• Tuberculosis and Respiratory Diseases
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• v.84 no.2
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• pp.148-158
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• 2021

Background: Radiotherapy is a common treatment option for lung or esophageal cancer, particularly when surgery is not feasible for patients with poor lung function. However, radiotherapy can affect pulmonary function and thereby induce pneumonitis or pneumonia, which can be fatal in patients with respiratory impairment. The purpose of this study is to evaluate if reductions in pulmonary function after radiotherapy can be minimized through simultaneous pulmonary rehabilitation (PR). Methods: In this matched case control study, we retrospectively analyzed patients who had undergone radiotherapy for thoracic malignant disease between January 2018 and June 2019. We analyzed results from pulmonary function tests and 6-minute walking tests (6MWT) conducted within the six months before and after radiotherapy treatment. Results: In total, results from 144 patients were analyzed, with 11 of the patients receiving PR and radiotherapy simultaneously. Of the 133 patients in the control group, 33 were matched with 11 patients in the PR group. Changes in forced expiratory volume in one second (FEV₁) and FEV₁/forced vital capacity were significantly different between the PR group and the matched control group (240 mL vs. -10 mL, p=0.017 and 5.5% vs. 1.0%, p=0.038, respectively). The median distance of 6MWT in the PR group also increased significantly, from 407.5 m to 493.0 m after radiotherapy (p=0.017). Conclusion: Simultaneous PR improved pulmonary function, particularly in measures of FEV₁, and exercise capacity for patients with lung or esophageal cancer even after radiotherapy treatment. These findings may provide an important base of knowledge for further large population studies with long-term follow-up analysis in the identification of the PR's effects during thoracic radiotherapy.

• Journal of Life Science
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• v.20 no.3
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• pp.437-443
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• 2010

This study was designed to examine the aerobic capacity and ventilatory response during an incremental exercise in elite high school cyclists. Twelve boys ($17{\pm}1\;yr$, $175{\pm}5\;cm$, $70{\pm}9\;kg$) participated in anthropometric measurements, incremental exercise testing, and pulmonary function tests. During incremental exercise testing using a cycle ergometer, their maximal oxygen uptake ($VO_2max$), maximal power output, ventilation, ventilatory equivalents for oxygen ($V_E/VO_2$) and carbon dioxide ($V_E/VCO_2$), respiratory rate, and tidal volume were measured. Time variables such as inspiratory time (Ti), expiratory time (Te), breathing time (Tb), and inspiratory duty cycle (Ti/Tb), as well as inspiratory flow rate ($V_T$/Ti) were assessed. Pulmonary function of vital capacity (FVC), forced expiratory volume in one second ($FEV_1$), $FEV_1$/FVC, and peak expiratory flow were evaluated. Their $VO_2max$, maximal heart rate, and Wmax were $57.5{\pm}3.9\;ml{\cdot}kg^{-1}{\cdot}min^{-1}$, $194.1{\pm}8.6\;beat{\cdot}min^{-1}$, and 452 W, respectively. $VO_2max$ was not related to any anthropometric parameters. Most ventilatory variables progressively increased with exercise intensity. As intensity increased, Ti, Tb, Tb decreased while Ti/Tb was maintained. Below an intensity of 250 W, height, weight, body mass index, and body surface were highly correlated with $V_T$/Ti and Ti/Tb (p<0.05). Collectively, $VO_2max$ appeared to be lower than adult cyclists, suggesting a different pattern of ventilatory control as age advances. Morphological characteristics were not related to $VO_2max$ in the population. Time variables of ventilatory response seemed to be related only at an exercise intensity level of less than 250 W. $V_T$/Ti may be related to exercise endurance capacity, but Ti/Tb was similar to adult cyclists.

• Tuberculosis and Respiratory Diseases
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• v.70 no.3
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• pp.199-205
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• 2011

Social welfare services for respiratory-disabled persons in Korea are offered based on the respiratory impairment grade, which is determined by 3 clinical parameters; dyspnea, forced expiratory volume in 1 second ($FEV_1$), and arterial oxygen tension. This grading system has several limitations in the objective assessment of respiratory impairment. We reviewed several guidelines for the evaluation of respiratory impairment and relevant articles. Then, we discussed a new grading system with respiratory physicians. Both researchers and respiratory physicians agreed that pulmonary function tests are essential in assessing the severity of respiratory impairment, forced vital capacity (FVC), $FEV_1$ and single breath diffusing capacity ($DL_{co}$) are the primarily recommended tests. In addition, we agreed that arterial blood gas analysis should be reserved for selected patients. In conclusion, we propose a new respiratory impairment grading system utilizing a combination FVC, $FEV_1$ and $DL_{co}$ scores, with more social discussion included.

• Tuberculosis and Respiratory Diseases
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• v.40 no.3
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• pp.259-266
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• 1993

Background: To evaluate the risk factor of pneumothorax (PNX) which is the most common complication of CT-guided needle aspiration of the lung, we have examined the frequency of PNX according to the presence of obstructive ventilatory impairment determined by pulmonary function tests. Methods: A comparative study of analysis of forecd expiratory volume and folw-volume curves, and determinations of diffusing capacity taken before procedure were made between each 16 cases with PNX and controls with no PNX. Each of the control group was matched for sex, age, height, and size and depth of lesion with the former. Results: 1) In comparison of vital capacity and parameters derived from forced expiratory volume curve between two groups, VC and FVC were not significantly different, whereas $FEV_1$, $FEV_1$/FVC%, and FEF25-75% showed a significant decrease in the PNX gorup. Also, in the PNX group, all the observed values of parameters analyzed from flow-volune curve were siginificantly reduced in the PNX group compared with those in the control group. 2) The diffusing capacity tended to decrease along with varying individual differences in the PNX group. 3) Patients who had obstructive ventilatory impairment according to the results of pulmonary function tests experienced a twofold increase in the frequency of PNX and a sixfold increase in the frequency of chest tube drainage for treatment of PNX compared with those whose results were normal. Conclusion: These findings suggest that the exact evaluation of obstructive lung disease determined by pulmonary function test be considered assessing a pastient's risk for PNX in the patients who will take the CT-guided needle aspiration of the lung.

• The Korean Journal of Physiology
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• v.1 no.2
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• pp.199-213
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• 1967

Circulatory and respiratory activities were observed in men exposed to the environment of engine room of a cruising Republic of Korea Navy ship and compared to the control values obtained in an ordinary laboratory room on land. The environment of an engine room of cruising navy ship was presumed to be a multiple stress acting on men. The environment of the engine room included high temperature $(35-42^{\circ}C)$, low relative humidity (20-38% saturation), vibration (about 7 cycles per second), rolling and pitching of ship and noises. Sixteen men were divided into two groups consisted of each 8 subjects. Subjects of sea duty group had experience of continuous on board duty averaging 3.5 years. Men of land duty group had no experience of on board activity. On land observations were made on one day prior to the boarding and leaving the port and four days after landing. In between observations in the engine room were made on the first, 5 th, 9 th, 12 th, and 14 th day of on board activity. The whole experimental period lasted for 20 days. Measurements on circulatory and respiratory parameters were at standing resting state (after 30 minutes standing in the case of on land study and 15 minutes in engine room study) and within one minute after cessation of on the spot running of which rhythm was 30/min. and lasted for 5 minutes. Oxygen consumption and pulmonary function test were done in the period of two minutes from the 3rd to 5th minutes of running. The following results were obtained. 1. Body temperature showed no change regardless of group difference or on land or on board measurements. 2. Pulse rate increased markedly after boarding the ship id both groups. Pulse rate increased from the first day on board at rest and after exercise as compared to the on land control value. This increase in pulse rate was more marked after exercise. Sea duty group showed less increase in pulse rate at rest than the land duty group. Standing and resting pulse rate of sea duty group on lam was 81 and increased to 87 at the 5th day on board and remained smaller than the land duty group throughout the period on board. Control standing and resting pulse rate of land duty group on land was 76 and reached 89 at the 9th day on board and thereafter decreased a little. Pulse rate of land duty group at rest on board remained greater than that of sea duty group throughout the period on board. 3. Systolic blood pressure of sea duty group increased after boarding the ship and remained higher than the control value on land. In the land duty group, however, systolic blood pressure decreased during the period on board the ship. Diastolic blood pressure decreased in both groups. 4. Resting breathing rate of land duty group increased and remained higher than the control value on land. In sea duty group, however, resting breathing rate showed a transient increase on the 1st day on board and decreased thereafter to the control value on land and kept the same level throughout the period of cruise. Absolute value of breathing rate in the sea duty group was greater than the land duty group both at rest and after exercise. 5. There was a lowering of breathing efficiency in both groups. Thus, increases in tidal volume and minute ventilation volume and decreases in maximum breathing capacity, vital capacity, capacity ratio and air velocity Index were observed after boarding the ship. An increase in ventilation equivalent was also observed in both groups. The lowering of breathing efficiency was more marked in the land duty group than the sea duty group. 6. Energy expediture increased in both groups during their stay on the ship and was more marked in the sea duty group. 7, Lactate concentration in venous blood at rest and after exercise increased after boarding the ship and no group difference was observed.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.1
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• pp.13-29
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• 2023

Overcoming the death valley, a period in which resources are depleted and profitability declines or stagnates in the entrepreneurial process, is an essential procedure for success. In this study, we examined how the strategic orientation(technology, customer, competitor orientations) and absorptive capacity(potential, realized capacities) of startups affect the possibility of startups to overcome the challenges of death valley, and also empirically analyzed whether support of open innovation and venture capital has a moderating influence to the overcoming of death valley. The result of this study shows that customer orientation and realized absorptive capacity have a positive influence on overcoming the death valley. In addition, we found that the support of open innovation and venture capital has a moderating effect only in the technology orientation among the three types of strategic orientations. The result of this research emphasizes (1) the need for startups to take a more customer-oriented approach to overcome the death valley. The customer-oriented behavior and strategies of startups are vital for their longterm survival and success if we consider the fact that most of the companies investigated in this study were technology-based startups and only customer orientation showed significant results in overcoming the death valley. The research outcome also shows that (2) implementing innovation in a more open way and securing venture capital funding can make it easier for startups to overcome the death valley. This study has academic significance in that it empirically analyzed the relationship of key factors influencing the overcoming of death valley in a situation where the majority of existing research remains at the conceptual level of discussion or methodology of case study. Furthermore, this research also provides practical implications for the establishment and implementation of effective strategies to confront the challenges of death valley for startups, government and related organizations.

• Tuberculosis and Respiratory Diseases
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• v.42 no.5
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• pp.713-722
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• 1995

Background: Chest X-ray of coal workers' pneumoconiosis and shipyard welders' lung show similar and regular opacities mostly, it is very difficult that we distinguish the former from the latter by only chest X-ray. so we performed this study to understand the progression of the disease and to provide the disease by considering pulmonary function and other factors in proportion to the profusion of small regular opacities of chest X-ray in both groups. Method: 430 coal workers' pneumoconiosis were compared with 311 shipyard welders' lung by the number, the age, the duration of dust exposure, %vital capacity(%VC), %FEV1.0, the type of ventilatory impairment, the combined pulmonary disease according to the profusion of small regular opacities on the chest radiographs, which were classified into category 0/1, category 1, and category 2. Result: 1) the percent of category 2 in coal workers' pneumoconiosis was 54.4%. the percent of category 1, and category 2 in welders' lung were 60.0%, 7.4%. the progression to the category 2 was higher in coal workers' pneumoconiosis than in welders' lung 2) The mean age was higher in coal workers' pneumoconiosis than in welders' lung, significantly increased in proportion to the progresion of profusion of small regular opacities in both groups 3) There was no difference in the duration of dust exposure by category 1/0, but the duration of dust exposure by category 1, 2 in coal workers' pneumoconiosis more significantly increased than in welders' lung. the duration in the proportion of category 2 to category 0/1, 1 significantly increased in the proportion to small regular opacities in coal workers' pneumoconiosis. but there was no significant difference in the proportion to small regular opacities in duration of dust exposure in welders' lung. 4) There was no significant difference of mean values of %VC(%vital capacity)in both groups except for category 1. the mean values of %VC had no relationship between the progression of small regular opacities in both groups. 5) The mean values of %FEV1.0 decreased more significantly in coal workers' pneumoconiosis than in welders' lung except for category 0/1. and decreased significantly in proportion to the profusion of small regular opacities in coal workers' pneumoconiosis. there was significant difference of %FEV1.0 in the proportion of category 2 to category 011 in welders' lung. 6) there were no significant difference of %FEV1.0, %VC in smoker and nonsmoker in both groups. 7) With regard to the type of ventilation in both groups in coal workers' pneumoconiosis 21.4 percent of patients belonged to the restrictive type, 11.6 percent to the obstructive type, 5.6 percent to the combined type, but in welders' lung 21.8 percent to the restrictive type, 2.9 percent to the obstructive type, 1.9 percent to the combined type. 8. in the pulmonary disease, the incidence of the pulmonary tuberculosis was the most in both groups, was more in coal workers' pneumoconiosis than welders' lung Conclusion: If we compare coal workers' pneumoconiosis with electric arc welders'lung by considering pulmonary function and other factors in proportion to the profusion of chest X-ray, I think that we will have the better result in understanding the progression of the disease and provision of the disease in both groups.

• Journal of Chest Surgery
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• v.30 no.9
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• pp.920-926
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• 1997

Remarkable effect of pain relief and prevention of the postoperative Complications after thoracotomy has been achieved by continuous intravenous analgesia. This study was carried out with thirty patients who underwent posterolateral thoraco tony. The patients were divided into three groups: Group I(n= 10), the patients with intermittent intramuscular analgesia(piroxicam 20 mg), Group II(n=10), the patients with continuous epidural analgesia(0.5% bupivacaine 30m1 + normal saline 30 ml + morphine 10 mg), and Group III(n= 10) the patients with controlled intravenous infusion of analgesics(fentanyl 2500 mfg +normal saline 10 ml). The results w re as follows; 1) There were no significant changes of vital signs, between groups. 2) Tidal volume and FVC were significantly improved in the group II and III compared with the group I during the first postoperative day. 3) A significant reduction of immediate post-thoracotomy pain was achieved in the group II and III compared with the group I. 4) The limitation of motion in the operative side was less in the group II and III compared with the group I. 5) A signi(icant reduction of the postoperative analgegics consumption was noticed in group II and III. 6) Significant complications were not occured during follow-up period in all groups.

• Tuberculosis and Respiratory Diseases
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• v.47 no.5
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• pp.609-617
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• 1999

Background: The aims of this study were to assess the etiologies, survival and prognostic factors of patients with chronic cor pulmonale visited Pusan National University Hospital. Methods : This study included 103 patients with chronic cor pulmonale. There were 67 men and 36 women. The diagnosis of chronic cor pulmonale was primarily based on the presence of underlying lung disorder and echocardiographic finding of enlarged or hypertrophied right ventricle. Other clinical data including patients' symptoms and signs, findings of arterial blood gas analysis, hematologic and biochemical laboratory and pulmonary function test were assessed. Results: The most common underlying lung disorder was pulmonary tuberculosis(59.2%) and chronic obstructive pulmonary disease was the next(28.2%). The survival rate was 57% in one year, 45% in two years, and 34% in three years. The prognostic factors were maximal voluntary ventilation(MVV), forced vital capaoity(FVC), $FEV_1$ serum Na, vital capacity(VC), serum albumin and peak expiratory flow(PEF) in univariate analysis. And in multivariate analysis, serum albumin(p=0.0144) and VC(p=0.0078) were statistically significant. Conclusion: Pulmonary tuberculosis was the most important underlying lung disorder in chronic cor pulmonale. The survival rate was 57% in one year, 45% in two years, and 34% in three years. Serum albumin (p=0.0144) and VC(p=0.0078) were statistically significant prognostic factors.

• Journal of Chest Surgery
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• v.29 no.9
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• pp.951-958
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• 1996

Bet een November 1991 and December 1993, twelve patients (Male: 2, Female: 10) who had mitral valve disease without primary pulmonary disease underwent mitral valve replacement. The pulmonary function test (PFT) was performed preoperatively and postoperatively (mean, 9 months after operation). Mitral valve replacement was indicated for mitral stenosis in 9 patients and for mitral insufficiency in 3 patients. Preoperative WHh functional class were 111 in 11 patients and class rV in 1 patient. Postoperatively, ten patients (83 %) were classified into NYHA functional class 1. There was a significant decrease in cardiothoracic ratio (CTR) postoperatively (p< 0.05). The pulmonary function before operation was low compared with predicted values in vital capacity (VC) and forced mid-expiratory flow (FEF 25∼75 %). The FEF 25%-75% and maximal voluntary ventilation (MW) were low compared with predicted values postoperatively. There was no significant difference in the pulmonary function before an after op- eration. Twelve patients were divided into 2 groups according to the early postoperative NYHA functional class. In class I group, the postoperative pulmonary function was significantly improved in 6 parameters (RV, FRC, TLC, FEVI , FEVI /FVC, and FEF 25∼75%), but in class ll group, there was no significant change in the pulmonary function after operation.