This paper reports the results of the large-scale field testing of composite materials with antibacterial properties in a tropical climate. The composite materials, based on a cotton fabric with a coating of metal oxide nanoparticles (TiO2 and/or ZnO), were produced using high-power ultrasonic treatment. The antibacterial properties of the materials were studied in laboratory tests on solid and liquid nutrient media using bacteria of different taxonomic groups (Escherichia coli, Chromobacterium violaceum, Pseudomonas chlororaphis). On solid media, the coatings were able to achieve a >50% decrease in the number of bacteria. The field tests were carried out in a tropical climate, at the Climate test station “Hoa Lac” (Hanoi city, Vietnam). The composite materials demonstrated long-term antibacterial activity in the tropical climate: the number of microorganisms remained within the range of 1–3% in comparison with the control sample for the duration of the experiment (3 months). Ten of the microorganisms that most frequently occurred on the surface of the coated textiles were identified. The bacteria were harmless, while the fungi were pathogenic and contributed to fabric deterioration. Tensile strength deterioration was also studied, with the fabrics coated with metal oxides demonstrating a better preservation of their mechanical characteristics over time, (there was a 42% tensile strength decrease for the reference non-coated sample and a 21% decrease for the sample with a ZnO + CTAB coating).

Imbalance between exogenous damaging agents and protective factors in the gastro-duodenum tract can lead to peptic ulcer disease. Herbal medicines could be an effective treatment to human gastric ulcers. This study aimed to investigate the protective effect of AGAR-HP hard capsules on cysteamine-induced gastric-duodenal ulcers in experimental rats. The animals were divided into five treatment groups: Group 1 (control) and group 2 (model) were treated with distilled water, group 3 received esomeprazole at 10 mg/kg, group 4 received AGAR-HP at 0.074 g/kg, and group 5 received AGAR-HP at 0.221 g/kg. All the rats were treated for seven consecutive days. On day 7, peptic-duodenal ulcer were induced by oral cysteamine 400 mg/kg. The number of rats with the ulcer, the number of ulcers per rat, and the ulcer index of each group were recorded. Compared to group 2, AGAR-HP at high dose reduced the mean number of ulcers and the ulcer index under macroscopic and microscopic examinations. These parameters also decreased in the group of AGAR-HP low doses compared to the cysteamine control group. AGAR-HP hard capsules showed some protective effect on cysteamine-induced gastric ulcers in experimental rats.

Background Tracheal resection and reconstruction are the most effective treatments for tracheal stenosis, but the difficulties are surgery and maintaining ventilation performed on the patient’s same airway. High-flow oxygen has begun to be applied to prolong the apnoea time in the tracheal anastomosis period for tracheal resection and reconstruction. This study aims to evaluate the effectiveness of apneic conditions with high-flow oxygen as the sole method of gas exchange during anastomosis construction. Methods A prospective study was performed on 16 patients with tracheal stenosis, with ages ranging from 19 to 70, who underwent tracheal resection and reconstruction from April 2019 to August 2020 in 108 Military Central Hospital. During the anastomosis phase using high flow oxygen of 35–40 l.min-1 delivered across the open tracheal with an endotracheal tube (ETT) at the glottis in apnoeic conditions. Results The mean (SD) apnoea time was 20.91 (2.53) mins. Mean (SD) time anastomosis was 22.9 (2.41) mins. The saturation of oxygen was stable during all procedures at 98–100%. Arterial blood gas analysis showed mean (SD) was hypercapnia and acidosis acute respiratory after 10 mins of apnoea and 20 mins apnoea respectively. However, after 15 mins of ventilation, the parameters are ultimately returned to normal. All 16 patients were extubated early and safely at the end of the operation. There were no complications, such as bleeding, hemothorax, pneumothorax, or barotrauma. Conclusion High-flow oxygen across the open tracheal under apnoeic conditions can provide a satisfactory gas exchange to allow tubeless anesthesia for tracheal resection and reconstruction.

Previous findings by Köprülü (2014) indicated that at least 75% of communication taking place in the classroom was non-verbal behavior; besides, nonverbal messages were supposed to reflect what an individual was actually thinking and feeling more accurately. Based on this specific function, the present study explores the relation between students' nonverbal classroom behaviour and academic interest and achievement. Two hundred eighty-eight students from Vietnam National University and other universities participated in this study. Questionnaire survey and observation were the primary methods used. The results showed a low positive correlation between students’ frequency of nonverbal behavior in the classroom and their learning interests. However, students’ learning interest explained 18% of the variation of their gestures relating to a sitting posture, in which two variables named positive emotion and assignment completion contributed significantly to the regression model. This finding suggested that the lecturers could rely on students’ behaviors, such as sitting with their back straight, looking at the lecturer, and nodding, to determine students’ academic interests during class.

Objective: This study aimed to evaluate the effectiveness of high‐flow oxygen as the sole method of gas exchange in apnoeic conditions during anastomosis construction. Subject and method: Between April 2019 and August 2020, 16 patients with tracheal stenosis, ages ranging from 19 to 70, underwent tracheal resection and reconstruction. Patients received total anesthesia and neuromuscular blocking agents for the duration of their surgery. During the anastomosis phase using high flow oxygen of 35 - 40 l.min‐1 delivered across an open tracheal with an endotracheal tube (ETT) at the glottis in apnoeic conditions. Result: The mean (SD) apnoea time was 20.91 ± 2.53 mins. Mean (SD) time anastomosis was 22.9 ± 2.41 mins. The saturation of oxygen was stable during all procedures at 98-100%. One patient experienced an oxygen desaturation episode to a value between 88% and 90% lasting less than 2 mins. Arterial blood gas analysis showed that there was hypercapnia and acidosis acute respiratory with pH 7.25 ± 0.04; PaCO2 67.57 ± 14.71mmHg, and PaO2 167.12 ± 76.23mmHg after 10 mins of apnoea and pH was 7.17 ± 0.05; PaCO2 79.63 ± 13.39mmHg and PaO2 186.19 ±  60.14mmHg after 20 mins apnoea, respectively. However, after 15 mins of ventilation, the parameters are ultimately returned to normal. The blood pressure and heart rate are stable at times. All 16 patients were extubated early and safely at the end of the operation. There were no complications, such as bleeding, hemothorax, pneumothorax, or barotrauma. Conclusion: High-flow oxygen across an open tracheal under apnoeic conditions can provide a satisfactory gas exchange to allow tubeless anesthesia for tracheal resection and reconstruction. The surgical field is ultimately in spacious, optimal conditions for anastomosis.