473 research outputs found

    Tunable strong plasmon-exciton coupling based on borophene and deep subwavelength perovskite grating

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    Two-dimensional materials support deeply confined and tunable plasmonic modes, which have great potential for achieving device miniaturization and flexible manipulation. In this paper, we propose a diffraction-unlimited system composed of borophene layer and perovskite grating to investigate the strong coupling between the borophene guiding plasmon (BGP) and perovskite exciton (PE) mode. The resonant energy of BGP mode could be electrically tuned to match the energy of PE mode, and a remarkable Rabi splitting is attained under zero-detuning condition. The splitting energy could reach 230 meV due to the strong field enhancement provided by BGP mode. Consequently, an active reflective phase modulation with 1.76{\pi} range is achieved by dynamically manipulating the detuning. Furthermore, by increasing the distance between the borophene layer and perovskite grating, a parity-time symmetry breaking could be observed with the vanished energy splitting. Our results deepen the understanding of light-matter interaction at the sub-wavelength scale and provide a guideline for designing active plasmonic devices.Comment: 9 pages, 4 figure

    Construction and prokaryotic expression of the fusion gene PRRSV GP5 and Mycobacterium bovis Hsp70

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    Porcine reproductive and respiratory syndrome (PRRS) is an economically important swine disease that has devastated the swine industry worldwide. Vaccination with live attenuated vaccine or inactivated vaccine is the main treatment to control PRRS. However, the disadvantages such as virulence resumption of the attenuated vaccine and low immunogenicity of the inactivated vaccine call for a more efficient and safer genetically engineered vaccine. In this study, the structural protein GP5 of the PRRS virus (PRRSV), one of the major protective antigens which stimulates a protective immune response was selected to develop a genetically engineered subunit vaccine. In order to promote the immune reaction of the host to GP5, heat shock protein 70 (Hsp70) was selected as immuno-adjuvant to enhance PRRSV GP5 immunogenicity. The Hsp70 gene was amplified by PCR from attenuated Mycobacterium bovis, and the PRRSV GP5 gene was amplified by RT-PCR from the total RNA of PRRSV SCQ strain which was isolated, identified and maintained by the Animal Biotechnological Center, Sichuan Agricultural University, China. The fusion expressing plasmid pET32-GP5-Hsp70 was constructed and expressed in Escherichia coli BL21. Ni2+-chelating resin was used to purify the His-tagged fusion protein expressed under optimized expressing conditions. The rabbit anti-GP5-Hsp70 fusion protein antibody was made, and Western blot assay verified the successful expression of the fusion protein, making it possible for further investigation whether Hsp70 could improve the immunogenicity of the PRRSV GP5 subunit vaccine, or evaluating the immunogenicity of the GP5-Hsp70 subunit vaccine.Keywords: Porcine reproductive and respiratory syndrome virus (PRRSV) GP5 gene, Mycobacterium bovis Hsp70 gene, cloning, prokaryotic expression, identification.African Journal of Biotechnology Vol. 12(30), pp. 4754-476

    Transcriptome Analysis of Metapenaeus affinis Reveals Genes Involved in Gonadal Development

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    Metapenaeus affinis is a crustacean with important commercial value in the fishery of the South China Sea. Overfishing has resulted in the decline of the wild population and germplasm degradation. However, there is little background knowledge about its gonadal development, and there is a lack of research on the development of this species. To better understand the molecular regulatory mechanisms during gonadal development, here, we performed RNA-Seq on immature and mature ovaries and compared their transcriptomic signatures. 126,930,488 and 122,677,356 clean sequencing reads were obtained from the Illumina sequencing platform, respectively. 394 differentially expressed genes (DEGs) were identified, of which 136 were up-regulated, and 258 were down-regulated. Further analysis revealed rich transcriptional sequences, which have homology with genes related to reproduction and development. Expression patterns of COX, GPX, E3s, PCNA, STPK, and other genes were changed during ovarian development. Validation by qRT-PCR demonstrated the reliability of RNA-Seq. This study has made a significant contribution to the currently available sequence data of M. affinis and provided reference data for the development of genetic and breeding work

    Newton-Cartan Gravity and Torsion

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    We compare the gauging of the Bargmann algebra, for the case of arbitrary torsion, with the result that one obtains from a null-reduction of General Relativity. Whereas the two procedures lead to the same result for Newton-Cartan geometry with arbitrary torsion, the null-reduction of the Einstein equations necessarily leads to Newton-Cartan gravity with zero torsion. We show, for three space-time dimensions, how Newton-Cartan gravity with arbitrary torsion can be obtained by starting from a Schroedinger field theory with dynamical exponent z=2 for a complex compensating scalar and next coupling this field theory to a z=2 Schroedinger geometry with arbitrary torsion. The latter theory can be obtained from either a gauging of the Schroedinger algebra, for arbitrary torsion, or from a null-reduction of conformal gravity.Comment: 21 page

    Antibacterial and Antiviral Roles of a Fish β-Defensin Expressed Both in Pituitary and Testis

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    Defensins are a group of cationic peptides that exhibit broad-spectrum antimicrobial activity. In this study, we cloned and characterized a β-defensin from pituitary cDNA library of a protogynous hermaphroditic orange-spotted grouper (Epinephelus coioides). Interestingly, the β-defensin was shown to be dominantly expressed in pituitary and testis by RT-PCR and Western blot analysis, and its transcript level is significantly upregulated in reproduction organs from intersexual gonad to testis during the natural and artificial sex reversal. Promoter sequence and the responsible activity region analyses revealed the pituitary-specific POU1F1a transcription binding site and testis-specific SRY responsible site, and demonstrated that the pituitary-specific POU1F1a transcription binding site that locates between −180 and −208 bp is the major responsible region of grouper β-defensin promoter activity. Immunofluorescence localization observed its pituicyte expression in pituitary and spermatogonic cell expression in testis. Moreover, both in vitro antibacterial activity assay of the recombinant β-defensin and in vivo embryo microinjection of the β-defensin mRNA were shown to be effective in killing Gram-negative bacteria. And, its antiviral role was also demonstrated in EPC cells transfected with the β-defensin construct. Additionally, the antibacterial activity was sensitive to concentrations of Na+, K+, Ca2+ and Mg2+. The above intriguing findings strongly suggest that the fish β-defensin might play significant roles in both innate immunity defense and reproduction endocrine regulation

    Expression of Endoplasmic Reticulum Stress-Related Factors in the Retinas of Diabetic Rats

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    Recent reports show that ER stress plays an important role in diabetic retinopathy (DR), but ER stress is a complicated process involving a network of signaling pathways and hundreds of factors, What factors involved in DR are not yet understood. We selected 89 ER stress factors from more than 200, A rat diabetes model was established by intraperitoneal injection of streptozotocin (STZ). The expression of 89 ER stress-related factors was found in the retinas of diabetic rats, at both 1- and 3-months after development of diabetes, by quantitative real-time polymerase chain reaction arrays. There were significant changes in expression levels of 13 and 12 ER stress-related factors in the diabetic rat retinas in the first and third month after the development of diabetes, Based on the array results, homocysteine- inducible, endoplasmic reticulum stress-inducible, ubiquitin-like domain member 1(HERP), and synoviolin(HRD1) were studied further by immunofluorescence and Western blot. Immunofluorescence and Western blot analyses showed that the expression of HERP was reduced in the retinas of diabetic rats in first and third month. The expression of Hrd1 did not change significantly in the retinas of diabetic rats in the first month but was reduced in the third month

    Salidroside Inhibits HMGB1 Acetylation and Release through Upregulation of SirT1 during Inflammation

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    HMGB1, a highly conserved nonhistone DNA-binding protein, plays an important role in inflammatory diseases. Once released to the extracellular space, HMGB1 acts as a proinflammatory cytokine that triggers inflammatory reaction. Our previous study showed that salidroside exerts anti-inflammatory effect via inhibiting the JAK2-STAT3 signalling pathway. However, whether salidroside inhibits the release of HMGB1 is still unclear. In this study, we aim to study the effects of salidroside on HMGB1 release and then investigate the potential molecular mechanisms. In an experimental rat model of sepsis caused by CLP, salidroside administration significantly attenuated lung injury and reduced the serum HMGB1 level. In RAW264.7 cells, we investigated the effects of salidroside on LPS-induced HMGB1 release and then explored the underlying molecular mechanisms. We found that salidroside significantly inhibited LPS-induced HMGB1 release, and the inhibitory effect was correlated with the HMGB1 acetylation levels. Mechanismly, salidroside inhibits HMGB1 acetylation through the AMPK-SirT1 pathway. In addition, SirT1 overexpression attenuated LPS-induced HMGB1 acetylation and nucleocytoplasmic translocation. Furthermore, in SirT1 shRNA plasmid-transfected cells, salidroside treatment enhanced SirT1 expression and reduced LPS-activated HMGB1 acetylation and nucleocytoplasmic translocation. Collectively, these results demonstrated that salidroside might reduce HMGB1 release through the AMPK-SirT1 signalling pathway and suppress HMGB1 acetylation and nucleocytoplasmic translocation

    Heavy the Sea

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    Solo Museum show Transformer Station Cleveland Jan - April 2017 Immersive installations take the audience into an alternate orphic world, moving from beds to swamps and caves, in search of a primordial return. Here, the photographic is loosened from its referent, slipping in and out of darkness, cloaked in dripping inks, bathed in subtle hues, evoking a liquid space of night. Narratives of loss and desire are entangled like the glistening tentacles wrapped around the artist’s body. Like the coral of the Red Sea said to be formed by Medusa’s blood spilled upon seaweed, Teichmann’s work transforms one thing into another, sliding between autobiography, fiction and myth, still and moving image, sculpture and painting. Esther Teichmann’s photographs, films and writings, picture mothers like caves, sisters like seashells, lovers like moons, tears like waterfalls. Entering the octopus darkness of Teichmann’s caverns we find ingestion and emission, mother and daughter, sister and sister, black and white, lover and lover, surrealism’s erotic jolt: the irritant that makes the pearl. Seashells with apertures like cameras. The womb as oceanic. Lovers as moons. Holding as withholding. Day as night. A zine published by Transformer Station, designed by the artist and Studio Hato, combines short stories and images by the artist with poems written in response to the work by artist-historian and writer Carol Mavor. Esther collaborated with the composer Deirdre Gribbin for Fulmine, a multi-screen film installation. Gribbin’s string quartet score will be performed live on certain days throughout the exhibition period. Founded in 2013, Transformer Station is a contemporary art museum located in Cleveland that presents the work of nationally and internationally recognized artists. It engages audiences with innovative experiences through its inspiring and thought provoking events and programming. Transformer Station alternates as a venue for exhibitions curated by the Bidwells from their renowned collection of contemporary art and exhibitions organized by the Cleveland Museum of Art. Fred Bidwell, Director of Transformer Station, is also founder and executive director of FRONT a new art triennial coming to Cleveland in the summer of 2018, under the artistic direction of Michelle Grabner and Jens Hoffman. Carol Mavor is an American writer, art historian, artist and a Professor of Art History at Manchester University. She has published five books. The first four were published by Duke University Press: Pleasures Taken: Performances of Sexuality and Loss in Victorian Photographs, Becoming: The Photographs of Clementina, Viscountess, Hawarden, Reading Boyishly: Roland Barthes, J. M. Barrie, Jacques Henri Lartigue, Marcel Proust, and D. W. Winnicott and Black and Blue: The Bruising Passion of Camera Lucida, La Jetée, Sans soleil and Hiroshima mon amour. The most recent monograph, Blue Mythologies: Reflections on a Colour, and her forthcoming book, Through the Eyes and Mouth of the Fairy Tale, are both published by Reaktion. Mavor has written extensively on Teichmann’s work in her books and for journals including Cabinet magazine and Frieze Masters. Deirdre Gribbin is a London based Irish composer Her music has been performed worldwide including The Lincoln Center for the Performing Arts, New York. Her orchestral work Empire States was an award winner in the 2003 UNESCO International Rostrum of Composers. Composed for feature films and theatre Gribbin is Senior Fellow in Composition at Trinity College of Music London, Fellow of the Royal Society of Arts. Cleveland based string quartet, OPUS 216, comprised of independent, classically trained musicians, will perform Gribbin’s work in costumes created by the artist, continuing their history of collaboration with other creative disciplines and institutions, including the Cleveland Museum of Art

    Constructing Multiple Tasks for Augmentation: Improving Neural Image Classification With K-means Features

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    Multi-task learning (MTL) has received considerable attention, and numerous deep learning applications benefit from MTL with multiple objectives. However, constructing multiple related tasks is difficult, and sometimes only a single task is available for training in a dataset. To tackle this problem, we explored the idea of using unsupervised clustering to construct a variety of auxiliary tasks from unlabeled data or existing labeled data. We found that some of these newly constructed tasks could exhibit semantic meanings corresponding to certain human-specific attributes, but some were non-ideal. In order to effectively reduce the impact of non-ideal auxiliary tasks on the main task, we further proposed a novel meta-learning-based multi-task learning approach, which trained the shared hidden layers on auxiliary tasks, while the meta-optimization objective was to minimize the loss on the main task, ensuring that the optimizing direction led to an improvement on the main task. Experimental results across five image datasets demonstrated that the proposed method significantly outperformed existing single task learning, semi-supervised learning, and some data augmentation methods, including an improvement of more than 9% on the Omniglot dataset

    Ring structure amino acids affect the suppressor activity of melon aphid-borne yellows virus P0 protein

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    AbstractMelon aphid-borne yellows virus (MABYV) is a newly identified polerovirus occurring in China. Here, we demonstrate that the MABYV encoded P0 (P0MA) protein is a strong suppressor of post-transcriptional gene silencing (PTGS) with activity comparable to tobacco etch virus (TEV) HC-Pro. In addition we have shown that the LP F-box motif present at the N-terminus of P0MA is required for suppressor activity. Detailed mutational analyses on P0MA revealed that changing the conserved Trp 212 with non-ring structured amino acids altered silencing suppressor functions. Ala substitutions at positions 12 and 211 for Phe had no effect on P0 suppression-activity, whereas Arg and Glu substitutions had greatly decreased suppressor activity. Furthermore, substitutions targeting Phe at position 30 also resulted in reduced P0 suppression-activity. Altogether, these results suggest that ring structured Trp/Phe residues in P0 have important roles in suppressor activity
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