22 research outputs found
Potential of Biochar Production from Agriculture Residues at Household Scale: A Case Study in Go Cong Tay District, Tien Giang Province, Vietnam
This study was conducted in Go Cong Tay district (Tien Giang province, Vietnam) to estimate the potential of using residue from rice production, particularly, rice straw, to produce biochar at household scale. The annual rice yield of Go Cong Tay district is 185,072 tons/year. It creates about 233,190 tons of rice straw per year. Currently, most of these residues are open burned by the farmers. This study examined the experimental biochar production in different modes of combustion (6 h, 10 h and 15 h). The results show that 6 h of combustion is the best condition due to high yield of biochar, less ash and low amounts of incompleted biochar. With 100 kg of rice straw sticks, 48.25 ± 2.25 kg of biochar was produced. The amount of ash and incompleted biochar was low, 0.75 ± 0.13 kg and 3.95 ± 1.33 kg, respectively. The thermal energy of biochar from rice straw is about 4,030 kcal/kg, which is higher than other similar materials such as chaff, sawdust, etc. The suggested model of biochar production is compatible with household scale due to the short time of combustion, high productivity and the method is easy to perform. This practice reduces agricultural waste, protects soil and creates useful thermal energy for household activities (e.g., cooking). The ash created from biochar production can be used for fertilizing
Assessing Vegetation Cover Change Using Remote Sensing: Case Study at Binh Duong Province, Vietnam
This study aims to present the application of remote sensing in monitoring vegetation change in Binh Duong Province, Vietnam. The study used Landsat 5 images in the year 2010 and Landsat 8 images in the years 2015 and 2020 to investigate the area of vegetation. The maximum likelihood classification method (MLC) was used to classify land cover and an accuracy matrix was computed to validate the classification results. The references data were collected to support classification and accuracy assessment processes including land use maps in 2010, 2015, and 2020. In addition, collected field points and UAV (unmanned aerial vehicle) in 2020 were used. The overall accuracies are 81.27%, 84.41%, and 83.86%, and Kappa indices were 0.76, 0.80, and 0.80, corresponding to 2010, 2015, and 2020. The results showed that as compared to 2010 and 2015, the area of vegetation in 2020 decreased 10% and 8%, respectively. The average vegetation cover per capita was 740 m2 person-1 in 2020, compared to 1000 m2 person-1 in 2015 and 1200 m2 person-1 in 2010. This reduction was obvious in urban areas in the province, due to the need for construction and development. The study provides meaningful information on vegetation change and green area per capita in Binh Duong Province from 2010 to 2020
Caveats of fungal barcoding: a case study in Trametes s.lat. (Basidiomycota: Polyporales) in Vietnam reveals multiple issues with mislabelled reference sequences and calls for third-party annotations
DNA barcoding using the nuclear internal transcribed spacer (ITS) has become prevalent in surveys of fungal diversity. This approach is, however, associated with numerous caveats, including the desire for speed, rather than accuracy, through the use of automated analytical pipelines, and the shortcomings of reference sequence repositories. Here we use the case of a specimen of the bracket fungus Trametes s.lat. (which includes the common and widespread turkey tail, T. versicolor) to illustrate these problems. The material was collected in Vietnam as part of a biodiversity inventory including DNA barcoding approaches for arthropods, plants and fungi. The ITS barcoding sequence of the query taxon was compared against reference sequences in GenBank and the curated fungal ITS database UNITE, using BLASTn and MegaBLAST, and was subsequently analysed in a multiple alignment-based phylogenetic context through a maximum likelihood tree including related sequences. Our results initially indicated issues with BLAST searches, including the use of Frairwise local alignments and sorting through Total score and E value, rather than Percentage identity, as major shortcomings of the DNA barcoding approach. However, after thorough analysis of the results, we concluded that the single most important problem of this approach was incorrect sequence labelling, calling for the implementation of third-party annotations or analogous approaches in primary sequence repositories. In addition, this particular example revealed problems of improper fungal nomenclature, which required reinstatement of the genus name Cubamyces (= Leioirametes), with three new combinations: C. flavidus, C lactineus and C. menziesii. The latter was revealed as the correct identification of the query taxon, although the name did not appear among the best BLAST hits. While the best BLAST hits did correspond to the target taxon in terms of sequence data, their label names were misleading or unresolved, including [Fungal endophyte], [Uncultured fungus], Basidiomycota, Trametes cf. cubensis, Lenzites elegans and Geotrichum candidum (an unrelated ascomycetous contaminant). Our study demonstrates that accurate identification of fungi through molecular barcoding is currently not a fast-track approach that can be achieved through automated pipelines
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
Spatiotemporal evolution of SARS-CoV-2 Alpha and Delta variants during large nationwide outbreak of COVID-19, Vietnam, 2021
We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions
Effectiveness of perindopril/amlodipine fixed-dose combination in the treatment of hypertension: a systematic review
Background: Uncontrolled blood pressure is a major risk factor for cardiovascular diseases. Fixed-dose combination (FDC) therapy offers a promising approach to addressing this challenge by providing a convenient single-tablet solution that enhances the effectiveness of blood pressure control. In our systematic review, we assess the effectiveness of perindopril/amlodipine FDC in managing blood pressure.Methods: We conducted a comprehensive search across four primary electronic databases, namely, PubMed, Virtual Health Library (VHL), Global Health Library (GHL), and Google Scholar, as of 8 February 2022. Additionally, we performed a manual search to find relevant articles. The quality of the selected articles was evaluated using the Study Quality Assessment Tools (SQAT) checklist from the National Institute of Health and the ROB2 tool from Cochrane.Results: Our systematic review included 17 eligible articles. The findings show that the use of perindopril/amlodipine FDC significantly lowers blood pressure and enhances the quality of blood pressure control. Compared to the comparison group, the perindopril/amlodipine combination tablet resulted in a higher rate of blood pressure response and normalization. Importantly, perindopril/amlodipine FDC contributes to improved patient adherence with minimal side effects. However, studies conducted to date have not provided assessments of the cost-effectiveness of perindopril/amlodipine FDC.Conclusion: In summary, our analysis confirms the effectiveness of perindopril/amlodipine FDC in lowering blood pressure, with combination therapy outperforming monotherapy and placebo. Although mild adverse reactions were observed in a small subset of participants, cost-effectiveness assessments for this treatment remain lacking in the literature
Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial
Background
Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population.
Methods
AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921.
Findings
Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months.
Interpretation
Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke
Potential of Biochar Production from Agriculture Residues at Household Scale: A Case Study in Go Cong Tay District, Tien Giang Province, Vietnam
This study was conducted in Go Cong Tay district (Tien Giang province, Vietnam) to estimate the potential of using residue from rice production, particularly, rice straw, to produce biochar at household scale. The annual rice yield of Go Cong Tay district is 185,072 tons/year. It creates about 233,190 tons of rice straw per year. Currently, most of these residues are open burned by the farmers. This study examined the experimental biochar production in different modes of combustion (6 h, 10 h and 15 h). The results show that 6 h of combustion is the best condition due to high yield of biochar, less ash and low amounts of incompleted biochar. With 100 kg of rice straw sticks, 48.25 ± 2.25 kg of biochar was produced. The amount of ash and incompleted biochar was low, 0.75 ± 0.13 kg and 3.95 ± 1.33 kg, respectively. The thermal energy of biochar from rice straw is about 4,030 kcal/kg, which is higher than other similar materials such as chaff, sawdust, etc. The suggested model of biochar production is compatible with household scale due to the short time of combustion, high productivity and the method is easy to perform. This practice reduces agricultural waste, protects soil and creates useful thermal energy for household activities (e.g., cooking). The ash created from biochar production can be used for fertilizing
Effects of simulated microgravity on the morphology of mouse embryonic fibroblasts (MEFs)
This study aimed to assess the effects of simulated microgravity on mouse embryonic fibroblast (MEF) morphology. The results showed that the area of MEFs under simulated microgravity was 7843.39 +/- 551.31 mu m(2) which was lower than the control group (9832.72 +/- 453.86 mu m(2)) (p < 0.001). The nuclear area of MEFs under simulated microgravity (290.76 +/- 4.58 mu m(2)) and the control group (296.8 +/- 4.58 mu m(2)) did not statistically differ. In addition, the nuclear shape value of the MEFs under simulated microgravity and the control group did not statistically differ (0.86 +/- 0.006 vs. 0.87 +/- 0.003, respectively). The nuclear intensity of MEFs under simulated microgravity (19361 +/- 852) was higher than the control group (16997 +/- 285) (P <0.05). Moreover, the flow cytometry analysis indicated the reduced GO/G1 phase cell ratio and the increased S phase and G2/M phase cell ratio in MEFs under simulated microgravity. Simulated microgravity also induced a decrease in diameter of actin filament bundles of the MEFs under simulated microgravity (1.61 +/- 0.33 mu m) compared to the control group (1.79 +/- 0.32 mu m) (P <0.01). These results revealed that simulated microgravity is capable of inducing the morphological changes of mouse embryonic fibroblasts
Metagenomic insights into lignocellulose-degrading genes through Illuminabased de novo sequencing of the microbiome in vietnamese native goats’ rumen
The scarcity of enzymes having an optimal activity in lignocellulose deconstruction is an obstacle for industrial-scale conversion of cellulosic biomass into biofuels. With the aim of mining novel lignocellulolytic enzymes, a ~9 Gb metagenome of bacteria in Vietnamese native goats’ rumen was sequenced by Illumina platform. From the data, 821 ORFs encoding carbohydrate esterases (CEs) and polysaccharide lyases (PLs) serving for lignocellulose pre-treatment, 816 ORFs encoding 11 glycoside hydrolase families (GHs) of cellulases, and 2252 ORFs encoding 22 GHs of hemicellulases, were mined. The carbohydrate binding module (CBM) was also abundant with 763 ORFs, of which 480 ORFs are located with lignocellulolytic enzymes. The enzyme modularity analysis showed that CBMs are usually present in endoglucanase, endo 1,3-beta-D-glucosidase, and endoxylanase, whereas fibronectin 3-like module (FN3) mainly represents in GH3 and immunoglobulin-like domain (Ig) was located in GH9 only. Every domain located in each ORF was analyzed in detail to contribute enzymes’ modularity which is valuable for modelling, to study the structure, and for recombinant production. With the aim of confirming the annotated results, a mined ORF encoding CBM63 was highly expressed in E. coli in soluble form. The purified recombinant CBM63 exhibited no cellulase activity, but enhanced a commercial cellulase activity in the destruction of a paper filter