Using the 4^th derivatives of reproducibility water spectra.

<p>Fourth derivative spectra of 10 scans of refilled water (reproducibility test) prepared with different gap sizes (offset was applied for visualization).</p

Air spectra for detecting spectral errors.

<p>Spectra of blank air recorded shortly after a reference scan or two hours later.</p

Water spectra used for performance tests.

<p>a) Plot of 10 spectra for repeatability and reproducibility tests, respectively (offset was applied for visualization), and b) the mean spectra of the two tests.</p

Evaluation of SD and CV of water spectra.

<p>a) SD plots and b) CV plots of the reproducibility and repeatability tests done with 10 scans, respectively.</p

Using the 4^th derivatives of repeatability water spectra.

<p>Fourth derivative spectra of 10 consecutive scans of water (repeatability test) prepared with different gap sizes (different levels of offset was applied for visualization).</p

Applicability of 700–800 nm spectral interval in water measurements.

<p>Second derivative spectra (with 5-point gap) of water recorded at different temperatures (see on upper color scale), using three different spectrometers.</p

Evaluating the mean centered water spectra.

<p>a) Spectra of 10 consecutive scans of water (repeatability test) and b) the mean centered spectra of the scans.</p

Evaluating spectra after subtraction of smoothed ones.

<p>a) Smooth-based noise spectrum of 10 consecutive water scans (repeatability test) and b) plot of cumulative noise.</p

Using the 4^th derivatives of air spectra.

<p>Fourth derivative spectra of blank air recorded shortly after a reference scan or two hours later, prepared with different gap sizes (different levels of offset was applied for visualization).</p

Schematic illustration representing multi-step transformation of water structures during the fibril formation.

<p>In the nucleation phase, free water molecules, free OH and protein hydrating water molecular species were initially dominating, but afterwards hydrogen-bonded water networks were developed, which was considered essential for nucleation by interlinking protein molecules. In the elongation phase, the hydrogen bonds were decayed gradually towards the state observed in bulk water, and slight increase of hydrating water onto amyloid fibrils was also observed. The aquagram patterns at 6, 10, 18 min are also represented at corresponding stages of the fibril formation.</p