Blocking SLC7A11 attenuates the proliferation of esophageal squamous cell carcinoma cells.

The role of ferroptosis-associated gene SLC7A11 in esophageal cancer progression is largely unknown, therefore, the effects of blocking SLC7A11 on esophageal squamous cell carcinoma (ESCC) cells are evaluated. Results showed that SLC7A11 was overexpressed in ESCC tissues both in mRNA and protein levels. Blocking SLC7A11 using Erastin suppressed the proliferation and colony formation of ESCC cells, decreased cellular ATP levels, and improved ROS production. Sixty-three SLC7A11-binding proteins were identified using the IP-MS method, and these proteins were enriched in four signaling pathways, including spliceosome, ribosome, huntington disease, and diabetic cardiomyopathy. The deubiquitinase inhibitors PR-619, GRL0617, and P 22077 could reduce at least 40% protein expression level of SLC7A11 in ESCC cells, and PR-619 and GRL0617 exhibited suppressive effects on the cell viability and colony formation ability of KYSE30 cells, respectively. Erastin downregulated GPX4 and DHODH and also reduced the levels of ß-catenin, p-STAT3, and IL-6 in ESCC cells. In conclusion, SLC7A11 was overexpressed in ESCC, and blocking SLC7A11 using Erastin mitigated malignant phenotypes of ESCC cells and downregulated key ferroptosis-associated molecules GPX4 and DHODH. The therapeutic potential of targeting SLC7A11 should be further evaluated in the future.

DFT Study on the CO2 Reduction to C2 Chemicals Catalyzed by Fe and Co Clusters Supported on N-Doped Carbon.

The catalytic conversion of CO2 to C2 products through the CO2 reduction reaction (CO2RR) offers the possibility of preparing carbon-based fuels and valuable chemicals in a sustainable way. Herein, various Fen and Co5 clusters are designed to screen out the good catalysts with reasonable stability, as well as high activity and selectivity for either C2H4 or CH3CH2OH generation through density functional theory (DFT) calculations. The binding energy and cohesive energy calculations show that both Fe5 and Co5 clusters can adsorb stably on the N-doped carbon (NC) with one metal atom anchored at the center of the defected hole via a classical MN4 structure. The proposed reaction pathway demonstrates that the Fe5-NC cluster has better activity than Co5-NC, since the carbon-carbon coupling reaction is the potential determining step (PDS), and the free energy change is 0.22 eV lower in the Fe5-NC cluster than that in Co5-NC. However, Co5-NC shows a better selectivity towards C2H4 since the hydrogenation of CH2CHO to CH3CHO becomes the PDS, and the free energy change is 1.08 eV, which is 0.07 eV higher than that in the C-C coupling step. The larger discrepancy of d band center and density of states (DOS) between the topmost Fe and sub-layer Fe may account for the lower free energy change in the C-C coupling reaction. Our theoretical insights propose an explicit indication for designing new catalysts based on the transition metal (TM) clusters supported on N-doped carbon for multi-hydrocarbon synthesis through systematically analyzing the stability of the metal clusters, the electronic structure of the critical intermediates and the energy profiles during the CO2RR.

Cu2+ activated persulfate for sulfamethazine degradation.

Sulfonamide antibiotics (SAs) are widely used in veterinary medicine but are poorly metabolized in biological systems; thus, they can cause a selective pressure to promote the proliferation of antibiotic resistant pathogens and threaten human health. Persulfate (PS)-based advanced oxidation processes (AOPs) have been applied for SA degradation, but using transition metal ions as PS activators is relatively limited. In this study, sulfamethazine (SMZ) was used as a model SA to evaluate the performance of a Cu2+ -activated PS system. Cu2+-PS exhibited better SMZ removal than other metal ions, and 25 mg/L SMZ can be degraded in the presence of 0.2 mM Cu2+ and 2.5 g L-1 PS within 120 min. Various anions inhibited SMZ degradation to different degrees except HCO3-. Among the cations, Fe3+ significantly inhibited SMZ removal, while Ni2+ increased the removal rate. High concentrations of humic acid and protein also increased the degradation rate of SMZ. Radical and singlet oxygen quenching experiments, together with the results of electron spin-resonance spectroscopy (ESR), showed that the main active species generated from Cu2+-PS are SO4·- and ·OH. The degradation pathway of SMZ was identified through HPLC-HRMS. Direct SO4·- and ·OH oxidation products of SMZ were not found, suggesting that the complex formed between Cu2+ and SMZ may affect the fate of SMZ. On the other hand, the efficiency and selectivity of Cu2+-PS against different SAs were confirmed. Overall, this study provides a facile and effective method for SMZ and other SA removal.

Detection and miss rates of autofluorescence imaging of adenomatous and polypoid lesions during colonoscopy: a systematic review and meta-analysis.

BACKGROUND AND STUDY AIMS: Autofluorescence imaging (AFI) is an endoscopic imaging technique used to increase the detection of premalignant gastrointestinal lesions, and it has gradually become popular in recent years. This meta-analysis was performed to examine whether AFI provides greater efficacy in the detection of adenomatous and polypoid lesions and can even prevent the failure to detect a single adenoma or polyp. The aim of the study was to systematically review the efficacy of AFI in increasing detection rates and decreasing miss rates. METHODS: Pertinent articles were identified through a search of databases up to December 2013 that included patients who had undergone two same-day colonoscopies (AFI and white light endoscopy [WLE]), followed by polypectomy. Fixed and random effects models were used to detect significant differences between AFI and WLE in regard to adenoma detection rate (ADR), polyp detection rate (PDR), adenoma miss rate (AMR), polyp miss rate (PMR), and procedural time. RESULTS: A total of 1199 patients from six eligible studies met the inclusion criteria. No significant differences were found in ADR (odds ratio [OR] 1.01; 95 % confidence interval [95 %CI] 0.74 - 1.37), PDR (OR 0.86; 95 %CI 0.57 - 1.30), or advanced ADR (OR 1.22; 95 %CI 0.69 - 2.17). The AMR (OR 0.62; 95 %CI 0.44 - 0.86) and PMR (OR 0.64; 95 %CI 0.48 - 0.85) by AFI were significantly lower than those by WLE. The procedural time of AFI was significantly longer than that of WLE (mean 8.00 minutes; 95 %CI 1.59 - 14.41). Subgroup meta-analysis for the other characteristics was not performed because of insufficiency of the primary data. CONCLUSIONS: AFI decreases AMR and PMR significantly compared with WLE but does not improve ADR or PDR. AMR and PMR may be decreased by using AFI in flat and small lesions or when less experienced endoscopists perform the procedure.

Biosorption of Zn(II) on the different Ca-alginate beads from aqueous solution.

The performance of a new biosorbent system, consisting of a fungal biomass immobilized within an orange peel cellulose absorbent matrix, for the removal of Zn(2+) heavy metal ions from an aqueous solution was tested. The amount of Zn(II) ion sorption by the beads was as follows; orange peel cellulose with Phanerochaete chrysosporium immobilized Ca-alginate beads (OPCFCA) (168.61 mg/g) > orange peel cellulose immobilized Ca-alginate beads (OPCCA) (147.06 mg/g) > P. chrysosporium (F) (125.0 mg/g) > orange peel cellulose (OPC) (108.70 mg/g) > plain Ca-alginate bead (PCA) (98.26 mg/g). The Zn(2+) concentration was 100 to 1000 mg/L. The widely used Langmuir and Freundlich isotherm models were utilized to describe the biosorption equilibrium process. The isotherm parameters were estimated using linear and non-linear regression analysis. The Box-Behnken model was found to be in close agreement with the experimental values, as indicated by the correlation coefficient value of 0.9999.

Structural studies of Na-montmorillonite exchanged with Fe2+, Cr3+, and Ti4+ by N2 adsorption and EXAFS.

The structures of Fe(2+)-, Cr(3+)-, and Ti(4+)-modified montmorillonite prepared from ion exchange of the Na-clay with Fe(2+), Cr(3+), and Ti(4+) were investigated. Conventional BET surface area and spectroscopic analysis by extended adsorption fine structure (EXAFS) were applied. It was shown that the BET surface area of Na-clay was similar to that of Fe-clay, but somewhat different from those of Cr- and Ti-clay; it decreased in the order Na- > Fe- > Ti- > Cr-montmorillonite. This sequence appeared to be consistent with the ion size Na(+) (0.95 nm)>Fe(2+) (0.65 nm)>Cr(3+) (0.62 nm), except for Ti(4+) (0.69 nm). EXAFS data showed that some Si atoms within montmorillonite were replaced by Ti atoms and that a neostructure of titanium oxide was formed.

Adsorption of basic dyes onto montmorillonite.

Ca-montmorillonite (Ca-Mont) was exchanged with titanium cations and the adsorption equilibrium and kinetics of Basic Green 5 (BG5) and Basic Violet 10 (BV10) on these montmorillonites were measured to examine the ion-exchange effects on the basic dyes adsorption. The relationship between the dye adsorption and the alteration of pore structures of montmorillonite induced by ion-exchange processes was discussed. Moreover, the changes in the surface and pore structure of montmorillonites during adsorption were characterized based on classical and fractal analyses of the nitrogen adsorption isotherms as well as the XRD patterns. The decrease in BET surface area of montmorillonites after adsorption of dyes was interpreted in terms of both the coverage of some surface roughness (surface screening effect) and the inhibition of the movement of nitrogen molecule into some pores (pore blocking effect). The surface fractal dimension D was used to examine whether or not the surface screening effect exists and the pore blocking effect was examined with the changes of mean pore size before and after adsorbing basic dyes.