Hypoventilation Yoga Exercises: Effects on Respiratory Metabolism

Aim. Assessment of changes in respiratory metabolism and parameters of external respiration during hypoventilation yoga exercises. Material and methods. 22 experienced volunteers (18 men and 4 women, mean age 42.95 ± 8.14 years) performed yoga breathing exercises with a frequency of 3 times per minute, 1.5 times per minute, 1 time per minute, as well as free breathing for 2 minutes. Respiratory rate (RR), minute ventilation (MV), tidal volume (TV), partial pressure of CO2 in expired air at the end of exhalation (PetCO2), percentage of O2 in expired air (FeO2) and hemoglobin saturation (SpO2) were recorded. Results and discussion. The breathing regimen with RR = 3 times / min is hyperventilating, accompanied by a statistically significant increase in respiratory minute volume (RMV) and a decrease in PetCO2; hemoglobin saturation indices are not changed. Breathing with a frequency of 1.5 times/min is accompanied by a statistically significant decrease in RMV compared to the rest state, as well as an increase in PetCO2 and a decrease in FeO2, that is, it is hypoventilating, although there is a certain heterogeneity within this subgroup depending on the recruited tidal volume. Indicators of hemoglobin saturation with a given breathing mode do not change. The breathing regimen with RR = 1 time / min is accompanied by a statistically significant decrease in the RMV, an increase in PetCO2 and a decrease in FeO2; the average values of hemoglobin saturation do not change, but the minimum saturation values (observed once during each respiratory cycle) are statistically significantly lower than at the rest state. These results suggest that hypoventilating yoga exercises may have a positive effect on cerebral blood flow and cerebrovascular reactivity. Conclusion. Performing yoga breathing exercises at the respiration rate of 1.5 and 1 times per minute is accompanied by statistically significant hypoventilation, alveolar hypercapnia and hypoxia.

The practice of the Investigation process: the impact of cognitive conflict on the improvement of the training of concept «Composition of inspired air and expired air» for the pupils of primary cycle.

The first one left this research concerns the place of cognitive conflict in the Investigation on the alert scientific at the level of primary education. The second part is interested in the impact of cognitive conflict on the improvement of training. The methodology rests the basics on a question put down to the pupils of sixth primary year in different Tunisian schools by the way the composition of air which they inspire and that of the air which is expired. Answers given by the pupils show well that there is a problem linked to previous erroneous conception. Our research aims at improving the training of this concept by cognitive conflict. Therefore, we worked out for the pupils an experience based on observation and text given to every pupil allowing a cognitive conflict and objective is to cause a conceptual change. Obtained results show a positive impact of cognitive conflict on the acquisition of this concept and training improvement.

Oral malodor: Epidemiology, Etiology, Physiology, Diagnosis, Counseling aspects and clinical management- An overview

Breath malodor is a social problem, and most patients complained about breath malodor in most countries. The etiological chain of breath malodor originated from the volatile sulfur compounds (VSC), gingival and periodontal diseases. When the threshold concentration, odor power, and volatility of the molecules increase in the expired air, it results in unpleasant breath odor. There are many tests to diagnose oral malodor, and the clinical management includes mechanical reduction of nutrients, clinical reduction of oral microorganisms, conversion, and masking of volatile sulfur compounds. When the dentist's treatment of oral malodor is not successful, then referral to the physician is warranted.

Toilets dominate environmental detection of SARS-CoV-2 virus in a hospital

BackgroundRespiratory and faecal aerosols play a suspected role in transmitting the SARS-CoV-2 virus. We performed extensive environmental sampling in a dedicated hospital building for Covid-19 patients in both toilet and non-toilet environments, and analysed the associated environmental factors.MethodsWe collected data of the Covid-19 patients. 107 surface samples, 46 air samples, two exhaled condensate samples, and two expired air samples were collected were collected within and beyond the four three-bed isolation rooms. We reviewed the environmental design of the building and the cleaning routines. We conducted field measurement of airflow and CO2 concentrations.FindingsThe 107 surface samples comprised 37 from toilets, 34 from other surfaces in isolation rooms (ventilated at 30-60 L/s), and 36 from other surfaces outside isolation rooms in the hospital. Four of these samples were positive, namely two ward door-handles, one bathroom toilet-seat cover and one bathroom door-handle; and three were weakly positive, namely one bathroom toilet seat, one bathroom washbasin tap lever and one bathroom ceiling-exhaust louvre. One of the 46 air samples was weakly positive, and this was a corridor air sample. The two exhaled condensate samples and the two expired air samples were negative.InterpretationThe faecal-derived aerosols in patients’ toilets contained most of the detected SARS-CoV-2 virus in the hospital, highlighting the importance of surface and hand hygiene for intervention.FundingThe work were partially supported by the National Natural Science Foundation of China (no 41977370), the Research Grants Council of Hong Kong’s (no 17202719) (no C7025-16G), and Scientific Research Fund of Jiangsu Provincial Department of Health (no S21017002).