156 research outputs found
Building a Model of Organizational Activities Experience in Natural Sciences under Stem Education Orientation
STEM educational-oriented Natural Science experience activities are learner-oriented activities Taking learners as the center in all natural science research activities applying engineering technology and mathematics STEM in solving practical problems Based on theoretical research on experiential activities STEM education and the characteristics of Natural Sciences the article studies the educational forces inside and outside the school From there it is proposed to build a model of organizational structure for experiential activities in Natural Sciences oriented toward STEM education The results of this research are meaningful in helping principals see the importance and significance of coordinating educational forces inside and outside the school in organizing experiential activities in Natural Sciences according to orientation STEM education for student
Somatic embryogenesis and plant regeneration from leaf callus with genetic stability validation using SCoT markers in Paramignya trimera, a medicinal plant native to Vietnam
Xao tam phan (Paramignya trimera (Oliv.) Guillaum) is a medicinal plant native to Vietnam, that is renowned for its therapeutic properties, particularly for the treatment of various ailments, including cancer. This study investigated in vitro propagation of P. trimera through somatic embryogenesis and shoot organogenesis using leaf callus. Various culture media, plant growth regulators, malt extract, and carbon sources were evaluated to optimize callus induction and somatic embryo formation from leaf explants. DNA barcoding confirmed 96.96% to 100% homology with P. trimera specimens from Khanh Hoa province, Vietnam. The highest callus formation rate, reaching 100%, was observed in one-year-old explants cultured in Woody Plant Medium (WPM) supplemented with 2.0 mg L-1 naphthaleneacetic acid (NAA) and 0.2 mg L-1 benzylaminopurine (BAP) in the dark for over six weeks. In WPM supplemented with 30 g L-1 sucrose, 4.0 mg L-1 BAP, and 500 mg L-1 malt extract, globular stage embryos developed into embryoids and shoots and buds clumped at 10 and 18 weeks, respectively. Shoot organogenesis was observed in WPM supplemented with 30 g L-1 sucrose and 0.07 mg L-1 thidiazuron (TDZ) after 18 weeks of culture. Genetic fidelity assessments using 12 SCoT markers indicated that in vitro plantlets were homologous to the mother plant. This study provides a viable method for the conservation and sustainable cultivation of Xao tam phan, ensuring a stable supply of this valuable medicinal resource
Geochemistry and evolution of groundwater resources in the context of salinization and freshening in the southernmost Mekong Delta, Vietnam
Study region
Ca Mau Province (CMP), Mekong Delta (MD), Vietnam.
Study focus
Groundwater from deep aquifers is the most reliable source of freshwater in the MD but extensive overexploitation in the last decades led to the drop of hydraulic heads and negative environmental impacts. Therefore, a comprehensive groundwater investigation was conducted to evaluate its composition in the context of Quaternary marine transgression and regression cycles, geochemical processes as well as groundwater extraction.
New hydrological insights for the region
The abundance of groundwater of Na-HCO type and distinct ion ratios, such as Na/Cl, indicate extensive freshwater intrusion in an initially saline hydrogeological system, with decreasing intensity from upper Pleistocene to deeper Miocene aquifers, most likely during the last marine regression phase 60–12 ka BP. Deviations from the conservative mixing line between the two endmembers seawater and freshwater are attributed to ion-exchange processes on mineral surfaces, making ion ratios in combination with a customized water type analysis a useful tool to distinguish between salinization and freshening processes. Elevated salinity in some areas is attributed to HCO generation by organic matter decomposition in marine sediments rather than to seawater intrusion. Nevertheless, a few randomly distributed locations show strong evidence of recent salinization in an early stage, which may be caused by the downwards migration of saline Holocene groundwater through natural and anthropogenic pathways into deep aquifers
Damage detection of structural based on indirect vibration measurement results combined with Artificial Neural Network
In Structural Health Monitoring (SHM), damage detection and maintenance are among the most critical factors. For surface damage, damage detection is simple and easy to perform. However, detecting and repairing is difficult for damage hidden deep in the structure. Using the structure's dynamic features, damage can be detected and repaired in time. With the development of sensor technology, indirect vibration measurement solutions give accurate results, minimizing errors by infinitely increasing the number of measurements. This solution offers a great opportunity to reduce the cost of structural health monitoring. Based on the large amount of data obtained from indirect monitoring, artificial intelligence technologies can be used to obtain a more comprehensive model of SHM. In this paper, the dynamic responses of the structure will be extracted and determined through a vehicle crossing the bridge. Based on the results of structural dynamic response, a finite element model is built and updated so that this model can represent the real structure. Damage cases will be analyzed and evaluated as input to train the Artificial neural network. The trained network can detect damage through regular health monitoring by indirect methods
Damage detection of structural based on indirect vibration measurement results combined with Artificial Neural Network
In Structural Health Monitoring (SHM), damage detection and maintenance are among the most critical factors. For surface damage, damage detection is simple and easy to perform. However, detecting and repairing is difficult for damage hidden deep in the structure. Using the structure's dynamic features, damage can be detected and repaired in time. With the development of sensor technology, indirect vibration measurement solutions give accurate results, minimizing errors by infinitely increasing the number of measurements. This solution offers a great opportunity to reduce the cost of structural health monitoring. Based on the large amount of data obtained from indirect monitoring, artificial intelligence technologies can be used to obtain a more comprehensive model of SHM. In this paper, the dynamic responses of the structure will be extracted and determined through a vehicle crossing the bridge. Based on the results of structural dynamic response, a finite element model is built and updated so that this model can represent the real structure. Damage cases will be analyzed and evaluated as input to train the Artificial neural network. The trained network can detect damage through regular health monitoring by indirect methods
Groundwater Use Habits and Environmental Awareness in Ca Mau Province, Vietnam: Implications for Sustainable Water Resource Management
The Vietnamese Mekong Delta including Ca Mau province (CMP) is seriously affected by land subsidence. Groundwater over-extraction is considered to be a major driver for this process. To address the reduction of groundwater (GW) extraction as a potential counter measure for further subsidence, this study focuses on understanding the importance of GW in people\u27s life and water using habits as well as their awareness with current environmental problems in Ca Mau. Therefore, GW sampling campaigns and surveys were conducted in all 9 districts of Ca Mau province in 2019 and 2020. The analyzed water samples showed a connection with information from questionnaires and created a general picture of water using habits. GW plays an important role in people\u27s lives, it is used for washing, cooking, drinking and other activities. People use GW for different purposes depending on their perception of water quality. For important and direct health related purposes, such as cooking or drinking, people prepare to treat water more carefully or choose another alternative water resource. The analytical approach to evaluation results based on viewpoints from general to detail helped to dig deeper into people\u27s stories to explain research results with their behavior in each situation. When people are dependent on GW and have no option to use alternative water resources, the importance level of GW in their life increases and their awareness of GW over-extraction becomes less. If people have another water source to use such as tap water (TW), habits of using GW change. This opens up the idea that a potential alternative water will reduce the dependence of people on GW and protect GW from over-exploitation. Besides, people in Ca Mau do not have much awareness of land subsidence or the reason leading to environmental problems. Therefore, raising the awareness of people by well-design education campaigns should be strongly considered
Occurrence, Toxicity and Adsorptive Removal of the Chloramphenicol Antibiotic in Water: A Review
Chloramphenicol is a broad-spectrum bacterial antibiotic used against conjunctivitis, meningitis, plague, cholera, and typhoid fever. As a consequence, chloramphenicol ends up polluting the aquatic environment, wastewater treatment plants, and hospital wastewaters, thus disrupting ecosystems and inducing microbial resistance. Here, we review the occurrence, toxicity, and removal of chloramphenicol with emphasis on adsorption techniques. We present the adsorption performance of adsorbents such as biochar, activated carbon, porous carbon, metal-organic framework, composites, zeolites, minerals, molecularly imprinted polymers, and multi-walled carbon nanotubes. The effect of dose, pH, temperature, initial concentration, and contact time is discussed. Adsorption is controlled by π-π interactions, donor-acceptor interactions, hydrogen bonding, and electrostatic interactions. We also discuss isotherms, kinetics, thermodynamic data, selection of eluents, desorption efficiency, and regeneration of adsorbents. Porous carbon-based adsorbents exhibit excellent adsorption capacities of 500-1240 mg
The Effectiveness of Oral Mini-Pulse Methylprednisolonein - the Treatment of Alopecia Areata in Vietnam
BACKGROUND: Systemic corticosteroid is used to treat alopecia areata, but it is associated with side effects. Mini-pulse therapy is thought to be effective but able to reduce side effects.
AIM: The study aimed to evaluate the effectiveness of oral mini-pulse methylprednisolone in the treatment of alopecia areata.
METHODS: Patients received methylprednisolone 16 mg orally for 2 consecutive days every week.
RESULTS: After 3 months, among patients, 40% recovered well, and 55.6% recovered fairly. After 6 months, 82.2% recovered well, 17.8% recovered fairly. No adverse events were detected, and the recurrence rate was low (2.2%).
CONCLUSION: Oral mini-pulse methylprednisolone therapy is an effective and safe therapeutic option for alopecia areata without side effects, and the time of the treatment is short
Early Treatment with Imiquimod 5% Cream of Periungual Warts in Vietnam: The Poorer, the Better
AIM: To evaluate the efficacy of imiquimod 5% in periungual wart treatment.
MATERIAL AND METHODS: A group of 40 patients were recruited to apply imiquimod 5 % cream once daily for 5 consecutive days per week in 8 weeks. They were classified into 3 levels: Mild (the total lesion area ≤ 25 mm2), moderate (25 mm2 <total lesion area ≤ 50 mm2), severe (total lesion area > 50 mm2). The outcome was evaluated at the 4th and the 8th week. The result was graded as excellent (complete clearance), good (≥ 50% clearance) and poor (< 50% clearance).
RESULTS: The total area of the wart lesion got decreased significantly from the beginning to the 4th and the 8th week (36.7 mm2 vs 16.8 mm2, p = 0.0001 and 16.8 mm2 vs 8.8 mm2, p = 0.01). The complete clearance rate at the 4th week was lower than that at the 8th week significantly (22.5% vs 72.5%, p = 0.04). The clearance rate of patients suffering severe warts was lower significantly than that of mild/ moderate patients (82.8% vs 45.5%, p = 0.03). The duration of the disease in people who responded completely to imiquimod was shorter than that of patients partially responded (10.2 ± 14.1 months vs 22.3 ± 14.3 months, p = 0.02). Adverse effects were not common, mild and local only. Recurrence rate after 6 months of follow up was 3.5%.
CONCLUSION: In conclusion, Imiquimod 5% cream is a safe and effective drug in the treatment of periungual warts
Microneedling Therapy for Atrophic Acne Scar: Effectiveness and Safety in Vietnamese Patients
AIM: To evaluate the effectiveness and safety of micro-needling therapy in atrophic acne scar treatment.
METHOD: A prospective, single centred study was implemented in a total of 31 patients suffering from atrophic acne scar grade 2 to 4 of Goodman and Baron scaring grading system was recruited. They were treated by microneedle derma roller every week in 3 months. The scars were evaluated by a magic system camera and by dermatologists clinically using Goodman and Baron scaring grading system, and Lipper and Perez score at baseline, at final treatment, 1 month and 2 months after the final treatment.
RESULTS: The results showed improvement in all patients. The mean of Goodman and Barron’s grade was decreased from 3.29 ± 0.59 at baseline, 2.23 ± 0.56 at final treatment, 1.93 ± 0.58 one month after the completion of therapy and to 1.77 ± 0.57 two months after the completion of therapy (with the p-value < 0.05). Similarly, Lipper and Perez score also dropped significantly from 36.48 ± 12.07 at baseline to 23.16 ± 15.01 at final treatment, to 17.83 ± 7.00 one month after the final treatment and to 16.37 ± 7.29 at two months after the final treatment (p-value < 0.05). Skin roughness and hyperpigmented spots got improved significantly. History of having nodular-cystic or vulgaris acne did not affect the effectiveness of the therapy. Side effects of the therapy were burning sensation, erythema but they were very mild and recovered in 1-2 days. No severe complication and post-inflammatory hyperpigmentation were noted. 83.3% of the patients satisfied after the completion of the therapy.
CONCLUSION: Skin needling is an effective and safe method for the treatment of atrophic acne scars
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