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1.
J Hazard Mater ; : 121740, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31796351

RESUMO

Chemical functionalization is essential for tuning the physical-chemical characters and broadening the potential applications of covalent organic frameworks (COFs). Based on the multistep postsynthetic modification strategy, Eu (III)-functionalized 3D COF (Eu-3D-COF) was prepared by grafting of Eu (III) onto the carboxyl-funtionalized 3D-COF (COOH-3D-COF). With micropores dominated microspheres structure, Eu-3D-COF exhibited superior adsorption affinity to multi-rings contained quinones based on the π-π interaction, coordination and hydrogen-bonding interactions, especially to 9,10-phenanthrenequinone (PQ) whose adjacent carbonyl oxygens resulting preferable synergistic chelation interaction with Eu(III) was responsible for the maximum adsorption capacity, which was confirmed by instrumental characterizations. The adsorptivity of Eu-3D-COF was apparently improved in comparison with COOH-3D-COF. More importantly, grafting of Eu(III) turned on the fluorescence of the COF, making Eu-3D-COF also a superior chemosensor for sensing application. Its fluorescent can be selectively quenched by quinones, especially by PQ based on the PQ-Eu and PQ-COF interactions co-dominated energy transfer. Therefore, both as an adsorbent and a chemosensor, the multi-functional COF was explored for quinones adsorption and sensing detection investigation in detail. Eu-3D-COF has promising application potentials for hazardous quinones adsorption and sensing detection, which also opens new perspectives for inorganic-organic 3D-COF construction and multi-functional applications.

2.
World Neurosurg ; 128: 464-472, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31132489

RESUMO

BACKGROUND: To systematically assess the efficacy and safety between flow diversion and coiling for patients with unruptured intracranial aneurysms. METHODS: Potential academic articles were identified from Cochrane Library, Medline, PubMed, EMBASE, ScienceDirect, and other databases. The time range we retrieved from was the inception of electronic databases to February 2019. Gray studies were identified from the references of included literature reports. STATA version 11.0 was used to analyze the pooled data. RESULTS: A total of 11 articles (10 retrospective studies and 1 prospective study) were involved in our study. The overall participants of the coiling group were 611, whereas 576 were in the flow diversion group. Our meta-analysis showed that flow diversion was preferable for unruptured intracranial aneurysms as its lower value of total cost per case (weighted mean difference, 5705.906; 95% confidence interval [CI], [4938.536, 6473236]; P < 0.001), fluoroscopy time per case (weighted mean difference, 25.786; 95% CI, 17.169-34.377; P < 0.001), and retreatment rates (odds ratio [OR], 7.127; 95% CI, [3.525, 14.410]; P < 0.001), at the same time, a higher rate of immediate completed occlusion (OR, 0.390; 95% CI, [0.224, 0.680]; P = 0.001) and follow-up completed occlusion (OR, 0.173; 95% CI, [0.080, 0.375]; P < 0.001) was demonstrated in the flow diversion group. There was no difference on intraoperative complication rates (P = 0.070), procedure-related mortality (P = 0.609) and rupture rates (P = 0.408), modified Rankin Scale (mRS) 0-2 at discharge (P = 0.077), and mRS 0-2 at follow-up (P = 0.484). CONCLUSIONS: The use of flow diversion for the treatment of unruptured intracranial aneurysms may reduce total cost per case, fluoroscopy time per case, retreatment rates, and increases immediate completed occlusion and follow-up completed occlusion rates without affecting the results of mRS and intraoperative complication.


Assuntos
Procedimentos Endovasculares/métodos , Aneurisma Intracraniano/cirurgia , Humanos , Stents , Resultado do Tratamento
3.
Dalton Trans ; 47(14): 4840-4846, 2018 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-29541714

RESUMO

A ship in bottle nanocomposite was fabricated as a novel adsorbent for lanthanides by immobilizing a lanthanide-sensitive polymer into mesocellular siliceous foam (MCF). The MCF was used as a novel carrier for immobilization of the polymer, and the polymer was synthesized via in situ ring-opening polymerization of 2-methyl-2-oxazoline (MOL) and divinylbenzene (DVB) in the presence of MCFs. The substantially physically modified MCF-based composite exhibited superior adsorptivity and selectivity to lanthanides due to its exceptional properties, which was employed for lanthanide adsorption from aqueous solution by a facile solid-liquid separation procedure. The adsorption of lanthanides by the composite was systematically studied including adsorption parameter investigation and adsorption mechanism evaluation. The adsorption isotherms and kinetics were also investigated and proved to follow the Langmuir model and the pseudo-second-order model. The adsorption thermodynamics study indicated that the adsorption process was thermodynamically favorable, endothermic and spontaneous. The prepared inorganic-organic hybrid composite has superior selectivity and specificity to lanthanides, which can be used for lanthanide enrichment and separation of lanthanides from actinides.

4.
Anal Chim Acta ; 1011: 40-49, 2018 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-29475484

RESUMO

A novel analytical method based on magnetic solid-phase extraction (MSPE) coupled with high performance liquid chromatography-diode array detection (HPLC-DAD) was established for three herbicides simultaneous determination. The key of the method was the explored extractant, which was a composite of hollow carbon nanospheres (HCSs) enhanced magnetic carboxylic MWCNTs (HCSs@Fe3O4-MWCNTs-COOH). MWCNTs-COOH was inserted in the pores of HCSs by oscillation and sonication with the capillary forces, making the carboxylic groups and structure intervals of the composite increase as compared to MWCNTs-COOH, therefore the extractant exhibited enhanced hydrophilicity, dispersibility, adsorptivity and selectivity. The extractant was sensitive to analytes with the structure of multi-aromatic ring, more hydrogen bond acceptor and large molecular polar surface area, which can be attributed to hydrogen bonding and π-π electron-donor-acceptor (EDA) interactions. The morphology, structure and magnetic property of the extractant were characterized. Then the explored extractant based MSPE-HPLC-DAD method was applied for bifenox (BFO), dichlobenil (DCB) and diclofop methyl (DCM) determination from wheat flour samples. Prior to real sample analysis, critical extraction parameters such as solution pH, extraction time, salt addition and temperature were investigated and optimized, and the analytical method was evaluated. It was indicated that the method had satisfactory linearities with the linear coefficients above 0.99, good precision with the RSD less than 3.5%, desirable recoveries ranged from 88.8% to 96.6%, and low limits of detection (LOD) that were 0.39, 0.24, and 0.68 ng/g for DCB, BFO and DCM, respectively. The established MSPE-HPLC-DAD method has great potentials for trace polar herbicides selective determination from complex matrix samples.

5.
Artigo em Inglês | MEDLINE | ID: mdl-28570934

RESUMO

A novel magnetic solid-phase extraction (MSPE) based method was established for aromatic amino acids (AAAs) selective determination. Central to the method was the adopted extractant. An explored composite of metal organic frameworks (MOFs) and magnetic carbon nanotubes (CNTs) was employed for that, which exhibited superior adsorption affinity and selectivity to AAAs as compared to other amino acids with the mechanisms attributed to multiple hydrogen bonding and π-π electron-donor-acceptor (EDA) interactions. The morphology, structure and magnetic behavior of the composite were characterized and related MSPE procedure was established. Critical extraction conditions including pH, extraction time, temperature and salt addition were investigated and optimized. Subsequently the concentrations of three AAAs tryptophan (Trp), tyrosine (Tyr) and phenylalanine (Phe) in Lanzhou lily were determined by the composite based MSPE procedure coupled with high performance liquid chromatography-ultraviolet detection (HPLC-UV). The composite provided a superior sample clean-up function and many of the matrix interferences were eliminated, thus ensured AAAs were accurately and efficiently determined. The results showed that the method had good linearities with the linear coefficients above 0.99, desirable recoveries ranged from 88.0% to 96.8% with the RSD less than 5.1%, satisfactory precision and low limits of detection (LODs) which were respectively 0.04, 0.11, and 0.87ng/g for Trp, Tyr and Phe. The composite based MSPE-HPLC-UV method has great potentials for the AAAs selective determination from complex matrix samples.


Assuntos
Aminoácidos Aromáticos/análise , Nanocompostos/química , Nanotubos de Carbono/química , Extração em Fase Sólida/métodos , Adsorção , Aminoácidos Aromáticos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Óxido Ferroso-Férrico , Concentração de Íons de Hidrogênio , Fenômenos Magnéticos , Sais , Temperatura Ambiente , Fatores de Tempo
6.
Talanta ; 168: 136-145, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28391833

RESUMO

A novel, efficient, and high-selectivity magnetic solid-phase extraction (MSPE) adsorbent based on Fe3O4 nanoparticles, hydroxylated multi-walled carbon nanotubes (MWCNTs-OH) and metal-organic frameworks (MOFs) was prepared and applied for trace aromatic acids determination in solid samples by applying a template-free in situ strategy. The morphology, configuration and magnetic behavior of the adsorbent were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectra, and vibrating sample magnetometer (VSM). The adsorbent can achieve the selective extraction of aromatic acids from the aromatic mixture in apple samples, which was mainly promoted by intermolecular hydrogen bonding and π-π electron-donor-acceptor (EDA) interaction. The potential application of the adsorbent was evaluated by MSPE of trace 1-naphthylacetic acid (NAA), cinnamic acid (CA) and terephthalic acid (TPA) from apple samples under the optimal conditions which were investigated. Satisfactory linearities were obtained in a range of 5-500ng/g and the recoveries of three aromatic acids at three spiked levels ranged from 91.2% to 98.0% with the relative standard deviations (RSD) of less than 5.5%. The limits of detection (LODs) for CA, TPA and NAA were 0.17, 0.61, and 0.86ng/g. The satisfactory results confirmed the great potential of the novel adsorbent for the selective extraction of aromatic acids from complex sample matrices.

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