bluuebunny/crossref_metadata_2025 huggingface dataset:
A learning-centred approach to teaching linguistic knowledge: Teachers’ perception of teaching periods 1 and 2(/3) in the new English curriculum for secondary schools in Vietnam
Authors: Tung Nguyen Thanh
Published: April 2021

The new curriculum was promulgated at the end of 2018. Therefore, there is a need to investigate how teachers perceive the teaching of linguistic knowledge in addition to skills to develop secondary school learners’ communicative competence. The study was carried out during the three months of July, August and October of 2020 in the three provinces of Kien Giang, Ben Tre and Lam Dong with the participation of 120 teachers from 106 secondary schools. Data were collected in the form of group poster presentations for the first two/three periods in the textbooks for the new curriculum and analyzed according to three aspects of form, meaning and use for linguistic knowledge and their sequence. The findings of the study indicate that the teacher participants have a vague idea about teaching the aspects of linguistic knowledge from a learning-centered approach, do not know their sequence of meaning, form and use, and normally follow the activities and their order in the textbook as the only resort available.
Impacts of using cartoons as an instructional tool on English communicative skills of young learners at a Vietnamese primary school
Authors: Nhung Le Thi Thuy , Dieu Tran Doan Vuong
Published: April 2021

This study examined the impact of the use of cartoons on the speaking and listening skills of students in a primary school in a rural area in Vietnam and their attitudes towards the use of cartoons as a learning tool in their English classes. The study employed an experimental research design to collect data. Participants included 70 fifth-graders divided into two groups, the control group and the experiment group. The control group was taught regular English lessons. The experiment group learned similar lessons but cartoons were added to the English lesson to practice speaking and listening skills for six weeks. Before and after the experiment, the speaking and listening skills of the two groups were measured by a pretest and a posttest. In addition, the students in the experiment group were surveyed using a questionnaire to examine their attitudes towards watching cartoons for learning purposes. The findings show the English speaking and listening skills of the students in the experimental group improved more significantly than those of the students in the control group. Besides, the students in the experiment group expressed positive attitudes towards watching cartoons in English classes. The findings had implications for English language teachers at primary schools in Vietnam and in other non-dominant English speaking countries to include visual materials in their English lessons to enhance young learners’ English proficiency.
Highland Hill tribe language - an extinct language system needed to be saved
Authors: Chau Tang Minh
Published: April 2021

Highland is a typical area in Vietnam with a great deal of unique things for people to study and discover. Among them are culture and language, the two reciprocal elements to create communities called Hill tribes. Original Hill tribes came to the Highland long time ago and set up their life based on their root culture until now. When studying about Hill tribes, we realize that their culture is very interesting and worth tracing. Therefore, how to conserve Hill tribes’ culture is what we need to take into consideration as soon as possible.
Students’ perception of the advantages and disadvantages of learning English for biology with native and non-native English-speaking teachers
Authors: Thien Pham Cu , Tuyen Tran Thi Thanh , Hung Huynh Cong Minh
Published: April 2021

English for Biology is a course in the bachelor training program of Biology Teacher Education at Ho Chi Minh City University of Education. A research on 126 students from Department of Biology of this University on the advantages and disadvantages of learning English for Biology with native and non-native English-speaking teachers was carried out in January, 2018. Data on their perceptions towards the reasons why they liked studying with the teachers were gained from questionnaires. Thirty students in this research were also randomly selected for interview to get their suggestions for the better achievement of learning English for Biology. The results showed that 52 students (41.3%) liked studying English for Biology with non-native English-speaking teachers, whereas 40 students (31.7%) liked learning with native English-speaking teachers, and 34 students (27.0%) preferred studying with both kinds of teachers. Students also suggested some ways to improve the learning effectiveness including regular practice, learner autonomy, environment for practice and so on. The research result will help the Dean take into consideration the importance of teachers in teaching and learning English for Biology.
How the factor of reading hours affect extensive reading of teenage elementary level students at North America International school
Authors: Tram Dang Hoang Bich , Hung Huynh Cong Minh
Published: April 2021

Extensive reading has been received much attention because of its benefits for second language learners. This paper aims to determine the effect of the reading hour factor on the efficiency of extensive reading process of teenage students at North America International School. The experiment was conducted so as to find out whether increasing reading hours has any impact on learners reading performance. The study implications could either announce the teachers and educators the relationship between reading hours and extensive reading or employ in teaching and learning reading extensively. Besides, the revealed findings will provide the teachers proper insights of implementing a successful extensive reading program.
Individual factors that keep online English learners from greater success: the case of HCMC Open University
Authors: Tuyen Nguyen Chau Bich
Published: April 2021

A variety of challenges in online training are found in numerous learning environments such as cultural background, accessibility, technology, learning content and so on. In the developed or western societies, the online training has been developing in a stable way for decades, while numerous typical obstacles seem to be visible in developing countries including student support, flexibility, teaching and learning activities, access, academic confidence, localization and attitudes (Andersson, 2008). These difficulties are not excluded in the context of online English training system (OETS) at Ho Chi Minh City Open University (HCMCOU). Although this institution ever makes effort to limit these possible challenges for ages, plenty of impactful issues leading to serious difficulties of OETS also obviously exist. Hence, to fully explore the key factors that cause greater barriers in this training system, a qualitative on traditions of bioghaphy and grounded theory method was applied. The qualitative data is to be collected from the responses on openended questionaire sent for 30 online English majors and indirect interviews with 5 salient learners were also conducted. The findings show that some minor limitations of learners such as negative learning habits, willpower shortage and neglected learning perception lead to greater barriers of online English training.
Theorizing the relationality of skilled migrants’ transnational mobilities
Authors: Chi Nguyen Hong
Published: April 2021

The issue of transnational mobilities of skilled migrants has been studied from multidisciplinary dynamics. They are built on various theoretical frameworks and methodological tools and at the same time, propose innovative approaches to understanding internationalism. Aiming to add further nuance to the field of transnational migration, this article outlines a theoretical perspective attending to inter-relational aspects in skilled migrants’ transnational mobilities which are reflective of their embeddedness in the world. This perspective is based on a critical review of literature on skilled migration and transnationalism which primarily argues that migrants follow their life pursuits and make sense of their migratory experiences under influences of socio-economic, political and cultural regularities that shape their subjectivities in transnational mobilities. By extending the conventional perception of these influences, it is argued in this paper that transnational mobilities are shaped and re-shaped through at least 5 interrelated aspects of migrants’ lived experience, from the initiation of migration to relocating to the destination country and making professional and personal plans. Therefore, the relationality of transnational mobilities can be theorised through skilled migrants’ entwinement with the world in multiple spaces and temporalities. This article has the potential to contribute a unifying framework to migration research methodologies which currently tend to examine each or some of migrants’ aspects of experiences separately.
Lecturers and E-lecturers in cross-border education in the context of the fourth industrial revolution
Authors: Son Nguyen Duc
Published: April 2021

Nowadays, globalization has given birth to various forms of non-traditional education. These forms of education are transcending borders and traversing boundaries of space and time. The evolution of information technology in the context of Industry 4.0 has transformed education rapidly and, at the same time, resulted in new problems. This paper discusses the role, the importance and the relationship between lecturers (in universities) and e-lecturers (in the virtual reality environment) when implementing cross-border education. In addition, the article also mentions the changes of universities, lecturers, curriculums and teaching methods when deploying distance e-learning programs in Industry 4.0. The article uses conceptual model, diagrams and interdisciplinary methods such as education, culture, science and technology to investigate e-lecturers’ concept and provide solutions for improving the capacity of lecturers and the quality of teaching cross-border training programs in universities.
Combined learning, a good solution for Vietnamese universities
Authors: Hoa Pham Thi Thu
Published: April 2021

Information technology has created tremendous chances in higher education across the globe. With the availability and flexibility of learning online, there are increasing competitions between online learning and traditional, face-to-face classroom. These two types of learning both have their pros and cons. From the advantages and disadvantages of online learning, universities have recently changed the way of their teaching through combining online learning and traditional classroom. Therefore, it is necessary to investigate and understand the advancements of the combination of the two types of learning. In this paper, we will introduce the advantages and disadvantages of online learning and the combined learning. We also share our experience on teaching at Flinders University, South Australia through Flinders learning online system. From this knowledge, we will suggest some solutions about building a combined learning system which is suitable for Vietnamese universities.
The effect of integrating teaching cross-cultural knowledge and teaching listening skill in tertiary education on improving EFL students' intercultural communication competence
Authors: Oanh Thieu Thi Hoang
Published: April 2021

Teaching cross-cultural knowledge in language teaching is drawing more and more attention nowadays. This study investigated the effect of integrating teaching cross-cultural issues and teaching listening skill on students’ intercultural competence. The participants were 30 Vietnamese students of English as a foreign language (EFL) who participated in the course on Listening 2 in the second year of their MBA program in Kien Giang University, Vietnam. The study consisted of an experimental study based on a pretest-posttest research design on integration of cross-cultural issues and teaching listening. The intercultural sensitivity self-assessment questionnaire (ISSAQ) that serves as a pre-test at the beginning of the semester is based on the theoretical framework put forth by Bennett and Bennett (2004). It is to elicit a self-assessment of their intercultural knowledge, behaviors and attitudes. During the ten-week intervention, besides helping students master the language and listening skill, the researcher helped promote students’ cross-cultural competence with the process-oriented intercultural teaching mode by Li (2016). At the end of the course, the posttest was given to measure the effects of the integration model on students’ intercultural communication competence. The results of the study suggested that integrating cross-cultural knowledge and language teaching could improve EFL students' intercultural communication competence (ICC).
A literature review of washback effects of assessment on language learning
Authors: Ha Nguyen Thi Thanh
Published: April 2021

This paper reviews the empirical studies on washback effects of assessment on language learning. The study begins with the definitions of washback, its equivalent terms, and dimensions of washback. Then it summarizes the empirical studies of washback on three most frequently investigated areas, namely learners’ motivation, behaviours, and achievement. Finally, it examines the mechanism by which washback on learning is generated. The findings show how complex and context-dependent test washback is and, based on these findings, the authors provide some recommendations for future research.
Critical theory and the implementation of lifelong learning in Vietnam
Authors: Khuc Phan Thi Tra
Published: April 2021

Lifelong learning is the continuous acquisition of knowledge and skills which occurs throughout life with an emphasis on the full development of personality. Despite the increasing interest of Vietnamese policy makers in promoting lifelong learning, the implementation of lifelong learning at universities is still limited. This research delineated and critiqued the policies and the current practices of lifelong learning at the college level of the Ministry of Education and Training in Vietnam (MOET) under the perspective of critical theory. From the discussion of the policies and practices that the MOET was implementing, recommendations for the policy makers were made with the aim of helping Vietnamese students embrace their right to lifelong learning and fulfill the personal and democratic purpose of education.
Critical thinking - An essential skill for English pedagogical major students: Review and applications
Authors: Van Vu Thi Hong , My Nguyen Van
Published: April 2021

In the international integration and globalization context and the strong influences of the fourth industrial revolution (Industry 4.0), critical thinking (CT) is becoming a more and more important skill that students need to be trained. To undergraduate students, critical thinking is not only a key study skill to meet the targets of the university curriculum but also the individuals’ ability to think independently and make appropriate decisions in real-life situations. Consequently, preparing students to utilize the widest range of academic language skills through analysis, synthesis, and problem-solving facilitates them to the highest levels of academic achievement and the future continuous professional development. This article analyses the crucial roles of critical thinking skills in teaching English as a foreign language (EFL) and developing practical professionals for English pedagogical major students. For practical purposes, examples of activities and steps of implementation are given to enhance critical thinking skills for students at HCM City University of Education, Vietnam.
Japanese language learners’ perceptions of strategies use and their effectiveness in kanji learning
Authors: Huan To Quoc Minh
Published: April 2021

Kanji learning is considered to be a hard job when it comes to learning Japanese. However, studies on kanji learning strategies are uncommon in Japanese language academia in Vietnam. In other countries, many research models on kanji learning strategy use and effectiveness were developed. With regard to language context in Vietnam, this paper reports an investigation on the relationship between strategy use and effectiveness, and learners’ perceived effectiveness of kanji learning strategy. Data collected from 122 learners has given some solid answers to the questions on strategy use – effectiveness relationship and perceived effectiveness of learners.
The alignment between the ESP course materials and the English language used in the hotel setting in Vietnam
Authors: Van Vu Thi Hong
Published: April 2021

This article examines the alignment between the ESP course materials – English for hotel majored students – and the English language used in the hotel setting in Vietnam. English textbooks which were commonly used in the ESP courses for hospitality students were reviewed for the limits on the portion of the written materials in comparison with the English language used by the hotel staff in the real-life setting. Content analysis was adopted for analyzing the course materials, particularly the activities provided for students to practice listening and speaking skills. The findings reveal that the textbooks cover a wide range of activities for students to practice communicative skills. However, most activities were situated in environments that were unfamiliar to students and that might limit students’ ability to meet guests’ needs.
Autonomous responsibilities, abilities and behaviours: An appraisal of English-majored students
Authors: Hoa Truong Minh
Published: April 2021

Learner autonomy has become the prevailing theme of language education for nearly four past decades, especially its three constructs such as responsibilities, abilities and behaviors. Thus, the current study embraced salient traits of a survey research design to scrutinize these constructs as appraised by the Vietnamese tertiary learners. The study recruited the participation of 80 English-majored students at Hung Vuong University, Vietnam. Their appraisal was elucidated by a quantitative instrument, that is, a 28-item questionnaire whose descriptive statistics were yielded by SPSS 22.0. The study found that a greater proportion of the informants ultimately recognized their autonomous responsibilities, acknowledged their autonomous abilities, and estimated some autonomous behaviors both inside and outside the classroom. Brief conclusion was made at the end of the paper.
An investigation into reading strategies used by Vietnamese non-English major students at Kien Giang University
Authors: Minh Nguyen Thi Ngoc , Nga Nguyen Thuy
Published: April 2021

This paper aimed at investigating the frequencies of reading strategies employed by Vietnamese non-English major students while taking a reading comprehension test at Kien Giang University. Data was collected through a questionnaire delivered to 117 sophomores who majored in Economics, Accounting and Construction at Kien Giang University. The results from the descriptive statistics showed that Vietnamese non-English majors were medium strategy users. Of the three types of reading strategies, cognitive strategies were the most frequently used, followed by metacognitive and support reading strategies. Out of 27 reading strategies, students reportedly used item number 14 “I read the text again for better understanding.” at the highest frequency while rating item number 2 “I determined what the type of the text is.” the least frequency.
The effects of grouping types on promoting critical thinking in EFL collaborative writing
Authors: Tram Nguyen Thi Minh , Quyen Bui Thi Thuc
Published: April 2021

Nurturing critical thinking (CT) has been acknowledged as a core objective of tertiary education, and drawn attention from academia of teaching English as a Foreign Language (EFL), particularly in EFL argumentative writing. It has been claimed that collaborative learning which stimulates the active exchange of ideas within small groups not only increases interest among the participants but also promotes critical thinking. One of the important aspects of learning and teaching through collaboration is the group composition or grouping “who with whom”. The present study was an attempt to investigate the impact of homogeneous and heterogeneous groupings on critical thinking in collaborative writing. Having been required to write an argumentative essay as a pre-test, 75 participants, who were categorized by their prior critical thinking levels, were assigned into three group types: heterogeneous, homogeneous high and homogeneous low groups. As a consequence, four types of students were considered their improvement before and after the experiment: high-level students in heterogeneous groups, lowlevel students in heterogeneous groups, high-level students in homogeneous groups, low-level students in homogeneous groups. The results demonstrated that learners improved their critical thinking level through collaborative writing, whether working with stronger or weaker peers. However, heterogeneous grouping showed superiority over homogeneous grouping at the low level. The results revealed that cooperative learning could be especially beneficial for low students. It is hoped that the findings of the present study will give teachers deep insights into group compositions in collaborative learning courses, and will help them make better group experiences for students.
Giải pháp phát triển đội ngũ trí thức trong quá trình công nghiệp hóa, hiện đại hóa ở tỉnh Trà Vinh hiện nay
Authors: Hằng Lê Thúy
Published: April 2021

Nghiên cứu này được thực hiện với mục tiêu phân tích thực trạng đội ngũ trí thức tỉnh Trà Vinh trong quá trình công nghiệp hóa, hiện đại hóa. Nghiên cứu sử dụng các phương pháp: lịch sử, logic và thống kê số liệu thứ cấp về số lượng trí thức phân theo trình độ ở tỉnh Trà Vinh. Kết quả nghiên cứu cho thấy có 3 hạn chế dẫn đến thực trạng đội ngũ trí thức tỉnh Trà Vinh trong những năm vừa qua. Dựa vào kết quả nghiên cứu, tác giả đề xuất một số giải pháp nhằm phát triển đội ngũ trí thức phục vụ quá trình công nghiệp hóa, hiện đại hóa ở tỉnh Trà Vinh hiện nay.
Vài suy nghĩ tự sự lịch sử và văn chương nhân một tình tiết nghiên cứu Tam quốc chí diễn nghĩa của Hsia Chih-Tsing
Authors: Tân Lê Thời
Published: April 2021

Trao đổi của chúng tôi với C.T.Hsia xoay quanh chú dẫn liên quan đến tình tiết "Đồng Tước Đài Phú” trong Tam Quốc Chí Diễn Nghĩa. Chú dẫn này cho thấy nhà nghiên cứu vô hình trung không có phân biệt người và việc trong sử với người và việc trong văn. Tâm lí nệ sử và phản xạ khảo cứu vị khảo cứu vô hình trung đã trở thành chướng ngại vật trên con đường đọc hiểu tự sự tiểu thuyết. Mải vận dụng kiến thức sử kí để chú dẫn một cách cô lẻ tình tiết tự sự trong tiểu thuyết khiến nhà nghiên cứu quên đi bản thân mình thực ra đang vãng cảnh” ngôi đài được dựng lên” trong văn chương chứ không chỉ là một di tích bên bờ con sông lịch sử! Đài chim sẻ đồng” bên bờ sông Chương đó đã lưu danh Đồng Tước ” vào trong Tam Quốc Chí và Tam Quốc Chí Diễn Nghĩa theo những cách khác nhau. Tiểu thuyết và sử kí đã khác nhau thì Dễn Nghĩa của nhà hê bình văn chương và nhà nghiên cứu lịch sử cũng đâu có thể cùng một cách thức! Bài viết này chính là xoay quanh một tinh thần cơ bản như thế.
Mô hình liên thế hệ tự giúp nhau của người cao tuổi và vai trò của công tác xã hội
Authors: Đồng Nguyễn Văn
Published: April 2021

Nghiên cứu này được thực hiện trên 200 người cao tuổi (độ tuổi từ 60 - 80 tuổi), hiện đang sinh hoạt trong mô hình liên thế hệ tự giúp nhau tại địa bàn huyện Hoằng Hóa (Thanh Hóa); nghiên cứu sử dụng phương pháp điều tra bảng hỏi kết hợp phỏng vấn sâu để thu thập thông tin. Mục đích nhằm làm rõ thực trạng hoạt động của mô hình qua 4 hoạt động chính: Chăm sóc sức khỏe; hỗ trợ sinh kế tạo việc làm; giải trí - thể dục thể thao; truyền thông nâng cao nhận thức về chính sách người cao tuổi. Đồng thời, phân tích vai trò của nhân viên công tác xã hội trong can thiệp và trợ giúp người cao tuổi đang sinh hoạt trong mô hình. Qua kết quả nghiên cứu cho thấy, hầu hết người cao tuổi khi tham gia mô hình này thì điều kiện sức khỏe đều được cải thiện, có việc làm và nâng cao thu nhập, hiểu biết về chính sách và tiếp cận chính sách tốt hơn, đời sống tinh thần được cải thiện do tham gia các câu lạc bộ giải trí - thể dục thể thao.
Ý thức thuộc về của lao động di dân: Khái niệm, thang đo và những xu hướng nghiên cứu
Authors: Quân Đỗ Hồng
Published: April 2021

Ý thức thuộc về (sense of belonging) là một chủ đề nghiên cứu xuyên suốt hơn 50 năm qua trong lĩnh vực tâm lý học xã hội và phần lớn những nghiên cứu này xuất phát từ những quốc gia phương Tây. Bài viết này nhằm mục đích điểm lại những chiều kích của khái niệm ý thức thuộc về; những xu hướng nghiên cứu chính; cũng như những đề xuất cho hướng phân tích này trong bối cảnh xã hội Việt Nam. Phương pháp nghiên cứu được chúng tôi sử dụng là phân tích tư liệu thứ cấp. Nhìn chung, qua việc phân tích, chúng tôi nhận thấy sự hiện diện của ba xu hướng chính gồm: (1) ý thức thuộc về và vai trò của sự tin cậy, vốn xã hội; (2) ý thức thuộc về và ý thức về bản sắc cộng đồng, sự kiến tạo xã hội về biểu tượng cộng đồng và; (3) ý thức thuộc về và sự gắn kết xã hội.
Study of chemical-based induced bacterial ghost applied in vaccine production
Authors: Thanh Doan Duy , Hanh Tran Xuan
Published: April 2021

Introduction: Bacterial ghosts (BGs), known as the empty cell envelope of gram-negative bacteria lacking cytoplasmic content yet retaining all unaltered morphological and structural features of their living counterparts, are widely studied and used as the platform for the production of the vaccines as well as the transporting drug and gene delivery. However, the study related to the creation of BGs based on gene expression is still limited because of the difference in cell wall structure between microorganisms. Therefore, in the current study, for the aims to determine chemicals combination and minimum inhibition concentration (MIC) to optimize BGs production.

Material and method: Salmonella choleraesuis strain was collected from NAVETCO company. The study used critical concentrations from chemical combination to convert salmonella cells to BGs. Chemicals combination and MIC, temperature, shaking speed were optimized using Plakett- Burman matrix and response surface methodology. Cell structure was determined by using a scanning electron microscope, experimental mice were vaccinated and challenged with virulence to determine immune responses of bacterial ghost.

Results: The appropriate chemicals for the production of BGs biomass were NaOH 3.125 mg/ml; SDS 1.15 mg/ml, H2O2 8.79 µl/ml, ethanol. The observation of morphology, BGs have remained the structure and shape, which were like the living microbial cells.

Conclusions: The conditions of BGs production have been identified to produce large amounts of bacterial ghost biomass to further application in vaccine production and pharma.
A comparison between Hydrochloric acid and Trifluoroacetic acid in hydrolysis method of exopolysaccharide from Ophiocordyceps sinensis in Monosaccharide composition analysis by GC-FID
Authors: Hang Le Thi Thuy , Chau Ha Bao , Nam Tran Van Hai , Thong Pham Minh , Phu Dang Hoang , Hiep Dinh Minh , Thang Nguyen Tien
Published: April 2021

The monosaccharide composition is one of the crucial factors affecting the bioactivity of exopolysaccharide (EPS) in Cordyceps species. Therefore, many scientists have studied, analyzed monosaccharide composition and structure of EPS from Cordyceps species, especially Ophiocordyceps sinensis (O. sinensis). This study aimed to compare hydrochloric acid (HCl) with trifluoroacetic acid (TFA) in the EPS hydrolysis process in monosaccharide composition analysis by Gas Chromatography with Flame-Ionization Detection (GC-FID). The hydrolysis is a crucial step in forming the acetyl derivative, which helps the GC-FID technique to have good results in monosaccharide composition analysis. The results showed that hydrolysis with HCl gave a higher hydrolysis efficiency and was more suitable than hydrolysis by TFA in pretreatment to EPS for GC-FID. Hydrolysis results were analyzed through thin-layer chromatography and high-performance liquid chromatography (HPLC), then Acetyl derivatives were produced and finally analyzed by GC-FID to determine the monosaccharide composition of EPS. For EPS hydrolyzed by HCl, the analytical results presented that this sample had 6 kinds of monosaccharides, including rhamnose, arabinose, xylose, mannose, glucose, and galactose; the most monosaccharide was glucose. The EPS hydrolyzed by TFA only detected three kinds of monosaccharides, including mannose, arabinose, and galactose, mainly mannose. The study has set a foundation for further analysis of monosaccharide composition and structure of EPS from O. sinensis.
Screening of the matrix metalloproteinase inhibitory activity on extracts from Cordyceps neovolkiana DL0004 and Cordyceps takaomontana DL0038A fungi
Authors: Hong Nguyen Nguyet , Tim Cao Ha , Dung Nguyen Chi , Hiep Dinh Minh , Suong Ngo Ke
Published: April 2021

Matrix metalloproteinases (MMPs) are endopeptidases, they are involved in tumor growth, and the processes of invasion and metastasis. Cordyceps spp. were recorded to have the anticancer potential. In previous studies, extracts from Cordyceps neovolkiana strain DL0004 and Cordyceps takaomontana strain DL0038A were capable of cytotoxic activity against MCF-7 and Jurkat cell lines. In this study, 26 extracts were prepared from biomasses and fruit bodies of C. neovolkiana DL0004 and C. takaomontana DL0038A, then proceed to screen for MMP inhibition assay by concentration ranges of 2000 µg/mL, 200 µg/mL, 20 µg/mL. The results showed that the CPS extract of the fruit body of the C. neovolkiana DL0004 had the highest activity in MMP inhibition with 84.27 ± 4.59% at 2000 µg/mL. The results were achievement for further studies of metastatic inhibition activities of Cordyceps extracts.
Studies on antimicrobial activities of endophytic bacteria isolated from Neem tree (Azadirachta indica)
Authors: Linh Duong Nhat , Thien Bui Van , Ni Tran Thi Ai , Duy Nguyen Thanh , Minh Nguyen Van , Dong Tran Cat
Published: April 2021

The objective of this study is to isolate endophytic bacteria from Azadirachta indica (neem). We isolated 7 strains of endogenous bacteria from the neem tree. By investing the anti-fungal and antibacterial activities of endophytic bacteria in A. indica by well diffusion agar method, we noticed there was KT2 strain which resisted to Salmonella typhi and Staphylococcus aureus (10.67 ± 0.33 mm and 9.67 ± 0.33 mm), KT3 strain showed the inhibitory activity to three human pathogenic fungal (Candida albicans, Trichophyton mentagrophytes, Trichophyton rubrum), two strains (KT1, KT2) which resisted to C. albicans and T. rubrum. According to Cowan and Steel's manual, the result of biochemical identification showed that the KT2 strain was the Bacillus subtilis species.
Predicting the bearing capacity of pile installed into cohesive soil concerning the spatial variability of SPT data (A case study)
Authors: Tham Duong Hong , Manh Truong Nhu
Published: April 2021

Nowadays, in situ tests have played a viable role in geotechnical engineering and construction technology. Besides lab tests conducted on undisturbed soil samples, many different kinds of in-situ tests were used and proved to be more efficient in foundation design such as pressuremeter PMT, cone penetration test CPT, standard SPT, etc. Among them, a standard penetration test (SPT for short) is easy to carry out at the site. For decades, it has proved reliable to sandy soil, but many viewpoints and opinions argued that the test was not appropriately applicable to cohesive soil because of scattered and dispersed data of SPT blow counts through different layers. This paper firstly studies how reliable the SPT data can predict the physical and mechanical properties; secondly, the soil strength is determined in terms of corrected N-SPT values, and finally the bearing capacity of a pile penetrating cohesion soil. By analyzing data from 40 boreholes located in 18 projects in Ho Chi Minh City, South VietNam, coefficients of determination between SPT numbers and physical and mechanical properties of different soil kinds are not the same: R2 = 0.623 for sand, =0.363 for sandy clay and =0.189 for clay. The spatial variability of soil properties is taken into account by calculating the scale of fluctuation θ=4.65m beside the statistically-based data in horizontal directions. Finally, the results from two theoretical approaches of predicting pile bearing capacity were compared to those of finite element program Plaxis 3D and static load test at site. Correlation between the capacity computed by using corrected N-values instead of soil strength and results of static load test has proved to be well suitable in evaluating the bearing capacity of driven and jack-in piles, particularly installing in the cohesive soil using the SPT blows.
In silico analysis of hypermethylation in CpGislands of UCHL1 gene’s promoter in nasopharyngeal carcinoma
Authors: Thuan Lao Duc , Hue Thieu Hong , Nam Hoang Van , Danh Nguyen Hoang , Thuy Le Huyen Ai , Kha Ngo Dong , Tuan Nguyen Hoang Anh
Published: April 2021

Background and Objective: The methylation of Ubiquitin C-Terminal Hydrolase L1 (UCHL1) gene has been reported in many human cancers including nasopharyngeal carcinoma (NPC). In Vietnam, the methylation of

UCHL1 gene’s promoter in NPC has not been demonstrated yet. In this study, a systematic literature revision was carried out to summarize the current evidences about the frequencies of UCHL-1 gene’s promoter methylation in

NPC for further application in Vietnamese population.

Methods: A systematic literature analysis was conducted based on the comprehensive studies. Moreover, many bioinformatic tools such as Methprimer, TFsearch, IDT OligoAnalyzer 3.1 were used to predict the CpG

islands, transcriptional factors, and to pick up the MSP (Methylation-Specific PCR) primers.

Results: Total of three previous studies were summarized and accessed for eligibility from literature research. As the results, the average weight methylated frequencies were 72.4% and 13.0% for NPC and non-cancerous

samples, respectively. The significant association between UCHL-1 promoter methylation and NPC with the OR of 10.459 (95% CI = 4.915 – 22.254, p < 0.001) and RR of 4.117 (95% CI = 1.958 – 6.645, p < 0.0001) based on the

random effects model, was observed. Moreover, we were successful in predicting the CpG islands as well as identifying transcriptional factor binding sites which served as “hot spot” for ideal primer pick up and located in gene promoter.

Conclusion: The methylation of UCHL-1 gene promoter was significantly associated and contributed to NPC developmentin which it could be further applied in evaluation of UCHL-1 gene promoter status in Vietnamese population.
Research antioxidant activity of chitooligosacchride by UV-VIS absorption spectrocopy
Authors: Hoai Bui Van , Nghiep Ngo Dai , Quang Dao An , Phuong Nguyen Thi Nam
Published: April 2021

Chitosan with 80% degree of deacetylation was hydrolyzed by cellulase of Trichoderma viride to prepare chitooligosaccharides (COSs) by the fractionation of the COSs with ultrafiltration membrane. The antioxidant

activities of the COSs were clarified in this study by reducing power and free radical scavenging ability assay by UV-VIS absorption spectrum. The results show that the COS 1 (10,000-5,000 Da), COS 2 (5,000-3,000 Da), COS 3 (3,000-1,000 Da) and COS 4 (less than1,000 Da) segments have antioxidant properties.The antioxidant activitives of the COSs increased with the increment of concentration, and they also depended on molecular weight.
Rational protein design for enhancing thermal stability of industrial enzymes
Authors: Tuan Le Quang Anh
Published: April 2021

Enzymes possessing many excellent properties such as high selectivity, consuming less energy, and producing less side products or waste have been widely applied as biocatalysts in pharmaceutical production and many industries such as biofuel, biomaterials, biosensor, food, and environmental treatment. Although enzymes have shown its potential as biocatalysts for many industrial applications, natural enzymes were not originated for manufacturing process which requires harsh reaction conditions such as high temperature, alkaline pH, and organics solvents. It was reported that reduction of final conversion of several enzymatic reactions was declined at high temperature. Protein engineering to improve the enzymes’ thermostability is crucial to extend the use of the industrial enzymes and maximize effectiveness of the enzyme-based procesess. Various industrial enzymes with improved thermostability were produced through rational protein engineering using different strategies. This review

is not aimed to cover all successful rational protein engineering studies. The review focuses on some effective strategies which have widely used to increase the thermostability of several industrial enzymes through introduction of disulfide bonds and introduction of proline.
Isolation endophytic bacteria from elephant grass (pennisetum purpureum schumach) and their potential application
Authors: Diem Pham Nu Kieu , Chau Nguyen Ngoc Bao , Quoc Nguyen Bao
Published: April 2021

In this study, 25 endophytic bacteria were isolated and purified from rhizome, stem and leaf of the elephant grass, which were tested for their biological control properties. The number of living and dead brown plant hoppers were recorded and the mortality rate was analyzed by using Abbott’s formula. The results indicated that three endophytic bacteria including VBL1, VBT1 and VBT5 showed the highest biological control of Nilaparvata lugens at the mortality rate 46.95%, 55.02% and 55.02%, respectively after 8 days of screening and significant difference compared to other isolates (P
Screening of endophytes from rubber trees (hevea brasiliensis) for biological control of Corticium salmonicolor
Authors: Minh Nguyen Van , Phuc Mai Huu , Linh Duong Nhat , Ni Tran Thi A , Duc Tran Kien , Nghia Nguyen Anh
Published: April 2021

28 leaves and living-tissue samples of rubber tree (Hevea brasiliensis) were collected from Ho Chi Minh City, Binh Phuoc province and Binh Duong province (Viet Nam). We isolated and screened endophytes that have potential application as agents for biocontrol of Corticium salmonicolor, the agent of Pink Disease in rubber trees. As a result, 21 strains of endophytic bacteria and 14 strains of endophytic fungi were isolated. Antagonistic activity of the endophytes towards C. salmonicolor was checked by using a dual culture. Testing results showed that: T9, T15 and T16 strains have inhibited C. salmonicolor. T9 and T16 strains showed result that 100% of inhibiting C. salmonicolor at the concentration of 1:1. In the test of ability to kill C. salmonicolor, T9 and T16 strains showed that they could kill C. salmonicolor

after 3 sprays of bacterial filtrate. T9 and T6 strains, which were identified by biochemical methods, have similar characteristics to Bacillus thuringiensis.
Meta-analysis: Assocation between promoter hypermethylation of DAPK (Death-Associated Protein Kinase) and cervical cancer
Authors: Thuan Lao Duc , Phuong Truong Kim
Published: April 2021

Purpose: Death-associated protein kinase (DAPK or DAPK1) is an important tumor suppressor protein that involved in the regulation of cell activities. The aberrant methylation of DAPK promoter has been reported in patients with cervical cancer. However, the association between of DAPK1 and cervical cancer was not always unification, in previous studies. Therefore, in current study, a meta-analysis was performed for association of between DAPK gene’s promoter hypermethylated and cervical cancer.

Methods: A systematic literature analysis was conducted based on the previous studies published in PubMed, PubMed Central (NCBI), Google by using following keywords: cervical cancer, cervical carcinoma, Methylation, by the end of January, 2018. The association between DAPK promoter methylation and cervical cancer was evaluated by odds ratio (ORs) and 95% confidence intervals (CI). To evaluate the potential sources of heterogeneity, the meta-regression analysis and subgroup analysis were conducted.

Results: A total of 21 case-control studies which relevant to the association between DAPK1 gene’s promoter methylation frequency and cervical cancer, that including 1600 cancer cases and 1011 control cases (non-cancerous cases). The analysis results indicated that the characteristic of candidate gene’s promoter methylation increased the cervical cancer risk through the calculation of OR value (OR = 21.25; 95% CI = 8.73 – 52.97; p < 0.001; Random effect model). The association between DAPK1 gene’s promoter hypermethylation was confirmed in all the subgroups analyses, including materials and assays methods, ethnicity. Furthermore, this association is higher in cervical squamous cell carcinoma than cervical adenocarcinoma and is a characteristic of late-stage disease.

Conclusion: The hypermethylated DAPK1 gene’s promoter was also one of etiological factor, lead to the cervical tumorigenesis.
Big-eged bugs Geocoris: Diets research and potential of use in prevention of a number of insect pests in Vietnam
Authors: Chau Nguyen Ngoc Bao , Nhu Le Thuy To
Published: April 2021

Big-eyed bugs Geocoris spp. (Lygaeidae, Hemiptera) are small insects that is found in many parts of the world. They are beneficial because they eat a multitude of insect pests in agriculture. Big-eyed bugs Geocoris spp. are insects that receive research attention in Florida and elsewhere because of the benefits that this species give to plants (Mead, 2001). Big-eyed bugs reproduce many generations in a year on weeds, perennial crops, bushes. In spring the female big-eyed bugs start laying eggs on the bud, the leaves of the host plant. Understanding the biology and the role of predator Geocoris spp. in ecosystem will provide an alternative method in sustainable agriculture development. In this short review, we discuss some convenient diets for the application of mass rearing Geocoris spp.
Đa dạng hệ thực vật ở thị xã Duyên Hải tỉnh Trà Vinh
Authors: Sơn Đặng Văn , Sơn Hoàng Nghĩa , Tiến Trần Văn , Tú Nguyễn Văn
Published: April 2021

Từ kết quả nghiên cứu đã xác định được ở thị xã Duyên Hải tỉnh Trà Vinh có 273 loài, 209 chi, 78 họ của 2 ngành thực vật bậc cao có mạch là ngành Dương xỉ (Polypodiophyta) và ngành Ngọc lan (Magnoliophyta). Giá trị sử dụng của thực vật cũng được thống kê và chia làm 5 nhóm gồm: làm thuốc có 186 loài, làm cảnh có 26 loài, cho gỗ có 15 loài, thực phẩm có 15 loài, và gia dụng có 6 loài. Dạng thân của thực vật được chia làm 6 nhóm chính là cây thân thảo có 141 loài, cây bụi có 46 loài, dây leo có 36 loài, gỗ nhỏ có 25 loài, gỗ lớn có 22 loài và bán ký sinh có 3 loài. Đồng thời, ghi nhận được 3 kiểu sinh cảnh thực vật hiện diện ở khu vực nghiên cứu là Sinh cảnh thực vật tự nhiên (với 7 kiểu quần hợp), Sinh cảnh thực vật trên đất canh tác và Sinh cảnh thực vật trên đất thổ cư.
Phân chia các kiểu cấu trúc nền công trình phục vụ quy hoạch và phát triển bền vững Thành phố Huế đến năm 2030
Authors: Nhàn Nguyễn Thị Thanh , Quỳnh Trần Thị Ngọc , Nhiều Dương Vĩnh
Published: April 2021

Thành phố Huế nằm trong vùng kinh tế trọng điểm của miền Trung, là đô thị loại I. Ngày nay Huế còn được biết đến là thành phố của Festival. Nơi đây, hoạt động xây dựng và chỉnh trang đô thị đang diễn ra với tốc độ khá nhanh. Cấu trúc nền công trình là một phần không thể tách rời trong môi trường địa chất, nó còn là cơ sở cho việc qui hoạch phát triển đô thị, định hướng trong khảo sát địa chất công trình, thiết kế công trình. Cấu trúc nền công trình khu vực thành phố Huế được phân chia thành 3 kiểu, 4 phụ kiểu, 3 dạng cấu trúc nền (CTN) trong giới hạn chiều sâu nghiên cứu đến chiều sâu mà môi trường địa chất chịu ảnh hưởng của các tác động hoạt động kinh tế - công trình ≥ 30m. Đây là cơ sở giúp các nhà qui hoạch, xây dựng quyết định chọn, phân bố hợp lý các công trình xây dựng, giúp các nhà khảo sát, thiết kế chọn phương khảo sát thích hợp, khai thác hợp lý lãnh thổ và bảo vệ môi trường địa chất bền vững.
Dự đoán sự tiêu tán áp lực nước lỗ rỗng của bài toán bấc thấm (bài toán 1D)
Authors: Nghĩa Nguyễn Trọng
Published: April 2021

Bấc thấm (PVD) được sử dụng khá rộng rãi trong việc thúc đẩy nhanh quá trình cố kết trong đất yếu, qua đó tăng cường tính chất của đất và giảm lún. Giải bài toán cố kết của bấc thấm được giải bằng nhiều phương pháp khác nhau như: Phương pháp giải tích, Phương pháp sai phân hữu hạn và phương pháp phần tử hữu hạn. Trong đó, phương pháp giải tích với kỹ thuật biến đổi Laplace đã làm cho bài toán giải tích trở nên mạnh hơn và có thể giải được hầu hết các trường hợp chất tải theo thời gian. Bài báo này trình bày phương pháp sử dụng kỹ thuật biến đổi Laplace để giải bài toán PVD xuyên một phần vào trong đất với giả sử đầu mũi là không thấm. Lời giải sử dụng biện pháp tích hợp các bài toán cố kết phương đứng và ngang để có được phương pháp tính cố kết đơn giản theo 1D. Cùng với giả sử đầu mũi là không thấm, bài toán đã giảm đi các biến trong quá trình tính toán và trở nên đơn giản hơn rất nhiều. Lý thuyết tính toán được kiểm nghiệm lại với kết quả đo tại một đập thử nghiệm ở sân bay quốc tế Thái Lan. Áp lực nước lỗ rỗng và độ lún từ kết quả tính toán lý thuyết là tương thích cao với kết quả đo đạc thực tế.
Ảnh hưởng của các chất điều hòa tăng trưởng thực vật trong sự hình thành rễ bất định ở hồng tầm xuân và hồng nhung
Authors: Quỳnh Huỳnh Thị Xuân , Hương Trần Thanh , Việt Bùi Trang
Published: April 2021

Các chất điều hòa tăng trưởng thực vật Indole-3-acetic acid (IAA), Indole-3-butyric acid (IBA), 1-Napthalene acetic acid (NAA) và 2,4 dichlorophenoxyacetic (2,4-D) ở các nồng độ khác nhau được dùng để cảm ứng sự tạo rễ bất định từ khúc cắt cành giâm cây hồng Tầm Xuân (Rosa canina L.) và khúc cắt chồi ngọn in vitro cây Hồng Nhung (Rosa hydrida L.). Các biến đổi hình thái và sinh lý trong quá trình hình thành rễ bất định được phân tích. Sự hình thành rễ bất định từ khúc cắt cành giâm cây hồng Tầm Xuân trải qua bốn giai đoạn: hoạt hóa tế bào tại vùng tượng tầng, hình thành vùng tế bào mô phân sinh ngọn rễ, tạo sơ khởi rễ và kéo dài rễ. NAA ở nồng độ 300 mg/L thích hợp cho sự phát triển rễ bất định từ khúc cắt cành giâm hồng Tầm Xuân. Trong quá trình phát triển rễ bất định, đặc biệt vào giai đoạn tạo sơ khởi rễ, có sự tăng mạnh cường độ hô hấp và hoạt tính IAA. Mối liên hệ giữa các chất điều hòa tăng trưởng thực vật, cường độ hô hấp và sự phát sinh hình thái rễ được thảo luận. Sự phối hợp bổ sung IBA 0,5 mg/L và IAA 0,5 mg/L vào môi trường MS ½ kích thích mạnh sự tạo rễ in vitro từ các khúc cắt chồi ngọn Hồng Nhung, phù hợp cho sự tạo các cây in vitro hoàn chỉnh.