Interdisciplinary education in the context of protection of water resources: A case study in Vietnam

The incorporation of interdisciplinary education, a topic of significant global interest, is increasingly being recognized as a key aspect of educational innovation in Vietnam. This recognition extends to several fields, including STEM (Science, Technology, Engineering, and Mathematics) education.This research aims to design and implement a STEM situation associated with the context of water protection in Vietnam for 10th-grade students in which students mobilize the knowledge of Physics (specific gravity, Archimedes' principle) and Mathematics (volume) to design a salinometer. This device measures the salinity of the water. The research methodology is based on the observed increase in saline levels in the coastal regions of Vietnam in recent years, which has had a substantial impact on agriculture and the livelihoods of millions of people. This methodology aims to provide realistic scenarios for students to address and resolve these problems. A total of forty students in the 10th grade were involved in a teaching situation that consisted of five distinct phases. Forty 10th-grade students participated in a teaching situation conducted in five phases. The results showed that the situation helped students strengthen and connect their physics and mathematics knowledge, create a vibrant learning atmosphere, enhance communication, and develop problem-solving competency. Furthermore, the teaching situation also needs to be revised regarding the measurement practices of Vietnamese students. The situation contributes to educating students' awareness of current events, protecting Vietnamese water resources, and the importance of sustainable development. In addition, we can use the same teaching process as in this research to develop other STEM teaching situations

Preparation of self-assembly silica redox nanoparticles to improve drug encapsulation and suppress the adverse effect of doxorubicin

Background and Purpose: The utilization of doxorubicin (DOX) in clinal trials is also challenging owing to its adverse effects, including low oral bioavailability, generation of reactive oxygen species (ROS), cardiotoxicity, and epithelial barrier damage. Recently, scavenging of ROS reduced the cytotoxicity of DOX, suggesting a new approach for using DOX as an anticancer treatment. Thus, in this study, non-silica and silica redox nanoparticles (denoted as RNPN and siRNP, respectively) with ROS scavenging features have been designed to encapsulate DOX and reduce its cytotoxicity. Experimental Approach: DOX-loaded RNPN (DOX@RNPN) and DOX-loaded siRNP (DOX@siRNP) were prepared by co-dissolving DOX with RNPN and siRNP, respectively. The size and stability of nanoparticles were characterized by the dynamic light scattering system. Additionally, encapsulation efficiency, loading capacity, and release profile of DOX@RNPN and DOX@siRNP were identified by measuring the absorbance of DOX. Finally, the cytotoxicity of DOX@RNPN and DOX@siRNP against normal murine fibroblast cells (L929), human hepatocellular carcinoma cells (HepG2), and human breast cancer cells (MCF-7) were also investigated. Key results: The obtained result showed that RNPN exhibited a pH-sensitive character while silanol moieties improved the stability of siRNP in physiological conditions. DOX@RNPN and DOX@siRNP were formed at several tens of nanometers in diameter with narrow distribution. Moreover, DOX@siRNP stabilized under different pH buffers, especially gastric pH, and improved encapsulation of DOX owing to the addition of silanol groups. DOX@RNPN and DOX@siRNP maintained anticancer activity of DOX against HepG2, and MCF-7 cells, while their cytotoxicity on L929 cells was significantly reduced compared to free DOX treatment. Conclusion: DOX@RNPN and DOX@siRNP could effectively suppress the adverse effect of DOX, suggesting the potential to become promising nanomedicines for cancer treatments

A prospective multi-center observational study of children hospitalized with diarrhea in Ho Chi Minh City, Vietnam.

We performed a prospective multicenter study to address the lack of data on the etiology, clinical and demographic features of hospitalized pediatric diarrhea in Ho Chi Minh City (HCMC), Vietnam. Over 2,000 (1,419 symptomatic and 609 non-diarrheal control) children were enrolled in three hospitals over a 1-year period in 2009-2010. Aiming to detect a panel of pathogens, we identified a known diarrheal pathogen in stool samples from 1,067/1,419 (75.2%) children with diarrhea and from 81/609 (13.3%) children without diarrhea. Rotavirus predominated in the symptomatic children (664/1,419; 46.8%), followed by norovirus (293/1,419; 20.6%). The bacterial pathogens Salmonella, Campylobacter, and Shigella were cumulatively isolated from 204/1,419 (14.4%) diarrheal children and exhibited extensive antimicrobial resistance, most notably to fluoroquinolones and third-generation cephalosporins. We suggest renewed efforts in generation and implementation of policies to control the sale and prescription of antimicrobials to curb bacterial resistance and advise consideration of a subsidized rotavirus vaccination policy to limit the morbidity due to diarrheal disease in Vietnam

Spatiotemporal evolution of SARS-CoV-2 Alpha and Delta variants during large nationwide outbreak of COVID-19, Vietnam, 2021

We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions

An Outbreak of Severe Infections with Community-Acquired MRSA Carrying the Panton-Valentine Leukocidin Following Vaccination

Background: Infections with community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) are emerging worldwide. We investigated an outbreak of severe CA-MRSA infections in children following out-patient vaccination. Methods and Findings: We carried out a field investigation after adverse events following immunization (AEFI) were reported. We reviewed the clinical data from all cases. S. aureus recovered from skin infections and from nasal and throat swabs were analyzed by pulse-field gel electrophoresis, multi locus sequence typing, PCR and microarray. In May 2006, nine children presented with AEFI, ranging from fatal toxic shock syndrome, necrotizing soft tissue infection, purulent abscesses, to fever with rash. All had received a vaccination injection in different health centres in one District of Ho Chi Minh City. Eight children had been vaccinated by the same health care worker (HCW). Deficiencies in vaccine quality, storage practices, or preparation and delivery were not found. Infection control practices were insufficient. CA-MRSA was cultured in four children and from nasal and throat swabs from the HCW. Strains from children and HCW were indistinguishable. All carried the Panton-Valentine leukocidine (PVL), the staphylococcal enterotoxin B gene, the gene complex for staphylococcal-cassette-chromosome mec type V, and were sequence type 59. Strain HCM3A is epidemiologically unrelated to a strain of ST59 prevalent in the USA, althoughthey belong to the same lineage. Conclusions. We describe an outbreak of infections with CA-MRSA in children, transmitted by an asymptomatic colonized HCW during immunization injection. Consistent adherence to injection practice guidelines is needed to prevent CA-MRSA transmission in both in- and outpatient settings

Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial

Background Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke

Une étude didactique des praxéologies de la représentation en perspective dans la géométrie de l'espace, en France et au Viêt-Nam

Perspective representation is based on several choices for teaching: mode of representation, code writing and reading to fill the information loss in the passage of three-dimensional object to two-dimensional object, approach to teaching the passage of a geometry object in space to a drawing. Our study poses questions for the choices in French and Vietnamese educational systems and their effects on student studying. By using the anthropological theory of didactics, we studied the institutional relation and personal relation of French and Vietnamese students for "perspective representation" object. For the first objective (institutional relation), we characterized the modes of representation and approaches mathematics, then we established the praxeologies of reference on the "perspective representation" object. The technologies and theories of the praxeologies are based on perspective representation's rules of drawings (rules of conservation and non-conservation, rules of the third dimension, rules for a "well informed" drawing) that we explicited. By applying the model of reference to analyze the programs and textbooks, we clarified the specific points of teaching the perspective representation in France and Vietnam. Finally, we established hypotheses about the implicit rules of the didactic contract, as the constituents of technologies of personal praxeologies, of perspective representation. These rules are based on the third dimension and specific to certain solids. For the second objective (personal relation), we designed a questionnaire for the students on a task type so-called reading a drawing. The questionnaire is used to check the mentioned hypotheses and to clarify the personal praxeologies of the passage from a geometric object in space to a drawing (personal technology / theory).La représentation en perspective s'appuie sur plusieurs choix pour l'enseignement : mode de représentation, code d'écriture et de lecture pour combler la perte d'information dans le passage de trois dimensions à deux dimensions, approche pour enseigner le passage d'un objet géométrique de l'espace à un dessin. Notre étude questionne ces choix dans les deux systèmes éducatifs français et vietnamien et leurs effets sur l'apprentissage des élèves. En nous plaçant dans le cadre de la Théorie anthropologique du didactique, nous avons étudié les rapports institutionnel et personnel d'élèves français et vietnamien à l'objet « représentation en perspective ».Pour le premier (rapport institutionnel), nous avons caractérisé les modes de représentation et leurs approches mathématiques, puis nous avons élaboré les praxéologies de références relatives à l'objet « représentation en perspective ». Les technologies et théories de ces praxéologies s'appuient sur les règles de représentation du dessin en perspective (règles de conservation et de non conservation, règles de la troisième dimension, règles pour un dessin « bien informé ») que nous avons explicitées. Ensuite, nous avons utilisé ce modèle de référence pour l'analyse des programmes et des manuels ce qui nous a permis de mettre en évidence les points spécifiques de l'enseignement de la représentation en perspective en France et au Viêt-Nam. Enfin, nous avons formulé des hypothèses sur les règles implicites du contrat didactique, en tant que constituants des technologies des praxéologies personnelles de la représentation en perspective. Ces règles portent sur la troisième dimension et sont spécifiques à certains solides.Pour le deuxième (rapport personnel), nous avons fait passer aux élèves un questionnaire sur un type de tâches concernant la lecture d'un dessin. Ce questionnaire permet de mettre à l'épreuve les hypothèses précédentes et de mettre en lumière les praxéologies personnelles du passage d'un objet géométrique de l'espace à un dessin (technologie/théorie personnelle)

A didactic study of praxeologies about perspective representation in the space geometry, in France and Vietnam

La représentation en perspective s'appuie sur plusieurs choix pour l'enseignement : mode de représentation, code d'écriture et de lecture pour combler la perte d'information dans le passage de trois dimensions à deux dimensions, approche pour enseigner le passage d'un objet géométrique de l'espace à un dessin. Notre étude questionne ces choix dans les deux systèmes éducatifs français et vietnamien et leurs effets sur l'apprentissage des élèves. En nous plaçant dans le cadre de la Théorie anthropologique du didactique, nous avons étudié les rapports institutionnel et personnel d'élèves français et vietnamien à l'objet « représentation en perspective ».Pour le premier (rapport institutionnel), nous avons caractérisé les modes de représentation et leurs approches mathématiques, puis nous avons élaboré les praxéologies de références relatives à l'objet « représentation en perspective ». Les technologies et théories de ces praxéologies s'appuient sur les règles de représentation du dessin en perspective (règles de conservation et de non conservation, règles de la troisième dimension, règles pour un dessin « bien informé ») que nous avons explicitées. Ensuite, nous avons utilisé ce modèle de référence pour l'analyse des programmes et des manuels ce qui nous a permis de mettre en évidence les points spécifiques de l'enseignement de la représentation en perspective en France et au Viêt-Nam. Enfin, nous avons formulé des hypothèses sur les règles implicites du contrat didactique, en tant que constituants des technologies des praxéologies personnelles de la représentation en perspective. Ces règles portent sur la troisième dimension et sont spécifiques à certains solides.Pour le deuxième (rapport personnel), nous avons fait passer aux élèves un questionnaire sur un type de tâches concernant la lecture d'un dessin. Ce questionnaire permet de mettre à l'épreuve les hypothèses précédentes et de mettre en lumière les praxéologies personnelles du passage d'un objet géométrique de l'espace à un dessin (technologie/théorie personnelle).Perspective representation is based on several choices for teaching: mode of representation, code writing and reading to fill the information loss in the passage of three-dimensional object to two-dimensional object, approach to teaching the passage of a geometry object in space to a drawing. Our study poses questions for the choices in French and Vietnamese educational systems and their effects on student studying. By using the anthropological theory of didactics, we studied the institutional relation and personal relation of French and Vietnamese students for "perspective representation" object. For the first objective (institutional relation), we characterized the modes of representation and approaches mathematics, then we established the praxeologies of reference on the "perspective representation" object. The technologies and theories of the praxeologies are based on perspective representation's rules of drawings (rules of conservation and non-conservation, rules of the third dimension, rules for a "well informed" drawing) that we explicited. By applying the model of reference to analyze the programs and textbooks, we clarified the specific points of teaching the perspective representation in France and Vietnam. Finally, we established hypotheses about the implicit rules of the didactic contract, as the constituents of technologies of personal praxeologies, of perspective representation. These rules are based on the third dimension and specific to certain solids. For the second objective (personal relation), we designed a questionnaire for the students on a task type so-called reading a drawing. The questionnaire is used to check the mentioned hypotheses and to clarify the personal praxeologies of the passage from a geometric object in space to a drawing (personal technology / theory)

The natural history and transmission potential of asymptomatic severe acute respiratory syndrome coronavirus 2 infection

Background Little is known about the natural history of asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Methods We conducted a prospective study at a quarantine center for coronavirus disease 2019 in Ho Chi Minh City, Vietnam. We enrolled quarantined people with reverse-transcription polymerase chain reaction (RT-PCR)–confirmed SARS-CoV-2 infection, collecting clinical data, travel and contact history, and saliva at enrollment and daily nasopharyngeal/throat swabs (NTSs) for RT-PCR testing. We compared the natural history and transmission potential of asymptomatic and symptomatic individuals. Results Between 10 March and 4 April 2020, 14 000 quarantined people were tested for SARS-CoV-2; 49 were positive. Of these, 30 participated in the study: 13 (43%) never had symptoms and 17 (57%) were symptomatic. Seventeen (57%) participants imported cases. Compared with symptomatic individuals, asymptomatic people were less likely to have detectable SARS-CoV-2 in NTS collected at enrollment (8/13 [62%] vs 17/17 [100%]; P = .02). SARS-CoV-2 RNA was detected in 20 of 27 (74%) available saliva samples (7 of 11 [64%] in the asymptomatic group and 13 of 16 [81%] in the symptomatic group; P = .56). Analysis of RT-PCR positivity probability showed that asymptomatic participants had faster viral clearance than symptomatic participants (P  Conclusions Asymptomatic SARS-CoV-2 infection is common and can be detected by analysis of saliva or NTSs. The NTS viral loads fall faster in asymptomatic individuals, but these individuals appear able to transmit the virus to others

Multimodal analysis of methylomics and fragmentomics in plasma cell-free DNA for multi-cancer early detection and localization

Despite their promise, circulating tumor DNA (ctDNA)-based assays for multi-cancer early detection face challenges in test performance, due mostly to the limited abundance of ctDNA and its inherent variability. To address these challenges, published assays to date demanded a very high-depth sequencing, resulting in an elevated price of test. Herein, we developed a multimodal assay called SPOT-MAS (screening for the presence of tumor by methylation and size) to simultaneously profile methylomics, fragmentomics, copy number, and end motifs in a single workflow using targeted and shallow genome-wide sequencing (~0.55×) of cell-free DNA. We applied SPOT-MAS to 738 non-metastatic patients with breast, colorectal, gastric, lung, and liver cancer, and 1550 healthy controls. We then employed machine learning to extract multiple cancer and tissue-specific signatures for detecting and locating cancer. SPOT-MAS successfully detected the five cancer types with a sensitivity of 72.4% at 97.0% specificity. The sensitivities for detecting early-stage cancers were 73.9% and 62.3% for stages I and II, respectively, increasing to 88.3% for non-metastatic stage IIIA. For tumor-of-origin, our assay achieved an accuracy of 0.7. Our study demonstrates comparable performance to other ctDNA-based assays while requiring significantly lower sequencing depth, making it economically feasible for population-wide screening