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1.
J Fungi (Basel) ; 10(4)2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38667917

RESUMO

Fusarium sacchari is a causal agent of sugarcane Pokkah boeng, an important fungal disease that causes a considerable reduction in yield and sugar content in susceptible varieties of sugarcane worldwide. Despite its importance, the fungal factors that regulate the virulence of this pathogen remain largely unknown. In our previous study, mapping of an insertional mutant defect in virulence resulted in the identification of a cutinase G-box binding protein gene, designated FsCGBP, that encodes a C2H2-type transcription factor (TF). FsCGBP was shown to localize in the nuclei, and the transcript level of FsCGBP was significantly upregulated during the infection process or in response to abiotic stresses. Deletion or silencing of FsCGBP resulted in a reduction in mycelial growth, conidial production, and virulence and a delay in conidial germination in the F. sacchari. Cutinase genes FsCUT2, FsCUT3, and FsCUT4 and the mitogen-activated protein kinase (MAPK) genes FsHOG1, FsMGV1, and FsGPMK1, which were significantly downregulated in ΔFsCGBP. Except for FsHOG1, all of these genes were found to be transcriptionally activated by FsCGBP using the yeast one-hybrid system in vitro. The deletion of individual cutinase genes did not result in any of the phenotypes exhibited in the ΔFsCGBP mutant, except for cutinase activity. However, disruption of the MAPK pathway upon deletion of FsMGV1 or FsGPMK1 resulted in phenotypes similar to those of the ΔFsCGBP mutant. The above results suggest that FsCGBP functions by regulating the MAPK pathway and cutinase genes, providing new insights into the mechanism of virulence regulation in F. sacchari.

2.
Front Microbiol ; 14: 1301062, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38029145

RESUMO

Fusarium oxysporum f. sp. cubense tropical race 4 (FocTR4) is a devastating phytopathogen responsible for significant losses in banana production worldwide. Trichoderma and other biocontrol agents (BCAs) have been used as suitable disease control methods for banana Fusarium wilt. In this study, the endophytic T. koningiopsis Tk905 strain was isolated from the roots of dendrobe plants and identified utilizing morphological and molecular analyses. Antifungal activity tests revealed that Tk905 effectively inhibited mycelial growth with inhibition rates ranging from 26.52 to 75.34%. Additionally, Tk905 covered the pathogen mycelia, and spores were observed on or around the pathogen hyphae. The average root and shoot fresh weights and plant height, of Tk905-inoculated plants were significantly higher than those of the untreated plants. Furthermore, Tk905 treatment significantly increased the activity of antioxidant enzymes, such as catalase (CAT), phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), and peroxidase (POD), suggesting that Tk905 may enhance plant defence systems by activating their antioxidant mechanisms. Most importantly, Tk905-treated plants inoculated by three methods exhibited significantly lower disease incidence and severity than untreated plants. The protective effects of Tk905 against FocTR4 infection were not only observed in the early stages of infection but persisted throughout the experiment, suggesting that T. koningiopsis Tk905 can provide long-lasting protection against Fusarium wilt.

3.
Opt Lett ; 48(7): 1714-1717, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37221748

RESUMO

A method for the quantitative measurement of two-dimensional density field distributions based on deflectometry is proposed. With this method, from the point of view of the inverse Hartmann test, the light rays emitted from the camera reach the screen after being disturbed by the shock-wave flow field. After the coordinates of the point source are obtained by using the phase information, the deflection angle of the light ray can be calculated, and then the distribution of the density field can be determined. The principle of density field measurement deflectometry (DFMD) is described in detail. In the experiment, the density fields in wedge-shaped models with three different wedge angles are measured in supersonic wind tunnels, the experimental results from the proposed method are compared with the theoretical results, and the measurement error is found to be around 2.76 × 10-3kg/m3. This method has the advantages of fast measurement, a simple device, and low cost. It provides a new approach, to the best of our knowledge, to measuring the density field of a shock-wave flow field.

4.
ACS Nano ; 17(11): 10844-10856, 2023 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-37204014

RESUMO

Sodium metal anode, featured by favorable redox voltage and material availability, offers a feasible avenue toward high-energy-density devices. However, uneven metal deposition and notorious dendrite proliferation synchronously hamper its broad application prospects. Here, a three-dimensional (3D) porous hierarchical silver/reduced graphene oxide (Ag/rGO) microlattice aerogel is devised as a sodiophilic monolith, which is realized by a direct ink writing 3D printing technology. The thus-printed Na@Ag/rGO electrode retains a durable cycling lifespan over 3100 h at 3.0 mA cm-2/1.0 mAh cm-2, concurrently harvesting a high average Coulombic efficiency of 99.80%. Impressively, it can be cycled for 340 h at a stringent condition of 6.0 mA cm-2 with a large areal capacity of 60.0 mAh cm-2 (∼1036.31 mAh g-1). Meanwhile, the well-regulated Na ion flux and uniform deposition kinetics are systematically probed by comprehensive electroanalytical analysis and theoretical simulations. As a result, assembled Na metal full battery delivers a long cycling sustainability over 500 cycles at 100 mA g-1 with a low per-cycle decay of 0.85%. The proposed strategy might inspire the construction of high-capacity Na metal anodes with appealing stability.

5.
ACS Nano ; 16(6): 9105-9116, 2022 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-35666854

RESUMO

Featuring a high theoretical capacity, low cost, and abundant resources, sodium metal has emerged as an ideal anode material for sodium ion batteries. However, the real feasibility of sodium metal anodes is still hampered by the uncontrolled sodium dendrite problems. Herein, an artificial three-dimensional (3D) hierarchical porous sodiophilic V2CTx/rGO-CNT microgrid aerogel is fabricated by a direct-ink writing 3D printing technology and further adopted as the matrix of Na metal to deliver a Na@V2CTx/rGO-CNT sodium metal anode. Upon cycling, the V2CTx/rGO-CNT electrode can yield a superior cycling life of more than 3000 h (2 mA cm-2, 10 mAh cm-2) with an average Coulombic efficiency of 99.54%. More attractively, it can even sustain a stable operation over 900 h at 5 mA cm-2 with an ultrahigh areal capacity of 50 mAh cm-2. In situ and ex situ characterizations and density functional theory simulation analyses prove that V2CTx with abundant sodiophilic functional groups can effectively guide the sodium metal nucleation and uniform deposition, thus enabling a dendrite-free morphology. Moreover, a full cell pairing a Na@V2CTx/rGO-CNT anode with a Na3V2(PO4)3@C-rGO cathode can deliver a high reversible capacity of 86.27 mAh g-1 after 400 cycles at 100 mA g-1. This work not only clarifies the superior Na deposition chemistry on the sodiophilic V2CTx/rGO-CNT microgrid aerogel electrode but also offers an approach for fabricating advanced Na metal anodes via a 3D printing method.

6.
Appl Opt ; 61(11): 3101-3106, 2022 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-35471285

RESUMO

Based on the impedance matching method, we have numerically demonstrated a broadband tunable multilayer structure in a terahertz (THz) regime. The switchable functional characteristics of the absorber can be achieved by utilizing the phase transition property of vanadium dioxide (VO2). When VO2 is in the metallic state, the designed device behaves as a broadband absorber with an absorbance greater than 90% under normal incident from a 4.5 to 10 THz range. When VO2 is in the insulating state, the absorption in this band is down to near 0%. Moreover, this high absorption band shows a good polarization insensitive property and can be maintained over a range of incident angles up to 45°. Our proposed device exhibits the merits of wideband reconfigure absorbance in THz, and the absorber can be easily fabricated without involving any lithographic process, both of which are very attractive to potential THz applications such as sensing, camouflaging, and modulation of THz waves.

7.
Sheng Li Xue Bao ; 55(4): 388-94, 2003 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-12937816

RESUMO

The effect of bombesin (BOM) on non-cholinergic excitatory synaptic transmission of the guinea pig inferior mesenteric ganglion (IMG) was investigated by intracellular recording. Repetitive stimulation of the colon nerves (1 ms, 25 Hz, 4 s) elicited a burst of action potentials, which was followed by a long-lasting depolarization in 74.3% (52/70) of the IMG neurons. The depolarization was not blocked by nicotinic (d-tubocurarine, 100 micromol/L) and muscarinic (atropine, 1 micromol/L) antagonists, but was eliminated in a low Ca(2+)/high Mg(2+) Krebs solution, indicating that the depolarization was due to the release of non-cholinergic transmitters. Superfusing the ganglia with BOM (10 micromol/L, 1 min) induced a slow depolarization in 66.5% (109/164) neurons tested. The BOM response was not appreciably changed in low Ca(2+)/high Mg(2+) Krebs solution (n=6, P>0.05), suggesting that BOM depolarized the neurons by acting directly on the postsynaptic membrane rather than via a release of other endogenous depolarizing substances. In a total of 102 cells that exhibited late slow excitatory postsynaptic potential (ls-EPSP), superfusion of the ganglia with BOM produced a membrane depolarization in 82 neurons (80%), while the remaining 20 cells (20%) exhibited no response to BOM. In 18 neurons with ls-EPSP, 4 (22%) neurons were sensitive to both BOM and SP; 6 (33%) and 5 (28%) neurons were only sensitive to BOM and SP, respectively. The remaining 3 (17%) neurons were insensitive to both BOM and SP. Membrane resistance (Rm) had no apparent change in 47.3%, 59.5 % of the neurons tested during the ls-EPSP (n=55) and BOM depolarization (n=84), respectively, but had a marked decrease in 38.2%, 27.4%, and a marked increase in the remaining 14.5%, 13.1% of the neurons. However, when the Rm change accompanying ls-EPSP was compared with that accompanying BOM depolarization (n=20) in the same neuron, the changes in Rm were always parallel. Moreover, ls-EPSP (n=6) and BOM depolarization (n=8) were all augmented by conditioning hyperpolarization. The extrapolated values of the reversal potentials of ls-EPSP and BOM depolarization were 46.0+/-8.0 and 50.0+/-7.0 mV (n=8, P>0.05), respectively. In 14 BOM-sensitive neurons, a ls-EPSP was elicited by repetitive colon nerve stimulation. Superfusion of BOM (10 micromol/L) in these cells initially caused a large depolarization and then membrane potential gradually subsided to resting level in the continuous presence of BOM. Stimulation of the presynaptic nerves at this time failed to elicit a detecable ls-EPSP in 2 neurons and induced a much smaller one in 10 cells, while the ls-EPSP in the remaining 2 neurons was not appreciably affected. On the other hand, prolonged superfusion of BOM had no effect on the amplitude and duration of ls-EPSP in 6 BOM-insensititive neurons studied (P>0.05). The amplitude and duration of SP-induced depolarization were not altered by prolonged superfusion of BOM (n=4, P>0.05) Superfusion of tyr(4) D-phe(12) bombesin (1 micromol/L, 10 15 min), a BOM receptor antagonist, did not cause any noticeable changes in passive membrane properties nor block nicotinic f-EPSPs, but markedly suppressed (n=5) or completely abolished (n=11) BOM depolarization in all 16 neurons tested Similarly, tyr(4) D-phe(12) bombesin partially or completely antagonized the ls-EPSP in 9 out of a total of BOM sensitive neurons (n=11). The ls-EPSP elicited in the remaining two neurons was insignificantly affected by this drug. However, following 10 20 min of wash with Krebs solution the ls-EPSP was reversed. In contrast, superfusion of the ganglia with tyr(4) D-phe(12) bombesin did not change the amplitude and duration (P>0.05) of ls-EPSP in 10 BOM-insensitive cells. Similarly, the amplitude and duration of SP-induced depolarization were not appreciably affected by tyr(4) D-phe(12) bombesin (n=6, P>0.05). In conclusion, our results indicate that BOM may be another transmitter mediating the ls-EPSP in the guinea pig IMG and that there is no cross-desensitization of BOM receptors and SP receptors.


Assuntos
Bombesina/farmacologia , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Gânglios Simpáticos/fisiologia , Transmissão Sináptica/efeitos dos fármacos , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Estimulação Elétrica , Potenciais Pós-Sinápticos Excitadores/fisiologia , Feminino , Gânglios Simpáticos/efeitos dos fármacos , Cobaias , Técnicas In Vitro , Masculino
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