Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Small ; 18(14): e2107250, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35166038

RESUMO

Particulate matter (PM) pollution has become a serious environmental concern. Nanofibrous filters are widely reported to remove PM from polluted air. Herein, efficient and lightweight PM air filters are presented using airflow synergistic needleless electrospinning composed of auxiliary fields such as an airflow field and a secondary inductive electric field. Compared to needleless electrospinning with other spinnerets, it significantly improves productivity, fiber diameter, and porosity of fibrous air filters. The instant noodle-like nanofiber structure can also be controlled by adjusting the airflow velocity. These air filters exhibit high (2.5 µm particulate matter) PM2.5 removal efficiency (99.9%) and high (0.3 µm particulate matter) PM0.3 removal efficiency (99.1%), low pressure drop (56 Pa for PM2.5 and 78 Pa for PM0.3 ), and large dust holding capacitance (the maximum value is 168 g m-2 for PM2.5 , while 102 g m-2 for PM0.3 ). Meanwhile, the proposed PM filters are also tested suitable and stable to other polluted air filtrations such as cigarette smoke and sawdust. The large-scale synthesis of such an attractive nanofiber structure presents the great potential of high-performance filtration/separation materials.


Assuntos
Filtros de Ar , Nanofibras , Filtração , Material Particulado , Porosidade
2.
Nanoscale ; 13(39): 16680-16689, 2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34590639

RESUMO

Due to the complexity of surgery for large-area bone injuries, implanting a large volume of materials into the injury site remains a big challenge in orthopedics. To solve this difficulty, in this study, a series of biomimetic hydroxyapatite/shape-memory composite scaffolds were designed and synthesized with programmable pore structures, based on poly(ε-caprolactone) (PCL), polytetrahydrofuran (PTMG) and the osteoconductive hydroxyapatite (HA). The obtained scaffolds presented various pore structures, high connectivity, tunable mechanical properties, and excellent shape memory performance. Moreover, the mineralization activity of the developed scaffolds could enhance the formation of hydroxyapatite and they showed good biocompatibility in vitro. The in vivo experiments show that scaffolds could promote the formation of new bone in critical size cranial defects. The programmable porous scaffold biomaterials exhibited potential application promise in bone regeneration.


Assuntos
Biomimética , Alicerces Teciduais , Regeneração Óssea , Durapatita , Poliésteres , Porosidade , Engenharia Tecidual
3.
J Ginseng Res ; 43(4): 600-605, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31695566

RESUMO

BACKGROUND: The leaves and roots of Panax ginseng are rich in ginsenosides. However, the chemical compositions of the leaves and roots of P. ginseng differ, resulting in different medicinal functions. In recent years, the aerial parts of members of the Panax genus have received great attention from natural product chemists as producers of bioactive ginsenosides. The aim of this study was the isolation and structural elucidation of novel, minor ginsenosides in the leaves of P. ginseng and evaluation of their antiinflammatory activity in vitro. METHODS: Various chromatographic techniques were applied to obtain pure individual compounds, and their structures were determined by nuclear magnetic resonance and high-resolution mass spectrometry, as well as chemical methods. The antiinflammatory effect of the new compounds was evaluated on lipopolysaccharide-stimulated RAW 264.7 cells. RESULTS AND CONCLUSIONS: Two novel, minor triterpenoid saponins, ginsenoside LS1 (1) and 5,6-didehydroginsenoside Rg3 (2), were isolated from the leaves of P. ginseng. The isolated compounds 1 and 2 were assayed for their inhibitory effect on nitric oxide production in LPS-stimulated RAW 264.7 cells, and Compound 2 showed a significant inhibitory effect with IC50 of 37.38 µM compared with that of NG-monomethyl-L-arginine (IC50 = 90.76 µM). Moreover, Compound 2 significantly decreased secretion of cytokines such as prostaglandin E2 and tumor necrosis factor-α. In addition, Compound 2 significantly suppressed protein expression of inducible nitric oxide synthase and cyclooxygenase-2. These results suggested that Compound 2 could be used as a valuable candidate for medicinal use or functional food, and the mechanism is warranted for further exploration.

4.
J Ethnopharmacol ; 228: 179-187, 2019 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-30268651

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: A multi-herb Chinese medicinal formula consisting of a variety of medicinal and edible materials has long been consumed as a hot drink and immune enhancer for its efficiency to increase disease resistance in Xinjiang, China. However, no fundamental data has been collected associated with traditional consumption. The present work was designed to evaluate the immunostimulatory role of Xinjiang herbal tea (XMT-WE) in RAW 264.7 macrophages and cyclophosphamide (CTX)-induced immunosuppression mice model. MATERIALS AND METHODS: RAW 264.7 cells were treated with various concentrations of XMT-WE. Nitric oxide (NO) levels were determined using Griess reagents, and pro-inflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α were investigated with a cytometric bead array kit. The effects on mRNA expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, and TNF-α were investigated. Furthermore, activation of nuclear factor (NF)-κB and AP-1 mitogen-activated protein kinase (MAPK) signaling pathways was investigated. RESULTS: Pre-treatment with XMT-WE significantly increased secretion of NO, IL-6, and TNF-α. In addition, XMT-WE markedly increased expression of iNOS, COX-2, and TNF-α as well as AP-1 and NF-κB translocation from the cytoplasm into the nucleus, which was associated with an increase of phosphorylated ERK, JNK, and p38 as well as membrane receptors such as toll-like receptor (TLR) 2 and TLR4. Moreover, XMT-WE promoted the secretion of interleukin-2 (IL-2) and interferon-γ (IFN-γ) in cyclophosphamide (CTX)-induced immunosuppressive mice. CONCLUSION: These results indicated that XMT-WE at 50 µg/ml exerts immunomodulatory activity via TLR2/4-mediated MAPK signaling pathways in RAW 264.7 cells. Furthermore, in vivo experiments revealed that XMT-WE at the dose of 50 and 100 mg/kg strongly stimulated inflammatory cytokines.


Assuntos
Fatores Imunológicos/farmacologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Chás de Ervas , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Ciclofosfamida , Citocinas/metabolismo , Terapia de Imunossupressão , Camundongos , Camundongos Endogâmicos BALB C , Células RAW 264.7 , Transdução de Sinais
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA