Chemical composition and antimicrobial activity of the essential oil from leaves of Magnolia coriacea (Hung T. Chang & B. L. Chen) figlar growing in Vietnam

Leaf essential oil of Magnolia coriacea (Hung T. Chang B. L. Chen) Figlar growing wild in the Bat Dai Son Nature Reserve, Ha Giang Province, Viet Nam was obtained by hydrodistillation and its chemical composition was analyzed using GC/MS. In total, 45 compounds were detected in the essential oil, accounting for 87.1% of the oil, in which 37 compounds were identified accounting for 66.9%. Bicyclogermacrene (12.6%) and spathulenol (17.0%) were the main components of the leaf essential oil of M. coriacea. Antimicrobial activity of the essential oil sample was tested against three microorganism strains using an agar disk diffusion method. The results show that the inhibitory zone diameters ranged from 8.5 to 20.5 mm. Median inhibitory concentration (IC50) and minimum inhibitory concentration (MIC) of the essential oil was determined using microdilution broth susceptibility assay against seven test microorganism strains. Bacillus subtilis had the highest sensitivity with IC50 and MIC values of 185.9 and 512 µg/mL, respectively. 

Impacts of Payment for Forest Ecosystem Services on Local livelihoods in A Luoi District, Thua Thien Hue Province, Viet Nam

This paper analyses the impacts of the national Payment for Forest Environmental Services (PFES) policy in A Luoi district, Thua Thien Hue province, Viet Nam. There are mixed impacts of PFES in A Luoi district. While some surveyed households have experienced increases in income since PFES, for many other incomes have fallen. Our findings show PFES impacts on local communities and individuals are limited because most forest areas are managed by state agencies, leaving only 17.9% of PFES payments being channeled to these groups, while the rest goes to state government agencies and commune people’s committees. This disparity in PFES payments has further widened the income gap between state agencies and local households.  PFES payments currently contribute little to household incomes, averaging only 2.64% of total earnings. PFES has little impact and additionality in advancing land tenure security and reducing natural forest product exploitation for generating income as impacts are similar to those found in non-PFES villages. PFES poverty reduction impacts vary from village to village, but in general, percentages of poor households receiving PFES payments range from 1% to 59%

Antidepressive and anxiolytic effects of ostruthin, a TREK-1 channel activator

We screened a library of botanical compounds purified from plants of Vietnam for modulators of the activity of a two-pore domain K+ channel, TREK-1, and we identified a hydroxycoumarin-related compound, ostruthin, as an activator of this channel. Ostruthin increased whole-cell TREK-1 channel currents in 293T cells at a low concentration (EC50 = 5.3 μM), and also activity of the TREK-2 channel (EC50 = 3.7 mM). In contrast, ostruthin inhibited other K+ channels, e.g. human ether-à-go-go-related gene (HERG1), inward-rectifier (Kir2.1), voltage-gated (Kv1.4), and two-pore domain (TASK-1) at higher concentrations, without affecting voltage-gated potassium channel (KCNQ1 and 3). We tested the effect of this compound on mouse anxiety- and depression-like behaviors and found anxiolytic activity in the open-field, elevated plus maze, and light/dark box tests. Of note, ostruthin also showed antidepressive effects in the forced swim and tail suspension tests, although previous studies reported that inhibition of TREK-1 channels resulted in an antidepressive effect. The anxiolytic and antidepressive effect was diminished by co-administration of a TREK-1 blocker, amlodipine, indicating the involvement of TREK-1 channels. Administration of ostruthin suppressed the stress-induced increase in anti-c-Fos immunoreactivity in the lateral septum, without affecting immunoreactivity in other mood disorder-related nuclei, e.g. the amygdala, paraventricular nuclei, and dorsal raphe nucleus. Ostruthin may exert its anxiolytic and antidepressive effects through a different mechanism from current drugs

Factors affecting corruption in the public sector: evidence from Vietnam

This research utilizes a structural equation modeling (SEM) technique to comprehensively examine the intricate interactions among various factors influencing corruption in Vietnam's public sector. The findings reveal that certain factors, including inadequate anti-corruption policies and enforcement, a lack of accountability and transparency in anti-corruption endeavors, and significant income disparities between public officials and anti-corruption measures, significantly and positively impact the cultural and social norms associated with anti-corruption. Additionally, insufficient cultural and social standards exert a notable and positive influence on the level of corruption in the public sector. The outcomes of this study provide valuable insights for developing effective policies and strategies that promote accountability, transparency, and good governance to combat corruption in Vietnam's public sector

Study of antihyperglycaemic activity in streptozotocin induced diabetic mice and antioxidant activities of medicinal plant extracts

Some extracts of medicinal plants have demonstrated potential benefits in treatment of different diseases for centuries such as antihyperglycemic, antioxidant, anti-inflammatory, antibacterial. The purpose of this study is to evaluate the effect of extracts from several herbal plants, such as Gymnema sylvestre, Stevia rebaudiana, Cinnamomum cassia, Zea may, Ocimum basilicumon blood glucose level in streptozotocin (STZ) induced diabetic miceand to offer scientific proofs for the identified antihyperglycemic effect by investigating on mechanismsof the most effective extract. The results proved that diabetic mice treated with 70% ethanol extracts of Gymnema sylvestre leaves and Stevia rebaudiana leaves showed significant reduction of the blood glucose levels at a dose of 500 mg/kg body weight when compared to control (p0,05). Antihyperglycemic activity of Gymnema sylvestre (57,68%) and Stevia rebaudiana extracts (54,93%) were significantly higher than other extracts. The inhibition of α-amylase and α-glucosidase activity of Gymnema sylvestreand, Stevia rebaudiana extracts were carried out in vitro. The result demonstrated that these Gymnema sylvestre and Stevia rebaudiana extracts exerted significant inhibition and specific on intestinal α-amylase and α-glucosidases activities. Using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay showed that Gymnema sylvestre and Stevia rebaudiana extracts exhibited relatively low antioxidant activity with the concentration of a sample required for 50% scavenging of the DPPH free radical of 115,88 ± 1,16 µg/ml and 160,27 ± 2,01 µg/mlcompared to vitamin C (49,16 ± 1,26 µg/ml).

Study on conformational structure of tamarind seed polysaccharide and its sulfated derivative by light scattering method

The aim of this study was to study the conformational changing when sulfated groups were introduced to the molecular chain of native tamarind seed polysaccharide (TSP). Light Scattering (LS) method was used to determine conformation of TSP and its sulfated derivative TSPS. The results indicated that both TSP and TSPS have a highly branched and more sphere-like molecule; however, after sulfation, the TSPS became more branched structure than native polysaccharide. Keywords. Tamarind seed polysaccharide, conformation, light scattering

Factors Affecting Firms’ Performance: The Case of Vietnam construction firms

In the context of Vietnam's international economic integration, improving the performance of enterprises is increasingly important because it not only affects businesses but also affects the development prospects of the economy. The purpose of the paper is to consider the impact of factors on the performance of listed construction companies in the period of 2012-2018. By means of an empirical analysis, this study uses Eviews econometric software and table data techniques. This study found the factors that positively impact on performance are asset structure, capital structure and firm size that negatively impact the performance of Vietnam listed construction firms. These findings support business administrators in selecting appropriate business and production plans to increase the operating performance of businesses in the construction industry. Keywords: Profitability, construction firms DOI: 10.7176/RJFA/11-2-15 Publication date: January 31st 202

ASSESSMENT OF THE POTENTIAL FOR DEVELOPMENT OF AGRITOURISM IN BINH DINH PROVINCE, VIETNAM

This study evaluates the potential for agritourism development in Binh Dinh Province, Central Vietnam. The analytical hierarchical process is used to determine the weights of four factors with 25 measurement criteria to assess agritourism potential. The research results show that Binh Dinh Province has great agritourism potential based on four evaluation factors, including (1) local agricultural tourism resources, (2) the trend for agritourism development and the agritourism market, (3) the local community’s willingness, and (4) the supporting activities of the local government. In particular, the local agricultural tourism resources factor received the highest score, followed by the local community’s willingness and the supporting activities of the local government. The trend for agritourism development and the agritourism market was rated the lowest. Therefore, Binh Dinh has viable opportunities to encourage the growth of agritourism to improve farmers’ livelihoodsDu lịch nông nghiệp đem lại nhiều cơ hội cho phát triển kinh tế cũng như đa dạng hóa các loại hình du lịch và cải thiện đời sống sinh kế của người dân. Nghiên cứu sử dụng phương pháp phân tích thứ bậc (AHP) để tính các trọng số của các tiêu chí đánh giá tiềm năng phát triển du lịch nông nghiệp tại các huyện, thị xã phía bắc tỉnh Bình Định. Tiếp theo, kết quả mô hình hóa sơ đồ mạng cho thấy cả 4 địa phương An Lão, Hoài Ân, Phù Mỹ, thị xã Hoài Nhơn đều được đánh giá ở mức điểm cao về tiềm năng phát triển du lịch nông nghiệp trên các khía cạnh tài nguyên du lịch, xu hướng phát triển du lịch, sự ủng hộ của người dân địa phương và sự quan tâm của chính quyền địa phương. Tuy nhiên, yếu tố xu hướng phát triển thị trường du lịch nông nghiệp được đánh giá ở mức điểm thấp hơn. Điều này cũng xuất phát từ việc phát triển du lịch nông nghiệp tại các huyện, thị xã phía Bắc tỉnh Bình Định cũng mới bắt đầu nhận được sự quan tâm trong vài năm gần đây, số lượt khách tham quan các huyện, thị xã phía Bắc tỉnh Bình Định còn ít so với tiềm năng du lịch của địa bàn

Hall Coefficient in the Presence of Strong Electromagnetic Waves Caused by Confined Electrons and Phonons in a Rectangular Quantum Wire

The analytic expression for the Hall Coefficient (HC) caused by the confined electrons in the presence of a strong electromagnetic wave (EMW) including the effect of phonon confinement in rectangular quantum wires (RQWs) is calculated by using the quantum kinetic equation for electrons in the case of electron - optical phonon scattering. It is because the expression of the HC for the confined phonon case contains indexes m, m' which are specific to the phonon confinement. The expression in a RQW is different from that for the case of unconfined phonons in a RQW or in 2D. The results are numerically calculated and discussed for a GaAs/GaAsAl RQW. The numerical results show that HC in a RQW can have both negative and positive values. This is different from the case of the absence of EMW and the case presence of EMW including the effect of phonon unconfinement in a RQW. These results are also compared with those in the case of unconfined phonons in a RQW and confined phonons in a quantum well. The conductivity in the case of confined phonon has more resonance peaks compared with that in case of unconfined phonons in a RQW. This new property is the same in quantum well. All results are compared with the case of unconfined phonons to see differences

Factors affecting career turnover intention after graduation among nursing students: A cross-sectional study in Central Vietnam

Background & Aim: Turnover intention can predict the actual turnover behavior of nurses. Previous studies identified a variety of factors influencing nurses' turnover intention. However, few studies investigate nursing students' career turnover intention. This study aimed to examine turnover intention and associated factors among nursing students in Central Vietnam. Methods & Materials: A cross-sectional study was implemented among 425 nursing students recruited through a multistage sampling technique from April to May 2022. Data were collected using a questionnaire including demographic characteristics, fear of COVID-19, perceived academic stress, and turnover intention. Descriptive statistics were used to describe demographic characteristics and study variables. Independent t-test, one-way analysis of variance, and Pearson's correlation coefficients were computed to examine the association between variables. Results: Approximately one-third (32.5%) of the respondents will look for jobs without patient contact, 32.2% would not study nursing if given a choice, and 31.1% often think of not staying in the nursing profession. The sum scores of turnover intention ranged from 3 to 15 with a mean of 9.19 (SD= 2.49). The turnover intention was associated with the year of study, the reason to study nursing, and preparation for nursing school (p<.05). Perceived academic stress had a moderate correlation with turnover intention (r= -.325, p<.05). In contrast, the association between fear of COVID-19 and turnover intention was not significant. Conclusion: A considerable number of nursing students had turnover intention upon graduation. Factors affecting turnover intention should be considered to retain students in educational programs and avoid a future nursing shortage