Enhancement of UV-assisted TiO2 degradation of ibuprofen using Fenton hybrid process at circumneutral pH

A synergistic UV/TiO2/Fenton (PCF) process is investigated for the degradation of ibuprofen (IBP) at circumneutral pH. The IBP decay in the PCF process is much faster than that with the conventional UV, UV/H2O2, Fenton, photo-Fenton, and photocatalysis processes. The kinetics analysis showed that the IBP decay follows a two-stage pseudo-first order profile, that is, a fast IBP decay (k(1)) followed by a slow decay (k(2)). The effects of various parameters, including initial pH level, dosage of Fenton's reagent and TiO2, wavelength of UV irradiation, and initial IBP concentration, are evaluated. The optimum pH level, [Fe2+](0), [Fe2+](0)/[H2O2](0) molar ratio, and [TiO2](0) are determined to be approximately 4.22, 0.20 mmol/L, 1/40, and 1.0 g/L, respectively. The IBP decay at circumneutral pH (i.e., 6.0-8.0 for wastewater) shows the same IBP decay efficiency as that at the optimum pH of 4.22 after 30 min, which suggests that the PCF process is applicable for the treatment of wastewater in the circumneutral pH range. The lnk(1) and lnk(2) are observed to be linearly correlated to 1/pH(0), [IBP](0), [H2O2](0), [H2O2](0)/[Fe2+](0) and ln[TiO2](0). Mathematical models are therefore derived to predict the IBP decay. (C) 2018, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved

Enhanced photocatalytic degradation of ciprofloxacin over Bi2O3/(BiO)(2)CO3 heterojunctions: Efficiency, kinetics, pathways, mechanisms and toxicity evaluation

In this study, the degradation of antibiotic ciprofloxacin (CIP) over Bi2O3/(BiO)(2)CO3 heterojunctions under simulated solar light irradiation (SSL-Bi2O3/(BiO)(2)CO3) was examined for the first time. The results showed that the Bi2O3/(BiO)(2)CO3 heterojunctions dramatically improved CIP decay efficiency. The effect of parameters showed that the CIP decay was optimized with the Bi2O3/(BiO)(2)CO3 dosage of 0.5 g/L and a wide pH range of 4.0-8.3, based on which, a kinetic model was derived to predict the remaining CIP concentration. It was found that the presence of anions like SO42-, NO3- and HCO3- decelerated the CIP decay, while the co-existence of Cl- accelerated the CIP decay. Six degradation intermediates were identified by ultra-performance liquid chromatography coupled with mass analyzer (UPLC/MS) and ion chromatographic (IC) analysis, and the decay pathways and degradation mechanism of CIP were proposed by combining the experiment data with theoretical calculation of frontier electron densities. Hydroxyl radical's reaction, photo-hole (h(+)) oxidation and reductive defluorination were found to involve in the CIP decay. The efficient alleviation on total organic carbon (TOC) and toxicity indicated that the complete mineralization and de-toxicity are possible by this system with sufficient reaction time

Structural phase transitions in ionic conductor Bi 2 O 3 by temperature dependent XPD and XAS

The superionic behavior of cubic δ-phase Bi2O3, a metastable phase at high temperature, is of great interests from both scientific and technological perspectives. With the highest ionic conductivity among all known compounds, the δ-phase Bi2O3 possesses promising applications in solid-oxide fuel cells. Previous investigations pointed out the α to δ- phase transition occurs during the heating process, as supported by the X-ray and Neutron diffraction experiments. Through in situ measurements of the long-range order structure and the local structure by X-ray powder diffraction and X-ray absorption spectroscopy, we investigated the evolution of the structures under different temperatures. Both techniques provided ample evidence that the existence of meta-stable β-phase are crucial for forming the defective fluorite cubic δ phase. Our finding suggested that the phase transition from tetragonal β-phase to δ-phase is an influencing factor for the generation of the oxygen-ion pathways

Integrated Bioinformatic Analysis Reveals TXNRD1 as a Novel Biomarker and Potential Therapeutic Target in Idiopathic Pulmonary Arterial Hypertension

Idiopathic pulmonary arterial hypertension (IPAH) is a life-threatening cardiopulmonary disease lacking specific diagnostic markers and targeted therapy, and its mechanism of development remains to be elucidated. The present study aimed to explore novel diagnostic biomarkers and therapeutic targets in IPAH by integrated bioinformatics analysis. Four eligible datasets (GSE117261, GSE15197, GSE53408, GSE48149) was firstly downloaded from GEO database and subsequently integrated by Robust rank aggregation (RRA) method to screen robust differentially expressed genes (DEGs). Then functional annotation of robust DEGs was performed by GO and KEGG enrichment analysis. The protein-protein interaction (PPI) network was constructed followed by using MCODE and CytoHubba plug-in to identify hub genes. Finally, 10 hub genes were screened including ENO1, TALDO1, TXNRD1, SHMT2, IDH1, TKT, PGD, CXCL10, CXCL9, and CCL5. The GSE113439 dataset was used as a validation cohort to appraise these hub genes and TXNRD1 was selected for verification at the protein level. The experiment results confirmed that serum TXNRD1 concentration was lower in IPAH patients and the level of TXNRD1 had great predictive efficiency (AUC:0.795) as well as presents negative correlation with mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR). Consistently, the expression of TXNRD1 was proved to be inhibited in animal and cellular model of PAH. In addition, GSEA analysis was performed to explore the functions of TXNRD1 and the results revealed that TXNRD1 was closely correlated with mTOR signaling pathway, MYC targets, and unfolded protein response. Finally, knockdown of TXNRD1 was shown to exacerbate proliferative disorder, migration and apoptosis resistance in PASMCs. In conclusion, our study demonstrates that TXNRD1 is a promising candidate biomarker for diagnosis of IPAH and plays an important role in PAH pathogenesis, although further research is necessary

Low Expression of TBX4 Predicts Poor Prognosis in Patients with Stage II Pancreatic Ductal Adenocarcinoma

This study was designed to investigate the expression of the T-box transcription factor 4 (TBX4), a tumor biomarker that was previously identified by proteomics, in pancreatic ductal adenocarcinoma (PDAC) and evaluate its clinical utility as a potential prognostic biomarkers for PDAC. The expression of TBX4 was detected in 77 stage II PDAC tumors by immunohistochemistry, and the results were analyzed with regard to clinicopathological characteristics and overall survival. Moreover, Tbx4 promoter methylation status in primary PDAC tumors and normal adjacent pancreas tissues was measured by bisulfite sequencing. Among 77 stage II PDAC tumors, 48 cases (62.3%) expressed TBX4 at a high level. No significant correlation between TBX4 expression and other clinicopathological parameters, except tumor grade and liver metastasis recurrence, was found. The survival of patients with TBX4-high expression was significantly longer than those with TBX4-low expression (P = 0.010). In multivariate analysis, low TBX4 expression was an independent prognostic factor for overall survival in patients with stage II PDAC. TBX4 promoter methylation status was frequently observed in both PDAC and normal adjacent pancreas. We conclude that a low level of TBX4 expression suggests a worse prognosis for patients with stage II PDAC. Down-regulation of the TBX4 gene in pancreas is less likely to be regulated by DNA methylation

Enhanced effect of microdystrophin gene transfection by HSV-VP22 mediated intercellular protein transport

Background: Duchenne musclar dystrophy (DMD) is an X-linked recessive disease caused by mutations of dystrophin gene, there is no effective treatment for this disorder at present. Plasmidmediated gene therapy is a promising therapeutical approach for the treatment of DMD. One of the major issues with plasmid-mediated gene therapy for DMD is poor transfection efficiency and distribution. The herpes simplex virus protein VP22 has the capacity to spread from a primary transduced cell to surrounding cells and improve the outcome of gene transfer. To improve the efficiency of plasmid-mediated gene therapy and investigate the utility of the intercellular trafficking properties of VP22-linked protein for the treatment for DMD, expression vectors for C-terminal versions of VP22-microdystrophin fusion protein was constructed and the VP22-mediated shuttle effect was evaluated both in vitro and in vivo. Results: Our results clearly demonstrate that the VP22-microdystrophin fusion protein could transport into C2C12 cells from 3T3 cells, moreover, the VP22-microdystrophin fusion protein enhanced greatly the amount of microdystrophin that accumulated following microdystrophin gene transfer in both transfected 3T3 cells and in the muscles of dystrophin-deficient (mdx) mice. Conclusion: These results highlight the efficiency of the VP22-mediated intercellular protein delivery for potential therapy of DMD and suggested that protein transduction may be a potential and versatile tool to enhance the effects of gene delivery for somatic gene therapy of DMD.National Natural Science Foundation of China (30370510, 30170337); CMB Fund (4209347); the Key Project of the State Ministry of Public Health (2001321); and National Nature Science Foundation of China (30400322)

Quantitative investigation of two metallohydrolases by X-ray absorption spectroscopy near-edge spectroscopy

The last several years have witnessed a tremendous increase in biological applications using X-ray absorption spectroscopy (BioXAS), thanks to continuous advancements in synchrotron radiation (SR) sources and detector technology. However, XAS applications in many biological systems have been limited by the intrinsic limitations of the Extended X-ray Absorption Fine Structure (EXAFS) technique e.g., the lack of sensitivity to bond angles. As a consequence, the application of the X-ray absorption near-edge structure (XANES) spectroscopy changed this scenario that is now continuously changing with the introduction of the first quantitative XANES packages such as Minut XANES (MXAN). Here we present and discuss the XANES code MXAN, a novel XANES-fitting package that allows a quantitative analysis of experimental data applied to Zn K-edge spectra of two metalloproteins: Leptospira interrogans Peptide deformylase (LiPDF) and acutolysin-C, a representative of snake venom metalloproteinases (SVMPs) from Agkistrodon acutus venom. The analysis on these two metallohydrolases reveals that proteolytic activities are correlated to subtle conformation changes around the zinc ion. In particular, this quantitative study clarifies the occurrence of the LiPDF catalytic mechanism via a two-water-molecules model, whereas in the acutolysin-C we have observed a different proteolytic activity correlated to structural changes around the zinc ion induced by pH variations