368 research outputs found

    Far-Field Tunable Nano-focusing Based on Metallic Slits Surrounded with Nonlinear-Variant Widths and Linear-Variant Depths of Circular Dielectric Grating

    Full text link
    In this work, we design a new tunable nanofocusing lens by the linear-variant depths and nonlinear-variant widths of circular grating for far field practical applications. The constructively interference of cylindrical surface plasmon launched by the subwavelength metallic structure can form a subdiffraction-limited focus, and the focal length of the this structures can be adjusted if the each groove depth and width of circular grating are arranged in traced profile. According to the numerical calculation, the range of focusing points shift is much more than other plasmonic lens, and the relative phase of emitting light scattered by surface plasmon coupling circular grating can be modulated by the nonlinear-variant width and linear-variant depth. The simulation result indicates that the different relative phase of emitting light lead to variant focal length. We firstly show a unique phenomenon for the linear-variant depths and nonlinear-variant widths of circular grating that the positive change and negative change of the depths and widths of grooves can result in different of variation trend between relative phases and focal lengths. These results paved the road for utilizing the plasmonic lens in high-density optical storage, nanolithography, superresolution optical microscopic imaging, optical trapping, and sensing.Comment: 14pages,9figure

    Effects of environment and nutritional conditions on mycelial growth of Ganoderma boninense

    Get PDF
    The Basal Stem Rot disease is caused by the soil-borne pathogen, Ganoderma boninense. It is an annihilating and widespread disease in oil palm (Elaeis guineensis Jacq.). The nutritional studies were conducted to know the best sources of carbon and nitrogen, ideal pH regimes, the best humidity and optimum temperature required for the mycelial growth of G. boninense. Out of six carbon sources tested, fructose and glucose proved to be the best carbon sources for the mycelial growth of G. boninense. Out of five nitrogen sources tested, ammonium citrate and ammonium nitrate were noticeably found as the best nitrogen sources for the mycelial growth. Studies on different pH regimes in medium with 83% potatoes and 75% lignocellulosic materials revealed that the ideal pH regimes for the mycelial growth were 4-5. The best humidity for mycelial growth of G. boninense was found between 50-60%. It is suitable to grow between 25 and 32°C, while the optimum temperature is 32°C. This information can be used as a guideline for Ganoderma’s disease prevention study and control strategies in the oil palm plantation in the future

    Genetic Mapping of Head Size Related Traits in Common Carp (Cyprinus carpio)

    Get PDF
    Head size is important economic trait for many aquaculture fish which is directly linked to their carcass yield. The genetic basis of head size trait remains unclear in many widely cultured fish species. Common carp (Cyprinus carpio) is one of the most widely studied fish due to its importance on both economic and environmental aspects. In this study, we performed genome-wide association study using 433 Yellow River carp individuals from multiple families to identify loci and genes potentially associated with head size related traits including head length (HL), head length/body length ratio (HBR), eye diameter (ED), and eye cross (EC). QTL mapping was utilized to filter the effects of population stratification and improve power for the candidates identification in the largest surveyed family with a published genetic linkage map. Twelve SNPs showed significant for head size traits in GWAS and 18 QTLs were identified in QTL mapping. Our study combining both GWAS and QTL mapping could compensate the deficiency from each other and advance our understanding of head size traits in common carp. To acquire a better understanding of the correlation between head size and body growth, we also performed comparisons between QTLs of head size traits and growth-related traits. Candidate genes underlying head size traits were identified surrounding the significant SNPs, including parvalbumin, srpk2, fsrp5, igf1, igf3, grb10, igf1r, notch2, sfrp2. Many of these genes have been identified with potential functions on bone formation and growth. Igf1 was a putative gene associated with both head size and body growth in Yellow River carp. The teleost-specific igf3 was a candidate head size related gene, related to both HL and HBR. Our study also indicated the importance of Igf signaling pathway for both growth and head size determination in common carp, which could be potentially used in future selective breeding in common carp as well as other species

    Effects of MRP8, LPS, and Lenalidomide on the Expressions of TNF- α

    Get PDF
    Astrocytes are now recognized as a heterogeneous class of cells with many important and diverse functions in healthy and diseased central nervous system (CNS). MicroRNAs (miRNAs) are small, noncoding RNAs which may have key roles in astrocytes activation in response to various stimuli. We performed quantitative real-time PCR (qPCR) to detect changes in the expressions of brain-enriched miRNAs (124, 134, 9, 132, and 138), inflammation-related miRNAs (146a, 21, 181a, 221, and 222), and tumor necrosis factor alpha (TNF-α) in the rat primary astrocyte cultures after stimulation with myeloid-related protein 8 (MRP8) and lipopolysaccharides (LPS). Further, we inhibited the expression of TNF-α in the astrocytes by using TNF-α inhibitor (lenalidomide) and tested for the first time the effect of this inhibition on the expressions of the same tested miRNAs. Stimulation of the astrocytes with MRP8 or LPS leads to significant upregulation of miRNAs (124, 134, 9, 132, 146a, 21, 181a, 221, and 222), while miRNA-138 was downregulated. TNF-α inhibition with lenalidomide leads to opposite expressions of the tested miRNAs. These miRNAs may play an important role in activation of the astrocytes and may be a novel target for cell-specific therapeutic interventions in multiple CNS diseases

    Identification of RE1-Silencing Transcription Factor as a Promoter of Metastasis in Pancreatic Cancer

    Get PDF
    Pancreatic cancer is characterized by its rapid progression and early metastasis. This requires further elucidation of the key promoters for its progression and metastasis. In this study, we identified REST as the hub gene of a gene module which is closely associated with cancer stage by weighted gene correlation network analysis. Validation with the TCGA database, western blot analysis of human pancreatic cancer cell lines (AsPC-1, Capan-2, SW-1990, and PANC-1) and immunohistochemical analysis of paraffin-embedded pancreatic cancer tissue sections showed that REST was enriched in tissue samples of advanced stage and metastatic phenotype cell lines. Survival analysis with the TCGA database and our own follow-up data suggested that patients with higher expression level of REST showed worse overall survival rate. In vitro functional experiments suggested that knockdown of REST suppressed proliferation, migration, invasion and epithelial-mesenchymal transition of AsPC-1 and PANC-1 cells. In vivo experiments (a subcutaneous BALB/c nude mouse model and a superior mesenteric vein injection BALB/c nude mouse model) suggested that knockdown of REST suppressed growth and metastasis of xenograft tumor. Finally, we investigated the underlying molecular mechanism of REST and identified REST as a potential downstream target of MAPK signaling pathway. In conclusion, our results of bioinformatic analysis, in vitro and in vivo functional analysis suggested that REST may serve as a promoter of metastasis in pancreatic cancer

    Physical Properties of H II Regions in M51 from Spectroscopic Observations

    Full text link
    M51 and NGC 5195 is an interacting system that can be explored in great details with ground-based telescopes. The H II regions in M51 were observed using the 2.16 m telescope of the National Astronomical Observatories of the Chinese Academy of Sciences and the 6.5 m Multiple Mirror Telescope with spatial resolution of less than 100\sim100 pc. We obtain a total of 113 spectra across the galaxy and combine the literature data of Croxall et al. to derive a series of physical properties, including the gas-phase extinction, stellar population age, star formation rate (SFR) surface density, and oxygen abundance. The spatial distributions and radial profiles of these properties are investigated in order to study the characteristics of M51 and the clues to the formation and evolution of this galaxy. M51 presents a mild radial extinction gradient. The lower gas-phase extinction in the north spiral arms compared to the south arms are possibly caused by the past encounters with the companion galaxy of NGC 5195. A number of H II regions have the stellar age between 50 and 500 Myr, consistent with the recent interaction history by simulations in the literatures. The SFR surface density presents a mild radial gradient, which is ubiquitous in spiral galaxies. There is a negative metallicity gradient of 0.08-0.08 dex Re1R_{e}^{-1} in the disk region, which is also commonly found in many spiral galaxies. It is supported by the "inside-out" scenario of galaxy formation. We find a positive abundance gradient of 0.26 dex Re1R_{e}^{-1} in the inner region. There are possible reasons causing the positive gradient, including the freezing of the chemical enrichment due to the star-forming quenching in the bulge and the gas infall and dilution due to the pseudobulge growth and/or galactic interaction.Comment: 20 pages, 8 figures, 1 appendix, Accepted for publication in PASP. Comments and suggestions are welcom

    The diversity and biogeography of microeukaryotes in the euphotic zone of the northwestern Pacific Ocean

    Get PDF
    Abstract(#br)Microeukaryotes are the key ecosystem drivers mediating marine productivity, the food web and biogeochemical cycles. The northwestern Pacific Ocean (NWPO), as one of the world’s largest oligotrophic regions, remains largely unexplored regarding diversity and biogeography of microeukaryotes. Here, we investigated the community composition and geographical distribution of microeukaryotes collected from the euphotic zone of three different regions in the NWPO using high-throughput sequencing of the 18S rRNA gene and quantified the contributions of environmental factors on the distributions of microeukaryotes. The relative abundance of different group taxa, except for Ciliophora, presented distinct patterns in each region, and Metazoa and Dinoflagellata dominated the community, contributing approximately half of reads abundance. Spatial and environmental factors explained 66.01% of community variation in the NWPO. Temperature was the most important environmental factor significantly correlated with community structure. Bacterial biomass was also significantly correlated with microeukaryotic distribution, especially for Dinoflagellata and Diatomea. Network analysis showed strong correlations between microeukaryotic groups and free-living bacteria and different bacterial taxa were correlated with specific microeukaryotic groups, indicating that their interactions enabled microeukaryotic groups to adapt to diverse environments. This study provides a first glance at the diversity and geographical distribution of microeukaryotes in the NWPO and sheds light on the biotic and abiotic factors in shaping the microeukaryotic community in the ocean

    The diversity and biogeography of microeukaryotes in the euphotic zone of the northwestern Pacific Ocean.

    Get PDF
    Microeukaryotes are the key ecosystem drivers mediating marine productivity, the food web and biogeochemical cycles. The northwestern Pacific Ocean (NWPO), as one of the world’s largest oligotrophic regions, remains largely unexplored regarding diversity and biogeography of microeukaryotes. Here, we investigated the community composition and geographical distribution of microeukaryotes collected from the euphotic zone of three different regions in the NWPO using high-throughput sequencing of the 18S rRNA gene and quantified the contributions of environmental factors on the distributions of microeukaryotes. The relative abundance of different group taxa, except for Ciliophora, presented distinct patterns in each region, and Metazoa and Dinoflagellata dominated the community, contributing approximately half of reads abundance. Spatial and environmental factors explained 66.01% of community variation in the NWPO. Temperature was the most important environmental factor significantly correlated with community structure. Bacterial biomass was also significantly correlated with microeukaryotic distribution, especially for Dinoflagellata and Diatomea. Network analysis showed strong correlations between microeukaryotic groups and free-living bacteria and different bacterial taxa were correlated with specific microeukaryotic groups, indicating that their interactions enabled microeukaryotic groups to adapt to diverse environments. This study provides a first glance at the diversity and geographical distribution of microeukaryotes in the NWPO and sheds light on the biotic and abiotic factors in shaping the microeukaryotic community in the ocean

    Inadequate gastric preparation and its associated factors for magnetically controlled capsule endoscopy

    Get PDF
    Goals: To explore factors associated with inadequate gastric preparation for MCE.Background: Factors associated with inadequate gastric preparation for magnetically controlled capsule endoscopy (MCE) remains unclear.Study: Data of patients who underwent MCE from June 2021 to July 2022 were prospectively collected. The gastric cleanliness score (GCS) of the six stomach regions (gastric cardia, fundus, body, angulus, antrum, and pylorus) was recorded. Patients with GCS score ≥18 were defined as the adequate preparation. Factors related to inadequate gastric preparation were analyzed using a logistic regression model with estimated odds ratios (OR).Results: The mean GCS score of 211 patients was 17.01 ± 2.82. In the multivariable analysis, proton pump inhibitor (PPI) use (OR 3.57; 95% CI 1.69–7.95; p < 0.01) and premedication time after administering simethicone <30 min (OR 2.86; 95% CI 1.10–7.39; p = 0.03) were independent risk factors for inadequate gastric preparation. Comparing the gastric cleanliness of different locations, the median GCS of the lower stomach [10.00, IQR (9.50, 11.00)] was significantly higher than that of the upper stomach [7.00, IQR (6.00, 8.00)] (p <0.001).Conclusion: PPI use and inadequate premedication time (<30 min) may reduce the quality of gastric preparation for MCE. The type, dose, duration of medication, and discontinuation time of PPIs was well worth further exploration. Appropriate control of the type and time of premedication may be the key to improving overall gastric cleanliness
    corecore