Science and Technology Development Journal - Natural Sciences 2022-01-19T20:48:23+00:00 Phuc Van Pham Open Journal Systems Protein immobilization on the surface of silica nanoparticles: Applications and prospects in biomedicine 2021-12-18T21:41:25+00:00 Khanh-Thien Le Tinh Hoang Pham Hieu Tran-Van <p>Silica nanoparticles, known as a basic material, have been widely used in biomedical applications due to their beneficial characteristics such as inertness, biocompatibility, large surface area, and clearance. The immobilization of proteins on the surface of silica-based biomaterials plays a crucial role in the development of biosensors in particular and modern biotechnological applications in general including detection, diagnosis, and creation of optimal drug delivery systems for therapies, especially cancer treatment, and more recently for Covid-19 vaccine delivery. Among various strategies of protein immobilization, oriented immobilization could efficiently guarantee the interaction affinity and binding sites of proteins onto targeted molecules thus the biological activity and function of the immobilized protein would be preserved. In this review, various protein immobilization methods to construct protein-functionalized silica-based biomaterials and their featured applications were collectively summarized. Generally, this review provided an insight into bio-functionalization of silica-based biomaterials for advanced biotechnological and biomedical applications.</p> 2021-12-18T21:41:25+00:00 ##submission.copyrightStatement## Application of electrical imaging and multichannel analysis of surface waves methods to survey the structure foundation at the Districts 2 and 9 of Ho Chi Minh City 2021-12-18T21:05:53+00:00 Nguyen Nhat Kim Ngan Nguyen Van Thuan Vo Manh Khuong Dinh Quoc Tuan Nguyen Quang Dung <p>In geophysics, multichannel analysis of surface waves (MASW) is employed to survey the stiffness of soil environment by the values of shear wave velocity (VS), while 2D electrical imaging method is utilized to examine the conductivity of soil environment by the values of resitivity (). In this study presented the results of 1D VS from MASW and 2D section from electrical imaging method to study the soil environment of structure foundation at districts 2 and 9 in Ho Chi Minh city were presented. The results of stratification of geology at two areas obtained from above two approaches were similar. The obtained results revealed that the geology between district 2 and 9 were quite different. For the area at the district 2, from the surface to the depth of 20 m, the resistivity and the shear wave velocity increased 10–50 m and 50–300 m/s, respectively. Moreover, the thick silty layer with the thickness of 1718 m and the small values of resistivity and VS were also detected in this site. For the area at the district 9, the geological foundation was stiffer than the one of the district 2. Concretely, from the surface to the depth of more than 30 m, the resistivity and the shear wave velocity increased from 10300 m and 200450 m/s, respectively. The geological foundation was found to be most of clays. In addition, the silty clay layer at several sites along the survey line was observed, while the stiff sandy clay layer was recognized at the depth of 27 m.</p> 2021-12-18T21:05:52+00:00 ##submission.copyrightStatement## Use of turmeric fibers as reinforcement phase in composite materials with epoxy resin 2022-01-04T04:00:38+00:00 NGUYEN TRUNG ĐO ANH TU DANG TAM THI BANG DAO QUOC KIEN LUU NHIEN HON LE NHAN THUC CHI HA <p>This paper presents a study on the application of fibers of turmeric residue (Curcuma longa) to solve the pollution problem of by-products after starch refining and improve the economic value of turmeric. The investigation uses turmeric by-products into fabricating composite based on epoxy resin to apply in the construction field, interior decoration as well as turning this by-product into a source of renewable materials. Turmeric pulp fibers are treated by NaOH solution to remove lignin, while maleic anhydride (MA) is used as a compatibility agent between the two phases of the material, helping to improve the properties of the composite. The physicochemical properties of the composite materials were determined by analytical methods: Fourier transforms infrared spectroscopy (FT-IR), X-ray diffraction (XRD), canning electron microscopy (SEM), and Thermogravimetric analysis (TGA). Composite material samples were further analyzed for physical and mechanical properties such as impact strength, flexural strength, and tensile strength. The results obtained the tensile strength and flexural strength of composite materials from turmeric baits reached values of 30,29 MPa and 133,11 MPa, respectively, higher than the tensile strength and flexural strength of epoxy. With a high content (60%) of turmeric residue, epoxy resin / natural turmeric fiber composite material is a new product with potential for practical applications and contributes to environmental protection.</p> 2022-01-04T04:00:37+00:00 ##submission.copyrightStatement## Study on the scavenging DPPH radical inhibitory activity of some medicinal plants collected at Ma Da forest, Dong Nai province 2022-01-04T04:07:39+00:00 Hai Xuan Nguyen Tho Huu Le Truong Nhat Van Do Thy Anh Nguyen Mai Thanh Thi Nguyen <p>Abstract Free radicals are formed in the human body to prevent virus and bacteria infections. However, they can react with macromolecules including protein, lipid, DNA (deoxyribonucleic acid) inducing serious diseases such as aging, heart disease, stroke, cancer, genetic mutations, weakened immune system and more. Therefore, antioxidant substances are required for the protection against oxidizing agents. Many synthetic antioxidant compounds have shown toxic and/or mutagenic effects which stimulated the interest of researchers to find out for natural antioxidants. Several analytical methods have been developed to determine the antioxidant capacity of natural substances. The most famous antioxidant assay is the DPPH free radical scavenging because it is simple, rapid, and convenient. 23 methanolic extracts from 16 medicinal plants, collected at the Ma Da forest in Dong Nai province, were investigated for their antioxidant activity by the DPPH method. The results indicated that all the studied extracts showed an inhibition of over 50% at the concentration of 100 µg mL-1, 22 illustrated greater than 50% inhibition at 50 µg mL-1, and 18 demonstrated over 50% inhibition at 25 µg mL-1. Ten MeOH extracts exhibited strong inhibitory activity with more than 50% inhibition at 10 µg mL-1 and three showed 50% inhibition at 5 µg mL-1. Among them, the bark wood of Anisoptera costata and Dipterocarpus costatus, belonging to Dipterocarpaceae family, displayed the highest DPPH free radical scavenging activity, with the IC50 values of approximately 3.15 µg mL-1. These values are similar with the positive control, trolox (IC50 = 2.73 µg mL-1). To the best of our knowledge, this is the first time that these extracts possessing the DPPH free radical scavenging activity were reported.</p> 2022-01-04T04:07:39+00:00 ##submission.copyrightStatement## Using normalized full gradient of gravity anomalies to detect geological structures with mineral oil and gas potential 2022-01-04T20:59:36+00:00 Nghia Huu Pham Duy Hoang Dang <p>In deep structural studies such as determining oil and ore deposits, the normalized full gradient (NFG) method is used with relatively high accuracy. In this paper, by using an algorithm combining the change of the coefficient N and the potential field expansion according to the Fourier series to determine the gravity documents were analyzed. The maximum normalized full gradient could be determined based on the found normalized full gradient values. The studied geological structure (or foreign body) was determined at the location with the maximum total gradient with a defined depth. The models were set up for the purpose of finding the results and verifying the accuracy in the geophysical problem. Therefore, two models were established representing two types of geological structures: solid minerals with δ &gt; 0 and liquid minerals with δ &lt; 0. Research results of the two modeling problems were equal. The exact position possessing the maximum normalized full gradient was determined. Application of these models on the actual gravimetric data measured on a measuring line in the Songkhla basin southwest of the Gulf of Thailand showed the presence of a liquid-mineral geological structure. According to the field information, there were a number of oil fields in this area that had been identified and are in the process of being exploited. Thus, this position would be the center of the oil field, because the obtained result is in full agreement with the published depth of the well.</p> 2022-01-05T00:00:00+00:00 ##submission.copyrightStatement## Long-term variations of the water quality and cyanobacterial community in Tri An Reservoir, Dong Nai province 2022-01-04T21:02:06+00:00 Lưu Thanh Phạm Tài Ngọc Đoàn Yến Thị Hoàng Trần Thái Thành Trần Lượm Thị Lê Đăng Ngọc Trần Quảng Xuân Ngô <p>This study aimed to investigate the long-term variations of water quality, trophic status and cyanobacteria community in Tri An reservoir from 2008 to 2019. Based on that, the impacts of artificial dam on water quality and trophic status were accessed. Results showed that the water quality index (WQI) ranked from moderate to good status with a gradual deterioration in the quality. In contrast, the trophic status calculated basing on total nitrogen (TN) and total phosphorus (TP) concentrations indicated that the water condition was light-eutrophic to hyper-eutrophic. This indicated that the WQI was not appropriate to classify the water quality, particularly in Tri An reservoir. During the last several years, cyanobacteria, mainly Microcystis spp., was dominant and formed blooms in the reservoir. Excessive of using fertilizers and pesticides, increased aquacultural, agricultural and industrial activities, and changed in land surface were commonly considered as main causes. In addition, this study highlighted that artificial dams could alter water current, enhance the accumulation of pollutants and increase the water residence time, resulting in water eutrophication and cyanobacteria blooms in Tri An reservoir.</p> 2022-01-05T00:00:00+00:00 ##submission.copyrightStatement## Investigation and assessment of radioactivity background around the coal-fired power plant at Duyen Hai commune, Tra Vinh province 2022-01-10T20:31:00+00:00 Ba Ngọc Vũ Phong Thu Nguyễn Huỳnh Thắng Văn Nguyễn Phương Trúc Huỳnh Hải Hồng Võ Thuyên Xuân Lê Hồng Loan Thị Trương <p>In this study, the outdoor absorbed dose rate, the annual effective dose equivalent and the excess lifetime cancer risk due to natural radioactivity exposure in soil samples around the coal-fired power plant at Duyen Hai commune, Tra Vinh province were evaluated by using a low background gamma spectrometer with HPGe detector. The results showed that the average radioactivity values of 226Ra, 232Th và 40K in 28 collected soil samples were 38.52 ± 2.55, 36.45 ± 2.70 and 454.20 ± 31.79 Bq kg-1, respectively. The average values of 58.75 nGy h-1, 0.07 mSv y-1 and 0.25 ×10-3 for the outdoor absorbed dose rate, the annual effective dose equivalent and the excess lifetime cancer risk due to the gamma-ray exposure from collected soil samples were within the limits recommended by UNSCEAR (2000). The results did not show the risk of natural radiation exposure from the observed soil samples due to the geology or radioactivity deposition from fly ash for the population in the area around the surveyed coal-fired power plant. It is necessary to periodically survey the radioactivity background and the health hazards to update data, as well as to reflect the variation and the accumulation of radioactivity in the soil according to the operating time of the coal-fired power plant.</p> 2022-01-10T20:31:00+00:00 ##submission.copyrightStatement## Chemical constituents and anti-inflammatory activity of the fructus gardeniae (Gardenia Jasminoides Ellis) 2022-01-10T20:46:03+00:00 Trinh Pham Thi Nhat Ngoc Anh Hoang Van Tan Phan Thanh Danh Tong Minh An Tran Nguyen Tram Kim Thi Pham Dung Tien Le <p>Iridoid glycosides and tetraterpenoids are the main groups of phytochemicals in the fructus gardenia, These compounds exhibited biological activities such as anti-inflammatory, anti-infective, antioxidant activities; stimulate endothelial cell regeneration, or inhibit liver fibrosis, Vietnamese use gardenia fruit for the treatment of nephritis, urinary tract infections, infectious hepatitis,,, However, studies on chemical compositions and biological activity, Especially, the anti-inflammatory activity of gardenia fruit collected in Dak Lak has not been studied much, In this study, we evaluated the anti-inflammatory activity of the extracts through in vitro model by determining the inhibition of NO and TNF-α and isolated the purified compounds from the bioactive fraction, The results of the anti-inflammatory activity assay on Raw264,7 cells indicated that ethanol 50%, ethanol 70%, and water extracts inhibited NO and TNF-α production, Based on chromatographic techniques using silica gel and macroporous resin D101 as adsorbents, two iridoid compounds as geniposide (1) and genipin-1-O-β-D-gentiobioside (2) were isolated and determined, These two compounds showed a strong inhibitory effect on TNF-α secretion.</p> 2022-01-10T20:46:03+00:00 ##submission.copyrightStatement## α-glucosidase inhibitory effect of flavones from the leaves of Muntingia calabura L. 2022-01-10T21:00:38+00:00 Huu Tho Le Tam Thanh Thi Tran Truong Nhat Van Do Hai Xuan Nguyen Phuc Thanh Le Thy Anh Nguyen Mai Thanh Thi Nguyen <p>Type 2 diabetes mellitus is one of the most common metabolic disorders and causes dangerous complications. The inhibition of α-glucosidase by drugs of natural origin is one of the therapeutic methods that has been used widely for stabilizing postprandial hyperglycemia. Especially, the potential effects of flavonoids in diabetes mellitus have been studied. In this study, the composition investigation of the methanol extract of the leaves of Muntingia calabura L. led to four flavone compounds, including izalpinin (1), 5-hydroxyl-3,7-dimethoxyflavone (2), techtochrysin (3), and methylgnaphaliin (4). The chemical structures of these compounds were determined based on analysis of NMR spectral data and reference comparisons. Four compounds exhibited the α-glucosidase inhibitory effect in a concentration-dependent manner. Compounds izalpinin (1) and 5-hydroxyl-3,7-dimethoxyflavone (2) have the α-glucosidase inhibitory activity with IC50 values of 61.4 and 156.1 µM, respectively, that is more potent than acarbose (IC50 = 214.5 µM). The relationship of the flavone structural and α-glucosidase inhibitory activity showed that a hydroxyl or methoxyl substituent at the olefinic carbon C-3 is likely to increase the activity. In contrast, the presence of methoxyl at the aromatic carbon C-8 strongly reduces the activity. This study has contributed to the natural ingredient and bioactive dataset of Vietnamese medicinal plants for diabetic treatment.</p> 2022-01-10T21:00:37+00:00 ##submission.copyrightStatement## Tổng hợp hệ xúc tác quang-Fenton dị thể Fe2O3/perlite với đặc tính nổi trên mặt nước giúp dễ thu hồi 2022-01-14T07:07:58+00:00 Van Duoc Nguyen Nhut Linh Nguyen Thanh Tuyen Pham Thi Hung Thinh Truong Thanh Dang Khoa Nguyen Anh Quynh Nhu Le Thi The Luan Nguyen Chau Ngoc Hoang Tien Khoa Le <p>Nhằm tạo ra xúc tác quang-Fenton dị thể vừa có khả năng xử lý nước thải hiệu quả, vừa có khả năng thu hồi dễ dàng sau phản ứng, chúng tôi đã tổng hợp bột Fe<sub>2</sub>O<sub>3</sub> phủ trên bề mặt đá perlite bằng phương pháp kết tủa – xử lý nhiệt đơn giản theo hai quy trình: kết tủa oxalat và kết tủa hydroxid. Sản phẩm tạo thành được đặc tính hóa thông qua các kỹ thuật nhiễu xạ tia X, kính hiển vi điện tử quét phát xạ trường và phổ hấp thu nguyên tử. Hoạt tính xúc tác của các mẫu được đánh giá dựa vào khả năng phân hủy phẩm nhuộm methylene xanh dưới ánh sáng UVA và ánh sáng khả kiến trong sự hiện diện của H<sub>2</sub>C<sub>2</sub>O<sub>4</sub>. Kết quả cho thấy các mẫu xúc tác Fe<sub>2</sub>O<sub>3</sub>/perlite không chỉ thể hiện khả năng phân hủy tốt methylene xanh mà còn sở hữu đặc tính nổi trên mặt nước, thuận lợi cho việc tách xúc tác ra khỏi dung dịch. Giữa hai quy trình điều chế, các hạt Fe<sub>2</sub>O<sub>3</sub> được điều chế từ kết tủa FeC<sub>2</sub>O<sub>4</sub> có dạng hình que xếp chồng với mức độ tinh thể hóa cao nên bám dính tốt vào đá perlite, giúp tăng hàm lượng ion Fe<sup>3+</sup> trên bề mặt xúc tác, từ đó đem lại hoạt tính xúc tác cao hơn mẫu được điều chế theo quy trình kết tủa hydroxid. Ngoài ra, sau 3 lần thu hồi và tái sử dụng, hoạt tính xúc tác của mẫu này chỉ giảm rất nhẹ, hứa hẹn cho việc ứng dụng vào thực tế.</p> 2022-01-14T07:07:57+00:00 ##submission.copyrightStatement## The morphometry, biomass, and respiration of free living nematodes in the Ba Lai river, Ben Tre province, Viet Nam 2022-01-14T07:40:36+00:00 Thai Thanh Tran Yen Thi My Nguyen Tan Van Lam Hoai Ngoc Pham Quang Xuan Ngo <p>Free living nematodes play an important role in benthic ecosystem processes and they have been widely used as an efficient tool to assess the environmental quality status. Although the morphometry and biomass are two important aspects to consider in ecological studies of free living nematodes, little attention has been paid to these characteristics. The paper aimed to describe the morphometry, biomass, and respiration of free living nematodes in the Ba Lai River, Ben Tre province, Vietnam. The study also evaluated the relationship between these characteristics and the salinity of the river. The results showed that nematodes communities were dominated by slender, followed by long/thin, and stout. The individuals in nematodes communities in the Ba Lai River were characterised by small sizes in both length and width, leading to the low biomass and respiration. The mean individual biomass (µgC.inds-1) ranged from 0.02 to 0.045, while the assemblage biomass (mgC.m-2) varied from 1.28 to 224.29. The mean individual respiration (nlO2.hour-1.inds-1) ranged from 0.32 to 0.67, and between 0.27 and 24.99 for the assemblage respiration ( In addition, the length, length/width ratio, the proportion of morphological groups, total biomass, total respiration, and respiration rate were significantly correlated with the salinity of the river. This was the first time that the evaluation of the respiration of free living nematode communities in Vietnam was done. Besides traditional features (e.g. abundance, biodiversity, distribution patterns), these studied characteristics, including the morphometry, biomass, and respiration of free living nematodes, could be used as a potential tool for bioindicators.</p> 2022-01-14T07:40:36+00:00 ##submission.copyrightStatement## Methane emissions from river sediment affected by dams: Study on Ba Lai river, Ben Tre province 2022-01-19T20:33:59+00:00 Hoai Pham Ngoc Thai Tran Thanh Yen Nguyen Thi My Dong Nguyen Van Huynh Nguyen Thi Thuy Tran Kim Tinh Tran Bijeesh Kozhikkodan Veettil Quang Xuan Ngo Phan Thi Thanh Huyen <p>The phenomenon of greenhouse gas emissions from sediments of water bodies with dams and reservoirs has been recorded from many parts of the world. Even though Vietnam is a country with having many dams and reservoirs, this issue has not been fully studied, despite the fact that greenhouse emissions are potentially dangerous to the environment and ecosystems. This study analyzed sediment samples from Ba Lai River in Ben Tre province during the rainy season of 2019. The objectives of the present study are: (i) analyzing methane content emitted from river sediments, (ii) analyzing the relationship between methane content and Ba Lai River environmental parameters, (iii) comparing methane content in the Ba Lai River sediments with other dammed waters in the world. The results of the present study showed that the amount of methane (ppm) emissions is quite high, which varied from 117 ± 2.01 to 8073 ± 251.57. The sampling stations in the upstream of the dam showed higher emission of greenhouse gases than the stations located in the downstream. The pH of the sediments was negatively correlated with the emitted CH4 content (r = -0.83, p-value = 0.0001). The results obtained from the present study provided the first scientific information on the methane content formed in the dam conditions in order to assess the potential long-term impacts of the Ba Lai dam on greenhouse gas emissions.</p> 2022-01-19T20:33:59+00:00 ##submission.copyrightStatement## Designing, fabricating and testing at a laboratory scale a water desalination system using electrodialysis 2022-01-19T20:48:23+00:00 Linh Duy Nguyen Quoc Van Nguyen Nga Thi Thao Nguyen San Tu Tran Tin Chanh Duc Doan Dung My Thi Dang Chien Mau Dang <p>Salinity-contaminated water caused by seawater intrusion and droughts in provinces of the Mekong Delta in Vietnam is one of the most serious issues that people here face every year. In this study, a desalination system using electrodialysis (ED) technology was designed, fabricated and tested as an alternative to reverse osmosis (RO) technology. The ED stack, an important part of this desalination system, was designed with a size of 12 × 12 cm. It was composed of 16 cells consisting of cation and anion membranes connected in series and the active area of the ion-selective membranes was 8×8 cm. The ED stack was fabricated by commercially available materials. The desalination system using this ED stack was then set up and tested at a laboratory scale in the batch mode where the dilute and concentrate streams were recirculated up to the desired salinity. The effects of the applied voltage and salt concentration were studied. The results showed that the ED system was able to reduce the salinity of 3.0 g/L, 5.0 g/L, and 7.0 g/l to below 0.5 g/L within 25 min, 38 min, and 52 min, respectively, for an input water of 1.6 L at the applied voltage of 16 V. The study showed a promising application of the ED technology for the water desalination in Vietnam.</p> 2022-01-19T20:48:16+00:00 ##submission.copyrightStatement##