Vietnam Journal of Science and Technology最新文献

{"title":"Synergistic influences of ground granulated blast-furnace slag and silica fume on the viscosity of extremely low W/B cement pastes","authors":"Cong Thang Nguyen, Q. Phung, Van Tuan Nguyen","doi":"10.15625/2525-2518/18103","DOIUrl":"https://doi.org/10.15625/2525-2518/18103","url":null,"abstract":"Particularly with a low water/binder ratio, the synergistic effects of supplemental cementitious materials (SCMs) have drawn a lot of interest in improving the characteristics of cement-based products. The effects of SCMs, such as silica fume (SF) and ground granulated blast furnace slag (GGBS) with varying fineness, on the setting time, saturation point, and viscosity of ultra-high performance cement pastes (UHPCP), are examined experimentally in this work. 56 mixes with various SF and BFS substitutions and exceptionally low water/binder ratios (0.16, 0.20) were used in the experiments. This work demonstrates the synergistic effects of SCMs from several angles, including the UHPCP fresh characteristics. It is shown that carefully regulating the water/binder ratio, the BFS fineness, and most significantly the addition of an ideal SF content will have a beneficial synergistic effect on the fresh qualities of UHPCP. However, utilizing high BFS replacement is discouraged as it may have a negative impact on viscosity.","PeriodicalId":506542,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"40 35","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141645167","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":"Ag/Fe3O4 bifunctional nanocomposite for SERS detection of non-steroidal anti-inflammation drug diclofenac","authors":"Thi Thanh Ngan Nguyen, Duy Hai Bui, Do Chung Pham, Magdalena Osial, Marcin Pisarek, Anna Tycova, Thi Nam Pham, Thi Thanh Ngan Nguyen, Thi Thu Vu","doi":"10.15625/2525-2518/20157","DOIUrl":"https://doi.org/10.15625/2525-2518/20157","url":null,"abstract":"In this work, a bifunctional nanocomposite based on silver and iron oxide nanoparticles (AgNPs/Fe3O4) was prepared and then used as SERS substrate (surface-enhanced Raman spectroscopy) for sensing diclofenac which is one of the most widely used non-steroid anti-inflammation drugs. AgNPs/Fe3O4 nanocomposite was synthesized by combining co-precipitation of iron oxide and in-situ reduction of silver nanoparticles. Morphology and structural studies revealed a conjugated structure in which silver nanoparticles (80 nm in diameter) were surrounded by iron oxide nanoparticles (18 nm in diameter). There is a slight blue-shift in position of plasmon peak from 405 nm for silver nanoparticles to 375 nm for AgNPs/Fe3O4 nanocomposite. Even the saturation magnetization (Ms) of the Ag/Fe3O4 nanocomposite only reached 28 emu.g-1 but still good enough for immobilizing nanocomposite structures onto the substrate. The use of AgNPs/Fe3O4 nanocomposite as SERS substrate for sensing application was demonstrated with using diclofenac as a model. The detection limit and enhancement factor of the SERS-based diclofenac sensor were found to be 10-12 M and 2.6×1010, respectively. Such kind of bifunctional nanocomposite will probably help us to avoid time-consuming process to immobilize metal nanoparticles onto the surface, and also allow us to regenerate the substrate for multiple uses.","PeriodicalId":506542,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"26 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141349987","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":"A SINGLE-CHAMBER MICROBIAL FUEL CELL AS AN ALTERNATIVE BIOSENSOR FOR CONTINUOUS AND ONSITE DETERMINATION OF BOD IN WASTEWATER","authors":"Dinh Thi, Thu Ha, Pham Ngoc Phat","doi":"10.15625/2525-2518/19181","DOIUrl":"https://doi.org/10.15625/2525-2518/19181","url":null,"abstract":"The two main pollution parameters, BOD (Biochemical Oxygen Demand) and COD (Chemical Oxygen Demand), are crucial factors in assessing water quality and pollution levels. Currently, COD can be measured using sensor devices, while BOD relies on the activity of microorganisms. Traditionally, the quantification of biologically oxidizable organic carbon involves measuring oxygen consumption over a five-day period, commonly known as the BOD5 test. However, the BOD5 test has several disadvantages, such as its time-consuming nature, unsuitability for process control, and the requirement for highly skilled samplers. It was hypothesized that the output of a single-chamber microbial fuel cell (SCMFC) with an air cathode could serve as an alternative method for measuring BOD. To validate this hypothesis, this study conducted some experiments using the model of SCMFC. When artificial wastewater, utilizing sodium acetate as fuel, was employed, a strong linear correlation (R2 > 0.99) between the total charge transferred and BOD5 concentration was confirmed. Additionally, the linear relationship was also investigated for real domestic wastewater. This relationship was also examined for real domestic wastewater, resulting in a combined correlation with an R2 value exceeding 0.98. Until now, research on biosensors (particularly SCMFC-based biosensors) in Vietnam has been relatively new and not extensively conducted. The results of this study could provide a solid foundation for the development of continuous and onsite BOD sensors to monitor BOD concentrations in wastewater streams.","PeriodicalId":506542,"journal":{"name":"Vietnam Journal of Science and Technology","volume":" 33","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141371734","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 a multiplex real-time PCR assay for simultaneous detection of common colistin and carbapenemase genes","authors":"Le Thi Thuy, Do Quang Minh, Le Thi Thu Hang, Dong Van Quyen, A. Bañuls, Nguyen Quang Huy","doi":"10.15625/2525-2518/19130","DOIUrl":"https://doi.org/10.15625/2525-2518/19130","url":null,"abstract":"Carbapenem and colistin are often used as last-resort treatment for Gram-negative multi-drug resistant (MDR) bacteria. Nevertheless, co-resistance of these drugs is threatening the global healthcare system. Rapid and accurate detection of carbapenem and colistin resistant bacteria is critical for adequate antibiotic therapy and infection control, particularly in the context of an outbreak. The presence of blaNDM, blaKPC, blaIMP-1 and blaOXA-48 is responsible for greater than 95% phenotypic resistance in carbapenem-resistant Enterobacteriaceae, while mcr-1 is the most prevalent and well disseminated of all mcr genes in colistin-resistant strains. In this study, we aim to develop a multiplex real time-PCR assay for simultaneous detection of the five genes blaNDM, blaKPC, blaIMP-1, blaOXA-48 and mcr-1. The melting curve-based multiplex real time PCR assay was established with the dissociation temperature range extended from 76°C to 87°C. The whole process is completed within one hour and half, allowing rapid screening of the five genes in cultured bacteria samples with a limit of detection of 10 CFU/ml. The proposed multiplex real-time PCR assay is a robust, reliable and rapid method for the detection of bacterial strains carrying blaOXA-48, blaIMP, blaNDM, blaKPC and mcr-1 gene individually or in cocktail of genes. This assay will be a valuable tool for surveillance and monitoring of MDR bacteria additionally resistant to either carbapenem or colistin or both drugs.","PeriodicalId":506542,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140717208","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":"ANALYTICAL PROCEDURES USING SEM/EDX EQUIPMENT FOR DETERMINING HEAVY METALS CONTENTS IN FLY ASH GENEREATED FROM DOMESTIC SOLID WASTE INCINERATORS: A CASESTUDY OF SOCSON WASTE-TO-POWER PLANT IN HANOI","authors":"Ngo Tra Mai, Khuat Thi Hong, Nguyen Thi Thuy Hang, Nghiem Thi Ha Lien, Van Huu Tap, Phan Thi Thanh Hang, Trinh Thi Tham, Vu Duc Toan, Nguyen Thi Hoa, Nguyen Hung Son, Nguyen Trong Nghia, Tran Thien Cuong, Dao Thanh Duong, Do Thi Lan Chi","doi":"10.15625/2525-2518/18198","DOIUrl":"https://doi.org/10.15625/2525-2518/18198","url":null,"abstract":"The researching and establishing of as process for analyzing fly ash generated from a domestic solid waste treatment plant by SEM/EDX method were investigated. Three sampling series with twelve (12) fly ash samples collected at SocSon waste-to-power plant were used for: (i) analytical procedure establishment; (ii) standardization; and (iii) test analysis. At each measurement, a cross-check with one random sample using XRF method was carried out to verify the accuracy of the SEM/EDX measurements. As a result, a 6-step measurement procedure has been proposed, including: experimental preparation, sample weighting, liquid/solid phase separation, sample drying, sample measurement and data processing. And for procedure adjustment, liquid/solid phase separation were repeated twice while drying time was doubly increased from 24h to 48h to collect ll heavy metal contaminated residues. The proposed procedure could provide results in about 3-5 seconds without any requirement of sample digestion while most of the heavy metalspresent in fly ash, including low-content ones such as Ag, Cd and Cr were simultaneously displayed. The standardized measurement procedure was applied to test the hazardous properties of fly ash by comparing with QCVN 07:2009/BTNMT – National Technical Regulations on Hazardous waste thresholds. The results identified that fly ash could be primarily considered as hazardous waste with 5/14 heavy metal parameters exceed the limit from 1,7 to 9,5 times and needs to be collected and treated properly. This result is also quite similar to the studies that have been done in China, the US or Vietnam. Thus, SEM/EDX method could be used for analyzing heavy metal components in fly ash samples of solid waste treatment plants.","PeriodicalId":506542,"journal":{"name":"Vietnam Journal of Science and Technology","volume":" 65","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140221162","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":"Ecdysterols and triterpene glycoside from Achyranthes aspera L. and their NO production inhibitory activity","authors":"Hoàng Thi Ngoc Lan, Nguyen Thi Ngoc Mai, Bui Thi Thao Anh, Duong Thi Dung, Bui Huu Tai, Phan Van Kiem","doi":"10.15625/2525-2518/18462","DOIUrl":"https://doi.org/10.15625/2525-2518/18462","url":null,"abstract":"Phytochemical study on the methanolic extract of the aerial parts of Achyranthes aspera led to the isolation of six compounds including five ecdysterols, makisterone A (1), achyranthesterone A (2), 24(28)-dehydromakisterone A (3), podecdysone C (4), 20-hydroxyecdysone (5), and 3-O-α-L-rhamnopyranosyl-(1→3)-β-D-glucuronopyranosyl-oleanolic acid 28-O-β-D-glucopyranosyl ester (6). Compounds 1-5 were first isolated from A. aspera. Their chemical structures were identified by 1D and 1D NMR spectra in comparison with the published data in literature. Al five ecdysterol significantly showed NO production inhibition effects in LPS-activated RAW264.7 cells with the IC50 values ranging from 27.21 to 40.47 µM compared to that of positive control compound, L-NMMA, 32.24 µM.","PeriodicalId":506542,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140242761","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":"EGFR-T790M mutation associated with acquired resistance to first-generation EGFR tyrosine kinase inhibitors in Vietnamese Non-Small-Cell Lung Cancer patients","authors":"Le Hoan, Tran Khanh Chi, Tran Van Khanh, Thieu Thi Tra My, Ngoc Cuong Nguyen","doi":"10.15625/2525-2518/18061","DOIUrl":"https://doi.org/10.15625/2525-2518/18061","url":null,"abstract":"Background: non-small cell lung cancer (NSCLC) patients who had epidermal growth factor receptor (EGFR) mutations sensitive to EGFR tyrosine kinase inhibitors (TKIs) had a high response rate to target therapies. Epidermal growth factor receptor (EGFR) T790M mutation is the most common mechanism of acquired resistance to first-generation EGFR TKIs. Objective: The aim of this study was to analyze the incidence of EGFR T790 mutation, the progression-free survival (PFS) in the patients who progress on the first‑ generation EGFR‑TKIs. This study also investigates the correlation between T790M mutation and clinical, subclinical features, progression-free survival of NSCLC Vietnamese patients. \u0000Patients and methods: We analyzed 66 NSCLC patients who had acquired resistance to first-generation EGFR-TKIs. The clinical data, PFS and the mechanism of acquired resistance were obtained. The Kaplan-Meier method and the log-rank test were used to analyze the PFS and compare between subgroups of patient characteristics. The correlations between the patient’s characteristics and EGFR-T790M mutation status were analyzed by Chi-square and Fisher’s exact tests. \u0000Results: At the progressive period, EGFR T790M mutation was detected in 54.5% of patients. The median PFS were 14.48 ± 3.9 months (range: 8- 26 months). Patients who were older than 60 years old or had comorbidities had significantly shorter PFS than the subgroups without (P≤0.05). The age, gender, smoking status, comorbidities, pathological features were not significantly correlated with the development of EGFR-T790M (P > 0.05). The average PFS was not significantly different between the EGFR-T790M group and the non-EGFR-T790M group (P=0.642). \u0000Conclusion: In our cohort study, more than half of all patients had T790M mutation after being treated with first-generation EGFR TKIs. Age and comorbidities were associated with PFS but the EGFR-T790M mutation was not correlated with PFS.","PeriodicalId":506542,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"18 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140258579","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":"Potential inhibitory activities of phytoconstituents in Salvia miltiorrhiza against coronary heart disease drug targets using docking and ADMET studies","authors":"Thi Thuy Duong Man, Ngoc Long Nguyen, Hai Son Pham, Thi Hoai Van Tran, Long Giang Bach, Pham Quoc Long, Viet-Hai Ha, Tien Lam Do, Thi Hong Minh Pham, Thị Thùy Hương Lê","doi":"10.15625/2525-2518/18215","DOIUrl":"https://doi.org/10.15625/2525-2518/18215","url":null,"abstract":"Coronary heart disease (CHD) is one of the leading causes of death worldwide. The effectiveness of the current drugs is still restricted due to high side effects; thus, it is urgently needed to discover novel compounds for drug development. In the field of drug discovery research, the main target receptors for chemotherapy are identified as ACE, PPAR-γ, HMGR, COX-2, and thrombin. In this study, docking simulations were performed for phytoconstituents of Salvia miltiorrhiza Bunge in searching for compounds with potential inhibitory activities against these proteins. As a result, six compounds were suggested as potential multitarget inhibitors and could be considered for further drug development studies based on docking conformation and ADMET property analysis.","PeriodicalId":506542,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"781 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140273194","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":"INFLUENCE OF THE REDUCING AGENTS ON MORPHOLOGY AND PROPERTIES OF SIVER STRUCTURES ON PAPER","authors":"Thi Bich Ngoc Nguyen","doi":"10.15625/2525-2518/17088","DOIUrl":"https://doi.org/10.15625/2525-2518/17088","url":null,"abstract":"Abstract. A paper-based SERS substrate with tunable plasmonic properties and excellent flexibility has been applied in various fields. These SERS substrates were prepared using a direct chemical reduction synthesis method for the present work. The isotropic and anisotropic morphology of silver structures on cellulose paper fiber were controlled by the types of reducing agents: (1) sodium borohydride (NaBH4), (2) ascorbic acid (L-AA), (3) glucose, (4) formaldehyde (HCHO). The plasmon characterization of silver structures on paper was systematically investigated. The fabricated paper-based SERS substrates were used to detect melamine in an aqueous solution and determine the influence of type reducing agents on the enhancement factor (EF) and signal uniformity of SERS substrates.    ","PeriodicalId":506542,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"17 18","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140270175","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":"DESIGN NEURAL NETWORK-PID CONTROLLER FOR TRAJECTORY TRACKING OF DIFFERENTIAL DRIVE MOBILE ROBOT","authors":"Nguyễn Hồng Thái","doi":"10.15625/2525-2518/18066","DOIUrl":"https://doi.org/10.15625/2525-2518/18066","url":null,"abstract":"This paper proposes the design of a neural network controller based on a sample controller for controlling the trajectory-tracking motion of a differential drive mobile robot (DDMR). Firstly, the trajectory tracking model for DDMR is established based on position error. Next, a perceptron neural network is designed with three hidden layers to control the trajectory tracking of DDMR. The backpropagation algorithm is used to train the neural network with training data obtained from the PID controller with time-varying parameters. The authors have developed this approach and experimentally verified it with minor tracking errors. The neural network's weight matrix (W) and bias vector (b) are updated in real-time, providing an advantage over other methods. The effectiveness of the proposed controller is demonstrated by the DDMR's NURBS trajectory tracking error, which does not exceed 2.17 cm, and the DDMR's motion error, with linear and angular velocities not exceeding 0.004 m/s and 0.0007 rad/s, respectively. The proposed controller can supplement traditional controllers in controlling the trajectory of autonomous mobile robots, thereby improving the ability to generate local trajectories to avoid dynamic obstacles by the neural network","PeriodicalId":506542,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"12 21","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140278075","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}