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1.
Opt Lett ; 48(10): 2688-2691, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-37186741

RESUMO

Natural in-plane hyperbolic crystals (such as α-MoO3) and natural monoclinic crystals (such as ß-Ga2O3) have recently drawn great research focus. Despite their obvious similarities, however, these two kinds of materials are usually studied as separate topics. In this Letter, we explore the intrinsic relationship between materials like α-MoO3 and ß-Ga2O3 under the framework of transformation optics, providing another perspective to understand the asymmetry of hyperbolic shear polaritons. It is worth mentioning that we demonstrate this novel, to the best of our knowledge, method from theoretical analysis and numerical simulations, which maintain a high degree of consistency. Our work not only combines natural hyperbolic materials with the theory of classical transformation optics, but also opens new avenues for future studies of various natural materials.

2.
J Ethnopharmacol ; 305: 116119, 2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-36596398

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Rheumatoid arthritis (RA) is a common systemic autoimmune disease with high morbidity and disability rate. Currently, there is no effective allopathic treatment for RA, and most of the drugs provoke many adverse effects. Simiao Yong'an decoction (SMYAD) is a traditional Chinese prescription for the treatment of sore and gangrene caused by hot poison. With the development of pharmacology and clinical research, SMYAD has remarkable anti-inflammatory properties and has been used for RA treatments for years. AIM OF THE STUDY: This study aimed to investigate the anti-arthritic effect of SMYAD and further explore the immunopharmacological mechanisms. MATERIALS AND METHODS: Arthritis was induced in DBA/1 mice by two-time immunizations. Collagen-induced rheumatoid arthritis (CIA) mice were divided into 4 groups: control, model, methotrexate (MTX), and SMYAD group (n = 6). The administration groups were given MTX (0.5 mg/kg/3 d) and SMYAD (4.5 g/kg/d) by gavage from day 14. The arthritis index (AI) score was evaluated every 3 days after the second immunization. Hematoxylin and eosin (H&E) staining, Safranin-O fast green staining, Trap staining, and Micro-CT were used to measure the histopathology injuries and bone destruction of joints. Granulocyte changes in the spleen, bone marrow, and period blood were analyzed by flow cytometry. The expression of inflammatory cytokines and chemokines in joints were detected by qRT-PCR. SMYAD-containing serum was obtained from SD rats gavaged with SMYAD. Neutrophils were isolated from peripheral blood and bone marrow for the in vitro experiments of transwell cell assay, apoptosis assay, reactive oxygen species (ROS) generation and neutrophil extracellular traps (NETs) formation. RESULTS: SMYAD significantly relieved arthritis severity in CIA mice. The AI score was significantly decreased in the SMYAD group compared with the model group. Additionally, SMYAD alleviated inflammatory infiltration, cartilage damage, osteoclast formation, and bone damage in the ankle joints. In the flow cytometry assay, SMYAD significantly reduced granulocytes number in the spleen and bone marrow, while increased in peripheral blood. Furthermore, compared with the CIA group, SMYAD suppressed the mRNA levels of inflammatory factors including TNF-α, IL-1ß, IL-6 and chemokines CXCL1, CXCL2, and IL-8 in the inflamed joints. In the in vitro studies, 20% SMYAD-containing serum effectively inhibited the migration of neutrophils, promoted neutrophils apoptosis, reduced ROS production and NETs formation. CONCLUSION: Collectively, our results demonstrated that SMYAD effectively restrained arthritis in CIA mice by modulating neutrophil activities.


Assuntos
Artrite Experimental , Artrite Reumatoide , Camundongos , Ratos , Animais , Artrite Experimental/patologia , Neutrófilos/metabolismo , Espécies Reativas de Oxigênio , Ratos Sprague-Dawley , Camundongos Endogâmicos DBA , Artrite Reumatoide/tratamento farmacológico , Citocinas/metabolismo , Metotrexato
3.
Front Chem ; 7: 426, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31245361

RESUMO

Biomass obtained from organic residues gradually becomes one of the optimal renewable feedstock of value added chemicals. Herein, the Co-N-C catalyst was prepared via a hard-template and etching method using the casein as C and N sources, magnesium oxide as the template, and cobalt porphyrin as the metal precursor. The obtained Co-N-C catalyst exhibited excellent catalytic performance for selective oxidation of ethylbenzene with a conversion rate of 96.5% under mild conditions. Moreover, the catalysts were investigated by techniques such as BET, XRD, Raman, transmission electron microscopic (TEM), and X-ray photoelectron spectroscopy (XPS). The results showed that the etching progress could improve the dispersion of Co and the exposure of active sites. Herein, the efficient oxidation of ethylbenzene was attributed to the well-dispersed Co-N species and the increased specific surface area.

4.
RSC Adv ; 9(17): 9462-9467, 2019 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-35520717

RESUMO

Heteroatom doping has been demonstrated to be an effective strategy for improving the performance of catalysts. In this paper, cobalt carbon catalysts co-doped with nitrogen and sulfur (N and S) were synthesized through a hydrothermal method with chelate composites involving melamine, thioglycolic acid (C2H4O2S), and tetrahydrate cobalt acetate (Co(OAc)2·4H2O). In addition, the selective oxidation of ethylbenzene under solvent-free conditions with molecular oxygen was used as a probe reaction to evaluate the activity of the catalysts. The optimized catalyst shows an ethylbenzene conversion of 48% with an acetophenone selectivity of 85%. Furthermore, the catalysts were systematically characterized by techniques such as TEM, SEM, XRD, Raman, and XPS. The results reveal that the species of cobalt sulfides and synergistic effects between N and S has inserted a key influence on their catalytic performance.

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