• Journal of the Korean Society of Clothing and Textiles
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• v.44 no.4
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• pp.626-638
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• 2020

In this study, protective masks were designed in varying internal volume and analyzed in regards to wearing effect. Masks were measured by surface temperature and subjective wear evaluation. Four experimental masks were created with an increasing distance between the mask center line and nose in increments. The distances were set at 0.0 cm (M0), 2.0 cm (M2), 4.0 cm (M4), and 6.0 cm (M6). The area and volume of each experimental mask was measured and both measurements had a positive correlation with the set distances. Among the experimental masks, M2 was the most breathable. The heat between the face and the mask created by exhalation was able to escape from the mask and provided the highest comfort sensation when worn. Conversely, an internal volume that is too large would decrease its comfort because repetitive breathing deforms the appearance of the mask and adversely affects its fit. Therefore, creating and maintaining the optimal internal volume of the M2 mask is important to achieve maximum thermal sensation and ease of wear.

• Tuberculosis and Respiratory Diseases
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• v.50 no.4
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• pp.415-425
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• 2001

Background : The correlation between the high resolution computed tomography(HRCT) emphysema score and the physiologic parameters including resting and exercise pulmonary function test was investigated in 14 patients($60.6{\pm}10.3$ years) with pulmonary emphysema. Methods : The patients underwent a HRCT, a resting pulmonary function test, and incremental exercise testing(cycle ergometer, 10 W/min). Computed tomography scans were obtained on a GE highlight at 10 mm intervals using 10 mm collimation, from the apex to the base after a full inspiration. The emphysema scores were determined by a CT program 'Density mask' outlining the areas with attenuation values less than -900 HU, indicating the emphysema areas, and providing an overall percentage of lung involvement by emphysema. Results : Among the resting PFT parameters, only the diffusing capacity(r=-0.75) and $PaO_2$ (r=-0.66) correlated with the emphysema score(p<0.05). Among the exercise test parameters, the emphysema score correlated significantly with the maximum power(r=-0.74), maximum oxygen consumption(r=-0.68), anaerobic threshold(V-slope method: r=-0.69), maximal $O_2$-pulse(r=-0.73), and the physiologic dead space ratio at the maximum workload(r=-0.80)(p<0.01). Conclusion: We could find that exercise testing parameters showed a much better correlation with the HRCT emphysema score, which is known to have a good correlation with the pathologic severity than the resting PIT parameters. Therefore it is suggested that exercise testing is superior to resting PIT for estimating in the estimation of the physiologic disturbance in emphysema patients.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.4
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• pp.508-513
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• 2018

Tidal volume by sevoflurane in small amounts is stable due to the increase in the breathing rate. But alveolus ventilation decreases due to sevoflurane as the degree of sedation increases; this ultimately causes $PaCO_2$ to rise. The occurrence of suppression of breath increases the risk of severe hypoxia and hypercapnia in deeply sedated patients with disabilities. Sevoflurane inhalation anesthesia has a number of risks and may have unexpected problems with hemodynamic changes depending on the underlying state of the body. This study was conducted to examine the stability of internal acid-base system caused by respiratory depression occurring when patients with disabilities are induced by sevoflurane. Anesthetic induction was carried out by placing a mask on top of the patient's face and through voluntary breathing with 4 vol% of sevoflurane, 4 L/min of nitrous oxide, and 4 L/min of oxygen. After the patient's loss of consciousness and muscle relaxation, IV line was inserted by an expert and intravenous blood gas was analyzed by extracting blood from vein. In a deeply sedated state, the average amount of pH of the entire patients was measured as $7.36{\pm}0.06$. The average amount of $PvCO_2$ of the entire patients was measured as $48.8{\pm}8.50mmHg$. The average amount of $HCO_3{^-}$ of the entire patients was measured as $27.2{\pm}3.0mmol/L$. In conclusion, in dental treatment of patients with disabilities, the internal acid base response to inhalation sedation using sevoflurane is relatively stable.