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차량 충돌 방지용 24㎓ 레이더 주파수대의 근거리 전파손실특성
하덕호(Deock-Ho Ha),류지열(Jee-Youl Ryu),김성운(Sung-Un Kim),최연욱(Yeon-Wook Choi) 한국정보기술학회 2011 한국정보기술학회논문지 Vol.9 No.8
In this paper, we describe the short range propagation loss characteristic of 24㎓ frequency band used for automotive collision avoidance radar (ACAR). To investigate the radio propagation characteristic of ACAR signals, we used 24㎓ UMCW (Un-Modulated Continuous Wave) signals using by several polarized antenna combinations. To detect the accurate message data for safety guiding ACAR, we analyze and investigate the optimum receiving condition from the short range UMCW signal of the 24㎓ frequency. From the measurement analysis, it can be clearly seen that the short range UMCW signal can be encountered to multipath interference due to scattering rays from the ground plane and adjacent moving obstacles. In addition, it was also found that the received signal strength of circularly co-polarized antenna shows the most strong envelopes and best fading reduction effect.
Sang Un Park,Deok-Jong Ahn,Hyeon-Jeong Jeon,Tae Ryong Kwon,Hyoun-Sub Lim,Bo-Seong Choi,Kwang-Hyun Baek,Hanhong Bae 고려인삼학회 2012 Journal of Ginseng Research Vol.36 No.2
An light-emitting diode (LED)-based light source was used as a monochromatic light source to determine the responses of raw ginseng roots (Panax ginseng Meyer) to specifi c emission spectra with respect to the production of ginsenosides. The ginsenoside content in the ginseng roots changed in response to the LED light treatments at 25℃ relative to the levels in the control roots that were treated in the dark or at 4℃ for 7 d. Ginseng roots were exposed to LEDs with four different peak emission wavelengths, 380, 450, 470, and 660 ㎚, in closed compartments. Compared with the control 4℃-treated roots, roots that were treated with 450 and 470 ㎚ light showed a signifi cantly increased production of ginsenosides (p<0.05), with increases of 64.9% and 74.1%, respectively. The contents of the ginsenosides Rb2, Rc, and Rg₁ were signifi cantly higher (p<0.05) in the 450 and 470 ㎚-treated root samples. The ratio of protopanaxadiol ginsenosides (Rb₁, Rb₂, Rc, and Rd) to protopanaxatriol ginsenosides (Rg₁, Rg₂, Re, and Rf) was signifi cantly higher (p<0.05) in the 450 and 470 ㎚-treated root samples than in the control 4℃-treated roots. This is the fi rst report that demonstrates the increase and conversion of ginsenosides in raw ginseng roots in response to exposure to LED light.
Choi, Seong-Heon,Lee, Jee Young,Lee, Sung-Un,Lee, Soo-Min,Park, Sora,Jung, Yee-Hong The Society of Korean Medicine 2014 대한한의학회지 Vol.35 No.4
Objectives: A 54-year-old advanced gastric cancer patient developed severe fluid retention after docetaxel chemotherapy, at cumulative dose of $930mg/m^2$, with no improvement using diuretics or prophylactic glucocorticoids. Consequently, he changed chemotherapy regimen from docetaxel to paclitaxel. After he treated with herbal decoction Bangkihwangki-tang (BHT), which is widely used to treat several symptoms including edema in traditional Korean medicine, docetaxel-induced fluid retention (DIFR) was significantly improved along with associated symptoms, such as peripheral edema, pleural and pericardial effusion, pain, scleroderma, and hypoesthesia. As the symptoms were relieved, his performance status and ambulatory ability were improved. During herbal treatment, he continued chemotherapy without any problems and didn't show any adverse events related to herbal medicine. Although there is possibility of natural improvement progress after withdrawal of docetaxel, he showed shorter recovery period and significant improvement despite of severity of initial symptoms.
Choi, Kyung Un,Yun, Jeong Sup,Lee, Il Hwan,Heo, Soon Chul,Shin, Sang Hun,Jeon, Eun Su,Choi, Yoon Ji,Suh, Dong‐,Soo,Yoon, Man‐,Soo,Kim, Jae Ho Wiley Subscription Services, Inc., A Wiley Company 2011 International journal of cancer: Journal internati Vol.128 No.2
<P><B>Abstract</B></P><P>Lysophosphatidic acid (LPA) is a bioactive lipid crucial for the initiation and progression of ovarian cancer. Identification of LPA‐induced biomarkers is necessary for predicting prognosis of ovarian cancer patients. Here we report periostin, an extracellular matrix protein, as an LPA‐induced protein in stromal cells and as a prognostic marker in patients with epithelial ovarian cancer (EOC). In human EOC tissues, periostin was mainly expressed in cancer‐associated stromal fibroblasts, but not in cancer cells. The expression levels of periostin highly correlated with poor survival and tumor recurrence of ovarian cancer patients. Treatment of human adipose tissue‐derived stromal cells with LPA or conditioned media from human ovarian adenocarcinoma cell lines, such as SK‐OV‐3 and OVCAR‐3, induced expression of periostin. The periostin expression induced by cancer‐conditioned media was abrogated by silencing of the LPA receptor 1 expression using small hairpin RNA lentivirus. Recombinant periostin stimulated adhesion and invasion of SK‐OV‐3 human ovarian adenocarcinoma cells and induced expression of matrix metalloprotease‐2 in the cancer cells. These results suggest that LPA is associated with the expression of periostin in cancer‐associated fibroblasts of EOC.</P>
Sang Ho Rha,Jisim Jung,Yoonsoo Jung,Yoon Jang Chung,Un Ki Kim,Eun Suk Hwang,Byoung Keon Park,Tae Joo Park,Jung-Hae Choi,Cheol Seong Hwang IEEE 2012 IEEE transactions on electron devices Vol.59 No.12
<P>The transmission-line method (TLM) was adopted to clarify the causes of device performance variation according to the source/drain metal electrode and device structure of a thin-film transistor using an amorphous indium-gallium-zinc-oxide channel. Using the TLM, the channel characteristics independent of contact resistance were extracted for the two different contact metals, i.e., Ti and Mo. Based on these results, the mobility characteristics were compared in terms of device scaling and contact structure in the source/drain overlap region. In addition, the transport characteristics according to the contact structure of the source/drain metal electrode were investigated in detail and reproduced using the simulation model.</P>
Choi, Sang-Il,Lee, Su-Un,Kim, Woo Youn,Choi, Ran,Hong, Kwangwoo,Nam, Ki Min,Han, Sang Woo,Park, Joon T. American Chemical Society 2012 ACS APPLIED MATERIALS & INTERFACES Vol.4 No.11
<P>Modification of the electronic structure and lattice contraction of Pt alloy nanocatalysts through control over their morphology and composition has been a crucial issue for improving their electrocatalytic oxygen reduction reaction (ORR) activity. In the present work, we synthesized PtCo alloy nanocubes with controlled compositions (Pt<SUB><I>x</I></SUB>Co NCs, <I>x</I> = 2, 3, 5, 7, and 9) by regulating the ratio of surfactants and the amount of Co precursor to elucidate the effect of the composition of nanocatalysts on their ORR activity. Pt<SUB><I>x</I></SUB>Co NCs had a Pt-skin structure after electrochemical treatment. The electrocatalysis experiments revealed a strong correlation between ORR activity and Co composition. Pt<SUB>3</SUB>Co NCs exhibited the best ORR performance among the various Pt<SUB><I>x</I></SUB>Co NCs. From density functional theory calculations, a typical volcano-type relationship was established between ORR activity and oxygen binding energy (<I>E</I><SUB>OB</SUB>) on NC surfaces, which showed that Pt<SUB>3</SUB>Co NCs had the optimal <I>E</I><SUB>OB</SUB> to achieve the maximum ORR activity. X-ray photoelectron spectroscopy and X-ray diffraction measurements demonstrated that the electronic structure and lattice contraction of the Pt<SUB><I>x</I></SUB>Co NCs could be tuned by controlling the composition of NCs, which are highly correlated with the trends of <I>E</I><SUB>OB</SUB> change.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2012/aamick.2012.4.issue-11/am301824w/production/images/medium/am-2012-01824w_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am301824w'>ACS Electronic Supporting Info</A></P>
Synthesis of Antineoplaston A10 Analogs as Potential Antitumor Agents
Choi, Bo Gil,Kim, Ok Young,Chung, Byung Ho,Cho, Won Jea,Cheon, Seung Hoon,Choi, Sang Un,Lee, Chong Ock 전남대학교 약품개발연구소 1998 약품개발연구지 Vol.7 No.1
Several aniline mustard analogues were obtained by introducing N,N-bis(2-chloroethyl)amino moiety to phenyl ring of A10 analogues in order to increase reactivity of A10 analogs and selectivity into DNA. The in vitro antitumor activity of synthesized compounds was evaluated using five different solid tumor cell lines by SRB method. Aniline mustard analogues exhibited more potent antitumor activity than A10 analogs. Especially, m-aniline mustard of benzoyl analogue displayed remarkable antitumor activity.
Indian Hedgehog signalling triggers Nkx3.2 protein degradation during chondrocyte maturation.
Choi, Seung-Won,Jeong, Da-Un,Kim, Jeong-Ah,Lee, Boyoung,Joeng, Kyu Sang,Long, Fanxin,Kim, Dae-Won Biochemical Society 2012 The Biochemical journal Vol.443 No.3
<P>The Ihh (Indian Hedgehog) pathway plays an essential role in facilitating chondrocyte hypertrophy and bone formation during skeletal development. Nkx3.2 (NK3 homeobox 2) is initially induced in chondrocyte precursor cells, maintained in early-stage chondrocytes and down-regulated in terminal-stage chondrocytes. Consistent with these expression patterns, Nkx3.2 has been shown to enhance chondrocyte differentiation and cell survival, while inhibiting chondrocyte hypertrophy and apoptosis. Thus, in the present study, we investigated whether Nkx3.2, an early-stage chondrogenic factor, can be regulated by Ihh, a key regulator for chondrocyte hypertrophy. We show that Ihh signalling can induce proteasomal degradation of Nkx3.2. In addition, we found that Ihh can suppress levels of Lrp (low-density-lipoprotein-receptor-related protein) (Wnt co-receptor) and Sfrp (secreted frizzled-related protein) (Wnt antagonist) expression, which, in turn, may selectively enhance Lrp-independent non-canonical Wnt pathways in chondrocytes. In agreement with these findings, Ihh-induced Nkx3.2 degradation requires Wnt5a, which is capable of triggering Nkx3.2 degradation. Finally, we found that Nkx3.2 protein levels in chondrocytes are remarkably elevated in mice defective in Ihh signalling by deletion of either Ihh or smoothened. Thus these results suggest that Ihh/Wnt5a signalling may play a role in negative regulation of Nkx3.2 for appropriate progression of chondrocyte hypertrophy during chondrogenesis.</P>
Nearly single-crystalline GaN light-emitting diodes on amorphous glass substrates
Choi, Jun Hee,Zoulkarneev, Andrei,Kim, Sun Il,Baik, Chan Wook,Yang, Min Ho,Park, Sung Soo,Suh, Hwansoo,Kim, Un Jeong,Bin Son, Hyung,Lee, Jae Soong,Kim, Miyoung,Kim, Jong Min,Kim, Kinam Springer Science and Business Media LLC 2011 Nature photonics Vol.5 No.12