We calculate the vibrational density-of-states in an insulating nanoparticle that is in weak mechanical contact with a semi-infinite substrate. The work is motivated by a recent experiment by Yang et al., where the low-energy phonon density-of-states of Y2O3 nanoparticles doped with Eu 3þ was measured. Preliminary results presented here, based on the conventional quasiparticle-pole approximatio...

After the prediction that strong enough optical activity may result in negative refraction and negative reflection, more and more artificial chiral metamaterials were designed and fabricated at difference frequency ranges from microwaves to optical waves. Therefore, a simple and robust method to retrieve the effective constitutive parameters for chiral metamaterials is urgently needed. Here, we...

The evolution of nest weaving, the inclusion of larval silk in the nest walls, is considered one of the pinnacles of cooperative behaviour in social insects. Within the four ant genera in which this has evolved, Oecophylla are unique in being the only group that precedes the deposition of larval silk by actively manipulating the leaf substrate to form a nest chamber. Here we provide the first d...

The anaphase-promoting complex/cyclosome (APC/C) is a protein-ubiquitin ligase (E3) that initiates the final events of mitosis by catalyzing the ubiquitination and proteasomal destruction of securin, cyclins, and other substrates [1, 2]. Like other members of the RING family of E3s [3, 4], the APC/C catalyzes direct ubiquitin transfer from an E2-ubiquitin conjugate (E2-Ub) to lysine residues on...

The activity of lysosomal sphingolipid hydrolases is usually estimated in vitro from complex assays on cell lysates under artificial conditions including the presence of detergents and substrate analogs. However, the measure of their effective activity in situ (i.e., in living cells) is necessary to understand the normal intracellular sphingolipid turnover. Moreover, their determination in cell...

determination of streptokinase activity is usually accomplished through two assay methods: a) clot lysis, b) chromogenic substrate assay. in this study the biological activity of two streptokinase products, namely streptase®, which is a native product and heberkinasa®, which is a recombinant product, was determined against the third international reference standard using the two forementioned a...

Accurate identification of substrates of a protease is critical in defining its physiological functions. We previously predicted that Dsg-2 (desmoglein-2), a desmosomal protein, is a candidate substrate of the transmembrane serine protease matriptase. The present study is an experimental validation of this prediction. As demanded by our published method PNSAS [Prediction of Natural Substrates f...