Topology is being widely adopted to understand and to categorize quantum matter in modern physics. The nexus of topology orders, which engenders distinct quantum phases with benefits to both fundamental research and practical applications for future quantum devices, can be driven by topological phase transition through modulating intrinsic or extrinsic ordering parameters. The conjoined topology, however, is still elusive in experiments due to the lack of suitable material platforms. Here we use scanning tunneling microscopy, angle-resolved photoemission spectroscopy, and theoretical calculations to investigate the doping-driven band structure evolution of a quasi-one-dimensional material system, bismuth halide, which contains rare multiple band inversions in two time-reversal-invariant momenta. According to the unique bulk-boundary correspondence in topological matter, we unveil a composite topological phase, the coexistence of a strong topological phase and a high-order topological phase, evoked by the band inversion associated with topological phase transition in this system. Moreover, we reveal multiple-stage topological phase transitions by varying the halide element ratio: from high-order topology to weak topology, the unusual dual topology, and trivial/weak topology subsequently. Our results not only realize an ideal material platform with composite topology, but also provide an insightful pathway to establish abundant topological phases in the framework of band inversion theory.
Abstract Background: Rice is a temperature-sensitive crop that can sustain dramatic damage from low temperatures. Overexpression of the Lsi1 gene ( Lsi1 -OX) in rice enhances its chilling tolerance. This study revealed that a serine hydroxymethyltransferase ( Os SHMT) mainly localised in the endoplasmic reticulum (ER) is involved in increasing tolerance to chilling. Results: A higher transcription level of Os SHMT was detected in Lsi1 -OX rice than in the wild type. Histone H1 and nucleic acid binding protein were found to bind to the promoter region of OsSHMT and regulate its expression, and the transcription levels of these proteins were also up-regulated in the Lsi1 -OX rice. Moreover, Os SHMT interacts with ATP synthase subunit α, heat shock protein Hsp70, mitochondrial substrate carrier family protein, ascorbate peroxidase 1 and ATP synthase subunit β. Lsi1 -encoded protein Os NIP2;1 also interacts with ATP synthase subunit β, and the coordination of these proteins appears to function in reducing reactive oxygen species, as the H 2 O 2 content of transgenic OsSHMT Arabidopsis thaliana was lower than that of the non-transgenic line under chilling treatment. Conclusions: Our results indicate that ER-localised Os SHMT plays a role in scavenging H 2 O 2 to enhance the chilling tolerance of Lsi1 -OX rice and that ATP synthase subunit β is an intermediate junction between Lsi1 and Os SHMT.
The antibiotic resistance ( ARE ) subfamily of ABC ( ATP ‐binding cassette) proteins confers resistance to a variety of clinically important ribosome‐targeting antibiotics and plays an important role in infections caused by pathogenic bacteria. However, inhibitors of ARE proteins have rarely been reported. Here, OptrA, a new member of the ARE proteins, was used to study inhibitors of these types of proteins. We first confirmed that destroying the catalytic activity of OptrA could restore the sensitivity of host cells to antibiotics. Then, fragment‐based screening, a drug screening method, was used to screen for inhibitors of OptrA. The competitive saturation transfer difference experiments, docking, and molecular dynamics were used to determine the binding sites and mode of interactions between OptrA and fragment screening hits. In this study, we first find a novel and specific inhibitor of OptrA ( CP 1), which suppressed the ATP ase activity of OptrA in vitro by 30%. A hydrogen bond formed between the 8‐position phenylcyclic cyano group in CP 1 and the amino acid residue Lys‐271 allows CP 1 to form a stable complex with OptrA protein. These findings provide a theoretical basis for the further optimization of the inhibitor structure to obtain inhibitors with higher efficiencies.
The optical technique of imaging through scattering media based on the optical memory effect (OME) sustains a limited field-of-view (FOV). Therefore, a prior-free imaging method is proposed to reconstruct multiple objects through the scattering media beyond the OME range. Based on the mixed speckle simplex separation strategy designed in this method, separating speckles of sub-objects is simplified as seeking the vertices of the mixed speckle simplex. An effective initial analysis of the mixed speckle simplex constructed by random intensity modulation is provided by vertex component analysis. The exact speckles of sub-objects are then separated by the specially designed non-negative matrix factorization algorithm. The multiple hidden objects can be recovered from the separated speckles respectively. The feasibility and imaging effects of the proposed method have been demonstrated via experiments. Multi-object imaging through the scattering media beyond at least four times the OME range has been realized. This work effectively advances speckle separation strategies to enlarge the limited FOV for imaging through scattering media.
The ability to form biofilms on surfaces makes Staphylococcus aureus the main pathogenic factor in implanted medical device infections. The aim of this study was to discover a biofilm inhibitor distinct from the antibiotics used to prevent infections resulting from S. aureus biofilms. Here, we describe kaempferol, a small molecule with anti-biofilm activity that specifically inhibited the formation of S. aureus biofilms. Crystal violet (CV) staining and fluorescence microscopy clearly showed that 64 μg/ml kaempferol inhibited biofilm formation by 80%. Meanwhile, the minimum inhibitory concentration (MIC) and growth curve results indicated that kaempferol had no antibacterial activity against the tested bacterial strain. Kaempferol inhibited the primary attachment phase of biofilm formation, as determined by a fibrinogen-binding assay. Moreover, a fluorescence resonance energy transfer (FRET) assay and quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) analyses revealed that kaempferol reduced the activity of S. aureus sortaseA (SrtA) and the expression of adhesion-related genes. Based on these results, kaempferol provides a starting point for the development of novel anti-biofilm drugs, which may decrease the risk of bacterial drug resistance, to prevent S. aureus biofilm-related infections.
Hypertension (HT) is the most common public-health challenge and shows a high incidence around the world. Cardiovascular diseases are the leading cause of mortality and morbidity among the elderly (age > 65 years) in the United States. Now, there is widespread acceptance of the causal link between HT and acute myocardial infarction (MI). This is the first data-mining study to identify co-expressed differentially expressed genes (co-DEGs) between HT and MI (relative to normal control) and to uncover potential biomarkers and therapeutic targets of HT-related MI. In this manuscript, HT-specific DEGs and MI-specific DEGs and differentially expressed microRNAs (DE-miRNAs) were identified in Gene Expression Omnibus (GEO) datasets GSE24752, GSE60993, GSE62646, and GSE24548 after data consolidation and batch correction. Subsequently, enrichment in Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways as well as protein–protein interaction networks were identified, and single-gene gene set enrichment analysis was performed to determine the affected biological categories and networks. Cross-matching of the results on co-DE-miRNAs and predicted miRNAs targeting the co-DEGs was conducted and discussed as well. We found that MYC and HIST1H2BO may be associated with HT, whereas FCGR1A, FYN, KLRD1, KLRB1, and FOLR3 may be implicated in MI. Moreover, co-DEGs FOLR3 and NFE2 with predicted miRNAs and DE-miRNAs, especially miR-7 and miR-548, may be significantly associated and show huge potential as a new set of novel biomarkers and important molecular targets in the course of HT-related MI.
Abstract Studies on the roles of long non‐coding RNA in atherosclerosis (AS) have been extensively explored. However, the action of lncRNA highly upregulated in liver cancer (HULC) in AS still needs in‐depth investigations. Hence, this study is launched towards the translation of HULC‐oriented mechanism in AS. Mouse AS models were established by high cholesterol and high fat feeding. AS mice were injected with restored HULC or phosphatidylinositide 3‐kinase/protein kinase B (PI3K/AKT) signaling pathway inhibitor to explore their roles in AS. Blood lipid, inflammation and oxidative stress were detected as well as HULC, PI3K, phosphated‐PI3K (p‐PI3K), AKT, p‐AKT, and aortic vascular cell apoptosis were determined. HULC was poorly expressed, p‐PI3K and p‐AKT were highly expressed in AS. HULC inhibited the PI3K/AKT signaling pathway. In AS, by inhibition of PI3K/AKT signaling pathway, restored HULC restrained atherosclerotic plaque formation, alleviated aortic intimal damage and reduced collagen fiber content in aorta, down‐regulated blood lipid levels, and inhibited inflammation, oxidative stress and aortic vascular cell apoptosis. Our study elucidates that HULC alleviates AS via inhibition of the PI3K/AKT signaling pathway, which provides a potential biomarker for treatment of AS.
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