Ministry of Science and Technology, Vietnam最新文献

{"title":"Preparation of nano zinc borate and investigation of flame-retardancy of ternary combination nano zinc borate/red phosphorus/expandable graphite on HDPE","authors":"Thi Hanh Nguyen, Thi Nhung Hac, Van Toan Hoang, Nhat Thuy Giang Le, Mai Ha Hoang, Van Tuyen Nguyen","doi":"10.31276/vjst.66(1).56-61","DOIUrl":"https://doi.org/10.31276/vjst.66(1).56-61","url":null,"abstract":"Nano zinc borates were successfully synthesised from aqueous solutions of zinc sulfate, boric acid, and sodium hydroxide via the precipitation method. The effects of pH, temperature, and surfactants on the structure and morphologies of nano zinc borates were investigated. The nano zinc borates obtained at the pH of 7 to 8 were well-crystallised monophase Zn[B3O4(OH)3]. The morphologies of nano zinc borates were highly impacted by the reaction temperature and the surfactants. At the range of temperatures from 70 to 80oC, the nano zinc borates were nanoplates of 40-50 nm in thickness. The nano zinc borates grew out of the surface to form nanorods at 90oC and nanowhiskers at 100oC. The nano zinc borates modified with surfactants tended to form larger and thinner plate-like nanoparticles. In the presence of Tween 80, petal-like nano zinc borates were achieved. The petal-like nano zinc borates showed good flame retardant synergistic effects with red phosphorus and expandable graphite on high-density polyethylene matrix. Additionally, the nano zinc borates nanopetals significantly improved the mechanical properties of red phosphorus/expandable graphite/high-density polyethylene composites.","PeriodicalId":18650,"journal":{"name":"Ministry of Science and Technology, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140495887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of expression vector with the Pgrac100 promoter induced by IPTG and integrated gfp+ gene into Bacillus subtilisgenome at lacA locus","authors":"Thi Bich Phuong Chu, D. Nguyen, Thi Phuong Trang Phan","doi":"10.31276/vjst.66(1).75-80","DOIUrl":"https://doi.org/10.31276/vjst.66(1).75-80","url":null,"abstract":"Bacillus subtilis is a prospective gram - positive bacterium that offers an opportunity for the production of recombinant proteins in the pharmaceutical, agricultural, industrial, and food industries.The goal of this study was to develop an integrative inducible expression system by incorporating the Pgrac100 promoter into the lacA locus of the B. subtilis genome. The results showed that the Pgrac100 promoter was able to strictly control the expression of the target protein, with induction factors of 3.3, 7.6, and 10.8 after 4 hours under induction with 0.01, 0.1, and 1 mM Isopropulβ-D-1-thiogalactopyranoside (IPTG), respectively. The duration of induction and the concentration of IPTG had significant effects on the efficacy of target protein expression. Specifically, when induced with 0.1 mM IPTG after 4 hours, there was a significant rise in GFP expression, accounting for 13% of the total cellular protein. Our new vector system provided more options for the production of recombinant proteins in basic research and industrial applications.","PeriodicalId":18650,"journal":{"name":"Ministry of Science and Technology, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140495888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chemical components and antimicrobial activity of essential oil from leaf of Aristolochia balansae Franch.","authors":"Dam Ngoc Anh Luu, Van Huong Bui, Van Truong Do, Thi Kieu Oanh Nguyen","doi":"10.31276/vjst.66(1).14-18","DOIUrl":"https://doi.org/10.31276/vjst.66(1).14-18","url":null,"abstract":"Aristolochia balansae Franch. belonging to Aristolochiasubgenus Siphisia (Aristolochiaceae) is rarely distributed in Northern Vietnam. This study is the first time to determine the chemical composition and antimicrobial activity from essential oils of leaves collected in Ba Thuoc district, Thanh Hoa province in November 2021. The essential oils from the leaves of A. balansae were obtained by hydrodistillation using Clevenger-type apparatus and analysed by gas chromatography coupled with mass spectrometry. The yield of the essential oil was 0.15% of fresh weight, the essential oil is light yellow, lighter than water. Sixty-three components were identified, which present 78.58% of the total composition of the leaf’s essential oil. The main components were sesquiterpenes and oxygenated sesquiterpenes. The constituents occurring in higher amounts in the essential oil were γ-Eudesmol (6.98% of the total composition of the leaf’s essential oil), α-Humulene (6.22%), β-Selinene (4.5%), Eudesma-4(14),7(11)-diene (3.53%), α-trans-Bergamotene (3.27%), and Limonene (3.02%). This essential oil showed weak antimicrobial activities to most of the tested microbial strains in a concentration of 10%.","PeriodicalId":18650,"journal":{"name":"Ministry of Science and Technology, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140495787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accumulation of mercury in muscle of orange-spotted spinefoot(Siganus guttatus Bloch, 1787) by age and season in the coastal Quang Binh","authors":"Van Thiep Vo, Thi Thu Phuong Le, Thi Huong Binh Nguyen","doi":"10.31276/vjst.66(1).36-41","DOIUrl":"https://doi.org/10.31276/vjst.66(1).36-41","url":null,"abstract":"Orange-spotted spinefoot (Siganus guttatus) is not only a fish with high economic value, rich in nutrients, but also popular with people for consumption. This research was carried out from November 2021 to May 2022, in the coastal and estuaries of Quang Binh province. A total of 60 samples of orange-spotted spinefoot were collected by age group, wet season, and dry season to analyse the accumulation of mercury (Hg) in their muscles. The Hg concentration was analysed by cold vapour atomic absorption spectroscopy. Research results showed a strong correlation between the length and weight of fish both in the wet and dry seasons. The age group has a strong influence on the accumulation of Hg in their muscles, the older fish group has a higher aggregation of Hg than the younger fish group. Although the average value of Hg concentration in the muscle of orange-spotted spinefoot in the dry season is higher than in the wet season, analysis results of “Tukey’s HSD test” showed that there was no significant difference.","PeriodicalId":18650,"journal":{"name":"Ministry of Science and Technology, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140495120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optical properties of Eu3+ - doped Sr2TiO4 phosphor powder synthesised by solid-phase reaction method","authors":"V. Chu, Thi Anh Xuan Chu, Thi Hue Lo, Minh Quy Bui, Thi Tam Khieu, Phuong Thao Nguyen, Kim Dan Ho, Tien Ha Le","doi":"10.31276/vjst.66(1).62-67","DOIUrl":"https://doi.org/10.31276/vjst.66(1).62-67","url":null,"abstract":"Fluorescent powder Sr2TiO4 doped with Eu3+ ions was synthesised by the solid-phase reaction method with a sintering temperature of 1200oC in the air with a 1-6% doping concentration. The resulting material has a perovskite structure of I4/mmm space group, and the Eu3+ ion doping concentration does not change the material’s structure. This characteristic space group of the material was also investigated through the Raman scattering spectrum with characteristic peaks at positions 145, 240, 448, and 699 cm-1 corresponding to vibrational modes with 2A1g + 2Egcharacteristic states of Sr2TiO4 material. The results showed that the material absorbs strongly in the ultraviolet and blue light regions with characteristic peaks of the Sr2TiO4 matrix and Eu3+ ions to emit strongly in the red light region with characteristic emission peaks of Eu3+ ions in the background network when moving from the excited state 5D0 to state 7Fj (j is a positive integer number). Fluorescence quenching was also observed at a doping concentration of 4% Eu3+ ions. The fabricated material is suitable for coating applications on nUV-LED LED chips.","PeriodicalId":18650,"journal":{"name":"Ministry of Science and Technology, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140496411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Research on production and testing of antifungal activity Phytophthora spp. causing fruit rot and Colletotrichum spp. causing anthracnose of silver nanoparticles, chitosan and turmeric resin bioproducts","authors":"Duc Danh Cao, The Tam Le, Van Binh Thai, Thi Ngan Tran, Dang Quang Le, D. Ho, Cao Cuong Nguyen, Thi Ha Nguyen, Thi Thu Hiep Le, Phuong Chi Tran, Thi Ngan Duong","doi":"10.31276/vjst.66(1).42-49","DOIUrl":"https://doi.org/10.31276/vjst.66(1).42-49","url":null,"abstract":"In this paper, the research team made samples of bio-products (BN) of turmeric resin combined with silver nanoparticles and chitosan and investigated the factors affecting the production of BN preparations. Specifically, the results of research on the production of BN preparations including ingredients, additives, mixing ratios, and technological parameters have been calculated and tested to obtain nano-preparations with the highest durability and dispersion. The experimental results obtained the optimal set of parameters for production at a pilot scale of 5 litres/batch are the ratio of active ingredients/additives =3/1, the optimal temperature for the mixing process is 40-45oC, the stirring speed is 500 rpm, and the time is 60 minutes. From here, we have successfully fabricated 18 samples of BN1-BN18 preparations with colours ranging from light yellow to dark yellow. Antifungal activity was tested against Colletotrichum spp. causing anthracnose disease and fruit rot disease caused by Phytophthora spp., the results showed that BN1-BN18 products exhibited good antifungal activity, and antifungal activity increased gradually when the content of turmeric oil resin increased.","PeriodicalId":18650,"journal":{"name":"Ministry of Science and Technology, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140495529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase transitions of smectic-isotropic phase in liquid crystals","authors":"Thi Phuong Thuy Nguyen, Thi Van Anh Nguyen, Van Thanh Ngo","doi":"10.31276/vjst.66(1).01-07","DOIUrl":"https://doi.org/10.31276/vjst.66(1).01-07","url":null,"abstract":"Smectic phases formed by rod-like molecules with long axes that are parallel and also arranged in planes. The smectic-isotropic phase transition is a phase change from the liquid crystal to the liquid phase. In this work, we use a mobile 6-state Potts model to study the nature of the smectic-isotropic phase transition. Microscopic interactions between neighbouring molecules in this model are supplemented with the Lennard-Jones potential. This study applies Monte Carlo simulation with the Wang-Landau algorithm to determine the characteristics of smectic-isotropic phase transitions. It is shown clearly that the smectic phase goes to the isotropic phase and undergoes a first-order transition. The results also point out that when the temperature increases, molecules on the surface are orientationally disordered, then the molecules gradually lose their positional order. These results are in agreement with experiments that revealed the coexistence of the smectic and isotropic phasesduring the phase transition process in accordance with experimental studies.","PeriodicalId":18650,"journal":{"name":"Ministry of Science and Technology, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140508420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plant-parasitic nematodes associated with Paphiopedilum appletonianum (Gower) Rolfe 1896","authors":"T. Le, Thi Duyen Nguyen, H. T. Nguyen, V. T. Bui, Van Sinh Nguyen, Van Tien Tran, Quang Phap Trinh","doi":"10.31276/vjst.66(1).19-23","DOIUrl":"https://doi.org/10.31276/vjst.66(1).19-23","url":null,"abstract":"The genus Paphiopedilum Pfitzer includes many plant species that are threatened with extinction. The groups of plant-parasitic nematodes that have been published parasitising orchids show that the stem and leaf nematode group and the root nematode group are all present and cause direct damage to this orchid genus. Besides, plant-parasitic nematodes are also one of the vectors for other pests to invade and cause quality damage to commercial orchids. Therefore, this study was carried out with the goal of initially identifying the main nematode species that parasitises Paphiopedilum appletonianum (Gower) Rolfe 1896 collected in Ba Na natural forest (Da Nang) to serve for prevention of plant diseases in the conservation of this orchid species. As a result, for the first time, 12 species of plant-parasitic nematodes associated with Paphiopedilum appletonianum in Vietnam have been recorded. The study has described the two main species, Paratrichodorus minor and Helicotylenchus dihystera, that are present with high density in soil and that are present also in stems and roots, what enables the appropriate preventive measures could be undertaken during the conservation of this rareorchid species.","PeriodicalId":18650,"journal":{"name":"Ministry of Science and Technology, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140508555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the involvement of HSC70 gene in the growth and development of tomato","authors":"Tuan Nam Vu, Quang Ha Dao, Nhat Linh Nguyen, Han Ly Luu, Hong Hanh Ha, Thi Thu Hue Huynh, Thi Thu Hien Le","doi":"10.31276/vjst.66(1).29-35","DOIUrl":"https://doi.org/10.31276/vjst.66(1).29-35","url":null,"abstract":"Tomato is one of the high-value agricultural crops. The HSP70 gene family is thought to play an important role in plant tolerance to various environmental factors. A family member known as HSC70 is predicted to be involved in plant growth and development, however, its biological functions have not been demonstrated clearly. This study was conducted with the aim to characterise the HSC70 gene in tomato plants and evaluate its contribution to tomato growth through phenotypic analysis of plant mutants with defects in the HSC70 gene. The research results showed that nonsense mutationin the HSC70 gene caused short plant and reduced the seed germination rate and fruit set rate of tomato. However, these missense mutations did not change these phenotypes significantly. The leaf shape, leaf structure, and flowering time of tomato were not affected by the HSC70 mutations. These findings provided preliminary insights for further study on the role of the HSC70gene in the germination, elongation, and fruit setting of tomato plants.","PeriodicalId":18650,"journal":{"name":"Ministry of Science and Technology, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140508403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Factors affecting adherence to ARV of HIV-infected adolescents at the Outpatient Clinic, Vietnam National Children’s Hospital in 2022-2023","authors":"Thi Dung Trinh, Thien Hai Do, Thi Van Nguyen, Thi Bich Ho, Thi Ngoc Tran, LeMai Nguyen, Thi Lien Tinh Phung, Thanh Dong Nguyen, Xuan Binh Vuong, Thi Bao Ngoc Nguyen, Thi Thu Hang Nguyen, Thi Hong Nguyen, Thanh Thuy Dang, Thi Dung Nguyen, Thi Hang Le, Thi Xuyen Tran","doi":"10.31276/vjst.65(12).28-33","DOIUrl":"https://doi.org/10.31276/vjst.65(12).28-33","url":null,"abstract":"Objectives: (1) Describe the characteristics of pediatric patients and treatment adherence of HIV-infected adolescents at the Outpatient Clinic of the Vietnam National Children’s Hospital in 2022-2023; (2) Analysis of some factors affecting adherence to ARV treatment of HIV-infected adolescents. Research subject and method: The study was carried out on 222 HIV-infected adolescents who met the research criteria to visit the Outpatient Clinic of the Vietnam National Children’s Hospital in 2022-2023 by cross-sectional descriptive research method. Results: The treatment adherence rate of adolescents accounted for 84.2%. Some factors affecting adherence to ARV treatment of HIV-infected adolescents include: children who attended counselling classes at the clinic were 2.32 times more compliant than children who did not (p<0.05); educated children with the same level of education as the age group of ARVs are 3.46 times higher than the age group with no education equivalent to the age group (CI95% 1.39-8.57, X2=7.87, p=0); children whose HIV status was fully disclosed at 10-12 years of age had higher adherence rates than children whose HIV status was revealed at other time points, this result is statistically significant (X2=10.5, p<0.05); the primary caregivers participating in the study who knew well about HIV/AIDS helped children to adhere to ARV treatment higher than those whose primary caregivers lacked knowledge about HIV/AIDS, this result is statistically significant (X2=6.5, p<0.05). Conclusion: The ARV adherence rate of adolescents accounts for 84.2%, this rate is not high. A number of factors increase the rate of treatment adherence: children become infected at 10-12 years of age, children attend HIV counselling classes, educational attainment equivalent to age, caregivers' knowledge of HIV main squirrel.","PeriodicalId":18650,"journal":{"name":"Ministry of Science and Technology, Vietnam","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139158537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}