A Text-based Approach For Link Prediction on Wikipedia Articles

This paper present our work in the DSAA 2023 Challenge about Link Prediction for Wikipedia Articles. We use traditional machine learning models with POS tags (part-of-speech tags) features extracted from text to train the classification model for predicting whether two nodes has the link. Then, we use these tags to test on various machine learning models. We obtained the results by F1 score at 0.99999 and got 7th place in the competition. Our source code is publicly available at this link: https://github.com/Tam1032/DSAA2023-Challenge-Link-prediction-DS-UIT_SATComment: Accepted by DSAA 2023 Conference in the DSAA Student Competition Sectio

SYNTHESIS OF STARCH MODIFIED MONTMORILLONITE AS AN EFFECTIVE ADSORBENT FOR Pb (II) REMOVAL FROM WATER

The adsorbent is prepared by the montmorillonite co-modification with starch for the removal of Pb (II) ions from aqueous solution. The Fourier-transformed infrared (FTIR), X-ray diffraction (XRD) spectroscopies were used to determine the structure and characteristics of the adsorbent. The main factors affecting the removal of Pb (II) ions were investigated, including the effect of pH, contact time, adsorbent dosage and the initial concentration of Pb (II). Batch process can be used for adsorption and equilibrium studies. The experimental data were fitted using Freundlich and Langmuir adsorption models. The Langmuir isotherm best fitted the experimental data with R2 0.99 and maximum Pb (II) adsorption capacity of 21.5 mg/g indicated monolayer adsorption. Kinetic studies using pseudo-first-order and pseudo-second-order rate models showed that the process complied well with the pseudo second-order rate model

The impact of zerovalent cobalt nanoparticle on photosynthesis - related genes expression in soybean leaves Glycine max (L.) Merr. (Dt26)

Photosynthesis is an important physiological process in plants. It plays a crucial role in plant growth and development. In this study, we investigated the impact of zerovalent cobalt nanoparticles on the photosynthesis and expressing of gene involving in this process in leave of soybean Glycine max (L) Merr “DT26” at different growth stages. The results showed that treatment of zerovalent cobalt nanoparticles made in Vietnam and USA (with two doses of 0.17 and 16.67 mg/kg of soybean seed) enhanced the photosynthesis of soybean by increasing the content of chlorophyll a and the ratio of Fv/Fm compared with the control (without treatment of zerovalent cobalt nanoparticles). These values tended to increase and reached the maximum value at 40 days and then decreased in at 70 days. The expression level of photosynthesis-related genes of soybean leaves also changed depending on the soybean’s growth stage and concentration of zerovalent cobalt nanoparticles being treated. The genes psaA, Lhca, psaB, Cytb6f (belonging to photosystem I) and psbA, psbB, psbC, psbD, psbE (belonging to photosystem II) in the experimental fomulas were higher expressed than that in control group at 20 and 70 days. However, at 40 days, the expression levels of these genes were significantly different. Obtained results supplied the basis for understanding the active mechanism of the above genes to control/regulates photosynthetic activity of plants with and without the presence of zerovalent cobalt nanoparticles as well as under stress conditions. 

Corrosion of stainless steel water storage tanks exposed in coastal atmospheric conditions

Results of corrosion survey for stainless steel tanks used in water storage at various coastal areas are presented. Corrosion damages were revealed at both the outer and inner surfaces of tanks made of 304 and 201 steel grades. Corrosion deterioration was more severely observed for the atmospheric areas with higher airborne salinity and time of wetness.  Corrosion products examined by visual inspection and SEM-EDX technique show relatively distinctive characteristics for outer and inner surfaces which are attributed to different mechanisms of corrosion initiated by various corrosive agents in the atmosphere. Atmospheric chlorides from airborne sources are considered the main reason for causing corrosion of 304 and 201 steel grade water tanks

Awareness and preparedness of healthcare workers against the first wave of the COVID-19 pandemic: A cross-sectional survey across 57 countries.

BACKGROUND: Since the COVID-19 pandemic began, there have been concerns related to the preparedness of healthcare workers (HCWs). This study aimed to describe the level of awareness and preparedness of hospital HCWs at the time of the first wave. METHODS: This multinational, multicenter, cross-sectional survey was conducted among hospital HCWs from February to May 2020. We used a hierarchical logistic regression multivariate analysis to adjust the influence of variables based on awareness and preparedness. We then used association rule mining to identify relationships between HCW confidence in handling suspected COVID-19 patients and prior COVID-19 case-management training. RESULTS: We surveyed 24,653 HCWs from 371 hospitals across 57 countries and received 17,302 responses from 70.2% HCWs overall. The median COVID-19 preparedness score was 11.0 (interquartile range [IQR] = 6.0-14.0) and the median awareness score was 29.6 (IQR = 26.6-32.6). HCWs at COVID-19 designated facilities with previous outbreak experience, or HCWs who were trained for dealing with the SARS-CoV-2 outbreak, had significantly higher levels of preparedness and awareness (p<0.001). Association rule mining suggests that nurses and doctors who had a 'great-extent-of-confidence' in handling suspected COVID-19 patients had participated in COVID-19 training courses. Male participants (mean difference = 0.34; 95% CI = 0.22, 0.46; p<0.001) and nurses (mean difference = 0.67; 95% CI = 0.53, 0.81; p<0.001) had higher preparedness scores compared to women participants and doctors. INTERPRETATION: There was an unsurprising high level of awareness and preparedness among HCWs who participated in COVID-19 training courses. However, disparity existed along the lines of gender and type of HCW. It is unknown whether the difference in COVID-19 preparedness that we detected early in the pandemic may have translated into disproportionate SARS-CoV-2 burden of disease by gender or HCW type

Study on the effect of single and mixtured of cobalt nanoparticles on the change of photosynthesis parameters and antioxidant enzymes activity of soybean seedlings glycine max (l.) merr. (DT26)

Soybean (Glycine max (L) Merr.) is one of the major crops grown worldwide for human food and animal feed. Nanotechnology is one of the most potential tools in modern agriculture to improve crop productivity. In this paper, we investigated the effect of single and mixture cobalt nanoparticles on the change of photosynthesis - related parameters and antioxidant enzyme activity of soybean Glycine max (L) Merr “DT26” at different growth stages under pilot scale. The results showed that all form of cobalt nanoparticles treatment enhanced the photosynthesis of soybean by increasing the content of chlorophyll a, Pn and the ratio of Fv/Fm. These values tended to increase and reached the maximum value at fifth trifoliate stage and then decreased at the beginning bloom stage. The activity of antioxidant enzymes such as superoxide dismutase and peroxidase (when seeds were treated with USA single colbalt nanoparticles at concentration of 16.67 mg/kg) and catalase (with USA single colbalt nanoparticles at concentration of 0.17 mg/kg) were increased in 2.11, 1.85 and 1.60 times respectively compared to the control group (without the treatment of colbalt nanoparticles) while ascorbate peroxidase was reached highest value (increased in 2.73 times) under the condition of Vietnam single colbalt nanoparticles at the dose of 0.17 mg/kg seeds. This suggests that cobalt nanoparticles treatment has generated oxidative stresses and soybean DT26 has the self-protection mechanism by increasing the activity of antioxidant enzymes in order to reduce the amount of H2O2 and O2 which accumulates in the leaf cells

Isolation of pyruvic acid producing Halomomas sp. bacterial strain from mangrove forest of Khanh Hoa province

Pyruvic acid (pyruvate) is a central intermediate in carbon and energy metabolism in all organisms. It is widely used in the industrial biosynthesis of high - value compounds and food additives. Biotechnological pyruvate production has attracted attention as a potential alternative method of pyruvate synthesis. From 27 soil and mud samples collected from mangrove forests of Cam Ranh, Khanh Hoa province, we isolated 10 bacterial strains belonging to Halomonas genus. Among them, 9 strains were able to synthesis and secreted pyruvate in the culture medium. The maximal pyruvate production was in MC8 strain with value of 0.110 ± 0.015 g/L. MC8 strain was Gram-negative, short rod-shaped, 1,56 ± 0,07 in width, 5,09 ± 0,38 µm in length, non-flagella and nonmotile. MC8 strain was positive for oxidase and catalase activities and reduction of nitrate to nitrite and nitrogen. Cells were able to growth at salt concentrations of from 0.5 to 20%, temperature ranging from 20 to 45ºC and pH ranging from 5 to 12. The major fatty acids of MC8 biomass were C16:0; C18:1w7c và C12:0 3OH. Phylogenetic analyses based on 16S rRNA gene sequencing showed that MC8 strain possessed the highest similarity of 98.5% to the strain Halomonas flava. Based on morphological, biochemical characteristics and 16S rRNA gene sequencing, MC8 strain was identified as H. flava. This is the first study of Halophilic bacteria which is capable of pyruvate synthesis in Vietnam. Thus, these obtained results provided important insights into the production of pyruvate using Halomonas strains

Magnetic nanoparticles embedded in microlasers for controlled transport in different sensing media

In recent years, whispering gallery mode microlasers have attracted tremendous interest in sensing due to their ultra-high sensitivity at atomic levels. However, due to the non-magnetic properties, it is difficult to locate the microlasers at hard-to-reach positions, thus, limiting their sensing potential in many in-vitro and in-vivo applications. In this work, we report magnetic microlasers fabricated by encapsulating Ni0.2Zn0.8Fe2O4 magnetic nanoparticles (MNPs) within their cavity made of bovine serum albumin. The presence of MNPs allows the transportable actuation of the magnetic microlasers while maintaining lasing emission characteristics. Microlasers with various concentrations of MNPs are investigated to identify the optimum concentration that can balance a good magnetization, a low lasing threshold, and a high quality (Q) factor. These magnetic microlasers can be employed for sensing applications where sensors need to be navigated through different sensing media. As a proof of concept, we observed a clear shift of lasing wavelength of a magnetic microlaser while dragging it through different adjacent media by magnetic navigation. This result demonstrates the potential applications of magnetic microlasers for future biological and chemical applications.11Nsciescopu

Study on biocharacteristics of Symbiodinium sp. isolated from soft coral in coastal water of Quang Nam, south central Vietnam

Phototrophic dinoflagellates of the genus Symbiodinium (= zooxanthellae) are well known as symbionts of corals. They play an important role in maintaining the healthy as well as establishment of new reefs. In addition, products such as toxins or pigments from these symbiotic microalgae are potentially important for applications in the biomedical sciences, especially in new drug development. In this study, we isolated successfully a symbiotic microalga from soft coral Sinularia sp. which was collected in Cu Lao Cham coastal waters of Quang Nam province. Based on morphological characteristics and 18S rRNA gene sequences, isolated SHM8 strain was identified as Symbiodinium goreaui. This symbiont was cultured in different media such as ASP-A8, F2, ES, IMK, K, and L1. L1 culture medium supplemented with taurine concentration of 4.88 mM led to the cell density of SHM8 strain increased in 50% compared to control on day 2 in cultivation; amino acid mixture enhanced cell density by 31.7% on day 5 in cultivation. Supplementation of carbon source (bicarbonate salt of 16.8 g/L) and nitrogen source (nitrate salt of 0.055 g/L) enhanced the cell density by 40% and 27%, respectively on day 6 in culture. Obtained results in this study proved that this microalga can live independently without host. Successful isolation and cultivation of Symbiodinium microalga are one of the necessary conditions for promising researches on the natural bioactive substances from this microalgal biomass in the future in Vietnam.   Citation: Dang Diem Hong, Pham Van Nhat, Hoang Thi Huong Quynh, Luu Thi Tam, Ngo Thi Hoai Thu, Nguyen Cam Ha, Hoang Thi Lan Anh, Nguyen Hoai Nam, Nguyen Thi Minh Hang, Chau Van Minh, 2017. Study on biocharacteristics of Symbiodinium sp. isolated from soft coral in coastal water of Quang Nam, south central Vietnam. Tap chi Sinh hoc, 39(3): 367-375. DOI: 10.15625/0866-7160/v39n3.10112. *Corresponding author: [email protected] Received 19 June 2017, accepted 20 August 201