Trace element distribution mapping in pharmaceutical and biological samples using laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy (LIBS) has numerous advantages like determination of ppb-ppm level concentrations, microdestructivity, the ability of making high resolution laterally (µm) or depth-resolved (100 nm) analysis, sensitive measurement of heavy and light elements and direct analysis of solid samples with minimal sample preparation. The aim of the present work was to demonstrate that LIBS is a suitable analytical technique to assess the trace element distribution of pharmaceutical and biological samples. As test samples, we used specimens of chickpea milkvetch (Astragalus cicer), a perennial plant with excellent nutritional value and a commercially available dietary supplement pill (Supradyn)

The feasibility of liquid sample microanalysis using polydimethylsiloxane microfluidic chips with in-channel and in-port laser-induced breakdown spectroscopy detection

accepte

Suboptimal zinc supply affects the S-nitrosoglutathione reductase enzyme and nitric oxide signaling in Arabidopsis

The S-nitrosoglutathione reductase (GSNOR), a key regulator of nitric oxide (NO) signaling, requires zinc (Zn) cofactors for its catalytic activity. Possible changes in GSNOR function and NO signaling due to limited Zn supply and participation of GSNOR in response to Zn deficiency have not yet been examined. The wild-type Arabidopsis thaliana seedlings (Col-0) and the overproducer of GSNOR (35S::FLAG-GSNOR1) were grown in agar medium supplemented with 15 µM (full Zn), 1.5 µM (Zn/10) and 0 µM (Zn0) zinc sulfate. Limited availability of Zn in the nutrient medium during the experimental period resulted in a significantly reduced Zn content in the roots and shoots of Arabidopsis and altered the expression of Zn deficiency marker genes; however, the Zn content did not reflect Zn deficiency in the seedlings. GSNOR has no effect on the Zn limitation-induced reduction in the in planta Zn content. Suboptimal Zn supply results in a smaller but more active GSNOR protein pool in Col-0 A. thaliana. In 35S::FLAG-GSNOR1, overproduction possibly compensates for the negative effects of reduced Zn supply, resulting in unchanged GSNOR expression, protein abundance, and activity. Suboptimal Zn supply alters NO but did not modify peroxynitrite and hydrogen peroxide levels and exerts a pronitrant effect in the plant proteome. Overall, this is the first report to show that limited Zn supply affects the GSNOR enzyme at the gene and protein levels but not at the activity level and modifies reactive species levels and physiological nitroproteome in Arabidopsis