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51.
将次磷酸铝(AHP)和石墨烯(RGO)协效应用于聚对苯二甲酸丁二醇酯(PBT)的阻燃处理。采用极限氧指数、垂直燃烧分析、微型量热分析、热失重分析等研究了PBT复合材料的阻燃性能。结果表明,适量RGO的加入能明显改善PBT的抗滴落性能; PBT/AHP-0.5 %RGO(质量分数,下同)样品的热释放速率峰值最低,从PBT/20 %AHP的518.7 W/g降低到433.0 W/g,下降了约16.52 %;RGO在合适的比例下可以促进PBT/AHP-0.5 %RGO样品残炭外表面形成较多数量,致密的囊泡,有效地阻碍了可燃性小分子的逸出,改善了材料的阻燃性能。 相似文献
52.
53.
Xin Zhang Janet L. Huebner Virginia Byers Kraus 《International journal of molecular sciences》2021,22(15)
Along with cytokines, extracellular vesicles (EVs) released by immune cells in the joint contribute to osteoarthritis (OA) pathogenesis. By high-resolution flow cytometry, we characterized 18 surface markers and 4 proinflammatory cytokines carried by EVs of various sizes in plasma and synovial fluid (SF) from individuals with knee OA, with a primary focus on immune cells that play a major role in OA pathogenesis. By multiplex immunoassay, we also measured concentrations of cytokines within (endo) and outside (exo) EVs. EVs carrying HLA-DR, -DP and -DQ were the most enriched subpopulations in SF relative to plasma (25–50-fold higher depending on size), suggesting a major contribution to the SF EV pool from infiltrating immune cells in OA joints. In contrast, the CD34+ medium and small EVs, reflecting hematopoietic stem cells, progenitor cells, and endothelial cells, were the most significantly enriched subpopulations in plasma relative to SF (7.3- and 7.7-fold higher). Ratios of EVs derived from neutrophils and lymphocytes were highly correlated between SF and plasma, indicating that plasma EVs could reflect OA severity and serve as systemic biomarkers of OA joint pathogenesis. Select subsets of plasma EVs might also provide next generation autologous biological products for intra-articular therapy of OA joints. 相似文献
54.
Sílvia C. Rodrigues Renato M. S. Cardoso Patricia C. Freire Cludia F. Gomes Filipe V. Duarte Ricardo Pires das Neves Joana Simes-Correia 《International journal of molecular sciences》2021,22(18)
Umbilical cord blood (UCB) has long been seen as a rich source of naïve cells with strong regenerative potential, likely mediated by paracrine signals. More recently, small extracellular vesicles (sEV), such as exosomes, have been shown to play essential roles in cell-to-cell communication, via the transport of numerous molecules, including small RNAs. Often explored for their potential as biomarkers, sEV are now known to have regenerative and immunomodulating characteristics, particularly if isolated from stem cell-rich tissues. In this study, we aim to characterize the immunomodulating properties of umbilical cord blood mononuclear cell-derived sEV (UCB-MNC-sEV) and explore their therapeutic potential for inflammatory skin diseases. UCB-MNC-sEV were shown to shift macrophages toward an anti-inflammatory phenotype, which in turn exert paracrine effects on fibroblasts, despite previous inflammatory stimuli. Additionally, the incubation of PBMC with UCB-MNC-sEV resulted in a reduction of total CD4+ and CD8+ T-cell proliferation and cytokine release, while specifically supporting the development of regulatory T-cells (Treg), by influencing FOXP3 expression. In a 3D model of psoriatic skin, UCB-MNC-sEV reduced the expression of inflammatory and psoriatic markers IL6, IL8, CXCL10, COX2, S100A7, and DEFB4. In vivo, UCB-MNC-sEV significantly prevented or reversed acanthosis in imiquimod-induced psoriasis, and tendentially increased the number of Treg in skin, without having an overall impact on disease burden. This work provides evidence for the anti-inflammatory and tolerogenic effect of UCB-MNC-sEV, which may be harnessed for the treatment of Th17-driven inflammatory skin diseases, such as psoriasis. 相似文献
55.
Supramolecular assemblies from chitosan-graft-β-cyclodextrin (CS-g-CD) and benzimidazole ended poly(ethylene glycol)-block-poly(ε-caprolactone) (PEG-b-PCL-BM) were formed based on the inclusion complexation between β-cyclodextrin and benzimidazole. The supra-amphiphiles self-assembled into complex vesicles with PCL/β-CD as the hydrophobic membrane, hydrophilic PEG and CS as the corona. The hydrophobic membrane and aqueous lumen of vesicles exhibited efficient entrapment both for hydrophobic curcumin (CUR) and hydrophilic doxorubicin (DOX). The drug loading of vesicles was more than 20.2% and 38.4% for CUR and DOX, respectively. Decreasing pH to acidic condition or increasing temperature, more controllable and rapid release of two drugs was observed. Cytotoxicity assays revealed that dual drug-loaded vesicles retained high cell proliferation inhibition efficiency than free drugs.GRAPHICAL ABSTRACT 相似文献
56.
在概述隧道结巨磁电阻效应及其机理的基础上,综合介绍了多层薄膜结构、微颗粒膜结构和近年来出现的基于多晶隧道结结构的巨磁电阻效应及其相关材料的研究最新进展。重点讨论了涉及隧道结磁电阻材料类型、化学组成、结构与性能、制备技术以及潜在的应用前景,对制备工艺简单、成本低并可能带来突破性发展的多晶隧道结巨磁电阻材料作了展望。 相似文献
57.
Noga Gal Dr. Sofiya Kolusheva Dr. Noemi Kedei Dr. Andrea Telek Taiyabah A. Naeem Nancy E. Lewin Langston Lim Poonam Mannan Susan H. Garfield Dr. Saïd El Kazzouli Dr. Dina M. Sigano Dr. Victor E. Marquez Dr. Peter M. Blumberg Prof. Raz Jelinek 《Chembiochem : a European journal of chemical biology》2011,12(15):2331-2340
N‐methyl‐substituted diacylglycerol–indololactones (DAG–indololactones) are newly synthesized effectors of protein kinase C (PKC) isoforms and exhibit substantial selectivity between RasGRP3 and PKCα. We present a comprehensive analysis of membrane interactions and biological activities of several DAG–indololactones. Translocation and binding activity assays underline significant variations between the PKC translocation characteristics affected by the ligands as compared to their binding activities. In parallel, the fluorescent properties of the ligands were employed for analysis of their membrane association profiles. Specifically, we found that a slight change in the linkage to the indole ring resulted in significant differences in membrane binding and association of the DAG–indololactones with lipid bilayers. Our analysis shows that seemingly small structural modifications of the hydrophobic regions of these biomimetic PKC effectors contribute to pronounced modulation of membrane interactions of the ligands. 相似文献
58.
研究了经不同低频脉冲电流密度退火的Co66.3Fe3.7Si12B18非晶薄带的巨磁阻抗(GMI)效应。结果表明,在低频脉冲电流下,巨磁阻抗效应的大小与退火电流密度密切相关。非晶带的GMI变化率△Z/Z先随退火电流密度的增加而增强,当电流密度为104A/mm^2时,△Z/Z达到最大值53.8%,此后随电流密度增大,GMI变化率开始减小。对脉冲电流退火影响巨磁阻抗效应的机制作了定性分析。并分析了由脉冲电流退火在材料内感生的横向各向异性场凤对GMI效应的影响,发现HK有利于提高GMI效应的峰值,但同时存在一个临界值,当超过这个值时,GMI效应的峰值减弱。 相似文献
59.
通过微观分析研究添加B对LaFe_(11.5)Si_(1.5)快淬带中α-Fe杂相的影响,并探讨LaFe_(11.5)Si_(1.5)B_x (x=0.5,0.7,1.0)化合物的磁相变和磁热效应.与LaFe_(11.5)Si_(1.5)比较, 加入B后快淬薄带的显微组织显著细化, 在较高B含量的快淬薄带中还得到了非晶态结构.经1000 ℃回火2~10 h后,快淬试样均结晶为立方NaZn_(13)型的La(Fe,Si)_(13)化合物结构.含B快淬薄带经过较短时间的热处理就能得到单相结构,而且残留的α-Fe含量显著降低.磁性能测试表明,随着B含量的增大,LaFe_(11.5)Si_(1.5)B_x (x=0.5,0.7,1.0)化合物的居里温度略有升高;当B含量较低时,化合物具有一级磁相变特征并表现出与LaFe_(11.5)Si_(1.5)化合物相同的巨大磁热效应. 相似文献
60.
综述了阴/阳离子表面活性剂混合溶液在浓度比较高时出现的双水相和囊泡现象,并对这种双水相形成条件和囊泡的稳定性进行了比较详细的讨论。阴/阳离子表面活性剂混合溶液中的双水相现象只能在两个非常狭窄的区域形成,可能由不同浓度的胶束溶液、胶束溶液与液晶相或囊泡等组成。在一定的条件下,比较稳定的囊泡可以自发或经过超声处理形成。 相似文献