CHEMICAL CONSTITUENTS OF THE ETHYL ACETATE EXTRACT OF THE FRUIT BODIES OF PHELLINUS GILVUS

Five fungal secondary metabolites named 1,2,4,5-tetrachloro-3,6-dimethoxybenzene (1); ergosterol (2); ergosterol peroxide (3); (E)- 4-(3,4-dihydroxyphenyl)but-3-en-2-one (4) and [Bi-1,4-cyclohexandien-1-yl]-3,3’,6,6’-tetrone, 4, 4’-dihydroxyl-2,2’,5,5’-tetramethyl (5) were purified from ethyl acetate extract of the fruit bodies of Phellinus gilvus collected at Pu Mat national park, Nghe An province. Their structures were charaterized by 1D, 2D NMR and GC-MS spectroscopies. Especially, the structure of compound 1 was confirmed by X-ray crystallographic analysis. The antimicrobial and cytotoxicity activities of compounds 1 were also evaluated. This is the first report on the chemical constituents of Vietnamese Phellinus gilvus

COMMUTERS' EXPOSURE TO PARTICULATE MATTER AND CARBON MONOXIDE IN HANOI : A PILOT STUDY

Joint Research on Environmental Science and Technology for the Eart

Examining the Nursing Workforce Shortage in Vietnam : Implications for Nursing Education

This study examines the nursing human resource crisis in Vietnam that emerged in the wake of the COVID-19 pandemic. A literature review encompassing policy documents, statistics, reports, guidelines, news, media, and academic publications was conducted. Even before the pandemic, Vietnam grappled with a nursing shortage, with a nurse-to-population ratio significantly below the global average. The shortage of nurses jeopardizes nurse-to-patient ratios, patient safety, and equitable access to high-quality healthcare services. The nursing human resource crisis in Vietnam is further exacerbated by the limited capacity of nursing education institutions. Without substantial investments in nursing education, projections indicate that Vietnam may face a crisis of lacking nursing professionals in the near future. The post-COVID-19 nursing crisis in Vietnam underscores the urgent need for reforms in nursing education. Policy interventions should prioritize strategic workforce planning and increased financial investments in nursing education and training programs

Anti-inflammatory activity of methyl ferulate isolated from Stemona tuberosa Lour

AbstractObjectiveTo evaluate the anti-inflammatory activity of methyl ferulate (MF) isolated from the roots of Stemona tuberosa (S. tuberosa) Lour (Stemonaceae) in lipopolysaccharide activated macrophage cells.MethodsMethanol extracts of a root powder of S. tuberosa were prepared for isolation of a potential anti-inflammatory agent using ultrasound extraction combined with repeated chromatography on silica gel. After the quantitative analyses, anti-inflammatory activity of the isolated compound was evaluated by measurement of cytokine release, NO generation, expression of cyclooxygenase-2 and phosphorylation of mitogen activated protein kinases including p38 and c-Jun NH2-terminal kinase using quantitative kits and Western blotting with specific antibodies.ResultsThe isolation process yielded a potential anti-inflammatory compound with a purity level of 99% determined by high performance liquid chromatography. The compound was identified as MF by using nuclear magnetic resonance. MF strongly inhibited the release of pro-inflammatory cytokines from macrophages, including IL-6, TNFα, IFNγ, yet it did not affect the anti-inflammatory cytokine IL-10. Phosphorylation of p38 and c-Jun NH2-terminal kinase were clearly reduced in MF-treated macrophages stimulated with lipopolysaccharide. cyclooxygenase-2 expression and NO generation by macrophages were also suppressed when the cells were treated with MF.ConclusionsThe data suggested that MF is a possible inhibitor of the mitogen activated phosphor kinase pathway and could be a potential anti-inflammatory agent isolated for the first time in medicinal plant S. tuberosa

Adaptive fuzzy-neural network effectively disturbance compensate in sliding mode control for dual arm robot

In this study, an Adaptive Backstepping Sliding Mode Controller (ABSMC) is introduced based on the Radial Basis Function (RBF) neural network and a fuzzy logic modifier. The proposed method is used to control a Dual-Arm Robot (DAR) – a nonlinear structure with unstable parameters and external disturbances. The control aims to track the motion trajectory of both arms in the flat surface coordinate within a short time, maintaining stability, and ensuring that the tracking error converges in finite time, especially when influenced by unforeseen external disturbances. The nonlinear Backstepping Sliding Mode Control (BSMC) is effective in trajectory tracking control; however, undesired phenomena may occur if there are uncertain disturbances affecting the system or model parameters change. It is proposed to use a neural network to estimate a nonlinear function to handle unknown uncertainties of the system. The neural network parameters can be adaptively adjusted to optimal values through adaptation rules derived from Lyapunov's theorem. Additionally, fuzzy logic theory is also employed to adjust the controller parameters to accommodate changes or unexpected impacts. The performance of the Fuzzy Neural Network Backstepping Sliding Mode Control (FNN-BSMC) is evaluated through simulation results using Matlab/Simulink software. Two simulation cases are conducted: the first case assumes stable model parameters without uncertain disturbances affecting the joints, while the second case considers a model with changing parameters and disturbances. Simulation results demonstrate the effective adaptability of the proposed method when the system model is affected by various types of uncertainties from the environmen

PURIFICATION OF PHOSPHOGYPSUM FOR USE AS CEMENT RETARDER BY SULPHURIC ACID TREATMENT

Phosphogypsum is a by-product of the wet phosphoric acid production. In this study, chemical compositions of phosphogypsum waste (PG) in Hai Phong diammonium phosphate plant (DAP1) and Lao Cai diammonium phosphate plant (DAP2) in Vietnam were surveyed for the purpose of gypsum recovery by P2O5, F removal to meet TCVN11833 for use treated gypsum as cement retarder. Studies of impurities P2O5, F, TOC removal by sulfuric acid 10 % at 28 0C was presented. The results found that the combination of a low concentration of sulfuric acid treatment, washing, lime neutralizing, and thermal treatment was successful in Phoshogypsum treatment for use as cement retarder. The cement test proved that treated PG could partially replace natural gypsum as a retarder.Keywords:  phosphogypsum treatment, phosphorus pentoxide removal, calcium sulfate transition phase, cement retarder.

Primary pulmonary T-cell lymphoma mimicking asthma and community-acquired pneumonia: a rare case report

Primary pulmonary T-cell lymphoma (PPTL) is a rare disease. Diagnosing PPTL is challenging due to non-specific clinical symptoms and imaging. A 32-year-old female presented with persistent fever, cough, and dyspnoea. The symptoms were initially treated as asthma and community-acquired pneumonia without improvement. Chest computed tomography (CT) revealed bilateral consolidations with a CT angiogram sign, and flexible bronchoscopy showed infiltrative lesions causing bronchial stenosis. Histopathological examination of the tissue biopsy identified T-cell lymphoma through immunohistochemical staining positive for CD3. This case highlights the importance of considering differential diagnoses such as PPTL in patients with atypical presentations of asthma or non-resolving pneumonia. This case also demonstrates the diagnostic utility of flexible bronchoscopy in identifying airway obstruction due to malignant cells, which can mimic asthma

Cytotoxic steroids from the mushroom Ganoderma australe collected in Laos

Five steroids named stigmasterol (1), ergosterol peroxide (2), ganodertriol M (3), lucidumol B (4) and kansenone (5) were purified from the ethyl acetate extract of fruit bodies of the mushroom Ganoderma australe collected in Savannakhet province, Laos. Their structures were characterized by the combination of HR-MS, one and two dimensional NMR spectroscopic analyses. In addition, ergosterol peroxide  and kansenone showed good cytotoxicity against four cancer cell lines, KB (human epidermal carcinoma), MCF7 (human breast carcinoma), SK-LU-1 (human lung carcinoma) and Hep-G2 (hepatocellular carcinoma). This is the first report on the chemical constituents and cytotoxic steroids from Ganoderma sp. in Laos

INFLUENCE OF SYNTHESIS FACTORS ON PROPERTIES OF GEOPOLYMERS BASED ON RED MUD AND RICE HUSK ASH

In this paper, the effect of mixing ratio of raw materials, curing temperature and time on geopolymerization between red mud and rice husk ash were investigated. The results showed that the optimum conditions were SiO2/Al2O3 ratio of 4 and Na2O/Al2O3 ratio of 2.0, curing temperature of 100oC and curing time of 24 hours. The compressive strength, bulk density, total shrinkage of the obtained product were 22.8 MPa, 2.39 g.cm-3, 15%, respectively that met requirement of unsintered bricks using for construction