Search results for " COMPOSITES"
showing 10 items of 1620 documents
Is the special pair structure a good strategy for the kinetics during the last step of the energy transfer with the nearest antenna? A chemical model…
2013
A cofacial bis(Mg(II)porphyrin)-C(6)H(4)-free base ([Mg(2)]-bridge-FB) dyad shows S(1) energy transfer in both directions and much slower rates than similar monoporphyrin systems are observed.
Structure of the 5′ untranslated region in SARS-CoV-2 genome and its specific recognition by innate immune systemviathe human oligoadenylate synthase…
2022
2′-5′-Oligoadenylate synthetase 1 (OAS1) is one of the key enzymes driving the innate immune system response to SARS-CoV-2 infection whose activity has been related to COVID-19 severity. OAS1 is a sensor of endogenous RNA that triggers the 2′-5′-oligoadenylate/RNase L pathway. Upon SARS-CoV-2 infection, OAS1 is responsible for the recognition of viral RNA and has been shown to possess a particularly high sensitivity for the 5′-untranslated (5′-UTR) RNA region, which is organized in a double-strand stem loop motif (SL1). Here we report the structure of the SL1/OAS1 complex also rationalizing the high affinity for OAS1.
Boolean operations mediated by an ion-pair receptor of a multi-readout molecular logic gate
2013
A heteroditopic BODIPY dye that performs all basic Boolean operations with a cation (K+) and an anion (F-) as inputs and absorption, transmission and fluorescence as outputs is described. The molecular logic gate can also act as a digital comparator between the inputs.
A pH-triggered bistable copper(II) metallacycle as a reversible emulsion switch for biphasic processes.
2013
A unique bistable copper-metallacyclic complex is used as an elegant molecular switch for the reversible formation of emulsions by simple pH variation. This switch may have several exciting applications in biphasic processes such as catalysis and separation science technologies.
Touching the upper limit for ferromagnetic interactions in hetero-bridged dinuclear [Cu-2(II)] complexes using a novel N-5-dinucleating ligand bearin…
2012
A novel N-5-dinucleating ligand 4-amino-3,5-bis(bipyridine-2-yl)-1,2,4-triazole allows the preparation for the first time, and under mild conditions, of single and mixed amido(R-NH-)-bridged copper(II) complexes, the latter exhibiting very strong ferromagnetic coupling.
A highly selective, Hg2+ triggered hydrogelation: modulation of morphology by chemical stimuli
2013
We report the first Hg(2+) selective hydrogelation by 4'-[4-(4-aminophenyl)phenyl]-2,2':6',2''-terpyridine. The gel showed remarkable response towards specific chemical agents such as benzo-18-crown-6 ether and K(+) which enabled extensive modulation of the gel morphology.
Multiscale microstructural characterization of particulate-reinforced composite with non-destructive X-ray micro- and nanotomography
2018
Abstract Methods based on X-ray tomography are developed to study the relevant statistical quantities describing the microstructural inhomogeneity of particulate reinforced composites. The developed methods are applied in estimating microstructural inhomogeneity parameters of composites containing metallic glass particles in metal matrix, extruded in varying pressure loads. This study indicates that the critical characteristics with regard to the effect of particle clustering are cluster size and shape, local volume fraction of particles in the cluster and the distance between clusters. The results demonstrate that the spatial distribution of reinforcement is very uneven and the amount of p…
Physical and biological properties of electrospun poly( d , l ‐lactide)/nanoclay and poly( d , l ‐lactide)/nanosilica nanofibrous scaffold for bone t…
2021
Electrospun scaffolds exhibiting high physical performances with the ability to support cell attachment and proliferation are attracting more and more scientific interest for tissue engineering applications. The inclusion of inorganic nanoparticles such as nanosilica and nanoclay into electrospun biopolymeric matrices can meet these challenging requirements. The silica and clay incorporation into polymeric nanofibers has been reported to enhance and improve the mechanical properties as well as the osteogenic properties of the scaffolds. In this work, for the first time, the physical and biological properties of polylactic acid (PLA) electrospun mats filled with different concentrations of n…
The effect of silica nanoparticles on the morphology, mechanical properties and thermal degradation kinetics of polycarbonate
2012
Abstract Polycarbonate/silica nanocomposites with different silica quantities were prepared by a melt compounding method. The effect of silica amount, in the range 1–5 wt.%, on the morphology, mechanical properties and thermal degradation kinetics of polycarbonate (PC) was investigated. Clusters of silica nanoparticles were well dispersed in the polycarbonate whose structure remained amorphous. NMR results showed intermolecular interactions involving the carbonyl groups of different polymeric chains which did not affect the intramolecular rotational motions. The presence of the lowest silica content showed a decrease in the storage and loss moduli below the glass transition temperature, pro…
Spark plasma sintering of zirconia/nano-nickel composites
2015
Open Access