Test Technology Newsletter

Journal of Electronic Testing -     

Application potential of bone marrow mesenchymal stem cell (BMSCs) based tissue-engineering for spinal cord defect repair in rat fetuses with spina bifida aperta

Spina bifida aperta are complex congenital malformations resulting from failure of fusion in the spinal neural tube during embryogenesis. Despite surgical repair of the defect, most patients who survive with spina bifida aperta have a multiple system handicap due to neuron deficiency of the defective spinal cord. Tissue engineering has emerged as a novel treatment for replacement of lost tissue. This study evaluated the prenatal surgical approach of transplanting a chitosan–gelatin scaffold seeded with bone marrow mesenchymal stem cells (BMSCs) in the healing the defective spinal cord of rat fetuses with retinoic acid induced spina bifida aperta. Scaffold characterisation revealed the porous structure, organic and amorphous content. This biomaterial promoted the adhesion, spreading and in vitro viability of the BMSCs. After transplantation of the scaffold combined with BMSCs, the defective region of spinal cord in rat fetuses with spina bifida aperta at E20 decreased obviously under stereomicroscopy, and the skin defect almost closed in many fetuses. The transplanted BMSCs in chitosan–gelatin scaffold survived, grew and expressed markers of neural stem cells and neurons in the defective spinal cord. In addition, the biomaterial presented high biocompatibility and slow biodegradation in vivo. In conclusion, prenatal transplantation of the scaffold combined with BMSCs could treat spinal cord defect in fetuses with spina bifida aperta by the regeneration of neurons and repairmen of defective region.     

Delignification kinetics of empty fruit bunch (EFB): a sustainable and green pretreatment approach using malic acid-based solvents

Recently, the development of efficient and environmentally benign solvents has received great attention to replace current harsh organic solvents. In this context, low-transition-temperature mixtures (LTTMs) have emerged as favorable green solvents for biomass delignification. Palm oil biomass, empty fruit bunch (EFB) was pretreated with commercial l-malic acid and microwave hydrothermally extracted cactus malic acid-derived LTTMs at 60, 80, and 100 °C. The LTTMs applied in this study were derived from malic acid–choline chloride–water and malic acid–monosodium glutamate–water with a molar ratio of 2:4:2 and 3:1:5, respectively. Three first-order reactions were used to express the delignification kinetic model of EFB. The first term was based on the initial stage and assigned as infinite due to the fast rate of delignification which could not be detected. The second and third terms were proportional to bulk and residual delignification stages. A good agreement was obtained between the kinetic model and the experimental data obtained in this study with R²?≥?0.91. The activation energies for the delignification reactions using l-malic acid and cactus malic acid-based LTTMs in the bulk and residual stages were approximated as 36–56 and 19–26 kJ/mol and 34–90 and 47–87 kJ/mol, respectively.     

Exploring and comparing the best “direct methods” forthe efficient training of MLP-networks

It is well known that the main difficulties of the algorithms based on backpropagation are the susceptibility to local minima and the slow adaptivity to the patterns during the training. In this paper, we present a class of algorithms, which overcome the above difficulties by utilizing some "direct" numerical methods for the computation of the matrices of weights. In particular, we investigate the performances of the FBFBK-LSB (least-squares backpropagation) algorithms and iterative conjugate gradient singular-value decomposition (ICGSVD), respectively, introduced by Barmann and Biegler-Konig (1993) and by the authors. Numerical results on several benchmark problems show a major reliability and/or efficiency of our algorithm ICGSVD.     

On the undecidability of the limit behavior of Cellular Automata

Cellular Automata (CA) are discrete dynamical systems and an abstract model of parallel computation. The limit set of a cellular automaton is its maximal topological attractor. A well-known result, due to Kari, says that all nontrivial properties of limit sets are undecidable. In this paper we consider the properties of limit set dynamics, i.e. properties of the dynamics of CA restricted to their limit sets. There can be no equivalent of Kari’s theorem for limit set dynamics. Anyway we show that there is a large class of undecidable properties of limit set dynamics, namely all properties of limit set dynamics which imply stability or the existence of a unique subshift attractor. As a consequence we have that it is undecidable whether the cellular automaton map restricted to the limit set is the identity map and whether it is closing, injective, expansive, positively expansive and transitive.     

基于改进傅里叶描绘子的CBIR系统

在现有的基于傅里叶描绘子的CBIR系统中,为了提高检索速度,一般需要舍去物体轮廓经傅里叶变换后的大部分高频分量.当物体轮廓在细节部分具有较高能量时,此方法不具备有效性.为尽可能保证检索准确率并兼顾检索速度,在原有傅里叶描绘子上进行扩展,避免直接舍去高频分量,引入Fisher判别分析法将描绘子映射到子空间进行降维,并保证...     

一种基于触发机制的轮转算法

在负载平衡技术中,必须使用合适的算法进行成员选择,以决定由哪个副本对象处理到来的客户请求。传统轮转负载平衡算法只能在某些特定条件下平衡负载。针对该缺点,结合普通轮转算法和加权算法的优点,提出一种基于触发机制的轮转算法。实验结果表明,该算法能感知后段资源。     

基于SCA的遗留系统移植研究与实现

针对传统遗留系统在面向服务计算移植过程中存在的重复性和多样性问题,提出一种基于服务组件框架（SCA）的遗留系统移植方案,将遗留系统移植到SCA组件系统中,通过python扩展生成器生成可以被该脚本调用的模块,在硬件平台上进行模拟,实验结果表明,该方案是可行的,能够避免因面向服务实现形式的差异而造成的重复移植。