How has Learning Motivation of University Students in Vietnam Changed during COVID-19 Pandemic?

With the data from 2,082 students at National Economics University, this article focuses on assessing the decline in learning motivation of undergraduates during the fourth wave of COVID-19 in Vietnam. Using exploratory factor analysis (EFA), descriptive statistics, and One_Way ANOVA tests, it was evident that the decline in learning motivation was noticeable in most students surveyed. Specifically, 36.1% of the survey respondents experienced severe demotivation with all 4 expressions “Distracted”, “Exhausted”, “Uninterested” and “Lack of responsibility for learning”. Furthermore, the level of motivation decline tended to rise significantly among the groups of students with the following characteristics: first-year students, male gender, and low academic performance. The abovementioned results alert educational and training institutions to pay proper attention and comprehensively evaluate the learning motivation of their students. Moreover, supportive measures should be implemented to improve learning motivation for the young in the “post-COVID-19” period

Genetic variation and outcrossing rate of Dipterocarpus dyeri in the Tan Phu tropical rain forest (Dong Nai), Vietnam

Dipterocarpus dyeri (Dipterocarpaceae) is widely distributed in lowland rainforests in southeastern Vietnam. Due to over- exploitation and habitat destruction in the 1980s and 1990s, this species is listed as threatened. Understanding the genetic variation and mating rate among D. dyeri population that occurs in forest patches is necessary to establish effectively conservation strategies for this species. To conserve the species in tropical forests, genetic diversity and mating rate were investigated using eight microsatellites (single sequence repeat, SSR) as markers. All of the eight loci were polymorphic. A total of 36 different alleles were observed across the loci screened. The SSR data indicated high genetic diversity (NA = 4.5; HO = 0.542 and HE = 0.667) and high inbreeding value, FIS= 0,182. The mating system parameters were determined using the mixed mating model and the results indicated high outcrossing rate (tm=0.81 and ts=0.675) and lowselfing rate (0.19). Difference of tm-ts value indicated that inbreeding contributed to selfing rate for this species in the Tan Phu tropical rain forest. The results reflected that D. dyeri habitat in this area has been restored and the number of individuals was high, about 500 individuals. However, seedlings were not found so far in this study. These results indicated the importance of conserving of the genetic resources of Dipterocarpus dyeri species in the Tan Phu rain forest. The conservation strategy should include an establishment of an ex-situ conservation site with new big population for this species from all genetic groups, which might improve its fitness under different environmental stresses. 

Partial purification and characterization of a superoxide distimutase (SOD1) from black tiger shrimps Penaeus monodon

Superroxide dismutase (SOD, EC.1.15.1.1) is the enzyme which dismutates superoxide radicals and plays an important role in protection of living cells against oxidative stress. SOD is also involved in immune response in shrimps. In this study, it was found that the total SOD activity of black tiger shrimp muscular tissues is 10 fold higher than that of the haemolymph, however, the specific activity of SOD in the shrimp haemolymph is 9.2 fold higher than that of muscular tissues. By using active gel electrophoresis, 2 different SOD forms were found in black tiger shrimps (one in muscular tissues and two in haemolymph).Using DE-52 cellulose and Q-Sepharose ion exchange column chromatography, one SOD (SOD1) from black tiger shrimp haemolymph was partially purified, and its purity was 31.2 times higher than that of the starting haemolymph. The SOD1 was shown to have mainly one protein band of approximately 24 kDa on SDS-PAGE. SOD1 was most active at 45oC and pH of 5.5. At a concentration of 5 mM, Mn2+ strongly activated SOD1 (up 200% activity), Ca2+ và Zn2+ could increase approximately 20% activity while Cu2+ inhibited more than 60% ativity of the enzyme.

Enzimatska obrada iskorištenih listića zelenog čaja i njihova primjena u proizvodnji čajnog peciva s velikim udjelom prehrambenih vlakana

Research background. By-products of food industry have been studied as sources of high fibre and antioxidant ingredients for healthy food products, because of their economic and environmental benefits. However, the soluble dietary fibre content of these materials is usually lower than the recommended value that is claimed to bring positive health effects. Enzymatic treatment could be an efficient method for modifying insoluble and soluble dietary fibre contents of these materials. The purpose of this study is to investigate the effects of enzymatic treatment conditions on soluble, insoluble and total dietary fibre mass fractions in spent green tea leaves, and evaluate the quality of dough and cookies when different mass fractions of untreated and treated leaves were added to the recipe. Experimental approach. The mass fractions of soluble, insoluble and total dietary fibre in spent tea leaf powder was evaluated after the leaves were treated with cellulase amount of 0−25 U/g for 0 to 2 h. Wheat flour was replaced by untreated and treated spent tea leaf powder at 0, 10, 20, 30 and 40% in cookie formulation. Textural properties of dough, proximate composition, physical properties and overall acceptability of cookies were analysed. Results and conclusions. The appropriate conditions for enzymatic treatment were enzyme loading of 20 U/g and biocatalytic time of 1.5 h, under which the mass fraction of soluble dietary fibre in spent tea leaves increased by 144.5% compared to that of the control sample. The addition of spent tea leaves led to the increase in dough hardness. Increase in the spent tea leaf amount also enhanced fibre mass fraction, antioxidant activity and hardness of cookies but reduced their overall acceptability. Moreover, the enzymatic treatment of spent tea leaves improved the soluble to total dietary fibre ratio of the cookies, which influenced their textural properties and health benefits. The cookies with added 20% untreated or treated spent tea leaves were overall accepted by the panel. Novelty and scientific contribution. For the first time, spent tea leaves have been treated with enzymes to improve their soluble to total dietary fibre ratio. The treated spent tea leaves are a new promising high-fibre antioxidant ingredient for cookie preparation.Pozadina istraživanja. Nusproizvodi prehrambene industrije ispituju se iz ekonomskih i ekoloških razloga kao izvori sastojaka s velikim udjelom prehrambenih vlakana i antioksidacijskim učinkom koji se mogu upotrijebiti u proizvodnji zdrave hrane. Međutim, udjel topljivih prehrambenih vlakana u nusproizvodima je obično manji od preporučenih vrijednosti koje mogu imati pozitivan učinak na zdravlje. Enzimatska obrada bi mogla biti učinkovita metoda modificiranja netopljivih i topljivih prehrambenih vlakana iz otpada prehrambene industrije. Svrha je ovog rada bila ispitati utjecaj različitih uvjeta enzimatske obrade na masene udjele topljivih, netopljivih i ukupnih prehrambenih vlakana u iskorištenim listićima zelenog čaja, te procijeniti kakvoću tijesta i čajnog peciva s dodatkom različitih masenih udjela obrađenih i neobrađenih listića. Eksperimentalni pristup. Maseni udjeli topljivih, netopljivih i ukupnih prehrambenih vlakana u prahu od iskorištenih listića zelenog čaja mjereni su nakon njihove obrade s 0–25 U/g celulaze tijekom 0 do 2 h. U smjesi za čajno pecivo je pšenično brašno zamijenjeno s 0, 10, 20, 30 i 40 % obrađenog ili neobrađenog praha iskorištenih listića zelenog čaja. Ispitani su tekstura tijesta te kemijski sastav, fizikalna svojstva i ukupna prihvatljivost dobivenog čajnog peciva. Rezultati i zaključci. Pri povoljnim uvjetima enzimatske obrade, a to su 20 U/g enzima i vrijeme trajanja biokatalitičkog procesa od 1,5 sata, maseni udjel topljivih prehrambenih vlakana u iskorištenim listićima zelenog čaja porastao je za 144,5 % u usporedbi s kontrolnim uzorkom. Dodatkom iskorištenih listića zelenog čaja povećala se tvrdoća tijesta. Povećanjem količine listića čaja povećali su se i maseni udjel vlakana, antioksidacijska svojstva i tvrdoća čajnog peciva, ali se smanjila njihova prihvatljivost. Osim toga, enzimatskom se obradom iskorištenih listića zelenog čaja poboljšao omjer topljivih i ukupnih vlakana u čajnom pecivu, što je utjecalo na njegovu teksturu i pozitivan učinak na zdravlje. Panel ocjenjivača je okarakterizirao čajno pecivo s dodatkom 20 % obrađenih ili neobrađenih iskorištenih listića čaja kao prihvatljive. Novina i znanstveni doprinos. Prvi put je enzimatskom obradom iskorištenih listića zelenog čaja poboljšan njihov omjer topljivih i ukupnih prehrambenih vlakana. Obrađeni iskorišteni listići zelenog čaja novi su obećavajući sastojak s antioksidacijskim svojstvima koji se može upotrijebiti u pripremi čajnog peciva

ĐIỆN CỰC NANO CẤU TRÚC 3D - PHÂN LỚP DỊ THỂ CỦA CdS/ZnO/Pt/WO3 TRONG VIỆC NÂNG CAO HIỆU SUẤT TÁCH NƯỚC QUANG ĐIỆN HÓA

In this work, we report the synthesis of the hierarchical structure of a CdS/ZnO/Pt/WO3 electrode for photoeletrochemical water splitting application. The photoanode was synthesized via the hydrothermal and atomic layer deposition methods. The morphological and structural properties of CdS/ZnO/Pt/WO3 nanoplates were carefully investigated by using SEM, TEM, and XRD techniques. The CdS/ZnO/Pt/WO3-based photoelectrode has a photocurrent density of 8,5 mA·cm-2 and a photoconversion efficiency of 7.9% at a supplied potential of –0,85 V in a 0.5 M Na2S solution. This photocurrent density is twice higher than that of the CdS/ZnO/FTO electrode. Due to built-in potential and efficiently collecting the photo-carriers generated from the ZnO/CdS heterojunction under illumination, the CdS/ZnO/Pt/WO3 electrode exhibits enhanced performance of the photoelectrochemical cell. This is a promising approach to the synthesis of heterojunction layers of semiconductor together with nanostructures for fabricating photoelectrodes of the photoelectrochemical cell to enhance hydrogen production efficiency.Trong bài báo này, chúng tôi nghiên cứu chế tạo điện cực có cấu trúc 3D phân lớp dị thể (cây – cành – nhánh) CdS/ZnO/Pt/WO3 ứng dụng cho tách nước quang điện hóa. Điện cực được tổng hợp bằng phương pháp thủy nhiệt và lắng đọng lớp nguyên tử. Hình thái học, cấu trúc tinh thể, và thành phần nguyên tố của điện cực này được nghiên cứu bằng kính hiển vi điện tử quét (FE–SEM), kính hiển vị điện tử truyền qua (HR–TEM) và nhiễu xạ tia X (XRD). Nghiên cứu tính chất quang điện hóa của cấu trúc CdS/ZnO/Pt/WO3, chúng tôi thu được mật độ dòng quang điện là 8,5 mA·cm-2 và hiệu suất chuyển đổi năng lượng ánh sáng mặt trời thành năng lượng hydro 7,9 %% tại thế cung cấp –0,85 V trong dung dịch chất điện ly Na2S với nồng độ 0,5 mol/L. Cấu trúc 3D phân lớp này có mật độ dòng quang điện của điện cực cao hơn gấp hai lần so với các cấu trúc CdS/ZnO trên điện cực thủy tinh phủ oxit thiếc pha tạp bằng flo. Đây là một hướng tiếp cận rất hứa hẹn tổng hợp các cấu trúc nano phân lớp dị thể nhằm nâng cao hiệu quả sản xuất hydro

EFFECT OF CULTURE CONDITIONS FOR ANTIMICROBIAL ACTIVITY OF MARINE - DERIVED FUNGUS ASPERGILLUS FLOCCULOSUS 01NT.1.1.5

The biosynthesis of compounds with antibiotic activity produced by marine fungi, strongly depends on their growth conditions. A good understanding of the role of culture conditions in the biosynthesis of metabolites may lead to better exploitation of microbial metabolites. In this study, the influence of culture conditions including incubation period, initial pH and salinity on antimicrobial activity and secondary metabolites production of marine fungus 01NT.1.1.5 was investigated. This isolate, obtained from sponge Stylissa sp. in Nha Trang Bay, exhibited a broad spectrum of in vitro antimicrobial activity to Bacillus cereus ATCC 11778, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, Listeria monocytogenes ATCC 19111, Streptococcus faecalis ATCC 19433 and Candida albicans ATCC 10231. According to morphological characteristics and sequence analysis of 28S rDNA, the fungus was identified as Aspergillus flocculosus. The results indicated that antimicrobial activity and metabolite amount were highest when the fungus was cultivated in rice medium with incubation period of 20 days. The optimum salinity of 35 g/L and initial pH of 6.0 were found for the maximum antibiotic production. The colony growth, antimicrobial activity and production of secondary metabolites of the strain A. flocculosus 01NT.1.1.5 varied depending on salt concentrations and initial pH of medium. Particularly, extract of this fungus only showed activity against C. albicans when it was cultured in medium with 30-35 g/L salinity and initial pH 4.0-8.0. The results  indicate that salinity and initial pH along with cultivation period are important factors influencing antimicrobial activity and secondary metabolites of A. flocculosus 01NT.1.1.5, and might be for other marine fungi

Evaluation of factors related to entrepreneurial intentions among young pharmacists in the Mekong Delta region: a cross - sectional study in Vietnam

At present, a new wave of entrepreneurship has emerged and made a significant impact in Vietnam despite challenges. The study aims to assess the factors related to the entrepreneurial intentions of young pharmacists in 2023 in the Mekong Delta region. A cross-sectional descriptive method was conducted, involving interviews with 815 young pharmacists living in the Mekong Delta region, via a pre-designed research questionnaire. Results showed that 6 out of 43 variables were eliminated after Cronbach’s alpha was run. The Kaiser-Meyer-Olkin coefficient (0.5–0.923) indicated statistical significance and suitable conditions for Exploratory Factor Analysis. Confirmatory Factor Analysis and Structural Equation Modeling results were consistent with market data. With the impact of difficulties, attitude, perception of behavioral control, subjective norms, achievement needs on knowledge, and knowledge on entrepreneurial intentions (p < 0.05). In conclusion, the study successfully collected samples and gained a deeper understanding of the factors influencing the entrepreneurial intentions of young pharmacists

Research to support and inform the development, implementation and/or evaluation of tobacco control policies in relation to the framework convention on tobacco control in low and middle-income countries

In order to enforce policies on tobacco control in Vietnam, reliable information on health and socio-economic hazards associated with tobacco farming is needed. The study investigates the harmful impact of tobacco cultivation and processing on health of tobacco farmers in a rural community in northern Vietnam. Objectives included estimation of health care costs as well as health beliefs related to tobacco cultivation and processing. The health of those who cultivate the crop is constantly put in peril. The study confirms that tobacco farming does not bring prosperity to the farmers while causing them a lot of health problems, especially among women

Biflavones and megastigmane glycosides from the leaves of Antidesma bunius.

Two biflavones, podocarpusflavone A (1) and amentoflavone (2) and two megastigmane glycosides, byzantionoside B (3) and (6S,9R)-roseoside (4) were isolated from the methanol extract of the leaves of Antidesma bunius. Their structures were determined by spectroscopic methods and in comparison with the published data. Keywords. Antidesma bunius, Euphorbiaceae, biflavone, megastigmane