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1.
Genes Brain Behav ; 18(5): e12559, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30806012

RESUMO

Several reports have shown that methyl CpG-binding protein 2 (MeCP2), brain-derived neurotrophic factor (BDNF), phospho-cAMP response element-binding protein (p-CREB) and microRNAs may be important in regulating academic performance because of their roles in neuropsychiatry and cognitive diseases. The first goal of this study was to explore the associations among MeCP2, BDNF, CREB and academic performance. This study also examined the pathway responsible for the effects of MeCP2, BDNF, p-CREB and microRNAs on academic performance. Scores from the basic competency test, an annual national competitive entrance examination, were used to evaluate academic performance. Subjects' plasma RNA was extracted and analyzed. This study determined that participants in the higher academic performance group had a significant difference in MECP2 mRNA expression compared with the lower academic performance group. We then used neuronal human derived neuroblastoma cell line (SH-SY5Y) cells with inducible MeCP2 expression from a second copy of the gene as a gain-of-function model and found that MeCP2 overexpression positively affected p-CREB and BDNF expression initially. After negative feedback, the p-CREB and BDNF levels subsequently decreased. In the neuronal phenotype examination, we found a significant reduction in total outgrowth and branches in MeCP2-induced cells compared with noninduced cells. This work describes pathways that may be responsible for the effects of MeCP2, BDNF, p-CREB and microRNAs on academic performance. These results may shed light on the development of promising clinical treatment strategies in the area of neuropsychological adjustment.


Assuntos
Desempenho Acadêmico , Epigênese Genética , Adolescente , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Linhagem Celular Tumoral , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Feminino , Mutação com Ganho de Função , Humanos , Masculino , Proteína 2 de Ligação a Metil-CpG/genética , Proteína 2 de Ligação a Metil-CpG/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo
2.
Artigo em Inglês | MEDLINE | ID: mdl-30010582

RESUMO

Neural oscillatory activities existing in multiple fre-quency bands usually represent different levels of neurophysiolog-ical meanings, from micro-scale to macro-scale organizations. In this study, we adopted Holo-Hilbert spectral analysis (HHSA) to study the amplitude-modulated (AM) and frequency-modulated (FM) components in sensorimotor Mu rhythm, induced by slow- and fast-rate repetitive movements. The HHSA-based approach is a two-layer empirical mode decomposition (EMD) architecture, which firstly decomposes the EEG signal into a series of frequency-modulated intrinsic mode functions (IMF) and then decomposes each frequency-modulated IMF into a set of amplitude-modulated IMFs. With the HHSA, the FM and AM components were incor-porated with their instantaneous power to achieve full-informa-tional spectral analysis. We observed that the instantaneous power induced by slow-rate movements was significantly higher than that induced by fast-rate movements (p < 0.01, Wilcoxon signed rank test). The alpha-band AM frequencies induced by slow-rate movements were higher than those induced by fast-rate move-ments, while no statistical difference was found in beta-band AM frequencies. In addition, to study the functional coupling between the primary sensorimotor area and other brain regions, spectral coherence was applied and statistical difference was found in frontal area in slow-rate versus fast-rate movements. The discrep-ancy between slow- and fast-rate movements might be owing to the change of motor functional modes from default mode network (DMN) to automatic timing with the increase of movement rates. The use of HHSA for oscillatory activity analysis can be an effi-cient tool to provide informative interaction among different fre-quency bands.

3.
Artigo em Inglês | MEDLINE | ID: mdl-29019914

RESUMO

As urbanization increases around the world and fewer and fewer people have easy access to completely natural places, there is a growing need to understand how the landscapes we design and inhabit impact our health and wellbeing.[...].


Assuntos
Meio Ambiente , Saúde , Humanos , Qualidade de Vida , Urbanização
4.
Nanoscale Res Lett ; 12(1): 315, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28454481

RESUMO

We report a low current collapse GaN-based high electron mobility transistor (HEMT) with an excellent thermal stability at 150 °C. The AlN was grown by N2-based plasma enhanced atomic layer deposition (PEALD) and shown a refractive index of 1.94 at 633 nm of wavelength. Prior to deposit AlN on III-nitrides, the H2/NH3 plasma pre-treatment led to remove the native gallium oxide. The X-ray photoelectron spectroscopy (XPS) spectroscopy confirmed that the native oxide can be effectively decomposed by hydrogen plasma. Following the in situ ALD-AlN passivation, the surface traps can be eliminated and corresponding to a 22.1% of current collapse with quiescent drain bias (V DSQ) at 40 V. Furthermore, the high temperature measurement exhibited a shift-free threshold voltage (V th), corresponding to a 40.2% of current collapse at 150 °C. The thermal stable HEMT enabled a breakdown voltage (BV) to 687 V at high temperature, promising a good thermal reliability under high power operation.

5.
Sci Rep ; 6: 39046, 2016 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-27976723

RESUMO

Repetitive movements at a constant rate require the integration of internal time counting and motor neural networks. Previous studies have proved that humans can follow short durations automatically (automatic timing) but require more cognitive efforts to track or estimate long durations. In this study, we studied sensorimotor oscillatory activities in healthy subjects and chronic stroke patients when subjects were performing repetitive finger movements. We found the movement-modulated changes in alpha and beta oscillatory activities were decreased with the increase of movement rates in finger lifting of healthy subjects and the non-paretic hands in stroke patients, whereas no difference was found in the paretic-hand movements at different movement rates in stroke patients. The significant difference in oscillatory activities between movements of non-paretic hands and paretic hands could imply the requirement of higher cognitive efforts to perform fast repetitive movements in paretic hands. The sensorimotor oscillatory response in fast repetitive movements could be a possible indicator to probe the recovery of motor function in stroke patients.


Assuntos
Mãos/fisiopatologia , Movimento/fisiologia , Paresia/fisiopatologia , Acidente Vascular Cerebral/complicações , Idoso , Estudos de Casos e Controles , Feminino , Dedos/fisiopatologia , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Desempenho Psicomotor , Recuperação de Função Fisiológica , Acidente Vascular Cerebral/fisiopatologia
6.
Opt Express ; 24(17): 19978-87, 2016 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-27557273

RESUMO

A large enhancement of color-conversion efficiency of colloidal quantum dots in light-emitting diodes (LEDs) with novel structures of nanorods embedded in microholes has been demonstrated. Via the integration of nano-imprint and photolithography technologies, nanorods structures can be fabricated at specific locations, generating functional nanostructured LEDs for high-efficiency performance. With the novel structured LED, the color-conversion efficiency of the existing quantum dots can be enhanced by up to 32.4%. The underlying mechanisms can be attributed to the enhanced light extraction and non-radiative energy transfer, characterized by conducting a series of electroluminescence and time-resolved photoluminescence measurements. This hybrid nanostructured device therefore exhibits a great potential for the application of multi-color lighting sources.

7.
Opt Express ; 24(11): 11387-95, 2016 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-27410067

RESUMO

In this study, high-performance InGaN-based green light-emitting diodes (LEDs) with a quaternary InAlGaN/GaN superlattice electron blocking layer (QSL-EBL) have been demonstrated. The band structural simulation was employed to investigate the electrostatic field and carriers distribution, show that the efficiency and droop behavior can be intensively improved by using a QSL-EBL in LEDs. The QSL-EBL structure can reduce the polarization-related electrostatic fields in the multiple quantum wells (MQWs), leading to a smoother band diagram and a more uniform carriers distribution among the quantum wells under forward bias. In comparison with green LEDs with conventional bulk-EBL structure, the light output power of LEDs with QSL-EBL was greatly enhanced by 53%. The efficiency droop shows only 30% at 100 A/cm2 comparing to its peak value, suggesting that the QSL-EBL LED is promising for future white lighting with high performance.

8.
BMJ Open ; 6(5): e009925, 2016 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-27207620

RESUMO

OBJECTIVE: To investigate the effects of congruence between preferred and perceived learning environments on learning outcomes of nursing students. SETTING: A nursing course at a university in central Taiwan. PARTICIPANTS: 124 Taiwanese nursing students enrolled in a 13-week problem-based Fundamental Nursing curriculum. DESIGN AND METHODS: Students' preferred learning environment, perceptions about the learning environment and learning outcomes (knowledge, self-efficacy and attitudes) were assessed. On the basis of test scores measuring their preferred and perceived learning environments, students were assigned to one of two groups: a 'preferred environment aligned with perceived learning environment' group and a 'preferred environment discordant with perceived learning environment' group. Learning outcomes were analysed by group. OUTCOME MEASURES: Most participants preferred learning in a classroom environment that combined problem-based and lecture-based instruction. However, a mismatch of problem-based instruction with students' perceptions occurred. Learning outcomes were significantly better when students' perceptions of their instructional activities were congruent with their preferred learning environment. CONCLUSIONS: As problem-based learning becomes a focus of educational reform in nursing, teachers need to be aware of students' preferences and perceptions of the learning environment. Teachers may also need to improve the match between an individual student's perception and a teacher's intention in the learning environment, and between the student's preferred and actual perceptions of the learning environment.


Assuntos
Comportamento do Consumidor , Educação em Enfermagem/métodos , Aprendizagem Baseada em Problemas , Estudantes de Enfermagem/psicologia , Atitude do Pessoal de Saúde , Estudos Transversais , Currículo , Escolaridade , Meio Ambiente , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Percepção , Autoeficácia , Inquéritos e Questionários , Taiwan
9.
Sci Rep ; 6: 19757, 2016 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-26794268

RESUMO

The epitaxy of high-power gallium nitride (GaN) light-emitting diode (LED) on amorphous silicon carbide (a-SixC(1-x)) buffer is demonstrated. The a-SixC(1-x) buffers with different nonstoichiometric C/Si composition ratios are synthesized on SiO2/Si substrate by using a low-temperature plasma enhanced chemical vapor deposition. The GaN LEDs on different SixC(1-x) buffers exhibit different EL and C-V characteristics because of the extended strain induced interfacial defects. The EL power decays when increasing the Si content of SixC(1-x) buffer. The C-rich SixC(1-x) favors the GaN epitaxy and enables the strain relaxation to suppress the probability of Auger recombination. When the SixC(1-x) buffer changes from Si-rich to C-rich condition, the EL peak wavelengh shifts from 446 nm to 450 nm. Moreover, the uniform distribution contour of EL intensity spreads between the anode and the cathode because the traping density of the interfacial defect gradually reduces. In comparison with the GaN LED grown on Si-rich SixC(1-x) buffer, the device deposited on C-rich SixC(1-x) buffer shows a lower turn-on voltage, a higher output power, an external quantum efficiency, and an efficiency droop of 2.48 V, 106 mW, 42.3%, and 7%, respectively.

10.
Neural Plast ; 2016: 6851592, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26819771

RESUMO

Considerable evidence has suggested that the epigenetic regulation of N-methyl-D-aspartate (NMDA) glutamate receptors plays a crucial role in neuropsychiatric disorders. Previous exploratory studies have been primarily based on evidence from patients and have rarely sampled the general population. This exploratory study examined the relationship of single-nucleotide polymorphism (SNP) variations in the genes encoding the NMDA receptor (i.e., GRIN1, GRIN2A, GRIN2B, GRIN2C, and GRIN2D) with emotion and social behavior in adolescents. For this study, 832 tenth-grade Taiwanese volunteers were recruited, and their scores from the Beck Youth Inventories were used to evaluate their emotional and social impairments. Based on these scores, GRIN1 (rs4880213) was significantly associated with depression and disruptive behavior. In addition, GRIN2B (rs7301328) was significantly associated with disruptive behavior. Because emotional and social impairment greatly influence learning ability, the findings of this study provide important information for clinical treatment and the development of promising prevention and treatment strategies, especially in the area of psychological adjustment.


Assuntos
Comportamento do Adolescente/fisiologia , Emoções/fisiologia , Polimorfismo de Nucleotídeo Único , Receptores de N-Metil-D-Aspartato/genética , Comportamento Social , Adolescente , Epigênese Genética , Feminino , Estudos de Associação Genética , Genótipo , Humanos , Masculino
11.
IEEE Trans Neural Syst Rehabil Eng ; 24(5): 603-15, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26625417

RESUMO

This paper studies the amplitude-frequency characteristic of frontal steady-state visual evoked potential (SSVEP) and its feasibility as a control signal for brain computer interface (BCI). SSVEPs induced by different stimulation frequencies, from 13 ~ 31 Hz in 2 Hz steps, were measured in eight young subjects, eight elders and seven ALS patients. Each subject was requested to participate in a calibration study and an application study. The calibration study was designed to find the amplitude-frequency characteristics of SSVEPs recorded from Oz and Fpz positions, while the application study was designed to test the feasibility of using frontal SSVEP to control a two-command SSVEP-based BCI. The SSVEP amplitude was detected by an epoch-average process which enables artifact-contaminated epochs can be removed. The seven ALS patients were severely impaired, and four patients, who were incapable of completing our BCI task, were excluded from calculation of BCI performance. The averaged accuracies, command transfer intervals and information transfer rates in operating frontal SSVEP-based BCI were 96.1%, 3.43 s/command, and 14.42 bits/min in young subjects; 91.8%, 6.22 s/command, and 6.16 bits/min in elders; 81.2%, 12.14 s/command, and 1.51 bits/min in ALS patients, respectively. The frontal SSVEP could be an alternative choice to design SSVEP-based BCI.


Assuntos
Esclerose Amiotrófica Lateral/fisiopatologia , Esclerose Amiotrófica Lateral/reabilitação , Interfaces Cérebro-Computador , Potenciais Evocados Visuais , Córtex Visual/fisiopatologia , Percepção Visual , Adulto , Envelhecimento , Auxiliares de Comunicação para Pessoas com Deficiência , Eletroencefalografia/métodos , Estudos de Viabilidade , Lobo Frontal , Humanos , Pessoa de Meia-Idade , Desempenho Psicomotor , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
12.
Biomed Res Int ; 2015: 520619, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26137484

RESUMO

This exploratory study examines the relationship between cardiometabolic risk factors (blood pressure, waist circumference, BMI, and total cholesterol) and cognitive/academic performance. In this study, 1297 Taiwanese tenth-grade volunteers are recruited. Scores from the Basic Competency Test, an annual national competitive entrance examination, are used to evaluate academic performance. Cognitive abilities are accessed via the Multiple Aptitude Test Battery. The results indicate that systolic blood pressure is significantly, negatively associated with academic performance, both in male and female subjects. BMI and waist circumference are associated with verbal reasoning performance with an inverse U-shaped pattern, suggesting that both low and high BMI/waist circumference may be associated with lower verbal reasoning performance.


Assuntos
Doenças Cardiovasculares/fisiopatologia , Cognição/fisiologia , Aprendizagem/fisiologia , Adolescente , Pressão Sanguínea , Índice de Massa Corporal , Doenças Cardiovasculares/sangue , Colesterol/sangue , Feminino , Humanos , Insulina/sangue , Masculino , Síndrome Metabólica/sangue , Síndrome Metabólica/fisiopatologia , Obesidade/sangue , Obesidade/fisiopatologia , Fatores de Risco , Taiwan , Triglicerídeos/sangue , Circunferência da Cintura
13.
PLoS One ; 9(12): e115809, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25549101

RESUMO

Spinocerebellar ataxia type 17 (SCA17) involves the expression of a polyglutamine (polyQ) expanded TATA-binding protein (TBP), a general transcription initiation factor. TBP interacts with other protein factors, including high mobility group box 1 (HMGB1), to regulate gene expression. Previously, our proteomic analysis of soluble proteins prepared from mutant TBP (TBP/Q61) expressing cells revealed a reduced concentration of HMGB1. Here, we show that HMGB1 can be incorporated into mutant TBP aggregates, which leads to reduced soluble HMGB1 levels in TBP/Q(61∼79) expressing cells. HMGB1 overexpression reduced mutant TBP aggregation. HMGB1 cDNA and siRNA co-transfection, as well as an HSPA5 immunoblot and luciferase reporter assay demonstrated the important role of HMGB1 in the regulation of HSPA5 transcription. In starvation-stressed TBP/Q36 and TBP/Q79 cells, increased reactive oxygen species generation accelerated the cytoplasmic translocation of HMGB1, which accompanied autophagy activation. However, TBP/Q79 cells displayed a decrease in autophagy activation as a result of the reduction in the cytoplasmic HMGB1 level. In neuronal SH-SY5Y cells with induced TBP/Q(61∼79) expression, HMGB1 expression was reduced and accompanied by a significant reduction in the total outgrowth and branches in the TBP/Q(61∼79) expressing cells compared with the non-induced cells. The decreased soluble HMGB1 and impaired starvation-induced autophagy in cells suggest that HMGB1 may be a critical modulator of polyQ disease pathology and may represent a target for drug development.


Assuntos
Regulação da Expressão Gênica , Proteína HMGB1/fisiologia , Ataxias Espinocerebelares/genética , Autofagia/genética , Citoplasma/metabolismo , Células HEK293 , Proteína HMGB1/genética , Proteína HMGB1/metabolismo , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Humanos , Estresse Oxidativo , Proteína de Ligação a TATA-Box/genética , Proteína de Ligação a TATA-Box/metabolismo , Proteína de Ligação a TATA-Box/fisiologia
14.
Appl Opt ; 53(27): G192-7, 2014 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-25322130

RESUMO

Therapeutic use of Chinese herbal medicines (CHMs) is a new approach to treat neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease. The detection of soma volume and neurite outgrowth of living neurons is a highly relevant biomarker related to various application fields, including therapy efficacy and drug safety evaluation. Through the use of digital holographic microscopy (DHM), we may evaluate the therapeutic effect of CHMs in curing neurodegeneration. Panax ginseng has been used in traditional Chinese herbal medicine for centuries. In this study, DHM is applied to monitor the three-dimensional morphology change of retinoic acid-induced human neuroblastoma SH-SY5Y cells during Panax ginseng treatment. We demonstrate the capability of DHM to detect noninvasively SH-SY5Y cell apoptosis and rescue through the measurement of neuronal volume and neurite outgrowth regulation without any labeling reagent. Through DHM, we observed the phase images of the rapidly shrinking cells with decreasing soma volume and shortening neurite outgrowth during glutamate treatments. Then shrinkage in glutamate-induced cells is significantly alleviated during Panax ginseng treatment. The results through DHM are consistent with the result from MTT assay for assessing cell viability during Panax ginseng treatment. Thus, we suggest that application of DHM for measuring soma volume and neurite outgrowth of living neurons may be one appropriate therapeutic evaluation for CHMs.


Assuntos
Monitoramento de Medicamentos/métodos , Medicamentos de Ervas Chinesas/farmacologia , Holografia/métodos , Microscopia/métodos , Neuroblastoma/tratamento farmacológico , Neuroblastoma/patologia , Panax/química , Linhagem Celular Tumoral , Avaliação Pré-Clínica de Medicamentos/métodos , Humanos , Imagem Tridimensional/métodos , Fitoterapia/métodos , Processamento de Sinais Assistido por Computador , Tecnologia Farmacêutica/métodos , Resultado do Tratamento
15.
Front Psychol ; 5: 906, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25177309

RESUMO

Urban streetscapes are outdoor areas in which the general public can appreciate green landscapes and engage in outdoor activities along the street. This study tested the extent to which the degree of awareness of urban street trees impacts attention restoration and perceived restorativeness. We manipulated the degree of awareness of street trees. Participants were placed into four groups and shown different images: (a) streetscapes with absolutely no trees; (b) streetscapes with flashes of trees in which participants had minimal awareness of the content; (c) streetscapes with trees; and (d) streetscapes with trees to which participants were told to pay attention. We compared the performance of 138 individuals on measures of attention and their evaluations of perceived restorativeness. Two main findings emerged. First, streetscapes with trees improved the performance of participants on attentional tests even without their awareness of the trees. Second, participants who had raised awareness of street trees performed best on the attentional test and rated the streetscapes as being more restorative. These findings enhance our knowledge about the role of an individual's awareness of restorative elements and have implications for designers and individuals who are at risk of attentional fatigue.

16.
Nanoscale Res Lett ; 9(1): 505, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25258616

RESUMO

The flip chip ultraviolet light-emitting diodes (FC UV-LEDs) with a wavelength of 365 nm are developed with the ex situ reactive plasma deposited (RPD) AlN nucleation layer on patterned sapphire substrate (PSS) by an atmospheric pressure metal-organic chemical vapor deposition (AP MOCVD). The ex situ RPD AlN nucleation layer can significantly reduce dislocation density and thus improve the crystal quality of the GaN epitaxial layers. Utilizing high-resolution X-ray diffraction, the full width at half maximum of the rocking curve shows that the crystalline quality of the epitaxial layer with the (RPD) AlN nucleation layer is better than that with the low-temperature GaN (LT-GaN) nucleation layer. The threading dislocation density (TDD) is estimated by transmission electron microscopy (TEM), which shows the reduction from 6.8 × 10(7) cm(-2) to 2.6 × 10(7) cm(-2). Furthermore, the light output power (LOP) of the LEDs with the RPD AlN nucleation layer has been improved up to 30 % at a forward current of 350 mA compared to that of the LEDs grown on PSS with conventional LT-GaN nucleation layer.

17.
Opt Express ; 22(4): 4516-22, 2014 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-24663772

RESUMO

Micro-patterned PDMS film was fabricated and combined with LED chip on board (COB) package to improve the emission uniformity of LED chip. The micro scale patterned sapphire substrate (PSS) was used as a mold to fabricate micro-cone patterned PDMS (MC-PDMS) film. A strong scattering effect from this MC-PDMS film can be verified by the high haze ratio and the Bi-directional Transmission effect. The angle dependent color temperature measurement system was used to measure the ΔCCT of COB with and without MC-PDMS. The measurement results indicate that the ΔCCT was reduced from 1025K to 428K. This improvement can effectively eliminate the yellow ring effect of LED chip. This technology can be thus considered as a cost-effective way for the next generation of light source packages.

18.
Opt Express ; 22(2): 2007-12, 2014 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-24515210

RESUMO

This work investigates the resonant modes of a 12-fold symmetric defect free photonic quasicrystal (PQC) nanorod array using finite difference time domain (FDTD) simulation. Localized modes can exist in PQC without introducing defects due to the lack of translational symmetry. The resonant modes of the unit cell PQC and the one time expanded PQC from unit cell are systematically examined. The resonant spectrum is that of a single rod modified by the interaction among PQC nanorods. The mode confinement is contributed by guided resonance and destructive interference scattering. The self-scaling similarity of resonant spectrum and mode profile are also investigated.

19.
Nanoscale Res Lett ; 9(1): 2494, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26089001

RESUMO

This letter demonstrates a p-type raised source-and-drain (raised S/D) junctionless thin-film transistors (JL-TFTs) with a dual-gate structure. The raised S/D structure provides a high saturation current (>1 µA/µm). The subthreshold swing (SS) is 100 mV/decade and the drain-induced barrier lowering (DIBL) is 0.8 mV/V, and the I on/I off current ratio is over 10(8) A/A for L g = 1 µm. Using a thin channel structure obtains excellent performance in the raised S/D structure. Besides the basic electrical characteristics, the dual-gate structure can also be used to adjust V th in multi-V th circuit designs. This study examines the feasibility of using JL-TFTs in future three-dimensional (3D) layer-to-layer stacked high-density device applications.

20.
Opt Express ; 21(20): 23030-5, 2013 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-24104218

RESUMO

We report the fabrication and studies of electrically driven green, olivine, and amber color nanopyramid GaN light emitting diodes (LEDs). InGaN/GaN multiple quantum wells (MQWs) were grown on the nanopyramid semipolar facets. Compared with the commonly used (0001) c-plane MQWs, the semipolar facet has lower piezoelectric field, resulting in much faster radiative recombination efficiency. This is important for high In content MQWs. The measured internal quantum efficiencies for green, olivine, and amber color LED are 30%, 25%, and 21%, respectively. The radiative and non-radiative lifetime of the semipolar MQWs are also investigated.

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