Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 135
Filtrar
1.
FASEB J ; 38(9): e23638, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38713098

RESUMO

Diabetic retinopathy (DR) is associated with ocular inflammation leading to retinal barrier breakdown, vascular leakage, macular edema, and vision loss. DR is not only a microvascular disease but also involves retinal neurodegeneration, demonstrating that pathological changes associated with neuroinflammation precede microvascular injury in early DR. Macrophage activation plays a central role in neuroinflammation. During DR, the inflammatory response depends on the polarization of retinal macrophages, triggering pro-inflammatory (M1) or anti-inflammatory (M2) activity. This study aimed to determine the role of macrophages in vascular leakage through the tight junction complexes of retinal pigment epithelium, which is the outer blood-retinal barrier (BRB). Furthermore, we aimed to assess whether interleukin-10 (IL-10), a representative M2-inducer, can decrease inflammatory macrophages and alleviate outer-BRB disruption. We found that modulation of macrophage polarization affects the structural and functional integrity of ARPE-19 cells in a co-culture system under high-glucose conditions. Furthermore, we demonstrated that intravitreal IL-10 injection induces an increase in the ratio of anti-inflammatory macrophages and effectively suppresses outer-BRB disruption and vascular leakage in a mouse model of early-stage streptozotocin-induced diabetes. Our results suggest that modulation of macrophage polarization by IL-10 administration during early-stage DR has a promising protective effect against outer-BRB disruption and vascular leakage. This finding provides valuable insights for early intervention in DR.


Assuntos
Barreira Hematorretiniana , Diabetes Mellitus Experimental , Retinopatia Diabética , Interleucina-10 , Macrófagos , Animais , Humanos , Masculino , Camundongos , Barreira Hematorretiniana/metabolismo , Barreira Hematorretiniana/patologia , Polaridade Celular/efeitos dos fármacos , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Experimental/metabolismo , Retinopatia Diabética/metabolismo , Retinopatia Diabética/patologia , Modelos Animais de Doenças , Interleucina-10/metabolismo , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Epitélio Pigmentado da Retina/metabolismo , Epitélio Pigmentado da Retina/patologia , Epitélio Pigmentado da Retina/efeitos dos fármacos , Estreptozocina
2.
Small ; 20(35): e2308317, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38564785

RESUMO

Proactive management of foodborne illness requires routine surveillance of foodborne pathogens, which requires developing simple, rapid, and sensitive detection methods. Here, a strategy is presented that enables the detection of multiple foodborne bacteria using a 3D nanostructure swab and deep learning-based Raman signal classification. The nanostructure swab efficiently captures foodborne pathogens, and the portable Raman instrument directly collects the Raman signals of captured bacteria. a deep learning algorithm has been demonstrated, 1D convolutional neural network with binary labeling, achieves superior performance in classifying individual bacterial species. This methodology has been extended to mixed bacterial populations, maintaining accuracy close to 100%. In addition, the gradient-weighted class activation mapping method is used to provide an investigation of the Raman bands for foodborne pathogens. For practical application, blind tests are conducted on contaminated kitchen utensils and foods. The proposed technique is validated by the successful detection of bacterial species from the contaminated surfaces. The use of a 3D nanostructure swab, portable Raman device, and deep learning-based classification provides a powerful tool for rapid identification (≈5 min) of foodborne bacterial species. The detection strategy shows significant potential for reliable food safety monitoring, making a meaningful contribution to public health and the food industry.


Assuntos
Aprendizado Profundo , Microbiologia de Alimentos , Nanoestruturas , Análise Espectral Raman , Análise Espectral Raman/métodos , Nanoestruturas/química , Doenças Transmitidas por Alimentos/microbiologia , Bactérias/isolamento & purificação
3.
Am J Primatol ; 85(9): e23532, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37357545

RESUMO

The common marmoset (Callithrix jacchus) is considered an ideal species for developing genetically modified nonhuman primates (NHP) models of human disease, particularly eye disease. They have been proposed as a suitable bridge between rodents and other NHP models due to their similar ophthalmological features to humans. Prenatal ultrasonography is an accurate and reliable diagnostic tool for monitoring fetal development and congenital malformation. We monitored fetal eye growth and development using noninvasive ultrasonography in 40 heads of clinically normal fetuses during pregnancy to establish the criteria for studying congenital eye anomalies in marmosets. The coronal, sagittal, and transverse planes were useful to identify the facial structures for any associated abnormalities. For orbital measurements, biorbital distance (BOD), ocular diameter (OD), interorbital distance (IOD), and total axial length (TAL) were measured in the transverse plane and carefully identified for intraorbital structures. As a result, high correlations were observed between delivery-based gestational age (GA) and biparietal diameter (BPD), BOD, OD, and TAL. The correlation assessments based on BOD provide more reliable results for monitoring eye growth and development in normal marmosets than any other parameters since BOD has the highest correlation coefficient according to both delivery-based GA and BPD among ocular measurements. In conclusion, orbital measurements by prenatal ultrasonography provide reliable indicators of marmoset eye growth, and it could offer early diagnostic criteria to facilitate the development of eye disease models and novel therapies such as genome editing technologies in marmosets.

4.
FASEB J ; 35(3): e21403, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33559185

RESUMO

The retinal pigment epithelium (RPE) undergoes characteristic structural changes and epithelial-mesenchymal transition (EMT) during normal aging, which are exacerbated in age-related macular degeneration (AMD). Although the pathogenic mechanisms of aging and AMD remain unclear, transforming growth factor-ß1 (TGF-ß1) is known to induce oxidative stress, morphometric changes, and EMT as a senescence-promoting factor. In this study, we examined whether intravitreal injection of TGF-ß1 into the mouse eye elicits senescence-like morphological alterations in the RPE and if this can be prevented by suppressing mammalian target of rapamycin complex 1 (mTORC1) or NADPH oxidase (NOX) signaling. We verified that intravitreal TGF-ß1-induced stress fiber formation and EMT in RPE cells, along with age-associated morphometric changes, including increased variation in cell size and reduced cell density. In RPE cells, exogenous TGF-ß1 increased endogenous expression of TGF-ß1 and upregulated Smad3-ERK1/2-mTORC1 signaling, increasing reactive oxygen species (ROS) production and EMT. We demonstrated that inhibition of the mTORC1-NOX4 pathway by pretreatment with 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR), an activator of AMP-dependent protein kinase, or GKT137831, a NOX1/4 inhibitor, decreased ROS generation, prevented stress fiber formation, attenuated EMT, and improved the regularity of the RPE structure in vitro and in vivo. These results suggest that intravitreal TGF-ß1 injection could be used as a screening model to investigate the aging-related structural and functional changes to the RPE. Furthermore, the regulation of TGF-ß-mTORC1-NOX signaling could be a potential therapeutic target for reducing pathogenic alterations in aged RPE and AMD.


Assuntos
Alvo Mecanístico do Complexo 1 de Rapamicina/fisiologia , NADPH Oxidases/fisiologia , Epitélio Pigmentado da Retina/patologia , Fator de Crescimento Transformador beta1/fisiologia , Animais , Células Cultivadas , Senescência Celular , Transição Epitelial-Mesenquimal , Injeções Intravítreas , Degeneração Macular/tratamento farmacológico , Degeneração Macular/metabolismo , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina/antagonistas & inibidores , Camundongos , Camundongos Endogâmicos C57BL , NADPH Oxidases/antagonistas & inibidores , Pirazolonas/farmacologia , Piridonas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Epitélio Pigmentado da Retina/fisiologia , Transdução de Sinais/fisiologia
5.
Electrophoresis ; 39(3): 456-461, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28960347

RESUMO

This work presents a handy, fast, and compact bufferless gel electrophoresis chip (BGEC), which consists of precast agarose gel confined in a disposable plastic body with electrodes. It does not require large volumes of buffer to fill reservoirs, or the process of immersing the gel in the buffer. It withstands voltages up to 28.4 V/cm, thereby allowing DNA separation within 10 min with a similar separation capability to the standard gel electrophoresis. The results suggest that our BGEC is highly suitable for in situ gel electrophoresis in forensic, epidemiological settings and crime scenes where standard gel electrophoresis equipment cannot be brought in while quick results are needed.


Assuntos
DNA/isolamento & purificação , Eletroforese em Gel de Ágar/métodos , Soluções Tampão , Eletrodos , Eletroforese em Gel de Ágar/instrumentação
6.
Sensors (Basel) ; 18(9)2018 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-30235826

RESUMO

Since the increment of the threat to public health caused by foodborne pathogens, researches have been widely studied on developing the miniaturized detection system for the on-site pathogen detection. In the study, we focused on the development of portable, robust, and disposable film-based polymerase chain reaction (PCR) chip containing a multiplex chamber for simultaneous gene amplification. In order to simply fabricate and operate a film-based PCR chip, different kinds of PCR chambers were designed and fabricated using polyethylene terephthalate (PET) and polyvinyl chloride (PVC) adhesive film, in comparison with commercial PCR, which employs a stereotyped system at a bench-top scale. No reagent leakage was confirmed during the PCR thermal cycling using the film PCR chip, which indicates that the film PCR chip is structurally stable for rapid heat cycling for DNA amplification. Owing to use of the thin film to fabricate the PCR chip, we are able to realize fast thermal transfer from the heat block that leads to short PCR amplification time. Moreover, using the film PCR chip, we could even amplify the target pathogen with 10 CFU mL-1. The artificially infected milk with various concentration of Bacillus cereus was successfully amplified on a single film PCR chip. On the basis of the reliable results, the developed film PCR chip could be a useful tool as a POCT device to detect foodborne pathogens via genetic analysis.


Assuntos
Contaminação de Alimentos/análise , Reação em Cadeia da Polimerase/instrumentação , Reação em Cadeia da Polimerase/métodos , Animais , Bacillus cereus/genética , Bacillus cereus/isolamento & purificação , Temperatura Alta , Leite/microbiologia
7.
Chemistry ; 22(12): 4036-45, 2016 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-26879000

RESUMO

Red phosphorescent iridium(III) complexes based on fluorine-, phenyl-, and fluorophenyl-substituted 2-arylquinoline ligands were designed and synthesized. To investigate their electrophosphorescent properties, devices were fabricated with the following structure: indium tin oxide (ITO)/4,4',4''-tris[2-naphthyl(phenyl)amino]triphenylamine (2-TNATA)/4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB)/4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP): 8% iridium (III) complexes/bathocuproine (BCP)/tris(8-hydroxyquinolinato)aluminum (Alq3)/8-hydroxyquinoline lithium (Liq)/Al. All devices, which use these materials showed efficient red emissions. In particular, a device exhibited a saturated red emission with a maximum luminance, external quantum efficiency, and luminous efficiency of 14200 cd m(-2), 8.44%, and 6.58 cd A(-1) at 20 mA cm(-2), respectively. The CIE (x, y) coordinates of this device are (0.67, 0.33) at 12.0 V.

8.
Analyst ; 141(4): 1319-24, 2016 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-26765056

RESUMO

Design and fabrication of electrodes is key in the development of electrochemical sensors with superior electrochemical performances. Herein, an enzymeless electrochemical sensor is developed for detection of hydrogen peroxide based on the use of highly ordered polyoxometalate (POM)-doped polyaniline (PANI) nanopillar films. The electrodeposition technique enables the entrapment of POMs into PANI during electropolymerization to produce thin coatings of POM-PANI. Electrochemical investigations of the POM-PANI/nanopillar electrode showed well-defined multiple pairs of redox peaks and rapid electron transfer. The nanopillar structure facilitated the diffusion of the electrolyte and thus, enhanced the redox reaction. In particular, the POM-PANI/nanopillar electrode was incorporated into a flow injection biosensor and it demonstrates its electrocatalytic activity to detect hydrogen peroxide with high sensitivity, rapid response time, and low detection limit.


Assuntos
Compostos de Anilina/química , Peróxido de Hidrogênio/análise , Nanoestruturas/química , Nanotecnologia/instrumentação , Compostos de Tungstênio/química , Eletroquímica , Eletrodos , Peróxido de Hidrogênio/química
9.
J Nanobiotechnology ; 14(1): 35, 2016 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-27129379

RESUMO

BACKGROUND: It has been reported that both chemical and physical surface patterns influence cellular behaviors, such as cell alignment and elongation. However, it still remains unclear how actin filament and microtubules (MTs) differentially respond to these patterns. RESULTS: We examined the effects of chemical and physical patterns on cell elongation and alignment by observing actin filament and MTs of retinal pigment epithelium-1(RPE-1) cells, which were cultured on either fibronectin (FN)-line pattern (line width and spacing: 1 µm) or FN-coated 1 µm gratings with two different depths (0.35 or 1 µm). On the surface with either FN-line pattern or micrograting structure, the cell aspect ratios were at least two times higher than those on the surface with no pattern. Cell elongation on the gratings depended on the depth of the gratings. Cell elongation and alignment on both FN-line pattern and 1 µm gratings with 0.35 µm depth were perturbed either by inhibition of actin polymerization or MT depletion, while cell elongation and alignment on 1 µm gratings with 1 µm depth were perturbed only by MT depletion. CONCLUSIONS: Our results suggest that the contribution of actin filaments and MTs to the elongation and alignment of epithelial cells on microgratings depends on the groove depth of these gratings.


Assuntos
Citoesqueleto de Actina/ultraestrutura , Forma Celular/efeitos dos fármacos , Células Epiteliais/ultraestrutura , Microtúbulos/ultraestrutura , Citoesqueleto de Actina/efeitos dos fármacos , Linhagem Celular , Forma Celular/fisiologia , Citocalasina D/farmacologia , Células Epiteliais/efeitos dos fármacos , Fibronectinas/química , Fibronectinas/farmacologia , Humanos , Microtúbulos/efeitos dos fármacos , Nocodazol/farmacologia , Epitélio Pigmentado da Retina/efeitos dos fármacos , Epitélio Pigmentado da Retina/ultraestrutura , Propriedades de Superfície
10.
Bioprocess Biosyst Eng ; 39(5): 725-33, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26946491

RESUMO

Macrocyclic carbohydrate rings were formed via enzymatic reactions around single-walled carbon nanotubes (SWNTs) as a catalyst. Cyclodextrin glucanotransferase, starch substrate and SWNTs were reacted in buffer solution to yield cyclodextrin (CD) rings wrapped around individual SWNTs. Atomic force microscopy showed the resulting complexes to be rings of 12-50 nm in diameter, which were highly soluble and dispersed in aqueous solution. They were further characterized by Raman and Fourier transform infrared spectroscopy and molecular simulation using density functional theory calculation. In the absence of SWNT, hydrogen bonding between glucose units determines the structure of maltose (the precursor of CD) and produces the curvature along the glucose chain. Wrapping SWNT along the short axis was preferred with curvature in the presence of SWNTs and with the hydrophobic interactions between the SWNTs and CD molecules. This synthetic approach may be useful for the functionalization of carbon nanotubes for development of nanostructures.


Assuntos
Carboidratos/química , Glucosiltransferases/química , Nanotubos de Carbono , Ciclodextrinas/química , Microscopia de Força Atômica , Microscopia Eletrônica de Transmissão , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman
11.
Sensors (Basel) ; 16(12)2016 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-27999291

RESUMO

In this study, we developed lateral flow assay (LFA) biosensors for the detection of hepatitis B surface antigens using well-controlled gold nanoparticles (AuNPs). To enhance colorimetric signals, a seeded growth method was used for the preparation of size-controlled AuNPs with a narrow size distribution. Different sizes of AuNPs in the range of 342-137.8 nm were conjugated with antibodies and then optimized for the efficient detection of LFA biosensors. The conjugation stability was investigated by UV-vis spectroscopy of AuNP dispersion at various pH values and concentrations of antibody. Based on optimized conjugation conditions, the use of 42.7 ± 0.8 nm AuNPs exhibited superior performance for the detection of LFAs relative to other sizes of AuNPs.


Assuntos
Ouro/química , Antígenos de Superfície da Hepatite B/análise , Nanopartículas Metálicas/química , Tamanho da Partícula , Reologia/métodos , Cor , Humanos , Nanopartículas Metálicas/ultraestrutura , Kit de Reagentes para Diagnóstico , Espectrofotometria Ultravioleta
12.
Small ; 11(34): 4292-7, 2015 09 09.
Artigo em Inglês | MEDLINE | ID: mdl-26060049

RESUMO

Bio-inspired 3D hierarchical nanowebs are fabricated using silicon micropillars, carbon nanotubes (CNT), and manganese oxide. The Si pillars act as artificial branches for growing CNTs and the secondary metal coating strengthens the structures. The simple but effective structure provides both chemical and mechanical stability to be used as a green catalyst for recycling waste polymers into raw materials.


Assuntos
Química Verde/métodos , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestrutura , Tomografia por Emissão de Pósitrons , Silício/química , Análise Espectral Raman
13.
J Nanosci Nanotechnol ; 15(2): 1628-31, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26353704

RESUMO

We have designed and synthesized three blue emitters based on 9-naphthylanthracene derivatives connected with various electron-withdrawing group such as 4-fluorobenzene, 2,4-difluorobenzene and 2,3,4,5,6-pentafluorobenzene (1-3). Multilayered OLEDs with the structure of ITO (180 nm)/NPB (50 nm)/Blue materials 1-3 (30 nm)/TPBi (15 nm)/Liq (2 nm)/AI (100 nm) have been fabricated to investigate their electroluminescent properties. In particular, the device using 3 showed efficient blue electroluminescent properties with a luminous, power, external quantum efficiency and CIE coordinates of 0.71 cd/A, 1.98 Im/W, 1.34% at 20 mA/cm2 and (x = 0.16, y = 0.20) at 10.0 V, respectively. In addition, a deep blue OLED using 1 with CIE coordinates (x = 0.15, y = 0.11) at 10.0 V exhibited a luminous, power, external quantum efficiency of 2.12 cd/A, 3.04 Im/W and 1.17% at 20 mA/cm2, respectively.


Assuntos
Antracenos/química , Cor , Fluorbenzenos/química , Iluminação/instrumentação , Nanopartículas/química , Semicondutores , Transporte de Elétrons , Desenho de Equipamento , Análise de Falha de Equipamento , Teste de Materiais
14.
J Nanosci Nanotechnol ; 15(2): 1456-9, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26353672

RESUMO

We investigated a light emission mechanism of blue phosphorescent organic light emitting diodes (PHOLEDs), using a stepwise doping profile of 2, 8, and 14 wt.% within the emitting layer (EML). We fabricated several blue PHOLEDs with phosphorescent blue emitter iridium(III) bis[(4,6-difluorophenyl)-pyridinato-N,C2]picolinate doped in N,N'-dicarbazolyl-3,5-benzene as a p-type host material. A blue PHOLED with the highest doping concentration as part of the EML close to an electron transporting layer showed a maximum luminous efficiency of 20.74 cd/A, and a maximum external quantum efficiency of 10.52%. This can be explained by effective electron injection through a highly doped EML side. Additionally, a white OLED based on the doping profile was fabricated with two thin red EMLs within a blue EML maintaining a thickness of 30 nm for the entire EML. Keywords: Blue Phosphorescent Organic Light Emitting Diodes, Stepwise Doping Structure, Charge Trapping Effect.


Assuntos
Cor , Iluminação/instrumentação , Nanocompostos/química , Compostos Orgânicos/química , Semicondutores , Transferência de Energia , Desenho de Equipamento , Análise de Falha de Equipamento , Teste de Materiais , Nanocompostos/ultraestrutura
15.
J Nanosci Nanotechnol ; 14(8): 6185-8, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25936084

RESUMO

A new yellow fluorescent material, (2Z)-3-[4,4"-bis(dimethylamino)-1,1':4',1"-terphenyl-2'-yl]-2-phenylacrylonitrile (BDAT-P), have been synthesized for use in organic light-emitting diodes. Opto-electronic properties of device with the structure of ITO (180 nm)/NPB (50 nm)/MADN:PFVtPh (SYB-41) 8% (17 nm)/CBP (5 nm)/CBP:Ir(pq)2acac 8% (3 nm)/CBP (5 nm)/MADN:BDAT-P 8% (3 nm)/CBP (5 nm)/MADN:SYB-41 8% (17 nm)/TPBi (40 nm)/Liq (2 nm)/Al (100 nm) was measured and revealed that BDAT-P was sufficiently applicable as a dopant of one of emitting layers in white light-emitting diodes. Maximum luminance of device was measured to be 26,950 cd/m2. Maximum luminous and quantum efficiency were observed to be 14.22 cd/A and 6.58%, respectively. The device emitted warm white light corresponding to Commission Internationale de l'Eclairage (CIExy) coordinates of (0.372, 0.424) at 11 V, (0.375,0.417) at 12 V, (0.372,0.409) at 13 V, (0.366, 0.401) at 14 V, and (0.360, 0.393) at 15 V, respectively.


Assuntos
Acrilonitrila/análogos & derivados , Técnicas Eletroquímicas , Luz , Compostos de Terfenil/química , Acrilonitrila/química , Luminescência , Espectroscopia de Ressonância Magnética , Espectrometria de Massas de Bombardeamento Rápido de Átomos
16.
J Nanosci Nanotechnol ; 14(7): 5304-8, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24758022

RESUMO

The series of new iridium complexes, Ir(C--N)2(LX), (main ligand, C--N = the anion of 2-phenylpyridine (ppy), 4-difluoro-2-phenylpyridine (F2-ppy) and 4-methyl-2,3-diphenylquinoline (4-Me-2,3-dpq); ancillary ligand, LX = 2-(2-hydroxyphenyl)benzoxazolate (BOX) and 2-(2-hydroxyphenyl)benzothiazolate (BTZ)) were prepared and their luminescence properties were investigated. We expected that the relative energy levels of the main ligands and ancillary ligands in the complexes could determine the possibility of interligand energy transfer (ILET) in the complexes and thereby luminescence properties. As the main ligands, F2-ppy, ppy and 4-Me-2,3-dpq, which have drastically different energy gap between the HOMO and LUMO energy levels, were chosen and their complexes were synthesized. BOX and BTZ were chosen as the ancillary ligands which can form a stable 6-membered metallacycle with the iridium center. The iridium complexes showed various emission ranges from 510 to 643 nm, depending upon the relative energy levels of their main and ancillary ligands. The studies of photoabsorption, electrochemistry, photoluminescence and electroluminescence revealed that ILET might contribute to absorption and luminescence process of the iridium complexes containing the ppy-based ligands and BOX.

17.
J Nanosci Nanotechnol ; 14(8): 5979-82, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25936040

RESUMO

In this work, we designed and synthesized two red emitters 2-(6,8-di-tert-butyl-2-(2-(1,1-dimethyl-7-(trimethylsilyl)-7-((trimethylsilyl)methyl)-1,2,3,5,6,7-hexahydropyrido[3,2,1-ij]quinolin-9-yl)vinyl)-4H-chromen-4-ylidene)malononitrile (Red 1) and 2-(6,8-di-tert-butyl-2-(2-(1,1,7-trimethyl-7-t-butyl)-1,2,3,5,6,7-hexahydropyrido[3,2,1-ij]quinolin-9-yl)vinyl)-4H-chromen-4-ylidene)malononitrile (Red 2). To explore the electro-luminescence properties of these materials, multilayered OLEDs using these materials as dopants in a Alq3 host were fabricated. Particularly, by using Red 1 as a dopant in emitting layer, device 1 showed the luminous and power efficiencies of 0.81 cd/A and 0.43 lm/W at 20 mA/cm2, respectively. The CIE coordinates of this device was (0.65, 0.34) at 7.0 V, which is close to the NTSC standard CIE coordinates of (0.67,0.32) for red emission.


Assuntos
Benzopiranos/química , Fluorescência , Luz , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray
18.
J Nanosci Nanotechnol ; 14(8): 6116-9, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25936068

RESUMO

A series of bipolar anthracene derivatives containing pyridine as an electron withdrawing group and cabazole, triphenylamine and indole as electron donating groups were synthesized and characterized. Particularly, Device E, 9-(4'-(10-(pyridin-2-yl)anthracen-9-yl)biphenyl-4-yl)-9H-carbazol exhibits a high-efficient deep-blue EL emission with the luminous efficiency (LE) of 2.31 cd/A, power efficiency (PE) of 1.39 lm/W and quantum efficiency (QE) of 1.94% at 500 nit. This compound shows the maximum wavelength of the electroluminescence (EL) at 467 nm and the CIE x, y coordinates of (0.16,0.14) at 6 V.


Assuntos
Antracenos/química , Luz , Piridinas/química , Espectrometria de Massas , Espectroscopia de Prótons por Ressonância Magnética
19.
J Nanosci Nanotechnol ; 14(8): 6217-20, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25936090

RESUMO

Blue fluorescent materials based on diphenylaminofluorenylstyryl derivatives connected with the various end-capping aromatic groups were synthesized and characterized. An OLED, using (E)-9,9-diethyl-7-(4-(4-fluoronaphthalen-1-yl)styryl)-N,N-diphenyl-9 H-fluoren-2-amine(5) in emitting layer, was fabricated. This device showed the highly efficient blue emission with the maximum luminance of 5138 cd/m2, the luminous efficiency of 3.92 cd/A, the power efficiency of 3.17 lm/W, the external quantum efficiency of 2.90% at 20 mA/cm2 and CIE x, y coordinates of (0.14, 0.17).


Assuntos
Fluorenos/química , Luz , Espectroscopia de Ressonância Magnética , Espectrometria de Massas de Bombardeamento Rápido de Átomos , Espectrofotometria Ultravioleta
20.
J Nanosci Nanotechnol ; 14(11): 8337-41, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25958524

RESUMO

Green phosphorescent organic light emitting diodes (PHOLEDs) were developed using a mixed layer system. They were fabricated with 4,4'-N,N'-dicarbazolyl-biphenyl (CBP) and typical charge transporting materials, which are 4,4'-bis[N-(naphthyl)-N-phenylamino]biphenyl (NPB) as a hole transporting material and 1,3,5-tris(N-phenylbenzimidazole-2-yl)benzene (TPBi) as an electron transporting material, mixed at each interface in a stacked organic layer to reduce the hole injection barrier and extend the recombination zone. We introduced a mixed layer for the hole transporting layer side, the electron transporting layer side, and on both sides to make a bulk heterojunction. This reduced the driving voltage, and the luminous efficiency (LE) was increased to 500 cd/m2. The optimized device showed a maximum LE of 59.87 cd/A and a maximum external quantum efficiency of 17.52%.


Assuntos
Substâncias Luminescentes/química , Semicondutores , Compostos de Bifenilo/química , Desenho de Equipamento , Nanotecnologia/instrumentação , Nanotecnologia/métodos
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa