• Title/Summary/Keyword: ECV

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The characterization of electronic materials (전자재료의 특성분석)

  • 박인식
    • Electrical & Electronic Materials
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    • v.8 no.5
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    • pp.658-663
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    • 1995
  • 전자재료라 총칭하는 재료의 종류는 셀 수 없을 정도로 많다. 대표적인 전자재료로는 반도체재료를 들 수 있으며 다음으로는 전기광학 소자의 재료로 쓰이는 여러가지 광학용 단결정, 그리고 저항이나 축전지 등의 제조에 사용되는 여러가지 재료들도 이에 포함된다. 이러한 전자재료의 특성을 평가하는 방법도 여러가지 있겠으나 여기에서는 그 범위를 임의로 반도체레이저의 제조에 사용되는 화합물반도체에 국한시켜 각 공정별로 이떠한 평가방법이 사용되는지, 그리고 각각의 특성평가 방법에 대하여 간략하게 알아보기로 한다.

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Effects of Puerariae Radix extract on Cisplatin-Induced Apoptosis of Rat Mesangial Cells (갈근(葛根) 추출물이 cisplatin에 의해 유도된 rat mesangial cell의 apoptosis에 미치는 영향)

  • Hong, Jae-Eui;Shin, Jo-Young;Ju, Sung-Min;Jeon, Byung-Hun;Lee, Si-Hyeong
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.24 no.2
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    • pp.220-227
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    • 2010
  • Puerariae radix (PR) is a popular natural herb and a traditional food in Asia, which has antithrombotic and anti-allergic properties and stimulates estrogenic activity. One of the major side effects of cisplatin is nephrotoxicity, leading to acute renal failure. Recent study has suggested a role of ROS and p53 in renal cell injury by cisplatin. We studied that protective effects of PR on cisplatin-induced apoptosis in rat mesangial cell. Rat mesangial cell was preincubated with PR (50, 100, 150 and 200 ${\mu}g/m{\ell}$) for 12 hr and then treated with 30 ${\mu}M$ cisplatin for 24 hr. Protective effect of PR on cisplatin-induced apoptosis in ECV304 cells was determined using MTT assay, FDA-PI staining, flow cytometric analysis, caspase-3 activity assay, ROS assay and western blot. Our results showed that PR inhibited in cisplatin-induced apoptosis and ROS production in ECV304 cells. Moreover, PR reduced ERK, p38 and JNK activation that increased in cisplatin-treated rat mesangial cell. Furthermore, activation of p53 by cisplatin in rat mesangial cell was inhibited by PR treatment. These results suggest that protective effect of PR on cisplatin-induced apoptosis in rat mesangial cell may be associated with reduction of ERK, p38, JNK, p53 activation.

Growth of InGaP on Ge substrates by metalorganic chemical vapor deposition for triple junction solar cells

  • Lee, Sang-Su;Yang, Chang-Jae;Sin, Geon-Uk;Yun, Ui-Jun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.133-133
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    • 2010
  • 3-5족 화합물 반도체를 이용한 집광형 삼중 접합 태양전지는 35% 이상의 광변환 효율로 주목을 받고 있다. 일반적으로 삼중 접합 태양전지는 넓은 영역대의 파장을 흡수하기 위해 밴드갭이 다른 InGaP, GaAs, Ge이 사용된다. 그 중 하부셀은 기계적 강도가 높고 장파장을 흡수할 수 있는 Ge이 사용되는데, p-type Ge 기판위에 III-V 결정막 성장 시 5족 원소가 확산되어 pn접합을 형성하게 된다. 이러한 구조를 가진 Ge 하부셀이 효율적으로 홀-전자 쌍을 형성하기 위해서는 두꺼운 베이스와 얇은 에미터 접합이 필요하다. InGaP의 phosphorus는 낮은 확산계수로 인해 GaAs의 arsenic에 비해 얇은 접합이 형성 가능하며, Ge표면 에칭효과가 더 적다는 장점이 있다. 이를 고려해 우리 연구그룹에서는 metalorganic chemical vapor depostion(MOCVD)을 이용하여 Ge기판위에 성장한 InGaP layer의 특성을 관찰해 보았다. <111>로 $6^{\circ}$ 기울어진 p-type Ge(100) 기판위에 MOCVD를 통해 InGaP layer를 형성하였고, 성장된 layer를 atomic force microscope(AFM)와 high-resolution x-ray diffraction(HRXRD)을 이용하여 표면형상, 조성, 응력상태 등을 각각 관찰하였다. 또한 phosphorus 확산에 의해 형성되는 도핑농도는 electrochemical capacitance-voltage(ECV)을 이용하여 관찰하였다. 성장된 Ge기판위의 InGaP layer의 경우 특징적으로 높이 50 nm, 밑변 길이 $1\;{\mu}m$의 경사진 표면을 관찰할 수 있었으며, 이러한 구조는 TMIn과 TMGa의 비율이 증가 할수록 감소하였다. 따라서 이러한 경사진 형태의 구조는 격자 불일치 때문인 것으로 판단된다. 추가적으로 V/III ratio의 최적화를 통해 1.3 nm의 표면 거칠기를 갖는 InGaP layer를 얻을 수 있었다. ECV를 통해 Ge 하부셀의 pn접합 형성을 관찰한 결과 약 160 nm에서 접합이 형성되는 것을 관찰할 수 있었다. 또한, 같은 성장 조건의 샘플을 1000 초 열처리 후에 접합깊이의 변화를 관찰한 결과 180 nm에서 접합이 관찰되었지만, GaAs의 arsenic에 의한 pn접합은 열처리 후에 그 깊이가 170 nm에서 300 nm로 증가 하였다. 따라서 삼중접합 태양전지의 제작 공정을 고려할 경우 phosphorus에 의한 접합 형성이 Ge 하부셀의 동작 특성에 유리할 것으로 판단된다.

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Anti-metastastic Effects of ingredients of Fuzhengfangaitang (부정방암탕(扶正防癌湯) 구성(構成) 약물(藥物)의 암전이(癌轉移) 억제(抑制)에 대한 연구(硏究))

  • Park, Joon-Hyuck;Yu, Young-Beob;Shim, Bum-Sang;Choi, Seung-Hoon;Ahn, Koo-Seok
    • THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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    • v.7 no.1
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    • pp.39-60
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    • 2001
  • Fuzhengfangaitang is a prescript for inhibiting recurrence and metastasis of cancer. We had examined the anti-metatstastic effect of Fuzhengfangaitang. Furthermore, we performed the following experiments with ingredients of Fuzhengfangaitang. The purpose of this thesis is to study what ingredients of Fuzhengfangaitang have more valuable anti-cancer effects. And the results are listed below: 1. Cell Viability assay At the dose of 400$\mu$g/ml, most ingredients of Fuzhengfangaitang depressed viability of ECV-304. And especially, Scutellaria barbata D. DON$50{\mu}g/ml$ : 53.118%, $100{\mu}g/ml$: 49.092%, $200{\mu}g/ml$ : 43.765%, $400{\mu}g/ml$ : 12.747%), Polygonum bistorta L.($50{\mu}g/ml$ : 45.554%, $100{\mu}g/ml$ : 45.554%, $200{\mu}g/ml$ : 0.0%, $400{\mu}g/ml$ : 0.0%) and Psoralea corylifolia L.($50{\mu}g/ml$ : 86.591%, $100{\mu}g/ml$ : 81.307%, $200{\mu}g/ml$ : 24.801%, $400{\mu}g/ml$ : 3.111%) highly depressed cell viability more than the other ingredients. (${\alpha}$<0.05) 2. Cell Proliferation assay Proliferation assay with ingredients of Fuzhengfangaitang on ECV-304 showed that Crataegus pinnatifuda BGE ($50{\mu}g/ml$: 63.276%, $100{\mu}g/ml$ : 64.092%, $200{\mu}g/ml$ : 68.966% $400{\mu}g/ml$ : 38.517%, ED50=$296.974{\mu}g/ml$), Polygonum bistorta L.($50{\mu}g/ml$ : 83.981%, $100{\mu}g/ml$ : 86.997%, $200{\mu}g/ml$ : 58.780%, $400{\mu}g/ml$ : 26.408%), ED50=$266.725{\mu}g/ml$) and Psoralea corylifolia L.($50{\mu}g/ml$ : 103.037%, $100{\mu}g/ml$ : 82.529%, $200{\mu}g/ml$ : 2.829%, $400{\mu}g/ml$ : 0.998%), ED50=$177.369{\mu}g/ml$) depressed cell proliferation more than the other ingredients. 3. Tube Formation assay Compared with the control group, most ingredients of Fuzhengfangaitang did not remarkably inhibited the Tube Formation assay of ECV-304 at the dose of $100{\mu}g/ml$. But, Polygonum bistorta L. highly inhibited the tube formation of ECV -304 at the lower dose of $50{\mu}g/ml$. 4. Rat Aortic Ring assay In comparison with the control group, Scutellaria barbata D. DON., root of Polygonum bistorta L. and Psoralea corylifolia L. restricted the angiogenesis of the rat aortic ring at the dose of $100{\mu}g/ml$. And the other ingredients of Fuzhengfangaitang did not restricted the angiogenesis of the rat aortic ring at that dose. Especially, Polygonum bistorta L. highly inhibited the angiogenesis of the rat aortic ring at the lower dose of $50{\mu}g/ml$. From our research, the anti-angiogenic effects of the ingredients of Fuzhengfangaitang was proven. Moreover, it will be helpful for designing more effective prescription for anti angiogenesis.

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Cytoprotective effects of eupatilin, a novel antioxidative flavone, in oxidative stress- induced gastric mucosal cell damage

  • Oh, Tae-Young;Kim, Ju-Mi;Ahn, Byoung-Ok;Kim, Won-Bae;Park, Eun-Joo;Kim, Yong-Seok;Lee, Zee-Won;Ha, Kwon-Soo
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.129.1-129.1
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    • 2003
  • Alcohol, Helicobacter pylori, stress and NSAIDs-activated neutrophils all produce reactive oxygen species (ROS), which play an important role in gastric mucosal damage. Eupatilin is an active component of Artemisia asiatica possessing cytoprotective effect. The effect of eupatilin on the production of ROS and cellular damage in AGS and ECV304 cells were evaluated to prove the cytoprotective action against the above mentioned gastric mucosal cell damages. (omitted)

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Light-Chain Cardiac Amyloidosis: Cardiac Magnetic Resonance for Assessing Response to Chemotherapy

  • Yubo Guo;Xiao Li;Yajuan Gao;Kaini Shen;Lu Lin;Jian Wang;Jian Cao;Zhuoli Zhang;Ke Wan;Xi Yang Zhou;Yucheng Chen;Long Jiang Zhang;Jian Li;Yining Wang
    • Korean Journal of Radiology
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    • v.25 no.5
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    • pp.426-437
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    • 2024
  • Objective: Cardiac magnetic resonance (CMR) is a diagnostic tool that provides precise and reproducible information about cardiac structure, function, and tissue characterization, aiding in the monitoring of chemotherapy response in patients with light-chain cardiac amyloidosis (AL-CA). This study aimed to evaluate the feasibility of CMR in monitoring responses to chemotherapy in patients with AL-CA. Materials and Methods: In this prospective study, we enrolled 111 patients with AL-CA (50.5% male; median age, 54 [interquartile range, 49-63] years). Patients underwent longitudinal monitoring using biomarkers and CMR imaging. At follow-up after chemotherapy, patients were categorized into superior and inferior response groups based on their hematological and cardiac laboratory responses to chemotherapy. Changes in CMR findings across therapies and differences between response groups were analyzed. Results: Following chemotherapy (before vs. after), there were significant increases in myocardial T2 (43.6 ± 3.5 ms vs. 44.6 ± 4.1 ms; P = 0.008), recovery in right ventricular (RV) longitudinal strain (median of -9.6% vs. -11.7%; P = 0.031), and decrease in RV extracellular volume fraction (ECV) (median of 53.9% vs. 51.6%; P = 0.048). These changes were more pronounced in the superior-response group. Patients with superior cardiac laboratory response showed significantly greater reductions in RV ECV (-2.9% [interquartile range, -8.7%-1.1%] vs. 1.7% [-5.5%-7.1%]; P = 0.017) and left ventricular ECV (-2.0% [-6.0%-1.3%] vs. 2.0% [-3.0%-5.0%]; P = 0.01) compared with those with inferior response. Conclusion: Cardiac amyloid deposition can regress following chemotherapy in patients with AL-CA, particularly showing more prominent regression, possibly earlier, in the RV. CMR emerges as an effective tool for monitoring associated tissue characteristics and ventricular functional recovery in patients with AL-CA undergoing chemotherapy, thereby supporting its utility in treatment response assessment.

The dependence of the properties of InP grown by chloride vapor phase epitaxy on the growth temperature and on the $PCl_3/H_2$ molar fraction (Chloride VPE법에 의한 InP 에피층 성장시 성장온도 및 $PCl_3/H_2$ 몰비에 따른 특성변화)

  • 김현수;신동석;최인훈
    • Journal of the Korean Vacuum Society
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    • v.6 no.1
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    • pp.61-68
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    • 1997
  • We examined the dependence of the growth of undoped InP epilayer by chloride vapor phase epitaxy on the growth temperature and on the $PCl_3$molar fraction. The growth temperature was varied from $620^{\circ}C$ to $650^{\circ}C$ and the $PCl_3$molar franction from $2.5{\times}10^{-2}$ to $4.5{\times}10^{-2}$. The undoped InP epilayer with hillock free surface was obtained at the growth temperature of $640^{\circ}C$ and at the PCl$_3$molar fraction of $3.0{\times}10^{-2}$. The surface morphology was improved with a decrease of the PCl$_3$molar fraction. The carrier concentration measured by Hall and ECV was less than $1{\times}10^{14}cm^{-3}$. The resistivity of the undoped InP epilayer, measured by using four probe method, showed a high value of <$3.0{\times}10^6{\Omega}\textrm{cm}$.

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Microvascular Myocardial Ischemia in Patients With Diabetes Without Obstructive Coronary Stenosis and Its Association With Angina

  • Yarong Yu;Wenli Yang;Xu Dai;Lihua Yu;Ziting Lan;Xiaoying Ding;Jiayin Zhang
    • Korean Journal of Radiology
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    • v.24 no.11
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    • pp.1081-1092
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    • 2023
  • Objective: To investigate the incidence of microvascular myocardial ischemia in diabetic patients without obstructive coronary artery disease (CAD) and its relationship with angina. Materials and Methods: Diabetic patients and an intermediate-to-high pretest probability of CAD were prospectively enrolled. Non-diabetic patients but with an intermediate-to-high pretest probability of CAD were retrospectively included as controls. The patients underwent dynamic computed tomography-myocardial perfusion imaging (CT-MPI) and coronary computed tomography angiography (CCTA) to quantify coronary stenosis, myocardial blood flow (MBF), and extracellular volume (ECV). The proportion of patients with microvascular myocardial ischemia, defined as any myocardial segment with a mean MBF ≤ of 100 mL/min/100 mL, in patients without obstructive CAD (Coronary Artery Disease-Reporting and Data System [CAD-RADS] grade 0-2 on CCTA) was determined. Various quantitative parameters of the patients with and without diabetes without obstructive CAD were compared. Multivariable analysis was used to determine the association between microvascular myocardial ischemia and angina symptoms in diabetic patients without obstructive CAD. Results: One hundred and fifty-two diabetic patients (mean age: 59.7 ± 10.7; 77 males) and 266 non-diabetic patients (62.0 ± 12.3; 167 males) were enrolled; CCTA revealed 113 and 155 patients without obstructive CAD, respectively. For patients without obstructive CAD, the mean global MBF was significantly lower for those with diabetes than for those without (152.8 mL/min/100 mL vs. 170.4 mL/min/100 mL, P < 0.001). The mean ECV was significantly higher for diabetic patients (27.2% vs. 25.8%, P = 0.009). Among the patients without obstructive CAD, the incidence of microvascular myocardial ischemia (36.3% [41/113] vs. 10.3% [16/155], P < 0.001) and interstitial fibrosis (69.9% [79/113] vs. 33.3% [8/24], P = 0.001) were significantly higher in diabetic patients than in the controls. The presence of microvascular myocardial ischemia was independently associated with angina symptoms (adjusted odds ratio = 3.439, P = 0.037) in diabetic patients but without obstructive CAD. Conclusion: Dynamic CT-MPI + CCTA revealed a high incidence of microvascular myocardial ischemia in diabetic patients without obstructive CAD. Microvascular myocardial ischemia is strongly associated with angina.

Chemotherapy-Related Cardiac Dysfunction: Quantitative Cardiac Magnetic Resonance Image Parameters and Their Prognostic Implications

  • Jinhee Kim;Yoo Jin Hong;Kyunghwa Han;Jin Young Kim;Hye-Jeong Lee;Jin Hur;Young Jin Kim;Byoung Wook Choi
    • Korean Journal of Radiology
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    • v.24 no.9
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    • pp.838-848
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    • 2023
  • Objective: To quantitatively analyze the cardiac magnetic resonance imaging (CMR) characteristics of chemotherapy-related cardiac dysfunction (CTRCD) and explore their prognostic value for major adverse cardiovascular events (MACE). Materials and Methods: A total of 145 patients (male:female = 76:69, mean age = 63.0 years) with cancer and heart failure who underwent CMR between January 2015 and January 2021 were included. CMR was performed using a 3T scanner (Siemens). Biventricular functions, native T1 T2, extracellular volume fraction (ECV) values, and late gadolinium enhancement (LGE) of the left ventricle (LV) were compared between those with and without CTRCD. These were compared between patients with mild-to-moderate CTRCD and those with severe CTRCD. Cox proportional hazard regression analysis was used to evaluate the association between the CMR parameters and MACE occurrence during follow-up in the CTRCD patients. Results: Among 145 patients, 61 had CTRCD and 84 did not have CTRCD. Native T1, ECV, and T2 were significantly higher in the CTRCD group (1336.9 ms, 32.5%, and 44.7 ms, respectively) than those in the non-CTRCD group (1303.4 ms, 30.5%, and 42.0 ms, respectively; P = 0.013, 0.010, and < 0.001, respectively). They were not significantly different between patients with mild-to-moderate and severe CTRCD. Indexed LV mass was significantly smaller in the CTRCD group (65.0 g/m2 vs. 78.9 g/mm2; P < 0.001). According to the multivariable Cox regression analysis, T2 (hazard ratio [HR]: 1.14, 95% confidence interval [CI]: 1.01-1.27; P = 0.028) and quantified LGE (HR: 1.07, 95% CI: 1.01-1.13; P = 0.021) were independently associated with MACE in the CTRCD patients. Conclusion: Quantitative parameters from CMR have the potential to evaluate myocardial changes in CTRCD. Increased T2 with reduced LV mass was demonstrated in CTRCD patients even before the development of severe cardiac dysfunction. T2 and quantified LGE may be independent prognostic factors for MACE in patients with CTRCD.