[Comparative study on different methods of detecting eosinophils in nasal polyps]

Objective: To investigate whether there were differences between the three stains for eosinophil counting in nasal polyps. Method: Three serial sections of formalin-fxed, paraffn-embedded tissues of 23 cases of nasal polyps were stained with Congo red,Chromotrope 2R and conventional HE staining, respectively. The stained sections were converted to digital pathology using a digital slice scanner. The qualitative assessment of the staining results was made in terms of specificity, contrast and background staining. Eosinophils were quantitatively evaluated and statistically analyzed using the Image J Analysis System and GraphPad Prism 5 statistical software. Result: Congo red staining and Chromotrope 2R staining were more specific than conventional HE staining. Chromotrope 2R had the lowest background staining. The majority of Congo red staining (n=20) was lighter in the background than in the conventional HE, while a small number of cases (n=3) background staining slightly stronger. Both Congo red staining and Chromotrope 2R staining had statistically significant differences compared with conventional HE staining (P<0.05), but there was no significant difference between Congo red staining and Chromotrope 2R staining (P>0.05). Conclusion: Congo red staining and Chromotrope 2R staining are more suitable for accurate counting of eosinophils, and the use of these two methods contributes to the harmonization of eosinophil count criteria in the ECRSwNP definition.

Definitive screening design applied to electrochemical degradation of Chromotrope 2R with BDD anodes

Here, a novel three-level definitive screening design (DSD) was initially employed to investigate the electrochemical degradation of Chromotrope 2R (C2R) with boron-doped diamond (BDD) anodes. Experiments were performed using a synthetic C2R solution containing five supporting electrolytes (Na₂SO₄, NaCl, Na₃PO₄, NaNO₃ and Na₂CO₃). The effects of nine quantitative parameters on C2R removal rate: initial C2R concentration (50-100 mg L^-1), applied current density (1.29-3.87 mA cm^-2), Na₂SO₄ concentration (0-10 mM), NaCl concentration (0-10 mM), Na₃PO₄ concentration (0-10 mM), NaNO₃ concentration (0-10 mM), Na₂CO₃ concentration (0-10 mM), flow rate (300-500 mL min^-1) and temperature (10-50 °C), were investigated. The model obtained was validated and used to select three most significant variables for further investigation. Interestingly, the differing roles of electrolytes during the electrolysis revealed the ion-selective nature of BDD anode system. A five-level central composite rotatable design (CCRD) was then employed to describe the C2R conversion as a function of applied current density, NaCl concentration and temperature. The results obtained confirmed the strong capability of DSD to separate and identify the significant variables in BDD technology. Moreover, the strategy (DSD plus CCRD) employed here enabled a significant reduction in the number of experiments (from over 500 to only 38) compared to traditional screening methods. The possible degradation mechanism of C2R in BDD anode cells was also proposed.

Application of montmorillonite-Cu(II)ethylenediamine catalyst for the decolorization of Chromotrope 2R with H₂O₂ in aqueous solution

The kinetics of decolorization of Chromotrope 2R (C2R) was studied spectrophotometrically using the montmorilloniteK10-Cu(II)ethylenediamine composite (MMTK10-Cu(en)2) as catalyst and H2O2 as oxidant in aqueous solution. The catalyst was prepared and characterized by SEM, FTIR, XRD and TGA techniques. The dependence of reaction rate on H2O2 concentration was examined under UV irradiation in the presence and absence of the catalyst, and in the presence of the catalyst without the UV irradiation. In all these reaction systems, the rate increased up to a maximum value and then decreased. The rate increased with increasing the concentration of the dye reaching a maximum. Also, the rate of decolorization reaction showed a significant increase with increasing the amount of the catalyst and temperature. The addition of NaCl to the reaction medium has accelerated the rate effectively. A similar catalyst, MMTKSF-Cu(en)2, has also been employed and was found to be less efficient compared with MMTK10-Cu(en)2.