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Temperature Matters: Bacterial Response to Temperature Changeby Seongjoon Moon, Soojeong Ham, Juwon Jeong, Heechan Ku, Hyunhee Kim & Changhan LeeJournal of Microbiology 2023, 61, 343–357; https://doi.org/10.1021/acsaem.3c00130AbstractTemperature is one of the most important factors in all living organisms for survival. Being a unicellular organism, bacterium requires sensitive sensing and defense mechanisms to tolerate changes in temperature. During a temperature shift, the structure and composition of various cellular molecules including nucleic acids, proteins, and membranes are affected. In addition, numerous genes are induced during heat or cold shocks to overcome the cellular stresses, which are known as heat- and cold-shock proteins. In this review, we describe the cellular phenomena that occur with temperature change and bacterial responses from a molecular perspective, mainly in Escherichia coli.Keywords: Heat shock; Cold shock; Thermosensor; Heat shock protein; Chaperone; Cold shock protein
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56
- 작성자박은영
- 작성일2024-02-06
- 426
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- 작성자박은영
- 작성일2024-02-06
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Plasma Surface Modification of 3Y-TZP at Low and Atmospheric Pressures with Different Treatment Times by Sung Un Kang, Chul-Ho Kim, Sanghyun You, Da-Young Lee, Yu-Kwon Kim , Seung-Joo Kim, Chang-Koo Kim, Hee-Kyung Kim International Journal of Molecular Sciences 2023, 24(8), 7663; https://doi.org/10.3390/ijms24087663 AbstractThe efficiency of plasma surface modifications depends on the operating conditions. This study investigated the effect of chamber pressure and plasma exposure time on the surface properties of 3Y-TZP with N2/Ar gas. Plate-shaped zirconia specimens were randomly divided into two categories: vacuum plasma and atmospheric plasma. Each group was subdivided into five subgroups according to the treatment time: 1, 5, 10, 15, and 20 min. Following the plasma treatments, we characterized the surface properties, including wettability, chemical composition, crystal structure, surface morphology, and zeta potential. These were analyzed through various techniques, such as contact angle measurement, XPS, XRD, SEM, FIB, CLSM, and electrokinetic measurements. The atmospheric plasma treatments increased zirconia’s electron donation (?−) capacity, while the vacuum plasma treatments decreased ?− parameter with increasing times. The highest concentration of the basic hydroxyl OH(b) groups was identified after a 5 min exposure to atmospheric plasmas. With longer exposure times, the vacuum plasmas induce electrical damage. Both plasma systems increased the zeta potential of 3Y-TZP, showing positive values in a vacuum. In the atmosphere, the zeta potential rapidly increased after 1 min. Atmospheric plasma treatments would be beneficial for the adsorption of oxygen and nitrogen from ambient air and the generation of various active species on the zirconia surface.Keywords: plasma gases; zirconium oxide; surface properties; atmospheric pressure; vacuum
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- 작성자박은영
- 작성일2024-01-16
- 409
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Reformulating land-use regression method as sign-constrained regularized regressions: Advantages and improvementsby Soon-Sun Kwon, Hosik Choi, Whanhee Lee, Yeonjin Kim, Hwan-Cheol Kim, Woojoo LeeEnvironmental Modelling & Software 2023, 11(12), 105653; https://doi.org/10.1016/j.envsoft.2023.105653AbstractLand-use regression is a popular method for predicting ambient pollutant concentrations at points of interest where no measurements are taken. However, the model-building process is complicated, and systematically understanding when and how the process works is difficult. To overcome these limitations, we reformulate the existing land use regression method as a sign-constrained regression problem with an explicit objective function to be minimized. This novel formulation always leads to estimated regression coefficients that satisfy the predefined direction based on subject matter knowledge while simultaneously substantially improving the prediction performance of the existing land-use regression method. The advantages of the proposed sign-constrained regression method are confirmed through a numerical study and real data analysis.Keywords: Land use regression; Sign constraints; Penalized regression methods; Prediction; Interpretability
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- 작성자박은영
- 작성일2024-01-16
- 366
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Large‐Area Structure‐Selective Synthesis of Symmetry‐Broken MoSe2 and Their Broadband Nonlinear Optical Responseby Joohyeon Ahn, Seongju Ha, Jungseok Choi, Dong‐Il Yeom, Youngdong YooAdvanced Optical Materials 2023, 11(12); https://doi.org/10.1002/adom.202203116AbstractTransition metal dichalcogenides (TMDCs) have various electronic and optical properties depending on their structure, so they can be used as a fascinating material in various applications including photonics, electronics, optoelectronics, and valleytronics. In particular, spiral TMDCs grown through the formation of screw dislocations exhibit novel electronic and optical properties different from layer-by-layer TMDCs. However, large-area structure-selective synthesis of TMDCs remains challenging. Here, this work reports for the first time the large-area structure-selective synthesis of monolayer MoSe2 and spiral MoSe2 using a flux-controlled chemical vapor deposition method. Under a low MoSe2 flux condition, monolayer MoSe2 is synthesized, whereas thick spiral MoSe2 is synthesized under a high flux condition. Under a medium flux condition, both monolayer and spiral MoSe2 are synthesized. In addition, through the nonlinear optical (NLO) signal analysis of monolayer MoSe2 and spiral MoSe2, the giant enhancement of NLO signals induced by the combined effect of breaking inversion symmetry and the excitonic resonance effects in the synthesized MoSe2 is confirmed. Monolayer MoSe2 and spiral MoSe2 synthesized using this method are expected to be used as advanced optical materials for novel electronics, optoelectronics, and NLO applications.
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- 작성자박은영
- 작성일2024-01-16
- 411
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- 작성자박은영
- 작성일2024-01-16
- 369
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Special Issue on Nano-Electronic Devices and Functional Applicationsby Chuljin Hwang and Sungjun Parkapplied science 2023, 13(11), 6692; https://doi.org/10.3390/app13116692Nano-electronic devices and materials hold considerable promise due to their inherent structural and material benefits, such as device miniaturization, increased integration density, and reduced power consumption. Streamlined techniques for nano-scale fabrication of these devices and materials, which are compatible with large-scale production and solution processes, help us to further understand their operational mechanisms or their respective formation processes. These advancements have resulted in significant breakthroughs in functional electronic devices, including light-emitting diodes, photodetectors, photovoltaics, transistors, and sensors. In addition, devices that feature flexibility and stretchability offer unprecedented performance for user-friendly electronic applications. This Special Issue is dedicated to discussing the most recent advancements and trends in nano-electronic devices and materials research. It includes a total of seven papers—five original research articles and two review articles as follows.
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- 작성일2024-01-16
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Assessment of attenuation of varicella-zoster virus vaccines based on genomic comparisonby Jae Yun Moon, Jina Seo, Jaewoo Lee, Daechan ParkJournal of Medical Virology, 2023, 95(3); https://doi.org/10.1002/jmv.28590AbstractLive attenuated varicella-zoster virus (VZV) vaccines are used to prevent chickenpox and shingles. Single nucleotide polymorphisms (SNPs) that occur during the attenuation of parental strains are critical indicators of vaccine safety. To assess the attenuation of commercial VZV vaccines, genetic variants were comprehensively examined through high-throughput sequencing of viral DNA isolated from four VZV vaccines (Barycela, VarilRix, VariVax, and SKY Varicella). Whole-genome comparison of the four vaccines with the wild-type strain (Dumas) revealed that the sequences are highly conserved on a genome-wide scale. Among the 196 common variants across the four vaccines, 195 were already present in the genome of the parental strain (pOka), indicating that the variants occurred during the generation of the parental strain from the Dumas strain. Compared to the pOka genome, the vaccines exhibited distinct variant frequencies on a genome-wide and within an attenuation-related open reading frame. In particular, attenuation-associated 42 SNPs showed that Barycela, VarilRix, VariVax, and SKY Varicella are in ascending order regarding similarity with pOka-like genotypes, which in turn, might provide genomic evidence for the levels of attenuation. Finally, the phylogenetic network analysis demonstrated that genetic distances from the parental strain correlated with the attenuation levels of the vaccines.
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- 작성자박은영
- 작성일2024-01-15
- 543
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40
- 작성자박은영
- 작성일2024-01-15
- 430
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38
- 작성자박은영
- 작성일2023-01-16
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