University of Naples Federico II

About: University of Naples Federico II is a education organization based out in Naples, Campania, Italy. It is known for research contribution in the topics: Population & Cancer. The organization has 29291 authors who have published 68803 publications receiving 1920149 citations. The organization is also known as: Università degli Studi di Napoli Federico II & Naples University.

High level expression of the HMGI (Y) gene during embryonic development.

Abstract: The HMGI protein family includes three proteins, named HMG-I, HMG-Y and HMGI-C. The first two proteins are coded for by the same gene, HMGI (Y), through an alternative splicing mechanism. Their expression is elevated in neoplastic tissues and cells and this overexpression has a causal role in the process of cellular neoplastic transformation. We demonstrate that the HMGI (Y) gene is expressed at very low levels in normal adult tissues, whereas in embryonic tissues it is expressed at high levels comparable to those detected in neoplastic tissues. Specifically, a very high expression of the HMGI (Y) gene was detected in all embryonic tissues at 8.5 dpc. Then in the following days, even though the gene is expressed essentially in all tissues, an abundant gene expression was restricted to some tissues. These results indicate an important role of the HMGI (Y) gene in development.

Influence of chemical treatments on mechanical properties of hemp fiber reinforced composites

Abstract: Natural Fibers Reinforced Composites (NFRC) are finding much interest as a substitute for glass or carbon reinforced polymer composites, like for instance automobile interior linings (roof, rear wall, side panel lining), shipping pallets, construction products (i.e. composite roof tiles), furniture and household products (i.e. storage containers, window and picture frames as well as food service trays, toys and flower pots) as well as fan houses and blades. However, a notable disadvantage of lignocellulosic fibers as reinforcements is their polarity which makes it incompatible with hydrophobic thermoplastic matrix. This incompatibility results in poor interfacial bonding between the fibers and the matrix. This in turn leads to impaired mechanical properties of the composites. This defect can be remedied by chemical modification of fibers so as to make it less hydrophilic. In this paper experiments have been performed to further the development of natural fiber reinforced composites. Untreated and treated surfaces of hemp fibers were characterized using Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM). Fiber-matrix adhesion was promoted by fiber surface modifications using an alkaline treatment and (3-Glycidyloxypropyl) trimethoxysilane coupling agent. The mechanical behaviour of epoxy matrix composite reinforced with woven hemp was studied and mechanical test results show that silane treatment of hemp fibers improves, both tensile and flexural properties of the composites, although no high values are obtained.

The single, ancient origin of chromist plastids.

Abstract: Algae include a diverse array of photosynthetic eukaryotes excluding land plants Explaining the origin of algal plastids continues to be a major challenge in evolutionary biology Current knowledge suggests that plastid primary endosymbiosis, in which a single-celled protist engulfs and “enslaves” a cyanobacterium, likely occurred once and resulted in the primordial alga This eukaryote then gave rise through vertical evolution to the red, green, and glaucophyte algae However, some modern algal lineages have a more complicated evolutionary history involving a secondary endosymbiotic event, in which a protist engulfed an existing eukaryotic alga (rather than a cyanobacterium), which was then reduced to a secondary plastid Secondary endosymbiosis explains the majority of algal biodiversity, yet the number and timing of these events is unresolved Here we analyzed a five-gene plastid data set to show that a taxonomically diverse group of chlorophyll c2-containing protists comprising cryptophyte, haptophyte, and stramenopiles algae (Chromista) share a common plastid that most likely arose from a single, ancient (≈1,260 million years ago) secondary endosymbiosis involving a red alga This finding is consistent with Chromista monophyly and implicates secondary endosymbiosis as an important force in generating eukaryotic biodiversity

Hydrogen Sulfide Is an Endogenous Inhibitor of Phosphodiesterase Activity

Abstract: Objective— Recent studies have demonstrated that hydrogen sulfide (H 2 S) is produced within the vessel wall from l-cysteine regulating several aspects of vascular homeostasis. H 2 S generated from cystathione γ-lyase (CSE) contributes to vascular tone; however, the molecular mechanisms underlying the vasorelaxing effects of H 2 S are still under investigation. Methods and Results— Using isolated aortic rings, we observed that addition of l-cysteine led to a concentration-dependent relaxation that was prevented by the CSE inhibitors dl-propargylglyicine (PAG) and β-cyano-l-alanine (BCA). Moreover, incubation with PAG or BCA resulted in a rightward shift in sodium nitroprusside-and isoproterenol-induced relaxation. Aortic tissues exposed to PAG or BCA contained lower levels of cGMP, exposure of cells to exogenous H 2 S or overexpression of CSE raised cGMP concentration. RNA silencing of CSE expression reduced intracellular cGMP levels confirming a positive role for endogenous H 2 S on cGMP accumulation. The ability of H 2 S to enhance cGMP levels was greatly reduced by the nonselective phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine. Finally, addition of H 2 S to a cell-free system inhibited both cGMP and cAMP breakdown. Conclusion— These findings provide direct evidence that H 2 S acts as an endogenous inhibitor of phosphodiesterase activity and reinforce the notion that this gasotransmitter could be therapeutically exploited.