• Child Health Nursing Research
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• v.6 no.2
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• pp.224-239
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• 2000

This descriptive study was conducted to understand the contents and degree of parental stress level in the NICU patients, and to give a baseline data in developing nursing intervention program. Subjects were the 62 mother of hospitalized newborn in NICU of 1 University Hospital in Taejon City from May 1st, 1999 to November 30th, 1999, who agreed to take part in this study. The instrument used in this study were Parental Stressor Scales : NICU(PSS:NICU) developed by Miles et al. and validated by 3 NICU practitioners and 3 child health nursing faculties. The questionnaire has 4 dimensions and 45 items; sight and sounds of NICU(5 items), babies' appearance and behavior(19 items), parental role alteration and relationship with their baby(10 items), communication with health team(11 items). The questionnaire asks parents to rate each item on a five-point Likert type scale that ranges from (1) to (5). Total scores representing overall stress from the NICU environment are calculated by summing response to each item. A high score indicates high stress. A subscale score is calculated by summing the responses to each item in the subscale. Cronbach's α coefficients were .93. The data was analyzed as average, Frequency, Standard deviation, t-test, ANOVA, Pearson correlation coefficient by use of SPSS/PC+. The results of this study is summarized as follows ; 1. The total perceived stress level score of mothers was slightly high(3.6±.7). The highest scored dimension was 'appearance and behavior of the baby'(3.9±1.5), and next were 'relationship with their baby and parental role change'(3.5±1.4), 'communication with health team'(3.4±.9), 'sight and sounds of NICU'(3.2±.8). 2. Two variables were statistically significant with PSS:NICU total scale ; mother's perceived severity of the baby's condition (r=.482, P=.002) and mother's religious attendance(t=2.83, P=.01). The more the mother perceive their baby's condition severe, the higher the total stress score. There were high stress score noted in the mother of no religious attendance. 3. Four variables were statistically significant with NICU environment subscale ; mother's educational background(F=3.45, P=.04), religious attendance(t=2.28, P=.04), sex of the baby(t=2.83, P=.01) and NICU patients' hospital day(r=.359, P=.004). That is mother with high educational background and girl baby were high NICU environment subscale score. 4. Four variables were statistically significant with appearance and behavior of the baby subscale ; when first saw baby(F=3.52, P=.04), incubator care(t=2.83, P=.01), mother's perceived severity of the baby's condition(r=.303, P=.017), number of NICU visit(r=.441, P=.002). That is, seeing the baby first in the NICU and recieved incubator care was very stressful. Also, the more the mother perceive their baby's condition severe and more NICU visit, the higher the appearance and behavior of the baby subscale stress score. 5. Four variables were statistically significant with relationship with their baby and parental role change subscale ; when first saw baby(F=3.37, P=.04), sex of the baby(t=2.36, P=.03), incubator care(t=5.60, P=.00), mother's perceived severity of the baby's condition(r=.401, P=.001). That is, seeing the baby first in the NICU and girl baby was very stressful. Also, the more the mother perceive their baby's condition severe, the higher the relationship with their baby and parental role change subscale stress score. 6. Three variables were statistically significant with communication with health team subscale ; mother's educational background (F=3.63, P=.04), incubator care(t=4.24, P=.00), gestational age(r=-.394, P=.047), and birth weight(r=-.460, P=.004). That is, mother with high educational background and receiving incubator care were high communication with health team subscale score. Also, the shorter the gestational age and smaller the baby's birth weight, the higher the communication with health team subscale score. In conclusion, information about physical environment of NICU, the mother's perceived severity of baby's illness state, maternal role change related variables and the knowledge of characteristics of NICU patients must be included in nursing intervention program of mother's of NICU patients in reducing the maternal stress and anxiety level.

• Tuberculosis and Respiratory Diseases
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• v.46 no.5
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• pp.628-635
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• 1999

Background : Maximal expiratory flow rate is determined by the size of airway, elastic recoil pressure and the collapsibility of airway in the lung. The obstruction of expiratory flow is one of the major functional impairments of emphysema, which represents COPD. Nevertheless, expiratory narrowing of upper airway may be recruited as a mechanism for minimizing airway collapse, and maintaining lung volume and hyperinflation by an endogenous positive end-expiratory pressure in patients with airflow obstruction. We investigated the physiologic role of trachea in respiration in emphysema. Method : We included 20 patients diagnosed as emphysema by radiologic and physiologic criteria from January to August in 1997 at Seoul Municipal Boramae Hospital. Chest roentgenogram, high resolution computed tomography(HRCT), and pulmonary function tests including arterial blood gas analysis and body plethysmography were taken from each patient. Cross-sectional area of trachea was measured according to the respiratory cycle on the level of aortic arch by HRCT and calibrated with body surface area. We compared this corrected area with such parameters of pulmonary function tests as $PaCO_2$, $PaO_2$, airway resistance, lung compliance and so on. Results : Expiratory cross-sectional area of trachea had significant correlation with $PaCO_2$ (r=-0.61, p<0.05), $PaO_2$ (r=0.6, p<0.05), and minute ventilation (r=0.73, p<0.05), but inspiratory cross-sectional area did not (r=-0.22, p>0.05 with $PaCO_2$, r=0.26, p>0.05 with $PaO_2$, and r=0.44, p>0.05 with minute ventilation). Minute ventilation had significant correlation with tidal volume (r=0.45, p<0.05), but it had no significant correlation with respiratory frequency (r=-0.31, p>0.05). Cross-sectional area of trachea had no significant correlation with other parameters of pulmonary function including $FEV_1$, FVC, $FEV_1$/FVC, peak expiratory flow, residual volume, diffusing capacity, airway resistance, and lung compliance, whether the area was expiratory or inspiratory. Conclusion : Cross-sectional area of trachea narrowed during expiration in emphysema, and its expiratory area had significant correlation with $PaCO_2$, $PaO_2$, and minute ventilation.

• Tuberculosis and Respiratory Diseases
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• v.46 no.5
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• pp.662-673
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• 1999

Background : Pressure-controlled ventilation (PCV) is frequently used recently as the initial mode of mechanical ventilation in the patients with respiratory failure. Theoretically, because of its high initial inspiratory flow, pressure-controlled ventilation has lower peak inspiratory pressure and improved gas exchange than volume-controlled ventilation (VCV). But the data from previous studies showed controversial results about the gas exchange. Moreover, the comparison study between PCV and VCV with various inspiration : expiration time ratios (I : E ratios) is rare. So this study was performed to compare the respiratory mechanics and gas exchange between PCV and VCV with various I : E raitos. Methods : Nine patients receiving mechanical ventilation for respiratory failure were enrolled. They were ventilated by both PCV and VCV with various I : E ratios (1 : 2, 1 : 1.3 and 1.7 : 1). $FiO_2$, tidal volume, respiratory rate and external positive end-expiratory pressure (PEEP) were kept constant throughout the study. After 20 minutes of each ventilation mode, arterial blood gas, airway pressures, expired $CO_2$ were measured. Results : In both PCV and VCV, as the I : E ratio increased, the mean airway pressure was increased, and $PaCO_2$ and physiologic dead space fraction were decreased. But P(A-a)$O_2$ was not changed. In all three different I : E ratios, peak inspiratory pressure was lower during PCV, and mean airway pressure was higher during PCV. But $PaCO_2$ level, physiologic dead space fraction and P(A-a)$O_2$ were not different between PCV and VCV with three different I : E ratios. Conclusion : There was no difference in gas exchange between PCV and VCV under the same tidal volume, frequency and I : E ratio.

• Clinical and Experimental Pediatrics
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• v.45 no.8
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• pp.1007-1015
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• 2002

Purpose : The aim of this study is to find a method to diagnose and treat children who showed benign hemophagocytic histiocytes in bone marrow examination. Methods : We analyzed the clinical data of thirty patients retrospectively who showed benign hemophagocytic histiocytes in bone marrow examination from January 1995 to November 2001 at Keimyung University Dong-san Hospital. Bone marrow histiocytes were classified into a few, some, and many according to the number of histiocytes comparing with the white cells. Results : The age of thirty patients ranged from two months to 15 years. The median age was 5.6 years with male predominance(2.3 : 1). The most frequent clinical manifestation was fever; others were respiratory symptom, hepatosplenomegaly, lymphadenopathy and skin rash(in order of frequency). Common laboratory findings were leukopenia, thrombocytopenia, anemia and abnormal liver function test. Infection was present in 30 patients; causative organisms were documented in 15 patients, and bacterial infection was more common. Epstein Barr virus was the cause of infection in four patients. Bone marrow examination showed a few(20.0%), some(75.0%) and many(30.0%) hemophagocytic histiocytes. Combination immunochemotherapy including immunoglobulin, steroids and cyclosporine were helpful in 22 out of 30 patients. The mortality rate was high in young patients who showed some to many hemophagocytic histiocytes. Conclusion : Bone marrow examinations and early detection of histiocytes will be helpful in children who have fever, hepatosplenomegaly and abnormal liver function test. Immunochemotherapy were helpful and further investigation will be needed for the detection of the relationship between the bone marrow findings and prognosis.

• Pediatric Infection and Vaccine
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• v.17 no.2
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• pp.83-90
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• 2010

Purpose : Although the incidence of polymicrobial bloodstream infection (PBSI) has increased, only a few studies have so far focused on children. Therefore, in an effort to prevent more serious situations in pediatric patients, we analyzed the clinical features, organisms, and laboratory results of PBSI. Methods : We performed a retrospective review of the case records of 97 patients with polymicrobial bloodstream infection in the Severance hospital, from 2001 to 2008. Using t-test and chi-square test, we analyzed the underlying medical conditions, clinical characteristics, organisms, and laboratory results of those patients. Results : Annual incidence of polymicrobial bloodstream infection increased from 1.4 % in 2001 to 10.9% in 2008 in pediatric patients. Immunocompromised hemato-oncological malignancy was found in 31 (31.9%) patients, and was the most common underlying medical condition; cardiovascular disease was found in 15 patients (15.4%), neurologic disease in 10 patients (10.3%), and so on. Gram positive organisms were recovered in 143 cases and gram negative organisms were recovered in 101 cases of PBSI. Staphylococcus epidermidis was the most common organism. Factors affecting mortality included underlying medical disease, immune status, nosocomial infection, and central catheter-related infection, for which the rate of mortality showed a greater increase (P<0.05). Conclusion : Due to the close connection between PBSI and fatal conditions or high mortality, it requires more aggressive management. Compared with previous studies, we discovered that immunocompromised hemato-oncological malignancy was the most common underlying medical condition and that frequency of gram-positive bacteria and fungus isolated has increased.

• Applied Chemistry for Engineering
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• v.24 no.5
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• pp.551-557
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• 2013

In the present study, pristine carbon nanotube (p-CNT) and thiolated carbon naotube (t-CNT) electrodes were investigated to improve their detectabilities for cadmium (Cd) and lead (Pb). In addition, we evaluate which reaction mechanism is used when the electrolyte contains both Cd and Pb metals. Square wave stripping was employed for analyzing the sensitivity for the metals. A frequency of 30 Hz, a deposition potential of -1.2 V vs. Ag/AgCl and a deposition time of 300 s were used as optimal SWSV parameters. t-CNT electrodes show the better sensitivity for both Cd and Pb metals than that of p-CNT electrodes. In case of Cd, sensitivities of p-CNT and t-CNT electrodes were $3.1{\mu}A/{\mu}M$ and $4.6{\mu}A/{\mu}M$, respectively, while the sensitivities for Pb were $6.5{\mu}A/{\mu}M$ (p-CNT) and $9.9{\mu}A/{\mu}M$ (t-CNT), respectively. The better sensitivity of p-CNT electrodes is due to the enhancement in the reaction rate of metal ions that are facilitated by thiol groups attached on the surface of CNT. When sensitivity was measured for the detection of Cd and Pb metals present simultaneously in the electrolyte, Pb indicates better sensitivity than Cd irrespective of electrode types. It is ascribed to the low standard electrode potential of Pb, which then promotes the possibility of oxidation reaction of the Pb metal ions. In turn, the Pb metal ions are deposited on the electrode surface faster than that of Cd metal ions and cover the electrode surface during deposition step, and thus Pb metals that cover the large portion of the surface are more easily stripped than that of Cd metals during stripping step.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.18 no.2
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• pp.122-128
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• 2007

This study aims to analyze the voices of the patients with voice disorders including vocal fold paralysis, vocal fold cyst and vocal nodule/polyp in the aspect of acoustic phonetics. This study intends to collect subsidiary acoustic data in order to make a speech treatment and an standardization of vocal disorders. Subjects and Methods: The subjects of this study were 64 adult patients who underwent indirect laryngoscopy and laryngostroboscopy, and were diagnosed as vocal fold paralysis, vocal fold cyst or vocal nodule/polyp. Experimental group consisted of 20 patients who were diagnosed as vocal fold paralysis, 21 patients who were diagnosed as vocal fold cyst and had the average age of 42.0 $({\pm}10.03)$ ; and 23 patients who were diagnosed as vocal nodule/polyp and had the average age of 40.9 $({\pm}13.75)$. For the methodology of this study, the patients listed above were asked to sit in a comfortable position at intervals of 10cm apart from the patient's mouth and a microphone, and subsequently to phonate a vowel sound /e/ for the maximum phonation time with natural tone and vocal volume then the sound was directly inputted on a computer. During recording, sampling rate was set to 44,100Hz and the 1-second area corresponding to stable zone except the first and the last stage of waveform of the vowel sound /e/ vocalized by the individual patients was analyzed. Results: First, there was no statistically significant difference in jitter and shimmer between vocal fold paralysis and vocal fold cyst, while there was highly statistically significant difference in them between vocal fold paralysis and vocal nodule/polyp. Second, looking into the mean values obtained from NNE, HNR and SNR results associated with noise ratio, the disease showing the most abnormal characteristics was vocal fold paralysis, followed by cyst and nodule/polyp in order. For NNE, there was statistically significant difference between vocal nodule/polyp, and cyst or paralysis. In other words, it was found that the NNE of vocal nodule/polyp was weaker than that of cyst or paralysis. Similarly, HNR and SNR also showed the same characteristics; there was statistically significant difference between vocal fold paralysis and vocal fold cyst or nodule/polyp, and HNR and SNR values of vocal fold paralysis were lower than those of vocal fold cyst or nodule/polyp. Conclusion: For vocal fold paralysis, the abnormal values of acoustic parameters associated with frequency, amplitude and noise ratio were statistically significantly higher than those of vocal fold cyst and nodule/polyp. This finding suggests that the voices of the patients with vocal fold paralysis are the most severely injured due to less stability of vocal fold movement, asymmetry and incomplete glottic closure. In addition, there was no statistically significant difference in the acoustic parameters of tremor among vocal fold paralysis, vocal fold cyst and vocal nodule/polyp. Further studies need to ascertain reasonable acoustic parameters with various vocal disorders as well as to clarify the correlation between acoustics-based objective tools and subjective evaluations.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.3
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• pp.60-68
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• 2009

This work proposes a 10b 200MS/s 65nm CMOS ADC for high-definition video systems such as HDTV requiring high resolution and fast operating speed simultaneously. The proposed ADC employs a four-step pipeline architecture to minimize power consumption and chip area. The input SHA based on four capacitors reduces the output signal range from $1.4V_{p-p}$ to $1.0V_{p-p}$ considering high input signal levels at a low supply voltage of 1.2V. The proposed three-stage amplifiers in the input SHA and MDAC1 overcome the low output resistance problem as commonly observed in a 65nm CMOS process. The proposed multipath frequency-compensation technique enables the conventional RNMC based three-stage amplifiers to achieve a stable operation at a high sampling rate of 200MS/s. The conventional switched-bias power-reduction technique in the sub-ranging flash ADCs further reduces power consumption while the reference generator integrated on chip with optional off-chip reference voltages allows versatile system a locations. The prototype ADC in a 65nm CMOS technology demonstrates a measured DNL and INL within 0.19LSB and 0.61LSB, respectively. The ADC shows a maximum SNDR of 54.BdB and 52.4dB and a maximum SFDR of 72.9dB and 64.8dB at 150MS/S and 200MS/s, respectively. The proposed ADC occupies an active die area of $0.76mm^2$ and consumes 75.6mW at a 1.2V supply voltage.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.6
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• pp.434-449
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• 2019

In this study, we develop a new cross-shore sediment module which takes the effect of infra-gravity waves of bound mode, and boundary layer streaming on the sediment transport into account besides the well-known asymmetry and under-tow. In doing so, the effect of individual random waves occurring during the unit observation period of 1 hr on sediment transport is also fully taken into account. To demonstrate how the individual random waves would affect the sediment transport, we numerically simulate the non-linear shoaling process of random wavers over the beach of uniform slope. Numerical results show that with the consistent frequency Boussinesq Eq. the application of which is lately extended to surf zone, we could simulate the saw-tooth profile observed without exception over the surf zone, infra-gravity waves of bound mode, and boundary-layer streaming accurately enough. It is also shown that when yearly highest random waves are modeled by the equivalent nonlinear uniform waves, the maximum cross-shore transport rate well exceeds the one where the randomness is fully taken into account as much as three times. Besides, in order to optimize the free parameter K involved in the long-shore sediment module, we carry out the numerical simulation to trace the yearly shoreline change of Mang-Bang beach from 2017.4.26 to 2018.4.20 as well, and proceeds to optimize the K by comparing the traced shoreline change with the measured one. Numerical results show that the optimized K for Mang-Bang beach would be 0.17. With K = 0.17, via yearly grand circulation process comprising severe erosion by consecutively occurring yearly highest waves at the end of October, and gradual recovery over the winter and spring by swell, the advance of shore-line at the northern and southern ends of Mang-Bang beach by 18 m, and the retreat of shore-line by 2.4 m at the middle of Mang-Bang beach can be successfully duplicated in the numerical simulation.

• Tuberculosis and Respiratory Diseases
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• v.41 no.4
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• pp.354-362
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• 1994

Objectives and Methods : The presence of aneuploidy or high proliferative activity in cytologic specimens is considered as complementary for the diagnosis of malignancy. To evaluate the diagnostic usefulness of DNA ploidy and cell cycle analysis in lung cancer, we compared the diagnostic yielding rates of DNA ploidy test by brushing specimens using flow cytometry with bronchoscopic forceps biopsy and brushing cytology. Results : Of the seventy-six cases, 55 cases proved to have malignant diseases(squamous cell cancer: 27, adenocarcinoma: 7, large cell cancer: 1, undifferentiated: 4 and small cell cancer: 16). The incidence of aneuploidy in lung cancer patients was 32.7%(18/55), as opposed to no cases in benign disease. And the proportion of high proliferative activity(S+G2M>22%) in lung cancer patients was 42.9%(15/35), but none in benign diseases. In fifty-six of 75 cases(74.7%), cytology of brushing specimens and DNA analysis(either aneuploidy or high proliferative activity vs. diploidy and low proliferative activity) were in concordance. The sensitivity with only brushing cytology was 41.8%(23/55), but with the addition of DNA analysis, it was increased to 56.4%(31/55), without decreasing the specificity(100%). And there was a case whose clue for malignancy was absent except aneuploidy, and he was confirmed to have squamous cell cancer following open thoracotomy. There were no differences in the frequency of aneuploidy or high proliferative activity between histologic subtypes of bronchogenic malignancy. Conclusions : The diagnostic detection rate of lung cancer was improved with the addition of DNA ploidy and cell cycle analysis, and the presence of aneuploidy or high proliferative activity was a relatively specific indicator of malignant disease. It would be useful to test DNA ploidy and cell cycle analysis with brushing specimen for the diagnosis of bronchogenic malignancy particularly in patients whose biopsy specimen could not be obtainable.