636 results on '"HYUN-WOO KIM"'
Search Results
2. Sigma-1 receptor increases intracellular calcium in cultured astrocytes and contributes to mechanical allodynia in a model of neuropathic pain
- Author
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Hyun-Woo Kim, Jae-Gyun Choi, Jang Hern Lee, Jaehyuk Kim, Jin Bong Park, Dong-Wook Kang, and Sheu-Ran Choi
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medicine.medical_specialty ,Neuroactive steroid ,Calcium in biology ,Mice ,Peripheral Nerve Injuries ,Internal medicine ,medicine ,Animals ,Receptors, sigma ,Cells, Cultured ,Progesterone ,Sigma-1 receptor ,Glial fibrillary acidic protein ,biology ,business.industry ,General Neuroscience ,Spinal cord ,Disease Models, Animal ,Endocrinology ,medicine.anatomical_structure ,Spinal Cord ,Hyperalgesia ,Astrocytes ,Neuropathic pain ,biology.protein ,Neuralgia ,Calcium ,Sciatic nerve ,business ,Neurosteroids ,Astrocyte - Abstract
Recent studies have revealed that glial sigma-1 receptor (Sig-1R) in the spinal cord may be a critical factor to mediate sensory function. However, the functional role of Sig-1R in astrocyte has not been clearly elucidated. Here, we determined whether Sig-1Rs modulate calcium responses in primary cultured astrocytes and pathological changes in spinal astrocytes, and whether they contribute to pain hypersensitivity in naive mice and neuropathic pain following chronic constriction injury (CCI) of the sciatic nerve in mice. Sig-1R was expressed in glial fibrillary acidic protein (GFAP)-positive cultured astrocytes. Treatment with the Sig-1R agonist, PRE-084 or neurosteroid dehydroepiandrosterone (DHEA) increased intracellular calcium responses in cultured astrocytes, and this increase was blocked by the pretreatment with the Sig-1R antagonist, BD-1047 or neurosteroid progesterone. Intrathecal administration of PRE-084 or DHEA for 10 days induced mechanical and thermal hypersensitivity and increased the number of Sig-1R-immunostained GFAP-positive cells in the superficial dorsal horn (SDH) region of the spinal cord in naive mice, and these changes were inhibited by administration with BD-1047 or progesterone. In CCI mice, intrathecal administration of BD-1047 or progesterone at post-operative day 14 suppressed the developed mechanical allodynia and the number of Sig-1R-immunostained GFAP-positive cells that were increased in the SDH region of the spinal cord following CCI of the sciatic nerve. These results demonstrate that Sig-1Rs play an important role in the modulation of intracellular calcium responses in cultured astrocytes and pathological changes in spinal astrocytes and that administration of BD-1047 or progesterone alleviates the Sig-1R-induced pain hypersensitivity and the peripheral nerve injury-induced mechanical allodynia.
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- 2022
3. Online continual learning in image classification: An empirical survey
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Scott Sanner, Zheda Mai, Jihwan Jeong, David Quispe, Ruiwen Li, and Hyun-Woo Kim
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FOS: Computer and information sciences ,Computer Science - Machine Learning ,Memory buffer register ,Matching (statistics) ,Class (computer programming) ,Forgetting ,Contextual image classification ,Computer science ,business.industry ,Computer Vision and Pattern Recognition (cs.CV) ,Cognitive Neuroscience ,Computer Science - Computer Vision and Pattern Recognition ,Machine learning ,computer.software_genre ,Machine Learning (cs.LG) ,Computer Science Applications ,Domain (software engineering) ,Artificial Intelligence ,Classifier (linguistics) ,Key (cryptography) ,Artificial intelligence ,business ,computer - Abstract
Online continual learning for image classification studies the problem of learning to classify images from an online stream of data and tasks, where tasks may include new classes (class incremental) or data nonstationarity (domain incremental). One of the key challenges of continual learning is to avoid catastrophic forgetting (CF), i.e., forgetting old tasks in the presence of more recent tasks. Over the past few years, many methods and tricks have been introduced to address this problem, but many have not been fairly and systematically compared under a variety of realistic and practical settings. To better understand the relative advantages of various approaches and the settings where they work best, this survey aims to (1) compare state-of-the-art methods such as MIR, iCARL, and GDumb and determine which works best at different experimental settings; (2) determine if the best class incremental methods are also competitive in domain incremental setting; (3) evaluate the performance of 7 simple but effective trick such as "review" trick and nearest class mean (NCM) classifier to assess their relative impact. Regarding (1), we observe iCaRL remains competitive when the memory buffer is small; GDumb outperforms many recently proposed methods in medium-size datasets and MIR performs the best in larger-scale datasets. For (2), we note that GDumb performs quite poorly while MIR -- already competitive for (1) -- is also strongly competitive in this very different but important setting. Overall, this allows us to conclude that MIR is overall a strong and versatile method across a wide variety of settings. For (3), we find that all 7 tricks are beneficial, and when augmented with the "review" trick and NCM classifier, MIR produces performance levels that bring online continual learning much closer to its ultimate goal of matching offline training., Comment: Accepted for publication in the Elsevier's Neurocomputing journal. Codes available at https://github.com/RaptorMai/online-continual-learning
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- 2022
4. Machine Learning Simulation of Land Cover Impact on Surface Urban Heat Island Surrounding Park Areas
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Hyun-Woo Kim, Dakota Aaron McCarty, and Jaekyung Lee
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Geographic information system ,Land surface temperature ,Geography, Planning and Development ,TJ807-830 ,land use land cover ,urbanization ,Land cover ,Management, Monitoring, Policy and Law ,TD194-195 ,Machine learning ,computer.software_genre ,extreme gradient boost ,Renewable energy sources ,Urbanization ,GE1-350 ,Urban heat island ,Environmental effects of industries and plants ,Land use ,Renewable Energy, Sustainability and the Environment ,business.industry ,Urban sprawl ,urban heat island ,Environmental sciences ,shapley additive explanation ,Dallas ,Geography ,park characteristic ,Artificial intelligence ,business ,Surface urban heat island ,computer - Abstract
The urban heat island effect has been studied extensively by many researchers around the world with the process of urbanization coming about as one of the major culprits of the increasing urban land surface temperatures. Over the past 20 years, the city of Dallas, Texas, has consistently been one of the fastest growing cities in the United States and has faced rapid urbanization and great amounts of urban sprawl, leading to an increase in built-up surface area. In this study, we utilize Landsat 8 satellite images, Geographic Information System (GIS) technologies, land use/land cover (LULC) data, and a state-of-the-art methodology combining machine learning algorithms (eXtreme Gradient Boosted models, or XGBoost) and a modern game theoretic-based approach (Shapley Additive exPlanation, or SHAP values) to investigate how different land use/land cover classifications impact the land surface temperature and park cooling effects in the city of Dallas. We conclude that green spaces, residential, and commercial/office spaces have the largest impacts on Land Surface Temperatures (LST) as well as the Park’s Cooling Intensity (PCI). Additionally, we have found that the extent and direction of influence of these categories depends heavily on the surrounding area. By using SHAP values we can describe these interactions in greater detail than previous studies. These results will provide an important reference for future urban and park placement planning to minimize the urban heat island effect, especially in sprawling cities.
- Published
- 2023
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5. Real-time ultrafast oscilloscope with a relativistic electron bunch train
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Young Chan Kim, Mi Hye Kim, Nikolay Vinokurov, Fabian Rotermund, Sunjeong Park, Kyu-Ha Jang, Hyeon Sang Bark, Young Uk Jeong, In Hyung Baek, Hyun Woo Kim, Kitae Lee, Junho Shin, and Key Young Oang
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Terahertz radiation ,Optical metrology ,Science ,General Physics and Astronomy ,Physics::Optics ,Electron ,Characterization and analytical techniques ,Article ,General Biochemistry, Genetics and Molecular Biology ,law.invention ,Optics ,Ultrafast photonics ,law ,Waveform ,Oscilloscope ,Physics ,Multidisciplinary ,Matter waves and particle beams ,business.industry ,General Chemistry ,Pulse (physics) ,Deflection (physics) ,business ,Waveguide ,Ultrashort pulse - Abstract
The deflection of charged particles is an intuitive way to visualize an electromagnetic oscillation of coherent light. Here, we present a real-time ultrafast oscilloscope for time-frozen visualization of a terahertz (THz) optical wave by probing light-driven motion of relativistic electrons. We found the unique condition of subwavelength metal slit waveguide for preserving the distortion-free optical waveform during its propagation. Momentary stamping of the wave, transversely travelling inside a metal slit, on an ultrashort wide electron bunch enables the single-shot recording of an ultrafast optical waveform. As a proof-of-concept experiment, we successfully demonstrated to capture the entire field oscillation of a THz pulse with a sampling rate of 75.7 TS/s. Owing to the use of transversely-wide and longitudinally-short electron bunch and transversely travelling wave, the proposed “single-shot oscilloscope” will open up new avenue for developing the real-time petahertz (PHz) metrology., A travelling wave inside a metal slit can reveal its own waveform by probing deflecting motions of charged particles. Here, a real-time THz oscilloscope was demonstrated by utilizing the relativistic electrons and the subwavelength slit waveguide.
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- 2021
6. Techno-economic analysis of livestock urine and manure as a microalgal growth medium
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Boreum Lee, Hyun-Woo Kim, Jae-Cheol Lee, Byong-Hun Jeon, and Hankwon Lim
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Livestock ,Cost estimate ,business.industry ,Biomass ,Economic feasibility ,Photobioreactor ,Raw material ,Pulp and paper industry ,Manure ,Photobioreactors ,Microalgae ,Animals ,Production (economics) ,Environmental science ,business ,Waste Management and Disposal - Abstract
Microalgae have the potential to utilize the nutrients in livestock urine and manure (LUM) for the production of useful biomass, which can be used as a source of bioindustry. This study aims to evaluate the economic benefits of LUM feedstock that have not been clearly discussed before. Two types of photobioreactors were designed with a capacity of 200 m3 d-1. Using the experimental data, the economic feasibility of the suggested processes was evaluated via techno-economic analysis. Itemized cost estimation indicated that the submerged membrane photobioreactor has a lower unit production cost (5.4 $ to 5.1 $ kg−1) than the conventional photobioreactor system (14.6 $ to 13.8 $ kg−1). In addition, LUM-based growth is another good option for reducing the unit production cost of biomass. The revenues from lowering the cost of LUM treatment significantly contribute to enhancing the economic profitability, where the break-even prices were 1.18 $ m−3 (photobioreactor) and 0.98 $ m−3 (submerged membrane photobioreactor). Finally, this study provides several emerging suggestions to reduce microalgal biomass production costs.
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- 2021
7. A Study on the issue of compulsory subscription of personal information protection insurance
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Hyun Woo Kim
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business.industry ,Internet privacy ,Business ,Personally identifiable information - Published
- 2021
8. NPClassifier: A Deep Neural Network-Based Structural Classification Tool for Natural Products
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Pieter C. Dorrestein, Garrison W. Cottrell, Louis-Félix Nothias, Justin J. J. van der Hooft, Christopher A. Leber, Kyo Bin Kang, William H. Gerwick, Raphael Reher, Hyun-Woo Kim, and Mingxun Wang
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Neural Networks ,Bioinformatics ,Computer science ,Medicinal & Biomolecular Chemistry ,Pharmaceutical Science ,Computational biology ,Ontology (information science) ,Machine learning ,computer.software_genre ,Medical and Health Sciences ,Genome ,Analytical Chemistry ,Computer ,Taxonomy (general) ,Biological property ,Bioinformatica ,Drug Discovery ,Metabolome ,Life Science ,Organism ,Pharmacology ,Biological Products ,Artificial neural network ,business.industry ,Deep learning ,Organic Chemistry ,Structural classification ,Biological Sciences ,Biosynthetic Pathways ,Complementary and alternative medicine ,Chemical Sciences ,Molecular Medicine ,Neural Networks, Computer ,Artificial intelligence ,business ,computer - Abstract
Computational approaches such as genome and metabolome mining are becoming essential to natural products (NPs) research. Consequently, a need exists for an automated structure-type classification system to handle the massive amounts of data appearing for NP structures. An ideal semantic ontology for the classification of NPs should go beyond the simple presence/absence of chemical substructures, but also include the taxonomy of the producing organism, the nature of the biosynthetic pathway, and/or their biological properties. Thus, a holistic and automatic NP classification framework could have considerable value to comprehensively navigate the relatedness of NPs, and especially so when analyzing large numbers of NPs. Here, we introduce NPClassifier, a deep-learning tool for the automated structural classification of NPs from their counted Morgan fingerprints. NPClassifier is expected to accelerate and enhance NP discovery by linking NP structures to their underlying properties.
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- 2021
9. A 90-day Repeated Oral Dose Toxicity Study of Mixed Extract of Fenugreek Seeds and Lespedeza Cuneata in Rats
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Hyun-Woo Kim, Kyeong Soo Lee, Hyun Jin Park, and Hong Hwan Nho
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Oral dose ,Lespedeza cuneata ,biology ,Individual animal ,Urinalysis ,medicine.diagnostic_test ,General symptoms ,business.industry ,Physiology ,biology.organism_classification ,Blood chemistry ,Toxicity ,Medicine ,business ,Normal range - Abstract
This study was aimed at assessing the safety of a mixed extract of fenugreek seeds and Lespedeza cuneata (YHM), which effectively relieves male menopausal symptoms. To this end, male and female Sprague-Dawley rats were divided into the following groups and repeatedly administered YHM orally for 90 days: control, low-dose (500 mg/kg/day), intermediate-dose (1,000 mg/kg/day), and high-dose (2,000 mg/kg/day) groups. The animals were monitored for general symptoms; their body weights and electrolyte levels were measured; and urinalysis, blood chemistry and biochemistry tests, and histopathological tests were performed to assess the toxicity of YHM. The no-observed-adverse-effect level of YHM was 2,000 mg/kg/day for all male and female rats. While in the YHM-administered and control groups, most parameters were within the normal range; some rats in the high-dose group showed changes not induced by the test substance but which may be specific to an individual animal or may occur naturally. Thus, on the basis of our findings, we consider that YHM may be a safe, non-toxic substance for alleviating male menopausal symptoms.
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- 2021
10. Clinical Features of Genetic Creutzfeldt-Jakob Disease with E200K Mutation
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Hyun Woo Kim, Gha-Hyun Lee, Jiyoung Kim, Dae Soo Jung, and Jae Wook Cho
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Genetics ,business.industry ,mental disorders ,Medicine ,Disease ,business ,E200k mutation ,nervous system diseases - Abstract
Although genetic Creutzfeldt-Jakob disease (CJD) is a rare neurodegenerative disorder, cases of genetic CJD with E200K mutation are being increasingly reported in Korea. However, the clinical features and course of genetic CJD with E200K mutation in Korea remain unclear. We describe the clinical features and course of genetic CJD with E200K mutation in a patient who initially presented with rapid progressive memory impairment and myoclonus.
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- 2021
11. Results of development and application of convergence talent training (STEAM) programs using Artificial Intelligence (AI) and Big Data
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Hyun Woo Kim and Je Seong Lee
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Development (topology) ,business.industry ,Computer science ,Big data ,Convergence (relationship) ,Artificial intelligence ,business ,Training (civil) - Published
- 2021
12. Improvement in Self-Heating Characteristic by Utilizing Sapphire Substrate in Omega-Gate-Shaped Nanowire Field Effect Transistor for Wearable, Military, and Aerospace Application
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Jong-Ho Lee, Young Suh Song, Hyun-Woo Kim, and Junsu Yu
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Materials science ,Transistors, Electronic ,Biomedical Engineering ,Nanowire ,Silicon on insulator ,Wearable computer ,Bioengineering ,02 engineering and technology ,Substrate (printing) ,Heat sink ,01 natural sciences ,Heating ,Wearable Electronic Devices ,Thermal conductivity ,0103 physical sciences ,Aluminum Oxide ,Humans ,General Materials Science ,Aerospace ,010302 applied physics ,Nanowires ,business.industry ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Military Personnel ,Optoelectronics ,Field-effect transistor ,0210 nano-technology ,business - Abstract
In this study, we propose an omega-shaped-gate nanowire field effect transistor (ONWFET) with a silicon-on-sapphire (SOS) substrate. In order to investigate improvements in the self-heating characteristic with the use of a SOS substrate, the lattice temperature is examined using a Synopsys Sentaurus 3D Technology computer-aided design (TCAD) simulator with the results compared to those with a silicon-on-insulator (SOI) substrate. To validate the proposed structure with the SOS substrate, the locations of hot spots and heat dissipation paths (heat sinks) depending on the substrate materials are also analyzed. The electrical characteristics, specifically the on-current (Ion), off-current (Ioff), and subthreshold swing (SS), were investigated as well. Hence, it is demonstrated here that incorporating a SOS substrate can improve both the self-heating characteristic and the SS at the same time. Therefore, enhanced logic devices are feasible if using an ONWFET with a SOS substrate. Examples include wearable devices and military and future aerospace applications achieved by the radiation-resistant material Al2O3 that has high thermal conductivity.
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- 2021
13. The Change of Self-heating according to Bottom Oxide and Package which are based on 3㎚ Multi-nanosheet Field Effect Transistor
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Yoongeun Seon, Changhyun Yoo, Myounggon Kang, Hyun-Woo Kim, and Jongwook Jeon
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chemistry.chemical_compound ,Materials science ,chemistry ,business.industry ,Oxide ,Optoelectronics ,Field-effect transistor ,Self heating ,business ,Nanosheet - Published
- 2021
14. The Intertextual Rhetoric of the Apostrophe to Zion (11QPsa XXII, 1–15)
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Hyun Woo Kim
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Literature ,History ,Biblical studies ,business.industry ,Jewish studies ,media_common.quotation_subject ,Religious studies ,Dead Sea Scrolls ,Art ,Rhetoric ,Apostrophe (figure of speech) ,business ,Hebrew Bible ,media_common - Abstract
Considerable agreement has existed concerning the intertextual relations between the Apostrophe to Zion (Ap Zion) and Third Isaiah. But I propose to reread Ap Zion as a literary and theological response to the most famous lament over Zion, exemplified in the book of Lamentations. The common acrostic feature and leitmotif of Zion shared by Lamentations and Ap Zion clearly reflect the latter’s deliberate attention to the former. In this reconsideration, I argue that the much-acclaimed intertextuality between Ap Zion and Third Isaiah is the consequence of the pre-established Isaianic inner-biblical allusion (Second Isaiah) to Lamentations. To expand on this proposal, the paper will explore the multilayered intertextuality between Lam 2, Isa 49, and Ap Zion through classifying their lexical, thematic, structural, and theological associations.
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- 2021
15. Deep Packet Filtering Mechanism for Secure Internetworks
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Hyun Woo Kim and Eun et.al
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Word embedding ,Network packet ,business.industry ,Computer science ,General Mathematics ,Opcode ,Deep learning ,ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS ,Filter (signal processing) ,Static analysis ,Education ,Computational Mathematics ,Identification (information) ,Computational Theory and Mathematics ,Word2vec ,Artificial intelligence ,business ,Computer network - Abstract
In this paper, we propose a Deep Packet Filtering Mechanism (DPFM) to analyze and filter malicious data packets moving between network environments. DPFM analyzes the behavior of malicious packets on the network and extracts information about the network as a sequence. After performing the word embedding process on the extracted sequence data using the word2vec technique, it detects malicious packets on the network by learning the LSTM model. In the past, research on filters to prevent malicious packets from entering the network by converting packets into data at the sending and receiving destinations and analyzing their purpose and maliciousness is insufficient. Since DPFM proceeds at the network boundary to analyze and extract malicious packets, primary detection is possible. In this paper, more accurate identification is possible by deep learning of network packets as well as OPcode and system calls, which are static analysis data.
- Published
- 2021
16. Detection of damage locations and damage steps in pile foundations using acoustic emissions with deep learning technology
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Hyun-Woo Kim, Alipujiang Jierula, Tae-Min Oh, Joon-Hyun Lee, Jong-Won Lee, and Shuhong Wang
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Damage detection ,business.industry ,Acoustics ,Deep learning ,Data set ,Compressive strength ,Acoustic emission ,Architecture ,Evaluation methods ,Pile cap ,Artificial intelligence ,business ,Pile ,Geology ,Civil and Structural Engineering - Abstract
The aim of this study is to propose a new detection method for determining the damage locations in pile foundations based on deep learning using acoustic emission data. First, the damage location is simulated using a back propagation neural network deep learning model with an acoustic emission data set acquired from pile hit experiments. In particular, the damage location is identified using two parameters: the pile location (PL) and the distance from the pile cap (DS). This study investigates the influences of various acoustic emission parameters, numbers of sensors, sensor installation locations, and the time difference on the prediction accuracy of PL and DS. In addition, correlations between the damage location and acoustic emission parameters are investigated. Second, the damage step condition is determined using a classification model with an acoustic emission data set acquired from uniaxial compressive strength experiments. Finally, a new damage detection and evaluation method for pile foundations is proposed. This new method is capable of continuously detecting and evaluating the damage of pile foundations in service.
- Published
- 2021
17. Purcell-enhanced photoluminescence of few-layer MoS2 transferred on gold nanostructure arrays with plasmonic resonance at the conduction band edge
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Tae-Wan Kim, Seunghyun Moon, Sang Hwan Nam, Dong-Hwan Kim, Jeong Seop Lee, Kyoung-Ho Kim, Evan S. H. Kang, Jong-Woo Kim, ChaeHo Shin, Hyun Woo Kim, KwangJun Ahn, and Yung Doug Suh
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Nanostructure ,Photoluminescence ,Materials science ,business.industry ,Physics::Optics ,Purcell effect ,Optical field ,Effective mode volume ,Optoelectronics ,General Materials Science ,Surface plasmon resonance ,business ,Plasmon ,Excitation - Abstract
Plasmonic coupling of metallic nanostructures with two-dimensional molybdenum disulfide (MoS2) atomic layers is an important topic because it provides a pathway to manipulate the optoelectronic properties and to overcome the limited optical cross-section of the materials. Plasmonic enhanced light-matter interaction of a MoS2 layer is known to be mainly governed by optical field enhancement and the Purcell effect, while the discrimination of the contribution from each mechanism to the plasmonic enhancement is challenging. Here, we investigate photoluminescence (PL) enhancement from few-layer MoS2 transferred on Au nanostructure arrays with controlled localized surface plasmon resonance (LSPR) spectral positions that were detuned from the excitation wavelengths. Two distinctive regimes in LSPR mode-dependent PL enhancement were revealed showing a maximum enhancement (∼40-fold) with zero detuning and a modest enhancement (∼10-fold) with the red-shift detuned LSPR from the excitation wavelength, which were attributed to LSPR-induced optical field enhancement and the Purcell effect, respectively. By applying the experimental parameters into the Purcell effect formalism, an effective mode volume of ∼0.016λ03 was estimated. Our work provides an insight into how to utilize few-layer MoS2 as a base material for optoelectronics by harnessing Purcell-enhanced optical responsivity.
- Published
- 2021
18. Reaction condition optimization for non-oxidative conversion of methane using artificial intelligence
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Seung Ju Han, Seok Ki Kim, Hyun Woo Kim, Yong-Tae Kim, Gyoung S. Na, Jungho Shin, Sung Woo Lee, and Hyunju Chang
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Fluid Flow and Transfer Processes ,Reaction conditions ,business.industry ,Computer science ,Process Chemistry and Technology ,Decision tree ,Coke ,Non oxidative ,Chemical reaction ,Catalysis ,Methane ,chemistry.chemical_compound ,chemistry ,Chemistry (miscellaneous) ,Yield (chemistry) ,Chemical Engineering (miscellaneous) ,Artificial intelligence ,business ,Global optimization ,Metaheuristic - Abstract
Chemical reactions typically have numerous controllable factors that need to be optimized to yield the desired products. Although traditional experimental methods are limited to explore possible combinations of these factors, artificial intelligence (AI) can provide the optimal solution based on chemical reaction data. In this study, we optimize the non-oxidative conversion of methane to C2 compounds using AI, such as machine learning (ML) to predict experimental results and metaheuristics to optimize reaction conditions. A decision tree-based machine learning method can reasonably predict the reaction outcomes (CH4 conversion, C2 yield, and selectivities for C2 and coke) with an error of < 5%. Trained ML models are applied to maximize the C2 yield by optimizing the reaction parameters with metaheuristics. We can simultaneously enhance the C2 yield and suppress the coke formation by improving the multi-objective function for the optimization. We believe that our method will be helpful to optimize the chemical reaction conditions with multiple targets.
- Published
- 2021
19. Factors Related to Utilization of Smoking Cessation Support Service among Attempters for Quitting Smoking
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Hyun-Woo Kim
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Service (business) ,medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Medicine ,Smoking cessation ,business ,Psychiatry - Published
- 2020
20. Design and Control of a Sphere Robot Using a Control Moment Gyroscope Actuator for Navigation
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Hyun-Woo Kim and Seul Jung
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0209 industrial biotechnology ,Heading (navigation) ,Computer science ,business.industry ,Robotics ,02 engineering and technology ,Gimbal ,Computer Science Applications ,Computer Science::Robotics ,Control moment gyroscope ,020901 industrial engineering & automation ,Control and Systems Engineering ,Control theory ,Joystick ,Torque ,Robot ,Artificial intelligence ,Actuator ,business - Abstract
In this paper, the design and control of a sphere robot are presented. A small double gimbal control moment gyroscope(DGCMG) designed and analyzed as an indirect actuator for the rotational torque generation. The heading angle of the robot is controlled by a DGCMG and the driving position is controlled by DC motors. The DGCMG has been developed in a scissored-pair configuration which has two gimbals in the opposite direction to maximize the induced torque by double and cancel out the unwanted torque in the plane. Experimental studies of not only position control but also heading control of the sphere robot commanded by a joystick are conducted to demonstrate the functionality of the robot.
- Published
- 2020
21. Fabrication of strontium-substituted hydroxyapatite scaffolds using 3D printing for enhanced bone regeneration
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Young-Jin Kim and Hyun Woo Kim
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Scaffold ,Materials science ,Fabrication ,business.industry ,Mechanical Engineering ,Regeneration (biology) ,3D printing ,Bioceramic ,Microporous material ,Extracellular matrix ,Chemical engineering ,Mechanics of Materials ,General Materials Science ,Bone regeneration ,business - Abstract
The use of porous three-dimensional (3D) bioceramic scaffolds to facilitate the regeneration of bone defects has attracted great attention because their structures closely mimic the natural extracellular matrix. 3D printing is a versatile method for the fabrication of 3D scaffolds. In this study, 3D strontium-substituted hydroxyapatite (Sr-HA) bioceramic scaffolds were prepared by simple precipitation and 3D printing method. The resulting scaffolds exhibited interconnected microporous structures of strands and a single-phase crystal due to HA, meaning that no changes in the phase composition and microstructure of the scaffolds with the Sr content were observed. However, their dissolution rate and biological performance were substantially influenced by changes in the Sr content of the scaffolds. The optimal Sr content in the Sr-HA scaffolds for enhanced proliferation and differentiation of cells were identified by comparing four compositions of the Sr-HA scaffolds. The results of in vitro bioactivity tests demonstrated that the Sr5-HA scaffold with 0.05 of Sr/(Ca + Sr) molar ratio promoted more rapid cell proliferation, osteogenic differentiation, and cellular mineralization compared with the other scaffolds. Therefore, Sr-HA scaffolds have the potential for application in bone regeneration as new bone graft substitutes.
- Published
- 2020
22. Applying Machine Learning Algorithms to Predict Potential Energies and Atomic Forces during C-H Activation
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Yong Tae Kim, Hyun Woo Kim, Seunghee Lee, Tae-Wook Ko, Jonggul Lee, Jino Im, Seok Ki Kim, Hyunju Chang, and YunKyong Hyon
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010302 applied physics ,Feature engineering ,Work (thermodynamics) ,Artificial neural network ,business.industry ,Computer science ,General Physics and Astronomy ,02 engineering and technology ,Solid material ,021001 nanoscience & nanotechnology ,Machine learning ,computer.software_genre ,01 natural sciences ,Improved performance ,Molecular dynamics ,0103 physical sciences ,Artificial intelligence ,Extreme gradient boosting ,0210 nano-technology ,business ,Algorithm ,computer - Abstract
Molecular dynamics (MD) simulations are useful in understanding the interaction between solid materials and molecules. However, performing MD simulations is possible only when interatomic potentials are available and constructing such interatomic potentials usually requires additional computational work. Recently, generating interatomic potentials was shown to be much easier when machine learning (ML) algorithms were used. In addition, ML algorithms require new descriptors for improved performance. Here, we present an ML approach with several categories of atomic descriptors to predict the parameters necessary for MD simulations, such as the potential energies and the atomic forces. We propose several atomic descriptors based on structural information and find that better descriptors can be generated from eXtreme gradient boosting (XGBoost). Moreover, we observe fewer descriptors that perform better in predicting the potential energies and the forces during methane activation processes on a catalytic Pt(111) surface. These results were consistently observed in two different ML algorithms: fully-connected neural network (FNN) and XGBoost. Taking into account the advantages of FNN and XGBoost, we propose an efficient ML model for estimating potential energies. Our findings will be helpful in developing new ML potentials for long-time MD simulations.
- Published
- 2020
23. Case of Treatment Using Adaptive Servo-Ventilation in a Patient with Central Sleep Apnea after a Lateral Medullary Infarction
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Hyun-Woo Kim, Dae Jin Kim, Sue Jean Mun, Jae Wook Cho, and Jeong Su Choi
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medicine.medical_specialty ,lcsh:R5-920 ,Central sleep apnea ,Medullary cavity ,business.industry ,adaptive servo ventilation ,Adaptive servo ventilation ,medicine.medical_treatment ,Infarction ,030204 cardiovascular system & hematology ,medicine.disease ,central sleep apnea ,respiratory tract diseases ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,Cardiology ,Continuous positive airway pressure ,business ,lcsh:Medicine (General) ,030217 neurology & neurosurgery ,continuous positive airway pressure - Abstract
Central sleep apnea (CSA) is characterized by respiratory failure of at least 10 seconds without any effort of the chest and abdomen in the absence of upper airway resistance during sleep. In this case, the patient experiences respiratory failure that does not meet the CSA diagnostic criteria and CSA symptoms. Magnetic resonance imaging diffusion-weighted imaging (MRI DWI) scans revealed a lateral medullary infarction. Continuous positive airway pressure (CPAP) was applied as a primary treatment for CSA and respiratory failure. During the titration of CPAP, the apnea-hypopnea index (AHI) and arousal index (AI) were worse than the results before its use (AHI: 42.5/hr→82.8/hr, AI: 21.7/hr→40.8h). As a result, adaptive servo-ventilation (ASV) was chosen as the secondary treatment. Compared to the night-polysomnography results before the ASV treatment, the AHI improved (42.5/hr→8.6/hr). Therefore, ASV is a potential treatment for CSA and respiratory failure in these patients.
- Published
- 2020
24. Treatment of electrical wrist stimulation reduces chemotherapy-induced neuropathy and ultrasound vocalization via modulation of spinal NR2B phosphorylation
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O Sang Kwon, Suk-Yun Kang, Hyun-Woo Kim, Se Kyun Bang, Seong Jin Cho, Kwang-Ho Choi, Su-Yeon Seo, Hwa Seung Yoo, Yeonhee Ryu, and Jin Sun Lee
- Subjects
Male ,0301 basic medicine ,medicine.medical_treatment ,Analgesic ,Antineoplastic Agents ,Electric Stimulation Therapy ,Stimulation ,Docetaxel ,Receptors, N-Methyl-D-Aspartate ,Mice ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Animals ,Phosphorylation ,Mice, Inbred ICR ,Chemotherapy ,business.industry ,General Neuroscience ,Ultrasound ,medicine.disease ,030104 developmental biology ,Peripheral neuropathy ,Spinal Cord ,Anesthesia ,Neuropathic pain ,Neuralgia ,NMDA receptor ,Vocalization, Animal ,business ,030217 neurology & neurosurgery ,medicine.drug - Abstract
Docetaxel, a chemotherapeutic agent used to treat breast cancer, produces a robust painful neuropathy that is aggravated by mechanical and thermal stimuli. This study was undertaken to investigate the analgesic effects of electrical stimulation on docetaxel-induced neuropathic pain in mice and to identify associated changes in ultrasound vocalizations. Peripheral neuropathy was induced with intraperitoneally injected docetaxel (5 mg/kg) on 3 times every 2 days in male ICR mice. Electrical wrist stimulation was administered and pain behavior signs were evaluated by von Frey filaments and thermal stimulation on the hind paw. Ultrasound vocalizations were measured using ultrasound microphones, after electrical stimulation. After mice developed docetaxel-induced neuropathic pain behavior, an electrical stimulation temporarily attenuated mechanical allodynia and thermal hyperalgesia. In formalin and NMDA test, pain-induced mice showed increases in 10-30 kHz ultrasound vocalizations, but not in 30-50 and 50-80 kHz vocalizations. Treatment with docetaxel selectively increased 10-30 kHz ultrasound vocalizations, whereas electrical stimulation caused a meaningful decrease. Moreover, electrical stimulation suppressed the docetaxel-enhanced phosphorylation of the NMDA receptor NR2B subunit in the spinal dorsal horn. These results of the analgesic effect of electrical stimulation in chemotherapy-induced neuropathy could potentially provide a new method to treat and manage peripheral neuropathy in patients with cancer.
- Published
- 2020
25. An understanding ability of leaders who are perceived by excellent athletics in track and field hurdles
- Author
-
Hye-Lim Jung and Hyun-Woo Kim
- Subjects
business.industry ,Public relations ,Psychology ,business ,Track and field athletics - Published
- 2020
26. From Words to Numbers: Getting Started with Text Analysis for Applied Social Scientists
- Author
-
Hyun Woo Kim and Hyejung Chang
- Subjects
World Wide Web ,Text mining ,Computer science ,business.industry ,Unstructured data ,General Medicine ,Python (programming language) ,business ,computer ,Data preparation ,computer.programming_language - Published
- 2020
27. Malicious Packet Filtering Scheme of Network Parameter on Internetwork Topology Using Deep Learning
- Author
-
Eun-Ha Song and Hyun-Woo Kim
- Subjects
Scheme (programming language) ,Packet filtering ,Computer science ,business.industry ,Deep learning ,Topology (electrical circuits) ,Artificial intelligence ,Network parameter ,Topology ,business ,computer ,computer.programming_language - Published
- 2020
28. Narcolepsy, How do We Manage it?
- Author
-
Jae Wook Cho and Hyun-Woo Kim
- Subjects
medicine.medical_specialty ,Pitolisant ,Methylphenidate ,business.industry ,Armodafinil ,Modafinil ,medicine.disease ,chemistry.chemical_compound ,chemistry ,medicine ,Psychiatry ,business ,medicine.drug ,Narcolepsy - Published
- 2020
29. Sinus floor augmentation using mixture of mineralized cortical bone and cancellous bone allografts: Radiographic and histomorphometric evaluation
- Author
-
Hyun-Woo Kim, Sang Joun Yu, Hong In Shin, Seong-Ho Choi, Yo Seob Seo, Won-Pyo Lee, Kyeong Ok Lim, and Byung Ock Kim
- Subjects
Sinus Floor Augmentation ,Maxillary sinus ,Radiography ,Bone augmentation ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Bone regeneration ,General Dentistry ,Dental alveolus ,Xenografts ,Bone substitutes ,business.industry ,030206 dentistry ,Allografts ,lcsh:RK1-715 ,medicine.anatomical_structure ,lcsh:Dentistry ,030220 oncology & carcinogenesis ,Cortical bone ,Original Article ,business ,Nuclear medicine ,Cancellous bone ,Sinus floor augmentation - Abstract
Background/purpose: Due to the pneumatization of the maxillary sinus, the sinus floor augmentation is often performed to implant placement in the maxillary posterior region. The aim was to perform radiographic and histomorphometric evaluation after placement of mixed allografts (cortical freeze-dried bone allograft [FDBA] 50%:cancellous FDBA 50%) during sinus floor augmentation. Materials and methods: In 37 patients, anorganic bovine bone (ABB, sites = 16), mineralized cancellous bone allograft (MCBA, sites = 15), and mixed allografts (Mixed AG, sites = 20) were placed during sinus floor elevation via the lateral approach (LSFE), at total 51 sites with residual alveolar bone height (RBH) 0.05). The mean ABH of ABB, MCBA, and mixed AG groups after 6 months was similar (13.72 ± 4.55 mm, 11.83 ± 3.31 mm, and 12.53 ± 2.97 mm, respectively; P > 0.05). In the ABB, MCBA, and mixed AG groups, the proportion of newly formed bone (NB) was similar (36.13 ± 10.01%, 39.26 ± 10.72%, and 31.27 ± 18.31%, respectively; P > 0.05). Conclusion: This result demonstrated that mixed AG led to sufficient bone augmentation and histologically comparable NB formation as compared to ABB and MCBA for sinus floor augmentation.
- Published
- 2020
30. Adaptive resource management using many-core processing for fault tolerance based on cyber–physical cloud systems
- Author
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Young-Sik Jeong, Gangman Yi, Hyun-Woo Kim, and Jong Hyuk Park
- Subjects
020203 distributed computing ,Speedup ,Computer Networks and Communications ,Computer science ,business.industry ,Node (networking) ,Distributed computing ,Real-time computing ,Cyber-physical system ,Fault tolerance ,Cloud computing ,02 engineering and technology ,computer.software_genre ,Hardware and Architecture ,Virtual machine ,High availability ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Resource management ,business ,computer ,Software - Abstract
With the increasing utilization of cloud computing and cyber–physical systems (CPSs), which allow the expression and control of the real world in a virtual environment, researches related to these subjects are being actively conducted in various areas. The convergence of CPS and cloud computing is being researched primarily because of their high availability, high-performance computing, and high-throughput computing. CPS consisting of numerous sensors, actuators, controllers, and control managers requires optimized modeling, simulation, and resource management technologies to integrate physical elements with computing elements for processing, which will provide high-throughput computing and high-reliability services. But the main problem of sensor resource management is that information of sensors cannot be approached in case that a sensor failure occurs at the sensing target area. Thus, various researches have been done to reconstruct the topology, but the self-topology configuration of sensors causes unnecessary events and battery consumption from various sensor nodes. In this paper, adaptive resource management (ARM) is proposed to 1) minimize information loss due to the irregular lifespan of resources, such as sensors and actuators; and 2) quickly respond to any problems. ARM uses the many-core of GPU to speed up fault handling, parallelizes the sensor information to select an alternate node of the fault node, and presents the performance evaluation results of the execution time of CPU and GPU.
- Published
- 2020
31. Mystery Case: Anti-NMDAR encephalitis with overlapping demyelinating syndrome
- Author
-
Hyun Woo Kim, Sheheryar A. Jamali, Christopher J. Lamb, and Alfonso S Lopez Chiriboga
- Subjects
Adult ,Anti-N-Methyl-D-Aspartate Receptor Encephalitis ,Male ,business.industry ,Immunology ,Humans ,Medicine ,Demyelinating Autoimmune Diseases, CNS ,Neurology (clinical) ,Anti-NMDAR Encephalitis ,business - Published
- 2020
32. Effects of Incorporating Non-elastic Taping into PNF Techniques on Muscle Activities, Balance, and Gait in Patients with Chronic Stroke
- Author
-
Young-Han Park and Hyun-woo Kim
- Subjects
medicine.medical_specialty ,Physical medicine and rehabilitation ,Gait (human) ,business.industry ,Medicine ,In patient ,Muscle activity ,business ,medicine.disease ,Stroke ,Chronic stroke ,Balance (ability) - Published
- 2020
33. Design of Hybrid Lower Control Arm using Finite Element Analysis
- Author
-
Seong Kook Park, Seung Hyun Nam, Yeong Chun Lee, Hyun Woo Kim, In Hee Park, and Soon Chan Kwon
- Subjects
Control arm ,business.industry ,Mechanical Engineering ,Structural engineering ,business ,Finite element method ,Mathematics - Published
- 2020
34. Costless Performance Improvement in Machine Learning for Graph-Based Molecular Analysis
- Author
-
Gyoung S. Na, Hyun Woo Kim, and Hyunju Chang
- Subjects
Computer science ,General Chemical Engineering ,Library and Information Sciences ,Machine learning ,computer.software_genre ,01 natural sciences ,Machine Learning ,Chemical science ,Molecular property ,Drug Discovery ,0103 physical sciences ,Global structure ,010304 chemical physics ,Artificial neural network ,business.industry ,Graph based ,General Chemistry ,0104 chemical sciences ,Computer Science Applications ,Molecular analysis ,010404 medicinal & biomolecular chemistry ,Graph (abstract data type) ,Neural Networks, Computer ,Artificial intelligence ,Performance improvement ,business ,computer - Abstract
Graph neural networks (GNNs) have attracted significant attention from the chemical science community because molecules can be represented as a featured graph. In particular, graph convolutional network (GCN) and its variants have been widely used and have shown a state-of-the-art performance in analyzing molecules, such as molecular label classification, drug discovery, and molecular property prediction. However, in molecular analysis, existing GCNs have two fundamental limitations: (1) information of the molecular scale is distorted and (2) global structures in a molecule are ignored. These limitations can seriously degrade the performance in the machine learning-based molecular analysis because the scale and global structure information of a molecule occasionally have a significant effect on the molecular properties. To overcome the limitations of existing GCNs, we comprehensively analyzed the structure of GCNs and developed a costless solution for the limitations of GCNs. To demonstrate the effectiveness of our solution, extensive experiments were conducted on various benchmark datasets.
- Published
- 2020
35. Insomnia symptoms and obesity are associated with aggression independent of depression in patients with epilepsy
- Author
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Hyo Jae Kim, Yong Seo Koo, Hyun Woo Kim, and Sang-Ahm Lee
- Subjects
Adult ,Male ,Poison control ,Hostility ,03 medical and health sciences ,Epilepsy ,0302 clinical medicine ,Sleep Initiation and Maintenance Disorders ,Republic of Korea ,medicine ,Humans ,Obesity ,Depression ,Aggression ,business.industry ,Epworth Sleepiness Scale ,General Medicine ,Middle Aged ,Stepwise regression ,medicine.disease ,Health Surveys ,Cross-Sectional Studies ,Neurology ,Anxiety ,Female ,Neurology (clinical) ,medicine.symptom ,business ,Body mass index ,030217 neurology & neurosurgery ,Clinical psychology - Abstract
Purpose : There has been little research conducted into aggression in persons with epilepsy (PWE). We determine whether sleep disturbances and obesity are associated with aggression in PWE independent of psychological distress. Methods : This was a cross-sectional study. The Aggression Questionnaire (AQ-K), the Insomnia Severity Index (ISI), the Epworth Sleepiness Scale (ESS), the Patient Health Questionnaire-9 (PHQ-9), and the Generalized Anxiety Disorder-7 (GAD-7) were utilized in the study. A stepwise linear regression analysis was used. Results : A total of 104 participants (49% men) were included. Mean AQ-K score was 51.4 (SD 12.6). PHQ-9 scores ≥10 and GAD-7 scores ≥7 were noted in 26.9% and 24.0% of participants, respectively. In a stepwise linear regression model, AQ-K scores were positively associated with PHQ-9 scores ≥10 (p = 0.002), ISI scores (p = 0.007), body mass index (BMI) (p = 0.001), and composite scores of epilepsy severity (p = 0.013). This model explained 46.6% of the variance in the AQ-K. In the subscale analyses, different variables were identified as independent factors associated with different subscales of the AQ-K. For example, physical aggression was related to a PHQ-9 score ≥10, men, and perampanel usage, whereas hostility was related to a GAD-7 score ≥7, polytherapy, and BMI. Conclusions : Insomnia symptoms and obesity were related to overall aggressive behavior in PWE independent of depressive symptoms. The individual subscales of the AQ were correlated differently with the various factors including male sex, obesity, depressive symptoms, anxiety, insomnia symptoms, epilepsy severity, polytherapy, and the use of perampanel.
- Published
- 2020
36. Comparison between the Neurological Disorders Depression Inventory for Epilepsy and the Patient Health Questionnaire-9 in patients with epilepsy according to antiepileptic drug load
- Author
-
Ji-Ye Jeon, Sang-Ahm Lee, Hyun-Woo Kim, and Hyo Jae Kim
- Subjects
Adult ,Male ,medicine.medical_specialty ,Antiepileptic drug ,Suicidal Ideation ,03 medical and health sciences ,Epilepsy ,0302 clinical medicine ,Internal medicine ,Republic of Korea ,medicine ,Brief Psychiatric Rating Scale ,Humans ,In patient ,Depression (differential diagnoses) ,Mini-international neuropsychiatric interview ,Receiver operating characteristic ,Depression ,business.industry ,Curve analysis ,General Medicine ,Middle Aged ,medicine.disease ,Health Surveys ,humanities ,Patient Health Questionnaire ,Neurology ,Anticonvulsants ,Female ,Neurology (clinical) ,Nervous System Diseases ,business ,030217 neurology & neurosurgery - Abstract
We compared the Neurological Disorders Depression Inventory for Epilepsy (NDDI-E) with the Patient Health Questionnaire-9 (PHQ-9) according to different antiepileptic drug (AED) loads in people with epilepsy (PWE).Depression and suicidality were assessed with the Mini International Neuropsychiatric Interview (MINI), the NDDI-E, and the PHQ-9. A receiver operating characteristic (ROC) curve analysis was used. Sensitivity and specificity of the NDDI-E and PHQ-9 were compared between an AED load2 and ≥2.Of 213 participants included, 22.5 % were diagnosed with current depression by the MINI, and 9 % had a moderate to severe risk of suicide. Using the cutoff of 9.5 and 13.5 for the PHQ-9 and NDDI-E, respectively, in the total group, the PHQ had a higher sensitivity (91.7 %) but lower specificity (75.8 %) than the NDDI-E (66.7 % and 87.3 %, respectively) (p0.001). In a group with an AED load2, the sensitivity and specificity did not differ between the PHQ-9 and NDDI-E. In a group with an AED load ≥2, however, the PHQ-9 had a higher sensitivity (90.9 %, p0.063) but lower specificity (65.2 %, p0.001) than the NDDI-E (68.2 % and 81.2 %, respectively). For screening of suicide risk, the sensitivity and specificity were not different between the PHQ-9 and NDDI-E in all tested groups. The negative predictive values of both instruments were above 95 % for suicide risk.In patients with a low AED load, the sensitivity and specificity did not differ between the PHQ-9 and NDDI-E. In contrast, in patients with a high AED load, the PHQ-9 had a poor specificity whereas the NDDI-E had a poor sensitivity.
- Published
- 2020
37. Towards jitter-free ultrafast electron diffraction technology
- Author
-
Fabian Rotermund, Key Young Oang, Sunjeong Park, Jungwon Kim, Mi Hye Kim, Thomas Feurer, Young Chan Kim, Hyun Woo Kim, Kitae Lee, Junho Shin, In Hyung Baek, Young Uk Jeong, Kyu-Ha Jang, Sunglae Cho, Seong Hee Park, and Nikolay Vinokurov
- Subjects
Materials science ,business.industry ,Terahertz radiation ,Ultrafast electron diffraction ,Attosecond ,02 engineering and technology ,Electron ,021001 nanoscience & nanotechnology ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,010309 optics ,Root mean square ,Optics ,Temporal resolution ,0103 physical sciences ,0210 nano-technology ,business ,Ultrashort pulse ,Jitter - Abstract
Stroboscopic visualization of nuclear or electron dynamics in atoms, molecules or solids requires ultrafast pump and probe pulses and a close to perfect synchronization between the two. We have developed a 3 MeV ultrafast electron diffraction (UED) probe technology that nominally reduces the electron bunch duration and the arrival time jitter to the subfemtosecond level. This simple configuration uses a radiofrequency photogun and a 90° achromatic bend and is designed to provide effectively jitter-free conditions. Terahertz streaking measurements reveal an electron bunch duration of 25 fs, even for a charge as high as 0.6 pC, and an arrival time jitter of 7.8 fs, the latter limited by only the measurement accuracy. From pump–probe measurements of photoexcited bismuth films, the instrument response function was determined to be 31 fs. This pioneering jitter-free technique paves the way towards UED of attosecond phenomena in atomic, molecular and solid-state dynamics. An ultrafast electron diffraction facility with an overall temporal resolution of 31 fs root mean square is developed. Even for a charge as high as 0.6 pC, the electron bunch duration and timing jitter are 25 fs and less than 10 fs, respectively.
- Published
- 2019
38. Monocular Camera based Real-Time Object Detection and Distance Estimation Using Deep Learning
- Author
-
Sanghyun Park and Hyun Woo Kim
- Subjects
Computer science ,business.industry ,Deep learning ,Computer vision ,Artificial intelligence ,business ,Object detection ,Monocular camera - Published
- 2019
39. Low dose radiation attenuates inflammation and promotes wound healing in a mouse burn model
- Author
-
Hyunkoo Kang, HyeSook Youn, Hyun-Woo Kim, Jeongha Kim, Beomseok Son, Sungmin Lee, BuHyun Youn, and Seon Young Nam
- Subjects
Keratinocytes ,0301 basic medicine ,Burn injury ,Inflammation ,Dermatology ,Radiation Dosage ,Systemic inflammation ,Biochemistry ,Cell Line ,Proinflammatory cytokine ,Mice ,030207 dermatology & venereal diseases ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Animals ,Molecular Biology ,Skin ,Wound Healing ,integumentary system ,business.industry ,Interleukin ,Mice, Inbred C57BL ,Disease Models, Animal ,HaCaT ,030104 developmental biology ,Cancer research ,Cytokines ,Female ,Tumor necrosis factor alpha ,medicine.symptom ,Burns ,Wound healing ,business ,Oxidation-Reduction ,Signal Transduction - Abstract
Background Burn injuries are devastating traumas that functionally affect a variety of organ systems. As intensive inflammatory responses induced by burns can lead to multiple organ failures and impaired skin regeneration increases risk of infectious complex, multimodal therapeutic approaches are needed. Objectives To investigate the role of low dose radiation (LDR) treatment for regulation of excessive inflammation and wound healing after burn injury. Methods Mouse burn model was established by generating third-degree burn injury in dorsal skin and local LDR less than 100 mGy was delivered to the mice. After 3 or 12 days after burn injury, systemic inflammation in liver, lung, spleen, and kidney and skin wound healing were assessed. For investigation of molecular mechanisms, HaCaT keratinocytes were administrated with serum from mice with burn injury and alteration of viability and cornification biomarkers are assessed. Results In a mouse burn model, expression of proinflammatory cytokines, interleukin (IL)-1β, IL-6, and tumor necrosis factor-α, were downregulated by LDR in major organs and wound healing capacity was increased by LDR. In skin tissue, we observed the alleviation of reactive oxygen species generation and increased antioxidant gene expression by LDR. In addition, we found that treatment of serum from mice with burn injury and LDR increased proliferation and cornification in HaCaT cells through activation of focal adhesion kinase signaling pathway. Conclusion LDR could reduce proinflammatory signaling pathway and increase skin wound healing after burn injury. Therefore, the present study suggested LDR as a novel treatment for burn injury patients.
- Published
- 2019
40. Prevalence and Treatment Outcome of Displaced High-Long Oblique Supracondylar Humeral Fractures in Children
- Author
-
Kun-Bo Park, Joo Hyung Han, Hoon Park, Mudit Shah, and Hyun Woo Kim
- Subjects
Orthodontics ,long oblique fracture ,Percutaneous ,business.industry ,Radiography ,Elbow ,Pediatrics ,RJ1-570 ,Percutaneous pinning ,humerus ,medicine.anatomical_structure ,children ,Pediatrics, Perinatology and Child Health ,Medicine ,Displacement (orthopedic surgery) ,Humerus ,Olecranon fossa ,business ,Original Research ,supracondylar fracture ,percutaneous pinning ,Fixation (histology) - Abstract
Aim: The treatment protocol for supracondylar humeral fracture has mainly been based only on the severity of displacement and percutaneous pinning has been recommend as a first treatment. However, a long oblique fracture line is difficult to fix by the traditional cross pinning. The purpose of this study is to assess the prevalence of high-long oblique supracondylar humeral (HLO) fracture and evaluate the surgical outcome of percutaneous pin fixation.Methods: We reviewed 690 children who had undergone an operation for the displaced supracondylar humeral fracture. HLO fracture was defined as having a fracture line starting from either cortex above the metaphyseal-diaphyseal junction and finishing at the opposite cortex around or below the olecranon fossa. Clinical and radiographic parameter outcomes were assessed.Results: There were 14 patients diagnosed with the HLO fracture (14/690) and all the patients were treated by pin fixation. The median age was 5 years 1 month (range, 2–11 years). The common mode of injury was direct contact injury to the elbow. There were 6 patients with lateral HLO fracture, and 8 patients had medial HLO type. In medial HLO type, medial pinning only was done in 3 patients due to the difficulty in lateral pin insertion. In addition, the lateral pin was not a bicortical fixation through capitellum entry in 2 patients who had it fixed by cross pinning. The final Baumann angle and lateral humero-capitellar angle were 20.5 (5–67.6) degrees and 49.3 (23.3–71.9) degrees, respectively, without statistical significance compared to the normal side. Flynn's cosmetic grade showed satisfactory results in all patients.Conclusion: The prevalence of HLO fractures was 2% in the displaced supracondylar humeral fracture. The mechanism of injury of HLO fractures may be direct contact injury. In medial HLO fractures, medial pinning is important for stability, and sometimes lateral pinning was impossible. Contrarily, lateral HLO fracture could easily be fixed by lateral-only pinning, but the correct lateral pinning is necessary because medial pinning is difficult. The HLO fracture is a difficult pattern to treat by traditional percutaneous pinning and another surgical option should be considered.
- Published
- 2021
41. Burn Injury-Induced Pain and Depression-Like Behavior in Mice
- Author
-
Hyun-Woo Kim, Dong-Wook Kang, Miae Lee, Jaehyuk Kim, Sheu-Ran Choi, Jin Bong Park, and Jae-Gyun Choi
- Subjects
Burn injury ,General Immunology and Microbiology ,Depression ,business.industry ,General Chemical Engineering ,General Neuroscience ,Pain ,medicine.disease ,General Biochemistry, Genetics and Molecular Biology ,Mice ,Allodynia ,Hyperalgesia ,Gait analysis ,Anesthesia ,Quality of Life ,medicine ,Scalding ,Animals ,Nociception assay ,medicine.symptom ,Burns ,business ,Depression (differential diagnoses) ,Behavioural despair test - Abstract
Scalding water is the most common cause of burn injury in both elderly and young populations. It is one of the major clinical challenges because of the high mortality and sequelae in low- and middle-income countries. Burns frequently induce intense spontaneous pain and persistent allodynia as well as life-threatening problem. More importantly, excessive pain is often accompanied by depression, which may significantly decrease the quality of life. This article shows how to develop an animal model for the study of burn-induced pain and depression-like behavior. After anesthesia, burn injury was induced by dipping one hind paw of the mouse into hot water (65 °C ± 0.5 °C) for 3 s. The von Frey test and automated gait analysis were performed every 2 days after burn injury. In addition, depression-like behavior was examined using the forced swimming test, and the rota-rod test was performed to differentiate the abnormal motor function after burn injury. The main purpose of this study is to describe the development of an animal model for the study of burn injury-induced pain and depression-like behavior in mice.
- Published
- 2021
42. Insomnia moderates the association between recurrent seizures and emotional instability in persons with epilepsy
- Author
-
Su-Hyun Han, Kayeong Im, Eun Ju Choi, Han Uk Ryu, Gha-Hyun Lee, Ji-Ye Jeon, Ha-rin Yang, Hyun-Woo Kim, and Sang-Ahm Lee
- Subjects
Male ,medicine.medical_specialty ,Psychological intervention ,Emotional Instability ,Behavioral Neuroscience ,Epilepsy ,Seizures ,Internal medicine ,Sleep Initiation and Maintenance Disorders ,Insomnia ,medicine ,Humans ,Association (psychology) ,Sleep disorder ,business.industry ,Depression ,Stepwise regression ,medicine.disease ,Cross-Sectional Studies ,Neurology ,Female ,Neurology (clinical) ,Levetiracetam ,medicine.symptom ,business ,medicine.drug - Abstract
PURPOSE We investigated the moderating effect of sleep disturbance on the association between seizure recurrence and emotional instability in patients with epilepsy, independent of psychological distress. METHODS This was a cross-sectional study. Patients completed the short form of the Affective Lability Scale (ALS-18), Insomnia Severity Index (ISI), Patient Health Questionnaire-9 (PHQ-9), and Generalized Anxiety Disorder-7 (GAD-7). A stepwise linear regression analysis and an analysis of covariance with an interaction term were performed. RESULTS A total of 171 subjects (63.2% men) were included. The mean ALS-18 score was 15.6 ± 11.3. An ISI ≥ 15, PHQ-9 ≥ 10, and GAD-7 ≥ 7 were noted in 20.5%, 18.1%, and 23.4% of subjects, respectively. A stepwise linear regression analysis found that recurrent seizures in the last year, an ISI ≥ 15, a GAD-7 ≥ 7, and use of levetiracetam were significant and independent factors that were positively associated with higher ALS-18 scores. The coefficient of determination for the model was 0.331. The interaction between recurrent seizures and an ISI ≥ 15 had a significant effect on the ALS-18 scores (F = 6.812, p = 0.010, partial eta2 = 0.040). An ISI ≥ 15 was associated with ALS-18 scores in patients without seizure recurrence (p
- Published
- 2021
43. Psychomotor Speed Predicts Outcome in Patients with Acute Meningitis and Encephalitis: A Prospective Observational Study
- Author
-
Sang-Ahm Lee, Min Ju Kim, Soyeon An, Yong Seo Koo, and Hyun-Woo Kim
- Subjects
Adult ,Pediatrics ,medicine.medical_specialty ,Neuropsychological Tests ,03 medical and health sciences ,0302 clinical medicine ,Event-related potential ,medicine ,Humans ,Cognitive Dysfunction ,Meningitis ,030304 developmental biology ,Aged ,Psychomotor learning ,0303 health sciences ,business.industry ,Glasgow Outcome Scale ,Neuropsychology ,Cognition ,Electroencephalography ,General Medicine ,medicine.disease ,Neurology ,Encephalitis ,Observational study ,Neurology (clinical) ,business ,030217 neurology & neurosurgery - Abstract
Background and Purpose. Although acute meningitis and encephalitis are known to cause cognitive dysfunction, the prognostic values of neuropsychological and neurophysiological tests in predicting clinical outcomes are seldom studied. We investigated specific neurocognitive dysfunction and event-related potentials (ERPs), which can predict functional outcomes in patients with acute meningitis and encephalitis. Methods. We enrolled consecutive adult patients with acute meningitis and encephalitis and performed neuropsychological tests and ERP studies using a passive auditory oddball paradigm at enrollment. Patient functional outcomes were assessed using the Glasgow Outcome Scale at 6 (GOS6) months after discharge. Results. Twenty-two patients were included in the study. Among 21 patients who performed neuropsychological tests, Korean-Trail Making Test-Elderly's version, Part A time (TMT-A time) correlated with GOS6, which remained significant even after controlling for age. We identified a significant association between TMT-A time and P3a latency. Post-hoc analysis showed that patients with longer TMT-A time (≥23 s) tended to have longer P3a latency than those with shorter TMT-A time. Conclusions. Decreased psychomotor speed predicted poor clinical outcomes. Because TMT-A time can be performed at the bedside in a relatively short time, this might be a useful neuropsychological biomarker to predict or monitor clinical outcomes. Furthermore, passive oddball P3a may be useful in patients with more severe disease who are unable to perform the TMT task.
- Published
- 2021
44. Hip-Spine Syndrome in Patients With Spinal Cord Injuries: Hyperlordosis Associated With Severe Hip Flexion Contracture
- Author
-
Byoung Kyu Park, Kun-Bo Park, Woo Sung Do, Hyun Woo Kim, and Isaac Rhee
- Subjects
musculoskeletal diseases ,medicine.medical_specialty ,Flaccid paralysis ,Hyperlordosis ,lumber hyperlordosis ,Pediatrics ,RJ1-570 ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Deformity ,hip-spine syndrome ,hip flexion contracture ,Spinal cord injury ,Original Research ,030222 orthopedics ,Cobb angle ,business.industry ,Spinal cord ,medicine.disease ,paraplegic ,Functional Independence Measure ,spinal cord injury ,Surgery ,medicine.anatomical_structure ,Pediatrics, Perinatology and Child Health ,medicine.symptom ,Contracture ,business ,030217 neurology & neurosurgery - Abstract
Aim: Spinal cord injury (SCI)-related flaccid paralysis may result in a debilitating hyperlordosis associated with a progressive hip flexion contracture. The aim of this study was to evaluate the correction of hip flexion contractures and lumbar hyperlordosis in paraplegic patients that had a history of spinal cord injuries.Methods: A retrospective review was performed on 29 hips of 15 consecutive patients who underwent corrective surgeries for severe hip flexion deformity from 2006 to 2018. The mean age at surgery was 10.1 years (2.7 to 15.8), and the mean follow-up was 68 months (7 to 143). Relevant medical, surgical, and postoperative information was collected from the medical records and radiographs.Results: Improvements were seen in the mean hip flexion contracture (p < 0.001) with 100% hip correction at surgery and 92.1% at the latest follow-up. Mean lumbar lordosis decreased (p = 0.029) while the mean Cobb angle increased (p = 0.001) at the latest follow up. Functional score subdomains of the Spinal Cord Independence Measure, Functional Independence Measure, and modified Barthel activities of daily living (ADL) scores remained the same at the final follow-up.Conclusion: For paraplegic SCI patients, we found an association between treating the hip flexion contracture and indirect correction of their lumbar hyperlordosis. We recommend the surgeon carefully examine the hip pathology when managing SCI-related spinal deformities, especially increased lumbar lordosis.
- Published
- 2021
45. Comparisons of clinical characteristics, brain MRI findings, and responses to epidural blood patch between spontaneous intracranial hypotension and post-dural puncture headache: retrospective study
- Author
-
Jae Wook Cho, Hyun-Woo Kim, Gha-Hyun Lee, and Jiyoung Kim
- Subjects
medicine.medical_specialty ,Post-dural-puncture headache ,Spontaneous intracranial hypotension ,Intracranial Hypotension ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,Magnetic resonance imaging ,0302 clinical medicine ,Cerebrospinal fluid ,Humans ,Medicine ,RC346-429 ,Vein ,Retrospective Studies ,Epidural blood patch ,business.industry ,Research ,Brain ,General Medicine ,medicine.anatomical_structure ,Anesthesia ,Vomiting ,Neurology. Diseases of the nervous system ,Neurology (clinical) ,Neurosurgery ,Post-Dural Puncture Headache ,medicine.symptom ,business ,Blood Patch, Epidural ,030217 neurology & neurosurgery ,Straight sinus - Abstract
Background Spontaneous intracranial hypotension and post-dural puncture headache are both caused by a loss of cerebrospinal fluid but present with different pathogeneses. We compared these two conditions concerning their clinical characteristics, brain imaging findings, and responses to epidural blood patch treatment. Methods We retrospectively reviewed the records of patients with intracranial hypotension admitted to the Neurology ward of the Pusan National University Hospital between January 1, 2011, and December 31, 2019, and collected information regarding age, sex, disease duration, hospital course, headache intensity, time to the appearance of a headache after sitting, associated phenomena (nausea, vomiting, auditory symptoms, dizziness), number of epidural blood patch treatments, and prognosis. The brain MRI signs of intracranial hypotension were recorded, including three qualitative signs (diffuse pachymeningeal enhancement, venous distention of the lateral sinus, subdural fluid collection), and six quantitative signs (pituitary height, suprasellar cistern, prepontine cistern, mamillopontine distance, the midbrain-pons angle, and the angle between the vein of Galen and the straight sinus). Results A total of 105 patients (61 spontaneous intracranial hypotension patients and 44 post-dural puncture headache patients) who met the inclusion criteria were reviewed. More patients with spontaneous intracranial hypotension required epidural blood patch treatment than those with post-dural puncture headache (70.5% (43/61) vs. 45.5% (20/44); p = 0.01) and the spontaneous intracranial hypotension group included a higher proportion of patients who underwent epidural blood patch treatment more than once (37.7% (23/61) vs. 13.6% (6/44); p = 0.007). Brain MRI showed signs of intracranial hypotension in both groups, although the angle between the vein of Galen and the straight sinus was greater in the post-dural puncture headache group (median [95% Confidence Interval]: 85° [68°-79°] vs. 74° [76°-96°], p = 0.02). Conclusions Patients with spontaneous intracranial hypotension received more epidural blood patch treatments and more often needed multiple epidural blood patch treatments. Although both groups showed similar brain MRI findings, the angle between the vein of Galen and the straight sinus differed significantly between the groups.
- Published
- 2021
46. THz-driven Electron Deflection for Streaking and Undulators
- Author
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Young Uk Jeong, Kyu-Ha Jang, Hyun Woo Kim, In Hyung Baek, Zoltan Ollmann, Mozhgan Hayati, Young Chan Kim, Wim Leemans, Mi Hye Kim, Carl Schroeder, Thomas Feurer, Key Young Oang, and David Rohrbach
- Subjects
Physics ,Photon ,business.industry ,Terahertz radiation ,Physics::Optics ,Field strength ,Electron ,Streaking ,Split-ring resonator ,Resonator ,Optics ,Deflection (physics) ,Physics::Accelerator Physics ,business - Abstract
In recent years, it has been shown that intense THz pulses are powerful tools to manipulate, deflect or accelerate ultrashort electron bunches. The THz range is of interest, since the corresponding wavelengths are well-matched to a typical electron bunch size of several tens of microns. Here, we propose to use split-ring resonators (SRR) as key-elements to realize various tasks in electron accelerators. Through a judicious choice of shape and geometry these structure exhibit a considerable near-field enhancement, boosting the incident THz field strength by a factor of ten or more.
- Published
- 2021
47. Deep learning model and train method to increase the speed and accuracy in inline TFT-PAD area inspection
- Author
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Da hyun Park, Hyo jin Lee, Hyun woo Kim, Seong baek Yoon, Yun hyeok Kim, and Hyeong jin Kim
- Subjects
Liquid-crystal display ,Computer science ,business.industry ,Machine vision ,Deep learning ,education ,Transistor ,Training (meteorology) ,Image segmentation ,law.invention ,Reduction (complexity) ,law ,Computer vision ,Segmentation ,Artificial intelligence ,business - Abstract
In actual industrial sites, the ability of the deep learning model to detect defects at a high speed and reducing the time required to train the model is also a very important issue. In this paper, we propose a fast and accurate deep learning model and training method that can be applied to inspect the TFT-LCD(The Film Transistor - Liquid Crystal Display) PAD area image. The deep learning model we propose is a lightweight model based on U-net. By training only about 250,000 parameters, it was possible to confirm excellent performance in defect segmentation. In addition, a study on train data was also conducted so that the model can learn more effectively. We studied a method of training both normal images (images without defects) and abnormal images (images with defects), and it was confirmed that this performance showed better performance than when only data with defects were learned. It was shown that the method of learning both normal and abnormal results in a 50% or more reduction in the incidence of false judgment images than the method of learning only simple abnormal data.
- Published
- 2021
48. Effect of Calcitonin Gene-Related Peptide Receptor Antagonists on Migraine Treatment: A Meta-Analysis
- Author
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Jiyoung Kim, Hyun Woo Kim, Kyoungjune Pak, Gha-Hyun Lee, and Jae Wook Cho
- Subjects
Calcitonin gene-related peptide receptor antagonist ,Text mining ,business.industry ,Meta-analysis ,Medicine ,Migraine treatment ,business ,Bioinformatics - Abstract
Background: The pathophysiology of migraine has been researched incessantly, and it has been suggested that calcitonin gene-related peptide (CGRP) is associated with migraine attacks. CGRP receptor blockers are attracting attention for migraine prevention and treatment of acute episodes, and CGRP receptor antagonists have been shown to be effective in treating acute migraine headaches. This meta-analysis aimed to assess the effect of available CGRP receptor antagonists, focusing on their therapeutic doses for acute migraine treatment.Methods: We performed a systematic search of MEDLINE (from inception to March 2021) and EMBASE (from inception to March 2021) for English publications using the keywords “migraine” and “Calcitonin gene-related peptide,” limited to human studies.Results: Five studies that focused on examining the effects of CGRP receptor antagonists on acute migraine treatment met the eligibility criteria for this meta-analysis. The pooled analysis demonstrated that the CGRP receptor antagonist improved freedom from pain (OR=2.066, 95% confidence interval [CI] 1.766–2.418, I2=0%), absence of bothersome symptoms (OR=1.606, 95% CI=1.408–1.830, I2=0%), pain relief (OR=1.791, 95% CI=1.598–2.008, I2=0%), and freedom from nausea (OR=1.361, 95% CI=1.196–1.548, I2=0%), significantly more than the placebo. Conclusions: CGRP receptor antagonists are effective for acute migraine treatment and are expected to be used clinically as emerging therapeutic agents.
- Published
- 2021
49. Revisiting Platinum-Based Anticancer Drugs to Overcome Gliomas
- Author
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HyeSook Youn, Hyun-Woo Kim, Jaewan Jeon, Hyunkoo Kang, Hae Yu Kim, Sunmi Jo, BuHyun Youn, and Sungmin Lee
- Subjects
Drug ,QH301-705.5 ,medicine.medical_treatment ,media_common.quotation_subject ,chemistry.chemical_element ,Antineoplastic Agents ,Platinum Compounds ,Drug resistance ,Review ,therapeutic efficacy ,Catalysis ,Inorganic Chemistry ,medicine ,Humans ,Biology (General) ,Physical and Theoretical Chemistry ,QD1-999 ,Molecular Biology ,Survival rate ,Spectroscopy ,media_common ,Cisplatin ,Chemotherapy ,Clinical Trials as Topic ,Temozolomide ,platinum-based anticancer drugs ,drug resistance ,business.industry ,Brain Neoplasms ,Organic Chemistry ,General Medicine ,Survival Analysis ,Computer Science Applications ,Radiation therapy ,Gene Expression Regulation, Neoplastic ,Chemistry ,Treatment Outcome ,chemistry ,Drug Resistance, Neoplasm ,Cancer research ,brain tumors ,Platinum ,business ,Glioblastoma ,medicine.drug - Abstract
Although there are many patients with brain tumors worldwide, there are numerous difficulties in overcoming brain tumors. Among brain tumors, glioblastoma, with a 5-year survival rate of 5.1%, is the most malignant. In addition to surgical operations, chemotherapy and radiotherapy are generally performed, but the patients have very limited options. Temozolomide is the most commonly prescribed drug for patients with glioblastoma. However, it is difficult to completely remove the tumor with this drug alone. Therefore, it is necessary to discuss the potential of anticancer drugs, other than temozolomide, against glioblastomas. Since the discovery of cisplatin, platinum-based drugs have become one of the leading chemotherapeutic drugs. Although many studies have reported the efficacy of platinum-based anticancer drugs against various carcinomas, studies on their effectiveness against brain tumors are insufficient. In this review, we elucidated the anticancer effects and advantages of platinum-based drugs used in brain tumors. In addition, the cases and limitations of the clinical application of platinum-based drugs are summarized. As a solution to overcome these obstacles, we emphasized the potential of a novel approach to increase the effectiveness of platinum-based drugs.
- Published
- 2021
50. Intractable Tuberculous Meningitis With Paradoxical Reactions Treated by Anti–Tissue Necrosis Factor-α Therapy
- Author
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Hyun-Woo Kim, Sang-Ahm Lee, Hyo Jae Kim, Yong Seo Koo, Sung-Han Kim, and Keonwoo Kim
- Subjects
medicine.medical_specialty ,Necrosis ,business.industry ,Tuberculosis Meningitis ,Case ,Paradoxical reaction ,medicine.disease ,Gastroenterology ,Tuberculous meningitis ,Corticosteroid therapy ,Internal medicine ,Medicine ,Tissue necrosis ,In patient ,Neurology (clinical) ,medicine.symptom ,business - Abstract
Paradoxical reactions during the treatment of tuberculous meningitis indicate the worsening of pre-existing tuberculous lesions or the appearance of new tuberculous lesions in patients who initially showed improvement after anti-tuberculosis treatment.1 High-dose corticosteroid therapy is the most preferred first-line treatment, but there is no definite consensus on the management of paradoxical reactions when corticosteroids have failed. Here, we report successful treatment of a tuberculosis meningitis patient with corticosteroid-refractory paradoxical reaction using anti-tissue necrosis factor α (anti-TNF-α) therapy.
- Published
- 2020
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