A New Carvotacetone Derivative from the Aerial Part of Sphaeranthus africanus.

Sphaeranthus africanus L. is native in Vietnam. Little is known about α-glucosidase inhibition of Sphaeranthus africanus and its isolated compounds.

Insights into the synthesis strategies of plant-derived cyclotides.

Cyclotides are plant peptides characterized with a head-to-tail cyclized backbone and three interlocking disulfide bonds, known as a cyclic cysteine knot. Despite the variations in cyclotides peptide sequences, this core structure is conserved, underlying their most useful feature: stability against thermal and chemical breakdown. Cyclotides are the only natural peptides known to date that are orally bioavailable and able to cross cell membranes.

Factors affecting the social and emotional health of adolescents: A cross-sectional study in Vietnam.

The period of puberty in youth brings various changes in their psychology which can make their social and emotional development unbalanced. The current study aimed to identify the factors affecting the adolescents social-emotional health. We conducted a cross-sectional study on 600 Vietnamese adolescents selected conveniently from the three regions of Vietnam during the outbreak of COVID-19 pandemic.

Sphaeranthone A, a new carvotacetone from the leaves of .

A new carvotacetone sphaeranthone A and four known compounds 3-angeloyloxy-5-[2″,3″-epoxy-2″-methylbutanoyloxy]-7-hydroxycarvotacetone (), 3-angeloyloxy-5-[3″-chloro-2″-hydroxy-2″-methylbutanoyloxy]-7-hydroxycarvotacetone (), chrysosplenol D (), and 3--methylquercetin () were isolated from leaves of growing in Vietnam. Their chemical structures were elucidated by extensive 1D and 2D NMR analysis and high-resolution mass spectroscopy as well as comparisons in literature. Compounds were evaluated for the alpha-glucosidase inhibition.

Effects of functional groups in iron porphyrin on the mechanism and activity of oxygen reduction reaction.

The activity of the oxygen reduction reaction (ORR) on the cathode is one of the dominant factors in the performance of proton exchange membrane fuel cells. Iron porphyrin has low cost, environmental benignity, and maximum efficiency of metal usage. Therefore, this material can be a promising single-atomic metal dispersion catalyst for fuel cell cathodes.

α-Glucosidase inhibitory activities of flavonoid derivatives isolated from : and studies.

In continuation of our search for bioactive compounds from the () plant, we describe herein eight flavonoid-type compounds including mearsetin (1), mearnsitrin (2), kampferol (3), afzelin (4), quercetin (5), quercitrin (6), myricitin (7), and naringenin (8) with the aim of investigating their antidiabetic properties. Compounds 3 and 5 were selected for aromatic bromination to provide two new products 3a and 5a, respectively. All compounds showed promising α-glucosidase inhibition, with IC values ranging from 9.

Anxiety as a mediator in the relationship between the socioeconomic impact of COVID-19 and quality of life: a cross-sectional study in Vietnam.

Previous studies have investigated the effects of the pandemic on quality of life; both economical and psychosocial effects were explored. Some studies also mentioned mediating factors as mechanisms in this relationship; however, the mediating role of anxiety has not been examined. The present study examined the mediating effects of anxiety on the relationship between socioeconomic impact of COVID-19 and quality of life.

The relationship between transmission misinformation, COVID-19 stress and satisfaction with life among adults.

The perplexing evolution of the COVID-19 pandemic has had a significant effect on the spiritual lives of Vietnamese people in general, and particularly adults. The objective of this study was to ascertain the link between adult satisfaction with life and COVID-19 stress in Vietnam and investigate if COVID-19 transmission disinformation modifies the effect of COVID-19 stress on adult satisfaction with life. A total of 435 Vietnamese adults were enrolled online to finish answering, including the Satisfaction with Life Scale (SL), the COVID-19 Stress Scale (CS), and the COVID-19 Transmission Misinformation Scale (CTMS), consisting of 350 females and 85 males.

Thickness measurement of material plates using low-activity sources with various energies in gamma-ray transmission technique.

This study proposes an approach based on the gamma-ray transmission technique to accurately determine the thickness of material plates using a low-activity source. For this purpose, we have set up an experimental configuration without collimators for both source and detector. Besides, a Monte Carlo simulation model using MCNP6 code has been created with the same geometric parameters as the empirical one.

anti-inflammatory, molecular docking and molecular dynamics simulation of oleanane-type triterpenes from aerial parts of .

Bioactive-guided investigation of the aerial parts of Naiki, Tagane, and Yahara (Rubiaceae) led to the isolation of four triterpenes, including two new triterpenes recurvatanes A and B (1 and 2), along with two known compounds 3β,6β,23-trihydroxyolean-12-en-28-oic acid (3) and 3β,6β,19α,23-tetrahydroxyolean-12-en-28-oic acid (4). The chemical structures of the compounds were identified from spectroscopic data and by comparison with the literature. A comprehensive review of NMR data of the oleanane-type triterpenes bearing 3-hydroxy and 4-hydroxymethylene groups indicated the characteristic spectroscopic features in this series.

Two New α-Glucosidase Inhibitory Depsidones from the Lichen Parmotrema cristiferum (Taylor) Hale.

A bioactivity-guided investigation of the lichen Parmotrema cristiferum (Taylor) Hale (Parmeliaceae) led to the isolation of two new depsidones, cristifones A and B (1 and 2). The structures of the isolated compounds were identified by spectroscopic methods and comparison with the literature data. Compound 1 showed the initial combined structures of depsidone and depside cores.

Room-temperature spin injection from a ferromagnetic semiconductor.

Spin injection using ferromagnetic semiconductors at room temperature is a building block for the realization of spin-functional semiconductor devices. Nevertheless, this has been very challenging due to the lack of reliable room-temperature ferromagnetism in well-known group IV and III-V based semiconductors. Here, we demonstrate room-temperature spin injection by using spin pumping in a BiSb/(Ga,Fe)Sb heterostructure, where (Ga,Fe)Sb is a ferromagnetic semiconductor (FMS) with high Curie temperature (T) and BiSb is a topological insulator (TI).

Diorygmones A-B, two new guaiane-sesquiterpenes from the cultured lichen mycobiont of .

is a native crustose-lichen in Vietnam. A mycobiont of this lichen was isolated, then cultivated. The present study described the isolation and structural elucidation of two new guaiane-type sesquiterpenes, namely diorygmones A-B.

Determination of the growth performance and reproductive season of wild Channa lucius (Cuvier, 1831) populations of genus Channa (Channidae, Perciformes) in the Mekong Delta, Vietnam.

This study aimed to investigate the growth and spawning characteristics of wild Channa lucius (Cuvier, 1831) populations in the Mekong Delta, Vietnam. The study was carried out from March 2011 to February 2012. The length-weight relationship of C.

THE DIVERSITY OF CERCARIAE FROM FRESHWATER SNAILS IN LOWLAND AREAS OF BINH DINH AND PHU YEN PROVINCES, VIETNAM.

A survey was conducted in the lowland areas of Binh Dinh and Phu Yen provinces in south central Vietnam to study the diversity of digenean cercariae within freshwater snails. These regions are known as highly endemic areas for the transmission of liver flukes, Fasciola spp. and Opisthorchis viverrini.

Computational Study on the Nature of Bonding between Silver Ions and Nitrogen Ligands.

In this paper, the nature of silver ion-nitrogen atom bonding in the complexation with ammonia, azomethine, pyridine, and hydrogen cyanide from one to four coordinations is studied at the B97-1 level of density functional theory. The results indicate that the two-coordinated complex of the silver ion with different nitrogen ligands representing sp, sp, and sp orbital hybridizations is the most stable form having the shortest Ag-N bond distance, highest vibrational frequencies, largest bond order, and favorable Gibbs free energy of formation. Natural bond orbital analyses further show that σ-donation from the nitrogen lone pair to the silver empty 5s orbital is dominant in the dative metal-ligand bonding character with N-sp having the largest contribution among the different N atomic orbital hybridizations.

Mediation effects of post-series depression on the relationship between life satisfaction and positive mental health of Vietnamese: A cross-sectional study in COVID-19 pandemic context.

Vietnam, a middle-income country, has been suffering four waves of the Coronavirus disease 2019 (COVID-19) pandemic and a massive lockdown to suppress the spread of this infectious disease. Consequently, COVID-19 has caused psychological ramifications and affected humankind's life satisfaction. Because of the lockdown period, numerous people had plentiful time.

Mediation Effects of Premarital Sexual Permissiveness on the Relationship Between Expectations for Marriage and Marital Intention of Vietnamese Undergraduate Students.

Purpose: The purpose of this study was to investigate the direct and indirect effects of expectations for marital relationships and premarital sexual permissiveness on intent to marry of Vietnamese emerging adults.

Patients And Methods: Our cross-sectional study was focused on emerging adults including 344 participants, undergraduate students from universities in Viet Nam. This study was assessed by using the PLS-SEM approach.

Gagones A-F: Six prenylated chalcones from the heartwood of Mansonia gagei.

Six undescribed prenylated chalcones gagones A-F were isolated from the acetone fraction of Mansonia gagei heartwood. Their structures were unambiguously established based on spectroscopic analysis (HRESIMS, 1D and 2D NMR), as well as comparison to literature data. Their absolute configurations were elucidated using DP4 and electronic circular dichroism calculations.

Engineering of appropriate pore size combined with sulfonic functionalization in a Zr-MOF with reo topology for the ultra-high removal of cationic malachite green dye from an aqueous medium.

A Zr-based metal-organic framework with reo topology, denoted as Reo-MOF-1, was fabricated through a solvothermal method capable of efficiently removing the cationic MG dye from an aqueous medium. The effect of pH solution, adsorbent content, adsorption isotherm, and kinetics on the MG capture was observed to determine the optimal conditions. Accordingly, the maximum adsorption capacity of MG over H⊂Reo-MOF-1 reaches the value of 2532.

The Role of Self-Compassion on Psychological Well-Being and Life Satisfaction of Vietnamese Undergraduate Students During the COVID-19 Pandemic: Hope as a Mediator.

The simultaneous occurrence of the COVID-19 pandemic and the transition to adulthood have posed particular obstacles to university students' mental health. However, it remains unclear whether hope promotes mental health in the relationship between self-compassion, psychological well-being, and life satisfaction. Therefore, this study investigated the role of hope as a mediator in the relationship between self-compassion, psychological well-being, and life satisfaction among Vietnamese undergraduate students in the context of the COVID-19 pandemic.

The effect of vaccination beliefs regarding vaccination benefits and COVID-19 fear on the number of vaccination injections.

The Coronavirus disease pandemic of 2019 is a vast worldwide public health hazard, impacting people of all ages and socioeconomic statuses. Vaccination is one of the most effective methods of controlling a pandemic like COVID-19. This study aims to investigate the relationship between the number of vaccination injections and fear of COVID-19 and test whether beliefs benefit from vaccination COVID-19 mediate the effect of fear of COVID-19 on the number of vaccination injections.

Characteristics of Ag-incorporated bioactive glasses prepared by a modified sol-gel method with a shortened synthesis time and without the use of catalysts.

This work presents the preparation of bioactive glasses 70SiO-(26 - )CaO-4PO-AgO (with = 0, 1, 3, 10 mol%) by a modified sol-gel method with reduced synthesis time based on hydrothermal reaction in a medium without acid or base catalysts. The synthetic materials were characterized by several physical-chemical techniques such as TG-DSC, XRD, SEM, TEM, and N adsorption/desorption measurement. The analysis data confirmed that the glass sample not containing Ag has a completely amorphous structure, while glass samples containing Ag exhibited a pure phase of metallic nano-silver in the glass amorphous phase.

Electrocatalytic H evolution using binuclear cobalt complexes as catalysts.

We report herein on the use of two binuclear cobalt complexes with the ,'-bis(salicylidene)-phenylmethanediamine ligand as catalysts for the H evolution in DMF solution with acetic acid as proton source. Both experimental analyses (electrochemical analysis, spectroscopy analysis) and theoretical analysis (foot-of-the wave analysis) were employed. These catalysts required an overpotential of 470 mV to catalyze the H evolution and generated H gas with a faradaic efficiency of 85-95% as calculated on the basis of after 5 hour bulk electrolysis.