MAP4K4 deficiency in CD4+ T cells aggravates lung damage induced by ozone-oxidized black carbon particles

As the main composition of combustion, black carbon (BC) is becoming more and more noticeable at home and abroad. Ozone-oxidized black carbon (oBC) was produced through aging of ozone, one of the near-surface pollutants, to black carbon. And oBC was found to be more oxidation and cell toxicity when compared with BC. Besides, as a key cell of immunity, whether CD4⁺ T cell would involve in lung inflammation induced by particular matter is still unclear. This study aims to observe the effect of oBC on lung damage in mice and discuss how the functional MAP4K4 defect CD4⁺ T cells (conditional knockout of MAP4K4) presents its role in this process.In our study, MAP4K4 deletion in CD4⁺ T cells (MAP4K4 cKO) could increase cell number of macrophages, lymphocytes and neutrophils in bronchoalveolar lavage fluid (BALF) exposed to oBC. MAP4K4 deletion in CD4⁺ T cell also affected CD4⁺ T cell differentiation in mediastinal lymph nodes after oBC stimulation. The number of CD4⁺ IL17⁺ T cell increased obviously. The levels of IL-6 mRNA of lung in MAP4K4 cKO mice was higher than that in wild type mice after exposed to oBC, while the level of IL-6 in BALF had the same trend. Histological examination showed that MAP4K4 deletion in CD4⁺ T cells affected lung inflammation induced by oBC. Results indicated that MAP4K4 cKO in CD4⁺ T cells upgraded the level of inflammation in lung when exposed to oBC, which may be connected to the CD4⁺ T cell differentiation and JNK, ERK and P38 pathways.     

水中邻苯二甲酸酯吸附材料的研究进展

邻苯二甲酸酯(PAEs)被广泛应用于食品包装、玩具和医疗产品,以改善其塑性和弹性。PAEs易于向水体中迁移,并因其具有内分泌干扰特性而成为目前最受公众关注的污染物之一。笔者总结了目前吸附法处理PAEs的最新研究和发展趋势,重点综述了各类吸附材料如活性炭、壳聚糖、人工合成树脂、粘土矿物材料对PAEs的吸附效能和机制,并在此基础上对吸附法处理PAEs的发展方向进行展望。     

人工心瓣用热解炭断裂韧性研究及断口形貌分析

人工心瓣中常用材料主要是包覆在石墨基体上的热解炭。为研究人工心瓣用热解炭材料断裂韧性,采用MTS电动力学测试系统,对石墨、纯热解炭及不同厚度热解炭包覆石墨复合材料4种DC(T)圆盘样品进行紧凑拉伸实验,利用实验所得数据绘制载荷-位移(P-V)曲线,根据ASTM标准E399规定的方法确定临界载荷值以及计算断裂韧性值,并对样品断口形貌进行显微观察。结果表明:两种热解炭包覆石墨复合材料断裂韧性值大于纯热解炭以及石墨的相应值,石墨断裂韧性值大于纯热解炭断裂韧性值;在热解炭包覆石墨复合材料中,涂层与基体厚度比值大的对应断裂韧性值反而小;显微观察热解炭断口较为平整,石墨断口较为粗糙,且热解炭及石墨在裂纹扩展区以及过载断裂区的断口形貌基本上是一致的。     

Electroactive High‐Temperature Shape Memory Polymers with High Recovery Stress Induced by Ground Carbon Fibers

Electroactive shape memory polymers (SMPs) are suitable for remote controllable actuators or applications where direct heat is inconvenient, and herein an electroactive shape memory polyimide (EASMPI) is reported for the first time. EASMPI is synthesized by incorporating ground carbon fibers (GCFs) into a polyimide matrix to form a compact conductive network, and percolation threshold of 0.312 S m^?1 meets the demands of both electroactive and shape memory effects. The glass transition temperature of 302 °C for EASMPI is much higher than that of other electroactive SMPs, and its shape recovery is activated effectively by a voltage of 15.87 V. Recovery stress is crucial for shape memory materials to output work, and EASMPI produces high recovery stress of 40.1 MPa. The possible mechanisms are discussed, and GCF mainly accounts for its electroactivity and recovery stress. EASMPI shows vast potential in practical applications with its electroactive shape memory effect and high recovery stress at high temperature.     

Improving the Acid and Base Resistance of Polyurethane Using Carbon Nanotubes

This paper demonstrates that carbon nanotubes (CNTs) can be used as an effective filler for inhibiting the hydrolysis of polyurethane (PU) under acidic and basic conditions. Although it has been reported that CNTs can quench the radicals on its surface, for the first time, it is confirmed that CNTs undergo reactions that have an inhibiting effect on ion‐mediated hydrolysis. Attenuated total reflectance–infrared spectroscopy measurements on PU and PU–CNT samples reveal that CNTs inhibit the hydrolysis of PU in both acid and alkaline environments. Via quantum chemical calculations, it is shown that CNTs can trap H⁺ ions and OH^? ions on their surface. It is also shown that CNTs can trap multiple ions, even though electrical repulsion is to be expected. The results reveal that CNTs can also function as a hydrolysis inhibitor in addition to their known functions as an antioxidant.     

三维多孔电磁复合支架构建与理化表征

模拟心肌细胞外基质(ECM)的组织结构和电生理特性,构建具有导电性和超顺磁响应性的三维多孔纳米纤维复合材料支架,为细胞黏附、增殖和分化提供有利的微环境。以明胶为壳层、聚乳酸为芯层,并在各层中引入四氧化三铁纳米颗粒,采用共轴静电纺丝技术,制备纳米纤维薄膜;将其粉碎并与碳纤维混合,经冷冻干燥和交联处理,得到三维多孔支架。用扫描电镜和透射电镜观察支架形貌及结构,用四探针仪测定支架的电导率,用振动样品磁强计测量支架磁滞回线,用万能材料试验机检测支架材料的压缩应力-应变曲线;根据质量和体积计算支架密度,根据支架吸水前后质量计算吸水率。用CCK-8和Western Blot,分析细胞在支架上的活性及功能。支架内部呈多孔蜂窝结构,孔隙间相互贯通;当碳纤维含量为0、1、3、5 mg/mL时,支架密度分别为73.07、72.56、65.88、63.34 mg/cm³,吸水率分别为1 164.60%、1 186.48%、1 284.84%、1 323.66%;电导率分别为0、0.008 8、0.246 7、2.662 5 s/m,最大磁饱和强度分别为3.68、3.15、2.45、2.90 emu/g,抗压缩能力也相应提高。上述复合材料支架能够显著促进心肌细胞成熟相关蛋白Cx43和RhoA的表达,诱导心肌细胞向成熟分化。三维多孔电磁复合支架同时具有超顺磁性和导电性,微观上具有纳米纤维网络和多孔结构,并通过碳纤维的复合,使力学性能得到显著提高,支持心肌细胞生长并促进其成熟。     

Hazardous Petroleum Sludge-Derived Nitrogen and Oxygen Co-Doped Carbon Material with Hierarchical Porous Structure for High-Performance All-Solid-State Supercapacitors

Rational design and sustainable preparation of high-performance carbonaceous electrode materials are important to the practical application of supercapacitors. In this work, a cost-effective synthesis strategy for nitrogen and oxygen co-doped porous carbon (NOC) from petroleum sludge waste was developed. The hierarchical porous structure and ultra-high surface area (2514.7 m² g⁻¹) of NOC electrode materials could provide an efficient transport path and capacitance active site for electrolyte ions. The uniform co-doping of N and O heteroatoms brought enhanced wettability, electrical conductivity and probably additional pseudo-capacitance. The as-obtained NOC electrodes exhibited a high specific capacitance (441.2 F g⁻¹ at 0.5 A g⁻¹), outstanding rate capability, and cycling performance with inconspicuous capacitance loss after 10,000 cycles. Further, the assembled all-solid-state MnO₂/NOC asymmetrical supercapacitor device (ASC) could deliver an excellent capacitance of 119.3 F g⁻¹ at 0.2 A g⁻¹ under a wide potential operation window of 0–1.8 V with flexible mechanical stability. This ASC device yielded a superior energy density of 53.7 W h kg⁻¹ at a power density of 180 W kg⁻¹ and a reasonable cycling life. Overall, this sustainable, low-cost and waste-derived porous carbon electrode material might be widely used in the field of energy storage, now and into the foreseeable future.