104 research outputs found

    Enhanced-Surface-Area TiO2-Based Nanotube for Photocatalytic Applications

    Get PDF
    This study utilized chemical method to reform titania nanopowder into larger surface area titania-based nanotubes (NTs). Various factors, such as reaction temperature, concentration, time, and aging time were investigated to determine their effects toward NT properties. The formation of the titania-based NTs was carried out under the conditions of 10N NaOH reaction medium, at reaction temperature and time of 116°C and 23 hours, respectively. Subsequent aging was done at 40°C for 24 hours. The NTs were further resintered at 400°C for 1 hour to improve their crystallinity and photocatalytic efficiency. Result indicates that the aging process is significant for the NT synthesis process. The treated titania-based NTs have an average surface area of 247.91 m2/g with nearly 100% photodecomposition of methylene blue in 15 minutes

    Realization of Polarization Control in High-Order Harmonic Generation

    Get PDF
    The nature of high-order harmonic generation process limits the harmonics emission to linear polarization. In this paper, we review the recent progress to generate elliptically or circularly polarized high-harmonic EUV pulses. We further demonstrate how complete control of polarization state of isolated high-harmonic pulse can be realized today by noncollinear focusing of two driving pulses with identical ellipticity but counter-rotating helicity. This paper opens a path towards the study of the fastest dynamics--down to attosecond time scales--in circular dichroism of magnetic materials, chiral molecules, and electronic spin motion.Taiwan Ministry of Science and Technology; Academia Sinica; Junta de Castilla y León; Ministerio de Economía y Competitividad; Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation; Ministerio de Ciencia, Innovación y Universidades for a Ramón y Cajal; European Social Fund; Ministerio de Educación, Cultura y Deporte

    AV-SUPERB: A Multi-Task Evaluation Benchmark for Audio-Visual Representation Models

    Full text link
    Audio-visual representation learning aims to develop systems with human-like perception by utilizing correlation between auditory and visual information. However, current models often focus on a limited set of tasks, and generalization abilities of learned representations are unclear. To this end, we propose the AV-SUPERB benchmark that enables general-purpose evaluation of unimodal audio/visual and bimodal fusion representations on 7 datasets covering 5 audio-visual tasks in speech and audio processing. We evaluate 5 recent self-supervised models and show that none of these models generalize to all tasks, emphasizing the need for future study on improving universal model performance. In addition, we show that representations may be improved with intermediate-task fine-tuning and audio event classification with AudioSet serves as a strong intermediate task. We release our benchmark with evaluation code and a model submission platform to encourage further research in audio-visual learning.Comment: Submitted to ICASSP 2024; Evaluation Code: https://github.com/roger-tseng/av-superb Submission Platform: https://av.superbbenchmark.or

    Comparison of Immediate and 2-Year Outcomes between Excimer Laser-Assisted Angioplasty with Spot Stent and Primary Stenting in Intermediate to Long Femoropopliteal Disease

    Get PDF
    Background. To compare the clinical outcomes between excimer laser-assisted angioplasty (ELA) with spot stent (group A) and primary stenting (group B) in intermediate to long femoropopliteal disease. Methods. Outcomes of 105 patients totaling 119 legs treated with two different strategies were analyzed retrospectively in a prospectively maintained database. Results. Baseline characteristics were similar in both groups. Better angiographic results and lesser increase of serum C-reactive protein levels (0.60 ± 0.72 versus 2.98 ± 0.97 mg/dL, P<0.001) after the intervention were obtained in Group B. Group A had inferior 1-year outcomes due to higher rate of binary restenosis (67% versus 32%, P=0.001) and lower rate of primary patency (40% versus 58%, P=0.039). Rates of amputation-free survival, target vessel revascularization, assisted primary patency, and stent fracture at 24 months were similar in both groups (80% versus 82%, P=0.979, 65% versus 45%, P=0.11, 78% versus 80%, P=0.75 and 6.3% versus 6.8%, P=0.71, resp.). Conclusion. Greater vascular inflammation after ELA with spot stent resulted in earlier restenosis and inferior 1-year clinical outcomes than primary stenting. This benefit was lost in the primary stenting group at 2 years due to late catch-up restenosis. Active surveillance with prompt intervention was required to maintain the vessel patency

    Polarization control of isolated high-harmonic pulses

    Get PDF
    High-harmonic generation driven by femtosecond lasers makes it possible to capture the fastest dynamics in molecules and materials. However, thus far, the shortest isolated attosecond pulses have only been produced with linear polarization, which limits the range of physics that can be explored. Here, we demonstrate robust polarization control of isolated extreme-ultraviolet pulses by exploiting non-collinear high-harmonic generation driven by two counter-rotating few-cycle laser beams. The circularly polarized supercontinuum is produced at a central photon energy of 33 eV with a transform limit of 190 as and a predicted linear chirp of 330 as. By adjusting the ellipticity of the two counter-rotating driving pulses simultaneously, we control the polarization state of isolated extreme-ultraviolet pulses—from circular through elliptical to linear polarization—without sacrificing conversion efficiency. Access to the purely circularly polarized supercontinuum, combined with full helicity and ellipticity control, paves the way towards attosecond metrology of circular dichroism.The experimental work was carried out at National Tsing Hua University, Institute of Photonics Technologies, supported by the Ministry of Science and Technology, Taiwan (grants 105-2112-M-007-030-MY3, 105-2112-M-001-030 and 104-2112-M-007-012-MY3). The concept of isolated circularly polarized attosecond pulses was developed by C.H.-G., D.D.H., M.M.M., C.G.D., H.C.K., A.B. and A.J.-B.. C.H.-G. acknowledges support from the Marie Curie International Outgoing Fellowship within the EU Seventh Framework Programme for Research and Technological Development (2007–2013), under Research Executive Agency grant agreement no. 328334. C.H.-G. and L.P. acknowledge support from Junta de Castilla y León (SA046U16) and the Ministerio de Economía y Competitividad (FIS2013-44174-P, FIS2016-75652-P). C.H.-G. acknowledges support from a 2017 Leonardo Grant for Researchers and Cultural Creators (BBVA Foundation). M.M.M. and H.C.K. acknowledge support from the Department of Energy Basic Energy Sciences (award no. DE-FG02-99ER14982) for the concepts and experimental set-up. For part of the theory, A.B., A.J.-B., C.G.D., M.M.M. and H.C.K. acknowledge support from a Multidisciplinary University Research Initiatives grant from the Air Force Office of Scientific Research (award no. FA9550-16-1-0121). A.J.-B. also acknowledges support from the US National Science Foundation (grant no. PHY-1734006). This work utilized the Janus supercomputer, which is supported by the US National Science Foundation (grant no. CNS-0821794) and the University of Colorado, Boulder. This research made use of the high-performance computing resources of the Castilla y León Supercomputing Center (SCAYLE, www.scayle.es), financed by the European Regional Development Fund (ERDF). J.L.E. acknowledges support from the National Science Foundation Graduate Research Fellowship (DGE-1144083). L.R. acknowledges support from the Ministerio de Educación, Cultura y Deporte (FPU16/02591)

    Identification and Characterization of Glycine- and Arginine-Rich Motifs in Proteins by a Novel GAR Motif Finder Program

    No full text
    Glycine- and arginine-rich (GAR) motifs with different combinations of RG/RGG repeats are present in many proteins. The nucleolar rRNA 2&prime;-O-methyltransferase fibrillarin (FBL) contains a conserved long N-terminal GAR domain with more than 10 RGG plus RG repeats separated by specific amino acids, mostly phenylanalines. We developed a GAR motif finder (GMF) program based on the features of the GAR domain of FBL. The G(0,3)-X(0,1)-R-G(1,2)-X(0,5)-G(0,2)-X(0,1)-R-G(1,2) pattern allows the accommodation of extra-long GAR motifs with continuous RG/RGG interrupted by polyglycine or other amino acids. The program has a graphic interface and can easily output the results as .csv and .txt files. We used GMF to show the characteristics of the long GAR domains in FBL and two other nucleolar proteins, nucleolin and GAR1. GMF analyses can illustrate the similarities and also differences between the long GAR domains in the three nucleolar proteins and motifs in other typical RG/RGG-repeat-containing proteins, specifically the FET family members FUS, EWS, and TAF15 in position, motif length, RG/RGG number, and amino acid composition. We also used GMF to analyze the human proteome and focused on the ones with at least 10 RGG plus RG repeats. We showed the classification of the long GAR motifs and their putative correlation with protein/RNA interactions and liquid&ndash;liquid phase separation. The GMF algorithm can facilitate further systematic analyses of the GAR motifs in proteins and proteomes

    Identification and Characterization of Glycine- and Arginine-Rich Motifs in Proteins by a Novel GAR Motif Finder Program

    No full text
    Glycine- and arginine-rich (GAR) motifs with different combinations of RG/RGG repeats are present in many proteins. The nucleolar rRNA 2′-O-methyltransferase fibrillarin (FBL) contains a conserved long N-terminal GAR domain with more than 10 RGG plus RG repeats separated by specific amino acids, mostly phenylanalines. We developed a GAR motif finder (GMF) program based on the features of the GAR domain of FBL. The G(0,3)-X(0,1)-R-G(1,2)-X(0,5)-G(0,2)-X(0,1)-R-G(1,2) pattern allows the accommodation of extra-long GAR motifs with continuous RG/RGG interrupted by polyglycine or other amino acids. The program has a graphic interface and can easily output the results as .csv and .txt files. We used GMF to show the characteristics of the long GAR domains in FBL and two other nucleolar proteins, nucleolin and GAR1. GMF analyses can illustrate the similarities and also differences between the long GAR domains in the three nucleolar proteins and motifs in other typical RG/RGG-repeat-containing proteins, specifically the FET family members FUS, EWS, and TAF15 in position, motif length, RG/RGG number, and amino acid composition. We also used GMF to analyze the human proteome and focused on the ones with at least 10 RGG plus RG repeats. We showed the classification of the long GAR motifs and their putative correlation with protein/RNA interactions and liquid–liquid phase separation. The GMF algorithm can facilitate further systematic analyses of the GAR motifs in proteins and proteomes

    Cylindrical Rod Phosphor Structure for Laser-Driven White Lighting

    No full text
    In this article, a cylindrical rod phosphor structure was developed and used for laser-driven white lighting. The blue light emitting from the laser diode (LD) with limited divergence enters the cylindrical rod containing phosphor and excites the yellow phosphor particles in the cylindrical rod to generate white light. Multiple phosphor blends with yellow and red phosphors were also applied to the cylindrical rod phosphor structure to enhance the red luminescence of white light with a low correlated color temperature (CCT). An advanced structure with a surrounding transparent layer around the central cylindrical rod containing phosphors was also investigated to enhance the possibility of the blue light absorption by phosphors in the cylindrical rod region away from the LD. The cylindrical rod phosphor structures with or without the surrounding transparent layer were fabricated to produce laser-driven white lighting, and the optical characteristics of the cylindrical rod phosphor structures with different phosphor concentrations or yellow-to-red phosphor weight ratios were examined

    A High-Content Screening Assay for the Discovery of Novel Proteasome Inhibitors from Formosan Soft Corals

    No full text
    The ubiquitin-proteasome system (UPS) is a major proteolytic pathway that safeguards protein homeostasis. The main 26S proteasome consists of a 20S catalytic core proteasome and a 19S substrate recognition proteasome. UPS dysfunction underlies many important clinical diseases involving inflammation, tumors, and neurodegeneration. Currently, three 20S proteasome inhibitors, bortezomib, carfilzomib, and ixazomib, have been approved for the treatment of multiple myeloma. We aim to screen UPS inhibitors for biomedical purposes. The protein interaction network of human cytomegalovirus UL76 targets UPS, resulting in aggregations of ubiquitinated proteins termed aggresomes. In this study, we demonstrated that cell-based high-content measurements of EGFP-UL76 aggresomes responded to bortezomib and MG132 treatment in a dose-dependent manner. Employing this high-content screening (HCS) assay, we screened natural compounds purified from Formosan soft corals. Four cembrane-based compounds, sarcophytonin A (1), sarcophytoxide (2), sarcophine (3), and laevigatol A (4), were found to enhance the high-content profiles of EGFP-UL76 aggresomes with relative ratios of 0.2. By comparison to the mechanistic action of proteasome inhibitors, compounds 1 and 3 modulated the accumulation of ubiquitinated proteins, with a unique pattern likely targeting 19S proteasome. We confirmed that the EGFP-UL76 aggresome-based HCS system greatly improves the efficacy and sensitivity of the identification of proteasome inhibitors
    • …
    corecore