• Asian Pacific Journal of Cancer Prevention
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• 제15권4호
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• pp.1655-1658
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• 2014

Objective: To find a more appropriate alternative to D-dimer cutoff value for the diagnosis of deep vein thrombosis (DVT) in cancer patients. Methods: A total of 711 cancer patients with symptoms suspicious of DVT were included in the study. D-dimer levels were assessed using ELISA. All patients were subjected to imaging procedures. Results: Among 711 patients with cancer, 466 (65.5%) were females and 245 (34.5%) were males, with an average age of $57.3{\pm}13.23$ years. The mean age in the DVT group was significantly higher than in the non-DVT group (P<0.05). The D-dimer levels of the DVT group were significantly higher than those of the non-DVT group (P<0.05). The incidence rate of DVT varied significantly according to cancer type (P<0.05). Increasing age and lung cancer were significantly correlated with D-dimer levels (P<0.05), and a one-year increase in age was associated with a 14.28 ng/ml increase in the D-dimer value. The optimal cutoff point for D-dimer was found to be 981 ng/ml, with a sensitivity of 86.4%, specificity of 79.4%, and accuracy of 82.6%. If the D-dimer cutoff point was set to 981ng/ml, the specificity would increase from 61.8% to 85.5% without loss of sensitivity in patients aged 40 years or younger. In patients aged more than 40 years, the new cutoff almost doubled the specificity with slightly reduced sensitivity. Conclusion: In cancer patients, a new cutoff value of 981 ng/ml effectively improved the exclusion of DVT, especially for patients aged more than 40 years.

• 대한의생명과학회지
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• 제23권2호
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• pp.118-127
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• 2017

Elevated serum uric acid and resting heart rate are risk factors and predictors of metabolic syndrome. However, few studies have examined the optimal cutoff value for serum uric acid and resting heart rate to predict metabolic syndrome in Korean adults. Subjects for this study were 22,302 adults (average age 45 years old), who underwent health screening examination from January 2010 to December 2012 at the Health Promotion Center of one hospital in Gyeonggi-do for general health check-up. The uric acid and resting heart rate cutoff values were calculated by ROC analysis for metabolic syndrome. Elevated serum uric acid and resting heart rate were associated with an increased prevalence of metabolic syndrome in Korean adults. The optimal cutoff value for uric acid level to predict metabolic syndrome in adults was 4.95 mg/dL (male 6.35, female 4.55) and optimal cutoff value for resting heart rate to predict metabolic syndrome was 68 beats per minute (male 66, female 68). However, serum uric acid and resting heart rate were found to have limitations for the diagnosis of metabolic syndrome.

• 한국콘텐츠학회논문지
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• 제12권10호
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• pp.385-394
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• 2012

본 연구의 목적은 생애전환기 건강진단 골밀도 검사시 측정도구(DEXA, QUS, RA)에 따른 진단범위의 유효성을 평가하는 것이다. DEXA를 이용한 골밀도 검사 결과 T-score -2.5를 기준으로 할 때 QUS의 cutoff 값은 -1.733이며, 이때 민감도는 70.4%, 특이도는 59.5%이었고 T-score -3.0을 기준으로 할 때 cutoff 값은 -2.323으로 이때 민감도는 70.4%, 특이도는 56.8%이었다. DEXA를 이용한 골밀도 검사 결과 T-score -2.5를 기준으로 할 때 RA의 cutoff 값은 -1.675이며, 이때 민감도는 70.0%, 특이도는 63.7%이었고 T-score -3.0을 기준으로 할 때 cutoff 값은 -2.325로 이때 민감도는 70.0%, 특이도는 42.9%로 QUS와 RA의 측정도구 간에 큰 차이를 보이지 않았다. 골밀도 측정도구의 상관관계와 재현성에 대한 평가에서는 일부 차이를 제외하고는 측정도구 간 및 측정도구의 반복 측정값 간에 유의한 차이를 보이지 않았다. ROC 분석에서 측정도구별 평균골밀도 측정결과는 DEXA를 기준으로 할 때 RA와 QUS는 모두 유효한 것으로 판단된다. 다만, 생애전환기 골다공증 진단에 보다 정확한 결과를 얻기 위해서는 성별이나 연령층, 다양한 측정부위별 정량화된 결과를 진단기준의 보정지표로 고려하는 것이 필요하다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권5호
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• pp.1949-1953
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• 2014

Background: CA125 and HE4 are used in calculating Risk of Malignancy Algorithm (ROMA); and Risk of Malignancy Index (RMI). However, studies showed that normal levels of CA125, and HE4 differ among ethnicities such as between Asians and Caucasians, thus affecting the accuracy of the RMI score and ROMA in predicting ovarian malignancy. This study aimed to determine whether new or modified cutoff values for Ca125, HE4, the RMI score, and ROMA resulted in a better prediction of malignancy compared with the previous or standard ones. Materials and Methods: Serum level of CA125 and HE4 from 128 patients with diagnosis of ovarian tumor that had been collected before surgery at Cipto Mangunkusumo General Hospital (CMH) in Jakarta from November 2010 until May 2011 were reviewed and analysed. The standard cutoff values of these biomarkers, RMI, and ROMA were modified by using logistic regression model. The modified cutoff values were compared to the standard cutoff values in terms of sensitivity, specificity, and accuracy. Results: The modified cutoff value of CA125, HE4, RMI score and ROMA were 165.2 U/mL, 103.4 pM, 368.7, 28/54. The sensitivity and specificity of the modified cutoff values CA125, HE 4, RMI score and ROMA in differentiating benign from malignant and borderline were 67% and 75,4%; 73.1% and 85.2%; 73.1% and 80.3%; and 77.6% and 86.9%. While the sensitivity and specificity of the standard cutoff value of CA125; HE4; RMI score; and ROMA were 91% and 24.6%; 83.6% and 65%; 80.6% and 65.6%; and 91.0% and 42.6%. The accuracy of modified cutoff values compared with standard cutoff values were: 71.2% vs 59.3%, 78.9% vs 75% vs, 76.5% vs 73.4%, and 82% vs 67.9%. Conclusions: The new or modified cutoff values of Ca125, HE4, RMI score and ROMA resulted in higher accuracy compared to the previous or standard ones, at the cost of reduced sensitivity.

• Clinical and Experimental Reproductive Medicine
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• 제23권3호
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• pp.283-292
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• 1996

Objective: To determine the cutoff value of clomiphene citrate challenge test(CCCT) that can predict the normal and abnormal(diminished) ovarian response group and to assess the usefulness of CCCT as a predictor of ovarian reserve. Materials and Methods: From March 1994 to Februry 1996, CCCT was performed to 129 infertile patients and among them, 20 patients whose basal FSH on the third day of menstrual cycle was more than 20 mIU/ml were excluded. At the same time, the same CCCT was performed to the fifteen healthy volunteers with proven fertility to determine the cutoff value of CCCT. Results; 1) A FSH value higher than 23.4 mIU/ml, measured on the 10th day of menstrual cycle, was defined as a abnormal ovarian response. The cutoff value of 23.4 mIU/ml is more than 2 standard deviations(SD) above the mean value of 15 healthy women after CCCT. 2) The abnormal CCCT group, the subpopulation with a FSH value of 23.4 mIU/ml or more, was 7.3%(8/109) and their mean age was higher than the normal CCCT group($36.5{\pm}4.5$ vs. $32.9{\pm}4.8$, P = 0.059). And the percentage of the patients older than 35 years of the abnormal CCCT group was significantly higher than that of the normal CCCT group(62.5% vs. 38.6%, p <0.05). 3) There was no correlation between the hormone values of the third day and the 10th day of menstrual cycle before and after CCCT except between FSH of the third day and the 10th day. Conclusion: The CCCT is a good method to predict the individual ovarian response to COH for ART, especially in the patients who has no other abnormal findings that predict poor prognosis. And it is neccessary to determine the cutoff value of CCCT by the large numbers of randomized study, and combining the previously proven prognostic factors, it can be applicated in many individual centers for evaluate the ovarian response before ART program.

• 한국산학기술학회논문지
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• 제17권2호
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• pp.246-251
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• 2016

도로조명 중 누출광을 고려하지 않은 보안등이 아직도 많이 사용되어 주거지 침입광이 발생되고 있다. 이러한 도로조명의 침입광 저감을 위해 차광판이 설치되고 있지만, 효과가 미미하거나 미적 요소 및 안전성에 문제가 있다. 본 연구에서는 침입광 효율적인 저감을 위해 차광판 구조별 저감 특성을 연구하였으며, 그 방법으로 조명시뮬레이션 프로그램인 Relux 활용하였다. 또한 시뮬레이션의 값의 정확성을 알기 위해 실제 측정값과 검증하였다. 그 결과 (상)도색 글로브를 제외한 모든 차광판에서 후사광 저감 효과가 뛰어났으며, 도장형 차광판의 경우 전사광도 줄어들어 글레어 저감도 효율 적인 것으로 확인되었다. (상)도색 글로브는 위쪽으로 가는 빛을 아래로 반사시켜 후사광 전사광 모두 증가하였지만, 스카이 글로우(Sky glow) 저감에 효율적인 차광판으로 확인되었다. 시뮬레이션 값과 실측값은 90 %의 일치률을 보였다.

• Environmental Analysis Health and Toxicology
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• 제23권2호
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• pp.67-77
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• 2008

It has been observed that the linear relationship between the logarithm of bioconcentration factor (log BCF) of highly hydrophobic chemicals and their log $K_{ow}$ breaks when log $K_{ow}$ becomes greater than 6.0. Consequently, super hydrophobic chemicals were not thought to cause baseline toxicity as a single compound. Researchers often call this phenomenon as "hydrophobicity cutoff" meaning that bioconcentration or corresponding baseline toxicity has a certain cutoff at high log $K_{ow}$ value of hydrophobic organic pollutants. The underlying assumption is that the increased molecular size with increasing hydrophobicity prohibits highly hydrophobic compounds from crossing biological membranes. However, there are debates among scientists about mechanisms and at which log $K_{ow}$ this phenomenon occurs. This paper reviews three hypotheses to explain observed "cutoff": steric effects, kinetic or physiological limitations, and chemical activity cutoff. Although the critical molecular size that makes biological membranes not permeable to hydrophobic organic chemicals is uncertain, size effects in combination with kinetic limitation would explain observed non-linearity between log BCF and log $K_{ow}$. Chemical activity of hydrophobic chemicals generally decreases with increasing melting point at their aqueous solubility. Thus, there may be a chemical activity cutoff of baseline toxicity if there is a critical chemical activity over which baseline effects can be observed.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.234-234
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• 2011

Electron-neutral collision frequency is one of the important parameters in the plasma physics and in industrial plasma engineering. We can understand the momentum, energy, and charge transport properties of the plasma using electron-neutral collision frequency.[1] The wave-cutoff method is a diagnostic method for the electron density measurement, but the cutoff peak value depends on gas pressure. The wave-cutoff signal becomes unclear as increasing gas pressure. The reason of pressure dependence is that the electron-neutral collision disturbs electron motion so that microwave can propagate through plasma at plasma frequency.[2] Using the pressure dependence of wave-cutoff method we can find the electron-neutral collision frequency. At first we tried to confirm this method using well known gas such as Ar. The cutoff signal decrease as increasing gas pressure (the simulation result). The wave-cutoff signal is unclear at a gas pressure of 500 mTorr. (electron density $1.0{\times}10^{10}/cm^3$, electron temperature 1.7 eV, electron -neutral collision frequency~1 GHz). In this condition, the electron-neutral collision frequency is closed to the wave-cutoff frequency.

• 한국멀티미디어학회논문지
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• 제12권1호
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• pp.107-121
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• 2009

대기전력(Standby power) 소모가 발생하는 첫 번째 요인은 전원에서 IC로 들어오면서 거쳐야하는 기동전압 때문이며 나머지 하나는 IC가 동작할 때의 전류 때문이다. 본 논문에서는 대기전력 상태와 차단 시점의 패턴분석을 통해서 자동 On/Off할 수 있도록 하는 간단한 모듈장치 구성과 알고리즘 적용에 목적을 두었다. 이를 위해서 전력 신호분석과 모델링에 근간을 두었으며 대기전력 절감을 위해서 On/Off 차단기준을 마련했다. On/Off 차단 시점을 찾기 위해서 $1^{st}$ SCS와 $2^{nd}$ SCS의 차분값(subtraction value), 그리고 콘센트로부터 유입된 초당 샘플링 계수에 대한 중간값(median value)을 중요한 파라미터로써 정의한 다음 대기전력 상태에서의 유사그룹 및 유력패턴 그룹 생성 알고리즘을 수행했다.

• Journal of Gastric Cancer
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• 제23권3호
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• pp.476-486
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• 2023

Purpose: The optimal tumor mutational burden (TMB) value for predicting treatment response to programmed cell death-1 (PD-1) checkpoint inhibitors in advanced gastric cancer (AGC) remains unclear. We aimed to investigate the optimal TMB cutoff value that could predict the efficacy of PD-1 checkpoint inhibitors in AGC. Materials and Methods: Patients with AGC who received pembrolizumab or nivolumab between October 1, 2020, and July 27, 2021, at Samsung Medical Center in Korea were retrospectively analyzed. The TMB levels were measured using a next-generation sequencing assay. Based on receiver operating characteristic curve analysis, the TMB cutoff value was determined. Results: A total 53 patients were analyzed. The TMB cutoff value for predicting the overall response rate (ORR) to PD-1 checkpoint inhibitors was defined as 13.31 mutations per megabase (mt/Mb) with 56% sensitivity and 95% specificity. Based on this definition, 7 (13.2%) patients were TMB-high (TMB-H). The ORR differed between the TMB-low (TMB-L) and TMB-H (8.7% vs. 71.4%, P=0.001). The progression-free survival and overall survival (OS) for 53 patients were 1.93 (95% confidence interval [CI], 1.600-2.268) and 4.26 months (95% CI, 2.992-5.532). The median OS was longer in the TMB-H (20.8 months; 95% CI, 2.292-39.281) than in the TMB-L (3.31 months; 95% CI, 1.604-5.019; P=0.049). Conclusions: The TMB cutoff value for predicting treatment response in AGC patients who received PD-1 checkpoint inhibitor monotherapy as salvage treatment was 13.31 mt/Mb. When applying the programmed death ligand-1 status to TMB-H, patients who would benefit from PD-1 checkpoint inhibitors can be selected.