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1.
Sci Total Environ ; 945: 173864, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38879032

RESUMO

Cyanobacteria blooms (CBs) caused by eutrophication pose a global concern, especially Microcystis aeruginosa (M. aeruginosa), which could release harmful microcystins (MCs). The impact of microplastics (MPs) on allelopathy in freshwater environments is not well understood. This study examined the joint effect of adding polystyrene (PS-MPs) as representative MPs and two concentrations (2 and 8 mg/L) of pyrogallol (PYR) on the allelopathy of M. aeruginosa. The results showed that the addition of PS-MPs intensified the inhibitory effect of 8 mg/L PYR on the growth and photosynthesis of M. aeruginosa. After a 7-day incubation period, the cell density decreased to 69.7 %, and the chl-a content decreased to 48 % compared to the condition without PS-MPs (p < 0.05). Although the growth and photosynthesis of toxic Microcystis decreased with the addition of PS-MPs, the addition of PS-MPs significantly resulted in a 3.49-fold increase in intracellular MCs and a 1.10-fold increase in extracellular MCs (p < 0.05). Additionally, the emission rates of greenhouse gases (GHGs) (carbon dioxide, nitrous oxide and methane) increased by 2.66, 2.23 and 2.17-fold, respectively (p < 0.05). In addition, transcriptomic analysis showed that the addition of PS-MPs led to the dysregulation of gene expression related to DNA synthesis, membrane function, enzyme activity, stimulus detection, MCs release and GHGs emissions in M. aeruginosa. PYR and PS-MPs triggered ROS-induced membrane damage and disrupted photosynthesis in algae, leading to increased MCs and GHG emissions. PS-MPs accumulation exacerbated this issue by impeding light absorption and membrane function, further heightening the release of MCs and GHGs emissions. Therefore, PS-MPs exhibited a synergistic effect with PYR in inhibiting the growth and photosynthesis of M. aeruginosa, resulting in additional risks such as MCs release and GHGs emissions. These results provide valuable insights for the ecological risk assessment and control of algae bloom in freshwater ecosystems.


Assuntos
Gases de Efeito Estufa , Microcistinas , Microcystis , Microplásticos , Pirogalol , Microcystis/fisiologia , Microcystis/efeitos dos fármacos , Microcistinas/toxicidade , Microplásticos/toxicidade , Alelopatia , Poluentes Químicos da Água/toxicidade , Fotossíntese/efeitos dos fármacos
2.
Small ; : e2402255, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38837847

RESUMO

The application of electrically conductive 1D coordination polymers (1D CPs) in nanoelectronic molecular recognition is theoretically promising yet rarely explored due to the challenges in their synthesis and optimization of electrical properties. In this regard, two tetrathiafulvalene-based 1D CPs, namely [Co(m-H2TTFTB)(DMF)2(H2O)]n (Co-m-TTFTB), and {[Ni(m-H2TTFTB)(CH3CH2OH)1.5(H2O)1.5]·(H2O)0.5}n (Ni-m-TTFTB) are successfully constructed. The shorter S···S contacts between the [M(solvent)3(m-H2TTFTB)]n chains contribute to a significant improvement in their electrical conductivities. The powder X-ray diffraction (PXRD) under different organic solvents reveals the flexible and dynamic structural characteristic of M-m-TTFTB, which, combined with the 1D morphology, lead to their excellent performance for sensitive detection of volatile organic compounds. Co-m-TTFTB achieves a limit of detection for ethanol vapor down to 0.5 ppm, which is superior to the state-of-the-art chemiresistive sensors based on metal-organic frameworks or organic polymers at room temperature. In situ diffuse reflectance infrared Fourier transform spectroscopy, PXRD measurements and density functional theory calculations reveal the molecular insertion sensing mechanism and the corresponding structure-function relationship. This work expands the applicable scenario of 1D CPs and opens a new realm of 1D CP-based nanoelectronic sensors for highly sensitive room temperature gas detection.

3.
Aging (Albany NY) ; 16(9): 7979-7999, 2024 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-38742934

RESUMO

BACKGROUND: Xiaochaihu (XCH) decoction is a traditional Chinese prescription that has been recorded in the pharmacopeia of the People's Republic of China. In China, the XCH decoction is used clinically to treat a variety of tumors, including breast cancer. However, its potential mechanism of action is still undefined. METHODS: The chemical compounds in the XCH decoction were identified via Q Exactive Orbitrap LC-MS/MS. Then, we screened the active ingredients and targets in the XCH decoction from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). Next, Cytoscape and Metascape were used to construct an active ingredient-target-disease network, which included a protein-protein interaction (PPI) network, GO enrichment analysis, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Finally, we used molecular docking and in vitro experiments to verify the results of network pharmacology analysis. RESULTS: More than 70 major compounds were identified by Q Exactive Orbitrap LC-MS/MS analysis from the XCH decoction. A total of 162 active ingredients and 153 targets related to the XCH decoction and breast cancer were identified, and a compound-target-disease network was constructed. GO and KEGG analyses revealed that the XCH decoction regulated the drug response, apoptosis process, cancer pathway, and PI3K/Akt signaling pathway. Molecular docking and experimental validation indicated that the XCH decoction suppressed proliferation and induced apoptosis in breast cancer cells by regulating the expression of apoptosis-related proteins and inhibiting the PI3K/Akt pathway. CONCLUSIONS: This study suggested that the XCH decoction can be used to treat breast cancer by inhibiting cell proliferation, inducing apoptosis and downregulating the PI3K/Akt signaling pathway.


Assuntos
Neoplasias da Mama , Medicamentos de Ervas Chinesas , Farmacologia em Rede , Mapas de Interação de Proteínas , Humanos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/uso terapêutico , Feminino , Simulação de Acoplamento Molecular , Transdução de Sinais/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Espectrometria de Massas em Tandem , Células MCF-7 , Proteínas Proto-Oncogênicas c-akt/metabolismo , Apoptose/efeitos dos fármacos , Medicina Tradicional Chinesa
4.
Mol Nutr Food Res ; 68(10): e2300737, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38700077

RESUMO

SCOPE: Yogurt consumption is related to a decreased risk of colorectal cancer (CRC), but whether such association is causal remains unclear. Patients with familial adenomatous polyposis (FAP) are at increased risk of CRC development. Here, the study investigates the efficacy of yogurt for intestinal polyposis chemoprevention in ApcMin/+ mice, a preclinical model for human FAP. METHODS AND RESULTS: A 10-week yogurt supplementation (15 g kg-1) in ApcMin/+ mice significantly reduces the intestinal polyp number (6.50 ± 0.97 versus 1.80 ± 0.49; p < 0.001) compared to controls. 16S rRNA gene-based microbiota analysis suggests that yogurt supplementation may greatly modulate the gut microbiome composition, especially in the relative abundance of Lactobacillus and Bifidobacterium. Importantly, the fecal concentration of d-lactate (d-Lac, 0.39 ± 0.04 µmol g-1 versus 8.14 ± 0.62 µmol g-1; p < 0.001) is boosted by yogurt, while oral administration with d-Lac (125 or 250 mg kg-1) reduces the polyp number by 71.43% or 77.14% (p < 0.001), respectively. The study also observes that d-Lac does not affect cell viability and anchorage-independence in CRC cells, but it greatly suppresses epidermal growth factor (EGF) or 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced cell transformation in preneoplastic cells. Mechanistically, it demonstrates that d-Lac may attenuate epithelial cell transformation by targeting PI3K/AKT/ß-catenin axis. CONCLUSION: Yogurt protects against intestinal polyposis in ApcMin/+ mice, and d-Lac may partially account for the chemopreventive effects above.


Assuntos
Neoplasias Colorretais , Microbioma Gastrointestinal , Iogurte , Animais , Neoplasias Colorretais/prevenção & controle , Microbioma Gastrointestinal/efeitos dos fármacos , Polipose Adenomatosa do Colo/genética , Polipose Adenomatosa do Colo/prevenção & controle , Humanos , Camundongos Endogâmicos C57BL , Camundongos , Masculino , Ácido Láctico , Carcinogênese/efeitos dos fármacos , Fezes/microbiologia , Fezes/química , Proteína da Polipose Adenomatosa do Colo/genética
5.
Heliyon ; 10(9): e30676, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38774085

RESUMO

Through numerical simulation, this study investigates the flow field characteristics of the variable diameter stabilizer in drilling tools under various conditions. It analyzes the influence of different flow rates and speeds on axial velocity and pressure distribution. The results indicate that more significant flow rates correspond to higher average axial velocities across sections, facilitating the transport of drilling fluid and cuttings. Increasing rotational speed leads to greater pressure differences between adjacent sections, consequently elevating the overall pressure drop of the tool, which, to some extent, aids in transporting drilling fluid with cuttings. During rotation, the vortex zone on the backside of the stabilizer creates a hovering and accumulation of cuttings, causing mud agglomeration, thereby affecting tool performance. During structural optimization of the tool, priority should be given to a transitional design of the outlet area in the functional core zone, aiming to alleviate the impact of abrupt structural expansions on cuttings transport.

6.
ACS Appl Mater Interfaces ; 16(17): 21782-21789, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38635211

RESUMO

Improving the efficiency of platinum group metals (Pt, Pd, Rh, etc.) in catalytic oxidation reactions remains an urgent topic. The conflict between the low-temperature activity and high-temperature stability of noble metals can hardly reach a consensus. For instance, Pt cluster catalysts supported on CeO2 with high low-temperature activity will suffer from deactivation due to the redispersion under high-temperature lean-burn reaction conditions. Herein, two Pt1/CeO2 prepared by the incipient wetness impregnation method using different Pt precursors possessed varied Pt-O and Pt-O-Ce coordination numbers (CNs). They showed various priorities in CO oxidation versus NH3 selective catalytic oxidation, materials with higher CNPt-O-Ce selectively catalyzing NH3 oxidation to N2 more superior, conversely materials with lower CNPt-O-Ce performing better in CO oxidation. After activation by H2 reduction, both formed massive Pt clusters on the CeO2 surface but showed drastically distinct stability in lean-burn CO oxidation reactions. By summarizing the experimental results of high-angle annular dark-field scanning transmission electron microscopy, X-ray absorption spectroscopy, Raman spectroscopy, in situ diffuse reflectance infrared Fourier transform spectroscopy, etc., it is beyond doubt that the difference in the initial states of Pt1 due to distinct precursors indeed determine the redispersion behavior of the reduced Pt clusters on CeO2. Materials with lower CNPt-O-Ce and higher CNPt-O are more likely to form robust Pt clusters, as they are not conducive to Pt anchoring, thus restricting the reversible structural evolution occurring under lean-burn CO oxidation and reductive conditions. This approach serves as a guide for the convenient and efficient construction and exploration of robust Pt cluster catalysts.

7.
Sci Total Environ ; 912: 168972, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38043822

RESUMO

The response of the microbes to total petroleum hydrocarbons (TPHs) in three types of oilfield soils was researched using metagenomic analysis. The ranges of TPH concentrations in the grassland, abandoned well, working well soils were 1.16 × 102-3.50 × 102 mg/kg, 1.14 × 103-1.62 × 104 mg/kg, and 5.57 × 103-3.33 × 104 mg/kg, respectively. The highest concentration of n-alkanes and 16 PAHs were found in the working well soil of Shengli (SL) oilfield compared with those in Nanyang (NY) and Yanchang (YC) oilfields. The abandoned well soils showed a greater extent of petroleum biodegradation than the grassland and working well soils. Α-diversity indexes based on metagenomic taxonomy showed higher microbial diversity in grassland soils, whereas petroleum-degrading microbes Actinobacteria and Proteobacteria were more abundant in working and abandoned well soils. RDA demonstrated that low moisture content (MOI) in YC oilfield inhibited the accumulation of the petroleum-degrading microbes. Synergistic networks of functional genes and Spearman's correlation analysis showed that heavy petroleum contamination (over 2.10 × 104 mg/kg) negatively correlated with the abundance of the nitrogen fixation genes nifHK, however, in grassland soils, low petroleum content facilitated the accumulation of nitrogen fixation genes. A positive correlation was observed between the abundance of petroleum-degrading genes and denitrification genes (bphAa vs. nirD, todC vs. nirS, and nahB vs. nosZ), whereas a negative correlation was observed between alkB (alkane- degrading genes) and amo (ammonia oxidation), hao (nitrification). The ecotoxicity of petroleum contamination, coupled with petroleum hydrocarbons (PH) degradation competing with nitrifiers for ammonia inhibited ammonia oxidation and nitrification, whereas PH metabolism promoted the denitrification process. Moreover, positive correlations were observed between the abundance of amo gene and MOI, as well as between the abundance of the dissimilatory nitrate reduction gene nirA and clay content. Thus, improving the soil physicochemical properties is a promising approach for decreasing nitrogen loss and alleviating petroleum contamination in oilfield soils.


Assuntos
Petróleo , Poluentes do Solo , Petróleo/análise , Campos de Petróleo e Gás , Solo/química , Amônia/análise , Biodegradação Ambiental , Hidrocarbonetos/análise , Alcanos , Microbiologia do Solo , Poluentes do Solo/análise
8.
Chemosphere ; 344: 140291, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37769915

RESUMO

Cabbage waste returned soil was studied to assess the short-term influences of the application of cabbage waste biochar (CB), pine wood biochar (PB), and co-pyrolysed biochar (PCB) on soil dissolved organic matter (DOM) evolution. The decrease in DOM and soil organic matter (SOM) content was greater in the biochar-added soils during 35 days of decomposition. The DOM and SOM content in PCB added group decreased by 26.96 mg L-1 and 4.48 g kg-1, respectively. The increase in relative abundance of humic acid-like substances in DOMs was higher in the biochar-added soils during decomposition, which increased by 4.29% in PCB added group. PCB addition also resulted in a high SOM content (initial content of 78.82 g kg-1), and mineral elements were introduced into the soil, thus increasing soil pH (7.81) and electrical conductivity (574.67 µs cm-1). Moreover, the addition of biochars attenuated the decrease in average relative abundance of Bacillaceae and promoted bacterial proliferation during decomposition. The application of biochars regulated the soil bacterial community and promoted organic matter conversion and soil DOM evolution.


Assuntos
Brassica , Solo , Solo/química , Matéria Orgânica Dissolvida , Carvão Vegetal/química
9.
Chemosphere ; 340: 139801, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37574086

RESUMO

Combination of microbial fuel cell (MFC) and advanced oxidation process (AOP) is promising for pollutant removal. In this paper, Cu0-loaded carbon cloth cathode by electrodeposition (Cu@CC-PS-MFC) was applied to enhance 2,4-dichlorophenol (2,4-DCP) degradation based on persulfate (PS) activation in microbial fuel cell. Cu0 exhibited a typical structure of face-centered cubic metal polyhedron on carbon cloth. The removal of 2,4-DCP by Cu@CC-PS-MFC (75.6%) was enhanced by more than 50% compared to CC-PS-MFC (49.2%) after 1 h of reaction. 30 mg/L 2,4-DCP in Cu@CC-PS-MFC was completely removed and achieved a high mineralization (80.6%) after 9 h of reaction under optimized condition with low dissolved copper ion concentration (0.615 mg/L). Meanwhile, more than 90% removal of 2,4-DCP was stably achieved with flow operation condition (hydraulic residence time of 7.2 h). The change of copper valent state Cu0/Cu2O/CuO was the main mechanism of PS activation with main reactive species of O•H and O21. The bioanode of MFC enhanced the in-situ regeneration of ≡Cu+ and ≡Cu0 on the catalyst surface by transporting electrons, which was believed to contribute to good catalyst lifetime and excellent 2,4-DCP removal. Electrodeposited copper contributes to the enhanced degradation of 2,4-DCP with energy recovery at the same time which can further broaden the application MFC.


Assuntos
Fontes de Energia Bioelétrica , Clorofenóis , Cobre/química , Oxirredução
10.
Chem Commun (Camb) ; 59(41): 6219-6222, 2023 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-37129088

RESUMO

With the introduction of potassium species, the catalytic oxidation performance over the Pt1/CeO2 catalyst was significantly enhanced, where potassium ions acted as structural and electronic promoters, and formed Pt-O-K interactions with Pt to directly regulate the coordination environment and electronic state of Pt and the metal-support interaction between Pt and CeO2.

11.
Sci Total Environ ; 885: 163740, 2023 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-37146832

RESUMO

1The combination of carbonaceous materials and microbial degradation is an attractive measure in improving the removal efficiency of organic pollutants in water environment. In this study, the anaerobic dechlorination in a coupled system of ball-milled plastic chars (BMPCs) and the microbial consortium were investigated. The anaerobic microorganism cultured from raw sludge (CAM) contributed to the dechlorination of the 2,4,6-trichlorophenol (2,4,6-TCP) into 4-chlorophenol (4-CP) as the final product via ortho-dechlorination in all testing groups. The dechlorination rate was accelerated in different BMBC plus CAM groups than that in only CAM group (0.048 d-1), of which, it was greater in BMPC-500 plus CAM group (0.375 d-1) than that in BMPC-700 plus CAM group (0.171 d-1). The electron exchange capacity (EEC) of BMPCs decreased with the increase of pyrolysis temperature (0.053 mmol e-/g for BMPC-500 and 0.037 mmol e-/g for BMPC-700), which directly affected anaerobic dechlorination. Direct interspecies electron transfer (DIET) of BMPCs also boosted the biogas yield by 1.5 times compared to that without BMPCs. Microbial community analysis illustrated that BMPCs helped to enrich the putative dechlorinating bacteria. The abundance of Clostridium_aenus_stricto_12, as a dominant dechlorinator, significantly increased from 0.02 % to 11.3 % (without BMPCs), 39.76 % (BMPC-500) and 9.3 % (BMPC-700), and followed by, Prevotella and Megaspheara, which was reported to take part in anaerobic dechlorination and digestion as H2 producers, also increased in the presence of BMPC. This study contributes to the realization of 2,4,6-TCP in-situ reduction technology and provides a scientific reference for anaerobic dechlorination by cultured anaerobes combined with BMPCs.


Assuntos
Bactérias Anaeróbias , Elétrons , Anaerobiose , Bactérias Anaeróbias/metabolismo , Água/metabolismo , Biodegradação Ambiental
12.
Front Pharmacol ; 14: 1117391, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37081961

RESUMO

Background: Sound drug safety information is important to optimize patient management, but the widely recognized comprehensive landscape of culprit-drugs that cause severe cutaneous adverse reactions (SCARs) is currently lacking. Objective: The main aim of the study is to provide a comprehensive landscape of culprit-drugs for SCARs to guide clinical practice. Methods: We analyzed reports associated with SCARs in the FDA Adverse Event Reporting System database between 1 January 2004 and 31 December 2021 and compiled a list of drugs with potentially serious skin toxicity. According to this list, we summarized the reporting proportions of different drugs and drug classes and conducted disproportionality analysis for all the drugs. In addition, the risk characteristic of SCARs due to different drugs and drug classes was summarized by the positive-negative distribution based on the results of the disproportionality analysis. Results: A total of 77,789 reports in the FDA Adverse Event Reporting System database were considered SCAR-related, of which lamotrigine (6.2%) was the most reported single drug followed by acetaminophen (5.8%) and allopurinol (5.8%) and antibacterials (20.6%) was the most reported drug class followed by antiepileptics (16.7%) and antineoplastics (11.3%). A total of 1,219 drugs were reported as culprit-drugs causing SCARs in those reports, and the largest number of drugs belonged to antineoplastics. In disproportionality analysis, 776 drugs showed at least one positive pharmacovigilance signal. Drugs with the most positive signals were lamotrigine, acetaminophen, furosemide, and sulfamethoxazole/trimethoprim. Conclusion: Our study provided a real-world overview of SCARs to drugs, and the investigation of SCAR positive-negative distribution across different drugs revealed its risk characteristics, which may help optimize patient management.

13.
Langmuir ; 39(22): 7566-7577, 2023 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-37078889

RESUMO

This study was to develop a low-cost N-doped porous biocarbon adsorbent that can directly adsorb CO2 in high-temperature flue gas from fossil fuel combustion. The porous biocarbon was prepared by nitrogen doping and nitrogen-oxygen codoping through K2CO3 activation. Results showed that these samples exhibited a high specific surface area of 1209-2307 m2/g with a pore volume of 0.492-0.868 cm3/g and a nitrogen content of 0.41-3.3 wt %. The optimized sample CNNK-1 exhibited a high adsorption capacity of 1.30 and 0.27 mmol/g in the simulated flue gas (14.4 vol % CO2 + 85.6 vol % N2) and a high CO2/N2 selectivity of 80 and 20 at 25 and 100 °C and 1 bar, respectively. Studies revealed that too many microporous pores could hinder CO2 diffusion and adsorption due to the decrease of CO2 partial pressure and thermodynamic driving force in the simulated flue gas. The CO2 adsorption of the samples was mainly chemical adsorption at 100 °C, which depended on the surface nitrogen functional groups. Nitrogen functional groups (pyridinic-N and primary and secondary amines) reacted chemically with CO2 to produce graphitic-N, pyrrolic-like structures, and carboxyl functional groups (-N-COOH). Nitrogen and oxygen codoping increased the amount of nitrogen doping content in the sample, but acidic oxygen functional groups (carboxyl groups, lactones, and phenols) were introduced, which weakened the acid-base interactions between the sample and CO2 molecules. It was demonstrated that SO2 and water vapor had inhibition effects on CO2 adsorption, while NO nearly has no effect on the complex flue gas. Cyclic regenerative adsorption showed that CNNK-1 possessed excellent regeneration and stabilization ability in complex flue gases, indicating that corncob-derived biocarbon had excellent CO2 adsorption in high-temperature flue gas.

14.
Front Pharmacol ; 14: 1128219, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36937879

RESUMO

Background and aim: Infectious disease (ID) consultation can improve multidrug-resistant organism (MDRO) treatment outcomes. However, the impact of clinical pharmacists' ID consultation on MDRO therapy, especially early initiation, has not been reported. In this study, we try to explore the impact of the pharmacist early active consultation (PEAC) on MDRO patient management. Methods: We conducted a prospective historical controlled study based on PEAC in MDRO patients. The retrospective control group was patients hospitalized 18 months before the PEAC initiation, and the prospective PEAC group was patients hospitalized 18 months after the PEAC initiation. Primary endpoint was 30-day all-cause mortality. Secondary outcomes were MDRO clinical outcome, duration of antibiotic use, length of stay, antibiotic consumption and antibiotic costs. Further subgroup analysis of secondary outcomes was performed by the condition at admission, MDRO pathogenicity and MDRO clinical outcome. Results: 188 MDRO patients were included. After adjusting for potential predictors, PEAC reduced the 30-day all-cause mortality by 70% (HR 0.30, 95% CI 0.09-0.96, p = 0.042). PEAC group had clinical improvement than control group (89.47% vs. 65.59%, p < 0.001), especially in patients with non-severe clinical conditions at admission (98.41% vs. 70.18%, p < 0.001). However, no significant differences were found between groups in length of stay, antibiotics consumption, and antibiotics costs. Conclusion: Early active pharmacy ID consultation can reduce 30-day all-cause mortality and improve clinical outcomes in MDRO patients.

15.
Chemistry ; 29(16): e202203432, 2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36567623

RESUMO

The size effect on nanoparticles, which affects the catalysis performance in a significant way, is crucial. The tuning of oxygen vacancies on metal-oxide support can help reduce the size of the particles in active clusters of Pt, thus improving catalysis performance of the supported catalyst. Herein, Ce-Sn solid solutions (CSO) with abundant oxygen vacancies have been synthesized. Activated by simple CO reduction after loading Pt species, the catalytic CO oxidation performance of Pt/CSO was significantly better than that of Pt/CeO2 . The reasons for the elevated activity were further explored regarding ionic Pt single sites being transformed into active Pt clusters after CO reduction. Due to more exposed oxygen vacancies, much smaller Pt clusters were created on CSO (ca. 1.2 nm) than on CeO2 (ca. 1.8 nm). Consequently, more exposed active Pt clusters significantly improved the ability to activate oxygen and directly translated to the higher catalytic oxidation performance of activated Pt/CSO catalysts in vehicle emission control applications.

16.
Sci Total Environ ; 856(Pt 2): 159186, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36202351

RESUMO

The reduction process of pollutants by nano zero-valent iron (nZVI) is limited by mass transfer and its effective utilization, and previous studies have ignored the electron loss caused by its oxidative passivation. The carbon-coated structure can effectively inhibit the oxidation of nZVI, but the effectiveness of carbon-coated nZVI (Fe0@C) as a reducing agent in soil remediation is unclear. Therefore, in this study, the Fe0@C/surfactant system was used to remove soil-adsorbed nitrobenzene (NB) to simultaneously enhance the mass transfer process and effective utilization of nZVI. The results showed that the use of surfactants effectively promoted the desorption of NB adsorbed by the soil, and the desorption process was affected by factors such as the type and concentration of surfactants, water-soil ratio, and soil organic matter (SOM) content. The enhanced desorption of NB by the surfactant in the soil system promoted the effective contact between the composite and NB, thereby enhancing the reduction of NB by the composite. In addition, Fe0@C exhibited excellent performance for the reduction of soil-adsorbed NB compared with the conventional nZVI, and this advantage was more obvious in the potting soil system. However, the composite will be gradually passivated due to the alkaline environment during the reduction process, and this phenomenon was especially obvious in the campus soil system. When the pH value decreased from 9 to 3, the proportion of aniline (AN) generated in the campus soil system increased from 19.37 % to 69.29 %. In addition, in potting soil systems with high SOM content, the adsorption of soil particles to the composite and the high dissolved organic matter (DOM) content resulting from the high SOM content also negatively affected the reduction process. The conclusions of this study demonstrate the great potential of the Fe0@C/surfactant system for in-situ contaminated site remediation applications.


Assuntos
Recuperação e Remediação Ambiental , Poluentes do Solo , Poluentes Químicos da Água , Ferro/química , Solo/química , Tensoativos/química , Carbono , Poluentes Químicos da Água/análise , Nitrobenzenos/química , Poluentes do Solo/química
17.
Org Lett ; 24(43): 7983-7987, 2022 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-36300950

RESUMO

A direct acetylation of inert C(sp3)-H bonds was developed that was catalyzed by decatungstate under visible light irradiation and was followed by radical addition-disassociation with phenylsulfonyl ethanone oxime. The reaction displays site-selectivity in multiple C(sp3)-H bonds without prefunctionalization and directing groups. Various functional groups are well-tolerated and natural molecules are structurally feasible. CF3-modified phenylsulfonyl ethanone oxime was discovered to be necessary for enhancing the electrophilicity of imine and lowering the C-S bond cleavage energy.


Assuntos
Oximas , Catálise , Acetilação
18.
Nat Prod Res ; : 1-7, 2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36070589

RESUMO

This study introduced the preparation of a novel HOF-loaded PU sponge (HOF-3@PU) composite for the sustainable and efficient purification of catalpol and ajugol from Rehmannia glutinosa leaves for the first time. HOF-3 was selected as the best adsorbent from the five synthesised HOFs. HOF-3@PU was prepared by ultrasonication, and the loading conditions were optimised. The results showed that the optimum adsorption conditions are as follows: adsorption liquid volume: 160 mL, flow rate: 3.0 mL/min, pH: 6.0, concentration: 1.62 mg/mL for catalpol and 2.18 mg/mL for ajugol. The optimum desorption conditions are as follows: desorption agent: ethanol, volume fraction: 60%, flow rate: 2.0 mL/min, volume: 300 mL and pH: 6.0. Under the optimal process conditions, the adsorption capacities of catalpol and ajugol were 75.62 and 68.41 mg/g, the desorption rates were 78.5 and 86.4% and the purities were 38.7 and 36.5%, respectively.

19.
Adv Mater ; 34(43): e2205153, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35999183

RESUMO

Hollow nanostructures with fascinating properties have inspired numerous interests in broad research fields. Cell-mimicking complex hollow architectures with precise active components distributions are particularly important, while their synthesis remains highly challenging. Herein, a "top-down" chemical surgery strategy is introduced to engrave the 3-aminophenol formaldehyde resin (APF) spheres at nanoscale. Undergoing the cleavage of (Ar)CN bonds with ethanol as chemical scissors and subsequent repolymerization process, the Solid APF transform to multilevel hollow architecture with precise nanospatial distribution of organic functional groups (e.g., hydroxymethyl and amine). The transformation is tracked by electron microscopy and solid-state nuclear magnetic resonance techniques, the category and dosage of alcohol are pivotal for constructing multilevel hollow structures. Moreover, it is demonstrated the evolution of nanostructures accompanied with unique organic microenvironments is able to accurately confine multiple gold (Au) nanoparticles, leading to the formation of pomegranate-like particles. Through selectively depositing palladium (Pd) nanoparticles onto the outer shell, bimetallic Au@APF@Pd catalysts are formed, which exhibit excellent hydrogenation performance with turnover frequency (TOF) value up to 11257 h-1 . This work provides an effective method for precisely manipulating the nanostructure and composition of polymers at nanoscale and sheds light on the design of catalysts with precise spatial active components.

20.
Environ Sci Pollut Res Int ; 29(51): 77685-77697, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35680752

RESUMO

Ball-milled plastic char (BMPC) was manufactured by ball-milling of native plastic char (PC) that was synthesized via slow pyrolysis of polyethylene terephthalate (PET) water bottle waste, and its adsorption characteristics of aqueous phenanthrene (PHE), phenol, and 2,4,6-trichlorophenol (2,4,6-TCP) and its possible mechanisms were investigated. With the increase of PC pyrolysis temperature, the specific surface area of BMPC increased obviously, forming larger functional groups compared to PC. Boehm titration showed that total acidic groups of BMPC decreased significantly with the increase of pyrolysis temperature. The sorption kinetics of three adsorbates was adequately simulated by pseudo-second-order model (R2 > 0.99). Langmuir model fitted well the adsorption isotherms of PHE and phenol, while Freundlich model simulated the adsorption isotherm of 2,4,6-TCP better. The adsorption amount of PHE, phenol, and 2,4,6-TCP increased significantly as the pyrolysis temperature increased. The maximum BMPC adsorption capacity reached 21.9 mg·g-1 (for PHE), 106 mg·g-1 (for phenol), and 303 mg·g-1 (for 2,4,6-TCP) at 25 °C in aqueous solution. FTIR analysis suggested that surface sorption-based π-π interaction was a dominant mechanism of PHE adsorption; meanwhile, H-bonding between O-containing groups on BMPC and hydroxyl groups of adsorbates was responsible for phenol and 2,4,6-TCP removal. This paper shows that BMPC can be used as adsorbent for treating aromatic compounds in aqueous environment and has an economic worth of application.


Assuntos
Poluentes Ambientais , Fenantrenos , Poluentes Químicos da Água , Adsorção , Plásticos , Polietilenotereftalatos , Carvão Vegetal , Poluentes Químicos da Água/análise , Cinética , Fenol , Fenóis
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