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1.
Front Chem ; 10: 1022779, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36176895

RESUMO

Doping of heteroatoms into carbon materials is a popular method to modify their physicochemical structures and has been widely used in the fields of energy conversion and storage. This study aims to investigate the effect of doping atmosphere on the catalytic performance of nitrogen and sulfur co-doped biochar supported Ru in the production of phenolic monomers from lignin hydrogenolysis. The results showed that the catalyst prepared under CO2 atmosphere (Ru@CNS-CO2) was able to produce phenolic monomers from corncob lignin with a yield up to 36.41 wt%, which was significantly higher than that from the run over N2-prepared catalyst (Ru@CNS-N2). The characterization of the catalysts demonstrated that the CNS-CO2 support had a larger specific surface area, richer C=S and C-S groups, and higher oxygen content than CNS-N2, resulting in finer Ru particles and more Ru0 content on the CNS-CO2 support. The Ru@CNS-CO2 catalyst exhibited high activity in hydrogenation and fragmentation of ß-O-4 linkages.

2.
ACS Appl Mater Interfaces ; 13(41): 48923-48933, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34628849

RESUMO

The earth-abundant iron and nitrogen doped carbon (Fe-N-C) catalyst has great potential to substitute noble metal catalysts for oxygen reduction reaction (ORR) in H2-O2 proton exchange membrane fuel cells (PEMFCs). Herein, we report the preparation of Fe-N4 moiety doped carbon nanotubes (CNTs) by ball milling and two-step pyrolysis with dual metal-organic frameworks (MOFs) as the precursor. This catalyst shows high ORR catalytic performance and stability. Different from traditional inorganic iron sources, the MOF structure can effectively prevent the iron metal from aggregating during pyrolysis. In PEMFC, the catalyst shows high current density (0.39 A/cm2 at 0.7 V) and power density (850 mW/cm2). Such a method brings inspiration for the reasonable design of FeNC catalysts with high catalytic activity for H2-O2 PEMFCs.

3.
ACS Appl Mater Interfaces ; 13(41): 48774-48783, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34628856

RESUMO

The oxygen evolution reaction (OER) is crucial for hydrogen production from water splitting and rechargeable metal-air batteries. However, the four-electron mechanism results in slow reaction kinetics, which needed to be accelerated by efficient catalysts. Herein, a hybrid catalyst of novel nickel-iron layered double hydroxide (NiFe LDH) on porous indium tin oxide (ITO) is presented to lower the overpotential of the OER. The as-prepared NiFe LDH@ITO catalyst showed superior catalytic activity toward the OER with an overpotential of only 240 mV at a current density of 10 mA/cm2. The catalyst also offered high stability with almost no activity decay after more than 200 h of chronopotentiometry test. Furthermore, the applications of NiFe LDH@ITO in (flexible) rechargeable zinc-air batteries exhibited a better performance than commercial RuO2 and can remain stable in cycling tests. It is supposed that the superior catalytic behavior originates from the ITO conductive framework, which prevents the agglomeration and facilitates the electron transfer during the OER process.

4.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-877207

RESUMO

Objective@#To compare the color stability of Biodentine and mineral trioxide aggregate (MTA) within the blood environment in vitro and to further investigate the underlying reasons for such color instability. @*Methods @#We first generated Biodentine and MTA discs with a diameter of 5 mm and a height of 3 mm. 24 discs of each material were randomly divided into two groups: the deionized water group and the defibrinated sheep blood group. Discs of each group were immersed for 1 day or 7 days before assessments. First, all discs were photographed to directly compare the discoloration of Biodentine and MTA. The color degree of the two materials was tested by a spectrophotometer. Then, the high-resolution morphological characteristics were observed by scanning electron microscopy. Finally, the chemical contents of each element in the material were measured by energy-dispersive spectroscopy.@*Results @#Compared to immediately after stripping, a change in the brightness of discs after immersion in defibrinated sheep blood for 1 day was observed only in MTA. On the 7th day after being immersed in blood, the colors of both the Biodentine and MTA discs darkened and turned deep red, but the darkness of the MTA discs increased significantly. The color change of MTA immersed in blood was measured on a spectrophotometer with a greater 7-day ∆E (21.257 ± 0.955) than the Biodentine 7-day ∆E (5.833 ± 0.501) (t=24.781, P < 0.001). MTA exhibits more discoloration as the immersion time goes on. A significant difference was noted between the 1-day ∆E(6.233 ± 0.888) and the 7-day ∆E(t=19.956, P < 0.001) of MTA immersed in blood. However, there was no statistically significant difference between the 1-day ∆E (6.790 ± 0.831) and the 7-day ∆E(t=1.707, P=0.163) of Biodentine immersed in blood. It was observed by scanning electron microscopy that after 7 days of immersion in the defibrinated sheep ablood, the surface porosity of MTA was larger than that of Biodentine, and the crystal edge of MTA became rounded and blunt. The analysis by energy-dispersive X-ray spectroscopy showed that the oxygen content decreased and the bismuth content increased in MTA after immersion in defibrinated sheep blood for 7 days. Zirconium was not detected in Biodentine due to its low radiodensity, but the contents of other elements were stable in Biodentine after immersion in defibrinated sheep blood for 7 days. @* Conclusion@#The color stability of Biodentine within the blood environment is better than that of MTA in vitro, which is mainly related to the low surface porosity and stable composition of the anti-radiation agent of Biodentine.

5.
Genomics ; 112(6): 3856-3861, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32562828

RESUMO

Marfan syndrome is a heritable autosomal-dominant connective tissue disorder and it was typically caused by mutations in FBN1. However, the synonymous mutation was seldom recorded to be related to Marfan syndrome. Hereon, Multiplex ligation-dependent probe amplification failed to detect a copy number variant involving FBN1 but a synonymous mutation c.4773A > G (p.Gly1591Gly) was identified by NGS in exon 39. RNA was extracted from patient's aortic tissue and reverse polymerase chain reaction demonstrated the presence of a shortened mRNA transcript. Results of minigene models indicated that c.4773A > G was bona fide responsibility for the aberrant splicing pattern, and artificial mutations of c.4773A > C and c.4773A > T also gave rise to fragments with exon 39 entire skipped. Together, the novel synonymous mutations in c.4773 position (A > G, C, T), middle of exon 39 of FBN1 gene, was found to be associated with Marfan syndrome by altering the splicing pattern of pre-mRNA.


Assuntos
Éxons , Fibrilina-1/genética , Síndrome de Marfan/genética , Mutação , Adulto , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Splicing de RNA
6.
DNA Cell Biol ; 39(5): 909-917, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32150689

RESUMO

The aims of this study were to investigate the expression of prolyl 4-hydroxylase subunit alpha-1 (P4HA1) and its relationship with clinicopathological features in lung cancer (LC), breast cancer (BC), and head and neck cancer (HNSC) and to discuss the possibility of P4HA1 being a potential diagnostic and prognostic biomarker. Data on the RNA expression profile, protein expression profile, and relevant clinical information were downloaded from The Cancer Genome Atlas (TCGA) and The Human Protein Atlas databases. The relationship between P4HA1 mRNA expression and clinicopathological features was evaluated. Survival analysis was performed to assess overall survival (OS) and relapse-free survival (RFS). The multivariate Cox regression model was employed to analyze the independent prognostic factors. Finally, protein-protein interaction networks were constructed and enrichment analysis was performed to identify the latent P4HA1-related terms and pathways. This study showed that P4HA1 was upregulated in three types of tumor tissues (p < 0.05) and high P4HA1 was significantly relevant to the clinical features of patients with LC, BC, or HNSC. Survival analysis indicated that patients with high P4HA1 had unfavorable clinical outcomes. Multivariate analysis showed that the high P4HA1 expression was an independent prognostic factor for poor OS and RFS in LC and HNSC patients. Bioinformatic analysis was performed to predict P4HA1-interacted proteins and further evaluate possible signal pathways. In the current study, the rising P4HA1 was identified in LC, BC, and HNSC and significantly correlated with the clinicopathological features of patients. High P4HA1, suggesting poor clinical outcomes, could be used as an early diagnostic and prognostic biomarker for patients with aforementioned tumors.


Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias/diagnóstico , Neoplasias/genética , Pró-Colágeno-Prolina Dioxigenase/genética , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Feminino , Genômica , Neoplasias de Cabeça e Pescoço/diagnóstico , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Neoplasias/patologia , Prognóstico , Análise de Sobrevida
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