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[PC-0012] Pre-study for early detection of Fusarium fujikuroi via fluorescence imaging method
Jaeyoung Kim(Jaeyoung Kim),Younguk Kim(Younguk Kim),Hyeonso Ji(Hyeonso Ji),Songlim Kim(Songlim Kim),Hyoja Oh(Hyoja Oh),Youngjun Mo(Youngjun Mo),Kyunghwan Kim(Kyunghwan Kim),Jeongho Baek(Jeongho Baek) 한국육종학회 2022 한국육종학회 공동학술발표집 Vol.2022 No.-
Kim, Jeongho,Kim, Kyung Hwan,Oang, Key Young,Lee, Jae Hyuk,Hong, Kiryong,Cho, Hana,Huse, Nils,Schoenlein, Robert W.,Kim, Tae Kyu,Ihee, Hyotcherl The Royal Society of Chemistry 2016 Chemical communications Vol.52 No.19
<P>Characterization of transient molecular structures formed during chemical and biological processes is essential for understanding their mechanisms and functions. Over the last decade, time-resolved X-ray liquidography (TRXL) and time-resolved X-ray absorption spectroscopy (TRXAS) have emerged as powerful techniques for molecular and electronic structural analysis of photoinduced reactions in the solution phase. Both techniques make use of a pump-probe scheme that consists of (1) an optical pump pulse to initiate a photoinduced process and (2) an X-ray probe pulse to monitor changes in the molecular structure as a function of time delay between pump and probe pulses. TRXL is sensitive to changes in the global molecular structure and therefore can be used to elucidate structural changes of reacting solute molecules as well as the collective response of solvent molecules. On the other hand, TRXAS can be used to probe changes in both local geometrical and electronic structures of specific X-ray-absorbing atoms due to the element-specific nature of core-level transitions. These techniques are complementary to each other and a combination of the two methods will enhance the capability of accurately obtaining structural changes induced by photoexcitation. Here we review the principles of TRXL and TRXAS and present recent application examples of the two methods for studying chemical and biological processes in solution. Furthermore, we briefly discuss the prospect of using X-ray free electron lasers for the two techniques, which will allow us to keep track of structural dynamics on femtosecond time scales in various solution-phase molecular reactions.</P>
Kim, Tae Wu,Yang, Cheolhee,Kim, Youngmin,Kim, Jong Goo,Kim, Jeongho,Jung, Yang Ouk,Jun, Sunhong,Lee, Sang Jin,Park, Sungjun,Kosheleva, Irina,Henning, Robert,van Thor, Jasper J.,Ihee, Hyotcherl The Royal Society of Chemistry 2016 Physical chemistry chemical physics Vol.18 No.13
<P>Real-time probing of structural transitions of a photoactive protein is challenging owing to the lack of a universal time-resolved technique that can probe the changes in both global conformation and light-absorbing chromophores of the protein. In this work, we combine time-resolved X-ray solution scattering (TRXSS) and transient absorption (TA) spectroscopy to investigate how the global conformational changes involved in the photoinduced signal transduction of photoactive yellow protein (PYP) is temporally and spatially related to the local structural change around the light-absorbing chromophore. In particular, we examine the role of internal proton transfer in developing a signaling state of PYP by employing its E46Q mutant (E46Q-PYP), where the internal proton transfer is inhibited by the replacement of a proton donor. The comparison of TRXSS and TA spectroscopy data directly reveals that the global conformational change of the protein, which is probed by TRXSS, is temporally delayed by tens of microseconds from the local structural change of the chromophore, which is probed by TA spectroscopy. The molecular shape of the signaling state reconstructed from the TRXSS curves directly visualizes the three-dimensional conformations of protein intermediates and reveals that the smaller structural change in E46Q-PYP than in wild-type PYP suggested by previous studies is manifested in terms of much smaller protrusion, confirming that the signaling state of E46Q-PYP is only partially developed compared with that of wildtype PYP. This finding provides direct evidence of how the environmental change in the vicinity of the chromophore alters the conformational change of the entire protein matrix.</P>
Kim, Kyung Hwan,Ki, Hosung,Oang, Key Young,Nozawa, Shunsuke,Sato, Tokushi,Kim, Joonghan,Kim, Tae Kyu,Kim, Jeongho,Adachi, Shin‐,ichi,Ihee, Hyotcherl WILEY‐VCH Verlag 2013 Chemphyschem Vol.14 No.16
<P><B>Abstract</B></P><P>The mechanism of a photochemical reaction involves the formation and dissociation of various short‐lived species on ultrafast timescales and therefore its characterization requires detailed structural information on the transient species. By making use of a structurally sensitive X‐ray probe, time‐resolved X‐ray liquidography (TRXL) can directly elucidate the structures of reacting molecules in the solution phase and thus determine the comprehensive reaction mechanism with high accuracy. In this work, by performing TRXL measurements at two different wavelengths (400 and 267 nm), the reaction mechanism of I<SUB>3</SUB><SUP>−</SUP> photolysis, which changes subtly depending on the excitation wavelength, is elucidated. Upon 400 nm photoexcitation, the I<SUB>3</SUB><SUP>−</SUP> ion dissociates into I<SUB>2</SUB><SUP>−</SUP> and I. By contrast, upon 267 nm photoexcitation, the I<SUB>3</SUB><SUP>−</SUP> ion undergoes both two‐body dissociation (I<SUB>2</SUB><SUP>−</SUP>+I) and three‐body dissociation (I<SUP>−</SUP>+2I) with 7:3 molar ratio. At both excitation wavelengths, all the transient species ultimately disappear in 80 ns by recombining to form the I<SUB>3</SUB><SUP>−</SUP> ion nongeminately. In addition to the reaction dynamics of solute species, the results reveal the transient structure of the solute/solvent cage and the changes in solvent density and temperature as a function of time.</P>
Kim, Tae Wu,Lee, Jae Hyuk,Choi, Jungkweon,Kim, Kyung Hwan,van Wilderen, Luuk J.,Guerin, Laurent,Kim, Youngmin,Jung, Yang Ouk,Yang, Cheolhee,Kim, Jeongho,Wulff, Michael,van Thor, Jasper J.,Ihee, Hyotch American Chemical Society 2012 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.134 No.6
<P>Photoreceptor proteins play crucial roles in receiving light stimuli that give rise to the responses required for biological function. However, structural characterization of conformational transition of the photoreceptors has been elusive in their native aqueous environment, even for a prototype photoreceptor, photoactive yellow protein (PYP). We employ pump probe X-ray solution scattering to probe the structural changes that occur during the photocycle of PYP in a wide time range from 3.16 mu s to 300 ms. By the analysis of both kinetics and structures of the intermediates, the structural progression of the protein in the solution phase is vividly visualized. We identify four structurally distinct intermediates and their associated five time constants and reconstructed the molecular shapes of the four intermediates from time-independent, species-associated difference scattering curves. The constructed structures of the intermediates show the large conformational changes such as the protrusion of N-terminus, which is restricted in the crystalline phase due to the crystal contact and thus could not be clearly observed by X-ray crystallography. The protrusion of the N-terminus and the protein volume gradually increase with the progress of the photocycle and becomes maximal in the final intermediate, which is proposed to be the signaling state. The data not only reveal that a common kinetic mechanism is applicable to both the crystalline and the solution phases, but also provide direct evidence for how the sample environment influences structural dynamics and the reaction rates of the PYP photocycle.</P>
Kim JeongHo,Yang Chae Eun,Kim Sug Won,Kim Jiye 대한성형외과학회 2023 Archives of Plastic Surgery Vol.50 No.1
Background: The coronavirus disease 2019 (COVID-19) outbreak has had a major impact worldwide. Several countries have implemented restrictions on social interaction (“social distancing”). Several studies have reported that the epidemiology of trauma patients, such as those with facial bone fractures, has changed after COVID-19 pandemic. This study aimed to further explore these specific changes. Methods: This was a retrospective study of patients who presented to a single institution with facial bone fractures between January 1, 2016, and December 31, 2020. Baseline patient demographics, clinical information, type of fracture, etiology, and operative management were compared before and after COVID-19. Results: Of all cases, 3,409 occurred before COVID-19, and 602 occurred after COVID-19. Since the outbreak of COVID-19, the number of patients with facial fractures has not decreased significantly. A significant increase was noted in fractures that occurred outdoors (p<0.001). However, a decrease was observed in operative management between the groups (p<0.001). There was no significant difference in the proportion of assault, fall-down, industrial accident, or roll-down. In contrast, the proportion of traffic accidents and slip-down categories increased significantly (p<0.05). Moreover, a significant decrease was found in the proportion of the sports category (p=0.001) Conclusions: It was confirmed through this study that COVID-19 pandemic also affected epidemiology of facial fractures. Focusing on these changes, it is necessary to develop safety measures to reduce facial fractures.