Effect of different inorganic filler over isothermal and non-isothermal crystallization of polypropylene homopolymer

In this study, the effect of several inorganic fillers: silicon oxide (SiO₂), nanoclay (C20A), alumina (Al₂O₃), and calcium carbonate (CaCO₃) on the crystallization behavior of polypropylene were analyzed for composites with fixed filler content (5 mass%) prepared by intensive mixing following by compression molding. In addition, for calcium carbonate, which produces the highest increase on toughness, PP grafted with maleic anhydride (PP-g-MA) was added to enhance the compatibility. In that case, different content of particles was used (from 5 to 20 mass%) and the synergic effect of both incorporations was demonstrated. For this purpose, isothermal and non-isothermal crystallization tests were carried out in the bulk (by differential scanning calorimetry). In addition, the spherulitic growth was studied (by optical microscopy). Different models were used to predict the relative degree of crystallinity and several parameters were analyzed. All results indicate that whereas alumina and calcium carbonate acted as nucleating agents, silica and nanoclay displayed an opposite behavior. The full models that take into account the different parameters during cooling under isothermal and non-isothermal conditions were used to construct continuous cooling transformation and time temperature transformation diagrams. Both kind of diagrams provide a fundamental tool to understand the crystallization behavior of studied composites and are useful to determine the processing conditions.     

Analysis of biomarkers characteristic of porcine liver injury--from biomolecular logic gates to an animal model

A biocatalytic cascade for the analysis of the simultaneous increase in the concentration of two biomarkers characteristic of liver injury (alanine transaminase, ALT, and lactate dehydrogenase, LDH) was tested on real samples acquired from an animal model (domestic pigs, Sus scrofa domesticus) suffering from traumatic liver injury. A two-step reaction biocatalyzed in the presence of both enzyme-biomarkers resulted in the oxidation of NADH followed by optical absorbance measurements. A simple qualitative, YES/NO, test allowed for distinction between animals with and without the presence of liver injury with the probability of 92%. These data represent the first demonstration of applying binary logic systems for the analysis of real biomedical samples.     

A new synthesis of 4′-trifluoromethyl-2,2′:6′,2″-terpyridine

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Extraction and separation of lanthanides from aqueous chloride and nitrate media using mixtures of binary extractants based on secondary and tertiary amines

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Solvent-free silica gel mediated decarboxylation of C–O coupling products of β-diketones and β-oxo esters with malonyl peroxides

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Stabilization of mixture of two rigid solids modeling temperature and porosity

In this paper we investigate the asymptotic behavior of solutions to the initial boundary value problem for a mixture of two rigid solids modeling temperature and porosity. Our main result is to establish conditions which ensure the analyticity and the exponential stability of the corresponding semigroup.     

Implanted biofuel cell operating in a living snail

Implantable biofuel cells have been suggested as sustainable micropower sources operating in living organisms, but such bioelectronic systems are still exotic and very challenging to design. Very few examples of abiotic and enzyme-based biofuel cells operating in animals in vivo have been reported. Implantation of biocatalytic electrodes and extraction of electrical power from small living creatures is even more difficult and has not been achieved to date. Here we report on the first implanted biofuel cell continuously operating in a snail and producing electrical power over a long period of time using physiologically produced glucose as a fuel. The "electrified" snail, being a biotechnological living "device", was able to regenerate glucose consumed by biocatalytic electrodes, upon appropriate feeding and relaxing, and then produce a new "portion" of electrical energy. The snail with the implanted biofuel cell will be able to operate in a natural environment, producing sustainable electrical micropower for activating various bioelectronic devices.