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1.
Entropy (Basel) ; 26(9)2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-39330144

RESUMO

Quantum secure direct communication (QSDC) is a quantum communication paradigm that transmits confidential messages directly using quantum states. Measurement-device-independent (MDI) QSDC protocols can eliminate the security loopholes associated with measurement devices. To enhance the practicality and performance of MDI-QSDC protocols, we propose a one-photon-interference MDI QSDC (OPI-QSDC) protocol which transcends the need for quantum memory, ideal single-photon sources, or entangled light sources. The security of our OPI-QSDC protocol has also been analyzed using quantum wiretap channel theory. Furthermore, our protocol could double the distance of usual prepare-and-measure protocols, since quantum states sending from adjacent nodes are connected with single-photon interference, which demonstrates its potential to extend the communication distance for point-to-point QSDC.

2.
Chem Asian J ; 18(1): e202200954, 2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36378015

RESUMO

Here we report a copper-catalyzed protocol for the synthesis of α-chloroketones from aromatic alkenes including electron-deficient olefins under visible-light irradiation. Preliminary mechanistic studies show that the peroxo Cu(II) species is the key intermediate and hydroperoxyl (HOO⋅) and chlorine (Cl⋅) radicals can be generated by ligand-to-metal charge transfer (LMCT).


Assuntos
Alcenos , Luz , Cobre , Catálise
3.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1041-1042: 98-103, 2017 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-28027522

RESUMO

A method for solid-phase extraction (SPE) of corilagin from natural plant extracts based on molecularly imprinted polymers (MIPs) was developed. For the preparation of corilagin-MIP monoliths, 4-vinylpyridine was used as functional monomer, and ethylene glycol dimethacrylate was used as cross-linking monomer, using a mixture of 1-butyl-3-methylimidazoliumtetrafluoroborate (ionic liquid)-N,N-dimethylformamide-dimethyl sulfoxide as a porogen. A morphological characteristic of the corilagin imprinted monolith was further studied by scanning electron microscopy and nitrogen sorption method. The greatest imprinting factor of COR was up to 9. The MIPs were used as solid-phase extraction (SPE) sorbents for purification of COR and the mean recoveries of corilagin was 78.0% with COR purity of 98.0% from the crude extract of phyllanthus urinaria L. The resulting COR-imprinted polymer also displayed the good performance of fragment imprinting polymer for gallic acid with the mean recoveries of 94.0% and purity of 99.7%.


Assuntos
Glucosídeos/isolamento & purificação , Taninos Hidrolisáveis/isolamento & purificação , Líquidos Iônicos/química , Impressão Molecular/métodos , Extração em Fase Sólida/métodos , Cromatografia Líquida de Alta Pressão , Dimetil Sulfóxido/química , Dimetilformamida/química , Glucosídeos/análise , Taninos Hidrolisáveis/análise , Imidazóis/química , Nitrogênio , Tamanho da Partícula , Porosidade
4.
J Chromatogr A ; 1438: 171-8, 2016 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-26896914

RESUMO

Boronate-affinity monolithic column was first prepared via polystyrene (PS) as porogen in this work. The monolithic polymer was synthetized using 4-vinylphenylboronic acid (4-VPBA) as functional monomer, ethylene glycol dimethacrylate (EDMA) as crosslinker monomer, and a mixture of PS solution in tetrahydrofuran, the linear macromolecular porogen, and toluene as porogen. Isoquercitrin (ISO) and hyperoside (HYP), isomer diol flavonoid glycosides, can be baseline separated on the poly(VPBA-co-EDMA) monolith. The effect of polymerization variables on the selectivity factor, e.g., the ratio of monomer to crosslinker (M/C), the amount of PS and the molecular weight of macromolecular porogen was investigated. The surface properties of the monolithic polymer were characterized by scanning electron microscopy and nitrogen adsorption. The best polymerization condition was the M/C ratio of 7:3, and the PS concentration of 40 mg/ml. The poly(VPBA-co-EDMA) polymer was also applied to extract cis-diol flavonoid glycosides from the crude extraction of cotton flower. After treated by poly(VPBA-co-EDMA) for solid phase extraction, high purity ISO and HYP (>99.96%) can be obtained with recovery of 83.7% and 78.6%, respectively.


Assuntos
Ácidos Borônicos/química , Polímeros/síntese química , Extração em Fase Sólida/métodos , Adsorção , Substâncias Macromoleculares/química , Metacrilatos/química , Peso Molecular , Polimerização , Polímeros/química , Poliestirenos/química
5.
Anal Bioanal Chem ; 407(24): 7401-12, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26210545

RESUMO

One of the main challenges in the preparation of molecularly imprinted polymers (MIPs) is the substantial initial amount of template needed because of the requirement of high load capacities for most applications. A new strategy of macromolecular crowding was suggested to solve this problem by reducing the amount of template in the polymerization recipe. In a ternary porogenic system of polystyrene (PS) (crowding agent), tetrahydrofuran, and toluene, an imprinted monolithic column with high porosity and good permeability was synthesized using a mixture of ellagic acid (template), acrylamide, and ethylene glycol dimethacrylate. The effect of polymerization factors, including monomer-template molar ratio and the molecular weight and concentration of PS, on the imprinting effect of the resulting MIP monoliths was systematically investigated. At a high ratio of monomer-template (120:1), the greatest imprinting factor of 32.4 was obtained on the MIP monolith with the aid of macromolecular crowding agent. The PS-based imprinted monolith had imprinting even at the extremely high ratio of functional monomer to template of 1510:1. Furthermore, an off-line solid-phase extraction based on the ground MIP was conducted, and the purification recovery of ellagic acid from pomegranate-rind extract was up to 80 %. In conclusion, this approach based on macromolecular crowding is simple, and is especially valuable for those applications of MIP preparation for which a rare template is used.


Assuntos
Substâncias Macromoleculares/química , Impressão Molecular , Peso Molecular , Extração em Fase Sólida
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