Effects of post-veraison irrigation on the phenolic composition of Vitis vinifera L. cv. ‘Xinomavro’ grapes

‘Xinomavro’ (the second planted red Greek variety behind ‘Agiorgitiko’) generally produces wines that are light in colour but with increased astringency, possibly related to grape flavonoid amount and composition; although irrigation is accepted as an effective means to enhance grape phenolic maturity, its role has not yet been sufficiently studied in the case of Xinomavro. This study aimed to determine the effect of post-veraison irrigation on berry anthocyanin and proanthocyanidin amount and composition, of field-grown Xinomavro vines (Vitis vinifera L.), under the typical summer conditions of Northern Greece. In a 10-year-old Xinomavro vineyard, two post-veraison watering regimes were applied—irrigation starting 20 days after veraison (mid-ripening irrigation, MRI) and irrigation starting immediately after veraison was completed (after veraison irrigation, AVI)—alongside non irrigated vines (NI), and vines irrigated continuously from berry set through harvest (continuous irrigation, CI). Proanthocyanidin composition was determined in both skins and seeds by employing phloroglucinolysis followed by HPLC-UV and MS detection (high-performance liquid chromatographic with tandem mass spectrometric and ultraviolet absorbance detection), and the anthocyanin profile was identified only in the skin extracts by HPLC-UV (high-performance liquid chromatographic with ultraviolet absorbance detection). Post-veraison irrigation increased yield parameters and reduced anthocyanin levels and the proportion of their stable forms (acylated vs. non-acylated, tri-oxygenated and methoxylated on the B-ring vs. di-oxygenated and hydroxylated), compared to NI vines; however, these effects were more pronounced in the case of early post-veraison irrigation (AVI) than late-season irrigation (MRI). Irrigation also increased the mean Degree of Polymerization (mDP) and prodelphinidin percentage of skin tannins and decreased mDP of seed tannins. In the light of the necessity to control the accelerated ripening under the increasingly hotter and drier climatic conditions, late irrigation (MRI) might provide a solution to avoid excessive sugar levels and allow a slightly higher yield without significant reductions in berry phenolic content. The results suggest that the optimisation of the timing of irrigation could provide an effective adaptation strategy to climate change in Mediterranean viticultural areas.

Study on Liquid Phase Hydrogenation Technology of White Oil

Using Aspen Plus simulation software to simulate the hydrogen solubility of white oil raw materials, and calculate the de-aromatic hydrogen consumption. The liquid hydrogenation technology of white oil was studied by using 100mL uplink liquid hydrogenation evaluation device. The research results show that the ultraviolet absorbance of the liquid phase hydrogenation product is no more than 0.1, and saybolt color, copper plate corrosion, readily carbonizable substance can meet the quality requirements under the conditions of 230℃, 17 Mpa and LHSV 0.5 h-1. 2000 hours liquid phase hydrogenation test shows the stability of product quality which meets the food grade standard, and the liquid phase hydrogenation technology is feasible.

Comparison of dialysis dose through real-time Kt/V by ultraviolet absorbance of spent dialysate, single-pool Daugirdas II, and Kt/BSA according to sex and age

ABSTRACT Background: Kt/V OnLine (Kt/VOL) avoids inaccuracies associated with the estimation of urea volume distribution (V). The study aimed to compare Kt/VOL, Kt/V Daugirdas II, and Kt/BSA according to sex and age. Methods: Urea volume distribution and body surface area were obtained by Watson and Haycock formulas in 47 patients. V/BSA was considered as a conversion factor from Kt/V to Kt/BSA. Dry weight was determined before the study. Kt/VOL was obtained on DIALOG machines. Results: Pearson correlation between Kt/VOL vs Kt/VII and Kt/VOL vs Kt/BSA was significant for males (r = 0.446, P = 0.012 and r = -0.476 P = 0.007) and individuals < 65 years (0.457, P = 0.019 and -0.549 P = 0.004), but not for females and individuals ≥ 65 years. V/BSA between individuals < 65 and individuals ≥ 65 years were 18.28 ± 0.15 and 18.18 ± 0.16 P = 0.000). No agreement between Kt/VII vs Kt/BSA. Men and individuals > 65 years received a larger dialysis dose than, respectively, females and individuals < 65 years, in the comparison between Kt/VOL versus Kt/VII. V/BSA ratios among men and women were respectively 18.29 ± 0.13 and 18.12 ± 0.15 P = 0.000. Conclusions: Kt/VOL allows recognition of real-time dose regardless of sex and age.

Size-resolved analysis of trace elements in the dissolved fraction (<0.45 μm) of soil solutions using a novel lysimeter and asymmetrical flow field-flow fractionation coupled to ultraviolet absorbance and inductively coupled plasma mass spectrometry

The distributions of dissolved (<0.45 μm) trace elements (TEs) amongst major colloidal forms in soils have implications for their availability, accessibility, and toxicity to plants and animals. The size-resolved distributions of TE species in soil solutions were collected using lysimeters and were measured using asymmetrical flow field-flow fractionation (AF4) coupled to ultraviolet absorbance (UV) and inductively coupled plasma mass spectrometry (ICP-MS). Using this AF4-UV-ICPMS system, dissolved TEs were separated by size, and concentrations in major forms were quantified: “truly dissolved” primarily ionic and small molecules <ca. 1 kDa, organic-dominated colloids, and primarily inorganic colloids. The soil solutions were collected under vacuum using a novel surgical (316L) stainless steel (SS) lysimeter with a 5 μm pore size. Analyses were performed in the metal-free, ultraclean SWAMP laboratory. The acid-cleaned lysimeters yielded excellent blank values for TEs of environmental interest (i.e., Li, Al, V, Mn, Co, Cu, As, Mo, Ag, Cd, Ba, Pb, Th, and U). Lysimeter sampling offers the major advantage that it can minimize disturbances to the natural TE concentrations and distributions amongst major dissolved colloidal forms in soil solutions and thus provides information that is relevant to plant uptake.

Characterization of a Chromium (III) Ion Probe and its MOF-Supported Material

In order to explore more functional supported probe material, the ultraviolet absorbance together with fluorescence properties of a probe with the structure of salicylaldehyde Schiff-base in various solvents and pHs were investigated after its synthesis. When the concentration of Cr3+ ion was in the range of 3~7×10-5 mol•L-1, the complex reaction between the probe and Cr3+ could be used for quantitation of the latter, which was developed by UV absorbance intensity of the complex and the concentration of Cr3+ ion. Ultraviolet analytic results determined that they were complexed in the molar ratio of 1:1. Finally, the MOF-supported probe material was successfully synthesized for further application, which realized the immobilization of the probe through simple operations.