Representation of the water concentration profiles expressed in terms of molar fractions within the droplet, and of vapor pressures in the air space.

<p>Representation of the water concentration profiles expressed in terms of molar fractions within the droplet, and of vapor pressures in the air space.</p

Plot of the theoretical water equilibration rates expected by the proposed model and by FM, and evaluation of the models against experimental data taken from literature.

<p>A: Experimental sets #1 (298 K) and #2 (277 K) of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0001998#pone-0001998-t001" target="_blank">Table 1 </a><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0001998#pone.0001998-Fowlis1" target="_blank">[3]</a>. B: Experimental set #3 of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0001998#pone-0001998-t001" target="_blank">Table 1 </a><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0001998#pone.0001998-Mikol1" target="_blank">[7]</a>.</p

Experimental details and physicochemical parameters of the water evaporation experiments used to validate the theoretical model.

§<p>Value estimated from freezing point depression measurements <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0001998#pone.0001998-Mikol1" target="_blank">[7]</a>.</p>†<p>The vapor diffusion coefficients reported at 298 K and 277 K <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0001998#pone.0001998-Fowlis1" target="_blank">[3]</a> were not considered to change significantly for (i) 293 K and 295.9 K, and for (ii) 276 K, respectively.</p

The measured influence of the droplet-to-reservoir distance on the average concentration of NaCl in the droplet after a 121 h evaporation period – experimental set #5 of Table 1[5] – and the theoretical profiles expected from Equations 19 and 27 for the same set of conditions.

<p>The measured influence of the droplet-to-reservoir distance on the average concentration of NaCl in the droplet after a 121 h evaporation period – experimental set #5 of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0001998#pone-0001998-t001" target="_blank">Table 1</a><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0001998#pone.0001998-Luft1" target="_blank">[5]</a> – and the theoretical profiles expected from Equations 19 and 27 for the same set of conditions.</p

Scheme of the hanging drop method adopted on the derivation of the mathematical model.

<p>Scheme of the hanging drop method adopted on the derivation of the mathematical model.</p

Running away from Thermodynamics To Promote or Inhibit Crystal Growth

Impurities/additives may be either detrimental or beneficial to many different crystal growth applications. Determined to a great extent by thermodynamics, their effects are hardly avoided once supersaturation, temperature, pH, and impurity content are established. In this work we introduce the rate of supersaturation variation <i>R</i>_σ as a new variable that can dramatically influence crystal growth relatively to steady-state conditions. We show that the crystal growth of a model protein can be accelerated, retarded, or even suppressed by altering <i>R</i>_σ. Our results provide insight into the mechanism by which fast supersaturation variation prevents the adsorption equilibrium from being restored. When impurity adsorption onto kink sites gets delayed, crystal growth is enhanced and a “purifying” effect takes place. If, instead, impurity desorption from kink sites gets delayed, then a “poisoning” effect takes place. The same rationale is used to elucidate fundamental challenges that inspired this work. Included in this list are the nonlinear acceleration kinetics of growth layers and the growth rate hysteresis. While attenuating impurity incorporation, the purifying effect is expected to be important for the production of high quality lattices during single crystal growth. On the other hand, the poisoning effect opens new possibilities for crystal growth inhibition during pathological mineralization

TTR spheroid oligomers and protofibrils.

<p><b>A.</b> 1×1 µm² AFM height contrast image of a mixed population of spheroid oligomers and short protofibrils. Black arrows point out examples of spheroid oligomers with various shapes and sizes. <b>Inset,</b> magnified view of a protofibril displaying a stack-like arrangement of flat, disc-shaped oligomers reminiscent of annular origin. <b>B.</b> 1×1 µm² AFM height contrast image of a mixed population of spheroid oligomers and longer protofibrils. Black arrows point out examples of spheroid oligomers with various shapes and sizes. <b>Inset</b>, magnified view of a protofibril in which the underlying periodic structure is probably helical. <b>C.</b> Topographical molecular volume histogram of 341 (<i>n</i>) spheroid TTR oligomers. The numbers above the modes correspond to the mean values of gaussian fits.</p

Formation and disappearance of annular oligomers.

<p><b>A.</b> Dynamic light scattering spectra of native TTR and at given time points after the start of acidification where the emergence of a small population of larger particles follows a trend towards smaller apparent hydrodynamic radii (Rh_app). <b>B.</b> Time course of the apparent size of the different populations during aggregation and their corresponding weighted average. The arrows indicate the times points where images shown in C and D were taken. <b>C & D.</b> AFM images (phase contrast) of particles taken at 9 and 12 h respectively and where annular oligomers (C) and spheroid (D) oligomers can be observed. The inset represents a 50×50 nm topography image of the corresponding samples (height scale up to 2.5 nm) <b>E.</b> Height-contrast AFM image of annular oligomers undergoing transitions. <b>E.</b> Magnified view of fusing annular oligomers indicated in <i>D</i>. Height, amplitude and phase contrast images (left to right) are shown. Scale bar, 10 nm.</p

Disassembly of TTR protofibrils.

<p><b>A.</b> AFM height contrast image recorded after 1 minute of sample dilution into PBS. <b>B.</b> AFM height (top) and amplitude (bottom) contrast images recorded after 5 minutes of sample dilution into PBS. <b>C.</b> AFM height (top) and amplitude (bottom) contrast images recorded after 15 minutes of sample dilution into PBS. <b>Insets</b>, magnified image of a single annular oligomer (left) and a laterally-associated doublet of annular oligomers (right). <b>D.</b> Distribution of the diameter of annular oligomers observed during assembly (yellow) and disassembly (purple). <b>E.</b> Distribution of the topographical height of annular oligomers observed during assembly (yellow) and disassembly (purple).</p

Model of TTR protofibril assembly and disassembly.

<p>Relevant dimensions and periodicity parameters of the intermediates are indicated where applicable. Length of the arrows scale with the hypothesized transition kinetics.</p