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Sung J, Kwon O, Kim D, Kim K. Bilateral subdural empyemas with meningitis secondary to acute barosinusitis. Eur Ann Otorhinolaryngol Head Neck Dis 2018; 135:457-459. [DOI: 10.1016/j.anorl.2018.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 03/26/2018] [Indexed: 10/28/2022]
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77
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Baek SH, Kim JS, Jang MJ, Kim YH, Kwon O, Oh JH, Kang SY, Kang JH, Park KH, Park YS, Park KS, Shin DW, Kim BJ, Kim SM. Low body mass index can be associated with the risk and poor outcomes of neuromyelitis optica with aquaporin-4 immunoglobulin G in women. J Neurol Neurosurg Psychiatry 2018; 89:1228-1230. [PMID: 29371414 PMCID: PMC6227799 DOI: 10.1136/jnnp-2017-317202] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 11/22/2017] [Accepted: 01/01/2018] [Indexed: 01/01/2023]
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78
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Abstract
The hallmark of nucleophilic phosphine catalysis is the initial nucleophilic addition of a phosphine to an electrophilic starting material, producing a reactive zwitterionic intermediate, generally under mild conditions. In this Review, we classify nucleophilic phosphine catalysis reactions in terms of their electrophilic components. In the majority of cases, these electrophiles possess carbon-carbon multiple bonds: alkenes (section 2), allenes (section 3), alkynes (section 4), and Morita-Baylis-Hillman (MBH) alcohol derivatives (MBHADs; section 5). Within each of these sections, the reactions are compiled based on the nature of the second starting material-nucleophiles, dinucleophiles, electrophiles, and electrophile-nucleophiles. Nucleophilic phosphine catalysis reactions that occur via the initial addition to starting materials that do not possess carbon-carbon multiple bonds are collated in section 6. Although not catalytic in the phosphine, the formation of ylides through the nucleophilic addition of phosphines to carbon-carbon multiple bond-containing compounds is intimately related to the catalysis and is discussed in section 7. Finally, section 8 compiles miscellaneous topics, including annulations of the Hüisgen zwitterion, phosphine-mediated reductions, iminophosphorane organocatalysis, and catalytic variants of classical phosphine oxide-generating reactions.
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79
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Xu Q, Dupper NJ, Smaligo AJ, Fan YC, Cai L, Wang Z, Langenbacher AD, Chen JN, Kwon O. Catalytic Enantioselective Synthesis of Guvacine Derivatives through [4 + 2] Annulations of Imines with α-Methylallenoates. Org Lett 2018; 20:6089-6093. [PMID: 30246538 PMCID: PMC6173629 DOI: 10.1021/acs.orglett.8b02489] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
P-Chiral [2.2.1] bicyclic phosphines (HypPhos catalysts) have been applied to reactions between α-alkylallenoates and imines, producing guvacine derivatives. These HypPhos catalysts were assembled from trans-4-hydroxyproline, with the modular nature of the synthesis allowing variations of the exocyclic P and N substituents. Among them, exo-( p-anisyl)-HypPhos was most efficacious for [4 + 2] annulations between ethyl α-methylallenoate and imines. Through this method, ( R)-aplexone was identified as being responsible for the decrease in the cellular levels of cholesterol.
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80
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Kang K, Lee WW, Kwon O, Kim BK. Unilateral arm flapping gait as a manifestation of synkinesis following recurrent strokes. Neurol India 2018; 66:1493-1494. [PMID: 30233031 DOI: 10.4103/0028-3886.241358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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81
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Lee CJ, Swain M, Kwon O. Synthesis of Cyclic β-Silylalkenyl Triflates via an Alkenyl Cation Intermediate. Org Lett 2018; 20:5474-5477. [PMID: 30118234 PMCID: PMC6133754 DOI: 10.1021/acs.orglett.8b02398] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Trimethylsilylalkyne derivatives are transformed into cyclic β-silylalkenyl triflates through cationic cyclization and subsequent trapping of the alkenyl cation by a triflate anion. β-Silylcyclohexenyl triflates and 3-trimethylsilyl-1,4-dihydronaphth-2-yl triflates are generated efficiently using this methodology. These products provide ready access to substituted cyclohexynes, exemplified by a concise total synthesis of β-apopicropodophyllin.
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82
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Park KH, Waters P, Woodhall M, Lang B, Smith T, Sung JJ, Kim KK, Lim YM, Kim JE, Kim BJ, Park JS, Lim JG, Kim DS, Kwon O, Sohn EH, Bae JS, Yoon BN, Kim NH, Ahn SW, Oh J, Park HJ, Shin KJ, Hong YH. Correction: Myasthenia gravis seronegative for acetylcholine receptor antibodies in South Korea: Autoantibody profiles and clinical features. PLoS One 2018; 13:e0200225. [PMID: 29958297 PMCID: PMC6025849 DOI: 10.1371/journal.pone.0200225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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83
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Smaligo AJ, Vardhineedi S, Kwon O. Carvone-Derived P-Stereogenic Phosphines: Design, Synthesis, and Use in Allene-Imine [3 + 2] Annulation. ACS Catal 2018; 8:5188-5192. [PMID: 30393576 DOI: 10.1021/acscatal.8b01081] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We have prepared a previously unreported family of P-stereogenic [2.2.1] bicyclic chiral phosphines through straightforward syntheses starting from the natural product carvone. This design rationale prompted the development of an unforeseen C-dealkenylation reaction. We have applied these organocatalysts in the asymmetric syntheses of a bevy of pyrrolines, obtained in high yields and enantioselectivities, including a biologically active small molecule, efsevin.
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84
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Kang K, Lee WW, Lee JJ, Park JM, Kwon O, Kim BK. Association of higher waist circumference with milder stroke severity in acute ischaemic stroke. Neurol Res 2018; 40:785-794. [PMID: 29856277 DOI: 10.1080/01616412.2018.1479346] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVES Although higher body mass index (BMI) was reported to be associated with increased stroke incidence, having a higher BMI is known to be associated with better clinical outcomes after stroke. However, BMI has shown conflicting associations with baseline stroke severity. The aim of our study was to assess the relationship between waist circumference (WC) at admission and baseline stroke severity among patients with ischaemic stroke. METHODS The WC of acute stroke patients was divided into sex-specific quartiles. Baseline stroke severity was categorised as mild [National Institutes of Health Stroke Scale (NIHSS) score 0-4], moderate (NIHSS score 5-10), and severe (NIHSS score ≥11). Multinomial logistic regression was used and reference categories were men or women in the lowest sex-specific WC quartiles who had experienced a mild stroke. RESULTS A total of 637 female and 766 male patients were included. The adjusted OR of severe stroke were 1.3 (95% CI, 0.7-2.4) for male patients in the third WC quartile, 0.7 (95% CI, 0.3-1.5) for male patients in the second WC quartile, and 0.4 (95% CI, 0.2-0.8) for male patients in the top WC quartile. The adjusted OR of severe stroke for female patients in the third WC quartile, the second WC quartile, and the top WC quartile were 0.8 (95% CI, 0.4-1.5), 0.4 (95% CI, 0.2-0.9), and 0.7 (95% CI, 0.3-1.3), respectively. DISCUSSION Higher WC at admission is associated with milder baseline stroke severity among patients with acute ischaemic stroke. ABBREVIATIONS BMI: body mass index; CE: cardioembolism; CI: confidence interval; LAA: large-artery atherosclerosis; NIHSS: National Institutes of Health Stroke Scale; OR: odds ratio; SAO: small-artery occlusion; WC: waist circumference.
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85
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Iyengar A, Caceres Polo M, Sowell B, Kwon O, Adams E, Reardon L, Ardehali A, DePasquale E. Recipient Working Status is Independently Associated with Outcomes in Heart Transplantation. J Heart Lung Transplant 2018. [DOI: 10.1016/j.healun.2018.01.852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
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86
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Bailey K, Iyengar A, Kwon O, Caceras M, Eisenring C, Ross D, Ardehali A. Ambulatory Status Improves Outcomes in Patients Bridged to Lung Transplantation with ECMO. J Heart Lung Transplant 2018. [DOI: 10.1016/j.healun.2018.01.630] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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87
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Iyengar A, Goel A, Caceres Polo M, Kwon O, Eisenring C, Biniwale R, DePasquale E, Ardehali A. Intellectual Disability and Pediatric Lung Transplantation. J Heart Lung Transplant 2018. [DOI: 10.1016/j.healun.2018.01.1042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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88
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Iyengar A, Khurshudyan A, Kwon O, Caceres Polo M, Eisenring C, Biniwale R, Ross D, Ardehali A. Cardiopulmonary Bypass Use Does Not Affect Outcomes in Single Lung Transplantation. J Heart Lung Transplant 2018. [DOI: 10.1016/j.healun.2018.01.1178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
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89
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Iyengar A, Caceres Polo M, Kwon O, Schaenman J, Biniwale R, Ross D, DePasquale E, Ardehali A. Single vs. Double Lung Transplantation in Patients over Age 65. J Heart Lung Transplant 2018. [DOI: 10.1016/j.healun.2018.01.1180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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90
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Iyengar A, Caceres Polo M, Kwon O, Faiq N, Biniwale R, DePasquale E, Ardehali A. Recipient Working Status is Independently Associated with Outcomes in Lung Transplantation. J Heart Lung Transplant 2018. [DOI: 10.1016/j.healun.2018.01.1179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
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91
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Nag A, Li Y, Basset G, Kwon O, Clarke C. Identifying genes required for the use of
p‐coumarate
in coenzyme Q biosynthesis in
Saccharomyces cerevisiae. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.672.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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92
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Park KH, Waters P, Woodhall M, Lang B, Smith T, Sung JJ, Kim KK, Lim YM, Kim JE, Kim BJ, Park JS, Lim JG, Kim DS, Kwon O, Sohn EH, Bae JS, Yoon BN, Kim NH, Ahn SW, Oh J, Park HJ, Shin KJ, Hong YH. Myasthenia gravis seronegative for acetylcholine receptor antibodies in South Korea: Autoantibody profiles and clinical features. PLoS One 2018. [PMID: 29518096 PMCID: PMC5843234 DOI: 10.1371/journal.pone.0193723] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Acquired myasthenia gravis (MG) is a prototype autoimmune disease of the neuromuscular junction, caused in most patients by autoantibodies to the muscle nicotinic acetylcholine receptor (AChR). There seem to be ethnic and regional differences in the frequency and clinical features of MG seronegative for the AChR antibody. This study aimed to describe the autoantibody profiles and clinical features of Korean patients with generalized MG seronegative for the AChR antibody. A total of 62 patients with a high index of clinical suspicion of seronegative generalized MG were identified from 18 centers, and we examined their sera for antibodies to clustered AChR, muscle-specific tyrosine kinase (MuSK), and low-density lipoprotein receptor-related protein 4 (LRP4) by cell-based assays (CBA) and to MuSK by radioimmunoprecipitation assay (RIPA). We also included 8 patients with ocular MG, 3 with Lambert-Eaton myasthenic syndrome, 5 with motor neuron disease, and 9 with other diagnoses as comparators for the serological testing. Antibodies were identified in 25/62 (40.3%) patients: 7 had antibodies to clustered AChR, 17 to MuSK, and 2 to LRP4. Three patients were double seropositive: 1 for MuSK and LRP4, and 2 for MuSK and clustered AChR. The patients with MuSK antibodies were mostly female (88.2%) and characterized by predominantly bulbar involvement (70%) and frequent myasthenic crises (58.3%). The patients with antibodies to clustered AChR, including 2 with ocular MG, tended to have a mild phenotype and good prognosis.
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93
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Zhang K, Cai L, Yang Z, Houk KN, Kwon O. Bridged [2.2.1] bicyclic phosphine oxide facilitates catalytic γ-umpolung addition-Wittig olefination. Chem Sci 2018; 9:1867-1872. [PMID: 29732112 PMCID: PMC5909331 DOI: 10.1039/c7sc04381c] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 01/02/2018] [Indexed: 12/13/2022] Open
Abstract
A novel bridged [2.2.1] bicyclic phosphine oxide, devised to circumvent the waste generation and burdens of purification that are typical of reactions driven by the generation of phosphine oxides, has been prepared in three steps from commercially available cyclopent-3-ene-1-carboxylic acid. The performance of this novel phosphine oxide was superior to those of current best-in-class counterparts, as verified experimentally through kinetic analysis of its silane-mediated reduction. It has been applied successfully in halide-/base-free catalytic γ-umpolung addition-Wittig olefinations of allenoates and 2-amidobenzaldehydes to produce 1,2-dihydroquinolines with good efficiency. One of the 1,2-dihydroquinoline products was converted to known antitubercular furanoquinolines.
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94
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Kye MS, Lee JJ, Kim BK, Kwon O, Park JM, Kang K, Lee WW. Aphasic Status Epilepticus Associated with Uremia. J Epilepsy Res 2018; 7:115-117. [PMID: 29344470 PMCID: PMC5767488 DOI: 10.14581/jer.17018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Accepted: 11/07/2017] [Indexed: 12/18/2022] Open
Abstract
Aphasic status epilepticus (ASE) is a rare disorder characterized by recurrent aphasia without impairment of other cognitive functions. A 76-year-old woman with chronic kidney disease developed ASE after neglecting peritoneal dialysis. Magnetic resonance imaging failed to demonstrate an appropriate lesion. Electroencephalography demonstrated ictal discharges in the left frontotemporal leads. ASE disappeared after intravenous valproic acid and correction of uremia. This is the first case report of ASE in a patient with acute aggravation of uremia.
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95
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Schweitzer MK, Wilting F, Sedej S, Dreizehnter L, Dupper NJ, Tian Q, Moretti A, My I, Kwon O, Priori SG, Laugwitz KL, Storch U, Lipp P, Breit A, Mederos y Schnitzler M, Gudermann T, Schredelseker J. Suppression of Arrhythmia by Enhancing Mitochondrial Ca 2+ Uptake in Catecholaminergic Ventricular Tachycardia Models. JACC Basic Transl Sci 2017; 2:737-747. [PMID: 29354781 PMCID: PMC5774336 DOI: 10.1016/j.jacbts.2017.06.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 06/26/2017] [Accepted: 06/27/2017] [Indexed: 11/30/2022]
Abstract
Cardiovascular disease-related deaths frequently arise from arrhythmias, but treatment options are limited due to perilous side effects of commonly used antiarrhythmic drugs. Cardiac rhythmicity strongly depends on cardiomyocyte Ca2+ handling and prevalent cardiac diseases are causally associated with perturbations in intracellular Ca2+ handling. Therefore, intracellular Ca2+ transporters are lead candidate structures for novel and safer antiarrhythmic therapies. Mitochondria and mitochondrial Ca2+ transport proteins are important regulators of cardiac Ca2+ handling. Here we evaluated the potential of pharmacological activation of mitochondrial Ca2+ uptake for the treatment of cardiac arrhythmia. To this aim,we tested substances that enhance mitochondrial Ca2+ uptake for their ability to suppress arrhythmia in a murine model for ryanodine receptor 2 (RyR2)-mediated catecholaminergic polymorphic ventricular tachycardia (CPVT) in vitro and in vivo and in induced pluripotent stem cell-derived cardiomyocytes from a CPVT patient. In freshly isolated cardiomyocytes of RyR2R4496C/WT mice efsevin, a synthetic agonist of the voltage-dependent anion channel 2 (VDAC2) in the outer mitochondrial membrane, prevented the formation of diastolic Ca2+ waves and spontaneous action potentials. The antiarrhythmic effect of efsevin was abolished by blockade of the mitochondrial Ca2+ uniporter (MCU), but could be reproduced using the natural MCU activator kaempferol. Both mitochondrial Ca2+ uptake enhancers (MiCUps), efsevin and kaempferol, significantly reduced episodes of stress-induced ventricular tachycardia in RyR2R4496C/WT mice in vivo and abolished diastolic, arrhythmogenic Ca2+ events in human iPSC-derived cardiomyocytes.
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96
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Kwon O. P001 Validation of the prescreening intradermal skin test for predicting hypersensitivity of iodinated contrast media. Ann Allergy Asthma Immunol 2017. [DOI: 10.1016/j.anai.2017.08.070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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97
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Park J, Kang K, Lee W, Lee J, Kwon O, Kim B. NOAC failure in patients with elevated renal clearance. J Neurol Sci 2017. [DOI: 10.1016/j.jns.2017.08.2760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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98
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Kim EK, Kim H, Kwon O, Chang N. Associations between fruits, vegetables, vitamin A, β-carotene and flavonol dietary intake, and age-related macular degeneration in elderly women in Korea: the Fifth Korea National Health and Nutrition Examination Survey. Eur J Clin Nutr 2017; 72:161-167. [DOI: 10.1038/ejcn.2017.152] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 07/18/2017] [Accepted: 07/19/2017] [Indexed: 12/25/2022]
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99
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Lee S, Koo H, Kwon O, Jae Park Y, Choi H, Lee K, Ahn B, Min Park Y. The Role of Charge Balance and Excited State Levels on Device Performance of Exciplex-based Phosphorescent Organic Light Emitting Diodes. Sci Rep 2017; 7:11995. [PMID: 28931910 PMCID: PMC5607313 DOI: 10.1038/s41598-017-12059-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 09/01/2017] [Indexed: 11/08/2022] Open
Abstract
The design of novel exciplex-forming co-host materials provides new opportunities to achieve high device performance of organic light emitting diodes (OLEDs), including high efficiency, low driving voltage and low efficiency roll-off. Here, we report a comprehensive study of exciplex-forming co-host system in OLEDs including the change of co-host materials, mixing composition of exciplex in the device to improve the performance. We investigate various exciplex systems using 5-(3-4,6-diphenyl-1,3,5-triazin-2-yl)phenyl-3,9-diphenyl-9H-carbazole, 5-(3-4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-9-phenyl-9H-3,9'-bicarbazole, and 2-(3-(6,9-diphenyl-9H-carbazol-4-yl)phenyl)-4-phenylbenzo[4,5]thieno[3,2-d]pyrimidine, as electron transporting (ET: electron acceptor) hosts and 9,9'-dipenyl-9H, 9'H-3,3'-bicarbazole and 9-([1,1'-biphenyl]-4-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole as hole transporting (HT: electron donor) hosts. As a result, a very high current efficiency of 105.1 cd/A at 103 cd/m2 and an extremely long device lifetime of 739 hrs (t95: time after 5% decrease of luminance) are achieved which is one of the best performance in OLEDs. Systematic approach, controlling mixing ratio of HT to ET host materials is suggested to select the component of two host system using energy band matching and charge balance optimization method. Furthermore, our analysis on exciton stability also reveal that lifetime of OLEDs have close relationship with two parameters; singlet energy level difference of HT and ET host and difference of singlet and triplet energy level in exciplex.
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100
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Fernández-Del-Río L, Nag A, Gutiérrez Casado E, Ariza J, Awad AM, Joseph AI, Kwon O, Verdin E, de Cabo R, Schneider C, Torres JZ, Burón MI, Clarke CF, Villalba JM. Kaempferol increases levels of coenzyme Q in kidney cells and serves as a biosynthetic ring precursor. Free Radic Biol Med 2017; 110:176-187. [PMID: 28603085 PMCID: PMC5539908 DOI: 10.1016/j.freeradbiomed.2017.06.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 05/29/2017] [Accepted: 06/06/2017] [Indexed: 12/27/2022]
Abstract
Coenzyme Q (Q) is a lipid-soluble antioxidant essential in cellular physiology. Patients with Q deficiencies, with few exceptions, seldom respond to treatment. Current therapies rely on dietary supplementation with Q10, but due to its highly lipophilic nature, Q10 is difficult to absorb by tissues and cells. Plant polyphenols, present in the human diet, are redox active and modulate numerous cellular pathways. In the present study, we tested whether treatment with polyphenols affected the content or biosynthesis of Q. Mouse kidney proximal tubule epithelial (Tkpts) cells and human embryonic kidney cells 293 (HEK 293) were treated with several types of polyphenols, and kaempferol produced the largest increase in Q levels. Experiments with stable isotope 13C-labeled kaempferol demonstrated a previously unrecognized role of kaempferol as an aromatic ring precursor in Q biosynthesis. Investigations of the structure-function relationship of related flavonols showed the importance of two hydroxyl groups, located at C3 of the C ring and C4' of the B ring, both present in kaempferol, as important determinants of kaempferol as a Q biosynthetic precursor. Concurrently, through a mechanism not related to the enhancement of Q biosynthesis, kaempferol also augmented mitochondrial localization of Sirt3. The role of kaempferol as a precursor that increases Q levels, combined with its ability to upregulate Sirt3, identify kaempferol as a potential candidate in the design of interventions aimed on increasing endogenous Q biosynthesis, particularly in kidney.
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