investigated in the UVA365/ClO2/NaClO process. When ClO2 acted as the main oxidant, HO• and Cl• were the main active species, while when NaClO was the main oxidant, ClO• played a role in the system. Both chloride ion (Cl-), bicarbonate ion (HCO3-), and nitrate ion (NO3-) can promote the reaction system. As the concentration of NaClO in the reaction solution increased, the generation of chlorates will decrease. The UVA365/ClO2/NaClO process can effectively control the formation of volatile disinfection by-products (DBPs), and with the increase of ClO2 dosage, the formation of DBPs can also decrease.

Assuntos

Carbamazepina , Compostos Clorados , Óxidos , Raios Ultravioleta , Poluentes Químicos da Água , Purificação da Água , Carbamazepina/química , Poluentes Químicos da Água/química , Compostos Clorados/química , Purificação da Água/métodos , Óxidos/química , Cinética , Hipoclorito de Sódio/química , Modelos Químicos

RESUMO

Pyrrolizidine alkaloids (PAs) and their N-oxides (PANOs) are phytotoxins produced by various plant species and have been emerged as environmental pollutants. The sorption/desorption behaviors of PAs/PANOs in soil are crucial due to the horizontal transfer of these natural products from PA-producing plants to soil and subsequently absorbed by plant roots. This study firstly investigated the sorption/desorption behaviors of PAs/PANOs in tea plantation soils with distinct characteristics. Sorption amounts for seneciphylline (Sp) and seneciphylline-N-oxide (SpNO) in three acidic soils ranged from 2.9 to 5.9 µg/g and 1.7 to 2.8 µg/g, respectively. Desorption percentages for Sp and SpNO were from 22.2% to 30.5% and 36.1% to 43.9%. In the mixed PAs/PANOs systems, stronger sorption of PAs over PANOs was occurred in tested soils. Additionally, the Freundlich models more precisely described the sorption/desorption isotherms. Cation exchange capacity, sand content and total nitrogen were identified as major influencing factors by linear regression models. Overall, the soils exhibiting higher sorption capacities for compounds with greater hydrophobicity. PANOs were more likely to migrate within soils and be absorbed by tea plants. It contributes to the understanding of environmental fate of PAs/PANOs in tea plantations and provides basic data and clues for the development of PAs/PANOs reduction technology.

Assuntos

Camellia sinensis , Alcaloides de Pirrolizidina , Poluentes do Solo , Solo , Alcaloides de Pirrolizidina/química , Alcaloides de Pirrolizidina/análise , Solo/química , Camellia sinensis/química , Poluentes do Solo/análise , Poluentes do Solo/química , Óxidos/química , Adsorção

RESUMO

Monolithic catalysts with excellent O3 catalytic decomposition performance were prepared by in situ loading of Co-doped KMn8O16 on the surface of nickel foam. The triple-layer structure with Co-doped KMn8O16/Ni6MnO8/Ni foam was grown spontaneously on the surface of nickel foam by tuning the molar ratio of KMnO4 to Co(NO3)2·6H2O precursors. Importantly, the formed Ni6MnO8 structure between KMn8O16 and nickel foam during in situ synthesis process effectively protected nickel foam from further etching, which significantly enhanced the reaction stability of catalyst. The optimum amount of Co doping in KMn8O16 was available when the molar ratio of Mn to Co species in the precursor solution was 2:1. And the Mn2Co1 catalyst had abundant oxygen vacancies and excellent hydrophobicity, thus creating outstanding O3 decomposition activity. The O3 conversion under dry conditions and relative humidity of 65%, 90% over a period of 5 hr was 100%, 94% and 80% with the space velocity of 28,000 hr-1, respectively. The in situ constructed Co-doped KMn8O16/Ni foam catalyst showed the advantages of low price and gradual applicability of the preparation process, which provided an opportunity for the design of monolithic catalyst for O3 catalytic decomposition.

Assuntos

Compostos de Manganês , Níquel , Óxidos , Ozônio , Óxidos/química , Níquel/química , Compostos de Manganês/química , Ozônio/química , Catálise , Umidade , Cobalto/química , Modelos Químicos , Poluentes Atmosféricos/química

RESUMO

In this study, a string of Cr-Mn co-modified activated coke catalysts (XCryMn1-y/AC) were prepared to investigate toluene and Hg0 removal performance. Multifarious characterizations including XRD, TEM, SEM, in situ DRIFTS, BET, XPS and H2-TPR showed that 4%Cr0.5Mn0.5/AC had excellent physicochemical properties and exhibited the best toluene and Hg0 removal efficiency at 200℃. By varying the experimental gas components and conditions, it was found that too large weight hourly space velocity would reduce the removal efficiency of toluene and Hg0. Although O2 promoted the abatement of toluene and Hg0, the inhibitory role of H2O and SO2 offset the promoting effect of O2 to some extent. Toluene significantly inhibited Hg0 removal, resulting from that toluene was present at concentrations orders of magnitude greater than mercury's or the catalyst was more prone to adsorb toluene, while Hg0 almost exerted non-existent influence on toluene elimination. The mechanistic analysis showed that the forms of toluene and Hg0 removal included both adsorption and oxidation, where the high-valent metal cations and oxygen vacancy clusters promoted the redox cycle of Cr3+ + Mn3+/Mn4+ ↔ Cr6+ + Mn2+, which facilitated the conversion and replenishment of reactive oxygen species in the oxidation process, and even the CrMn1.5O4 spinel structure could provide a larger catalytic interface, thus enhancing the adsorption/oxidation of toluene and Hg0. Therefore, its excellent physicochemical properties make it a cost-effective potential industrial catalyst with outstanding synergistic toluene and Hg0 removal performance and preeminent resistance to H2O and SO2.

Assuntos

Poluentes Atmosféricos , Mercúrio , Óxidos , Tolueno , Tolueno/química , Óxidos/química , Poluentes Atmosféricos/química , Mercúrio/química , Coque , Catálise , Cromo/química , Adsorção , Manganês/química , Compostos de Manganês/química , Modelos Químicos

RESUMO

Modern laboratory medicine relies on analytical instruments for bacterial detection, focusing on biosensors and optical sensors for early disease diagnosis and treatment. Thus, Density Functional Theory (DFT) was utilized to study the reactivity of glycine interacted with metal oxides (ZnO, MgO, and CaO) for bacterial detection. Total dipole moment (TDM), frontier molecular orbitals (FMOs), FTIR spectroscopic data, electronic transition states, chemical reactivity descriptors, nonlinear optical (NLO) characteristics, and molecular electrostatic potential (MESP) were all investigated at the B3LYP/6-31G(d, p) level using DFT and Time-Dependent DFT (TD-DFT). The Coulomb-attenuating approach (CAM-B3LYP) was utilized to obtain theoretical electronic absorption spectra with the 6-31G(d, p) basis set to be more accurate than alternative quantum chemical calculation approaches, showing good agreement with the experimental data. The TDM and FMO investigation showed that glycine/CaO model has the highest TDM (10.129Debye) and lowest band gap (1.643 eV). The DFT computed IR and the experimental FTIR are consistent. The calculated UV-vis spectra showed a red shift with an increase in polarity following an increase in the absorption wavelength due to the interaction with ZnO, MgO, and CaO. Among the five solvents of water, methanol, ethanol, DMSO and acetone, the water and DMSO enhances the UV-Vis absorption. Glycine/CaO model showed high linear polarizability (14.629 × 10-24esu) and first hyperpolarizability (23.117 × 10-30esu), indicating its potential for nonlinear optical applications. The results showed that all model molecules, particularly glycine/CaO, contribute significantly to the development of materials with potential NLO features for sensor and optoelectronic applications. Additionally, MESP confirmed the increased electronegativity of the studied structures. Additionally, glycine/ZnO nanocomposite was synthesized and characterized using IR and UV-visible spectroscopy to determine their structural and spectroscopic features. It was discovered that there was good agreement between the DFT computed findings and the related experimental data. The antibacterial activity of glycine/ZnO nanocomposites against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa were studied in terms of concentration and time. The results showed that increasing the concentration of glycine/ZnO nanocomposite significantly enhanced its antibacterial efficacy by lowering optical density. Notably, Pseudomonas aeruginosa exhibited lower susceptibility to the nanocomposite compared to S. aureus, requiring higher concentrations for effective bactericidal action. In summary, this study contributes novel insights into the dual functionality of glycine-metal oxide complexes, with significant implications as optical biosensor for microbial detection.

Assuntos

Compostos de Cálcio , Glicina , Óxido de Magnésio , Óxidos , Óxido de Zinco , Óxido de Zinco/química , Óxido de Magnésio/química , Óxidos/química , Glicina/química , Compostos de Cálcio/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Teoria da Densidade Funcional , Bactérias , Eletricidade Estática

RESUMO

As a pivotal transition metal oxide, manganese dioxide (MnO2) has garnered significant attention owing to its abundant reserves, diverse crystal structures and exceptional performance. Nanosizing MnO2 results in smaller particle sizes, larger specific surface areas, optimized material characteristics, and expanded application possibilities. With the burgeoning research efforts in this field, MnO2 has emerged as a promising nanomaterial for tumor diagnosis and therapy. The distinctive properties of MnO2 in regulating the tumor microenvironment (TME) have attracted considerable interest, leading to a rapid growth in research on MnO2-based nanomaterials for tumor diagnosis and treatment. Additionally, MnO2 nanomaterials are also gradually showing up in the regulation of chronic inflammatory diseases. In this review, we mainly summarized the recent advancements in various MnO2 nanomaterials for tumor diagnosis and therapy. Furthermore, we discuss the current challenges and future directions in the development of MnO2 nanomaterials, while also envisaging their potential for clinical translation.

Assuntos

Compostos de Manganês , Nanoestruturas , Neoplasias , Óxidos , Microambiente Tumoral , Compostos de Manganês/química , Óxidos/química , Humanos , Nanoestruturas/química , Neoplasias/tratamento farmacológico , Microambiente Tumoral/efeitos dos fármacos , Animais

RESUMO

Highly stable copper nanocluster (CuNCs) with aggregation-induced emission (AIE) properties was synthesized. α-, ß-, and γ- MnO2 were utilized as quenchers, with CuNCs fluorescence quenching of 48.9%, 91.5%, and 96.6%, respectively. L-ascorbate-2-phosphate (AAP) was hydrolyzed by acid phosphatase (ACP), and ascorbic acid (AA) was formed. Then, MnO2 could be restored by AA, and the fluorescence of the CuNCs could be restored. An on-off-on detection platform with a high signal/noise ratio was constructed for the sensing of ACP. The fluorescence recovery rate of the CuNCs was related to the crystal forms of MnO2. Then, the equilibrium constants (K) for the reaction between AA and MnO2 were calculated to evaluate the reaction process. Compared with the K values of CuNCs/α-MnO2 and CuNCs/γ-MnO2, the K values for AA and ß-MnO2 were maximum. The CuNCs/ß-MnO2 system exhibited optimal fluorescence recovery for the sensitive detection of ACP. In the concentration range 0.005-0.06 U/mL, the detection limit was 0.0028 U/mL. The determination  of serum ACP levels also revealed satisfactory results. This study provides novel insights into enhancing the sensitivity of the determination  of quenchers in different crystal form.

Assuntos

Fosfatase Ácida , Cobre , Compostos de Manganês , Nanopartículas Metálicas , Óxidos , Compostos de Manganês/química , Óxidos/química , Cobre/química , Fosfatase Ácida/química , Fosfatase Ácida/metabolismo , Nanopartículas Metálicas/química , Ácido Ascórbico/química , Ácido Ascórbico/análogos & derivados , Limite de Detecção , Espectrometria de Fluorescência/métodos , Humanos

RESUMO

BACKGROUND: This study aimed to compare the marginal adaptation of a single customized gutta percha cone with calcium silicate-based sealer versus mineral trioxide aggregate (MTA) and Biodentine apical plugs in simulated immature permanent teeth. METHODS: Thirty-nine extracted human maxillary anterior teeth were selected, prepared to simulate immature permanent teeth with an apical diameter 1.1 mm, placed in moist foam and divided into three groups. Group 1: Obturation with a single customized gutta percha cone and calcium silicate sealer. Group 2: MTA apical plug. Group 3: Biodentine apical plug. After incubation, teeth were horizontally sectioned at 1 mm and 3 mm from the apex and marginal adaptation was evaluated using scanning electron microscope (SEM). RESULTS: Biodentine showed the least mean gap size at both 1 and 3 mm from the apex with no statistically significant differences compared to MTA (p > 0.05). The single customized cone with calcium silicate based sealer showed the greatest mean gap size at both 1 and 3 mm from the apex with a statistically significant difference compared to the other groups (p < 0.001). CONCLUSION: Biodentine and MTA apical plugs provide a significantly better marginal adaptation to the dentinal walls than a single customized gutta percha cone with calcium silicate based sealer in simulated immature permanent teeth.

Assuntos

Compostos de Alumínio , Compostos de Cálcio , Adaptação Marginal Dentária , Combinação de Medicamentos , Guta-Percha , Óxidos , Materiais Restauradores do Canal Radicular , Silicatos , Humanos , Guta-Percha/uso terapêutico , Técnicas In Vitro , Obturação do Canal Radicular/métodos , Microscopia Eletrônica de Varredura , Ápice Dentário/efeitos dos fármacos , Teste de Materiais

RESUMO

Chlorine dioxide (ClO2) is a strong oxidizing agent and an efficient disinfectant. Due to its broad-spectrum bactericidal properties, good inactivation effect on the vast majority of bacteria and pathogenic microorganisms, low resistance to drugs, and low generation of halogenated by-products, chlorine dioxide is widely used in fields such as water purification, food safety, medical and public health, and living environment. This review introduced the properties and application status of chlorine dioxide, compared the action mode, advantages and disadvantages of various disinfectants. The mechanism of chlorine dioxide inactivating bacteria, fungi and viruses were reviewed. The lethal target of chlorine dioxide to bacteria and fungi is to destroy the structure of cell membrane, change the permeability of cell membrane, and make intracellular substances flow out, leading to their death. The lethal targets for viruses are the destruction of viral protein capsids and the degradation of RNA fragments. The purpose of this review is to provide more scientific guidance for the application of chlorine dioxide disinfectants.

Assuntos

Bactérias , Compostos Clorados , Desinfetantes , Desinfecção , Fungos , Óxidos , Vírus , Compostos Clorados/farmacologia , Óxidos/farmacologia , Desinfetantes/farmacologia , Desinfecção/métodos , Bactérias/efeitos dos fármacos , Vírus/efeitos dos fármacos , Fungos/efeitos dos fármacos , Purificação da Água/métodos , Humanos

RESUMO

Water contamination is a serious issue that has an impact on the whole globe. In the current work, adsorption technique was used to remove synthetic Reactive Blue MEBF 222 textile dye utilizing Cd-doped Co (Co1 - xCd1.5xFeO3), Zn-doped Co (Co1 - xZn1.5xFeO3), Cr-doped Co (Co1 - xCr1.5xFeO3), Zn-doped Ni (Ni1 - xZn1.5xFeO3), and Cr-doped Ni (Ni1 - xCr1.5xFeO3) perovskites, synthesized by sol-gel auto-combustion approach. According to the findings of batch adsorption studies, maximum adsorption was observed at pH 3 (45.62 mg/g), 0.01 g/50 ml dosage (36.67 mg/g), 60 min (14.31 mg/g), 100 ppm dye concentration (47.41 mg/g), and 308 K (35.96 mg/g) for Co1 - xCd1.5xFeO3; at 3 pH (42.94 mg/g), 0.01 g/50 ml dosage (35.33 mg/g), 60 min (12.88 mg/g), 100 ppm dye concentration (40.52 mg/g), and 308 K (31.31 mg/g) for Co1 - xZn1.5xFeO3; at 2 pH (38.82 mg/g), 0.01 g/50 ml dosage (32.20 mg/g), 60 min (11.98 mg/g), 100 ppm dye concentration (33.54 mg/g), and 308 K (29.34 mg/g) for Co1 - xCr1.5xFeO3; at 2 pH (34.97 mg/g), 0.01 g/50 ml dosage (30.41 mg/g), 60 min (10.46 mg/g), 100 ppm dye concentration (27.19 mg/g), and 308 K (26.12 mg/g) for Ni1 - xZn1.5xFeO3; and at 2 pH (31.22 mg/g), 0.01 g/50 ml dosage (25.04 mg/g), 60 min (9.48 mg/g), 100 ppm dye concentration (21.73 mg/g), and 308 K (23.61 mg/g) for Ni1 - xCr1.5xFeO3. The pseudo-second-order model showed good fitness for adsorption kinetic data. Electrolytes, detergents/surfactants, and heavy metal ions had a substantial impact on the adsorption potential. The column adsorption experiments demonstrated optimal bed height, flow rate, and intake dye concentration to be 3 cm, 1.8 ml/min, and 70 mg/l, respectively, in the column experiment. With an adsorption capacity of 44.1 mg/g, reactive blue (RB) 222 dye was able to achieve its maximum adsorption. Detailed desorption of RB 222 dye was also achieved. The novelty of this adsorption method lies in its eco-friendliness, ease of handling, and cost-effectiveness.

Assuntos

Cobalto , Corantes , Níquel , Eliminação de Resíduos Líquidos , Águas Residuárias , Poluentes Químicos da Água , Poluentes Químicos da Água/química , Corantes/química , Adsorção , Níquel/química , Águas Residuárias/química , Eliminação de Resíduos Líquidos/métodos , Cobalto/química , Óxidos/química , Compostos de Cálcio/química , Têxteis , Titânio

RESUMO

BACKGROUND: The aim of this study was to compare postoperative pain following total pulpotomy (TP) and root canal treatment (RCT) in mature molar teeth with irreversible pulpitis. To compare the traditional pulpitis classification system with the Wolters system in evaluating postoperative pain. METHODS: Eighty mandibular molars with irreversible pulpitis were included and classified according to the Wolters (moderate/severe pulpitis). The teeth were randomly assigned to two groups (RCT or TP). RCT was performed following standardized protocols. TP was performed to the level of the canal orifices, and hemostasis was achieved with 2.5% sodium hypochlorite. A 3 mm layer of MTA was placed as the pulpotomy material. The teeth were restored with glass ionomer cement followed by composite. Pain scores were recorded preoperatively and, at 6, 12, 24, 48, and 72 h and 7 days after the interventions. The data were statistically analyzed using the Mann-Whitney U test, the Friedman test, the Wilcoxon signed-rank test, and the Spearman's correlation test. The significance level was set at 0.05. RESULTS: Sixty-four patients were analyzed at the one-week follow-up and all were diagnosed as irreversible pulpitis according to the AAE; 22 teeth were classified as moderate and 42 teeth were classified as severe pulpitis according to Wolters. There was no significant difference between TP and RCT in pain scores in moderate pulpitis patients (p > 0.05). There was a significant difference between TP and RCT at 24 and 72 h of severe pulpitis; higher pain scores were observed in the RCT (p < 0.05). CONCLUSIONS: In patients with moderate pulpitis, the TP procedure allowed symptom relief more quickly than RCT. In patients with severe pulpitis, TP provided for significantly lower pain scores compared to RCT at both 24 and 72 h. CLINICAL TRIAL REGISTRATION: The study was retrospectively registered with ClinicalTrials.gov (NCT05923619). Date of Registration: 06/16/23.

Assuntos

Dente Molar , Medição da Dor , Dor Pós-Operatória , Pulpite , Pulpotomia , Tratamento do Canal Radicular , Humanos , Pulpite/cirurgia , Pulpite/terapia , Pulpotomia/métodos , Dor Pós-Operatória/etiologia , Dor Pós-Operatória/classificação , Dente Molar/cirurgia , Estudos Prospectivos , Feminino , Masculino , Tratamento do Canal Radicular/efeitos adversos , Tratamento do Canal Radicular/métodos , Adulto , Adulto Jovem , Materiais Restauradores do Canal Radicular/uso terapêutico , Seguimentos , Silicatos/uso terapêutico , Combinação de Medicamentos , Pessoa de Meia-Idade , Óxidos/uso terapêutico , Compostos de Alumínio/uso terapêutico , Cimentos de Ionômeros de Vidro , Compostos de Cálcio/uso terapêutico , Restauração Dentária Permanente/métodos , Resinas Compostas , Hipoclorito de Sódio/uso terapêutico

RESUMO

There is a long-standing debate over the effectiveness of chemical extraction methods in assessing soil metal phytoavailability. This study addresses the limitations of widely-used chemical extraction methods and presents the water-extractable pool as a more reliable indicator based on wheat pot experiments using homogenized agricultural soil amended with lime materials, phosphate, and biochar. Over 120 days' pot experiments, Cd accumulation in whole wheat plants and tissues exhibited positive relationships with water-extractable Cd concentrations at heading and maturity stage (Spearman's rho: 0.521-0.851; P < 0.05), revealing that the water-extractable pool instead of other pools better indicates wheat metal accumulation. Water-extractable metal concentrations are effective in assessing phytoavailability of metals primarily in ionic forms in soil solution (e.g, Zn, Cd), but less reliable for metals strongly complexed with dissolved organic matter (DOM) or sensitive to redox conditions. It demonstrated that water-extractable metal concentrations and chemical forms are key factors, fundamentally determined by metal properties and impacted by environmental factors. This study clarifies a more direct link between chemical extraction and plant metal uptake mechanisms. Given the extensive application of chemical extraction methods over several decades, this study will help advance soil metal risk assessment and remediation practices.

Assuntos

Metais Pesados , Poluentes do Solo , Triticum , Água , Triticum/metabolismo , Triticum/química , Poluentes do Solo/metabolismo , Poluentes do Solo/química , Metais Pesados/metabolismo , Metais Pesados/química , Água/química , Óxidos/química , Compostos de Cálcio/química , Carvão Vegetal/química , Solo/química

RESUMO

Treating bone defect concomitant with microbial infection poses a formidable clinical challenge. Addressing this dilemma necessitates the implementation of biomaterials exhibiting dual capabilities in anti-bacteria and bone regeneration. Of particular significance is the altered microenvironment observed in infected bones, characterized by acidity, inflammation, and an abundance of reactive oxygen species (ROS). These conditions, while challenging, present an opportunity for therapeutic intervention in the context of contaminated bone defects. In this study, we developed an oriented composite scaffold containing copper-coated manganese dioxide (MnO2) nanoparticles loaded with parathyroid hormone (PMPC/Gelatin). The characteristics of these scaffolds were meticulously evaluated and confirmed the high sensitivity to H+, responsive drug release and ROS elimination. In vitro antibacterial analysis underscored the remarkable ability of PMPC/Gelatin scaffolds to substantially suppressed bacterial proliferation and colony formation. Furthermore, this nontoxic material demonstrated efficacy in mitigating ROS levels, thereby fostering osteogenic differentiation of bone marrow mesenchymal stem cells and enhancing angiogenic ability. Subsequently, the infected models of bone defects in rat skulls were established to investigate the effects of composite scaffolds on anti-bacteria and bone formation in vivo. The PMPC/Gelatin treatment exhibited excellent antibacterial activity, coupled with enhanced vascularization and osteogenesis at the defect sites. These compelling findings affirm that the PMPC/Gelatin composite scaffold represents a promising avenue for anti-bacteria and bone regeneration.

Assuntos

Antibacterianos , Regeneração Óssea , Gelatina , Compostos de Manganês , Células-Tronco Mesenquimais , Osteogênese , Óxidos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio , Alicerces Teciduais , Animais , Osteogênese/efeitos dos fármacos , Alicerces Teciduais/química , Ratos , Regeneração Óssea/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Células-Tronco Mesenquimais/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Gelatina/química , Óxidos/química , Óxidos/farmacologia , Compostos de Manganês/química , Compostos de Manganês/farmacologia , Masculino , Crânio/efeitos dos fármacos , Nanopartículas/química , Cobre/química , Cobre/farmacologia , Diferenciação Celular/efeitos dos fármacos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia

RESUMO

Testing the biocompatibility of commercially available dental materials is a major challenge in dental material science. In the present study, the biocompatibility of four commercially available dental materials Mineral Trioxide Aggregate, Biodentine, Harvard BioCal-CAP and Oxford ActiveCal PC was investigated. The biocompatibility analysis was performed on zebrafish embryos and larvae using standard toxicity tests such as survivability and hatching rates. Comparative toxicity analysis of toxicity was performed by measuring apoptosis using acridine orange dye and whole mount immunofluorescence methods on zebrafish larvae exposed to the dental materials at different dilutions. Toxicity analysis showed a significant decrease in survival and hatching rates with increasing concentration of exposed materials. The results of the apoptosis assay with acridine orange showed greater biocompatibility of Biodentine, Oxford ActiveCal PC, Harvard BioCal-CAP and Biodentine compared to MTA, which was concentration dependent. Consequently, this study has shown that showed resin-modified calcium silicates are more biocompatible than traditional calcium silicates.

Assuntos

Materiais Biocompatíveis , Compostos de Cálcio , Teste de Materiais , Silicatos , Peixe-Zebra , Animais , Peixe-Zebra/embriologia , Compostos de Cálcio/farmacologia , Compostos de Cálcio/toxicidade , Silicatos/farmacologia , Silicatos/toxicidade , Apoptose/efeitos dos fármacos , Larva/efeitos dos fármacos , Óxidos/toxicidade , Óxidos/farmacologia , Agentes de Capeamento da Polpa Dentária e Pulpectomia/farmacologia , Capeamento da Polpa Dentária/métodos , Embrião não Mamífero/efeitos dos fármacos , Compostos de Alumínio/toxicidade , Combinação de Medicamentos

RESUMO

In recent years, the integration of radiotherapy and nanocatalytic medicine has gained widespread attention in the treatment of breast cancer. Herein, the glucose oxidase (GOx) and MnO2 nanoparticles co-modified multifunctional liposome of GOx-MnO2@Lip was constructed for enhanced radiotherapy. Introduction of GOx would not only elevate the glucose consumption to starve the cancer cells, but also increased the endogenous H2O2 level. Meanwhile, high intracellular GSH concentration facilitated the release of Mn2+ to amplify the cytotoxic ·OH through cascade catalytic reactions within the tumor microenvironment, resulting in a favorable tumor suppression rate of 74.45 %. Furthermore, the blood biochemical and blood routine demonstrated that GOx-MnO2@Lip had no obvious toxic side effects. Therefore, this work provided a potential vehicle for synergistic cancer starving therapy, chemodynamic therapy and radiotherapy for improving therapeutic efficacy of breast cancer.

Assuntos

Neoplasias da Mama , Glucose Oxidase , Lipossomos , Compostos de Manganês , Óxidos , Radiossensibilizantes , Compostos de Manganês/química , Compostos de Manganês/farmacologia , Glucose Oxidase/metabolismo , Feminino , Óxidos/química , Óxidos/farmacologia , Neoplasias da Mama/patologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/radioterapia , Radiossensibilizantes/farmacologia , Animais , Humanos , Linhagem Celular Tumoral , Peróxido de Hidrogênio/metabolismo , Camundongos Endogâmicos BALB C , Catálise , Camundongos , Nanopartículas/química , Microambiente Tumoral/efeitos dos fármacos

RESUMO

This paper addresses the influence of bubbling flow and service life of the Ti|Ti-Ru-Ir-oxides anode during the electrosynthesis of HClO in a laboratory-scale filter-press-type electrolyzer. The electrolyzer was assembled in a flow plant in recirculation mode. Polarization curves in rotating disk electrode (RDE) revealed the coexistence of the oxygen evolution reaction (OER) during HClO electrosynthesis in diluted chloride solutions (containing 35 mM NaCl at pH 3). CFD simulations of the two-phase (O2-H2O) flow were obtained by solving simultaneously the Navier-Stokes and charge conservation equations using a finite element method code. The O2-H2O simulations show the efficient gas release in the electrolyzer provoked by the continuous phase (H2O) inertia and the well-engineered cell design. The moderated O2 dispersion caused a quasi-homogeneous current distribution along the anode. However, the current efficiency during HClO electrosynthesis gave values of ∼32% provoked by the OER on the anode. The HClO accumulations (from 3.02 to 6.64 mM) showed excellent agreement with CFD simulations. The accelerated life tests revealed that the Ti | Ti-Ru-Ir-oxides anode has a lifetime of at least 26 years during the HClO electrosynthesis in diluted chloride solutions.

Assuntos

Eletrodos , Ácido Hipocloroso , Oxigênio , Titânio , Ácido Hipocloroso/química , Titânio/química , Oxigênio/química , Óxidos/química , Eletrólise