RESUMO
Even though transition metals can activate Oxone to degrade toxic contaminants, bimetallic materials possess higher catalytic activities because of synergistic effects, making them more attractive for Oxone activation. Herein, nanoscale CuCo-bearing N-doped carbon (CuCoNC) can be designed to afford a hollow structure as well as CuCo species by adopting cobaltic metal organic frameworks as a template. In contrast to Co-bearing N-doped carbon (CoNC), which lacks the Cu dopant, CuCo alloy nanoparticles (NPs) are contained by the Cu dopant within the carbonaceous matrix, giving CuCoNC more prominent electrochemical properties and larger porous structures and highly nitrogen moieties. CuCoNC, as a result, has a significantly higher capability compared to CoNC and Co3O4 NPs, for Oxone activation to degrade a toxic contaminant, Rhodamine B (RDMB). Furthermore, CuCoNC+Oxone has a smaller activation energy for RDMB elimination and maintains its superior effectiveness for removing RDMB in various water conditions. The computational chemistry insights have revealed the RDMB degradation mechanism. This study reveals that CuCoNC is a useful activator for Oxone to eliminate RDMB.
RESUMO
Metal Organic Frameworks (MOFs) represent a promising class of metallic catalysts for reduction of nitrogen-containing contaminants (NCCs), such as 4-nitrophenol (4-NP). Nevertheless, most researches involving MOFs for 4-NP reduction employ noble metals in the form of fine powders, making these powdered noble metal-based MOFs impractical and inconvenient for realistic applications. Thus, it would be critical to develop non-noble-metal MOFs which can be incorporated into macroscale and porous supports for convenient applications. Herein, the present study proposes to develop a composite material which combines advantageous features of macroscale/porous supports, and nanoscale functionality of MOFs. In particular, copper foam (CF) is selected as a macroscale porous medium, which is covered by nanoflower-structured CoO to increase surfaces for growing a cobaltic MOF, ZIF-67. The resultant composite comprises of CF covered by CoO nanoflowers decorated with ZIF-67 to form a hierarchical 3D-structured catalyst, enabling this ZIF-67@Cu foam (ZIF@CF) a promising catalyst for reducing 4-NP, and other NCCs. Thus, ZIF@CF can readily reduce 4-NP to 4-AP with a significantly lower Ea of 20â¯kJ/mol than reported values. ZIF@CF could be reused over 10 cycles and remain highly effective for 4-NP reduction. ZIF@CF also efficiently reduces other NCCs, such as 2-nitrophenol, 3-nitrophenol, methylene blue, and methyl orange. ZIF@CF can be adopted as catalytic filters to enable filtration-type reduction of NCCs by passing NCC solutions through ZIF@CF to promptly and conveniently reduce NCCs. The versatile and advantageous catalytic activity of ZIF@CF validates that ZIF@CF is a promising and practical heterogeneous catalyst for reductive treatments of NCCs.
Assuntos
Estruturas Metalorgânicas , Nitrogênio , Catálise , Cobalto , MetaisRESUMO
Aerobic oxidation of 5-Hydroxymethylfurfural (HMF) to 2,5-Diformylfuran (DFF) using O2 gas represents a sustainable approach for valorization of lignocellulosic compounds. As manganese dioxide (MnO2) is validated as a useful oxidation catalyst and many crystalline forms of MnO2 exist, it is critical to explore how the crystalline structures of MnO2 influence their physical/chemical properties, which, in turn, determine catalytic activities of MnO2 crystals for HMF oxidation to DFF. In particular, six MnO2 crystals, α-MnO2, ß-MnO2, γ-MnO2, δ-MnO2, ε-MnO2, and λ-MnO2 are prepared and investigated for their catalytic activities for HMF oxidation to DFF. With different morphologies and crystalline structures, these MnO2 crystals possess very distinct surficial chemistry, redox capabilities, and textural properties, making these MnO2 exhibit different catalytic activities towards HMF conversion. Especially, ß-MnO2 can produce much higher DFF per surface area than other MnO2 crystals. ß-MnO2 could achieve the highest CHMF = 99% and YDFF = 97%, which are much higher than the reported values in literature, possibly because the surficial reactivity of ß-MnO2 appears to be highest in comparison to other MnO2 crystals. Especially, ß-MnO2 could exhibit YDFF > 90% over 5 cycles of reusability test, and maintain its crystalline structure, revealing its advantageous feature for aerobic oxidation of HMF to DFF. Through this study, the relationship between morphology, surface chemistry, and catalytic activity of MnO2 with different crystal forms is elucidated for providing scientific insights into design, application and development of MnO2-based materials for aerobic oxidation of bio-derived molecules to value-added products.
RESUMO
BACKGROUND & PROBLEMS: Patients with critical illnesses face an elevated risk of medical adhesive relation skin injuries (MARSI), which have negative, subsequent impacts on recovery and quality of healthcare. PURPOSE: The aim of this project was to decrease the incidence of MARSI in the surgical intensive care unit and to improve the accuracy of MARSI preventive care implementation. RESOLUTIONS: The intervention included the implementation of product-use cards, high-risk warning slogans, education programs, experience workshops, and a standard prevention-care protocol for MARSI. RESULTS: After project implementation, the incidence rate of MARSI decreased from 18.2% to 0%-9.3%, and the accuracy rate of preventive care increased from 38.6% to 95.5%. CONCLUSIONS: This project effectively reduced the incidence of skin injury and improved the quality of critical care. The skills related to the care and prevention of MARSI have been implemented throughout the hospital.
Assuntos
Adesivos , Dermatopatias , Adesivos/efeitos adversos , Cuidados Críticos , Humanos , Incidência , Unidades de Terapia Intensiva , Pele , Dermatopatias/cirurgiaRESUMO
As cobalt (Co) represents an effective transition metal for activating Oxone to degrade contaminants, tricobalt tetraoxide (Co3O4) is extensively employed as a heterogeneous phase of Co for Oxone activation. Since Co3O4 can be manipulated to exhibit various shapes, 2-dimensional plate-like morphology of Co3O4 can offer large contact surfaces. If the large plate-like surfaces can be even porous, forming porous nanoplate Co3O4 (PNC), such a PNC should be a promising catalyst for Oxone activation. Therefore, a facile but straightforward method is proposed to prepare such a PNC for activating Oxone to degrade pollutants. In particular, a cobaltic coordination polymer with a morphology of hexagonal nanoplate, which is synthesized through coordination between Co2+ and thiocyanuric acid (TCA), is adopted as a precursor. Through calcination, CoTCA could be transformed into hexagonal nanoplate-like Co3O4 with pores to become PNC. This PNC also shows different characteristics from the commercial Co3O4 nanoparticle (NP) in terms of surficial reactivity and textural properties. Thus, PNC exhibits a much higher catalytic activity than the commercial Co3O4 NP towards activation of Oxone to degrade a model contaminant, salicylic acid (SA). Specifically, SA was 100% degraded by PNC activating Oxone within 120 min, and the Ea of SA degradation by PNC-activated Oxone is 70.2 kJ/mol. PNC can also remain stable and effective for SA degradation even in the presence of other anions, and PNC could be reused over multiple cycles without significant loss of catalytic activity. These features validate that PNC is a promising and useful Co-based catalyst for Oxone activation.
Assuntos
Cobalto/química , Óxidos/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Catálise , Polímeros , Porosidade , Ácidos Sulfúricos , ÁguaRESUMO
Although zero valent zinc (ZVZ) is a strong reductant, studies using ZVZ for bromate reduction are rare. In this study, ZVZ is prepared by acid-washing zinc powder with HCl and used to reduce bromate. The effect of acid-washing on the morphology of zinc powder is also examined. Zinc powder inefficiently reduces bromate, but ZVZ obtained by acid-washing zinc powder eliminates bromate and converts it to bromide. A higher dose of ZVZ enhances elimination efficiency perhaps because the formation of a passivation layer of zinc oxide could be scattered on the large surface of ZVZ. Elevated temperature also substantially improves both elimination efficiency and kinetics. The effect of pH is shown to have the most significant impact on the bromate elimination; elimination efficiency and kinetics are tremendously bolstered at pH = 3, whereas the elimination of bromate is completely suppressed under alkaline conditions. ZVZ can reduce bromate to bromide even in the presence of other anions and also be reused multiple times. Thus, ZVZ can be easily prepared and used to efficiently reduce bromate to bromide. The findings presented here are essential to the design and implementation of bromate elimination in water using zero-valent metals.
RESUMO
Aluminum scrap (AS) is adopted for the first time as a readily available aluminum source to prepare zero-valent aluminum (ZVAl) for removing bromate from water via a reductive reaction. Since aluminum is easily oxidized to aluminum oxide (Al2O3) on exposure to air, an acid-washing pretreatment on AS is developed to remove the layer of Al2O3. HCl is found as the most effective acid to pretreat AS and the HCl-pretreated or acid-washed AS (AWAS) is able to remove bromate from water and convert it to bromide. Factors, such as temperature, pH, co-existing anions, and particle size, which influence the bromate removal using AWAS are also investigated. The mechanism of bromate removal by AWAS can be attributed to both reduction and adsorption. The elevated temperature also significantly improves bromate removal capacity of AWAS as well as the reaction kinetics. The bromate removal capacity of AWAS is substantially improved under acidic conditions. However, the basic conditions and co-existing anions suppress or interfere with the interaction between bromate and AWAS, leading to much lower removal capacities. The recyclability of AWAS is also evaluated and the acid-washing regeneration is necessary to restore its capacity. However, the mass of AWAS can gradually decrease due to multi-cycle acid-washing regeneration. Through this study, the valorization of AS via acid-washing is demonstrated and optimization of acid-washing parameters is presented. Our findings reveal that the acid-washing is a useful technique to utilize AS as an inexpensive and efficient material for removing bromate from water.
Assuntos
Alumínio/química , Bromatos/química , Bromatos/isolamento & purificação , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Água/química , Adsorção , Bromatos/toxicidade , Brometos/química , Concentração de Íons de Hidrogênio , Cinética , Oxirredução , Temperatura , Poluentes Químicos da Água/toxicidadeRESUMO
The goal of our study was to assess the association between R497K and intron1 (CA) n repeat genetic polymorphisms of the EGF (epidermal growth factor) receptor and the clinical outcome of patients with advanced non-small cell lung cancer treated with EGF receptor tyrosine kinase inhibitor. We determined the genotypes for R497K and intron1 (CA) n repeat genetic polymorphisms of 70 Chinese patients with advanced non-small cell lung cancer. Genetic polymorphisms were correlated with the clinical outcome of treatment with EGF receptor tyrosine kinase inhibitor. In a subgroup of patients whose tumor tissues were available for mutation analysis and IHC (immunohistochemistry) assay, the associations between the EGF receptor mutations, the EGF receptor protein expression levels and EGF receptor polymorphisms were analyzed. The results indicated that patients with a lower number of EGF receptor CA repeats (any allele < or =16 CA) were more likely to have higher EGF receptor protein expression levels, better response, and longer survival time than were patients with a higher number of CA repeats (both alleles >16 CA) after therapy targeted at the EGF receptor (P=0.021; P=0.014; P=0.0392, respectively). In contrast, the R497K polymorphism had no relationship with EGF receptor protein expression levels or the clinical outcome of the patients treated with EGF receptor tyrosine kinase inhibitor (P=0.49; P=0.452, respectively), and there were no associations between the two polymorphisms and somatic mutations (P=0.916; P=0.562, respectively). Overall, our data suggest that the intron1 (CA) n polymorphism of the EGF receptor gene may be associated with the sensitivity to and the prognosis of non-small cell lung cancer after EGF receptor targeted inhibitor treatment.