Effect of conductive filler on the impedance behaviors of activated carbon based electric double layer capacitors

Carbon aerogel, carbon black and graphite were used to analyze the influence of conductive filler on the impedance behaviors of activated carbon based electric double layer capacitors (EDLCs). According to the electrochemical impedance spectrum (EIS) data, a new equivalent circuit model was proposed involving the kinetic characteristics of ion diffusion, furthermore, Marquardt fit procedure was applied to the EIS data to obtain the model parameter values. The results indicated that carbon aerogel could significantly decrease the resistance of EDLCs by increasing the diffusion coefficient of ions within electrodes and decreasing the interface resistance because of its suitable particle size, mesoporous structures and finely-branched particle performance.     

房颤患者心房肌细胞凋亡水平的变化

目的:研究心房颤动(房颤)患者心房肌细胞凋亡指数的变化,探讨房颤与心房肌细胞重构的关系。方法:38例风湿性心脏病二尖瓣狭窄换瓣术者,其中窦性心律者13例(A组)、阵发性房颤及房颤持续时间<6个月者8例(B组)、房颤持续时间>6个月者17例(C组)。外科手术时取3组病人右心耳组织少许,利用TUNEL法观察心房肌细胞凋亡指数。结果:房颤患者(B、C组)心房肌细胞凋亡指数比窦性心律者(A组)显著增高,分别为44.53%±11.08%,67.96%±16.09%对19.68%±15.36%,P均<0.05;凋亡指数与房颤持续时间成正相关。结论:心房肌细胞重构可能在房颤的发生或维持中起重要作用,是慢性房颤转复为窦性心律后心房收缩功能延迟恢复的主要原因。     

The influence of torsion on disc herniation when combined with flexion

The role of torsion in the mechanical derangement of intervertebral discs remains largely undefined. The current study sought to investigate if torsion, when applied in combination with flexion, affects the internal failure mechanics of the disc wall when exposed to high nuclear pressure. Thirty ovine lumbar motion segments were each positioned in 2° axial rotation plus 7° flexion. Whilst maintained in this posture, the nucleus of each segment was gradually injected with a viscous radio-opaque gel, via an injection screw placed longitudinally within the inferior vertebra, until failure occurred. Segments were then inspected using micro-CT and optical microscopy in tandem. Five motion segments failed to pressurize correctly. Of the remaining 25 successfully tested motion segments, 17 suffered vertebral endplate rupture and 8 suffered disc failure. Disc failure occurred in mature motion segments significantly more often than immature segments. The most common mode of disc failure was a central posterior radial tear involving a systematic annulus–endplate–annulus failure pattern. The endplate portion of these radial tears often propagated contralateral to the direction of applied axial rotation, and, at the lateral margin, only those fibres inclined in the direction of the applied torque were affected. Apart from the 2° of applied axial rotation, the methods employed in this study replicated those used in a previously published study. Consequently, the different outcome obtained in this study can be directly attributed to the applied axial rotation. These inter-study differences show that when combined with flexion, torsion markedly reduces the nuclear pressure required to form clinically relevant radial tears that involve cartilaginous endplate failure. Conversely, torsion appears to increase the disc wall’s resistance to radial tears that do not involve cartilaginous endplate failure, effectively halving the disc wall’s overall risk of rupture.     

Production, microstructural characterization and mechanical properties of as-cast Ti-10Mo-xNb alloys

Abstract:  Beta titanium (Ti) alloys are one of the most promising groups of Ti alloys for biomedical applications. This work presents the production, microstructural characterization, and mechanical properties of as-cast Ti-10Mo-xNb (x = 0, 3, 6, 9, 20, and 30) alloys. They were produced via arc melting and characterized by scanning electron microscopy and X-ray diffraction. The density of each alloy was measured by the Archimedes method and the mechanical characterization was carried out by using the Vickers microhardness test and Young's modulus measurements. The results show a near β microstructure for niobium (Nb) contents lower or equal to 9 wt% while β single-phase microstructure was obtained for higher Nb additions. The microhardness values decreased with the increase of Nb content in the alloys. The elastic modulus values of Ti-10Mo-3Nb and Ti-10Mo-20Nb alloys were lower than those of cp Ti and Ti-6Al-4V.     

Threonine-imbalanced diet alters first-meal microstructure in rats

Diets limiting in an essential amino acid have long been known to suppress food intake. The purpose of this study was to examine the microstructure of feeding behavior of rats within the very first meal of an imbalanced diet. Rats were preconditioned for 12 days on a Baseline diet and were then given a test diet with either a corrected amino acid profile or a diet imbalanced with respect to the essential amino acid threonine. Overall, first-meal intake and first-meal duration were robustly and significantly reduced by the Imbalanced diet but not altered by the Corrected diet. The Corrected diet caused an increase in the number of feeding bouts during the first meal. The Imbalanced diet increased the duration of pauses during the first meal. Most rats in the Imbalanced group stopped eating after just 15 min of exposure to the diet, but those still eating after this time tended to have a lower rate of eating compared to those eating the Corrected diet. On the basis of these results, we conclude that changes in microstructure and meal duration contribute to the reduction in food intake upon exposure to amino-acid-deficient diets.     

多载荷下带有生理限定应力的松质骨细观结构模拟

松质是骨的重要组成部分，属多胞体结构，由于构成松质骨的小梁骨尺寸较小，形状多变，因此给松质骨的研究增加了困难。本文把负反馈调节的生理特征引入骨再造模拟中，提出带有生理限定应力的骨再造自适应模型。模型具有骨再造局部适应的正反馈调节与整体控制的负反馈调节的生理调整过程，使骨结构内的应力控制在生理限定应力以下，维持骨力学环境的稳定。使用此模型在几种不同的力学环境下模拟了松质骨结构，定量地预测了松质骨细观结构与其力学环境的对应关系，同时表明了松质骨细观结构与力学环境的适应性。模拟结果与真实松质骨细观结构的典型部分相一致。     

维药骆驼刺种子微形态特征的研究

应用光学显微镜和扫描电镜，结合野外调查结果，对维吾尔族习用药骆驼刺的种子微形态特征进行了对比分析，结果表明：不同地方居群的骆驼刺在种子微形态特征方面存在着极大的相似性，种子形状均为肾形，表面纹饰基本为条纹状，各居群间在条纹的粗细、长短和曲折程度方面存在一定差异，这些特征反映了骆驼刺种子徽形态特征的稳定性和生态因素的影响及居群变异的普遍性。     

Preparation of Dashanzha Wan by three-dimensional printingOA

Objective: To use three-dimensional(3D) printing technology to prepare Dashanzha Wan.Methods: The standard formula proportion of Dashanzha Wan was used to prepare printable materials(normally called the ink) for 3D printing, and different doses and shapes of Dashanzha Wan were prepared. Then, the rheological properties, texture characteristics, scanning electron microscopy, and content of ursolic acid were evaluated.Results: Dashanzha Wan ink showed good shear thinning properties, which is very ...     

GnRHa主动免疫对幼鼠子宫发育的作用

目的探讨促性腺激素释放激素激动剂(GnRHa)主动免疫对幼鼠子宫发育的作用。方法 60只昆明雌鼠随机均分为四组,分别颈部皮下注射不同剂量阿拉瑞林抗原,各组均连续注射7 d。在0 d、7 d、14 d和21 d测定体重,于21 d处理小鼠,显微镜观察子宫的组织结构变化,并用Motic imagles软件测定分析图像数据。结果阿拉瑞林能明显抑制子宫的发育,且剂量越大作用越明显。EG-Ⅲ的UWT明显缩小(P<0.05);实验组EET均小于对照组(P<0.05)。EG-Ⅰ子宫腔轻度缩小;EG-Ⅱ子宫腔和腺体管腔缩小,子宫管壁明显变薄;内膜皱襞减少,上皮变薄;EG-Ⅲ子宫壁变薄,子宫腺减少,内膜细胞胞核变小,上皮变薄,胞质明显减少。结论阿拉瑞林主动免疫能显著抑制幼鼠的子宫发育,且连续重复免疫对小鼠具有毒性作用,剂量越大,作用越明显。     

食物蛋白质对幼鼠脑核酸、蛋白质含量和超微结构的影响

本文研究了不同来源食物蛋白质对出生５及２６日龄Ｗｉｓｔａｒ大鼠脑中ＤＮＡ、ＲＮＡ和蛋白质含量及脑超微结构的影响。结果表明：全蛋、鱼肉及补充蛋氨酸和牛磺酸后的大豆组３者间，脑ＤＮＡ、ＲＮＡ和蛋白质含量无显著性差异（Ｐ＞０．０５），全谷组则均显著低于其它各组（Ｐ＜０．０５）。相关分析表明，食物蛋白质氨基酸评分与脑ＤＮＡ含量呈正相关（Ｐ＜０．０５）。透射电镜下观察到全谷组大脑皮质及海马区有神经元固缩，核锯齿样变，线粒体肿胀、嵴断裂，粗面内质网扩张、核蛋白体颗粒脱落，神经毡区水肿等异常改变；而补充后的大豆组和全蛋组则结构正常。提示：在大鼠脑发育的快速增长期，脑细胞数及与蛋白质合成密切相关的膜性细胞器最易受到蛋白质营养不良的影响。