Biosourced Aromatic Derivatives in the Upcycling of Recycled PET: Mellophanic Dianhydride as a Chain Extender

The synthesis of mellophanic dianhydride (MEDA) from biosourced 1,2,3,4-benzene tetracarboxylic derivatives and its use as a chain extender for mechanically recycled PET (R-PET) as an alternative to traditional oil-based pyromellitic dianhydride (PMDA) is reported. The rheological tests performed on the R-PET extruded with MEDA have shown similar results to those obtained with PMDA, and dynamic mechanical thermal analysis (DMTA) showed that, in the 90–110 °C range (i.e., the temperature range commonly used for blow molding of bottles), Young’s modulus of R-PET containing MEDA is about 20% higher in comparison to that of pristine R-PET. The advantage of MEDA is that it can be prepared using building blocks obtained from agricultural waste via a sustainable protocol, whereas PMDA is a product of oil-based chemistr

High Cell Diversity and Complex Peptidergic Signaling Underlie Placozoan Behavior.

Placozoans, together with sponges, are the only animals devoid of a nervous system and muscles, yet both respond to sensory stimulation in a coordinated manner. How behavioral control in these free-living animals is achieved in the absence of neurons and, more fundamentally, how the first neurons evolved from more primitive cells for communication during the rise of animals are not yet understood [1-5]. The placozoan Trichoplax adhaerens is a millimeter-wide, flat, free-living marine animal composed of six morphologically identified cell types distributed across a simple body plan [6-9]: a thin upper epithelium and a columnar lower epithelium interspersed with a loose layer of fiber cells in between. Its genome contains genes encoding several neuropeptide-precursor-like proteins and orthologs of proteins involved in neurosecretion in animals with a nervous system [10-12]. Here we investigate peptidergic signaling in T. adhaerens. We found specific expression of several neuropeptide-like molecules in non-overlapping cell populations distributed over the three cell layers, revealing an unsuspected cell-type diversity of T. adhaerens. Using live imaging, we discovered that treatments with 11 different peptides elicited striking and consistent effects on the animals' shape, patterns of movement, and velocity that we categorized under three main types: (1) crinkling, (2) turning, and (3) flattening and churning. Together, the data demonstrate a crucial role for peptidergic signaling in nerveless placozoans and suggest that peptidergic volume signaling may have pre-dated synaptic signaling in the evolution of nervous systems

Computational methodology to determine fluid related parameters on non regular three-dimensional scaffolds

The application of three-dimensional (3D) biomaterials to facilitate the adhesion, proliferation, and differentiation of cells has been widely studied for tissue engineering purposes. The fabrication methods used to improve the mechanical response of the scaffold produce complex and non regular structures. Apart from the mechanical aspect, the fluid behavior in the inner part of the scaffold should also be considered. Parameters such as permeability (k) or wall shear stress (WSS) are important aspects in the provision of nutrients, the removal of metabolic waste products or the mechanically-induced differentiation of cells attached in the trabecular network of the scaffolds. Experimental measurements of these parameters are not available in all labs. However, fluid parameters should be known prior to other types of experiments. The present work compares an experimental study with a computational fluid dynamics (CFD) methodology to determine the related fluid parameters (k and WSS) of complex non regular poly(L-lactic acid) scaffolds based only on the treatment of microphotographic images obtained with a microCT (lCT). The CFD analysis shows similar tendencies and results with low relative difference compared to those of the experimental study, for high flow rates. For low flow rates the accuracy of this prediction reduces. The correlation between the computational and experimental results validates the robustness of the proposed methodology.The authors gratefully acknowledge research support from the Spanish Ministry of Science and Innovation through research project DPI2010-20399-C04-01. The Instituto de Salud Carlos III (ISCIII) through the CIBER initiative and the Platform for Biological Tissue Characterization of the Centro de Investigacion Biomedica en Red en Bioingenieria, Biomateriales y Nanomedicina (CIBER-BBN) are also gratefully acknowledged.Acosta Santamaría, VA.; Malvé, M.; Duizabo, A.; Mena Tobar, A.; Gallego Ferrer, G.; García Aznar, J.; Doblare Castellano, M.... (2013). Computational methodology to determine fluid related parameters on non regular three-dimensional scaffolds. Annals of Biomedical Engineering. 41(11):2367-2380. https://doi.org/10.1007/s10439-013-0849-8S236723804111Acosta Santamaría, V., H. Deplaine, D. Mariggió, A. R. Villanueva-Molines, J. M. García-Aznar, J. L. Gómez Ribelles, M. Doblaré, G. Gallego Ferrer, and I. Ochoa. Influence of the macro and micro-porous structure on the mechanical behavior of poly(l-lactic acid) scaffolds. J. Non-Cryst. Solids 358(23):3141–3149, 2012.Adachi, T., Y. Osako, M. Tanaka, M. Hojo, and S. J. Hollister. 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New reactions of furoxans: Formation of alkynes and cyclobutaphenanthrenes

Diarylfuroxans were found to give diaryacetylenes upon irradiation at 254 nm. Cyclobutaphenanthrenes were also obtained when reaction was carried out in the presence of alkenes. The acetylenic derivative is supposed to arise by loss of (NO)2 from a diazete-N,N-dioxide. Unimolecular and collision activated dissociation studies by tandem mass spectrometry also support the loss of (NO)2 from diarylfuroxans molecular ions

NUCLEOPHILIC DISPLACEMENT OF THE METHOXY GROUP IN 5-METHOXYISOXAZOLE

The reaction of 5-methoxy-3-phenylisoxazole, 1a, with primary and secondary alcohols in the presence of acids gives 5-alkoxy derivatives 1b-d in almost quantitative yields