Prevalence and trend of hepatitis C virus infection among blood donors in Chinese mainland: a systematic review and meta-analysis

<p>Abstract</p> <p>Background</p> <p>Blood transfusion is one of the most common transmission pathways of hepatitis C virus (HCV). This paper aims to provide a comprehensive and reliable tabulation of available data on the epidemiological characteristics and risk factors for HCV infection among blood donors in Chinese mainland, so as to help make prevention strategies and guide further research.</p> <p>Methods</p> <p>A systematic review was constructed based on the computerized literature database. Infection rates and 95% confidence intervals (95% CI) were calculated using the approximate normal distribution model. Odds ratios and 95% CI were calculated by fixed or random effects models. Data manipulation and statistical analyses were performed using STATA 10.0 and ArcGIS 9.3 was used for map construction.</p> <p>Results</p> <p>Two hundred and sixty-five studies met our inclusion criteria. The pooled prevalence of HCV infection among blood donors in Chinese mainland was 8.68% (95% CI: 8.01%-9.39%), and the epidemic was severer in North and Central China, especially in Henan and Hebei. While a significant lower rate was found in Yunnan. Notably, before 1998 the pooled prevalence of HCV infection was 12.87% (95%CI: 11.25%-14.56%) among blood donors, but decreased to 1.71% (95%CI: 1.43%-1.99%) after 1998. No significant difference was found in HCV infection rates between male and female blood donors, or among different blood type donors. The prevalence of HCV infection was found to increase with age. During 1994-1995, the prevalence rate reached the highest with a percentage of 15.78% (95%CI: 12.21%-19.75%), and showed a decreasing trend in the following years. A significant difference was found among groups with different blood donation types, Plasma donors had a relatively higher prevalence than whole blood donors of HCV infection (33.95% <it>vs </it>7.9%).</p> <p>Conclusions</p> <p>The prevalence of HCV infection has rapidly decreased since 1998 and kept a low level in recent years, but some provinces showed relatively higher prevalence than the general population. It is urgent to make efficient measures to prevent HCV secondary transmission and control chronic progress, and the key to reduce the HCV incidence among blood donors is to encourage true voluntary blood donors, strictly implement blood donation law, and avoid cross-infection.</p

Potential of Core-Collapse Supernova Neutrino Detection at JUNO

JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

Detection of the Diffuse Supernova Neutrino Background with JUNO

As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO

Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30$M_{\odot}$ for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

Antennes directives 3D entièrement métalliques et constituées d’arrangements quasipériodiques de cellules Phénix de type guide d’onde

Reflectarray antenna can be seen as a combination of reflector antenna and array antenna. It has the advantages of high gain, low profile, low cost and easy manufacturing. Also, it is able to manipulate the main beam by controlling the geometrical pattern of the unit, including its shape and direction. In contrast to phased array antennas, such manipulation of the radiation is obtained in reflectarray without increasing the complexity of the array beamforming network. Among possible solutions, the phoenix cell is a topology of reflectarray cell with high potential. The geometric variation over the reflectarray aperture is smoothed out owing to the rebirth ability of the phoenix cell. This thesis explores the possibilities offered by additive manufacturing in designing actual 3D metalonly antennas. A 3D waveguide-type phoenix cell has been proposed, analyzed, and modeled using an equivalent circuit. Different high-gain antennas made of 3D phoenix cells have been designed, simulated, and analyzed, two of which have been fabricated to further demonstrate their performance. Good agreement between simulations and measurements has been achieved.Un réseau réflecteur peut être considéré comme une combinaison entre antenne réflecteur et antenne réseau. Il présente les avantages d'un gain élevé, d'un faible encombrement, d'un coût réduit et d'une fabrication facile. De plus, il est possible de manipuler la forme et la direction du faisceau principal en contrôlant la géométrie des cellules unitaires constituant le réseau. Cette opération s’effectue beaucoup plus simplement que pour un réseau à rayonnement direct où elle nécessite de concevoir un répartiteur de puissance complexe. Parmi les solutions possibles, la cellule Phénix est une topologie de cellule de réseau réflecteur avec un fort potentiel. Parce qu’elle permet de revenir à la géométrie initiale après un cycle complet de 360°, la cellule Phénix permet d’éviter les brusques variations de géométrie sur l’ouverture rayonnante. Cette thèse explore les possibilités offertes par la fabrication additive dans la conception d'antennes métalliques 3D réelles. Une cellule Phénix de type guide d'ondes 3D a été proposée, analysée et modélisée à l'aide d'un circuit équivalent. Différentes antennes à gain élevé fabriquées à partir de cellules Phénix 3D ont été conçues, simulées et analysées, dont deux ont été fabriquées pour démontrer leurs performances. Une bonne concordance entre les simulations et les mesures a été obtenue

Dual-Band Metal-Only Antenna Combining Reflectarray and Reflector Functionalities

International audienceThis paper presents a dual band metal-only antenna that operates at 20/40GHz. The proposed metal-only antenna combines the functionalities of reflectarray and parabolic reflector antennas. The unit cell consists of a square waveguide with short circuit termination and a square metallic block in the center. At 20GHz, the reflected beam is determined by a parabolic surface. At 40GHz, the reflected beam is controlled by the phase distribution of cells in the antenna. The gain increases with frequency in the lower frequency band, which is similar to what happens in a parabolic reflector antenna. The aperture efficiency at 20/40GHz is about 22.99/43.79%

Dual-Band Metal-Only Antenna Combining Reflectarray and Reflector Functionalities

International audienceThis paper presents a dual band metal-only antenna that operates at 20/40GHz. The proposed metal-only antenna combines the functionalities of reflectarray and parabolic reflector antennas. The unit cell consists of a square waveguide with short circuit termination and a square metallic block in the center. At 20GHz, the reflected beam is determined by a parabolic surface. At 40GHz, the reflected beam is controlled by the phase distribution of cells in the antenna. The gain increases with frequency in the lower frequency band, which is similar to what happens in a parabolic reflector antenna. The aperture efficiency at 20/40GHz is about 22.99/43.79%

Metal-Only Reflectarray Generating Two Independent Beams with Orthogonal Linear Polarizations

International audienceThis paper presents a Metal-Only reflectarray antenna generating two independent beams with orthogonal linear polarizations. Such reflecctarray is based on a dual polarized cell that allows to control the reflection phase of incident waves independently in both polarizations. The simulated gains of the two beams at 25 GHz are 30.77 dBi and 30.14 dBi respectively

Améliorée de la bande passante de réseau réflecteur entièrement métallique à base de cellules Phoenix 3D

International audienceCet article étudie des réseaux réflecteurs entièrement métalliques à base de cellules Phoenix 3D, pour une réalisation en fabrication additive. La possibilité de faire varier la géométrie de la cellule dans les trois dimensions offre un avantage pour accroître la bande passante. Ici, l'effet de la hauteur des cellules est mis à profit pour atteindre une bande passante (-1dB sur le gain) de 18% à 20GHz

Améliorée de la bande passante de réseau réflecteur entièrement métallique à base de cellules Phoenix 3D

International audienceCet article étudie des réseaux réflecteurs entièrement métalliques à base de cellules Phoenix 3D, pour une réalisation en fabrication additive. La possibilité de faire varier la géométrie de la cellule dans les trois dimensions offre un avantage pour accroître la bande passante. Ici, l'effet de la hauteur des cellules est mis à profit pour atteindre une bande passante (-1dB sur le gain) de 18% à 20GHz