SS-OCT 방식을 이용한 생체의 표피단면 영상 획득

김훈섭,임해진,엄진섭 江原大學校 産業技術硏究所 2008 産業技術硏究 Vol.28 No.A

In this paper, the swept source optical coherence tomography system has realized using a free-space interferometer based on a beam splitter, Personal computer has completed the control for tunable wavelength laser digitally and the B-scan motor as well. From each experiment for an onion and a salmon egg, we confirmed that the in vivo epidermal cross-sectional images for tliem can be obtained appropriately.

Spectral-Domain 광 계측을 위한 CCD 이미지 센서 드라이버 제작

김훈섭,이정렬,엄진섭 江原大學校 産業技術硏究所 2007 産業技術硏究 Vol.27 No.B

This paper presents Spectral-Domain optical measurement system using self-fabricated CCD sensor driver. The light source is a high brightness white LED and the detector is a 2048 array typed CCD image sensor. I have fabricated the CCD sensor driver to generate four pulse signals, which are the CCD-driving pulses. Using this Spectral Domain optical measurement system, the distance value between the reference mirror and the sample mirror can be obtained successfully.

루프 미러로 구성된 기준팔을 가지는 파장 스위핑 OCT 구현

김훈섭,남궁명우,이정렬,엄진섭 江原大學校 産業技術硏究所 2007 産業技術硏究 Vol.27 No.B

As a reflector of reference arm in OCT systems, a coated fiber reflector has mostly used. Instead, this paper has realized the swaept source optical coherence tomography system using a loop mirror within a reference ann. Through the expehments for a tilted thin glass plate, we found that the loop mirror is better than the coated fiber typed mirror for obtaining the clear image.

Photophysical Properties of Thermally Activated Delayed Fluorescent Materials upon Distortion of Central Axis of Donor Moiety

Kim, Hyung Suk,Park, Hansol,Park, So-Ra,Lee, Sang Hoon,Ahn, Yunho,Lee, Yong Sup,Suh, Min Chul American Chemical Society 2018 JOURNAL OF PHYSICAL CHEMISTRY C - Vol.122 No.50

<P>In this study, we showed the distortion of the central axis of the donor moiety can switch critically the rate of the reverse intersystem crossing (<I>k</I><SUB>RISC</SUB>) process, which is the trigger point to modulate the lifetime of delayed fluorescence. To achieve <I>k</I><SUB>RISC</SUB>, what we desired (10<SUP>5</SUP> to 10<SUP>6</SUP> s<SUP>-1</SUP>) in a series of donor-acceptor-donor (D-A-D) type thermally activated delayed fluorescence (TADF) materials, the donor groups (phenoxazine and phenothiazine) were selectively introduced. Maintaining the near orthogonality between donor and acceptor (benzonitrile) moiety, the occurrence of the distortion of the central axis of the donor moiety could make the effect of locally excited triplet state (<SUP>3</SUP>LE). In other words, the interaction between <SUP>3</SUP>LE and the charge transfer counterparts (i.e., <SUP>1</SUP>CT and <SUP>3</SUP>CT) contributes an opposite propensity of <I>k</I><SUB>RISC</SUB> for each of the target TADF materials when those are dissolved in solution and condensed in solid state. Herein, we have theoretically and experimentally shown the photophysical behavior of common D-A-D type TADF upon the different systems.</P> [FIG OMISSION]</BR>

Heteroleptic Cyclometalated Iridium(III) Complexes Supported by Triarylborylpicolinate Ligand: Ratiometric Turn-On Phosphorescence Response upon Fluoride Binding

Sharma, Sanjeev,Kim, Hyungjun,Lee, Young Hoon,Kim, Taewon,Lee, Yoon Sup,Lee, Min Hyung American Chemical Society 2014 Inorganic Chemistry Vol.53 No.16

<P>Heteroleptic cyclometalated iridium(III) complexes (C^N)<SUB>2</SUB>Ir(Bpic) (<B>4</B>–<B>6</B>) (C^N = <I>dfppy</I> (<B>4</B>), <I>ppy</I> (<B>5</B>), <I>btp</I> (<B>6</B>)) supported by triarylborylpicolinate (Bpic) ancillary ligand were synthesized and characterized. X-ray diffraction study of <B>5</B> confirmed N^O chelation of the Bpic ligand to the iridium center forming an (C^N)<SUB>2</SUB>Ir–borane conjugate. While the UV/vis absorption bands of <B>4</B>–<B>6</B> remained almost unchanged in the low-energy region upon fluoride addition, a ratiometric turn-on phosphorescence response was observed for <B>4</B> and <B>5</B>. In contrast, the phosphorescence of <B>6</B> was little affected by fluoride binding. Experimental and theoretical studies suggest that the LUMO in neutral <B>4</B> and <B>5</B> is dominated by the Bpic ligand, which makes the weakly emissive <SUP>3</SUP>ML′CT/<SUP>3</SUP>LL′CT (L = C^N; L′ = Bpic) states as the lowest-energy triplet excited state, while the fluoride binding to <B>4</B> and <B>5</B> induces the highly emissive <SUP>3</SUP>MLCT/<SUP>3</SUP>ππ* states centered on the (C^N)<SUB>2</SUB>Ir moiety. Thermally induced conversion from the <SUP>3</SUP>MLCT/<SUP>3</SUP>ππ* to the <SUP>3</SUP>ML′CT/<SUP>3</SUP>LL′CT states is suggested to be responsible for the low-energy weak phosphorescence in <B>4</B> and <B>5</B>.</P><P>Heteroleptic (C^N)<SUB>2</SUB>Ir(Bpic) complexes supported by N^O chelating triarylborylpicolinate (Bpic) ancillary ligand were synthesized and characterized. Fluoride binding to the B atom of the Bpic ligand led to a novel ratiometric turn-on phosphorescence response. Switching of the weakly emissive <SUP>3</SUP>ML′CT/<SUP>3</SUP>LL′CT state to the highly emissive <SUP>3</SUP>MLCT state centered on the (C^N)<SUB>2</SUB>Ir moiety is suggested to be responsible for the observed turn-on phosphorescence response.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/inocaj/2014/inocaj.2014.53.issue-16/ic501286m/production/images/medium/ic-2014-01286m_0010.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ic501286m'>ACS Electronic Supporting Info</A></P>

건조 수산가공식품의 방사능 및 중금속 오염도 조사

이지연,정진아,전종섭,이성봉,권혜정,김정은,이병훈,모아라,최옥경,Lee, Ji-Yeon,Jeong, Jin-A,Jeon, Jong-Sup,Lee, Seong-Bong,Kwon, Hye-Jung,Kim, Jeong-Eun,Lee, Byoung-Hoon,Mo, A-Ra,Choi, Ok-Kyung 한국식품위생안전성학회 2021 한국식품위생안전성학회지 Vol.36 No.3

건조 수산가공식품의 안전성 확보를 위해 2020년 경기도 내 유통 중인 건조 수산가공식품 12품목 120건을 수거하여 방사능(¹³¹I, ¹³⁴Cs, ¹³⁷Cs) 및 중금속(납, 카드뮴, 비소, 수은) 함량을 분석하였다. 모든 시료에서 자연 방사성 핵종 중 하나인 ⁴⁰K만 검출되었으며, 인공 방사성 물질인 ¹³¹I, ¹³⁴Cs, ¹³⁷Cs는 최소검출가능농도(MDA) 이하의 값을 나타내었다. 중금속의 평균 함량[평균±표준편차(최소값-최대값)]은 생물로 환산하였을 때 납 0.066±0.065(N.D.-0.332) mg/kg, 카드뮴 0.200±0.406(N.D.-2.941) mg/kg, 비소 3.630±3.170(0.371-15.007) mg/kg, 수은 0.009±0.011(0.0005-0.0621) mg/kg 이었으며, 수산물에서 중금속 기준이 있는 제품의 경우 모두 기준 규격 이내로 나타났다. 국내산 제품과 수입산 제품의 중금속 함량은, 조개의 카드뮴과 새우의 수은 함량에서만 유의적인 차이를 나타내었다(P<0.05). 본 연구 결과, 유통 중인 건조 수산가공식품에서 방사능 및 중금속은 안전한 수준인 것으로 판단되나, 식품 중 특히 수산물에서 방사능 오염에 대한 국민의 우려가 크기 때문에 국민들의 불안감 해소를 위해 방사능 검사는 지속적으로 필요할 것으로 생각된다. 또 향후 건조 수산가공식품 중에서도 건조된 형태로 직접 섭취 가능한 제품의 중금속 관리 기준 설정을 위한 기초 자료로 활용할 수 있을 것이다. A total of 120 samples corresponding to 12 categories of dried processed fishery products distributed in Gyeonggi-do were examined for radioactivity contamination (¹³¹I, ¹³⁴Cs, ¹³⁷Cs) and heavy metals (lead, cadmium, arsenic, and mercury). One natural radioactive material, ⁴⁰K, was detected in all products, while the artificial radioactive materials ¹³¹I, ¹³⁴Cs and ¹³⁷Cs were not detected at above MDA (minimum detectable activity) values. The detection ranges of heavy metals converted by biological basis were found as follows: Pb (N.D.-0.332 mg/kg), Cd (N.D.-2.941 mg/kg), As (0.371-15.007 mg/kg), Hg (0.0005-0.0621 mg/kg). Heavy metals were detected within standard levels when there was an acceptable standard, but the arsenic content was high in most products, although none of the products had a permitted level of arsenic. In the case of dried processed fishery products, there are products that are consumed by restoring moisture to its original state, but there are also many products that are consumed directly in the dry state, so it will be necessary to set permitted levels for heavy metals considering this situation in the future. In addition, Japan has decided to release contaminated water from the Fukushima nuclear power plant into the ocean, so there is high public concern about radioactivity contamination of food, including fishery products. Therefore, continuous monitoring of various food items will be necessary to ease consumers' anxiety.

<i>In vivo</i> monitoring of CD44 ⁺ cancer stem-like cells by γ-irradiation in breast cancer

KIM, MI HYUN,KIM, MIN HWAN,KIM, KWANG SEOK,PARK, MYUNG-JIN,JEONG, JAE-HOON,PARK, SEUNG WOO,JI, YOUNG HOON,KIM, KWANG IL,LEE, TAE SUP,RYU, PHIL YOUL,KANG, JOO HYUN,LEE, YONG JIN D.A. Spandidos 2016 International journal of oncology Vol.48 No.6

<P>There is increasing evidence that cancer contains cancer stem cells (CSCs) that are capable of regenerating a tumor following chemotherapy or radiotherapy. CD44 and CD133 are used to identify CSCs. This study investigated non-invasive <I>in vivo</I> monitoring of CD44-positive cancer stem-like cells in breast cancer by γ-irradiation using molecular image by fusing the firefly luciferase (fLuc) gene with the CD44 promoter. We generated a breast cancer cell line stably expressing fLuc gene by use of recombinant lentiviral vector controlled by CD44 promoter (MCF7-CL). Irradiated MCF7-CL spheres showed upregulated expression of CD44 and CD133, by immunofluorescence and flow cytometry. Also, gene expression levels of CSCs markers in irradiated spheres were clearly increased. CD44<SUP>+</SUP> CSCs increased fLuc expression and tumor growth <I>in vivo</I> and <I>in vitro</I>. When MCF7-CL was treated with siCD44 and irradiated, CD44 expression was inhibited and cell survival ratio was decreased. MCF7-CL subsets were injected into the mice and irradiated by using a cobalt-60 source. Then, <I>in vivo</I> monitoring was performed to observe the bioluminescence imaging (BLI). When breast cancer was irradiated, relative BLI signal was increased, but tumor volume was decreased compared to non-irradiated tumor. These results indicate that increased CD44 expression, caused by general feature of CSCs by irradiation and sphere formation, can be monitored by using bioluminescence imaging. This system could be useful to evaluate CD44-expressed CSCs in breast cancer by BLI <I>in vivo</I> as well as <I>in vitro</I> for radiotherapy.</P>

Minimum number of antennas and degrees of freedom of multiple-input–multiple-output multi-user two-way relay X channels

Tae-Hoon Kim,Dong-Sup Jin,Jaehong Kim,Jong-Seon No,Habong Chung IET 2015 IET COMMUNICATIONS Vol.9 No.4

<P>In this study, the minimum number of antennas at each user is derived to obtain 2<I>M</I><SUP>2</SUP> degrees of freedom (DOF) in the <I>M</I> × 1 × <I>M</I> multiple-input-multiple-output (MIMO) multi-user two-way relay X channels. Based on the design of beamforming vectors for the conventional signal space alignment scheme, it is shown that each user needs at least ⌈<I>M</I><SUP>2</SUP><I>-</I> (<I>M</I>/2)⌉ antennas to obtain DOF 2<I>M</I><SUP>2</SUP> with the relay having <I>M</I><SUP>2</SUP> antennas. As the number of users increases, the number of antennas also increases, which makes the implementation difficult. In an effort to reduce the number of antennas, the authors propose a new beamforming scheme of MIMO multi-user two-way relay X channels using the time extension. Through the numerical analysis, it is confirmed that the proposed scheme with time extension is a good alternative scheme to replace the conventional scheme.</P>

갑상선 결절의 감별진단에 있어 탄성 초음파검사

김정훈,최재영,최영식<SUP>1<,SUP>,정미희<SUP>2<,SUP>,정경순<SUP>2<,SUP>,Jung Hoon Kim,M,D,Jae Young Choi,M,D,Young Sik Choi,M,D,<SUP>1<,SUP>,Mi Hee Jung,M,D,<SUP>2<,SUP> and Kyung Soon Jung,M,D,<SUP>2<,SUP> 대한갑상선-내분비외과학회 2011 The Koreran journal of Endocrine Surgery Vol.11 No.1

Purpose: Ultrasound (US) elastography is a newly developed imaging technique for assessing tissue stiffness by measuring the degree of the tissue's deformation in response to the application of an external force. This technique has recently been applied for making the diagnosis of nodular thyroid disease. The purpose of this study was to evaluate the diagnostic utility of US elastography for differentiating benign thyroid nodules from malignant thyroid nodules. Methods: A total of 63 consecutive patients with thyroid nodules and who were referred for surgical treatment were examined in this study. Seventy-five nodules in these patients were examined by US B-mode, color Doppler US and US elastography. The final diagnosis was obtained from the histologic findings. The tissue stiffness on ultrasound elastography was scored from 1 (elasticity in the whole nodule) to 5 (no elasticity in the nodule and in the posterior shadowing). Results: On US elastography, 18 of 32 benign nodules (56.3%) had a score of 1 to 3, whereas 23 of 43 malignant nodules (62.8%) had a score of 4 to 5. With applying a US elastography score of 4-5 as an indicator for malignancy, the sensitivity, specificity, positive predictive value and negative predictive value of US elastography were 65.9%, 52.9%, 62.8% and 56.3%, respectively. Of the 14 follicular tumors, 12 were follicular adenoma and four were follicular carcinoma. The sensitivity and specificity of US elastography for diagnosing follicular carcinoma were 50.0% and 81% (56=69), respectively. The positive and negative predictive values were 55.2% (16=29) and 60.0%, respectively. The accuracy of the technique was 57.1%. The findings of US elastography were not significantly correlated with the histopathologic findings. Conclusion: This study has shown that US elastography may be not useful for differentiating between benign and malignant thyroid nodules. Further studies are needed to confirm the usefulness of US elastography for making the differential diagnosis of thyroid nodules. (Korean J Endocrine Surg 2011;11:12-17)

Myristoleic Acid Promotes Anagen Signaling by Autophagy through Activating Wnt/β-Catenin and ERK Pathways in Dermal Papilla Cells

( Youn Kyung Choi ),( Jung-il Kang ),( Jin Won Hyun ),( Young Sang Koh ),( Ji-hoon Kang ),( Chang-gu Hyun ),( Kyung-sup Yoon ),( Kwang Sik Lee ),( Chun Mong Lee ),( Tae Yang Kim ),( Eun-sook Yoo ),( H 한국응용약물학회 2021 Biomolecules & Therapeutics(구 응용약물학회지) Vol.29 No.2

Alopecia is a distressing condition caused by the dysregulation of anagen, catagen, and telogen in the hair cycle. Dermal papilla cells (DPCs) regulate the hair cycle and play important roles in hair growth and regeneration. Myristoleic acid (MA) increases Wnt reporter activity in DPCs. However, the action mechanisms of MA on the stimulation of anagen signaling in DPCs is not known. In this study, we evaluated the effects of MA on anagen-activating signaling pathways in DPCs. MA significantly increased DPC proliferation and stimulated the G2/M phase, accompanied by increasing cyclin A, Cdc2, and cyclin B1. To elucidate the mechanism by which MA promotes DPC proliferation, we evaluated the effect of MA on autophagy and intracellular pathways. MA induced autophagosome formation by decreasing the levels of the phospho-mammalian target of rapamycin (phospho-mTOR) and increasing autophagy-related 7 (Atg7) and microtubule-associated protein 1A/1B-light chain 3II (LC3II). MA also increased the phosphorylation levels of Wnt/β-catenin proteins, such as GSK3β (Ser⁹) and β-catenin (Ser⁵⁵² and Ser⁶⁷⁵). Treatment with XAV939, an inhibitor of the Wnt/β-catenin pathway, attenuated the MA-induced increase in β-catenin nuclear translocation. Moreover, XAV939 reduced MA-induced effects on cell cycle progression, autophagy, and DPC proliferation. On the other hand, MA increased the levels of phospho (Thr²⁰²/Tyr²⁰⁴)-extracellular signal regulated kinases (ERK). MA-induced ERK phosphorylation led to changes in the expression levels of Cdc2, Atg7 and LC3II, as well as DPC proliferation. Our results suggest that MA promotes anagen signaling via autophagy and cell cycle progression by activating the Wnt/β-catenin and ERK pathways in DPCs.