Search

White radish sliced at 4 mm thickness was dehydrated by traditional osmotic dehydration (TOD) with nine types of osmotic solutions prepared by a randomized combining three levels concentration of sucrose and sodium chloride. The mass transfer characteristics were evaluated through the moisture diffusivity (Dm) and solid diffusivity (Ds), the fit of model was also estimated based on three popular models, including Newton, Henderson, and Pabis and Weibull. The results showed that white radish had the highest Dm and Ds value in the 4% salt and 15% sucrose solution, which presented that the fastest transfer process occurred in this solution. In addition, the Weibull model was the best model due to the highest R2 and the lowest root mean square error and chi-square, which means this model could fully describe the mass transfer (moisture/solid transfer) behavior of white radish.

Saltwater intrusion is a potential risk damaging crop diversity and productivity due to degraded soil physicochemical properties. However, little is known about how salinity affects the structure and function of soil nematodes community in intensive rice cultivated area. This study aimed (1) to assess the impacts of saltwater intrusion on the nematode community in alluvial and acid sulfate soils; and (2) to evaluate its relation with soil conditions. Saltwater intrusion reduced the abundance of both free-living nematodes (FLN) and plant-parasitic nematodes (dominated by Hirschmanniella) in soils. FLN community was different among sites with different physicochemical properties. The omnivorous genera Aporcelaimellus and Thornenema were only found in non-salt-affected alluvial soil, whilst Mesodorylaimus was dominant in salt-affected acid sulfate soil, suggesting that this genus might be tolerant to higher EC and soluble Na+, K+, Ca2+. The bacterivorous nematodes (dominant taxa Chronogaster, Rhabdolaimus) were dominant in both non-salt affected and salt-affected alluvial soils, which accounted for 48% and 40%, respectively, whilst it accounted for 21% in salt-affected acid sulfate soil. The abundance of fungivorous nematodes (Aphelenchoides, Ditylenchus, Filenchus) were greater in salt-affected alluvial soil in contrast to the other treatments, suggesting that these might be tolerant to salinity and low pH. Saltwater intrusion reduced biological diversity (Margalef, Shannon-Wiener, and Hill’s indices), maturity index (∑MI, MI25), and clearly affected functional guilds of nematode community, especially c-p 5 group was reduced in both salt-affected soils. This study suggests that saltwater intrusion showed a potential risk in the degradation of soil properties, as indicated by the altered nematode community, trophic structure, functional guilds and their ecological indices in paddy fields.

Background: Direct-Acting Antivirals (DAAs) are recommended as first-line of drugs for the treatment of chronic hepatitis C virus (HCV) infection in Vietnam in 2016. Since then, Hospital for Tropical Diseases (HTD), Ho Chi Minh City, Vietnam introduced DAAs based treatment for all newly presented chronic HCV patients. Here, we report the sociodemographic, clinical, biochemical, and virologic characteristics of patients and the direct medical cost associated with DAAs treatment. Methods: We conducted a retrospective cross-sectional study among chronic HCV patients attended at HTD from March 2016 to October 2017 and treated with DAAs. We used an extract of the patient’s electronic medical record containing demographics, clinical presentations, laboratory results, drug prescription, and cost of treatment at the hospital for data analysis. Results: 2817 chronic HCV patient received DAAs treatment during the study period. The mean age was 55.0 years, and 54.9% (1546/2817) of the patients were female. HCV genotype 1, 2, 3 and 6 prevalence was 32.1% (904/2817), 12.7% (359/2817), 0.4% (10/2817), and 54.7% (1542/2817) respectively. The mean HCV viral load was 3.1 × 106 copies/ml, including 46.9% (1322/2817) had ≥106 copies/ml. 70.64% (1990/2817) and 16.15% (455/28817) of the patients received Sofosbuvir (SOF)/Ledipasvir (LDV) ± Ribavirin (RBV) and SOF/Daclatasvir (DCV) ± RBV therapy respectively. The average drug cost for a 12-week of SOF/LDV ± RBV and SOF/DCV ± RBV treatment was US$2068 - 2230 and US$2417 - 2472, respectively. Conclusion: Genotype 6 was the most predominant genotype in southern Vietnam. The preferred treatment for chronic HCV infection was SOF/LDV ± RBV for 12 weeks.

This study evaluated surface water quality changes in Ben Tre province using multivariate statistical analyses. The water monitoring data were collected from the Department of Natural Resources and Environment of Ben Tre province in 2020, which 13 water parameters have been measured, including pH, water temperature (T), salinity (Sal), turbidity (Turb), total suspended solids (TSS), dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), ammonium (NH4+_N), nitrate (NO3-_N), orthophosphate (PO43-_P), iron (Fe) and coliform bacteria. Water quality was assessed using national technical regulations on surface water quality of QCVN 08-MT: 2015/BTNMT. Spatiotemporal variation of water quality was evaluated using cluster analysis (CA) while potential pollution sources and key water variables influencing water quality were evaluated using principal component analysis (PCA). The findings showed that the water parameters of turbidity, salinity, TSS, DO, BOD, COD, NH4+_N, PO43-_P, Fe and coliform exceeded the allowable limits of QCVN 08-MT:2015/BTNMT. The water parameters of BOD, COD, NO3-_N, PO43-_P in the rainy season tended to be higher than those in the dry season. Cluster analysis divided surface water quality into 7 clusters, thus reducing 8 sampling sites, and 2 monitoring times of frequency. Principal component analysis identified 13 potential pollution sources affecting surface water quality in the study area, in which, 76.10 % of the variation in surface water quality were contributed by PC1, PC2, PC3, PC4 and PC5. PCA results also showed that 13 observed water parameters significantly contribute to the variation in water quality. The current study results could be very useful in reducing sites and frequency of surface water quality monitoring in Ben Tre province. HIGHLIGHTS The water quality in the study area was polluted by suspended particulate matters, organics, nutrients, heavy metals and salinity. Thirteen potential water pollution sources have been identified by principal component ananlysis (PCA), in which, 76.1 % of surface water quality variations were explained by five key sources sources of PC1-PC5 The water quality parameters of BOD, COD, NO3-_N, PO43-_P in the rainy season tended to be higher than those in the dry season Cluster analysis (CA) suggested the current surface water monitoring sites and frequency of the sampling could be reduced by 8 and 2, respectively, thus, saving the monitoring cost GRAPHICAL ABSTRACT

Background: Hepatitis C virus (HCV) genotype 6 is the commonest cause of chronic hepatitis C infection in much of southeast Asia, but data on the effectiveness of direct-acting antiviral agents (DAAs) against this genotype are limited. We conducted a retrospective cohort study of patients attending the Hospital for Tropical Diseases (HTD), Ho Chi Minh City, Vietnam, to define the effectiveness of DAAs in the treatment of chronic HCV genotype 6 in actual practice. Methods: We included all patients with genotype 6 infections attending our hospital between March 2016 and October 2017 who received treatment with sofosbuvir-based DAA treatment regimens, and compared their responses with those with genotype 1 infections. Results: 1758 patients (1148 genotype 6, 65.4%; 610 genotype 1, 34.6%) were analyzed. The majority of patients (1480, 84.2%) received sofosbuvir/ledipasvir (SOF/LDV) ± ribavirin (RBV); 278 (15.8%) received sofosbuvir/Daclatasvir (SOF/DCV) ± RBV. The median age of the patients was 57 years, (interquartile range (IQR) 46–64 years) The baseline HCV viral load (log IU/ml) was significantly higher in patients infected with genotype 6 compared with those infected with genotype 1 (6.8, 5.3–6.6 versus 6.3, 5.3–6.5 log10 IU/ml, p = Conclusions: Our study suggests that patients with HCV genotype 6 infection in Vietnam may respond less well to treatment with sofosbuvir based DAAs than patients with genotype 1 infections. Further studies are needed to confirm this observation and to define whether it is driven by genotype-specific mutations.