Jagiellonian University

About: Jagiellonian University is a education organization based out in Krakow, Poland. It is known for research contribution in the topics: Population & Catalysis. The organization has 17438 authors who have published 44092 publications receiving 862633 citations. The organization is also known as: Academia Cracoviensis & Akademia Krakowska.

Adsorption of S-S containing proteins on a colloidal silver surface studied by surface-enhanced Raman spectroscopy.

Abstract: We present a Raman and surface-enhanced Raman scattering (SERS) study of the following proteins containing S-S group(s): alpha chymotrypsin (alpha-CHT), insulin, lysozyme, oxytocin (OXT), Streptomyces subtilisin inhibitor (SSI), and trypsin inhibitor (STI). The SERS study is performed in order to understand the adsorption mechanism of the above-mentioned proteins on a colloidal silver surface. The SERS spectra presented here show bands associated mainly with aromatic amino acid vibrations. In addition, two distinct vibrations of the -C-S-S-C- fragment are observed in the Raman and SERS spectra, i.e., nu(SS) and nu(CS). The enhancement of the nu(SS) vibration in the SERS spectra yields evidence that the intact disulfide bridge(s) is (are) located near the silver surface. This finding is supported by the presence of the nu(CS) mode(s). The presence of nus(COO-) and nu(C-COO-) in the SERS spectra in the 1384-1399 cm(-1) and 909-939 cm(-1) regions, respectively, indicate that the negatively charged COO- groups (aspartic and glutamic acids) assist in the binding on the positively charged silver surface. The Raman amide I and III bands observed in the 1621-1633 and 1261-1289 cm(-1) ranges, respectively, indicate that the alpha-helical conformation is favored for binding to the surface over the random coil or beta-sheet conformations. In addition, the presence of the imino group of Trp and/or His indicates that these amino acid residues may also bind to the silver sol.

Search for direct top-squark pair production in final states with two leptons in pp collisions at √s = 8 TeV with the ATLAS detector

Abstract: A search is presented for direct top-squark pair production in final states with two leptons (electrons or muons) of opposite charge using 203 fb−1 of pp collision data at √s = 8 TeV, collected by the ATLAS experiment at the Large Hadron Collider in 2012 No excess over the Standard Model expectation is found The results are interpreted under the separate assumptions (i) that the top squark decays to a b-quark in addition to an on-shell chargino whose decay occurs via a real or virtual W boson, or (ii) that the top squark decays to a t-quark and the lightest neutralino A top squark with a mass between 150 GeV and 445 GeV decaying to a b-quark and an on-shell chargino is excluded at 95% confidence level for a top squark mass equal to the chargino mass plus 10 GeV, in the case of a 1 GeV lightest neutralino Top squarks with masses between 215 (90) GeV and 530 (170) GeV decaying to an on-shell (off-shell) t-quark and a neutralino are excluded at 95% confidence level for a 1 GeV neutralino