The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Donald G. Truhlar - One of the best experts on this subject based on the ideXlab platform.
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Comparative DFT Study of van der Waals Complexes: Rare-Gas Dimers, Alkaline-Earth Dimers, Zinc Dimer, and Zinc-Rare-Gas Dimers
The journal of physical chemistry. A, 2006Co-Authors: Yan Zhao, Donald G. TruhlarAbstract:Recent interest in the application of density functional theory prompted us to test various functionals for the van der Waals interactions in the rare-gas Dimers, the alkaline-earth metal Dimers, zinc Dimer, and zinc-rare-gas Dimers. In the present study, we report such tests for 18 DFT functionals, including both some very recent functionals and some well-established older ones. We draw the following conclusions based on the mean errors in binding energies and complex geometries: (1) B97-1 gives the best performance for predicting the geometry of rare-gas Dimers, whereas M05-2X and B97-1 give the best energetics for rare-gas Dimers. (2) PWB6K gives the best performance for the prediction of the geometry of the alkaline-earth metal Dimers, zinc Dimers, and zinc-rare-gas Dimers. M05-2X gives the best energetics for the metal Dimers, whereas B97-1 gives the best energetics for the zinc-rare-gas Dimers. (3) The M05 functional is unique in providing good accuracy for both covalent transition-metal Dimers and van der Waals metal Dimers. (4) The combined mean percentage unsigned error in geometries and energetics shows that M05-2X and MPWB1K are the overall best methods for the prediction of van der Waals interactions in metal and rare-gas van der Waals Dimers.
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comparative dft study of van der waals complexes rare gas Dimers alkaline earth Dimers zinc Dimer and zinc rare gas Dimers
Journal of Physical Chemistry A, 2006Co-Authors: Yan Zhao, Donald G. TruhlarAbstract:Recent interest in the application of density functional theory prompted us to test various functionals for the van der Waals interactions in the rare-gas Dimers, the alkaline-earth metal Dimers, zinc Dimer, and zinc-rare-gas Dimers. In the present study, we report such tests for 18 DFT functionals, including both some very recent functionals and some well-established older ones. We draw the following conclusions based on the mean errors in binding energies and complex geometries: (1) B97-1 gives the best performance for predicting the geometry of rare-gas Dimers, whereas M05-2X and B97-1 give the best energetics for rare-gas Dimers. (2) PWB6K gives the best performance for the prediction of the geometry of the alkaline-earth metal Dimers, zinc Dimers, and zinc-rare-gas Dimers. M05-2X gives the best energetics for the metal Dimers, whereas B97-1 gives the best energetics for the zinc-rare-gas Dimers. (3) The M05 functional is unique in providing good accuracy for both covalent transition-metal Dimers and...
Yan Zhao - One of the best experts on this subject based on the ideXlab platform.
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Comparative DFT Study of van der Waals Complexes: Rare-Gas Dimers, Alkaline-Earth Dimers, Zinc Dimer, and Zinc-Rare-Gas Dimers
The journal of physical chemistry. A, 2006Co-Authors: Yan Zhao, Donald G. TruhlarAbstract:Recent interest in the application of density functional theory prompted us to test various functionals for the van der Waals interactions in the rare-gas Dimers, the alkaline-earth metal Dimers, zinc Dimer, and zinc-rare-gas Dimers. In the present study, we report such tests for 18 DFT functionals, including both some very recent functionals and some well-established older ones. We draw the following conclusions based on the mean errors in binding energies and complex geometries: (1) B97-1 gives the best performance for predicting the geometry of rare-gas Dimers, whereas M05-2X and B97-1 give the best energetics for rare-gas Dimers. (2) PWB6K gives the best performance for the prediction of the geometry of the alkaline-earth metal Dimers, zinc Dimers, and zinc-rare-gas Dimers. M05-2X gives the best energetics for the metal Dimers, whereas B97-1 gives the best energetics for the zinc-rare-gas Dimers. (3) The M05 functional is unique in providing good accuracy for both covalent transition-metal Dimers and van der Waals metal Dimers. (4) The combined mean percentage unsigned error in geometries and energetics shows that M05-2X and MPWB1K are the overall best methods for the prediction of van der Waals interactions in metal and rare-gas van der Waals Dimers.
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comparative dft study of van der waals complexes rare gas Dimers alkaline earth Dimers zinc Dimer and zinc rare gas Dimers
Journal of Physical Chemistry A, 2006Co-Authors: Yan Zhao, Donald G. TruhlarAbstract:Recent interest in the application of density functional theory prompted us to test various functionals for the van der Waals interactions in the rare-gas Dimers, the alkaline-earth metal Dimers, zinc Dimer, and zinc-rare-gas Dimers. In the present study, we report such tests for 18 DFT functionals, including both some very recent functionals and some well-established older ones. We draw the following conclusions based on the mean errors in binding energies and complex geometries: (1) B97-1 gives the best performance for predicting the geometry of rare-gas Dimers, whereas M05-2X and B97-1 give the best energetics for rare-gas Dimers. (2) PWB6K gives the best performance for the prediction of the geometry of the alkaline-earth metal Dimers, zinc Dimers, and zinc-rare-gas Dimers. M05-2X gives the best energetics for the metal Dimers, whereas B97-1 gives the best energetics for the zinc-rare-gas Dimers. (3) The M05 functional is unique in providing good accuracy for both covalent transition-metal Dimers and...
Janet R Sparrow - One of the best experts on this subject based on the ideXlab platform.
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the all trans retinal Dimer series of lipofuscin pigments in retinal pigment epithelial cells in a recessive stargardt disease model
Proceedings of the National Academy of Sciences of the United States of America, 2007Co-Authors: Young Pyo Jang, Steffen Jockusch, Nathan Fishkin, Nicholas J Turro, Janet R SparrowAbstract:The bis-retinoid pigments that accumulate in retinal pigment epithelial cells as lipofuscin are associated with inherited and age-related retinal disease. In addition to A2E and related cis isomers, we previously showed that condensation of two molecules of all-trans-retinal leads to the formation of a protonated Schiff base conjugate, all-trans-retinal Dimer-phosphatidylethanolamine. Here we report the characterization of the related pigments, all-trans-retinal Dimer-ethanolamine and unconjugated all-trans-retinal Dimer, in human and mouse retinal pigment epithelium. In eyecups of Abcr−/− mice, a model of recessive Stargardt macular degeneration, all-trans-retinal Dimer-phosphatidylethanolamine was increased relative to wild type and was more abundant than A2E. Total pigment of the all-trans-retinal Dimer series (sum of all-trans-retinal Dimer-phosphatidylethanolamine, all-trans-retinal Dimer-ethanolamine, and all-trans-retinal Dimer) increased with age in Abcr−/− mice and was modulated by amino acid variants in Rpe65. In in vitro assays, enzyme-mediated hydrolysis of all-trans-retinal Dimer-phosphatidylethanolamine generated all-trans-retinal Dimer-ethanolamine, and protonation/deprotonation of the Schiff base nitrogen of all-trans-retinal Dimer-ethanolamine was pH-dependent. Unconjugated all-trans-retinal Dimer was a more efficient generator of singlet oxygen than A2E, and the all-trans-retinal Dimer series was more reactive with singlet oxygen than was A2E. By analyzing chromatographic properties and UV-visible spectra together with mass spectrometry, mono- and bis-oxygenated all-trans-retinal Dimer photoproducts were detected in Abcr−/− mice. The latter findings are significant to an understanding of the adverse effects of retinal pigment epithelial cell lipofuscin.
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the all trans retinal Dimer series of lipofuscin pigments in retinal pigment epithelial cells in a recessive stargardt disease model
Proceedings of the National Academy of Sciences of the United States of America, 2007Co-Authors: So Ra Kim, Young Pyo Jang, Steffen Jockusch, Nathan Fishkin, Nicholas J Turro, Janet R SparrowAbstract:The bis-retinoid pigments that accumulate in retinal pigment epithelial cells as lipofuscin are associated with inherited and age-related retinal disease. In addition to A2E and related cis isomers, we previously showed that condensation of two molecules of all-trans-retinal leads to the formation of a protonated Schiff base conjugate, all-trans-retinal Dimer-phosphatidylethanolamine. Here we report the characterization of the related pigments, all-trans-retinal Dimer-ethanolamine and unconjugated all-trans-retinal Dimer, in human and mouse retinal pigment epithelium. In eyecups of Abcr−/− mice, a model of recessive Stargardt macular degeneration, all-trans-retinal Dimer-phosphatidylethanolamine was increased relative to wild type and was more abundant than A2E. Total pigment of the all-trans-retinal Dimer series (sum of all-trans-retinal Dimer-phosphatidylethanolamine, all-trans-retinal Dimer-ethanolamine, and all-trans-retinal Dimer) increased with age in Abcr−/− mice and was modulated by amino acid variants in Rpe65. In in vitro assays, enzyme-mediated hydrolysis of all-trans-retinal Dimer-phosphatidylethanolamine generated all-trans-retinal Dimer-ethanolamine, and protonation/deprotonation of the Schiff base nitrogen of all-trans-retinal Dimer-ethanolamine was pH-dependent. Unconjugated all-trans-retinal Dimer was a more efficient generator of singlet oxygen than A2E, and the all-trans-retinal Dimer series was more reactive with singlet oxygen than was A2E. By analyzing chromatographic properties and UV-visible spectra together with mass spectrometry, mono- and bis-oxygenated all-trans-retinal Dimer photoproducts were detected in Abcr−/− mice. The latter findings are significant to an understanding of the adverse effects of retinal pigment epithelial cell lipofuscin.
Faiez Zannad - One of the best experts on this subject based on the ideXlab platform.
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plasma d Dimer concentrations predicting stroke risk and rivaroxaban benefit in patients with heart failure and sinus rhythm an analysis from the commander hf trial
European Journal of Heart Failure, 2020Co-Authors: Joao Pedro Ferreira, Stefan D Anker, Mandeep R Mehra, Dirk J Van Veldhuisen, William M Byra, John G F Cleland, Barry H Greenberg, Faiez ZannadAbstract:BACKGROUND D-Dimer is a marker of fibrin degradation that reflects intra-vascular coagulation. Therefore, plasma concentrations of D-Dimer might predict thromboembolic risk and rivaroxaban treatment effect. AIMS To investigate the association between D-Dimer levels and the risk of stroke and other thrombotic, bleeding and fatal events, and whether D-Dimer concentrations could predict rivaroxaban 2.5mg/bd (vs. placebo) effect in patients enrolled in the COMMANDER-HF trial who were in sinus rhythm, had HFrEF and coronary artery disease. METHODS Survival models with treatment-by-plasma D-Dimer interaction. Baseline measurement of D-Dimer was available in 4,107 (82%) of 5,022 patients enrolled. Median (percentile25-75 ) follow-up was 21 (12.9-32.8) months. RESULTS The median (percentile25-75 ) plasma concentration of D-Dimer was 360 (215-665)ng/mL. The D-Dimer tertiles were: 1) ≤255; 2) 256-515; 3) >515ng/mL. Patients within the tertile-3 were older, and had lower BMI, blood pressure, hemoglobin, eGFR, and LVEF. Higher plasma D-Dimer concentrations were independently associated with higher rates of death, stroke, and venous thromboembolism. For example, the all-cause death adjusted HR (95%CI) of tertile-3 vs. tertile-1 was 1.77 (1.48-2.11), p<0.001. The effect of rivaroxaban was similar in each tertile of D-Dimer for all outcomes except stroke. Patients within the tertile-3 had the greatest absolute and relative stroke reduction (HR [95%CI] tertile-1=1.16 [0.49-2.74], tertile-2=1.45 [0.77-2.73], and tertile-3=0.36 [0.18-0.70]; interactionp =0.008). The number-needed-to-treat to prevent one stroke in tertile-3 was 36. CONCLUSION In COMMANDER-HF, rivaroxaban reduced the risk of stroke but the benefit may be confined to patients with D-Dimer concentrations above 515ng/mL. Prospective trials are warranted to confirm these findings.
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plasma d Dimer concentrations predicting stroke risk and rivaroxaban benefit in patients with heart failure and sinus rhythm an analysis from the commander hf trial
European Journal of Heart Failure, 2020Co-Authors: Joao Pedro Ferreira, Stefan D Anker, Mandeep R Mehra, William M Byra, John G F Cleland, Barry H Greenberg, Carolyn S P Lam, Dirk J Van Veldhuisen, Faiez ZannadAbstract:AIMS D-Dimer is a marker of fibrin degradation that reflects intravascular coagulation. Therefore, plasma concentrations of D-Dimer might predict thromboembolic risk and rivaroxaban treatment effect. The aims of this study were to investigate the association between D-Dimer levels and the risk of stroke and other thrombotic, bleeding and fatal events, and whether D-Dimer concentrations could predict rivaroxaban 2.5 mg twice daily (vs. placebo) effect in patients enrolled in the COMMANDER-HF trial who were in sinus rhythm, had heart failure with reduced ejection fraction and coronary artery disease. METHODS AND RESULTS Survival models with treatment-by-plasma D-Dimer interaction. Baseline measurement of D-Dimer was available in 4107 (82%) of 5022 patients enrolled. Median (percentile25-75 ) follow-up was 21 (12.9-32.8) months. The median (percentile25-75 ) plasma concentration of D-Dimer was 360 (215-665) ng/mL. The D-Dimer tertiles were: (i) ≤255 ng/mL; (ii) 256-515 ng/mL; and (iii) >515 ng/mL. Patients within the tertile 3 were older, and had lower body mass index, blood pressure, haemoglobin, estimated glomerular filtration rate, and left ventricular ejection fraction. Higher plasma D-Dimer concentrations were independently associated with higher rates of death, stroke, and venous thromboembolism. For example, the all-cause death adjusted hazard ratio (HR) (95%CI) of tertile 3 vs. tertile 1 was 1.77 [95% confidence interval (CI) 1.48-2.11; P < 0.001]. The effect of rivaroxaban was similar in each tertile of D-Dimer for all outcomes except stroke. Patients within the tertile 3 had the greatest absolute and relative stroke reduction (tertile 1: HR 1.16, 95% CI 0.49-2.74; tertile 2: HR 1.45, 95% CI 0.77-2.73; tertile 3: HR 0.36, 95% CI 0.18-0.70; P for interaction = 0.008). The number-needed-to-treat to prevent one stroke in tertile 3 was 36. CONCLUSIONS In COMMANDER-HF, rivaroxaban reduced the risk of stroke but the benefit may be confined to patients with D-Dimer concentrations above 515 ng/mL. Prospective trials are warranted to confirm these findings.
Young Pyo Jang - One of the best experts on this subject based on the ideXlab platform.
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the all trans retinal Dimer series of lipofuscin pigments in retinal pigment epithelial cells in a recessive stargardt disease model
Proceedings of the National Academy of Sciences of the United States of America, 2007Co-Authors: Young Pyo Jang, Steffen Jockusch, Nathan Fishkin, Nicholas J Turro, Janet R SparrowAbstract:The bis-retinoid pigments that accumulate in retinal pigment epithelial cells as lipofuscin are associated with inherited and age-related retinal disease. In addition to A2E and related cis isomers, we previously showed that condensation of two molecules of all-trans-retinal leads to the formation of a protonated Schiff base conjugate, all-trans-retinal Dimer-phosphatidylethanolamine. Here we report the characterization of the related pigments, all-trans-retinal Dimer-ethanolamine and unconjugated all-trans-retinal Dimer, in human and mouse retinal pigment epithelium. In eyecups of Abcr−/− mice, a model of recessive Stargardt macular degeneration, all-trans-retinal Dimer-phosphatidylethanolamine was increased relative to wild type and was more abundant than A2E. Total pigment of the all-trans-retinal Dimer series (sum of all-trans-retinal Dimer-phosphatidylethanolamine, all-trans-retinal Dimer-ethanolamine, and all-trans-retinal Dimer) increased with age in Abcr−/− mice and was modulated by amino acid variants in Rpe65. In in vitro assays, enzyme-mediated hydrolysis of all-trans-retinal Dimer-phosphatidylethanolamine generated all-trans-retinal Dimer-ethanolamine, and protonation/deprotonation of the Schiff base nitrogen of all-trans-retinal Dimer-ethanolamine was pH-dependent. Unconjugated all-trans-retinal Dimer was a more efficient generator of singlet oxygen than A2E, and the all-trans-retinal Dimer series was more reactive with singlet oxygen than was A2E. By analyzing chromatographic properties and UV-visible spectra together with mass spectrometry, mono- and bis-oxygenated all-trans-retinal Dimer photoproducts were detected in Abcr−/− mice. The latter findings are significant to an understanding of the adverse effects of retinal pigment epithelial cell lipofuscin.
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the all trans retinal Dimer series of lipofuscin pigments in retinal pigment epithelial cells in a recessive stargardt disease model
Proceedings of the National Academy of Sciences of the United States of America, 2007Co-Authors: So Ra Kim, Young Pyo Jang, Steffen Jockusch, Nathan Fishkin, Nicholas J Turro, Janet R SparrowAbstract:The bis-retinoid pigments that accumulate in retinal pigment epithelial cells as lipofuscin are associated with inherited and age-related retinal disease. In addition to A2E and related cis isomers, we previously showed that condensation of two molecules of all-trans-retinal leads to the formation of a protonated Schiff base conjugate, all-trans-retinal Dimer-phosphatidylethanolamine. Here we report the characterization of the related pigments, all-trans-retinal Dimer-ethanolamine and unconjugated all-trans-retinal Dimer, in human and mouse retinal pigment epithelium. In eyecups of Abcr−/− mice, a model of recessive Stargardt macular degeneration, all-trans-retinal Dimer-phosphatidylethanolamine was increased relative to wild type and was more abundant than A2E. Total pigment of the all-trans-retinal Dimer series (sum of all-trans-retinal Dimer-phosphatidylethanolamine, all-trans-retinal Dimer-ethanolamine, and all-trans-retinal Dimer) increased with age in Abcr−/− mice and was modulated by amino acid variants in Rpe65. In in vitro assays, enzyme-mediated hydrolysis of all-trans-retinal Dimer-phosphatidylethanolamine generated all-trans-retinal Dimer-ethanolamine, and protonation/deprotonation of the Schiff base nitrogen of all-trans-retinal Dimer-ethanolamine was pH-dependent. Unconjugated all-trans-retinal Dimer was a more efficient generator of singlet oxygen than A2E, and the all-trans-retinal Dimer series was more reactive with singlet oxygen than was A2E. By analyzing chromatographic properties and UV-visible spectra together with mass spectrometry, mono- and bis-oxygenated all-trans-retinal Dimer photoproducts were detected in Abcr−/− mice. The latter findings are significant to an understanding of the adverse effects of retinal pigment epithelial cell lipofuscin.
