• Title/Summary/Keyword: Regression Curve

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Fibulin-3 as a Diagnostic Biomarker in Patients with Malignant Mesothelioma

  • Kaya, Halide;Demir, Melike;Taylan, Mahsuk;Sezgi, Cengizhan;Tanrikulu, Abdullah Cetin;Yilmaz, Sureyya;Bayram, Mehmet;Kaplan, Ibrahim;Senyigit, Abdurrahman
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.4
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    • pp.1403-1407
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    • 2015
  • Background: New tumour biomarkers are being intensely investigated for malignant mesothelioma (MM). Fibulin-3 is produced in MM but its role remains uncertain. The aim of this study was to evaluate the validity of measuring serum fibulin-3 in the diagnosis and prognosis of MM. Materials and Methods: This prospective study was performed on 43 patients and 40 healthy controls who were admitted to our hospital between January 2012 and January 2014. Data from MM patients, including demographic and clinical features, routine laboratory data, levels of serum fibulin-3, and treatment outcomes were defined as potential prognostic factors. The receiver operating characteristic (ROC) curve for fibulin-3 was used to detect the cut-off value with highest sensitivity and specificity. Univariate survival analysis was performed using the Kaplan-Meier method in patients with MM. Afterwards, the possible factors identified with univariate analyses were entered into the cox regression analysis. Results: Our results revealed that patients with MM had significantly higher serum levels of fibulin-3 than controls. The results showed that the best cut-off point was 36.6 ng/ml with an AUC (area under the curve)=0.976, sensitivity=93.0% and specificity=90.0. In our study, the initial significant poor prognostic factors were advanced stage, high white blood cell count, high platelet count, high C-reactive protein (p<0.05 for each variable). Later, according to multivariate analysis the results showed only advanced stage as significant parameter (p=0.040). Conclusions: We determined that real use for serum fibulin-3 was not for prognosis but for diagnosis in MM. Also advanced stage was associated with poor MM prognosis.

Usefulness of End-tidal Carbon Dioxide as a Predictor of Emergency Intervention in Major Trauma Patients (중증 외상 환자에서의 응급중재술 시행 예측 인자로서의 호기말 이산화탄소 분압의 유용성)

  • Kim, Sung Ho;Kim, Seunghwan;Lee, Jae Gil;Chung, Sung Phil;Kim, Seung Ho
    • Journal of Trauma and Injury
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    • v.27 no.4
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    • pp.133-138
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    • 2014
  • Purpose: If the survival of patients suffering from severe blunt trauma is to be improved, appropriate interventions should be taken immediately. The purpose of this study is to evaluate the clinical utility of end-tidal carbon dioxide ($ETCO_2$) as a surrogate marker for predicting both the need for intervention and the prognosis. Methods: This is a prospective observational study. Nasal cannula was applied to measure $ETCO_2$, and the following parameters, which are known to be related to the prognosis for a patient, were recorded: injury severity score (ISS), revised trauma score (RTS), arterial blood gas (ABG), lactate, and hemoglobin (Hb). To evaluate the outcome, we investigated the details of emergent interventions and expired patients. Results: A total of 93 patients were enrolled in this study. Emergent intervention was significantly associated with systolic blood pressure (sBP, p-value=0.001), $ETCO_2$ (p-value<0.001), serum lactate level (p-value<0.001), pH (p-value< 0.003), $HCO_3$ (p-value=0.004), base excess (p-value<0.002), ISS (p-value<0.001) and RTS (p-value=0.005). In the multivariate logistic regression, only $ETCO_2$ (odds ratio (OR): 0.897, 95% confidence interval (CI): 0.792-0.975, p-value= 0.048) and ISS (OR: 1.132, 95% CI: 1.053-1.233, p-value=0.002) were associated with emergent intervention whereas $ETCO_2$ (p-value=0.973) and ISS (p-value=0.511) were not statistically significant in predicting the survival of patients in the univariate analysis. An optimal ETCO cut-off of 29 mmHg on the ROC curve was determined, with the area under the ROC curve (AUC) being 0.824 (0.732-0.917)]. Conclusion: This study has revealed that $ETCO_2$, which can be rapid and easily measured through a nasal cannula, and the ISS may be prognostic indicators of emergent interventions in Emergency Departments.

Tc-99m-DAPA Pulmonary Clearance in Normals (정상성인에서의 Tc-99m-DTPA 폐제거율)

  • Chung, Soo-Kyo;Yang, Woo-Jin;Sohn, Hyung-Sun;Shinn, Kyung-Sub;Bahk, Yong-Whee
    • The Korean Journal of Nuclear Medicine
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    • v.28 no.3
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    • pp.338-342
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    • 1994
  • Pulmonary clearance of Tc-99m-DTPA(PCD) has been used for the measurement of polmonary epithelial permeability. It has been reported to be increased not only in variety of polmonary diseases including ARDS, interstitial fibrosis, and smokers, but also in normal subjects on positive end expiratory pressure respirator, or after exercise. It was also noted that decrease of pulmonary blood flow due to pulmonary arterial obstruction results in delayed PCD. Normal range of PCD varies with institutes. We prospectively measured PCD in 17 normals (5 males and 12 females) consisted of staffs and trainees in the department of radiology of Kangnam St. Mary's hospital using original Bark Nebulizer (India). Age ranged from 32 to 43 years. 370 MBq of Tc-99m-DTPA was inhaled in supine position and supine posterior images were subsequently obtained with 1 min/frame, $64{\times}64$ matrix and word mode for 30min. Regions of interest were set on each lung, whole lungs, and upper, middle and lower thirds of right lung, respectively. Best fit regression curve was obtained by least square method from initial 7min after peak activity on each curve and time for half clearance of maximum activity (t1/2) was calculated. Mean t1/2 was $51{\pm}11.2min$ for whole lung. There was no significant difference between t1/ 2 of right and left lungs. Initial uptake was higher in the lower third and t1/2 was shorter in the lower third than in the upper third(P<0.05). We reviewed several reports on PCD and compared our data with the others. In this study, faster clearance in the lower third may be due to the position imaged with or the environment the subjects belong to, and further investigation is under way.

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Comparison of Landslide Susceptibility Analysis Considering the Characteristics of Landslide Trigger Points (산사태 발생지점의 특성을 고려한 취약성 분석 비교)

  • Shin, Hyun Woo;Lee, Su Gon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.36 no.2
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    • pp.59-66
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    • 2018
  • This study examined the correlation among topography, forest type, soil and geology in Inje area where landslides occurred during heavy rainfall from July 11 to July 18, 2006 to assess the landslide susceptibility. In order to assess the susceptibility of future landslides, landslides occurred in Inje area were classified into slide type and flow type, and slope angle, aspect, curvature, ridge and valley were extracted from the area. The landslide susceptibility was assessed by applying diameter class, age class, density, and forest type to Bayesianbased LR (Logistic Regression) model and WOE (Weight of Evidence) model, and the fitness of modeling was verified by predict rate curve. As the results of susceptibility assessment, using all landslides without no distintion, it was found that 75% of the LR model and 73% of the WOE model were fit in terms of the top 20% of the landslides. According to slide type and flow type in the top 20% of the landslides, it was found that 71% of the LR model and 69% of the WOE model were fit in terms of the slide type. Whereas, it was found that 86% of the LR model and 82% of the WOE model were fit in terms of the flow type. That is, the results of the LR model showed higher fitness than the results of the WOE model, and the fitness of the flow type was higher than that of the slide type. Consequently, it suggests that it is reasonable to assess and verify the landslide susceptibility according to the types of landslides.

Determination of Hot Air Drying Characteristics of Squash (Cucurbita spp.) Slices

  • Hong, Soon-jung;Lee, Dong Young;Park, Jeong Gil;Mo, Changyeun;Lee, Seung Hyun
    • Journal of Biosystems Engineering
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    • v.42 no.4
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    • pp.314-322
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    • 2017
  • Purpose: This study was conducted to investigate the hot air drying characteristics of squash slices depending on the drying conditions (input air velocity, input air temperature, and sample thickness). Methods: The developed drying system was equipped with a controllable air blower and electric finned heater, drying chamber, and ventilation fan. Squash (summer squash called Korean zucchini) samples were cut into slices of two different thicknesses (5 and 10 mm). These were then dried at two different input air temperatures (60 and $70^{\circ}C$) and air velocities (5 and 7 m/s). Six well-known drying models were tested to describe the experimental drying data. A non-linear regression analysis was applied to determine model constants and statistical indices such as the coefficient of determination ($R^2$), reduced chi-square (${\chi}^2$), and root mean square error (RMSE). In addition, the effective moisture diffusivity ($D_{eff}$) was estimated based on the curve of ln(MR) versus drying time. Results: The results clearly showed that drying time decreased with an increase in input air temperature. Slice thickness also affected the drying time. Air velocity had a greater influence on drying time at $70^{\circ}C$ than at $60^{\circ}C$ for both thicknesses. All drying models accurately described the drying curve of squash slices regardless of slice thickness and drying conditions; the Modified Henderson and Pabis model had the best performance with the highest R2 and the lowest RMSE values. The effective moisture diffusivity ($D_{eff}$) changes, obtained from Fick's diffusion method, were between $1.67{\times}10^{-10}$ and $7.01{\times}10^{-10}m^2/s$. The moisture diffusivity was increased with an increase in input air temperature, velocity, and thickness. Conclusions: The drying time of squash slices varied depending on input temperature, velocity, and thickness of slices. The further study is necessary to figure out optimal drying condition for squash slices with retaining its original quality.

Age and Growth of the Asian Clam Potamocorbula ustulata ustulata (Reeve, 1844) on the West Coast of Korea (한국 서해산 쇄방사늑조개, Potamocorbula ustulata ustulata (Reeve, 1844) 의 연령과 성장)

  • Ryu, Dong-Ki;Kim, Yeong-Hye
    • The Korean Journal of Malacology
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    • v.23 no.1
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    • pp.17-23
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    • 2007
  • Samples of Potamocorbula ustulata ustulata were collected monthly from October 2004 to November 2005 in the Jujin estuary of Gochang, Chollabuk-do, west coast of Korean peninsula. Age of P. ustulata ustulata was determined by the rings on the shell. The relationship between the shell length and the ring diameter in each ring group was expressed as a regression line. Therefore, there is a correspondence in each ring formation. Based on the monthly variation of the marginal index (MI') of the shell, it is assumed that the ring of this species was formed once a year during October to December. The relationship between the shell length (SL) and the shell height (SH; mm) was highly correlated with shell height as the following equation: SH = 0.6438 SL + 0.5642 ($r^2\;=\;0.978$). The shell length (SL) - shell width (SW) relation was also expressed by the following equation: SW = 0.4352 SL - 0.5675 ($r^2\;=\;0.957$). Shell length (SL; mm) and the total weight (TW; g) followed: $TW\;=\;6.999\;{\times}\;10^{-5}\;SL^{3.2542}(r^2\;=\;0.975)$. Growth curves for the shell length and the total weight fitted to the von Bertalanffy's growth curve were expressed respectively as: $$SL_t=30.77[1-e^{-0.4572(t+0.7371)}],\;TW_t=4.87[1-e^{-0.4572(t+0.7371)}]^{3.2542}.$$

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Seismic structural demands and inelastic deformation ratios: Sensitivity analysis and simplified models

  • Chikh, Benazouz;Laouami, Nacer;Mebarki, Ahmed;Leblouba, Moussa;Mehani, Youcef;Kibboua, Abderrahmane;Hadid, Mohamed;Benouar, Djillali
    • Earthquakes and Structures
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    • v.13 no.1
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    • pp.59-66
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    • 2017
  • Modern seismic codes rely on performance-based seismic design methodology which requires that the structures withstand inelastic deformation. Many studies have focused on the inelastic deformation ratio evaluation (ratio between the inelastic and elastic maximum lateral displacement demands) for various inelastic spectra. This paper investigates the inelastic response spectra through the ductility demand ${\mu}$, the yield strength reduction factor $R_y$, and the inelastic deformation ratio. They depend on the vibration period T, the post-to-preyield stiffness ratio ${\alpha}$, the peak ground acceleration (PGA), and the normalized yield strength coefficient ${\eta}$ (ratio of yield strength coefficient divided by the PGA). A new inelastic deformation ratio $C_{\eta}$ is defined; it is related to the capacity curve (pushover curve) through the coefficient (${\eta}$) and the ratio (${\alpha}$) that are used as control parameters. A set of 140 real ground motions is selected. The structures are bilinear inelastic single degree of freedom systems (SDOF). The sensitivity of the resulting inelastic deformation ratio mean values is discussed for different levels of normalized yield strength coefficient. The influence of vibration period T, post-to-preyield stiffness ratio ${\alpha}$, normalized yield strength coefficient ${\eta}$, earthquake magnitude, ruptures distance (i.e., to fault rupture) and site conditions is also investigated. A regression analysis leads to simplified expressions of this inelastic deformation ratio. These simplified equations estimate the inelastic deformation ratio for structures, which is a key parameter for design or evaluation. The results show that, for a given level of normalized yield strength coefficient, these inelastic displacement ratios become non sensitive to none of the rupture distance, the earthquake magnitude or the site class. Furthermore, they show that the post-to-preyield stiffness has a negligible effect on the inelastic deformation ratio if the normalized yield strength coefficient is greater than unity.

Fatigue Analysis based on Kriging for Flaperon Joint of Tilt Rotor Type Aircraft (틸트 로터형 항공기의 플랩퍼론 연결부에 대한 크리깅 기반 피로해석)

  • Park, Young-Chul;Jang, Byoung-Uk;Im, Jong-Bin;Lee, Jung-Jin;Lee, Soo-Yong;Park, Jung-Sun
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.6
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    • pp.541-549
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    • 2008
  • The fatigue analysis is performed to avoid structural failure in aerospace structures under repeated loads. In this paper, the fatigue life is estimated for the design of tilt rotor UAV. First of all, the fatigue load spectrum for tilt rotor UAV is generated. Fatigue analysis is done for the flaperon joint which may have FCL(fracture critical location). Tilt rotor UAV operates at two modes: helicopter mode such as taking off and landing; fixed wing mode like cruising. To make overall fatigue load spectrum, FELIX is used for helicopter mode and TWIST is used for fixed wing mode. The other hand, the Kriging meta model is used to get S-N regression curve for whole range of material life when S-N test data are analyzed. And then, the second order of S-N curve is accomplished by the least square method. In addition, the coefficient of determination method is used to ensure how accuracy it has. Finally, the fatigue life of flaperon joint is compared with that obtained by MSC. Fatigue.

Development of Predicting Models of the Operating Speed Considering on Traffic Operation Characteristics and Road Alignment Factors In Express Highways (고속도로 교통운영 특성 및 도로선형요소를 반영한 주행속도 예측모형 개발)

  • Lee, Jeom-Ho;Hong, Da-Hui;Lee, Su-Beom
    • Journal of Korean Society of Transportation
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    • v.24 no.5 s.91
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    • pp.109-121
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    • 2006
  • The road should be designed in the consistent alignment which the driver can drive safely. Also, proper highway environments in order to maintain optimal operational speeds on highway sections should be provided In design stage, for highway environments, it is essential for an operational speed estimation model to different highway environments. If a method which could evaluate the status of the road safety is developed through this operational speed estimation model, it is possible to provide safe and more comfortable highways to road users. In the study factors to effect on operational speeds are classified into three groups horizontal & vertical alignments and traffic operation characteristic factors. Factors are chosen to effect on operational speeds by using collation analysis as classifications of tangent sections, horizontal curve sections and vertical curve sections. In order to develop operational speed estimation models in express highways, multi-regression analysis has been used in this study using the selected factors. This study has meaning that the developed estimation models for operational speeds and evaluation of degree of safety to horizontal and vortical alignments simultaneous. In order to represent whole area of the country with the developed models, the models should be re-analyzed with vast data related with road alignment factors in the near future.

Dose- Response Curves of Mouse Jejunal Crypt Cells by Multifractionated Irradiation (다분할조사에 의한 마우스공장소낭선 세포의 선량반응곡선)

  • Hong, Seong-Eon;Ahn, Chi-Yul
    • Radiation Oncology Journal
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    • v.4 no.2
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    • pp.89-97
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    • 1986
  • Using as assay for jejunal crypt stem cell survival, dose-response curves for the reproductive capacity of crypt stem cells of mouse jejunum exposed to multifractionated gamma-ray irradiation (single, 2, 3, 4, 5, 8, 10, 12, and 16 fractions) were analyzed and single-dose survival curve of these cells was constructed. The following conclusion were drawn: 1) Survival curves for higher numbers of dose fractions were displaced to higher dose, and characterized by increasingly shallower slopes. 2) The single-dose survival curve had broad shoulder, Dq=460 cGy, remaining near-exponential over initial dose range 0 to 300 cGy, with initial slope 1Do=474 cGy. 3) At fractionated dose En the range of 180 to 450 cGy, the average recovered dose per fraction interval was approximately $50\%$ of the dose per fraction. 4) The value of $\alpha/\beta$ ratio by using of linear regression analysis for the reciprocal dose plots was 8.3 Gy which lied in the range of 6-14 Gy for early-reacting tissues. 5) The linear-quadratic model for dose-response formula offers valid approximations for at 1 doses to be used in radiotherapy, only two parameters to be determined, and considerable convenience in practical applications.

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