To assess the role of in-flight transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), we investigated a cluster of cases among passengers on a 10-hour commercial flight. ...Affected persons were passengers, crew, and their close contacts. We traced 217 passengers and crew to their final destinations and interviewed, tested, and quarantined them. Among the 16 persons in whom SARS-CoV-2 infection was detected, 12 (75%) were passengers seated in business class along with the only symptomatic person (attack rate 62%). Seating proximity was strongly associated with increased infection risk (risk ratio 7.3, 95% CI 1.2-46.2). We found no strong evidence supporting alternative transmission scenarios. In-flight transmission that probably originated from 1 symptomatic passenger caused a large cluster of cases during a long flight. Guidelines for preventing SARS-CoV-2 infection among air passengers should consider individual passengers' risk for infection, the number of passengers traveling, and flight duration.
Multidrug-resistant Plasmodium falciparum undermines the efficacy of currently deployed antimalarial therapies in southern Viet Nam.
Between May 2017 and December 2018, this prospective, open-label, ...single-arm, observational clinical trial, conducted in Binh Phuoc, Dak Nong, Gia Lai, Khanh Hoa, and Ninh Thuan provinces, evaluated the safety and efficacy of oral pyronaridine-artesunate once daily for 3 consecutive days in adults and children with microscopically confirmed P. falciparum malaria. Patients were treated as inpatients for Days 0-3, with follow-up visits on Days 7, 14, 21, 28, 35, and 42. The primary outcome was the proportion of polymerase chain reaction (PCR)-adjusted adequate clinical and parasitological response (ACPR) at Day 42.
The cumulative incidence of PCR-adjusted ACPR at Day 42 was 96.1% (95% confidence interval CI 91.4-98.2; Kaplan-Meier). In the per-protocol analysis, the proportion of patients with Day 42 PCR-adjusted ACPR was 96.1% (147/153; 95% CI 91.7-98.5). The proportion of patients with parasitemia at Day 3 was 24.0% (40/167; 95% CI 17.7-31.2). The prevalences of the Kelch13 (C580Y) mutation were: in Binh Phuoc, 97.7% (43/44); in Dak Nong, 96.2% (25/26); in Gia Lai, 57.8% (37/64); in Khanh Hoa, 66.6% (6/9); and in Ninh Thuan, 3.6% (1/28). The majority of artemisinin-resistant isolates also had increased plasmepsin2 copy number (75.9%; 85/112). There was 1 isolate (Binh Phuoc) that had Kelch13 (C580Y) plus increased plasmepsin2 and Pfmdr1 copy numbers. Asymptomatic transient increases in alanine transaminase and aspartate transaminase were observed at Day 7, resolving by Day 28.
Pyronaridine-artesunate can be used to diversify antimalarial therapy in areas of artemisinin-resistant P. falciparum in Viet Nam.
ACTRN12618001274268.
Photocatalytic hydrogen (H2) generation derived by water has been considered as a renewable energy to solve environmental problems and global energy crises. Thus, it is necessary to explore the most ...effective photocatalysts by using multi-cocatalysts, due to an intimate interaction between different components. Therefore, we already synthesized the TiO2/Ti3C2/g-C3N4 (TTC) photocatalyst from g-C3N4 and Ti3C2 MXene via a calcination technique, and applied this composite for H2 evolution. By making use of titanium atom from Ti3C2 MXene, titanium dioxide (TiO2) was in-body developed, which leads to form a close heterostructure between metallic material and semiconductors. Besides, g-C3N4 amorphous with highly surface area also contributes to harvest light irradiation during photocatalytic activity. The optimized TTC-450 heterostructure showed a super H2 generation efficiency than those of pure g-C3N4 and other samples. Besides, TTC-450 sample also exhibited great recyclability after 4 runs. The proposed mechanism illustrates the efficient movement of generated electrons in TTC system, which leads to high H2 evolution efficiency. Moreover, the obtained results consistently emphasize the TiO2/Ti3C2/g-C3N4 composite would be a unique material for H2 production and broaden applications of MXene materials.
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•TiO2/Ti3C2/g-C3N4 ternary composites are prepared via a calcination method.•Ti3C2 MXenes are used as a precursor for in situ transformation of TiO2 phases.•TiO2/Ti3C2/g-C3N4 photocatalyst exhibits a remarkable H2 evolution performance.•A proposed mechanism for H2 evolution toward TiO2/Ti3C2/g-C3N4 was illustrated.
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► A facile synthesis of MgO nanoplates using cetyltrimethylammonium bromide was presented. ► Mechanism for the formation of nanostructured MgO particles was proposed. ► MgO nanoplates ...revealed high BET surface areas. ► MgO nanoplates exhibited a highly adsorptive performance for removal of reactive blue 19 dye.
Magnesium oxide (MgO) has been known as an excellent adsorbent for a variety of the environmentally polluted compounds. This work describes a synthesis of nanostructured MgO particles via a facile procedure by using cetyltrimethylammonium bromide (CTAB). Powder X-ray diffraction, thermal gravimetric, and differential thermal gravimetry (TGA/DTG) analyses were performed to characterize the physical properties of synthesized MgO particles and field emission-scanning electron microscopy (FE-SEM) was used to observe their morphology, whereas nitrogen adsorption–desorption isotherms and Brunauer–Emmett–Teller (BET) method were used to calculate the total surface areas of the samples. The adsorptive performance was studied by batch experiments for reactive blue (RB) 19 dye removal. The results showed that as-prepared MgO particles revealed hexagonal-like shaped platelets with an average diameter in the range of 49–91nm and a mean thickness of 19–25nm; meanwhile, MgO CTAB-free particles are aggregated, tiny nanoparticles with an average width of 22nm and an average length of 77nm. The maximum adsorption capacity of as-prepared nanostructured MgO for reactive blue (RB) 19 dye was 250mgg−1. Furthermore, the correlation between structural characterization (mean size, pore, surface) of the samples and the adsorption performance was also discussed in details.
Hand-foot-mouth disease (HFMD) is an emerging infectious disease that affects thousands of children every year in Vietnam, especially in the Mekong Delta Region (MDR). This study aims to analyse both ...provincial and regional level effects of climate factors on HFMD in multiple provinces of this high-risk region. Generalized linear models were used to analyse the daily effects of average temperature, humidity and rainfall on HFMD incidence in each province (provincial-level effects), and random-effect meta-analysis was used to estimate the pooled effect size of these climate–HFMD associations (regional-level effects). Daily effects of the climate factors on HFMD were found at both provincial level and regional level. At provincial level, temperature and humidity had statistically significant positive associations with HFMD while rainfall had both positive and negative associations with HFMD at different lag days. At regional level, temperature and humidity were positively associated with HFMD at lag 0 days (1.7%; 95%CI 0.1%–3.3%) and at lag 3 days (0.3%; 95%CI 0.1%–0.5%), respectively. In contrast, rainfall was found to be negatively associated with HFMD at lag 5 days (− 0.3%; 95%CI − 0.4% to − 0.1%). Heterogeneities of the effects of rainfall on HFMD were found to be higher than those of temperature or humidity. This is the first study to address the climate–HFMD associations in multiple provinces of the MDR. These associations draw attention to climate-related health issues and will help in developing an environment-based early warning system for HFMD prevention and control.
In the present work, a novel composite consisting of magnetite, activated carbon from spent coffee grounds and natural clay (MACCC) was prepared by a one-pot synthesis method via a simultaneous ...activation and magnetization processes. Various techniques (XRD, FTIR, SEM, TEM, EDX, BET) were utilized to characterize the synthesized composite before utilizing it as an adsorbent for removal of Cu(II), Ni(II) and Pb(II) ions from aqueous solutions. Conditions for removal of heavy metals were thoroughly optimized as 25 °C, pH of 5.5, adsorbent dosage of 2 g L
−1
, and a contact time of 60 min. Three models of pseudo first-, second-order and intraparticle diffusion as well as three models of Langmuir, Freundlich, and Temkin were used to analyze kinetics and isotherms of the adsorption process. Thermodynamics was discussed completely. Regeneration and recyclability of the adsorbent were also evaluated. Based on the analysis of experimental results, a possible adsorption mechanism of heavy metals onto the synthesized composite was proposed. The maximum capacities caculated from Langmuir model followed the order of Pb(II) > Cu(II) > Ni(II) as 143.56, 96.16 and 84.86 mg·g
−1
, respectively. The overall results indicated that MACCC is a potential adsorbent for removal of toxic Pb(II), Cu(II) and Ni(II) ions from wastewater due to simple preparation, high removal efficiency and good recyclability.
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•We have demonstrated a facile method to prepare Fe2O3 nanoparticles.•The gas sensing properties of α-Fe2O3 have been invested.•The results show potential application of α-Fe2O3 NPs ...for CO sensors in environmental monitoring.
Iron oxide nanoparticles (NPs) were prepared via a simple hydrothermal method for high performance CO gas sensor. The synthesized α-Fe2O3 NPs were characterized by X-ray diffraction, nitrogen adsorption/desorption isotherm, scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED). The SEM, TEM results revealed that obtained α-Fe2O3 particles had a peanut-like geometry with hemispherical ends. The response of the α-Fe2O3 NPs based sensor to carbon monoxide (CO) and various concentrations of other gases were measured at different temperatures. It found that the sensor based on the peanut-like α-Fe2O3 NPs exhibited high response, fast response–recovery, and good selectivity to CO at 300°C. The experimental results clearly demonstrated the potential application of α-Fe2O3 NPs as a good sensing material in the fabrication of CO sensor.
In this paper, we describe DNA electrochemical detection for genetically modified organism (GMO) based on multi-wall carbon nanotubes (MWCNTs)-doped polypyrrole (PPy). DNA hybridization is studied by ...quartz crystal microbalance (QCM) and electrochemical impedance spectroscopy (EIS). An increase in DNA complementary target concentration results in a decrease in the faradic charge transfer resistance (
R
ct
) and signifying “signal-on” behavior of MWCNTs-PPy-DNA system. QCM and EIS data indicated that the electroanalytical MWCNTs-PPy films were highly sensitive (as low as 4
pM of target can be detected with QCM technique). In principle, this system can be suitable not only for DNA but also for protein biosensor construction.
Ethanol extract of bougainvillea leaves was carbonized by a solvothermal method to synthesize red-emitting carbon quantum dots (R-CQD) in which embedded chlorophyll are red-emitting centers.
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•The green synthesis of red-emitting quantum dots is presented.•Ethanol extract of bougainvillea leaves was used as a carbon source.•Chlorophyll dyes retained in the quantum dots respond for the red emission.•The use of quantum dots as phosphor in horticultural LEDs is demonstrated.
Light emitting diodes (LEDs) having the emission spectra that match the absorption regions of a target plant are strongly demanded for vertical farming. Herein, we demonstrate the use of red-emitting carbon quantum dots (R-CQDs) as a phosphor to fabricate cost-effective horticultural LEDs. R-CQDs having chlorophyll molecules embedded in a carbogenic matrix were solvothermally synthesized using ethanol extract of bougainvillea leaves as a green carbon source. R-CQDs emit a narrow band maximizing at 670 nm originated from the chlorophyll centers when excited either the carbogenic matrix or embedded chlorophyll. R-CQD phosphor converts partially 410 nm light emitted from a LED chip to red and far red regions, thus offering cheaper, single – chip LEDs for agriculture lighting.
It is vital to have high sensitivity in gas sensors to allow the exact detection of dangerous gases in the air and at room temperature. In this study, we used 2D MXenes and MoS2 materials to create a ...Ti3C2–MoS2 composite with high metallic conductivity and a wholly functionalized surface for a significant signal. At room temperature, the Ti3C2–MoS2 composite demonstrated clear signals, cyclic response curves to NO2 gas, and gas concentration-dependent. The sensitivities of the standard Ti3C2–MoS2 (TM_2) composite (20 wt% MoS2) rose dramatically to 35.8%, 63.4%, and 72.5% when increasing NO2 concentrations to 10 ppm, 50 ppm, and 100 ppm, respectively. In addition, the composite showed reaction signals to additional hazardous gases, such as ammonia and methane. Our findings suggest that highly functionalized metallic sensing channels could be used to construct multigas-detecting sensors that are very sensitive in air and at room temperature.
The hypothesized NO2-sensing mechanism of the Ti3C2–MoS2 composite. Display omitted
•Formation of Ti3C2–MoS2 composite from MXenes and MoS2.•Clear signal and concentration-dependent to NO2 gas.•Used to construct multigas-detection sensors in the air.
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