Pyrolysis of giant mullein (Verbascum thapsus L.) in a fixed-bed reactor: Effects of pyrolysis parameters on product yields and character

Slow pyrolysis of giant mullein (Verbascum thapsus L.) stalks have been carried out in a fixed-bed tubular reactor with (Al₂O₃, ZnO) and without catalyst at four different temperatures between 400 to 550°C with a constant heating rate of 50°C/min and with a constant sweeping gas (N₂) flow rate of 100 cm³/min. The amounts of bio-char, bio-oil, and gas produced were calculated and the compositions of the obtained bio-oils were determined by gas chromatography-mass spectrometry. The effects of pyrolysis parameters, such as temperature and catalyst, on the product yields were investigated. The results show that both temperature and catalyst have significant effects on the conversion of Verbascum thapsus L. into solid, liquid, and gaseous products. The highest liquid yield of 40.43% by weight including the aqeous phase was obtained with 10% zinc oxide catalyst at 500°C temperature. Sixty-seven different products were identified by gas chromatography-mass spectrometry in the bio-oils obtained at 500°C temperature.     

面向微型机器人的无线供电系统变空间尺度问题综述

超磁致执行器(GMA)具有结构简单、位移大以及输出力强、机械强度高等优点,可作为微型机器人的动力装置,其核心元件超磁致伸缩材料可通过电磁场驱动,从而实现微型机器人远程无线供电。在实际应用中,随着微型机器人运动轨迹的变化,GMA与供电系统发射线圈的空间位置关系即空间尺度也实时变化,进而影响无线供电系统的传输特性,包括传输功率和传输效率。基于此,重点论述了无线供电系统在变空间尺度情况下的工作机理及现有问题的解决方案,为实现微型机器人高效稳定供电提供参考和借鉴。     

Advances and Perspectives in Dental Pulp Stem Cell Based Neuroregeneration Therapies

Human dental pulp stem cells (hDPSCs) are some of the most promising stem cell types for regenerative therapies given their ability to grow in the absence of serum and their realistic possibility to be used in autologous grafts. In this review, we describe the particular advantages of hDPSCs for neuroregenerative cell therapies. We thoroughly discuss the knowledge about their embryonic origin and characteristics of their postnatal niche, as well as the current status of cell culture protocols to maximize their multilineage differentiation potential, highlighting some common issues when assessing neuronal differentiation fates of hDPSCs. We also review the recent progress on neuroprotective and immunomodulatory capacity of hDPSCs and their secreted extracellular vesicles, as well as their combination with scaffold materials to improve their functional integration on the injured central nervous system (CNS) and peripheral nervous system (PNS). Finally, we offer some perspectives on the current and possible future applications of hDPSCs in neuroregenerative cell therapies.     

Stabilization of heavy metals in biochar pyrolyzed from phytoremediated giant reed (Arundo donax) biomass

The pyrolysis of phytoremediated giant reed (Arundo donax) biomass could cause secondary pollution of heavy metals. The stabilization of heavy metals in the pyrolysis process with external materials such as Al₂O₃, CaCO₃, FeCl₃ and NaOH, was studied. The results showed that 37% As and 97% Cd in biochar were stabilized when giant reed powder was pyrolyzed at 250 °C with 5% Al₂O₃ for 2 h. Furthermore, 59% Pb in biochar was stabilized at 400 °C with 5% CaCO₃ for 1 h. Under biochar produced in optimized pyrolysis conditions, Cd mainly existed in a residual fraction, while Pb and As mainly existed in oxidizable fraction in BCR analysis. In XRD analysis, As was only found in Ca₂As₂O₇; Cd in biochar mainly existed in Cd (AlCl₄)₂, CdPbO₃ or CdSO₃; and Pb mainly existed as Pb₃O₂SO₄.     

The Role of Extracellular Vesicles in the Progression of Human Neuroblastoma

The long-underestimated role of extracellular vesicles in cancer is now reconsidered worldwide by basic and clinical scientists, who recently highlighted novel and crucial activities of these moieties. Extracellular vesicles are now considered as king transporters of specific cargoes, including molecular components of parent cells, thus mediating a wide variety of cellular activities both in normal and neoplastic tissues. Here, we discuss the multifunctional activities and underlying mechanisms of extracellular vesicles in neuroblastoma, the most frequent common extra-cranial tumor in childhood. The ability of extracellular vesicles to cross-talk with different cells in the tumor microenvironment and to modulate an anti-tumor immune response, tumorigenesis, tumor growth, metastasis and drug resistance will be pinpointed in detail. The results obtained on the role of extracellular vesicles may represent a panel of suggestions potentially useful in practice, due to their involvement in the response to chemotherapy, and, moreover, their ability to predict resistance to standard therapies—all issues of clinical relevance.     

Gb3 Glycosphingolipids with Fluorescent Oligoene Fatty Acids: Synthesis and Phase Behavior in Model Membranes

Glycosphingolipids are involved in a number of physiological and pathophysiological processes, and they serve as receptors for a variety of bacterial toxins and viruses. To investigate their function in lipid membranes, fluorescently labeled glycosphingolipids are highly desirable. Herein, a synthetic route to access Gb₃ glycosphingolipids with fluorescently labeled fatty acids, consisting of pentaene and hexaene moieties either at the terminus or in the middle of the acyl chain, has been developed. The fluorescent properties of the Gb₃ derivatives were investigated in small unilamellar vesicles composed of a raft-like mixture. Phase-separated giant unilamellar vesicles (GUVs) allowed the quantification of the apparent partitioning coefficients of the Gb₃ compounds by means of confocal fluorescence laser scanning microscopy. The determined partition coefficients demonstrate that the Gb₃ derivatives are preferentially localized in the liquid-disordered (l_d) phase. To analyze whether the compounds behave like their physiological counterparts, Cy3-labeled (Cy: cyanine) Shiga toxin B subunits (STxB) were specifically bound to Gb₃-doped GUVs. However, the protein was favorably localized in the l_d phase, in contrast to results reported for STxB bound to naturally occurring Gb₃, which is discussed in terms of the packing density of the lipids in the liquid-ordered (l_o) phase.     

超磁致伸缩材料在骨传导听觉装置上的应用

超磁致伸缩材料(简称GMM)是制作低频换能器的理想功能材料。介绍了GMM的磁致伸缩机理及其本身特性;与传统磁致伸缩材料以及当前广泛应用在骨传导听觉装置上的电磁和压电材料进行了分析比较;综述了GMM在骨传导听觉装置上的应用现状;重点介绍了骨传导发音振子的设计构想,并且对超磁致伸缩式骨传导听觉装置在军事通信上的应用进行了展望。     

巨柱框架-核心筒-伸臂桁架结构体系施工过程的动态模拟

考虑高强混凝土的收缩、徐变对竖向变形及结构应力的影响,运用有限元软件,结合武汉中心工程实例,对巨柱框架-核心筒-伸臂桁架结构体系施工过程进行力学模拟和受力性态分析。计算结果表明:在重力与施工荷载作用下,楼层的标高位置与设计位置存在变形差异,最大变形差异发生在塔楼中间部分;核心筒超前施工对塔楼的竖向变形存在一定的影响,但对整体变形影响较小,可以在施工过程中通过找平进行调整。     

基于GMM的气动伺服阀和蠕动机械的实验研究

阐述了利用国产超磁致伸缩材料（GMM）研制的新型气动伺服阀和蠕动机械的结构及工作原理,并对它们进行了实验研究,实验结果表明：GMM气动了阀具有较宽的压力控制特性、良好的线性度和较快的响应速度;GMM蠕动机械结构简单,能可靠地实现双向控运动。     

叠堆式超磁致伸缩致动器的模型预测滑模控制

根据新型电液伺服阀的驱动要求,设计了叠堆式超磁致伸缩致动器(SGMA),为补偿其固有的非线性,提高位移输出精度,研究了SGMA的控制策略,并对控制策略进行了仿真和实验验证。首先,采用永磁体和GMM棒交替排布的结构形式设计了SGMA,有助于提高偏置磁场的均匀性;然后,根据SGMA的结构特点,将其视为多自由度振动系统,建立了系统的位移输出模型;接着,在输出模型的基础上,结合模型预测控制与滑模控制策略,设计了模型预测滑模控制器;最后,进行了控制策略仿真和实验验证。实验结果表明,模型预测滑模控制器能够实现SGMA的精密控制。在阶跃控制实验中,系统稳定时间低于1.5ms,无超调和稳态误差;在正弦控制实验中,系统最大控制误差约为0.83μm,相对值约为6.9%,证明了控制策略的有效性。