2,647 research outputs found

    Trilinear Fourier multipliers on Hardy spaces

    Full text link
    In this paper, we obtain the Hp1×Hp2×Hp3HpH^{p_1}\times H^{p_2}\times H^{p_3}\to H^p boundedness for trilinear Fourier multiplier operators, which is a trilinear analogue of the multiplier theorem of Calder\'on and Torchinsky (Adv. Math. 24 : 101-171, 1977). Our result improves the trilinear estimate in the very recent work of the authors, Lee, Heo, Hong, Park, and Yang (Math. Ann., to appear ) by additionally assuming an appropriate vanishing moment condition, which is natural in the boundedness into the Hardy space HpH^p for 0<p10<p\le 1

    DNA microarrays on nanoscale-controlled surface

    Get PDF
    We have developed new surface to ensure a proper spacing between immobilized biomolecules. While DNA microarray on this surface provided each probe DNA with ample space for hybridization with incoming target DNAs, the microarray showed enhanced discrimination efficiency for various types of single nucleotide polymorphism. The high discrimination efficiency holds for all tested cases (100:<1 for internal mismatched cases; 100:<28 for terminal mismatched ones). In addition, by investigating influence of hybridization temperature and washing condition on the fluorescence intensity and the discrimination efficiency with and without controlled mesospacing, it was observed that the nanoscale-controlled surface showed good discrimination efficiency in a wide range of temperature (37–50°C), and hybridization behavior on the surface was in agreement with the solution one. Intriguingly, it was found that washing process after the hybridization was critical for the high discrimination efficiency. For the particular case, washing process was so efficient that only 30 s washing was sufficient to reach the optimal discrimination ratio

    What sentiment attracts tourists? Analysis of tourist attractions based on consumer\u27s sentiment

    Get PDF
    This study tried to derive meaningful insights from consumers\u27 sentiments about tourist attractions. First, through descriptive statistics, seven sentiments representing tourist attractions were identified, and the unique sentiments about certain tourist attractions were identified. On the basis of the network analysis results, four interesting travel routes based on the sentiment theme were constructed, and four insights on the sentiment were presented. Finally, through the regression analysis, one negative word, two positive words, and three network centrality measures that significantly affect the number of visitors were identified. By applying social network analysis, more specific and differentiated conclusions have been drawn. It also provided useful implications for tourist attractions

    Jitter reduction technique for acoustic radiation force impulse microscopy via photoacoustic detection

    Get PDF
    We demonstrate a jitter noise reduction technique for acoustic radiation force impulse microscopy via photoacoustic detection (PA-ARFI), which promises to be capable of measuring cell mechanics. To reduce the jitter noise induced by Q-switched pulsed laser operated at high repetition frequency, photoacoustic signals from the surface of an ultrasound transducer are aligned by cross-correlation and peak-to-peak detection, respectively. Each method is then employed to measure the displacements of a target sample in an agar phantom and a breast cancer cell due to ARFI application, followed by the quantitative comparison between their performances. The suggested methods for PA-ARFI significantly reduce jitter noises, thus allowing us to measure displacements of a target cell due to ARFI application by less than 3 μm. © 2015 Optical Society of America.1

    Editorial

    Get PDF

    Effect of Information Disclosure Policy on Control of Infectious Disease:MERS-CoV Outbreak in South Korea

    Get PDF
    This study examined the effect of disclosing a list of hospitals with Middle East respiratory syndrome coronavirus (MERS-CoV) patients on the number of laboratory-confirmed MERS-CoV cases in South Korea. MERS-CoV data from 20 May 2015 to 5 July 2015 were from the Korean Ministry of Health & Welfare website and analyzed using segmented linear autoregressive error models for interrupted time series. This study showed that the number of laboratory-confirmed cases was increased by 14.629 on June 5 (p < 0.001). However, this number was significantly decreased following disclosure of a list of hospitals with MERS-CoV cases (Estimate = −0.948; p < 0.001). Disclosing the list of hospitals exposed to MERS-CoV was critical to the prevention of further infection. It reduced the number of confirmed MERS-CoV cases. Thus, providing accurate and timely information is a key to critical care response

    Effect of Phosphatidylserine on Unitary Conductance and Ba2+ Block of the BK Ca2+–activated K+ Channel: Re-examination of the Surface Charge Hypothesis

    Get PDF
    Incorporation of BK Ca2+–activated K+ channels into planar bilayers composed of negatively charged phospholipids such as phosphatidylserine (PS) or phosphatidylinositol (PI) results in a large enhancement of unitary conductance (gch) in comparison to BK channels in bilayers formed from the neutral zwitterionic lipid, phospatidylethanolamine (PE). Enhancement of gch by PS or PI is inversely dependent on KCl concentration, decreasing from 70% at 10 mM KCl to 8% at 1,000 mM KCl. This effect was explained previously by a surface charge hypothesis (Moczydlowski, E., O. Alvarez, C. Vergara, and R. Latorre. 1985. J. Membr. Biol. 83:273–282), which attributed the conductance enhancement to an increase in local K+ concentration near the entryways of the channel. To test this hypothesis, we measured the kinetics of block by external and internal Ba2+, a divalent cation that is expected to respond strongly to changes in surface electrostatics. We observed little or no effect of PS on discrete blocking kinetics by external and internal Ba2+ at 100 mM KCl and only a small enhancement of discrete and fast block by external Ba2+ in PS-containing membranes at 20 mM KCl. Model calculations of effective surface potential sensed by the K+ conduction and Ba2+-blocking reactions using the Gouy-Chapman-Stern theory of lipid surface charge do not lend support to a simple electrostatic mechanism that predicts valence-dependent increase of local cation concentration. The results imply that the conduction pore of the BK channel is electrostatically insulated from the lipid surface, presumably by a lateral distance of separation (>20 Å) from the lipid head groups. The lack of effect of PS on apparent association and dissociation rates of Ba2+ suggest that lipid modulation of K+ conductance is preferentially coupled through conformational changes of the selectivity filter region that determine the high K+ flux rate of this channel relative to other cations. We discuss possible mechanisms for the effect of anionic lipids in the context of specific molecular interactions of phospholipids documented for the KcsA bacterial potassium channel and general membrane physical properties proposed to regulate membrane protein conformation via energetics of bilayer stress
    corecore