Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 78
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Inorg Chem ; 63(4): 2282-2288, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38232293

RESUMO

A highly promising electrocatalyst has been designed and prepared for the hydrogen evolution reaction (HER). This involves incorporating well-dispersed Ir nanoparticles into a cobalt-based metal-organic framework known as Co-BPDC [Co(bpdc)(H2O)2, BPDC: 4,4'-biphenyldicarboxylic acid]. Ir@Co-BPDC demonstrates exceptional HER activity in alkaline media, surpassing both commercial Pt/C and recent noble-metal catalysts. Theoretical results indicate that electron redistribution, induced by interfacial bonds, optimizes the adsorption energy of water and hydrogen, thereby enhancing our understanding of the superior properties of Ir@Co-BPDC for HER.

2.
Proc Natl Acad Sci U S A ; 118(14)2021 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-33785590

RESUMO

Compelling evidence indicates that radiotherapy (RT) has a systemic inhibitory effect on nonirradiated lesions (abscopal effect) in addition to the ablation of irradiated tumors. However, this effect occurs only in rare circumstances in clinical practice, and mechanisms underlying the abscopal effect of RT are neither fully understood nor therapeutically utilized. Here we identified that intercellular adhesion molecule-1 (ICAM-1), an inducible glycoprotein of the immunoglobulin superfamily, is up-regulated in nonirradiated tumors responsive to RT. ICAM-1 expression in preclinical animal models can be noninvasively detected by optical imaging and positron emission tomography (PET) using near-infrared fluorescence dye- and 64Cu-labeled imaging probes that we synthesized, respectively. Importantly, the expression levels of ICAM-1 determined by quantitative PET imaging showed a strong negative linear correlation with the growth of nonirradiated tumors. Moreover, genetic or pharmacologic up-regulation of ICAM-1 expression by either an intratumoral injection of engineered recombinant adenovirus or systemic administration of a Toll-like receptor 7 agonist-capsulated nanodrug could induce markedly increased abscopal responses to local RT in animal models. Mechanistic investigation revealed that ICAM-1 expression can enhance both the activation and tumor infiltration of CD8+ T cells to improve the responses of the nonirradiated tumors to RT. Together, our findings suggest that noninvasive PET imaging of ICAM-1 expression could be a powerful means to predict the responses of nonirradiated tumors to RT, which could facilitate the exploration of new combination RT strategies for effective ablation of primary and disseminated lesions.


Assuntos
Antineoplásicos/administração & dosagem , Imiquimode/administração & dosagem , Molécula 1 de Adesão Intercelular/metabolismo , Neoplasias Experimentais/radioterapia , Adenoviridae , Animais , Biomarcadores/metabolismo , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/metabolismo , Avaliação Pré-Clínica de Medicamentos , Molécula 1 de Adesão Intercelular/administração & dosagem , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Linfócitos do Interstício Tumoral/metabolismo , Camundongos Endogâmicos BALB C , Nanopartículas , Neoplasias Experimentais/diagnóstico por imagem , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/metabolismo , Tomografia por Emissão de Pósitrons
3.
Molecules ; 29(9)2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38731608

RESUMO

In this paper, Cu-BTC derived mesoporous CuS nanomaterial (m-CuS) was synthesized via a two-step process involving carbonization and sulfidation of Cu-BTC for colorimetric glutathione detection. The Cu-BTC was constructed by 1,3,5-benzenetri-carboxylic acid (H3BTC) and Cu2+ ions. The obtained m-CuS showed a large specific surface area (55.751 m2/g), pore volume (0.153 cm3/g), and pore diameter (15.380 nm). In addition, the synthesized m-CuS exhibited high peroxidase-like activity and could catalyze oxidation of the colorless substrate 3,3',5,5'-tetramethylbenzidine to a blue product. Peroxidase-like activity mechanism studies using terephthalic acid as a fluorescent probe proved that m-CuS assists H2O2 decomposition to reactive oxygen species, which are responsible for TMB oxidation. However, the catalytic activity of m-CuS for the oxidation of TMB by H2O2 could be potently inhibited in the presence of glutathione. Based on this phenomenon, the colorimetric detection of glutathione was demonstrated with good selectivity and high sensitivity. The linear range was 1-20 µM and 20-300 µM with a detection limit of 0.1 µM. The m-CuS showing good stability and robust peroxidase catalytic activity was applied for the detection of glutathione in human urine samples.


Assuntos
Colorimetria , Cobre , Glutationa , Peróxido de Hidrogênio , Nanoestruturas , Glutationa/análise , Glutationa/química , Colorimetria/métodos , Cobre/química , Nanoestruturas/química , Catálise , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/análise , Porosidade , Oxirredução , Ácidos Ftálicos/química , Humanos , Benzidinas/química , Limite de Detecção
4.
Biomacromolecules ; 24(4): 1648-1661, 2023 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-36883261

RESUMO

The use of polydopamine-based bioinspired nanomaterials has shed new light on advanced drug delivery arising from their efficient surface functionalization. More recently, the polydopamine self-assemblies formed in two different modalities, i.e., nonporous and mesoporous nanoparticles, have begun to attract attention due to their expedient and versatile properties. However, their possibility for use in dermal drug delivery for local therapy, as well as their interaction with the skin, has not yet been demonstrated. Our study aimed to compare and explore the feasibility of the self-assembled nonporous polydopamine nanoparticles (PDA) and mesoporous polydopamine nanoparticles (mPDA) for local skin drug delivery. The formation of the PDA and mPDA structures was confirmed by the UV-vis-NIR absorption spectrum, the Fourier transform infrared spectroscopy, and the nitrogen adsorption/desorption isotherms. Using retinoic acid (RA) as the model drug, their effects on drug loading, release, photostability, skin penetration, and radical scavenging were investigated. Laser scanning confocal microscopy (LSCM) and hematoxylin and eosin (H&E) were introduced to probe their delivery routes and possible interaction with the skin. The results indicated that both PDA and mPDA could reduce the photodegradation of RA, and mPDA showed significantly better radical scavenging activity and drug loading capacity. The ex vivo permeation study revealed that both PDA and mPDA significantly enhanced the delivery of RA into the deep skin layers by comparison with the RA solution, in which follicular and intercellular pathways existed, and alteration in the structure of stratum corneum was observed. In light of drug loading capacity, size controllability, physical stability, as well as radical scavenging activity, mPDA was more preferable due to the improvement of these factors. This work demonstrated the feasibility and promising application of PDA and mPDA nanoparticles for dermal drug delivery, and the comparative concept of these two types of biomaterials can provide implications for their use in other fields.


Assuntos
Sistemas de Liberação de Medicamentos , Nanopartículas , Sistemas de Liberação de Medicamentos/métodos , Polímeros/química , Nanopartículas/química
5.
Inorg Chem ; 62(39): 16170-16181, 2023 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-37722103

RESUMO

In response to the growing concern for environmental pollution, two lanthanide compounds {[Ln(L)(H2O)]·4H2O}n (where Ln = Tb and Gd, H3L = 1-amino-2,4,6-benzene tricarboxylic acid) were synthesized using a -NH2 modified ligand and systematically characterized. Both compounds exhibit remarkable fluorescence response, adsorption of CrO42- ions, and photocatalytic degradation properties, as well as exceptional acid-base and thermal stability. Remarkably, the pH-dependent 1-Tb exhibits exceptional performance as a fluorescent probe for detecting Fe3+ and CrO42-/Cr2O72- ions in aqueous solutions, while also serving as a ratiometric fluorescent probe for the detection of Cr3+, offering rapid response, high sensitivity, selectivity, and recoverability advantages in application. Moreover, 1-Tb exhibits excellent detection capabilities and displays effective adsorption of CrO42- ions, with a maximum adsorption capacity of 230.71 mg/g. On the other hand, 1-Gd exhibits superior performance compared to 1-Tb in the photocatalytic degradation of antibiotics. The degradation mechanism is further elucidated by conducting experiments with DFT theoretical calculations.

6.
Molecules ; 28(8)2023 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-37110844

RESUMO

Blueberry is the source of a variety of bioactive substances, including phenolic compounds, such as anthocyanins, pterostilbene, phenolic acids, etc. Several studies have revealed that polyphenols in blueberry have important bioactivities in maintaining health, such as antioxidant and anti-tumor activities, immune regulation, the prevention of chronic diseases, etc. Therefore, these phenolic compounds in blueberries have been widely used in the field of healthcare, and the extraction, isolation, and purification of phenolic compounds are the prerequisites for their utilization. It is imperative to systematically review the research progress and prospects of phenolic compounds present in blueberries. Herein, the latest progress in the extraction, purification, and analysis of phenolic compounds from blueberries is reviewed, which can in turn provide a foundation for further research and usage of blueberries.


Assuntos
Mirtilos Azuis (Planta) , Antocianinas/análise , Fenóis/análise , Polifenóis/análise , Antioxidantes/farmacologia , Antioxidantes/análise , Frutas/química
7.
Inorg Chem ; 61(30): 11866-11878, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35857312

RESUMO

Two isomorphic lanthanide compounds {[Ln(ddpp)(H2O)]·CH3CN}n (Ln = Eu and Gd, H4ddpp = 2,5-di(2',4'-dicarboxylphenyl)pyridine) were synthesized. Complex 1-Eu displays ultrahigh acid-base stability and thermal stability. Furthermore, luminescence measurements revealed that 1-Eu could detect quinolone antibiotics with an ultralow limit of detection in aqueous solution. The ratiometric probe properties for sensing antibiotics could be attributed to the incompletely sensitized Eu3+ ion of the ligand. Remarkably, it is interesting that 1-Gd exhibits excellent tetracycline degradation properties under visible light. Ultraviolet-visible diffuse reflectance spectroscopy and valence band X-ray photoelectron spectroscopy were carried out to investigate the photodegradation mechanisms. Moreover, a rational explanation for the fluorescent probe and photocatalysis behavior of these two complexes was also discussed with the assistance of density functional theory calculations.


Assuntos
Elementos da Série dos Lantanídeos , Estruturas Metalorgânicas , Antibacterianos , Elementos da Série dos Lantanídeos/química , Ligantes , Medições Luminescentes/métodos
8.
Int J Mol Sci ; 23(17)2022 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-36077154

RESUMO

The paper reports a strategy to synthesize Cd0.9Co0.1S nanorods (NRs) via a one-pot solvothermal method. Remarkably, the pencil-shaped Cd0.9Co0.1S NRs with a large aspect ratio and good polycrystalline plane structure significantly shorten the photogenerated carrier transfer path and achieve fast separation. An appropriate amount of Co addition enhances visible light-harvesting and generates a photothermal effect to improve the surface reaction kinetics and increases the charge transfer rate. Moreover, the internal electric field facilitates the separation and transfer of carriers and effectively impedes their recombination. As a result, the optimized Cd0.9Co0.1S NRs yield a remarkable H2 evolution rate of 8.009 mmol·g-1·h-1, which is approximately 7.2 times higher than that of pristine CdS. This work improves the photocatalytic hydrogen production rate by tuning and optimizing electronic structures through element addition and using the photothermal synergistic effect.


Assuntos
Compostos de Cádmio , Nanotubos , Cádmio , Compostos de Cádmio/química , Eletricidade , Luz , Nanotubos/química
9.
Nanotechnology ; 32(50)2021 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-34500443

RESUMO

A highly dispersed Mn/TiO2catalyst, which has high efficiency for NO conversion with CO and almost completed N2selectivity at a low-temperature range (350-550 K), was investigated using experimental and DFT theoretical calculation. The characterization results illustrated that the catalyst assembled with nanoparticles and the Mn doping into the TiO2surface lattice led to the formation of Mn-O-Ti configuration, which enhanced the dispersion of Mn on the body of TiO2. The DFT study mapped out the complete catalytic cycle, including reactants adsorption, oxygen vacancy generation, N2O intermediates formation, N2formation in Eley-Rideal (ER), Langmuir-Hinshelwood, and termolecular Eley-Rideal mechanisms. With thermodynamic and kinetic analysis combined with experimental results, the ER reaction process was considered to be the fundamental mechanism over the highly dispersed Mn/TiO2catalyst. The calculation results indicated that N2O was a significant intermediate. However, the rapid N2O reduction process led to high N2selectivity. The rate-limiting step was the deoxygenation step of NO-MnOv/TiO2from N-O bond scission. The active site Mn-Ovpair embedded in Mn/TiO2was responsible not only for the formation of N-Mn/TiO2in the ER-1 step but also for the N2O deoxygenation process to make the final product N2in the ER-2 step. The synergetic effect between Mn 3d electron and the oxygen vacancy of TiO2were responsible for the catalytic activity of Mn/TiO2.

10.
Opt Lett ; 45(15): 4120-4123, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32735238

RESUMO

We propose a hybrid protocol for sending-or-not-sending (SNS) twin-field quantum key distribution: replacing the signal source by heralded single-photon source (HSPS) in the original SNS protocol, while decoy sources are still unchanged. Numerical simulation shows that after adopting this HSPS, the performance in key rate and secure distance is much improved.

11.
Eur J Nucl Med Mol Imaging ; 47(4): 991-1002, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31897587

RESUMO

PURPOSE: The role that gut microbiota plays in determining the efficacy of the anti-tumor effect of immune checkpoint inhibitors is gaining increasing attention, and fecal bacterial transplantation has been recognized as a promising strategy for improving or rescuing the effect of immune checkpoint inhibition. However, techniques for the precise monitoring of in vivo bacterial behaviors after transplantation are limited. In this study, we aimed to use metabolic labeling and subsequent positron emission tomography (PET) imaging to track the in vivo behaviors of gut bacteria that are responsible for the efficacy of anti-PD-1 therapy in living mice. METHODS: The antitumor effect of anti-PD-1 blockade was tested in a low-response 4T1 syngeneic mouse model with or without fecal transplantation and with or without broad-spectrum antibiotic imipenem treatment. High-throughput sequencing analyses of 16S rRNA gene amplicons in feces of 4T1 tumor-bearing mice pre- and post-anti-PD-1 treatment were performed. The identified bacteria, Bacteroides fragilis (B. fragilis), were labeled with 64Cu and fluorescence dye by the metabolic labeling of N3 followed by click chemistry. In vivo PET and optical imaging of B. fragilis were performed in mice after oral gavage. RESULTS: The disturbance of gut microbiota reduced the efficacy of anti-PD-1 treatment, and the combination of B. fragilis gavage and PD-1 blockade was beneficial in rescuing the antitumor effect of anti-PD-1 therapy. Metabolic oligosaccharide engineering and biorthogonal click chemistry resulted in successful B. fragilis labeling with 64Cu and fluorescence dye with high in vitro and in vivo stability and no effect on viability. PET imaging successfully detected the in vivo behaviors of B. fragilis after transplantation. CONCLUSION: PET tracking by metabolic labeling is a powerful, noninvasive tool for the real-time tracking and quantitative imaging of gut microbiota. This strategy is clinically translatable and may also be extended to the PET tracking of other functional cells to guide cell-based adoptive therapies.


Assuntos
Microbioma Gastrointestinal , Animais , Antibacterianos , Camundongos , Imagem Óptica , Tomografia por Emissão de Pósitrons , RNA Ribossômico 16S
12.
Mol Pharm ; 17(4): 1215-1225, 2020 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-32167771

RESUMO

Inspired by the structure and function of the mussel adhesive protein, a facile strategy involving oxidative polymerization of dopamine was proposed for surface modification of nanostructured lipid carriers (NLCs) to promote drug delivery in the skin. The formation of a polydopamine (PDA) layer rounding the surface of NLCs was confirmed by the X-ray photoelectron spectroscopy and the Fourier transform infrared spectroscopy studies. Using terbinafine (TBF) as a model drug, the in vitro permeation study revealed that the PDA coating significantly enhanced the delivery of TBF from NLCs to the deep skin layers, where the follicular pathway played an essential role as suggested by the hair follicle blocking and differential tape stripping experiments, as well as the laser scanning confocal microscopy study by using Nile red as the fluorescent probe. The cellular investigation indicated that the PDA coating led to a higher cellular uptake of nanoparticles in human immortalized keratinocytes (HaCaT) without causing additional cytotoxicity. Using endocytic inhibitors, it was found that the lipid raft/caveolae-mediated endocytosis was strongly involved in the internalization of both the PDA modified and unmodified NLCs. Our results suggested that surface modification of NLCs with PDA coating improved the intracutaneous drug delivery mainly via the follicular pathway, which provided an avenue for the development of potential drug delivery carriers for dermal use.


Assuntos
Portadores de Fármacos/química , Folículo Piloso/efeitos dos fármacos , Indóis/química , Lipídeos/química , Nanopartículas/química , Nanoestruturas/química , Polímeros/química , Pele/efeitos dos fármacos , Animais , Linhagem Celular , Sistemas de Liberação de Medicamentos/métodos , Endocitose/efeitos dos fármacos , Humanos , Injeções Intradérmicas/métodos , Queratinócitos/efeitos dos fármacos , Nanopartículas/administração & dosagem , Preparações Farmacêuticas/química , Suínos
13.
Opt Express ; 27(21): 29479-29490, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31684208

RESUMO

We theoretically investigate the entanglement between two macroscopic rotating mirrors in a Laguerre-Gaussian (L-G) cavity, in which they exchange orbital angular momentum with a same L-G cavity mode, and we examine the influence of various factors such as angular frequencies of two mirrors, effective detuning, temperature and orbital angular momentum of L-G cavity mode on the entanglement. The results show that in some range of mirrors' angular frequencies the entanglement will appear and has strong robustness. And we also study the range of effective detuning and the minimum orbital angular momentum of the L-G cavity mode required to generate entanglement.

14.
Emerg Med J ; 36(9): 529-534, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31326954

RESUMO

BACKGROUND: Trauma team activation criteria have a variable performance in the paediatric population. We aimed to identify predictors for high-level resource utilisation during trauma resuscitation in the ED. METHODS: A retrospective study was conducted in the ED of a tertiary paediatric hospital. Patient data were collected from trauma surveillance registry and analysis was performed to identify significant predictors. We then assessed the sensitivity and specificity of proposed models with respect to observed patient outcomes. RESULTS: Among 11 282 cases, the mean age was 6.1±4.9 (SD) years old. Fall was the most common mechanism of injury in 7364 (65.3%) patients. Eighty-eight (0.8%) patients required at least one high-level resource. Significant predictors for high-resource utilisation were overall GCS of <14 (relative risk (RR) 38.841, 95% CI 21.328 to 70.739, p<0.001), high-risk mechanisms of fall from height and motor vehicle collision (RR 7.863, 95% CI 4.687 to 13.192, p<0.001), as well as age-specific tachycardia (RR 1.796, 95% CI 1.145 to 2.817, p=0.0108). A model consisting of GCS and high-risk mechanism would under-triage 21 (0.2%) patients and over-triage 681 (6.0%) patients. When age-specific tachycardia was added, 8 (0.1%) less patients would be under-triaged but an additional 3251 (28.9%) patients would be over-triaged. CONCLUSION: As utilisation of high-level resources in paediatric trauma was rare, it was difficult to find an appropriate balance between under-triage and over-triage. Between the two, minimising the proportion of under-triage is more important as patient safety is paramount in paediatric trauma care.


Assuntos
Utilização de Instalações e Serviços/estatística & dados numéricos , Fidelidade a Diretrizes/estatística & dados numéricos , Padrões de Prática Médica/estatística & dados numéricos , Ressuscitação/estatística & dados numéricos , Ferimentos e Lesões/terapia , Criança , Pré-Escolar , Utilização de Instalações e Serviços/organização & administração , Utilização de Instalações e Serviços/normas , Feminino , Escala de Coma de Glasgow/estatística & dados numéricos , Hospitais Pediátricos/organização & administração , Hospitais Pediátricos/normas , Hospitais Pediátricos/estatística & dados numéricos , Humanos , Lactente , Masculino , Guias de Prática Clínica como Assunto , Padrões de Prática Médica/organização & administração , Padrões de Prática Médica/normas , Sistema de Registros/estatística & dados numéricos , Ressuscitação/normas , Estudos Retrospectivos , Singapura , Centros de Atenção Terciária/organização & administração , Centros de Atenção Terciária/normas , Centros de Atenção Terciária/estatística & dados numéricos , Centros de Traumatologia/organização & administração , Centros de Traumatologia/normas , Centros de Traumatologia/estatística & dados numéricos , Triagem/organização & administração , Triagem/normas , Triagem/estatística & dados numéricos , Ferimentos e Lesões/diagnóstico
15.
Inorg Chem ; 56(3): 1713-1721, 2017 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-28094932

RESUMO

A series of five unique d-f heteronuclear luminescent metal-organic frameworks (MOFs) in an entangled polyrotaxane array and the light-harvesting block homonuclear zinc compound have been isolated successfully and characterized. The series of isostructural polymers feature 3,4-connected (4.82)(4.83.92)(6.8.9)2(6.92)(83) topology and high stability, exhibiting diverse void spaces. By taking advantage of the isostructural MOFs 2 and 3, the intensities of red and green emissions can be modulated by adjusting the ratios of EuIII and TbIII ions correspondingly, and white-light emission can be generated by a combination of different doped TbIII and EuIII concentrations. The Tb-Zn-based framework {[Tb3Zn6(bipy2)2(Hmimda)7 (H2O)3]·5H2O}n (3; H3mimda = 2-methyl-1-H-imidazole-4,5-dicarboxylic acid and bipy = 4,4'-bipyridine) can detect trace MgII ion with relatively high sensitivity and selectivity. Dehydrated MOF 3a shows a remarkable emission quenching effect through the introduction of I2 solids. Further investigation indicates that it exhibits turn on/off switchable properties for small solvent molecules or heavy-metal ions. Steady/transient-state near-IR luminescence properties for MOFs 1, 4, and 5 were investigated under visible-light excitation.

16.
Phys Rev Lett ; 117(2): 023901, 2016 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-27447507

RESUMO

We numerically study the propagation of a few-cycle pulse carrying orbital angular momentum (OAM) through a dense atomic system. Nonlinear precursors consisting of high-order vortex harmonics are generated in the transmitted field due to carrier effects associated with ultrafast Bloch oscillation. The nonlinear precursors survive to propagation effects and are well separated with the main pulse, which provides a straightforward way to measure precursors. By virtue of carrying high-order OAM, the obtained vortex precursors as information carriers have potential applications in optical information and communication fields where controllable loss, large information-carrying capacity, and high speed communication are required.

17.
Opt Express ; 23(13): 17046-55, 2015 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-26191713

RESUMO

This numerical study demonstrates that Doppler redshift exists in the reflected spectrum of a few-cycle pulse, propagating through a dense medium. It manifests itself in two different forms, a sharp low-frequency spike (LFS) located at the red edge of the reflected spectrum and a relatively broader redshift near the carrier frequency. With the variation of the laser and medium parameters, the dominant reflection mechanism changes between bulk generation of backwards propagation waves and nonlinear reflection near the front face. This leads to the manifestation of Doppler effect changing accordingly between the two different forms. This study unifies the physical mechanism behind the LFS and dynamic nonlinear optical skin effect, which enriches the theoretical explanation of the spectral redshift of few-cycle pulse propagation beyond the intrapulse four-wave mixing.

18.
Inorg Chem ; 54(5): 2088-90, 2015 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-25689139

RESUMO

A Cu(+)-CP based on the tetranuclear unit {[(HSQPA)2Cu4(bipy)4]·2H2O}n·2nH2O has been constructed through Cu(2+) salt, 2-(sulfonylquinlium-8-yloxy)phthalic acid (H3SQPA), and 4,4'-bipyridine (bipy). This Cu(+)-CP combined with 2,2,6,6-tetramethylpiperidine-1-oxyl as the cocatalyst is an effective catalyst for aerobic oxidation of alcohols and the synthesis of benzoxazoles and can be recycled at least four times without losing its catalytic activity.


Assuntos
Álcoois/química , Benzoxazóis/síntese química , Cobre/química , Óxidos N-Cíclicos/química , Compostos Organometálicos/química , Polímeros/química , Benzoxazóis/química , Catálise , Modelos Moleculares , Estrutura Molecular , Compostos Organometálicos/síntese química , Oxirredução
19.
Nanotechnology ; 25(41): 415402, 2014 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-25258306

RESUMO

Nitrogen-rich graphene sheets were successfully achieved via facile thermal condensation of glucose and dicyandiamide at different temperatures during which dicyandiamide acts both as nitrogen source and sacrifice template. Devoid of surfactants or poisonous organic solvents, this small-molecule synthetic approach is a simple and cost-effective way to obtain nitrogen-rich graphene sheets (NRGS) with high specific surface area and large pore volume. Shown to be a promising anode material, the NRGS displayed high reversible capacity, excellent rate capability, and superior cycle performance. The superior lithium-storage performance is ascribed to the unique features of NRGS, including a large quantity of defects due to the high nitrogen doping level, favorable lithium ion transportation channels by virtue of the large surface area, and ultrahigh pore volume, as well as the crumpled two-dimensional structure.

20.
Talanta ; 278: 126462, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38917552

RESUMO

The high toxicity of dichromate anion (Cr2O72-) its accurate necessitates its sensitive and effective detection to safeguard human health. The study introduces a Eu-MOF fluorescent probe, named as Eu-TDCA, synthesized using 2,5-thiophenedicarboxylic acid (H2TDCA) as a bridging ligand for the detection of Cr2O72- in aqueous media. The probe suspension can detect Cr2O72- through fluorescence quenching, and the detection process exhibits a wide linear range (0-85 and 85-230 mg/L), low limit of detection (LOD, 5.1 µg/L) and rapid response speed (2 min). Furthermore, a portable Eu-TDCA-loaded paper-based probe, integrated with a smartphone color recognition app, was developed for the visual, sensitive and quantitative detection of Cr2O72- in real lake and river water samples, achieving satisfactory recoveries of 99.72%-103.75 %. Additionally, an advanced logic gate device was designed to simplify the detection process, providing a new direction for intelligent on-line detection of analytes.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA