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Noh Y, Smolyanitsky A. Memristive Response and Capacitive Spiking in Aqueous Ion Transport through Two-Dimensional Nanopore Arrays. J Phys Chem Lett 2024; 15:665-670. [PMID: 38206569 PMCID: PMC10947333 DOI: 10.1021/acs.jpclett.3c03156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
In living organisms, information is processed in interconnected symphonies of ionic currents spiking through protein ion channels. As a result of dynamic switching of their conductive states, ion channels exhibit a variety of current-voltage nonlinearities and memory effects. Fueled by the promise of computing architectures entirely different from von Neumann, recent attempts to identify and harness similar phenomena in artificial nanofluidic environments focused on demonstrating analogue circuit elements with memory. Here we explore aqueous ionic transport through two-dimensional (2D) membranes featuring arrays of ion-trapping crown-ether-like pores. We demonstrate that for aqueous salts featuring ions with different ion-pore binding affinities, memristive effects emerge through coupling between the time-delayed state of the system and its transport properties. We also demonstrate a nanopore array that behaves as a capacitor with a strain-tunable built-in barrier, yielding behaviors ranging from current spiking to an ohmic response. By focusing on the illustrative underlying mechanisms, we demonstrate that realistically observable memory effects may be achieved in nanofluidic systems featuring crown-porous 2D membranes.
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Affiliation(s)
- Yechan Noh
- Applied Chemicals and Materials Division, National Institute of Standards and Technology, Boulder, 80305, Colorado, United States
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, 94720, California, United States
| | - Alex Smolyanitsky
- Applied Chemicals and Materials Division, National Institute of Standards and Technology, Boulder, 80305, Colorado, United States
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2
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Noh Y, Aluru NR. Scaling of ionic conductance in a fluctuating single-layer nanoporous membrane. Sci Rep 2023; 13:19813. [PMID: 37957224 PMCID: PMC10643653 DOI: 10.1038/s41598-023-46962-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Accepted: 11/07/2023] [Indexed: 11/15/2023] Open
Abstract
Single-layer membranes have emerged as promising candidates for applications requiring high transport rates due to their low resistance to molecular transport. Owing to their atomically thin structure, these membranes experience significant microscopic fluctuations, emphasizing the need to explore their impact on ion transport processes. In this study, we investigate the effects of membrane fluctuations on the elementary scaling behavior of ion conductance [Formula: see text] as a function of ion concentration [Formula: see text], represented as [Formula: see text], using molecular dynamics simulations. Our findings reveal that membrane fluctuations not only alter the conductance coefficient [Formula: see text] but also the power-law exponent [Formula: see text]. We identify two distinct frequency regimes of membrane fluctuations, GHz-scale and THz-scale fluctuations, and examine their roles in conductance scaling. Furthermore, we demonstrate that the alteration of conductance scaling arises from the non-linearity between ion conductance and membrane shape. This work provides a fundamental understanding of ion transport in fluctuating membranes.
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Affiliation(s)
- Yechan Noh
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - N R Aluru
- Walker Department of Mechanical Engineering, Oden Institute for Computational Engineering and Sciences, University of Texas at Austin, Austin, 78712, USA.
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3
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Noh Y, Aluru NR. Ion transport in two-dimensional flexible nanoporous membranes. Nanoscale 2023. [PMID: 37337690 DOI: 10.1039/d3nr00875d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2023]
Abstract
Ion transport is a fundamental mechanism in living systems that plays a role in cell proliferation, energy conversion, and maintaining homeostasis. This has inspired various nanofluidic applications such as electricity harvesting, molecular sensors, and molecular separation. Two dimensional (2D) nanoporous membranes are particularly promising for these applications due to their ultralow transport barriers. We investigated ion conduction across flexible 2D membranes via extensive molecular dynamics simulations. We found that the microscopic fluctuations of these membranes can significantly increase ion conductance, for example, by 320% in Cu-HAB with 0.5 M KCl. Our analysis of ion dynamics near the flexible membranes revealed that ion hydration is destabilized when the membrane fluctuated within a specific frequency range leading to improved ion conduction. Our results show that the dynamic coupling between the fluctuating membrane and ions can play a crucial role in ion conduction across 2D nanoporous membranes.
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Affiliation(s)
- Yechan Noh
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Narayana R Aluru
- Walker Department of Mechanical Engineering, Oden Institute for Computational Engineering & Sciences, University of Texas at Austin, Austin 78712, USA.
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4
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Noh Y, Aluru NR. Effect of interfacial vibrational coupling on surface wettability and water transport. Phys Rev E 2022; 106:025106. [PMID: 36109939 DOI: 10.1103/physreve.106.025106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 08/09/2022] [Indexed: 06/15/2023]
Abstract
We report that the atomic-scale vibrational coupling at the solid-fluid interface can substantially alter the interfacial properties such as wettability and fluid slip. The wettability of water droplets on substrates subjected to various vibrational frequencies is studied using molecular dynamics simulation. The contact angle increases (i.e., becomes more hydrophobic) when the oscillation frequency of the substrate matches the intermolecular bending frequency of liquid water. We investigate the underlying mechanism by examining the dynamics of water molecules at the interface and find that the temporal contact between the solid and fluid is shorter when the frequencies match, resulting in weak solid-fluid adsorption. We further report that the vibrational match at the interface reduces wall-fluid friction and enhances water transport through the nanopore. Our findings demonstrate the importance of the atomic-scale vibrational coupling at the solid-fluid interface on the physicochemical behavior of nanodevices and biological nanochannels.
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Affiliation(s)
- Yechan Noh
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - N R Aluru
- Walker Department of Mechanical Engineering, Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, Texas 78712, USA
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Noh Y, Kim H, Lee S. The moderated mediating effect of gender in the relationship between unemployment, depression, and suicide during the COVID-19 pandemic: An examination based on big data. Eur Psychiatry 2022. [PMCID: PMC9564104 DOI: 10.1192/j.eurpsy.2022.369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Introduction
The COVID-19 pandemic, and the consequent recession, have caused a decline in the job market, with the resultant job insecurity increasing the risk of depression. While this affected all genders, suicidal thoughts were observed to be more common among women than men, suggesting that the impact of unemployment on depression varies by gender, with gender differences affecting the outcome of depression.
Objectives
This study aims to verify the moderating effect of gender on the structural relationship between unemployment, depression, and suicide during the COVID-19 pandemic by using online search trend data.
Methods
The study utilized the search trend data from Naver’s Data Lab service, by analyzing the searches of men and women under 65, between March, 2020 and September 12, 2021. The search terms were “unemployment,” “depression,” and “suicide.” The analysis examined 1121 searches using the Model 7 research model through the SPSS Process Macro to verify the moderating effect of gender on the mediating pathways for unemployment, depression, and suicide.
Results
We observed that searches for “unemployment” significantly increased with searches for “depression” (B=1.860, p<.001) and “suicide” (B=.860, p<.001). The analysis further revealed that the correlation between the increase in searches relating to depression and unemployment was seen more in women than men. This resulted in an accompanying increase in the volume of searches for suicide (B=2.341, p<.001).
Conclusions
The job insecurity caused by the COVID-19 pandemic led to varying degrees of depression according to gender. Thus, social security measures related to unemployment, depression, and suicide interventions require a gender-specific approach.
Disclosure
No significant relationships.
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Jiang X, Zhao C, Noh Y, Xu Y, Chen Y, Chen F, Ma L, Ren W, Aluru NR, Feng J. Nonlinear electrohydrodynamic ion transport in graphene nanopores. Sci Adv 2022; 8:eabj2510. [PMID: 35030026 PMCID: PMC8759738 DOI: 10.1126/sciadv.abj2510] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 11/22/2021] [Indexed: 05/25/2023]
Abstract
Mechanosensitivity is one of the essential functionalities of biological ion channels. Synthesizing an artificial nanofluidic system to mimic such sensations will not only improve our understanding of these fluidic systems but also inspire applications. In contrast to the electrohydrodynamic ion transport in long nanoslits and nanotubes, coupling hydrodynamical and ion transport at the single-atom thickness remains challenging. Here, we report the pressure-modulated ion conduction in graphene nanopores featuring nonlinear electrohydrodynamic coupling. Increase of ionic conductance, ranging from a few percent to 204.5% induced by the pressure—an effect that was not predicted by the classical linear coupling of molecular streaming to voltage-driven ion transport—was observed experimentally. Computational and theoretical studies reveal that the pressure sensitivity of graphene nanopores arises from the transport of capacitively accumulated ions near the graphene surface. Our findings may help understand the electrohydrodynamic ion transport in nanopores and offer a new ion transport controlling methodology.
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Affiliation(s)
- Xiaowei Jiang
- Laboratory of Experimental Physical Biology, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Chunxiao Zhao
- Laboratory of Experimental Physical Biology, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Yechan Noh
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yang Xu
- Laboratory of Experimental Physical Biology, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Yuang Chen
- Laboratory of Experimental Physical Biology, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Fanfan Chen
- Laboratory of Experimental Physical Biology, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
| | - Laipeng Ma
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Wencai Ren
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Narayana R. Aluru
- Walker Department of Mechanical Engineering, Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, Texas, TX 78712, USA
| | - Jiandong Feng
- Laboratory of Experimental Physical Biology, Department of Chemistry, Zhejiang University, Hangzhou 310027, China
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Abstract
Water purification using 2D nanoporous membranes has been drawing significant attention for over a decade because of fast water transport in ultrathin membranes. We perform a comprehensive study using molecular dynamics (MD) simulations on water desalination using 2D flexible membranes where the coupling between the fluid dynamics and mechanics of the membrane plays an important role. We observe that a considerable deformation and fluctuation in the 2D membrane results in an enhanced water permeability (up to 122%) along with a slight decrease in the salt rejection rate (less than 11%). Simulations on harmonically vibrating membranes indicate that the vibrational match at the membrane-water interface can significantly increase the permeance. We conduct mechanical stability tests and discuss the maximum endurable pressure of 2D porous membranes for water desalination. These findings will contribute to advances in applications using ultrathin membranes, such as energy harvesting and molecular separation.
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Affiliation(s)
- Yechan Noh
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - N R Aluru
- Walker Department of Mechanical Engineering, Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin 78712, United States
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Abstract
The unique properties of aqueous electrolytes in ultrathin nanopores have drawn a great deal of attention in a variety of applications, such as power generation, water desalination, and disease diagnosis. Inside the nanopore, at the interface, properties of ions differ from those predicted by the classical ionic layering models (e.g., Gouy-Chapman electric double layer) when the thickness of the nanopore approaches the size of a single atom (e.g., nanopores in a single-layer graphene membrane). Here, using extensive molecular dynamics simulations, the structure and dynamics of aqueous ions inside nanopores are studied for different thicknesses, diameters, and surface charge densities of carbon-based nanopores [ultrathin graphene and finite-thickness carbon nanotubes (CNTs)]. The ion concentration and diffusion coefficient in ultrathin nanopores show no indication of the formation of a Stern layer (an immobile counter-ionic layer) as the counter-ions and nanopore atoms are weakly correlated in time compared to the strong correlation observed in thick nanopores. The weak correlation observed in ultrathin nanopores is indicative of a weak adsorption of counter-ions onto the surface compared to that of thick pores. The vanishing counter-ion adsorption (ion-wall correlation) in ultrathin nanopores leads to several orders of magnitude shorter ionic residence times (picoseconds) compared to the residence times in thick CNTs (seconds). The results of this study will help better understand the structure and dynamics of aqueous ions in ultrathin nanopores.
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Affiliation(s)
- Mohammad Heiranian
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Yechan Noh
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Narayana R Aluru
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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Seo MY, Nam DH, Kong DS, Lee SH, Noh Y, Jung YG, Kim HY, Chung SK, Lee KE, Hong SD. Extended approach or usage of nasoseptal flap is a risk factor for olfactory dysfunction after endoscopic anterior skullbase surgery: results from 928 patients in a single tertiary center. Rhinology 2020; 58:574-580. [PMID: 32662778 DOI: 10.4193/rhin20.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND The aim of this study was to compare olfactory function change in patients who underwent endoscopic skull-base surgery. METHODOLOGY A total of 928 patients were included in this retrospective study. Olfactory function was measured using the non- validated Likert scale (0â€"100), the Cross-Cultural Smell Identification Test (CC-SIT) and the butanol threshold test (BTT). Patients were divided into two groups: an endoscopic trans-sellar approach group (ETA, n = 768) and an extended endoscopic endonasal approach group (EEEA, n = 160). The ETA group was sub-divided into Nasoseptal flap (NSF) and no NSF groups. RESULTS Non-validated olfactory function significantly worsened in the EEEA and ETA-NSF groups compared with that in the ETA- no NSF group for at least 6 months post-operatively. Validated olfactory impairment (BTT and CC-SIT) was also significantly worse in the EEEA and NSF groups compared with that in the ETA-no NSF group 3 months post-operatively. Additionally, the degrees of non-validated and validated olfactory deterioration were not significantly different between the EEEA and ETA-NSF groups. We also found that CC-SIT score changes were significantly impaired in tuberculum sellae meningioma patients than in craniopharyn- gioma patients. CONCLUSIONS We conclude that NSF was the key factor that led to olfactory impairment after endoscopic skull-base surgery.
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Affiliation(s)
- M Y Seo
- Department of Otorhinolaryngology - Head and Neck Surgery, Korea University College of Medicine, Korea University Ansan Hospital, Ansan, South Korea; Department of Otorhinolaryngology - Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - D-H Nam
- Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - D-S Kong
- Department of Otorhinolaryngology - Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - S H Lee
- Department of Otorhinolaryngology - Head and Neck Surgery, Korea University College of Medicine, Korea University Ansan Hospital, Ansan, South Korea
| | - Y Noh
- Department of Otorhinolaryngology - Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Y G Jung
- Department of Otorhinolaryngology - Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - H Y Kim
- Department of Otorhinolaryngology - Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - S-K Chung
- Department of Otorhinolaryngology - Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - K E Lee
- Department of Otorhinolaryngology - Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - S D Hong
- Department of Otorhinolaryngology - Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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Abstract
Ionic transport through a charged nanopore at low ion concentration is governed by the surface conductance. Several experiments have reported various power-law relations between the surface conductance and ion concentration, i.e., Gsurf ∝ c0α. However, the physical origin of the varying exponent, α, is not yet clearly understood. By performing extensive coarse-grained Molecular Dynamics simulations for various pore diameters, lengths, and surface charge densities, we observe varying power-law exponents even with a constant surface charge and show that α depends on how electrically "perfect" the nanopore is. Specifically, when the net charge of the solution in the pore is insufficient to ensure electroneutrality, the pore is electrically "imperfect" and such nanopores can exhibit varying α depending on the degree of "imperfectness". We present an ionic conductance theory for electrically "imperfect" nanopores that not only explains the various power-law relationships but also describes most of the experimental data available in the literature.
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Affiliation(s)
- Yechan Noh
- Department of Mechanical Science and Engineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Narayana R Aluru
- Department of Mechanical Science and Engineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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11
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Kim K, Kim D, Kang S, Kim T, Shin D, Cho M, Noh Y, Suh T. SU-F-J-183: Interior Region-Of-Interest Tomography by Using Inverse Geometry System. Med Phys 2016. [DOI: 10.1118/1.4956091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Kim D, Lee S, Kim S, Kang S, Kim T, Kim K, Cho M, Shin D, Noh Y, Suh T. TH-CD-207A-06: Optimizing Four-Dimensional Digital Tomosynthesis Acquisition Based On Respiratory Guidance. Med Phys 2016. [DOI: 10.1118/1.4958175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Kim T, Kim S, Kim D, Kang S, Cho M, Kim K, Shin D, Noh Y, Suh T. SU-F-T-91: Development of Real Time Abdominal Compression Force (ACF) Monitoring System. Med Phys 2016. [DOI: 10.1118/1.4956227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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14
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Cho M, Kim S, Kim T, Kim D, Kang S, Kim K, Shin D, Noh Y, Suh T. SU-D-BRA-01: Feasibility Study for Swallowing Prediction Using Pressure Sensors. Med Phys 2016. [DOI: 10.1118/1.4955634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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15
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Noh Y, Kim S, Kim T, Kang S, Kim D, Cho M, Kim K, Shin D, Suh T. SU-F-J-44: Development of a Room Laser Based Real-Time Alignment Monitoring System Using An Array of Photodiodes. Med Phys 2016. [DOI: 10.1118/1.4955952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Shafti A, Andorno F, Marchese N, Arolfo S, Aydin A, Elhage O, Noh Y, Wurdemann HA, Arezzo A, Dasgupta P, Althoefer K. Comfort and learnability assessment of a new soft robotic manipulator for minimally invasive surgery. Annu Int Conf IEEE Eng Med Biol Soc 2016; 2015:4861-4. [PMID: 26737382 DOI: 10.1109/embc.2015.7319482] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Laparoscopic surgeons perform precise and time consuming procedures while holding awkward poses in their upper body and arms. There is an ongoing effort to produce robotic tools for laparoscopic surgery that will simplify these tasks and reduce risk of errors to help both the surgeon and the patient. STIFF-FLOP is an ongoing EU FP7 project focusing on this by creating a stiffness controllable soft robotic manipulator. This paper reports on a study to test the soft manipulator's learnability and the effort associated with its use. The tests involved a limited prototype of the manipulator with a custom built test rig and EMG acquisition system. Task times and video recordings along with EMG waveforms from the forearm muscles of participants (n=25) were measured for objective assessment. A questionnaire was also provided to the participants for subjective assessment. The data shows that in average EMG levels were 25.9% less in RMS when using the STIFF-FLOP arm than when conventional laparoscopic tools were used. In terms of learnability, from the first to the second attempt on the STIFF-FLOP manipulator, elapsed time was reduced by an average of 32.1%. Further details and analysis of the EMG signals as well as time and questionnaire results is presented in the paper.
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Noh Y, Sung YH, Lee J, Kim EY. Nigrosome 1 Detection at 3T MRI for the Diagnosis of Early-Stage Idiopathic Parkinson Disease: Assessment of Diagnostic Accuracy and Agreement on Imaging Asymmetry and Clinical Laterality. AJNR Am J Neuroradiol 2015; 36:2010-6. [PMID: 26294646 DOI: 10.3174/ajnr.a4412] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 04/12/2015] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE In the early stages of idiopathic Parkinson disease, motor symptoms are usually asymmetric. We aimed to assess the feasibility of nigrosome 1 detection at 3T MR imaging to analyze the agreement of its asymmetry and clinical laterality. MATERIALS AND METHODS High-resolution 3D multiecho imaging was performed at 3T MR imaging in 13 healthy subjects and 24 patients with idiopathic Parkinson disease confirmed by N-3-fluoropropyl-2-β-carbomethoxy-3-β-(4-iodophenyl) nortropane ((18)F-FP-CIT) PET. The nigrosome 1 detection findings by using the MR imaging data were rated as "normal," "possibly abnormal," and "abnormal" by 2 independent reviewers. The degree of (18)F-FP-CIT binding was visually assessed in the caudate nucleus and putamen on PET images. Clinical laterality was evaluated by scores of the Unified Parkinson Disease Rating Scale, Part III. Asymmetry of the affected nigrosome 1 and the degree of (18)F-FP-CIT binding were analyzed for agreement with clinical laterality. RESULTS The diagnostic sensitivity, specificity, and accuracy of the nigrosome 1 detection at 3T MR imaging was 100%, 84.6%, and 94.6%, respectively. Interrater agreements for the abnormality and asymmetry of nigrosome 1 were excellent (κ = 0.863 and 0.835, respectively). In patients with idiopathic Parkinson disease, the agreement of asymmetry between clinical laterality and nigrosome 1 detection was good (κ = 0.724). The degree of the (18)F-FP-CIT PET binding showed fair agreement (κ = 0.235) with clinical laterality. CONCLUSIONS The abnormality involving nigrosome 1 can be detected at 3T MR imaging with an accuracy of 94.6%. The clinical laterality is in high concordance with the laterality of the nigrosome 1 detection at 3T (κ = 0.724).
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Affiliation(s)
- Y Noh
- From the Departments of Neurology (Y.N., Y.H.S.)
| | - Y H Sung
- From the Departments of Neurology (Y.N., Y.H.S.)
| | - J Lee
- Department of Electrical and Computer Engineering (Jongho Lee), Seoul National University, Seoul, Korea
| | - E Y Kim
- Radiology (E.Y.K.), Gachon University Gil Medical Center, Incheon, Korea
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Faragasso A, Stilli A, Bimbo J, Noh Y, Liu H, Nanayakkara T, Dasgupta P, Wurdemann HA, Althoefer K. Endoscopic add-on stiffness probe for real-time soft surface characterisation in MIS. Annu Int Conf IEEE Eng Med Biol Soc 2015; 2014:6517-20. [PMID: 25571489 DOI: 10.1109/embc.2014.6945121] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This paper explores a novel stiffness sensor which is mounted on the tip of a laparoscopic camera. The proposed device is able to compute stiffness when interacting with soft surfaces. The sensor can be used in Minimally Invasive Surgery, for instance, to localise tumor tissue which commonly has a higher stiffness when compared to healthy tissue. The purely mechanical sensor structure utilizes the functionality of an endoscopic camera to the maximum by visually analyzing the behavior of trackers within the field of view. Two pairs of spheres (used as easily identifiable features in the camera images) are connected to two springs with known but different spring constants. Four individual indenters attached to the spheres are used to palpate the surface. During palpation, the spheres move linearly towards the objective lens (i.e. the distance between lens and spheres is changing) resulting in variations of their diameters in the camera images. Relating the measured diameters to the different spring constants, a developed mathematical model is able to determine the surface stiffness in real-time. Tests were performed using a surgical endoscope to palpate silicon phantoms presenting different stiffness. Results show that the accuracy of the sensing system developed increases with the softness of the examined tissue.
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Yoon CW, Kang M, Shin HY, Jeon S, Yang JJ, Kim ST, Noh Y, Kim GH, Kim HJ, Kim YJ, Kim JH, Cho H, Ye BS, Lee JM, Choi SH, Im K, Moon HS, Na DL, Seo SW. Higher C-peptide levels are associated with regional cortical thinning in 1093 cognitively normal subjects. Eur J Neurol 2014; 21:1318-23, e80-1. [DOI: 10.1111/ene.12485] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 05/05/2014] [Indexed: 11/28/2022]
Affiliation(s)
- C. W. Yoon
- Department of Neurology; Inha University School of Medicine; Incheon South Korea
| | - M. Kang
- Center for Health Promotion; Samsung Medical Center; Sungkyunkwan University School of Medicine; Seoul South Korea
| | - H. Y. Shin
- Center for Health Promotion; Samsung Medical Center; Sungkyunkwan University School of Medicine; Seoul South Korea
| | - S. Jeon
- Department of Biomedical Engineering; Hanyang University; Seoul South Korea
| | - J.-J. Yang
- Department of Biomedical Engineering; Hanyang University; Seoul South Korea
| | - S. T. Kim
- Department of Radiology; Samsung Medical Center; Sungkyunkwan University School of Medicine; Seoul South Korea
| | - Y. Noh
- Department of Neurology; Gachon University Gil Medical Center; Incheon South Korea
| | - G. H. Kim
- Department of Neurology; Ewha Womans University Mokdong Hospital; Ewha Womans University School of Medicine; Seoul South Korea
| | - H. J. Kim
- Department of Neurology; Samsung Medical Center; Sungkyunkwan University School of Medicine; Seoul South Korea
| | - Y. J. Kim
- Department of Neurology; Samsung Medical Center; Sungkyunkwan University School of Medicine; Seoul South Korea
| | - J.-H. Kim
- Department of Neurology; Samsung Medical Center; Sungkyunkwan University School of Medicine; Seoul South Korea
| | - H. Cho
- Department of Neurology; Gangnam Severance Hospital; Yonsei University College of Medicine; Seoul South Korea
| | - B. S. Ye
- Department of Neurology; Yonsei University College of Medicine; Seoul South Korea
| | - J. M. Lee
- Department of Biomedical Engineering; Hanyang University; Seoul South Korea
| | - S. H. Choi
- Department of Neurology; Inha University School of Medicine; Incheon South Korea
| | - K. Im
- Division of Newborn Medicine; Boston Children's Hospital; Harvard Medical School; Boston MA USA
| | - H.-S. Moon
- Department of Neurology; Kangbuk Samsung Hospital; Sungkyunkwan University School of Medicine; Seoul South Korea
| | - D. L. Na
- Department of Neurology; Samsung Medical Center; Sungkyunkwan University School of Medicine; Seoul South Korea
| | - S. W. Seo
- Department of Neurology; Samsung Medical Center; Sungkyunkwan University School of Medicine; Seoul South Korea
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KO Y, Cho B, Yi B, Kwak J, Song S, Je H, Ahn S, Noh Y. SU-E-T-185: Feasibility Study of Dose Rate Modulated Arc Therapy (DrMAT) for Lung SBRT. Med Phys 2014. [DOI: 10.1118/1.4888515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Kim HJ, Ye BS, Yoon CW, Noh Y, Kim GH, Cho H, Jeon S, Lee JM, Kim JH, Seong JK, Kim CH, Choe YS, Lee KH, Kim ST, Kim JS, Park SE, Kim JH, Chin J, Cho J, Kim C, Lee JH, Weiner MW, Na DL, Seo SW. Cortical thickness and hippocampal shape in pure vascular mild cognitive impairment and dementia of subcortical type. Eur J Neurol 2014; 21:744-51. [PMID: 24495089 DOI: 10.1111/ene.12376] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 12/27/2013] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND PURPOSE The progression pattern of brain structural changes in patients with isolated cerebrovascular disease (CVD) remains unclear. To investigate the role of isolated CVD in cognitive impairment patients, patterns of cortical thinning and hippocampal atrophy in pure subcortical vascular mild cognitive impairment (svMCI) and pure subcortical vascular dementia (SVaD) patients were characterized. METHODS Forty-five patients with svMCI and 46 patients with SVaD who were negative on Pittsburgh compound B (PiB) positron emission tomography imaging and 75 individuals with normal cognition (NC) were recruited. RESULTS Compared with NC, patients with PiB(-) svMCI exhibited frontal, language and retrieval type memory dysfunctions, which in patients with PiB(-) SVaD were further impaired and accompanied by visuospatial and recognition memory dysfunctions. Compared with NC, patients with PiB(-) svMCI exhibited cortical thinning in the frontal, perisylvian, basal temporal and posterior cingulate regions. This atrophy was more prominent and extended further toward the lateral parietal and medial temporal regions in patients with PiB(-) SVaD. Compared with NC subjects, patients with PiB(-) svMCI exhibited hippocampal shape deformities in the lateral body, whilst patients with PiB(-) SVaD exhibited additional deformities within the lateral head and inferior body. CONCLUSIONS Our findings suggest that patients with CVD in the absence of Alzheimer's disease pathology can be demented, showing cognitive impairment in multiple domains, which is consistent with the topography of cortical thinning and hippocampal shape deformity.
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Affiliation(s)
- H J Kim
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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Ye BS, Seo SW, Yang JJ, Kim HJ, Kim YJ, Yoon CW, Cho H, Noh Y, Kim GH, Chin J, Kim JH, Jeon S, Lee JM, Na DL. Comparison of cortical thickness in patients with early-stage versus late-stage amnestic mild cognitive impairment. Eur J Neurol 2013; 21:86-92. [DOI: 10.1111/ene.12251] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Accepted: 07/12/2013] [Indexed: 11/28/2022]
Affiliation(s)
- B. S. Ye
- Department of Neurology; Sungkyunkwan University School of Medicine; Samsung Medical Center; Seoul Korea
| | - S. W. Seo
- Department of Neurology; Sungkyunkwan University School of Medicine; Samsung Medical Center; Seoul Korea
| | - J.-J. Yang
- Department of Biomedical Engineering; Hanyang University; Seoul Korea
| | - H. J. Kim
- Department of Neurology; Sungkyunkwan University School of Medicine; Samsung Medical Center; Seoul Korea
| | - Y. J. Kim
- Department of Neurology; Sungkyunkwan University School of Medicine; Samsung Medical Center; Seoul Korea
| | - C. W. Yoon
- Department of Neurology; Inha University School of Medicine; Incheon Korea
| | - H. Cho
- Department of Neurology; Sungkyunkwan University School of Medicine; Samsung Medical Center; Seoul Korea
| | - Y. Noh
- Department of Neurology; Gachon University Gil Medical Center; Incheon Korea
| | - G. H. Kim
- Department of Neurology; Sungkyunkwan University School of Medicine; Samsung Medical Center; Seoul Korea
| | - J. Chin
- Department of Neurology; Sungkyunkwan University School of Medicine; Samsung Medical Center; Seoul Korea
| | - J.-H. Kim
- Department of Neurology; Sungkyunkwan University School of Medicine; Samsung Medical Center; Seoul Korea
| | - S. Jeon
- Department of Biomedical Engineering; Hanyang University; Seoul Korea
| | - J. M. Lee
- Department of Biomedical Engineering; Hanyang University; Seoul Korea
| | - D. L. Na
- Department of Neurology; Sungkyunkwan University School of Medicine; Samsung Medical Center; Seoul Korea
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Bartolomeo L, Noh Y, Kasuya Y, Nagai M, Zecca M, Sessa S, Cosentino S, Saito K, Lin Z, Ishii H, Takanishi A. Biomechanical evaluation of the phases during simulated endotracheal intubation (ETI): pilot study on the effect of different laryngoscopes. Annu Int Conf IEEE Eng Med Biol Soc 2013; 2013:4887-4890. [PMID: 24110830 DOI: 10.1109/embc.2013.6610643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Endotracheal Intubation (ETI) is a common airway procedure used to connect the larynx and the lungs through a windpipe in patients under emergency situations. The process is carried out by a laryngoscope inserted into the mouth, used to help doctors in visualizing the glottis and inserting the tube. Currently, very few studies on objective evaluation of the biomechanics of the doctors during the procedure have been done. Additionally, these studies have been concentrated only on the overall performance analysis, without any segmentation, with a consequent loss of important information. In this paper, the authors present a preliminary study on a methodology to objectively evaluate and segment the biomechanical performance of doctors during the ETI, using surface electromyography and inertial measurement units. In particular, the validation has been performed by comparing three kinds of laryngoscopes involving an expert doctor. Finally, results are presented and commented.
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Cho H, Jeon S, Kim GH, Shin JS, Kim CH, Noh Y, Seo SW, Na DL. Changes in Cortical Thickness in Early Onset Versus Late Onset Alzheimer's Disease: A Three-Year Longitudinal Study (P05.042). Neurology 2012. [DOI: 10.1212/wnl.78.1_meetingabstracts.p05.042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Ko Y, Park S, Ahn S, Lee S, Shin S, Noh Y, Kim J, Choi E. SU-FF-J-54: Effectiveness of 4D CT On Stereotactic Radiosurgery of Lung Cancer. Med Phys 2006. [DOI: 10.1118/1.2240832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Kim B, Ahn Y, Noh Y, Kim C, Lee J, Kim J, Yoon E, Lee H, Choi S. P-511 Clinical utility of adenosine triphosphate-based chemosensitivityresponse assay (ATP-CRA) in non-small cell lung cancer: Preliminary study. Lung Cancer 2005. [DOI: 10.1016/s0169-5002(05)81004-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Ahn Y, Kim Y, Kim D, Lim D, Huh S, Lee J, Kang M, Shin S, Kim B, Noh Y. Radiation therapy results for primary orbital non-Hodgkin's lymphoma. Eur J Cancer 2001. [DOI: 10.1016/s0959-8049(01)80829-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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