Broadband and tunable fiber polarizer based on a graphene photonic crystal fiber.

The recent flourishing development of two-dimensional (2D) graphene has sparked considerable interest and extensive research on graphene-based optical fiber polarizers. However, studies on graphene-optical fiber polarizers focused on the structure with graphene films attached to side-polished fibers, which face challenges such as low birefringence of 10-6, low polarization extinction ratio (PER), and narrow polarizing window of tens of nanometers. Here, a fiber polarizer based on a graphene-photonic crystal fiber (Gr-PCF) is proposed firstly, which exhibits high birefringence of ∼2.5 × 10-3, high PER of ∼111 dB/mm, broad polarizing window of >400 nm, and tunable polarization states. Graphene or graphene/hBN/graphene (Gr/hBN/Gr) heterojunctions are attached to the surface of two square holes in the PCF to make one of the polarizing modes attenuate significantly. The tunability of the Fermi level (EF) in Gr/hBN/Gr enables the proposed device to function as a polarizer or a polarization-maintaining fiber. The combination of PCF's endless single-mode feature and graphene's broadband optical response feature enables the fiber polarizer to exhibit a wide spectrum range with single-mode transmission characteristics.

Nonvolatile Electro-optic Response of Graphene Driven by Ferroelectric Polarization.

Two-dimensional materials (2DMs) have exhibited remarkably tunable optical characteristics, which have been applied for significant applications in communications, sensing, and computing. However, the reported tunable optical properties of 2DMs are almost volatile, impeding them in the applications of multifarious emerging frameworks such as programmable operation and neuromorphic computing. In this work, nonvolatile electro-optic response is developed by the graphene-Al2O3-In2Se3 heterostructure integrating with microring resonators (MRRs). In such compact devices, the optical absorption coefficient of graphene is substantially tuned by the out-of-plane ferroelectric polarization in α-In2Se3, resulting in a nonvolatile optical transmission in MRRs. This work demonstrates that integrating graphene with ferroelectric materials paves the way to develop nonvolatile devices in photonic circuits for emerging applications such as optical neural networks.

Electrostatic Force-Assisted Transfer of Flexible Silicon Photodetector Focal Plane Arrays for Image Sensors.

Flexible photodetectors are pivotal in contemporary optoelectronic technology applications, such as data reception and image sensing, yet their performance and yield are often hindered by the challenge of heterogeneous integration between photoactive materials and flexible substrates. Here, we showcase the potential of an electrostatic force-assisted transfer printing technique for integrating Si PIN photodiodes onto flexible substrates. This clean and dry process eliminates the need for chemical etchants, making it a highly desirable method for manufacturing high-performance flexible photodetector arrays, expanding their widespread applications in electronic eyes, robotics, and human-machine interaction. As a demonstration, a 5 × 5 flexible Si photodetector focal plane array is constructed for imaging sensors and shaped into a convex semicylindrical form to achieve a π field of view with long-term mechanical and thermal stability. Such an approach provides a high yield rate and consistent performance, with the single photodetector demonstrating exceptional characteristics, including a responsivity of 0.61 A/W, a response speed of 39.77 MHz, a linear dynamic range of 108.53 dB, and a specific detectivity of 2.75 × 1012 Jones at an applied voltage of -3 V at 940 nm.

Marine sourced tripeptide SRP and its sustained-release formulation SRP-PLGA-MS exhibiting antihypertensive effect in spontaneously hypertensive rats and HUVECs.

Biopeptides from Sipunculus nudus were reported with good ACE inhibitory activity, and the tripeptide SRP was one with the highest ACE inhibition rate. However, the disadvantage of short half-life limited the development of peptide drugs. Moreover, the distinct mechanism of the peptide inhibiting ACE remained unknown. Thus, in this study, a sustained release formulation of SRP-PLGA-MS was designed and prepared. Its long-lasting antihypertensive effect as well as improvement of vascular pathomorphology was verified in spontaneously hypertensive rat (SHR). In addition, the anti-oxidant activity of SRP in human umbilical vein endothelial cells (HUVECs) was evaluated. The results showed that SRP inhibited the production of ROS and NO, which involve the NADPH oxidase, and Keap1/Nrf2 signaling pathway. This study demonstrated that SRP-PLGA-MS had the potential to develop sustained-release drugs for hypertension treatment.

Characterization and Differentiation of Grain Proteomes from Wild-Type Puroindoline and Variants in Wheat.

Premium wheat with a high end-use quality is generally lacking in China, especially high-quality hard and soft wheat. Pina-D1 and Pinb-D1 (puroindoline genes) influence wheat grain hardness (i.e., important wheat quality-related parameter) and are among the main targets in wheat breeding programs. However, the mechanism by which puroindoline genes control grain hardness remains unclear. In this study, three hard wheat puroindoline variants (MY26, GX3, and ZM1) were compared with a soft wheat variety (CM605) containing the wild-type puroindoline genotype. Specifically, proteomic methods were used to screen for differentially abundant proteins (DAPs). In total, 6253 proteins were identified and quantified via a high-throughput tandem mass tag quantitative proteomic analysis. Of the 208 DAPs, 115, 116, and 99 proteins were differentially expressed between MY26, GX3, and ZM1 (hard wheat varieties) and CM605, respectively. The cluster analysis of protein relative abundances divided the proteins into six clusters. Of these proteins, 67 and 41 proteins were, respectively, more and less abundant in CM605 than in MY26, GX3, and ZM1. Enrichment analyses detected six GO terms, five KEGG pathways, and five IPR terms that were shared by all three comparisons. Furthermore, 12 proteins associated with these terms or pathways were found to be differentially expressed in each comparison. These proteins, which included cysteine proteinase inhibitors, invertases, low-molecular-weight glutenin subunits, and alpha amylase inhibitors, may be involved in the regulation of grain hardness. The candidate genes identified in this study may be relevant for future analyses of the regulatory mechanism underlying grain hardness.

Genome-wide systematic characterization of the NRT2 gene family and its expression profile in wheat (Triticum aestivum L.) during plant growth and in response to nitrate deficiency.

BACKGROUND: Wheat (Triticum aestivum L.) is a major cereal crop that is grown worldwide, and it is highly dependent on sufficient N supply. The molecular mechanisms associated with nitrate uptake and assimilation are still poorly understood in wheat. In plants, NRT2 family proteins play a crucial role in NO3- acquisition and translocation under nitrate limited conditions. However, the biological functions of these genes in wheat are still unclear, especially their roles in NO3- uptake and assimilation. RESULTS: In this study, a comprehensive analysis of wheat TaNRT2 genes was conducted using bioinformatics and molecular biology methods, and 49 TaNRT2 genes were identified. A phylogenetic analysis clustered the TaNRT2 genes into three clades. The genes that clustered on the same phylogenetic branch had similar gene structures and nitrate assimilation functions. The identified genes were further mapped onto the 13 wheat chromosomes, and the results showed that a large duplication event had occurred on chromosome 6. To explore the TaNRT2 gene expression profiles in wheat, we performed transcriptome sequencing after low nitrate treatment for three days. Transcriptome analysis revealed the expression levels of all TaNRT2 genes in shoots and roots, and based on the expression profiles, three highly expressed genes (TaNRT2-6A.2, TaNRT2-6A.6, and TaNRT2-6B.4) were selected for qPCR analysis in two different wheat cultivars ('Mianmai367' and 'Nanmai660') under nitrate-limited and normal conditions. All three genes were upregulated under nitrate-limited conditions and highly expressed in the high nitrogen use efficiency (NUE) wheat 'Mianmai367' under low nitrate conditions. CONCLUSION: We systematically identified 49 NRT2 genes in wheat and analysed the transcript levels of all TaNRT2s under nitrate deficient conditions and over the whole growth period. The results suggest that these genes play important roles in nitrate absorption, distribution, and accumulation. This study provides valuable information and key candidate genes for further studies on the function of TaNRT2s in wheat.

Circ_0003356 suppresses gastric cancer growth through targeting the miR-668-3p/SOCS3 axis.

BACKGROUND: Circular RNAs (circRNAs) have attracted extensive attention as therapeutic targets in gastric cancer (GC). Circ_0003356 is known to be downregulated in GC tissues, but its cellular function and mechanisms remain undefined. AIM: To investigate the role of circ_0003356 in GC at the molecular and cellular level. METHODS: Circ_0003356, miR-668-3p, and SOCS3 expression were assessed via quantitative real time-polymerase chain reaction (qRT-PCR). Wound healing, EdU, CCK-8, flow cytometry and transwell assays were used to analyze the migration, proliferation, viability, apoptosis and invasion of GC cells. The subcellular localization of circ_0003356 was monitored using fluorescence in situ hybridization. The interaction of circ_0003356 with miR-668-3p was confirmed using RIP-qRT-PCR, RNA pull-down, and dual luciferase reporter assays. We observed protein levels of genes via western blot. We injected AGS cells into the upper back of mice and performed immunohistochemistry staining for examining E-cadherin, N-cadherin, Ki67, and SOCS3 expressions. TUNEL staining was performed for the assessment of apoptosis in mouse tumor tissues. RESULTS: Circ_0003356 and SOCS3 expression was downregulated in GC cells, whilst miR-668-3p was upregulated. Exogenous circ_0003356 expression and miR-668-3p silencing suppressed the migration, viability, proliferation, epithelial to mesenchy-mal transition (EMT) and invasion of GC cells and enhanced apoptosis. Circ_0003356 overexpression impaired tumor growth in xenograft mice. Targeting of miR-668-3p by circ_0003356 was confirmed through binding assays and SOCS3 was identified as a downstream target of miR-668-3p. The impacts of circ_0003356 on cell proliferation, apoptosis, migration, invasion and EMT were reversed by miR-668-3p up-regulation or SOCS3 down-regulation in GC cells. CONCLUSION: Circ_0003356 impaired GC development through its interaction with the miR-668-3p/SOCS3 axis.

Identification of qnrVF in a Multidrug-Resistant Vibrio furnissii Clinical Strain.

We found a new qnr gene, qnrVF1, carried by a multidrug resistance plasmid in a clinical Vibrio furnissii isolate. QnrVF1 exhibits 44.6% to 72.5% similarity in identity with other Qnr family proteins. QnrVF alleles are mainly encoded by chromosomes of V. furnissii and Vibrio fluvialis. Phylogenic analysis showed that QnrVF1 and QnrVF2 form a distinct clade in Qnr proteins. Thus, qnrVF represents a new qnr family. In addition, the qnrVF1 gene is often flanked by the mobile element ISCR1. Thus, it is likely that qnrVF1 is mobilized by ISCR1 from chromosome to plasmid in V. furnissii. IMPORTANCE Quinolones are widely used drugs. Bacteria contain a quinolone resistance gene, which mediates resistance to quinolones. Currently, seven families of Qnr proteins, QnrVC, QnrA, QnrB, QnrC, QnrD, QnrE, and QnrS, have been identified. However, it is unclear whether there are any other qnr families. In this study, we identified a new qnr family, qnrVF. We found many V. furnissii and V. fluvialis strains that possess chromosomal qnrVF alleles, suggesting that V. furnissii and V. fluvialis are the reservoirs of qnrVF. We also found that QnrVF1 confers low-level resistance to quinolones. ISCR1 may facilitate the spread of qnrVF1. The emergence and spread of qnrVF may pose a considerable threat to public health.

Cloning of a COBL gene determining brittleness in diploid wheat using a MapRseq approach.

Plant tissue brittleness is related to cellular structure and lodging. MED0031 is a mutant identified previously from ethyl methane sulfonate treatment of diploid wheat accession TA2726, showing brittleness in both stem and leaf. In microscopic and histological observations, the mutant was found to have less large vascular bundles per unit area, a thinner sclerenchyma cell wall, and a broader parenchyma, compared with the wild type. The mutated gene, TmBr1, was mapped to a 0.056 cM interval on chromosome 5Am. This gene was cloned using a MapRseq approach that searched the candidate gene through combination of the prior target gene mapping information with SNP calling and discovery of differentially expressed genes from RNA_seq data of the wild type and a BC3F2 bulk showing the mutant phenotype. TmBr1 encodes a COBL protein and a nonsense mutation within the region coding for the conserved COBRA domain caused premature translation termination. Introduction of TmBr1 to Arabidopsis AtCOBL4 mutant rescued the phenotype, demonstrating their functional conservation. Apart from the effect on cellulose content, the TmBr1 mutation might modulate synthesis of noncellulosic polysaccharide pectin as well. Application of the MapRseq approach to isolation of genes present in recombination cold spots and complicated genomes was discussed.

Identification of Wheat Inflorescence Development-Related Genes Using a Comparative Transcriptomics Approach.

Inflorescence represents the highly specialized plant tissue producing the grains. Although key genes regulating flower initiation and development are conserved, the mechanism regulating fertility is still not well explained. To identify genes and gene network underlying inflorescence morphology and fertility of bread wheat, expressed sequence tags (ESTs) from different tissues were analyzed using a comparative transcriptomics approach. Based on statistical comparison of EST frequencies of individual genes in EST pools representing different tissues and verification with RT-PCR and RNA-seq data, 170 genes of 59 gene sets predominantly expressed in the inflorescence were obtained. Nearly one-third of the gene sets displayed differentiated expression profiles in terms of their subgenome orthologs. The identified genes, most of which were predominantly expressed in anthers, encode proteins involved in wheat floral identity determination, anther and pollen development, pollen-pistil interaction, and others. Particularly, 25 annotated gene sets are associated with pollen wall formation, of which 18 encode enzymes or proteins participating in lipid metabolic pathway, including fatty acid ω-hydroxylation, alkane and fatty alcohol biosynthesis, and glycerophospholipid metabolism. We showed that the comparative transcriptomics approach was effective in identifying genes for reproductive development and found that lipid metabolism was particularly active in wheat anthers.

Sequence variations of the partially dominant DELLA gene Rht-B1c in wheat and their functional impacts.

Rht-B1c, allelic to the DELLA protein-encoding gene Rht-B1a, is a natural mutation documented in common wheat (Triticum aestivum). It confers variation to a number of traits related to cell and plant morphology, seed dormancy, and photosynthesis. The present study was conducted to examine the sequence variations of Rht-B1c and their functional impacts. The results showed that Rht-B1c was partially dominant or co-dominant for plant height, and exhibited an increased dwarfing effect. At the sequence level, Rht-B1c differed from Rht-B1a by one 2kb Veju retrotransposon insertion, three coding region single nucleotide polymorphisms (SNPs), one 197bp insertion, and four SNPs in the 1kb upstream sequence. Haplotype investigations, association analyses, transient expression assays, and expression profiling showed that the Veju insertion was primarily responsible for the extreme dwarfing effect. It was found that the Veju insertion changed processing of the Rht-B1c transcripts and resulted in DELLA motif primary structure disruption. Expression assays showed that Rht-B1c caused reduction of total Rht-1 transcript levels, and up-regulation of GATA-like transcription factors and genes positively regulated by these factors, suggesting that one way in which Rht-1 proteins affect plant growth and development is through GATA-like transcription factor regulation.