Study on the effect of processing methods on the total polyphenol, 2,3,5,4’-tetrahydroxystilben-2-O-β-D-glucoside, and physcion contents in Fallopia multiflora Thunb. Haraldson root

This study investigated the changes in the ingredients in Fallopia multiflora Thunb. Haraldson (FMT) root after processing it with different methods such as soaking, stewing, and steaming or combined methods. The total polyphenol, 2,3,5,4′-tetrahydroxystilben-2-O-β-D-glucoside (THSG), and physcion contents in FMT products after processing were determined using high-performance liquid chromatography (HPLC) and ultraviolet-visible (UV-VIS) methods. The results demonstrated that the processing method and time significantly affected the contents of polyphenol, THSG, and physcion. The physcion and total polyphenol content increased or decreased during processing depending upon the processing time, while the THSG content gradually decreased with an increase in the processing time. The content of physcion (a substance that can cause liver toxicity) was analysed, and the suitable conditions for processing of the FMT products were determined as initial soaking in rice swill for 24 h and subsequent stewing with black beans and water for 12 h

The pedagogical training management of gifted high school teachers in the region of Red River Delta based on a competency approach

Pedagogical training for teachers is always an important issue of every education system. Teachers impart knowledge, give academic advice to students, and assist students in applying knowledge to develop society. This study investigated the gifted high school teacher pedagogical training management in the region of the Red River Delta according to the competency approach. Based on the available data, the research indicated three main things: (i) Professional pedagogical competence of gifted high school teachers; (ii) Pedagogical training activities for gifted high school teachers; (iii) Management of pedagogical training activities for gifted high school teachers. This study conducted a survey of 547 departmental and school managers in gifted high school teachers in nine provinces in Red River Delta, including Hanoi, Ha Nam, Thai Binh, Nam Dinh, Hai Duong, Hung Yen, Bac Ninh, Quang Ninh, and Vinh Phuc. These findings are only preliminary research, and they will be an important basis for proposing management solutions to improve the effectiveness of pedagogical training activities for gifted high school teachers

AN INVESTIGATION INTO THE USE OF COLLOCATIONS IN ACADEMIC ESSAYS OF ENGLISH-MAJORED STUDENTS OF THE HIGH-QUALITY PROGRAM AT CAN THO UNIVERSITY, VIETNAM

One of the main goals of language learners is to master all four skills of listening, speaking, reading and writing when it comes to their acquisition of the target language. However, during the process of learning English, learners inevitably face a variety of challenges related to their writing including grammatical errors, word choice, organization, idea development, and most importantly their difficulties in using collocations (Duong & Nguyen, 2021). Therefore, this study has been conducted to investigate the students’ use of English collocations in their academic essays associated with their difficulties so that appropriate pedagogical approaches and practices would be taken into consideration in order to help students improve their English collocational competences in academic writing. This descriptive study was carried out with 103 English-majored students of the High-quality program of the School of Foreign Languages at Can Tho University, Vietnam. A 5-point Likert scale survey with 18 questionnaire items was employed to examine the frequency of students' exposure to as well as their usage of English collocations, and their difficulties in using English collocations. The results of this study have shown that the most commonly used collocations in the students’ academic essays were ‘verb + noun’, and ‘adjective + noun’ lexical collocations. Additionally, the research outcomes have revealed that the types of English collocations that the students were more likely to make the most mistakes belonged to ‘verb + adverb’, and ‘adjective + noun’ lexical collocations.  Article visualizations

DECOLORIZATION OF AZO DYES BY PURPLE NON-SULFUR BACTERIA

Joint Research on Environmental Science and Technology for the Eart

flavonoids from Fissistigma acuminatissima

From the leaves of Fissistigma acuminatissima growing in Vietnam, two flavonoids, catechin and isorhamnetin-3-o-rutinoside were isolated. Their structures were characterized on the basis of MS and NMR spectra data and comparison with reported data.Keywords: Annonaeae; Fissistigma acuminatissima; catechin; isorhamnetin-3-o-rutinoside

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

Synthesis and Optical Characterization of Dye Doped in Ormosil Nanospheres for Bioapplications

Dye-doped ORMOSIL (organically modified silicate) nanoparticles (NPs) have significant advantages over single-dye labeling in signal amplification, photostability and surface modification for various biological applications. The dyes: Rhodamine 6G (R6G) and Rhodamine B (RB) were successfully incorporated into ORMOSIL nanoparticles fabricated by micellar nanochemistry from Trimethoxysilane CH$_3$Si(OCH$_3$)$_3$ precursor. The optical characterization of dye-doped ORMOSIL NPs was studied in comparison with it’s of free dye in solution. The results shown that the photostability of ORMOSIL dye doped nanospheres is much improved in comparison with it’s of dye in solution. Other studies of the photophysical properties such as anisotropy, fluorescence lifetime and energy transfer were also done

NONLINEAR CHARACTERISTICS OF SQUARE SOLID-CORE PHOTONIC CRYSTAL FIBERS WITH VARIOUS LATTICE PARAMETERS IN THE CLADDING

Nonlinear characteristics of fused silica, solid-core photonic crystal fibers (PCFs) with a square array of air holes are studied numerically. We present a novel design that emphasizes the difference in air hole diameters in the photonic cladding. These PCFs have the advantages of flat dispersion, high nonlinearity, and low attenuation. Based on simulation results, three optimal structures, denoted #F1, #F2, and #F3, having anomalous and all-normal dispersions in the near-infrared range are selected to investigate characteristic properties at the pump wavelength. Such PCFs open up many possibilities for nonlinear optical applications, especially supercontinuum generation

INFLUENCE OF STRUCTURAL PARAMETERS ON OPTICAL CHARACTERISTICS OF PHOTONIC CRYSTAL FIBERS WITH CIRCULAR LATTICE

We demonstrate in this study that near-zero, ultra-flattened chromatic dispersion can be achieved over a wide range of wavelengths in photonic crystal fibers (PCFs) by means of slight variations in the geometrical parameters of the cladding. To do that, a new solid-core circular PCF design with various air hole diameters and lattice constants is presented, and the design features are numerically analyzed in detail. After 40 simulations, we determined three structures that possess optimal dispersion with the following lattice constants (Ʌ) and filling factors for the first ring (d1/Ʌ): Ʌ = 0.8 µm, d1/Ʌ = 0.45 for #F1, Ʌ = 0.9 µm, d1/Ʌ = 0.45 for #F2, and Ʌ = 1.0 µm, d1/Ʌ = 0.45 for #F3. High nonlinearity and low attenuation are outstanding features of our model. With these advantages, the proposed fibers are targeted for smooth flat broadband supercontinuum generation for near-infrared applications

The Relationship between Public Debt, Budget Deficit, and Sustainable Economic Development in Developing Countries: The Role of Corruption Control

This study investigates the effects of public debt and budget deficits on the sustainable economic development of developing countries, taking into account the role of control of corruption. The two-step GMM method was applied for unbalanced panel data of 59 developing countries from 2004 to 2015. The study found that public debt and the budget deficit had negative effects on sustainable development, while the effect of control of corruption was positive. Moreover, using interaction terms between control of corruption and public debt and budget deficit, respectively, empirical results showed that controlling corruption limited these adverse effects. Thus, if the objective is to achieve sustainable economic development, developing countries should not see raising public debt or maintaining budget deficits as a strategy for economic development. The study contributes empirical evidence to the theory of debt overhang, crowded effects, and institutional theory in the context of developing countries. The implications are also discussed in this paper