RNA-Seq Provides Insights into the Mechanisms Underlying Ilyonectria robusta Responding to Secondary Metabolites of Bacillus methylotrophicus NJ13.

(1) Background: Ilyonectria robusta can cause ginseng to suffer from rusty root rot. Secondary metabolites (SMs) produced by Bacillus methylotrophicus NJ13 can inhibit the mycelial growth of I. robusta. However, the molecular mechanism of the inhibition and response remains unclear. (2) Methods: Through an in vitro trial, the effect of B. methylotrophicus NJ13's SMs on the hyphae and conidia of I. robusta was determined. The change in the physiological function of I. robusta was evaluated in response to NJ13's SMs by measuring the electrical conductivity, malondialdehyde (MDA) content, and glucose content. The molecular interaction mechanism of I. robusta's response to NJ13's SMs was analyzed by using transcriptome sequencing. (3) Results: NJ13's SMs exhibited antifungal activity against I. robusta: namely, the hyphae swelled and branched abnormally, and their inclusions leaked out due to changes in the cell membrane permeability and the peroxidation level; the EC50 value was 1.21% (v/v). In transcripts at 4 dpi and 7 dpi, the number of differentially expressed genes (DEGs) (|log2(fold change)| > 1, p adj ≤ 0.05) was 1960 and 354, respectively. NJ13's SMs affected the glucose metabolism pathway, and the sugar-transporter-related genes were downregulated, which are utilized by I. robusta for energy production. The cell wall structure of I. robusta was disrupted, and chitin-synthase-related genes were downregulated. (4) Conclusions: A new dataset of functional responses of the ginseng pathogenic fungus I. robusta was obtained. The results will benefit the development of targeted biological fungicides for I. robusta and the study of the molecular mechanisms of interaction between biocontrol bacteria and phytopathogenic fungi.

Luminescent Hydrogel Based on Silver Nanocluster/Malic Acid and Its Composite Film for Highly Sensitive Detection of Fe3.

Metal nanoclusters (NCs) with excellent photoluminescence properties are an emerging functional material that have rich physical and chemical properties and broad application prospects. However, it is a challenging problem to construct such materials into complex ordered aggregates and cause aggregation-induced emission (AIE). In this article, we use the supramolecular self-assembly strategy to regulate a water-soluble, atomically precise Ag NCs (NH4)9[Ag9(C7H4SO2)9] (Ag9-NCs, [Ag9(mba)9], H2mba = 2-mercaptobenzoic acid) and L-malic acid (L-MA) to form a phosphorescent hydrogel with stable and bright luminescence, which is ascribed to AIE phenomenon. In this process, the AIE of Ag9-NCs could be attributed to the non-covalent interactions between L-MA and Ag9-NCs, which restrict the intramolecular vibration and rotation of ligands on the periphery of Ag9-NCs, thus inhibiting the ligand-related, non-radiative excited state relaxation and promoting radiation energy transfer. In addition, the fluorescent Ag9-NCs/L-MA xerogel was introduced into polymethylmethacrylate (PMMA) to form an excellently fluorescent film for sensing of Fe3+. Ag9-NCs/L-MA/PMMA film exhibits an excellent ability to recognize Fe3+ ion with high selectivity and a low detection limit of 0.3 µM. This research enriches self-assembly system for enhancing the AIE of metal NCs, and the prepared hybrid films will become good candidates for optical materials.

Mobility Extraction in 2D Transition Metal Dichalcogenide Devices-Avoiding Contact Resistance Implicated Overestimation.

Schottky barrier (SB) transistors operate distinctly different from conventional metal-oxide semiconductor field-effect transistors, in a unique way that the gate impacts the carrier injection from the metal source/drain contacts into the channel region. While it has been long recognized that this can have severe implications for device characteristics in the subthreshold region, impacts of contact gating of SB in the on-state of the devices, which affects evaluation of intrinsic channel properties, have been yet comprehensively studied. Due to the fact that contact resistance (RC ) is always gate-dependent in a typical back-gated device structure, the traditional approach of deriving field-effect mobility from the maximum transconductance (gm ) is in principle not correct and can even overestimate the mobility. In addition, an exhibition of two different threshold voltages for the channel and the contact region leads to another layer of complexity in determining the true carrier concentration calculated from Q = COX * (VG -VTH ). Through a detailed experimental analysis, the effect of different effective oxide thicknesses, distinct SB heights, and doping-induced reductions in the SB width are carefully evaluated to gain a better understanding of their impact on important device metrics.

Light-Emitting Diodes Based on Colloidal Silicon Quantum Dots with Octyl and Phenylpropyl Ligands.

Colloidal silicon quantum dots (Si QDs) hold ever-growing promise for the development of novel optoelectronic devices such as light-emitting diodes (LEDs). Although it has been proposed that ligands at the surface of colloidal Si QDs may significantly impact the performance of LEDs based on colloidal Si QDs, little systematic work has been carried out to compare the performance of LEDs that are fabricated using colloidal Si QDs with different ligands. Here, colloidal Si QDs with rather short octyl ligands (Octyl-Si QDs) and phenylpropyl ligands (PhPr-Si QDs) are employed for the fabrication of LEDs. It is found that the optical power density of PhPr-Si QD LEDs is larger than that of Octyl-Si QD LEDs. This is due to the fact that the surface of PhPr-Si QDs is more oxidized and less defective than that of Octyl-Si QDs. Moreover, the benzene rings of phenylpropyl ligands significantly enhance the electron transport of QD LEDs. It is interesting that the external quantum efficiency (EQE) of PhPr-Si QD LEDs is lower than that of Octyl-Si QD LEDs because the benzene rings of phenylpropyl ligands suppress the hole transport of QD LEDs. The unbalance between the electron and hole injection in PhPr-Si QD LEDs is more serious than that in Octyl-Si QD LEDs. The currently obtained highest optical power density of ∼0.64 mW/cm2 from PhPr-Si QD LEDs and highest EQE of ∼6.2% from Octyl-Si QD LEDs should encourage efforts to further advance the development of high-performance optoelectronic devices based on colloidal Si QDs.

Subjective and Objective Video Quality Assessment of 3D Synthesized Views With Texture/Depth Compression Distortion.

The quality assessment for synthesized video with texture/depth compression distortion is important for the design, optimization, and evaluation of the multi-view video plus depth (MVD)-based 3D video system. In this paper, the subjective and objective studies for synthesized view assessment are both conducted. First, a synthesized video quality database with texture/depth compression distortion is presented with subjective scores given by 56 subjects. The 140 videos are synthesized from ten MVD sequences with different texture/depth quantization combinations. Second, a full reference objective video quality assessment (VQA) method is proposed concerning about the annoying temporal flicker distortion and the change of spatio-temporal activity in the synthesized video. The proposed VQA algorithm has a good performance evaluated on the entire synthesized video quality database, and is particularly prominent on the subsets which have significant temporal flicker distortion induced by depth compression and view synthesis process.