The mechanism of degradation of alizarin red by a white-rot fungus Trametes gibbosa.

BACKGROUND: Alizarin red (AR) is a typical anthraquinone dye, and the resulting wastewater is toxic and difficult to remove. A study showed that the white rot fungus Trametes gibbosa (T. gibbosa) can degrade dye wastewater by decolorization and has its own enzyme-producing traits. METHODS: In this study, transcriptome sequencing was performed after alizarin red treatment for 0, 3, 7, 10, and 14 h. The key pathways and key enzymes involved in alizarin red degradation were found to be through the analysis of KEGG and GO. The Glutathione S-transferase (GST), manganese peroxidase (MnP) and laccase activities of T. gibbosa treated with alizarin red for 0-14 h were detected. LC-MS and GC-MS analyses of alizarin red decomposition products after 7 h and 14 h were performed. RESULTS: The glutathione metabolic pathway ko00480, and the key enzymes GST, MnP, laccase and CYP450 were selected. Most of the genes encoding these enzymes were upregulated under alizarin red conditions. The GST activity increased 1.8 times from 117.55 U/mg prot at 0 h to 217.03 U/mg prot at 14 h. The MnP activity increased 2.9 times from 6.45 to 18.55 U/L. The laccase activity increased 3.7 times from 7.22 to 27.28 U/L. Analysis of the alizarin red decolourization rate showed that the decolourization rate at 14 h reached 20.21%. The main degradation intermediates were found to be 1,4-butene diacid, phthalic acid, 1,1-diphenylethylene, 9,10-dihydroanthracene, 1,2-naphthalene dicarboxylic acid, bisphenol, benzophenol-5,2-butene, acrylaldehyde, and 1-butylene, and the degradation process of AR was inferred. Overall, 1,4-butene diacid is the most important intermediate product produced by AR degradation. CONCLUSIONS: The glutathione metabolic pathway was the key pathway for AR degradation. GST, MnP, laccase and CYP450 were the key enzymes for AR degradation. 1,4-butene diacid is the most important intermediate product. This study explored the process of AR biodegradation at the molecular and biochemical levels and provided a theoretical basis for its application in practical production.

Prognostic value of the SYNTAX score on myocardial injury and salvage in STEMI patients after primary percutaneous coronary intervention: a single-center retrospective observational study.

BACKGROUND: SYNTAX score (SS) was shown to positively correlate with postprocedural myocardial injury in patients after elective coronary artery intervention, but evidence about the association of SS with myocardial salvage in ST-segment elevation myocardial infarction (STEMI) patients is still needed. This study aimed to evaluate the prognostic value of SS for myocardial injury and salvage assessed by cardiac magnetic resonance (CMR) after primary percutaneous coronary intervention (PCI) in STEMI patients. METHODS: This single-center retrospective study consecutively enrolled STEMI patients who had undergone primary PCI within 12 h from symptom onset. Both angiography and CMR were performed during hospitalization, and patients were divided into low SS (SS ≤ 22), mediate-high SS (SS > 22) groups. Correlation and multivariable analyses were performed. RESULTS: A total of 149 STEMI patients (96 low SS, 53 mediate-high SS) were included. In terms of myocardial injury parameters, there was a positive correlation (p < 0.001, Spearman r = 0.292) between SS and infarct size (IS), and a negative correlation (p < 0.001, Spearman r = - 0.314) between SS and myocardial salvage index (MSI). In the multivariable model, SS (> 22 as categorical variable, OR = 2.245, 95% CI [1.002-5.053], p = 0.048; as continuous variable, OR = 1.053, 95% CI [1.014-1.095], p = 0.008) was significantly associated with high IS (≥ mean 35.43). The areas under the receiver operating characteristic (ROC) curves of SS for high IS and low MSI (≤ median 28.01) were 0.664 and 0.610. CONCLUSIONS: In STEMI patients undergoing primary PCI, SYNTAX score positively correlated with infarct size and negatively with myocardial salvage, indicating an independent predictive value of the myocardial injury.

Effect of alkali cations on heterogeneous photo-Fenton process mediated by Prussian blue colloids.

This article evaluates Prussian blue (iron hexacyanoferrate) colloids as a heterogeneous photo-Fenton catalyst for the degradation of Rhodamine B. The emphasis is laid on the effects of alkali metal cations on the photo-Fenton process. The facts show that alkali cations strongly affect the degradation rate of organic species. The degradation rates of Rhodamine B, Malachite Green, and Methyl Orange in the presence of KCl, KNO(3), and K(2)SO(4), respectively, are faster than their degradation rates in the presence of the corresponding sodium salts. The average degradation rates of Rhodamine B in 0.2 M KCl, NaCl, RbCl, and CsCl solution, decline in sequence, and the rate in KCl solution is greater than that without any salt added deliberately. Thus, potassium ions accelerate the degradation rate, but sodium, rubidium, and cesium ions slow the rate. The order of the rates is R(K)>R>R(Na)>R(Rb)>R(Cs), which is consistent with that of the voltammetric oxidation currents of Prussian blue in the corresponding cation solutions. This phenomenon is attributed to the molecular recognition of the microstructure in Prussian blue nanoparticles to the alkali cations. The reaction mechanism of the photo-Fenton process has also been explored.