• 한국광학회지
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• 제31권3호
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• pp.148-154
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• 2020

본 논문에서는 주기적인 구멍배열(periodic hole array, PHA) 패턴을 가진 나노금속구조 컬러필터의 문제점인 입사광의 각도에 따른 컬러필터 중심파장의 이동을 해결하기 위해 새로운 구멍 패턴인 polyperiodic hole array (PPHA)를 제시한다. 먼저 녹색파장대역 컬러필터를 만들기 위해 구멍의 직경과 주기를 정했으며 propagation length와 skin depth를 고려해 단위셀의 크기, 금속과 유전체의 두께를 설정했다. PPHA 패턴을 만들기 위해 주기적인 구멍배열을 국부적으로 회전시켜 전체적으로는 비주기적이지만 부분적으로 주기적인 패턴을 만들었다. 그 결과 PHA 패턴과 대비하여 PPHA 패턴 나노금속구조 컬러필터는 입사광각이 0°에서 30°까지 증가하였을 때 파장의 이동도가 최대 40% 개선되었다. 본 연구를 통해 나노금속구조 컬러필터의 성능을 향상시킬 수 있으며 디스플레이, 이미지 센서 등 이미징 디바이스 분야에 접목시켜 산업적으로 활용할 수 있을 것으로 예상한다.

• Archives of Pharmacal Research
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• 제27권5호
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• pp.524-530
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• 2004

Epilepsy or the occurrence of spontaneous recurrent epileptiform discharges (SREDs, seizures) is one of the most common neurological disorders. Shift in the balance of brain between excitatory and inhibitory functions due to different types of structural or functional alterations may cause epileptiform discharges. N-Methyl-D-aspartate (NMDA) receptor dysfunctions have been implicated in modulating seizure activities. Seizures and epilepsy are clearly dependent on elevated intracellular calcium concentration ([C $a^{2+}$]$_{i}$ ) by NMDA receptor activation and can be prevented by NMDA antagonists. This perturbed [C $a^{2+}$]$_{i}$ levels is forerunner of neuronal death. However, therapeutic tools of elevated [C $a^{2+}$]$_{i}$ level during status epilepticus (SE) and SREDs have not been discovered yet. Our previous study showed fast inhibition of ginseng total saponins and ginsenoside R $g_3$ on NMDA receptor-mediated [C $a^{2+}$]$_{i}$ in cultured hippocampal neurons. We, therefore, examined the direct modulation of ginseng on hippocampal neuronal culture model of epilepsy using fura-2-based digital $Ca^{2+}$ imaging and neuronal viability assays. We found that ginseng total saponins and ginsenoside R $g_3$ inhibited $Mg^{2+}$ free-induced increase of [C $a^{2+}$]$_{i}$ and spontaneous [C $a^{2+}$]$_{i}$ oscillations in cultured rat hippocampal neurons. These results suggest that ginseng may playa neuroprotective role in perturbed homeostasis of [C $a^{2+}$]$_{i}$ and neuronal cell death via the inhibition of NMDA receptor-induced SE or SREDs.d SE or SREDs..

• 대한화학회지
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• 제51권6호
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• pp.513-519
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• 2007

수용액에서 vesicle을 형성하는 고분자, poly(sodium acrylamidoundecanoate)(PSAU)와 수용성 형광다이, TPADSB-C를 합성하고 흡수 및 형광 분광기를 이용하여 광학적 특성을 연구하였다. N-phenyl naphthylamine을 형광 probe로 사용하여 PSAU의 농도가 0.01 g/L 이상에서 고분자들의 응집에 의해 vesicle을 형성함을 확인하였다. 수용성 형광다이의 형광 특성을 vesicle의 존재유무에 따라 조사함으로써 형광다이 주위의 미세환경의 변화에 따른 광학적 특성 의 변화를 측정하였다. 형광다이를 고분자 vesicle안에 침투시킬 경우 형광체 주변의 미세 환경(극성 등)의 변화에 따라 수용액 대비 발광 파장은 blue-shift하였고 형광 효율도 90%로 증가하였다. 본 연구는 형광다이를 함유하고 있는 고분 자 vesicle이 바이오이메징 응용에 있어 효과적이고 안정적이면서 biocompatible한 레이블용 테그로 사용될 수 있음을 보여준다.

• Archives of Pharmacal Research
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• 제28권2호
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• pp.195-202
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• 2005

Free radicals and reactive oxygen species (ROS) caused by UV exposure or other environmental factors are critical players in cellular damage and aging. In order to develop a new antiphotoaging agent, this work focused on the antioxidant effects of the extract of tinged autumnal leaves of Acer palmatum. One compound was isolated from an ethyl acetate soluble fraction of the A. palmatum extract using silica gel column chromatography. The chemical structure was identified as apigenin-8-C-beta-D-glucopyranoside, more commonly known as vitexin, by spectral analysis including LC-MS, FT-IR, UV, $^{1}H-$, and $^{13}C-NMR$. The biological activities of vitexin were investigated for the potential application of its anti-aging effects in the cosmetic field. Vitexin inhibited superoxide radicals by about $70\%$ at a concentration of $100\;{\mu}g/mL$ and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals by about $60\%$ at a concentration of $100\;{\mu}g/mL$. Intracellular ROS scavenging activity was indicated by increases in dichlorofluorescein (DCF) fluorescence upon exposure to UVB $20\;mJ/cm^2$ in cultured human dermal fibroblasts (HDFs) after the treatment of vitexin. The results show that oxidation of 5-(6-)chloromethyl-2',7'-dichlo-rodihydrofluorescein diacetate ($CM-H_{2}DCFDA$) is inhibited by vitexin effectively and that vitexin has a potent free radical scavenging activity in UVB-irradiated HDFs. In ROS imaging using a confocal microscope we visualized DCF fluorescence in HDFs directly. In conclusion, our findings suggest that vitexin can be effectively used for the prevention of UV-induced adverse skin reactions such as free radical production and skin cell damage.

• Imaging Science in Dentistry
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• 제35권2호
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• pp.111-114
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• 2005

A 15-year-old patient, who had been diagnosed and treated as Burkitt cell type acute lymphoblastic leukemia (ALL-L3) already, visited our department. He complained of gingival enlargement and loosening teeth 1 month ago. The clinical examination revealed anterior open bite, gingival enlargement, and nontender swelling particularly in molar regions of both jaws. Deep periodontal pockets and severe mobility was shown on most of the teeth. The panoramic radiographs showed severe bone destruction and extrusion of the molars. The contrast enhanced CT showed multiple enhanced mass and bone marrow obliteration in both jaws. Chemotherapy was done and the swelling was subsided at 1 month later. In conclusion, radiologic findings of leukemia with soft tissue mass, known as chloroma or granulocytic sarcoma, mimic those of lymphoma, so blood test may be needed for the final diagnosis.

• Imaging Science in Dentistry
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• 제36권3호
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• pp.169-175
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• 2006

The Inflammatory myofibroblastic tumor (inflammatory pseudotumor) is a rarely occurring soft tissue lesion of unknown etiology. It can be of any location, but commonly it is found in lungs. It has been considered as a nonneoplastic reactive inflammatory lesion, but nowadays, confusion and dispute about its character is increasing due to its high recurrence rate and metastasis. We present a patient who had been diagnosed with an inflammatory pseudotumor in the right maxilla area, 1 year before visiting our hospital. After that, her pain and swelling did not resolved and she visit our hospital. On radiographic examination, aggressively infiltrative growth of the lesion with destruction of adjacent bony structure was noted. We found unusual aggressiveness of the inflammatory myofibroblastic tumor of the head and neck region. Because the typical behavior of the inflammatory myofibroblastic tumor is not defined yet, we recommend the surgical excision of the lesion and close follow-up.

• Tuberculosis and Respiratory Diseases
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• 제77권3호
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• pp.116-123
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• 2014

Background: Mesenchymal stem cells (MSCs) obtained from bone marrow or adipose tissue can successfully repair emphysematous animal lungs, which is a characteristic of chronic obstructive pulmonary disease. Here, we describe the cellular distribution of MSCs that were intravenously injected into mice with elastase-induced emphysema. The distributions were also compared to the distributions in control mice without emphysema. Methods: We used fluorescence optical imaging with quantum dots (QDs) to track intravenously injected MSCs. In addition, we used a human Alu sequence-based real-time polymerase chain reaction method to assess the lungs, liver, kidney, and spleen in mice with elastase-induced emphysema and control mice at 1, 4, 24, 72, and 168 hours after MSCs injection. Results: The injected MSCs were detected with QD fluorescence at 1- and 4-hour postinjection, and the human Alu sequence was detected at 1-, 4- and 24-hour postinjection in control mice (lungs only). Injected MSCs remained more in mice with elastase-induced emphysema at 1, 4, and 24 hours after MSCs injection than the control lungs without emphysema. Conclusion: In conclusion, our results show that injected MSCs were observed at 1 and 4 hours post injection and more MSCs remain in lungs with emphysema.

• Nuclear Medicine and Molecular Imaging
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• 제41권2호
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• pp.141-151
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• 2007

파킨슨병은 노년층에 가장 흔한 퇴행성 뇌질환 중의 하나로 진행성핵상마비, 다중계 위축, 루이체 치매 등과 같은 비전형 파킨슨병과 임상적으로 감별이 어려울 수 있다. 파킨슨병과 비전형 파킨슨병의 감별은 치료방침 결정과 예후평가뿐만 아니라 파킨슨병의 원인과 병태생리를 연구하고 새로운 치료법 개발에 있어서도 매우 중요하다. 파킨슨병과 비전형 파킨슨병과 같이 파킨슨 증후군을 유발하는 질환은 선조체내 도파민 신경의 퇴행성 변화를 흔히 동반하지만 병태생리학적으로 서로 다른 뇌피질 및 피질하 구조물에서의 신경세포 소실을 동반하고 있다. 따라서 국소 시냅스 활성도와 신경 및 시냅스의 손상, 그리고 원발병변과 기능적으로 연결된 원격부위의 기능이상 등을 대변하는 뇌포도당 대사를 F-18FDG PET으로 평가하는 것은 파킨슨 병의 감별진단과 병태생리를 평가하는데 유용하다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.763-764
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• 2013

A three-dimensional image capturing device and its signal processing algorithm and apparatus are presented. Three dimensional information is one of emerging differentiators that provides consumers with more realistic and immersive experiences in user interface, game, 3D-virtual reality, and 3D display. It has the depth information of a scene together with conventional color image so that full-information of real life that human eyes experience can be captured, recorded and reproduced. 20 Mega-Hertz-switching high speed image shutter device for 3D image capturing and its application to system prototype are presented[1,2]. For 3D image capturing, the system utilizes Time-of-Flight (TOF) principle by means of 20MHz high-speed micro-optical image modulator, so called 'optical resonator'. The high speed image modulation is obtained using the electro-optic operation of the multi-layer stacked structure having diffractive mirrors and optical resonance cavity which maximizes the magnitude of optical modulation[3,4]. The optical resonator is specially designed and fabricated realizing low resistance-capacitance cell structures having small RC-time constant. The optical shutter is positioned in front of a standard high resolution CMOS image sensor and modulates the IR image reflected from the object to capture a depth image (Figure 1). Suggested novel optical resonator enables capturing of a full HD depth image with depth accuracy of mm-scale, which is the largest depth image resolution among the-state-of-the-arts, which have been limited up to VGA. The 3D camera prototype realizes color/depth concurrent sensing optical architecture to capture 14Mp color and full HD depth images, simultaneously (Figure 2,3). The resulting high definition color/depth image and its capturing device have crucial impact on 3D business eco-system in IT industry especially as 3D image sensing means in the fields of 3D camera, gesture recognition, user interface, and 3D display. This paper presents MEMS-based optical resonator design, fabrication, 3D camera system prototype and signal processing algorithms.

• Molecules and Cells
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• 제39권7호
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• pp.566-572
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• 2016

Lysosomes are cellular organelles containing diverse classes of catabolic enzymes that are implicated in diverse cellular processes including phagocytosis, autophagy, lipid transport, and aging. Lysosome-associated membrane proteins (LAMP-1 and LAMP-2) are major glycoproteins important for maintaining lysosomal integrity, pH, and catabolism. LAMP-1 and LAMP-2 are constitutively expressed in Salmonella-infected cells and are recruited to Salmonella-containing vacuoles (SCVs) as well as Salmonella- induced filaments (Sifs) that promote the survival and proliferation of the Salmonella. LAMP-3, also known as DC-LAMP/CD208, is a member of the LAMP family of proteins, but its role during Salmonella infection remains unclear. DNA microarray analysis identified LAMP-3 as one of the genes responding to LPS stimulation in THP-1 macrophage cells. Subsequent analyses reveal that LPS and Salmonella induced the expression of LAMP-3 at both the transcriptional and translational levels. Confocal Super resolution N-SIM imaging revealed that LAMP-3, like LAMP-2, shifts its localization from the cell surface to alongside Salmonella. Knockdown of LAMP-3 by specific siRNAs decreased the number of Salmonella recovered from the infected cells. Therefore, we conclude that LAMP-3 is induced by Salmonella infection and recruited to the Salmonella pathogen for intracellular proliferation.