116 research outputs found

    Norovirus GII.17: The Emergence and Global Prevalence of a Novel Variant

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    A rare norovirus (NoV) genotype GII.17 has recently emerged and rapidly became predominant in most East Asian countries in the winters of 2014–2015. In this study, we report the diversity of NoV GII.17 in detail; a total of 646 GII.17 sequences obtained during 1978–2015 were analyzed and subjected to meta-analysis. At least five major recombinant GII.17 clusters were identified. Each recombinant variant group appeared to have emerged following the time order: GII.P4-GII.17 (1978–1990), GII.P16-GII.17 (2001–2004), GII.P13-GII.17 (2004–2010), GII.Pe-GII.17 (2012–2015) and GII.P3-GII.17 (2011–2015). The newly emerged GII.P3-GII.17 variant, which exhibited significant sequence and structure variations, is evolving toward a unique lineage. Our results indicate that circulation of GII.17 appears to change every 3–5 years due to replacement by a newly emerged variant and that the evolution of GII.17 is sequentially promoted by inter-genotype recombination, which contributes to the exchange between non-GII.17 and GII.17 RdRp genes and drives the evolution of GII.17 capsid genes

    What They Gain Depends on What They Do: An Exploratory Empirical Research on Effective Use of Mobile Healthcare Applications

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    Mobile healthcare application receives widespread attention, although it has advanced technology and user-friendly design, when users don’t use it effectively, it seems worthless. Research mainly focus on technology improvement. But how to improve user behavior to match the technology is another essential factor for facilitating effective use from managerial perspective. We introduced the task technology fit theory to explain the mechanism when user using the applications. We added perceived e-health literacy as moderator variable, considering the user characteristic and medical environment. The data was collected from student samples of two schools (medical and non-medical related universities), totally 178 valid samples. Our research indicates adaptation and learning behavior have significantly positive impact on the efficiency use and effectiveness use. The perceived e-health literacy only has significant moderator effect on learning behavior. Our study provides practical implications for both software providers and users to achieve effective use of mobile healthcare applications

    In Search of Infall Motion in Molecular Clumps. IV. Mapping of the Global Infall Sources

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    We have used the IRAM 30-m telescope to map some targets with HCO+^+ (1-0) and H13^{13}CO+^+ (1-0) lines in order to search for gas infall evidence in the clumps. In this paper, we report the mapping results for 13 targets. All of these targets show HCO+^+ emissions, while H13^{13}CO+^+ emissions are observed in ten of them. The HCO+^+ integrated intensity maps of ten targets show clear clumpy structures, and nine targets show clumpy structures in the H13^{13}CO+^+ maps. Using the RADEX radiative transfer code, we estimate the column density of H13^{13}CO+^+, and determine the abundance ratio [H13^{13}CO+^+]/[H2_2] to be approximately 10−12^{-12} to 10−10^{-10}. Based on the asymmetry of the HCO+^+ line profiles, we identify 11 targets show blue profiles, while six clumps have global infall evidence. We use the RATRAN and two-layer models to fit the HCO+^+ line profiles of these infall sources, and analyze their spatial distribution of the infall velocity. The average infall velocities estimated by these two models are 0.24 -- 1.85 km s−1^{-1} and 0.28 -- 1.45 km s−1^{-1}, respectively. The mass infall rate ranges from approximately 10−5^{-5} to 10−2^{-2} M⊙_{\odot} yr−1^{-1}, which suggests that intermediate- or high-mass stars may be forming in the target regions

    XAF1 expression and regulatory effects of somatostatin on XAF1 in prostate cancer cells

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    <p>Abstract</p> <p>Background</p> <p>Somatostatin prevents cell proliferation by inducing apoptosis. Downregulation of the <it>XAF1 </it>transcript may occur during the development of prostate cancer. It is interesting to evaluate the potential regulatory effects of somatostatin on <it>XAF1 </it>expression during the development of prostate cancer cells.</p> <p>Methods</p> <p><it>XAF1 </it>mRNA and protein expression in human prostate epithelial cells RWPE-1, androgen dependent prostate cancer LNCaP, and androgen independent DU145 and PC3 cells were evaluated using RT-PCR and Western blot. The regulation of <it>XAF1 </it>mRNA and protein expression by somatostatin and its analogue Octreotide was evaluated.</p> <p>Results</p> <p>Substantial levels of <it>XAF1 </it>mRNA and proteins were detected in RWPE-1 cells, whereas prostate cancer cells LNCaP, DU145 and PC3 exhibited lower <it>XAF1 </it>expression. Somatostatin and Octreotide up-regulated <it>XAF1 </it>mRNA and protein expression in all prostate cancer cell lines.</p> <p>Conclusions</p> <p><it>XAF1 </it>down-regulation may contribute to the prostate cancer development. The enhanced <it>XAF1 </it>expression by somatostatin indicates a promising strategy for prostate cancer therapy.</p

    In search for infalling clumps in molecular clouds -- A catalogue of CO blue-profiles

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    We have started a systematic survey of molecular clumps with infall motions to study the very early phase of star formation. Our first step is to utilize the data products by MWISP to make an unbiased survey for blue asymmetric line profiles of CO isotopical molecules. Within a total area of ∟\sim 2400 square degrees nearby the Galactic plane, we have found 3533 candidates showing blue-profiles, in which 3329 are selected from the 12^{12}CO&13^{13}CO pair and 204 are from the 13^{13}CO&C18^{18}O pair. Exploration of the parametric spaces suggests our samples are in the cold phase with relatively high column densities ready for star formation. Analysis of the spatial distribution of our samples suggests that they exist virtually in all major components of the Galaxy. The vertical distribution suggest that the sources are located mainly in the thick disk of ∟\sim 85 parsec, but still a small part are located far beyond Galactic midplane. Our follow-up observation indicates that these candidates are a good sample to start a search for infall motions, and to study the condition of very early phase of star formation

    Research on Control Strategy of High-Speed Grid-Connected FESS (Flywheel Energy Storage System) Based on Dual-PWM Converter

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    FESS (flywheel energy storage system) motor is used in important load fields for instance rail transit; meanwhile the power flow is formed through the connection between FESS (flywheel energy storage system) and power grid system, which can critically improve the power flow fluctuation caused by new energy grid integration regarding wind and photovoltaic generation concerning that the motor speed in FESS is related to its energy storage capacity. Aiming at the limitation of current low motor speed in the FESS, this article puts forward a high-speed grid-connected FESS, and designs a model via the proposed dual-PWM two-stage control form, which is named as double closed-loop control. In this article, the FESS, as well as the power grid system, is analyzed and simulated in three stages: charging, pre-grid connection and grid connection. In this way, the flywheel motor speed and DC bus voltage signal are sampled to design the flywheel motor side with the proposed method. Then the grid-connected double closed-loop control method is designed for the sampling observation points, which realizes the efficient design on the control strategy of proposed high-speed grid-connected FESS and the verification of voltage and current parameters. The simulation experiments show that the operation process of the grid-connected FESS motor obtains its rapid speed response characteristic, which can meet the proposed design requirements during the charging and discharging process

    Case Study of Mesoscale Precipitation Areas within the Comma Head of an Extratropical Cyclone

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    On 12&ndash;13 February 2016, a record-breaking rain&ndash;snow event during the passage of an extratropical cyclone occurred in Shandong Province, China, in which the 24 h precipitation totals at 48 of 123 national meteorological stations in Shandong Province broke their historical records for the month of February, and a further 25 stations recorded their second-largest February totals. This paper investigates the evolution of the mesoscale precipitation areas and the mechanisms responsible for the formation, organization, and maintenance of the mesoscale precipitation areas, using FY-2G satellite data, Doppler radar observations, and a Weather Research and Forecasting (WRF) model numerical simulation at 4 km grid spacing. The main results show that the comma head cloud of the cyclone developed from four echo strips. Intense precipitation was related to the mesoscale elongated precipitation areas (EPAs) of reflectivity &gt;30 dBZ within the stratiform clouds. The formation and development of the EPAs coincided with the activities of a low-level shear line and an associated increase in frontogenesis. The simulated EPAs occurred in an environment of conditional instability (CI), inertial instability (II), and conditional symmetric instability (CSI). In the initial stage of the elongated rainfall areas (ERAs), rainfall was initiated by the frontal forcing in the presence of elevated CI, and II was generated by upright convection. During the development stage of the ERAs, the CI was absent, and condensational heating was enhanced. II occurred in the absence of upright convection, and it seems likely that the presence of II is a diabatic signature of the precipitation itself. Upper-level II intensified the convective systems by enhancing outflow aloft, and II caused the ERAs to organize. Thus, II played an important role in the organization and maintenance of the ERAs. The frontogenesis provided the dynamic condition for the release of the instability. Enhanced CSI and II intensified slantwise convection, and combining with enhanced frontogenesis, intensified the ERAs. The echo, ascent, and frontogenesis in snowfall areas were weaker than those in rainfall areas

    Case Study of Mesoscale Precipitation Areas within the Comma Head of an Extratropical Cyclone

    No full text
    On 12–13 February 2016, a record-breaking rain–snow event during the passage of an extratropical cyclone occurred in Shandong Province, China, in which the 24 h precipitation totals at 48 of 123 national meteorological stations in Shandong Province broke their historical records for the month of February, and a further 25 stations recorded their second-largest February totals. This paper investigates the evolution of the mesoscale precipitation areas and the mechanisms responsible for the formation, organization, and maintenance of the mesoscale precipitation areas, using FY-2G satellite data, Doppler radar observations, and a Weather Research and Forecasting (WRF) model numerical simulation at 4 km grid spacing. The main results show that the comma head cloud of the cyclone developed from four echo strips. Intense precipitation was related to the mesoscale elongated precipitation areas (EPAs) of reflectivity >30 dBZ within the stratiform clouds. The formation and development of the EPAs coincided with the activities of a low-level shear line and an associated increase in frontogenesis. The simulated EPAs occurred in an environment of conditional instability (CI), inertial instability (II), and conditional symmetric instability (CSI). In the initial stage of the elongated rainfall areas (ERAs), rainfall was initiated by the frontal forcing in the presence of elevated CI, and II was generated by upright convection. During the development stage of the ERAs, the CI was absent, and condensational heating was enhanced. II occurred in the absence of upright convection, and it seems likely that the presence of II is a diabatic signature of the precipitation itself. Upper-level II intensified the convective systems by enhancing outflow aloft, and II caused the ERAs to organize. Thus, II played an important role in the organization and maintenance of the ERAs. The frontogenesis provided the dynamic condition for the release of the instability. Enhanced CSI and II intensified slantwise convection, and combining with enhanced frontogenesis, intensified the ERAs. The echo, ascent, and frontogenesis in snowfall areas were weaker than those in rainfall areas
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