Evolution 60s uv visible spectrophotometer

Total phenolic content (TPC as mg/L of gallic acid equivalents) was determined according to Gambacorta et al. [37] (link). Flavonoids (F, as mg/L of (+)-catechin), anthocyanins (A, as mg/L of malvidin-3-glucoside), flavans reactive with vanillin (FRV, as mg/L of (+)-catechin) and proanthocyanidins (P, as mg/L of cyanidin chloride) were determined according to Gambacorta et al. [38] . Colour indices (T, tonality; CI, colour intensity) were evaluated according to the Glories procedure [39] . An Evolution 60 s UV–visible spectrophotometer (ThermoFisher Scientific, Rodano, Italy) was employed for the spectrophotometric measures.

The ferric reducing antioxidant power (FRAP) assay was performed according to the modified procedure described by Benzie and Strain [33 (link)]. Briefly, 50 μL of the sample or Trolox solution was mixed with 1000 μL of working FRAP reagent. The reaction mixture was thermostatted for 4 min at 37 °C. The absorbance was measured against the blank solution at 593 nm using an Evolution 60S UV-Visible spectrophotometer (Thermo Scientific, Waltham, MA, USA). The working FRAP reagent was prepared by mixing 20 mM iron (III) chloride and 10 mM TPTZ solutions with 300 mM acetate buffer (pH 3.6) in a proportion of 1:1:10, respectively. All samples were analysed in triplicate. The results were expressed as micromoles of Trolox equivalents per gram of dry matter of plant material (μM Trolox/g d.w.) based on the calibration curve: y = 0.0021x − 0.0108, R² = 0.998 (μM/L).

Dissolution testing was carried out using an Erweka light DT 126 (Erweka Gmbh, DE) with an apparatus 2 paddle rotating at 100 rpm. A 0.1 M hydrochloric acid medium was freshly prepared using double-distilled water and maintained at 37 °C with pH1.2. Dissolution samples were collected at 1 min, 2.5 min, 5 min, 15 min, 30 min, 45 min and 60 min in 5 mL aliquots each time using emerald plastic syringes (Fisher Scientific, Loughborough, UK), passed through 0.45 µm PVDF syringe filter (Fisher Scientific, Loughborough, UK) and diluted further with 10 mL dissolution media. All diluted samples were measured at 254 nm using the Evolution 60S UV-Visible spectrophotometer (Thermo Fisher Scientific, Loughborough, UK).

Following decellularization, 200 μL of the veins′ storage buffer was added to 2 mL Luria Broth for incubation at 37°C for 5 days. OD was measured at 600 nm with Evolution 60s UV-visible Spectrophotometer (Thermofisher, USA). Potential bacterial contamination was determined by comparison against a negative control (Luria Broth without added components).

DPV is poorly soluble in water (<1 µg/mL), making it difficult to assess its release from the formulations [5 (link)]. There have been numerous attempts to adequately evaluate the release of DPV from different types of formulations, and most to date have used media based on isopropanol [13 (link),34 (link)]. In this scenario, it was necessary to select a dissolution medium to overcome the low solubility of this drug in water in order to perform the release test in sink conditions. DPV solubility was therefore assessed in various aqueous media: namely, isopropanol or propanol/water mixtures, isopropanol and propanol/SVF mixtures and SLS in water and SVF dissolutions. An excess of DPV was added to 5 mL of various media in test tubes, which were then introduced in a shaking water bath (Selecta^® UNITRONIC320 OR, Barcelona, Spain) at room temperature and 15 rpm. The saturation of all the media was obtained after 72 h. The samples were filtered and the concentration of DPV was evaluated in a UV-visible spectrophotometer (Thermo Fisher Scientific^® Evolution 60S UV-Visible Spectrophotometer, Waltham, MA, USA). All the results were compared to the desired solubility by a unilateral t-student comparison (H₀ → Solubility higher than desired, H₁ → Solubility equal to or lower than desired), α = 0.05.

Teflon™ filters were pre- and post-weighed using a Mettler Toledo ultramicrobalance (Model XP2U, Columbus, OH, USA) in a temperature- and humidity-controlled glovebox (PlasLabs Model 890 THC, Lansing, MI, USA) to determine total PM_2.5 mass. An EEL43M Smokestain Reflectometer (Diffusion Systems, Ltd., London, UK) was used to measure BC absorbance (abs); this method relies on optical properties of the sample (reflection of light through the exposed filter) to estimate the concentration of light-absorbing carbon in a PM sample. To further detail the elemental composition of PM_2.5, inductively-coupled plasma mass spectrometry (ICP-MS) was performed on Teflon™ filters according to documented protocols (ESS INO Method 400.4; EPA Method 1638) [35 (link)] by Wisconsin State Laboratory of Hygiene. Organic constituent concentrations were measured using thermal desorption gas-chromatography mass-spectrometry (TD-GCMS) on quartz fiber filters by Desert Research Institute (DRI) (Reno, NV, USA). For passive (24-h/day) NO₂ concentrations, Ogawa passive badges were analyzed by water-based extraction and spectrophotometry on a Thermo Scientific Evolution 60S UV-Visible Spectrophotometer, Waltham, MA, USA).