Analysis of factors associated with the development of delayed encephalopathy following acute carbon monoxide poisoning.

In this study, we analyzed the factors influencing the development of delayed encephalopathy in patients with acute carbon monoxide poisoning (ACOP) (DEACMP) following conventional treatment such as hyperbaric oxygen therapy (HBOT). Between January 2012 and January 2022, we retrospectively analyzed 775 patients with ACOP, who were admitted to the Second Department of Rehabilitation Medicine and received HBOT in the Second Hospital of Hebei Medical University. These patients were divided into the non-DEACMP and DEACMP groups based on their follow-up; we then compared the general data, clinical characteristics, admission examination, and treatment between the two groups to identify risk factors for the development of DEACMP. The DEACMP group comprised of 168 cases, while the non-DEACMP group consisted of 607 cases. Univariate analysis showed that there were 20 possible prognostic factors in the non-DEACMP and DEACMP groups. The results of multivariable regression analyses suggested that the occurrence of DEACMP was significantly correlated with advanced age, the combination of multiple medical histories, the duration of CO exposure, the duration of coma, poisoning degree, the Interval between ACOP and the first HBOT, the total number of HBOTs, and the combination with rehabilitation treatment. DEACMP patients who are older, have more comorbidities, prolonged CO exposure, prolonged coma, severe intoxication, long intervals between ACOP and the first HBOT, fewer HBOT treatments, and who are not treated with a combination of rehabilitative therapies have a poor prognosis.

Nano-scale minerals in-situ supporting CeO2 nanoparticles for off-on colorimetric detection of L-penicillamine and Cu2+ ion.

Realizing the high value-added utilization of cheap minerals in environmental catalysis has important practical significance. Herein, four nano-scale minerals, namely halloysite (Hal) nanotubes, palygorskite (Pal) nanorods, and montmorillonite (Mon) and hydrotalcite (LDH) nanosheets, were selected for in-situ supporting CeO2 nanoparticles (NPs) by a facile one-pot hydrothermal method. Among various nanocomposites (NCs), CeO2/Pal behaves the highest peroxidase-like activity, attributing to larger surface area for uniformly dispersing CeO2 NPs and more exposed active oxygen vacancy (Ovac) defects. A novel off-on colorimetric strategy was constructed for detecting toxic L-penicillamine (LPA) and Cu2+ ion with limit of detections (LODs) of 8.37 and 9.80 µM, respectively. Density functional theory (DFT) calculations show that the Ovac defect on CeO2(111) surface can catalyze the heterolytic cleavage of H2O2 into H2O and oxygen radical (•O), instead of being two hydroxyl radicals (•OH) on clean surface. It can also act as trapping site for O2 and H2O adsorption, improving the oxygen affinity and hydrophilicity of CeO2/Pal. This study provides a feasible strategy for designing mineral-based nanozymes and an insight into the possible catalytic mechanism.

Magnetic Flower-like Fe-Doped CoO Nanocomposites with Dual Enzyme-like Activities for Facile and Sensitive Determination of H2O2 and Dopamine.

Herein, a new series of magnetic Fe-doped CoO nanocomposites (Fe-CoO NCs) with dual enzyme-like activities (peroxidase and oxidase) were successfully synthesized. The molar ratio of Fe3+/Co2+ salts during the solvothermal process determined the morphology and catalytic activity of the NCs. Among them, the flower-like 0.15Fe-CoO NCs showed high peroxidase-mimicking activity over a wider pH range of 4-5 and a temperature range of 30-50 °C. Such nanozymes were applied for constructing a facile and sensitive colorimetric sensor to detect H2O2 and dopamine (DA) in the linear ranges of 6-20 and 2-10 µM with limits of detection (LODs) of 4.40 and 1.99 µM, respectively. The excellent magnetic separation performance and successful DA detection in human urine samples validated the promising application of CoO-based nanozymes in medical diagnosis. The superior catalytic behaviors of 0.15Fe-CoO NCs could be ascribed to the high surface area, open mesoporous structure, increased surface active species, and the facile redox of Fe3+/Fe2+ and Co3+/Co2+. Based on the results of the fluorescent probe and radical trapping tests, the possible mechanism that Fe doping promoted the decomposition of H2O2 to produce hydroxyl radical (•OH) and superoxide radical (•O2-) was proposed.

Hg2+ Significantly Enhancing the Peroxidase-Like Activity of H2TCPP/ZnS/CoS Nanoperoxidases by Inducing the Formation of Surface-Cation Defects and Application for the Sensitive and Selective Detection of Hg2+ in the Environment.

Exploring excellent peroxidase mimics with enhanced peroxidase-like activity is important to the construction of a fast, low-cost, and convenient colorimetric sensing platform for heavy ions. In this work, 5,10,15,20-tetrakis(4-carboxyphenyl)porphyrin (H2TCPP) was first used to modify ZnS/CoS and make it show better peroxidase-like activity. The metal-cation vacancies generated by Hg2+ contacting H2TCPP/ZnS/CoS further stimulate the catalytic activity. It is reported that the addition of Hg2+ usually causes a decrease of the peroxidase-like activity of metal sulfides. Oppositely, in our work, Hg2+ can trigger the colorimetric signal amplification because of lots of metal-cation vacancies generated on the surface of the nanocomposites (bimetallic sulfides). The peroxidase-like activity of ZnS/CoS was evaluated by virtue of the chromogenic substrate 3,3,5,5-tetramethylbenzidine (TMB) from colorless to blue in 3 min. The enhanced catalytic activity of H2TCPP/ZnS/CoS was attributed to lots of active sites from the metal-cation defects on the surface of H2TCPP/ZnS/CoS as well as the synergistic effect of porphyrin molecules and ZnS/CoS. The adsorption behavior of H2O2 on the H2TCPP/ZnS/CoS surface with defects was studied by density functional theory calculation. Thus, a colorimetric sensing platform based on Hg2+ trigger signal amplification has been successfully constructed, which can be used to sensitively and selectively determine Hg2+ in environmental samples.

N,N-dicarboxymethyl Perylene-diimide modified CeCoO3: Enhanced peroxidase activity, synergetic catalytic mechanism and glutathione colorimetric sensing.

N,N-dicarboxymethyl Perylene-diimide (PDI) modified CeCoO3 nanocomposites were prepared by a two-step method. After modification with PDI molecules, the obtained PDI-CeCoO3 nanocomposites were demonstrated to possess the heightened peroxidase-like activity, compared with that of pure CeCoO3 nanoparticles. In the presence of H2O2, the heightened peroxidase-like behaviors of PDI-CeCoO3 were evaluated by the oxidation of the colorless substrate 3,3,5,5-tetramethylbenzidine (TMB) into blue oxTMB, which was detected visually only in 4 min. Importantly, a systematic study of catalytic activity of PDI-CeCoO3 by different means, including fluorescent probe, electrochemical data, diffuse reflection spectra together with free radical scavenger is executed, verifying that the catalytic activity were from O2- and electron holes (h+). And, the transfer of photogenerated carriers in the PDI-CeCoO3 was the Z-scheme heterojuntion mechanism. Furthermore, the peroxidase-like activity of PDI-CeCoO3 was significantly inhibited by Glutathione (GSH), resulting in fading of blue oxTMB. Based on this, a colorimetric assay for GSH biosensing has been developed. And, the liner range for GSH detection is from 1 to 10 µM with a detection limit of 0.658 µM. The recovery of GSH with different concentrations from 90.0% to 105.9% and the relative standard deviation (RSD) from 1.9% to 5.1%. This colorimetric sensor can be used to detect GSH in real samples.

Carboxymethyl cellulose capsulated zein as pesticide nano-delivery system for improving adhesion and anti-UV properties.

In order to further enhance hydrophilicity of zein and achieve nano-scale pesticide system, phosphorylated zein (P-Zein) was incorporated with graft copolymer CMC-g-PDMDAAC by electrostatic interaction, in which carboxymethyl cellulose (CMC) and diallyldimethylammonium chloride (DMDAAC) as monomers. P-Zein/CMC-g-PDMDAAC was applied to encapsulate model pesticide avermectin (AVM) via electrostatic interaction to achieve AVM@P-Zein/CMC-g-PDMDAAC nano-pesticides. The stability, drug loading, anti-ultraviolet, adhesion, sustained-release and toxicity of nano-pesticides presented considerable behavior confirmed via various characteristics. The results indicated that AVM@P-Zein/CMC-g-PDMDAAC had an average particle size of 360 nm, and possessed favorable dispersion performance and excellent anti-ultraviolet property compared to P-Zein. And comparatively, encapsulation efficiency increased up to 82.11%. In addition, adhesion performance of AVM@P-Zein/CMC-g-PDMDAAC on foliage also improved by about 20% compared to P-Zein. Also, AVM@P-Zein/CMC-g-PDMDAAC can intelligently control pesticide release by adjusting monomer ratio and pH values. More importantly, such nano-pesticide system presented no significant difference on toxicity in comparison with bare AVM.

Perylene diimide-functionalized CeO2 nanocomposite as a peroxidase mimic for colorimetric determination of hydrogen peroxide and glutathione.

A novel perylene diimide (PDI) functionalized CeO2 nanocomposite (NC) was successfully fabricated via one-pot hydrothermal method. Compared with pure CeO2 nanoparticles (CeO2 NPs), the NC catalyst presents more Ce3+ and active oxygen species and exhibits a higher peroxidase mimicking activity towards the oxidation 3,3',5,5'-tetramethylbenzidine by H2O2 to form a blue product with an absorption maximum at 652 nm. The composite catalyst shows high sensitivity and selectivity toward H2O2 determination in the range of 20 to 80 µM with a limit of detection (LOD) of 2.59 µM. Based on the colorimetric method, a sensitive method for detecting the reduced glutathione (GSH) was also established over arrange of 1~4 µM with a LOD of 0.92 µM. Electron spin resonance (ESR) experiments suggest that the active radicals during the catalytic processes are •OH and •O2-. A possible synergistic catalytic mechanism is discussed. Graphical abstract Schematic presentation of the possible catalytic mechanism for colorimetric determination of hydrogen peroxide and glutathione based on the peroxidase-like activity perylene-diimide (PDI) functionalized CeO2 nanocomposite.