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Levine DS, Tilley TD, Andersen RA. Evidence for the Existence of Group 3 Terminal Methylidene Complexes. Organometallics 2016. [DOI: 10.1021/acs.organomet.6b00394] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Ziegler MS, Levine DS, Lakshmi KV, Tilley TD. Aryl Group Transfer from Tetraarylborato Anions to an Electrophilic Dicopper(I) Center and Mixed-Valence μ-Aryl Dicopper(I,II) Complexes. J Am Chem Soc 2016; 138:6484-91. [PMID: 27176131 DOI: 10.1021/jacs.6b00802] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis of discrete, cationic binuclear μ-aryl dicopper complexes [Cu2(μ-η(1):η(1)-Ar)DPFN]X (Ar = C6H5, 3,5-(CF3)2C6H3, and C6F5; DPFN = 2,7-bis(fluoro-di(2-pyridyl)methyl)-1,8-naphthyridine; X = BAr4(-) and NTf2(-); Tf = SO2CF3) was achieved by treatment of a dicopper complex [Cu2(μ-η(1):η(1)-NCCH3)DPFN]X2 (X = PF6(-) and NTf2(-)) with tetraarylborates. Structural characterization revealed symmetrically bridging aryl groups, and (1)H NMR spectroscopy evidenced the same structure in solution at 24 °C. Electrochemical investigation of the resulting arylcopper complexes uncovered reversible redox events that led to the synthesis and isolation of a rare mixed-valence organocopper complex [Cu2(μ-η(1):η(1)-Ph)DPFN](NTf2)2 in high yield. The solid-state structure of the mixed-valence μ-phenyl complex exhibits inequivalent copper centers, despite a short Cu···Cu distance. Electronic and variable-temperature electron paramagnetic resonance spectroscopy of the mixed-valence μ-phenyl complex suggest that the degree of spin localization is temperature-dependent, with a high degree of spin localization observed at lower temperatures. Electronic structure calculations agree with the experimental results and suggest that the spin is localized almost entirely on one metal center.
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Liberman-Martin AL, Levine DS, Liu W, Bergman RG, Tilley TD. Biaryl Reductive Elimination Is Dramatically Accelerated by Remote Lewis Acid Binding to a 2,2′-Bipyrimidyl–Platinum Complex: Evidence for a Bidentate Ligand Dissociation Mechanism. Organometallics 2016. [DOI: 10.1021/acs.organomet.5b01003] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Liberman-Martin AL, Levine DS, Ziegler MS, Bergman RG, Tilley TD. Lewis acid–base interactions between platinum(ii) diaryl complexes and bis(perfluorophenyl)zinc: strongly accelerated reductive elimination induced by a Z-type ligand. Chem Commun (Camb) 2016; 52:7039-42. [DOI: 10.1039/c6cc02433e] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Z-type interactions between bis(perfluorophenyl)zinc and platinum(ii) diaryl complexes supported by 1,10-phenanthroline (phen), 2,2′-bipyridine (bpy), and bis(dimethylphosphino)ethane (dmpe) ligands are reported.
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Hamby T, Levine DS. Response-Scale Formats and Psychological Distances Between Categories. APPLIED PSYCHOLOGICAL MEASUREMENT 2016; 40:73-75. [PMID: 29881037 PMCID: PMC5978528 DOI: 10.1177/0146621615597961] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
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Levine DS, Tilley TD, Andersen RA. C–H Bond Activations by Monoanionic, PNP-Supported Scandium Dialkyl Complexes. Organometallics 2015. [DOI: 10.1021/acs.organomet.5b00213] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kiumarsi B, Lewis FL, Levine DS. Optimal control of nonlinear discrete time-varying systems using a new neural network approximation structure. Neurocomputing 2015. [DOI: 10.1016/j.neucom.2014.12.067] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Weichman ML, Kim JB, DeVine JA, Levine DS, Neumark DM. Vibrational and Electronic Structure of the α- and β-Naphthyl Radicals via Slow Photoelectron Velocity-Map Imaging. J Am Chem Soc 2015; 137:1420-3. [DOI: 10.1021/ja5124896] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Oakton E, Vilé G, S. Levine D, Zocher E, Baudouin D, Pérez-Ramírez J, Copéret C. Silver nanoparticles supported on passivated silica: preparation and catalytic performance in alkyne semi-hydrogenation. Dalton Trans 2014; 43:15138-42. [DOI: 10.1039/c4dt01320d] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
When X = SiMe3, small (2.1 ± 0.5 nm) densely packed silica-supported Ag particles can be prepared, which show an improved catalytic activity (per gram) whilst maintaining high alkene selectivity.
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Tee MC, Chan SK, Nguyen V, Strugnell SS, Yang J, Jones S, Tiwari P, Levine DS, Wiseman SM. Incremental value and clinical impact of neck sonography for primary hyperparathyroidism: a risk-adjusted analysis. Can J Surg 2013; 56:325-31. [PMID: 24067517 DOI: 10.1503/cjs.015612] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Despite the different preoperative imaging modalities available for parathyroid adenoma localization, there is currently no uniform consensus on the most appropriate preoperative imaging algorithm that should be routinely followed prior to the surgical management of primary hyperparathyroidism (PHPT). We sought to determine the incremental value of adding neck ultrasonography to scintigraphy-based imaging tests. METHODS In a single institution, surgically naive patients with PHPT underwent the following localization studies before parathyroidectomy: 1) Tc-99m sestamibi imaging with single photon emission computed tomography/computed tomography (SPECT/CT) or Tc-99m sestamibi imaging with SPECT alone, or 2) ultrasonography in addition to those tests. We retrospectively collected data and performed a multivariate analysis comparing group I (single study) to group II (addition of ultrasonography) and risk of bilateral (BNE) compared with unilateral (UNE) neck exploration. RESULTS Our study included 208 patients. Group II had 0.45 times the odds of BNE versus UNE compared with group I (unadjusted odds ratio [OR] 0.45, 95% confidence interval [CI] 0.25-0.81, p = 0.008). When adjusting for patient age, sex, preoperative calcium level, use of intraoperative PTH monitoring, preoperative PTH level, adenoma size, and number of abnormal parathyroid glands, Group II had 0.48 times the odds of BNE versus UNE compared with group I (adjusted OR 0.48, 95% CI 0.23-1.03, p = 0.06). In a subgroup analysis, only the addition of ultrasonography to SPECT decreased the risk of undergoing BNE compared with SPECT alone (unadjusted OR 0.40, 95% CI 0.19-0.84, p = 0.015; adjusted OR 0.38, 95% CI 0.15-0.96, p = 0.043). CONCLUSION The addition of ultrasonography to SPECT, but not to SPECT/CT, has incremental value in decreasing the extent of surgery during parathyroidectomy, even after adjusting for multiple confounding factors.
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Perlovsky LI, Levine DS. The Drive for Creativity and the Escape from Creativity: Neurocognitive Mechanisms. Cognit Comput 2012. [DOI: 10.1007/s12559-012-9154-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Marinescu SC, Levine DS, Zhao Y, Schrock RR, Hoveyda AH. Isolation of pure disubstituted E olefins through Mo-catalyzed Z-selective ethenolysis of stereoisomeric mixtures. J Am Chem Soc 2011; 133:11512-4. [PMID: 21718001 DOI: 10.1021/ja205002v] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Monoaryloxide-pyrrolide (MAP) complexes of molybdenum were employed for the selective ethenolysis of 1,2-disubstituted Z olefins in the presence of the corresponding E olefins. Reactions were performed in the presence of 0.02-3.0 mol % catalyst at 22 °C under 20 atm ethylene. We have demonstrated that the Z isomer of an easily accessible E:Z mixture can be destroyed through ethenolysis and the E alkene thereby isolated readily in high yield and exceptional stereoisomeric purity.
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Paulus PB, Levine DS, Brown V, Minai AA, Doboli S. Modeling Ideational Creativity in Groups: Connecting Cognitive, Neural, and Computational Approaches. SMALL GROUP RESEARCH 2010. [DOI: 10.1177/1046496410369561] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Many creative activities take place in a group context, whether in short-term meetings, work teams, or by means of electronic interaction. The group creative process necessarily involves the exchange of ideas or information. Recent models of group creativity have focused on the cognitive underpinnings of this type of group creative process, primarily based on the group brainstorming literature. The authors describe an elaborated computational version of their cognitive model of group creativity and related computational models, and highlight some plausible neural bases for various involved processes. The major findings and theoretical perspectives in this literature are summarized and some potentially fruitful empirical and theoretical directions are highlighted. It is hoped that this comprehensive treatment can be a basis for integrating the present literature and providing useful predictions for further research on this topic.
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Abstract
Theories of cognitive processes, such as decision making and creative problem solving, for a long time neglected the contributions of emotion or affect in favor of analysis based on use of deliberative rules to optimize performance. Since the 1990s, emotion has increasingly been incorporated into theories of these cognitive processes. Some theorists have in fact posited a “dual-systems approach” to understanding decision making and high-level cognition. One system is fast, emotional, and intuitive, while the other is slow, rational, and deliberative. However, one’s understanding of the relevant brain regions indicate that emotional and rational processes are deeply intertwined, with each exerting major influences on the functioning of the other. Also presented in this paper are neural network modeling principles that may capture the interrelationships of emotion and cognition. The authors also review evidence that humans, and possibly other mammals, possess a “knowledge instinct,” which acts as a drive to make sense of the environment. This drive typically incorporates a strong affective component in the form of aesthetic fulfillment or dissatisfaction.
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Levine DS. Evolution or culture, but music may soothe the savage breast. Phys Life Rev 2010; 7:39-40; discussion 49-54. [DOI: 10.1016/j.plrev.2010.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Accepted: 01/12/2010] [Indexed: 10/20/2022]
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Levine DS, Wiseman SM. Fusion imaging for parathyroid localization in primary hyperparathyroidism. Expert Rev Anticancer Ther 2010; 10:353-363. [DOI: 10.1586/era.10.11] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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Leven SJ, Levine DS. Multiattribute Decision Making in Context: A Dynamic Neural Network Methodology. Cogn Sci 2010. [DOI: 10.1207/s15516709cog2002_4] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Parks RW, Long DL, Levine DS, Crockett DJ, McGeer EG, McGeer PL, Dalton IE, Zec RF, Becker RE, Coburn KL, Siler G, Nelson ME, Bower JM. Parallel Distributed Processing and Neural Networks: Origins, Methodology and Cognitive Functions. Int J Neurosci 2009. [DOI: 10.3109/00207459109080640] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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45
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Iyer LR, Doboli S, Minai AA, Brown VR, Levine DS, Paulus PB. Neural dynamics of idea generation and the effects of priming. Neural Netw 2009; 22:674-86. [DOI: 10.1016/j.neunet.2009.06.019] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 05/31/2009] [Accepted: 06/25/2009] [Indexed: 11/28/2022]
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46
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Levine DS. Brain pathways for cognitive-emotional decision making in the human animal. Neural Netw 2009; 22:286-93. [DOI: 10.1016/j.neunet.2009.03.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Revised: 03/07/2009] [Accepted: 03/13/2009] [Indexed: 11/26/2022]
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Levine DS, Navarro OM, Chaudry G, Doyle JJ, Blaser SI. Imaging the complications of bone marrow transplantation in children. Radiographics 2007; 27:307-24. [PMID: 17374855 DOI: 10.1148/rg.272065088] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Bone marrow transplantation is frequently performed to restore hematologic and immunologic competence after chemotherapy and radiation therapy for a range of childhood malignancies, as well as to treat various congenital conditions in which hematologic and immunologic functions are depressed or absent. Potentially devastating complications may occur during the pre-engraftment period after bone marrow transplantation, when marrow aplasia may supervene for several weeks until engraftment occurs, as well as during the post-engraftment period (the 3 months after engraftment) and in subsequent months and years. Complications of bone marrow transplantation may be classified either according to the time interval between transplantation and the occurrence of the complication or according to the organ system affected. The range of complications that may affect the central nervous system and the rest of the body may be detected with ultrasonography, computed tomography, and magnetic resonance imaging. Neurologic, paranasal sinus, pulmonary, and abdominopelvic complications all may be seen after bone marrow transplantation. Graft-versus-host disease and lymphoproliferative disorders also may occur. The increasing use of bone marrow transplantation mandates that the radiologist be familiar with the full range of potential complications and their imaging appearances.
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Parks RW, Thiyagesh SN, Levine DS, Lee KH, Bhaker R, Mysore A, Ingram L, Young C, Birkett P, Pegg E, Woodruff PWR. Executive dysfunction screening test for neuropsychiatric disorders. Int J Neurosci 2007; 117:507-18. [PMID: 17365131 DOI: 10.1080/00207450600773525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The Analogies Understanding Test (AUT) was developed as a brief cognitive screening task of executive problem solving. A few of the test items at the beginning are "facilitated" as a means of engaging patients. Individuals with schizophrenia and mild Alzheimer's Disease (AD) made significantly less correct responses than their control groups. The schizophrenia patients, but not AD patients, made significantly more perseverations than controls on the AUT. As expected, AUT performance in schizophrenia patients correlated with the Wisconsin Card Sorting test measures. Preliminary findings suggest that the AUT test may be useful as a measure of executive dysfunction in neuropsychiatric patients.
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Chaudry G, Navarro OM, Levine DS, Oudjhane K. Abdominal manifestations of cystic fibrosis in children. Pediatr Radiol 2006; 36:233-40. [PMID: 16391928 DOI: 10.1007/s00247-005-0049-2] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2005] [Revised: 09/29/2005] [Accepted: 10/10/2005] [Indexed: 10/25/2022]
Abstract
Pulmonary complications remain the main cause of mortality in cystic fibrosis, but the presenting symptoms in children are often related to gastrointestinal or pancreaticobiliary disease. Furthermore, abdominal manifestations are now seen throughout childhood, from infancy to adolescence. The child might present in the neonatal period with meconium ileus or its attendant complications. The older child might present with distal intestinal obstruction syndrome or colonic stricture secondary to high doses of pancreatic enzyme replacement. Less-common gastrointestinal manifestations include intussusception, duodenitis and fecal impaction of the appendix. Most children also show evidence of exocrine pancreatic deficiency. Radiologically, the combination of fat deposition and pancreatic fibrosis leads to varying CT and MR appearances. A higher than normal incidence of pancreatic cysts and calcification is also seen. Decreased transport of water and chloride also increases the viscosity of bile, with subsequent obstruction of the biliary ductules. If extensive, this can progress to obstructive cirrhosis, portal hypertension and esophageal varices. Diffuse fatty infiltration, hypersplenism and gallstones are also commonly seen in these patients. We present a pictorial review of the radiological appearance of these abdominal manifestations. The conditions are dealt with individually, together with typical appearances in various imaging modalities.
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Coleman SL, Brown VR, Levine DS, Mellgren RL. A neural network model of foraging decisions made under predation risk. COGNITIVE AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2005; 5:434-51. [PMID: 16541813 DOI: 10.3758/cabn.5.4.434] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This article develops the cognitive-emotional forager (CEF) model, a novel application of a neural network to dynamical processes in foraging behavior. The CEF is based on a neural network known as the gated dipole, introduced by Grossberg, which is capable of representing short-term affective reactions in a manner similar to Solomon and Corbit's (1974) opponent process theory. The model incorporates a trade-off between approach toward food and avoidance of predation under varying levels of motivation induced by hunger. The results of simulations in a simple patch selection paradigm, using a lifetime fitness criterion for comparison, indicate that the CEF model is capable of nearly optimal foraging and outperforms a run-of-luck rule-of-thumb model. Models such as the one presented here can illuminate the underlying cognitive and motivational components of animal decision making.
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