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1.
Artigo em Inglês | MEDLINE | ID: mdl-36289065

RESUMO

Locusts (Locusta migratoria) have outstanding flying abilities, and most of their lift is provided by their hind wings. Insect aerodynamic performance is strongly affected by wing deformation during stroke, which is closely related to its functional morphology (particularly its mechanical properties). The cross-vein is one of the main morphologies in the hind wing of locusts. However, few studies on the mechanical properties of cross-veins have been conducted. This study evaluated the cross-veins of the locust hind wing using uniaxial tensile tester, scanning electron microscope, and finite element methods. Four cross-vein types were identified at different locations on the hind wing, including periodical semi- and full-ellipsoidal humps and periodical semi- and full-conical humps. The four cross-veins showed similar tensile stiffness but differed in bending compliance. We suggest that the mechanical properties of the four cross-veins can be attributed to their physiological functions. This study elucidates cross-veins of locust hind wing and contributes our understanding of the flapping flight mechanism in locusts.


Assuntos
Locusta migratoria , Animais , Locusta migratoria/fisiologia , Asas de Animais/anatomia & histologia , Voo Animal/fisiologia , Fenômenos Biomecânicos
2.
Appl Microbiol Biotechnol ; 107(15): 4873-4885, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37354265

RESUMO

Efficient FAD/FADH2 regeneration is vital for enzymatic biocatalysis and metabolic pathway optimization. Here, we constructed an efficient and simple FAD/FADH2 regeneration system through a combination of L-amino acid deaminase (L-AAD) and halogenase (CombiAADHa), which was applied for catalyzing the conversion of an L-amino acid to halide and an α-keto acid. For cell-free biotransformation, the optimal activity ratio of L-AAD and halogenase was set between 1:50 and 1:60. Within 6 h, 170 mg/L of 7-chloro-tryptophan (7-Cl-Trp) and 193 mg/L of indole pyruvic acid (IPA) were synthesized in the selected mono-amino acid system. For whole-cell biotransformation, 7-Cl-Trp and IPA synthesis was enhanced by 15% (from 96 to 110 mg/L) and 12% (from 115 to 129 mg/L), respectively, through expression fine-tuning and the strengthening of FAD/FADH2 supply. Finally, ultrasound treatment was applied to improve membrane permeability and adjust the activity ratio, resulting in 1.6-and 1.4-fold higher 7-Cl-Trp and IPA yields. The products were then purified. This system could also be applied to the synthesis of other halides and α-keto acids. KEY POINTS: • In this study, a whole cell FAD/FADH2 regeneration system co-expressing l-AAD and halogenase was constructed • This study found that the activity and ratio of enzyme and the concentration of cofactors had a significant effect on the catalytic process for the efficient co-production of 7-chlorotryptophan and indole pyruvate.


Assuntos
Ácido Pirúvico , Triptofano , Triptofano/metabolismo , Aminoácidos/metabolismo , Indóis/metabolismo , Cetoácidos/metabolismo , Regeneração
3.
J Neurosci ; 41(50): 10356-10364, 2021 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-34785579

RESUMO

Semantic processing is an amodal process with modality-specific information integrated in supramodal "convergence zones" or "semantic hub" with executive mechanisms that tailor semantic representation in a task-appropriate way. One unsolved question is how frontal control region dynamically interacts with temporal representation region in semantic integration. The present study addressed this issue by using inhibitory double-pulse transcranial magnetic stimulation over the left inferior frontal gyrus (IFG) or left posterior middle temporal gyrus (pMTG) in one of eight 40 ms time windows (TWs) (3 TWs before and 5 TWs after the identification point of speech), when human participants (12 females, 14 males) were presented with semantically congruent or incongruent gesture-speech pairs but merely identified the gender of speech. We found a TW-selective disruption of gesture-speech integration, indexed by the semantic congruency effect (i.e., a cost of reaction time because of semantic conflict), when stimulating the left pMTG in TW1, TW2, and TW7 but when stimulating the left IFG in TW3 and TW6. Based on the timing relationship, we hypothesize a two-stage gesture-speech integration circuit with a pMTG-to-IFG sequential involvement in the prelexical stage for activating gesture semantics and top-down constraining the phonological processing of speech. In the postlexical stage, an IFG-to-pMTG feedback signal might be implicated for the control of goal-directed representations and multimodal semantic unification. Our findings provide new insights into the dynamic brain network of multimodal semantic processing by causally revealing the temporal dynamics of frontal control and temporal representation regions.SIGNIFICANCE STATEMENT Previous research has identified differential functions of left inferior frontal gyrus (IFG) and posterior middle temporal gyrus (pMTG) in semantic control and semantic representation, respectively, and a causal contribution of both regions in gesture-speech integration. However, it remains largely unclear how the two regions dynamically interact in semantic processing. By using double-pulse transcranial magnetic stimulation to disrupt regional activity at specific time, this study for the first time revealed critical time windows when the two areas were causally involved in integrating gesture and speech semantics. Findings suggest a pMTG-IFG-pMTG neurocircuit loop in gesture-speech integration, which deepens current knowledge and inspires future investigation of the temporal dynamics and cognitive processes of the amodal semantic network.


Assuntos
Gestos , Córtex Pré-Frontal/fisiologia , Semântica , Percepção da Fala/fisiologia , Percepção Visual/fisiologia , Adulto , Feminino , Humanos , Masculino , Estimulação Magnética Transcraniana
4.
Cancer Sci ; 113(5): 1702-1711, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35201656

RESUMO

Parsaclisib, a potent, selective, next-generation PI3Kδ inhibitor, has shown clinical benefit in patients with relapsed or refractory B-cell lymphoma. We undertook a phase Ib study (CITADEL-111) evaluating safety, pharmacokinetics, and efficacy of parsaclisib in Japanese patients with relapsed or refractory B-cell malignancies. Patients received oral parsaclisib daily for 8 weeks then once weekly (10-mg dose, n = 3; 20-mg dose, n = 14). Pharmacokinetic samples were collected on days 1, 8, and 15, and efficacy was monitored according to Lugano criteria. At data cut-off (August 14, 2020), 6 patients (35.3%) remained on study treatment and 11 (64.7%) discontinued due to progressive disease (9 [52.9%]) or adverse events (2 [11.8%]). Median duration of treatment was 8.3 (range, 0.3-24.4) months. The most commonly reported nonhematologic adverse events were constipation (6 [35.3%]), nausea, and pyrexia (each 4 [23.5%]). Five patients (29.4%) experienced treatment-emergent new or worsening decreased neutrophils to grade 3 or 4. No treatment-emergent worsening in aminotransferase elevations to grade 3 or 4 were observed. Ten patients (58.8%) required dose interruption and 5 (29.4%) dose reduction. Body weight-normalized parsaclisib exposure was comparable between Japanese and Western patients. Objective response rate was 100% in follicular lymphoma (9 of 9 patients, including complete response in 2 patients [22.2%]) and marginal zone lymphoma (2 of 2 patients), and 16.7% in diffuse large B-cell lymphoma (1 of 6 patients). Results observed in Japanese patients with relapsed or refractory follicular or marginal zone lymphoma support further clinical development of parsaclisib in these patient populations.


Assuntos
Linfoma Folicular , Linfoma Difuso de Grandes Células B , Humanos , Japão , Linfoma Folicular/tratamento farmacológico , Linfoma Difuso de Grandes Células B/patologia , Pirazóis/uso terapêutico , Pirimidinas/efeitos adversos , Pirrolidinas
5.
J Cell Sci ; 133(6)2020 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-32051284

RESUMO

Self-incompatibility (SI) in the poppy Papaver rhoeas triggers dramatic alterations in actin within pollen tubes. However, how these actin alterations are mechanistically achieved remains largely unexplored. Here, we used treatment with the Ca2+ ionophore A23187 to mimic the SI-induced elevation in cytosolic Ca2+ and trigger formation of the distinctive F-actin foci. Live-cell imaging revealed that this remodeling involves F-actin fragmentation and depolymerization, accompanied by the rapid formation of punctate actin foci and subsequent increase in their size. We established that actin foci are generated and enlarged from crosslinking of fragmented actin filament structures. Moreover, we show that villins associate with actin structures and are involved in this actin reorganization process. Notably, we demonstrate that Arabidopsis VILLIN5 promotes actin depolymerization and formation of actin foci by fragmenting actin filaments, and controlling the enlargement of actin foci via bundling of actin filaments. Our study thus uncovers important novel insights about the molecular players and mechanisms involved in forming the distinctive actin foci in pollen tubes.


Assuntos
Actinas , Proteínas dos Microfilamentos , Tubo Polínico , Citoesqueleto de Actina , Actinas/genética , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/fisiologia , Tubo Polínico/genética
6.
Pharm Stat ; 21(1): 176-195, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34369053

RESUMO

Precision medicine is the systematic use of information that pertains to an individual patient to select or optimize that patient's preventative and therapeutic care. Recent studies have classified biomarkers into predictive and prognostic biomarkers based on their roles in clinical studies. To design a clinical trial for precision medicine, predictive biomarkers and prognostic biomarkers should both be included. In statistical analysis, biomarkers are mathematically treated as covariates. We first classify covariates into predictive and prognostic covariates according to their roles. We then provide a brief review of recent advances in adaptive designs that incorporate covariates. However, the literature includes no designs that incorporate both prognostic covariates and predictive covariates simultaneously. In this paper, we propose a new family of covariate-adjusted response-adaptive (CARA) designs that incorporate both prognostic and predictive covariates and the responses. It is important to note that the predictive biomarkers and prognostic biomarkers play different roles in the new designs. The advantages of the proposed methods are demonstrated via numerical studies, and some further statistical issues are also discussed.


Assuntos
Medicina de Precisão , Projetos de Pesquisa , Biomarcadores , Humanos
7.
J Integr Plant Biol ; 64(8): 1631-1645, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35713231

RESUMO

Autophagy is an intracellular degradation mechanism involved in antiviral defense, but the strategies employed by plant viruses to counteract autophagy-related defense remain unknown for the majority of the viruses. Herein, we describe how the Chinese wheat mosaic virus (CWMV, genus Furovirus) interferes with autophagy and enhances its infection in Nicotiana benthamiana. Yeast two-hybrid screening and in vivo/in vitro assays revealed that the 19 kDa coat protein (CP19K) of CWMV interacts with cytosolic glyceraldehyde-3-phosphate dehydrogenases (GAPCs), negative regulators of autophagy, which bind autophagy-related protein 3 (ATG3), a key factor in autophagy. CP19K also directly interacts with ATG3, possibly leading to the formation of a CP19K-GAPC-ATG3 complex. CP19K-GAPC interaction appeared to intensify CP19K-ATG3 binding. Moreover, CP19K expression upregulated GAPC gene transcripts and reduced autophagic activities. Accordingly, the silencing of GAPC genes in transgenic N. benthamiana reduced CWMV accumulation, whereas CP19K overexpression enhanced it. Overall, our results suggest that CWMV CP19K interferes with autophagy through the promotion and utilization of the GAPC role as a negative regulator of autophagy.


Assuntos
Vírus de Plantas , Viroses , Autofagia/genética , Gliceraldeído-3-Fosfato Desidrogenases/genética , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Doenças das Plantas , Nicotiana/genética , Nicotiana/metabolismo
8.
Plant Physiol ; 179(4): 1265-1272, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30824565

RESUMO

The plant leaf apoplast is a dynamic environment subject to a variety of both internal and external stimuli. In addition to being a conduit for water vapor and gas exchange involved in transpiration and photosynthesis, the apoplast also accumulates many nutrients transported from the soil as well as those produced through photosynthesis. The internal leaf also provides a protective environment for endophytic and pathogenic microbes alike. Given the diverse array of physiological processes occurring in the apoplast, it is expedient to develop methods to study its contents. Many established methods rely on vacuum infiltration of an apoplast wash solution followed by centrifugation. In this study, we describe a refined method optimized for maize (Zea mays) seedling leaves, which not only provides a simple procedure for obtaining apoplast fluid, but also allows direct calculation of apoplast hydration at the time of harvest for every sample. In addition, we describe an abbreviated method for estimating apoplast hydration if the full apoplast extraction is not necessary. Finally, we show the applicability of this optimized apoplast extraction procedure for plants infected with the maize pathogen Pantoea stewartii ssp stewartii, including the efficient isolation of bacteria previously residing in the apoplast. The approaches to establishing this method should make it generally applicable to other types of plants.


Assuntos
Botânica/métodos , Líquido Extracelular/metabolismo , Água/metabolismo , Zea mays/metabolismo , Interações Hospedeiro-Patógeno , Pantoea/fisiologia , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Zea mays/microbiologia
9.
Int J Biometeorol ; 64(12): 2077-2091, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32851452

RESUMO

Thermal indices as environmental risk indicators have been used to assess heat stress of dairy cows. The present study aimed to evaluate the predictive performance of the typical cattle-related thermal indices by comparing their prediction to heat stress levels and associations with some physiological responses. The study was conducted from August to September 2019 in a naturally ventilated barn in Jiangsu, China. Nine typical cattle-related thermal indices, i.e., temperature-humidity index (THI), black globe temperature index (BGHI), equivalent temperature index, effective temperature (ET) for dairy cows, respiratory rate predictor (RRP), adjusted temperature-humidity index (THIadj), heat load index (HLI), comprehensive climate index (CCI), and equivalent temperature index for cattle (ETIC), were evaluated. Respiration rate (RR) and body surface temperature (BST) were collected twice per day from a total of 287 lactating cows, 18 of which were continuously measured vaginal temperature (VT). Over the experimental period, the average daily RR, VT, and BST were 55.8 breaths/min, 38.7 °C, and 32.3 to 36.4 °C that depend on body positions, respectively. The study found that the prediction of THI, BGHI, THIadj, and CCI was closer to the actual heat stress conditions which were mild to moderate heat stress. Correlation analyses showed that RR, VT, and BST correlated most closely with effective temperature (r = 0.580; P < 0.05), BGHI (r = 0.642; P < 0.05), and CCI (r = 0.849; P < 0.05). In this evaluation, based on the comprehensive performance of CCI in the relatively accurate prediction to heat stress level and duration, detection on environmental differences between standing and lying zone, and correlations with some physiological responses, CCI is seemingly the promising thermal index to assess heat stress of housed dairy cows.


Assuntos
Transtornos de Estresse por Calor , Lactação , Animais , Temperatura Corporal , Bovinos , China , Feminino , Transtornos de Estresse por Calor/veterinária , Resposta ao Choque Térmico , Temperatura Alta , Umidade , Estresse Fisiológico
10.
J Environ Manage ; 263: 110323, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32174515

RESUMO

Metal tailings are potential sources of strong environmental pollution. In situ remediation involves the installation of a plant cover to stabilize materials and pollutants. Whether metal(loid)s are effectively immobilized in remediated tailing ponds submitted to heavy rainfall remains uncertain. In this study, tailing materials were collected from bare tailings (control), grass-planted (G) and grass-shrub planted (GS) areas on a former Pb/Zn mine site. Batch column experiments were performed with three rainfall intensities of 0.36, 0.48, and 0.50 mL min-1 for 18 d in the lab. The pH, Eh, Cd, Pb, Zn and As concentration in leachate were recorded. Selected leached tailing materials were finally characterized. Results showed that leachates from control were strongly acidic (pH 3.11-4.65), and that Cd, Pb, Zn and As were quickly released at high rate (e.g., 945 mg L-1 Zn). During the experiment up to 4% Cd present in the material was released and almost 1% Zn. With material collected from the G area, leachates were even more acidic (2.16-2.84) with a rainfall intensity of 0.50 mL min-1 and exhibited a high redox potential (588-639 mV). However, concentrations of metals in leachates were much lower than that in the control, except for Zn (e.g., 433 mg L-1), and they tended to decrease with time. Cumulative leaching rate was still relatively high (e.g., 0.68% Cd; 0.75% Zn) during the first eight days (stage I). However, with the GS treatment, leachate pH gradually raised from acid to alkaline values (3.9-8.2) during stage I, then remained high until the end of the experiment (stage II). Also, amounts of elements released during the 18 d were low in general. The releasing ratios of Cd (R2 > 0.95), Pb (R2 > 0.95), As (R2 > 0.87), and Zn (R2 > 0.90) fitted well with a two-constant model. In conclusion, under subtropical climate with heavy rainfall, phytostabilization is effective but immobilization of metals is higher with a combination of grass and shrub than with only grass to reduce leaching of As and Zn.


Assuntos
Metais Pesados , Poluentes do Solo/análise , Chumbo , Plantas , Poaceae , Zinco/análise
11.
J Neurosci ; 38(8): 1891-1900, 2018 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-29358361

RESUMO

Language and action naturally occur together in the form of cospeech gestures, and there is now convincing evidence that listeners display a strong tendency to integrate semantic information from both domains during comprehension. A contentious question, however, has been which brain areas are causally involved in this integration process. In previous neuroimaging studies, left inferior frontal gyrus (IFG) and posterior middle temporal gyrus (pMTG) have emerged as candidate areas; however, it is currently not clear whether these areas are causally or merely epiphenomenally involved in gesture-speech integration. In the present series of experiments, we directly tested for a potential critical role of IFG and pMTG by observing the effect of disrupting activity in these areas using transcranial magnetic stimulation in a mixed gender sample of healthy human volunteers. The outcome measure was performance on a Stroop-like gesture task (Kelly et al., 2010a), which provides a behavioral index of gesture-speech integration. Our results provide clear evidence that disrupting activity in IFG and pMTG selectively impairs gesture-speech integration, suggesting that both areas are causally involved in the process. These findings are consistent with the idea that these areas play a joint role in gesture-speech integration, with IFG regulating strategic semantic access via top-down signals acting upon temporal storage areas.SIGNIFICANCE STATEMENT Previous neuroimaging studies suggest an involvement of inferior frontal gyrus and posterior middle temporal gyrus in gesture-speech integration, but findings have been mixed and due to methodological constraints did not allow inferences of causality. By adopting a virtual lesion approach involving transcranial magnetic stimulation, the present study provides clear evidence that both areas are causally involved in combining semantic information arising from gesture and speech. These findings support the view that, rather than being separate entities, gesture and speech are part of an integrated multimodal language system, with inferior frontal gyrus and posterior middle temporal gyrus serving as critical nodes of the cortical network underpinning this system.


Assuntos
Gestos , Atividade Motora/fisiologia , Fala/fisiologia , Lobo Temporal/fisiologia , Adulto , Feminino , Humanos , Masculino , Estimulação Magnética Transcraniana , Adulto Jovem
12.
Anal Bioanal Chem ; 411(5): 1009-1017, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30552495

RESUMO

A novel fluorescent sensor based on bovine serum albumin stabilized gold/silver nanoclusters (BSA-Au/Ag NCs) was developed for sensitive and facile detection of alkaline phosphatase (ALP) activity. For this fluorescent sensor, ascorbic acid 2-phosphate (AAP) was decomposed into ascorbic acid (AA) and phosphate by catalysis with ALP. The initial red fluorescence of the BSA-Au/Ag NCs was effectively quenched by KMnO4 and then the fluorescence was recovered by addition of AA. The mechanism of interaction between BSA-Au/Ag NCs and KMnO4 and AA was studied with use of the fluorescence lifetime and UV-vis absorption spectra. The results indicated that the oxidation/reduction modulated by KMnO4/AA led to surface structure destruction/restoration of the BSA-Au/Ag NCs, resulting in fluorescence quenching/recovery. The proposed fluorescence-based method based on a dark background was used to detect ALP and had excellent sensitivity, with a detection limit of 0.00076 U/L. Moreover, the method was applied to the determination of added analytes, with satisfactory recoveries (97.0-105.0 %). In a simulated eutrophic water body, this method successfully detected ALP in actual water samples and could monitor the dynamic changes of ALP activity through visual observation. More importantly, the proposed fluorescent sensor not only has the advantages of simple operation and high sensitivity but has also been successfully used on filter paper to establish a rapid and visual test paper for ALP.


Assuntos
Fosfatase Alcalina/análise , Chlorella/enzimologia , Corantes Fluorescentes/química , Ouro/química , Nanopartículas Metálicas/química , Prata/química , Espectrometria de Fluorescência/métodos , Animais , Bovinos , Limite de Detecção , Soroalbumina Bovina/química , Água/análise
13.
Proc Natl Acad Sci U S A ; 113(17): 4688-93, 2016 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-27035959

RESUMO

Intent and mitigating circumstances play a central role in moral and legal assessments in large-scale industrialized societies. Although these features of moral assessment are widely assumed to be universal, to date, they have only been studied in a narrow range of societies. We show that there is substantial cross-cultural variation among eight traditional small-scale societies (ranging from hunter-gatherer to pastoralist to horticulturalist) and two Western societies (one urban, one rural) in the extent to which intent and mitigating circumstances influence moral judgments. Although participants in all societies took such factors into account to some degree, they did so to very different extents, varying in both the types of considerations taken into account and the types of violations to which such considerations were applied. The particular patterns of assessment characteristic of large-scale industrialized societies may thus reflect relatively recently culturally evolved norms rather than inherent features of human moral judgment.


Assuntos
Intenção , Julgamento , Humanos , Princípios Morais , População Rural , Sociedades
14.
PLoS Pathog ; 12(5): e1005609, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27191168

RESUMO

Bacterial AvrE-family Type-III effector proteins (T3Es) contribute significantly to the virulence of plant-pathogenic species of Pseudomonas, Pantoea, Ralstonia, Erwinia, Dickeya and Pectobacterium, with hosts ranging from monocots to dicots. However, the mode of action of AvrE-family T3Es remains enigmatic, due in large part to their toxicity when expressed in plant or yeast cells. To search for targets of WtsE, an AvrE-family T3E from the maize pathogen Pantoea stewartii subsp. stewartii, we employed a yeast-two-hybrid screen with non-lethal fragments of WtsE and a synthetic genetic array with full-length WtsE. Together these screens indicate that WtsE targets maize protein phosphatase 2A (PP2A) heterotrimeric enzyme complexes via direct interaction with B' regulatory subunits. AvrE1, another AvrE-family T3E from Pseudomonas syringae pv. tomato strain DC3000 (Pto DC3000), associates with specific PP2A B' subunit proteins from its susceptible host Arabidopsis that are homologous to the maize B' subunits shown to interact with WtsE. Additionally, AvrE1 was observed to associate with the WtsE-interacting maize proteins, indicating that PP2A B' subunits are likely conserved targets of AvrE-family T3Es. Notably, the ability of AvrE1 to promote bacterial growth and/or suppress callose deposition was compromised in Arabidopsis plants with mutations of PP2A genes. Also, chemical inhibition of PP2A activity blocked the virulence activity of both WtsE and AvrE1 in planta. The function of HopM1, a Pto DC3000 T3E that is functionally redundant to AvrE1, was also impaired in specific PP2A mutant lines, although no direct interaction with B' subunits was observed. These results indicate that sub-component specific PP2A complexes are targeted by bacterial T3Es, including direct targeting by members of the widely conserved AvrE-family.


Assuntos
Proteínas de Bactérias/metabolismo , Infecções por Bactérias Gram-Negativas/metabolismo , Proteína Fosfatase 2/metabolismo , Virulência/fisiologia , Arabidopsis/microbiologia , Infecções por Bactérias Gram-Negativas/imunologia , Imunoprecipitação , Solanum lycopersicum/microbiologia , Pantoea/metabolismo , Doenças das Plantas/microbiologia , Pseudomonas syringae/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Nicotiana/microbiologia , Técnicas do Sistema de Duplo-Híbrido , Sistemas de Secreção Tipo III , Zea mays/microbiologia
15.
Plant Physiol ; 175(3): 1438-1454, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28931628

RESUMO

During embryogenesis and organ formation, establishing proper gradient is critical for auxin function, which is achieved through coordinated regulation of both auxin metabolism and transport. Expression of auxin biosynthetic genes is often tissue specific and is regulated by environmental signals. However, the underlying regulatory mechanisms remain elusive. Here, we investigated the transcriptional regulation of a key auxin biosynthetic gene, l-Tryptophan aminotransferase of Arabidopsis1 (TAA1). A canonical and a novel Arabidopsis (Arabidopsis thaliana) response regulator (ARR) binding site were identified in the promoter and the second intron of TAA1, which were required for its tissue-specific expression. C-termini of a subset of the type B ARRs selectively bind to one or both cis elements and activate the expression of TAA1 We further demonstrated that the ARRs not only mediate the transcriptional regulation of TAA1 by cytokinins, but also mediate its regulation by ethylene, light, and developmental signals. Through direct protein-protein interactions, the transcriptional activity of ARR1 is enhanced by ARR12, DELLAs, and ethylene-insenstive3 (EIN3). Our study thus revealed the ARR proteins act as key node that mediate the regulation of auxin biosynthesis by various hormonal, environmental, and developmental signals through transcriptional regulation of the key auxin biosynthesis gene TAA1.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos/metabolismo , Transcrição Gênica , Arabidopsis/efeitos dos fármacos , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/genética , Sequência de Bases , Citocininas/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Luz , Mutação/genética , Regiões Promotoras Genéticas , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/efeitos da radiação , Transdução de Sinais/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacos , Transcrição Gênica/efeitos da radiação
16.
Opt Express ; 25(16): 18629-18642, 2017 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-29041060

RESUMO

The collection efficiency of light from a point-like emitter may be extremely poor due to aberrations induced by collection optics and the emission distribution of the source. Analyzing the aberrant wavefront (e.g., with a Shack-Hartmann sensor) and correcting accordingly can be infeasible on the single-photon level. We present a technique that uses a genetic algorithm to control a deformable mirror for correcting wavefront aberrations in single-photon signals from point emitters. We apply our technique to both a simulated point source and a real InAs quantum dot, achieving coupling increases of up to 50% and automatic reduction of system drift.

17.
Opt Lett ; 42(16): 3080-3083, 2017 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-28809877

RESUMO

We report the broadband terahertz (THz) radiation in ferromagnetic half-metallic Heusler alloy Co2MnSn thin film upon the irradiation of a femtosecond laser pulse at room temperature. The magnetic-, sample symmetry-, and pump fluence-dependent THz emission reveals that the THz radiation is originated from the magnetic-dipole radiation, i.e., the light-induced subpicosecond demagnetization. In addition, by optical pump-THz probe spectroscopy, we found that the photoexcited increase of the scattering rate of hot carriers thereby leads to the photoinduced negative THz conductivity in Co2MnSn thin film.

18.
Yi Chuan ; 39(7): 597-606, 2017 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-28757474

RESUMO

function between the circulation and the atmospheric environment. Lung diseases, including lung cancer, are among the leading causes of death in the modern society. Research on lung development, regeneration and cancer could provide significant insights for the development of therapeutic approaches on lung diseases. Hippo/YAP/TAZ signaling pathway regulates cell proliferation and differentiation, controls organ size, and plays an important role in response to mechanical forces. YAP/TAZ are expressed in many cell types and serve various regulatory functions in the embryonic and adult lungs. In this review, we mainly focus on the roles of Hippo/YAP/TAZ signaling pathway in embryonic lung development, regeneration and cancer. We postulate that Hippo/YAP/TAZ signaling may play potential roles in regulating the alveolar mechanics and immune responses in the lung.


Assuntos
Pneumopatias/etiologia , Pulmão/embriologia , Proteínas Serina-Treonina Quinases/fisiologia , Regeneração , Transdução de Sinais/fisiologia , Animais , Proteínas de Ciclo Celular , Via de Sinalização Hippo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Pulmão/fisiologia , Neoplasias Pulmonares/etiologia , Proteínas Nucleares/fisiologia , Fibrose Pulmonar/etiologia , Transativadores , Fatores de Transcrição/fisiologia , Proteínas com Motivo de Ligação a PDZ com Coativador Transcricional
19.
Plant Physiol ; 167(3): 1117-35, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25635112

RESUMO

AvrE family type III effector proteins share the ability to suppress host defenses, induce disease-associated cell death, and promote bacterial growth. However, despite widespread contributions to numerous bacterial diseases in agriculturally important plants, the mode of action of these effectors remains largely unknown. WtsE is an AvrE family member required for the ability of Pantoea stewartii ssp. stewartii (Pnss) to proliferate efficiently and cause wilt and leaf blight symptoms in maize (Zea mays) plants. Notably, when WtsE is delivered by a heterologous system into the leaf cells of susceptible maize seedlings, it alone produces water-soaked disease symptoms reminiscent of those produced by Pnss. Thus, WtsE is a pathogenicity and virulence factor in maize, and an Escherichia coli heterologous delivery system can be used to study the activity of WtsE in isolation from other factors produced by Pnss. Transcriptional profiling of maize revealed the effects of WtsE, including induction of genes involved in secondary metabolism and suppression of genes involved in photosynthesis. Targeted metabolite quantification revealed that WtsE perturbs maize metabolism, including the induction of coumaroyl tyramine. The ability of mutant WtsE derivatives to elicit transcriptional and metabolic changes in susceptible maize seedlings correlated with their ability to promote disease. Furthermore, chemical inhibitors that block metabolic flux into the phenylpropanoid pathways targeted by WtsE also disrupted the pathogenicity and virulence activity of WtsE. While numerous metabolites produced downstream of the shikimate pathway are known to promote plant defense, our results indicate that misregulated induction of phenylpropanoid metabolism also can be used to promote pathogen virulence.


Assuntos
Proteínas de Bactérias/metabolismo , Sistemas de Secreção Bacterianos , Pantoea/metabolismo , Propanóis/metabolismo , Zea mays/metabolismo , Zea mays/microbiologia , Sistemas de Secreção Bacterianos/efeitos dos fármacos , Bioensaio , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ontologia Genética , Genoma de Planta , Modelos Biológicos , Mutação/genética , Pantoea/efeitos dos fármacos , Pantoea/crescimento & desenvolvimento , Pantoea/patogenicidade , Fenilalanina Amônia-Liase/metabolismo , Plântula/efeitos dos fármacos , Plântula/genética , Plântula/microbiologia , Ácido Chiquímico/metabolismo , Transcrição Gênica/efeitos dos fármacos , Tiramina , Virulência/efeitos dos fármacos , Zea mays/efeitos dos fármacos , Zea mays/genética
20.
Anal Chem ; 86(5): 2521-5, 2014 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-24502339

RESUMO

Previous reports of fluorescent sensors for alcohols based on charge-transfer character of their excited state are based on mono-, di-, and tetra-phosphonate cavitands, which are capable of selecting analytes through shape/size selection and various specific H-bonding, CH-π, and cation-dipole interactions. To contrast, color changes based on absorption properties of the ground state are more suitable for direct observation with the naked eye. Three sensitive and selective colorimetric sensors for C1-C4 alcohols have been developed on the basis of alcohol-mediated ground-state intramolecular proton transfer. Reverse proton transfer induced by water achieves a fully reversible reaction. In addition, the solvent color indicates alcohol concentration.

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