Single‐Molecule Four‐Color FRET

Lee ,, Jinwoo,Lee ,, Sanghwa,Ragunathan, Kaushik,Joo, Chirlmin,Ha, Taekjip,Hohng, Sungchul WILEY‐VCH Verlag 2010 Angewandte Chemie Vol.122 No.51

<P><B>Sechs FRET‐Interfluorophoreffizienzen</B> <I>E</I><SUB><I>ij</I></SUB> (siehe Schema) wurden in Echtzeit durch eine Einzelmolekül‐Vierfarben‐FRET‐Technik mittels konfokaler Mikroskopie sowie Fluoreszenzmikroskopie mit interner Totalreflexion bestimmt. Das Verfahren wurde verwendet, um die korrelierte Bewegung der vier Arme der Holliday‐Junction und die Korrelation von RecA‐vermittelten Strangaustauschereignissen an beiden Enden eines synaptischen Komplexes zu untersuchen.</P>

1949년 사회주의 중국 건국이 중국철학에 미친 영향 : 사회주의 중국 성립 이전과 이후 풍우란(馮友蘭) 철학의 연속성과 단절성을 중심으로

이상화 ( Lee¸ Sanghwa ) 연세대학교 인문학연구원 2021 人文科學 Vol.122 No.-

이 연구의 목적은 사회주의 중국 건국 이전과 이후 풍우란(馮友蘭) 철학의 연속성과 단절성을 분석하여 사회주의 중국 건국이 중국철학에 끼친 영향을 규명하는 데 있다. 이를 위해서 먼저 중화인민공화국 성립 이전과 이후의 풍우란 철학의 단절성을 살펴볼 수 있다. 그 내용을 보면 첫째 철학에 대한 이해, 둘째 역사와 철학사에 대한 이해, 셋째 공상(개념, 보편)과 수상(개별, 특수)의 관계에서 단절성이 보인다. 이어서 연속성을 살펴볼 수 있다. 첫째 공상(보편성) 중심의 사유가 지속된다는 점, 둘째 서양중심의 학문관을 유지하고 있다는 점, 셋째 쓰인 역사와 쓰인 철학사를 본래 역사와 본래 철학사와 구분한다는 점이 풍우란의 연속성이라고 할 수 있다. 아울러 이러한 단절성과 연속성의 이유는 다음과 같다. 먼저 단절성의 이유는 1949년 이후에 풍우란에 대한 비판이 지속되었다는 점이다. 비판 내용을 보면, 풍우란 저작에 대한 계급성과 풍우란 철학의 형이상학에 대한 비판이 대부분이었다. 따라서 풍우란은 자신의 부르주아계급성, 형이상학성에서 벗어나야할 상황에 처해있었다. 또한 사회주의 중국의 지성계는 기존의 철학 혹은 중국철학에 대해 인정하는 범위가 정해져 있었다. 그에 맞춰 풍우란 사상은 변화할 수밖에 없었다. 그 범위는 물질의 1차성(유물주의)과 계급성, 그리고 변증법이었다. 이 범위에 맞지 않는 풍우란의 철학은 교정될 수밖에 없었다. 다음으로 연속성의 원인을 살펴볼 수 있다. 먼저 풍우란의 신실재론이 유물론과 내적·형식적으로 친화적이었다는 이유가 존재한다. 신실재론은 보편 논리의 실재성을 강조하고, 사적 유물론(유물사관)은 역사발전 법칙의 실재성을 인정한다. 풍우란의 입장에서 보면, 생각의 변화가 어렵지 않았다. 자신이 주장하던 ‘보편성’(공상)이 철저하게 물질을 기반으로 하고 있다는 점만 고려하면 유물론은 어렵지 않게 받아들일 수 있는 관점이었다. 또한 사회주의 중국에서 강조된 변증법도 풍우란의 사고를 유지할 수 있게 한 원동력이었다. 이 변증법을 통해 풍우란은 기계적 유물론에서 벗어나 자기 사고의 연속성을 유지할 수 있었기 때문이다. The purpose of this study is to analyze the continuity and disconnection of Fung Yulan’s philosophy before and after the founding of socialist China, and to identify the influence its founding had on Chinese philosophy. There were changes in Fung’s philosophy before and after the Chinese socialist revolution. First, a change in the understanding of philosophy; second, a change in the understanding of history and philosophy; and third, changes in the relationship between universal and special. We also look at the continuity of Fung’s philosophy. First, the universality-oriented reasons persist. Second, Fung maintains a Western-centered view of learning. Third, he distinguishes between written history and original history. In addition, the reasons for this disconnect and continuity are as follows. First, the reason for the disconnect is that criticism of Fung has persisted since 1949. The majority of the criticisms were about the work of Fung and the metaphysics of Fung’s philosophy. Fung was therefore in a situation where he had to deviate from his bourgeois class, metaphysics. In addition, the intellectual world of socialist China had a range of recognition for existing philosophy or Chinese philosophy. In response, the ideas of Fung had no choice but to change. The range was the primary nature of matter (physicalism), class, and dialectic. Fung’s philosophy not within this scope had to be corrected. Next, we can look at the causes of continuity. First of all, there is the reason that Fung's theory of neo-realism was friendly to materialism, internally and externally. Neoclassical theory emphasizes the practicality of universal logic, and historical materialism recognizes the practicality of the law of historical development. From Fung's point of view, changing his mind was not difficult. It is enough to understand that the universality(共相) that he claimed was thoroughly based on materials. Materialism was an acceptable point of view. In addition, the dialectic method emphasized in socialist China was also the driving force that enabled Fung to maintain his thinking. Through this dialectic, Fung was able to carry out and announce some deviations frommechanical materialism.

A crystallographic investigation of GaN nanostructures by reciprocal space mapping in a grazing incidence geometry

Lee, Sanghwa,Sohn, Yuri,Kim, Chinkyo,Lee, Dong Ryeol,Lee, Hyun-Hwi IOP Pub 2009 Nanotechnology Vol.20 No.21

<P>Reciprocal space mapping with a two-dimensional (2D) area detector in a grazing incidence geometry was applied to determine crystallographic orientations of GaN nanostructures <I> epitaxially</I> grown on a sapphire substrate. By using both unprojected and projected reciprocal space mapping with a proper coordinate transformation, the crystallographic orientations of GaN nanostructures with respect to that of a substrate were unambiguously determined. In particular, the legs of multipods in the <I>wurtzite phase</I> were found to preferentially nucleate on the sides of tetrahedral cores in the <I>zinc blende phase</I>. </P>

Enhancement of local surface plasmon resonance (LSPR) effect by biocompatible metal clustering based on ZnO nanorods in Raman measurements

Lee, Sanghwa,Lee, Seung Ho,Paulson, Bjorn,Lee, Jae-Chul,Kim, Jun Ki Elsevier 2018 Spectrochimica acta. Part A, Molecular and biomole Vol.204 No.-

<P><B>Abstract</B></P> <P>The development of size-selective and non-destructive detection techniques for nanosized biomarkers has many reasons, including the study of living cells and diagnostic applications. We present an approach for Raman signal enhancement on biocompatible sensing chips based on surface enhancement Raman spectroscopy (SERS). A sensing chip was fabricated by forming a ZnO-based nanorod structure so that the Raman enhancement occurred at a gap of several tens to several hundred nanometers. The effect of coffee-ring formation was eliminated by introducing the porous ZnO nanorods for the bio-liquid sample. A peculiarity of this approach is that the gold sputtered on the ZnO nanorods initially grows at their heads forming clusters, as confirmed by secondary electron microscopy. This clustering was verified by finite element analysis to be the main factor for enhancement of local surface plasmon resonance (LSPR). This clustering property and the ability to adjust the size of the nanorods enabled the signal acquisition points to be refined using confocal based Raman spectroscopy, which could be applied directly to the sensor chip based on the optimization process in this experiment. It was demonstrated by using common cancer cell lines that cell growth was high on these gold-clad ZnO nanorod-based surface-enhanced Raman substrates. The porosity of the sensing chip, the improved structure for signal enhancement, and the cell assay make these gold-coated ZnO nanorods substrates promising biosensing chips with excellent potential for detecting nanometric biomarkers secreted by cells.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A surface enhanced Raman spectroscopy (SERS) chip was fabricated by depositing gold on a ZnO - based nanorod structure. </LI> <LI> The nanorod heads grow first to form clusters as gold is sputtered on the ZnO nanorods. </LI> <LI> The process was optimized by adjusting the ZnO nanorod size and Au clusters, and verified by finite element analysis (FEM). </LI> <LI> Biocompatibility testing confirmed that the Raman-based sensing chip was suitable for monitoring of living cells. </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>[DISPLAY OMISSION]</P>

Reconfigurable spintronic physical unclonable functions based on spin-orbit torques in ferromagnet/nonmagnet/ferromagnet trilayer structures

Soogil Lee,Jaimin Kang,Jeong-Mok Kim,Taek-Hyeon Lee,Sungjun Lee,Donghyeon Han,Sanghwa Lee,Kab-Jin Kim,Byong-Guk Park 한국자기학회 2021 한국자기학회 학술연구발표회 논문개요집 Vol.31 No.1

Entering the era of Inter of Things (IOT), diverse smart devices generate and transfer enormous digital information. In this IOT environment, information security is becoming a critical issue because conventional software-based security technology is vulnerable to adversarial machine learning attacks. Thus, hardware-based security technology has been proposed to overcome this vulnerability, receiving much attention as an alternative. Especially, randomness of nature serves as an essential ingredient for the hardware-based security technology. For example, manufacturing processes of complementary-metal-oxide-semiconductor (CMOS) involves inevitable tolerances. Therefore, every electronic device is physically not identical despite the identical manufacturing processes. Those distinguishable device characteristics under the identical manufacturing process, so called “physical unclonable function (PUF)”, can potentially create non-identical output (response) under the identical input (challenge) generating unique identification of each electronic devices [1]. In this presentation, we demonstrate the spintronic PUF utilizing bottom-ferromagnet (FM)/nonmagnet/top-FM trilayer structures. Here, bottom and top FMs exhibit in-plane and perpendicular magnetic anisotropy, respectively. In these trilayer structures, field-free magnetization switching of top-FM is achieved by out-of-plane polarized spin current injection due to the interfacial spin precession mechanism, and the switching polarity is controlled by the in-plane magnetization direction of bottom-FM [2]. Under the identical demagnetization process of the bottom-FM, distinct magnetic domain distributions are formed on each identical wafer, consisting of a number of Hall-bar devices with random magnetization direction of bottom-FM along the demagnetization axis. These randomly distributed domains of bottom-FM on each wafer are electrically detected through the current-induced field-free spin-orbit torque switching polarity relies on the direction of bottom-FM. Therefore, these spintronic PUF wafers with unique pattern of domain distributions manifests itself as the unique electrical identification which can also be integrated into magnetic random access memory. Furthermore, we also discuss the reconfigurability and reliability of this spintronic PUF, providing great potential to hardware-based security applications because it is compatible with current CMOS technology.

4-<i>O</i>-methylgallic acid down-regulates endothelial adhesion molecule expression by inhibiting NF-κB-DNA-binding activity

Lee, Gwangsoo,Na, Hee-Jun,Namkoong, Seung,Jeong Kwon, Ho,Han, Sanghwa,Ha, Kwon-Soo,Kwon, Young-Guen,Lee, Hansoo,Kim, Young-Myeong Elsevier 2006 european journal of pharmacology Vol.551 No.1

<P><B>Abstract</B></P><P>We here investigated the functional effect of 4-<I>O</I>-methylgallic acid (4-OMGA), a major metabolite of gallic acid abundant in red wine, on vascular inflammation and its action mechanism. 4-OMGA inhibited the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in human umbilical vein endothelial cells (HUVECs) stimulated with tumor necrosis factor-α (TNF-α), resulting in the suppression of leukocyte adhesion to HUVECs. In addition, 4-OMGA inhibited the promoter activities of ICAM-1 and VCAM-1 and the activity of nuclear factor-κB (NF-κB) without affecting cytosolic IκB kinase (IKK) activation, inhibitor of κB (IκB) phosphorylation and degradation, and nuclear translocation of NF-κB. This compound did not alter nitric oxide (NO) generation, but inhibited reactive oxygen species (ROS) production in TNF-α-stimulated HUVECs, suggesting that NO and ROS are not involved in 4-OMGA-mediated inhibition of NF-κB activity. Moreover, 4-OMGA directly blocked the binding activity of NF-κB to its consensus DNA oligonucleotide, when pre-incubated with the nuclear extract from TNF-α-stimulated HUVECs, but not with the oligonucleotide alone. This inhibition was completely abolished by the addition of dithiothreitol. 4-OMGA exhibits an anti-inflammatory property by interfering with the formation of the NF-κB-DNA complex in the nuclei through direct and redox-sensitive interactions and may play an important role in the prevention of inflammatory responses such as the atherosclerotic process.</P>

Branched and crosslinked supracolloidal chains with diblock copolymer micelles having three well-defined patches

Lee, Sanghwa,Jang, Sukwoo,Kim, Kyungtae,Jeon, Jonghyuk,Kim, Sung-Soo,Sohn, Byeong-Hyeok unknown 2016 Chemical communications Vol. No.

<P>We report controlled branching and eventual crosslinking in supracolloidal chains by introducing well-defined trifunctional patchy micelles. Uniform micelles having three patches were induced from core-crosslinked micelles of diblock copolymers. Three patches in the micelles served as functional groups for crosslinking as well as branching in supracolloidal polymerization.</P>

Selective Mapping for Robust Data Transmission Using TxID Signal

LEE, Jaekwon,LEE, Sanghwa,KIM, Dong Ku 'Institute of Electronics, Information and Communi 2019 IEICE TRANSACTIONS ON COMMUNICATIONS - Vol.b102 No.4

An Optical Trap Combined with Three-Color FRET

Lee, Sanghwa,Hohng, Sungchul American Chemical Society 2013 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.135 No.49

<P>We developed a hybrid technique combining optical tweezers and single-molecule three-color fluorescence resonance energy transfer (FRET). In demonstrative experiments, we observed the force-sensitive correlated motion of three helical arms of a Holliday junction and identified the independent unfolding/folding dynamics of two DNA hairpins of the same length. With 3 times the number of observable elements of single-molecule FRET, this new instrument will enable the measurement of the complex, multidimensional effects of mechanical forces in various biomolecular systems, such as RNA and proteins.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2013/jacsat.2013.135.issue-49/ja408767p/production/images/medium/ja-2013-08767p_0004.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja408767p'>ACS Electronic Supporting Info</A></P>

Properties of phase transition of ice binding protein from Arctic yeast (LeIBP) utilizing differential scanning calorimetry (DSC) and Raman spectroscopy

Lee, Sanghwa,Lee, Jun Hyuck,Kim, Han-Woo,Hong, Jong Wook Elsevier 2018 Cryobiology Vol.85 No.-

<P><B>Abstract</B></P> <P>Ice binding proteins (IBPs) have been attracting significant interest on account of their characteristic of inhibiting ice growth and recrystallization. Owing to their unique characteristics, IBPs have been studied for applications in food, pharmaceuticals, and medicine, as well as from a general scientific point of view. In this study, we have used differential scanning calorimetry (DSC) and Raman spectroscopy as tools to understand the ice binding activity of the Arctic-yeast-originating extracellular ice binding glycoprotein (LeIBP) isolated from Leucosporidium sp. AY30. From the DSC results, an increase in the specific heat capacity was confirmed for 1 mg/mL LeIBP, which suggested that additional heat flow was required for the change in temperature. In addition, the temperature corresponding to the phase change of the solution was measured, and Raman spectroscopy was carried out on the frozen and molten phases, respectively. From the results of Raman analysis, we confirmed that the helical vibrations related to the ice binding sites on LeIBP were dramatically suppressed when the LeIBP solution was frozen. Furthermore, principal component analysis (PCA) of the Raman spectra yielded the contrast factor between the freezing and melting states. Both DSC and Raman spectroscopy are widely used to study the ice binding activity and the structural changes associated with molecular vibrations in cryobiology.</P>