Mechanism of peroxymonosulfate activation by nanoparticle Co@N-C: Experimental investigation and theoretical calculation.

The release of organic dyes, such as Rhodamine B (RhB), into industrial wastewater has led to significant issues with color pollution in aquatic environments. Herein, we prepared a cobalt nanoparticles (NPs)-based catalyst with the nitrogen-doped carbon-support (Co@N-C) for effective PMS activation. The Co@N-C/PMS system demonstrated the excellent catalytic activity of Co@N-C for activating PMS, achieving nearly 100% degradation of RhB. Singlet oxygen (1O2) and sulfate radicals (SO4•-) were dominant reactive oxygen species for RhB degradation. Density functional theory (DFT) calculations substantiated that the production of 1O2 commenced with the initial generation of *OH through hydrogen abstraction from PMS, culminating in the direct release of oxygen to form 1O2 (PMS→*OH→O*→1O2). The generation of SO4•- was attributed to electron transfer to PMS from the surface of Co NPs (Co0→Co2+→Co3+) and the C-N shell (Co2+→Co3+). The research findings provided new insights into the development of Co-based heterogeneous catalysis for advanced oxidation of refractory organic pollutants in wastewater treatment.

Trace Co(II) triggers peracetic acid activation in phosphate buffer: New insights into the oxidative species responsible for ciprofloxacin removal.

Peracetic acid (PAA) emerges as a promising disinfectant and oxidant applied worldwide, and its application has been broadened for advanced oxidation processes (AOPs) in wastewater treatment. Current studies on transition metal-activated AOPs utilized relatively high concentrations of catalysts, leading to potential secondary pollution concerns. This study boosts the understanding of reaction mechanism in PAA activation system under a low-level concentration. Herein, trace levels of Co(II) (1 µM) and practical dosages of PAA (50-250 µM) were employed, achieving noticeable ciprofloxacin (CIP) degradation efficiencies (75.8-99.0%) within 20 min. Two orders of magnitude of the CIP's antibacterial activity significantly decreased after Co(II)/PAA AOP treatment, which suggested the effective ecological risk control capability of the reaction system. The degradation performed well in various water matrices and the primary reactive species is proposed to be CoHPO4-OO(O)CCH3 complexes with scavenging tests and electron paramagnetic resonance tests. The degradation pathway of fluoroquinolones including piperazine ring-opening (dealkylation and oxidation), defluorination, and decarboxylation, were systematically elucidated. This study boosts a comprehensive and novel understanding of PAA-based AOP for CIP degradation.

Comparison of mini-open reduction and autologous bone grafting with closed reduction and intramedullary device insertion for tibial shaft fractures: a retrospective study.

BACKGROUND: We compared the clinical efficacy of mini-open reduction and autologous bone grafting (GM) and closed reduction (GC) using intramedullary nailing for the treatment of tibial shaft fractures. METHODS: This retrospective study included 70 tibial shaft fractures treated with GM or GC between January 2018 and December 2021. The demographic characteristics and clinical outcomes were compared between the two treatment methods. RESULTS: This study included 70 patients who were followed-up for 12.4 months. In total, 31 and 39 patients were treated with GM and GC, respectively. The operative duration was significantly shorter for GM (95.2 ± 19.3 min) than for GC (105.5 ± 22.2 min, p = 0.0454). The number of radiation times was significantly lower for GM (14.7 ± 6.3) than for GC (22.2 ± 9.2, p < 0.005). There were no statistically significant differences between the groups in terms of the wound complication or infection rates. The malunion and nonunion rates were high after GC than after GM, but there are no significant differences between the groups. CONCLUSIONS: Closed reduction and intramedullary nailing remains the first choice for tibial shaft fractures. GM is a safe and effective treatment worth considering. Future prospective randomized controlled trials are warranted.

Efficacy and mechanism of peroxymonosulfate activation by single-atom transition metal catalysts for the oxidation of organic pollutants: Experimental validation and theoretical calculation.

Single-atom catalysts can activate peroxymonosulfate (PMS) to enhance its oxidation of organic pollutants in water treatment. We synthesized a series of carbon-supported single-atom transition metal catalysts (MnN@C, FeN@C, CoN@C, NiN@C, and CuN@C) with similar compositions and structures. Their catalytic activity toward PMS activation and oxidation mechanisms were investigated using acid orange 7 (AO7) as a model pollutant. The degradation rate (min-1·mol-1·g·m-2) of AO7 followed order: FeN@C/PMS (7.576 × 103) > MnN@C/PMS (5.104 × 103) > CoN@C/PMS (1.919 × 103) ≫ NiN@C/PMS (0.058 × 103) > CuN@C/PMS (0.035 × 103). Electron transfer mediated by surface-activated PMS was found to be the main regime of AO7 oxidation in the catalytic systems. Density functional theory calculations indicated that the degradation of AO7 was promoted by the intense adsorption of PMS and the electron transfer between AO7 and the surface-activated PMS on the catalyst. The cleavage of the naphthalene ring and the azo group was the primary degradation pathway. The toxicity of the products was significantly reduced. This research provides valuable findings for preparing highly efficient single-atom transition metal catalysts for PMS-based degradation of toxic and refractory organic pollutants from water.

miRNA-331-3p Affects the Proliferation, Metastasis, and Invasion of Osteosarcoma through SOCS1/JAK2/STAT3.

MicroRNAs (miRNAs) are regulatory small noncoding RNAs that play a key role in several types of cancer. It has been reported that miR-331-3p is involved in the development and progression of various cancers, but there are few reports regarding osteosarcoma (OS). The public GEO database was used to analyze the survival difference of miR-331-3p in OS organizations. The level of cell proliferation assay was assessed by CCK-8 and colony formation. First, transwell and wound-healing assays were used to detect the transfer and invasion ability of miR-331-3p in OS. Second, TargetScan, miRDBmiR, TarBase, and dual-luciferase reporter gene assays were used to determine SOCS1 as a targeted regulator. Third, Western blot and immunohistochemistry were used to detect the expression of protein levels. Finally, a mouse model of subcutaneously transplantable tumors is used to evaluate the proliferation of OS in vivo. The low expression of miR-331-3p was negatively correlated with the overall survival of OS patients. Overexpression of miR-331-3p significantly inhibited cell proliferation, metastasis, and invasion. Moreover, miR-331-3p affected the occurrence and development of osteosarcoma by targeting the SOCS1/JAK2/STAT3 signaling pathway. Therefore, miR-331-3p reduces the expression of SOCS1 by combining with its 3'UTR, thereby activating the JAK2/STAT3 signaling pathway to regulate the progression of OS. This provides a new theoretical basis for the treatment of osteosarcoma.

Removal of active dyes by ultrafiltration membrane pre-deposited with a PSFM coagulant: Performance and mechanism.

A new, environmental friendly, polysilicate ferric manganese (PSFM) coagulant, composed of Fe, Mn and Si, was designed and developed. As part of the process, the PSFM flocs were then deposited onto an ultrafiltration (UF) membrane to increase the removal of active dyes and its antifouling properties in the presence of the active dye was tested. Influencing factors, such as dosage of coagulant and solution pH, were systematically investigated and included as the process optimization. The results show that PSFM flocs were well distributed on the membrane surface and a dense and homogeneous deposition layer was formed under optimal conditions. According to the characterization of PSFM floc by Fourier infrared (FTIR) and X-ray photoelectron spectroscopy (XPS), the major phase of PSFM floc is determined to be MnxFeySizOw(OH)i and the functional groups of this component contribute positively to the coagulation performance. The removal rate of the active yellow dye reached 86% at pH 5.0 with small and regular floc formed in the dense deposition layers. At pH 11.0 loose deposition layers were formed by large flocs and the removal of the active yellow dye reduce to 11%. Therefore, PSFM has a commendable potential to be used for producing a kind of deposited UF membrane with an excellent performance by controlling the forms of flocs and the deposition layers, which is the key mechanism to achieve a high efficiency for removal of active yellow dye.