활성제 첨가에 따른 ZnGa₂O₄ 형광체의 발광특성

홍범주,최형욱,Hong Beom-Joo,Choi Hyung-Wook 한국전기전자재료학회 2006 전기전자재료학회논문지 Vol.19 No.5

The $ZnGa_2O_4$ and Mn, Cr-doped $ZnGa_2O_4$ Phosphors were synthesized through conventional solid state reactions. The XRD patterns show that the $ZnGa_2O_4$ has a (3 1 1) main peak and a spinel phase. The emission wavelength of $ZnGa_2O_4$ showed main peak of 420 nm and maximum intensity at the sintering temperature of $1100^{\circ}C$. In the crystalline $ZnGa_2O_4$, the Mn shows green emission (510 nm, $^4T_1-^6A_1$) with a quenching concentration of 0.6 mol%, and the Cr shows red emission (705 nm, $^4T_2-^4A_2$) with a quenching concentration of 2 mol%. These results indicate that $ZnGa_2O_4$ Phosphors hold promise for potential applications in field emission display devices with high brightness operating in full color regions.

Tumor hypoxia and reoxygenation: the yin and yang for radiotherapy

홍범주,김정우,정회빈,복서연,김영은,안지완 대한방사선종양학회 2016 Radiation Oncology Journal Vol.34 No.4

Tumor hypoxia, a common feature occurring in nearly all human solid tumors is a major contributing factor for failures of anticancer therapies. Because ionizing radiation depends heavily on the presence of molecular oxygen to produce cytotoxic effect, the negative impact of tumor hypoxia had long been recognized. In this review, we will highlight some of the past attempts to overcome tumor hypoxia including hypoxic radiosensitizers and hypoxia-selective cytotoxin. Although they were (still are) a very clever idea, they lacked clinical efficacy largely because of ‘reoxygenation’ phenomenon occurring in the conventional low dose hyperfractionation radiotherapy prevented proper activation of these compounds. Recent meta-analysis and imaging studies do however indicate that there may be a significant clinical benefit in lowering the locoregional failures by using these compounds. Latest technological advancement in radiotherapy has allowed to deliver high doses of radiation conformally to the tumor volume. Although this technology has brought superb clinical responses for many types of cancer, recent modeling studies have predicted that tumor hypoxia is even more serious because ‘reoxygenation’ is low thereby leaving a large portion of hypoxic tumor cells behind. Wouldn’t it be then reasonable to combine hypoxic radiosensitizers and/or hypoxia-selective cytotoxin with the latest radiotherapy? We will provide some preclinical and clinical evidence to support this idea hoping to revamp an enthusiasm for hypoxic radiosensitizers or hypoxia-selective cytotoxins as an adjunct therapy for radiotherapy.

Apoptosis in Leukemic Cells Induced by Anti-Proliferative Coumarin Isolated from the Stem Bark of Fraxinus rhynchophylla

이범주,이익수,Chau Ha Pham,정순규,Sulhae Lee,홍광원,유희민 한국미생물·생명공학회 2020 Journal of microbiology and biotechnology Vol.30 No.8

Esculetin 6-O-β-D-arabinofuranosyl-(1 →6)-β-D-glucopyranoside (EAG) is a coumarin glycoside isolated from the stem bark of Fraxinus rhynchophylla. This study scrutinized the anti-proliferative activity of EAG on blood cancer-derived Jurkat leukemic cells. Cell viability assays in leukemic cancer cells determined that EAG possesses potent anti-proliferative effects. Moreover, treatment with EAG increased the proportion of apoptotic cells, resulted in cell cycle arrest being induced at the subG0/ G1 phase, and reduced the proportion of cells present in the S phase. In addition, mitochondrial membrane potential was reduced by EAG in Jurkat cells. Additionally, EAG triggered apoptosis that was mediated by the downregulation of BCL-XL, p-IκBα, and p-p65 expressions in addition to the upregulation of cleaved Caspase 3 and BAX expressions. These findings revealed that the toxic effect of EAG was mediated by intracellular signal transduction pathways that involved a mechanism in which reactive oxygen species (ROS) were upregulated. Thus, this study concludes that EAG could potentially serve as a therapeutic agent for leukemia.

기판온도 및 Annealing에 따른 ZnGa₂O₄ 형광체 박막의 특성

김용천,홍범주,권상직,이달호,김경환,박용서,최형욱,Kim, Yong-Chun,Hong, Beom-Joo,Kwon, Sang-Jik,Lee, Dal-Ho,Kim, Kyung-Hwan,Park, Yong-Seo,Choi, Hyung-Wook 한국전기전자재료학회 2005 전기전자재료학회논문지 Vol.18 No.2

A ZnGa$_2$O$_4$ phosphor target was synthesized through solid-state reactions at a calcine temperature of 700 $^{\circ}C$ and sintering temperature of 1300 $^{\circ}C$ in order to deposit ZnGa$_2$O$_4$ phosphor thin film at various temperature using rf magnetron sputtering system. A ZnGa$_2$O$_4$ phosphor thin film was deposited on Si(100) substrate and annealed by a rapid thermal processor(RTP) at 700 $^{\circ}C$, for 15 sec. The x-ray diffraction patterns of ZnGa$_2$O$_4$ phosphor target and thin film showed the main peak (311) direction. ZnGa$_2$O$_4$ thin film has better crystalization due to as function of increasing substrate and annealing temperature. The cathodoluminescence(CL) spectrums of ZnGa$_2$O$_4$ phosphor thin film showed the main peak 420 nm wavelength and the maximum intensity at the substrate temperature of 500 $^{\circ}C$ and annealing temperature of 700 $^{\circ}C$, for 15 sec.

ZnGa₂O₄ 형광체 타겟의 제작 및 특성분석

김용천,홍범주,권상직,김경환,박용서,최형욱,Kim, Yong-Chun,Hong, Beom-Joo,Kwon, Sang-Jik,Kim, Kyung-Hwan,Park, Yong-Seo,Choi, Hyung-Wook 한국전기전자재료학회 2004 전기전자재료학회논문지 Vol.17 No.12

The ZnGa$_2$O$_4$ phosphor target was synthesized through solid-state reactions as calcine and sintering temperature in order to deposit ZnGa$_2$O$_4$ Phosphor thin film by rf magnetron sputtering system. The x-ray diffraction patterns of ZnGa$_2$O$_4$ phosphor target showed the position of (311) main peak. The cathodoluminescence(CL) spectrums of ZnGa$_2$O$_4$ phosphor target showed main peak of 370 nm to 400 nm, and maximum intensity at the calcine temperature of $700^{\circ}C$ and sintering temperature of 130$0^{\circ}C$. It was possible to prepare The ZnGa$_2$O$_4$ phosphor thin film with synthesized ZnGa$_2$O$_4$ phosphor target and The prepared ZnGa$_2$O$_4$ phosphor thin film showed the position of (311) main peak.

Radiation-induced immune responses: mechanisms and therapeutic perspectives

정회빈,복서연,홍범주,Hyung-Seok Choi,안지완 대한혈액학회 2016 Blood Research Vol.51 No.3

Recent advancement in the radiotherapy technology has allowed conformal delivery of high doses of ionizing radiation precisely to the tumors while sparing large volume of the normal tissues, which have led to better clinical responses. Despite this technological advancement many advanced tumors often recur and they do so within the previously irradiated regions. How could tumors recur after receiving such high ablative doses of radiation? In this review, we outlined how radiation can elicit anti-tumor responses by introducing some of the cytokines that can be induced by ionizing radiation. We then dis-cuss how tumor hypoxia, a major limiting factor responsible for failure of radiotherapy, may also negatively impact the anti-tumor responses. In addition, we highlight how there may be other populations of immune cells including regulatory T cells (Tregs), mye-loid-derived suppressor cells (MDSCs), and tumor-associated macrophages (TAMs) that can be recruited to tumors interfering with the anti-tumor immunity. Finally, the impact of irradiation on tumor hypoxia and the immune responses according to different radio-therapy regimen is also delineated. It is indeed an exciting time to see that radiotherapy is being combined with immunotherapy in the clinic and we hope that this review can add an excitement to the field.

Effect of DNA extraction methods on the detection of porcine ingredients in halal cosmetics using real-time PCR

김유송,유희경,이범주,홍광원 한국응용생명화학회 2018 Applied Biological Chemistry (Appl Biol Chem) Vol.61 No.5

In recent years, halal cosmetics have attracted considerable attention worldwide. We developed a realtime PCR assay based on the mitochondrial gene ndh5 for rapid detection of porcine ingredients in halal cosmetic products. We also compared several DNA extraction methods for the most efficient approach in different types of cosmetics. Porcine template DNA was spiked into three types of cosmetics (liquid-type and powder-type mask packs, and cream) and extracted with five commercial DNA extraction kits and the CTAB method. The extraction efficiency of each method was evaluated by determining the detection limits of real-time PCR assay. The lowest detection limit of real-time PCR for each cosmetic product was as follows: 2.28 9 100 copies for liquid-type mask pack when the Power PrepTM DNA extraction kit and TIANamp Genomic DNA kit were used, 2.28 9 101 copies for powder-type mask pack when QIAamp DNA stool mini kit and the Power PrepTM DNA extraction kit were used, and 2.28 9 100 copies for cream when the Power PrepTM DNA extraction kit was used. The pig-specific real-time PCR assay facilitated the detection of trace amounts of the template DNA in cosmetics, and an appropriate DNA extraction method was used depending on the type of cosmetics.

당근, 느타리버섯 및 솔잎 추출물이 첨가된 화장품의 할랄인증을 위한 PCR 분석

장찬송,김태현,김유송,이범주,홍광원 한국산업식품공학회 2018 산업 식품공학 Vol.22 No.4

In recent years, interest in halal authentication from the domestic food and cosmetics field has been growing for advances into the overseas halal market. For halal authentication, the product must not contain haram ingredients derived from pig, dog, human, GMO, etc. In this study, the presence of haram ingredients in plant extracts (carrot, oyster mushroom, and pine needle) treated with papain and bromelain and cosmetics (mask pack and cream) containing these extracts were analyzed by PCR to confirm whether these cosmetics were suitable for halal authentication. Detection limits of the PCR method that specifically detected template DNA of human, pig, dog, and GMO were 1.29×103, 1.14×103, 1.24×102 and 2.02×103 copies/tube, respectively. PCR was not inhibited by the plant extracts or cosmetic ingredients. Results of PCR for the plant extracts or cosmetics containing these extracts were all negative. This PCR method could be used to rapidly identify the presence of haram ingredients in raw materials or final products during the manufacturing process of food and cosmetics.