The natural mummy of prince Cangrande, Lord of Verona, Italy (1291–1329 AD) was studied. Two samples were taken: rib bone and muscle. These samples were cleaved with trypsin and analysed by liquid chromatographic methods coupled to mass spectrometry (Q-TOF, ion-trap). Special attention was devoted to nonenzymatic protein modification––the deamidation of asparagine and glutamine. A huge amount of collagen was determined in the tissues of the mummy (covering over 80 % of the sequence)––collagen type I was identified in the rib bone and collagen types I and III in the muscle. A high overall percentage of asparaginyl and glutaminyl residues were deamidated (up to 92 %). In agreement with the literature we can suppose that the deamidation of really old samples (at least 100-years-old) is mainly dependent on the burial conditions and/or thermal age and cannot serve as a precise “molecular clock”.
The continuous introduction in the market of new psychoactive drugs (NPS) represents a well-known international emergency. Indeed, the European Monitoring Centre for Drugs and Drug Addiction and the United Nations Office on Drugs and Crime are paying great attention to the spread of NPS. In addition to the traditional analytical approaches based on GC-MS and HPLC-MS, also CE coupled with MS has proved to be a precious tool for the toxicological screening of biosamples. On these grounds, the aim of the present work was to test the application of CE-HRMS as a new screening tool for the rapid detection of these novel drugs in urine. Separations were performed in an uncoated fused-silica capillary with id of 75 μm with a total length of 100 cm, by applying a constant voltage of 15 kV. The QTOF-MS was implemented with an electrospray ion source operating in positive ionization full scan mode in the range of 100–1000 m/z. Under these conditions, different NPS has been tested, including eight cathinones, five phenethylamine, and seven tryptamines. The method was validated after optimization of the following analytical parameters: BGE composition and pH, separation voltage, sheath liquid composition, and flow rate and ESI source settings. The applicability of the method was successfully tested by analyzing a series of real urine samples obtained from drug users. 相似文献
A β-decaying high-spin isomer in (96)Cd, with a half-life T(1/2)=0.29(-0.10)(+0.11) s, has been established in a stopped beam rare isotope spectroscopic investigations at GSI (RISING) experiment. The nuclei were produced using the fragmentation of a primary beam of (124)Xe on a (9)Be target. From the half-life and the observed γ decays in the daughter nucleus, (96)Ag, we conclude that the β-decaying state is the long predicted 16(+) "spin-gap" isomer. Shell-model calculations, using the Gross-Frenkel interaction and the πν(p(1/2),g(9/2)) model space, show that the isoscalar component of the neutron-proton interaction is essential to explain the origin of the isomer. Core excitations across the N=Z=50 gaps and the Gamow-Teller strength, B(GT) distributions have been studied via large-scale shell-model calculations using the πν(g,d,s) model space to compare with the experimental B(GT) value obtained from the half-life of the isomer. 相似文献