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Fulltext Flagellin from Salmonella enteritidis Enhances the Immune Response of Fused F18 from Enterotoxigenic Escherichia coli

Tran-Mai AP, Tran HT, Mai QG, Huynh KQ, Tran TL, Tran-Van H

Trop Life Sci Res, 2022 Sep;33(3):19-32.
PMID: 36545054 DOI: 10.21315/tlsr2022.33.3.2

F18 plays an important role in helping Enterotoxigenic Escherichia coli (ETEC) binds to specific receptors on small intestinal enterocytes, followed by secreting of toxins causing diarrhea in post-weaning piglets (post-weaning diarrhea, PWD). However, the F18 subunit vaccine is not sufficient to stimulate an immune response that can protect weaning pigs from F18-positive ETEC (F18+ETEC). Recently, a body of evidence shows that flagellin protein (FliC) helps to increase the immunity of fused proteins. Therefore, in this study, we combined FliC with F18 to enhance the immune response of F18. The f18 gene was obtained from F18+ETEC, then was fused with the fliC gene. The expression of recombinant FliC-F18 protein was induced by Isopropyl-beta-D-Thiogalactopyranoside (IPTG). The purified protein was tested in vivo in mouse models to evaluate the immunostimulation. Results showed that the fusion of FliC and F18 protein increased the production of anti-F18 antibodies. Besides, the anti-F18 antibody in the collected antiserum specifically identified F18+ETEC. This result provides proof-of-concept for the development of subunit vaccine to prevent PWD using F18 antigen.
Fulltext Atomistic Study of the Bandgap Engineering of Two-Dimensional Silicon Carbide by Hydrogenation

Thu Tran HT, Nguyen PM, Van Nguyen H, Chong TV, Bubanja V, Van Vo H

ACS Omega, 2023 Jul 18;8(28):25424-25431.
PMID: 37483209 DOI: 10.1021/acsomega.3c02914

This work studied hydrogen adsorption by a two-dimensional silicon carbide using a combined molecular dynamics and density functional theory approach. The geometrical properties of partially and fully hydrogenated structures were investigated, considering the effect of zero-point energy. The preferred hydrogen atom location is on top of silicon atoms. The hydrogen interaction energies were obtained for the first time as the attractive force. For fully hydrogenated 2D SiC, the chair-like conformer is the most stable configuration, and the next is the boat-like conformer, while the table-like structure is not stable. The coverage and arrangement of the adsorbed hydrogen atoms significantly influence the values of the direct/indirect bandgaps of the considered systems, increasing the bandgap to 4.07, 3.64, and 4.41 eV for chair-like, table-like, and boat-like, respectively. Their dynamical stability was investigated by phonon dispersion calculations. The obtained results can serve as a guide for the application of hydrogenated two-dimensional silicon carbide in optoelectronic applications in manufacturing innovation.
Fulltext Physiological responses of rosewoods Dalbergia cochinchinensis and D. oliveri under drought and heat stresses

Hung TH, Gooda R, Rizzuto G, So T, Thammavong B, Tran HT, et al.

Ecol Evol, 2020 Oct;10(19):10872-10885.
PMID: 33072302 DOI: 10.1002/ece3.6744

Dalbergia cochinchinensis and D. oliveri are classified as vulnerable and endangered, respectively, in the IUCN Red List and under continued threat from deforestation and illegal harvesting for rosewood. Despite emerging efforts to conserve and restore these species, little is known of their responses to drought and heat stress, which are expected to increase in the Greater Mekong Subregion where the species co-occur and are endemic. In this study of isolated and combined drought and heat effects, we found that D. oliveri had an earlier stomatal closure and more constant midday water potential in response to increasing drought level, suggesting that D. oliveri is relatively isohydric while D. cochinchinensis is relatively anisohydric. Heat shock and drought had synergistic effects on stomatal closure. Our results indicate contrasting relationships in water relations, photosynthetic pigment levels, and total soluble sugars. An increase in chlorophyll a was observed in D. cochinchinensis during drought, and a concomitant increase in carotenoid content likely afforded protection against photo-oxidation. These physiological changes correlated with higher total soluble sugars in D. cochinchinensis. By contrast, D. oliveri avoided drought by reducing chlorophyll content and compromising productivity. Anisohydry and drought tolerance in D. cochinchinensis are adaptations which fit well with its ecological niche as a pioneering species with faster growth in young trees. We believe this understanding of the stress responses of both species will be crucial to their effective regeneration and conservation in degraded habitats and in the face of climate change.
Biodegradation of high di-(2-Ethylhexyl) phthalate (DEHP) concentration by food waste composting and its toxicity assessment using seed germination test

Tran HT, Lin C, Lam SS, Le TH, Hoang HG, Bui XT, et al.

Environ Pollut, 2023 Jan 01;316(Pt 2):120640.
PMID: 36403881 DOI: 10.1016/j.envpol.2022.120640

Di-(2-ethylhexyl) phthalate (DEHP), a plasticizer derived from phthalate ester, is used as an additive in industrial products such as plastics, paints, and medical devices. However, DEHP is known as an endocrine-disrupting chemical, causing cancers and adverse effects on human health. This study evaluated DEHP biodegradation efficiency via food waste composting during 35 days of incubation. At high DEHP concentrations (2167 mg kg-1) in food waste compost mixture, the DEHP biodegradation efficiency was 99% after 35 days. The highest degradation efficiency was recorded at the thermophilic phase (day 3 - day 11) with the biodegradation rate reached 187 mg kg-1 day-1. DEHP was metabolized to dibutyl phthalate (DBP) and dimethyl phthalate (DMP) and would be oxidized to benzyl alcohol (BA) and mineralized into CO2 and water via various metabolisms. Finally, the compost's quality with residual DEHP was evaluated using Brassica chinensis L. seeds via 96 h of germination tests. The compost (at day 35) with a trace amount of DEHP as the end product showed no significant effect on the germination rate of Brassica chinensis L. seeds (88%) compared to that without DEHP (94%), indicating that the compost can be reused as fertilizer in agricultural applications. These results provide an improved understanding of the DEHP biodegradation via food waste composting without bioaugmentation and hence facilitating its green remediation and conversion into value-added products. Nevertheless, further studies are needed on DEHP biodegradation in large-scale food waste composting or industrial applications.
Emerging waste-to-wealth applications of fly ash for environmental remediation: A review

Nguyen HT, Nguyen HT, Ahmed SF, Rajamohan N, Yusuf M, Sharma A, et al.

Environ Res, 2023 Mar 30;227:115800.
PMID: 37003549 DOI: 10.1016/j.envres.2023.115800

The considerable increase in world energy consumption owing to rising global population, intercontinental transportation and industrialization has posed numerous environmental concerns. Particularly, in order to meet the required electricity supply, thermal power plants for electricity generation are widely used in many countries. However, an annually excessive quantity of waste fly ash up to 1 billion tones was globally discarded from the combustion of various carbon-containing feedstocks in thermoelectricity plants. About half of the industrially generated fly ash is dumped into landfills and hence causing soil and water contamination. Nonetheless, fly ash still contains many valuable components and possesses outstanding physicochemical properties. Utilizing waste fly ash for producing value-added products has gained significant interests. Therefore, in this work, we reviewed the current implementation of fly ash-derived materials, namely, zeolite and geopolymer as efficient adsorbents for the environmental treatment of flue gas and polluted water. Additionally, the usage of fly ash as a catalyst support for the photodegradation of organic pollutants and reforming processes for the corresponding wastewater remediation and H2 energy generation is thoroughly covered. In comparison with conventional carbon-based adsorbents, fly ash-derived geopolymer and zeolite materials reportedly exhibited greater heavy metal ions removal and reached the maximum adsorption capacity of about 150 mg g-1. As a support for biogas reforming process, fly ash could enhance the activity of Ni catalyst with 96% and 97% of CO2 and CH4 conversions, respectively.
Fulltext The effect of chloroquine dose and primaquine on Plasmodium vivax recurrence: a WorldWide Antimalarial Resistance Network systematic review and individual patient pooled meta-analysis

Commons RJ, Simpson JA, Thriemer K, Humphreys GS, Abreha T, Alemu SG, et al.

Lancet Infect Dis, 2018 Sep;18(9):1025-1034.
PMID: 30033231 DOI: 10.1016/S1473-3099(18)30348-7

BACKGROUND: Chloroquine remains the mainstay of treatment for Plasmodium vivax malaria despite increasing reports of treatment failure. We did a systematic review and meta-analysis to investigate the effect of chloroquine dose and the addition of primaquine on the risk of recurrent vivax malaria across different settings.
METHODS: A systematic review done in MEDLINE, Web of Science, Embase, and Cochrane Database of Systematic Reviews identified P vivax clinical trials published between Jan 1, 2000, and March 22, 2017. Principal investigators were invited to share individual patient data, which were pooled using standardised methods. Cox regression analyses with random effects for study site were used to investigate the roles of chloroquine dose and primaquine use on rate of recurrence between day 7 and day 42 (primary outcome). The review protocol is registered in PROSPERO, number CRD42016053310.
FINDINGS: Of 134 identified chloroquine studies, 37 studies (from 17 countries) and 5240 patients were included. 2990 patients were treated with chloroquine alone, of whom 1041 (34·8%) received a dose below the target 25 mg/kg. The risk of recurrence was 32·4% (95% CI 29·8-35·1) by day 42. After controlling for confounders, a 5 mg/kg higher chloroquine dose reduced the rate of recurrence overall (adjusted hazard ratio [AHR] 0·82, 95% CI 0·69-0·97; p=0·021) and in children younger than 5 years (0·59, 0·41-0·86; p=0·0058). Adding primaquine reduced the risk of recurrence to 4·9% (95% CI 3·1-7·7) by day 42, which is lower than with chloroquine alone (AHR 0·10, 0·05-0·17; p<0·0001).
INTERPRETATION: Chloroquine is commonly under-dosed in the treatment of vivax malaria. Increasing the recommended dose to 30 mg/kg in children younger than 5 years could reduce substantially the risk of early recurrence when primaquine is not given. Radical cure with primaquine was highly effective in preventing early recurrence and may also improve blood schizontocidal efficacy against chloroquine-resistant P vivax.
FUNDING: Wellcome Trust, Australian National Health and Medical Research Council, and Bill & Melinda Gates Foundation.