Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Food Sci Biotechnol ; 32(9): 1205-1214, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37362812

RESUMEN

Some Escherichia coli serotypes cause diarrhea in infants and acute gastroenteritis. In this study, the incidence of Shiga toxin-producing (STEC) and enterohemorrhagic (EHEC) E. coli in 310 fresh raw beef samples and the presence of pathogenicity-associated virulence genes in the isolated strains were evaluated. The contamination rate reached 18.06% (STEC, 12.26%; EHEC, 5.81%). The highest rate of identified virulence genes was 8.38% for stx2 and 3.23% for stx2 and eae in STEC and EHEC, respectively. Vinegar N6 significantly lowered E. coli growth in beef samples, depending on its concentration (> 0.5%), treatment temperature (5 or 10 °C), and E. coli type (STEC, EHEC, or enteropathogenic), during 28 days of storage. However, no bactericidal effects were detected, unlike those observed for combined treatment with UV-C LED and vinegar N6. Treatment with vinegar N6 and UV-C LED together may significantly reduce E. coli growth in fresh beef, thereby improving food safety. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01260-x.

2.
J Exerc Rehabil ; 14(2): 207-212, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29740553

RESUMEN

We investigated the effect of exercise rehabilitation based on fine motor movement for the elderly with mild dementia. Using electroencephalogram (EEG), the change of brain wave of them based on fine motor movement and comparing the improvement level of cognitive ability and performance capability in daily living activity was recorded. The subjects were the elderly with mild dementia living in a sanatorium in Incheon city. Mini-Mental Status Examination, activity of daily living (ADL), and the influence on depression were examined. After 8-week exercise program, significant difference in cognitive function and ADL was observed, however, and there was no significant difference in depression. In the EEG, there was a significant difference in α-wave. This study suggests the chance to remind the necessity of exercise programs for improving cognitive function and ADL of the elderly with dementia.

3.
J Exerc Rehabil ; 14(2): 294-300, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29740566

RESUMEN

The purpose of this study is to analyze the differences among the hospitalized cancer patients on their perception of exercise and physical activity constraints based on their medical history. The study used questionnaire survey as measurement tool for 194 cancer patients (male or female, aged 20 or older) living in Seoul metropolitan area (Seoul, Gyeonggi, Incheon). The collected data were analyzed using frequency analysis, exploratory factor analysis, reliability analysis t-test, and one-way distribution using statistical program SPSS 18.0. The following results were obtained. First, there was no statistically significant difference between cancer stage and exercise recognition/physical activity constraint. Second, there was a significant difference between cancer stage and sociocultural constraint/facility constraint/program constraint. Third, there was a significant difference between cancer operation history and physical/socio-cultural/facility/program constraint. Fourth, there was a significant difference between cancer operation history and negative perception/facility/program constraint. Fifth, there was a significant difference between ancillary cancer treatment method and negative perception/facility/program constraint. Sixth, there was a significant difference between hospitalization period and positive perception/negative perception/physical constraint/cognitive constraint. In conclusion, this study will provide information necessary to create patient-centered healthcare service system by analyzing exercise recognition of hospitalized cancer patients based on their medical history and to investigate the constraint factors that prevents patients from actually making efforts to exercise.

4.
Sci Adv ; 2(10): e1601428, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27819053

RESUMEN

Although solution processing of small-molecule organic light-emitting diodes (OLEDs) has been considered as a promising alternative to standard vacuum deposition requiring high material and processing cost, the devices have suffered from low luminous efficiency and difficulty of multilayer solution processing. Therefore, high efficiency should be achieved in simple-structured small-molecule OLEDs fabricated using a solution process. We report very efficient solution-processed simple-structured small-molecule OLEDs that use novel universal electron-transporting host materials based on tetraphenylsilane with pyridine moieties. These materials have wide band gaps, high triplet energy levels, and good solution processabilities; they provide balanced charge transport in a mixed-host emitting layer. Orange-red (~97.5 cd/A, ~35.5% photons per electron), green (~101.5 cd/A, ~29.0% photons per electron), and white (~74.2 cd/A, ~28.5% photons per electron) phosphorescent OLEDs exhibited the highest recorded electroluminescent efficiencies of solution-processed OLEDs reported to date. We also demonstrate a solution-processed flexible solid-state lighting device as a potential application of our devices.

5.
ChemSusChem ; 7(4): 1125-32, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24616332

RESUMEN

Although rapid progress has been made recently in bulk heterojunction organic solar cells, systematic studies on an ultrathin interfacial layer at the electron extraction contact have not been conducted in detail, which is important to improve both the device efficiency and the lifetime. We find that an ultrathin BaF2 layer at the electron extraction contact strongly influences the open-circuit voltage (Voc ) as the nanomorphology evolves with increasing BaF2 thickness. A vacuum-deposited ultrathin BaF2 layer grows by island growth, so BaF2 layers with a nominal thickness less than that of single-coverage layer (≈3 nm) partially cover the polymeric photoactive layer. As the nominal thickness of the BaF2 layer increased to that of a single-coverage layer, the Voc and power conversion efficiency (PCE) of the organic photovoltaic cells (OPVs) increased but the short-circuit current remained almost constant. The fill factor and the PCE decreased abruptly as the thickness of the BaF2 layer exceeded that of a single-coverage layer, which was ascribed to the insulating nature of BaF2 . We find the major cause of the increased Voc observed in these devices is the lowered work function of the cathode caused by the reaction and release of Ba from thin BaF2 films upon deposition of Al. The OPV device with the BaF2 layer showed a slightly improved maximum PCE (4.0 %) and a greatly (approximately nine times) increased device half-life under continuous simulated solar irradiation at 100 mW cm(-2) as compared with the OPV without an interfacial layer (PCE=2.1 %). We found that the photodegradation of the photoactive layer was not a major cause of the OPV degradation. The hugely improved lifetime with cathode interface modification suggests a significant role of the cathode interfacial layer that can help to prolong device lifetimes.


Asunto(s)
Compuestos de Bario/química , Suministros de Energía Eléctrica , Fluoruros/química , Compuestos Orgánicos/química , Energía Solar , Electrodos
6.
Adv Mater ; 24(11): 1487-93, 2012 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-22344846

RESUMEN

A highly efficient simplified organic light-emitting diode (OLED) with a molecularly controlled strategy to form near-perfect interfacial layer on top of the anode is demonstrated. A self-organized polymeric hole injection layer (HIL) is exploited increasing hole injection, electron blocking, and reducing exciton quenching near the electrode or conducting polymers; this HIL allows simplified OLED comprised a single small-molecule fluorescent layer to exhibits a high current efficiency (∼20 cd/A).


Asunto(s)
Luz , Membranas Artificiales , Polímeros/química , Ensayo de Materiales , Estructura Molecular , Polímeros/síntesis química , Propiedades de Superficie
8.
ChemSusChem ; 4(3): 363-8, 2011 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-21265026

RESUMEN

It is a great challenge to develop solution-processed, polymeric hole-injection layers (HILs) that perform better than small molecular layers for realizing high-performance small-molecule organic light-emitting diodes (SM-OLEDs). We have greatly improved the injection efficiency and the current efficiency of SM-OLEDs by introducing conducting polymer compositions composed of polyaniline doped with polystyrene sulfonate and perfluorinated ionomer (PFI) as the HIL. During single spin-coating of conducting polymer compositions, the PFI layer was self-organized at the surface and greatly increased the film work function. It enhanced hole-injection efficiency and current efficiency by introducing a nearly ohmic contact and improving electron blocking. Our results demonstrate that solution-processed polyaniline HILs with tunable work functions are good candidates for reducing process costs and improving OLED performance.


Asunto(s)
Compuestos de Anilina , Conductividad Eléctrica , Técnicas Electroquímicas , Luz , Electrones , Polímeros , Poliestirenos , Soluciones
9.
Ultramicroscopy ; 108(10): 1106-9, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18547732

RESUMEN

Coating of 0.65Pb(Mg(1/3)Nb(2/3))O(3)-0.35PbTiO(3) (PMN-PT) relaxor ferroelectrics by a sol-gel method is followed by growth of epitaxial SrRuO(3) (SRO) metallic oxide electrodes on SrTiO(3) (STO) single-crystal substrate by pulsed laser deposition. High-quality PMN-PT films on SRO with preferred growth orientation were successfully fabricated by controlling the operation parameters. Structural properties of relaxor ferroelectric PMN-PT thin films on SRO/STO substrates have been studied by X-ray diffraction (XRD), transmission electron microscopy (TEM) and atomic force microscopy (AFM). In-plane and out-of-plane alignments of the heterostructure are confirmed and the structural twinning of the materials are also revealed.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...