Unexpected side reactions dominate the oxidative transformation of aromatic amines in the Co(II)/peracetic acid system.

Aromatic amines (AAs), ubiquitous in industrial applications, pose significant environmental hazards due to their resistance to conventional wastewater treatments. Peracetic acid (PAA)-based advanced oxidation processes (AOPs) have been proposed as effective strategies for addressing persistent AA contaminants. While the organic radicals generated in these systems are believed to be selective and highly oxidative, acetate residue complicates the evaluation of AA removal efficiency. In this work, we explored transformation pathways of AAs in a representative Co(II)-catalyzed PAA system, revealing five side reactions (i.e. nitrosation, nitration, coupling, dimerization, and acetylation) that yield 17 predominantly stable and toxic by-products. The dominant reactive species was demonstrated as Co-OOC(O)CH3, which hardly facilitated ring-opening reactions. Our findings highlight the potential risks associated with PAA-based AOPs for AA degradation and provide insights into selecting suitable catalytic systems aimed at efficient and by-product-free degradation of pollutants containing aromatic -NH2.

Unveiling singlet oxygen spin trapping in catalytic oxidation processes using in situ kinetic EPR analysis.

Singlet oxygen (1O2) plays a pivotal role in numerous catalytic oxidation processes utilized in water purification and chemical synthesis. The spin-trapping method based on electron paramagnetic resonance (EPR) analysis is commonly employed for 1O2 detection. However, it is often limited to time-independent acquisition. Recent studies have raised questions about the reliability of the 1O2 trapper, 2,2,6,6-tetramethylpiperidine (TEMP), in various systems. In this study, we introduce a comprehensive, kinetic examination to monitor the spin-trapping process in EPR analysis. The EPR intensity of the trapping product was used as a quantitative measurement to evaluate the concentration of 1O2 in aqueous systems. This in situ kinetic study was successfully applied to a classical photocatalytic system with exceptional accuracy. Furthermore, we demonstrated the feasibility of our approach in more intricate 1O2-driven catalytic oxidation processes for water decontamination and elucidated the molecular mechanism of direct TEMP oxidation. This method can avoid the false-positive results associated with the conventional 2D 1O2 detection techniques, and provide insights into the reaction mechanisms in 1O2-dominated catalytic oxidation processes. This work underscores the necessity of kinetic studies for spin-trapping EPR analysis, presenting an avenue for a comprehensive exploration of the mechanisms governing catalytic oxidation processes.

The preventive effects of different doses of atorvastatin on contrast-induced acute kidney injury after CT perfusion.

BACKGROUND: Contrast-induced acute kidney injury (CI-AKI) is a severe complication among patients receiving intravascular contrast media. The purpose of this study was to investigate the preventive effects of pretreatment of atorvastatin at intensive doses on CI-AKI after computed tomography (CT) perfusion. METHODS: The levels of serum creatinine (SCR), blood urea nitrogen (BUN), Cystatin C (CysC), estimated glomerular filtration rate (eGFR), high-sensitivity C-reactive protein (hs-CRP), and interleukin-6 (IL-6) in patients were compared between the observation group receiving 40 mg/kg atorvastatin and the control group receiving 20 mg/kg atorvastatin before and 72 h after CT examination. In addition, the incidence of CI-AKI was recorded. RESULTS: Compared with the control group, the incidence of renal injury in the observation group was significantly reduced, from 8% to 2% (χ2  = 6.62, p = 0.010). In addition, there was no notable difference in the levels of Scr, BUN, CysC, hs-CRP, and IL-6 before CT examination between two groups (p > 0.05). The levels of SCR, BUN, CysC, hs-CRP, and IL-6 were increased, while the levels of eGFR were decreased in the control group at 72 h after CT examination (p < 0.05). At 72 h after CT enhancement, the levels of BUN, CysC, and hs-CRP were prominently increased in the observation group (p < 0.05), while SCR, eGFR, and IL-6 did not change (p > 0.05). Compared with the control group, the levels of SCR, BUN, CysC, eGFR, hs-CRP, and IL-6 in the observation group were significantly decreased at 72 h after CT examination (p < 0.05). CONCLUSION: Intensive dose of atorvastatin pretreatment can prevent CI-AKI undergoing CT perfusion through lowering inflammation as well as renal function indexes SCR, CysC, BUN, and eGFR.

[Roles of monocyte chemoattractant protein-1, RANTES and Fractalkine on promoting vulnerability of atherosclerotic plaques].

OBJECTIVE: To elucidate the roles of monocyte chemotactic factors (MCP-1, RANTES and Fractalkine) on the vulnerability of atherosclerotic plaques in patients with stable (SAP) and unstable angina pectoris (UAP). METHODS: Patients with SAP (n = 50) and UAP (n = 50) underwent coronary angiography (CAG) and intravenous ultrasound (IVUS) were included in the study. Monocyte chemotaxis was assayed by the transwell chamber. Concentrations of hs-CRP, MCP-1, RANTES and Fractalkine were measured by Enzyme-linked-immunosorbent assay (ELISA). mRNA expression of MCP-1, RANTES and Fractalkine in the monocytes was detected by RT-PCR. RESULTS: IVUS evidenced soft lipid plaques in 48% UAP patients and in 16% SAP patients (P < 0.05). SAP patients had mainly fibrous and mixed plaques. Plaque burden and vascular remodeling index were significantly higher in UAP patients than in SAP patients (P < 0.01). The averaged number of migrated monocytes in the UAP patients were higher than that in patients with SAP (P < 0.01). Concentration of hs-CRP, MCP-1, RANTES and Fractalkine were significantly higher in UAP patients than those of SAP patients (P < 0.05 or P < 0.01). mRNA expression of MCP-1, RANTES and Fractalkine in patients with UAP was significantly higher than those of SAP patients (P < 0.05). CONCLUSION: Upregulated monocyte chemotactic factors (MCP-1, RANTES and Fractalkine) might promote coronary plaque vulnerability in UAP patients.

[Treatment of wide-necked cerebral aneurysms using stent and balloon-assisted technique].

OBJECTIVE: To discuss the avail of balloon and stent-assisted Guglielmi detachable coil (GDC) placement in treatment of wide-necked cerebral aneurysm. METHODS: Eighty-seven patients with 92 wide-necked aneurysms undergone endovascular procedures using the balloon and stent-assisted remodeling technique. Respectively, appropriate Neuroform stents delivered with a 5 mm landing zone on either side of the aneurysm neck, the microcatheter entered through the interstice, aneurysms were embolized at one or several times. Two catheters were used in balloon-remodeling technique, balloon were inflated across the neck of the aneurysms after the microcatheter entering the aneurysms, then the GDC were used to embolize the aneurysms. RESULTS: Thirty-one aneurysms were completely occluded, 3 subtotally (> 90%) and 1 incompletely (70% - 90%) occluded using stent-assisted technique, all carry arteries were unblocked, 3 patients with mild neurological dysfunction and no mortality. Fifty aneurysms were completely occluded and 4 incompletely occluded using balloon-assisted technique, 1 patients with mild neurological dysfunction and no mortality. Two aneurysms were completely occluded and 1 incompletely occluded using stent-assisted and balloon-assisted technique. The mean period of follow-up was 5.8 months. Rates of recanalization were 16.7% for stent-remodeling group and 12.5% for balloon-remodeling group. CONCLUSIONS: The stent and balloon-assisted remodeling technique are safe and effective in treating wide-necked aneurysms. Balloon-remodeling technique has more security comparing with stents.

[3-dimension computed tomography angiography and digital subtraction angiography in diagnosis of intracranial aneurysm: a comparative study].

OBJECTIVE: To compare the appliance values off 3-dimension computed tomography (CTA) and digital subtraction angiography (DSA) in diagnosis of intracranial aneurysm (ICA). METHODS: Eighty-six with subarachnoid hemorrhage underwent 2-D DSA, and 3-DCTA and 3-D DSA, both including maximum intensity projection (MIP) and multiple planner reconstruction (MPR), volume rending (VR). The accuracy, misdiagnosis rate, and missed diagnosis rate of these 3 techniques were compared. No significant complication was found. RESULTS: Ninety-four aneurysms were found in 74 patients. CTA examination obtained satisfactory MPR, MIP, and VR images in all patients. There was no significant difference in accuracy between 3D-DSA and 3D-CTA. In display of the aneurysm 3D-CTA was not significantly different from 2D-DSA in most cases. In display of the neck of aneurysm 3D-CTA was not significantly different from 3D-DSA, and these 3 techniques were both superior to 2D-DSA. CONCLUSION: 3D-CTA is the first choice examination technique for patients with subarachnoid hemorrhage. The information obtained by 2D-DSA, 3D-DSA, and 3D-CTA should be considered comprehensively.