Ph meter

Physicochemical analyses were executed following the guidelines of the Association of Official Analytical Chemists [13 ]. These analyses were conducted by triplicate for each production on the final days of ripening for each batch, utilizing the homogenized cheese employed in microbial analyses. The samples were homogenized in ultrapure water and measured using a pH meter (Hach Lange Spain S.L.U., Barcelona, Spain), previously calibrated with standard solutions from Scharlau Chemie S.A. The a_w was assessed using a Novasina Lab Master Water Activity Meter model SPRINT-TH 300 (Novasina AG, Lachen, Switzerland). The moisture content was determined through the dehydration of samples at 105 °C, supplemented with washed sea sand (Scharlau Chemie S.A.).
Instrumental color assessment was conducted using a Minolta CR-300 colorimeter (Konica Minolta, Osaka, Japan) equipped with illuminant D65, a 0° standard observer, and a 2.5 cm port/viewing area. The measurements were executed on the transversal section of the samples, following the principles outlined by the Commission Internationale de L’Éclairage [14 ]. Each sample underwent five measurements. The color coordinates measured included lightness (L*), redness (a*), and yellowness (b*).

Physicochemical analyses were conducted according to the Association of Official Agricultural Chemists [23 ]. They were performed for each production on days 0, 15, 30, and 60 for batches A, B, C, and D, by taking the homogenized cheese used for microbial analyses. The samples were homogenized in ultrapure water to be measured with a pH meter (Hach Lange Spain S.L.U., Barcelona, Spain) previously calibrated with standard solutions (Scharlau Chemie S.A.). The a_w was measured with a Novasina Lab Master Water activity meter model a_w SPRINT-TH 300 (Novasina AG, Lachen, Switzerland). Moisture content was calculated through the dehydration of samples at 105 °C with the addition of previously dehydrated washed sea sand (Scharlau Chemie S.A.).

The concentration of several growth factors involved in the ocular surface tissue regeneration, such as epidermal growth factor, platelet-derived growth factor, transforming growth factor-beta 1, vascular endothelial growth factor and insulin-like growth factor type I were analyzed to evaluate the lyophilization process effect on the PRGF eye drops. These growth factors were analyzed using the commercial enzyme-linked immunosorbent assay kits purchased from R&D Systems (Minneapolis, MN). The pH was analyzed with a pH meter (Hach Lange Spain; Barcelona, Spain), and the osmolarity was measured with the Advanced Model 3320 Micro-Osmometer (Tecil, Barcelona, Spain). All of these analyses were performed on the different PRGF samples obtained from the three healthy donors.

The activity level of the fungal cell-free (FCF) extracts in the synthesis of AgNPs was tested based on the studies of Al-Khuzai et al. [19 (link)]. AgNO₃ at a concentration of 0.5 mM (AgNO₃, Sigma-Aldrich St. Louis, MO, USA) was used, varying the reaction time (1, 3 and 6 h), temperature (20, 45 and 90 °C) and pH (6, 9 and 12), in the water bath (Julabo TW12, Seelbach, Germany). All reactions were conducted in triplicate.
The pH of the FCF extracts was adjusted using a pH meter (Hach, Cork, Ireland), sodium hydroxide (NaOH) and hydrochloric acid (HCl), both chemicals bought from Sigma-Aldrich (St. Louis, MO, USA). Ultrapure water and AgNO₃ were used as synthesis reaction control in the same reaction conditions.

The site was located at the Shanghai Chenshan Botanical Garden (N31°04′39″, E121°11′12″) in China. Soil pH and electrical conductivity were determined using a Hach pH meter (Hach Company, United States) and electrical conductivity instrument (Leici Company, China) on the supernatant of 1:5 soil and water mixtures. Soil properties were determined as outlined in Yan et al. (2009) (link); briefly, a SmartChem 200 flow-injection autoanalyzer was used to assess total N concentration (Kjeldahl) after digested with H₂SO₄ in glass tubes. Total C concentration of K₂SO₄-extracted solutions were measured using an automated Total Organic Carbon Analyzer (Shimadzu, TOC-Vcph, Japan). Soil organic matter (SOM) content using the oil bath—K₂CrO₄ titration method. Soil bulk density (BD) cores were also collected (using a 100 cm³ cylinder) from each plot for determination of BD, soil water content, and general porosity after being weighed before and after oven drying at 105°C for 24 h. The split-plot experimental design comprised four blocks divided in five 10 m × 10 m plots, in which the five treatments were randomly applied (Figure 1A). These treatments included spiking the soil with salts of different metals (Pb, Zn, and Cu), a treatment containing a mix of the three metals, and a control treatment without contamination. CuCl₂ (34.22 kg plot^-1), PbCl₂ (65.35 kg plot^-1), and ZnCl₂ (101.83 kg plot^-1) powders were applied as a spike to soil for each treatment in autumn 2014, mechanically incorporated into the first 25–30 cm, and left to equilibrate before samples were taken in autumn 2015 to assess metal content (Table 1). Four bulk soil samples (30 cm topsoil) taken in 2015 were homogenized and pooled for each plot. Soil samples were taken in a similar manner in autumn 2016 and soil was again assessed for metal content. Soil samples were air-dried before sieving (2-mm mesh) prior to Pb, Zn, and Cu concentration quantification using HNO₃ digestion for 5 h at 120°C, before inductively coupled plasma mass spectrometry. Each soil sample was assessed in duplicate (technical replicates), with method blanks and with reference material from the Chinese Academy of Measurement Sciences with recovery yields of all peaks ranging from 90 to 105%.