Dissolution dynamic nuclear polarization (DNP) has become one of the predominant implementations for DNP. However, the technical implementation of transferring the sample from the polarizer to the nuclear magnetic resonance (NMR) system remains challenging. There is a need for additional technical optimizations in order to use dissolution DNP for biochemical and chemical applications. Here we show how a newly designed pressure dissolution kit considerably improves spectral quality and stability by enabling highly reliable and fast sample transfer to the NMR system.
Edible olive drupes (from Olea europaea L.) are a high-value food commodity with an increasing production trend over the past two decades. In an attempt to prevent fraud issues and ensure quality, the International Olive Council (IOC) issued guidelines for their sensory evaluation. However, certain varieties, geographical origins and processing parameters are omitted. The aim of the present study was the development of a method for the quality assessment of edible olives from the Konservolia, Kalamon and Chalkidikis cultivars from different areas of Greece processed with the Spanish or Greek method. A rapid NMR-based untargeted metabolic profiling method was developed along with multivariate analysis (MVA) and applied for the first time in edible olives’ analysis complemented by the aid of statistical total correlation spectroscopy (STOCSY). Specific biomarkers, related to the classification of olives based on different treatments, cultivars and geographical origin, were identified. STOCSY proved to be a valuable aid towards the assignment of biomarkers, a bottleneck in untargeted metabolomic approaches.
Daily total ozone observations made with the Total Ozone Mapping Spectrometer (TOMS) flown on the satellite Nimbus‐7 during 1978–1992, have been used in order to investigate the increase in the daily broad‐band and spectral solar ultraviolet radiation reaching the ground through a recently developed parametric model. Total ozone reductions of 3.0% during summer time and 11% during winter time per decade, at St. Petersburg (60°N, 30°E), Russia, cause an increase in erythematically active ultraviolet irradiance of at least 7% and 22%, respectively.
The influence of photochemical pollution on the ultraviolet radiation reaching the ground is examined. For this purpose, a series of UY-A and UY-B measurements as well as the results of a simple parametric model are compared. It was found that the hypothesis of UY-B depletion is significant at an almost 95 per cent confidence level. It is also indicated that the effect of photochemical pollution on UY-B levels reaching the ground is roughly three times the same effect on UY-A levels.
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