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1. A strong acid that does not protonate water

Author

Stoyanov, ES, Kim, KC, and Reed, CA

Subjects
Theoretical and Computational Chemistry, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural)
Abstract

The nature of solvated acids in benzene and chlorinated hydrocarbon solvents is sensitively revealed by IR spectroscopy. Two similarly strong, structurally related acids, triflic acid (CF 3SO 3H) and the N-H acid bis-(trifluoromethylsulfonyl) imide ((CF 3SO 2) 2NH), behave quite differently toward water in. these media. Triflic acid protonates water at the one-equivalent level to give the hydronium ion, H 3O +. By contrast, bis(trifluoromethylsulfonyl) imide forms a simple hydrate, (CF 3SO 2) 2NH-OH 2, even with water at the two-equivalent level. The difference arises from the differing abilities of the conjugate base anions to engage in H-bonding and ion pairing. It illustrates how acidity in low-dielectric media is critically dependent on the nature of the conjugate base anion. νO-H and νN-H stretching frequencies indicate that the H-bonding acceptor ability for solvents toward acidic protons increases in the order carbon tetrachloride < benzene ∼ 1, 2-dichoroethane < water. With benzene, a marked tendency for acidic protons to H-bond to the π-face of the arene ring is noted and an IR signature of this solvation mode is observed.

Published
2004

2. Taming superacids: stabilization of the fullerene cations HC60+ and C60.+.

Author

Reed, CA, Kim, KC, Bolskar, RD, and Mueller, LJ

Subjects
Acids, Anions, Cations, Monovalent, Protons, Carbon, Fullerenes, Oxidants, Spectrophotometry, Infrared, Spectrum Analysis, Magnetic Resonance Spectroscopy, Molecular Structure, Oxidation-Reduction, Models, Chemical, General Science & Technology
Abstract

A new superacid, H(CB11H6X6) (where X = chlorine or bromine), whose conjugate base is the exceptionally inert CB11H6X6- carborane anion, separates Bronsted acidity from oxidizing capacity and anion nucleophilicity in a manner not previously achieved. Reaction of this superacid with C60 gives HC60+ as a stable ion in solution and in the solid state. In a separate experiment, an oxidant was developed such that the long-sought C60.+ ion can be synthesized in solution. The preparation of these two fullerene carbocations is a notable departure from the prevalent chemistry of C60, which is dominated by the formation of anions or the addition of nucleophiles. The H(CB11H6X6) superacid overcomes the major limitations of presently known superacids and has potentially wide application.

Published
2000

6. Photoprotective Effect of a Polyopes affinis (Harvey) Kawaguchi and Wang (Halymeniaceae)-Derived Ethanol Extract on Human Keratinocytes

Author

Hyun, YJ, Piao, MJ, Kim, KC, Zheng, J, Yao, CW, Cha, JW, Kang, HK, Yoo, ES, Koh, YS, Lee, NH, Ko, MH, and Hyun, JW

Subjects
Human keratinocytes, Polyopes affinis, Reactive oxygen species, Red algae, Ultraviolet B, Apoptosis, DNA fragmentation
Abstract

Purpose: To investigate the photoprotective effect of the ethanol extract of the red marine alga, Polyopes affinis (PAE) against ultraviolet B (UVB) radiation on cultured human keratinocytes.Methods: The 2',7'-dichlorodihydrofluorescein diacetate method was used to detect intracellular reactive oxygen species (ROS) generated by H2O2 treatment or UVB radiation. Cell viability was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT ) assay. Superoxide anion or hydroxyl radical was detected using an electron spin resonance spectrometer after reaction with the nitrone spin trap. Lipid peroxidation was assayed by determining the level of 8-isoprostane. Protein carbonyl formation was determined using a protein carbonyl ELISA kit. The degree of oxidative DNA damage was determined using an alkaline comet assay. Apoptosis was assessed by apoptotic bodies and DNA fragmentation.Results: PAE significantly scavenged the free radical 1,1-diphenyl-2-picrylhydrazyl, as well as hydrogen peroxide- and UVB-induced intracellular ROS. Furthermore, PAE showed 23 % scavenging effect of the superoxide anion and 33 % of the hydroxyl radical. PAE also absorbed UVB rays in the 280 – 320 nm range. PAE significantly decreased cellular damage resulting from UVB-induced oxidative stress to lipids, proteins, and DNA. Furthermore, PAE-treated keratinocytes showed significant reduction in UVB-induced apoptosis, as exemplified by fewer apoptotic bodies and reduced DNA fragmentation.Conclusion: These results suggest that PAE protects keratinocytes against UVB-induced oxidative stress by absorbing UVB rays and scavenging ROS, thereby reducing injury to cellular constituents.Keywords: Human keratinocytes, Polyopes affinis, Reactive oxygen species, Red algae, Ultraviolet B, Apoptosis, DNA fragmentation

Published
2014

7. An integrated map of genetic variation from 1,092 human genomes

Author

Altshuler, DM, Durbin, RM, Abecasis, GR, Bentley, DR, Chakravarti, A, Clark, AG, Donnelly, P, Eichler, EE, Flicek, P, Gabriel, SB, Gibbs, RA, Green, ED, Hurles, ME, Knoppers, BM, Korbel, JO, Lander, ES, Lee, C, Lehrach, H, Mardis, ER, Marth, GT, McVean, GA, Nickerson, DA, Schmidt, JP, Sherry, ST, Wang, J, Wilson, RK, Dinh, H, Kovar, C, Lee, S, Lewis, L, Muzny, D, Reid, J, Wang, M, Fang, X, Guo, X, Jian, M, Jiang, H, Jin, X, Li, G, Li, J, Li, Y, Li, Z, Liu, X, Lu, Y, Ma, X, Su, Z, Tai, S, Tang, M, Wang, B, Wang, G, Wu, H, Wu, R, Yin, Y, Zhang, W, Zhao, J, Zhao, M, Zheng, X, Zhou, Y, Gupta, N, Clarke, L, Leinonen, R, Smith, RE, Zheng-Bradley, X, Grocock, R, Humphray, S, James, T, Kingsbury, Z, Sudbrak, R, Albrecht, MW, Amstislavskiy, VS, Borodina, TA, Lienhard, M, Mertes, F, Sultan, M, Timmermann, B, Yaspo, M-L, Fulton, L, Fulton, R, Weinstock, GM, Balasubramaniam, S, Burton, J, Danecek, P, Keane, TM, Kolb-Kokocinski, A, McCarthy, S, Stalker, J, Quail, M, Davies, CJ, Gollub, J, Webster, T, Wong, B, Zhan, Y, Auton, A, Yu, F, Bainbridge, M, Challis, D, Evani, US, Lu, J, Nagaswamy, U, Sabo, A, Wang, Y, Yu, J, Coin, LJM, Fang, L, Li, Q, Lin, H, Liu, B, Luo, R, Qin, N, Shao, H, Xie, Y, Ye, C, Yu, C, Zhang, F, Zheng, H, Zhu, H, Garrison, EP, Kural, D, Lee, W-P, Leong, WF, Ward, AN, Wu, J, Zhang, M, Griffin, L, Hsieh, C-H, Mills, RE, Shi, X, Von Grotthuss, M, Zhang, C, Daly, MJ, DePristo, MA, Banks, E, Bhatia, G, Carneiro, MO, Del Angel, G, Genovese, G, Handsaker, RE, Hartl, C, McCarroll, SA, Nemesh, JC, Poplin, RE, Schaffner, SF, Shakir, K, Yoon, SC, Lihm, J, Makarov, V, Jin, H, Kim, W, Kim, KC, Rausch, T, Beal, K, Cunningham, F, Herrero, J, McLaren, WM, Ritchie, GRS, Gottipati, S, Keinan, A, Rodriguez-Flores, JL, Sabeti, PC, Grossman, SR, Tabrizi, S, Tariyal, R, Cooper, DN, Ball, EV, Stenson, PD, Barnes, B, Bauer, M, Cheetham, RK, Cox, T, Eberle, M, Kahn, S, Murray, L, Peden, J, Shaw, R, Ye, K, Batzer, MA, Konkel, MK, Walker, JA, MacArthur, DG, Lek, M, Herwig, R, Shriver, MD, Bustamante, CD, Byrnes, JK, De la Vega, FM, Gravel, S, Kenny, EE, Kidd, JM, Lacroute, P, Maples, BK, Moreno-Estrada, A, Zakharia, F, Halperin, E, Baran, Y, Craig, DW, Christoforides, A, Homer, N, Izatt, T, Kurdoglu, AA, Sinari, SA, Squire, K, Xiao, C, Sebat, J, Bafna, V, Burchard, EG, Hernandez, RD, Gignoux, CR, Haussler, D, Katzman, SJ, Kent, WJ, Howie, B, Ruiz-Linares, A, Dermitzakis, ET, Lappalainen, T, Devine, SE, Maroo, A, Tallon, LJ, Rosenfeld, JA, Michelson, LP, Kang, HM, Anderson, P, Angius, A, Bigham, A, Blackwell, T, Busonero, F, Cucca, F, Fuchsberger, C, Jones, C, Jun, G, Lyons, R, Maschio, A, Porcu, E, Reinier, F, Sanna, S, Schlessinger, D, Sidore, C, Tan, A, Trost, MK, Awadalla, P, Hodgkinson, A, Lunter, G, Marchini, JL, Myers, S, Churchhouse, C, Delaneau, O, Gupta-Hinch, A, Iqbal, Z, Mathieson, I, Rimmer, A, Xifara, DK, Oleksyk, TK, Fu, Y, Xiong, M, Jorde, L, Witherspoon, D, Xing, J, Browning, BL, Alkan, C, Hajirasouliha, I, Hormozdiari, F, Ko, A, Sudmant, PH, Chen, K, Chinwalla, A, Ding, L, Dooling, D, Koboldt, DC, McLellan, MD, Wallis, JW, Wendl, MC, Zhang, Q, Tyler-Smith, C, Albers, CA, Ayub, Q, Chen, Y, Coffey, AJ, Colonna, V, Huang, N, Jostins, L, Li, H, Scally, A, Walter, K, Xue, Y, Zhang, Y, Gerstein, MB, Abyzov, A, Balasubramanian, S, Chen, J, Clarke, D, Habegger, L, Harmanci, AO, Jin, M, Khurana, E, Mu, XJ, Sisu, C, Degenhardt, J, Stuetz, AM, Church, D, Michaelson, JJ, Ben, B, Lindsay, SJ, Ning, Z, Frankish, A, Harrow, J, Fowler, G, Hale, W, Kalra, D, Barker, J, Kelman, G, Kulesha, E, Radhakrishnan, R, Roa, A, Smirnov, D, Streeter, I, Toneva, I, Vaughan, B, Ananiev, V, Belaia, Z, Beloslyudtsev, D, Bouk, N, Chen, C, Cohen, R, Cook, C, Garner, J, Hefferon, T, Kimelman, M, Liu, C, Lopez, J, Meric, P, O'Sullivan, C, Ostapchuk, Y, Phan, L, Ponomarov, S, Schneider, V, Shekhtman, E, Sirotkin, K, Slotta, D, Zhang, H, Barnes, KC, Beiswanger, C, Cai, H, Cao, H, Gharani, N, Henn, B, Jones, D, Kaye, JS, Kent, A, Kerasidou, A, Mathias, R, Ossorio, PN, Parker, M, Reich, D, Rotimi, CN, Royal, CD, Sandoval, K, Su, Y, Tian, Z, Tishkoff, S, Toji, LH, Via, M, Yang, H, Yang, L, Zhu, J, Bodmer, W, Bedoya, G, Ming, CZ, Yang, G, You, CJ, Peltonen, L, Garcia-Montero, A, Orfao, A, Dutil, J, Martinez-Cruzado, JC, Brooks, LD, Felsenfeld, AL, McEwen, JE, Clemm, NC, Duncanson, A, Dunn, M, Guyer, MS, Peterson, JL, 1000 Genomes Project Consortium, Dermitzakis, Emmanouil, Universitat de Barcelona, Massachusetts Institute of Technology. Department of Biology, Altshuler, David, and Lander, Eric S.

Subjects
Natural selection, LOCI, Genome-wide association study, Evolutionary biology, Continental Population Groups/genetics, Human genetic variation, VARIANTS, Genoma humà, Binding Sites/genetics, 0302 clinical medicine, RARE, Sequence Deletion/genetics, WIDE ASSOCIATION, ddc:576.5, Copy-number variation, MUTATION, Exome sequencing, transcription factor, Conserved Sequence, Human evolution, Sequence Deletion, Genetics, RISK, 0303 health sciences, Multidisciplinary, Continental Population Groups, 1000 Genomes Project Consortium, Genetic analysis, Genomics, Polymorphism, Single Nucleotide/genetics, Research Highlight, 3. Good health, Algorithm, Multidisciplinary Sciences, Genetic Variation/genetics, Map, Science & Technology - Other Topics, Conserved Sequence/genetics, Integrated approach, General Science & Technology, Genetics, Medical, Haplotypes/genetics, Biology, Polymorphism, Single Nucleotide, Evolution, Molecular, 03 medical and health sciences, Genetic variation, Humans, Transcription Factors/metabolism, POPULATION-STRUCTURE, 1000 Genomes Project, Polymorphism, Nucleotide Motifs, Alleles, 030304 developmental biology, COPY NUMBER VARIATION, Science & Technology, Binding Sites, Human genome, Genome, Human, Racial Groups, Genetic Variation, Genetics, Population, Haplotypes, Genome, Human/genetics, untranslated RNA, 030217 neurology & neurosurgery, Transcription Factors, Genome-Wide Association Study
Abstract

By characterizing the geographic and functional spectrum of human genetic variation, the 1000 Genomes Project aims to build a resource to help to understand the genetic contribution to disease. Here we describe the genomes of 1,092 individuals from 14 populations, constructed using a combination of low-coverage whole-genome and exome sequencing. By developing methods to integrate information across several algorithms and diverse data sources, we provide a validated haplotype map of 38 million single nucleotide polymorphisms, 1.4 million short insertions and deletions, and more than 14,000 larger deletions. We show that individuals from different populations carry different profiles of rare and common variants, and that low-frequency variants show substantial geographic differentiation, which is further increased by the action of purifying selection. We show that evolutionary conservation and coding consequence are key determinants of the strength of purifying selection, that rare-variant load varies substantially across biological pathways, and that each individual contains hundreds of rare non-coding variants at conserved sites, such as motif-disrupting changes in transcription-factor-binding sites. This resource, which captures up to 98% of accessible single nucleotide polymorphisms at a frequency of 1% in related populations, enables analysis of common and low-frequency variants in individuals from diverse, including admixed, populations., National Institutes of Health (U.S.) (Grant RC2HL102925), National Institutes of Health (U.S.) (Grant U54HG3067)

Published
2012

8. A Fighter Pilot’s Lessons On Facing Adversity and Building Resilience: The key is to build resilience before facing adversity.

Author

Campbell, Kim “KC”

Subjects
FIGHTER pilots, ORGANIZATIONAL resilience
Abstract

The article offers information on lessons on facing adversity and building resilience. Topics include information on importance of building resilience before facing adversity; increasing importance of organizational resilience with time; and preparing for tough times so one can thrive in demanding situations.

Published
2023

9. A Fighter Pilot's Lessons On Facing Adversity and Building Resilience: The key is to build resilience before facing adversity.

Author

Campbell, Kim "KC"

Subjects
FIGHTER pilots, PSYCHOLOGICAL resilience, ORGANIZATIONAL resilience
Abstract

Preparation - Ensure your team is prepared bydeveloping crisis response plans and then takethe time to walk through or talk through differentscenarios that your team might face. COVER ARTICLE In this ever-changing, complex, dynamic world, weneed leaders who know how to face adversity andbuild resilience. [Extracted from the article]

Published
2023

10. The nature of the H3O+ hydronium ion in benzene and chlorinated hydrocarbon solvents. Conditions of existence and reinterpretation of infrared data

Author

Stoyanov, ES, Kim, KC, and Reed, CA

Abstract

Salts of the C3v symmetric hydronium ion, H3O +, have been obtained in the weakly basic solvents benzene, dichloromethane, and 1,2-dichloroethane. This is made possible by using carborane counterions of the type CHB11R5X 6- (R = H, Me, Cl; X = Cl, Br, I) because they combine the three required properties of a suitable counterion: very low basicity, low polarizability, and high chemical stability. The existence of the H 3O+ ion requires the formation of three more-or-less equivalent, medium-to-strong H-bonds with solvent oranion bases. With the least basic anions such as CHB11Cl11-, IR spectroscopy indicates that C3v symmetric trisolvates of formulation [H3O+ ·3Solv] are formed with chlorocarbon solvents and benzene, the latter with the formation of π bonds. When the solvents and anions have comparable basicity, contact ion pairs of the type [H 3O+·nSolv-Carborane] are formed and close to C 3v symmetry is retained. The conditions for the existence of the H3O+ ion are much more exacting than previously appreciated. Outside of the range of solvent basicity bounded at the lower end by dichloromethane and the upper end by tributyl phosphate, and with anions that do not meet the stringent requirements of weak basicity, low polarizability of high chemical stability, lower symmetry species are formed. One H-bond from H3O+ to the surrounding bases becomes stronger than the other two. The distortion from C3v symmetry is minor for bases weaker than dichloromethane. For bases stronger than tributyl phosphate, H 2O-H+-B type species are formed that are more closely related to the H5O2+ ion than to H 3O+. IR data allow criteria to be defined for the existence of the symmetric H3O+ ion. This includes a linear dependence between the frequencies of νmax(OH) and δ(OH3) within the ranges 3010-2536 cm-1 for νmax(OH) and 1597-1710 cm-1 for δ(OH 3). This provides a simple way to assess the correctness of the formulation of the proton state in monohydrated acids. In particular, the 30-year-old citation classic of the IR spectrum believed to arise from H 3O+ SbCl6- is re-interpreted in terms of (H2O)x·HSbCl6 hydrates. The correctness of the hydronium ion formulation in crystalline H3O +A- salts (A- = Cl-, NO 3-) is confirmed, although, when A- is a fluoroanion, distortions from C3v symmetry are suggested. © 2006 American Chemical Society.

Published
2006

11. The structure of the H3O+ hydronium ion in benzene

Author

Stoyanov, ES, Hoffmann, SP, Kim, KC, Tham, FS, and Reed, CA

Abstract

Infrared, X-ray structural, 1H NMR, and computational evidence for π-solvation of H3O+ by benzene molecules is presented. A salt with a discrete [H3O·3benzene]+ cation can be isolated using a very weakly interacting carborane counterion, CHB11Cl11-. π-Arene solvation of H3O+ explains the solubility of this salt in benzene solution. Similar results are indicated for the "Zundel-type" H5O2+ ion. These findings suggest structures for the active protonating species when strong acids are used as catalysts in arene solvents containing trace water. They are also relevant to structures that may be present in biological proton transport. Copyright © 2005 American Chemical Society.

Published
2005

12. Synthesis of the C59N+ carbocation. A monomeric azafullerene isoelectronic to C60

Author

Kim, KC, Hauke, F, Hirsch, A, Boyd, PDW, Carter, E, Armstrong, RS, Lay, PA, and Reed, CA

Abstract

A heterofullerene isoelectronic to C60 is reported. The azafullerenium cation C59N+ can be isolated in good yield as a carborane salt via the two-electron oxidation of the C-C bond of (C59N)2 dimer. [C59N][Ag(CB11H6Cl6)2] has been characterized by electronic, IR, Raman, and 13C NMR spectroscopies, MALDI spectrometry, DFT calculations, and X-ray crystallography. Copyright © 2003 American Chemical Society.

Published
2003

13. Et2Al+ alumenium ion-like chemistry. Synthesis and reactivity toward alkenes and alkene oxides

Author

Kim, KC, Reed, CA, Long, GS, and Sen, A

Abstract

Inert weakly coordinating carborane anions, CB11H6X6- (X = Cl, Br), allow access to the long sought, highly electrophilic diethylaluminum moiety in Et2Al(CB11H6X6). X-ray crystallography reveals ion-like structural features reminiscent of the corresponding trialkylsilylium species. Et2Al(CB11H6X6) is a potent catalyst for the electrophilic ethenation of benzene, the polymerization of cyclohexene oxide, and the oligomerization of ethene to a low molecular weight, highly branched product. Copyright © 2002 American Chemical Society.

Published
2002

17. A robust CUP pad structure design with thin pad metal for Cu wire bonding

Author

Han, ChangHee, primary, Kim, SG, additional, Shim, JH, additional, Jiang, DH, additional, Ko, SW, additional, Lee, BJ, additional, Kim, KC, additional, Lee, HG, additional, Yoon, JS, additional, Jiang, BT, additional, Hong, SW, additional, Kim, HD, additional, Yoo, IS, additional, Song, YS, additional, Kim, DalSoo, additional, and Choe, Shihyun, additional

Published
2010
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23. Data retention behavior in the embedded SONOS nonvolatile memory cell

Author

Chae, H.S., primary, Jung, Y.S., additional, Seo, S., additional, Han, J.H., additional, Hyun, J.W., additional, Park, G.W., additional, Um, M.Y., additional, Kim, J.-H., additional, Lee, B.J., additional, Kim, KC., additional, Cho, I.W., additional, Bae, G.J., additional, Lee, N.I., additional, Kang, S.T., additional, and Kim, C.W., additional

Published
2005
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32. Empetrum nigrum var. Japonicum extract suppresses γ-ray radiation-induced cell damage via inhibition of oxidative stress.

Author

Kim KC, Lee IK, Kang KA, Kim BJ, Kim D, Moon JY, Yoo BS, and Hyun JW

Abstract

The ethylacetate fraction of Empetrum nigrum var. japonicum (ENE) was shown to reduce intracellular reactive oxygen species (ROS) generated by γ-radiation and activate antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), and gluthathion peroxidase (GPx). ENE protected cells against radiation-induced cellular DNA damage, membrane lipid peroxidation, and protein modification, which are the main points of radiation-induced damage. In addition, ENE recovered cell viability by inhibiting apoptosis after cells were treated with radiation. ENE treatment also reduced γ-radiation induced Bax, and caspase 9 and 3 expression in irradiated cells. However, irradiated cells with ENE recovered Bcl-2 expression, which was reduced by radiation. This anti-apoptotic effect of ENE was due to the inhibition of mitogen-activated protein kinase kinase-4 (MKK4/SEK1)-c-Jun NH2-terminal kinase (JNK) cascades induced by γ-radiation. In summary, these results suggest that ENE protects cells against γ-radiation-induced oxidative stress via the reduction of ROS and attenuation of apoptosis. [ABSTRACT FROM AUTHOR]

Published
2011
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34. Ageing, chronic alcohol consumption and folate are determinants of genomic DNA methylation, p16 promoter methylation and the expression of p16 in the mouse colon.

Author

Sauer J, Jang H, Zimmerly EM, Kim KC, Liu Z, Chanson A, Smith DE, Mason JB, Friso S, and Choi SW

Abstract

Older age, dietary folate and chronic alcohol consumption are important risk factors for the development of colon cancer. The present study examined the effects of ageing, folate and alcohol on genomic and p16-specific DNA methylation, and p16 expression in the murine colon. Old (aged 18 months; n 70) and young (aged 4 months; n 70) male C57BL/6 mice were pair-fed either a Lieber-DeCarli liquid diet with alcohol (18% of energy), a Lieber-DeCarli diet with alcohol (18%) and reduced folate (0.25 mg folate/l) or an isoenergetic control diet (0.5 mg folate/l) for 5 or 10 weeks. Genomic DNA methylation, p16 promoter methylation and p16 gene expression were analysed by liquid chromatography-MS, methylation-specific PCR and real-time RT-PCR, respectively. Genomic DNA methylation was lower in the colon of old mice compared with young mice (P < 0.02) at 10 weeks. Alcohol consumption did not alter genomic DNA methylation in the old mouse colon, whereas it tended to decrease genomic DNA methylation in young mice (P = 0.08). p16 Promoter methylation and expression were higher in the old mouse colon compared with the corresponding young groups. There was a positive correlation between p16 promoter methylation and p16 expression in the old mouse colon (P < 0.02). In young mice the combination of alcohol and reduced dietary folate led to significantly decreased p16 expression compared with the control group (P < 0.02). In conclusion, ageing and chronic alcohol consumption alter genomic DNA methylation, p16 promoter methylation and p16 gene expression in the mouse colon, and dietary folate availability can further modify the relationship with alcohol in the young mouse. [ABSTRACT FROM AUTHOR]

Published
2010
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37. Estimating the dimensions of the rotator interval with use of magnetic resonance arthrography.

Author

Kim KC, Rhee KJ, Shin HD, Kim YM, Kim, Kyung-Cheon, Rhee, Kwang-Jin, Shin, Hyun-Dae, and Kim, Young-Mo

Abstract

Background: The goal of the present study was to define the dimensions of the normal rotator interval with magnetic resonance arthrography and to compare these dimensions with those in shoulders with known chronic anterior instability in order to determine if abnormalities of the rotator interval might be better understood and estimated preoperatively.Methods: We retrospectively reviewed a consecutive series of 202 shoulders that had undergone magnetic resonance arthrography between 2004 and 2005. Of these, 120 shoulders were included in the present study. These shoulders were divided into two groups according to the diagnosis. Group I comprised fifty shoulders with no instability, and Group II comprised seventy shoulders with chronic anterior instability. With use of magnetic resonance arthrography, the base and height of the rotator interval and the diameter of the glenoid were measured. Then, the area of the rotator interval and the rotator interval index were calculated.Results: In Group I, the mean estimated rotator interval dimensions (height and base), the mean calculated rotator interval area, and the mean rotation interval index were 16.73 mm, 48.59 mm, 406.47 mm(2), and 0.64, respectively. In Group II, these values were 21.87 mm, 49.40 mm, 540.06 mm(2), and 0.94, respectively. The shoulders in Group II differed significantly from the shoulders in Group I in terms of rotator interval height, rotator interval area, and rotator interval index (p < 0.01 for all).Conclusions: There are significant differences in the dimensions of the rotator interval between patients with and without recurrent anterior shoulder instability. Estimating the dimensions of the rotator interval with use of magnetic resonance arthrography may be valuable for assessing patients preoperatively. [ABSTRACT FROM AUTHOR]

Published
2007

39. Tibial unreamed intramedullary nailing using schanz screws in displaced diaphyseal segmental fractures.

Author

Kim KC, Lee JK, Hwang DS, Yang JY, Kim YM, Harwin SF, Kim, Kyung Cheon, Lee, June Kyu, Hwang, Deuk Soo, Yang, Jun Young, and Kim, Young Mo

Abstract

Reduction and manipulation using percutaneously fixated Schanz screws and unreamed intramedullary nailing facilitates fracture reduction, promotes early weight bearing, and decreases complications such as nonunion, malalignment, in failure. [ABSTRACT FROM AUTHOR]

Published
2007
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40. Secretions from primary hamster tracheal surface epithelial cells in culture: mucin-like glycoproteins, proteoglycans, and lipids

Author

Kim Kc, Bhaskar Kr, and Opaskar-Hincman H

Subjects
Pulmonary and Respiratory Medicine, Male, Glycoconjugate, Clinical Biochemistry, Hamster, In Vitro Techniques, chemistry.chemical_compound, Glucosamine, Cricetinae, Animals, Molecular Biology, Cells, Cultured, chemistry.chemical_classification, biology, Mesocricetus, Mucin, Mucins, Epithelial Cells, biology.organism_classification, Lipid Metabolism, Lipids, carbohydrates (lipids), Molecular Weight, Trachea, chemistry, Biochemistry, Cell culture, Chromatography, Gel, Proteoglycans, Glycoprotein, Fetal bovine serum
Abstract

Surface epithelial cells dissociated from hamster tracheas and grown on a thick collagen gel in the presence of 5% fetal bovine serum become highly enriched with secretory cells at confluence. In the present communication, we have analyzed secretory products from this primary hamster tracheal surface epithelial (HTSE) cell culture. The secreted glycoconjugates included high-molecular-weight mucin-like glycoproteins (HMW MLGP) and proteoglycans that comprised 22% and 5% of the total [3H]glycoconjugates secreted when [3H]glucosamine was added as a metabolic precursor. Among the proteoglycans were hyaluronic acids (53%), heparan sulfate proteoglycans (29%), and chrondroitin sulfate proteoglycans (18%). Chondroitin sulfates were mostly 4-sulfated. On the other hand, the secreted lipids included cholesterol, phospholipids, and glycolipids, and most of them were associated with HMW MLGP.

Published
1989

44. Twinned Metal-Organic Framework Nanoplates for Hydrocarbon Separation Membranes.

Author

Kim J, Kim M, Yu S, Yu J, Yu C, Kim T, Lee N, Ahn YH, Kim YH, Yoo S, Kim KC, Kim DW, and Eum K

Abstract

Filler morphology control is critical for enhancing the gas separation performance of mixed matrix membranes (MMMs). A vertical transport channel using the crystal twinning phenomenon is designed on the zeolitic imidazolate framework (ZIF) nanoplate. Twinned ZIF-8 (TZIF-8) nanoplate is prepared by controlling the shape of ZIF-L from nanosheet to twinned flake, followed by conversion into the ZIF-8 phase. With the addition of TZIF-8 in 6FDA-DAM polymer, propylene/propane selectivity is dramatically enhanced, showing propylene permeability of 40 Barrer and propylene/propane selectivity of 82. The separation performance surpasses the performance of MMMs reported so far, and the selectivity is comparable to that of polycrystalline ZIF-8 membranes. A transport mechanism study using mathematical models implies that the percolated twin fillers create rapid and selective gas channels for desired molecules and substantial tortuous pathways for undesired molecules., (© 2024 Wiley‐VCH GmbH.)

Published
2024
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45. Efficacy and Potential Mechanisms of Naringin in Atopic Dermatitis.

Author

Yoo SA, Kim KC, and Lee JH

Subjects
Animals, Mice, Disease Models, Animal, Dinitrochlorobenzene, Signal Transduction drug effects, Cytokines metabolism, Mice, Inbred BALB C, Female, Skin metabolism, Skin drug effects, Skin pathology, STAT Transcription Factors metabolism, Mast Cells drug effects, Mast Cells metabolism, Dermatitis, Atopic drug therapy, Dermatitis, Atopic metabolism, Dermatitis, Atopic pathology, Flavanones pharmacology, Flavanones therapeutic use
Abstract

Atopic dermatitis (AD) is one of the most prevalent chronic inflammatory skin diseases. Topical treatments are recommended for all patients regardless of severity, making it essential to develop an effective topical AD treatment with minimal side effects; We investigated the efficacy of topical application of naringin in AD and explored the possible mechanisms using an AD mouse model induced by 1-chloro-2,4-dinitrobenzene (DNCB). Clinical, histological, and immunological changes related to AD and Janus kinase ( JAK )-signal transducer and activator of transcription ( STAT ) signaling proteins in the skin tissues were measured as outcomes; Naringin treatment resulted in a significant improvement in dermatitis severity score and reduced epidermal thickness and mast cell count in the skin ( p < 0.05). Naringin also demonstrated the ability to inhibit DNCB-induced changes in interleukin ( IL ) 4, chemokine (C-C motif) ligand ( CCL ) 17, CCL22 , IL1β , interferon-gamma ( IFN-γ ), and tumor necrosis factor-alpha ( TNF-α ) levels by quantitative real-time polymerase chain reaction (qRT-PCR) and IL13 by enzyme-linked immunosorbent assay (ELISA) ( p < 0.05). Western blot results exhibited the decreased JAK1 , JAK2 , STAT1 , STAT3 , phospho-STAT3 , and STAT6 expression in the naringin-treated groups ( p < 0.05); The findings of this study suggest that topical naringin may effectively improve the symptoms of AD and could be used as a therapeutic agent for AD.

Published
2024
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46. Inability to Remove Locking Screws from the Femoral Neck System due to Stripping of the Screwdriver within the Locking Screw Head.

Author

Park JW, Cha YH, Kim JW, Kim HS, Nho JH, Jang BW, Kim JT, Kim JK, Kim TY, Kim KC, and Lee YK

Abstract

Objectives: The purposes of this study were to investigate the frequency of screwdriver stripping in the head of the locking screw that attaches to the side plate to the femur shaft among the patients who underwent implant removal after Femoral Neck System (FNS) for femoral neck fracture, to determine the risk factors for locking head screw stripping in FNS treatment of femoral neck fracture, and to suggest a surgical tip that removes FNS, which is difficult to remove due to screw stripping., Methods: Design: Retrospective cohort study., Setting: Eight Urban tertiary referral academic hospitals., Patient Selection Criteria: Included were patients with OTA/AO 31-B1, 31-B2, and 31-B3 femoral neck fractures who underwent surgical fixation with FNS from Nov 2019 to Feb 2023., Outcome Measures and Comparisons: The frequency of locking head screw stripping of FNS during the implant removal was evaluated., Results: Among the 47 patients (18 (38%) men and 29 (62%) women) who met the inclusion criteria with average age of 59.2 years (range, 28 to 94 years), 13 (27.7%) experienced screwdriver stripping in the head of the distal locking screw during FNS removal surgery. A higher BMI showed a borderline significant association with the stripping in the adjusted model (OR = 1.233; 95% CI: 0.988-1.539; p = 0.064). No other variables showed significant association with the stripped locking head screw (p>0.05)., Conclusions: Stripping of the screwdriver within the head of the distal locking screw occurred in over one quarter of cases. While a higher BMI demonstrated a borderline significant association, none of the other variables examined showed a statistically significant relationship with the stripped locking head screw., Levels of Evidence: Level III (retrospective cohort study)., Competing Interests: Conflict of interest: Each author certifies that he or she has no commercial associations (e.g., consultancies, stock ownership, equity interest, patent/licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Published
2024
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47. The Effects and Risk Factors of Femoral Neck Shortening after Internal Fixation of Femoral Neck Fractures.

Author

Lee DH, Kwon JH, and Kim KC

Subjects
Humans, Female, Male, Retrospective Studies, Risk Factors, Middle Aged, Aged, Adult, Postoperative Complications etiology, Femur Neck diagnostic imaging, Femur Neck surgery, Femoral Neck Fractures surgery, Femoral Neck Fractures diagnostic imaging, Fracture Fixation, Internal adverse effects, Fracture Fixation, Internal methods
Abstract

Backgroud: Internal fixation has been established as a treatment of choice in relatively young patients with femoral neck fractures. Due to the characteristics of femoral neck anatomy and blood supply, complications such as malunion, nonunion, avascular necrosis, and femoral neck shortening can occur after internal fixation of femoral neck fractures. Unlike other complications such as avascular necrosis or nonunion, femoral neck shortening has not been relatively well studied. This study aimed to investigate the risk factors and clinical outcomes of femoral neck shortening after internal fixation of femoral neck fractures., Methods: From June 2012 to July 2022, among 102 patients who underwent internal fixation of femoral neck fractures, 94 patients who met inclusion and exclusion criteria were retrospectively analyzed. Internal fixation of the femoral neck was done with cannulated compression screws or a femoral neck system. Patients were divided into 2 groups; femoral neck shortening (≥ 5 mm) and no shortening (< 5 mm) according to measurement on follow-up hip anteroposterior (AP) simple radiographs compared with postoperative hip AP simple radiographs. Demographic and radiographic data were compared between the 2 groups. The modified Harris Hip Score (mHHS) and a visual analog scale (VAS) were used to evaluate the clinical outcomes., Results: Among 94 patients, femoral neck shortening was observed in 33 (35.1%). In chi-square test, Pauwels angle, Garden type III or IV (displacement), and cortical comminution were significantly correlated with neck shortening ( p < 0.05). In the multifactorial logistic regression test, cortical comminution was significantly correlated with femoral neck shortening ( p < 0.01). The shortening group showed significantly lower clinical scores in terms of mHHS and VAS ( p < 0.01)., Conclusions: The femoral neck shortening group showed significantly lower clinical scores of mHHS and VAS than the no-shortening group. The presence of cortical comminution in preoperative hip computed tomography is a risk factor of femoral neck shortening after internal fixation of femoral neck fractures., Competing Interests: CONFLICT OF INTEREST: No potential conflict of interest relevant to this article was reported., (Copyright © 2024 by The Korean Orthopaedic Association.)

Published
2024
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48. Comparative Analysis of Bone Mineral Density of the Lumbar Spine, Hip, and Proximal Humerus in Patients with Unilateral Rotator Cuff Tears.

Author

Lee WY, Jeon YS, Kim KC, Shin HD, Joo YB, and Chung HJ

Subjects
Humans, Female, Middle Aged, Male, Aged, Absorptiometry, Photon, Adult, Osteoporosis complications, Bone Density, Lumbar Vertebrae surgery, Lumbar Vertebrae physiopathology, Humerus surgery, Humerus diagnostic imaging, Rotator Cuff Injuries surgery, Rotator Cuff Injuries physiopathology
Abstract

Background: The proximal humerus, a common site for osteoporotic fractures, is frequently overlooked in osteoporosis evaluations. This study aimed to evaluate the relationship between the conventional bone mineral density (BMD) measurement (at the lumbar spine and femur) and the BMD measurement at both proximal humeri (the asymptomatic side and the side with a rotator cuff tear [RCT]) in patients with unilateral RCT. Furthermore, we investigated clinical features indicative of osteoporosis in RCT patients and assessed the utility of proximal humerus BMD measurements., Methods: From April 2020 to September 2020, 87 patients who underwent arthroscopic repairs for unilateral RCTs were examined for age, onset, body mass index, menopause duration, passive range of motion, global fatty degeneration index, and RCT and retraction size. The regions of interest (ROIs) for the conventional BMD included the lumbar spine, femur neck, femur trochanter, and total femur. For the proximal humerus BMD, the ROIs included the head, lesser tuberosity, greater tuberosity (medial, middle, and lateral rows), and total humerus., Results: The conventional BMD of the lumbar spine, femur neck, femur trochanter, and femur total were 1.090, 0.856, 0.781, and 0.945 g/cm 2 , respectively. The head, lesser tuberosity, greater tuberosity (medial, middle, and lateral rows), and total BMD of the asymptomatic-side proximal humerus were 0.547, 0.544, 0.697, 0.642, 0.554, and 0.610 g/cm 2 , respectively. The average of proximal humerus BMD was significantly lower than that of conventional BMD ( p < 0.001). All ROIs BMD of the RCT-side proximal humerus were 0.497, 0.507, 0.619, 0.598, 0.517, and 0.560 g/cm 2 . There was no correlation between the conventional BMD and each proximal humerus BMD. All ROI BMD of the RCT-side proximal humerus was not significant in the multiple regression analysis with age, onset, body mass index, passive range of motion, global fatty degeneration index, and RCT and retraction size ( p > 0.05)., Conclusions: The proximal humerus BMD showed a completely different trend from that of conventional BMD and had no significant association with clinical features. Therefore, the proximal humerus BMD needs to be measured separately from the conventional BMD, as it may provide important information before rotator cuff repair surgery., Competing Interests: CONFLICT OF INTEREST: No potential conflict of interest relevant to this article was reported., (Copyright © 2024 by The Korean Orthopaedic Association.)

Published
2024
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49. Highly Permeable Mixed Matrix Membranes for Gas Separation via Dual Defect-Engineered Zeolitic Imidazolate Framework-8.

Author

Seong J, Nam KJ, An H, Yu S, Shin JH, Kim KC, Kang SG, Reddy KSSVP, Hong DY, Kim SJ, and Lee JS

Abstract

Defect engineering of metal-organic frameworks (MOFs) is a promising strategy for tailoring the interfacial characteristics between MOFs and polymers, aiming to create high-performance mixed matrix membranes (MMMs). This study introduces a new approach using dual defective alkylamine (AA)-modulated zeolitic imidazolate framework-8 (DAZIF-8), to develop high-flux MMMs. Tributylamine (TBA) and triethylamine (TEA) monodentate ligands coordinate with zinc ions in varying compositions. A mixture of Zn(CH 3 COO) 2 ·2H 2 O:2-methylimidazole (Mim):AA in a 1:1.75:5 molar ratio facilitates high-yield coordination between Zn and multiple organic ligands, including Zn-Mim, Zn-TEA, and Zn-TBA (>80%). Remarkably, DAZIF-8 containing 3 mol% TBA and 2 mol% TEA exhibits exceptional characteristics, such as a Brunauer-Emmett-Teller surface area of 1745 m 2 g -1 and enhanced framework rigidity. Furthermore, dual Zn-AA coordination sites on the framework's outer surface enhance compatibility with the polyimide (PI) matrix through electron donor-acceptor interactions, enabling the fabrication of high-loading MMMs with excellent mechanical durability. Importantly, the PI/DAZIF-8 (60/40 w/w) MMM demonstrates an unprecedented 759% enhancement in ethylene (C 2 H 4 ) permeability (281 Barrer) with a moderate ethylene/ethane (C 2 H 4 /C 2 H 6 ) selectivity of 2.95 compared to the PI, surpassing the polymeric upper limit for C 2 H 4 /C 2 H 6 separation., (© 2024 Wiley‐VCH GmbH.)

Published
2024
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50. Comparison of outcomes after total hip arthroplasty in hip fracture versus elective cases in patients over 60 years of age.

Author

Kim KC, Kwon JH, Park YC, and Lee DH

Abstract

Background: Total hip arthroplasty (THA) allows for the replacement of impaired parts of the hip joint with artificial ones. This study aimed to compare the differences in preoperative patient profiles, postoperative complications, and clinical outcomes of two patient groups: those who underwent THA for fractures and those who underwent THA electively for diseases such as osteoarthritis (OA) and avascular necrosis (AVN)., Methods: We retrospectively analyzed the data of patients who underwent THA between March 2012 and December 2021. Of 232 patients, 173 patients who met the exclusion and inclusion criteria were included. Patients were divided into two groups (Group 1: 113 patients diagnosed with OA or AVN; Group 2: 60 patients diagnosed with hip fracture). Pre- and postoperative Visual Analogue Scale (VAS), Koval scores, and postoperative modified Harris Hip Score (mHHS) were used to assess clinical outcomes. Demographic data and postoperative complications of the two groups were compared. After surgery, a rehabilitation protocol was initiated., Results: Patients in Group 2 (fracture) had more preoperative comorbidities than those in Group 1 (elective). Follow-up months are 26.22 ± 19.78 (Group 1), and 27.42 ± 17.02 (Group 2) respectively ( P  > 0.05). There were no statistical differences in the prevalence of postoperative complications between two groups ( P  > 0.05). Compared with Group 1(elective), Group 2(fracture) showed lower VAS ( P  < 0.01) at last follow-up, and no difference in Koval score ( P  = 0.77) and mHHS (P = 0.96) at last follow-up., Conclusion: Considering the characteristics of the two groups and their perioperative multidisciplinary care, THA for hip fractures can provide good clinical results compared to those with elective THA., Competing Interests: None, (© 2024 Professor P K Surendran Memorial Education Foundation. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

Published
2024
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