Stable-isotope techniques to investigate sources of plant water

Stable isotopologues of water (mainly 1H216O, HD16O and 1H218O) have been used for decades as tracers of the Earth's water cycle. In this chapter, we briefly describe the theoretical background and state-of-the-art techniques of the use of water stable isotopes to investigate the sources of plant water. We aim to provide the basic understanding of stable isotope fractionation within the Earth's critical zone that is relevant for studies of plant water sources. We then present a practical guide of their most common applications in field studies and the most common and up-to-date laboratory procedures. We finally introduce the existing statistical approaches for estimating the relative contributions of water sources to plant transpiration. By acknowledging the advantages and limitations of each approach, we aim to provide an overview of the current techniques to researchers in the fields of plant ecophysiology, ecohydrology and forest ecology, so that they can make informed decisions when designing their experiments

A comprehensive study into the migration potential of nano silver particles from food contact polyolefins

The potential of nano silver particles (Ag-NPs) to migrate from food contact polyolefins into food was systematically investigated. Migration studies were carried out using low density polyethylene (LDPE) films with different concentrations of incorporated Ag-NPs in contact with different EU-official food simulants simulating long-term storage with aqueous and fatty food contact. Detectable migration of total silver as measured by inductively coupled plasma mass spectrometry (ICP-MS) was found in aqueous food simulants only. Stability tests of Ag-NPs in these food simulants by asymmetric flow field-flow fractionation (AF4) analysis showed rapid oxidative dissolution of the Ag-NPs and demonstrated that only ionic silver was present in the migration solution. Non-detectability of silver both in the isooctane and 95 % ethanol migrates indicated that Ag-NPs would not be able to migrate. These findings were supported by a new approach of migration modeling showing that nanomaterials (NMs) in general are immobilized in a polymeric matrix, resulting in a very limited hypothetical potential for the migration of NMs smaller than 3-4 nanometer in diameter. However, such small nanoparticles are usually not found in polymer nanocomposites. The results of this study suggest that migration of nanoparticles from food contact plastics cannot lead to an exposure of the consumer

Risk assessment of ozone impact on Fagus crenata in Japan: consideration of atmospheric nitrogen deposition

Tropospheric ozone (O3) is considered to be the air pollutant relating to the decline of Fagus crenata forest in Japan. In the present study, we assessed a risk of O3 impact on the growth of F. crenata in Japan, giving consideration to the effects associated with atmospheric nitrogen (N) deposition based on the experimental study, national monitoring data for oxidant concentration and atmospheric N deposition, and a national vegetation survey. The average and maximum O3-induced relative growth reduction (RGred) of F. crenata across Japan were estimated to be 3.2 and 9.7%, respectively. Current levels of atmospheric N deposition were found to significantly affect the sensitivity of F. crenata to O3. When the N deposition was assumed as zero, the estimated average and maximum RGred were 2.3% and 5.7%, respectively. The inclusion of atmospheric N deposition data thus increased the estimated values for average and maximum RGred (by 38% and 71%, respectively). Our results demonstrate that a change in the sensitivity to O3 associated with atmospheric N deposition is an important consideration in the risk assessment of O3 impact on the growth of F. crenata in Japan

PRMT Inhibitors

The methylation of arginine residues in numerous protein targets is a post-translational modification that has gained increased interest in the scientific community over the past two decades. Arginine methylation is performed by the dedicated family of protein arginine methyltransferases and is known to be involved in a plethora of cellular pathways and biochemical mechanisms in both healthy and disease states. The development of inhibitors for these enzymes for use as biological tools can lead to a more detailed understanding of the functions of the different members of the PRMT family. In addition, a number of recent studies point towards PRMTs as therapeutic targets for a number of diseases and the first clinical trials with compounds inhibiting PRMTs are now underway. We here provide a broad overview of the current status of the inhibitors that have been developed against PRMTs using both high-throughput screening and rational design approaches.Microbial Biotechnolog