Myogenic Potential of Extracellular Matrix Derived from Decellularized Bovine Pericardium

Skeletal muscles represent 40% of body mass and its native regenerative capacity can be permanently lost after a traumatic injury, congenital diseases, or tumor ablation. The absence of physiological regeneration can hinder muscle repair preventing normal muscle tissue functions. To date, tissue engineering (TE) represents one promising option for treating muscle injuries and wasting. In particular, hydrogels derived from the decellularized extracellular matrix (dECM) are widely investigated in tissue engineering applications thanks to their essential role in guiding muscle regeneration. In this work, the myogenic potential of dECM substrate, obtained from decellularized bovine pericardium (Tissuegraft Srl), was evaluated in vitro using C2C12 murine muscle cells. To assess myotubes formation, the width, length, and fusion indexes were measured during the differentiation time course. Additionally, the ability of dECM to support myogenesis was assessed by measuring the expression of specific myogenic markers: α-smooth muscle actin (α-sma), myogenin, and myosin heavy chain (MHC). The results obtained suggest that the dECM niche was able to support and enhance the myogenic potential of C2C12 cells in comparison of those grown on a plastic standard surface. Thus, the use of extracellular matrix proteins, as biomaterial supports, could represent a promising therapeutic strategy for skeletal muscle tissue engineering.     

跨文化城市规划与设计:国际工作坊的本土反应(英文)

经过多次城市规划与设计的工作坊,现在我们有必要来总结下这些经验。工作坊已经深得同学们的喜爱,并因为其有利于激发学生的思维亮点,学校也乐于相对正式化地开展。当然,这里面也包括了利弊两方面,特别是中国快速发展背景下基于国际工作坊的风暴式新理念与相对稳定的专业培养需求在教育价值方面的权衡。本文综述了华南理工大学建筑学院和费拉拉大学合作的一些重要经验。首先是选择具有挑战性的城市个案,然后使用多语言共享关于问题的争议性辩论,最终培训出具有责任感的规划师。     

The Effect of Ferula communis Extract in Escherichia coli Lipopolysaccharide-Induced Neuroinflammation in Cultured Neurons and Oligodendrocytes

In recent decades, interest in natural compounds has increased exponentially due to their numerous beneficial properties in the treatment of various acute and chronic diseases. A group of plant derivatives with great scientific interest is terpenic compounds. Among the plants richest in terpenes, the genus Ferula L. is one of the most representative, and ferutinin, the most common sesquiterpene, is extracted from the leaves, rhizome, and roots of this plant. As reported in the scientific literature, ferutinin possesses antioxidant and anti-inflammatory properties, as well as valuable estrogenic properties. Neurodegenerative and demyelinating diseases are devastating conditions for which a definite cure has not yet been established. The mechanisms involved in these diseases are still poorly understood, and oxidative stress is considered to be both a key modulator and a common denominator. In the proposed experimental system, co-cultured human neurons (SH-SY5Y) and human oligodendrocytes (MO3.13) were treated with the pro-inflammatory agent lipopolysaccharide at a concentration of 1 μg/mL for 24 h or pretreated with ferutinin (33 nM) for 24 h and subsequently exposed to lipopolysaccharide 1 μg/mL for 24 h. Further studies would, however, be needed to establish whether this natural compound can be used as a support strategy in pathologies characterized by progressive inflammation and oxidative stress phenomena.     

Absorption correction of two-color laser-induced incandescence signals for soot volume fraction measurements

A numerical iterative procedure is presented for the evaluation of the effect of signal absorption in two-color laser-induced incandescence measurements. The correction process is applied to our experimental data in an axisymmetric flame [Appl. Opt. 44, 7414 (2005)]. The influence of signal trapping on peak soot temperature and on soot volume fraction has been found to be minimal. Some numerical tests were performed to investigate the effects of soot concentration, flame size, and soot refractive index on the magnitude of the signal absorption correction.     

Thermal storage effects on AlGaN/GaN HEMT

The effects of thermal storage on GaN–HEMT devices grown on SiC substrate have been investigated by DC and pulsed electrical measurements, breakdown measurements (by means of a Transmission Line Pulser, TLP), and optical and electron microscopy. After 3000 h of thermal storage testing at 300 °C, only a limited reduction of the DC drain saturation current and of the transconductance peak was observed (20% and 25% decrease, respectively). However, pulsed measurements on aged devices clearly highlight a dramatic current collapse effect that has been attributed to a creation of surface traps in the gate-to-drain and gate-to-source access region. On-state breakdown characterization carried out on aged devices did not highlight any noticeable changes with respect to the untreated devices similarly to the DC characterization. Failure analyses have demonstrated that a loss of adhesion of the passivation layer was responsible for the observed trap formation. An improved passivation deposition process was therefore developed, including a surface cleaning procedure aimed at preventing passivation detaching. The devices fabricated using this new procedure do not show any enhancement of trapping effects up to 500 h of thermal stress at 300 °C.     

Effects of sub-lethal concentrations of hexanal and 2-(E)-hexenal on membrane fatty acid composition and volatile compounds of Listeria monocytogenes, Staphylococcus aureus, Salmonella enteritidis and Escherichia coli

In recent years, the interest in the possible use of natural alternatives to food additives to prevent bacterial and fungal growth has notably increased. Plants and plant products can represent a source of natural alternatives to improve the shelf-life and the safety of food. Some of these compounds, i.e. hexanal, hexanol, 2-(E)-hexenal and 3-(Z)-hexenol, produced throughout the lipoxygenase pathway have important roles in plant defence with a protective action towards microbial proliferation in wounded areas. Otherwise, hexanal and 2-(E)-hexenal have evidenced a marked antimicrobial activity against food spoilage and pathogenic microbial species both in model and real systems. The precise mechanisms of action of all these antimicrobial compounds are not yet clear. Because the usage of these compounds as antimicrobials in foods has to be supported by the comprehension of mechanisms of action of these compounds, the overall purpose of this work was to study the modifications of the cell membrane and volatile compounds of Listeria monocytogenes, Staphylococcus aureus, Salmonella enteritidis and Escherichia coli during the growth in the presence of sub-lethal doses of these two aldehydes. The results obtained evidenced that the tested molecules induced noticeable modifications of the composition of cell membrane and the volatile compounds produced during the growth. Although specific differences in relation to the species considered were identified, 2-(E)-hexenal and hexanal induced a marked increase of some membrane associated fatty acids, both linear and branched fatty acids as well as unsaturated fatty acids, and released free fatty acids.     

Thermal and mechanical behavior of thermoplastic composites reinforced with fibers enzymatically extracted from Ampelodesmos mauritanicus

This work investigates the morphology, the thermal, and mechanical properties of technical fibers extracted from the Ampelodesmos mauritanicus (Diss) grass using a process that combines mechanical, mild chemical, and enzymatic steps. The structure and the thermal stability of Diss fibers make them suitable as a reinforcing filler in polymer composites, which was assessed by manufacturing biocomposites with improved stiffness and a tensile strength not degraded by Diss fibers when compared to those of a commodity polymer and a biodegradable one, namely polypropylene and poly(lactic acid). This work confirms that enzyme mixtures obtained from commercially available products of relatively low cost can represent a simple and environmentally friendly means to extract less common natural fibers. POLYM. ENG. SCI., 59:2418–2428, 2019. © 2019 Society of Plastics Engineers     

Characterization of natural starter cultures used in the manufacture of Pasta Filata Cheese in Basilicata (Southern Italy)

Microbiological, chemical and technological analyses were used to characterize nine natural starter cultures used for the mnnufacture of Pasta Filata cheese in Basilicata (Southern Italy). The cultures were either dominated by thermophilic rods or mesophilic and/or thermophilic cocci. Principal component and cluster analysis discriminated between rods and coccus cultures and helped to estabilish relationships between the cultures and to evaluate the variability of cultures obtained from the same plant. A total of 156 isolates of lactic acid bacteria were obtained from the cultures and tentatively classified using biochemical and physiological tests and cluster analysis. Most of the lactobacilli were identified as Lactobacillus helveticus. Most cocci were classified in the genera Lactococcus or Enterococcus but identification at the species level was often impossible. The acid production and proteolyti activity of the isolates in skim milk were evaluated. Cluster analysis was used to group the isolates according to technological properties. Isolates belonging to some phenotypic clusters were consistently associated with some technological clusters.