150 results on '"Lee OS"'
Search Results
2. Low Cost Lower Bound Toughness Measurements
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McCowan, CN, primary, Dally, JW, additional, Vigliotti, DP, additional, and Lee, OS, additional
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3. Crack Tip Plasticity of a Tearing Crack
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Lee, OS, primary and Kobayashi, AS, additional
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4. Outbreak of pandemic influenza (H1N1) 2009 in pigs in Korea
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Moon Ok, Yeo Ci, Lee Jh, Bae Cw, Hun-Young Yoon, Lee Os, Lee Kk, Song Yk, Kim Sh, and Changhoon Park
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Male ,Veterinary medicine ,Swine ,medicine.disease_cause ,Virus ,Disease Outbreaks ,Influenza A Virus, H1N1 Subtype ,Orthomyxoviridae Infections ,Zoonoses ,Influenza, Human ,Pandemic ,Prevalence ,Influenza A virus ,medicine ,Animals ,Humans ,Pandemics ,Swine Diseases ,Korea ,General Veterinary ,biology ,Transmission (medicine) ,business.industry ,Outbreak ,General Medicine ,Virology ,Influenza A virus subtype H5N1 ,Human mortality from H5N1 ,biology.protein ,Female ,business ,Neuraminidase - Abstract
THE outbreak of human pandemic influenza (H1N1) 2009 (pH1N1) that was first recorded in Mexico and then the USA in April 2009 spread to a number of countries in Europe and Asia (World Health Organization [WHO] 2009). The aetiological agent of pH1N1 is a reassortant virus that contains six gene segments from a North American triple-reassortant swine H1-subtype virus and the neuraminidase (NA) and matrix (M) genes from a Eurasian lineage H1N1 swine influenza. This latter virus existed in pigs around 10 to 20 years ago, as determined by Bayesian molecular clock analysis (Garten and others 2009, Smith and others 2009). More recently, commercial pigs in Canada, Argentina, Australia, Singapore, Norway, the USA, Italy, Germany and the UK have been confirmed to be infected with the pH1N1 virus, suggesting efficient transmission between human beings as well as within pig populations (International Society for Infectious Diseases 2009). Pigs infected either artificially or naturally with pH1N1 show similar clinical signs to those of pigs infected with swine influenza A virus (SIV). Clinical signs vary from mild (characterised by depression, fever, sneezing and nasal discharge) to inapparent (Hofshagen and others 2009, Howden and others 2009, Brookes and others 2010, Pasma and Joseph 2010, Weingartl and others 2010, Welsh and others 2010). Reports suggest that in most of these cases, pH1N1-infected human beings transmitted the virus to pigs; however, in some cases in Canada, pigs were suspected to have infected other pigs directly (International Society for Infectious Diseases 2009, Pasma and Joseph 2010). Before the emergence of pH1N1 in South Korea, H1N1, H1N2 and H3N2 SIVs were the principal viruses isolated from pig populations (Lee and others 2008). However, due to its low mortality and economic impact, swine influenza was not designated as a nationally …
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- 2011
5. Current Status of Pediatric Surgical Practice in Korea: a Survey among the Members of Korean Association of Pediatric Surgeons
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Kim, WK, primary, Kim, SY, additional, Kim, SK, additional, Kim, IK, additional, Kim, JE, additional, Kim, CS, additional, Kim, HH, additional, Park, KW, additional, Park, YS, additional, Park, WH, additional, Park, JS, additional, Song, YT, additional, Yang, JW, additional, Oh, SM, additional, Lee, OS, additional, Lee, MO, additional, Lee, SK, additional, Lee, SC, additional, Chang, SI, additional, Jung, SE, additional, Jung, PM, additional, Choi, KJ, additional, Choi, SO, additional, Huh, YS, additional, and Hwang, EH, additional
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- 1997
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6. Current Status(1994) of Neonatal Surgery in Korea: Survey among the members of Korean Association of Pediatric Surgeons
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Kim, WK, primary, Kim, SY, additional, Kim, SK, additional, Kim, IK, additional, Kim, JC, additional, Park, KW, additional, Park, YS, additional, Park, WH, additional, Park, JS, additional, Song, YT, additional, Oh, SM, additional, Lee, OS, additional, Lee, MD, additional, Lee, SC, additional, Chang, SI, additional, Chung, ES, additional, Jung, PM, additional, Joe, JS, additional, Choi, SO, additional, Huh, YS, additional, and Hwang, EH, additional
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- 1996
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7. Branchial Anomalies in Korea: A Survey by the Korean Association of Pediatric Surgeons
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Park, WH, primary, Kwon, SI, additional, Kim, SY, additional, Kim, SC, additional, Kim, SK, additional, Kim, WK, additional, Kim, IK, additional, Kim, JE, additional, Kim, HH, additional, Park, KW, additional, Park, YS, additional, Park, JS, additional, Song, YT, additional, Ahn, WS, additional, Oh, NK, additional, Oh, SM, additional, Yoo, SY, additional, Lee, NH, additional, Lee, OS, additional, Lee, MD, additional, Lee, SC, additional, Lee, SK, additional, Chang, SI, additional, Chun, YS, additional, Chung, ES, additional, Chung, SY, additional, Chung, SE, additional, Chung, PM, additional, Cho, MH, additional, Choi, KJ, additional, Choi, SO, additional, Choi, SH, additional, Han, SJ, additional, Huh, YS, additional, Hong, C, additional, and Whang, EH, additional
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- 1996
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8. Diagnosis and Treatment of Hirschsprung's Disease in Korea: Current Status of 1992
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Yoo, SY, primary, Kim, SY, additional, Kim, WK, additional, Kim, IK, additional, Kim, JE, additional, Park, KW, additional, Park, WH, additional, Park, JS, additional, Song, YT, additional, Oh, SM, additional, Lee, OS, additional, Lee, MD, additional, Lee, SC, additional, Chang, SI, additional, Chung, SY, additional, Chung, ES, additional, Jung, PM, additional, Joo, JS, additional, Choi, KJ, additional, Choi, SO, additional, Choi, SH, additional, Huh, YS, additional, and Hwang, EH, additional
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- 1996
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9. Highly pathogenic avian influenza (H5N1) outbreaks in wild birds and poultry, South Korea.
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Kim HR, Lee YJ, Park CK, Oem JK, Lee OS, Kang HM, Choi JG, Bae YC, Kim, Hye-Ryoung, Lee, Youn-Jeong, Park, Choi-Kyu, Oem, Jae-Ku, Lee, O-Soo, Kang, Hyun-Mi, Choi, Jun-Gu, and Bae, You-Chan
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Highly pathogenic avian influenza (H5N1) among wild birds emerged simultaneously with outbreaks in domestic poultry in South Korea during November 2010-May 2011. Phylogenetic analysis showed that these viruses belonged to clade 2.3.2, as did viruses found in Mongolia, the People's Republic of China, and Russia in 2009 and 2010. [ABSTRACT FROM AUTHOR]
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- 2012
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10. Keratoplasty*
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Lee Os and Allen L
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Ophthalmology ,medicine.medical_specialty ,business.industry ,Preliminary report ,General surgery ,medicine.medical_treatment ,medicine ,MEDLINE ,business ,Corneal transplantation - Published
- 1949
11. Effects of Grammaticality and Morphological Complexity on the P600 Event-Related Potential Component.
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Alison S Mehravari, Darren Tanner, Emma K Wampler, Geoffrey D Valentine, and Lee Osterhout
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Medicine ,Science - Abstract
We investigated interactions between morphological complexity and grammaticality on electrophysiological markers of grammatical processing during reading. Our goal was to determine whether morphological complexity and stimulus grammaticality have independent or additive effects on the P600 event-related potential component. Participants read sentences that were either well-formed or grammatically ill-formed, in which the critical word was either morphologically simple or complex. Results revealed no effects of complexity for well-formed stimuli, but the P600 amplitude was significantly larger for morphologically complex ungrammatical stimuli than for morphologically simple ungrammatical stimuli. These findings suggest that some previous work may have inadequately characterized factors related to reanalysis during morphosyntactic processing. Our results show that morphological complexity by itself does not elicit P600 effects. However, in ungrammatical circumstances, overt morphology provides a more robust and reliable cue to morphosyntactic relationships than null affixation.
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- 2015
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12. Mesenchymal stem cell transplantation ameliorates motor function deterioration of spinocerebellar ataxia by rescuing cerebellar Purkinje cells
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Ma Wei-Hsien, Chen Yu-Fan, Chiang Yi-Hung, Chen Ming-Hsiang, Chang You-Kang, Tseng Chian-You, Soong Bin-Wen, Ho Jennifer H, and Lee Oscar K
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Medicine - Abstract
Abstract Background Spinocerebellar ataxia (SCA) refers to a disease entity in which polyglutamine aggregates are over-produced in Purkinje cells (PCs) of the cerebellum as well as other neurons in the central nervous system, and the formation of intracellular polyglutamine aggregates result in the loss of neurons as well as deterioration of motor functions. So far there is no effective neuroprotective treatment for this debilitating disease although numerous efforts have been made. Mesenchymal stem cells (MSCs) possess multi-lineage differentiation potentials as well as immuno-modulatory properties, and are theoretically good candidates for SCA treatment. The purpose of this study is to investigate whether transplantation of human MSCs (hMSCs) can rescue cerebellar PCs and ameliorate motor function deterioration in SCA in a pre-clinical animal model. Method Transgenic mice bearing poly-glutamine mutation in ataxin-2 gene (C57BL/6J SCA2 transgenic mice) were serially transplanted with hMSCs intravenously or intracranially before and after the onset of motor function loss. Motor function of mice was evaluated by an accelerating protocol of rotarod test every 8 weeks. Immunohistochemical stain of whole brain sections was adopted to demonstrate the neuroprotective effect of hMSC transplantation on cerebellar PCs and engraftment of hMSCs into mice brain. Results Intravenous transplantation of hMSCs effectively improved rotarod performance of SCA2 transgenic mice and delayed the onset of motor function deterioration; while intracranial transplantation failed to achieve such neuroprotective effect. Immunohistochemistry revealed that intravenous transplantation was more effective in the preservation of the survival of cerebellar PCs and engraftment of hMSCs than intracranial injection, which was compatible to rotarod performance of transplanted mice. Conclusion Intravenous transplantation of hMSCs can indeed delay the onset as well as improve the motor function of SCA2 transgenic mice. The results of this preclinical study strongly support further exploration of the feasibility to transplant hMSCs for SCA patients.
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- 2011
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13. On the production of singlet oxygen by the isoalloxazine ring in free and protein-bound flavin cofactors.
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Hovan A, Gala M, Sedláková D, Bánó G, Lee OS, Žoldák G, and Sedlák E
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Flavin cofactors, flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), as a part of flavoenzymes play a critical role in the catalysis of multiple reactions predominantly of a redox nature. Question arises why nature developed two very similar cofactors with an identical functional part - isoalloxazine ring. We believe that an answer is related to the fact that the isoalloxazine ring belongs to endogenous photosensitizers able to produce reactive and potentially harmful singlet oxygen,
1 O2 , with high efficiency, ΦΔ,FMN ∼ 0.6. In fact, in contrast with one main conformation of FMN in water, the presence of the adenosine mononucleotide in FAD induces a dynamic equilibrium of two main conformations - closed (∼80 %) and open (∼20 %). The presence of predominant closed conformation of FAD in water has a significant impact on the ΦΔ,FAD value, which is nearly 10-fold lower, ΦΔ,FAD ∼ 0.07, than that of FMN. On the other hand, based on our analysis of a non-homologous dataset of FAD containing 105 proteins, ∼75 % enzyme-bound FAD exists predominantly in open conformations but the ΦΔ values are significantly decreased, ΦΔ < 0.03. We addressed these contradictory observations by analysis of: (i) dependence of ΦΔ,FAD value on opening the FAD conformation by urea and (ii) amino acid propensities for isoalloxazine binding site. We demonstrated that urea-induced destabilization, in 7 M vs 0 M urea, of the closed FAD conformation leads to a ∼ 3-fold increase of ΦΔ , proving the causative relation between ΦΔ value and the flavin cofactor conformation. Detailed examination of the flavoproteins dataset clearly indicated positive propensities of three amino acids: glycine, cysteine, and tryptophan for isoalloxazine ring binding site. We hypothesize that both the closed conformation of free FAD and the arrangement of the isoalloxazine binding site is important for prevention of potentially harmful1 O2 production in cells., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier B.V. All rights reserved.)- Published
- 2024
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14. pH modulates efficiency of singlet oxygen production by flavin cofactors.
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Hovan A, Sedláková D, Lee OS, Bánó G, and Sedlák E
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Flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) are frequently used interchangeably in the catalysis of various reactions as part of flavoenzymes because they have the same functional component, the isoalloxazine ring. However, they differ significantly in their conformational properties. The inclusion of two planar rings in the structure of FAD greatly increases the range of possible conformations compared to FMN. An exemplary instance of this is the remarkable disparity in singlet oxygen efficiency production, Φ
Δ , between FMN and FAD. Under neutral pH conditions, FAD has low photosensitizing activity with ΦΔ ∼ 0.07 while FMN demonstrates high photosensitizing activity with ΦΔ ∼ 0.6. Both adenine rings and isoalloxazine in FAD contain pH titratable groups. Through comprehensive analysis of the kinetics of the transient absorbance of the triplet state and the phosphorescence of singlet oxygen from FAD and FMN, we determined the correlation between different conformational states and the pH-dependent generation of singlet oxygen. Based on our findings, we may deduce that within the pH range of pH 2 to pH 13, only two out of the five potential structural states of FAD are capable of efficiently producing singlet oxygen. There are two open conformations: (i) an acidic FAD conformation with a protonated adenine ring, which is around 10 times more populated than the neutral open FAD conformation, and (ii) a neutral pH FAD conformation, which is significantly less populated. The FAD conformer with a protonated adenine ring at acidic pH generates singlet oxygen with approximately 50% efficiency compared to the constantly open FMN at neutral pH. This may have implications for singlet oxygen synthesis in acidic environments., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)- Published
- 2024
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15. Slice-aware 5G network orchestration framework based on dual-slice isolation and management strategy (D-SIMS).
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Venkatapathy S, Srinivasan T, Lee OS, Jayaraman R, Jo HG, and Ra IH
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Network slicing is crucial to the 5G architecture because it enables the virtualization of network resources into a logical network. Network slices are created, isolated, and managed using software-defined networking (SDN) and network function virtualization (NFV). The virtual network function (VNF) manager must devise strategies for all stages of network slicing to ensure optimal allocation of physical infrastructure (PI) resources to high-acceptance virtual service requests (VSRs). This paper investigates two independent network slicing frameworks named as dual-slice isolation and management strategy (D-SIMS) and recommends the best of the two based on performance measurements. D-SIMS places VNFs for network slicing using self-sustained resource reservation (SSRR) and master-sliced resource reservation (MSRR), with some flexibility for the VNF manager to choose between them based on the degree to which the underlying physical infrastructure has been sliced. The present research work consists of two phases: the first deals with the creation of slices, and the second with determining the most efficient way to distribute resources among them. A deep neural network (DNN) technique is used in the first stage to generate slices for both PI and VSR. Then, in the second stage, we propose D-SIMS for resource allocation, which uses both the fuzzy-PROMETHEE method for node mapping and Dijkstra's algorithm for link mapping. During the slice creation phase, the proposed DNN training method's classification performance is evaluated using accuracy, precision, recall, and F1 score measures. To assess the success of resource allocation, metrics such as acceptance rate and resource effectiveness are used. The performance benefit is investigated under various network conditions and VSRs. Finally, to demonstrate the importance of the proposed work, we compare the simulation results to those in the academic literature., (© 2024. The Author(s).)
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- 2024
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16. cclib 2.0: An updated architecture for interoperable computational chemistry.
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Berquist E, Dumi A, Upadhyay S, Abarbanel OD, Cho M, Gaur S, Cano Gil VH, Hutchison GR, Lee OS, Rosen AS, Schamnad S, Schneider FSS, Steinmann C, Stolyarchuk M, Vandezande JE, Zak W, and Langner KM
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Interoperability in computational chemistry is elusive, impeded by the independent development of software packages and idiosyncratic nature of their output files. The cclib library was introduced in 2006 as an attempt to improve this situation by providing a consistent interface to the results of various quantum chemistry programs. The shared API across programs enabled by cclib has allowed users to focus on results as opposed to output and to combine data from multiple programs or develop generic downstream tools. Initial development, however, did not anticipate the rapid progress of computational capabilities, novel methods, and new programs; nor did it foresee the growing need for customizability. Here, we recount this history and present cclib 2, focused on extensibility and modularity. We also introduce recent design pivots-the formalization of cclib's intermediate data representation as a tree-based structure, a new combinator-based parser organization, and parsed chemical properties as extensible objects., (© 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).)
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- 2024
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17. Informing knowledge translation for selective dorsal rhizotomy: A survey of Australian clinicians and people with lived experience of cerebral palsy.
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Lewis JA, Paget SP, Wimalasundera N, Wynter M, Campbell L, Lee OS, Stewart K, Shah R, and McKay MJ
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Aim: Selective dorsal rhizotomy (SDR) is a neurosurgical intervention used to reduce spasticity in children with cerebral palsy (CP). There is minimal relevant, evidence-based information available for Australian families and clinicians. This study aims to investigate the knowledge of people with lived experience and clinicians regarding SDR, including how they currently access information and what information they seek., Methods: Adults with CP, carers of children with CP and clinicians treating children with CP were invited to complete an online survey. Data regarding participant demographics, current knowledge and confidence in knowledge about CP and SDR, information source/s used and participants level of trust in these sources are presented as counts and percentages. Comparisons in knowledge between groups were analysed., Results: A total of 114 surveys were completed: 63 clinicians, 48 carers, and 3 adults with CP. Eighty percent of clinicians were allied health professionals. People with lived experience were less confident in their knowledge about SDR compared to knowledge of CP (P < 0.001). Clinicians rated scientific research literature and the hospital team as the most useful and trustworthy information source. People with lived experience used a wider range of information sources including the internet, rating their community therapy team and other people with lived experience as the most useful., Conclusion: This study identified a lack of confidence in knowledge of SDR for people with lived experience, likely due to a gap in accessible and readable evidence-based information. While both groups differed in how they access information, there was agreement that greater information about SDR is needed., (© 2024 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).)
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- 2024
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18. PIP 2 Is An Electrostatic Catalyst for Vesicle Fusion by Lowering the Hydration Energy: Arresting Vesicle Fusion by Masking PIP 2 .
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Ali Moussa HY, Shin KC, Ponraj J, Park SH, Lee OS, Mansour S, and Park Y
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- Catalysis, Liposomes chemistry, SNARE Proteins metabolism, SNARE Proteins chemistry, Membrane Fusion drug effects, Phosphatidylinositol 4,5-Diphosphate chemistry, Phosphatidylinositol 4,5-Diphosphate pharmacology, Static Electricity, Water chemistry
- Abstract
Lipids are key factors in regulating membrane fusion. Lipids are not only structural components to form membranes but also active catalysts for vesicle fusion and neurotransmitter release, which are driven by soluble N -ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins. SNARE proteins seem to be partially assembled before fusion, but the mechanisms that arrest vesicle fusion before Ca
2+ influx are still not clear. Here, we show that phosphatidylinositol 4,5-bisphosphate (PIP2 ) electrostatically triggers vesicle fusion as an electrostatic catalyst by lowering the hydration energy and that a myristoylated alanine-rich C-kinase substrate (MARCKS), a PIP2 -binding protein, arrests vesicle fusion in a vesicle docking state where the SNARE complex is partially assembled. Vesicle-mimicking liposomes fail to reproduce vesicle fusion arrest by masking PIP2 , indicating that native vesicles are essential for the reconstitution of physiological vesicle fusion. PIP2 attracts cations to repel water molecules from membranes, thus lowering the hydration energy barrier.- Published
- 2024
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19. Design of AsLOV2 domain as a carrier of light-induced dissociable FMN photosensitizer.
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Felčíková K, Hovan A, Polák M, Loginov DS, Holotová V, Díaz C, Kožár T, Lee OS, Varhač R, Novák P, Bánó G, and Sedlák E
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- Protein Domains, Binding Sites, Amino Acids, Flavin Mononucleotide chemistry, Flavoproteins chemistry, Flavoproteins metabolism, Photosensitizing Agents
- Abstract
Flavin mononucleotide (FMN) is a highly efficient photosensitizer (PS) yielding singlet oxygen (
1 O2 ). However, its1 O2 production efficiency significantly decreases upon isoalloxazine ring encapsulation into the protein matrix in genetically encoded photosensitizers (GEPS). Reducing isoalloxazine ring interactions with surrounding amino acids by protein engineering may increase1 O2 production efficiency GEPS, but at the same time weakened native FMN-protein interactions may cause undesirable FMN dissociation. Here, in contrast, we intentionally induce the FMN release by light-triggered sulfur oxidation of strategically placed cysteines (oxidation-prone amino acids) in the isoalloxazine-binding site due to significantly increased volume of the cysteinyl side residue(s). As a proof of concept, in three variants of the LOV2 domain of Avena sativa (AsLOV2), namely V416C, T418C, and V416C/T418C, the effective1 O2 production strongly correlated with the efficiency of irradiation-induced FMN dissociation (wild type (WT) < V416C < T418C < V416C/T418C). This alternative approach enables us: (i) to overcome the low1 O2 production efficiency of flavin-based GEPSs without affecting native isoalloxazine ring-protein interactions and (ii) to utilize AsLOV2, due to its inherent binding propensity to FMN, as a PS vehicle, which is released at a target by light irradiation., (© 2024 The Protein Society.)- Published
- 2024
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20. Lanthanide transport in angstrom-scale MoS 2 -based two-dimensional channels.
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Wang M, Xiong Q, Wang M, Lewis NHC, Ying D, Yan G, Hoenig E, Han Y, Lee OS, Peng G, Zhou H, Schatz GC, and Liu C
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Rare earth elements (REEs), critical to modern industry, are difficult to separate and purify, given their similar physicochemical properties originating from the lanthanide contraction. Here, we systematically study the transport of lanthanide ions (Ln
3+ ) in artificially confined angstrom-scale two-dimensional channels using MoS2 -based building blocks in an aqueous environment. The results show that the uptake and permeability of Ln3+ assume a well-defined volcano shape peaked at Sm3+ . This transport behavior is rooted from the tradeoff between the barrier for dehydration and the strength of interactions of lanthanide ions in the confinement channels, reminiscent of the Sabatier principle. Molecular dynamics simulations reveal that Sm3+ , with moderate hydration free energy and intermediate affinity for channel interaction, exhibit the smallest dehydration degree, consequently resulting in the highest permeability. Our work not only highlights the distinct mass transport properties under extreme confinement but also demonstrates the potential of dialing confinement dimension and chemistry for greener REEs separation.- Published
- 2024
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21. Fabrication of gradient hydrogels using a thermophoretic approach in microfluidics.
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Kosmidis Papadimitriou A, Chong SW, Shen Y, Lee OS, Knowles TPJ, Grover LM, and Vigolo D
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- Tissue Engineering methods, Extracellular Matrix, Microfluidics, Hydrogels
- Abstract
The extracellular matrix presents spatially varying physical cues that can influence cell behavior in many processes. Physical gradients within hydrogels that mimic the heterogenous mechanical microenvironment are useful to study the impact of these cues on cellular responses. Therefore, simple and reliable techniques to create such gradient hydrogels are highly desirable. This work demonstrates the fabrication of stiffness gradient Gellan gum (GG) hydrogels by applying a temperature gradient across a microchannel containing hydrogel precursor solution. Thermophoretic migration of components within the precursor solution generates a concentration gradient that mirrors the temperature gradient profile, which translates into mechanical gradients upon crosslinking. Using this technique, GG hydrogels with stiffness gradients ranging from 20 to 90 kPa over 600 µ m are created, covering the elastic moduli typical of moderately hard to hard tissues. MC3T3 osteoblast cells are then cultured on these gradient substrates, which exhibit preferential migration and enhanced osteogenic potential toward the stiffest region on the gradient. Overall, the thermophoretic approach provides a non-toxic and effective method to create hydrogels with defined mechanical gradients at the micron scale suitable for in vitro biological studies and potentially tissue engineering applications., (Creative Commons Attribution license.)
- Published
- 2024
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22. The accuracy of digital templating in the preoperative planning of total knee arthroplasties: A systematic review and meta-analysis.
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Lee OS, Raheman F, and Jaiswal P
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- Humans, Preoperative Care methods, Prosthesis Fitting methods, Surgery, Computer-Assisted methods, Arthroplasty, Replacement, Knee methods, Knee Prosthesis
- Abstract
Aims: Accurately predicting the implant size in total knee arthroplasties could increase the efficiency of the operation, decrease the costs associated with the procedure and result in improved patient outcomes. To substantiate its continued use, digital templating must demonstrate itself to be an accurate tool in predicting component size in order for surgeons to confidently use it to optimize the procedure., Methods: A systematic literature review was performed and identified 16 studies within the Pubmed, Ebsco and Ovid-Embase databases, with 1189 TKR prostheses included for analysis. A quality of evidence assessment was performed on each study depending on the study design. A random effects meta-analysis model was used to pool overall implant accuracy and the reported inter-rater agreement when performing digital templating and displayed in a forest plot. Meta-regression was used analyze potential factors that may affect the accuracy of digital templating., Results: The pooled proportion of accurate templates with 0 margin of error was found to be 56% (52-61, 95CI), which increases to 96% (0.94-0.98, 95CI) when allowing for a 1 size margin of error. Subgroup analysis between femoral and tibial components concluded no statistically significant difference., Conclusions: This study supports the continued use of digital templating for planning total knee arthroplasties and recommends further subgroup analysis of patient age, body mass index and sex against accuracy. This review was registered in the International Prospective Register of Systematic Reviews Database under ID: CRD420222367461. No funding was provided for the completion of this systematic review., Background: Templating in the preoperative planning of total knee arthroplasties is a vital step in ensuring maximum operative efficiency. A method that can accurately predict the required implant size within 1 size could improve theatre turnover, decrease costs and benefit patient outcomes. The current literature on the accuracy of digital templating in total knee arthroplasties lacks a systematic review calculating the overall accuracy of the process, this study aims to address this gap., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)
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- 2024
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23. Lessons learnt in photocatalysis - the influence of solvent polarity and the photostability of the photocatalyst.
- Author
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Bryden MA, Millward F, Lee OS, Cork L, Gather MC, Steffen A, and Zysman-Colman E
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Herein, we show that there is significant variation in both the triplet energies and redox properties of photocatalysts as a function of solvent based on a study of eight PCs in four solvents of varying polarity. A range of photocatalytic electron and energy transfer reactions were investigated using a subset of the PCs. For the photoredox reactions, the yields are not correlated with solvent polarity. Instead, when the PC could promote the formation of the target product, we observed photodegradation for all PCs across all solvents, something that is rarely investigated in the literature. This, therefore, makes it difficult to ascertain whether the parent PC and/or the photodegraded product is responsible for the photochemistry, or indeed, whether photodegradation is actually detrimental to the reaction yield. Conversely, the PCs were found to be photostable for energy transfer reactions; however, yields were not correlated to the triplet energies of the PCs, highlighting that triplet energies alone are not a suitable descriptor to discriminate the performance between PCs in photoinduced energy transfer processes., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)
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- 2024
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24. Anomalously enhanced ion transport and uptake in functionalized angstrom-scale two-dimensional channels.
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Wang M, Sadhukhan T, Lewis NHC, Wang M, He X, Yan G, Ying D, Hoenig E, Han Y, Peng G, Lee OS, Shi F, Tiede DM, Zhou H, Tokmakoff A, Schatz GC, and Liu C
- Abstract
Emulating angstrom-scale dynamics of the highly selective biological ion channels is a challenging task. Recent work on angstrom-scale artificial channels has expanded our understanding of ion transport and uptake mechanisms under confinement. However, the role of chemical environment in such channels is still not well understood. Here, we report the anomalously enhanced transport and uptake of ions under confined MoS
2 -based channels that are ~five angstroms in size. The ion uptake preference in the MoS2 -based channels can be changed by the selection of surface functional groups and ion uptake sequence due to the interplay between kinetic and thermodynamic factors that depend on whether the ions are mixed or not prior to uptake. Our work offers a holistic picture of ion transport in 2D confinement and highlights ion interplay in this regime., Competing Interests: Competing interests statement:The authors declare no competing interest.- Published
- 2024
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25. Beneficial Effect of Curved Dilator System for Femoral Tunnel Creation in Preventing Femoral Tunnel Widening after Anterior Cruciate Ligament Reconstruction.
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Lee OS, Kim JI, Han SH, and Lee JK
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- Humans, Retrospective Studies, Tibia, Cluster Analysis, Femur surgery, Anterior Cruciate Ligament Reconstruction
- Abstract
Backgrounds and objectives: A prevalent concern in anterior cruciate ligament (ACL) reconstruction is postoperative tunnel widening. We hypothesized that employing a curved dilator system (CDS) for femoral tunnel creation can reduce this widening after ACL reconstruction compared to the use of a conventional rigid reamer. Materials and Methods: A retrospective study was conducted involving 56 patients who underwent primary ACL reconstruction between January 2012 and July 2013. The patients were categorized into two groups: the reamer group ( n = 28) and CDS group ( n = 28). All participants were followed up for a minimum of 2 years. Clinical assessment included the Lachman test and pivot-shift test, and the Lysholm score and subjective International Knee Documentation Committee scores. Radiographic evaluation covered the tunnel widening rate, represented as the ratio of the tunnel diameter 2 years after surgery to the tunnel diameter immediately after surgery, and the ratio (A/B) of femoral tunnel (A) to tibial tunnel (B) diameters at respective time points. Results: No significant disparities were found between the two groups in terms of clinical outcomes. However, the reamer group exhibited a greater femoral tunnel widening rate compared to the CDS group (reamer group vs. CDS group: 142.7 ± 22.0% vs. 128.0 ± 19.0% on the anteroposterior (AP) radiograph and 140.8 ± 14.2% vs. 122.9 ± 13.4% on the lateral radiograph; all p < 0.05). Two years post-operation, the A/B ratio rose in the reamer group (0.96 ± 0.05→1.00 ± 0.05 on the AP radiograph and 0.94 ± 0.03→1.00 ± 0.0.04 on the lateral radiograph; all p < 0.05), while it decreased in the CDS group (0.99 ± 0.02→0.96 ± 0.05 on the AP radiograph and 0.97 ± 0.03→0.93 ± 0.06 on the lateral radiograph; all p < 0.05). Conclusion: The use of CDS for femoral tunnel creation in primary ACL reconstruction provides a potential advantage by limiting tunnel widening compared to the conventional rigid-reamer approach.
- Published
- 2023
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26. Implicit Statistical Learning in L2 Sentence Processing: Individual Cognitive Differences.
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Lee OS
- Subjects
- Adult, Humans, Comprehension, Linguistics, Cognition, Language, Learning
- Abstract
This study investigates whether statistical learning ability, conceptualized as a cognitive ability to learn regularities implicitly, is a good predictor for L2 learners' online language processing performance. Native-English-speaking adults, as a control group, and native-Korean-speaking adult L2 learners of English participated. They completed: (a) an artificial grammar learning task containing nonadjacent dependencies in sequences of non-words, to test statistical learning ability; and (b) a self-paced English reading task containing relative clauses (RC) in which the "filler" and the "gap" formed a long-distance dependency, to test language processing. Both tasks' stimuli were presented element-by-element to mimic the incremental nature of online language processing. The results for the L1 group show that higher accuracy scores on the artificial grammar learning task did not predict higher sentence comprehension scores. The results for the L2 group, however, show a marginally significant correlation between accuracy scores on the artificial grammar learning task and sentence comprehension scores. For both groups, the reading time difference between grammatical and ungrammatical items in the artificial grammar learning task did predict the speed of reading times for items with RCs with a long-distance dependency in the sentence processing task: Larger differences in RTs in the artificial grammar task correlated with slower reading at the critical region of English RCs. These findings suggest a similar mechanism for online first and second language processing of core syntactic phenomena and for statistical learning ability that involves implicitly tracking distributional relations across elements., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
- Published
- 2023
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27. Development of digital mirror therapy for stroke-severe patients.
- Author
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Kim SB, Kye SA, and Lee OS
- Subjects
- Humans, Mirror Movement Therapy, Movement, Stroke therapy, Stroke Rehabilitation methods, Motor Cortex
- Abstract
Mirror therapy (MT), which is used in the existing stroke rehabilitation environment, has significant limitations for use with severe stroke patients. Since mirrors only reflect symmetrical movement, allowing a patient to observe precise asymmetrical movement is impossible. This study proposes a new MT system by developing a pyramid hologram technology that uses delayed motion to create realistic images. Significant differences, observed via electroencephalogram, were shown in all motor cortex channels immediately after the event in the delayed condition when compared to before the event (C3: p < 0.001; Cz: p < 0.001, C4: p < 0.001). The illusion of asymmetrical movement using the proposed system can be applied to severe stroke patients to increase the positive outcome of rehabilitation.
- Published
- 2023
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28. Goal setting, goal attainment and quality of life of children following selective dorsal rhizotomy.
- Author
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Lewis JA, Bear N, Smith N, Baker F, Lee OS, Wynter M, and Paget SP
- Subjects
- Humans, Quality of Life, Goals, Australia, Canada, Treatment Outcome, Rhizotomy methods, Cerebral Palsy rehabilitation
- Abstract
Aim: The aim of this study is to describe the individualized occupational performance issues identified by parents/carers and children prior to selective dorsal rhizotomy (SDR) surgery and analyse change up to 2 years post surgery in goal attainment and quality of life (QoL)., Method: The Australian SDR Research Registry (trial registration: ACTRN12618000985280) was used to extract data for individualized goals, goal attainment and QoL based on the Canadian Occupational Performance Measure (COPM) and the Cerebral Palsy Quality of Life Questionnaire for Children (CP QOL-Child parent-proxy) at baseline and 1 and 2 years following SDR. Change in mean scores was analysed using linear mixed models., Results: Fifty-two children had COPM scores at baseline and 1 and/or 2 years post, of which 28 had two QoL scores. COPM problem areas included leisure (n = 39), productivity (n = 37) and self-care (n = 173). The most common goals were walking (26.1%), participation in physical activities (17.7%) and transitions (14.1%). Mean COPM scores improved significantly between baseline to 1 year and baseline to 2 years (P < 0.001). Mean QoL scores improved between baseline to 1 year for functional QoL domains: participation and physical health (P = 0.003) and pain and impact of disability (P = 0.011)., Conclusions: Collaborative goal setting is an integral part of family-centred rehabilitation practice. The COPM was an appropriate individualized outcome measure in identifying meaningful goals for our SDR cohort. Results demonstrate improved scores in goal attainment and improvement in functional QoL domains. This paper highlights the need to include outcomes that measure daily life experiences., (© 2022 John Wiley & Sons Ltd.)
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- 2023
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29. Effects of Non-Pharmacological Sleep Interventions in Older Adults: A Systematic Review and Meta-Analysis.
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Gu HJ and Lee OS
- Subjects
- Humans, Female, Aged, Sleep, Sleep Wake Disorders therapy, Cognitive Behavioral Therapy, Aromatherapy, Meditation
- Abstract
This study investigated the effects of non-pharmacological interventions on sleep in older people through a systematic review and meta-analysis. We conducted a literature search using eight electronic databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol. Participant characteristics, the contents of the evaluated interventions, and the measured outcomes were systematically reviewed for 15 selected studies. We performed a meta-analysis to estimate the effect size for overall, aggregated sleep outcomes. Due to the small number of studies available for each intervention, only the overall effectiveness of non-pharmacological sleep interventions was evaluated. The evaluated interventions included exercise, aromatherapy, acupressure, cognitive behavior therapy, and meditation. Our results demonstrated that non-pharmacological interventions showed statistically significant effects on sleep (effect size = 1.00, 95% confidence interval: 0.16, 1.85, I
2 = 92%, p < 0.001). After confirming publication bias and removing outliers, we found no heterogeneity (I2 = 17%, p = 0.298), with a decrease in effect size to 0.70 (95% confidence interval: 0.47, 0.93). Non-pharmacological interventions are effective for improving sleep in older adults. Future studies should continue to investigate sleep problems and interventions addressing these problems in this demographic, particularly in older women. Objective measures should be used to follow-up on the evaluated sleep interventions over the long term.- Published
- 2023
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30. Changes in the femoral varus and rotational profiles are correlated in women with varus osteoarthritic lower limbs.
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Lee OS, Lee J, Lee MC, and Han HS
- Subjects
- Humans, Female, Retrospective Studies, Femur diagnostic imaging, Lower Extremity, Tibia, Knee Joint diagnostic imaging, Osteoarthritis, Knee complications, Osteoarthritis, Knee diagnostic imaging
- Abstract
Introduction: Previous studies have reported the relationship between coronal alignment of the lower limbs and the rotational profile of the femur and tibia. However, the relationship between coronal alignment of the femur and tibia and their rotational profiles in patients with varus osteoarthritic knees is unclear., Methods: One hundred women with varus osteoarthritic knees (varus OA group) and 50 women with neutrally aligned lower limbs without osteoarthritis (non-OA group) were evaluated retrospectively. The coronal alignment and rotational profile of the femur and tibia were evaluated, and the correlation between coronal alignment and rotational profile was analyzed, respectively., Results: The femoral anteversion, posterior condylar angle of the distal femur, and tibial torsion were significantly smaller in the varus OA group than in the non-OA group. In the varus OA group, the femoral anteversion and rotational profile of the distal femur had significantly negative correlations with the degree of femoral varus, while tibial torsion was not related to the degree of tibial varus. In the non-OA group, there was no relationship between coronal alignment and rotational profiles of the femur and tibia in both the varus OA and non-OA groups., Conclusion: Femoral anteversion and the rotational profile of the distal femur were negatively correlated with the degree of femoral varus in Asian women with varus osteoarthritic knees. This study enhanced the understanding of the relationship between changes in coronal alignment of the femur and tibia and their rotational profiles in patients with varus osteoarthritic lower limbs, although this study was limited by the small sample sizes and methodological quality., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2023
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31. Ethanol-Induced Condensation and Decondensation in DNA-Linked Nanoparticles: A Nucleosome-like Model for the Condensed State.
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Xiong Q, Lee OS, Mirkin CA, and Schatz G
- Subjects
- Ethanol chemistry, Gold, DNA chemistry, Water chemistry, Nucleosomes, Metal Nanoparticles
- Abstract
Inspired by the conventional use of ethanol to induce DNA precipitation, ethanol condensation has been applied as a routine method to dynamically tune "bond" lengths (i.e., the surface-to-surface distances between adjacent nanoparticles that are linked by DNA) and thermal stabilities of colloidal crystals involving DNA-linked nanoparticles. However, the underlying mechanism of how the DNA bond that links gold nanoparticles changes in this class of colloidal crystals in response to ethanol remains unclear. Here, we conducted a series of all-atom molecular dynamic (MD) simulations to explore the free energy landscape for DNA condensation and decondensation. Our simulations confirm that DNA condensation is energetically much more favorable under 80% ethanol conditions than in pure water, as a result of ethanol's role in enhancing electrostatic interactions between oppositely charged species. Moreover, the condensed DNA adopts B-form in pure water and A-form in 80% ethanol, which indicates that the higher-order transition does not affect DNA's conformational preferences. We further propose a nucleosome-like supercoiled model for the DNA condensed state, and we show that the DNA end-to-end distance derived from this model matches the experimentally measured DNA bond length of about 3 nm in the fully condensed state for DNA where the measured length is 16 nm in water. Overall, this study provides an atomistic understanding of the mechanism underlying ethanol-induced condensation and water-induced decondensation, while our proposed nucleosome-like model allows the design of new strategies for interpreting experimental studies of DNA condensation.
- Published
- 2023
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32. Effect of Posterior Tibial Slope Change on Postoperative Range of Motion and Clinical Outcomes after Posterior Cruciate-Substituting Total Knee Arthroplasty.
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Lee OS, Lee J, Lee MC, and Han HS
- Subjects
- Humans, Knee Joint surgery, Retrospective Studies, Prosthesis Design, Range of Motion, Articular, Arthroplasty, Replacement, Knee methods, Knee Prosthesis, Osteoarthritis, Knee surgery
- Abstract
The posterior tibial slope (PTS) is usually adjusted by less than 5 degrees, without considering its individual difference, during posterior cruciate-substituting (PS) total knee arthroplasty (TKA). The effect of these individual changes of PTS would be important because clinical results depending on postoperative PTS were reported conflictingly. We investigated the effect of the change in PTS on the postoperative range of motion (ROM) and clinical scores after PS TKA. We retrospectively reviewed 164 knees from 107 patients who underwent PS TKA with a 2-year follow-up. We analyzed the preoperative and postoperative PTS, ROM, visual analog scale pain scale, Western Ontario and McMaster University Index (WOMAC), Hospital for Special Surgery Knee Score, Knee Society Score, and Forgotten Joint Score (FJS). The association of the absolute change in PTS with ROM and clinical scores was analyzed using correlation analysis and multiple regression analysis. As a result, the mean PTS and mean ROM changed from 9.6 ± 3.4 and 120.1 ± 15.4 degrees preoperatively to 2.0 ± 1.3 and 128.4 ± 9.3 degrees postoperatively, and the mean PTS change was 7.6 ± 3.5 degrees. The PTS change had no statistically significant association with the postoperative ROM and clinical scoring systems, although it did have a weak positive correlation with WOMAC function, No 10 (difficulty in rising from sitting) (correlation coefficient = 0.342, p = 0.041), and moderate positive correlation with the FJS, No. 6 (awareness when climbing stairs) (correlation coefficient = 0.470, p = 0.001). The authors concluded that the amount of change in PTS did not affect the postoperative ROM and clinical scores, although proximal tibial resection with a constant target of PTS resulted in individually different changes in the PTS after PS TKA., Competing Interests: None declared., (Thieme. All rights reserved.)
- Published
- 2023
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33. Spacer Block Technique Was Superior to Intramedullary Guide Technique in Coronal Alignment of Femoral Component after Fixed-Bearing Medial Unicompartmental Knee Arthroplasty: A Case-Control Study.
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Lee OS, Lee MC, Shin CY, and Han HS
- Subjects
- Humans, Case-Control Studies, Retrospective Studies, Femur surgery, Tibia surgery, Knee Joint surgery, Arthroplasty, Replacement, Knee, Osteoarthritis, Knee surgery
- Abstract
Backgrounds and Objectives: The spacer block technique in unicompartmental knee arthroplasty (UKA) has still a concern related to the precise position of the component in the coronal and sagittal planes compared to intramedullary guide technique. The purposes of this study were to explore whether the spacer block technique would improve the radiological alignment of implants and clinical outcomes compared with the outcomes of the intramedullary guide technique in fixed-bearing medial UKA. Materials and Methods: In total, 115 patients who underwent unilateral, fixed-bearing medial UKA were retrospectively reviewed and divided into group IM (intramedullary guides; n = 39) and group SB (spacer blocks; n = 76). Clinical assessment included range-of-motion and patient-reported outcomes. Radiological assessment included the mechanical femorotibial angle, coronal and sagittal alignments of the femoral and tibial components, and coronal femorotibial congruence angle. Results: All clinical outcomes showed no significant differences between groups. The coronal femoral component angle was valgus 2.4° ± 4.9° in IM group and varus 1.1° ± 3.2° (p < 0.001). In group IM, the number of outlier in coronal femoral component angle (<−10° or 10°<) was 3 cases, while in group SB, there was no outlier (p = 0.014). The coronal femorotibial congruence angle was significantly less in group SB (mean 1.9°, range, −3.2°~8.2°) than in group IM (mean 3.4°, range, −9.6°~16.5°) (p = 0.028). Conclusions: In the group SB, the coronal alignment of femoral component was closer to neutral, and outlier was less frequent than in the group IM. The spacer block technique was more beneficial in achieving proper coronal alignment of the femoral component and congruence of femorotibial components compared to the intramedullary guide technique in fixed-bearing medial UKAs.
- Published
- 2022
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34. Decreases in scabies and lice cases among the pediatric and adult populations during COVID-19.
- Author
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Bonanno M, Lee OS, and Sayed C
- Subjects
- Adult, Animals, Child, Communicable Disease Control, Cross-Sectional Studies, Humans, Ivermectin, Pandemics, Permethrin, COVID-19 epidemiology, COVID-19 prevention & control, Insecticides, Lice Infestations epidemiology, Lice Infestations prevention & control, Phthiraptera, Scabies epidemiology, Scabies prevention & control
- Abstract
The influence of the nationwide lockdown orders during the COVID-19 pandemic on the transmission of scabies and lice remains unknown. We conducted a cross-sectional study utilizing UNC patient registry i2b2 to investigate monthly cases and prescriptions for scabies and lice in adult and pediatric patients in North Carolina. There were significant decreases in the cases and prescriptions for scabies and lice in the pediatric and adult populations. These results provide early insights on how COVID-19 pandemic lockdown orders affected the prevalence of these two conditions and suggest that physical distancing measures reduce transmission of these parasitic conditions., (© 2022 Wiley Periodicals LLC.)
- Published
- 2022
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35. Antibacterial Mechanism of Multifunctional MXene Nanosheets: Domain Formation and Phase Transition in Lipid Bilayer.
- Author
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Lee OS, Madjet ME, and Mahmoud KA
- Subjects
- Anti-Bacterial Agents pharmacology, Phase Transition, Phospholipids, Lipid Bilayers, Nanostructures
- Abstract
MXenes, two-dimensional metal carbides or nitrides with multifunctional surfaces, are one of the most promising antibacterial nanoscale materials. However, their putative bactericidal mechanism is elusive. To study their bactericidal mechanism, we investigated the interaction between a MXene nanosheet and a model bacterial membrane by molecular dynamics simulations and found that an adsorbed MXene on a membrane surface induced a local phase transition in a domain where the fluidity of the phospholipid in this domain at room temperature was comparable with that of the gel phase. The domain also showed a denser and thinner phospholipid membrane structure than the peripheral phospholipids. By comparing it with our previous experiments of the bactericidal activity of MXenes, we proposed the leakage of intercellular molecules at the phase boundary defects as a possible bactericidal mechanism of MXenes that leads to cell lysis. This study provides a useful model for tailoring new bactericidal nanomaterials.
- Published
- 2021
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36. Identification of the Key Parameters for Horizontal Transition Dipole Orientation in Fluorescent and TADF Organic Light-Emitting Diodes.
- Author
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Tenopala-Carmona F, Lee OS, Crovini E, Neferu AM, Murawski C, Olivier Y, Zysman-Colman E, and Gather MC
- Abstract
In organic light-emitting diodes (OLEDs), horizontal orientation of the emissive transition dipole moment (TDM) can improve light outcoupling efficiency by up to 50% relative to random orientation. Therefore, there have been extensive efforts to identify drivers of horizontal orientation. The aspect ratio of the emitter molecule and the glass-transition temperature (T
g ) of the films are currently regarded as particularly important. However, there remains a paucity of systematic studies that establish the extent to which these and other parameters control orientation in the wide range of emitter systems relevant for state-of-the-art OLEDs. Here, recent work on molecular orientation of fluorescent and thermally activated delayed fluorescent emitters in vacuum-processed OLEDs is reviewed. Additionally, to identify parameters linked to TDM orientation, a meta-analysis of 203 published emitter systems is conducted and combined with density-functional theory calculations. Molecular weight (MW) and linearity are identified as key parameters in neat systems. In host-guest systems with low-MW emitters, orientation is mostly influenced by the host Tg , whereas the length and MW of the emitter become more relevant for systems involving higher-MW emitters. To close, a perspective of where the field must advance to establish a comprehensive model of molecular orientation is given., (© 2021 The Authors. Advanced Materials published by Wiley-VCH GmbH.)- Published
- 2021
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37. Association of risk factors and bleeding complications in Asian patients taking edoxaban.
- Author
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Lee OS, Kim W, Jang BM, Min KH, Cho YS, Lee MK, and Lee KE
- Subjects
- Anticoagulants, Humans, Pyridines, Risk Factors, Thiazoles adverse effects, Treatment Outcome, Atrial Fibrillation, Factor Xa Inhibitors adverse effects
- Abstract
Aims: Asian patients are known to be more prone to bleeding complications than patients of other ethnicities. Therefore, there are possibilities of other risk factors that should be given special consideration for dosage adjustment in this specific ethnic group. This study aimed to investigate the risk factors for bleeding complications in Asian patients under appropriate edoxaban dosage regimens., Methods: Data on patients taking proper dosages, based on the Lixiana package insert, were analysed. Univariate and multivariable analyses were conducted to evaluate associations between risk factors and bleeding outcomes. Subgroup analysis was performed on high-risk patients for bleeding complications whose edoxaban dose was reduced according to the package insert., Results: In total, 346 patients were included. Among them, 32 patients experienced bleeding complications. Patients with weight ≤60 kg and with cancer showed around 3.3- and 3.4-fold increased risk of bleeding complications compared to heavier patients (>60 kg) and those without cancer, respectively. In subgroup analysis with high-risk patients who took low-dose edoxaban (15 and 30 mg), weight ≤60 kg remained a significant factor for bleeding outcomes., Conclusion: This study showed that weight ≤60 kg and the presence of cancers could affect bleeding complications, which occurred despite proper edoxaban treatment in Asian patients. Therefore, more strict dosage guideline could be considered in populations with high proportions of Asian ethnicities., (© 2020 British Pharmacological Society.)
- Published
- 2021
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38. Comparison of the Radiologic, Arthroscopic, and Clinical Outcomes between Repaired versus Unrepaired Medial Meniscus Posterior Horn Root Tear During Open Wedge High Tibial Osteotomy.
- Author
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Lee OS, Lee SH, and Lee YS
- Subjects
- Aged, Arthroscopy, Female, Humans, Knee Joint surgery, Magnetic Resonance Imaging, Male, Menisci, Tibial diagnostic imaging, Middle Aged, Osteoarthritis, Knee diagnosis, Osteoarthritis, Knee diagnostic imaging, Osteoarthritis, Knee rehabilitation, Osteotomy rehabilitation, Retrospective Studies, Rupture, Second-Look Surgery, Tibial Meniscus Injuries diagnosis, Tibial Meniscus Injuries diagnostic imaging, Tibial Meniscus Injuries rehabilitation, Treatment Outcome, Wound Healing, Menisci, Tibial surgery, Osteoarthritis, Knee surgery, Osteotomy methods, Tibia surgery, Tibial Meniscus Injuries surgery
- Abstract
The efficacy and outcomes for the concurrent repair of medial meniscus posterior horn root tear (MMPHRT) during open wedge high tibial osteotomy (OWHTO) are unclear. This study compared the radiologic, arthroscopic, and clinical outcomes between repaired and unrepaired MMPHRT during OWHTO. Fifty-seven patients were prospectively enrolled from 2014 to 2016. The radiologic, arthroscopic, and clinical outcomes were compared between 25 patients who underwent OWHTO with all-inside repair of MMPRT using FasT-Fix (repaired group) and 32 patients who underwent OWHTO without repair of MMPRT (unrepaired group) with a mean 2-year follow up in both groups. The meniscal healing status was classified as complete, partial, or no healing, according to second-look arthroscopic findings. The medial meniscal extrusion (MME) was evaluated using magnetic resonance imaging. The width of medial joint space, joint line convergence angle (JLCA), posterior tibial slope (PTS), Kellgren-Lawrence (KL) grade, hip-knee-ankle angle, and weight-bearing line ratio was evaluated on simple standing. The clinical outcomes were evaluated using the Knee Society score and the Western Ontario and McMaster University score. Healing rates (partial and complete) of the MMPHRT showed a statistical difference between the two groups (repaired group vs. unrepaired group, 19/25 (76%) vs. 13/32 (40.6%), p = 0.008). The postoperative MME showed no statistical differences between groups (repaired versus unrepaired group: 4.5 ± 1.3 mm vs. 4.5 ± 2.1 mm, p = 0.909). The postoperative width of medial joint space, JLCA, PTS, and KL grade all showed no statistical differences between groups after 2 years of OWHTO. Other radiologic parameters and clinical outcomes showed no statistical differences between groups. Repair of the MMPHRT during OWHTO showed a superior healing rate to the unrepaired MMPHRT. However, repair of the MMPHRT was not related to the radiologic and clinical outcomes. Therefore, there is no clear evidence of the need for the MMPHRT repair during OWHTO., Competing Interests: None declared., (Thieme. All rights reserved.)
- Published
- 2021
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39. Effect of post-operative anticoagulation management in patients who have undergone On-X mechanical heart valve replacement surgery on post-discharge warfarin therapy.
- Author
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Oh EM, Lee OS, Jang BM, Park S, Cho EJ, Kim KS, Suh SY, Cho YS, and Rhie SJ
- Subjects
- Adult, Aftercare, Aged, Female, Humans, International Normalized Ratio, Male, Middle Aged, Patient Compliance, Patient Discharge, Retrospective Studies, Time Factors, Anticoagulants therapeutic use, Heart Valve Prosthesis Implantation, Warfarin therapeutic use
- Abstract
What Is Known and Objective: We evaluated the effect of the proportion of time maintained within the target international normalized ratio (INR) postoperatively in hospitalized patients who underwent On-X mechanical heart valve replacement on warfarin therapy after discharge., Methods: Inclusion was patients who were ≥18 years, received warfarin for a minimum of 10 days without any interruptions during hospitalization and followed by the anticoagulation service (ACS) clinic after discharge between June 2006 and June 2016. Patients were excluded if they had incomplete medical records, INR goal changes, known as warfarin resistance, transferred to another facility or expired during the study. The patients were divided into 3 groups according to the proportion of time maintained within therapeutic INR range (TTR) from day 4 to 10 of warfarin initiation (low: <30%, moderate: ≥30% to <70%, and high: ≥70%). The number of days needed to reach target INR for 2 consecutive measurements after discharge and the number of ACS visits was compared among the groups., Results and Discussion: Among 539 postoperative patients, 273 were included. The baseline demographics were similar among the 3 groups. The mean time needed to reach target INR for 2 consecutive measurements was 68.6 ± 106.1 days. The low group required time needed to reach target INR for 2 consecutive measurements of 94.0 ± 140.9 days compared with 44.8 ± 57.1 days in the high group (P = .007). Additionally, the low group had more ACS visits than the high group (low, 6.6 ± 5.2 vs high, 4.6 ± 3.9; P = .025). Patient compliance affected the time needed to reach target INR for 2 consecutive measurements (compliant, 42.36 ± 58.5 days vs non-compliant, 132.0 ± 157.1 days, P < .001)., What Is New and Conclusion: The study implicated that high postoperative TTR would reduce the time to require post-discharge target INR and the number of ACS visits., (© 2020 John Wiley & Sons Ltd.)
- Published
- 2020
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40. Changes in hamstring strength after anterior cruciate ligament reconstruction with hamstring autograft and posterior cruciate ligament reconstruction with tibialis allograft.
- Author
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Lee OS and Lee YS
- Abstract
Aim: The aim of this study was to evaluate the changes in hamstring strength both after anterior cruciate ligament reconstruction (ACLR) with hamstring autograft followed by early rehabilitation and posterior cruciate ligament reconstruction (PCLR) with tibialis allograft followed by delayed rehabilitation., Methods: Isokinetic strengths of the quadriceps and hamstring muscles and endurances were compared between a group of 20 patients undergoing PCLR using a tibialis anterior allograft and a 1:2 matched control group of 40 patients undergoing ACLR using a hamstring autograft at 2 years after the operations. Clinical results were also compared using stability tests and the Lysholm and the International Knee Documentation Committee scores., Results: At 2 years after the operations, the torque deficit of the hamstring muscle in the involved leg compared to the uninvolved leg at both 60°/s and 120°/s was greater in the PCLR group than in the ACLR group (60°/s, 21.8 ± 14.0% versus 1.9 ± 23.9%, P = 0.0171; 120°/s, 15.3 ± 13.7% versus -0.7 ± 17.4%, p = 0.012, respectively). The peak torque of the hamstring muscle at 120°/s was significantly lower in the involved leg than in the uninvolved leg only in the PCLR group (71.3 ± 31.9 N∙m versus 81.9 ± 27.8 N∙m, P = 0.005). There was no significant difference in the clinical results between the groups except for a side-to-side difference in the tibial translation on Telos stress radiographs., Conclusion: The strength of the hamstring of the PCLR leg with allograft was significantly weaker than that of the unoperated leg after 2 years, whereas that of the ACLR leg with hamstring autograft maintained a similar level of strength compared to that of the uninvolved leg., Level of Evidence: Level III, case-control study.
- Published
- 2020
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41. Revisiting Arthroscopic Partial Meniscectomy for Degenerative Tears in Knees With Mild or No Osteoarthritis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
- Author
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Lee SH, Lee OS, Kim ST, and Lee YS
- Subjects
- Arthralgia prevention & control, Conservative Treatment, Humans, Osteoarthritis, Knee physiopathology, Randomized Controlled Trials as Topic, Tibial Meniscus Injuries physiopathology, Arthroscopy methods, Meniscectomy methods, Osteoarthritis, Knee complications, Tibial Meniscus Injuries complications, Tibial Meniscus Injuries surgery
- Abstract
Objective: The purpose of this systematic review and meta-analysis was to evaluate the efficacy of arthroscopic partial meniscectomy (APM) for symptomatic degenerative meniscal tear (DMT) in knees with mild or no osteoarthritis., Study Design: A systematic review and meta-analysis., Methods: MEDLINE, EMBASE, and Cochrane databases were systematically searched. The inclusion criteria were as follows: (1) English language; (2) randomized controlled trial (RCT); (3) comparison between APM and other treatment modalities as a primary objective; and (4) complete DMT in knees with mild or no osteoarthritis. Mild or no arthritis was defined as Kellgren-Lawrence grade 0 to 2 or Ahlbäck 0 to 1 on radiography. Statistical analysis of functional activity and pain after APM and conservative treatment or sham operation was performed using R version 3.3.1., Results: Five articles were included in the final analysis, and they were all RCTs. Four studies compared clinical results of APM with those for physical therapy, and one study compared APM with sham operation. The functional activity was not better in the APM group (296 cases) than in the conservative treatment or sham operation group (284 cases) (I: 0%, small level of heterogeneity). Pain was not reduced significantly in the APM group compared with that in the conservative treatment or sham operation group (I: 0∼90%, high level of heterogeneity)., Conclusions: This systematic review and meta-analysis of high-quality literature provides relatively strong evidence that APM did not improve functional activity or reduce pain compared with the results with conservative treatment or sham operation in knees with mild or no osteoarthritis.
- Published
- 2020
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42. Distribution of the Force in the Knee Joint during Daily Activities after Open Wedge High Tibial Osteotomy: A Rationale for the Proper Postoperative Management.
- Author
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Seo H, Lim D, Jang YW, Kang KS, Lee MC, Lee OS, Im BE, and Lee YS
- Subjects
- Activities of Daily Living, Adult, Aged, Biomechanical Phenomena, Female, Finite Element Analysis, Humans, Imaging, Three-Dimensional, Knee Joint diagnostic imaging, Knee Joint physiopathology, Male, Middle Aged, Osteoarthritis, Knee diagnostic imaging, Osteoarthritis, Knee physiopathology, Osteoarthritis, Knee rehabilitation, Postoperative Period, Range of Motion, Articular, Tibia diagnostic imaging, Tibia physiopathology, Tomography, X-Ray Computed, Weight-Bearing, Young Adult, Knee Joint surgery, Osteoarthritis, Knee surgery, Osteotomy methods, Osteotomy rehabilitation, Tibia surgery
- Abstract
The present study was conducted to evaluate the force distribution in knee joint during daily activities after open-wedge high tibial osteotomy (OWHTO). A three-dimensional proximal tibial finite element model (FEM) was created using Mimics software to evaluate computed tomography (CT) scans of the tibia after OWHTO. The anterior and posterior gaps were 7.0 and 12.1 mm, respectively, and the target opening angle was 12 degrees. The loading ratio of the medial and lateral tibial plateaus was 6:4. To evaluate force distribution in the knee joint during activities of daily living (ADLs) after OWHTO, peak von Mises stresses (PVMSs) were analyzed at the plate and posterolateral edge region of osteotomized tibia. ADLs associated with greater knee flexion (sitting 90 degrees, standing 90 degrees, bending 90 degrees, stepping up stairs 60 degrees, and stepping downstairs 30 and 60 degrees) yielded PVMSs ranging from 195.2 to 221.5 MPa at the posterolateral edge region. In particular, stepping downstairs with knee flexion to 60 degrees produced the highest PVMS (221.5 MPa), greater than the yield strength (100-200 MPa). The highest plate PVMS was greater than 300 MPa during ADLs associated with flexion angles of approximately 90 degrees. However, these values did not exceed the yield stress (760.0 MPa). Conclusively, higher force was generated during higher flexion associated with weight-bearing and stepping downstairs produced a high force (even at lower flexion) on the posterolateral area of the tibial plateau. Therefore, a caution should be exercised when engaging in knee flexion of approximately 90 degrees and stepping downstairs in the early postoperative period when patients follow a weight-bearing rehabilitation protocol. However, this study is based on modeling; further translational studies are needed prior to clinical application., Competing Interests: None declared., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)
- Published
- 2020
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43. Supramolecular Peptide Hydrogel-Based Soft Neural Interface Augments Brain Signals through a Three-Dimensional Electrical Network.
- Author
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Nam J, Lim HK, Kim NH, Park JK, Kang ES, Kim YT, Heo C, Lee OS, Kim SG, Yun WS, Suh M, and Kim YH
- Subjects
- Animals, Electricity, Electrochemical Techniques, Electrodes, Macromolecular Substances chemistry, Male, Mice, Mice, Inbred C57BL, Molecular Dynamics Simulation, Nerve Tissue chemistry, Particle Size, Surface Properties, Brain metabolism, Hydrogels chemistry, Nerve Tissue metabolism, Peptides chemistry
- Abstract
Recording neural activity from the living brain is of great interest in neuroscience for interpreting cognitive processing or neurological disorders. Despite recent advances in neural technologies, development of a soft neural interface that integrates with neural tissues, increases recording sensitivity, and prevents signal dissipation still remains a major challenge. Here, we introduce a biocompatible, conductive, and biostable neural interface, a supramolecular β-peptide-based hydrogel that allows signal amplification via tight neural/hydrogel contact without neuroinflammation. The non-biodegradable β-peptide forms a multihierarchical structure with conductive nanomaterial, creating a three-dimensional electrical network, which can augment brain signal efficiently. By achieving seamless integration in brain tissue with increased contact area and tight neural tissue coupling, the epidural and intracortical neural signals recorded with the hydrogel were augmented, especially in the high frequency range. Overall, our tissuelike chronic neural interface will facilitate a deeper understanding of brain oscillation in broad brain states and further lead to more efficient brain-computer interfaces.
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- 2020
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44. Dynamic Properties of Water Confined in Graphene-Based Membrane: A Classical Molecular Dynamics Simulation Study.
- Author
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Lee OS
- Abstract
We performed molecular dynamics simulations of water molecules inside a hydrophobic membrane composed of stacked graphene sheets. By decreasing the density of water molecules inside the membrane, we observed that water molecules form a droplet through a hydrogen bond with each other in the hydrophobic environment that stacked graphene sheets create. We found that the water droplet translates as a whole body rather than a dissipate. The translational diffusion coefficient along the graphene surface increases as the number of water molecules in the droplet decreases, because the bigger water droplet has a stronger van der Waals interaction with the graphene surface that hampers the translational motion. We also observed a longer hydrogen bond lifetime as the density of water decreased, because the hydrophobic environment limits the libration motion of the water molecules. We also calculated the reorientational correlation time of the water molecules, and we found that the rotational motion of confined water inside the membrane is anisotropic and the reorientational correlation time of confined water is slower than that of bulk water. In addition, we employed steered molecular dynamics simulations for guiding the target molecule, and measured the free energy profile of water and ion penetration through the interstice between graphene sheets. The free energy profile of penetration revealed that the optimum interlayer distance for desalination is ~10 Å, where the minimum distance for water penetration is 7 Å. With a 7 Å interlayer distance between the graphene sheets, water molecules are stabilized inside the interlayer space because of the van der Waals interaction with the graphene sheets where sodium and chloride ions suffer from a 3-8 kcal/mol energy barrier for penetration. We believe that our simulation results would be a significant contribution for designing a new graphene-based membrane for desalination.
- Published
- 2019
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45. Factors related to inappropriate edoxaban use.
- Author
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Jang BM, Lee OS, Shin EJ, Cho EJ, Suh SY, Cho YS, Koo Lee M, and Rhie SJ
- Subjects
- Aged, Anticoagulants adverse effects, Atrial Fibrillation drug therapy, Blood Coagulation drug effects, Female, Hemorrhage chemically induced, Humans, Male, Renal Insufficiency chemically induced, Republic of Korea, Retrospective Studies, Stroke chemically induced, Factor Xa Inhibitors adverse effects, Pyridines adverse effects, Thiazoles adverse effects
- Abstract
What Is Known and Objective: The aim of this study was to evaluate the appropriateness and clinical outcomes of edoxaban use, and to determine the role of clinical pharmacists in improving the efficacy and safety of edoxaban use., Methods: A retrospective study was performed by using an electronic medical record and anticoagulation clinical data from 600 patients who received edoxaban from 1 March 2016 to 16 July 2017 at a tertiary teaching university hospital. The appropriateness of edoxaban use was assessed using eight criteria based on drug use evaluation criteria developed by the American Society of Health-System Pharmacists drug use evaluation guidelines, details in Korea Food and Drug Administration approval of edoxaban. Clinical outcomes were evaluated between the appropriately prescribed and inappropriately prescribed groups regarding the incidence of thrombosis and bleeding episodes., Results and Discussion: After excluding 86 patients due to the inability to assess renal function, 514 were eligible. Appropriate use was found in 294 patients (57.2%). The most frequent inappropriate use of edoxaban was dose adjustment (60.8%) in accordance with the dosing recommendation in patients with renal insufficiency (creatinine clearance [CrCl] of 15-50 mL/min) and a low body weight of <60 kg. Moreover, there were three cases of edoxaban use in patients with prosthetic heart valves and moderate-to-severe mitral stenosis, and 15 cases of non-valvular atrial fibrillation in patients with CrCl >95 mL/min in whom edoxaban use is not recommended. Furthermore, we found that the factors related to the appropriateness of edoxaban use were <60 kg body weight (adjusted odds ratio [OR]: 0.310; confidence interval [CI]: 0.197-0.488) and CrCl <50 mL/min (adjusted OR: 0.629; CI: 0.404-0.980). There were 45 events (8.75%) of any bleeding, 9 (1.8%) of stroke/transient ischaemic attack (TIA) and four events (0.8%) of deep vein thrombosis (DVT)/pulmonary embolism (PE). However, there was no difference between the appropriately prescribed group (294 patients) and inappropriately prescribed group (220 patients) in the incidence of bleeding events (27 [9.2%] vs 18 [8.2%]), stroke/TIA (7 [2.4%] vs 2 [0.9%]) and DVT/PE (2 [0.7%] vs 2 [0.9%]), respectively., What Is New and Conclusion: Although edoxaban has a broad therapeutic window that does not require routine monitoring, it should be cautiously used in patients with renal insufficiency (CrCl <50 mL/min) and body weight <60 kg., (© 2019 John Wiley & Sons Ltd.)
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- 2019
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46. Retro-tubercular gap widening can be caused by inappropriate anterior osteotomy and large opening gap in the medial biplanar open-wedge HTO.
- Author
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Jo IH, Lee OS, Lee SH, Kim KW, and Lee YS
- Subjects
- Adult, Aged, Case-Control Studies, Female, Fractures, Bone, Humans, Male, Middle Aged, Observer Variation, Postoperative Period, Prostheses and Implants, Radiography, Reproducibility of Results, Retrospective Studies, Tomography, X-Ray Computed, Osteoarthritis, Knee surgery, Osteotomy adverse effects, Tibia surgery
- Abstract
Purpose: The purpose of this study was to investigate the causes of retro-tubercular gap widening and to confirm whether this widened gap causes instability of the osteotomy configuration during open-wedge high tibial osteotomy (OWHTO)., Methods: Operative records and radiologic findings of patients who underwent biplanar medial OWHTO between 2014 and 2016 were retrospectively evaluated. To identify the osteotomy configuration including lateral hinge fracture, postoperative simple radiographs and CT images were analyzed. Postoperative CT scan was used to evaluate the widening of the retro-tubercular gap, thickness, and axial angle of retro-tubercular osteotomy, as well as the ratios of anterior and posterior osteotomy, and hinge length. The correlation of each factor was evaluated and analyzed in accordance with the lateral hinge fracture (LHF)., Results: Widening of the retro-tubercular gap showed a significant correlation with the axial angle of retro-tubercular osteotomy, anterior osteotomy ratio, and opening gap distance, but not with the thickness of retro-tubercular osteotomy, posterior osteotomy ratio, and hinge length ratio. The LHF group showed significantly larger value than the non-LHF group with respect to the thickness of retro-tubercular osteotomy (P = 0.003), axial angle of retro-tubercular osteotomy (P = 0.033), retro-planar gap distance (P = 0.001), anterior osteotomy ratio (P = 0.000), and opening gap distance (P = 0.003). The hinge length ratio was smaller in the LHF group than in the non-LHF group (P = 0.001). However, the posterior osteotomy ratio was not different between the two groups (n.s.)., Conclusion: Retro-tubercular gap widening can be caused by inappropriate anterior osteotomy and large opening gap distance, which can be related to LHF. Therefore, anterior cortical osteotomy may also be an important factor for preventing instability of the proximal fragment in biplanar OWHTO., Level of Evidence: Case-control study, Level III.
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- 2019
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47. Similar Outcome, but Different Surgical Requirement in Conversion Total Knee Arthroplasty following High Tibial Osteotomy and Unicompartmental Knee Arthroplasty: A Meta-Analysis.
- Author
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Lee YS, Kim HJ, Mok SJ, and Lee OS
- Subjects
- Bone Transplantation, Humans, Knee Joint surgery, Osteoarthritis, Knee surgery, Osteotomy, Range of Motion, Articular, Reoperation, Treatment Outcome, Arthroplasty, Replacement, Knee, Tibia surgery
- Abstract
The present systematic review and meta-analysis were conducted to find out how effective any subsequent conversion total knee arthroplasty (TKA) would be after unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) and which is better in outcomes. A rigorous and systematic approach was used. Each of the selected studies was evaluated for methodological quality. Data were extracted by the following standardized protocol: study design, level of evidence, cases enrolled, age, sex ratio, follow-up, kind of index surgery, type of index surgery, average time to failure, mode of failure, surgical data, preclinical score, post-clinical score, and major related complications. Nineteen articles were included in the final analysis. In conversion TKA following UKA, revision components (metal augment, bone graft, and stem) were frequently used, and thicker polyethylene was used comparing to the primary TKA. In the conversion TKA following HTO, only stem was more common (relative risk of revision component UKA:HTO = 0.57:0.07). The estimated range of motions (ROM) of conversion TKA following HTO and UKA was 107.75° (101.93-113.58°) and 111.84° (108.41-115.26°), respectively ( p > 0.05). The knee scores of conversion TKA following HTO and UKA were 89.10 (86.45, 91.75) and 85.48 (79.82, 91.14), respectively ( p > 0.05). The function scores were 78.60 (72.44, 84.76) and 75.60 (69.85, 81.35), respectively ( p > 0.05). Clinical outcome was similar between conversion TKA following HTO and UKA. However, conversion TKA after UKA required more revision components and thicker polyethylene, while conversion TKA after HTO sometimes required a stem to bypass the osteotomy gap., Competing Interests: None declared., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)
- Published
- 2019
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48. Disparity between Preoperative Target Correction Amount and Postoperative Correction Amount in Open Wedge High Tibial Osteotomy.
- Author
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Lee OS, Lee ES, and Lee YS
- Abstract
Purpose: The purpose of this study was to evaluate the disparity between the preoperative target correction amount and the postoperative correction amount in open wedge high tibial osteotomy (OWHTO) in patients divided according to the planned osteotomy gap., Materials and Methods: Seventy-two patients were divided into two groups (group 1 with the planned opening gap lager than the mean opening gap length of total patients and group 2 with a smaller opening gap). The opening gap was determined according to the target weight bearing line (WBL) ratio on the preoperative whole leg radiograph. Absolute and relative values of the disparity between the target and postoperative WBL ratios were compared between groups in order to clarify whether the disparity was deviated toward over- or under-correction., Results: The absolute value of disparity between the target and postoperative WBL ratios in group 1 was significantly larger than that in group 2 (6.01%±5.68% vs. 3.32%±3.38%; p=0.02). However, there was no statistically significant difference in relative values between groups (p=0.54)., Conclusions: The postoperative WBL ratio after OWHTO was different from the preoperative target WBL ratio if the planned osteotomy gap was large. This mismatch was not deviated toward one side, either over- or under-correction.
- Published
- 2019
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49. Comparison of the regeneration of cartilage and the clinical outcomes after the open wedge high tibial osteotomy with or without microfracture: a retrospective case control study.
- Author
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Lee OS, Lee SH, Mok SJ, and Lee YS
- Subjects
- Aftercare, Cartilage Diseases diagnostic imaging, Cartilage Diseases pathology, Cartilage, Articular diagnostic imaging, Cartilage, Articular surgery, Case-Control Studies, Female, Humans, Knee Joint, Male, Middle Aged, Osteoarthritis, Knee diagnostic imaging, Osteoarthritis, Knee pathology, Regeneration, Retrospective Studies, Tibia diagnostic imaging, Tibia pathology, Tibia surgery, Treatment Outcome, Arthroplasty, Subchondral methods, Cartilage Diseases surgery, Cartilage, Articular pathology, Osteoarthritis, Knee surgery, Osteotomy methods
- Abstract
Background: It is unclear whether postoperative outcomes are associated with the cartilage regeneration after open wedge high tibial osteotomy (OWHTO) combined with microfracture. The purpose of this study was to evaluate the regeneration of the articular cartilage, radiologic, and clinical outcomes after OWHTO with and without microfracture., Methods: Eighty-seven patients who underwent OWHTO from 2014 to 2015 were retrospectively included in this study. Fifty-seven OWHTOs with microfracture on medial femoral condyle (MFC) (group 1) and 30 OWHTOs without microfracture (group 2) were compared at a mean 2-year follow-up. The regeneration of the articular cartilage was evaluated using International Cartilage Repair Society (ICRS) grade on the second-look arthroscopy and the magnetic resonance observation of cartilage repair tissue (MOCART) score on magnetic resonance imaging (MRI). The weight-bearing line (WBL) ratio, hip-knee-ankle (HKA) angle, joint line convergence angle (JLCA) and Ahlbäck grade were evaluated. The clinical outcomes were evaluated using the Western Ontario and McMaster University (WOMAC) scores and the Knee Society (KS)., Results: The articular cartilage in the MFC were regenerated in 67.8% of group 1 (43/57) and 58.6% of group 2 (16/30), respectively (p = 0.014). However, change of the ICRS grades of the medial tibial plateau, lateral and patellofemoral compartments showed no statistical difference between the groups. Total MOCART score in group 1 was superior to that in the group 2 at postoperative 2 years (41.8 ± 18.6 vs. 31.8 ± 19.8, p = 0.023). Regarding MOCART score, microfracture was only effective in the defect filling and integration to the border zone of the MFC (p < 0.001 and p = 0.035, respectively). Other radiologic and clinical outcomes showed no statistical differences between the groups., Conclusion: Microfracture of the MFC during OWHTO only helped the filling of the degenerative cartilage defect and the integration of the cartilage with adjacent cartilage. However, the clinical and radiologic outcome could not be improved by mircrofracture in the OWHTO.
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- 2019
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50. Comparison of the Leg-Length Change between Opening- and Closing-Wedge High Tibial Osteotomy: A Systematic Review and Meta-Analysis.
- Author
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Lee OS, Ahn S, and Lee YS
- Subjects
- Humans, Osteoarthritis, Knee surgery, Leg Length Inequality etiology, Osteotomy methods, Tibia surgery
- Abstract
The aim of this meta-analysis was to compare the effects of closing-wedge (CW) and opening-wedge (OW) high tibial osteotomies (HTOs) on the change in leg length. Our hypotheses were that leg length will increase after OW HTO and decrease after CW HTO, and the magnitude of the change in leg length would be negligible in both techniques. Multiple databases including MEDLINE, Embase, and Cochrane were searched for studies comparing the change in leg length after HTO with that before HTO. After testing for publication bias and heterogeneity, we aggregated variables by using the random-effects model. The weighted mean differences of leg length were estimated before and after OW and CW HTOs with 95% confidence intervals (CIs). Four studies that analyzed 127 OW HTOs and 175 CW HTOs were included in this meta-analysis. Leg length increased by 6.96 mm after OW HTO (95% CI: -3.43 to 17.36) and decreased by 1.95 mm after CW HTO (95% CI: -10.89 to 7). Additionally, the change in leg length after OW HTO had a positive correlation with the degree of correction. The leg length increased after OW HTO, and the increase was sufficiently large to cause clinical concerns. The change in leg length after CW HTO was negligible despite the decrease in length. Therefore, CW HTO seems to be a better treatment option than OW HTO if a large correction is required., Competing Interests: None., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)
- Published
- 2019
- Full Text
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