The Experts below are selected from a list of 129 Experts worldwide ranked by ideXlab platform
Melanie Schnell - One of the best experts on this subject based on the ideXlab platform.
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communication structural locking mediated by a water wire a high resolution rotational spectroscopy study on hydrated forms of a chiral Biphenyl Derivative
Journal of Chemical Physics, 2016Co-Authors: Melanie Schnell, Cristobal Perez, Sérgio R. DomingosAbstract:We report the observation of structural changes in an axially chiral molecule, Biphenyl-2-carboxaldehyde, due to aggregation with water. Using high-resolution broadband rotational spectroscopy we find that two water molecules link opposite sides of the molecule, resembling a water wire. We show that this effect can be explained by a cooperative rearrangement of both molecule and a water dimer. Hydrogen bonding interactions are shown to change the original structure upon aggregation of water. This phenomenon is insightful on the role of microsolvation in assisting structural morphing of stereo-selective chiral molecular systems.
M Van Der Auweraer - One of the best experts on this subject based on the ideXlab platform.
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efficient blue polymer light emitting diodes from a novel Biphenyl Derivative
Synthetic Metals, 2002Co-Authors: Yadong Jin, Hongzheng Chen, P L Heremans, K Aleksandrzak, H J Geise, Gustaaf Borghs, M Van Der AuweraerAbstract:Abstract A novel blue-emitting soluble Biphenyl Derivative 4,4-bis[2-(3,4,5-trimethoxyphenyl)vinyl]Biphenyl (TMPVB) was synthesized. It was dispersed into poly[2-(6′-cyano-6′-methylheptyloxy)-1,4-phenylene] (CNPPP), to form a blend film as the emissive layer in organic light-emitting diodes (OLEDs). Efficient Forster energy transfer from CNPPP to TMPVB molecules is proved in this film. We find that the emission is dominantly from the TMPVB molecules during the device operation. The best performing device has a peak external quantum efficiency of 1.2%, which is comparable to the best results obtained for devices based on blue-emitting polymers. Forster energy transfer and carrier trapping are considered to be the main mechanisms for exciton formation on TMPVB molecules under electrical excitation.
Hongzheng Chen - One of the best experts on this subject based on the ideXlab platform.
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efficient blue polymer light emitting diodes from a novel Biphenyl Derivative
Synthetic Metals, 2002Co-Authors: Yadong Jin, Hongzheng Chen, P L Heremans, K Aleksandrzak, H J Geise, Gustaaf Borghs, M Van Der AuweraerAbstract:Abstract A novel blue-emitting soluble Biphenyl Derivative 4,4-bis[2-(3,4,5-trimethoxyphenyl)vinyl]Biphenyl (TMPVB) was synthesized. It was dispersed into poly[2-(6′-cyano-6′-methylheptyloxy)-1,4-phenylene] (CNPPP), to form a blend film as the emissive layer in organic light-emitting diodes (OLEDs). Efficient Forster energy transfer from CNPPP to TMPVB molecules is proved in this film. We find that the emission is dominantly from the TMPVB molecules during the device operation. The best performing device has a peak external quantum efficiency of 1.2%, which is comparable to the best results obtained for devices based on blue-emitting polymers. Forster energy transfer and carrier trapping are considered to be the main mechanisms for exciton formation on TMPVB molecules under electrical excitation.
Ursula Ravens - One of the best experts on this subject based on the ideXlab platform.
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role of ikur in controlling action potential shape and contractility in the human atrium influence of chronic atrial fibrillation
Circulation, 2004Co-Authors: Erich Wettwer, Otto Hala, Torsten Christ, Jurgen F Heubach, Dobromir Dobrev, Michael Knaut, Andras Varro, Ursula RavensAbstract:Background— The ultrarapid outward current IKur is a major repolarizing current in human atrium and a potential target for treating atrial arrhythmias. The effects of selective block of IKur by low concentrations of 4-aminopyridine or the Biphenyl Derivative AVE 0118 were investigated on right atrial action potentials (APs) in trabeculae from patients in sinus rhythm (SR) or chronic atrial fibrillation (AF). Methods and Results— AP duration at 90% repolarization (APD90) was shorter in AF than in SR (300±16 ms, n=6, versus 414±10 ms, n=15), whereas APD20 was longer (35±9 ms in AF versus 5±2 ms in SR, P<0.05). 4-Aminopyridine (5 μmol/L) elevated the plateau to more positive potentials from −21±3 to −6±3 mV in SR and 0±3 to +12±3 mV in AF. 4-Aminopyridine reversibly shortened APD90 from 414±10 to 350±10 ms in SR but prolonged APD90 from 300±16 to 320±13 ms in AF. Similar results were obtained with AVE 0118 (6 μmol/L). Computer simulations of IKur block in human atrial APs predicted secondary increases in ICa...
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role of ikur in controlling action potential shape and contractility in the human atrium influence of chronic atrial fibrillation
Circulation, 2004Co-Authors: Erich Wettwe, Otto Hala, Jurgen F Heubach, Andras Varro, Torste Chris, Dobromi Dobrev, Michael Knau, Ursula RavensAbstract:BACKGROUND: The ultrarapid outward current I(Kur) is a major repolarizing current in human atrium and a potential target for treating atrial arrhythmias. The effects of selective block of I(Kur) by low concentrations of 4-aminopyridine or the Biphenyl Derivative AVE 0118 were investigated on right atrial action potentials (APs) in trabeculae from patients in sinus rhythm (SR) or chronic atrial fibrillation (AF). METHODS AND RESULTS: AP duration at 90% repolarization (APD90) was shorter in AF than in SR (300+/-16 ms, n=6, versus 414+/-10 ms, n=15), whereas APD20 was longer (35+/-9 ms in AF versus 5+/-2 ms in SR, P<0.05). 4-Aminopyridine (5 micromol/L) elevated the plateau to more positive potentials from -21+/-3 to -6+/-3 mV in SR and 0+/-3 to +12+/-3 mV in AF. 4-Aminopyridine reversibly shortened APD90 from 414+/-10 to 350+/-10 ms in SR but prolonged APD90 from 300+/-16 to 320+/-13 ms in AF. Similar results were obtained with AVE 0118 (6 micromol/L). Computer simulations of I(Kur) block in human atrial APs predicted secondary increases in I(Ca,L) and in the outward rectifiers I(Kr) and I(Ks), with smaller changes in AF than SR. The indirect increase in I(Ca,L) was supported by a positive inotropic effect of 4-aminopyridine without direct effects on I(Ca,L) in atrial but not ventricular preparations. In accordance with the model predictions, block of I(Kr) with E-4031 converted APD shortening effects of I(Kur) block in SR into AP prolongation. CONCLUSIONS: Whether inhibition of I(Kur) prolongs or shortens APD depends on the disease status of the atria and is determined by the level of electrical remodeling.
Eunmi Han - One of the best experts on this subject based on the ideXlab platform.
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electroluminescence characteristics of a novel Biphenyl Derivative with benzoxazole for organic light emitting diodes
Current Applied Physics, 2005Co-Authors: Sunghee Son, Jejung Yun, Sangyun Jung, Youngkun Kim, A V Kuhta, V K Olkhovik, Genadz Sasnouski, Eunmi HanAbstract:Abstract Green-emitting Biphenyl Derivative with benzoxazole (4,4′-bis[2-(1,3-benzoxazol-yl-1-ethenyl)]-2-hexyloxyBiphenyl) was newly synthesized. The benzoxazole, due to its electron-rich and good thermal stability, is introduced to enhance organic light-emitting diodes(OLEDs). This paper reports the optical and electrical characteristics by utilizing new Biphenyl Derivative with benzoxazole as the emitting layer for OLEDs. According to Thermogravimetric Analyzer (TGA) analysis, the weight ratio of that Biphenyl Derivative with benzoxazole starts to decrease at 350 °C, which suggests relatively good thermal property. The structure of the device is ITO/TPD or α-NPD (50 nm)/Biphenyl Derivative (50 nm)/LiF (0.5 nm)/Al (150 nm). The maximum luminance of the device using α-NPD is about 74,700 nW/cm2 at 9.6 V. With increase of applied voltage, the emitting zone changes from green to blue due to the influence of emission from α-NPD. On the other hand, the device based on TPD is 217,900 nW/cm2 at 6.4 V and the emitting zone of the device is constant regardless of the driving voltage.