The effect of combined maxillary pad movable appliance and FR-III functional appliance in the treatment of skeletal Class III malocclusion of deciduous teeth.

BACKGROUND: To evaluate the therapeutic effect of maxillary pad movable appliance combined with FR-III functional appliance in treating skeletal Class III malocclusion of deciduous teeth and provide a reference for optimizing clinical treatment methods. METHODS: A total of 30 pediatric patients were randomly selected between April 2012 and April 2019. They were in stage IIA osseous skeletal Class III malocclusion, treated with maxillary pad movable appliance to relieve the reverse, combined with FR-III functional appliance to maintain a median relationship to stage IIIA. A self-control study of children before and after treatment was used, and paired t-test was used to evaluate the changes in the measurement indexes of the IIA and IIIA stage X-rays and changes in the bone and soft tissue profiles. RESULTS: After 3 years of treatment, SNA, ANB, and NA-PA in the sagittal osteofacial index of the jawbones increased, SNB decreased, and the Y-axis angle in the vertical index of the jawbones increased. U1-SN, U1-NA, U1-NA distance, L1-MP, L1-NB, and L1-NB distance in the index of labial inclination of upper and lower central incisors increased, while U1-L1 decreased. The sagittal anomalies of the jawbones were improved, and there were significant differences before and after treatment (P < 0.05). FCA, ULP, and UL-EP increased, soft-tissue facial prominence and facial height increased, and the relationship between the upper lip and the aesthetic plane was harmonious. None of the 30 children with skeletal Class III malocclusion in the deciduous stage experienced recurrence in stage IIIA. CONCLUSIONS: Combined treatment with the maxillary pad movable appliance and the FR-III functional appliance is suitable for children with skeletal Class III malocclusion in the deciduous stage.

Application of sulfate radicals-based advanced oxidation technology in degradation of trace organic contaminants (TrOCs): Recent advances and prospects.

The large amount of trace organic contaminants (TrOCs) in wastewater has caused serious impacts on human health. In the past few years, Sulfate radical (SO4•-) based advanced oxidation processes (SR-AOPs) are widely recognized for their high removal rates of recalcitrant TrOCs from water. Peroxymonosulfate (PMS) and persulfate (PS) are stable and non-toxic strong oxidizing oxidants and can act as excellent SO4•- precursors. Compared with hydroxyl radicals(·OH)-based methods, SR-AOPs have a series of advantages, such as long half-life and wide pH range, the oxidation capacity of SO4•- approaches or even exceeds that of ·OH under suitable conditions. In this review, we present the progress of activating PS/PMS to remove TrOCs by different methods. These methods include activation by transition metal, ultrasound, UV, etc. Possible activation mechanisms and influencing factors such as pH during the activation are discussed. Finally, future activation studies of PS/PMS are summarized and prospected. This review summarizes previous experiences and presents the current status of SR-AOPs application for TrOCs removal. Misconceptions in research are avoided and a research basis for the removal of TrOCs is provided.

Insights into the mechanism of enhanced peroxymonosulfate degraded tetracycline using metal organic framework derived carbonyl modified carbon-coated Fe0.

Tetracycline (TC) is a commonly used antibiotic that has gained wide spread notoriety owing to its high environmental risks. In this study, rich carbonyl-modified carbon-coated Fe0 was obtained by pyrolysis of MIL-100(Fe) in an Ar atmosphere, and used to activate peroxymonosulfate (PMS) for the degradation of tetracycline in water. The roles of Fe0, carbon and surface carbonyl on PMS activation were investigated. Fe0 continuously activated PMS, acted as a sustained-release source of Fe2+, and could effectively activate PMS to produce SO4•-, O2•- and •OH. Carbon was found to do responsible for electron transportation during the activation of PMS and slow down the oxidation of Fe0. The carbonyl group on the carbon surface layer was the active site of 1O2, which explains the enhanced performance for TC degradation. When Ca = 0.1 g/L and C0 = 0.4 mM, TC degradation rate reached 96%, which was attributed to the synergistic effect of radicals (i.e., SO4•-, O2•-, •OH) and non-radical (i.e., 1O2). Finally, the degradation pathway was proposed by combining density functional theory (DFT) calculations with liquid chromatography-mass spectrometry (LC-MS), toxicities of the intermediate products were also evaluated. All results show that carbonyl-modified carbon-coated Fe0 possesses promising capacity for the removal of antibiotics from water.

Bicarbonate-enhanced iron-based Prussian blue analogs catalyze the Fenton-like degradation of p-nitrophenol.

P-nitrophenol (PNP), a widely used compound, is harmful to the environment and human health. In this study, four iron-based Prussian blue analogs (PBAs) were prepared by coprecipitation (Co-Fe PBA, Mn-Fe PBA, Cu-Fe PBA and Fe-Fe PBA). The Co-Fe PBA exhibited high peroxymonosulfate (PMS) activation performance for PNP degradation, removing over 90% of PNP in 60 min at an optimal pH of 7, temperature at 30 ℃, initial concentration of 20 mg/L, PBA dose of 0.2 g/L and PMS dose of 1 g/L. The physicochemical properties of the Co-Fe PBA were investigated by various characterization methods. The catalytic activity of PBA and the influence of various process parameters and water quality on the catalytic reaction were investigated to elucidate the mechanism of p-nitrophenol degradation by PBA-activated persulfate. Moreover, the mechanism of accelerated degradation of PNP under HCO3- conditions and the role of major reactive oxides were determined by EPR measurement methods and free radical trapping experiments. HCO3- was found to directly activate PMS to produce reactive oxygen species, and 1O2, ∙OH and SO4∙- were all greatly increased. This work presents a promising green heterogeneous catalyst for the degradation of emerging contaminants (ECs) in real wastewater with natural organic matter and coexisting anions by PMS activation.

[Biological availability of zinc lignosulfonate on calcareous soil of north Guoangdong Province].

Zinc lignosulfonate (Zn-LS) is a kind of organic fertilizers made from the by-products of paper industry. With leach and plot treatments, this paper studied the difference of the biological availability between Zn-LS and an inorganic Zn-fertilizer on calcareous soil of north Guangdong Province. The results indicated that the Zn of Zn-LS was less absorbed by calcareous soil. In soil B, when applying 10 mg x kg(-1) Zn, the dissolved amount of Zn-LS was 65.2% higher than that of inorganic Zn-fertilizer, corn grew well, and its biomass was higher. In soil A, when applying 10 mg x kg(-1) Zn of Zn-LS, the biomass of corn increased by 16.3%, and its Zn content was 81.2% higher. Therefore, biological availability of Zn-LS was better than that of inorganic Zn fertilizer.

[Effect of lignosulfonates on controlling of urea nitrogen transformation and nitrate accumulation in vegetable].

Indoor cultivation experiment and plot field experiment were conducted to study the effect of lignosulfonates on urea nitrogen transformation in soil and the mechanism of controlling nitrate pollution in vegetable. Results showed that lignosulfonates behaved inhibition effect on urea hydrolysis compared with the contrast treatment, the contents of remainder urea nitrogen treated with lignosulfonates was more than that of another kind of urease inhibitor hydroquinone in soil after 69 hours' cultivation. Lignosulfonates could reduce contents of nitrate in cabbage, it as well increase contents of vitamin C in a large degree, enhance the nitrate reductase activity, then accelerated nitrogen assimilation in plants. The urease activity was lower and contents of ammonium nitrogen in soil was larger after ingathering, lignosulfonates could keep nitrogen release slowly, and could be used as a kind of effective inhibitor to nitrogen fertilizer in the controlled-release fertilizers.