113 research outputs found
BdWRKY38 is required for the incompatible interaction of Brachypodium distachyon with the necrotrophic fungus Rhizoctonia solani
Rhizoctonia solani is a soilâborne necrotrophic fungus that causes sheath blight in grasses. The basal resistance of compatible interactions between R. solani and rice is known to be modulated by some WRKY transcription factors (TFs). However, genes and defense responses involved in incompatible interaction with R. solani remain unexplored, because no such interactions are known in any host plants. Recently, we demonstrated that Bd3â1, an accession of the model grass Brachypodium distachyon, is resistant to R. solani and, upon inoculation with the fungus, undergoes rapid induction of genes responsive to the phytohormone salicylic acid (SA) that encode the WRKY TFs BdWRKY38 and BdWRKY44. Here, we show that endogenous SA and these WRKY TFs positively regulate this accessionâspecific R. solani resistance. In contrast to a susceptible accession (Bd21), the infection process in the resistant accessions Bd3â1 and Tekâ3 was suppressed at early stages before the development of fungal biomass and infection machinery. A comparative transcriptome analysis during pathogen infection revealed that putative WRKYâdependent defense genes were induced faster in the resistant accessions than in Bd21. A gene regulatory network (GRN) analysis based on the transcriptome dataset demonstrated that BdWRKY38 was a GRN hub connected to many target genes specifically in resistant accessions, whereas BdWRKY44 was shared in the GRNs of all three accessions. Moreover, overexpression of BdWRKY38 increased R. solani resistance in Bd21. Our findings demonstrate that these resistant accessions can activate an incompatible host response to R. solani, and BdWRKY38 regulates this response by mediating SA signaling
Aspect ratio dependence of hysteresis property of high density Co wire array buried in porous alumina template
Abstract Co wire array with 50 nm intervals was formed by electrodeposition in porous alumina template that was formed on Si substrate. Coercive field of Co wire array under perpendicular magnetic field significantly increased when aspect ratio increased from 1.5 to 2.5. This behavior was well explained by the micromagnetic simulation when magnetic anisotropy axis was assumed to be parallel to the substrate.
Characterisation of different polymorphs of tris(8-hydroxyquinolinato)aluminium(III) using solid-state NMR and DFT calculations
<p>Abstract</p> <p>Background</p> <p>Organic light emitting devices (OLED) are becoming important and characterisation of them, in terms of structure, charge distribution, and intermolecular interactions, is important. Tris(8-hydroxyquinolinato)-aluminium(III), known as Alq<sub>3</sub>, an organomettalic complex has become a reference material of great importance in OLED. It is important to elucidate the structural details of Alq<sub>3 </sub>in its various isomeric and solvated forms. Solid-state nuclear magnetic resonance (NMR) is a useful tool for this which can also complement the information obtained with X-ray diffraction studies.</p> <p>Results</p> <p>We report here <sup>27</sup>Al one-dimensional (1D) and two-dimensional (2D) multiple-quantum magic-angle spinning (MQMAS) NMR studies of the meridional (<it>α</it>-phase) and the facial (<it>Ύ</it>-phase) isomeric forms of Alq<sub>3</sub>. Quadrupolar parameters are estimated from the 1D spectra under MAS and anisotropic slices of the 2D spectra and also calculated using DFT (density functional theory) quantum-chemical calculations. We have also studied solvated phase of Alq<sub>3 </sub>containing ethanol in its lattice. We show that both the XRD patterns and the quadrupolar parameters of the solvated phase are different from both the <it>α</it>-phase and the <it>Ύ</it>-phase, although the fluorescence emission shows no substantial difference between the <it>α</it>-phase and the solvated phase. Moreover, we have shown that after the removal of ethanol from the matrix the solvated Alq<sub>3 </sub>has similar XRD patterns and quadrupolar parameters to that of the <it>α</it>-phase.</p> <p>Conclusion</p> <p>The 2D MQMAS experiments have shown that all the different modifications of Alq<sub>3 </sub>have <sup>27</sup>Al in single unique crystallographic site. The quadrupolar parameters predicted using the DFT calculation under the isodensity polarisable continuum model resemble closely the experimentally obtained values. The solvated phase of Alq<sub>3 </sub>containing ethanol has structural difference from the <it>α</it>-phase of Alq<sub>3 </sub>(containing meridional isomer) from the solid-state NMR studies. Solid-state NMR can hence be used as an effective complementary tool to XRD for characterisation and structural elucidation.</p
[11C]CHIBA-1001 as a Novel PET Ligand for α7 Nicotinic Receptors in the Brain: A PET Study in Conscious Monkeys
BACKGROUND: The alpha7 nicotinic acetylcholine receptors (nAChRs) play an important role in the pathophysiology of neuropsychiatric diseases such as schizophrenia and Alzheimer's disease. However, there are currently no suitable positron emission tomography (PET) radioligands for imaging alpha7 nAChRs in the intact human brain. Here we report the novel PET radioligand [11C]CHIBA-1001 for in vivo imaging of alpha7 nAChRs in the non-human primate brain. METHODOLOGY/PRINCIPAL FINDINGS: A receptor binding assay showed that CHIBA-1001 was a highly selective ligand at alpha7 nAChRs. Using conscious monkeys, we found that the distribution of radioactivity in the monkey brain after intravenous administration of [11C]CHIBA-1001 was consistent with the regional distribution of alpha7 nAChRs in the monkey brain. The distribution of radioactivity in the brain regions after intravenous administration of [11C]CHIBA-1001 was blocked by pretreatment with the selective alpha7 nAChR agonist SSR180711 (5.0 mg/kg). However, the distribution of [11C]CHIBA-1001 was not altered by pretreatment with the selective alpha4beta2 nAChR agonist A85380 (1.0 mg/kg). Interestingly, the binding of [11C]CHIBA-1001 in the frontal cortex of the monkey brain was significantly decreased by subchronic administration of the N-methyl-D-aspartate (NMDA) receptor antagonist phencyclidine (0.3 mg/kg, twice a day for 13 days); which is a non-human primate model of schizophrenia. CONCLUSIONS/SIGNIFICANCE: The present findings suggest that [11C]CHIBA-1001 could be a novel useful PET ligand for in vivo study of the receptor occupancy and pathophysiology of alpha7 nAChRs in the intact brain of patients with neuropsychiatric diseases such as schizophrenia and Alzheimer's disease
Urticaria and infections
Urticaria is a group of diseases that share a distinct skin reaction pattern. Triggering of urticaria by infections has been discussed for many years but the exact role and pathogenesis of mast cell activation by infectious processes is unclear. In spontaneous acute urticaria there is no doubt for a causal relationship to infections and all chronic urticaria must have started as acute. Whereas in physical or distinct urticaria subtypes the evidence for infections is sparse, remission of annoying spontaneous chronic urticaria has been reported after successful treatment of persistent infections. Current summarizing available studies that evaluated the course of the chronic urticaria after proven Helicobacter eradication demonstrate a statistically significant benefit compared to untreated patients or Helicobacter-negative controls without urticaria (p < 0.001). Since infections can be easily treated some diagnostic procedures should be included in the routine work-up, especially the search for Helicobacter pylori. This review will update the reader regarding the role of infections in different urticaria subtypes
Development of reliable technique for evaluating the properties of water vapor barriers
A reliable technique for evaluating a barrier film, which is a key component used to encapsulate flexible organic light-emitting diodes (OLEDs), is required to reliably appraise the lifetimes of such devices. The water vapor transmission rates (WVTR) is commonly used as an indication for a barrier film. In this paper, the variables affecting WVTR measurements were investigated because the results of such evaluations typically vary widely even at a level of 10â3 g mâ2 dayâ1 at 40 °C and 90% relative humidity (RH). The reference films used for comparative measurements were prepared to eliminate the influence of the differences between individual barrier films. The measurement procedures were carefully investigated by using three WVTR measurement systems, which are based on different principles and different detectors. Consistency between the systems in terms of the WVTR was achieved at a level of 10â5 g mâ2 dayâ1 at 40 °C and 90%RH. These results prove the reliability of not only our evaluation but also of these three systems, provided the measurements are performed correctly. The lag time was also analyzed to determine those factors that can affect the measurement time. It was found that the time required for a system to reach the adsorption-desorption equilibrium state can affect the measurement time
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