843 research outputs found
Fear of travelling after COVID-19: The moderation effect of social distancing
COVID-19 has caused unparalleled public dread, which will most certainly impede tourist business recovery once the epidemic is gone. This research investigates the causes of the general public's epidemic travel anxiety, as well as how individuals impose self-protection, coping, and resilience with travel. The study blends theories such as protection motive theory, coping theory, and resilience theory to achieve the research goal. The primary data came from an online poll of 322 Southeast Asian travelers. According to the findings, the magnitude and vulnerability of the danger might induce "travel dread," which leads to protection motivation and precautionary travel behaviors during the pandemic. The findings also demonstrate that social distancing has memory consequences. In other words, individuals who willingly engaged in social separation during the pandemic are more likely to continue doing so in the post-COVID period since their long-term behavior has been influenced.Tomas Bata University in Zlín, TBU; Finance Authority of Maine, FAM
Roles of Gate-Oxide Thickness Reduction in Scaling Bulk and Thin-Body Tunnel Field-Effect Transistors
Tunnel field-effect transistor (TFET) has recently been considered as a promising candidate for low-power integrated circuits. In this paper, we present an adequate examination on the roles of gate-oxide thickness reduction in scaling bulk and thin-body TFETs. It is shown that the short-channel performance of TFETs has to be characterized by both the off-current and the subthreshold swing because their physical origins are completely different. The reduction of gate-oxide thickness plays an important role in maintaining low subthreshold swing whereas it shows a less role in suppressing off-state leakage in short-channel TFETs with bulk and thin-body structures. When scaling the gate-oxide thickness, the short-channel effect is suppressed more effectively in thin-body TFETs than in bulk devices. Clearly understanding the roles of scaling gate-oxide thickness is necessary in designing advanced scaled TFET devices
Pump-Induced Dynamical Tunneling in a Deformed Microcavity Laser
Pump-induced dynamical tunneling has been observed in free-space resonant optical pumping of a deformed microcavity by employing excitation spectroscopy. A focused-pump beam was injected into the cavity by refraction and then coupled to a high-Q cavity mode via dynamical tunneling. Pump-coupling efficiency as high as 50% and an effective coupling constant responsible for the tunneling were obtained from the observed pumping efficiency with a mode-mode coupling modelopen2
Screening for actinomyces isolated from soil with the ability to inhibit Xanthomonas oryzae pv. oryzae causing rice bacterial blight disease in Vietnam
Bacterial blight disease caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the major diseases in rice culture of Northen Vietnam, as well as other rice-growing regions of the world. In this study, we isolated and screened for actinomycete strains from Vietnam with the ability to inhibit Xoo isolates from northern Vietnam. From 90 actinomycete strains taken from soil in northern Vietnam in 2010, we screened for their antagonistic activity against 10 races of Xoo causing rice bacterial blight disease. Three actinomycete strains were found to inhibit all 10 Xoo races. Among the three strains, a strain namely VN10-A-44 was shown not to have the ability to produce toxic compounds and was selected for further study. The strain was identified as Streptomyces virginiae by 16S ribosomal RNA gene sequencing. We replaced soybean meal with tofu waste in antibiotic producing medium to improve antagonistic activity of VN10-A-44 against the Xoo pathogen and to make use of tofu waste for large-scale fermentation of VN10-A-44. We found that replacing soybean meal with 20 and 30 g of tofu waste/litter in the antibiotic producing medium gave the largest inhibition zone against the Xoo pathogen.Key words: Xanthomonas oryzae pv. oryzae, rice bacterial blight disease, Streptomyces virginiae, Vietnam
Rapid oxidative fragmentation of polypropylene with pH control in seawater for preparation of realistic reference microplastics
Various tiny plastic particles were retrieved from the sea and studied using scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) analysis to prepare realistic reference microplastics (MP). Most of the MP exhibited a diameter of < 20 × 10−6 m and 0.1–0.2 molar ratios of oxygen to carbon atoms (O/C), indicating that they primarily comprised polyethylene (PE), polypropylene (PP), and polystyrene (PS). It took a long time to reproduce such O/C ratios in standard laboratory weathering methods. For example, degrading of 30 × 30 × 0.060 mm PP film required 75 days for the 0.1 ratio, even with an advanced oxidation process (AOP) using a sulfate radical anion (SO4·−) initiator in distilled water at 65 °C. However, seawater drastically improved the PP degradation performance of AOP under a weak acid condition to achieve the 0.1 ratio of PP film in only 15 days. The combination of seawater and the SO4·− initiator accelerated the degradation process and showed that the MP’s size could be controlled according to the degradation time
The role of nutritional risk evaluation in predicting adverse outcomes among patients with severe COVID-19 in Vietnam
IntroductionAs sufficient nutrition helps alleviate catabolic stress and modulate the systemic inflammatory response of the body, it plays an indispensable role in the good prognosis of critically ill patients. Thus, this study aimed to investigate the malnutrition of patients with severe COVID-19 and its association with adverse treatment outcomes.MethodsWe conducted a retrospective cross-sectional study in two provincial hospitals in Hanoi from February to April 2022. Participants were patients with severe COVID-19 admitted to the Intensive Care Unit (ICU). Malnutrition risk were evaluated by Nutritional Risk Screening-2002 (NRS), Global Leadership Initiative on Malnutrition (GLIM), Prognostic Nutritional Index (PNI), and the adverse prognosis was assessed by Acute Physiology and Chronic Health Evaluation II (APACHE II). The multivariate receiver-operating characteristic (ROC) curve was applied to estimate the predictive ability of those criteria regarding worse treatment results.ResultsThe percentages of malnutrition measured by NRS, GLIM, PNI, and BMI were 62.6, 51.5, 42.9, and 16.6%, respectively. Patients with more severe malnutrition assessed by GLIM, PNI, and having above target fasting blood glucose (FBG) (≥10.0 mmol/L) were more likely to have higher APACHE scores. PNI had a better diagnostic performance than NRS and BMI (AUC = 0.84, 0.81, and 0.82, respectively). In addition, FBG revealed a good prognostic implication (AUC = 0.84).ConclusionA relatively high percentage of patients experienced moderate and severe malnutrition regardless of screening tools. Individuals at higher risk of malnutrition and high FBG were predicted to have more adverse treatment outcomes. It is recommended that nutritional screening should be conducted regularly, and personalizing nutritional care strategies is necessary to meet patients’ nutrient demands and prevent other nutrition-related complications
Camellia sinensis extract delays microbiological and oxidative changes in striped catfish fillets during frozen storage
peer reviewedThis study investigated the effects of tea leaf (Camellia sinensis) extract on the quality of striped catfish (Pangasianodon hypophthalmus) fillets during 18-months of frozen storage (-20 ± 2 °C). Fillet samples were submitted to the treatments Control (cold tap water), CS 7.63 (C. sinensis extract solution 7.63 µg/mL) and CS 625 (C. sinensis extract 625 µg/mL) and stored for 18 months, with collections performed at 0, 1, 3, 6, 9, 12 and 18 months. Total viable count, physicochemical parameters (water holding capacity, total volatile basic nitrogen, peroxide value, thiobarbituric acid reactive substances, moisture and pH), sensory properties and color measurement were evaluated. Results showed that fillets treated with C.a sinensis extracts slightly reduced lipid oxidation, inhibited bacterial growth and improved sensory properties compared to untreated samples, without causing significant changes in the other quality indicators. The findings indicated that the green tea leaf extract immersion treatments, contributed to the improved quality preservation of striped catfish fillets during frozen storage
Chemical constituents of Chirita drakei Burtt collected in Ha Long bay, Quang Ninh province, Viet Nam. Part 1. Compounds isolated from the n-hexane and ethyl acetate extracts.
Two triterpenes, an anthraquinone, two lignans and a phenolic compound were isolated from the n-hexane and ethyl acetate extracts of the aerial part of Chirita drakei Burtt collected in islands, on mountain slopes of Ha Long bay, Quang Ninh province. Their structures have been elucidated by mass, NMR spectroscopy and comparison with published data. There are no report on the chemical constituents of Chirita drakei before our study. Keywords. Chirita drakei, triterpene, anthraquinone, lignin
Effects of second litter syndrome on reproductive performance in sows
Background and Aim: The effects of second litter syndrome (SLS) on subsequent reproductive performance remain poorly understood. This study examined the impact of SLS on reproductive parameters such as piglets born alive (PBA), accumulative number of PBA (APBA), farrowing interval (FI), and risk of decreased PBA (DPBA) up to parity 5.
Materials and Methods: Data on 5,464 litters were recorded from 1,507 sow cards collected on five swine farms in northern Vietnam. A linear mixed-effect model was used to analyze the effect of SLS on the PBA, APBA, and FI. A generalized linear mixed model was used to analyze the effect of DPBA in parity n on the risk of DPBA in parity n + 1.
Results: About 47.8% of the sows contracted SLS (720/1507). Only APBA1-2 was significantly decreased by SLS. The APBA3-5 in SLS sows was comparable to that in non-SLS sows (41.8 vs. 41.9). Non-DPBA2 upped the risk for DPBA3 by 3.6-fold (95% confidence interval [CI]: 2.8–4.6). Moreover, non-DPBA3 increased the risk of DPBA4 (odds ratio [OR] = 2.7, 95% CI = 2.1–3.7), and non-DPBA4 increased the risk of DPBA5 (OR = 3.2, 95% CI = 2.3–4.7). The risks of developing DPBA4 and DPBA5 remained unchanged following SLS (p > 0.05). About 98.4% of sows underwent PBA fluctuations during their first five parities.
Conclusion: SLS does not appear to detrimentally affect PBA, APBA, and FI in subsequent parities. Therefore, SLS sows do not necessarily have future low reproductive performance or be culled. Future investigations should explore the mechanism of alternate decrease/increase patterns in PBA
Kinetics of neutralizing antibodies against Omicron variant in Vietnamese healthcare workers after primary immunization with ChAdOx1-S and booster immunization with BNT162b2
We studied the development and persistence of neutralizing antibodies against SARS-CoV-2 ancestral strain, and Delta and Omicron (BA.1 and BA.2) variants in Vietnamese healthcare workers (HCWs) up to 15 weeks after booster vaccination. We included 47 HCWs, including group 1 (G1, N = 21) and group 2 (G2; N = 26) without and with breakthrough Delta variant infection before booster immunization, respectively). The study participants had completed primary immunization with ChAdOx1-S and booster vaccination with BNT162b2. Neutralizing antibodies were measured using a surrogate virus neutralization assay. Of the 21 study participants in G1, neutralizing antibodies against ancestral strain, Delta variant, BA.1, and BA.2 were (almost) abolished at month 8 after the second dose, but all had detectable neutralizing antibodies to the study viruses at week 2 post booster dose. Of the 26 study participants in G2, neutralizing antibody levels to BA.1 and BA.2 were significantly higher than those to the corresponding viruses measured at week 2 post breakthrough infection and before the booster dose. At week 15 post booster vaccination, neutralizing antibodies to BA.1 and BA.2 dropped significantly, with more profound changes observed in those without breakthrough Delta variant infection. Booster vaccination enhanced neutralizing activities against ancestral strain and Delta variant compared with those induced by primary vaccination. These responses were maintained at high levels for at least 15 weeks. Our findings emphasize the importance of the first booster dose in producing cross-neutralizing antibodies against Omicron variant. A second booster to maintain long-term vaccine effectiveness against the currently circulating variants merits further research
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