Exploring the behaviour of water in glycerol solutions by using delayed luminescence

<div><p>The crucial role of water in the engine of life have encouraged many researchers in studying, both theoretically and experimentally, the possible “structure” of water. Many properties of water have been related to the interplay between two distinct and interconverting structural species, namely the low-density water (LDW) and the high-density water (HDW). Supported by the results obtained with other aqueous solutions, this paper deals with the possibility of using the ultra-weak delayed luminescence (DL) to investigate water structuring in a mixture with glycerol, characterized only by hydrogen bonds between the various molecules. Spectral and temporal characteristics of DL decays give information on the two components of the mixture, by evidencing the contribution of water at glycerol concentrations close to the values used in cryopreservation. DL results have shown a correlation with LDW clusters size as determined by other researchers on the basis of neutron diffraction experiments and computational modelling, as reported in Literature.</p></div

Theoretical fit of delayed luminescence time trend.

<p>DL time trend of a sample at glycerol mole fraction x_g = 0.26: (marker) experimental points; (solid line) fitting curve according to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0191861#pone.0191861.e003" target="_blank">Eq 3</a>.</p

Total number of counts vs temperature.

<p>Arrhenius plot of the total number of counts <i>N</i>_{<i>counts</i>} registered in the acquisition time interval for different glycerol mole fraction x_g: (open circle) x_g = 1.00, (grey square) x_g = 0.80, (open square) x_g = 0.26, (grey triangle) x_g = 0.09, (open diamond) x_g = 0.03, (grey circle) x_g = 0.00, pure water. If not explicitly reported, errors are within the markers size.</p

Rate distribution functions for DL decays.

<p>Rate distribution functions for DL decays from samples at different glycerol mole fraction x_g: (black solid line) x_g = 1.00, (grey solid line) x_g = 0.80, (dash-dotted line) x_g = 0.26, (dashed line) x_g = 0.09, (dotted line) x_g = 0.03, (grey dashed line) x_g = 0.00 (water). T = 20°C.</p

Time trends of delayed luminescence.

<p>Time trend of Delayed Luminescence, for different glycerol concentration (mole fraction, x_g), at room temperature (20°C). (open circle) x_g = 1.00, (grey square) x_g = 0.80, (open square) x_g = 0.26, (grey triangle) x_g = 0.09, (open diamond) x_g = 0.03, (grey circle) x_g = 0.00, pure water. Data are average values. Standard errors are within the markers size.</p

Emission spectra of delayed luminescence.

<p>DL emission spectra from samples of different mole fraction x_g: (black) x_g = 1.00, (dark grey) x_g = 0.80, (grey) x_g = 0.26, (backward slash) x_g = 0.09, (slash) x_g = 0.03, (white) x_g = 0.00 (water). T = 20°C. Experimental data are normalized taking into account the spectral dependence of filters’ transmittance and PMT quantum efficiency. Average values and standard deviations are reported.</p

ASAIO 2017 DEF.pptx

Presentation given at the ASAIO 2017 Meeting on ALMA score coming out from a multiistitutional experience of LVAD and BiVAD.<div>The factors entering in the ALMA score are analysed regarding their potential reversal before implantation.</div

Time trend of Delayed Luminescence emission from seeds.

<p>Typical Time trend of the DL emission from a seed at different irradiation doses: (○) native, (■) 100 Gy, (△) 1000 Gy. Data refers to the 450 nm spectral component. Markers denotes average values of 12 seeds. Standard errors are smaller than markers size.</p

Remote controlled irradiation system.

<p>Photograph of the remote controlled irradiation system. During ion beam exposure each hole contained a sample holder with 12 seeds according to the arrangement shown in the inset.</p

Relation between seedling growth and delayed luminescence yield.

<p>Normalized growth NG as a function of the normalized emission NE_as, after subtraction of DL emission of non-germinating seeds, for the two spectral components at (○) 450 nm, (△) 650 Gy. (^____) Best fit of both set of data according to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167998#pone.0167998.e004" target="_blank">Eq (4)</a>. Markers denote average values on the whole seeds data set at the same dose. Bars denote standard errors.</p