This study presents the removal of phosphate from aqueous solution using a new silver nanoparticles-loaded tea activated carbon (AgNPs-TAC) material. In order to reduce costs, the tea activated ...carbon was produced from tea residue. Batch adsorption experiments were conducted to evaluate the effects of impregnation ratio of AgNPs and TAC, pH solution, contact time, initial phosphate concentration and dose of AgNPs-AC on removing phosphate from aqueous solution. Results show that the best conditions for phosphate adsorption occurred at the impregnation ratio AgNPs/TAC of 3% w/w, pH 3, and contact time lasting 150 min. The maximum adsorption capacity of phosphate on AgNPs-TAC determined by the Langmuir model was 13.62 mg/g at an initial phosphate concentration of 30 mg/L. The adsorption isotherm of phosphate on AgNPs-TAC fits well with both the Langmuir and Sips models. The adsorption kinetics data were also described well by the pseudo-first-order and pseudo-second-order models with high correlation coefficients of 0.978 and 0.966, respectively. The adsorption process was controlled by chemisorption through complexes and ligand exchange mechanisms. This study suggests that AgNPs-TAC is a promising, low cost adsorbent for phosphate removal from aqueous solution.
Although it is unclear how Zn
2+
cooperates with Cu
2+
in synergistic antibacterial activity, a 1:10 ratio of Cu
2+
/Zn
2+
atoms and ethylenediaminetetra-acetic acid and urea ligands can be used to ...form a chelation complex containing Cu
2+
and Zn
2+
. This study investigated the effects of the combination of Cu
2+
and Zn
2+
in chelation with EDTA and urea. The results were compared with the outcomes of either copper or zinc alone against gram-negative
Escherichia coli (E. coli
) and gram-positive
Staphylococcus aureus (S. aureus
) bacteria. The antibacterial activity was determined through MICs, disc diffusion method, and bacterial cell growth curves. In addition, bacterial destruction by this chelation complex has been observed through SEM images. The presence of copper ion and zinc ion inside the bacterial cells has been proved through EDS measurements. The obtained results allowed us to draw conclusions that the use of both Cu
2+
and Zn
2+
in a chelation complex with EDTA and urea enhances the antimicrobial activity against these bacteria. The bacterial inhibition of this complex was stronger than that of Cu
2+
alone chelated with EDTA or CuSO
4
solution by approximately 100-fold for
S. aureus
and 20-fold for
E. coli
.
•The goals of economic efficiency and social equity are conflicting features of Vietnam’s rice policies.•Rice profit has markedly fallen during Vietnam’s high economic growth period despite the ...country’s effort to reverse it.•The terms of trade in rice production during Vietnam’s transition have deteriorated due to increasingly high labor costs.•Little investment in R&D and policy restricting farmers’ production choices have curbed technical change in rice production.•Government equity-targeting measures and increasingly aging farm workers have hindered the farm amalgamation process.
Increasing agricultural productivity is often deemed necessary to enhance rural income and ultimately narrow the urban–rural disparity in transitional economies. However, the objectives of social equity and economic efficiency can contradict each other, especially in the context of fierce competition for resources between agriculture and non-agricultural sectors and given the inherently and largely redundant and unskilled aging rural population that often occurs during the economic transition to a market economy. We investigate the case of Vietnam during its high growth period (2000–2016), over which the country introduced policies to increase efficiency in rice production and income for farmers. Contrary to expectations, we find a substantial fall in the terms of trade for rice, indicating a regression in farm income. This fall in the terms of trade did not enhance technical change, as seen in other countries, and only marginally improved technical efficiency in most regions. The reason stems from Vietnam’s limited investment in scientific research and development and policies that restrict farmers’ decision-making power in production, among others. We further examine the causes of inefficiency using data from two household surveys in 2004 and 2014 (with plot-level information) and semi-structured interviews with farmers in 2016–2017. The high ratio of aging farmworkers who are unable to find alternative employment during the transition emerges as an essential impediment to increases in rice productivity, in addition to previously documented land-use-related issues. This demographic feature, along with government equity-targeting measures, hinders the farm amalgamation progress, further limiting efforts to enhance efficiency. Thus, the goals of economic efficiency and social equity do indeed appear to be contradictory features of Vietnam’s rice policies, posing a significant development challenge for the country’s current and likely future progress.
Abstract
α-Thalassemia is a common inherited blood disorder manifested mainly by the deletions of α-globin genes. In geographical areas with high carrier frequencies, screening of α-thalassemia ...carrier state is therefore of vital importance. This study presents a novel method for identifying female carriers of common α-thalassemia deletions using samples routinely taken for non-invasive prenatal tests for screening of fetal chromosomal aneuploidies. A total of 68,885 Vietnamese pregnant women were recruited and α-thalassemia statuses were determined by gap-PCR, revealing 5344 women (7.76%) carried deletions including αα/−−
SEA
(4.066%), αα/−α
3.7
(2.934%), αα/−α
4.2
(0.656%), and rare genotypes (0.102%). A two-stage model was built to predict these α-thalassemia deletions from targeted sequencing of the HBA gene cluster on maternal cfDNA. Our method achieved F1-scores of 97.14–99.55% for detecting the three common genotypes and 94.74% for detecting rare genotypes (−α
3.7
/−α
4.2
, αα/−−
THAI
, −α
3.7
/−−
SEA
, −α
4.2
/−−
SEA
). Additionally, the positive predictive values were 100.00% for αα/αα, 99.29% for αα/−−
SEA
, 94.87% for αα/−α
3.7
, and 96.51% for αα/−α
4.2
; and the negative predictive values were 97.63%, 99.99%, 99.99%, and 100.00%, respectively. As NIPT is increasingly adopted for pregnant women, utilizing cfDNA from NIPT to detect maternal carriers of common α-thalassemia deletions will be cost-effective and expand the benefits of NIPT.
This study investigated the biomass production process from the laboratory to the pilot scale in order to use the nutrient-rich biomass of the diatom
Thalassiosira weissflogii
as live feed for ...white-leg shrimp (
Litopenaeus vannamei
) at larval stages (zoeal, mysis, and postlarval) and in commercial production in hatcheries in Vietnam. Our results showed that
T
.
weissflogii
was successfully cultured in 1–2 L Erlenmeyer flasks, 0.2–3.5 m
3
composite tanks, and 6.5 m
3
tubular photobioreactors, with the highest cell density of 1.6 × 10
6
cells mL
−1
reached after 6 days of culture. Under optimal culture conditions, the protein, lipid, and carbohydrate contents in this algal biomass were 13.2%, 20.0%, and 10.0% of dry cell weight, respectively. The fatty acid composition contains high amount of palmitic acid (C16:0, 43.11% of total fatty acid), and polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA, C20:5ω-3), approximated 16.5% of total fatty acid. In a 50 L larval rearing tank, at the optimal stocking density of 125 nauplii L
−1
, the survival percentage (75.55%), the total body length (from 5.376 ± 0.007 to 10.860 ± 0.030 mm), and weight (at from PL
1
to PL
12
stages) (from 0.145 ± 0.002 to 1.158 ± 0.005 g) of the white-leg shrimp larvae reached the highest values but the metamorphosis time (234 h) was shortest compared with the other stocking densities. Further, adding living
T
.
weissflogii
biomass to the diet of white-leg shrimp larvae at the nauplii 6 stage led to an increase in the body length, weight, and survival percentage of white-leg shrimp larvae of 21.17%, 35.7%, and 33% higher compared with those of larvae fed the control diet (without the addition of
T
.
weissflogii
), respectively. At the same time, the metamorphosis time of larvae (from Z
1
to PL
1
) decreased by 4 h compared to the control group. In intensive ponds (area of 6400 m
2
pond
−1
), using seed stocks at the postlarvae 12 stage that had been fed
T
.
weissflogii
, the final weight, yield, and survival percentage of the shrimp were increased by 7.3%, 14.2%, and 16.3%, respectively, compared with those of the control group. There were no statistically significant differences in the protein and carbohydrate contents in the shrimp flesh among the experimental and control group (
p
> 0.05). The lipid, omega-3, omega-6, and omega-9 fatty acid contents of shrimp flesh in experiment formula (per 100 g shrimp) were 1.21 g, 72.9 mg, 114 mg, and 86.1 mg, 11%, 29%, 21.6%, and 17.7% higher than that those in control, respectively. The obtained results show the great potential of using
T
.
weissflogii
as live feed on white-leg shrimp farms in Vietnam.
Oil pollution in marine environment caused by oil spillage has been a main threat to the ecosystem including the ocean life and to the human being. In this research, three indigenous purple ...photosynthetic strains
Rhodopseudomonas
sp. DD4, DQ41, and FO2 were isolated from oil-contaminated coastal zones in Vietnam. The cells of these strains were immobilized on different carriers including cinder beads (CB), coconut fiber (CF), and polyurethane foam (PUF) for diesel oil removal from artificial seawater. The mixed biofilm formed by using CB, CF, and PUF as immobilization supports degraded 90, 91, and 95% of diesel oil (DO) with the initial concentration of 17.2 g/L, respectively, after 14 days of incubation. The adsorption of DO on different systems was accountable for the removal of 12–16% hydrocarbons for different carriers. To the best of our knowledge, this is the first report on diesel oil degradation by purple photosynthetic bacterial biofilms on different carriers. Moreover, using carriers attaching purple photosynthetic bacteria to remove diesel oil in large scale is considered as an essential method for the improvement of a cost-effective and efficient bioremediation manner. This study can be a promising approach to eliminate DO from oil-contaminated seawater.
Accurate profiling of population‐specific recessive diseases is essential for the design of cost‐effective carrier screening programs. However, minority populations and ethnic groups, including ...Vietnamese, are still underrepresented in existing genetic studies. Here, we reported the first comprehensive study of recessive diseases in the Vietnamese population. Clinical exome sequencing data of 4503 disease‐associated genes obtained from a cohort of 985 Vietnamese individuals was analyzed to identify pathogenic variants, associated diseases and their carrier frequencies in the population. A total of 118 recessive diseases associated with 164 pathogenic or likely pathogenic variants were identified, among which 28 diseases had carrier frequencies of at least 1% (1 in 100 individuals). Three diseases were prevalent in the Vietnamese population with carrier frequencies of 2–12 times higher than in the world populations, including beta‐thalassemia (1 in 23), citrin deficiency (1 in 31), and phenylketonuria (1 in 40). Seven novel pathogenic and two likely pathogenic variants associated with nine recessive diseases were discovered. The comprehensive profile of recessive diseases identified in this study enables the design of cost‐effective carrier screening programs specific to the Vietnamese population.
Prevalent recessive diseases in Vietnam.
Rural finance has long been an important tool for poverty reduction and rural development by donors and governments, but the impacts have been controversial. Measuring impact is challenging due to ...identification problems caused by selection bias and governments’ targeted interventions, while randomised trial data are scarce and limited to contexts where little to no rural finance exists. Using an author‐collected dataset, we provide insights on a large‐scale long‐lasting subsidised rice credit programme in Myanmar, one of the poorest and, until recently, most economically isolated countries in Asia. Identification relies on a fuzzy regression discontinuity design, exploiting an arbitrary element to the credit provision rule which is based on rice landholding size. Although we find little evidence that rice yield or output is increased, we do see that the programme has some positive effects on total household income, suggesting a positive spillover effect on other farm income activities.
A simple design of a broadband multifunctional polarization converter using an anisotropic metasurface for X-band application is proposed. The proposed polarization converter consists of a periodic ...array of the two-corner-cut square patch resonators based on the FR-4 substrate that achieves both cross-polarization and linear-to-circular polarization conversions. The simulated results show that the polarization converter displays the linear cross-polarization conversion in the frequency range from 8 to 12 GHz with the polarization conversion efficiency above 90%. The efficiency is kept higher than 80% with wide incident angle up to 45°. Moreover, the proposed design achieves the linear-to-circular polarization conversion at two frequency bands of 7.42-7.6 GHz and 13-13.56 GHz. A prototype of the proposed polarization converter is fabricated and measured, showing a good agreement between the measured and simulated results. The proposed polarization converter exhibits excellent performances such as simple structure, multifunctional property, and large cost-efficient bandwidth and wide incident angle insensitivity in the linear cross polarization conversion, which can be useful for X-band applications. Furthermore, this structure can be extended to design broadband polarization converters in other frequency bands.
Persistent diarrhea is a severe gastroenteric disease with relatively high risk of pediatric mortality in developing countries. We conducted a randomized, double-blind, controlled clinical trial to ...evaluate the efficacy of liquid-form Bacillus clausii spore probiotics (LiveSpo CLAUSY; 2 billion CFU/5 mL ampoule) at high dosages of 4-6 ampoules a day in supporting treatment of children with persistent diarrhea. Our findings showed that B. clausii spores significantly improved treatment outcomes, resulting in a 2-day shorter recovery period (p < 0.05) and a 1.5-1.6 folds greater efficacy in reducing diarrhea symptoms, such as high frequency of bowel movement of ≥ 3 stools a day, presence of fecal mucus, and diapered infant stool scale types 4-5B. LiveSpo CLAUSY supportive treatment achieved 3 days (p < 0.0001) faster recovery from diarrhea disease, with 1.6-fold improved treatment efficacy. At day 5 of treatment, a significant decrease in blood levels of pro-inflammatory cytokines TNF-α, IL-17, and IL-23 by 3.24% (p = 0.0409), 29.76% (p = 0.0001), and 10.87% (p = 0.0036), respectively, was observed in the Clausy group. Simultaneously, there was a significant 37.97% decrease (p = 0.0326) in the excreted IgA in stool at day 5 in the Clausy group. Overall, the clinical study demonstrates the efficacy of B. clausii spores (LiveSpo CLAUSY) as an effective symptomatic treatment and immunomodulatory agent for persistent diarrhea in children.Trial registration: NCT05812820.
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