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Published By Vietnam National University Journal Of Science

2588-1140, 2588-1140

Author(s):  
Nguyen Huu Tho ◽  
Pham Hong Cam

The geometries, stabilities and electronic properties of vanadium-doped germanium clusters GenV0/+ (n=2-8) were systematically investigated by using density functional theory (DFT) at the PBE level and the 6-311+G(d) basis set. The results show that the geometries of lowest-energy structures of the cationic clusters are only significant different from those of the neutral at n = 6 or 7. The ground state of neutral clusters is a doublet, except Ge2V which is a quartet while that of cationic clusters is a triplet, except Ge8V+, which is a singlet. The average binding energy values generally increase with increasing cluster size. The results from average binding energies showed that it is more stable for the cationic than neutral clusters at the same size. Furthermore, the calculated values of fragmentation energy, second-order energy difference, HOMO-LUMO gap and adiabatic ionization potential suggest that the neutral clusters possess higher stability when n = 2, 5, 8 and the cations are more stable when n = 2, 3, 5 and 6.


Author(s):  
Bui Anh Thy ◽  
Nguyen Tang Truong ◽  
Kim Van Phuc ◽  
Nguyen Thien Thu ◽  
Nguyen Van Dung ◽  
...  

From the PRRSV virulent strain BG8 isolated from a PRRSV-infected pig, using serial passage method in MARC-145 cell line, we have successfully obtained an attenuated strain in 95th passage, named as BG895, with high potential to be a vaccine candidate. In this study, we present the results of the safety and efficacy evaluation of BG895 against PRRSV in experimental pigs. Trial results of vaccine formula using strain BG895 have very high safety when inoculating 5 doses/animal and 10 doses/animal. Evaluation of immune response by ELISA method showed that, from 14 days post inoculation, anti-PRRSV antibodies were detected in the serum of all inoculated pigs in vaccine batches with the lowest S/P index of 1.50 ± 0.4 and the highest S/P was 2.36 ± 0.1 from 28 days post inoculation. The IPMA method showed that the antibody titer of the vaccine reached ≥ 1/160 in 100% of pigs from 21 days post inoculation andreached ≥ 1/640 in 100% of pigs from 28 days post inoculation, indicating that the vaccine was effective at protecting 100% of pigs from 28 days post inoculation. The protective effect of the vaccine was evaluated by the virulent challenge from 28 days post inoculation with 1 dose/animal compared with the control group. The results showed that compared with all pigs in the control group with typical clinical manifestations of Blue-ear disease, all inoculated pigs had normal body temperature and weight gain, besides, the S/P index increased from 1.65 ± 0.1 to the highest 2.99 ± 0.2; the average antibody titer was >1/2560, and virus wasnot detected in nasal fluid by real-time RT-PCR from 7 days post challenge. These experimental results confirmed the safety and efficacy of the attenuated PRRS vaccine based on BG895strain.


Author(s):  
Le Thi Thanh Nhan ◽  
Nguyen Thuy Quynh ◽  
Le Lan Phuong ◽  
Bui Phuong Thao ◽  
Nguyen Thi Tu Linh ◽  
...  

For the prevalence of lung cancer and its poor diagnosis, the seeking of the efficient biomarkers for this disease is an urgent requirement, especially from non-invasive samples such as plasma. The mitochondria DNA (mtDNA) copy number change has been evaluated as a potential indicator of cancer risk, however, there have been few studies regarding mtDNA in plasma derived exosomes. In this study, the mtDNA copy number was measured on 29 plasma exosome samples of patients with non-small cell lung cancer (NSCLC) and 29 plasma exosome samples of cancer-free controls by real-time PCR assay, then being statistically analyzed to evaluate the relationship between these figures and several pathological features of NSCLC patients. As the results, the existence of mtDNA in exosomes isolated from plasma was detected through PCR assay using primers covering most of the mtDNA length. The relative mtDNA copy numbers determined in the exosomes of the disease and control groups were 1619.1 ± 2589.0 and 1207.0 ± 1550.0, respectively, whereas these values in two disease stages were 783.6 ± 759.3 (stage I-II) and 2647.0 ± 3584.0 (stage III-IV). Comparing among these groups, the difference was only statistically significant between the disease groups of stage I-II and stage III-IV (p<0.05), the group of stage III-IV and the control group (p<0.05). Indeed, the mtDNA copy number is associated with tumor stage and stage N (p<0.05). On the other aspect, the smoking habit of NSCLC patients could be an underlying reason behind the alteration in mtDNA copy number in the plasma exosomes. In short, our study demonstrates that the mtDNA copy number in exosomes resourced from plasma could be a potential biomarker for the detection and prognosis of NSCLC.


Author(s):  
Doan Thi Oanh ◽  
Duong Thi Thuy ◽  
Nguyen Thi Nhu Huong ◽  
Hoang Thi Quynh ◽  
Phung Duc Hieu ◽  
...  

Microplastics (particles with a size of less than 5 mm) are a rising environmental problem. Microplastics can disseminate in the air and accumulate in sediments as well as in microorganisms and humans, due to their small size. Sediment is considered to be the major repository of microplastics, particularly those of the PE type. Microplastics in massive amounts accumulated in sediments, perhaps as a result of point sources or diffuse contamination. Microplastic contamination can spread from industrial production facilities, urban areas, agricultural areas, or the air. The current study was carried out to explore the occurrence of MPs in sediments at discharge sources by evaluating 27 sediment samples taken from 9 distinct waste sources from industrial activity locations to determine the amount of microplastic contamination in sediments at discharge sources. Microplastics with relatively high density were found in all sediment samples in this research, ranging from 2,900 to 238,200 particles/kg dw. The most prevalent microplastics detected in sediment samples at these sites were fibers and fragments, accounting for 59-94% and 6-41%, respectively. Fiber microplastics ranged in size from 1000 to 9,000 µm, whereas fragment microplastics ranged from 200,000 to 2,100,000 µm2. Microplastics with < 1000 µm and 1000-2000 µm sizes accounted for a significant portion of the total, reaching 21.05-37.84% and 39.74-61.17%, respectively. The hue of microplastic particles in sediment samples obtained was highly varied.


Author(s):  
Nguyen Thi Hong Loan ◽  
Phung Bao Khanh ◽  
Le Ngoc Anh ◽  
Cao Vu Hung ◽  
Pham Van Anh ◽  
...  

A procedure for production of a real-time PCR kit for detection and quantitation of 6 common mitochondrial genome mutations including A3243G, G3380A, A8344G, T8993G, T8993C, G11778A using fluorescent locked nucleic acid (LNA) Taqman probes was reported. The procedure consists of designing of specific primers and LNA probes, selection of master mixture components and real-time PCR thermal conditions. The produced kit had specificity of 100% and sensitivity ≥ 1% and remained fully active after 7 days of storage at 25 oC or 20 days at 4 oC or 6 months at -20 oC. The kit was used to analyze A3243G, G3380A, A8344G, T8993G, T8993C, G11778A mutations from 69 patients tentatively diagnosed with mitochondrial diseases and 3 cases of A3243G carriers (4.34%) was found. In these cases, the A3243G mutation was heteroplasmic, maternally inherited, and the heteroplasmy level was shown to be related to the symptome expression.tome expression.


Author(s):  
Pham Thi Thu Uyen ◽  
Nguyen Hoai An ◽  
Pham The Hai ◽  
Bui Thi Viet Ha

Recent research generated information that human milk is not only a valuable source of nutrition, but it also provides a complex microbial community, containing especially Lactobacillus species - the major components of a great number of commercial probiotics. New findings on potential applications of Lactobacillus species revealed that these bacteria have abilities to produce anti-microbial exopolysaccharides (EPS) and to reduce cholesterol in culture broth. In this study, we successfully isolated and screened for Lactobacillus bacteria from human milk samples, and finally obtained four strains, including L. plantarum BM7.13, L. plantarum BM29.7, L. acidophilus BM10.8 and L. rhamnosus BM30.4. Researching the probiotic activities of these strains showed that all strains were tolerant to the low pH (3.0) and 0.3% bile salts. Characterization of the probiotic properties indicated that all selected Lactobacillus isolates had ESP (125-326 mg/L) and exhibited strong antimicrobial activities against pathogenic microbes, such as Escherichia coli, Staphylococcus aureus, Shigella flexneri and Salmonella typhimurium. Our results also indicated that all strains displayed cholesterol assimilation capabilities in culture broth with the maximum figure recorded for L. plantarum BM7.13.


Author(s):  
Vu Thi Thu ◽  
Phuong Thien Thuong

This study was conducted to evaluate the protective effect of Hesperdin (Hes) extracted from Citrus reticulata Blanco on cardiac mitochondria in hypoxia/reoxygenation (HR) injury in vitro. Methods: H9C2 cardiomyocytes were cultured under normal (control), HR, and treatment conditions. The reactive oxygen species and calcium levels in experimental groups were analyzed by using suitable fluorescence kits. Results: The obtained results showed that the addition of Hes at dose of  0,01562 mg/mL sharply decreased the mitochondrial oxidative stress of H9C2 cells under HR conditions. In particular, Hes showed the remarkable efficiency in maintaing cellular calcium levels. In HR-exposed H9C2 cell group, the hydrogen peroxide and superoxide levels were highly increased compared to those in control group (1,54±0,06 and 1,74±0,38, p<0,05). HR also strongly induced the elevation of cytosolic Ca²⁺ and mitochondial Ca²⁺ of H9C2 cardiomyocytes with the values were 1,96±0,05% and 1,62±0,33 (ratio to control, p<0,05), respectively. Interestingly, post-hypoxic supplementation of Hes effectivelly abolished the negative incresement of these indicators with the lower levels of reactive oxygen species and the better modulation of Ca²⁺ homeostasis. Conclusion: The present results are pilot data on the effects of Hes in protecting cardiac mitochondria against HR injury.


Author(s):  
Tran Huy Thai ◽  
Nguyen Thi Hien ◽  
Nguyen Duy Manh ◽  
Dinh Thi Thu Thuy ◽  
Nguyen Trung Thanh

The essential oils from the needles and branch of the Abies delaveyi subsp. fansipanensis was collected in Hoang Lien Natural Park, Lao Cai province and was obtained by steam distilation and the yields of essential oils were 0.27% and 0.08% from air-dry material. By the using GC/MS analysis, there are 44 and 52 constituents from needles and branch were identified and accounting 97.75% and 96.86% essential oil. The main constituents of needles essential oil were α-pinene (22.28%), β-phellandrene (17.80%), β-pinene (7.87%), α-cadinol (6.53%), myrcene (4.35%), δ-cadinene (4.39%). The main constituents of branchs essential oil were β-phellandrene (18.0%), α-pinene (10.95%), myrcene (10.76%), β-pinene (6.71%), abienol (6.71%). α-cadinol (3.31%). This is the first study on the chemical constituents of the essential oils from the needles and branchs of Abies delaveyi subsp. fansipanensis in Vietnam.


Author(s):  
Tran Duc Khanh ◽  
Vu Ha Giang ◽  
Trinh Thi Phong Huong ◽  
Vu Thanh Luan ◽  
Nguyen Thi Lan ◽  
...  

Titanium dioxide (TiO2) is widely applied in the field of pollution treatment due to its good catalytic properties and being an environmentally friendly material. In this study, TiO2 nanotubes were prepared from commercial TiO2 particles. The effects of carboxymethyl cellulose (CMC) and liquid glass (sodium silicate) on catalyst activity and catalyst adhesion on quartz tubes were investigated. Transmission microscopy (TEM), scanning microscope (SEM), X-ray diffraction (XRD), X-ray energy dispersive spectroscopy, Fourier transform infrared spectroscopy (FT-IR) were used for the characterization of the catalyst. In this study, the ethanol degradation ability of the catalyst, which was added with 0; 0.5; 1, and 1.5% liquid glass and calcined at 400 and 500oC, was determined. TiO2 nanotubes after preparation have a uniform diameter from 10-12 nm and an average length of about 150nm, specific surface area increases markedly compared to commercial granules (nearly 15 times). The results showed that CMC plays an important role in the thickness and distribution of TiO2 on the quartz surface. Liquid glass significantly affects the ethanol degradation efficiency.


Author(s):  
Nguyen Kim Nu Thao ◽  
Do Thuy Linh ◽  
Dinh Thi Ngoc Mai ◽  
Pham The Hai ◽  
Nguyen Hong Minh

Bacillus thuringiensis (Bt) is a significant bioinsecticidal agent that has been solely produced by liquid fermentation. With the increasing demand of bioinsecticides for organic agriculture, solid fermentation is preferred to enable low-cost and large-scale production of Bt. Therefore, in this study, we attempted to develop a solid state fermentation method to produce Bt by testing different solid substrates and also the effects of water percentage, fermentation time, temperature and seeding rate on the productions of biomass and parasporal crystal bodies (crystal proteins) of the Bt strain PAM33. Corn bran, rice bran and soybean meal are suitable to be utilized as substrates for biomass production. However, crystal proteins are only observed in solid fermentation using soybean meal as the substrate after 6 days of culture. The temperature range of 25-30°C and 10% seeding rate are the most suitable conditions for solid fermentation of strain PAM33 to obtain the bacterial density of approximate 109 CFU/g and the highest quantity of crystal proteins. This study shows that solid fermentation of Bt is feasible and effective to obtain bacterial biomass and crytal proteins by using cheap and available agricultural wastes. Thus, it can be a potential approach to produce the important Bt-based insecticide products for use in organic agriculture.


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