• Tuberculosis and Respiratory Diseases
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• v.43 no.2
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• pp.190-200
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• 1996

Background : Mechanical ventilation constitutes the last therapeutic method for acute respiratory failure when oxygen therapy and medical treatment fail to improve the respiratory status of the patient. This invasive ventilation, classically administered by endotracheal intubation or by tracheostomy, is associated with significant mortality and morbidity. Consequently, any less invasive method able to avoid the use of endotracheal ventilation would appear to be useful in high risk patient. Over recent years, the efficacy of nasal mask ventilation has been demonstrated in the treatment of chronic restrictive respiratory failure, particularly in patients with neuromuscular diseases. More recently, this method has been successfully used in the treatment of acute respiratory failure due to parenchymal disease. Method : We assessed the efficacy of Bilevel positive airway pressure(BiPAP) in the treatment of acute exacerbation of chronic obstructive pulmonary disease(COPD). This study prospectively evaluated the clinical effectiveness of a treatment schedule with positive pressure ventilation via nasal mask(Respironics BiPAP device) in 22 patients with acute exacerbations of COPD. Eleven patients with acute exacerbations of COPD were treated with nasal pressure support ventilation delivered via a nasal ventilatory support system plus standard treatment for 3 consecutive days. An additional 11 control patients were treated only with standard treatment. The standard treatment consisted of medical and oxygen therapy. The nasal BiPAP was delivered by a pressure support ventilator in spontaneous timed mode and at an inspiratory positive airway pressure $6-8cmH_2O$ and an expiratory positive airway pressure $3-4cmH_2O$. Patients were evaluated with physical examination(respiratory rate), modified Borg scale and arterial blood gas before and after the acute therapeutic intervention. Results : Pretreatment and after 3 days of treatment, mean $PaO_2$ was 56.3mmHg and 79.1mmHg (p<0.05) in BiPAP group and 56.9mmHg and 70.2mmHg (p<0.05) in conventional treatment (CT) group and $PaCO_2$ was 63.9mmHg and 56.9mmHg (p<0.05) in BiPAP group and 53mmHg and 52.8mmHg in CT group respectively. pH was 7.36 and 7.41 (p<0.05) in BiPAP group and 7.37 and 7.38 in cr group respectively. Pretreatment and after treatment, mean respiratory rate was 28 and 23 beats/min in BiPAP group and 25 and 20 beats/min in CT group respectively. Borg scale was 7.6 and 4.7 in BiPAP group and 6.4 and 3.8 in CT group respectively. There were significant differences between the two groups in changes of mean $PaO_2$, $PaCO_2$ and pH respectively. Conclusion: We conclude that short-term nasal pressure-support ventilation delivered via nasal BiPAP in the treatment of acute exacerbation of COPD, is an efficient mode of assisted ventilation for improving blood gas values and dyspnea sensation and may reduce the need for endotracheal intubation with mechanical ventilation.

• Journal of Trauma and Injury
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• v.33 no.1
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• pp.23-30
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• 2020

Purpose: Hemorrhagic shock is the leading cause of death in trauma patients worldwide. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a technique used to improve the hemodynamic stability of patients with traumatic shock and to temporarily control arterial hemorrhage. However, further research is required to determine whether REBOA with cardiopulmonary resuscitation (CPR) in near-arrest or arrest trauma patients can help resuscitation. We analyzed trauma patients who underwent REBOA according to their CPR status and evaluated the effects of REBOA in arrest situations. Methods: This study was a retrospective single-regional trauma center study conducted at a tertiary medical institution from February 2017 to November 2019. We evaluated the mortality of severely injured patients who underwent REBOA and analyzed the factors that influenced the outcome. Patients were divided into CPR and non-CPR groups. Results: We reviewed 1,596 trauma patients with shock, of whom 23 patients underwent REBOA (1.4%). Two patients were excluded due to failure and a repeated attempt of REBOA. The Glasgow Coma Scale score was lower in the CPR group than in the non-CPR group (p=0.009). Blood pressure readings at the emergency room were lower in the CPR group than in the non-CPR group, including systolic blood pressure (p=0.012), diastolic blood pressure (p=0.002), and mean arterial pressure (p=0.008). In addition, the mortality rate was higher in the CPR group (100%) than in the non-CPR group (50%) (p=0.012). The overall mortality rate was 76.2%. Conclusions: Our study suggests that if REBOA is deemed necessary in a timely manner, it is better to perform REBOA before an arrest occurs. Therefore, appropriate protocols, including pre-hospital REBOA, should be constructed to demonstrate the effectiveness of REBOA in reducing mortality in arrest or impending arrest patients.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.10
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• pp.1307-1313
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• 2011

The mechanical limited slip differential (LSD) in vehicles is being replaced by the electromagnetic LSD because of its fast response and better active control characteristics. The coil housing made of STS 304 is one of the most important parts in the solenoid assembly of the electromagnetic LSD. High geometrical accuracy is a prerequisite for the manufacture of such coil housings, but precision machining is difficult because of the use of STS 304 thin plate and the variance in machining variables. The aim of this study is to optimize the mean and variance of the shape accuracy in the coil housing by finding a robust solution for the machining process conditions. The mean and standard deviation of the jaw contact pressure, cutting speed, and feed rate are considered to be the major parameters for minimizing the geometrical mean and variance. The response surface model based on the second-order Taylor series is combined together to minimize the mean and variance of the shape accuracy of the coil housing.

• Journal of the Korean Ceramic Society
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• v.39 no.5
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• pp.503-510
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• 2002

Silicon carbide candle filters for the pressurized fluidized bed combustion system were fabricated by extrusion process. Carbon black was added to control the porosity. Inorganic additives such as clay and calcium carbonate were added to exhibit appropriate strength. Silicon carbide layer with a finer pore size (mean pore diameter ~$10{\mu}m$) was coated on the silicon carbide support layer (mean pore diameter ~$47{\mu}m$, porosity ∼40%). After that, the filter was sintered at 1400${\circ}C$ in air. We evaluated the filtration performances of the filter at 500${\circ}C$ and $5kgf/cm^2$ of pressure. As a result, high separation efficiency, >99.999% was measured. It is expected that silicon carbide candle filter can be successfully used for the pressurized fluidized bed combustion system.

• Journal of the Korean Dietetic Association
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• v.15 no.3
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• pp.311-327
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• 2009

This study was performed to determine the health and nutritional risk factors associated with hypertension in Koreans over the age of 50 in a high-income class (more than twice as much family income as the 2005 Korean minimum cost of living, 668,540 Won). A total of 505 subjects aged over 50 from the 2005 Korean National Health and Nutrition Examination Survey (KNHANES) were divided into two groups: A hypertension group (HG) (N=151, Systolic Blood Pressure ${\geq}$140 mmHg or Diastolic Blood Pressure ${\geq}$90 mmHg) and normal group (NG) (N=354). Subjects who took hypertension medicines or underwent diet therapy were excluded. In HG, mean daily alcohol intake and the amount of alcohol consumption per one occasion were significantly higher than in NG, respectively. A greater number of hypertension subjects answered that they drank alcohol to reduce stress as compared to normal subjects. HG also took fewer dietary supplements than NG. Mean body mass index (BMI), waist circumference, fasting blood sugar level, and 2 hour postprandial blood sugar following a glucose load were significantly higher in HG than in NG, respectively. Also, iron, thiamin, and niacin intakes and the consumption frequency of seaweeds were significantly lower in HG than in NG, respectively. Finally, obesity (BMI ${\geq}$25 $kg/m^2$), abdominal obesity (waist circumference ${\geq}$90 cm for males, ${\geq}$ 80 cm for females), high blood sugar level 2 hours after an oral glucose load (${\geq}$140~200 mg/dl), and hypertriglyceridemia (serum TG ${\geq}$200 mg/dl) were related to a significantly higher risk of hypertension in the subjects (odds ratio: 1.884~3.040). In conclusion, dietary factors such as higher alcohol consumption; lower intakes of iron, thiamin, and niacin; lower consumption frequency of seaweeds; and metabolic syndrome were associated with hypertension in the study subjects.

• The Korean Journal of Vision Science
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• v.20 no.4
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• pp.589-596
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• 2018

Purpose : We compared intraocular pressure (IOP) values measured by two types of tonometers in condition of normotensive and glaucomatous rat model. We tried to determine which of tonometer can more easily and accurately measure the IOP of animal model. Methods : Glaucomatous eyes were induced by intracameral injections of hyaluronic acid in right eyes of six-week-old male Spargue-Dawley (SD) rats. Normotensive contralateral eyes were left eyes of the SD rats. IOP was measured using a rebound tonometer (Tonolab) and a immersive tonometer ($Tonopen^{(R)}$ XL) about 3:00 pm. Results : The mean IOP values of normotensive control eyes were $10.80{\pm}1.03mmHg$ by Tonopen, and $15.10{\pm}0.73mmHg$ by Tonolab. They were statistically insignificant (p = .1). The mean IOP values of glaucomatous experimental eyes were $30.20{\pm}2.67mmHg$ by Tonopen, and $37.90{\pm}2.73mmHg$ by Tonolab. They were statistically insignificant (p = .95). High IOP values of glaucomatous eyes by two types of tonometers had strong positive correlation each other (r = .904, p < .01). Conclusion : This is the first study to compare IOP values using two types of tonometers between normotensive and glaucomatous model made by intracameral injection of hyaluronic acid. Tonopen should be used carefully when the IOP is within normal range, and both Tonopen and Tonolab can be used reliably when the IOP is high.

• Journal of Digital Convergence
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• v.12 no.5
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• pp.353-366
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• 2014

The purpose was to describe the state of healthcare-associated infection(HAI) control. Data were collected from 134 hospitals. The questionnaire developed by Kang[8] were modified. The mean of hospital beds was 556.4, 26.9% of hospitals were less than 300 beds. 99.3% of hospitals had infection control committee(ICC). ICC met 3.4 times a year. 54.5% of hospitals had one infection control practitioner(ICP). 95.5% of ICPs were nurse, 48.7% of ICPs had more than master's degree. Hospital experience of ICPs was 13.5 years. ICP experience was 3.2 years. 30.8% of ICPs worked for less than 1 year. All hospitals investigated HAI, 75.4% performed improvement activities. There are significant differences in existence of ICD, negative pressure room, computer program, numbers of ICPs according to hospital size. Manpower, organization, and facilities lacked in less than 300 beds. This conclusions will give baseline data to establish infection control system, manpower and practice in small-medium hospitals.

• Journal of Korean Academy of Nursing
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• v.8 no.1
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• pp.163-180
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• 1978

Much of a person's energy is spent in the effort of becoming a productive member of to-day's complex society. This activity may cause tension, and chronic unrelieved tension is an influential factor in blood pressure elevation. The problem of this study was to identify manifest needs and self-actualization of patients with essential hypertension, and to analyse and compare their manifest needs and selt-actualization with the selected general characteristics of We, sex, religion, occupation and level of education with a control group of patients with normal blood pressure readings. The purpose was to contribute to the planning of nursing interventions toward reducing the impact of complex psycho-somatic factors on the anxiety of patients with essential hypertension. The instruments used included selected items from the Edwards (1959) Personal Preference Schedule (EPPS) as adapted by Hwang (1965) and from the Personal Orientation Inventory (POI) (Shostrom 1964, 1974) adapted by Kim and Lee (1977) to measure manifest needs and self-actualization. The convenience sample was chosen from 149 persons who presented themselves for general physical examinations at Ewha University Medical Centre and 41 patients diagnosed with essential hypertension at three general hospitals in Seoul during June 1 and August 31, 1977. Forty-nine persons from the Ewha group with blood-pressure readings exceeding 150/90 were added to the experimental group. Data were analysed by the S.P.S.S. computer programme using t-test and tests for statistical significance. Statistically significant findings were as follows: A. Blood Pressure and Manifest Needs. 1. with the exception of Autonomy, patients with hypertension had significantly high scores on all variables Abasement, Achievement, Affiliation, Aggression, Dominance, Emotionality, Exhibitionism and Sex. 2. When mean scores of normal persons were compared by age groups, normal persons had higher scores in the following order on Abasement (50's, 40's, 20's, 30's), Achievement (50's, 30's, 40's, 20's), Affiliation (50's, 40's, 30's, 20's), Dominance (50's, 40's, 40's, 20's) and Exhibitionism (30's, 50's, 40's, 20's). In each case, there was a significant difference between the first and last age group scores. 3. When the mean scores of normal persons were compared by sex, normal men had higher scores than women on Achievement, Affiliation, Aggression, Dominance, Exhibitionism and Sex. Male patients had higher scores than female patients on Achievement, Dominance, Exhibitionism and Sex, but female patients scored higher in Emotionality. 4. Normal persons had higher scores related to religion in the following order on Achievement (Buddhism, no religion, Christianity). Hyper tensive patients had higher scores on. Exhibitionism (no religion, Christianity, Buddhism). 5. Normal persons had higher scores related to occupation in the following order on Achievement and Exhibitionism (unemployed, office workers, teachless, businessmen), Emotionality (office workers, unemployed, businessmen, teacher) and Sex (office workers, unemployed, teachers, businessmen). Hypertensive patients had higher scores on Achievement and Aggression (teachers, businessmen, office worker, unemployed), Dominance and Exhibitionism (businessmen, teacher, of ace workers, unemployed) and Sex (teachers, office worker, businessmen, unemployed). 6. Normal persons had higher scores related to level of edification in the following order on Abasement, Emotionality and Autonomy (secondary school graduation, university). Hypertensive patients had higher scores on Abasement (no education, primary, university, secondary), Achievement (no education, secondary, university, primary) , Dominance (university, no education, secondary, primary), Exhibitionism (university, secondary, no education, primary), and Sex (university, secondary, primary, no education). B. Blood Pressure and Self_Actualization 1, Patients with hypertension had significantly lower scores on all variables. 2. Normal persons had higher scores related to age groups in the following order on Existentiality (20's, 30's, 40's, 50's). Hypertensive patients showed no significantly different scores. 3. Normal women had higher scores than men on Time Competence. Normal men had higher scores on Feeling Reactivity. Male patients had higher scores than women on Self-Actualizing Value and Self-Regard. 4. Normal persons ha 1 higher scores related to religion on spontaneity (Buddhism, no religion, Christianity). Hypertensive patients had higher scores on Time Competence and Nature of Man (Buddhism, Christianity, no religion). 5. Normal persons had higher scores related to occupation in the following order on Existentiality (teachers, office workers, businessmen, unemployed) and Self-Regard (unemployed, office workers, teachers, businessmen). Hypertensive patients showed no significantly different scores. 6. Normal persons had higher scores related to level of education in the following order on Existentiality and Self-Acceptance (university, secondary). Hypertensive patients had higher scores on inner-Director (university, secondary, no education, primary) and Existentiality (university, secondary, primary, no education). Recommendations for nursing interventions with hypertensive patients with emotional problems or low self-actualization were made. 1. The nurse should encourage the patient through her interactions with other members of the medical team to accept counselling and health education. 2. Through her therapeutic interpersonal relationships with the patient, the nurse should help him discover the causes of his emotional tension. 3. Through her health teaching with the family, the nurse should encourage them to participate with the medical team in the patient's therapeutic plan and in providing him with the minimum possible emotional support. 4. Through frequent counselling with the obsessive-thinking and inflexible patient, the nurse should reevaluate the patient's behaviour and her interventions. 5. Seriously ill patients should be given needed reeducation by members of the professional medical team.

• Sleep Medicine and Psychophysiology
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• v.3 no.2
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• pp.32-42
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• 1996

Objectives : Upper airway resistance syndrome(UARS) is a sleep-related breathing disorder characterized by abnormal negative intrathoracic pressure during sleep. Abnormally increased negative intrathoracic pressure results in microarousal and sleep fragmentation which underlay UARS-associated complaints of daytime fatigue and sleepiness. Although daytime dysfunction in patients with UARS is comparable to that of sleep apnea syndrome, UARS has been relatively unnoticed in clinical setting. That is why UARS is apt to be excluded in diagnosing of sleep-related breathing disorders since its respiratory disturbance index and arterial oxygen saturation are within normal limits. The current study presents a summary of clinical and polysomnographic characteristics found in patients with UARS. The present study aims (1) to explore characteristics of patients diagnosed with UARS, (2) to characterize the polysomnographic findings of UARS patients, and (3) to enhance the understanding of UARS through those clinical and laboratory characteristics. Methods : This was a retrospective study of 20 UARS patients (male 15, female 5) and 30 obstructive sleep apnea (OSA) patients (male 21, female 9) at the Stanford Sleep Disorders Clinic. We diagnosed patients as having UARS when they met critenia, RDI < 5 characteristic findings of an elevated esophageal pressure($<-10\;cmH_2O$), frequent arousals secondary to an elevated esophageal pressure, and symptoms of daytime fatigue and sleepiness. We used polysomnographic value, which is standardized by Williams et al(1974), as normal control. Statiotical test were done with student t-tests. Results : (1) Mean age of UARS was $41.0\;{\pm}\;14.8$ years and OSA was $50.9\;{\pm}\;12.0$ years. UARS subject was significantly younger than OSA subject (p<0.05). (2) The total score of Epworth Sleepiness Scale (ESS) was UARS $9.7\;{\pm}\;6.3$ and OSAS $11.2\;{\pm}\;6.3$. There was no significant difference between two groups. (3) The mean body mass index was UARS $28.1\;{\pm}\;5.7\;kg/m^2$ and OSAS $32.9\;{\pm}\;7.0\;kg/m^2$. UARS had significantly lower meen body man index than OSAS subjects (p<0.05). (4) The polysomnographic parameters of UARS were not significantly different from those of OSA except RDI(p<0.001), $SaO_2$ (p<0.001) and slow wave sleep latency (p<0.05). (5) Compared with normal control, Total sleep time in UARS subjects was significantly shorter (p<0.001), sleep efficiency index was significantly lower (p<0.001), total awakening percentage was significantly higher (p<0.001), and sleep stage 1 (p<0.001) were significantly higher. (6) OSA patients showed poor sleep quality and distinct abnormal sleep architectures compared with normal control. Conclusions : Conclusions from the above results are as follows : (1) UARS patients were younger and had lower body mass index when umpared with OSA patients. (2) The quality of sleep and sleep architectures of the UARS and OSA patients are significantly different from those of normal control. (3) ESS scores and awakening frequencies of UARS are similar with those of OSA, suggesting that daytime dysfunction of UARS patients may be comparable to those of OSA patients. (4) The RDI and the $SaO_2$ which are important indicators in diagnosing sleep-related breathing disorders, of UARS subjects are close to normal value. (5) According to the the above results, we unclude that despite the absence of $SaO_2$ drops and the absence of an elevated number of apnea and hypopnea, subjects developed clinical complaints which were associated with laborious breathing, elevated Pes nadir, and frequently snoring. (6) Accordingly, we suggest including LIARS in the differential diagnosis list when sleep related breathing disorder is suspected clinically and overnight polysomnographic findings except snoring and frequent microarousal are within normal limits.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.8
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• pp.1100-1106
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• 2009

Recently, there are quite a lot of attention is drown on the researches related to of Miller method applied high expansion cycle. For this study, high expansion cycles are formed and analyzed with the base view point of thermodynamics, and the features of each factors are also investigated. As a result of analysis, the expansion-compression ratio is expected with a decrease of effective compression ratio as intake valve closing time retarded, however, the decrease of mean effective pressure and its output is accompanied with the counterflow of intake air. Accordingly, as the consequence of such failure, it is expected that an alternative is needed for the realization of high expansion cycles, and the improvement over thermal efficiency. To materialize such cycle, the control system to delay the closing time of intake valve was designed and VVT, the 3 S/B low speed diesel engine, is applied to evaluate the efficiency. The result of the trial shows that there was no significant errors.