Science and Technology Development Journal - Natural Sciences

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ISSN / EISSN : 2588-106X / 2588-106X
Total articles ≅ 412
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Thao Thi Phuong Dang, Linh Mỹ Đào, Tươi Văn Phan, Anh Mẫn Huỳnh
Science and Technology Development Journal - Natural Sciences, Volume 5; https://doi.org/10.32508/stdjns.v5i3.1039

Abstract:
Parkinson's is the second most common neurodegenerative disease in the world (after Alzheimer's), characterized by the degeneration of dopaminergic neurons and mobility impairment, which consequently severely reduces patient life quality. Up to now, Parkinson's Disease cannot be completely cured. Base on the relationship between oxidative stress and the formation, the progression of Parkinson's Disease, antioxidant compounds have been studied as potential candidates in rescue or retard disease progression. Resveratrol is a strong antioxidant, anti-inflammatory, anti-apoptosis compound that exists in many fruits, especially grapes, strawberries..., and has activity depends on the used concentration. In this study, we evaluated the potential of resveratrol for treating Parkinson's Disease at concentrations of 0.064 mg/g, 0.32 mg/g, 0.64 mg/g by utilizing the knockdown dUCH (Drosophila ubiquitin carboxyl-terminal hydrolase) Drosophila melanogaster model. This model can mimic the typical symptoms of Parkinson's Disease and has been proved for the efficiency in screening drugs to treat the disease. Our results showed that the use of resveratrol at a concentration of 0.32 mg/g was effective in preventing the degeneration of dopaminergic neurons and improving mobility in dUCH knockdown flies. These results provided scientific evidence for the development of functional products or drugs to support Parkinson's Disease treatment.
Nguyễn An Sơn, Hai Van Cao, Trieu Ngoc Le, Giang Van Nguyen, Ha Thi Nguyet Nguyen, Quynh Ngoc Dieu Tran, Tien Nguyen Thuy Bui, Duc Doan Dinh Le
Science and Technology Development Journal - Natural Sciences, Volume 5; https://doi.org/10.32508/stdjns.v5i3.1040

Abstract:
Potato is one of popular agricultural products grown and used in the world with high effective economic and nutritional value. In potatoes, there are always have some harmful bacteria species due to the sources of exposure from the seed, soil as well as the post-harvest environment which make deceasing the quality and quantity of potatoes. Usually, irradiation with gamma isotope sources is used in food irradiation, however, the disadvantage of the gamma source is the safe shielding reason even without the use of irradiation. Nowadays, X-ray irradiation in food is one of the methods interest to storage in long time. The first advantage of X-ray irradiation is that most of aerobic bacteria in food is killed, but does it not change the quality of the potato. Moreever, the advantage of an X-ray generator is that it does not have to cover up radiation when not in use. In this study, we have used low energy X-rays emitted from X-ray generator MBR-1618R-BE (Hitachi -Japan) to study the ability to kill aerobic bacteria in potatoes grown in Da Lat. After preparation, potato samples were irradiated at doses ranging from 50 Gy to 5000 Gy. The irradiated samples were homogenized and inoculated on Nutrient Agar and incubated at 370C in an incubator to check the changes of aerobic bacteria. The research showed that the number of aerobic bacteria decreased dramatically to a dose of 1000 Gy (the aerobic bacteria was only less than 0,6%), despite a sharp increase in the dose of irradiation, this number decreased a little. The results also showed that D10 dose was 471,34 Gy.
Nguyen Tuong Vy, Nguyen Thi Khoi Pham, Lam Quoc Ha
Science and Technology Development Journal - Natural Sciences, Volume 5, pp 1350-1364; https://doi.org/10.32508/stdjns.v5i3.958

Abstract:
Polyvinyl alcohol (PVA) is well-known in the packaging industry, especially in the food and medical fields with the ability to be completely biodegradable and easily soluble in cold water therefore products made from it are the environmentally friendly materials. However, the disadvantages of this polymer as quick dissolubility in water, poor moisture retention, weak mechanical properties reduce its applications. In this study, PVA, reinforced by “green” components at the nanometer-level such as nanocellulose fibers (CNF), graphene oxide (GO) nanosheets showed improvements in properties. Mechanical properties of all of nanocomposite films showed improvements in stress at break and modulus. Especially, reinforced GO and CNF films increased almost doubled and improved more 40% in modulus than the pure PVA film and films reinforced by only GO or CNF. When immersed in water (neutral pH) at room temperature, graphene oxide-reinforced films not only had effective improvements in swelling time but also supported to decrease water retension of film added CNF. The combined reinforcement also indicated a benefit in reducing the rate of water vapor loss of the film as well as the efficiency in declining the moisture absorption of the nanocomposite films. The PVA films reinforced by nanocellulose fibers and graphene oxide sheets overcomed some of the PVA's shortcomings. This helped expanding its applications in the field of environmentally friendly nanocomposite films.
Thong Nguyen Hoang, Thuyen Le Xuan, Van Tran Thi
Science and Technology Development Journal - Natural Sciences, Volume 5; https://doi.org/10.32508/stdjns.v5i3.1054

Abstract:
Microalgae blooms are one of the most serious environmental problems that greatly affect the living environment of aquatic organisms. They deplete the oxygen source in the water, seriously depleting the respiratory oxygen source for organisms living in the water body. Some species of microalgae are also capable of producing toxins, typically blue-green algae, poisoning aquatic organisms and causing death, health effects on human life when ingested. This paper presents the results of research on mapping algae concentration distribution to support water quality assessment for Dau Tieng reservoir. Landsat satellite imagery was used for qualitative and quantitative assessment of algae presence in the lake area. Calculation results showed that algae concentration had a linear correlation with the band ratio of the 3-band algorithm (3BDA (2), and was a combination of spectral reflective bands in the green wavelength bands GREEN, RED and near infrared NIR. We simulated the spatial distribution of algae concentrations on the entire lake area on 3 points of time when satellite images had been collected. Result of this study showed that remote sensing technology can be used for monitoring the appearance and change of algae concentration in water, which is an essential measurement for timely providing warnings as well as assisting in monitoring and managing water environment quality to minimize damages to people and the ecosystem.
Thế Luân Nguyễn, Tiến Khoa Lê, Châu Ngọc Hoàng, Hữu Khánh Hưng Nguyễn, Thị Kiều Xuân Huỳnh
Science and Technology Development Journal - Natural Sciences, Volume 5; https://doi.org/10.32508/stdjns.v5i2.1042

Abstract:
The Cu doped ZnO photocatalysts were prepared on ZnO substrate modified with copper nitrate by thermal shock method with different ratio % molar Cu : Zn = 0.3, 0.5, 1.0, 2.0 and 5.0 in order to study the impacts of copper content on the photocatalytic activity of ZnO under both UV and Vis light irradiation. The crystal structure, morphology bulk and surface were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). Their photocatalytic activities were studied via time-dependent degradation of methylene blue in aqueous solution. The results exhibit that crystal structure and morphology of Cu doped ZnO photocatalysts is not modified significally than ZnO original but surface charateristicschanged greatly. The photocatalyst was doped with copper content under 2% showed formation of Cu species. These samples perform photocatalytic activity higher than ZnO. The CuNZO-0.05-500 had the highest rate constants for methylene blue degradation (kUV = 6,901 h-1, kVIS = 0,224 h-1), which are about 2.2 times and 1.3 times higher than unmodified ZnO under UV light and Vis light, respectively. However, the CuNZO-5.0-500 which had the formation of CuO phase and unchangeable ZnO's surface has photocatalytic activity similar to pure ZnO.
Dung Thuy Nguyen, Thien Minh Ngo, Hoang Lam Huy Le
Science and Technology Development Journal - Natural Sciences, Volume 5; https://doi.org/10.32508/stdjns.v5i3.1013

Abstract:
The coastal area, from Tien Thanh to Ke Ga including Thuan Quy and Tan Thanh communes, is among the regions having a high economic growth rate of Ham Thuan Nam district, Binh Thuan province. The economic growth rate thanked to the development of coastal tourist sites and cultivating areas of dragon fruit, resulted in the increased water demand. Due to the limitation of the water supply system and surface water, the region's main supply comes from the groundwater. The massive and uncontrolled exploitation could lead to the exhaustion and pollution of water reservoirs in the coastal Quaternary aquifer. To serve the management and use of groundwater resources, we calculated the used reserves of the entire area by modeling the layer containing water in the area using the Modflow module of GMS software 10.4 (Groundwater Modeling System). The input data were collected through the suction pump experiment, water samples, survey on exploitation, and results of research reports of nearby areas. The normalized steady-state models showed that aquifers in the area were recharged by rainwater, and re-fed to rivers, partly forming the flows to the sea. If the amount of wasted water into the sea was considered as the total exploitable reserve, the used reserve of underground water in this area is 70,158 m3/day.
An Nang Vu, Anh Mai Tran, Nghi Tuyet Nguyen, Duyen My Ngoc Lam, Phong Pham Nam Le, Nhan Thuc Chi Ha, Hieu Van Le
Science and Technology Development Journal - Natural Sciences, Volume 5; https://doi.org/10.32508/stdjns.v5i3.924

Abstract:
In this work, nanohybrid of zinc oxide/ cellulose nanocrystals (ZnO/CNC) was successfully prepared by using a low cost and green method for photocatalytic degradation of methylene blue (MB). CNC had been derived through the hydrolysis reaction by citric/hydrochloric acid from the pure cellulose isolated from Vietnamese Nypa fruticans trunk. The obtained CNC with carboxyl groups could act as a stabilizing and supporting agent to anchor ZnO nanoparticles. The chemical and crystal structures, morphology, thermal and photocatalytic properties of the ZnO/CNC nanohybrid were characterized by FESEM, FTIR, XRD, FESEM, BET, EDX, TGA, DRS and photocatalytic tests. Analyses of FTIR spectra, XRD, and FESEM indicated that the ZnO nanocrystals with the size of 50 nm formed and loaded on the surface of CNC. The TGA analysis demonstrated that the ZnO loading sample (ZnO/CNC) had the thermal degradation onset temperature higher than that of neat CNC. ZnO/CNC cuold be absorpted ultraviolet light and have high value of specific surface area (SBET), based on the DRS spectra and the nitrogen adsorption – desorption isotherms analysis, respectively. ZnO/CNC displayed more photocatalytic activity than pure ZnO upon degradation of methylene blue due to strong interaction between the CNC and ZnO nanoparticles. The maximum degradation of MB was about 95% in 150 minutes for the ZnO/CNC.
, Kha Minh Lê, Thịnh Gia Phùng, Hoàng Văn Nguyễn, Phụng Mỹ Loan Lê
Science and Technology Development Journal - Natural Sciences, Volume 5; https://doi.org/10.32508/stdjns.v5i3.1032

Abstract:
In this work, a single phase of P2-Na0:67Mn0:75Ni0:25O2 (NaMNO) material was successfully synthesized via a coprecipitation method with the size varying from 2 to 4 mm. According to the atomic absorption spectroscopy (AAS), all the metallic elements were uniformly distributed in the bulk material with the desired ratio Mn¸Ni = 3¸1. The electrochemical properties of P2-NaNMO were investigated in carbonate-based electrolytes using 1M NaClO4 or 1M NaPF6. Among these electrolytes, this cathode exhibited the best electrochemical performance with initial capacity up to 205.7 mAh/g and capacity retention reaches 63.2% during 60 cycles when using 1M NaClO4/PC + 2% (v/v) VC. Indeed, vinylene carbonate (VC) additive plays an important role in improving the performance of NaMNO cathode through the formation of a stable cathode electrolyte interphase layer (CEI). Electrochemical impedance spectroscopy (EIS) was performed to demonstrate CEI layer formation indicated by the elevation of the electrode surface film and double layer impedance in the initial cycle. During cycling, galvanostatic intermittent titration technique (GITT) helps to calculate the Na+ ion diffusion coefficient, which was increased clearly at the working voltages of Mn3+/Mn4+ and Ni3+/Ni4+ redox couples.
Van Hung Phan, Thu Uyen Tran Thi, Tien Khoa Le
Science and Technology Development Journal - Natural Sciences, Volume 5, pp 1316-1325; https://doi.org/10.32508/stdjns.v5i3.1037

Abstract:
In this work, we proposed to immobilize Fe2O3 nanoparticles on the surface of magnetic CuFe2O4 particles by a facile impregnation – annealing method at different annealing temperatures (200, 300, 400 and 500°C) in order to create new heterogeneous photo-Fenton catalysts with enhanced catalytic performance for the oxidation of organic dyes. The influences of annealing temperatures used in the synthesis procedure on the phase composition, the morphology, the particle size and the surface functional groups of our catalysts were investigated by XRD, FE-SEM and FTIR techniques, respectively. The photo-Fenton catalytic performance was evaluated by the degradation of methylene blue under both UVA and visible light illumination in the presence of H2C2O4 as radical-producing source. According to the experimental results, Fe2O3 nanoparticles were successfully coated on CuFe2O4 surface, which successfully formed the α-Fe2O3 phase in the phase composition and also increased the Fe3+ content on the surface. As a consequence, the rate constant of photo-Fenton catalytic degradation of methylene blue over these samples were clearly improved. More especially, owing to the good magnetic property of CuFe2O4 component, our CuFe2O4/Fe2O3 samples were easy to be separated from the solution by a magnet, making them more feasible in practical applications of environmental treatment. Among our catalytic samples, the CuFe2O4/Fe2O3 sample annealed at 300°C showed the best performance with the highest rate constants under both UVA light and visible light. Its catalytic activities was found to be 6.8 times higher than CuFe2O4 under UVA light and 2.1 times higher than CuFe2O4 under visible light. However, when the annealing temperature was up to 500°C, the catalytic activity was reduced, which can be explained by the growth of particles and the stabilization of surface Fe-O bonds.
, Hoang Ngo Phan, Tuan Minh Nguy, Huong Thanh Tran
Science and Technology Development Journal - Natural Sciences, Volume 5; https://doi.org/10.32508/stdjns.v5i3.1063

Abstract:
Tomato is one of the most popular foods in the world. However, drought stress has strongly decreased the growth and yield of tomatoes. Therefore, the study on drought-tolerant tomatoes is essential. In this paper, tomato cultivar TN704, which is popularly grown in Vietnam's Southeast and Vietnam's Mekong Delta was selected. The combination of auxin (IAA, indoleacetic acid) and cytokinin (zeatin) at different concentrations was investigated to determine the effective regeneration media. Then, the drought pretreatment was applied to obtain drought-tolerant shoots. The drought tolerance of regenerated shoots was checked by culture in the drought stress condition after two generations (F1 and F2). The physiological and biochemical changes of regenerated shoots in the drought stress condition were analyzed. The MS 1 2 medium supplemented with 0.2 mg/L IAA and 0.5 mg/L zeatin was the effective medium for in vitro shoot regeneration from tomato leaves. The drought pretreatment (MS 1 2 with 20 g/L mannitol) increased the number of regenerated shoots which can develop in the drought stress condition. The regenerated shoots in the F1 and F2 generations grew strongly under drought conditions. The content of chlorophyll, carotenoid and proline, the intensity of respiration and photosynthesis, and the activity of auxin and cytokinin in leaves of F1 and F2 plant were higher than the control.
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