Background. Dengue is the most common arboviral infection of humans. There are currently no specific treatments for dengue. Balapiravir is a prodrug of a nucleoside analogue (called R1479) and an ...inhibitor of hepatitis C virus replication in vivo. Methods. We conducted in vitro experiments to determine the potency of balapiravir against dengue viruses and then an exploratory, dose-escalating, randomized placebo-controlled trial in adult male patients with dengue with <48 hours of fever. Results. The clinical and laboratory adverse event profile in patients receiving balapiravir at doses of 1500 mg (n = 10) or 3000 mg (n = 22) orally for 5 days was similar to that of patients receiving placebo (n = 32), indicating balapiravir was well tolerated. However, twice daily assessment of viremia and daily assessment of NS1 antigenemia indicated balapiravir did not measurably alter the kinetics of these virological markers, nor did it reduce the fever clearance time. The kinetics of plasma cytokine concentrations and the whole blood transcriptional profile were also not attenuated by balapiravir treatment. Conclusions. Although this trial, the first of its kind in dengue, does not support balapiravir as a candidate drug, it does establish a framework for antiviral treatment trials in dengue and provides the field with a clinically evaluated benchmark molecule. Clinical Trials Registration. NCT01096576.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
This article presents a multi-band right-hand circularly polarized antenna designed for the Cube Satellite (CubeSat). Based on a quadrifilar structure, the antenna provides circular polarization ...radiation suitable for satellite communication. Moreover, the antenna is designed and fabricated using two 1.6 mm thickness FR4-Epoxy boards connected by metal pins. In order to improve the robustness, a ceramic spacer is placed in the centerboard, and four screws are added at the corners to fix the antenna to the CubeSat structure. These additional parts reduce antenna damage caused by vibrations in the launch vehicle lift-off stage. The proposal has a dimension of 77 × 77 × 10 mm
and covers the LoRa frequency bands at 868 MHz, 915 MHz, and 923 MHz. According to the measurements in the anechoic chamber, antenna gains with the values of 2.3 dBic and 1.1 dBic are obtained for the 870 MHz and 920 MHz, respectively. Finally, the antenna is integrated into a 3U CubeSat that was launched by a Soyuz launch vehicle in September 2020. The terrestrial-to-space communication link was measured, and the antenna performance was confirmed in a real-life scenario.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Summary
Middle East respiratory syndrome (MERS) is a respiratory disease caused by MERS coronavirus. Because of lack of vaccination, various studies investigated the therapeutic efficacy of antiviral ...drugs and supportive remedies. A systematic literature search from 10 databases was conducted and screened for relevant articles. Studies reporting information about the treatment of MERS coronavirus infection were extracted and analyzed. Despite receiving treatment with ribavirin plus IFN, the case fatality rate was as high as 71% in the IFN‐treatment group and exactly the same in patients who received supportive treatment only. Having chronic renal disease, diabetes mellitus and hypertension increased the risk of mortality (P < .05), and chronic renal disease is the best parameter to predict the mortality. The mean of survival days from onset of illness to death was 46.6 (95% CI, 30.5‐62.6) for the IFN group compared with 18.8 (95% CI, 10.3‐27.4) for the supportive‐only group (P = .001). Delay in starting treatment, older age group, and preexisting comorbidities are associated with worse outcomes. In conclusion, there is no difference between IFN treatment and supportive treatment for MERS patients in terms of mortality. However, ribavirin and IFN combination might have efficacious effects with timely administration and monitoring of adverse events. Large‐scale prospective randomized studies are required to assess the role of antiviral drugs for the treatment of this high mortality infection.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
In this paper, a novel six-switch dual-output inverter is proposed. The three-switch leg in the proposed inverter is implemented with the dual-buck structure. Hence, it retains all the benefits of ...the conventional dual-buck inverter such as improved reliability owing to the absence of short-circuit problems and higher efficiency with the use of power metal-oxide-semiconductor field-effect transistor ( mosfet ) without reverse recovery issues on its body diode. In addition, the passive components can be reduced with the high switching frequency operation. A 3.5-kW, 400-V dc input mosfet -based hardware prototype was built and tested to verify the performance of the proposed inverter and a maximum efficiency of 97% was achieved.
Antibody response against nucleocapsid and spike proteins of SARS-CoV-2 in 11 persons with mild or asymptomatic infection rapidly increased after infection. At weeks 18-30 after diagnosis, all ...remained seropositive but spike protein-targeting antibody titers declined. These data may be useful for vaccine development.
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DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Antimicrobial resistance (AMR) is a global public health concern for both clinical and veterinary medicine. Rodent feces are one of the major infectious sources of zoonotic pathogens including AMR ...bacteria. So far, there are limited studies reported focused on Escherichia coli isolated in rodent feces from rural and suburban areas in Vietnam. In this study, we investigated the prevalence of antimicrobial resistance in E. coli isolated from feces samples of 144 urban rodents caught in Hanoi, Vietnam. A total of 59 AMR E. coli was isolated from urban rodents of which 42 were multidrug-resistant (MDR) isolates (resistance to at least three classes of antimicrobial agents), four were extended-spectrum β-lactamase (ESBL) producing isolates and five were colistin-resistant isolates. The highest prevalence of the resistance was against ampicillin (79.7%: 47/59), followed by tetracycline (78.0%: 46/59), nalidixic acid (67.8%: 40/59), sulfamethoxazole-trimethoprim (59.3%: 35/59), chloramphenicol (45.8%: 27/59), ciprofloxacin (44.1%: 26/59), cefotaxime (30.5%: 18/59), cefodizime (23.7%: 14/59), amoxicillin-clavulanate (22.0%: 13/59), and gentamicin (22.0%: 13/59). With regard to the virulence genes associated with diarrheagenic E. coli (DEC), only aaiC gene found in one AMR isolate. In general, the use of antimicrobials does not aim to treat rodents except for companion animals. However, our findings show the carriage of AMR and MDR E. coli in urban rodents and highlight the potential risk of rodents in Hanoi acting as a reservoir of transferable MDR E. coli, including ESBL-producing, colistin-resistant E. coli, and virulence-associated with DEC.
The insect bacterium Wolbachia pipientis is being introgressed into Aedes aegypti populations as an intervention against the transmission of medically important arboviruses. Here we compare Ae. ...aegypti mosquitoes infected with wMelCS or wAlbB to the widely used wMel Wolbachia strain on an Australian nuclear genetic background for their susceptibility to infection by dengue virus (DENV) genotypes spanning all four serotypes. All Wolbachia-infected mosquitoes were more resistant to intrathoracic DENV challenge than their wildtype counterparts. Blocking of DENV replication was greatest by wMelCS. Conversely, wAlbB-infected mosquitoes were more susceptible to whole body infection than wMel and wMelCS. We extended these findings via mosquito oral feeding experiments, using viremic blood from 36 acute, hospitalised dengue cases in Vietnam, additionally including wMel and wildtype mosquitoes on a Vietnamese nuclear genetic background. As above, wAlbB was less effective at blocking DENV replication in the abdomen compared to wMel and wMelCS. The transmission potential of all Wolbachia-infected mosquito lines (measured by the presence/absence of infectious DENV in mosquito saliva) after 14 days, was significantly reduced compared to their wildtype counterparts, and lowest for wMelCS and wAlbB. These data support the use of wAlbB and wMelCS strains for introgression field trials and the biocontrol of DENV transmission. Furthermore, despite observing significant differences in transmission potential between wildtype mosquitoes from Australia and Vietnam, no difference was observed between wMel-infected mosquitoes from each background suggesting that Wolbachia may override any underlying variation in DENV transmission potential.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this paper, we investigate an edge computing-assisted Metaverse system. This system involves a virtual service provider (VSP), which can partially offload sensing data collected from UAVs to an ...edge computing platform. The data is used to update its digital twins (DTs) to ensure the promptness of Metaverse services and satisfy the latency requirements of Metaverse users. However, designing such a system is challenging due to the dynamics of sensing data, the latency requirements of Metaverse users, channel conditions, and the available computing resources at both the VSP and EC. Therefore, we formulate the VSP's offloading problem as a stochastic problem and utilize deep reinforcement learning (DRL) algorithms. Simulation results are provided to validate the effectiveness of the learning algorithms.
The coronavirus disease 2019 (COVID-19) pandemic will have a large impact on the publishing industry. This research aims to investigate the influences of the COVID-19 pandemic situation, utilitarian ...and hedonic motivations on consumer intention to buy books online. It conceptualizes the effects of the COVID-19 pandemic as situational influences, which involve the closure of physical bookstores, health risks associated with visiting such stores, online shopping trend and additional marketing efforts from online bookstores during the pandemic. Data were collected from 275 Vietnamese consumers using an online survey. Multivariate data analysis reveals that the COVID-19 pandemic situation has a positive and significant impact on consumer intention toward online book shopping. Furthermore, while utilitarian motivation exerts a strong effect on consumer intention to purchase books online, the relationship between hedonic motivation and online purchase intention is positive but insignificant. These findings would assist key stakeholders such as publishers and online bookstores to improve the quality of their websites as well as develop their marketing campaigns.
A Novel Single-Phase Three-Level Dual-Buck Inverter Nguyen, Tien-The; Cha, Honnyong; Nguyen, Bang Le-Huy ...
IEEE transactions on power electronics,
2020-April, 2020-4-00, Volume:
35, Issue:
4
Journal Article
Peer reviewed
This article proposes a new single-phase three-level dual-buck inverter. The topology is derived from a simplified neutral-point clamped inverter that includes fewer active switches. The advantages ...of the proposed inverter are no shoot-through worries and no reverse recovery issue of the body diode of the power metal-oxide-semiconductor field-effect transistor compared with the conventional inverter; therefore, a high-reliability inverter can be achieved. The operation modes and pulsewidth modulation technique are analyzed in detail. Additionally, a switching scheme is proposed to balance and reduce the direct-current-link capacitance. A 1.4-kW prototype was built and tested to validate the theoretical analysis of the proposed converter.
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