Pd/MIL-100(Fe) as hydrogen activator for FeIII/FeII cycle: Fenton removal of sulfamethazine.

Masses of iron sludge generated from engineering practice of classic Fenton reaction constraints its further promotion. Accelerating the FeIII/FeII cycle may be conducive to reducing the initial ferrous slat dosage and the final iron sludge. Based on the reduction of Pd/MIL-100(Fe)-activated hydrogen, an improved Fenton system named MHACF-MIL-100(Fe) was developed at ambient temperature and pressure. 97.8% of sulfamethazine, the target pollutant in this work, could be degraded in 5 min under the conditions of 20 mM H2O2, 25 µM ferrous chloride, initial pH 3.0, 2 g·L-1 composite catalyst Pd/MIL-100(Fe) and hydrogen gas 60 mL·min-1. Combining density functional theory (DFT) calculation and intermediate detection, the degradation of this antibiotic was inferred to start from the cleavage of N-S bond. The catalytic of Pd/MIL-100(Fe), demonstrated by the removal efficiency of SMT and the catalyst morphology, remained intact after six reaction cycles. The present study provides an insight into the promotion of Fenton reaction.

Accelerated iron valence cycling in Fenton system using activated hydrogen enhanced by MIL-100(Fe) modified by nano-Pd0 Particle.

In this paper, a novel Fenton reaction system which was called MHACF-MIL-100(Fe) was constructed. In this system, based on active hydrogen-accelerated FeIII reduction, the hydroxyl radical was continuously produced with a trace amount of total iron. The MIL-100(Fe) modified with the nano-Pd0 particle could be used to activate the H2. Under normal temperature and pressure, the target organic pollutants, such as sulfamethazine and 4-chloro phenol, could be degraded fast. In the condition of initial aqueous solution pH 3, 2 g L-1 dosage of MIL-100(Fe) catalyst loaded with nano-Pd0, Pd/MIL-100(Fe), 20 mM 30 wt% hydrogen peroxide, 25 µM ferrous chloride and 60 mL H2 min-1, 97.8% of sulfamethazine and 100% 4-chloro phenol could be degraded within only 5 min, respectively. Although the surface of the catalyst exhibited more obvious defects and roughness after 5 consecutive destructive experiment cycles, its basic structure could be maintained. The removal efficiency could be maintained at least more than 79% (sulfamethazine) and 94% (4-chloro phenol). That may be mainly attributed to the degradation of hydroxyl radical.

Continuous synthesis of carbon dots with full spectrum fluorescence and the mechanism of their multiple color emission.

Carbon dots with different emission fluorescence have a great number of potential applications for various areas from in vitro imaging and biotherapy, due to the good biosafety of red fluorescent CDs, to efficient ion detection and photocatalysis, due to the excellent photoluminescence properties of blue fluorescent carbon dots. Traditional methods for the synthesis of full-spectrum carbon dots require 24 h of synthesis and complex column chromatography. In this paper, a facile and efficient microfluidic method to continuously synthesize small and uniform carbon dots with full-spectrum emission fluorescence is developed for the first time. The synthesis process could be reduced to 20 minutes. Through XPS analysis and DFT calculations, it is quantitatively revealed that the number of primary amino groups determines the energy gap of the carbon dots and thus determines the fluorescence emission wavelength of the carbon dots. Applications for precise Fe3+ detection and in vitro bio-imaging were successfully implemented, showing great potential application value of the carbon dots.

Risk factors for proton pump inhibitor refractoriness in Chinese patients with non-erosive reflux disease.

AIM: To analyze risk factors for refractoriness to proton pump inhibitors (PPIs) in patients with non-erosive reflux disease (NERD). METHODS: A total of 256 NERD patients treated with the PPI esomeprazole were enrolled. They were classified into symptom-free and residual symptoms groups according to Quality of Life in Reflux and Dyspepsia (QolRad) scale. All subjects completed questionnaires on psychological status (self-rating anxiety scale; self-rating depression scale) and quality of life scale (Short Form 36). Multivariate analysis was used to determine the predictive factors for PPI responses. RESULTS: According to QolRad, 97 patients were confirmed to have residual reflux symptoms, and the remaining 159 patients were considered symptom free. There were no significant differences between the two groups in lifestyle factors (smoking and alcohol consumption), age, Helicobacter pylori infection, and hiatal hernia. There were significant differences between the two groups in relation to sex, psychological distress including anxiety and depression, body mass index (BMI), and irritable bowel syndrome (IBS) (P < 0.05). Logistic regression analysis found that BMI < 23, comorbid IBS, anxiety, and depression were major risk factors for PPI resistance. Symptomatic patients had a lower quality of life compared with symptom-free patients. CONCLUSION: Some NERD patients are refractory to PPIs and have lower quality of life. Residual symptoms are associated with psychological distress, intestinal disorders, and low BMI.

Controllable microfluidic production of gas-in-oil-in-water emulsions for hollow microspheres with thin polymer shells.

Here we developed a simple and novel one-step approach to produce G/O/W emulsions with high gas volume fractions in a capillary microfluidic device. The thickness of the oil layer can be controlled easily by tuning the flow rates. We successfully used the G/O/W emulsions to prepared hollow microspheres with thin polymer shells.

Controllable gas/liquid/liquid double emulsions in a dual-coaxial microfluidic device.

This article presents a simple and novel approach to prepare monodispersed gas-in-oil-in-water (G/O/W) and gas-in-water-in-oil (G/W/O) double-emulsions in the same dual-coaxial microfluidic device. The effects of three phase flow rates on the sizes of microbubbles and droplets and the number of the encapsulated microbubbles were systematically studied. We successfully synthesized two different types of gas/liquid/liquid (G/L/L) double emulsions with different inner structures in the same geometry by adjusting the flow rates sequentially. Mathematical models were developed to predict the size and structures of the double emulsions. This simple approach gives a new idea for preparing hollow and porous microspheres with microbubbles as the direct core/pores templates.