HapX-mediated H2B deub1 and SreA-mediated H2A.Z deposition coordinate in fungal iron resistance.

Plant pathogens are challenged by host-derived iron starvation or excess during infection, but the mechanism through which pathogens counteract iron stress is unclear. Here, we found that Fusarium graminearum encounters iron excess during the colonization of wheat heads. Deletion of heme activator protein X (FgHapX), siderophore transcription factor A (FgSreA) or both attenuated virulence. Further, we found that FgHapX activates iron storage under iron excess by promoting histone H2B deubiquitination (H2B deub1) at the promoter of the responsible gene. Meanwhile, FgSreA is shown to inhibit genes mediating iron acquisition during iron excess by facilitating the deposition of histone variant H2A.Z and histone 3 lysine 27 trimethylation (H3K27 me3) at the first nucleosome after the transcription start site. In addition, the monothiol glutaredoxin FgGrx4 is responsible for iron sensing and control of the transcriptional activity of FgHapX and FgSreA via modulation of their enrichment at target genes and recruitment of epigenetic regulators, respectively. Taken together, our findings elucidated the molecular mechanisms for adaptation to iron excess mediated by FgHapX and FgSreA during infection in F. graminearum and provide novel insights into regulation of iron homeostasis at the chromatin level in eukaryotes.

Radix Bupleuri-Radix Paeoniae Alba Inhibits the Development of Hepatocellular Carcinoma through Activation of the PTEN/PD-L1 Axis within the Immune Microenvironment.

OBJECTIVE: This study investigated how Radix Bupleuri-Radix Paeoniae Alba (BP) was active against hepatocellular carcinoma (HCC). METHODS: Traditional Chinese medicine systems pharmacology (TCMSP) database was employed to determine the active ingredients of BP and potential targets against HCC. Molecular docking analysis verified the binding activity of PTEN with BP ingredients. H22 cells were used to establish an HCC model in male balb/c mice. Immunofluorescence staining, immunohistochemistry, flow cytometry, western blotting, enzyme-linked immunosorbent assay, and real-time quantitative PCR were used to study changes in proliferation, apoptosis, PTEN levels, inflammation, and T-cell differentiation in male balb/c mice. RESULTS: The major active ingredients in BP were found to be quercetin, kaempferol, isorhamnetin, stigmasterol, and beta-sitosterol. Molecular docking demonstrated that these five active BP ingredients formed a stable complex with PTEN. BP exhibited an anti-tumor effect in our HCC mouse model. BP was found to increase the CD8+ and IFN-γ+/CD4+ T cell levels while decreasing the PD-1+/CD8+ T and Treg cell levels in HCC mice. BP up-regulated the IL-6, IFN-γ, and TNF-α levels but down-regulated the IL-10 levels in HCC mice. After PTEN knockdown, BP-induced effects were abrogated. CONCLUSION: BP influenced the immune microenvironment through activation of the PTEN/PD-L1 axis, protecting against HCC.

Finite temperature dynamics of the Holstein-Tavis-Cummings model.

By employing the numerically accurate multiple Davydov Ansatz (mDA) formalism in combination with the thermo-field dynamics (TFD) representation of quantum mechanics, we systematically explore the influence of three parameters-temperature, photonic-mode detuning, and qubit-phonon coupling-on population dynamics and absorption spectra of the Holstein-Tavis-Cummings (HTC) model. It is found that elevated qubit-phonon couplings and/or temperatures have a similar impact on all dynamic observables: they suppress the amplitudes of Rabi oscillations in photonic populations as well as broaden the peaks and decrease their intensities in the absorption spectra. Our results unequivocally demonstrate that the HTC dynamics is very sensitive to the concerted variation of the three aforementioned parameters, and this finding can be used for fine-tuning polaritonic transport. The developed mDA-TFD methodology can be efficiently applied for modeling, predicting, optimizing, and comprehensively understanding dynamic and spectroscopic responses of actual molecular systems in microcavities.

Probing avoided crossings and conical intersections by two-pulse femtosecond stimulated Raman spectroscopy: Theoretical study.

This study leverages two-pulse femtosecond stimulated Raman spectroscopy (2FSRS) to characterize molecular systems with avoided crossings (ACs) and conical intersections (CIs) in their low-lying excited electronic states. By simulating 2FSRS spectra of microscopically inspired ACs and CIs models, we demonstrate that 2FSRS not only delivers valuable information on the molecular parameters characterizing ACs and CIs but also helps distinguish between these two systems.

[Bupleuri Radix-Paeoniae Radix Alba medicated plasma exerts effects on HepG2 hepatoma cells by regulating miR-1297/PTEN signaling axis].

The present study aimed to investigate the effect and mechanism of Bupleuri Radix-Paeoniae Radix Alba medicated plasma on HepG2 hepatoma cells by regulating the microRNA-1297(miR-1297)/phosphatase and tensin homologue deleted on chromosome 10(PTEN) signaling axis. Real-time quantitative PCR(RT-qPCR) was carried out to determine the mRNA levels of miR-1297 and PTEN in different hepatoma cell lines. The dual luciferase reporter assay was employed to verify the targeted interaction between miR-1297 and PTEN. The cell counting kit-8(CCK-8) was used to detect cell proliferation, and the optimal concentration and intervention time of the medicated plasma were determined. The cell invasion and migration were examined by Transwell assay and wound healing assay. Cell cycle distribution was detected by PI staining, and the apoptosis of cells was detected by Annexin V-FITC/PI double staining. The mRNA levels of miR-1297, PTEN, protein kinase B(Akt), and phosphatidylinositol 3-kinase(PI3K) were determined by RT-qPCR. Western blot was employed to determine the protein levels of PTEN, Akt, p-Akt, caspase-3, caspase-9, B-cell lymphoma-2(Bcl-2), and Bcl-2-associated X protein(Bax). The results showed that HepG2 cells were the best cell line for subsequent experiments. The dual luciferase reporter assay confirmed that miR-1297 could bind to the 3'-untranslated region(3'UTR) in the mRNA of PTEN. The medicated plasma inhibited the proliferation of HepG2 cells, and the optimal intervention concentration and time were 20% and 72 h. Compared with the blank plasma, the Bupleuri Radix-Paeoniae Radix Alba medicated plasma, miR-1297 inhibitor, miR-1297 inhibitor + medicated plasma all inhibited the proliferation, invasion, and migration of HepG2 cells, increased the proportion of cells in the G_0/G_1 phase, decreased the proportion of cells in the S phase, and increased the apoptosis rate. The medicated plasma down-regulated the mRNA levels of miR-1297, PI3K, and Akt and up-regulated the mRNA level of PTEN. In addition, it up-regulated the protein levels of PTEN, Bax, caspase-3, and caspsae-9 and down-regulated the protein levels of p-Akt, p-PI3K, and Bcl-2. In conclusion, Bupleuri Radix-Paeoniae Radix Alba medicated plasma can inhibit the expression of miR-1297 in HepG2 hepatoma cells, promote the expression of PTEN, and negatively regulate PI3K/Akt signaling pathway, thereby inhibiting the proliferation and inducing the apoptosis of HepG2 cells.

On-Surface Synthesis of Silole and Disila-Cyclooctene Derivatives.

The incorporation of Si atoms into organic compounds significantly increases a variety of functionality, facilitating further applications. Recently, on-surface synthesis was introduced into organosilicon chemistry as 1,4-disilabenzene bridged nanostructures were obtained via coupling between silicon atoms and brominated phenyl groups at the ortho position on Au(111). Here, we demonstrate a high generality of this strategy via syntheses of silole derivatives and nanoribbon structures with eight-membered sila-cyclic rings from dibrominated molecules at the bay and peri positions on Au(111), respectively. Their structures and electronic properties were investigated by a combination of scanning tunneling microscopy/spectroscopy and density functional theory calculations. This work demonstrates a great potential to deal with heavy group 14 elements in on-surface silicon chemistry.

Anodal online transcranial direct current stimulation facilitates visual motion perceptual learning.

Visual perceptual learning (VPL) has great potential implications for clinical populations, but adequate improvement often takes weeks to months to obtain; therefore, practical applications of VPL are limited. Strategies that enhance visual performance acquisition make great practical sense. Transcranial direct current stimulation (tDCS) could be beneficial to VPL, but thus far, the results are inconsistent. The current study had two objectives: (1) to investigate the effect of anodal tDCS on VPL and (2) to determine whether the timing sequence of anodal tDCS and training influences VPL. Anodal tDCS was applied on the left human middle temporal (hMT+) during training on a coherent motion discrimination task (online), anodal tDCS was also applied before training (offline) and sham tDCS was applied during training (sham). The coherent thresholds were measured without stimulation before, 2 days after and 1 month after training. All participants trained for five consecutive days. Anodal tDCS resulted in more performance improvement when applied during daily training but not when applied before training. Additionally, neither within-session improvement nor between-session improvement differed among the online, offline and sham tDCS conditions. These findings contribute to the development of efficient stimulation protocols and a deep understanding of the mechanisms underlying the effect of tDCS on VPL.

SUMOylation regulates low-temperature survival and oxidative DNA damage tolerance in Botrytis cinerea.

SUMOylation as one of the protein post-translational modifications plays crucial roles in multiple biological processes of eukaryotic organisms. Botrytis cinerea is a devastating fungal pathogen and capable of infecting plant hosts at low temperature. However, the molecular mechanisms of low-temperature adaptation are largely unknown in fungi. Combining with biochemical methods and biological analyses, we report that SUMOylation regulates pathogen survival at low temperature and oxidative DNA damage response during infection in B. cinerea. The heat shock protein (Hsp70) BcSsb and E3 ubiquitin ligase BcRad18 were identified as substrates of SUMOylation; moreover, their SUMOylation both requires a single unique SUMO-interacting motif (SIM). SUMOylated BcSsb regulates ß-tubulin accumulation, thereby affecting the stability of microtubules and consequently mycelial growth at low temperature. On the contrary, SUMOylated BcRad18 modulates mono-ubiquitination of the sliding clamp protein proliferating cell nuclear antigen (PCNA), which is involved in response to oxidative DNA damage during infection. Our study uncovers the molecular mechanisms of SUMOylation-mediated low-temperature survival and oxidative DNA damage tolerance during infection in a devastating fungal pathogen, which provides novel insights into low-temperature adaptation and pathogenesis for postharvest pathogens as well as new targets for inhibitor invention in disease control.

SUMOylation regulates pre-mRNA splicing to overcome DNA damage in fungi.

Pathogenic fungi are subject to DNA damage stress derived from host immune responses during infection. Small ubiquitin-like modifier (SUMO) modification and precursor (pre)-mRNA splicing are both involved in DNA damage response (DDR). However, the mechanisms of how SUMOylation and splicing coordinated in DDR remain largely unknown. Combining with biochemical analysis, RNA-Seq method, and biological analysis, we report that SUMO pathway participates in DDR and virulence in Fusarium graminearum, a causal agent of Fusarium head blight of cereal crops world-wide. Interestingly, a key transcription factor FgSR is SUMOylated upon DNA damage stress. SUMOylation regulates FgSR nuclear-cytoplasmic partitioning and its phosphorylation by FgMec1, and promotes its interaction with chromatin remodeling complex SWI/SNF for activating the expression of DDR-related genes. Moreover, the SWI/SNF complex was found to further recruit splicing-related NineTeen Complex, subsequently modulates pre-mRNA splicing during DDR. Our findings reveal a novel function of SUMOylation in DDR by regulating a transcription factor to orchestrate gene expression and pre-mRNA splicing to overcome DNA damage during the infection of F. graminearum, which advances the understanding of the delicate regulation of DDR by SUMOylation in pathogenic fungi, and extends the knowledge of cooperation of SUMOylation and pre-mRNA splicing in DDR in eukaryotes.

Strain-Sensitive On-Surface Ladderization by Non-Dehydrogenative Heterocyclization.

On-surface cyclodehydrogenation recently became an important reaction to planarize π-conjugated molecules and oligomers. However, the high-activation barrier to cleave the C-H bond often requires high-temperature annealing, consequently restricting structures of precursor molecules and/or leading to random fusion at their edges. Here, we present a synthesis of pyrrolopyrrole-bridged ladder oligomers from 11,11,12,12-tetrabromo-1,4,5,8-tetraaza-9,10-anthraquinodimethane molecules on Ag(111) with bond-resolved scanning tunnelling microscopy. This non-dehydrogenative cyclization between pyrazine and ethynylene/cumulene groups has a low-activation barrier for forming intermediary dimeric oligomer containing dipyrazinopyrrolopyrrolopyrazine units, thus giving new insight into the strain-sensitive in ladder-oligomer formation.

Ab initio simulation of peak evolutions and beating maps for electronic two-dimensional signals of a polyatomic chromophore.

By employing the doorway-window (DW) on-the-fly simulation protocol, we performed ab initio simulations of peak evolutions and beating maps of electronic two-dimensional (2D) spectra of a polyatomic molecule in the gas phase. As the system under study, we chose pyrazine, which is a paradigmatic example of photodynamics dominated by conical intersections (CIs). From the technical perspective, we demonstrate that the DW protocol is a numerically efficient methodology suitable for simulations of 2D spectra for a wide range of excitation/detection frequencies and population times. From the information content perspective, we show that peak evolutions and beating maps not only reveal timescales of transitions through CIs but also pinpoint the most relevant coupling and tuning modes active at these CIs.

Contracted description of driven degenerate multilevel quantum systems.

We formulate a contraction theorem that maps quantum dynamics of a multilevel degenerate system (DS) driven by a time-dependent external field to the dynamics of the corresponding contracted non-degenerate system (CNS) of lower dimension, provided transitions between each pair of degenerate levels in the DS have identical transition dipole moments. The theorem is valid for an external field of any strength and shape, with and without rotating wave approximation in the system-field interaction. It establishes explicit relations between DS and CNS observables, significantly simplifies numerical calculations, and clarifies physical origins of the field-induced DS dynamics.

Research and Application of Contactless Measurement of Transformer Winding Tilt Angle Based on Machine Vision.

In the process of producing winding coils for power transformers, it is necessary to detect the tilt angle of the winding, which is one of the important parameters that affects the physical performance indicators of the transformer. The current detection method is manual measurement using a contact angle ruler, which is not only time-consuming but also has large errors. To solve this problem, this paper adopts a contactless measurement method based on machine vision technology. Firstly, this method uses a camera to take pictures of the winding image and performs a 0° correction and preprocessing on the image, using the OTSU method for binarization. An image self-segmentation and splicing method is proposed to obtain a single-wire image and perform skeleton extraction. Secondly, this paper compares three angle detection methods: the improved interval rotation projection method, quadratic iterative least squares method, and Hough transform method and through experimental analysis, compares their accuracy and operating speed. The experimental results show that the Hough transform method has the fastest operating speed and can complete detection in an average of only 0.1 s, while the interval rotation projection method has the highest accuracy, with a maximum error of less than 0.15°. Finally, this paper designs and implements visualization detection software, which can replace manual detection work and has a high accuracy and operating speed.

Magnetism in Nonplanar Zigzag Edge Termini of Graphene Nanoribbons.

Graphene nanoribbons (GNRs) and nanographenes synthesized by on-surface reactions using tailor-made molecular precursors offer an ideal playground for a study of magnetism towards nano-spintronics. Although the zigzag edge of GNRs has been known to host magnetism, the underlying metal substrates usually veil the edge-induced Kondo effect. Here, we report the on-surface synthesis of unprecedented, π-extended 7-armchair GNRs using 7-bromo-12-(10-bromoanthracen-9-yl)tetraphene as the precursor. Characterization by scanning tunneling microscopy/spectroscopy revealed unique rearrangement reactions leading to pentagon- or pentagon/heptagon-incorporated, nonplanar zigzag termini, which demonstrated Kondo resonances even on bare Au(111). Density functional theory calculations indicate that the nonplanar structure significantly reduces the interaction between the zigzag terminus and the Au(111) surface, leading to a recovery of the spin localization of the zigzag edge. Such a distortion of planar GNR structures offers a degree of freedom to control the magnetism on metal substrates.

Multiple molecular interactions between alkyl groups and dissociated bromine atoms on Ag(111).

Multiple intermolecular interactions offer a high degree of controllability of on-surface molecular assemblies. Here, two kinds of molecular networks were formed by depositing 11,11,12,12-tetrabromo-1,4,5,8-tetraaza-9,10-anthraquinodimethane derivatives with two different alkyl groups in length (C4 and C8) on clean Ag(111) surfaces under ultrahigh vacuum. The detailed structures of each network before and after the cleavage of the C-Br bonds were investigated with high-resolution scanning tunneling microscopy at low temperature. We found that the diffusion of the Br atoms by high-temperature annealing plays a role in the formation of Br-mediated self-assembly. While dissociated Br atoms interacted with alkyl groups by hydrogen bonding through C-H⋯Br contacts in both systems, the different strengths of the van der Waals interactions between the alkyl groups resulted in the formation of different structures.

Simulation of Emission Spectra of Transition Metal Dichalcogenide Monolayers with the Multimode Brownian Oscillator Model.

The multimode Brownian oscillator model is employed to simulate the emission spectra of transition metal dichalcogenide (TMD) monolayers. Good agreement is obtained between measured and simulated photoluminescence spectra of WSe2, WS2, MoSe2, and MoS2 at various temperatures. The Huang-Rhys factor extracted from the model can be associated with that from the modified semiempirical Varshni equation at high temperatures. Individual mechanisms leading to the unique temperature-dependent emission spectra of those TMDs are validated by the multimode Brownian oscillator (MBO) fitting, while it is, in turn, confirmed that the MBO analysis is an effective method for studying the optical properties of TMD monolayers. Parameters extracted from the MBO fitting can be used to explore exciton-photon-phonon dynamics of TMDs in a more comprehensive model.

The Importin FgPse1 Is Required for Vegetative Development, Virulence, and Deoxynivalenol Production by Interacting with the Nuclear Polyadenylated RNA-Binding Protein FgNab2 in Fusarium graminearum.

Karyopherins are involved in transport through nuclear pore complexes. Karyopherins are necessary for nuclear import and export pathways and bind to their cargos. Polyadenylation of messenger RNA (mRNA) is necessary for various biological processes, regulating gene expression in eukaryotes. Until now, the association of karyopherin with mRNA polyadenylation has been less understood in plant pathogenic fungi. In our study, we focused on the biological functions of the karyopherin FgPse1 in Fusarium graminearum. The results showed that FgPse1 is involved in mycelial growth, asexual reproduction, virulence, and deoxynivalenol (DON) production. Co-immunoprecipitation and bimolecular fluorescence complementation showed that FgPse1 interacts with the nuclear polyadenylated RNA-binding protein FgNab2. Moreover, a fluorescence localization assay indicated that FgPse1 is necessary for the nuclear import of FgNab2. The nuclear import of FgNab2 regulates the expression of FgTri4, FgTri5, and FgTri6, which are essential for DON production. Thus, ΔFgPse1 and ΔFgNab2 showed consistent defects in DON production. In summary, our data indicated that FgPse1 is necessary for mycelial growth, virulence, and DON production, interacting with FgNab2 in F. graminearum. These results contribute to our understanding of the functions of importins in phytopathogenic fungi.

Dynamics of disordered Tavis-Cummings and Holstein-Tavis-Cummings models.

By employing the time-dependent variational principle and the versatile multi-D2 Davydov trial states, in combination with the Green's function method, we study the dynamics of the Tavis-Cummings model and the Holstein-Tavis-Cummings model in the presence of diagonal disorder and cavity-qubit coupling disorder. For the Tavis-Cummings model, time evolution of the photon population, the optical absorption spectra, and the hetero-entanglement between the qubits and the cavity mode are calculated by using the Green's function method to corroborate numerically exact results of Davydov's Ansätze. For the Holstein-Tavis-Cummings model, only the latter is utilized to simulate effects of disorder on the photon population dynamics and the absorption spectra. We have demonstrated that the complementary employment of analytical and numerical methods permits uncovering a fairly comprehensive picture of a variety of complex behaviors in disordered multidimensional polaritonic cavity quantum electrodynamics systems.

Near Fermi Superatom State Stabilized by Surface State Resonances in a Multiporous Molecular Network.

Two-dimensional honeycomb molecular networks confine a substrate's surface electrons within their pores, providing an ideal playground to investigate the quantum electron scattering phenomena. Besides surface state confinement, laterally protruding organic states can collectively hybridize at the smallest pores into superatom molecular orbitals. Although both types of pore states could be simultaneously hosted within nanocavities, their coexistence and possible interaction are unexplored. Here, we show that these two types of pore states do coexist within the smallest nanocavities of a two-dimensional halogen-bonding multiporous network grown on Ag(111) studied using a combination of scanning tunneling microscopy and spectroscopy, density functional theory calculations, and electron plane wave expansion simulations. We find that superatom molecular orbitals undergo an important stabilization when hybridizing with the confined surface state, following the significant lowering of its free-standing energy. These findings provide further control over the surface electronic structure exerted by two-dimensional nanoporous systems.

The influence of 'deliberate' implementation intention on medical students' risk decision task outcomes.

Implementation intention is a kind of behaviour choice strategy in which individuals adopt specific and definite behaviour patterns to achieve behavioural goals. The standard form is 'if something happens, then I will do something'. Previous studies have shown that implementation intention strategy is a fast and effective mental skill with notable advantages. However, adding the requirement of 'deliberate' to the implementation plan will increase the probability of decision adjustment to a certain extent. In this study, the classic Balloon Analogue Risk Task (BART) was selected as the evaluation index of risk decision-making, and the 'deliberate' implementation intention was adopted to explore the impact of this behavioural strategy on risk selection. The recruited medical students were divided into two groups: the implementation intention group (n = 37) and the control group (n = 34). The baseline assessment for the BART was performed by all participants, and the intensive training of 'deliberate' implementation intention to 'make as much money as possible' was conducted before the post-test decision-making after one week. The adjusted BART (adj BART) value and AvgIncome were significantly higher than those at baseline in the implementation intention group(adj BART value: baseline 12.63 ± 2.90, post-test: 14.78 ± 2.66, F = 15.978, p < 0.001, η 2 = 0.307; AvgIncome: baseline 12.43 ± 2.56, post-test 15.00 ± 2.57, F = 20.953, p < 0.001, η 2 = 0.368). The mixed-model ANOVAs showed that there was a significant interaction between test time and group (adj BART value: F = 4.859, p = 0.031, η 2 = 0.066; AvgIncome: F = 4.261, p = 0.043, η 2 = 0.058). Conclusion: The implementation of 'deliberate' intention can help medical students make more rational judgements in risk decision-making tasks, avoid over conservative behaviour and obtain more benefits.