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Low-dimensional nanostructures, especially one-dimensional materials, exhibit remarkable anisotropic characteristics due to their low symmetry, making them promising candidates for polarization-sensitive photodetection. Here, we present a chemical vapor deposition synthesis method for tellurium suboxide (TeOx), confirming the practicality of photodetectors constructed from TeOx nanowires (NWs) in high-responsivity, broadband, and polarization-sensitive detection. By precisely controlling the thermodynamics and kinetics of TeOx NWs growth, we achieve large-scale growth of TeOx NWs with highly controllable dimensions and propose a method to induce intrinsic built-in strain in TeOx NWs. Photodetectors based on quasi-one-dimensional TeOx NWs with ohmic contact demonstrate broadband spectral response (638-1550 nm), high responsivity (13 700 mA·W-1), and superior air stability. Particularly, owing to the inherent structural anisotropy of the photodetectors, they exhibit polarization-sensitive photodetection, with anisotropy ratios of 1.70 and 1.71 at 638 and 808 nm, respectively.
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All-inorganic cesium lead halide (CsPbX3, X = Cl, Br and I) perovskite quantum dots (QDs) have received enormous research interest because of their exceptional optoelectronic properties, but their low chemical stability under ambient conditions from inevitable defects restricts their practical applications. In an effort to enhance the stability of QDs, in this study, novel functional nanocomposites were fabricated by encapsulating perovskite QDs with zeolite X doped with iron ions. Focusing on the as-obtained nanocomposites labeled with QDs@Fe/X-n, doping a reasonable amount of Fe3+ ions can tremendously improve the order of perovskite lattices and reduce the halide vacancies. The results of stability improvement in nanocomposites with an optimal Fe3+ load (QDs@Fe/X-3) are presented. After storage in air for 100 days, the emission-peak position of the composites can remain almost unchanged, and the photoluminescence (PL) intensity can reach â¼98% of the original intensity. Additionally, the PL intensity of QDs@Fe/X-3 can decrease immediately when exposing it to a NH3 atmosphere at room temperature. The PL intensity can be linearly varied with a change in the NH3 concentration. The original value of the PL can be rapidly recovered by separating the sample from the NH3 environment. This work enables the QDs@Fe/X composite to be an ideal active material for ammonia sensing.
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Light addressable potentiometric sensor (LAPS) with the structure of electrolyte-insulator-semiconductor is a kind of field effect sensor that detects local potential changes caused by protonation and deprotonation between electrolyte and insulator by light pulse. And scanned light pulse allows two-dimensional imaging of the distribution of chemical/biological species on the surface of sensor. An important challenge is to achieve low-cost, strong anti-interference and high-performance silicon-based LAPS. In this study, we propose to combine microsphere lithography with wet etching to fabricate well-ordered, tunable and low-cost pyramidal pits-patterned silicon as semiconductor of LAPS. The morphology and optical properties of pyramidal pits-patterned silicon are tested and analyzed. The sensing characteristics and the pH imaging performance of LAPS are tested and evaluated. The experiment results and theoretical analyses show that LAPS with pyramidal pits-patterned silicon has acceptable pH response, good long-term stability, and high performance in terms of photocurrent enhancement ratio, signal-to-noise ratio and pH imaging. This work can provide a simple, low-cost, strong anti-interference and high-performance device for pH-related chemical/biological analysis.
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Semiconductores , Silicio , Potenciometría , Microesferas , Cromatografía de GasesRESUMEN
Comparing a family structure to a company, one can often think of parents as leaders and adolescents as employees. Stressful family environments and anxiety levels, depression levels, personality disorders, emotional regulation difficulties, and childhood trauma may all contribute to non-suicidal self-injury (NSSI) behaviors. We presented a support vector machine (SVM) based method for discovering the key factors among mazy candidates that affected NSSI in adolescents. Using SVM as the base learner, and the binary dragonfly algorithm was used to find the feature combination that minimized the objective function, which took into account both the prediction error and the number of selected variables. Unlike univariate model analysis, we used a multivariate model to explore the risk factors, which better revealed the interactions between factors. Our research showed that adolescent education level, anxiety and depression level, borderline and avoidant personality traits, as well as emotional abuse and physical neglect in childhood, were associated with mood disorders in adolescents. Furthermore, gender, adolescent education level, physical abuse in childhood, non-acceptance of emotional responses, as well as paranoid, borderline, and histrionic personality traits, were associated with an increased risk of NSSI. These findings can help us make better use of artificial intelligence technology to extract potential factors leading to NSSI in adolescents from massive data, and provide theoretical support for the prevention and intervention of NSSI in adolescents.
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Conducta Autodestructiva , Máquina de Vectores de Soporte , Inteligencia Artificial , Conducta Autodestructiva/etiología , Conducta Autodestructiva/psicología , Factores de RiesgoRESUMEN
Conservation of sandstone-based cultural heritage has attracted a great deal of interest. We propose herein a novel protecting strategy, via in situ fabrication of bentonite-based hydrogels (B-H) inside sandstones, where the bentonite-based hydrogels serve as the underlying cement. To create bentonite-based hydrogels with controllable structure, possessing good mechanical and anti-swelling properties, we have optimized forming time, appearance, and viscosity. The hydrogel precursor penetrated into the pores of the sandstone; the hydrogel would then form within 3-5 h. As found by employing a fluorescent tracer, the precursor remained controllably in place without any apparent change in the sandstone morphology. The bentonite-based hydrogels that formed inside the sandstones presented strong hydrogen bonding, coordination, and ionic bonding, as well as strong mechanical interlocking to the sandstone matrix. As a result, the sandstones possessed enhanced mechanical compressive strength and excellent resistance to acid, salt, and freeze-thaw cycles. Our approach provides for a non-destructive, eco-friendly, easy-to-use, and long-term strategy for cultural preservation, one with excellent protection effects.
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Active single-photon 3D imaging technology has been applied to 3D imaging of complex scenes in many frontier fields such as biomedicine, remote sensing mapping, etc. However, single-photon 3D imaging with strong background noise is still a major challenge. Several classical algorithms and machine learning methods have been proposed to solve the problem. In this paper, we propose a novel multi-stage synergistic recovery network to reconstruct an accurate depth map. In the model, we first extract multi-scale feature information using encoder and decoder architectures, then combine them with an original resolution network that retains complete spatial location information. Through this way, we can compensate the deficiencies of the original resolution network for multi-scale local feature extraction. Moreover, a self-supervised attention module (SAM) is constructed to weight local features between different stages, optimizing the feature exchange between different stages of the multi-stage architecture network. Our method currently performs the best of all the tested methods.
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The adverse effects of the COVID-19 vaccine have been discovered as the rapid application of the vaccines continues. Neurological complications such as transverse myelitis raise concerns as cases were observed in clinical trials. Transverse myelitis is a rare immune-mediated disease with spinal cord neural injury, resulting in neurological deficits in the motor, sensory, and autonomic system. Vaccine-related transverse myelitis is even rarer. We present a case of acute transverse myelitis after vaccination against COVID-19 with the ChAdOx1 nCOV-19 vaccine (AZD1222), which was the first case reported in Taiwan. Although it rarely occurs, post-vaccination neurological complications should not be ignored. As the pandemic of SARS-CoV-2 continues to spread and concern about vaccination efficacy and safety rises, heterologous vaccination were implemented in health public policy in several countries. A literature review of several clinical trials shows promising effects of mix-and-match vaccination. Further study on different combinations of vaccines can be expected.
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COVID-19 , Mielitis Transversa , Vacunas contra la COVID-19 , ChAdOx1 nCoV-19 , Humanos , Mielitis Transversa/inducido químicamente , SARS-CoV-2 , Vacunación/efectos adversosRESUMEN
BACKGROUND: Adrenoleukodystrophy (ALD) is an X-linked peroxisomal disorder caused by mutations in the ABCD1 gene. The clinical manifestations of ALD vary widely with some patients presenting with adrenomyeloneuropathy (AMN) that resembles the phenotype of hereditary spastic paraplegia (HSP). The aim of this study is to investigate the frequency, spectrum, and clinical features of ABCD1 mutations in Taiwanese patients with HSP phenotype. METHODS: Mutational analysis of the ABCD1 gene was performed in 230 unrelated Taiwanese patients with clinically suspected HSP by targeted resequencing. Clinical, electrophysiological, and neuroimaging features of the patients carrying an ABCD1 pathogenic mutation were characterized. RESULTS: Ten different ABCD1 mutations were identified in eleven patients, including two novel mutations (p.Q177Pfs*17 and p.Y357*) and eight ever reported in ALD cases of other ethnicities. All patients were male and exhibited slowly progressive spastic paraparesis with onset ages ranging from 21 to 50 years. Most of them had additional non-motor symptoms, including autonomic dysfunction in nine patients, sensory deficits in seven, premature baldness in seven, skin hyperpigmentation in five, psychiatric symptoms in one and cerebellar ataxia in one. Seven of the ten patients who ever received nerve conduction studies showed axonal polyneuropathy. Magnetic resonance imaging (MRI) revealed diffuse spinal cord atrophy in seven patients, cerebral white matter hyperintensity in one patient, and cerebellar involvement in one patient. CONCLUSIONS: ABCD1 mutations account for 4.8% (11/230) of the cases with HSP phenotype in Taiwan. This study highlights the importance to consider ABCD1 mutations in patients with clinically suspected HSP of unknown genetic causes.
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Miembro 1 de la Subfamilia D de Transportador de Casetes de Unión al ATP/genética , Adrenoleucodistrofia/genética , Pueblo Asiatico/genética , Paraplejía Espástica Hereditaria/genética , Adulto , Edad de Inicio , Estudios de Cohortes , Análisis Mutacional de ADN , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mutación/genética , Fenotipo , Taiwán , Adulto JovenRESUMEN
The chemical image sensor has attracted much attention because of its ability to visualize the spatial distribution of biochemical species in solution. However, the lateral diffusion of photo-generated carriers generated by illuminating backside of the substrate limits the spatial resolution of the sensor and the sharpness of the image. In this study, honeycomb meshed metal array based on microsphere lithography as working electrodes of the sensor is proposed. A focused light spot illuminates a plurality of periodic and ordered mesh holes and the metal electrodes adjacent to the mesh holes. For chemical imaging performance, sensors with honeycomb meshed working electrodes are developed for comparison with the sensor the flat working electrodes, and their spatial resolution is tested under the focused light spot with different sizes. Three interpretations of improved spatial resolution including enhanced recombination of the photo-generated holes by electrons during the initial stage of lateral diffusion and two boundary cases of modulated light illuminating meshed working electrodes on the substrate are elaborated. The experimental results show that the spatial resolution of sensor chips with honeycomb meshed working electrodes is better than that of the sensor with the flat working electrodes and is higher under the illumination condition of smaller light spots.
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Microesferas , ElectrodosRESUMEN
Accumulated beta-amyloid (Aß) in the brain is the hallmark of Alzheimer's disease (AD). Despite Aß accumulation is known to trigger cellular dysfunctions and learning and memory damage, the detailed molecular mechanism remains elusive. Recent studies have shown that the onset of memory impairment and learning damage in the AD animal is different, suggesting that the underlying mechanism of the development of memory impairment and learning damage may not be the same. In the current study, with the use of Aß42 transgenic flies as models, we found that Aß induces memory damage and learning impairment via differential molecular signaling pathways. In early stage, Aß activates both Ras and PI3K to regulate Rac1 activity, which affects mostly on memory performance. In later stage, PI3K-Akt is strongly activated by Aß, which leads to learning damage. Moreover, reduced Akt, but not Rac1, activity promotes cell viability in the Aß42 transgenic flies, indicating that Akt and Rac1 exhibit differential roles in Aß regulating toxicity. Taken together, different molecular and cellular mechanisms are involved in Aß-induced learning damage and memory decline; thus, caution should be taken during the development of therapeutic intervention in the future.
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Péptidos beta-Amiloides/toxicidad , Proteínas de Drosophila/metabolismo , Aprendizaje por Laberinto/fisiología , Trastornos de la Memoria/metabolismo , Fragmentos de Péptidos/toxicidad , Proteínas Proto-Oncogénicas c-akt/metabolismo , Proteínas de Unión al GTP rac/metabolismo , Animales , Animales Modificados Genéticamente , Drosophila , Proteínas de Drosophila/genética , Femenino , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Trastornos de la Memoria/inducido químicamente , Trastornos de la Memoria/genética , Ratones Transgénicos , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas de Unión al GTP rac/genéticaRESUMEN
BACKGROUND: Tai Chi exercise has been reported to enhance physical and mental health in the older adults; however, the mechanism remains elusive. TRIAL DESIGN: We recruited 289 older adults practicing Tai Chi for over 3 years, together with 277 age-matched older and 102 young adults as controls. 168 Tai Chi practitioners were successfully matched to 168 older controls aged 60-69 based on a propensity score for statistics. METHODS: Cerebrovascular function was evaluated by measuring the hemodynamics of the carotid artery. Spearman correlation was performed to validate the age-associated physiological parameters. RESULTS: Cerebrovascular function in older adults significantly degenerated compared with the young, and was substantially correlated with age. Compared with the older control group, Tai Chi practitioners showed significant improvements in CVHI (cerebral vascular hemodynamics indices) Score (P = 0.002), mean blood flow velocity (P = 0.014), maximal blood flow velocity (P = 0.04) and minimum blood flow velocity (P < 0.001), whereas the age-related increases in pulse wave velocity (P = 0.022), characteristic impedance (P = 0.021) and peripheral resistance (P = 0.044) were lowered. CONCLUSIONS: These data demonstrate a rejuvenation role of Tai Chi in improving the age-related decline of the cerebrovascular function. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR1900025187).
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Taichi Chuan , Anciano , Estudios Transversales , Ejercicio Físico , Humanos , Análisis de la Onda del PulsoRESUMEN
Alteration of fruit quality caused by environmental stress is a common but largely unresolved issue for plant cultivation and breeding practices. Phosphorus (P) deficiency may interfere with a variety of metabolic processes whose intermediate products are correlated with important fruit quality traits. However, how low P stress affects fruit quality has not been investigated in detail. In this study, we assessed the contents of major metabolites associated with tomato fruit quality under two low P treatments that started at the seedling or flowering stage. The major pigments and the key organic acids related to fruit sourness were differentially over-accumulated as fruit ripened under two low P treatments compared to those under the control treatment, while the total content of soluble sugars contributing to fruit sweetness was substantially reduced under both treatments. These changes were largely attributed to the alteration of enzyme activities in the relevant metabolic pathways. In particular, we found that low P stress from different developmental stages had differential effects on the activation of γ-aminobutyric acid shunt that were likely responsible for the preferential accumulation of different organic acids in tomato fruits. Our study suggested that low P stress strongly affected tomato fruit quality and the effects appeared to be variable under different regimes of low P conditions.
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Fósforo , Solanum lycopersicum , Estrés Fisiológico , Frutas/crecimiento & desarrollo , Frutas/metabolismo , Frutas/normas , Solanum lycopersicum/crecimiento & desarrollo , Solanum lycopersicum/metabolismo , Fósforo/metabolismo , Estrés Fisiológico/fisiologíaRESUMEN
The real-time monitoring of the working status of drainage tubes is crucial for successful surgical drainage and for informing clinicians of the drainage conditions of patients at different stages, to enable objective diagnosis and treatment. In this study, a method for monitoring the drainage condition of drainage tubes was proposed. The method was based on the principle of capacitance and was developed by analyzing the major states of drainage tubes in the process of drainage. Meanwhile, the principle of interdigital capacitance monitoring drainage was analyzed, and an interdigital capacitance device for the real-time monitoring of the working status of drainage tubes was designed. Ultimately, an experimental system for drainage simulation was established on the basis of the interdigital capacitance device and method for drainage monitoring. Results showed that the interdigital capacitance device for drainage monitoring can identify unobstructed or blocked drainage tubes effectively in real time. The device has a hydrophobic surface, so its electrodes do not undergo electrolysis and pollution due to adhesion. Hence the proposed capacitance-based method for monitoring the working states of drainage tubes has good application prospects in the postoperative drainage of abdominal and thoracic cavities.
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Drenaje/métodos , Capacidad Eléctrica , Simulación por Computador , Drenaje/instrumentación , Electrodos , Electrólisis , Diseño de Equipo , HumanosRESUMEN
One major role of an accurate distribution of abdominal adipose tissue is to predict disease risk. This paper proposes a novel effective three-level convolutional neural network (CNN) approach to automate the selection of abdominal computed tomography (CT) images on large-scale CT scans and automatically quantify the visceral and subcutaneous adipose tissue. First, the proposed framework employs support vector machine (SVM) classifier with a configured parameter to cluster abdominal CT images from screening patients. Second, a pyramid dilation network (DilaLab) is designed based on CNN, to address the complex distribution and non-abdominal internal adipose tissue problems of biomedical image segmentation in visceral adipose tissue. Finally, since the trained DilaLab implicitly encodes the fat-related learning, the transferred DilaLab learning and a simple decoder constitute a new network (DilaLabPlus) for quantifying subcutaneous adipose tissue. The networks are trained not only all available CT images but also with a limited number of CT scans, such as 70 samples including a 10% validation subset. All networks are yielding more precise results. The mean accuracy of the configured SVM classifier yields promising performance of 99.83%, while DilaLabPlus achieves a remarkable performance improvement an with average of 98.08 ± 0.84% standard deviation and 0.7 ± 0.8% standard deviation false-positive rate. The performance of DilaLab yields average 97.82 ± 1.34% standard deviation and 1.23 ± 1.33% standard deviation false-positive rate. This study demonstrates considerable improvement in feasibility and reliability for the fully automated recognition of abdominal CT slices and segmentation of selected abdominal CT in subcutaneous and visceral adipose tissue, and it has a high agreement with a manually annotated biomarker.
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Tejido Adiposo/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador/métodos , Redes Neurales de la Computación , Tejido Subcutáneo/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Abdomen/diagnóstico por imagen , Humanos , Máquina de Vectores de SoporteRESUMEN
Francisella noatunensis subsp. orientalis is a causative agent of systemic granulomatous disease in tilapia. The present study was designed to understand the genetic and phenotypic diversities among Taiwanese Fno isolates obtained from tilapia (n = 17) and green Texas cichlid (Herichthys cyanoguttatus) (n = 1). The enzymatic profiles of the isolates were studied using the API ZYM system. Phylogenetic tree analysis of the 16S rRNA and housekeeping gene and pulsed-field gel electrophoresis (PFGE) were carried out to determine the genotypic characters of all isolates. The phylogenetic tree showed similarity of 99%-100% nucleotide sequences of 16S rRNA and housekeeping genes compared to the Fno references genes from GenBank database. Comparatively, the results revealed an identical profile of enzymatic and PFGE pattern which was distincted from that of F. philomiragia. To understand the pathogenicity, the isolates were intraperitoneal injected to tilapia the gross lesions were observed concomitant with natural outbreak. Median lethal dose upon Nile tilapia and red tilapia were 9.06 × 103 CFU/fish and 2.08 × 102 CFU/fish, respectively. Thus, our data provide understanding the epidemiology of Taiwanese Fno isolates, and help in development of future control and prevention.
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Cíclidos , Enfermedades de los Peces/microbiología , Francisella/genética , Francisella/patogenicidad , Infecciones por Bacterias Gramnegativas/veterinaria , Animales , Infecciones por Bacterias Gramnegativas/microbiología , Filogenia , ARN Bacteriano/análisis , ARN Ribosómico 16S/análisis , Distribución Aleatoria , Taiwán , VirulenciaRESUMEN
The use of solar energy to drive organic reactions under mild conditions provides a sustainable pathway for green synthesis and has been one of the primary goals pursued by scientists. In this research, the cadmium indium sulfide (CdIn2S4) photocatalyst was prepared using a simple solvothermal method and was thoroughly characterized using X-ray powder diffraction, UV-visible absorption spectra, nitrogen adsorption-desorption isotherms, scanning electron microscopy, transmission electron microscopy and X-ray spectroscopy measurements. The photocatalytic performance of the CdIn2S4 photocatalyst was evaluated using photocatalytic synthesis of Schiff base compounds in a coupled system of aromatic alcohols and nitrobenzene under visible light irradiation. The yield of N-benzylideneaniline reached up to 32% in the coupled system of benzyl alcohol and nitrobenzene under visible light illumination for 8 h. Furthermore, the changes for the amounts of aromatic aldehydes and AL as intermediate products during the photocatalytic process were also investigated. Using isotopic tracing, a possible reaction mechanism for the photocatalytic synthesis of N-benzylideneaniline and the redox reactions in the coupled system of benzyl alcohol and nitrobenzene was proposed. It is hoped that this strategy can provide an effective pathway for the traditional organic synthesis and transformation using photocatalytic technology under mild conditions.
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Sulfur (S) can modulate plant responses to toxic heavy metals, but the underlying physiological and transcriptional regulation mechanisms remain largely unknown. To investigate the effects of S supply on lead (Pb)-induced toxicity in poplars, Populus deltoides monilifera (Aiton) Eckenw. saplings were exposed to 0 or 50 µM Pb together with one of the three S concentrations (0 (low S), 100 (moderate S) or 1500 (high S) µM Na2SO4). Populus deltoides roots absorbed Pb and it was partially translocated to the aerial organs, thereby decreasing the CO2 assimilation rate and leaf growth. Lead accumulation in poplars caused the overproduction of O2- and H2O2 to induce higher levels of total thiols (T-SH) and glutathione (GSH). Lead uptake by the roots and its accumulation in the aerial organs were repressed by low S application, but stimulated by high S supply. Lead-induced O2- and H2O2 production were exacerbated by S limitation, but alleviated by high S supply. Moreover, the concentrations of S-containing antioxidants including T-SH and GSH were reduced in S-deficient poplars, but increased in high S-treated plants, which corresponded well to the changes in the activities of enzymes involved in S assimilation and GSH biosynthesis. The transcript levels of both genes encoding sulfate transporters, i.e., SULTR1.1 and SULTR2.2, were elevated by low S application or high S supply in the roots, and the transcriptional upregulation of both genes was more pronounced under Pb exposure. Furthermore, the mRNA levels of several genes involved in S assimilation and the biosynthesis of GSH and phytochelatins, i.e., ATPS1, ATPS3, GSHS1, GSHS2 and PCS1, were upregulated in poplar roots with high S supply, particularly under Pb exposure. These results indicate that a high S supply can stimulate Pb accumulation and reduce its toxicity in poplars by improving S assimilation and stimulating the biosynthesis of S-containing compounds including T-SH and GSH.
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Plomo/toxicidad , Populus/efectos de los fármacos , Azufre/metabolismo , Relación Dosis-Respuesta a Droga , Plomo/metabolismo , Populus/crecimiento & desarrollo , Populus/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Azufre/deficienciaRESUMEN
An exciplex forming cohost system is employed to achieve a highly efficient organic light-emitting diode (OLED) with good electroluminescent lifetime. The exciplex is formed at the interfacial contact of a conventional star-shaped carbazole hole-transporting material, 4,4',4â³-tris(N-carbazolyl)-triphenylamine (TCTA), and a triazine electron-transporting material, 2,4,6-tris[3-(1H-pyrazol-1-yl)phenyl]-1,3,5-triazine (3P-T2T). The excellent combination of TCTA and 3P-T2T is applied as the cohost of a common green phosphorescent emitter with almost zero energy loss. When Ir(ppy)2(acac) is dispersed in such exciplex cohost system, OLED device with maximum external quantum efficiency of 29.6%, the ultrahigh power efficiency of 147.3 lm/W, and current efficiency of 107 cd/A were successfully achieved. More importantly, the OLED device showed a low-efficiency roll-off and an operational lifetime (τ80) of â¼1020 min with the initial brightness of 2000 cd/m2, which is 56 times longer than the reference device. The significant difference of device stability was attributed to the degradation of exciplex system for energy transfer process, which was investigated by the photoluminescence aging measurement at room temperature and 100 K, respectively.
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To investigate the physiological responses of poplars to amino acids as sole nitrogen (N) sources, Populus × canescens (Ait.) Smith plants were supplied with one of three nitrogen fertilizers (NH4NO3, phenylalanine (Phe) or the mixture of NH4NO3 and Phe) in sand culture. A larger root system, and decreased leaf size and CO2 assimilation rate was observed in Phe- versus NH4NO3-treated poplars. Consistently, a greater root biomass and a decreased shoot growth were detected in Phe-supplied poplars. Decreased enzymatic activities of nitrate reductase (NR), glutamate synthase (GOGAT) and glutamate dehydrogenase (GDH) and elevated activities of nitrite reductase (NiR), phenylalanine ammonia lyase (PAL), glutamine synthetase (GS) and asparagine synthase (AS) were found in Phe-treated roots. Accordingly, reduced concentrations of NH4+, NO3- and total N, and enhanced N-use efficiencies (NUEs) were detected in Phe-supplied poplars. Moreover, the transcript levels of putative Phe transporters ANT1 and ANT3 were upregulated, and the mRNA levels of NR, glutamine synthetase 2 (GS2), NADH-dependent glutamate synthase (NADH-GOGAT), GDH and asparagine synthetase 2 (ASN2) were downexpressed in Phe-treated roots and/or leaves. The 15N-labeled Phe was mainly allocated in the roots and only a small amount of 15N-Phe was translocated to poplar aerial parts. These results indicate that poplar roots can acquire Phe as an N source to support plant growth and that Phe-induced NUEs in the poplars are probably associated with NH4+ re-utilization after Phe deamination and the carbon bonus simultaneously obtained during Phe uptake.
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Nitrógeno/metabolismo , Fenilalanina/metabolismo , Proteínas de Plantas/metabolismo , Raíces de Plantas/metabolismo , Populus/metabolismo , Glutamato-Amoníaco Ligasa/metabolismo , Nitrato-Reductasa/metabolismo , Fenilanina Amoníaco-Liasa/metabolismo , Hojas de la Planta/metabolismoRESUMEN
Mutations in the cyclin F gene (CCNF) have been recently identified in a small number of patients with amyotrophic lateral sclerosis (ALS) and/or frontotemporal dementia, and their role in patients with ALS in Taiwan remains elusive. The aim of this study was to elucidate the frequency and spectrum of CCNF mutations in a Taiwanese ALS cohort of Han Chinese origin. Mutational analyses of the CCNF gene were performed using Sanger sequencing in a cohort of 255 unrelated patients with ALS. Among these patients, the genetic diagnoses of 204 patients remained unclear after mutations in SOD1, C9ORF72, TARDBP, FUS, ATXN2, OPTN, VCP, UBQLN2, SQSTM1, PFN1, HNRNPA1, HNRNPA2B1, MATR3, CHCHD10, TUBA4A, and TKB1 had been investigated. Two novel heterozygous missense mutations in CCNF, p.S222P (c.664T>C) and p.S532R (c.1596C>T), were identified; 1 in each patient with apparently sporadic ALS. In vitro functional study demonstrated that both mutations result in a general and cyclin F-mediated ubiquitin-proteasome pathway dysfunction. The frequency of CCNF mutations in ALS patients in Taiwan is, therefore, approximately 0.8% (2/255). These findings expand the mutational spectrum of CCNF and also emphasize the pathogenic role of CCNF mutations in ALS.