• Korean Journal of Radiology
• /
• 제22권6호
• /
• pp.951-958
• /
• 2021

Objective: To evaluate the usefulness of virtual monochromatic images (VMIs) obtained using dual-layer dual-energy CT (DL-DECT) for evaluating brain tumors. Materials and Methods: This retrospective study included 32 patients with brain tumors who had undergone non-contrast head CT using DL-DECT. Among them, 15 had glioblastoma (GBM), 7 had malignant lymphoma, 5 had high-grade glioma other than GBM, 3 had low-grade glioma, and 2 had metastatic tumors. Conventional polychromatic images and VMIs (40-200 keV at 10 keV intervals) were generated. We compared CT attenuation, image noise, contrast, and contrast-to-noise ratio (CNR) between tumor and white matter (WM) or grey matter (GM) between VMIs showing the highest CNR (optimized VMI) and conventional CT images using the paired t test. Two radiologists subjectively assessed the contrast, margin, noise, artifact, and diagnostic confidence of optimized VMIs and conventional images on a 4-point scale. Results: The image noise of VMIs at all energy levels tested was significantly lower than that of conventional CT images (p < 0.05). The 40-keV VMIs yielded the best CNR. Furthermore, both contrast and CNR between the tumor and WM were significantly higher in the 40 keV images than in the conventional CT images (p < 0.001); however, the contrast and CNR between tumor and GM were not significantly different (p = 0.47 and p = 0.31, respectively). The subjective scores assigned to contrast, margin, and diagnostic confidence were significantly higher for 40 keV images than for conventional CT images (p < 0.01). Conclusion: In head CT for patients with brain tumors, compared with conventional CT images, 40 keV VMIs from DL-DECT yielded superior tumor contrast and diagnostic confidence, especially for brain tumors located in the WM.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
• /
• pp.62-62
• /
• 2015

In this study, we study the effects of CF4 plasma treatment on the characteristics of enhancement mode (E-mode) AlGaN/GaN high electron mobility transistors (HEMTs). The CF4 plasma is generated by inductively coupled plasma reactive ion etching (ICP-RIE) system. The CF4 gas is decomposed into fluorine ions by ICP-RIE and then fluorine ions will effect the AlGaN/GaN interface to inhibit the electron transport of two dimension electron gas (2DEG) and increase channel resistance. The CF4 plasma method neither like the recessed type which have to utilize Cl2/BCl3 to etch semiconductor layer nor ion implantation needed high power to implant ions into semiconductor. Both of techniques will cause semiconductor damage. In the experiment, the CF4 treatment time are 0, 50, 100, 150, 200 and 250 seconds. It was found that the devices treated 100 seconds showed best electric performance. In order to prove fluorine ions existing and CF4 plasma treatment not etch epitaxial layer, the secondary ion mass spectrometer confirmed fluorine ions truly existing in the sample which treatment time 100 seconds. Moreover, transmission electron microscopy showed that the sample treated time 100 seconds did not have etch phenomena. Atomic layer deposition is used to grow Al2O3 with thickness 10, 20, 30 and 40 nm. In electrical measurement, the device that deposited 20-nm-thickness Al2O3 showed excellent current ability, the forward saturation current of 210 mA/mm, transconductance (gm) of 44.1 mS/mm and threshold voltage of 2.28 V, ION/IOFF reach to 108. As IV concerning the breakdown voltage measurement, all kinds of samples can reach to 1450 V.

• International Journal of Automotive Technology
• /
• 제6권3호
• /
• pp.235-242
• /
• 2005

This study introduces the Reliability-Based Design Optimization (RBDO) to enhance the kinematic and compliance (K & C) characteristics of automotive suspension system. In previous studies, the deterministic optimization has been performed to enhance the K & C characteristics. Unfortunately, uncertainties in the real world have not been considered in the deterministic optimization. In the design of suspension system, design variables with the uncertainties, such as the bushing stiffness, have a great influence on the variation of the suspension performances. There is a need to quantify these uncertainties and to apply the RBDO to obtain the design, satisfying the target reliability level. In this research, design variables including uncertainties are dealt as random variables and reliability of the suspension performances, which are related the K & C characteristics, are quantified and the RBDO is performed. The RBD-optimum is compared with the deterministic optimum to verify the enhancement in reliability. Thus, the reliability of the suspension performances is estimated and the RBD-optimum, satisfying the target reliability level, is determined.

• 대한원격탐사학회지
• /
• 제32권1호
• /
• pp.13-24
• /
• 2016

This paper presents a method to evaluate the performance of subpixel localization operators using target image data. Subpixel localization of edges is important to extract the precise shape of objects from images. In this study, each target image was designed to provide reference lines and edges to which the localization operators can be applied. We selected two types of moment-based operators: Gray-level Moment (GM) operator and Spatial Moment (SM) operator for comparison. The original edge localization operators with kernel size 5 are tested and their extended versions with kernel size 7 are also tested. Target images were collected with varying Camera-to-Object Distance (COD). From the target images, reference lines are estimated and edge profiles along the estimated reference lines are accumulated. Then, evaluation of the performance of edge localization operators was performed by comparing the locations calculated by each operator and by superimposing them on edge profiles. Also, enhancement of edge localization by increasing the kernel size was also quantified. The experimental result shows that the SM operator whose kernel size is 7 provides higher accuracy than other operators implemented in this study.

• 생약학회지
• /
• 제43권1호
• /
• pp.32-38
• /
• 2012

To examine the potentiation of Macrolepiota procera extracts (MPE-4) to act as adjuvant enhancing the tumor specific anti-tumor immune response, tumor vaccine prepared by boiling (HK vaccine) admixed with MPE-4 and immunized in mice. Vaccination of mice with HK vaccine in combination with MPE-4 resulted in higher inhibition in tumor metastasis compared with the mice of HK vaccine alone treatment against live syngeneic tumor cell challenge. The splenocytes from mice immunized HK vaccine mixed with MPE-4 was able to elicit a stronger cytotoxic T lymphocyte (CTL) response as compared with HK vaccine alone. In addition, the splenocytes from MPE-4 admixed HK vaccine immunized mice secreted a higher concentration of Th1 type cytokine such as IFN-${\gamma}$, and GM-CSF. Furthermore, the adoptive transfer of splenocytes from mice immunized HK vaccine and MPE-4 led to a more robust anti-tumour response than the HK vaccine alone. Overall, these results indicate that MPE-4 is a good candidate adjuvant of anti-tumor immune response.

• Clinical and Experimental Pediatrics
• /
• 제45권2호
• /
• pp.247-255
• /
• 2002

목 적 : 태아 간세포는 면역학적으로 미숙하여 이식에 따른 거부반응이 잘 일어나지 않으므로 조혈모세포 이식, 특히 자궁내 이식의 좋은 공여세포로 이용할 수 있으나 아직 국내에서는 이를 위한 기초연구가 미미한 실정이다. 연구자는 태아 간 단핵세포를 이용하여 면역조직학적 염색과 체외배양 결과를 분석하여 태아 간의 거핵구 집락형성과 관련된 기초자료를 마련하고자 이 연구를 시행하였다. 방 법: 임신중절시 수집한 태아 간조직과 특발성 혈소판 감소성 자반증 및 범혈구 감소증 환아의 골수에서 단핵세포를 분리한 후 $MegaCult^{TM}-C$ 배지에서 12일간 배양 후 성장인자 첨가에 따른 거핵구 집락형성을 관찰하였고, 5일간의 Flask 배양 후 유세포 분석기를 이용하여 CD34, CD41 양성세포를 측정하였으며, methylcellulose 배지를 이용하여 $37^{\circ}C$ 5% $CO_2$ 배양기에서 배양한 후 제 7일과 14일에 성장인자 첨가에 따른 CFU-GM 집락 수를 조사하였다. 결 과 : 태아 간의 단핵세포 수는 재태주령 11주에 비해서 19주에서 더 많았으며 세포생존율은 $91.2{\pm}3.4%$였다. $MegaCult^{TM}-C$ kit를 이용하여 12일간 배양시 재태주령 11주의 태아 간이 19주에 비해서 거핵구 집락 수가 많았고, 4례 모두 성장인자의 첨가에 따른 집락증폭의 상승효과는 없었으며 배양 후 형성된 거핵구 집락 수는 태아 간, 특발성 혈소판 감소성 자반증 환아의 골수, 범혈구 감소증 환아의 골수 순이었다. 거핵구 집락 중 순수집락 수는 태아 간이 특발성 혈소판 감소성 자반증 및 범혈구 감소증 환아의 골수에 비해서 유의하게 높았으며, 순수집락 중 large CFU-Mk의 비율은 태아 간이 특발성 혈소판 감소성 자반증 및 범혈구 감소증 환아의 골수에 비해서 높았으나 유의성은 보이지 않았다. 태아 간 단핵세포를 5일간 flask 배양한 후 CD34 양성세포의 발현율은 증가하였으나 성장인자의 첨가에 따른 집락증폭의 상승효과는 TPO 투여군에서만 있었고, CD41 양성세포의 발현율 역시 배양 후 증가하였으나 성장인자 첨가군에 비해서 대조군의 발현율이 너무 높은 결과를 보였다. Methylcellulose 배지를 이용한 단핵세포 배양에서 CFU-GM 집락 수는 태아 간의 경우 배양 7일에 비하여 14일에 감소하였고, 성장인자의 첨가에 따른 집락증폭의 상승효과는 태아 간에서는 모든 군에서 보였으나 특발성 혈소판 감소성 자반증에서는 GM-CSF 투여군에서만 있었으며 범혈구 감소증 환아의 골수에서는 없었다. 결 론: $MegaCult^{TM}-C$ 배지를 이용하여 태아 간세포를 배양하고 면역조직학적 염색으로 거핵구 집락형성을 성공적으로 관찰하였으며, 태아 간에서 얻은 거핵구 집락이 특발성 혈소판 감소성 자반증 및 범혈구 감소증 환아의 골수에서 얻은 집락에 비하여 집락수나 순수집락의 분포, 집락의 크기 등에서 우수한 것으로 나타났으나 태아 간 조혈모세포 이식의 실제적인 임상적용을 위해서는 체계적인 더 많은 연구가 필요할 것으로 생각된다.

• 대한암한의학회지
• /
• 제15권1호
• /
• pp.29-36
• /
• 2010

The anti-metastatic activity of water extract of Samguikoeuitang (WSGKE) consisting of Ginseng Radix, Angelicae Radix, Sophora flavescens and Coicis Semenwas examined. Ethanol extract of Samguikoeuitang (ESGKE) showed significant cytotoxicity against colon 26-M3.1 carcinoma cells, while WSGEK did not. However, WSGKE significantly increased the production of IL-6 and IL-12 in thioglycollate-induced macrophages from Balb/c mice, whereas ESGKE did not. WSGKE significantly increased natural killer (NK) cell cytotoxicity against effecter YAC-1 cells in an Effecter cells/Target ratio dependent manner. Also, WSGKE significantly suppressed lung metastasis after i.v. injection of colon26-M3.1 carcinoma cells. Inhibitory effect of WSGKE on lung metastasis totally abolished in NK cells-deficient mice by treatment with anti-asialo GM1 serum. In addition, the combination treatment of cisplatin and WSGKE (100 ${\mu}g$/mouse) prolonged the lifespan of mice inoculated by colon26-M3.1 cell. These findings suggest that WSGKE can inhibit lung metastasis and prolong life span via immunological enhancement as a Biological Response Modifier.

• 한국식품과학회지
• /
• 제36권3호
• /
• pp.484-489
• /
• 2004

인간의 장내 상재 세균이며 인간에게 다양한 건강 증진 효과를 부여하는 것으로 알려진 Bifidobacterium속을 유아의 분변으로부터 분리하여 세포질, 세포벽 및 배양액의 고분자 획분을 대상으로 in vitro에서 장관면역계를 경유한 골수세포 증식활성을 검토하였다 분리한 6종의 Bifidobacterium속 중에서 Bifidobacterium SL-21의 세포벽 성분(CWP)이 농도 의존적으로 가장 높은 골수세포의 증식을 나타내었다. 한편, 골수세포 증식은 Peyer's patch를 매개로 일어나는 반응이므로 Peyer's patch에 의해 생성되는 cytokine류의 활성을 측정하였다. B. bifidum SL-21의 세포벽 성분과의 반응에 의해 GM-CSF, IL-2 및 IL-6 등의 cytokine류의 생산 증가가 확인되었으며 cytokine의 생산은 반응한 세포벽 성분에 농도 의존적 경향을 보였고 골수세포 증식이 증가할수록 높은 cytokine 생산 증가를 나타냈다. 불용성인 B. bifidum SL-21 세포벽을 lysozyme 처리하여 수용화시켜 분자량에 따른 활성을 검토한 결과, 분자량 30-50 kDa의 획분에서 가장 높은 골수세포 증식활성이 측정되었다. 이와 같은 결과를 토대로 하여 B. bifidum SL-21 세포벽 성분이 Peyer's patch의 림프구를 활성화시키고 이들 활성화된 림프구에서 생성되는 cytokine류에 의해 골수세포 증식이 이루어짐을 확인할 수 있었다. 또한 이들 활성화된 면역세포는 CM-CSF, IL-2 및 IL-6 등의 전신순환 면역계의 증강에 중요한 역할을 갖는 cytokine류를 생산하였다.

• 대한본초학회지
• /
• 제37권3호
• /
• pp.9-19
• /
• 2022

Objectives : Angelicae Gigantis Radix (AG) is a plant of the Ranunculus family. AG have been reported to have various pharmacological effects on human health which include uterine growth promotion, anti-inflammatory, analgesic, and immune enhancement. However, research on dermatitis disease is insufficient. Therefore, we investigated the effects of AG on tumor necrosis factor-α (TNF-α)/interferon-γ (IFN-γ) stimulated HaCaT cell. Methods : To investigate the effect of AG on HaCaT cell, HaCaT cells were pre-treated with AG for 1 hour and then stimulated with TNF-α/IFN-γ. After 24 hours, media and cells were harvested to analyze the inflammatory mediators. Concentration of human interleukin-1beta (IL-1β), monocyte chemoattractant protein-1 (MCP-1), granulocyte-macrophage colony-stimulating factor (GM-CSF), and TNF-α in the media were assessed by ELISA. mRNA expression of human thymus and activation-regulated chemokine (TARC), IL-6, and IL-8 were analyzed by RT-PCR. Additionally, the mechanisms of mitogen-activated protein kinases (MAPKs) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway were investigated by Western blot. Results : The treatment of AG inhibited gene expression levels of IL-6, IL-8, and TARC and protein expression levels of IL-1β, MCP-1, and GM-CSF. Also, AG significantly reduced extracellular signal-regulated kinase (ERK) phosphorylation and NF-κB translocation in TNF-α/IFN-γ stimulated HaCaT cell. Conclusions : Taken together, these results demonstrate that AG can alleviate inflammatory diseases such as atopic dermatitis by regulating the expression of inflammatory cytokines. Also, it suggest that AG may a promising candidate drug for the treatment of inflammatory disease such as atopic dermatitis.

• 대한영상의학회지
• /
• 제84권1호
• /
• pp.240-252
• /
• 2023

목적 소아 환자에서 두부 컴퓨터단층촬영(이하 CT)에 대한 딥러닝 이미지 재구성(deep learning image reconstruction; 이하 DLIR; TrueFidelity; GE Healthcare, Milwaukee, WI, USA)의 효과를 평가하고자 한다. 대상과 방법 총 126개의 소아 두부 CT 이미지를 수집했으며, adaptive statistical iterative reconstruction (이하 ASiR)-V를 사용한 반복적 재구성 및 세 가지 수준의 DLIR을 사용한 재구성을 시행하였다. 각 이미지 세트 그룹은 환자의 연령에 따라 4개의 그룹으로 구분하였으며 각 연령군의 임상 및 방사선량 관련 데이터를 검토하였다. 양적 매개 변수에는 signal to noise ratio (이하 SNR) 및 contrast to noise ratio (이하 CNR)가 포함되었으며 질적 매개 변수로 영상의 잡음(noise), 회백질의 구분 정도, 선명도, 인공물 및 수용 가능성(acceptability), 영상의 질감이 포함되었고 이에 대한 평가와 비교를 시행하였다. 결과 모든 연령 그룹의 모든 수준의 SNR 및 CNR은 높은 수준의 DLIR 사용 시 증가하였다. ASiR-V와 비교했을 때 높은 수준의 DLIR은 SNR 및 CNR이 개선되었다(p < 0.05). 그리고 DLIR의 수준이 증가될수록 순차적인 잡음 감소, 회백질 구분 개선, 선명도 개선이 나타났다. 이러한 변수들에서 높은 수준의 DLIR 사용 시 ASiR-V와 유사한 정도의 수치가 측정되었다. 인공물과 수용 가능성의 경우에 적용된 DLIR 수준 간에 큰 차이를 보이지 않았다. 결론 소아 두부 CT에 고수준 DLIR을 적용하면 영상의 노이즈를 줄일 수 있으나 인공물 처리에 대한 개선이 필요하다.