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1.
Gut ; 2024 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-38960582

RESUMO

OBJECTIVE: Our study aimed to explore the influence of gut microbiota and their metabolites on intracranial aneurysms (IA) progression and pinpoint-related metabolic biomarkers derived from the gut microbiome. DESIGN: We recruited 358 patients with unruptured IA (UIA) and 161 with ruptured IA (RIA) from two distinct geographical regions for conducting an integrated analysis of plasma metabolomics and faecal metagenomics. Machine learning algorithms were employed to develop a classifier model, subsequently validated in an independent cohort. Mouse models of IA were established to verify the potential role of the specific metabolite identified. RESULTS: Distinct shifts in taxonomic and functional profiles of gut microbiota and their related metabolites were observed in different IA stages. Notably, tryptophan metabolites, particularly indoxyl sulfate (IS), were significantly higher in plasma of RIA. Meanwhile, upregulated tryptophanase expression and indole-producing microbiota were observed in gut microbiome of RIA. A model harnessing gut-microbiome-derived tryptophan metabolites demonstrated remarkable efficacy in distinguishing RIA from UIA patients in the validation cohort (AUC=0.97). Gut microbiota depletion by antibiotics decreased plasma IS concentration, reduced IA formation and rupture in mice, and downregulated matrix metalloproteinase-9 expression in aneurysmal walls with elastin degradation reduction. Supplement of IS reversed the effect of gut microbiota depletion. CONCLUSION: Our investigation highlights the potential of gut-microbiome-derived tryptophan metabolites as biomarkers for distinguishing RIA from UIA patients. The findings suggest a novel pathogenic role for gut-microbiome-derived IS in elastin degradation in the IA wall leading to the rupture of IA.

2.
Plant Physiol ; 192(2): 886-909, 2023 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-36852939

RESUMO

Autophagy and multivesicular bodies (MVBs) represent 2 closely related lysosomal/vacuolar degradation pathways. In Arabidopsis (Arabidopsis thaliana), autophagy is stress-induced, with deficiency in autophagy causing strong defects in stress responses but limited effects on growth. LYST-INTERACTING PROTEIN 5 (LIP5) is a key regulator of stress-induced MVB biogenesis, and mutation of LIP5 also strongly compromises stress responses with little effect on growth in Arabidopsis. To determine the functional interactions of these 2 pathways in Arabidopsis, we generated mutations in both the LIP5 and AUTOPHAGY-RELATED PROTEIN (ATG) genes. atg5/lip5 and atg7/lip5 double mutants displayed strong synergistic phenotypes in fitness characterized by stunted growth, early senescence, reduced survival, and greatly diminished seed production under normal growth conditions. Transcriptome and metabolite analysis revealed that chloroplast sulfate assimilation was specifically downregulated at early seedling stages in the atg7/lip5 double mutant prior to the onset of visible phenotypes. Overexpression of adenosine 5'-phosphosulfate reductase 1, a key enzyme in sulfate assimilation, substantially improved the growth and fitness of the atg7/lip5 double mutant. Comparative multi-omic analysis further revealed that the atg7/lip5 double mutant was strongly compromised in other chloroplast functions including photosynthesis and primary carbon metabolism. Premature senescence and reduced survival of atg/lip5 double mutants were associated with increased accumulation of reactive oxygen species and overactivation of stress-associated programs. Blocking PHYTOALEXIN DEFICIENT 4 and salicylic acid signaling prevented early senescence and death of the atg7/lip5 double mutant. Thus, stress-responsive autophagy and MVB pathways play an important cooperative role in protecting essential chloroplast functions including sulfur assimilation under normal growth conditions to suppress salicylic-acid-dependent premature cell-death and promote plant growth and fitness.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Cloroplastos , Sulfatos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Autofagia/genética , Cloroplastos/metabolismo , Corpos Multivesiculares/metabolismo , Mutação/genética , Sulfatos/metabolismo
3.
BMC Neurol ; 23(1): 45, 2023 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-36709247

RESUMO

BACKGROUND: Small multiple intracranial aneurysms (SMIAs) are known to be more prone to rupture than are single aneurysms. However, specific recommendations for patients with small MIAs are not included in the guidelines of the American Heart Association and American Stroke Association. In this study, we aimed to evaluate the feasibility of machine learning-based cluster analysis for discriminating the risk of rupture of SMIAs. METHODS: This multi-institutional cross-sectional study included 1,427 SMIAs from 660 patients. Hierarchical cluster analysis guided patient classification based on patient-level characteristics. Based on the clusters and morphological features, machine learning models were constructed and compared to screen the optimal model for discriminating aneurysm rupture. RESULTS: Three clusters with markedly different features were identified. Cluster 1 (n = 45) had the highest risk of subarachnoid hemorrhage (SAH) (75.6%) and was characterized by a higher prevalence of familiar IAs. Cluster 2 (n = 110) had a moderate risk of SAH (38.2%) and was characterized by the highest rate of SAH history and highest number of vascular risk factors. Cluster 3 (n = 505) had a relatively mild risk of SAH (17.6%) and was characterized by a lower prevalence of SAH history and lower number of vascular risk factors. Lasso regression analysis showed that compared with cluster 3, clusters 1 (odds ratio [OR], 7.391; 95% confidence interval [CI], 4.074-13.150) and 2 (OR, 3.014; 95% CI, 1.827-4.970) were at a higher risk of aneurysm rupture. In terms of performance, the area under the curve of the model was 0.828 (95% CI, 0.770-0.833). CONCLUSIONS: An unsupervised machine learning-based algorithm successfully identified three distinct clusters with different SAH risk in patients with SMIAs. Based on the morphological factors and identified clusters, our proposed model has good discrimination ability for SMIA ruptures.


Assuntos
Aneurisma Roto , Aneurisma Intracraniano , Hemorragia Subaracnóidea , Humanos , Aneurisma Intracraniano/epidemiologia , Aneurisma Intracraniano/complicações , Estudos Transversais , Hemorragia Subaracnóidea/epidemiologia , Hemorragia Subaracnóidea/etiologia , Análise por Conglomerados , Fatores de Risco , Aneurisma Roto/epidemiologia , Aneurisma Roto/complicações , Aprendizado de Máquina
4.
Eur Neurol ; 86(2): 107-115, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36724752

RESUMO

INTRODUCTION: Brain arteriovenous malformations (BAVMs) are high-flow intracranial vascular malformations characterized by the direct connection of arteries to veins without an intervening capillary bed. They are one of the main causes of intracranial hemorrhage and epilepsy, although morbidity is low. Angiogenesis, heredity, inflammation, and arteriovenous malformation syndromes play important roles in BAVM formation. Animal experiments and previous studies have confirmed that NOTCH4 may be associated with BAVM development. Our study identifies a connection between NOTCH4 gene polymorphisms and BAVM in a Chinese Han population. METHODS: We enrolled 150 patients with BAVMs confirmed by digital subtraction angiography (DSA) in the Department of Neurosurgery, Zhujiang Hospital, Southern Medical University from June 2017 to July 2019. Simultaneously, 150 patients without cerebrovascular disease were confirmed by computed tomography angiography/magnetic resonance angiography/DSA. DNA was extracted from peripheral blood and NOTCH4 genotypes were identified by PCR-ligase detection reaction. The χ2 test or Fisher's exact test was used to evaluate the differences in allele and genotype frequencies between the BAVM group, control group, bleeding group, and other complications. RESULTS: Two single-nucleotide polymorphisms (SNPs), rs443198 and rs438475, were significantly associated with BAVM. No SNP genotypes were significantly associated with hemorrhage or epilepsy. SNPs rs443198_AA-SNP and rs438475_AA-SNP may be associated with a lower risk of BAVM (p = 0.011, odds ratio (OR) = 0.459, 95% confidence interval (CI): 0.250-0.845; p = 0.033, OR = 0.759, 95% CI: 0.479-1.204). CONCLUSION: NOTCH4 gene polymorphisms were associated with BAVM and may be a risk factor in a Chinese Han population.


Assuntos
Epilepsia , Malformações Arteriovenosas Intracranianas , Humanos , Polimorfismo de Nucleotídeo Único , População do Leste Asiático , Encéfalo/patologia , Malformações Arteriovenosas Intracranianas/cirurgia , Receptor Notch4/genética
5.
Sensors (Basel) ; 23(14)2023 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-37514918

RESUMO

Thin film transistors (TFTs) as the core devices for displays, are widely used in various fields including ultra-high-resolution displays, flexible displays, wearable electronic skins and memory devices, especially in terms of sensors. TFTs have now started to move towards miniaturization. Similarly to MOSFETs problem, traditional planar structure TFTs have difficulty in reducing the channel's length sub-1µm under the existing photolithography technology. Vertical channel thin film transistors (V-TFTs) are proposed. It is an effective solution to overcome the miniaturization limit of traditional planar TFTs. So, we summarize the different aspects of VTFTs. Firstly, this paper introduces the structure types, key parameters, and the impact of different preparation methods in devices of V-TFTs. Secondly, an overview of the research progress of V-TFTs' active layer materials in recent years, the characteristics of V-TFTs and their application in examples has proved the enormous application potential of V-TFT in sensing. Finally, in addition to the advantages of V-TFTs, the current technical challenge and their potential solutions are put forward, and the future development trend of this new structure of V-TFTs is proposed.

6.
Plant Physiol ; 187(4): 2469-2484, 2021 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-34618061

RESUMO

The endoplasmic reticulum (ER) contains an elaborate protein quality control network that promotes protein folding and prevents accumulation of misfolded proteins. Evolutionarily conserved UBIQUITIN-ASSOCIATED DOMAIN-CONTAINING PROTEIN 2 (UBAC2) is involved in ER-associated protein degradation in metazoans. We have previously reported that two close UBAC2 homologs from Arabidopsis (Arabidopsis thaliana) not only participate in selective autophagy of ER components but also interact with plant-specific PATHOGEN-ASSOCIATED MOLECULAR PATTERN (PAMP)-INDUCED COILED COIL (PICC) protein to increase the accumulation of POWDERY MILDEW-RESISTANT 4 callose synthase. Here, we report that UBAC2s also interacted with COPPER (Cu) TRANSPORTER 1 (COPT1) and plasma membrane-targeted members of the Cu transporter family. The ubac2 mutants were significantly reduced in both the accumulation of COPT proteins and Cu content, and also displayed increased sensitivity to a Cu chelator. Therefore, UBAC2s positively regulate the accumulation of COPT transporters, thereby increasing Cu uptake by plant cells. Unlike with POWDERY MILDEW RESISTANCE 4, however, the positive role of UBAC2s in the accumulation of COPT1 is not dependent on PICC or the UBA domain of UBAC2s. When COPT1 was overexpressed under the CaMV 35S promoter, the increased accumulation of COPT1 was strongly UBAC2-dependent, particularly when a signal peptide was added to the N-terminus of COPT1. Further analysis using inhibitors of protein synthesis and degradation strongly suggested that UBAC2s stabilize newly synthesized COPT proteins against degradation by the proteasome system. These results indicate that plant UBAC2s are multifunctional proteins that regulate the degradation and accumulation of specific ER-synthesized proteins.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Transportador de Cobre 1/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Transportador de Cobre 1/metabolismo
7.
Plant Cell ; 31(1): 153-171, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30606781

RESUMO

Pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) is initiated upon PAMP recognition by pattern recognition receptors (PRR). PTI signals are transmitted through activation of mitogen-activated protein kinases (MAPKs), inducing signaling and defense processes such as reactive oxygen species (ROS) production and callose deposition. Here, we examine mutants for two Arabidopsis thaliana genes encoding homologs of UBIQUITIN-ASSOCIATED DOMAIN-CONTAINING PROTEIN 2 (UBAC2), a conserved endoplasmic reticulum (ER) protein implicated in ER protein quality control. The ubac2 mutants were hypersusceptible to a type III secretion-deficient strain of the bacterial pathogen Pseudomonas syringae, indicating a PTI defect. The ubac2 mutants showed normal PRR biogenesis, MAPK activation, ROS burst, and PTI-associated gene expression. Pathogen- and PAMP-induced callose deposition, however, was compromised in ubac2 mutants. UBAC2 proteins interact with the plant-specific long coiled-coil protein PAMP-INDUCED COILED COIL (PICC), and picc mutants were compromised in callose deposition and PTI. Compromised callose deposition in the ubac2 and picc mutants was associated with reduced accumulation of the POWDERY MILDEW RESISTANT 4 (PMR4) callose synthase, which is responsible for pathogen-induced callose synthesis. Constitutive overexpression of PMR4 restored pathogen-induced callose synthesis and PTI in the ubac2 and picc mutants. These results uncover an ER pathway involving the conserved UBAC2 and plant-specific PICC proteins that specifically regulate pathogen-induced callose deposition in plant innate immunity.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/microbiologia , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Glucanos/metabolismo , Glucosiltransferases/metabolismo , Mutação/genética , Imunidade Vegetal/genética , Imunidade Vegetal/fisiologia , Proteínas de Plantas/metabolismo , Pseudomonas syringae/patogenicidade
8.
Eur Radiol ; 32(8): 5633-5641, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35182202

RESUMO

OBJECTIVES: We proposed a new approach to train deep learning model for aneurysm rupture prediction which only uses a limited amount of labeled data. METHOD: Using segmented aneurysm mask as input, a backbone model was pretrained using a self-supervised method to learn deep embeddings of aneurysm morphology from 947 unlabeled cases of angiographic images. Subsequently, the backbone model was finetuned using 120 labeled cases with known rupture status. Clinical information was integrated with deep embeddings to further improve prediction performance. The proposed model was compared with radiomics and conventional morphology models in prediction performance. An assistive diagnosis system was also developed based on the model and was tested with five neurosurgeons. RESULT: Our method achieved an area under the receiver operating characteristic curve (AUC) of 0.823, outperforming deep learning model trained from scratch (0.787). By integrating with clinical information, the proposed model's performance was further improved to AUC = 0.853, making the results significantly better than model based on radiomics (AUC = 0.805, p = 0.007) or model based on conventional morphology parameters (AUC = 0.766, p = 0.001). Our model also achieved the highest sensitivity, PPV, NPV, and accuracy among the others. Neurosurgeons' prediction performance was improved from AUC=0.877 to 0.945 (p = 0.037) with the assistive diagnosis system. CONCLUSION: Our proposed method could develop competitive deep learning model for rupture prediction using only a limited amount of data. The assistive diagnosis system could be useful for neurosurgeons to predict rupture. KEY POINTS: • A self-supervised learning method was proposed to mitigate the data-hungry issue of deep learning, enabling training deep neural network with a limited amount of data. • Using the proposed method, deep embeddings were extracted to represent intracranial aneurysm morphology. Prediction model based on deep embeddings was significantly better than conventional morphology model and radiomics model. • An assistive diagnosis system was developed using deep embeddings for case-based reasoning, which was shown to significantly improve neurosurgeons' performance to predict rupture.


Assuntos
Aneurisma Roto , Aneurisma Intracraniano , Aneurisma Roto/diagnóstico por imagem , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Redes Neurais de Computação , Curva ROC
9.
Int J Mol Sci ; 23(21)2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36362299

RESUMO

The production of therapeutic and industrial recombinant proteins in plants has advantages over established bacterial and mammalian systems in terms of cost, scalability, growth conditions, and product safety. In order to compete with these conventional expression systems, however, plant expression platforms must have additional economic advantages by demonstrating a high protein production yield with consistent quality. Over the past decades, important progress has been made in developing strategies to increase the yield of recombinant proteins in plants by enhancing their expression and reducing their degradation. Unlike bacterial and animal systems, plant expression systems can utilize not only cell cultures but also whole plants for the production of recombinant proteins. The development of viral vectors and chloroplast transformation has opened new strategies to drastically increase the yield of recombinant proteins from plants. The identification of promoters for strong, constitutive, and inducible promoters or the tissue-specific expression of transgenes allows for the production of recombinant proteins at high levels and for special purposes. Advances in the understanding of RNAi have led to effective strategies for reducing gene silencing and increasing recombinant protein production. An increased understanding of protein translation, quality control, trafficking, and degradation has also helped with the development of approaches to enhance the synthesis and stability of recombinant proteins in plants. In this review, we discuss the progress in understanding the processes that control the synthesis and degradation of gene transcripts and proteins, which underlie a variety of developed strategies aimed at maximizing recombinant protein production in plants.


Assuntos
Cloroplastos , Plantas , Animais , Plantas/genética , Plantas/metabolismo , Proteínas Recombinantes/metabolismo , Transgenes , Cloroplastos/genética , Cloroplastos/metabolismo , Estabilidade Proteica , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Mamíferos/metabolismo
10.
Int J Mol Sci ; 23(3)2022 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-35163500

RESUMO

Glucosinolates are an important class of secondary metabolites in Brassicales plants with a critical role in chemical defense. Glucosinolates are chemically inactive but can be hydrolyzed by myrosinases to produce a range of chemically active compounds toxic to herbivores and pathogens, thereby constituting the glucosinolate-myrosinase defense system or the mustard oil bomb. During the evolution, Brassicales plants have developed not only complex biosynthetic pathways for production of a large number of glucosinolate structures but also different classes of myrosinases that differ in catalytic mechanisms and substrate specificity. Studies over the past several decades have made important progress in the understanding of the cellular and subcellular organization of the glucosinolate-myrosinase system for rapid and timely detonation of the mustard oil bomb upon tissue damage after herbivore feeding and pathogen infection. Progress has also been made in understanding the mechanisms that herbivores and pathogens have evolved to counter the mustard oil bomb. In this review, we summarize our current understanding of the function and organization of the glucosinolate-myrosinase system in Brassicales plants and discuss both the progresses and future challenges in addressing this complex defense system as an excellent model for analyzing plant chemical defense.


Assuntos
Brassica/metabolismo , Glucosinolatos/metabolismo , Glicosídeo Hidrolases/metabolismo , Animais , Vias Biossintéticas , Brassica/microbiologia , Brassica/parasitologia , Resistência à Doença , Hidrólise , Insetos/fisiologia , Proteínas de Plantas/metabolismo
11.
Int J Mol Sci ; 23(14)2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35887108

RESUMO

As the organelle of photosynthesis and other important metabolic pathways, chloroplasts contain up to 70% of leaf proteins with uniquely complex processes in synthesis, import, assembly, and turnover. Maintaining functional protein homeostasis in chloroplasts is vitally important for the fitness and survival of plants. Research over the past several decades has revealed a multitude of mechanisms that play important roles in chloroplast protein quality control and turnover under normal and stress conditions. These mechanisms include: (i) endosymbiotically-derived proteases and associated proteins that play a vital role in maintaining protein homeostasis inside the chloroplasts, (ii) the ubiquitin-dependent turnover of unimported chloroplast precursor proteins to prevent their accumulation in the cytosol, (iii) chloroplast-associated degradation of the chloroplast outer-membrane translocon proteins for the regulation of chloroplast protein import, (iv) chloroplast unfolded protein response triggered by accumulated unfolded and misfolded proteins inside the chloroplasts, and (v) vesicle-mediated degradation of chloroplast components in the vacuole. Here, we provide a comprehensive review of these diverse mechanisms of chloroplast protein quality control and turnover and discuss important questions that remain to be addressed in order to better understand and improve important chloroplast functions.


Assuntos
Proteínas de Cloroplastos , Cloroplastos , Proteínas de Cloroplastos/metabolismo , Cloroplastos/metabolismo , Fotossíntese , Plantas/metabolismo , Transporte Proteico , Ubiquitina/metabolismo
12.
J Integr Plant Biol ; 64(4): 821-835, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35142108

RESUMO

A central role of the endoplasmic reticulum (ER) is the synthesis, folding and quality control of secretory proteins. Secretory proteins usually exit the ER to enter the Golgi apparatus in coat protein complex II (COPII)-coated vesicles before transport to different subcellular destinations. However, in plants there are specialized ER-derived vesicles (ERDVs) that carry specific proteins but, unlike COPII vesicles, can exist as independent organelles or travel to the vacuole in a Golgi-independent manner. These specialized ERDVs include protein bodies and precursor-accumulating vesicles that accumulate storage proteins in the endosperm during seed development. Specialized ERDVs also include precursor protease vesicles that accumulate amino acid sequence KDEL-tailed cysteine proteases and ER bodies in Brassicales plants that accumulate myrosinases that hydrolyzes glucosinolates. These functionally specialized ERDVs act not only as storage organelles but also as platforms for signal-triggered processing, activation and deployment of specific proteins with important roles in plant growth, development and adaptive responses. Some specialized ERDVs have also been exploited to increase production of recombinant proteins and metabolites. Here we discuss our current understanding of the functional diversity, evolutionary mechanisms and biotechnological application of specialized ERDVs, which are associated with some of the highly remarkable characteristics important to plants.


Assuntos
Vesículas Revestidas pelo Complexo de Proteína do Envoltório , Complexo de Golgi , Vesículas Revestidas pelo Complexo de Proteína do Envoltório/metabolismo , Retículo Endoplasmático/metabolismo , Complexo de Golgi/metabolismo , Plantas/genética , Transporte Proteico
13.
Opt Express ; 29(5): 7833-7843, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33726277

RESUMO

With higher detectivity, lower response time, and good mechanical flexibility, perovskite photodetectors are supposed to be a promising alternative as the next generation of photodetectors. In this work, we fabricate a low temperature-processed flexible photodetector with ITO-ZnO Schottky contact via ALD technique which has a lower dark current decreasing from 2.04×10-8 A/cm2 to 1.70×10-9 A/cm2 under -0.5 V bias voltage actuation. With 530 nm laser irradiation, the flexible device exhibits excellent performance in detectivity of 6.19×1012 Jones and LDR of 103dB. It also exhibits superior bending stability after 5000 bending circles.

14.
Nanotechnology ; 32(2): 025207, 2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-32987367

RESUMO

In this letter, the performance of Zn-Sn-O (ZTO) thin film transistors (TFTs) has been greatly improved by Mo doping as an oxygen vacancy to control the residual electrons. The results show that the TFT with 3 at% Mo doping exhibits the best electrical characteristics with a high saturation mobility of 26.53 cm2 V-1 s-1, a threshold voltage of 0.18 V, a subthreshold swing of 0.32 V dec-1 and a large switching ratio of 2 × 106. The saturation mobility and switching ratio of Mo-doped Zn-Sn-O (MZTO, 3 at%) TFTs improved almost five and two orders of magnitude compared with ZTO TFTs, respectively. Therefore, the MZTO TFT has much potential for future electrical applications with its excellent properties.

15.
Nanotechnology ; 32(45)2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34415853

RESUMO

Unlike the traditional fabrication of distributed Bragg reflector (DBR) structure via atomic layer deposition or spin-coating, here the 1-6 pairs of magnesium fluoride (MgF2)/zinc sulfide (ZnS) alternative dielectric layers were grown via thermal evaporation. The absorption, transmission, reflection, and photoluminescence (PL) spectra were evaluated. 5 pair MgF2/ZnS denotes the largest reflectance (88.5% at 535 nm) together with a stopband at 450-650 nm among the 1- 6 pair dielectric layers, exhibiting the potential for using as DBR. Relative to the bare 4,4'-bis(carbazol-9-yl)biphenyl(CBP):(4s,6s)-2,4,5,6-tetra(9H-carbazol-9-yl) isophthalonitrile (4CzIPN) film, the PL intensity of CBP:4CzIPN/5 pair MgF2/ZnS DBR is enhanced and splitted into two peaks. The 5 pair alternative dielectric film presents more uniform aggregation over 4 pair MgF2/ZnS. The cross-sectional scanning electron microscopic image denotes explicit layering for the MgF2and ZnS. The organic light-emitting diode (OLED) incorporating 5 pair MgF2/ZnS DBR layers illustrates significantly improved electroluminescent (EL) performance due to the photons concentrated in the direction perpendicular to the DBR. The slightly narrowed EL spectrum is originated from the microcavity effect between the two Al electrodes. Here we develop a universal method for the DBR fabrication suitable to most of OLEDs.

16.
Int J Mol Sci ; 22(5)2021 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-33673633

RESUMO

Plants are constantly exposed to a wide range of potential pathogens and to protect themselves, have developed a variety of chemical and physical defense mechanisms. Callose is a ß-(1,3)-D-glucan that is widely distributed in higher plants. In addition to its role in normal growth and development, callose plays an important role in plant defense. Callose is deposited between the plasma membrane and the cell wall at the site of pathogen attack, at the plasmodesmata, and on other plant tissues to slow pathogen invasion and spread. Since it was first reported more than a century ago, defense-related callose deposition has been extensively studied in a wide-spectrum of plant-pathogen systems. Over the past 20 years or so, a large number of studies have been published that address the dynamic nature of pathogen-induced callose deposition, the complex regulation of synthesis and transport of defense-related callose and associated callose synthases, and its important roles in plant defense responses. In this review, we summarize our current understanding of the regulation and function of defense-related callose deposition in plants and discuss both the progresses and future challenges in addressing this complex defense mechanism as a critical component of a plant immune system.


Assuntos
Regulação da Expressão Gênica de Plantas , Glucanos/metabolismo , Glucosiltransferases/metabolismo , Interações Hospedeiro-Patógeno , Fenômenos Fisiológicos Vegetais , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética
17.
Int J Mol Sci ; 22(3)2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33498336

RESUMO

Autophagy is a major quality control system for degradation of unwanted or damaged cytoplasmic components to promote cellular homeostasis. Although non-selective bulk degradation of cytoplasm by autophagy plays a role during cellular response to nutrient deprivation, the broad roles of autophagy are primarily mediated by selective clearance of specifically targeted components. Selective autophagy relies on cargo receptors that recognize targeted components and recruit them to autophagosomes through interaction with lapidated autophagy-related protein 8 (ATG8) family proteins anchored in the membrane of the forming autophagosomes. In mammals and yeast, a large collection of selective autophagy receptors have been identified that mediate the selective autophagic degradation of organelles, aggregation-prone misfolded proteins and other unwanted or nonnative proteins. A substantial number of selective autophagy receptors have also been identified and functionally characterized in plants. Some of the autophagy receptors in plants are evolutionarily conserved with homologs in other types of organisms, while a majority of them are plant-specific or plant species-specific. Plant selective autophagy receptors mediate autophagic degradation of not only misfolded, nonactive and otherwise unwanted cellular components but also regulatory and signaling factors and play critical roles in plant responses to a broad spectrum of biotic and abiotic stresses. In this review, we summarize the research on selective autophagy in plants, with an emphasis on the cargo recognition and the biological functions of plant selective autophagy receptors.


Assuntos
Autofagia , Proteínas de Plantas/metabolismo , Plantas/metabolismo , Transdução de Sinais , Estresse Fisiológico , Proteínas Relacionadas à Autofagia/metabolismo , Receptores de Superfície Celular/metabolismo
18.
Plant Physiol ; 180(1): 212-227, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30770459

RESUMO

Plants produce different types of endoplasmic reticulum (ER)-derived vesicles that accumulate and transport proteins, lipids, and metabolites. In the Brassicales, a distinct ER-derived structure called the ER body is found throughout the epidermis of cotyledons, hypocotyls, and roots. NAI2 is a key factor for ER body formation in Arabidopsis (Arabidopsis thaliana). Homologs of NAI2 are found only in the Brassicales and therefore may have evolved specifically to enable ER body formation. Here, we report that three related Arabidopsis NAI2-interacting proteins (NAIP1, NAIP2, and NAIP3) play a critical role in the biogenesis of ER bodies and related structures. Analysis using GFP fusions revealed that all three NAIPs are components of the ER bodies found in the cotyledons, hypocotyls, and roots. Genetic analysis with naip mutants indicates that they have a critical and redundant role in ER body formation. NAIP2 and NAIP3 are also components of other vesicular structures likely derived from the ER that are formed independent of NAI2 and are present not only in the cotyledons, hypocotyls, and roots, but also in the rosettes. Thus, while NAIP1 is a specialized ER body component, NAIP2 and NAIP3 are components of different types of ER-derived structures. Analysis of chimeric NAIP proteins revealed that their N-terminal domains play a major role in the functional specialization between NAIP1 and NAIP3. Unlike NAI2, NAIPs have homologs in all plants; therefore, NAIP-containing ER structures, from which the ER bodies in the Brassicales may have evolved, are likely to be present widely in plants.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Retículo Endoplasmático/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Cotilédone/metabolismo , Retículo Endoplasmático/ultraestrutura , Regulação da Expressão Gênica de Plantas , Hipocótilo/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas de Membrana Transportadoras/genética , Filogenia , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas , Domínios Proteicos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo
19.
Nanotechnology ; 31(50): 505601, 2020 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-33006318

RESUMO

A room-temperature p-type NiOx film synthesized from a NiC2O4 precursor via hydrothermal treatment is employed as an electron blocking layer (EBL) to fabricate organic photodetectors (OPDs). A simple and efficient calcine process at 375 °C in air decomposes the NiC2O4 particles into NiOx, removes organic components and crystal water, and releases CO2 gas. Our experimental results indicate that this gaseous by-product prevents the agglomeration of NiOx, which yields smaller nanoparticles (5-10 nm). The formation of an EBL at room temperature improves device performance. After optimization, the performance parameters obtained, including dark current density, responsivity, specific detectivity and response, are 1.13 × 10-7 A cm-2, 0.74 A W-1, 3.86 × 1012 Jones, and 0.5/8 ms, respectively. Additionally, the dark current is reduced by more than an order of magnitude after the insertion of the NiOx layer. The proposed simple and easy method for producing an EBL could be beneficial for the commercial low-temperature and large-area preparation of OPDs.

20.
Nanotechnology ; 31(1): 015301, 2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31530745

RESUMO

Honeycomb porous polystyrene (PS) films with an aspect ratio of pore depth to pore diameter at approximately 1.0 were fabricated using the breath figure (BF) method. Two modes of water droplet coalescence in the pore growth were observed in real-time by optical microscopy. Pore size significantly increases with the increase in humidity and the decrease in substrate temperature. The porous pattern could emerge even at room temperature under high humidity of 80%. Boiling point and solvent density significantly influence the pore distribution and pore depth. Chloroform and tetrahydrofuran achieve more uniform hexagonal patterns than benzene and dichloromethane. Subsequently, to obtain nanometer porous PS film, the fast-evaporation BF process was designed by regulating the gradient substrate temperature and evaporation time, and porous mesoscopic PS film was obtained. The minimum pore diameter and corresponding pore depth are about 120 nm and 27 nm, respectively. Finally, the fast-evaporation BF process was applied to the honeycomb film formation of photovoltaic polymer poly(3-hexylthiophene) (P3HT), and the heat-resistant polymers polysulfone (PSF) and polyimide (PI).

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