Large‐area,polarisation‐sensitive plasmonic materials from colloidal lithography

The development of simple to prepare, polarization‐sensitive plasmonic apertures with two plasmonic modes, is described. To achieve these results, monocrystalline nanosphere lithography masks of 438 nm polystyrene spheres are modified with reactive ion etching before silver is subsequently evaporated through the mask at varied angles. As the angle of evaporation increases, round apertures, elliptical apertures or lines with bow‐tie like features between two lines are produced. A primary plasmon mode is shown at 570 nm, while a tunable plasmon mode is demonstrated between 700 nm and 900 nm. Finite‐difference time‐domain calculations agree with the observed results and predict that this method of fabrication can produce tunable plasmonic features throughout the NIR optical telecommunication wavelength range. Lastly, the excitation polarization angle is compared with that of plasmonic nanorods and asymmetric nano‐apertures systems to describe why the excitation polarization of the low energy mode is orthogonal to the long axis of the apertures. (© 2016 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)     

Provenance studies of the white marble of the cathedral of Como by neutron activation analysis and data reduction

Marble samples from major Italian quarries and from the Como Cathedral were analyzed for their trace element content, which is indicative of their provenance. Ca, Sc, Cr, Mn, Fe, Co, Rb, Sb, Cs, Ba, La, Ce, Sm, Eu, Gd, Ho, Tm, Yb, Lu, Hf, Th and U elements were determined by neutron activation analysis. Results as well as their precision and accuracy are presented and discussed. Data treatment has allowed to characterize the marble quarries on the basis of their trace element content, to identify the provenance of the marble used in the Como Cathedral and to show differences in the element distribution of new and weathered marble samples from the same quarry.     

Rare-earth elements abundance and distribution in pelagic sediments by instrumental neutron activation analysis

The geochemical behavior of REE has been tested in the Umbro-Marchean (Italy) pelagic sequences of Cretaceous-Paleocene age. REE were determined by INAA in a number of limestone, marl and clay samples. Both chondrite and shale normalized patterns are discussed: the observed REE amounts and distributions are mainly attributed to highly complex diagenetic processes.     

Enzyme modification by MPEG with an amino acid or peptide as spacer arms

A method for the modification of enzymes by MPEG carrying an amino acid or peptide as a spacer arm is described and tested with aliphatic or aromatic side chains amino acids. The procedure involves MPEG activation by p-nitrophenylchloroformate for the amino acid or peptide coupling that is in turn activated for the protein binding. The advantage of the method resides in the possibility to introduce proper reporter groups between the polymer and the protein as norleucine for a direct evaluation of the bound polymer chains, tryptophan for structural studies of the polymer-protein adduct, and radioactive amino acid for pharmacokinetic investigations. The method was positively tested with arginase, ribonuclease, and superoxide dismutase as enzymes of therapeutic value.     

Application of Combinatorial Procedures in the Search for Serine-Protease-Like Activity with Focus on the Acyl Transfer Step

Recursive deconvolution of a 729-membered peptide library has identified three active sequences, in which both Ser and His are present in one of the two tripeptidic chains generated on a steroidal scaffold (see structural formula), for the cleavage of an activated p-nitrophenyl ester. This combinatorial approach aims at searching for serine-protease-like activity.     

Perspectives from above and beyond the proton drip-line

This paper will review the dramatic increase in our knowledge of one and two proton unbound nuclei [1] such as recoil decay tagging [2] are revealing unique insights into the structure of nuclei beyond the proton drip-line. These studies of excited states provide complementary information to proton radioactivity studies, particularly regarding the role of deformation [3]. Radioactive beams are being used to study two-proton unbound resonances and to study explosive nuclear astrophysical reactions in the region of the proton drip-line.