Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Spectrochim Acta A Mol Biomol Spectrosc ; 222: 117239, 2019 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-31202031

RESUMEN

A novel fluorescent graft conjugated polymer (poly (2, 5-bis (Polyethylene glycol oxybutyrate)-1, 4-phenylethynylene-alt-1, 4-phenyleneethynylene, PPE-OB-PEG) has been designed and synthesized for the determination of aristolochic acid (AA). The detection conditions and detection characters of PPE-OB-PEG were systematically explored in this work. The fluorescence intensity of PPE-OB-PEG changes with the different concentration of AA. PPE-OB-PEG has a good linear range towards AA from 1.00 × 10-7 to 8.00 × 10-5 mol L-1 and the limit of detection (LOD) is 3.00 × 10-8 mol L-1 (S/N = 3). PPE-OB-PEG have been applied to detect AA in traditional Chinese medicine samples and the results are satisfactory. The experimental results show that PPE-OB-PEG can be used as a fluorescence probe for rapid and sensitive detection of AA.


Asunto(s)
Alquinos/química , Ácidos Aristolóquicos/análisis , Medicamentos Herbarios Chinos/química , Éteres/química , Colorantes Fluorescentes/química , Polietilenglicoles/química , Espectrometría de Fluorescencia/economía , Espectrometría de Fluorescencia/métodos , Factores de Tiempo
2.
Talanta ; 187: 314-320, 2018 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-29853053

RESUMEN

A novel fluorescent conjugated polymer (poly(2-amino-N-(2-((4-ethynylphenyl) ethynyl) phenyl)-5-guanidinopentanamide)-1,4-phenylethynylene-1,4-phenyleneethynylene, PPE-Arg) was synthesized in this paper. We found that PPE-Arg could be quenched by picric acid (PA). Photoinduced electron transfer (PET) mechanism can be used to describe the fluorescence quenching of PPE-Arg. It could be speculated that the photo-induced electrons may be transferred from PPE-Arg to nitroaromatic explosives. In this paper, the experiment conditions and detection performance of PPE-Arg were systematically studied. The experiment results demonstrate PPE-Arg as a sensor for PA has a good linear range from 5 × 10-7 to 6 × 10-5 mol L-1 with the calculated limit of detection (LOD) to be 1.0 × 10-7 mol L-1. Meanwhile, reaction time between PPE-Arg and PA is less than 1 min. This proposed sensor was applied to rapidly detect nitroaromatic explosives in environmental water samples and satisfactory results were obtained.

3.
Dalton Trans ; 46(47): 16446-16454, 2017 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-29143014

RESUMEN

The single crystals of two novel mixed-ligand copper(ii)-based complexes were obtained and characterized. These complexes can remarkably induce apoptosis, inhibit proliferation, suppress migration and metastasis, and inhibit angiogenesis to inhibit the growth of cervical cancer by down-regulating the expressions of the important proteins FAK, Akt and Erk1/2 or their phosphorylated proteins p-FAK, p-Akt, and p-Erk1/2 downstream of the VEGF/VEGFR2 signaling pathway.


Asunto(s)
Complejos de Coordinación/síntesis química , Complejos de Coordinación/farmacología , Cobre/química , Transducción de Señal/efectos de los fármacos , Factor A de Crecimiento Endotelial Vascular/metabolismo , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismo , Antineoplásicos/síntesis química , Antineoplásicos/química , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Técnicas de Química Sintética , Complejos de Coordinación/química , Humanos , Ligandos , Modelos Moleculares , Conformación Molecular
4.
J Child Psychol Psychiatry ; 51(9): 981-8, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20524939

RESUMEN

BACKGROUND: The 'broken mirror' theory of autism, which proposes that a dysfunction of the human mirror neuron system (MNS) is responsible for the core social and cognitive deficits in individuals with autism spectrum disorders (ASD), has received considerable attention despite weak empirical evidence. METHODS: In this electroencephalographic study, we examined mu suppression, as an indicator of sensorimotor resonance, concurrent with oculomotor performance while individuals (n = 20) with ASD and control participants (n = 20) either executed hand actions or observed hand actions or a moving dot. No difference in visual attention between groups was found as indicated by fixation duration and normalized fixation number on the presented stimuli. RESULTS: The mu suppression over the sensorimotor cortex was significantly affected by experimental conditions, but not by group membership, nor by the interaction between groups and conditions. Individuals with ASD, similar to the controls, exhibited stronger mu suppression when watching hand actions relative to a moving dot. Notably, participants with ASD failed to imitate the observed actions while their mu suppression indicating the MNS activity was intact. In addition, the mu suppression during the observation of hand actions was positively associated with the communication competence of individuals with ASD. CONCLUSION: Our study clearly challenges the broken mirror theory of autism. The functioning of the mirror neuron system might be preserved in individuals with ASD to a certain degree. Less mu suppression to action observation coupled with more communicational severity can reflect the symptom heterogeneity of ASD. Additional research needs to be done, and more caution should be used when reaching out to the media.


Asunto(s)
Trastornos Generalizados del Desarrollo Infantil/fisiopatología , Neuronas/fisiología , Adolescente , Adulto , Análisis de Varianza , Atención , Niño , Trastornos Generalizados del Desarrollo Infantil/diagnóstico , Dominancia Cerebral , Electroencefalografía/métodos , Fijación Ocular , Análisis de Fourier , Humanos , Masculino , Estimulación Luminosa/métodos , Adulto Joven
5.
J Zhejiang Univ Sci ; 5(5): 572-8, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15083544

RESUMEN

With the development of general-purpose processors (GPP) and video signal processing algorithms, it is possible to implement a software-based real-time video encoder on GPP, and its low cost and easy upgrade attract developers' interests to transfer video encoding from specialized hardware to more flexible software. In this paper, the encoding structure is set up first to support complexity scalability; then a lot of high performance algorithms are used on the key time-consuming modules in coding process; finally, at programming level, processor characteristics are considered to improve data access efficiency and processing parallelism. Other programming methods such as lookup table are adopted to reduce the computational complexity. Simulation results showed that these ideas could not only improve the global performance of video coding, but also provide great flexibility in complexity regulation.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...