• Journal of the Korean GEO-environmental Society
• /
• v.15 no.11
• /
• pp.43-51
• /
• 2014

In this study, a series of pullout experiments were conducted on geogrid with attached passive reinforcement with respect to silt containments. Experiments were performed on man-made sand ground containing different silt of 0 %, 17 %, 35 % under various normal stresses 30 kPa, 60 kPa, 120 kPa respectively. The pullout test results showed that passive reinforcement increased the pullout strength over all silt contained condition and showed up to 20 % increases for same soil condition. The test results converted to the coefficient of interaction of pullout test to investigate the effect of reinforcement and the case of passive reinforcement showed 0.7~1.6 distribution depend on a silt contents. Therefore it is concluded that the overall length of geogrid can be reduced under the low vertical stress conditions.

• Neonatal Medicine
• /
• v.17 no.1
• /
• pp.34-43
• /
• 2010

Purpose : The aim of this study was to examine whether hypercapnia during the first seven days of life was associated with severe intraventricular hemorrhage (IVH) in preterm infants requiring mechanical ventilation. Methods : A matched pair analysis was performed for 19 preterm infants with severe IVH(grade$\geq$3) and 38 infants with no severe IVH (normal or grade 1), who required mechanical ventilation for more than seven days. The univariate and multivariate analysis of severe IVH with maximal and minimal $PaCO_2$, averag $PaCO_2$, SD of $PaCO_2$, and difference in the $PaCO_2$ were assessed. The major perinatal factors and maximal ventilator index (VI) were also compared. Results : Infants with severe IVH had a higher maximal $PaCO_2$ (86.1$\pm$18.4 mmHg vs. 60.1$\pm$ 11.6 mmHg, P <0.001) and mean $PaCO_2$ (47.5$\pm$5.6 mmHg vs. 41.2$\pm$6.3 mmHg, P=0.004) and a larger SD or difference in $PaCO_2$ (14.0$\pm$4.4 mmHg vs. 9.0$\pm$2.4 mmHg; 60.3$\pm$20.9 mmHg vs. 35.5$\pm$11.8 mmHg, P <0.001). However the minimal $PaCO_2$ values did not differ between the groups. Disseminated intravascular coagulation, pulmonary hemorrhage, and the air leak syndrome were more frequent in the IVH group than in the controls. The maximal VI on each day was higher in the IVH group. The multivariate logistic regression analysis after controlling for bleeding tendency showed that the air leak syndrome, maximal VI, and maximal $PaCO_2$ were independently associated with severe IVH [OR, 1.324 (95% CI, 1.011-1.733; P=0.041)]. Conclusion : Extreme hypercapnia was significantly associated with severe IVH in preterm infants, after adjustment for major perinatal risk factors. Frequent monitoring of the $PaCO_2$ may be important for early detection of inadvertent hypercapnia and prompt correction of high PaCOS levels.

• Journal of Preventive Medicine and Public Health
• /
• v.42 no.1
• /
• pp.12-20
• /
• 2009

Objectives : The purpose of this study was to analyze the association between the pattern of prophylactic antibiotic use(PAU) and the surgical site infection(SSI) rate for major surgeries in Korea. Methods : We retrospectively reviewed the medical records of patients who underwent cardiac, colon and gastric surgery, hysterectomies and hip/knee replacements at 20 hospitals, and inclusive of over 500 beds. We randomly sampled 60 cases per surgery type for patients discharged between September and November, 2006. A total fo 2,924 cases were included in our analysis. Cox's proportional hazard analysis was conducted to evaluate the association between the pattern of PAU and SSI rate. Results : The proportion of patients who received their first prophylactic antibiotics(PA) 1 hour before incision was 65.5%, who received inappropriate PAs was 80.8%, and the proportion of patients whose PA was discontinued within 24 hours of surgery was 0.5%. The average duration of PAU after surgery was 9 days. The relative risk(RR) of SSI in patients who received their first PA more than 1 hour before incision was significantly higher than for those who received it within 1 hour prior to incision(RR=8.20, 95% CI=4.81-13.99). Inappropriate PA selection increased SSI rate, albeit with marginal significance(RR=1.97, 95% CI=0.96-4.03). Also, prolonged PAU following surgery had no effect on SSI rate. Conclusions : These results suggest that the pattern of PAU in the surgeries examined was not appropriate. Errors in the timing of PAU and of PA selection increase SSI rate. SSI rate remained unaltered following prolonged PAU after surgery.

• Journal of the korean Society of Automotive Engineers
• /
• v.14 no.6
• /
• pp.60-66
• /
• 1992

This study describes a theoretical analysis for the wall temperature of ceramic filter trap and pressures of inlet and outlet channel in the filter trap. In this study, the maximum wall temperature through filter trap length with time during the regeneration period showed a tendency moving from forward to backward. The pressure change of filter trap increased at the initial combustion but decreased with the combustion to be activated. So the pressure difference between initial and end regeneration at the inlet channel showed about 2kPa. The thermal regeneration period of this filter trap in the theoretical analysis showed about 200seconds in which the wall temperature was similar to the case of initial condition and the pressure showed about 1 kPa.

• Journal of Chest Surgery
• /
• v.21 no.5
• /
• pp.816-827
• /
• 1988

Since 1978, We have experienced 87 cases of Fontan operations and the candidates of that increased in numbers recently with the improvement of the diagnostic and operative technique. We studied the prerequisite factors and hemodynamics of 22 cases of Fontan operations, done during the last one year period, which were 3 tricuspid atresia, 16 functional single ventricle and 3 anatomic single ventricle. The mean age was 68 months and the mortality rate 24%, and 9 patients of under 4 years of age were operated with 22.2% mortality rate, but the youngest, 16 months of age, patient survived well without problems. The preoperative pulmonary artery pressure[PAP], pulmonary vascular resistance[PVR] and postoperative right atrial pressure[RAP], left atrial pressure[LAP] value influenced the mortality, but age, preoperative Hb, preoperative PaO2 and pulmonary artery index[PAI] did not. There were favorable survival tendency in under 15mmHg of preop. PAP, 2a of preop. PVR and under 25cmHyO of postop. RAP, under 15cmHyO of postop LAP. The younger, the more pleural effusion and the longer postoperative admission days. The higher preop. Hb related to the higher postop. transpulmonary pressure gradient and the lower preop. PaO2 and PAI. The higher preop. PaO2, the less pleural effusion and postop. admission days. Preop. PAP closely related to preop. PVR and postop. LAP and high PVR increased the pleural effusion and postop. admission days. The larger PAI, the larger CI. We concluded that there were so many factors influencing the postoperative condition, but preop. PAP, PVR, Hb, postop. RAP and LAP were the most ones.

• Journal of Korean Critical Care Nursing
• /
• v.15 no.3
• /
• pp.88-100
• /
• 2022

Purpose : This study aimed to identify risk factors for unplanned reintubation after planned extubation and to analyze the clinical outcomes in patients admitted to the intensive care unit after cardiac surgery. Methods : The study examined patients who underwent intubation and planned extubation admitted to the intensive care unit after cardiac surgery between January 1, 2017, and December 31, 2021. The reintubation group comprised 58 patients underwent unplanned reintubation within 7 days of planned extubation. The maintenance group comprised 116 patients who did not undergo reintubation and were matched with the reintubation group using the rational for matching criteria. Data were collected retrospectively from electronic medical records. We used the independent t-test, Mann-Whitney U test, 𝑥²-test, Fisher's exact test, and logistic regression analysis with SPSS/WIN 27.0. Results : The multivariate logistic regression analysis demonstrated that albumin (odds ratio [OR]=0.38, 95% confidence interval [CI]=0.20-0.72), surgery time (OR=1.54, 95% CI=1.20-1.97), PaO₂ before extubation (OR=0.85 per 10 mmHg, 95% CI=0.75-0.97), postoperative arrhythmia (OR=2.82, 95% CI=1.22-6.51), reoperation due to bleeding (OR=4.65, 95% CI=1.27-17.07), and postoperative acute renal failure (OR=2.97, 95% CI=1.09-8.04) were risk factors for unplanned reintubation. The reintubation group had a higher in-hospital mortality rate (𝑥²=33.74, p<.001), longer intensive care unit stay (Z=-7.81, p<.001), and longer hospital stay than the maintenance group (Z=-8.29, p<.001). Conclusion : These results identified risk factors and clinical outcomes of unplanned reintubation after planned extubation after cardiac surgery. These findings should be considered when developing and managing an intervention program to prevent and reduce the incidence of unplanned reintubation.

• Journal of The Korean Society of Clinical Toxicology
• /
• v.18 no.1
• /
• pp.18-25
• /
• 2020

Purpose: We studied the impact of arterial oxygen tension (PaO₂) on the long term neurologic outcome in patients with acute carbon monoxide poisoning. Methods: The study population included 311 patients who presented to emergency department with acute CO poisoning from January 2015 to January 2018. These patients underwent arterial blood gas testing at the time of presentation. The baseline demographic, clinical, laboratory, and clinical outcome data were recorded. The primary outcome of interest was the long term neurologic status. Results: The normoxia group was significantly older and it had a higher incidence of diffusion weighted MRI abnormality, and this group needed multiple HBO sessions compared to the group with moderate or severe hyperoxia. Also, the incidence of altered mentality at discharge was higher in the normoxia group than that of the moderate hyperoxia group. The incidence of a poor long term neurologic outcome was 11.3%. The incidence of a poor long term neurologic outcome decreased as the PaO₂ increased. The PaO₂ was significantly lower in patients with a poor long term neurologic outcome than that of the patients with a good outcome 198 (165.2 to 231.1) mmHg in the good outcome group vs. 154 (119-162) mmHg in poor outcome, p<0.001). In multivariate logistic regression analysis, PaO₂ was selected as an independent factor of the poor long-term neurologic outcome (OR 0.981 (95% CI: 0.968 to 0.995)) Conclusion: Higher PaO₂ was independently associated with a lower incidence of a poor long-term neurologic outcome.

• Journal of Biomedical Engineering Research
• /
• v.43 no.1
• /
• pp.19-26
• /
• 2022

The Comprehensive in vitro Proarrhythmic Assay(CiPA) project was launched for solving the hERG assay problem of being classified as high-risk groups even though they are low-risk drugs due to their high sensitivity. CiPA presented a protocol to predict drug toxicity using physiological data calculated based on the in-silico model. in this study, features calculated through the in-silico model are analyzed for correlation of changing action potential in the near future, and features are verified through predictive performance according to drug datasets. Using the O'Hara Rudy model modified by Dutta et al., Pearson correlation analysis was performed between 13 features(dVm/dtmax, APpeak, APresting, APD90, APD50, APDtri, Ca_peak, Ca_resting, CaD90, CaD50, CaDtri, qNet, qInward) calculated at 100 pacing, and between dVm/d_{tmax_repol} calculated at 1,000 pacing, and linear regression analysis was performed on each of the 12 training drugs, 16 verification drugs, and 28 drugs. Indicators showing high coefficient of determination(R²) in the training drug dataset were qNet 0.93, AP resting 0.83, APDtri 0.78, Ca resting 0.76, dVm/dt_max 0.63, and APD90 0.61. The indicators showing high determinants in the validated drug dataset were APDtri 0.94, APD90 0.92, APD50 0.85, CaD50 0.84, qNet 0.76, and CaD90 0.64. Indicators with high coefficients of determination for all 28 drugs are qNet 0.78, APD90 0.74, and qInward 0.59. The indicators vary in predictive performance depending on the drug dataset, and qNet showed the same high performance of 0.7 or more on the training drug dataset, the verified drug dataset, and the entire drug dataset.

• Tuberculosis and Respiratory Diseases
• /
• v.77 no.6
• /
• pp.243-250
• /
• 2014

Background: Information regarding prognostic value of growth differentiation factor 15 (GDF-15) and heart-type fatty acid-binding protein (H-FABP) in patients with chronic obstructive pulmonary disease (COPD) exacerbation is limited. The aim of this study was to investigate whether serum levels of GDF-15 and H-FABP predict an adverse outcome for COPD exacerbation. Methods: Clinical variables, including serum GDF-15 and H-FABP levels were compared in prospectively enrolled patients with COPD exacerbation that did or did not experience an adverse outcome. An adverse outcome included 30-day mortality and need for endotracheal intubation or inotropic support. Results: Ninety-seven patients were included and allocated into an adverse outcome (n=10) or a control (n=87) group. Frequencies of mental change and $PaCO_2$>37 mm Hg were significantly higher in the adverse outcome group (mental change: 30% vs. 6%, p=0.034 and $PaCO_2$>37 mm Hg: 80% vs. 22%, p<0.001, respectively). Serum GDF-15 elevation (>1,600 pg/mL) was more common in the adverse outcome group (80% vs. 43%, p=0.041). However, serum H-FABP level and frequency of serum H-FABP elevation (>755 pg/mL) did not differ between the two groups. Multivariate analysis showed that an elevated serum GDF-15 and $PaCO_2$>37 mm Hg were significant predictors of an adverse outcome (odds ratio [OR], 25.8; 95% confidence interval [CI], 2.7-243.8; p=0.005 and OR, 11.8; 95% CI, 1.2-115.3; p=0.034, respectively). Conclusion: Elevated serum GDF-15 level and $PaCO_2$>37 mm Hg were found to predict an adverse outcome independently in patients with COPD exacerbation, suggesting the possibility that serum GDF-15 could be used as a prognostic biomarker of COPD exacerbation.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.2
• /
• pp.781-784
• /
• 2013

Aim: The purpose of this study was to determine whether susceptibility to oral tongue squamous cell carcinoma (OSCC) is related to polymorphisms in the u-PA gene. Methods: We examined the rs2227564 C/T and rs2227562 G/A single nucleotide polymorphisms (SNPs) in 196 OSCC patients and 201 age- and gender-matched controls via direct sequencing and PCR-RFLP methods. Results: Significant differences were found in allelic and genotypic distributions of the rs2227564 and rs2227562 loci when comparing cases and controls. In addition, logistic analyses indicated that the rs2227564 C/T genotype was related to a 1.52-fold increased risk of developing OSCC (adjusted OR=1.521, 95%CI: 1.144~2.022, P=0.004). Linkage disequilibrium analysis was conducted and no association between the two loci was found (D'=0.031, $r^2$=0.000). Conclusions: Our findings provide evidence that the rs2227564 C/T SNP in the u-PA gene is associated with the development of OSCC.