Dual-Sensitivity Mode CMOS Image Sensor for Wide Dynamic Range Using Column Capacitors

( Sanggwon Lee ),( Myunghan Bae ),( Byoung-soo Choi ),( Jang-kyoo Shin ) 한국센서학회 2017 센서학회지 Vol.26 No.2

A wide dynamic range (WDR) CMOS image sensor (CIS) was developed with a specialized readout architecture for realizing highsensitivity (HS) and low-sensitivity (LS) reading modes. The proposed pixel is basically a three-transistor (3T) active pixel sensor (APS) structure with an additional transistor. In the developed WDR CIS, only one mode between the HS mode for relatively weak light intensity and the LS mode for the strong light intensity is activated by an external controlling signal, and then the selected signal is read through each column-parallel readout circuit. The LS mode is implemented with the column capacitors and a feedback structure for adjusting column capacitor size. In particular, the feedback circuit makes it possible to change the column node capacitance automatically by using the incident light intensity. As a result, the proposed CIS achieved a wide dynamic range of 94 dB by synthesizing output signals from both modes. The prototype CIS is implemented with 0.18-μm 1-poly 6-metal (1P6M) standard CMOS technology, and the number of effective pixels is 176 (H) × 144 (V).

고압 인젝터의 분사율 예측을 위한 경량 모델 개발

이상권 ( Sanggwon Lee ),배규한 ( Gyuhan Bae ),( Omer Faruk Atac ),문석수 ( Seoksu Moon ),강진석 ( Jinsuk Kang ) 한국분무공학회 2020 한국액체미립화학회지 Vol.25 No.4

To meet stringent emission regulations of automotive engines, fuel injection control techniques have advanced based on reliable and fast computing prediction models. This study aims to develop a reliable lightweight prediction model of fuel injection rates using a small number of input parameters and based on simple fluid dynamic theories. The prediction model uses the geometry of the injector nozzle, needle motion data, injection conditions and the fuel properties. A commercial diesel injector and US No. 2 diesel were used as the test injector and fuel, respectively. The needle motion data were measured using X-ray phase-contrast imaging technique under various fuel injection pressures and injection pulse durations. The actual injector rate profiles were measured using an injection rate meter for the validation of the model prediction results. In the case of long injection durations with the steady-state operation, the model prediction results showed over 99 % consistency with the measurement results. However, in the case of short injection cases with the transient operation, the prediction model overestimated the injection rate that needs to be further improved.

고압 인젝터의 과도 거동을 고려한 고응답 분사율 예측모델 개발

이상권(Sanggwon Lee),배규한(Gyuhan Bae),OMER FARUK ATAC,문석수(Seoksu Moon),강진석(Jinsuk Kang) 한국자동차공학회 2020 한국자동차공학회 부문종합 학술대회 Vol.2020 No.7

전문대학의 교육환경 개선방안

김달곤,이상권 경인여자대학 2002 경인논집 Vol.- No.9

The Ministry of Education & Human Resources Development have announced the plans of improvement of college education in ?? 2001. However, this have many problems including a permission of a college consolidation by special. We think that the ?? important thing to reform college education is to solve the irrationality and embezzlement of a private school.

Pulse control in a wide frequency range for a quasi-continuous wave diode-pumped cesium atom vapor laser by a pump modulation in the spectral domain

Hong, Seongjin,Kong, Byungjoo,Lee, Yong Soo,Song, Sanggwon,Kim, Seokjin,Oh, Kyunghwan The Optical Society 2018 Optics express Vol.26 No.20

모바일을 위한 JavaCv를 이용한 Tensoflow모델 구동환경 개발

박진상(JinSang Park),오상권(SangGwon Oh),이성진(SeongJin Lee) 한국컴퓨터정보학회 2020 한국컴퓨터정보학회 학술발표논문집 Vol.28 No.1

Design, synthesis and anti-melanogenic effect of cinnamamide derivatives

Ullah, Sultan,Park, Yujin,Ikram, Muhammad,Lee, Sanggwon,Park, Chaeun,Kang, Dongwan,Yang, Jungho,Akter, Jinia,Yoon, Sik,Chun, Pusoon,Moon, Hyung Ryong Elsevier 2018 Bioorganic & medicinal chemistry Vol.26 No.21

<P><B>Abstract</B></P> <P>Pigmentation disorders are attributed to excessive melanin which can be produced by tyrosinase. Therefore, tyrosinase is supposed to be a vital target for the treatment of disorders associated with overpigmentation. Based on our previous findings that an (<I>E</I>)-β-phenyl-α,β-unsaturated carbonyl scaffold can play a key role in the inhibition of tyrosinase activity, and the fact that cinnamic acid is a safe natural substance with a scaffolded structure, it was speculated that appropriate cinnamic acid derivatives may exhibit potent tyrosinase inhibitory activity. Thus, ten cinnamamides were designed, and synthesized by using a Horner-Emmons olefination as the key step. Cinnamamides <B>4</B> (93.72% inhibition), <B>9</B> (78.97% inhibition), and <B>10</B> (59.09% inhibition) with either a 2,4-dihydroxyphenyl, or 4-hydroxy-3-methoxyphenyl substituent showed much higher mushroom tyrosinase inhibition at 25 µM than kojic acid (18.81% inhibition), used as a positive control. Especially, the two cinnamamides <B>4</B> and <B>9</B> having a 2,4-dihydroxyphenyl group showed the strongest inhibition. Docking simulation with tyrosinase revealed that these three cinnamamides, <B>4</B>, <B>9</B>, and <B>10</B>, bind to the active site of tyrosinase more strongly than kojic acid. Cell-based experiments carried out using B16F10 murine skin melanoma cells demonstrated that all three cinnamamides effectively inhibited cellular tyrosinase activity and melanin production in the cells without cytotoxicity. There was a close correlation between cellular tyrosinase activity and melanin content, indicating that the inhibitory effect of the three cinnamamides on melanin production is mainly attributed to their capability for cellular tyrosinase inhibition. These results imply that cinnamamides having the (<I>E</I>)-β-phenyl-α,β-unsaturated carbonyl scaffolds are promising candidates for skin-lighting agents.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

The tyrosinase inhibitory effects of isoxazolone derivatives with a (<i>Z</i>)-β-phenyl-α, β-unsaturated carbonyl scaffold

Kim, Su Jeong,Yang, Jungho,Lee, Sanggwon,Park, Chaeun,Kang, Dongwan,Akter, Jinia,Ullah, Sultan,Kim, Yeon-Jeong,Chun, Pusoon,Moon, Hyung Ryong Elsevier 2018 Bioorganic & medicinal chemistry Vol.26 No.14

<P><B>Abstract</B></P> <P>Thirteen (<I>Z</I>)-4-(substituted benzylidene)-3-phenylisoxazol-5(4<I>H</I>)-ones were designed to confirm the geometric effect of the double bond of the β-phenyl-α, β-unsaturated carbonyl scaffold on tyrosinase inhibitory activity. Compounds <B>1a</B>–<B>1m</B>, which all possessed the (<I>Z</I>)-β-phenyl-α, β-unsaturated carbonyl scaffold, were synthesized using a tandem reaction consisting of an isoxazolone ring formation and a Knoevenagel condensation, and three starting materials, ethyl benzoylacetate, hydroxylamine and benzaldehydes. Some of the compounds showed inhibitory activity against mushroom tyrosinase as potent as compounds containing the “(<I>E</I>)”-β-phenyl-α, β-unsaturated carbonyl scaffold. Compounds <B>1c</B> and <B>1m</B> showed greater inhibitory activity than kojic acid: IC<SUB>50</SUB> = 32.08 ± 2.25 μM for <B>1c</B>; IC<SUB>50</SUB> = 14.62 ± 1.38 μM for <B>1m</B>; and IC<SUB>50</SUB> = 37.86 ± 2.21 μM for kojic acid. A kinetic study indicated that <B>1m</B> inhibited tyrosinase in a competitive manner and that it probably binds to the enzyme’s active site. In silico docking simulation supported binding of <B>1m</B> (−7.6 kcal/mol) to the active site of tyrosinase with stronger affinity than kojic acid (−5.7 kcal/mol). Similar results were obtained using cell-based assays, and in B16F10 cells, compound <B>1m</B> dose-dependently inhibited tyrosinase activity and melanogenesis. These results indicate the anti-melanogenic effect of compound <B>1m</B> is due to the inhibition of tyrosinase and (<I>Z</I>)-isomer of the β-phenyl-α, β-unsaturated carbonyl scaffold can, like its congener the (<I>E</I>)-isomer, act as an excellent scaffold for tyrosinase inhibition.</P> <P><B>Highlights</B></P> <P> <UL> <LI> (<I>Z</I>)-β-phenyl-α, β-unsaturated carbonyl compounds are prepared by a tandem reaction. </LI> <LI> (<I>Z</I>)-geometry is proved to be a core part of potent tyrosinase inhibitors. </LI> <LI> Compounds with the (<I>Z</I>)-geometry show anti-melanogenic activity in cell-based assays. </LI> <LI> Docking results support the compounds may bind to the active site of tyrosinase. </LI> <LI> Kinetic study implies the competitive inhibition between compounds and the substrate. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

MHY2251, a New SIRT1 Inhibitor, Induces Apoptosis via JNK/p53 Pathway in HCT116 Human Colorectal Cancer Cells

Kang Yong Jung,Kwon Young Hoon,Jang Jung Yoon,Lee Jun Ho,Lee Sanggwon,Park Yujin,Moon Hyung Ryong,Chung Hae Young,Kim Nam Deuk 한국응용약물학회 2023 Biomolecules & Therapeutics(구 응용약물학회지) Vol.31 No.1

Sirtuins (SIRTs) belong to the nicotinamide adenine dinucleotide (NAD+)-dependent class III histone deacetylase family. They are key regulators of cellular and physiological processes, such as cell survival, senescence, differentiation, DNA damage and stress response, cellular metabolism, and aging. SIRTs also influence carcinogenesis, making them potential targets for anticancer therapeutic strategies. In this study, we investigated the anticancer properties and underlying molecular mechanisms of a novel SIRT1 inhibitor, MHY2251, in human colorectal cancer (CRC) cells. MHY2251 reduced the viability of various human CRC cell lines, especially those with wild-type TP53. MHY2251 inhibited SIRT1 activity and SIRT1/2 protein expression, while promoting p53 acetylation, which is a target of SIRT1 in HCT116 cells. MHY2251 treatment triggered apoptosis in HCT116 cells. It increased the percentage of late apoptotic cells and the sub-G1 fraction (as detected by flow cytometric analysis) and induced DNA fragmentation. In addition, MHY2251 upregulated the expression of FasL and Fas, altered the ratio of Bax/Bcl-2, downregulated the levels of pro-caspase-8, -9, and -3 proteins, and induced subsequent poly(ADP-ribose) polymerase cleavage. The induction of apoptosis by MHY2251 was related to the activation of the caspase cascade, which was significantly attenuated by pre-treatment with ZVAD- FMK, a pan-caspase inhibitor. Furthermore, MHY2251 stimulated the phosphorylation of c-Jun N-terminal kinase (JNK), and MHY2251-triggered apoptosis was blocked by pre-treatment with SP600125, a JNK inhibitor. This finding indicated the specific involvement of JNK in MHY2251-induced apoptosis. MHY2251 shows considerable potential as a therapeutic agent for targeting human CRC via the inhibition of SIRT1 and activation of JNK/p53 pathway.

Tyrosinase inhibition and anti-melanin generation effect of cinnamamide analogues

Ullah, Sultan,Park, Chaeun,Ikram, Muhammad,Kang, Dongwan,Lee, Sanggwon,Yang, Jungho,Park, Yujin,Yoon, Sik,Chun, Pusoon,Moon, Hyung Ryong Academic Press 2019 Bioorganic chemistry Vol.87 No.-

<P><B>Abstract</B></P> <P>Abnormal melanogenesis results in excessive production of melanin, leading to pigmentation disorders. As a key and rate-limiting enzyme for melanogenesis, tyrosinase has been considered an important target for developing therapeutic agents of pigment disorders. Despite having an (<I>E</I>)-β-phenyl-α,β-unsaturated carbonyl scaffold, which plays an important role in the potent inhibition of tyrosinase activity, cinnamic acids have not attracted attention as potential tyrosinase inhibitors, due to their low tyrosinase inhibitory activity and relatively high hydrophilicity. Given that cinnamic acids’ structure intrinsically features this (<I>E</I>)-scaffold and following our experience that minute changes in the chemical structure can powerfully affect tyrosinase activity, twenty less hydrophilic cinnamamide derivatives were designed as potential tyrosinase inhibitors and synthesised using a Horner-Wadsworth-Emmons reaction. Four of these cinnmamides (<B>4</B>, <B>9</B>, <B>14</B>, and <B>19</B>) exhibited much stronger mushroom tyrosinase inhibition (over 90% inhibition) at 25 µM compared to kojic acid (20.57% inhibition); crucially, all four have a 2,4-dihydroxy group on the β-phenyl ring of the scaffold. A docking simulation using tyrosinase indicated that the four cinnamamides exceeded the binding affinity of kojic acid, and bound more strongly to the active site of tyrosinase. Based on the strength of their tyrosinase inhibition, these four cinnamamides were further evaluated in B16F10 melanoma cells. All four cinnamamides, without cytotoxicity, exhibited higher tyrosinase inhibitory activity (67.33 – 79.67% inhibition) at 25 μM than kojic acid (38.11% inhibition), with the following increasing inhibitory order: morpholino (<B>9</B>) = cyclopentylamino (<B>14</B>) < cyclohexylamino (<B>19</B>) < <I>N</I>-methylpiperazino (<B>4</B>) cinnamamides. Analysis of tyrosinase activity and melanin content in B16F10 cells showed that the four cinnamamides dose-dependently inhibited both cellular tyrosinase activity and melanin content and that their inhibitory activity at 25 μM was much better than that of kojic acid. The results of melanin content analysis well matched those of the cellular tyrosinase activity analysis, indicating that tyrosinase inhibition by the four cinnamamides is a major factor in the reduction of melanin production. These results imply that these four cinnamamides with a 2,4-dihydroxyphenyl group can act as excellent anti-melanogenic agents in the treatment of pigmentation disorders.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Twenty cinnamamide derivatives were synthesized as potential tyrosinase inhibitors. </LI> <LI> Four cinnmamides exhibited over 90% mushroom tyrosinase inhibitions than kojic acid. </LI> <LI> In B16F10 cells, four compounds strongly decreased tyrosinase activity and melanin. </LI> <LI> In docking study, four cinnamamides bind to tyrosinase strongerly than kojic acid. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>