Search

Your search keyword '"Kim, Tae-Kyoung"' showing total 914 results
Start Over Author "Kim, Tae-Kyoung"
914 results on '"Kim, Tae-Kyoung"'

1. Outcomes of Stereotactic Body Radiotherapy Compared with Surgical Resection in Patients with Hepatocellular Carcinoma and Macrovascular Invasion: A Propensity Score-Matched Analysis

Author

Yan, Michael, Li, Zhihao, Claasen, Marco P. A. W., Santiago, Anna T., Rajendran, Luckshi, Munoz-Schuffenegger, Pablo, Lee, Cameron, Magyar, Christian T. J., McGilvray, Ian, Shwaartz, Chaya, Reichman, Trevor, Moulton, Carol-Anne, Cleary, Sean, O’Kane, Grainne, Vogel, Arndt, Grant, Robert, Kim, Tae Kyoung, Naidoo, Catherine Soo-Yee, Hosni, Ali, Mesci, Aruz, Dawson, Laura A., and Sapisochin, Gonzalo

Published
2024
Full Text
View/download PDF

2. Sulfonamide Per- and Polyfluoroalkyl Substances Can Impact Microorganisms Used in Aromatic Hydrocarbon and Trichloroethene Bioremediation.

Author

Cook, Emily, Olivares, Christopher, Antell, Edmund, Tsou, Katerina, Kim, Tae-Kyoung, Cuthbertson, Amy, Higgins, Christopher, Sedlak, David, and Alvarez-Cohen, Lisa

Subjects
AFFF, PFAS, groundwater bioremediation, microbial toxicity, Biodegradation, Environmental, Hydrocarbons, Aromatic, Trichloroethylene, Sulfonamides
Abstract

Per- and polyfluoroalkyl substances (PFASs) from aqueous film forming foams (AFFFs) can hinder bioremediation of co-contaminants such as trichloroethene (TCE) and benzene, toluene, ethylbenzene, and xylene (BTEX). Anaerobic dechlorination can require bioaugmentation of Dehalococcoides, and for BTEX, oxygen is often sparged to stimulate in situ aerobic biodegradation. We tested PFAS inhibition to TCE and BTEX bioremediation by exposing an anaerobic TCE-dechlorinating coculture, an aerobic BTEX-degrading enrichment culture, and an anaerobic toluene-degrading enrichment culture to n-dimethyl perfluorohexane sulfonamido amine (AmPr-FHxSA), perfluorohexane sulfonamide (FHxSA), perfluorohexanesulfonic acid (PFHxS), or nonfluorinated surfactant sodium dodecyl sulfate (SDS). The anaerobic TCE-dechlorinating coculture was resistant to individual PFAS exposures but was inhibited by >1000× diluted AFFF. FHxSA and AmPr-FHxSA inhibited the aerobic BTEX-degrading enrichment. The anaerobic toluene-degrading enrichment was not inhibited by AFFF or individual PFASs. Increases in amino acids in the anaerobic TCE-dechlorinating coculture compared to the control indicated stress response, whereas the BTEX culture exhibited lower concentrations of all amino acids upon exposure to most surfactants (both fluorinated and nonfluorinated) compared to the control. These data suggest the main mechanisms of microbial toxicity are related to interactions with cell membrane synthesis as well as protein stress signaling.

Published
2024

4. ASO Visual Abstract: Outcomes of Stereotactic Body Radiotherapy Compared with Surgical Resection in Patients with Hepatocellular Carcinoma and Macrovascular Invasion—A Propensity Score-Matched Analysis

Author

Yan, Michael, Li, Zhihao, Claasen, Marco P. A. W., Santiago, Anna T., Rajendran, Luckshi, Munoz-Schuffenegger, Pablo, Lee, Cameron, Magyar, Christian T. J., McGilvray, Ian, Shwaartz, Chaya, Reichman, Trevor, Moulton, Carol-Anne, Cleary, Sean, O’Kane, Grainne, Vogel, Arndt, Grant, Robert, Kim, Tae Kyoung, Naidoo, Catherine Soo-Yee, Hosni, Ali, Mesci, Aruz, Dawson, Laura A., and Sapisochin, Gonzalo

Published
2024
Full Text
View/download PDF

5. Mineralization of a Fully Halogenated Organic Compound by Persulfate under Conditions Relevant to in Situ Reduction and Oxidation: Reduction of Hexachloroethane by Ethanol Addition Followed by Oxidation

Author

Kim, Tae-Kyoung and Sedlak, David L

Subjects
Inorganic Chemistry, Environmental Sciences, Chemical Sciences, Hydrocarbons, Chlorinated, Organic Chemicals, Carbon, Ethanol, Halogens, Racepinephrine, halogenated solvents, reductive dehalogenation, chlorate
Abstract

Fully halogenated compounds are difficult to remediate by in situ chemical oxidation (ISCO) because carbon-halogen bonds react very slowly with the species that typically initiate contaminant transformation: sulfate radical (SO4•-) and hydroxyl radical (•OH). To enable the remediation of this class of contaminants by persulfate (S2O82-)-based ISCO, we employed a two-phase process to dehalogenate and oxidize a representative halogenated compound (i.e., hexachloroethane). In the first phase, a relatively high concentration of ethanol (1.8 M) was added, along with concentrations of S2O82- that are typically used for ISCO (i.e., 450 mM). Hexachloroethane underwent rapid dehalogenation when carbon-centered radicals produced by the reaction of ethanol and radicals formed during S2O82- decomposition reacted with carbon-halogen bonds. Unlike conventional ISCO treatment, hexachloroethane transformation and S2O82- decomposition took place on the time scale of days without external heating or base addition. The presence of O2, Cl-, and NO3- delayed the onset of hexachloroethane transformation when low concentrations of S2O82- (10 mM) were used, but these solutes had negligible effects when S2O82- was present at concentrations typical of in situ remediation (450 mM). The second phase of the reaction was initiated after most of the ethanol had been depleted when thermolytic S2O82- decomposition resulted in production of SO4•- that oxidized the partially dehalogenated transformation products. With proper precautions, S2O82--based ISCO with ethanol could be a useful remediation technology for sites contaminated with fully halogenated compounds.

Published
2023

7. Newton Raphson Emulation Network for Highly Efficient Computation of Numerous Implied Volatilities

Author

Lee, Geon, Kim, Tae-Kyoung, Kim, Hyun-Gyoon, and Huh, Jeonggyu

Subjects
Quantitative Finance - Computational Finance
Abstract

In finance, implied volatility is an important indicator that reflects the market situation immediately. Many practitioners estimate volatility using iteration methods, such as the Newton--Raphson (NR) method. However, if numerous implied volatilities must be computed frequently, the iteration methods easily reach the processing speed limit. Therefore, we emulate the NR method as a network using PyTorch, a well-known deep learning package, and optimize the network further using TensorRT, a package for optimizing deep learning models. Comparing the optimized emulation method with the NR function in SciPy, a popular implementation of the NR method, we demonstrate that the emulation network is up to 1,000 times faster than the benchmark function.

Published
2022

8. Semi-Data-Aided Channel Estimation for MIMO Systems via Reinforcement Learning

Author

Kim, Tae-Kyoung, Jeon, Yo-Seb, Li, Jun, Tavangaran, Nima, and Poor, H. Vincent

Subjects
Electrical Engineering and Systems Science - Signal Processing
Abstract

Data-aided channel estimation is a promising solution to improve channel estimation accuracy by exploiting data symbols as pilot signals for updating an initial channel estimate. In this paper, we propose a semi-data-aided channel estimator for multiple-input multiple-output communication systems. Our strategy is to leverage reinforcement learning (RL) for selecting reliable detected symbols among the symbols in the first part of transmitted data block. This strategy facilitates an update of the channel estimate before the end of data block transmission and therefore achieves a significant reduction in communication latency compared to conventional data-aided channel estimation approaches. Towards this end, we first define a Markov decision process (MDP) which sequentially decides whether to use each detected symbol as an additional pilot signal. We then develop an RL algorithm to efficiently find the best policy of the MDP based on a Monte Carlo tree search approach. In this algorithm, we exploit the a-posteriori probability for approximating both the optimal future actions and the corresponding state transitions of the MDP and derive a closed-form expression for the best policy. Simulation results demonstrate that the proposed channel estimator effectively mitigates both channel estimation error and detection performance loss caused by insufficient pilot signals.

Published
2022

15. Regression of Likelihood Probability for Time-Varying MIMO Systems with One-Bit ADCs.

Author

Kim, Tae-Kyoung and Min, Moonsik

Subjects
*MIMO systems, *ANALOG-to-digital converters, *TIME-varying systems, *PROBLEM solving, *PROBABILITY theory
Abstract

This study proposes a regression-based approach for calculating the likelihood probability in time-varying multi-input multi-output (MIMO) systems using one-bit analog-to-digital converters. These time-varying MIMO systems often face performance challenges because of the difficulty in tracking changes in the likelihood probability. To address this challenge, the proposed method leverages channel statistics and decoded outputs to refine the likelihood. An optimization problem is then formulated to minimize the mean-squared error between the true and refined likelihood probabilities. A linear regression approach is derived to solve this problem, and a regularization technique is applied to further optimize the calculation. The simulation results indicate that the proposed method improves reliability by effectively tracking temporal variations in the likelihood probability and outperforms conventional methods in terms of performance. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

17. How to perform Contrast-Enhanced Ultrasound (CEUS)

Author

Dietrich, Christoph F, Averkiou, Michalakis, Nielsen, Michael Bachmann, Barr, Richard G, Burns, Peter N, Calliada, Fabrizio, Cantisani, Vito, Choi, Byung, Chammas, Maria C, Clevert, Dirk-André, Claudon, Michel, Correas, Jean-Michel, Cui, Xin-Wu, Cosgrove, David, D'Onofrio, Mirko, Dong, Yi, Eisenbrey, JohnR, Fontanilla, Teresa, Gilja, Odd Helge, Ignee, Andre, Jenssen, Christian, Kono, Yuko, Kudo, Masatoshi, Lassau, Nathalie, Lyshchik, Andrej, Meloni, Maria Franca, Moriyasu, Fuminori, Nolsøe, Christian, Piscaglia, Fabio, Radzina, Maija, Saftoiu, Adrian, Sidhu, Paul S, Sporea, Ioan, Schreiber-Dietrich, Dagmar, Sirlin, Claude B, Stanczak, Maria, Weskott, Hans-Peter, Wilson, Stephanie R, Willmann, Juergen Karl, Kim, Tae Kyoung, Jang, Hyun-Jung, Vezeridis, Alexandar, and Westerway, Sue

Subjects
Biomedical Imaging, guidelines, teaching, ultrasonography, cancer
Abstract

"How to perform contrast-enhanced ultrasound (CEUS)" provides general advice on the use of ultrasound contrast agents (UCAs) for clinical decision-making and reviews technical parameters for optimal CEUS performance. CEUS techniques vary between centers, therefore, experts from EFSUMB, WFUMB and from the CEUS LI-RADS working group created a discussion forum to standardize the CEUS examination technique according to published evidence and best personal experience. The goal is to standardise the use and administration of UCAs to facilitate correct diagnoses and ultimately to improve the management and outcomes of patients.

Published
2018

19. Contrast-enhanced ultrasound (CEUS) liver imaging reporting and data system (LI-RADS) 2017 – a review of important differences compared to the CT/MRI system

Author

Kim, Tae Kyoung, Noh, Seung Yeon, Wilson, Stephanie R, Kono, Yuko, Piscaglia, Fabio, Jang, Hyun-Jung, Lyshchik, Andrej, Dietrich, Christoph F, Willmann, Juergen K, Vezeridis, Alexander, and Sirlin, Claude B

Subjects
Cancer, Liver Disease, Rare Diseases, Liver Cancer, Biomedical Imaging, Digestive Diseases, 4.1 Discovery and preclinical testing of markers and technologies, Detection, screening and diagnosis, Algorithms, Carcinoma, Hepatocellular, Contrast Media, Humans, Liver, Liver Neoplasms, Magnetic Resonance Imaging, Tomography, X-Ray Computed, Ultrasonography, Carcinoma, Hepatocellular, Diagnosis, Ultrasonic, Diagnosis, Ultrasonic
Abstract

Medical imaging plays an important role in the diagnosis and management of hepatocellular carcinoma (HCC). The Liver Imaging Reporting and Data System (LI-RADS) was initially created to standardize the reporting and data collection of CT and MR imaging for patients at risk for HCC. As contrast-enhanced ultrasound (CEUS) has been widely used in clinical practice, it has recently been added to the LI-RADS. While CEUS LI-RADS shares fundamental concepts with CT/MRI LI-RADS, there are key differences between the modalities reflecting dissimilarities in the underlying methods of image acquisition and types of contrast material. This review introduces a recent update of CEUS LI-RADS and explains the key differences from CT/MRI LI-RADS.

Published
2017

20. Liquefied gas electrolytes for electrochemical energy storage devices

Author

Rustomji, Cyrus S, Yang, Yangyuchen, Kim, Tae Kyoung, Mac, Jimmy, Kim, Young Jin, Caldwell, Elizabeth, Chung, Hyeseung, and Meng, Y Shirley

Subjects
Affordable and Clean Energy, General Science & Technology
Abstract

Electrochemical capacitors and lithium-ion batteries have seen little change in their electrolyte chemistry since their commercialization, which has limited improvements in device performance. Combining superior physical and chemical properties and a high dielectric-fluidity factor, the use of electrolytes based on solvent systems that exclusively use components that are typically gaseous under standard conditions show a wide potential window of stability and excellent performance over an extended temperature range. Electrochemical capacitors using difluoromethane show outstanding performance from -78° to +65°C, with an increased operation voltage. The use of fluoromethane shows a high coulombic efficiency of ~97% for cycling lithium metal anodes, together with good cyclability of a 4-volt lithium cobalt oxide cathode and operation as low as -60°C, with excellent capacity retention.

Published
2017

21. American College of Radiology Contrast Enhanced Ultrasound Liver Imaging Reporting and Data System (CEUS LI-RADS) for the diagnosis of Hepatocellular Carcinoma: a pictorial essay

Author

Piscaglia, Fabio, Wilson, Stephanie R, Lyshchik, Andrej, Cosgrove, David, Dietrich, Christoph F, Jang, Hyun-Jung, Kim, Tae Kyoung, Salvatore, Veronica, Willmann, Juergen Karl, Sirlin, Claude B, and Kono, Yuko

Subjects
Carcinoma, Hepatocellular, Data Systems, Humans, Liver Neoplasms, Tomography, X-Ray Computed, United States, diagnostic radiology, contrast agents, tumor, Nuclear Medicine & Medical Imaging
Published
2017

31. Contrast Enhanced Ultrasound (CEUS) Liver Imaging Reporting and Data System (LI-RADS®): the official version by the American College of Radiology (ACR).

Author

Kono, Yuko, Lyshchik, Andrej, Cosgrove, David, Dietrich, Christoph F, Jang, Hyun-Jung, Kim, Tae Kyoung, Piscaglia, Fabio, Willmann, Juergen K, Wilson, Stephanie R, Santillan, Cynthia, Kambadakone, Avinash, Mitchell, Donald, Vezeridis, Alexander, and Sirlin, Claude B

Subjects
Humans, Carcinoma, Hepatocellular, Liver Neoplasms, Ultrasonography, United States, Nuclear Medicine & Medical Imaging
Published
2017

32. Liver Imaging Reporting and Data System Contrast-Enhanced US Nonradiation Treatment Response Assessment Version 2024

Author

Lyshchik, Andrej, primary, Fetzer, David T., additional, Kono, Yuko, additional, Wilson, Stephanie R., additional, Dietrich, Christoph F., additional, Clevert, Dirk A., additional, Meloni, Maria Franca, additional, Jang, Hyun-Jung, additional, Kim, Tae Kyoung, additional, Lee, Jeong Min, additional, Minami, Yasunori, additional, Kudo, Masatoshi, additional, Piscaglia, Fabio, additional, and Atzen, Sarah, additional

Published
2024
Full Text
View/download PDF

34. Crawling Into View

Author

Luther, Ryan A., Wang, David, Kim, Tae Kyoung, Khalili, Korosh, and Gold, Wayne L.

Published
2019

38. Autologous Hematopoietic Stem Cell Transplantation for Liver Transplant Recipients With Recurrent Primary Sclerosing Cholangitis: A Pilot Study

Author

Chruscinski, Andrzej, Juvet, Stephen, Moshkelgosha, Sajad, Renner, Eberhard, Lilly, Leslie, Selzner, Nazia, Bredeson, Christopher, Grant, David, Adeyi, Oyedele, Fischer, Sandra, Demetris, Anthony J., Zhang, Jianhua, Epstein, Maor, Macarthur, Meaghan, Clement, Anne Marie, Khalili, Korosh, Allan, David, Altouri, Sultan, Bence-Bruckler, Isabelle, Cattral, Mark, Fulcher, Jill, Galvin, Zita, Ghanekar, Anand, Greig, Paul, Huebsch, Lothar, Humar, Atul, Kew, Andrea, Kekre, Natasha, Kim, Tae Kyoung, McDiarmid, Sheryl, Martin, Lisa, McGilvray, Ian, Sabloff, Mitchell, Sapisochin, Gonzalo, Selzner, Markus, Smith, Robert, Tinckam, Kathryn, Yi, Tae Joon, Levy, Gary, and Atkins, Harold

Published
2022
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results