Prediction, screening and characterization of novel bioactive tetrapeptide matrikines for skin rejuvenation.

Background: Extracellular matrices play a critical role in tissue structure and function and aberrant remodelling of these matrices is a hallmark of many age-related diseases. In skin, loss of dermal collagens and disorganization of elastic fibre components are key features of photoageing. Although the application of some small matrix-derived peptides to aged skin has been shown to beneficially affect in vitro cell behaviour and, in vivo, molecular architecture and clinical appearance, the discovery of new peptides has lacked a guiding hypothesis.

XLF and APLF bind Ku80 at two remote sites to ensure DNA repair by non-homologous end joining.

The Ku70-Ku80 (Ku) heterodimer binds rapidly and tightly to the ends of DNA double-strand breaks and recruits factors of the non-homologous end-joining (NHEJ) repair pathway through molecular interactions that remain unclear. We have determined crystal structures of the Ku-binding motifs (KBM) of the NHEJ proteins APLF (A-KBM) and XLF (X-KBM) bound to a Ku-DNA complex. The two KBM motifs bind remote sites of the Ku80 α/β domain.

Calculation spreadsheet for uncertainty estimation of measurement results in gamma-ray spectrometry and its validation for quality assurance purpose.

An Excel calculation spreadsheet has been developed to estimate the uncertainty of measurement results in γ-ray spectrometry. It considers all relevant uncertainty components and calculates the combined standard uncertainty of the measurement result. The calculation spreadsheet has been validated using two independent open access software and is available for download free of charge at: https://nucleus.

IAEA's ALMERA network: Supporting the quality of environmental radioactivity measurements.

The International Atomic Energy Agency coordinates and provides methodological and analytical quality support to the network of Analytical Laboratories for the Measurement of Environmental Radioactivity (ALMERA), comprising 150 laboratories in 84 countries. Annual proficiency tests (PTs) are organized for the network laboratories using sets of different samples typically encountered in environmental and food monitoring laboratories. The PT system is designed to respond to the needs of the network for rapid response and reliable measurement results, and to metrological principles and international standards and guides.

Assessment of measurement result uncertainty in determination of (210)Pb with the focus on matrix composition effect in gamma-ray spectrometry.

Reference materials were used to assess measurement result uncertainty in determination of (210)Pb by gamma-ray spectrometry, liquid scintillation counting, or indirectly by alpha-particle spectrometry, using its daughter (210)Po in radioactive equilibrium. Combined standard uncertainties of (210)Pb massic activities obtained by liquid scintillation counting are in the range 2-12%, depending on matrices and massic activity values. They are in the range 1-3% for the measurement of its daughter (210)Po using alpha-particle spectrometry.