Aging of Vascular System Is a Complex Process: The Cornerstone Mechanisms

Aging is one of the most intriguing processes of human ontogenesis. It is associated with the development of a wide variety of diseases affecting all organs and their systems. The victory over aging is the most desired goal of scientists; however, it is hardly achievable in the foreseeable future due to the complexity and ambiguity of the process itself. All body systems age, lose their performance, and structural disorders accumulate. The cardiovascular system is no exception. And it is cardiovascular diseases that occupy a leading position as a cause of death, especially among the elderly. The aging of the cardiovascular system is well described from a mechanical point of view. Moreover, it is known that at the cellular level, a huge number of mechanisms are involved in this process, from mitochondrial dysfunction to inflammation. It is on these mechanisms, as well as the potential for taking control of the aging of the cardiovascular system, that we focused on in this review.     

In Vitro and In Vivo Modeling of Normal and Leukemic Bone Marrow Niches: Cellular Senescence Contribution to Leukemia Induction and Progression

Cellular senescence is recognized as a dynamic process in which cells evolve and adapt in a context dependent manner; consequently, senescent cells can exert both beneficial and deleterious effects on their surroundings. Specifically, senescent mesenchymal stromal cells (MSC) in the bone marrow (BM) have been linked to the generation of a supporting microenvironment that enhances malignant cell survival. However, the study of MSC’s senescence role in leukemia development has been straitened not only by the availability of suitable models that faithfully reflect the structural complexity and biological diversity of the events triggered in the BM, but also by the lack of a universal, standardized method to measure senescence. Despite these constraints, two- and three dimensional in vitro models have been continuously improved in terms of cell culture techniques, support materials and analysis methods; in addition, research on animal models tends to focus on the development of techniques that allow tracking leukemic and senescent cells in the living organism, as well as to modify the available mice strains to generate individuals that mimic human BM characteristics. Here, we present the main advances in leukemic niche modeling, discussing advantages and limitations of the different systems, focusing on the contribution of senescent MSC to leukemia progression.     

Effects of Dietary n-3 LCPUFA Supplementation on the Hippocampus of Aging Female Mice: Impact on Memory,Lipid Raft-Associated Glutamatergic Receptors and Neuroinflammation

Long-chain polyunsaturated fatty acids (LCPUFA), essential molecules whose precursors must be dietary supplied, are highly represented in the brain contributing to numerous neuronal processes. Recent findings have demonstrated that LCPUFA are represented in lipid raft microstructures, where they favor molecular interactions of signaling complexes underlying neuronal functionality. During aging, the brain lipid composition changes affecting the lipid rafts’ integrity and protein signaling, which may induce memory detriment. We investigated the effect of a n-3 LCPUFA-enriched diet on the cognitive function of 6- and 15-months-old female mice. Likewise, we explored the impact of dietary n-3 LCPUFAs on hippocampal lipid rafts, and their potential correlation with aging-induced neuroinflammation. Our results demonstrate that n-3 LCPUFA supplementation improves spatial and recognition memory and restores the expression of glutamate and estrogen receptors in the hippocampal lipid rafts of aged mice to similar profiles than young ones. Additionally, the n-3 LCPUFA-enriched diet stabilized the lipid composition of the old mice’s hippocampal lipid rafts to the levels of young ones and reduced the aged-induced neuroinflammatory markers. Hence, we propose that n-3 LCPUFA supplementation leads to beneficial cognitive performance by “rejuvenating” the lipid raft microenvironment that stabilizes the integrity and interactions of memory protein players embedded in these microdomains.     

天广直流输电系统过负荷功能研究

直流输电系统的快速响应和过负荷能力有利于提高整个电网的稳定性,基于天广直流输电系统的控制策略,介绍了其过负荷功能的计算和实现方法,并结合实例进行说明,最后还讨论了运行中应引起重视的相关问题。     

基于多子空间直和特征融合的人脸识别算法

多个子空间直和能保证多个子空间数据融合时多个子空间得到的特征向量相互两两正交,融合数据采用该特征表示时冗余最小,更有利于分类识别。本文基于多子空间直和进行特征融合,提出了一种新的人脸识别算法。通过 2DPCA算法,首先分别计算所有训练样本归一化后正脸、左侧脸及右侧脸图像的协方差矩阵的各P个最大特征值对应的P个相互正交的特征向量,然后通过选取3个子空间的部分满足直 和条件的特征向量组成各自的特征空间(投影空间),再将样本正脸、左侧脸及右侧脸图像分别向各自特征空间投影得到3个特征矩阵,最后将此3个特征矩阵融合为该样本的特征矩阵用于最近邻分类器进行分类识别。最终通过本文3组实验数据的对比说明了该 算法能减少计算量并且提高了识别率。     

Obesity and Bone Health: A Complex Relationship

Recent scientific evidence has shown an increased risk of fractures in patients with obesity, especially in those with a higher visceral adipose tissue content. This contradicts the old paradigm that obese patients were more protected than those with normal weight. Specifically, in older subjects in whom there is a redistribution of fat from subcutaneous adipose tissue to visceral adipose tissue and an infiltration of other tissues such as muscle with the consequent sarcopenia, obesity can accentuate the changes characteristic of this age group that predisposes to a greater risk of falls and fractures. Other factors that determine a greater risk in older subjects with obesity are chronic proinflammatory status, altered adipokine secretion, vitamin D deficiency, insulin resistance and reduced mobility. On the other hand, diagnostic tests may be influenced by obesity and its comorbidities as well as by body composition, and risk scales may underestimate the risk of fractures in these patients. Weight loss with physical activity programs and cessation of high-fat diets may reduce the risk. Finally, more research is needed on the efficacy of anti-osteoporotic treatments in obese patients.     

基于ST7单片机的太阳能直流供电系统控制器设计

设计一种用ST7单片机构成的全数字化太阳能直流供电系统控制器。系统在ST7单片机的控制下,能将太阳能电池转换的直流电进行有效存储和合理使用。系统充分利用了ST7单片机的软件资源,最大程度地简化了硬件电路,使电源具有较高的性价比和可靠性。     

Novel hybrid optimization algorithm using PSO and MADS for the trajectory estimation of a four track wheel skid-steered mobile robot

Several optimization algorithms, such as the particle swarm optimization (PSO), genetic algorithm (GA), and ant colony optimization, have previously been applied in order to reliably obtain more accurate trajectory estimation for mobile robot. However, these optimization algorithms can get easily trapped in local optima when solving a complex system, which has many local optima and many input variables. This paper proposes a novel hybrid optimization algorithm-based tuning of the extended Kalman filter, which involves the PSO and mesh adaptive direct search algorithms, prior to operation. As demonstrated by our experimental results, the advantages of the novel hybrid optimization algorithm resolve the limitations of other algorithms in the trajectory estimation of a four track wheel skid-steered mobile robot (4-TW SSMR).     

交直流并联输电系统的非线性鲁棒控制

针对含有常参数不确定性的交直流输电系统,使用自适应逆推方法设计了直流系统的非线性鲁棒控制器.基于该方法的设计,无需对原系统进行反馈线性化,并能保证闭环误差系统渐近稳定.设计过程表明逆推方法设计的控制器拥有更优越的性能.