Hydrometallurgical Recovery of Rare Earth Elements from Metallurgical Slags (2020–2026): A Critical Review

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Metallurgical slags generated from ironmaking, steelmaking, ferroalloy production, and molten salt electrolysis are increasingly recognized as secondary resources for critical raw materials, particularly rare earth elements (REEs) such as scandium, yttrium, and light REEs, which are incorporated into complex silicate, aluminate, and fluoride phases formed at high temperatures. This review critically evaluates hydrometallurgical routes for REE recovery across a wide range of slag systems, including blast furnace, basic oxygen furnace, electric arc furnace, bauxite residue–derived, FCC catalyst, and molten salt electrolytic slags, covering direct leaching approaches (acidic, alkaline, and ammoniacal), hybrid roast–leach processes (sulfation, chlorination, and alkali roasting), and downstream separation techniques such as selective precipitation and solvent extraction. Particular emphasis is placed on the role of slag mineralogy, phase assemblage, and glassy matrices in controlling leaching kinetics, selectivity, and impurity co-dissolution, with silicate-rich slags identified as the most challenging systems due to their polymerized structure, which limits reagent accessibility and often requires thermal pretreatment to achieve recoveries above 80–90%, typically at high reagent consumption (>50–300 kg/t). Comparative evaluation reveals that reported performance is frequently dominated by recovery metrics, while key parameters such as selectivity, reagent intensity, and process integration remain underreported, such that high extraction efficiencies do not necessarily translate into industrial feasibility. The main limitations across existing approaches include silica gel formation, extensive co-dissolution of matrix elements, and the generation of secondary residues, all of which negatively impact process stability and economic viability; moreover, most reported systems remain constrained by poor selectivity, high reagent intensity, and lack of continuous pilot-scale validation, limiting their industrial transferability. Future progress, therefore, depends on shifting from isolated process optimization to integrated, mineralogy-driven process design, supported by reduced reagent consumption, simplified separation flowsheets, and validation under industrially relevant conditions, positioning metallurgical slags as strategic secondary resources capable of supporting diversified and resilient REE supply chains within circular economy systems.

Enhancing the Surrounding Environment Exploration Competency for Primary School Students Through the 5E Instructional Model: An Experimental Study in Vietnam

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This study focuses on evaluating the effectiveness of the 5E instructional model (Engage – Explore – Explain – Elaborate – Evaluate) in developing the surrounding environment exploration competency for primary school students. Through a mixed-methods research approach, we conducted a pedagogical experiment on 113 third-grade students in Da Nang city with the theme “School”. The initial survey indicated a significant gap: while teachers are still accustomed to one-way transmission teaching methods, students have a desire to interact and freely experience in their learning.

After the experimental process, the group of students learning under the 5E model not only achieved higher average scores, but the percentage of students reaching a “Good” competency level was also significantly higher compared to the group learning under traditional methods. Notably, the analysis of 12 specific cases (case study) helped us recognize an uneven development among the skills. The students progressed very quickly in their ability to observe and collect information, but required more time along with continuous support from the teacher to practice asking questions and critical thinking. From these results, the study affirms that the 5E model is a practical solution to overcome the limitations of the old teaching approach, helping students change their passive learning habits to confidently explore knowledge, while simultaneously providing a practical foundation to replicate this instructional method.

Improving Inter-Hospital Transfer Documentation Through Standardisation and Accountability: A Quality Improvement Study in a Resource-Limited Sri Lankan Hospital

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Background: Incomplete transfer documentation contributes to communication failures, delayed clinical decision-making, and increased patient safety risks during inter-hospital transfers. These risks are amplified in resource-limited settings due to system inefficiencies, high workload, and lack of standardisation.¹–³

Objective: To improve the completeness, accuracy, and accountability of inter-hospital transfer documentation through structured system-level interventions.

Methods: A single-centre quality improvement study using Plan–Do–Study–Act (PDSA) cycles was conducted at Base Hospital Kinniya, Sri Lanka from January to June 2019 for a period of 6 months. A retrospective audit of 436 inter-hospital transfer forms was conducted using predefined criteria derived from Ministry of Health standards and stakeholder consensus. Two PDSA cycles were implemented: the first introduced staff training and a structured documentation seal; the second introduced a “probable diagnosis” field and a checking officer system. Key indicators included documentation of diagnosis, reason for transfer, vital signs, treatment given, and time of transfer. Descriptive statistics were used to analyse changes in documentation completeness.

Results: Baseline assessment demonstrated major deficiencies in documentation, including diagnosis (61.5%), treatment given (42.2%), time of transfer (14.7%), and oxygen saturation (26.6%). Following PDSA cycle 1, improvements were observed across all parameters. After PDSA cycle 2, near-complete compliance was achieved in most domains, including diagnosis (99.1%), heart rate (100%), blood pressure (100%), and time of transfer (98.6%). Treatment documentation improved to 94.9%, and oxygen saturation to 98.6%. Documentation verification reached 100% following introduction of a checking officer.

Conclusion: System-level interventions incorporating standardisation, training, and accountability significantly improved transfer documentation completeness. This low-cost, scalable approach is potentially applicable to similar resource-limited healthcare settings.

Analysis of the Relationship between Duration of Diabetes Mellitus and HbA1c Levels in Type 2 DM Patients at Primary Health Center in Kupang City

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Background: Type 2 diabetes mellitus (T2DM) is a growing global health challenge characterised by chronic hyperglycaemia and progressive metabolic dysfunction. Glycated haemoglobin (HbA1c) serves as the gold standard for assessing long-term glycaemic control and is closely linked to the risk of diabetes-related complications. Disease duration has been hypothesised to influence glycaemic outcomes; however, findings from previous studies remain inconsistent, warranting further investigation.

Objective: This study aimed to examine the association between disease duration and glycaemic control, as measured by HbA1c levels, in patients with type 2 diabetes mellitus.

Methods: An analytical observational study with cross-sectional design was conducted on 71 type 2 diabetes mellitus patients at three primary health centres in Kupang City from July to August 2025. Disease duration data were obtained through interviews and medical records, categorised as less than one year, one to five years, and more than five years. HbA1c levels were measured using high performance liquid chromatography method. Data analysis used Spearman’s correlation test with significance level of α=0.05.

Results: Mean HbA1c levels demonstrated an ascending trend across duration categories: 8.25±3.15% for less than one year, 9.06±2.14% for one to five years, and 9.92±2.76% for more than five years. Spearman correlation analysis revealed a statistically significant positive relationship between disease duration and HbA1c levels (r=0.247; p=0.038).

Conclusion: A significant positive correlation exists between type 2 diabetes mellitus duration and HbA1c levels, although with weak correlation strength. This finding emphasises the importance of regular glycaemic monitoring and comprehensive multifactorial management approaches, as glycaemic control is influenced not only by disease duration but also by modifiable factors including medication adherence, lifestyle modifications, and psychosocial support.

Educational Measures to Develop School Violence Prevention Skills for Junior High School Students

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School violence is becoming a pressing issue in the educational environment, negatively impacting the psychological development, personality, and learning process of junior high school students. Based on theoretical research on education in preventing school violence, this article clarifies the role of equipping students with the skills to identify, prevent, and respond to violent situations in school.Based on that theoretical foundation, the article proposes several measures to educate students in Ho Chi Minh City on skills to prevent school violence. These measures aim to contribute to building a safe and healthy school environment.

Comparative Economic Burden of Tuberculosis Patients with and Without Diabetes Mellitus in Kupang City, Indonesia: A Comparative Cross-Sectional Study

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Background: Tuberculosis and diabetes mellitus are major public health problems with a well-recognized bidirectional relationship. Diabetes mellitus increases the risk of active tuberculosis, while tuberculosis may worsen glycemic control. This comorbidity may also increase household economic burden through higher non-medical expenses, productivity loss, and catastrophic health expenditure. Evidence comparing the economic burden of tuberculosis patients with and without diabetes mellitus in Kupang City remains limited.

Objective: To compare the economic burden between tuberculosis patients without diabetes mellitus and tuberculosis patients with diabetes mellitus in Kupang City, Indonesia, in 2025.

Methods: This comparative cross-sectional study included 86 respondents, consisting of 43 tuberculosis patients without diabetes mellitus and 43 tuberculosis patients with diabetes mellitus who were receiving outpatient treatment at 10 primary health centers in Kupang City.

Results: A significant difference in economic burden was observed between the two groups. The median total cost among tuberculosis patients without diabetes mellitus was IDR 255,000, whereas the median total cost among tuberculosis patients with diabetes mellitus was IDR 850,000. Direct non-medical costs and indirect costs were also higher in the tuberculosis-diabetes mellitus group. Catastrophic costs were significantly more frequent in the TB-DM group than in the TB non-DM group (44.2% vs. 20.9%; p = 0.021).

Conclusion: Diabetes mellitus significantly increases the economic burden among tuberculosis patients. Compared with tuberculosis patients without diabetes mellitus, those with tuberculosis and diabetes mellitus incur higher total costs, greater non-medical expenditures, and higher indirect costs. These findings support the need for integrated tuberculosis-diabetes services and stronger financial protection strategies for vulnerable patients.

Application of Artificial Intelligence (AI) in Learning among Pre-service Teachers at Thu Dau Mot University: Current Status, Opportunities, and Challenges in the Context of Digital Transformation

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In the context of digital transformation in higher education, artificial intelligence (AI) is increasingly being utilized by pre-service teachers to support their learning. This study aims to analyze the current status, opportunities, and challenges of AI application at Thu Dau Mot University. A mixed-methods approach was employed, including a survey of 412 students and semi-structured interviews with 3 lecturers, 2 administrators, and 5 students.

The findings indicate that AI is widely used for information retrieval, learning support, and content generation, thereby enhancing learning effectiveness, fostering self-directed learning, and enabling personalized learning processes. However, several challenges remain, including over-reliance on technology, insufficient information evaluation skills, and risks related to academic integrity.

Based on these findings, the study proposes several recommendations to improve the effective integration of AI in teacher education, contributing to meeting the demands of digital transformation in higher education.

Multi-Tiered Scaffolding and Scaffold Fading in Teaching Chinese as a Second Language: Effects on Oral Proficiency and Pragmatic Adaptability

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While instructional scaffolding is widely recognized in Second Language Acquisition (SLA), its synchronous integration and the subsequent effects of scaffold fading in Teaching Chinese as a Second Language (TCSL) remain underexplored. This study proposes and empirically validates a multi-tiered scaffolding model—comprising linguistic, practice, and experiential scaffolds—tailored for TCSL oral instruction. A quasi-experimental, mixed-methods design was employed over a 15-week semester with 60 Vietnamese L1 learners. Quantitative data from pre- and post-tests, alongside pragmatic role-plays across three time points, demonstrated that the intervention significantly enhanced oral proficiency, yielding a massive effect size (Cohen’s d = 2.15) and effectively mitigating L1 tonal interference. Repeated Measures ANOVA confirmed the accelerated proceduralization of communicative competence (partial η² = .52). Furthermore, linear regression analysis of post-intervention survey data revealed that systematic scaffold fading is a significant predictor of sustained pragmatic adaptability and learner autonomy (R² = .41, p < .001). These findings advance Vygotskian Constructivism by providing a cohesive empirical evaluation framework, underscoring the necessity of intentional pedagogical withdrawal to cultivate an autonomy-driven learning ecosystem in global language education.​

The Role of Potassium Silicate in Quorum Quenching Against the Virulence of Ralstonia solanacearum, the Causal Agent of Bacterial Wilt in Tomato

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Bacterial wilt caused by Ralstonia solanacearum remains one of the most destructive constraints in tomato production worldwide. The pathogen’s virulence is tightly regulated by quorum sensing (QS), which controls exopolysaccharide (EPS) biosynthesis, extracellular enzyme secretion, and biofilm formation. Targeting QS through quorum quenching (QQ) represents a promising anti-virulence strategy without imposing the selective pressure associated with conventional bactericides. This study investigated the dual role of potassium silicate as (i) a QS-interfering agent that modulates bacterial virulence traits and (ii) an inducer of host systemic resistance. Potassium silicate at 1 mM significantly reduced EPS production and biofilm formation, whereas 2 mM enhanced peroxidase activity in tomato plants. Disease severity was reduced during the early stages of infection in silica-treated plants. These findings indicate that potassium silicate attenuates bacterial wilt development through the integrated modulation of pathogen virulence and host defense responses. This study provides mechanistic insight into silicon-mediated plant protection and highlights potassium silicate as a sustainable strategy for bacterial wilt management.

Factors Affecting Customer Satisfaction Towards Lоgistics Service Quality in Ba Ria – Vung Tau, Vietnam

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This study investigates the factors influencing customer satisfaction with logistics service quality in Ba Ria – Vung Tau, Vietnam using the SERVPERF model. Data were collected from 250 enterprises and analyzed using Cronbach’s Alpha, Exploratory Factor Analysis, Pearson correlation, and multiple regression. The results confirm that responsiveness, assurance, and tangibles have significant positive effects on customer satisfaction, with responsiveness showing the strongest impact. In contrast, empathy and reliability were not found to have significant effects in the final model. The findings also indicate that satisfaction varies across business sectors but shows no significant differences based on firm size or years of operation. These results suggest that logistics service providers should prioritize improving service responsiveness, staff competence, and physical facilities to enhance customer satisfaction.