Since the worldwide outbreak of the COVID‐19 pandemic in December 2019, Taiwan has successfully stopped the spread of COVID‐19. The policies and works of the epidemic control are a complex and ...dynamic process. This study applied the methodology of system dynamics to explore the structure of the COVID‐19 epidemic control system in Taiwan and analysed its system behaviours. The results show that the system is composed of key subsystems, such as national health insurance and quarantine, combined with government policies. Joint efforts among the central and local governments and the general public have been made to strengthen the quarantine of border entrants, encourage the public to wear masks and employ technology for contact tracing and tracking down those being tested positive with COVID‐19. Together with the efficient increase in the capacity of testing and medical treatments, these measures can effectively reach a balance between epidemic control and economic activities.
In this paper, atmospheric-pressure air and oxygen corona plasma jets under water surface have been used to generate plasma-activated water (PAW) to inactivate colletotrichum gloeosporioides ( C. ...gloeosporioides ) suspension. The atmospheric-pressure plasma jets in the water were characterized by measuring: 1) the electrical and optical properties for evaluating the plasma efficiency and 2) the physicochemical properties of PAW, including pH value, oxidation-reduction potential value, and the concentration of hydrogen peroxide, nitrite, and ozone. The aim of this paper is to investigate the effects of long-lived reactive oxygen and nitrogen species (RONS) and environmental factor (acidity) in PAW on fungicidal property. The results of antifungal activity show that the inactivation rate of C. gloeosporioides is higher using air-PAW than oxygen-PAW, and increases with increasing reaction time when preparation time of PAW is fixed as 30 min. This correlates well with measurements of the aqueous-phase long-lived RONS concentration such as nitrate and ozone, suggesting these species play crucial roles in the inactivation process.
Domestication of clonally propagated crops such as pineapple from South America was hypothesized to be a 'one-step operation'. We sequenced the genome of Ananas comosus var. bracteatus CB5 and ...assembled 513 Mb into 25 chromosomes with 29,412 genes. Comparison of the genomes of CB5, F153 and MD2 elucidated the genomic basis of fiber production, color formation, sugar accumulation and fruit maturation. We also resequenced 89 Ananas genomes. Cultivars 'Smooth Cayenne' and 'Queen' exhibited ancient and recent admixture, while 'Singapore Spanish' supported a one-step operation of domestication. We identified 25 selective sweeps, including a strong sweep containing a pair of tandemly duplicated bromelain inhibitors. Four candidate genes for self-incompatibility were linked in F153, but were not functional in self-compatible CB5. Our findings support the coexistence of sexual recombination and a one-step operation in the domestication of clonally propagated crops. This work guides the exploration of sexual and asexual domestication trajectories in other clonally propagated crops.
A new technique, plasma activated water (PAW), was used to inactivate bacteria on the tomato surface. The PAW was generated at 60 Watts (W) for 20 min using air flow rates at 6 or 10 standard liter ...per min (slm) with 1 or 2 plasma jet(s). Tomatoes inoculated with Salmonella Typhimurium, Escherichia coli, or Listeria monocytogenes were treated by the PAW for 30, 60, 90, 120, 150, 180 or 210 s. Significantly higher reductions (p < 0.05) of bacterial populations were obtained with 2 plasma jets. More than 5 log reductions of S. Typhimurium, E. coli, and L. monocytogenes were obtained when treated with 2 acting plasma jets for 30, 180, and 210 s, respectively. When treatment time increased, lower values of pH and higher values of oxidative reduction potential, nitrite, nitrate, ozone, and peroxide were obtained. An analysis of the electron paramagnetic resonance confirmed the generation of reactive oxygen species in PAW. This study showed that PAW was effective against bacteria on tomato surfaces and offered evidences for the antibacterial mechanism of PAW.
•Reducing S. Typhimurium, E. coli, and L. monocytogenes on tomato.•S. Typhimurium and L. monocytogenes was the most susceptible and resistant, respectively.•The concentrations of NO2−, NO3−, O3, and H2O2 were correlated with the antibacterial efficacy.•The generation of ROS was confirmed.
Coronavirus disease 2019 (COVID-19) vaccines were rapidly implemented globally and vaccine-associated immune-related hepatitis was recently reported. We aim to investigate its impact in regions ...endemic of chronic hepatitis B (CHB).
We retrospectively collected patients who developed hepatitis within 90 days after COVID-19 vaccination in Taiwan. The mechanisms of hepatitis included vaccine induced liver injury (VILI) and immune-related hepatitis, which are direct liver injuries defined as aspartate or alanine aminotransferase (AST or ALT) increased ≥ 5-fold upper limit of normal (ULN) and/or AST or ALT ≥ 3-fold of ULN with concurrent total bilirubin ≥ 2-fold of ULN. Indirect liver injury due to HBV reactivation was defined as HBsAg reverse seroconversion or significant rise in HBV DNA level. The demographics, clinical data, and course of hepatitis were compared statistically.
Twenty-five patients were included with a median age of 54. The culprit vaccines were ChAdOx1 nCoV-19 (n = 9), mRNA-1273 (n = 12), and BNT162b2 (n = 4). The characteristics of hepatitis were comparable regardless of vaccine subtypes. The median onset of hepatitis was 25 days post vaccination, with a peak of 10-fold ALT-increase. The etiologies included HBV reactivation (n = 10), VILI (n = 10), and immune-related hepatitis (n = 5). HBV reactivation accounts for 90% of vaccine-induced hepatitis in patients of CHB (n = 10), and two patients died. Patients with initial AST levels >500 U/L increased 27-fold risks of liver injury greater than moderate severity compared with those without.
COVID-19 vaccine induced hepatitis is a clinical significant complication, and HBV reactivation may account for a possible mechanism.
The consumption of fresh produce is steadily increasing and chlorine washing is the most commonly used method of disinfecting fresh produce. However, chlorine washing possesses a potential risk. ...Hence, this study used ozone microbubble (OMB) water to disinfect Salmonella Enteritidis, S. Typhimurium, Staphylococcus aureus, and Escherichia coli on tomatoes. After injecting ozone into the microbubble generator, OMB was fulfilled in a 10 L tank for 10 or 20 min. The inoculated tomatoes were washed for 30 or 60 s. Control groups included unwashed, water-washed, microbubble-only, and ozone-only. The microbial populations were significantly lower on the OMB-treated tomatoes than controls (p < 0.05), but not between various fulfilling or treatment time (p > 0.05). When tomatoes were treated with OMB with 10 min fulfilling and 30-s washing, the differences of tested bacteria and water washing, ozone-only, and microbubble-only were: S. Enteritidis: 4.11, 3.37, 2.54 log CFU/tomato; S. Typhimurium: 4.83, 4.50, 2.78 log CFU/tomato; E. coli: 4.31, 4.08, 2.09 log CFU/tomato; S. aureus: 4.12, 3.93, 2.82 log CFU/tomato. In addition, significant higher ozone concentrations and conductivity were detected in OMB water than other groups (p < 0.05). Color, texture, and sensory characteristics of the OMB-treated tomatoes were not significantly different from other groups (p > 0.05). This study demonstrated that OMB effectively inactivated bacteria on tomatoes and did not affect the physical and sensory characteristics of tomatoes.
The major pathogen associated with eggs is Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis) and chlorine washing is the most widely used for sanitization. Microbubble, a novel ...technique and able to operate in large quantity, has been presented to be an alternative method. Thus, microbubble water combining with ozone (OMB) was applied to disinfect S. Enteritidis spiked on shells at 107 cells per egg. OMB was generated by injecting ozone into a Nikuni microbubble system, then delivered into 10 L of water. After 5, 10, or 20 min of activation time, the eggs were placed into OMB and washed for 30 or 60 s. The controls involved unwashed, water washing, ozone only, and microbubble only (MB). The highest reduction, 5.19 log CFU/egg, was achieved by the combination of 20-min activation and 60-s washing, which was used for following tests of large water quantities. Comparing with the unwashed control, 4.32, 3.73 and 3.07 log CFU/egg reductions were achieved in 25, 80, and 100 L of water, respectively. The other system, Calpeda, with higher motor power was tested in 100 L and obtained a reduction of 4.15 log CFU/egg. The average diameter of bubbles generated by Nikuni and Calpeda pump systems were 29.05 and 36.50 μm, respectively, which both were within the microbubble definition of ISO. Much lower reductions, around 1–2 log10 CFU/egg, were shown with the treatments of ozone only and MB by the same operative parameters. After 15-day storage at ambient temperature, the OMB-treated eggs showed similar sensory quality with the unwashed ones. This is the first study demonstrating that OMB effectively inactivates S. Enteritidis on shell eggs in large quantity of water and does not diminished the sensory characteristics of eggs. Furthermore, bacterial population was under the detection limit in the OMB-treated water.
•Ozone microbubble (OMB) systems were able to inactivate S. Enteritidis on egg surfaces in large quantities of water.•The OMB applied on shell eggs achieved around 4 log CFU/egg reduction in 100 L.•OMB caused a less negative impact on egg freshness quality than commercial washing.
Atmospheric-pressure plasma enhances cell growth on two different pore sizes of honeycomb pattern on polylactide surface.
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•Different pore sizes of honeycomb pattern on PLA film are ...created.•The two-step plasma treatment provided the oxygen- and nitrogen-containing functional groups that had a major impact on cell cultivation.•The plasma treatment had a significant effect for cell proliferation.•The surface structures are the main influence on cell cultivation, while plasma treatment can indeed improve the growth environment.
In this paper, we compare the cell growth results of NIH-3T3 and Neuro-2A cells over 72h on flat and honeycomb structured PLA films without and with a two-step atmospheric-pressure nitrogen-based plasma jet treatment. We developed a fabrication system used for forming of a uniform honeycomb structure on PLA surface, which can produce two different pore sizes, 3–4μm and 7–8μm, of honeycomb pattern. We applied a previously developed nitrogen-based atmospheric-pressure dielectric barrier discharge (DBD) jet system to treat the PLA film without and with honeycomb structure. NIH-3T3 and a much smaller Neuro-2A cells were cultivated on the films under various surface conditions. The results show that the two-step plasma treatment in combination with a honeycomb structure can enhance cell growth on PLA film, should the cell size be not too smaller than the pore size of honeycomb structure, e.g., NIH-3T3. Otherwise, cell growth would be better on flat PLA film, e.g., Neuro-2A.
Electric power is the cornerstone of economic growth, as well as one of the major energy sources for modern society. Economic growth, the demand for electricity, the security of fuel supplies, ...power-generating technologies, and the impact on the environment must be considered in the development planning and policy making of electric power. In fact, the planning of electric power development and the establishment of power generation capacity are complex and dynamic processes, which are influenced by national policies, citizens’ acceptance, and domestic and international energy sources. Hence, this study adopted system dynamics methodology to explore the development of policy-based electric power planning in Taiwan, analyzed its system structure, and simulated the impact of energy source policies on Taiwan's power supply according to different scenarios of economic growth. The findings of this study showed that the power supply in Taiwan is mainly influenced by four sub-systems with three important level variables, including the installed capacity of thermal power, installed capacity of nuclear power, and installed capacity of renewable energy. Currently, Taiwan plans to eradicate nuclear power by 2025 and replace it with renewable energies, which could result in power shortages and power rationing.
•The history and crisis of Taiwan's electric power development is explored.•A dynamic model of Taiwan's electric power development is posed using system dynamics approach.•Impacts of different economic growth scenarios on electric power development are simulated.•Policy effects of the electric power plan in energy transition are discussed.
A configuration of magnetic-assisted-plasma (MAP) on helium-based atmospheric-pressure plasma jet (APPJ) with an axial magnetic-field of 0.587 T is proposed, which provides good ability for killing ...bacteria Escherichia coli on the agar surface. Optically, we confirmed that the MAP increased approximately 2.4 times in the electron density estimated by the Stark broadening of Hβ line emission, and approximately 1.5 times enhancement of atomic oxygen concentration measured by vacuum ultraviolet absorption spectroscopy (VUVAS). Moreover, the generation of hydroxyl radical in the water increased 1.5 times, confirmed by the spin-trapping electron spin-resonance technique. In addition, the bactericidal experiments demonstrated 2.4 times higher for E. coli by the MAP treatment. The MAP configuration is proposed to be highly useful for future bio-medical applications by enhancing the radical generation at the plasma/substrate interface region.
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